The kernel and its modules have sections containing the enum
string to value conversions. Rename this section because we
intend to store more than enums in it.
Link: http://lkml.kernel.org/r/20170531215653.3240-2-jeremy.linton@arm.com
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Originally reported by Adam and Dusty, it appears we have a small
race window in kauditd_thread(), as documented in the Fedora BZ:
* https://bugzilla.redhat.com/show_bug.cgi?id=1459326#c35
"This issue is partly due to the read-copy nature of RCU, and
partly due to how we sync the auditd_connection state across
kauditd_thread and the audit control channel. The kauditd_thread
thread is always running so it can service the record queues and
emit the multicast messages, if it happens to be just past the
"main_queue" label, but before the "if (sk == NULL || ...)"
if-statement which calls auditd_reset() when the new auditd
connection is registered it could end up resetting the auditd
connection, regardless of if it is valid or not. This is a rather
small window and the variable nature of multi-core scheduling
explains why this is proving rather difficult to reproduce."
The fix is to have functions only call auditd_reset() when they
believe that the kernel/auditd connection is still valid, e.g.
non-NULL, and to have these callers pass their local copy of the
auditd_connection pointer to auditd_reset() where it can be compared
with the current connection state before resetting. If the caller
has a stale state tracking pointer then the reset is ignored.
We also make a small change to kauditd_thread() so that if the
kernel/auditd connection is dead we skip the retry queue and send the
records straight to the hold queue. This is necessary as we used to
rely on auditd_reset() to occasionally purge the retry queue but we
are going to be calling the reset function much less now and we want
to make sure the retry queue doesn't grow unbounded.
Reported-by: Adam Williamson <awilliam@redhat.com>
Reported-by: Dusty Mabe <dustymabe@redhat.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
When compiling with -Wsuggest-attribute=format, gcc complains that some
functions in kernel/printk/printk_safe.c transmit their argument to
printf-like functions without having a printf attribute. Silence these
warnings by adding relevant __printf attributes.
Link: http://lkml.kernel.org/r/20170524054950.6722-1-nicolas.iooss_linux@m4x.org
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
The sanity check ensuring that the tick expiry cache (ts->next_tick)
is actually in sync with the hardware clock (dev->next_event) makes the
wrong assumption that the clock can't be programmed later than the
hrtimer deadline.
In fact the clock hardware can be programmed later on some conditions
such as:
* The hrtimer deadline is already in the past.
* The hrtimer deadline is earlier than the minimum delay supported
by the hardware.
Such conditions can be met when we program the tick, for example if the
last jiffies update hasn't been seen by the current CPU yet, we may
program the hrtimer to a deadline that is earlier than ktime_get()
because last_jiffies_update is our timestamp base to compute the next
tick.
As a result, we can randomly observe such warning:
WARNING: CPU: 5 PID: 0 at kernel/time/tick-sched.c:794 tick_nohz_stop_sched_tick kernel/time/tick-sched.c:791 [inline]
Call Trace:
tick_nohz_irq_exit
tick_irq_exit
irq_exit
exiting_irq
smp_call_function_interrupt
smp_call_function_single_interrupt
call_function_single_interrupt
Therefore, let's rather make sure that the tick expiry cache is sync'ed
with the tick hrtimer deadline, against which it is not supposed to
drift away. The clock hardware instead has its own will and can't be
used as a reliable comparison point.
Reported-and-tested-by: Sasha Levin <alexander.levin@verizon.com>
Reported-and-tested-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: James Hartsock <hartsjc@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Wright <tim@binbash.co.uk>
Link: http://lkml.kernel.org/r/1497326654-14122-1-git-send-email-fweisbec@gmail.com
[ Minor readability edit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU updates from Paul E. McKenney:
"The largest feature of this series is shrinking and simplification,
with the following diffstat summary:
79 files changed, 1496 insertions(+), 4211 deletions(-)
In other words, this series represents a net reduction of more than 2700
lines of code."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In case __irq_set_trigger() fails the resources requested via
irq_request_resources() are not released.
Add the missing release call into the error handling path.
Fixes: c1bacbae81 ("genirq: Provide irq_request/release_resources chip callbacks")
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/655538f5-cb20-a892-ff15-fbd2dd1fa4ec@gmail.com
Fixed checkpatch.pl warnings of "function definition argument FOO
should also have an identifier name"
Signed-off-by: Derek Robson <robsonde@gmail.com>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
The recent rework of the posix timer internals broke the magic posix
mechanism, which requires that relative timers are not affected by
modifications of the underlying clock. That means relative CLOCK_REALTIME
timers cannot use CLOCK_REALTIME, because that can be set and adjusted. The
underlying hrtimer switches the clock for these timers to CLOCK_MONOTONIC.
That still works, but reading the remaining time of such a timer has been
broken in the rework. The old code used the hrtimer internals directly and
avoided the posix clock callbacks. Now common_timer_get() uses the
underlying kclock->timer_get() callback, which is still CLOCK_REALTIME
based. So the remaining time of such a timer is calculated against the
wrong time base.
Handle it by switching the k_itimer->kclock pointer according to the
resulting hrtimer mode. k_itimer->it_clock still contains CLOCK_REALTIME
because the timer might be set with ABSTIME later and then it needs to
switch back to the realtime posix clock implementation.
Fixes: eae1c4ae27 ("posix-timers: Make use of cancel/arm callbacks")
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20170609201156.GB21491@outlook.office365.com
The recent posix timer rework moved the clearing of the itimerspec to the
real syscall implementation, but forgot that the kclock->timer_get() is
used by timer_settime() as well. That results in an uninitialized variable
and bogus values returned to user space.
Add the missing memset to timer_settime().
Fixes: eabdec0438 ("posix-timers: Zero settings value in common code")
Reported-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: http://lkml.kernel.org/r/20170609201156.GB21491@outlook.office365.com
clang -Wunused-function found one remaining function that was
apparently meant to be removed in a recent code cleanup:
kernel/cpu.c:565:20: warning: unused function 'check_for_tasks' [-Wunused-function]
Sebastian explained: The function became unused unintentionally, but there
is already a failure check, when a task cannot be removed from the outgoing
cpu in the scheduler code, so bringing it back is not really giving any
extra value.
Fixes: 530e9b76ae ("cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: http://lkml.kernel.org/r/20170608085544.2257132-1-arnd@arndb.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The refactoring of the posix-timer core to allow better code sharing
introduced inverted logic vs. SIGEV_NONE timers in common_timer_get().
That causes hrtimer_forward() to be called on active timers, which
rightfully triggers the warning hrtimer_forward().
Make sig_none what it says: signal mode == SIGEV_NONE.
Fixes: 91d57bae08 ("posix-timers: Make use of forward/remaining callbacks")
Reported-by: Ye Xiaolong <xiaolong.ye@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170609104457.GA39907@inn.lkp.intel.com
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Merge tag 'v4.12-rc5' into for-4.13/block
We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.
Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Revert commit 39b64aa1c0 (cpufreq: schedutil: Reduce frequencies
slower) that introduced unintentional changes in behavior leading
to adverse effects on some systems.
Reported-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
idle_task_exit() can be called with IRQs on x86 on and therefore
should use switch_mm(), not switch_mm_irqs_off().
This doesn't seem to cause any problems right now, but it will
confuse my upcoming TLB flush changes. Nonetheless, I think it
should be backported because it's trivial. There won't be any
meaningful performance impact because idle_task_exit() is only
used when offlining a CPU.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: f98db6013c ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler")
Link: http://lkml.kernel.org/r/ca3d1a9fa93a0b49f5a8ff729eda3640fb6abdf9.1497034141.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
'schedstats' kernel parameter should be set to enable/disable, so
correct the printk hint saying that it should be set to 'enable'
rather than 'enabled' to enable scheduler tracepoints.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1496995229-31245-1-git-send-email-marcin.nowakowski@imgtec.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Right now, we don't reset the id of spilled registers in case of
clear_all_pkt_pointers(). Given pkt_pointers are highly likely to
contain an id, do so by reusing __mark_reg_unknown_value().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Whenever we set the register to the type CONST_IMM, we currently don't
reset the id to 0. id member is not used in CONST_IMM case, so don't
let it become stale, where pruning won't be able to match later on.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
spilled_regs[] state is only used for stack slots of type STACK_SPILL,
never for STACK_MISC. Right now, in states_equal(), even if we have
old and current stack state of type STACK_MISC, we compare spilled_regs[]
for that particular offset. Just skip these like we do everywhere else.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
perf_sample_data consumes 386 bytes on stack, reduce excessive stack
usage and move it to per cpu buffer. It's allowed due to preemption
being disabled for tracing, xdp and tc programs, thus at all times
only one program can run on a specific CPU and programs cannot run
from interrupt. We similarly also handle bpf_pt_regs.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull CPU hotplug fix from Ingo Molnar:
"An error handling corner case fix"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Drop the device lock on error
Pull RCU fixes from Ingo Molnar:
"Fix an SRCU bug affecting KVM IRQ injection"
* 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
srcu: Allow use of Classic SRCU from both process and interrupt context
srcu: Allow use of Tiny/Tree SRCU from both process and interrupt context
Pull perf fixes from Ingo Molnar:
"This is mostly tooling fixes, plus an instruction pointer filtering
fix.
It's more fixes than usual - Arnaldo got back from a longer vacation
and there was a backlog"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
perf symbols: Kill dso__build_id_is_kmod()
perf symbols: Keep DSO->symtab_type after decompress
perf tests: Decompress kernel module before objdump
perf tools: Consolidate error path in __open_dso()
perf tools: Decompress kernel module when reading DSO data
perf annotate: Use dso__decompress_kmodule_path()
perf tools: Introduce dso__decompress_kmodule_{fd,path}
perf tools: Fix a memory leak in __open_dso()
perf annotate: Fix symbolic link of build-id cache
perf/core: Drop kernel samples even though :u is specified
perf script python: Remove dups in documentation examples
perf script python: Updated trace_unhandled() signature
perf script python: Fix wrong code snippets in documentation
perf script: Fix documentation errors
perf script: Fix outdated comment for perf-trace-python
perf probe: Fix examples section of documentation
perf report: Ensure the perf DSO mapping matches what libdw sees
perf report: Include partial stacks unwound with libdw
perf annotate: Add missing powerpc triplet
perf test: Disable breakpoint signal tests for powerpc
...
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Add CONFIG_CGROUP_BPF as a default configuration in android base config
since it is used to replace XT_QTAGUID in future.
Reviewed-at: https://android-review.googlesource.com/#/c/400374/
Signed-off-by: Chenbo Feng <fengc@google.com>
[AmitP: cherry-picked this change from Android common kernel]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds CONFIG_MODULES, CONFIG_MODULE_UNLOAD, and CONFIG_MODVERSIONS
which are required by the O release.
Reviewed-at: https://android-review.googlesource.com/#/c/364554/
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
[AmitP: cherry-picked this change from Android common kernel]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This adds CONFIG_IKCONFIG and CONFIG_IKCONFIG_PROC options, which are a
requirement for the O release.
Reviewed-at: https://android-review.googlesource.com/#/c/364553/
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
[AmitP: cherry-picked this change from Android common kernel]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable CPU domain PAN to ensure that normal kernel accesses are
unable to access userspace addresses.
Reviewed-at: https://android-review.googlesource.com/#/c/334035/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
[AmitP: cherry-picked this change from Android common kernel, updated
the commit message and re-placed the CONFIG_STRICT_KERNEL_RWX
config in sorted order]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Turn off the two kernel configs to disable related system ABI.
Reviewed-at: https://android-review.googlesource.com/#/c/264976/
Signed-off-by: Max Shi <meixuanshi@google.com>
[AmitP: cherry-picked this change from Android common kernel]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Enable PAN emulation using TTBR0_EL1 switching.
Reviewed-at: https://android-review.googlesource.com/#/c/325997/
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
[AmitP: cherry-picked this change from Android common kernel
and updated the commit message]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If compiler has stack protector support, set
CONFIG_CC_STACKPROTECTOR_STRONG.
Reviewed-at: https://android-review.googlesource.com/#/c/238388/
Signed-off-by: Jeff Vander Stoep <jeffv@google.com>
[AmitP: cherry-picked this change from Android common kernel]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull RCU fix from Paul E. McKenney:
" This series enables srcu_read_lock() and srcu_read_unlock() to be used from
interrupt handlers, which fixes a bug in KVM's use of SRCU in delivery
of interrupts to guest OSes. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tiny RCU's job is to be tiny, so this commit removes its RCU CPU
stall warning code. After this, there is no longer any need for
rcu_sched_ctrlblk and rcu_bh_ctrlblk to be in tiny_plugin.h, so this
commit also moves them to tiny.c.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU's debugging Kconfig options are in the unintuitive location
lib/Kconfig.debug, and there are enough of them that it would be good for
them to be more centralized. This commit therefore extracts RCU's Kconfig
options from init/Kconfig into a new kernel/rcu/Kconfig.debug file.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU's Kconfig options are scattered, and there are enough of them
that it would be good for them to be more centralized. This commit
therefore extracts RCU's Kconfig options from init/Kconfig into a new
kernel/rcu/Kconfig file.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The CONFIG_RCU_NOCB_CPU_ALL, CONFIG_RCU_NOCB_CPU_NONE, and
CONFIG_RCU_NOCB_CPU_ZERO Kconfig options are used only in testing and
are redundant with the rcu_nocbs= boot parameter. This commit therefore
removes these three Kconfig options and adjusts the rcutorture scripts
to use the boot parameter instead.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU's debugfs tracing used to be the only reasonable low-level debug
information available, but ftrace and event tracing has since surpassed
the RCU debugfs level of usefulness. This commit therefore removes
RCU's debugfs tracing.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Classic SRCU was only ever intended to be a fallback in case of issues
with Tree/Tiny SRCU, and the latter two are doing quite well in testing.
This commit therefore removes Classic SRCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The function srcutorture_get_gp_data() duplicated the check for
sp->batch_check0.head instead of also checking sp->batch_check1.head.
The only effect of this typo would be for rcutorture statistics to
understate the fraction of time that an SRCU grace period was in flight,
and only for Classic SRCU. This commit fixes this typo.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The PROVE_RCU_REPEATEDLY Kconfig option was initially added due to
the volume of messages from PROVE_RCU: Doing just one per boot would
have required excessive numbers of boots to locate them all. However,
PROVE_RCU messages are now relatively rare, so there is no longer any
reason to need more than one such message per boot. This commit therefore
removes the PROVE_RCU_REPEATEDLY Kconfig option.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Because raw_spin_lock_irqsave() and raw_spin_unlock_irqrestore()
both do typecheck() on their flags argument, there is no point in
duplicating this check in raw_spin_lock_irqsave_rcu_node() and
raw_spin_unlock_irqrestore_rcu_node(). This commit therefore saves
a few lines by removing this duplicated check.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The NO_HZ_FULL_SYSIDLE full-system-idle capability was added in 2013
by commit 0edd1b1784 ("nohz_full: Add full-system-idle state machine"),
but has not been used. This commit therefore removes it.
If it turns out to be needed later, this commit can always be reverted.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Anything that can be done with the RCU_KTHREAD_PRIO Kconfig option can
also be done with the rcutree.kthread_prio kernel boot parameter.
This commit therefore removes this Kconfig option.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
The RCU_TORTURE_TEST_SLOW_PREINIT, RCU_TORTURE_TEST_SLOW_PREINIT_DELAY,
RCU_TORTURE_TEST_SLOW_PREINIT_DELAY, RCU_TORTURE_TEST_SLOW_INIT,
RCU_TORTURE_TEST_SLOW_INIT_DELAY, RCU_TORTURE_TEST_SLOW_CLEANUP,
and RCU_TORTURE_TEST_SLOW_CLEANUP_DELAY Kconfig options are only
useful for torture testing, and there are the rcutree.gp_cleanup_delay,
rcutree.gp_init_delay, and rcutree.gp_preinit_delay kernel boot parameters
that rcutorture can use instead. The effect of these parameters is to
artificially slow down grace period initialization and cleanup in order
to make some types of race conditions happen more often.
This commit therefore simplifies Tree RCU a bit by removing the Kconfig
options and adding the corresponding kernel parameters to rcutorture's
.boot files instead. However, this commit also leaves out the kernel
parameters for TREE02, TREE04, and TREE07 in order to have about the
same number of tests slowed as not slowed. TREE01, TREE03, TREE05,
and TREE06 are slowed, and the rest are not slowed.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit uses TREE RCU's rnp->lock wrappers to replace a few explicit
memory barriers. This change also has the advantage of making SRCU's
memory-ordering properties be implemented in roughly the same way as they
are in Tree RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit moves the now-generic rnp->lock wrapper macros from
kernel/rcu/tree.h to kernel/rcu/rcu.h, thus allowing SRCU to use them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Use of smp_mb__after_unlock_lock() would allow SRCU to omit a full
memory barrier during callback execution, so this commit converts
raw_spin_lock_rcu_node() from inline functions to type-generic macros
to allow them to handle locks in srcu_node structures as well as
rcu_node structures.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Commit a5dd63efda ("lockdep: Use "WARNING" tag on lockdep splats")
substituted pr_warn() for printk() in places called out by Dmitry Vyukov.
However, this resulted in an ugly mix of pr_warn() and printk(). This
commit therefore changes printk() to pr_warn() or pr_cont(), depending
on the absence or presence of KERN_CONT. This is done in all functions
that had printk() changed to pr_warn() by the aforementioned commit.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_segcblist structure provides quite a bit of functionality, and
Tiny SRCU needs almost none of it. So this commit replaces Tiny SRCU's
uses of rcu_segcblist with a simple singly linked list with tail pointer.
This change significantly reduces Tiny SRCU's memory footprint, more
than making up for the growth caused by the creation of rcu_segcblist.c
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The call_srcu() docbook entry is currently in include/linux/srcu.h,
which causes needless processing for each include point. This commit
therefore moves this entry to kernel/rcu/srcutree.c, which the compiler
reads only once. In addition, the srcu_batches_completed() function is
used only within RCU and its torture-test suites. This commit therefore
also moves this function's declaration from include/linux/srcutiny.h,
include/linux/srcutree.h, and include/linux/srcuclassic.h to
kernel/rcu/rcu.h.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
If a given CPU never happens to ever start an SRCU grace period, the
grace-period sequence counter might wrap. If this CPU were to decide to
finally start a grace period, the state of its sdp->srcu_gp_seq_needed
might make it appear that it has already requested this grace period,
which would prevent starting the grace period. If no other CPU ever started
a grace period again, this would look like a grace-period hang. Even
if some other CPU took pity and started the needed grace period, the
leaf rcu_node structure's ->srcu_data_have_cbs field won't have record
of the fact that this CPU has a callback pending, which would look like
a very localized grace-period hang.
This might seem very unlikely, but SRCU grace periods can take less than
a microsecond on small systems, which means that overflow can happen
in much less than an hour on a 32-bit embedded system. And embedded
systems are especially likely to have long-term idle CPUs. Therefore,
it makes sense to prevent this scenario from happening.
This commit therefore scans each srcu_data structure occasionally,
with frequency controlled by the srcutree.counter_wrap_check kernel
boot parameter. This parameter can be set to something like 255
in order to exercise the counter-wrap-prevention code.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_request_urgent_qs_task() function is used only within RCU,
so there is no point in exporting it to the rest of the kernel from
nclude/linux/rcutiny.h and include/linux/rcutree.h. This commit therefore
moves this function to kernel/rcu/rcu.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The various functions similar to rcu_batches_started(), the
function show_rcu_gp_kthreads(), the various functions similar to
rcu_force_quiescent_state(), and the variables rcutorture_testseq and
rcutorture_vernum are used only within RCU. There is therefore no point
in exporting them to the kernel at large from include/linux/rcutiny.h
and include/linux/rcutree.h. This commit therefore moves all of these
to kernel/rcu/rcu.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_ftrace_dump() function is used only internally to RCU. This
commit therefore moves its declaration from include/linux/rcupdate.h
to kernel/rcu/rcu.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_is_nocb_cpu() function is used only internally to RCU. This
commit therefore moves its declaration from include/linux/rcupdate.h
to kernel/rcu/rcu.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The "__call_rcu(): Leaked duplicate callback" error message from
__call_rcu() has proven to be unhelpful. This commit therefore changes
it to "__call_rcu(): Double-freed CB" and adds the value of the pointer
passed in. The value of the pointer improves debuggability by allowing
correlation with tracing output, for example, the rcu:rcu_callback trace
event.
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The RCU_SCHEDULER_INACTIVE, RCU_SCHEDULER_INIT, and RCU_SCHEDULER_RUNNING
definitions are used only within RCU, so this commit moves them from
include/linux/rcupdate.h to kernel/rcu/rcu.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The __rcu_is_watching() function is currently not used, aside from
to implement the rcu_is_watching() function. This commit therefore
eliminates __rcu_is_watching(), which has the beneficial side-effect
of shrinking include/linux/rcupdate.h a bit.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The include/linux/rcupdate.h file contains a number of definitions that
are used only to communicate between rcutorture, rcuperf, and the RCU code
itself. There is no point in having these definitions exposed globally
throughout the kernel, so this commit moves them to kernel/rcu/rcu.h.
This change has the added benefit of shrinking rcupdate.h.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_gp_is_normal(), rcu_gp_is_expedited(), rcu_expedite_gp(), and
rcu_unexpedite_gp() functions are intended only for use within the
RCU implementation itself -- the sysfs access is what should be used
outside of RCU. This commit therefore moves the declarations for
these functions to kernel/rcu/rcu.h, and also includes this file into
kernel/rcu/rcutorture.c and kernel/rcu/rcuperf.c. This also has the
beneficial effect of shrinking rcupdate.c a bit.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_expedited and rcu_normal variables are used only by sysctl
and kernel/rcu/update.c, so it does not make sense to their extern
declarations in rcupdate.h. This commit therefore moves these
extern declarations to update.c.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The include/linux/rcupdate.h file is included by more than 200
files, so shrinking it should provide some build-time benefits.
This commit therefore moves several docbook comments from rcupdate.h to
kernel/rcu/update.c, kernel/rcu/tree.c, and kernel/rcu/tree_plugin.h, thus
reducing the number of times that the compiler has to scan these comments.
This likely provides only a small benefit, but every little bit helps.
This commit also fixes a malformed bulleted list noted by the 0day
Test Robot.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Wait/wakeup operations do not guarantee ordering on their own. Instead,
either locking or memory barriers are required. This commit therefore
adds memory barriers to wake_nocb_leader() and nocb_leader_wait().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: <stable@vger.kernel.org> # 4.6.x
- Revert a recent commit that attempted to avoid spurious wakeups
from suspend-to-idle via ACPI SCI, but introduced regressions on
some systems (Rafael Wysocki).
We will get back to the problem it tried to address in the next
cycle.
- Fix a possible division by 0 during intel_pstate initialization
due to a missing check (Rafael Wysocki).
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Merge tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These revert one problematic commit related to system sleep and fix
one recent intel_pstate regression.
Specifics:
- Revert a recent commit that attempted to avoid spurious wakeups
from suspend-to-idle via ACPI SCI, but introduced regressions on
some systems (Rafael Wysocki).
We will get back to the problem it tried to address in the next
cycle.
- Fix a possible division by 0 during intel_pstate initialization
due to a missing check (Rafael Wysocki)"
* tag 'pm-4.12-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()
Pull printk fix from Petr Mladek:
"This reverts a fix added into 4.12-rc1. It caused the kernel log to be
printed on another console when two consoles of the same type were
defined, e.g. console=ttyS0 console=ttyS1.
This configuration was never supported by kernel itself, but it
started to make sense with systemd. In other words, the commit broke
userspace"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
Revert "printk: fix double printing with earlycon"
The RCU_NOGP_WAKE_NOT, RCU_NOGP_WAKE, and RCU_NOGP_WAKE_FORCE flags
are used to mediate wakeups for the no-CBs CPU kthreads. The "NOGP"
really doesn't make any sense, so this commit does s/NOGP/NOCB/.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The synchronize_rcu_mult() function now detects duplicate requests
for the same grace-period flavor and waits only once for each flavor.
This commit therefore removes the ugly #ifdef from sched_cpu_deactivate()
because synchronize_rcu_mult(call_rcu, call_rcu_sched) now does what
the #ifdef used to be needed for.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Currently, doing synchronize_rcu_mult(call_rcu, call_rcu) might
(or might not) wait for two RCU grace periods. One approach is
of course "don't do that!", but in CONFIG_PREEMPT=n kernels,
synchronize_rcu_mult(call_rcu, call_rcu_sched) does exactly that.
This results in an ugly #ifdef in sched_cpu_deactivate().
This commit therefore makes __wait_rcu_gp() check for duplicates,
which in turn allows duplicates to be passed to synchronize_rcu_mult()
without risk of waiting twice on the same type of grace period.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds DEBUG_OBJECTS_RCU_HEAD checking to detect call_srcu()
counterparts to double-free bugs.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
In Tiny SRCU, __srcu_read_lock() is a trivial function, outweighed by
its EXPORT_SYMBOL_GPL(), and on many architectures, its call sequence.
This commit therefore moves it to srcutiny.h so that it can be inlined.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Comments can be helpful, but assertions carry more force. This commit
therefore adds lockdep_assert_held() and RCU_LOCKDEP_WARN() calls to
enforce lock-held and interrupt-disabled preconditions.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Comments can be helpful, but assertions carry more force. This
commit therefore adds lockdep_assert_held() and RCU_LOCKDEP_WARN()
calls to enforce lock-held and interrupt-disabled preconditions.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit makes srcu_bootup_announce() check for non-default values
of the auto-expedite holdoff time exp_holdoff and print a message if so.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Because exp_holdoff is not used outside of srcutree.c, it can be static.
This commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit updates rcu_bootup_announce_oddness() to check additional
Kconfig options and module/boot parameters.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a rcupdate_announce_bootup_oddness() function to
print out non-default values of significant kernel boot parameter
settings to aid in debugging.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds WARN_ON_ONCE() calls that trigger if either
rcu_sched_qs() or rcu_bh_qs() are invoked with preemption enabled.
In the immortal words of Peter Zijlstra: "these are much harder to ignore
than comments".
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a writer_holdoff boot parameter to rcuperf, which is
intended to be used to test Tree SRCU's auto-expediting. This
boot parameter is in microseconds, and defaults to zero (that is,
disabled). Set it to a bit larger than srcutree.exp_holdoff,
keeping the nanosecond/microsecond conversion, to force Tree SRCU
to auto-expedite more aggressively.
This commit also adds documentation for this parameter, and fixes some
alphabetization while in the neighborhood.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Common-case use of rcuperf must set rcuperf.nreaders=0 and if not built
as a module, rcuperf.shutdown. This commit therefore sets the default
for rcuperf.nreaders to zero and sets the default for rcuperf.shutdown
to zero if rcuperf is built as a module and to one otherwise.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit rearranges Tiny SRCU's srcu_struct structure, substitutes
u8 for bool, and shrinks counters down to short.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, the only way to tell whether a given kernel is running
Classic, Tiny, or Tree SRCU is to look at the .config file, which
can easily be lost or associated with the wrong kernel. This commit
therefore has Classic and Tree SRCU identify themselves at boot time.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a perf_type of "srcud", which species that rcuperf
test SRCU on a dynamically initialized srcu_struct.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The sync_rcu_preempt_exp_done() function returns a logical expression,
but its return type is nevertheless int. This commit therefore changes
the return type to bool.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit upgrades rcuperf so that it can do performance testing on
asynchronous grace-period primitives such as call_srcu(). There is
a new rcuperf.gp_async module parameter that specifies this new behavior,
with the pre-existing rcuperf.gp_exp testing expedited grace periods such as
synchronize_rcu_expedited, and with the default being to test synchronous
non-expedited grace periods such as synchronize_rcu().
There is also a new rcuperf.gp_async_max module parameter that specifies
the maximum number of outstanding callbacks per writer kthread, defaulting
to 1,000. When this limit is exceeded, the writer thread invokes the
appropriate flavor of rcu_barrier() to wait for callbacks to drain.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Removed the redundant initialization noted by Arnd Bergmann. ]
The synchronize_kernel() primitive was removed in favor of
synchronize_sched() more than a decade ago, and it seems likely that
rather few kernel hackers are familiar with it. Its continued presence
is therefore providing more confusion than enlightenment. This commit
therefore removes the reference from the synchronize_sched() header
comment, and adds the corresponding information to the synchronize_rcu(0
header comment.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Current rcuperf startup checks to see if the user asked to measure
only expedited grace periods, yet constrained all grace periods to be
normal, or if the user asked to measure only normal grace periods, yet
constrained all grace periods to be expedited. Useless tests of this
sort are aborted.
Unfortunately, making RCU work through the mid-boot dead zone [1] puts
RCU into expedited-only mode during that zone. Which happens to also
be the exact time that rcuperf carries out the aforementioned check.
So if the user asks rcuperf to measure only normal grace periods (the
default), rcuperf will now always complain and terminate the test.
This commit therefore moves the checks to rcu_perf_cleanup(). This has
the disadvantage of failing to abort useless tests, but avoids the need to
create yet another kthread and the need to do fiddly checks involving the
holdoff time. (Yes, another approach is to do the checks in a late-stage
init function, but that would require some way to communicate badness
to rcuperf's kthreads, and seems not worth the bother.)
[1] https://lwn.net/Articles/716148/
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Although preemptible RCU allows its read-side critical sections to be
preempted, general blocking is forbidden. The reason for this is that
excessive preemption times can be handled by CONFIG_RCU_BOOST=y, but a
voluntarily blocked task doesn't care how high you boost its priority.
Because preemptible RCU is a global mechanism, one ill-behaved reader
hurts everyone. Hence the prohibition against general blocking in
RCU-preempt read-side critical sections. Preemption yes, blocking no.
This commit enforces this prohibition.
There is a special exception for the -rt patchset (which they kindly
volunteered to implement): It is OK to block (as opposed to merely being
preempted) within an RCU-preempt read-side critical section, but only if
the blocking is subject to priority inheritance. This exception permits
CONFIG_RCU_BOOST=y to get -rt RCU readers out of trouble.
Why doesn't this exception also apply to mainline's rt_mutex? Because
of the possibility that someone does general blocking while holding
an rt_mutex. Yes, the priority boosting will affect the rt_mutex,
but it won't help with the task doing general blocking while holding
that rt_mutex.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Earlier versions of Tree SRCU were subject to a counter overflow bug that
could theoretically result in too-short grace periods. This commit
eliminates this problem by adding an update-side memory barrier.
The short explanation is that if the updater sums the unlock counts
too late to see a given __srcu_read_unlock() increment, that CPU's
next __srcu_read_lock() must see the new value of ->srcu_idx, thus
incrementing the other bank of counters. This eliminates the possibility
of destructive counter overflow as long as the srcu_read_lock() nesting
level does not exceed floor(ULONG_MAX/NR_CPUS/2), which should be an
eminently reasonable nesting limit, especially on 64-bit systems.
Reported-by: Lance Roy <ldr709@gmail.com>
Suggested-by: Lance Roy <ldr709@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently rcu_barrier() uses call_rcu() to enqueue new callbacks
on each CPU with a non-empty callback list. This works, but means
that rcu_barrier() forces grace periods that are not otherwise needed.
The key point is that rcu_barrier() never needs to wait for a grace
period, but instead only for all pre-existing callbacks to be invoked.
This means that rcu_barrier()'s new callbacks should be placed in
the callback-list segment containing the last pre-existing callback.
This commit makes this change using the new rcu_segcblist_entrain()
function.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Cc: stable@vger.kernel.org
Fixes: 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING")
Reported-by: Linu Cherian <linuc.decode@gmail.com>
Suggested-by: Linu Cherian <linuc.decode@gmail.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting
down a guest running iperf on a VFIO assigned device. This happens
because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt
context, while a worker thread does the same inside kvm_set_irq(). If the
interrupt happens while the worker thread is executing __srcu_read_lock(),
updates to the Classic SRCU ->lock_count[] field or the Tree SRCU
->srcu_lock_count[] field can be lost.
The docs say you are not supposed to call srcu_read_lock() and
srcu_read_unlock() from irq context, but KVM interrupt injection happens
from (host) interrupt context and it would be nice if SRCU supported the
use case. KVM is using SRCU here not really for the "sleepable" part,
but rather due to its IPI-free fast detection of grace periods. It is
therefore not desirable to switch back to RCU, which would effectively
revert commit 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING",
2014-01-16).
However, the docs are overly conservative. You can have an SRCU instance
only has users in irq context, and you can mix process and irq context
as long as process context users disable interrupts. In addition,
__srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and
Classic SRCU. For those two implementations, only srcu_read_lock()
is unsafe.
When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(),
in commit 5a41344a3d ("srcu: Simplify __srcu_read_unlock() via
this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments.
Therefore it kept __this_cpu_inc(), with preempt_disable/enable in
the caller. Tree SRCU however only does one increment, so on most
architectures it is more efficient for __srcu_read_lock() to use
this_cpu_inc(), and any performance differences appear to be down in
the noise.
Unlike Classic and Tree SRCU, Tiny SRCU does increments and decrements on
a single variable. Therefore, as Peter Zijlstra pointed out, Tiny SRCU's
implementation already supports mixed-context use of srcu_read_lock()
and srcu_read_unlock(), at least as long as uses of srcu_read_lock()
and srcu_read_unlock() in each handler are nested and paired properly.
In other words, it is still illegal to (say) invoke srcu_read_lock()
in an interrupt handler and to invoke the matching srcu_read_unlock()
in a softirq handler. Therefore, the only change required for Tiny SRCU
is to its comments.
Fixes: 719d93cd5f ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING")
Reported-by: Linu Cherian <linuc.decode@gmail.com>
Suggested-by: Linu Cherian <linuc.decode@gmail.com>
Cc: kvm@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit cf39bf58af.
The commit regression to users that define both console=ttyS1
and console=ttyS0 on the command line, see
https://lkml.kernel.org/r/20170509082915.GA13236@bistromath.localdomain
The kernel log messages always appeared only on one serial port. It is
even documented in Documentation/admin-guide/serial-console.rst:
"Note that you can only define one console per device type (serial,
video)."
The above mentioned commit changed the order in which the command line
parameters are searched. As a result, the kernel log messages go to
the last mentioned ttyS* instead of the first one.
We long thought that using two console=ttyS* on the command line
did not make sense. But then we realized that console= parameters
were handled also by systemd, see
http://0pointer.de/blog/projects/serial-console.html
"By default systemd will instantiate one serial-getty@.service on
the main kernel console, if it is not a virtual terminal."
where
"[4] If multiple kernel consoles are used simultaneously, the main
console is the one listed first in /sys/class/tty/console/active,
which is the last one listed on the kernel command line."
This puts the original report into another light. The system is running
in qemu. The first serial port is used to store the messages into a file.
The second one is used to login to the system via a socket. It depends
on systemd and the historic kernel behavior.
By other words, systemd causes that it makes sense to define both
console=ttyS1 console=ttyS0 on the command line. The kernel fix
caused regression related to userspace (systemd) and need to be
reverted.
In addition, it went out that the fix helped only partially.
The messages still were duplicated when the boot console was
removed early by late_initcall(printk_late_init). Then the entire
log was replayed when the same console was registered as a normal one.
Link: 20170606160339.GC7604@pathway.suse.cz
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Cc: Sabrina Dubroca <sd@queasysnail.net>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Nair, Jayachandran" <Jayachandran.Nair@cavium.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Now that (PI) futexes have their own private RT-mutex interface and
implementation we can easily add lockdep annotations to the existing
RT-mutex interface.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Deferrable vmstat_updater was missing in commit:
c1de45ca83 ("sched/idle: Add support for tasks that inject idle")
Add it back.
Signed-off-by: Aubrey Li <aubrey.li@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aubrey Li <aubrey.li@intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1496803742-38274-1-git-send-email-aubrey.li@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The stop class is invoked through stop_machine only.
This is dead code on UP builds.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170529210302.26868-3-nicolas.pitre@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We have been facing some problems with self-suspending constrained
deadline tasks. The main reason is that the original CBS was not
designed for such sort of tasks.
One problem reported by Xunlei Pang takes place when a task
suspends, and then is awakened before the deadline, but so close
to the deadline that its remaining runtime can cause the task
to have an absolute density higher than allowed. In such situation,
the original CBS assumes that the task is facing an early activation,
and so it replenishes the task and set another deadline, one deadline
in the future. This rule works fine for implicit deadline tasks.
Moreover, it allows the system to adapt the period of a task in which
the external event source suffered from a clock drift.
However, this opens the window for bandwidth leakage for constrained
deadline tasks. For instance, a task with the following parameters:
runtime = 5 ms
deadline = 7 ms
[density] = 5 / 7 = 0.71
period = 1000 ms
If the task runs for 1 ms, and then suspends for another 1ms,
it will be awakened with the following parameters:
remaining runtime = 4
laxity = 5
presenting a absolute density of 4 / 5 = 0.80.
In this case, the original CBS would assume the task had an early
wakeup. Then, CBS will reset the runtime, and the absolute deadline will
be postponed by one relative deadline, allowing the task to run.
The problem is that, if the task runs this pattern forever, it will keep
receiving bandwidth, being able to run 1ms every 2ms. Following this
behavior, the task would be able to run 500 ms in 1 sec. Thus running
more than the 5 ms / 1 sec the admission control allowed it to run.
Trying to address the self-suspending case, Luca Abeni, Giuseppe
Lipari, and Juri Lelli [1] revisited the CBS in order to deal with
self-suspending tasks. In the new approach, rather than
replenishing/postponing the absolute deadline, the revised wakeup rule
adjusts the remaining runtime, reducing it to fit into the allowed
density.
A revised version of the idea is:
At a given time t, the maximum absolute density of a task cannot be
higher than its relative density, that is:
runtime / (deadline - t) <= dl_runtime / dl_deadline
Knowing the laxity of a task (deadline - t), it is possible to move
it to the other side of the equality, thus enabling to define max
remaining runtime a task can use within the absolute deadline, without
over-running the allowed density:
runtime = (dl_runtime / dl_deadline) * (deadline - t)
For instance, in our previous example, the task could still run:
runtime = ( 5 / 7 ) * 5
runtime = 3.57 ms
Without causing damage for other deadline tasks. It is note worthy
that the laxity cannot be negative because that would cause a negative
runtime. Thus, this patch depends on the patch:
df8eac8caf ("sched/deadline: Throttle a constrained deadline task activated after the deadline")
Which throttles a constrained deadline task activated after the
deadline.
Finally, it is also possible to use the revised wakeup rule for
all other tasks, but that would require some more discussions
about pros and cons.
Reported-by: Xunlei Pang <xpang@redhat.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
[peterz: replaced dl_is_constrained with dl_is_implicit]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Romulo Silva de Oliveira <romulo.deoliveira@ufsc.br>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/5c800ab3a74a168a84ee5f3f84d12a02e11383be.1495803804.git.bristot@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When a contrained task is throttled by dl_check_constrained_dl(),
it may carry the remaining positive runtime, as a result when
dl_task_timer() fires and calls replenish_dl_entity(), it will
not be replenished correctly due to the positive dl_se->runtime.
This patch assigns its runtime to 0 if positive after throttling.
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: df8eac8caf ("sched/deadline: Throttle a constrained deadline task activated after the deadline)
Link: http://lkml.kernel.org/r/1494421417-27550-1-git-send-email-xlpang@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit introduces a per-runqueue "extra utilization" that can be
reclaimed by deadline tasks. In this way, the maximum fraction of CPU
time that can reclaimed by deadline tasks is fixed (and configurable)
and does not depend on the total deadline utilization.
The GRUB accounting rule is modified to add this "extra utilization"
to the inactive utilization of the runqueue, and to avoid reclaiming
more than a maximum fraction of the CPU time.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-10-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Instead of decreasing the runtime as "dq = -Uact dt" (eventually
divided by the maximum utilization available for deadline tasks),
decrease it as "dq = -max{u, (1 - Uinact)} dt", where u is the task
utilization and Uinact is the "inactive utilization".
In this way, the maximum fraction of CPU time that can be reclaimed
is given by the total utilization of deadline tasks.
This approach solves a fairness issue with "traditional" global GRUB
reclaiming: using the traditional GRUB algorithm, if tasks are
allocated to the various cores in a non-uniform way, the
reclaiming mechanism allows some tasks to reclaim more time than
others. This issue is visible starting 11 time-consuming tasks with
runtime 10ms and period 30ms (total utilization 3.666) on a 4-cores
system: some tasks will receive much more than the reserved runtime
(thanks to the reclaiming mechanism), while other tasks will receive
less than the reserved runtime.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-9-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The total rq utilization is defined as the sum of the utilisations of
tasks that are "assigned" to a runqueue, independently from their state
(TASK_RUNNING or blocked)
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-8-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch introduces the SCHED_FLAG_RECLAIM flag to specify
that a DL task is allowed to reclaim unused CPU time (using
the GRUB algorithm).
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-7-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Original GRUB tends to reclaim 100% of the CPU time... And this
allows a CPU hog to starve non-deadline tasks.
To address this issue, allow the scheduler to reclaim only a
specified fraction of CPU time, stored in the new "bw_ratio"
field of the dl runqueue structure.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-6-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
According to the GRUB (Greedy Reclaimation of Unused Bandwidth)
reclaiming algorithm, the runtime is not decreased as "dq = -dt",
but as "dq = -Uact dt" (where Uact is the per-runqueue active
utilization).
Hence, this commit modifies the runtime accounting rule in
update_curr_dl() to implement the GRUB rule.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-5-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that the inactive timer can be armed to fire at the 0-lag time,
it is possible to use inactive_task_timer() to update the total
-deadline utilization (dl_b->total_bw) at the correct time, fixing
dl_overflow() and __setparam_dl().
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-4-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch implements a more theoretically sound algorithm for
tracking active utilization: instead of decreasing it when a
task blocks, use a timer (the "inactive timer", named after the
"Inactive" task state of the GRUB algorithm) to decrease the
active utilization at the so called "0-lag time".
Tested-by: Claudio Scordino <claudio@evidence.eu.com>
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@santannapisa.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-3-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Active utilization is defined as the total utilization of active
(TASK_RUNNING) tasks queued on a runqueue. Hence, it is increased
when a task wakes up and is decreased when a task blocks.
When a task is migrated from CPUi to CPUj, immediately subtract the
task's utilization from CPUi and add it to CPUj. This mechanism is
implemented by modifying the pull and push functions.
Note: this is not fully correct from the theoretical point of view
(the utilization should be removed from CPUi only at the 0 lag
time), a more theoretically sound solution is presented in the
next patches.
Tested-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@arm.com>
Cc: Claudio Scordino <claudio@evidence.eu.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tommaso Cucinotta <tommaso.cucinotta@sssup.it>
Link: http://lkml.kernel.org/r/1495138417-6203-2-git-send-email-luca.abeni@santannapisa.it
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Hackbench recently suffered a bunch of pain, first by commit:
4c77b18cf8 ("sched/fair: Make select_idle_cpu() more aggressive")
and then by commit:
c743f0a5c5 ("sched/fair, cpumask: Export for_each_cpu_wrap()")
which fixed a bug in the initial for_each_cpu_wrap() implementation
that made select_idle_cpu() even more expensive. The bug was that it
would skip over CPUs when bits were consequtive in the bitmask.
This however gave me an idea to fix select_idle_cpu(); where the old
scheme was a cliff-edge throttle on idle scanning, this introduces a
more gradual approach. Instead of stopping to scan entirely, we limit
how many CPUs we scan.
Initial benchmarks show that it mostly recovers hackbench while not
hurting anything else, except Mason's schbench, but not as bad as the
old thing.
It also appears to recover the tbench high-end, which also suffered like
hackbench.
Tested-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: hpa@zytor.com
Cc: kitsunyan <kitsunyan@inbox.ru>
Cc: linux-kernel@vger.kernel.org
Cc: lvenanci@redhat.com
Cc: riel@redhat.com
Cc: xiaolong.ye@intel.com
Link: http://lkml.kernel.org/r/20170517105350.hk5m4h4jb6dfr65a@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The function was added by commit e5d1367f17 ("perf: Add cgroup
support") in 2011 and hasn't been used since then. Removing it fixes the
following warning when building with Clang:
kernel/events/core.c:696:19: error: unused function 'perf_cgroup_event_cgrp_time' [-Werror,-Wunused-function]
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170523215132.189049-1-mka@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Andi was asking about PERF_FORMAT_GROUP vs inherited events, which led
to the discovery of a bug from commit:
3dab77fb1b ("perf: Rework/fix the whole read vs group stuff")
- PERF_SAMPLE_GROUP = 1U << 4,
+ PERF_SAMPLE_READ = 1U << 4,
- if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
+ if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))
is a clear fail :/
While this changes user visible behaviour; it was previously possible
to create an inherited event with PERF_SAMPLE_READ; this is deemed
acceptible because its results were always incorrect.
Reported-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vince@deater.net>
Fixes: 3dab77fb1b ("perf: Rework/fix the whole read vs group stuff")
Link: http://lkml.kernel.org/r/20170530094512.dy2nljns2uq7qa3j@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Check the kretprobe maxactive is supported by kprobe_events
interface. To ensure the kernel feature, this changes ftrace
README to describe it.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Revert commit eed4d47efe (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.
That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.
The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit fb9a307d11 ("bpf: Allow CGROUP_SKB eBPF program to
access sk_buff") enabled programs of BPF_PROG_TYPE_CGROUP_SKB
type to use ld_abs/ind instructions. However, at this point,
we cannot use them, since offsets relative to SKF_LL_OFF will
end up pointing skb_mac_header(skb) out of bounds since in the
egress path it is not yet set at that point in time, but only
after __dev_queue_xmit() did a general reset on the mac header.
bpf_internal_load_pointer_neg_helper() will then end up reading
data from a wrong offset.
BPF_PROG_TYPE_CGROUP_SKB programs can use bpf_skb_load_bytes()
already to access packet data, which is also more flexible than
the insns carried over from cBPF.
Fixes: fb9a307d11 ("bpf: Allow CGROUP_SKB eBPF program to access sk_buff")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Chenbo Feng <fengc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A single BPF_OBJ_GET_INFO_BY_FD cmd is used to obtain the info
for both bpf_prog and bpf_map. The kernel can figure out the
fd is associated with a bpf_prog or bpf_map.
The suggested struct bpf_prog_info and struct bpf_map_info are
not meant to be a complete list and it is not the goal of this patch.
New fields can be added in the future patch.
The focus of this patch is to create the interface,
BPF_OBJ_GET_INFO_BY_FD cmd for exposing the bpf_prog's and
bpf_map's info.
The obj's info, which will be extended (and get bigger) over time, is
separated from the bpf_attr to avoid bloating the bpf_attr.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add BPF_MAP_GET_FD_BY_ID command to allow user to get a fd
from a bpf_map's ID.
bpf_map_inc_not_zero() is added and is called with map_idr_lock
held.
__bpf_map_put() is also added which has the 'bool do_idr_lock'
param to decide if the map_idr_lock should be acquired when
freeing the map->id.
In the error path of bpf_map_inc_not_zero(), it may have to
call __bpf_map_put(map, false) which does not need
to take the map_idr_lock when freeing the map->id.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add BPF_PROG_GET_FD_BY_ID command to allow user to get a fd
from a bpf_prog's ID.
bpf_prog_inc_not_zero() is added and is called with prog_idr_lock
held.
__bpf_prog_put() is also added which has the 'bool do_idr_lock'
param to decide if the prog_idr_lock should be acquired when
freeing the prog->id.
In the error path of bpf_prog_inc_not_zero(), it may have to
call __bpf_prog_put(map, false) which does not need
to take the prog_idr_lock when freeing the prog->id.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds BPF_PROG_GET_NEXT_ID and BPF_MAP_GET_NEXT_ID
to allow userspace to iterate all bpf_prog IDs and bpf_map IDs.
The API is trying to be consistent with the existing
BPF_MAP_GET_NEXT_KEY.
It is currently limited to CAP_SYS_ADMIN which we can
consider to lift it in followup patches.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch generates an unique ID for each created bpf_map.
The approach is similar to the earlier patch for bpf_prog ID.
It is worth to note that the bpf_map's ID and bpf_prog's ID
are in two independent ID spaces and both have the same valid range:
[1, INT_MAX).
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch generates an unique ID for each BPF_PROG_LOAD-ed prog.
It is worth to note that each BPF_PROG_LOAD-ed prog will have
a different ID even they have the same bpf instructions.
The ID is generated by the existing idr_alloc_cyclic().
The ID is ranged from [1, INT_MAX). It is allocated in cyclic manner,
so an ID will get reused every 2 billion BPF_PROG_LOAD.
The bpf_prog_alloc_id() is done after bpf_prog_select_runtime()
because the jit process may have allocated a new prog. Hence,
we need to ensure the value of pointer 'prog' will not be changed
any more before storing the prog to the prog_idr.
After bpf_prog_select_runtime(), the prog is read-only. Hence,
the id is stored in 'struct bpf_prog_aux'.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull cgroup fixes from Tejun Heo:
"Two cgroup fixes. One to address RCU delay of cpuset removal affecting
userland visible behaviors. The other fixes a race condition between
controller disable and cgroup removal"
* 'for-4.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: consider dying css as offline
cgroup: Prevent kill_css() from being called more than once
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
When the tick is stopped and we reach the dynticks evaluation code on
IRQ exit, we perform a soft tick restart if we observe an expired timer
from there. It means we program the nearest possible tick but we stay in
dynticks mode (ts->tick_stopped = 1) because we may need to stop the tick
again after that expired timer is handled.
Now this solution works most of the time but if we suffer an IRQ storm
and those interrupts trigger faster than the hardware clockevents min
delay, our tick won't fire until that IRQ storm is finished.
Here is the problem: on IRQ exit we reprog the timer to at least
NOW() + min_clockevents_delay. Another IRQ fires before the tick so we
reschedule again to NOW() + min_clockevents_delay, etc... The tick
is eternally rescheduled min_clockevents_delay ahead.
A solution is to simply remove this soft tick restart. After all
the normal dynticks evaluation path can handle 0 delay just fine. And
by doing that we benefit from the optimization branch which avoids
clock reprogramming if the clockevents deadline hasn't changed since
the last reprog. This fixes our issue because we don't do repetitive
clock reprog that always add hardware min delay.
As a side effect it should even optimize the 0 delay path in general.
Reported-and-tested-by: Octavian Purdila <octavian.purdila@nxp.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1496328429-13317-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allow BPF_PROG_TYPE_PERF_EVENT program types to attach to all
perf_event types, including HW_CACHE, RAW, and dynamic pmu events.
Only tracepoint/kprobe events are treated differently which require
BPF_PROG_TYPE_TRACEPOINT/BPF_PROG_TYPE_KPROBE program types accordingly.
Also add support for reading all event counters using
bpf_perf_event_read() helper.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
All required callbacks are in place. Switch the alarm timer based posix
interval timer callbacks to the common implementation and remove the
incorrect private implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.825471962@linutronix.de
Preparatory change to utilize the common posix timer mechanisms.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.747567162@linutronix.de
Preparatory change to utilize the common posix timer mechanisms.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.670026824@linutronix.de
Preparatory change to utilize the common posix timer mechanisms.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.592676753@linutronix.de
Preparatory change to utilize the common posix timer mechanisms.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.513694229@linutronix.de
Preparatory change to utilize the common posix timer mechanisms.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.434598989@linutronix.de
Replace the hrtimer calls by calls to the new try_to_cancel()/arm() kclock
callbacks and move the hrtimer specific implementation into the
corresponding callback functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.355396667@linutronix.de
Add timer_try_to_cancel() and timer_arm() callbacks to kclock which allow
to make common_timer_set() usable by both hrtimer and alarmtimer based
clocks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.278022962@linutronix.de
Zero out the settings struct in the common code so the callbacks do not
have to do it themself.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.200870713@linutronix.de
Replace the hrtimer calls by calls to the new forward/remaining kclock
callbacks and move the hrtimer specific implementation into the
corresponding callback functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.121437232@linutronix.de
Add two callbacks to kclock which allow using common_)timer_get() for both
hrtimer and alarm timer based clocks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211657.044915536@linutronix.de
Keep track of the activation state of posix timers. This is a preparatory
change for making common_timer_get() usable by both hrtimer and alarm timer
implementations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.967783982@linutronix.de
Use the new timer_rearm() callback to replace the conditional hardcoded
calls into the hrtimer and cpu timer code.
This allows later to bring the same logic to alarmtimers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.889661919@linutronix.de
That function is a misnomer. Rename it with a proper prefix to
posixtimer_rearm().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.811362578@linutronix.de
Add a timer_rearm() callback which is used to make the rescheduling of
posix interval timers independent of the underlying clock implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.732632167@linutronix.de
Having the k_clock pointer in the k_itimer struct avoids the lookup in
several code pathes and makes the next steps of unification of the hrtimer
and alarmtimer based posix timers simpler.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.641222072@linutronix.de
Preparatory patch to unify the alarm timer and hrtimer based posix interval
timer handling.
The interval is used as a criteria for rearming decisions so moving it out
of the clock specific data structures allows later unification.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.563922908@linutronix.de
hrtimer based posix-timers and posix-cpu-timers handle the update of the
rearming and overflow related status fields differently.
Move that update to the common rearming code.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.484936964@linutronix.de
None of these declarations is required outside of kernel/time. Move them to
an internal header.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/20170530211656.394803853@linutronix.de
Move it below the actual implementations as there are new callbacks coming
which would require even more forward declarations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.238209952@linutronix.de
The only user of this facility is ptp_clock, which does not implement any of
those functions.
Remove them to prevent accidental users. Especially the interval timer
interfaces are now more or less impossible to implement because the
necessary infrastructure has been confined to the core code. Aside of that
it's really complex to make these callbacks implemented according to spec
as the alarm timer implementation demonstrates. If at all then a nanosleep
callback might be a reasonable extension. For now keep just what ptp_clock
needs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.145036286@linutronix.de
Since the removal of the mmtimer driver the export is not longer needed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211656.052744418@linutronix.de
Having a IF_ENABLED(CONFIG_POSIX_TIMERS) inside of a
#ifdef CONFIG_POSIX_TIMERS section is pointless.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20170530211655.975218056@linutronix.de
The alarmtimer code has another source of potentially rearming itself too
fast. Interval timers with a very samll interval have a similar CPU hog
effect as the previously fixed overflow issue.
The reason is that alarmtimers do not implement the normal protection
against this kind of problem which the other posix timer use:
timer expires -> queue signal -> deliver signal -> rearm timer
This scheme brings the rearming under scheduler control and prevents
permanently firing timers which hog the CPU.
Bringing this scheme to the alarm timer code is a major overhaul because it
lacks all the necessary mechanisms completely.
So for a quick fix limit the interval to one jiffie. This is not
problematic in practice as alarmtimers are usually backed by an RTC for
suspend which have 1 second resolution. It could be therefor argued that
the resolution of this clock should be set to 1 second in general, but
that's outside the scope of this fix.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170530211655.896767100@linutronix.de
Andrey reported a alartimer related RCU stall while fuzzing the kernel with
syzkaller.
The reason for this is an overflow in ktime_add() which brings the
resulting time into negative space and causes immediate expiry of the
timer. The following rearm with a small interval does not bring the timer
back into positive space due to the same issue.
This results in a permanent firing alarmtimer which hogs the CPU.
Use ktime_add_safe() instead which detects the overflow and clamps the
result to KTIME_SEC_MAX.
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kostya Serebryany <kcc@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170530211655.802921648@linutronix.de
Shared interrupts do not go well with disabling auto enable:
1) The sharing interrupt might request it while it's still disabled and
then wait for interrupts forever.
2) The interrupt might have been requested by the driver sharing the line
before IRQ_NOAUTOEN has been set. So the driver which expects that
disabled state after calling request_irq() will not get what it wants.
Even worse, when it calls enable_irq() later, it will trigger the
unbalanced enable_irq() warning.
Reported-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: dianders@chromium.org
Cc: jeffy <jeffy.chen@rock-chips.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: tfiga@chromium.org
Link: http://lkml.kernel.org/r/20170531100212.210682135@linutronix.de
If an interrupt is marked NOAUTOEN then request_irq() installs the action,
but does not enable the interrupt via startup_irq(). The interrupt is
enabled via enable_irq() later from the driver. enable_irq() calls
irq_enable().
That means that for interrupts which have a irq_startup() callback this
callback is never invoked. Neither is irq_domain_activate_irq() invoked for
such interrupts.
If an interrupt depends on irq_startup() or irq_domain_activate_irq() then
the enable via irq_enable() is not enough.
Add a status flag IRQD_IRQ_STARTED_UP and use this to select the proper
mechanism in enable_irq(). Use the flag also to avoid pointless calls into
the low level functions.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: dianders@chromium.org
Cc: jeffy <jeffy.chen@rock-chips.com>
Cc: Brian Norris <briannorris@chromium.org>
Cc: tfiga@chromium.org
Link: http://lkml.kernel.org/r/20170531100212.130986205@linutronix.de
If a custom CPU target is specified and that one is not available _or_
can't be interrupted then the code returns to userland without dropping a
lock as notices by lockdep:
|echo 133 > /sys/devices/system/cpu/cpu7/hotplug/target
| ================================================
| [ BUG: lock held when returning to user space! ]
| ------------------------------------------------
| bash/503 is leaving the kernel with locks still held!
| 1 lock held by bash/503:
| #0: (device_hotplug_lock){+.+...}, at: [<ffffffff815b5650>] lock_device_hotplug_sysfs+0x10/0x40
So release the lock then.
Fixes: 757c989b99 ("cpu/hotplug: Make target state writeable")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170602142714.3ogo25f2wbq6fjpj@linutronix.de
Currently loading a cgroup skb eBPF program require a CAP_SYS_ADMIN
capability while attaching the program to a cgroup only requires the
user have CAP_NET_ADMIN privilege. We can escape the capability
check when load the program just like socket filter program to make
the capability requirement consistent.
Change since v1:
Change the code style in order to be compliant with checkpatch.pl
preference
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows cgroup eBPF program to classify packet based on their
protocol or other detail information. Currently program need
CAP_NET_ADMIN privilege to attach a cgroup eBPF program, and A
process with CAP_NET_ADMIN can already see all packets on the system,
for example, by creating an iptables rules that causes the packet to
be passed to userspace via NFLOG.
Signed-off-by: Chenbo Feng <fengc@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull livepatching fix from Jiri Kosina:
"Kconfig dependency fix for livepatching infrastructure from Miroslav
Benes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: Make livepatch dependent on !TRIM_UNUSED_KSYMS
16 __bpf_prog_run() interpreters for various stack sizes add .text
but not a lot comparing to run-time stack savings
text data bss dec hex filename
26350 10328 624 37302 91b6 kernel/bpf/core.o.before_split
25777 10328 624 36729 8f79 kernel/bpf/core.o.after_split
26970 10328 624 37922 9422 kernel/bpf/core.o.now
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The next set of patches will take advantage of stack_depth tracking,
so make sure that the program that does bpf_tail_call() has
stack depth large enough for the callee.
We could have tracked the stack depth of the prog_array owner program
and only allow insertion of the programs with stack depth less
than the owner, but it will break existing applications.
Some of them have trivial root bpf program that only does
multiple bpf_tail_calls and at init time the prog array is empty.
In the future we may add a flag to do such tracking optionally,
but for now play simple and safe.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
teach verifier to track bpf program stack depth
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
free up BPF_JMP | BPF_CALL | BPF_X opcode to be used by actual
indirect call by register and use kernel internal opcode to
mark call instruction into bpf_tail_call() helper.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Capabilities were augmented to include ambient capabilities in v4.3
commit 58319057b7 ("capabilities: ambient capabilities").
Add ambient capabilities to the audit BPRM_FCAPS and CAPSET records.
The record contains fields "old_pp", "old_pi", "old_pe", "new_pp",
"new_pi", "new_pe" so in keeping with the previous record
normalizations, change the "new_*" variants to simply drop the "new_"
prefix.
A sample of the replaced BPRM_FCAPS record:
RAW: type=BPRM_FCAPS msg=audit(1491468034.252:237): fver=2
fp=0000000000200000 fi=0000000000000000 fe=1 old_pp=0000000000000000
old_pi=0000000000000000 old_pe=0000000000000000 old_pa=0000000000000000
pp=0000000000200000 pi=0000000000000000 pe=0000000000200000
pa=0000000000000000
INTERPRET: type=BPRM_FCAPS msg=audit(04/06/2017 04:40:34.252:237):
fver=2 fp=sys_admin fi=none fe=chown old_pp=none old_pi=none
old_pe=none old_pa=none pp=sys_admin pi=none pe=sys_admin pa=none
A sample of the replaced CAPSET record:
RAW: type=CAPSET msg=audit(1491469502.371:242): pid=833
cap_pi=0000003fffffffff cap_pp=0000003fffffffff cap_pe=0000003fffffffff
cap_pa=0000000000000000
INTERPRET: type=CAPSET msg=audit(04/06/2017 05:05:02.371:242) : pid=833
cap_pi=chown,dac_override,dac_read_search,fowner,fsetid,kill,
setgid,setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,sys_time,
sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pp=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pe=chown,dac_override,dac_read_search,fowner,fsetid,kill,setgid,
setuid,setpcap,linux_immutable,net_bind_service,net_broadcast,
net_admin,net_raw,ipc_lock,ipc_owner,sys_module,sys_rawio,sys_chroot,
sys_ptrace,sys_pacct,sys_admin,sys_boot,sys_nice,sys_resource,
sys_time,sys_tty_config,mknod,lease,audit_write,audit_control,setfcap,
mac_override,mac_admin,syslog,wake_alarm,block_suspend,audit_read
cap_pa=none
See: https://github.com/linux-audit/audit-kernel/issues/40
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Handle tick interrupts whose regs are NULL, out of general paranoia. It happens
when hrtimer_interrupt() is called from non-interrupt contexts, such as hotplug
CPU down events.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull timer fixlet from Thomas Gleixner:
"Silence dmesg spam by making the posix cpu timer printks depend on
print_fatal_signals"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timers: Make signal printks conditional
Pull locking fix from Thomas Gleixner:
"A fix for a state leak which was introduced in the recent rework of
futex/rtmutex interaction"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex,rt_mutex: Fix rt_mutex_cleanup_proxy_lock()
Pull kthread fix from Thomas Gleixner:
"A single fix which prevents a use after free when kthread fork fails"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kthread: Fix use-after-free if kthread fork fails
One was simply a memory leak where not all was being freed that should
have been in releasing a file pointer on set_graph_function.
Then Thomas found that the ftrace trampolines were marked for read/write
as well as execute. To shrink the possible attack surface, he added
calls to set them to ro. Which also uncovered some other issues with
freeing module allocated memory that had its permissions changed.
Kprobes had a similar issue which is fixed and a selftest was added
to trigger that issue again.
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Merge tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace fixes from Steven Rostedt:
"There's been a few memory issues found with ftrace.
One was simply a memory leak where not all was being freed that should
have been in releasing a file pointer on set_graph_function.
Then Thomas found that the ftrace trampolines were marked for
read/write as well as execute. To shrink the possible attack surface,
he added calls to set them to ro. Which also uncovered some other
issues with freeing module allocated memory that had its permissions
changed.
Kprobes had a similar issue which is fixed and a selftest was added to
trigger that issue again"
* tag 'trace-v4.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
x86/ftrace: Make sure that ftrace trampolines are not RWX
x86/mm/ftrace: Do not bug in early boot on irqs_disabled in cpu_flush_range()
selftests/ftrace: Add a testcase for many kprobe events
kprobes/x86: Fix to set RWX bits correctly before releasing trampoline
ftrace: Fix memory leak in ftrace_graph_release()
Some freezer related variables are only used when either CONFIG_POSIX_TIMER
or CONFIG_RTC_CLASS are enabled. Hide them when both are off.
Fixes: d3ba5a9a34 ("posix-timers: Make posix_clocks immutable")
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Christoph Helwig <hch@lst.de>
There are no more modular users providing a posix clock. The register
function is now pointless so the posix clock array can be initialized
statically at compile time and the array including the various k_clock
structs can be marked 'const'.
Inspired by changes in the Grsecurity patch set, but done proper.
[ tglx: Massaged changelog and fixed the POSIX_TIMER=n case ]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Dimitri Sivanich <sivanich@hpe.com>
Link: http://lkml.kernel.org/r/20170526090311.3377-3-hch@lst.de
Fix kprobes to set(recover) RWX bits correctly on trampoline
buffer before releasing it. Releasing readonly page to
module_memfree() crash the kernel.
Without this fix, if kprobes user register a bunch of kprobes
in function body (since kprobes on function entry usually
use ftrace) and unregister it, kernel hits a BUG and crash.
Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: d0381c81c2 ("kprobes/x86: Set kprobes pages read-only")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If TRIM_UNUSED_KSYMS is enabled, all unneeded exported symbols are made
unexported. Two-pass build of the kernel is done to find out which
symbols are needed based on a configuration. This effectively
complicates things for out-of-tree modules.
Livepatch exports functions to (un)register and enable/disable a live
patch. The only in-tree module which uses these functions is a sample in
samples/livepatch/. If the sample is disabled, the functions are
trimmed and out-of-tree live patches cannot be built.
Note that live patches are intended to be built out-of-tree.
Suggested-by: Michal Marek <mmarek@suse.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Pull networking fixes from David Miller:
1) Fix state pruning in bpf verifier wrt. alignment, from Daniel
Borkmann.
2) Handle non-linear SKBs properly in SCTP ICMP parsing, from Davide
Caratti.
3) Fix bit field definitions for rss_hash_type of descriptors in mlx5
driver, from Jesper Brouer.
4) Defer slave->link updates until bonding is ready to do a full commit
to the new settings, from Nithin Sujir.
5) Properly reference count ipv4 FIB metrics to avoid use after free
situations, from Eric Dumazet and several others including Cong Wang
and Julian Anastasov.
6) Fix races in llc_ui_bind(), from Lin Zhang.
7) Fix regression of ESP UDP encapsulation for TCP packets, from
Steffen Klassert.
8) Fix mdio-octeon driver Kconfig deps, from Randy Dunlap.
9) Fix regression in setting DSCP on ipv6/GRE encapsulation, from Peter
Dawson.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits)
ipv4: add reference counting to metrics
net: ethernet: ax88796: don't call free_irq without request_irq first
ip6_tunnel, ip6_gre: fix setting of DSCP on encapsulated packets
sctp: fix ICMP processing if skb is non-linear
net: llc: add lock_sock in llc_ui_bind to avoid a race condition
bonding: Don't update slave->link until ready to commit
test_bpf: Add a couple of tests for BPF_JSGE.
bpf: add various verifier test cases
bpf: fix wrong exposure of map_flags into fdinfo for lpm
bpf: add bpf_clone_redirect to bpf_helper_changes_pkt_data
bpf: properly reset caller saved regs after helper call and ld_abs/ind
bpf: fix incorrect pruning decision when alignment must be tracked
arp: fixed -Wuninitialized compiler warning
tcp: avoid fastopen API to be used on AF_UNSPEC
net: move somaxconn init from sysctl code
net: fix potential null pointer dereference
geneve: fix fill_info when using collect_metadata
virtio-net: enable TSO/checksum offloads for Q-in-Q vlans
be2net: Fix offload features for Q-in-Q packets
vlan: Fix tcp checksum offloads in Q-in-Q vlans
...
The printk in early_irq_init() is cryptic and badly formatted:
NR_IRQS:33024 nr_irqs:968 16
The last number is the number of preallocated interrupts, so add a prefix
to it:
NR_IRQS: 33024, nr_irqs: 968, preallocated irqs: 16
Cleanup the formatting for better readability as well.
Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494318849-6733-1-git-send-email-vincent.legoll@gmail.com
The CPU hotplug callbacks are not covered by lockdep versus the cpu hotplug
rwsem.
CPU0 CPU1
cpuhp_setup_state(STATE, startup, teardown);
cpus_read_lock();
invoke_callback_on_ap();
kick_hotplug_thread(ap);
wait_for_completion(); hotplug_thread_fn()
lock(m);
do_stuff();
unlock(m);
Lockdep does not know about this dependency and will not trigger on the
following code sequence:
lock(m);
cpus_read_lock();
Add a lockdep map and connect the initiators lock chain with the hotplug
thread lock chain, so potential deadlocks can be detected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081549.709375845@linutronix.de
There are no more (known) nested calls to get_online_cpus() and all
observed lock ordering problems have been addressed.
Replace the magic nested 'rwsem' hackery with a percpu-rwsem.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081549.447014063@linutronix.de
Converting the cpu hotplug locking to a percpu rwsem unearthed hidden lock
ordering problems.
There is a wide range of locks involved in this: kprobe_mutex,
jump_label_mutex, ftrace_lock, text_mutex, event_mutex, module_mutex,
func_hash->regex_lock and a gazillion of lock order permutations with
nested get_online_cpus() calls.
Some of those permutations are potential deadlocks even with the current
nesting hotplug locking scheme, but they can't be discovered by lockdep.
The conversion of the hotplug locking to a percpu rwsem requires to prevent
nested locking, so it's required to take the hotplug rwsem early in the
call chain and establish a proper lock order.
After quite some analysis and going down the wrong road severa times the
following lock order has been chosen:
kprobe_mutex -> cpus_rwsem -> jump_label_mutex -> text_mutex
For kprobes which hook on an ftrace function trace point, it's required to
drop cpus_rwsem before calling into the ftrace code to avoid a deadlock on
the func_hash->regex_lock.
[ Steven: Ftrace interaction fixes ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20170524081549.104864779@linutronix.de
The conversion of the hotplug locking to a percpu rwsem unearthed lock
ordering issues all over the place.
The jump_label code has two issues:
1) Nested get_online_cpus() invocations
2) Ordering problems vs. the cpus rwsem and the jump_label_mutex
To cure these, the following lock order has been established;
cpus_rwsem -> jump_label_lock -> text_mutex
Even if not all architectures need protection against CPU hotplug, taking
cpus_rwsem before jump_label_lock is now mandatory in code pathes which
actually modify code and therefor need text_mutex protection.
Move the get_online_cpus() invocations into the core jump label code and
establish the proper lock order where required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Link: http://lkml.kernel.org/r/20170524081549.025830817@linutronix.de
perf, tracing, kprobes and jump_labels have a gazillion of ways to create
dependency lock chains. Some of those involve nested invocations of
get_online_cpus().
The conversion of the hotplug locking to a percpu rwsem requires to avoid
such nested calls. sys_perf_event_open() protects most of the syscall logic
against cpu hotplug. This causes nested calls and lock inversions versus
ftrace and kprobes in various interesting ways.
It's impossible to move the hotplug locking to the outer end of all call
chains in the involved facilities, so the hotplug protection in
sys_perf_event_open() needs to be solved differently.
Introduce 'pmus_mutex' which protects a perf private online cpumask. This
mutex is taken when the mask is updated in the cpu hotplug callbacks and
can be taken in sys_perf_event_open() to protect the swhash setup/teardown
code and when the final judgement about a valid event has to be made.
[ tglx: Produced changelog and fixed the swhash interaction ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: http://lkml.kernel.org/r/20170524081548.930941109@linutronix.de
takedown_cpu() is a cpu hotplug function invoking stop_machine(). The cpu
hotplug machinery holds the hotplug lock for write.
stop_machine() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.
Use stop_machine_cpuslocked() to avoid the nested call.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.423292433@linutronix.de
pcrypt_init_padata()
cpus_read_lock()
padata_alloc_possible()
padata_alloc()
cpus_read_lock()
The nested call to cpus_read_lock() works with the current implementation,
but prevents the conversion to a percpu rwsem.
The other caller of padata_alloc_possible() is pcrypt_init_padata() which
calls from a cpus_read_lock() protected region as well.
Remove the cpus_read_lock() call in padata_alloc() and document the
calling convention.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/20170524081547.571278910@linutronix.de
No users outside of padata.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-crypto@vger.kernel.org
Link: http://lkml.kernel.org/r/20170524081547.491457256@linutronix.de
Some call sites of stop_machine() are within a get_online_cpus() protected
region.
stop_machine() calls get_online_cpus() as well, which is possible in the
current implementation but prevents converting the hotplug locking to a
percpu rwsem.
Provide stop_machine_cpuslocked() to avoid nested calls to get_online_cpus().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.400700852@linutronix.de
Add cpuslocked() variants for the multi instance registration so this can
be called from a cpus_read_lock() protected region.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.321782217@linutronix.de
Some call sites of cpuhp_setup/remove_state[_nocalls]() are within a
cpus_read locked region.
cpuhp_setup/remove_state[_nocalls]() call cpus_read_lock() as well, which
is possible in the current implementation but prevents converting the
hotplug locking to a percpu rwsem.
Provide locked versions of the interfaces to avoid nested calls to
cpus_read_lock().
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.239600868@linutronix.de
The counting 'rwsem' hackery of get|put_online_cpus() is going to be
replaced by percpu rwsem.
Rename the functions to make it clear that it's locking and not some
refcount style interface. These new functions will be used for the
preparatory patches which make the code ready for the percpu rwsem
conversion.
Rename all instances in the cpu hotplug code while at it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081547.080397752@linutronix.de
Saw these compile errors on SPARC when queued rwlock feature is enabled.
CC kernel/locking/qrwlock.o
kernel/locking/qrwlock.c: In function ‘queued_read_lock_slowpath’:
kernel/locking/qrwlock.c:89: error: implicit declaration of function ‘arch_spin_lock’
kernel/locking/qrwlock.c:102: error: implicit declaration of function ‘arch_spin_unlock’
make[4]: *** [kernel/locking/qrwlock.o] Error 1
Include spinlock.h in qrwlock.c to fix it.
Signed-off-by: Babu Moger <babu.moger@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: Vijay Kumar <vijay.ac.kumar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
trie_alloc() always needs to have BPF_F_NO_PREALLOC passed in via
attr->map_flags, since it does not support preallocation yet. We
check the flag, but we never copy the flag into trie->map.map_flags,
which is later on exposed into fdinfo and used by loaders such as
iproute2. Latter uses this in bpf_map_selfcheck_pinned() to test
whether a pinned map has the same spec as the one from the BPF obj
file and if not, bails out, which is currently the case for lpm
since it exposes always 0 as flags.
Also copy over flags in array_map_alloc() and stack_map_alloc().
They always have to be 0 right now, but we should make sure to not
miss to copy them over at a later point in time when we add actual
flags for them to use.
Fixes: b95a5c4db0 ("bpf: add a longest prefix match trie map implementation")
Reported-by: Jarno Rajahalme <jarno@covalent.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, after performing helper calls, we clear all caller saved
registers, that is r0 - r5 and fill r0 depending on struct bpf_func_proto
specification. The way we reset these regs can affect pruning decisions
in later paths, since we only reset register's imm to 0 and type to
NOT_INIT. However, we leave out clearing of other variables such as id,
min_value, max_value, etc, which can later on lead to pruning mismatches
due to stale data.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, when we enforce alignment tracking on direct packet access,
the verifier lets the following program pass despite doing a packet
write with unaligned access:
0: (61) r2 = *(u32 *)(r1 +76)
1: (61) r3 = *(u32 *)(r1 +80)
2: (61) r7 = *(u32 *)(r1 +8)
3: (bf) r0 = r2
4: (07) r0 += 14
5: (25) if r7 > 0x1 goto pc+4
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
6: (2d) if r0 > r3 goto pc+1
R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14)
R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
7: (63) *(u32 *)(r0 -4) = r0
8: (b7) r0 = 0
9: (95) exit
from 6 to 8:
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=0,max_value=1 R10=fp
8: (b7) r0 = 0
9: (95) exit
from 5 to 10:
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=2 R10=fp
10: (07) r0 += 1
11: (05) goto pc-6
6: safe <----- here, wrongly found safe
processed 15 insns
However, if we enforce a pruning mismatch by adding state into r8
which is then being mismatched in states_equal(), we find that for
the otherwise same program, the verifier detects a misaligned packet
access when actually walking that path:
0: (61) r2 = *(u32 *)(r1 +76)
1: (61) r3 = *(u32 *)(r1 +80)
2: (61) r7 = *(u32 *)(r1 +8)
3: (b7) r8 = 1
4: (bf) r0 = r2
5: (07) r0 += 14
6: (25) if r7 > 0x1 goto pc+4
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=0,max_value=1
R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
7: (2d) if r0 > r3 goto pc+1
R0=pkt(id=0,off=14,r=14) R1=ctx R2=pkt(id=0,off=0,r=14)
R3=pkt_end R7=inv,min_value=0,max_value=1
R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
8: (63) *(u32 *)(r0 -4) = r0
9: (b7) r0 = 0
10: (95) exit
from 7 to 9:
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=0,max_value=1
R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
9: (b7) r0 = 0
10: (95) exit
from 6 to 11:
R0=pkt(id=0,off=14,r=0) R1=ctx R2=pkt(id=0,off=0,r=0)
R3=pkt_end R7=inv,min_value=2
R8=imm1,min_value=1,max_value=1,min_align=1 R10=fp
11: (07) r0 += 1
12: (b7) r8 = 0
13: (05) goto pc-7 <----- mismatch due to r8
7: (2d) if r0 > r3 goto pc+1
R0=pkt(id=0,off=15,r=15) R1=ctx R2=pkt(id=0,off=0,r=15)
R3=pkt_end R7=inv,min_value=2
R8=imm0,min_value=0,max_value=0,min_align=2147483648 R10=fp
8: (63) *(u32 *)(r0 -4) = r0
misaligned packet access off 2+15+-4 size 4
The reason why we fail to see it in states_equal() is that the
third test in compare_ptrs_to_packet() ...
if (old->off <= cur->off &&
old->off >= old->range && cur->off >= cur->range)
return true;
... will let the above pass. The situation we run into is that
old->off <= cur->off (14 <= 15), meaning that prior walked paths
went with smaller offset, which was later used in the packet
access after successful packet range check and found to be safe
already.
For example: Given is R0=pkt(id=0,off=0,r=0). Adding offset 14
as in above program to it, results in R0=pkt(id=0,off=14,r=0)
before the packet range test. Now, testing this against R3=pkt_end
with 'if r0 > r3 goto out' will transform R0 into R0=pkt(id=0,off=14,r=14)
for the case when we're within bounds. A write into the packet
at offset *(u32 *)(r0 -4), that is, 2 + 14 -4, is valid and
aligned (2 is for NET_IP_ALIGN). After processing this with
all fall-through paths, we later on check paths from branches.
When the above skb->mark test is true, then we jump near the
end of the program, perform r0 += 1, and jump back to the
'if r0 > r3 goto out' test we've visited earlier already. This
time, R0 is of type R0=pkt(id=0,off=15,r=0), and we'll prune
that part because this time we'll have a larger safe packet
range, and we already found that with off=14 all further insn
were already safe, so it's safe as well with a larger off.
However, the problem is that the subsequent write into the packet
with 2 + 15 -4 is then unaligned, and not caught by the alignment
tracking. Note that min_align, aux_off, and aux_off_align were
all 0 in this example.
Since we cannot tell at this time what kind of packet access was
performed in the prior walk and what minimal requirements it has
(we might do so in the future, but that requires more complexity),
fix it to disable this pruning case for strict alignment for now,
and let the verifier do check such paths instead. With that applied,
the test cases pass and reject the program due to misalignment.
Fixes: d117441674 ("bpf: Track alignment of register values in the verifier.")
Reference: http://patchwork.ozlabs.org/patch/761909/
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch makes it possible to pass additional arguments in addition
to uevent action name when writing /sys/.../uevent attribute. These
additional arguments are then inserted into generated synthetic uevent
as additional environment variables.
Before, we were not able to pass any additional uevent environment
variables for synthetic uevents. This made it hard to identify such uevents
properly in userspace to make proper distinction between genuine uevents
originating from kernel and synthetic uevents triggered from userspace.
Also, it was not possible to pass any additional information which would
make it possible to optimize and change the way the synthetic uevents are
processed back in userspace based on the originating environment of the
triggering action in userspace. With the extra additional variables, we are
able to pass through this extra information needed and also it makes it
possible to synchronize with such synthetic uevents as they can be clearly
identified back in userspace.
The format for writing the uevent attribute is following:
ACTION [UUID [KEY=VALUE ...]
There's no change in how "ACTION" is recognized - it stays the same
("add", "change", "remove"). The "ACTION" is the only argument required
to generate synthetic uevent, the rest of arguments, that this patch
adds support for, are optional.
The "UUID" is considered as transaction identifier so it's possible to
use the same UUID value for one or more synthetic uevents in which case
we logically group these uevents together for any userspace listeners.
The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
format where "x" is a hex digit. The value appears in uevent as
"SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable.
The "KEY=VALUE" pairs can contain alphanumeric characters only. It's
possible to define zero or more more pairs - each pair is then delimited
by a space character " ". Each pair appears in synthetic uevents as
"SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains
"SYNTH_ARG_" prefix to avoid possible collisions with existing variables.
To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID"
part for the synthetic uevent first.
If "UUID" is not passed in, the generated synthetic uevent gains
"SYNTH_UUID=0" environment variable automatically so it's possible to
identify this situation in userspace when reading generated uevent and so
we can still make a difference between genuine and synthetic uevents.
Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In most cases, a cgroup controller don't care about the liftimes of
cgroups. For the controller, a css becomes online when ->css_online()
is called on it and offline when ->css_offline() is called.
However, cpuset is special in that the user interface it exposes cares
whether certain cgroups exist or not. Combined with the RCU delay
between cgroup removal and css offlining, this can lead to user
visible behavior oddities where operations which should succeed after
cgroup removals fail for some time period. The effects of cgroup
removals are delayed when seen from userland.
This patch adds css_is_dying() which tests whether offline is pending
and updates is_cpuset_online() so that the function returns false also
while offline is pending. This gets rid of the userland visible
delays.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Link: http://lkml.kernel.org/r/327ca1f5-7957-fbb9-9e5f-9ba149d40ba2@oracle.com
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull ptrace fix from Eric Biederman:
"This fixes a brown paper bag bug. When I fixed the ptrace interaction
with user namespaces I added a new field ptracer_cred in struct_task
and I failed to properly initialize it on fork.
This dangling pointer wound up breaking runing setuid applications run
from the enlightenment window manager.
As this is the worst sort of bug. A regression breaking user space for
no good reason let's get this fixed"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
ptrace: Properly initialize ptracer_cred on fork
The more strict early boot preemption warnings found that
__set_sched_clock_stable() was incorrectly assuming we'd still be
running on a single CPU:
BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1
caller is debug_smp_processor_id+0x1c/0x1e
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc2-00108-g1c3c5ea #1
Call Trace:
dump_stack+0x110/0x192
check_preemption_disabled+0x10c/0x128
? set_debug_rodata+0x25/0x25
debug_smp_processor_id+0x1c/0x1e
sched_clock_init_late+0x27/0x87
[...]
Fix it by disabling IRQs.
Reported-by: kernel test robot <xiaolong.ye@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: lkp@01.org
Cc: tipbuild@zytor.com
Link: http://lkml.kernel.org/r/20170524065202.v25vyu7pvba5mhpd@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A recent commit added extra printks for CPU/RT limits. This can result in
excessive spam in dmesg.
Make the printks conditional on print_fatal_signals.
Fixes: e7ea7c9806 ("rlimits: Print more information when CPU/RT limits are exceeded")
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Arun Raghavan <arun@arunraghavan.net>
Accessing the mod structure (e.g. for mod->name) prior to having completed
check_modstruct_version() can result in writing garbage to the error logs
if the layout of the mod structure loaded from disk doesn't match the
running kernel's mod structure layout. This kind of mismatch will become
much more likely if a kernel is built with different randomization seed
for the struct layout randomization plugin.
Instead, add and use a new modinfo string for logging the module name.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
Since we're already using values from struct load_info, just pass this
pointer in directly and use what's needed as we need it. This allows us
to access future fields in struct load_info too.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
The cap_* fields swing in and out of PATH records.
If no capabilities are set, the cap_* fields are completely missing and when
one of the cap_fi or cap_fp values is empty, that field is omitted.
Original:
type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL
type=PATH msg=audit(04/20/2017 12:17:11.222:193) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fe=1 cap_fver=2
Normalize the PATH record by always printing all 4 cap_* fields.
Fixed:
type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=1 name=/lib64/ld-linux-x86-64.so.2 inode=787694 dev=08:03 mode=file,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:ld_so_t:s0 nametype=NORMAL cap_fp=none cap_fi=none cap_fe=0 cap_fver=0
type=PATH msg=audit(04/20/2017 13:01:31.679:201) : item=0 name=/home/sleep inode=1319469 dev=08:03 mode=file,suid,755 ouid=root ogid=root rdev=00:00 obj=system_u:object_r:bin_t:s0 nametype=NORMAL cap_fp=sys_admin cap_fi=none cap_fe=1 cap_fver=2
See: https://github.com/linux-audit/audit-kernel/issues/42
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
When I introduced ptracer_cred I failed to consider the weirdness of
fork where the task_struct copies the old value by default. This
winds up leaving ptracer_cred set even when a process forks and
the child process does not wind up being ptraced.
Because ptracer_cred is not set on non-ptraced processes whose
parents were ptraced this has broken the ability of the enlightenment
window manager to start setuid children.
Fix this by properly initializing ptracer_cred in ptrace_init_task
This must be done with a little bit of care to preserve the current value
of ptracer_cred when ptrace carries through fork. Re-reading the
ptracer_cred from the ptracing process at this point is inconsistent
with how PT_PTRACE_CAP has been maintained all of these years.
Tested-by: Takashi Iwai <tiwai@suse.de>
Fixes: 64b875f7ac ("ptrace: Capture the ptracer's creds not PT_PTRACE_CAP")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
might_sleep() and smp_processor_id() checks are enabled after the boot
process is done. That hides bugs in the SMP bringup and driver
initialization code.
Enable it right when the scheduler starts working, i.e. when init task and
kthreadd have been created and right before the idle task enables
preemption.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184736.272225698@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state check in boot_delay_msec() to handle the extra
states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184736.027534895@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state check in core_kernel_text() to handle the extra
states, i.e. to cover init text up to the point where the system switches
to state RUNNING.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20170516184735.949992741@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state check in async_run_entry_fn() and
async_synchronize_cookie_domain() to handle the extra states.
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.865155020@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A customer has reported a soft-lockup when running an intensive
memory stress test, where the trace on multiple CPU's looks like this:
RIP: 0010:[<ffffffff810c53fe>]
[<ffffffff810c53fe>] native_queued_spin_lock_slowpath+0x10e/0x190
...
Call Trace:
[<ffffffff81182d07>] queued_spin_lock_slowpath+0x7/0xa
[<ffffffff811bc331>] change_protection_range+0x3b1/0x930
[<ffffffff811d4be8>] change_prot_numa+0x18/0x30
[<ffffffff810adefe>] task_numa_work+0x1fe/0x310
[<ffffffff81098322>] task_work_run+0x72/0x90
Further investigation showed that the lock contention here is pmd_lock().
The task_numa_work() function makes sure that only one thread is let to perform
the work in a single scan period (via cmpxchg), but if there's a thread with
mmap_sem locked for writing for several periods, multiple threads in
task_numa_work() can build up a convoy waiting for mmap_sem for read and then
all get unblocked at once.
This patch changes the down_read() to the trylock version, which prevents the
build up. For a workload experiencing mmap_sem contention, it's probably better
to postpone the NUMA balancing work anyway. This seems to have fixed the soft
lockups involving pmd_lock(), which is in line with the convoy theory.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170515131316.21909-1-vbabka@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With CONFIG_RT_GROUP_SCHED=y, do_sched_rt_period_timer() sequentially
takes each CPU's rq->lock. On a large, busy system, the cumulative time it
takes to acquire each lock can be excessive, even triggering a watchdog
timeout.
If rt_rq->rt_time and rt_rq->rt_nr_running are both zero, this function does
nothing while holding the lock, so don't bother taking it at all.
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a767637b-df85-912f-ba69-c90ee00a3fb6@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When priority inheritance was added back in 2.6.18 to sched_setscheduler(), it
added a path to taking an rt-mutex wait_lock, which is not IRQ safe. As PI
is not a common occurrence, lockdep will likely never trigger if
sched_setscheduler was called from interrupt context. A BUG_ON() was added
to trigger if __sched_setscheduler() was ever called from interrupt context
because there was a possibility to take the wait_lock.
Today the wait_lock is irq safe, but the path to taking it in
sched_setscheduler() is the same as the path to taking it from normal
context. The wait_lock is taken with raw_spin_lock_irq() and released with
raw_spin_unlock_irq() which will indiscriminately enable interrupts,
which would be bad in interrupt context.
The problem is that normalize_rt_tasks, which is called by triggering the
sysrq nice-all-RT-tasks was changed to call __sched_setscheduler(), and this
is done from interrupt context!
Now __sched_setscheduler() takes a "pi" parameter that is used to know if
the priority inheritance should be called or not. As the BUG_ON() only cares
about calling the PI code, it should only bug if called from interrupt
context with the "pi" parameter set to true.
Reported-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@osdl.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: dbc7f069b9 ("sched: Use replace normalize_task() with __sched_setscheduler()")
Link: http://lkml.kernel.org/r/20170308124654.10e598f2@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
pick_next_pushable_dl_task(rq) has BUG_ON(rq->cpu != task_cpu(task))
when it returns a task other than NULL, which means that task_cpu(task)
must be rq->cpu. So if task == next_task, then task_cpu(next_task) must
be rq->cpu as well. Remove the redundant condition and make the code simpler.
This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551159-22367-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
pick_next_pushable_task(rq) has BUG_ON(rq_cpu != task_cpu(task)) when
it returns a task other than NULL, which means that task_cpu(task) must
be rq->cpu. So if task == next_task, then task_cpu(next_task) must be
rq->cpu as well. Remove the redundant condition and make the code simpler.
This way one unnecessary branch and two LOAD operations can be avoided.
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Juri Lelli <juri.lelli@arm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494551143-22219-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that we've added llist_for_each_entry_safe(), use it to simplify
an open coded version of it in sched_ttwu_pending().
Signed-off-by: Byungchul Park <byungchul.park@lge.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <kernel-team@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1494549584-11730-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The cpumasks in smp_call_function_many() are private and not subject
to concurrency, atomic bitops are pointless and expensive.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Inter-Processor-Interrupt(IPI) is needed when a page is unmapped and the
process' mm_cpumask() shows the process has ever run on other CPUs. page
migration, page reclaim all need IPIs. The number of IPI needed to send
to different CPUs is especially large for multi-threaded workload since
mm_cpumask() is per process.
For smp_call_function_many(), whenever a CPU queues a CSD to a target
CPU, it will send an IPI to let the target CPU to handle the work.
This isn't necessary - we need only send IPI when queueing a CSD
to an empty call_single_queue.
The reason:
flush_smp_call_function_queue() that is called upon a CPU receiving an
IPI will empty the queue and then handle all of the CSDs there. So if
the target CPU's call_single_queue is not empty, we know that:
i. An IPI for the target CPU has already been sent by 'previous queuers';
ii. flush_smp_call_function_queue() hasn't emptied that CPU's queue yet.
Thus, it's safe for us to just queue our CSD there without sending an
addtional IPI. And for the 'previous queuers', we can limit it to the
first queuer.
To demonstrate the effect of this patch, a multi-thread workload that
spawns 80 threads to equally consume 100G memory is used. This is tested
on a 2 node broadwell-EP which has 44cores/88threads and 32G memory. So
after 32G memory is used up, page reclaiming starts to happen a lot.
With this patch, IPI number dropped 88% and throughput increased about
15% for the above workload.
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/20170519075331.GE2084@aaronlu.sh.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We don't set an error code here which means that perf_event_alloc()
returns ERR_PTR(0) (in other words NULL). The callers are not expecting
that and would Oops.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 375637bc52 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20170522090418.hvs6icgpdo53wkn5@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_init_event() can't return NULL. If it did, the error handling is
incomplete and we would crash. I have removed this confusing dead code.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20170522090348.5g7yyld5en3yeky4@mwanda
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Fix RTC wakeup from suspend-to-idle broken by the recent rework
of ACPI wakeup handling (Rafael Wysocki).
- Update intel_pstate driver documentation to reflect the current
code and explain how it works in more detail (Rafael Wysocki).
- Fix an issue related to CPU idleness detection on systems with
shared cpufreq policies in the schedutil governor (Juri Lelli).
- Fix a possible build issue in the dbx500 cpufreq driver (Arnd
Bergmann).
- Fix a function in the power capping framework core to return
an error code instead of 0 when there's an error (Dan Carpenter).
- Clean up variable definition in the hibernation core (Pushkar
Jambhlekar).
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Merge tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These fix RTC wakeup from suspend-to-idle broken recently, fix CPU
idleness detection condition in the schedutil cpufreq governor, fix a
cpufreq driver build failure, fix an error code path in the power
capping framework, clean up the hibernate core and update the
intel_pstate documentation.
Specifics:
- Fix RTC wakeup from suspend-to-idle broken by the recent rework of
ACPI wakeup handling (Rafael Wysocki).
- Update intel_pstate driver documentation to reflect the current
code and explain how it works in more detail (Rafael Wysocki).
- Fix an issue related to CPU idleness detection on systems with
shared cpufreq policies in the schedutil governor (Juri Lelli).
- Fix a possible build issue in the dbx500 cpufreq driver (Arnd
Bergmann).
- Fix a function in the power capping framework core to return an
error code instead of 0 when there's an error (Dan Carpenter).
- Clean up variable definition in the hibernation core (Pushkar
Jambhlekar)"
* tag 'pm-4.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: dbx500: add a Kconfig symbol
PM / hibernate: Declare variables as static
PowerCap: Fix an error code in powercap_register_zone()
RTC: rtc-cmos: Fix wakeup from suspend-to-idle
PM / wakeup: Fix up wakeup_source_report_event()
cpufreq: intel_pstate: Document the current behavior and user interface
cpufreq: schedutil: use now as reference when aggregating shared policy requests
In order to ease debug, let's populate the domain name upfront, before any
MSI gets requested. This allows the domain to appear in the
irq_domain_mapping, and the user to easily find the expected data.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20170512115538.10767-4-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If the system is using ACPI, there is no of_node to display. But ACPI can
use a struct irqchip_fwid as a domain identifier, and it can be used to
display the name contained in that structure.
The output on such a system will look like this:
pMSI 0 0 0 irqchip@00000000e1180000
MSI 37 0 0 irqchip@00000000e1180000
GICv2m 37 0 0 irqchip@00000000e1180000
GICv2 448 448 0 irqchip@ffff000008003000
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20170512115538.10767-3-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Hierarchical domains seem to be hard to grasp, and a number of
aspiring kernel hackers find them utterly discombobulating.
In order to ease their pain, let's make them appear in
/sys/kernel/debug/irq_domain_mapping, such as the following:
96 0x81808 MSI 0x (null) RADIX MSI
96+ 0x00063 GICv2m 0xffff8003ee116980 RADIX GICv2m
96+ 0x00063 GICv2 0xffff00000916bfd8 LINEAR GICv2
[output compressed to fit in a commit log]
This shows that IRQ96 is implemented by a stack of three domains,
the + sign indicating the stacking.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: http://lkml.kernel.org/r/20170512115538.10767-2-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If a kthread forks (e.g. usermodehelper since commit 1da5c46fa9) but
fails in copy_process() between calling dup_task_struct() and setting
p->set_child_tid, then the value of p->set_child_tid will be inherited
from the parent and get prematurely freed by free_kthread_struct().
kthread()
- worker_thread()
- process_one_work()
| - call_usermodehelper_exec_work()
| - kernel_thread()
| - _do_fork()
| - copy_process()
| - dup_task_struct()
| - arch_dup_task_struct()
| - tsk->set_child_tid = current->set_child_tid // implied
| - ...
| - goto bad_fork_*
| - ...
| - free_task(tsk)
| - free_kthread_struct(tsk)
| - kfree(tsk->set_child_tid)
- ...
- schedule()
- __schedule()
- wq_worker_sleeping()
- kthread_data(task)->flags // UAF
The problem started showing up with commit 1da5c46fa9 since it reused
->set_child_tid for the kthread worker data.
A better long-term solution might be to get rid of the ->set_child_tid
abuse. The comment in set_kthread_struct() also looks slightly wrong.
Debugged-by: Jamie Iles <jamie.iles@oracle.com>
Fixes: 1da5c46fa9 ("kthread: Make struct kthread kmalloc'ed")
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jamie Iles <jamie.iles@oracle.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170509073959.17858-1-vegard.nossum@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
min_vecs is the minimum amount of vectors needed to operate in MSI-X mode
which may just include the vectors that don't need affinity.
Disabling affinity settings causes the qla2xxx driver scsi_add_host() to fail
when blk_mq is enabled as the blk_mq_pci_map_queues() expects affinity masks
on each vector.
Fixes: dfef358bd1 ("PCI/MSI: Don't apply affinity if there aren't enough vectors left")
Signed-off-by: Michael Hernandez <michael.hernandez@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # v4.10+
Markus reported that the glibc/nptl/tst-robustpi8 test was failing after
commit:
cfafcd117d ("futex: Rework futex_lock_pi() to use rt_mutex_*_proxy_lock()")
The following trace shows the problem:
ld-linux-x86-64-2161 [019] .... 410.760971: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_LOCK_PI
ld-linux-x86-64-2161 [019] ...1 410.760972: lock_pi_update_atomic: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000875 ret=0
ld-linux-x86-64-2165 [011] .... 410.760978: SyS_futex: 00007ffbeb76b028: 80000875 op=FUTEX_UNLOCK_PI
ld-linux-x86-64-2165 [011] d..1 410.760979: do_futex: 00007ffbeb76b028: curval=80000875 uval=80000875 newval=80000871 ret=0
ld-linux-x86-64-2165 [011] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=0000
ld-linux-x86-64-2161 [019] .... 410.760980: SyS_futex: 00007ffbeb76b028: 80000871 ret=ETIMEDOUT
Task 2165 does an UNLOCK_PI, assigning the lock to the waiter task 2161
which then returns with -ETIMEDOUT. That wrecks the lock state, because now
the owner isn't aware it acquired the lock and removes the pending robust
list entry.
If 2161 is killed, the robust list will not clear out this futex and the
subsequent acquire on this futex will then (correctly) result in -ESRCH
which is unexpected by glibc, triggers an internal assertion and dies.
Task 2161 Task 2165
rt_mutex_wait_proxy_lock()
timeout();
/* T2161 is still queued in the waiter list */
return -ETIMEDOUT;
futex_unlock_pi()
spin_lock(hb->lock);
rtmutex_unlock()
remove_rtmutex_waiter(T2161);
mark_lock_available();
/* Make the next waiter owner of the user space side */
futex_uval = 2161;
spin_unlock(hb->lock);
spin_lock(hb->lock);
rt_mutex_cleanup_proxy_lock()
if (rtmutex_owner() !== current)
...
return FAIL;
....
return -ETIMEOUT;
This means that rt_mutex_cleanup_proxy_lock() needs to call
try_to_take_rt_mutex() so it can take over the rtmutex correctly which was
assigned by the waker. If the rtmutex is owned by some other task then this
call is harmless and just confirmes that the waiter is not able to acquire
it.
While there, fix what looks like a merge error which resulted in
rt_mutex_cleanup_proxy_lock() having two calls to
fixup_rt_mutex_waiters() and rt_mutex_wait_proxy_lock() not having any.
Both should have one, since both potentially touch the waiter list.
Fixes: 38d589f2fd ("futex,rt_mutex: Restructure rt_mutex_finish_proxy_lock()")
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Bug-Spotted-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Link: http://lkml.kernel.org/r/20170519154850.mlomgdsd26drq5j6@hirez.programming.kicks-ass.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull networking fixes from David Miller:
"Mostly netfilter bug fixes in here, but we have some bits elsewhere as
well.
1) Don't do SNAT replies for non-NATed connections in IPVS, from
Julian Anastasov.
2) Don't delete conntrack helpers while they are still in use, from
Liping Zhang.
3) Fix zero padding in xtables's xt_data_to_user(), from Willem de
Bruijn.
4) Add proper RCU protection to nf_tables_dump_set() because we
cannot guarantee that we hold the NFNL_SUBSYS_NFTABLES lock. From
Liping Zhang.
5) Initialize rcv_mss in tcp_disconnect(), from Wei Wang.
6) smsc95xx devices can't handle IPV6 checksums fully, so don't
advertise support for offloading them. From Nisar Sayed.
7) Fix out-of-bounds access in __ip6_append_data(), from Eric
Dumazet.
8) Make atl2_probe() propagate the error code properly on failures,
from Alexey Khoroshilov.
9) arp_target[] in bond_check_params() is used uninitialized. This
got changes from a global static to a local variable, which is how
this mistake happened. Fix from Jarod Wilson.
10) Fix fallout from unnecessary NULL check removal in cls_matchall,
from Jiri Pirko. This is definitely brown paper bag territory..."
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
net: sched: cls_matchall: fix null pointer dereference
vsock: use new wait API for vsock_stream_sendmsg()
bonding: fix randomly populated arp target array
net: Make IP alignment calulations clearer.
bonding: fix accounting of active ports in 3ad
net: atheros: atl2: don't return zero on failure path in atl2_probe()
ipv6: fix out of bound writes in __ip6_append_data()
bridge: start hello_timer when enabling KERNEL_STP in br_stp_start
smsc95xx: Support only IPv4 TCP/UDP csum offload
arp: always override existing neigh entries with gratuitous ARP
arp: postpone addr_type calculation to as late as possible
arp: decompose is_garp logic into a separate function
arp: fixed error in a comment
tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0
netfilter: xtables: fix build failure from COMPAT_XT_ALIGN outside CONFIG_COMPAT
ebtables: arpreply: Add the standard target sanity check
netfilter: nf_tables: revisit chain/object refcounting from elements
netfilter: nf_tables: missing sanitization in data from userspace
netfilter: nf_tables: can't assume lock is acquired when dumping set elems
netfilter: synproxy: fix conntrackd interaction
...
* intel_pstate:
cpufreq: intel_pstate: Document the current behavior and user interface
* pm-cpufreq:
cpufreq: dbx500: add a Kconfig symbol
* pm-cpufreq-sched:
cpufreq: schedutil: use now as reference when aggregating shared policy requests
The assignmnet:
ip_align = strict ? 2 : NET_IP_ALIGN;
in compare_pkt_ptr_alignment() trips up Coverity because we can only
get to this code when strict is true, therefore ip_align will always
be 2 regardless of NET_IP_ALIGN's value.
So just assign directly to '2' and explain the situation in the
comment above.
Reported-by: "Gustavo A. R. Silva" <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull scheduler fix from Thomas Gleixner:
"A single scheduler fix:
Prevent idle task from ever being preempted. That makes sure that
synchronize_rcu_tasks() which is ignoring idle task does not pretend
that no task is stuck in preempted state. If that happens and idle was
preempted on a ftrace trampoline the machine crashes due to
inconsistent state"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Call __schedule() from do_idle() without enabling preemption
Pull irq fixes from Thomas Gleixner:
"A set of small fixes for the irq subsystem:
- Cure a data ordering problem with chained interrupts
- Three small fixlets for the mbigen irq chip"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Fix chained interrupt data ordering
irqchip/mbigen: Fix the clear register offset calculation
irqchip/mbigen: Fix potential NULL dereferencing
irqchip/mbigen: Fix memory mapping code
have kernel_waitid() collect the information needed for siginfo into
a small structure (waitid_info) passed to it; deal with copyout in
sys_waitid()/compat_sys_waitid().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
New helpers: kernel_waitid() and kernel_wait4(). sys_waitid(),
sys_wait4() and their compat variants switched to those. Copying
struct rusage to userland is left to syscall itself. For
compat_sys_wait4() that eliminates the use of set_fs() completely.
For compat_sys_waitid() it's still needed (for siginfo handling);
that will change shortly.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
when deleting an instance. It also creates a selftest that triggers that bug.
Fix the delayed optimization happening after kprobes boot up self tests
being removed by freeing of init memory.
Comment kprobes on why the delay optimization is not a problem for removal
of modules, to keep other developers from searching that riddle.
Fix another rcu isn't watching in stack trace tracing.
Naveen N. Rao (4):
ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()
ftrace/instances: Clear function triggers when removing instances
selftests/ftrace: Fix bashisms
selftests/ftrace: Add test to remove instance with active event triggers
Steven Rostedt (1):
tracing: Move postpone selftests to core from early_initcall
Steven Rostedt (VMware) (3):
ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
kprobes: Document how optimized kprobes are removed from module unload
tracing: Make sure RCU is watching before calling a stack trace
Thomas Gleixner (1):
tracing/kprobes: Enforce kprobes teardown after testing
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Merge tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
- Fix a bug caused by not cleaning up the new instance unique triggers
when deleting an instance. It also creates a selftest that triggers
that bug.
- Fix the delayed optimization happening after kprobes boot up self
tests being removed by freeing of init memory.
- Comment kprobes on why the delay optimization is not a problem for
removal of modules, to keep other developers from searching that
riddle.
- Fix another case of rcu not watching in stack trace tracing.
* tag 'trace-v4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Make sure RCU is watching before calling a stack trace
kprobes: Document how optimized kprobes are removed from module unload
selftests/ftrace: Add test to remove instance with active event triggers
selftests/ftrace: Fix bashisms
ftrace: Remove #ifdef from code and add clear_ftrace_function_probes() stub
ftrace/instances: Clear function triggers when removing instances
ftrace: Simplify glob handling in unregister_ftrace_function_probe_func()
tracing/kprobes: Enforce kprobes teardown after testing
tracing: Move postpone selftests to core from early_initcall
Pull block fixes from Jens Axboe:
"A small collection of fixes that should go into this cycle.
- a pull request from Christoph for NVMe, which ended up being
manually applied to avoid pulling in newer bits in master. Mostly
fibre channel fixes from James, but also a few fixes from Jon and
Vijay
- a pull request from Konrad, with just a single fix for xen-blkback
from Gustavo.
- a fuseblk bdi fix from Jan, fixing a regression in this series with
the dynamic backing devices.
- a blktrace fix from Shaohua, replacing sscanf() with kstrtoull().
- a request leak fix for drbd from Lars, fixing a regression in the
last series with the kref changes. This will go to stable as well"
* 'for-linus' of git://git.kernel.dk/linux-block:
nvmet: release the sq ref on rdma read errors
nvmet-fc: remove target cpu scheduling flag
nvme-fc: stop queues on error detection
nvme-fc: require target or discovery role for fc-nvme targets
nvme-fc: correct port role bits
nvme: unmap CMB and remove sysfs file in reset path
blktrace: fix integer parse
fuseblk: Fix warning in super_setup_bdi_name()
block: xen-blkback: add null check to avoid null pointer dereference
drbd: fix request leak introduced by locking/atomic, kref: Kill kref_sub()
sscanf is a very poor way to parse integer. For example, I input
"discard" for act_mask, it gets 0xd and completely messes up. Using
correct API to do integer parse.
This patch also makes attributes accept any base of integer.
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
The commit 42a0bb3f71 ("printk/nmi: generic solution for safe
printk in NMI") caused that printk stores messages into a temporary
buffer in NMI context.
The buffer is per-CPU and therefore the size is rather limited.
It works quite well for NMI backtraces. But there are longer logs
that might get printed in NMI context, for example, lockdep
warnings, ftrace_dump_on_oops.
The temporary buffer is used to avoid deadlocks caused by
logbuf_lock. Also it is needed to avoid races with the other
temporary buffer that is used when PRINTK_SAFE_CONTEXT is entered.
But the main buffer can be used in NMI if the lock is available
and we did not interrupt PRINTK_SAFE_CONTEXT.
The lock is checked using raw_spin_is_locked(). It might cause
false negatives when the lock is taken on another CPU and
this CPU is in the safe context from other reasons. Note that
the safe context is used also to get console semaphore or when
calling console drivers. For this reason, we do the check in
printk_nmi_enter(). It makes the handling consistent for
the entire NMI handler and avoids reshuffling of the messages.
The patch also defines special printk context that allows
to use printk_deferred() in NMI. Note that we could not flush
the messages to the consoles because console drivers might use
many other internal locks.
The newly created vprintk_deferred() disables the preemption
only around the irq work handling. It is needed there to keep
the consistency between the two per-CPU variables. But there
is no reason to disable preemption around vprintk_emit().
Finally, the patch puts back explicit serialization of the NMI
backtraces from different CPUs. It was removed by the
commit a9edc88093 ("x86/nmi: Perform a safe
NMI stack trace on all CPUs"). It was not needed because
the flushing of the temporary per-CPU buffers was serialized.
Link: http://lkml.kernel.org/r/1493912763-24873-1-git-send-email-pmladek@suse.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <rack+kernel@arm.linux.org.uk>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: x86@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Suggested-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
As stack tracing now requires "rcu watching", force RCU to be watching when
recording a stack trace.
Link: http://lkml.kernel.org/r/20170512172449.879684501@goodmis.org
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Pull networking fixes from David Miller:
1) Don't allow negative TCP reordering values, from Soheil Hassas
Yeganeh.
2) Don't overflow while parsing ipv6 header options, from Craig Gallek.
3) Handle more cleanly the case where an individual route entry during
a dump will not fit into the allocated netlink SKB, from David
Ahern.
4) Add missing CONFIG_INET dependency for mlx5e, from Arnd Bergmann.
5) Allow neighbour updates to converge more quickly via gratuitous
ARPs, from Ihar Hrachyshka.
6) Fix compile error from CONFIG_INET is disabled, from Eric Dumazet.
7) Fix use after free in x25 protocol init, from Lin Zhang.
8) Valid VLAN pvid ranges passed into br_validate(), from Tobias
Jungel.
9) NULL out address lists in child sockets in SCTP, this is similar to
the fix we made for inet connection sockets last week. From Eric
Dumazet.
10) Fix NULL deref in mlxsw driver, from Ido Schimmel.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (27 commits)
mlxsw: spectrum: Avoid possible NULL pointer dereference
sh_eth: Do not print an error message for probe deferral
sh_eth: Use platform device for printing before register_netdev()
mlxsw: spectrum_router: Fix rif counter freeing routine
mlxsw: spectrum_dpipe: Fix incorrect entry index
cxgb4: update latest firmware version supported
qmi_wwan: add another Lenovo EM74xx device ID
sctp: do not inherit ipv6_{mc|ac|fl}_list from parent
udp: make *udp*_queue_rcv_skb() functions static
bridge: netlink: check vlan_default_pvid range
net: ethernet: faraday: To support device tree usage.
net: x25: fix one potential use-after-free issue
bpf: adjust verifier heuristics
ipv6: Check ip6_find_1stfragopt() return value properly.
selftests/bpf: fix broken build due to types.h
bnxt_en: Check status of firmware DCBX agent before setting DCB_CAP_DCBX_HOST.
bnxt_en: Call bnxt_dcb_init() after getting firmware DCBX configuration.
net: fix compile error in skb_orphan_partial()
ipv6: Prevent overrun when parsing v6 header options
neighbour: update neigh timestamps iff update is effective
...
Pull pid namespace fixes from Eric Biederman:
"These are two bugs that turn out to have simple fixes that were
reported during the merge window. Both of these issues have existed
for a while and it just happens that they both were reported at almost
the same time"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
pid_ns: Fix race between setns'ed fork() and zap_pid_ns_processes()
pid_ns: Sleep in TASK_INTERRUPTIBLE in zap_pid_ns_processes
Mauro says:
This patch series convert the remaining DocBooks to ReST.
The first version was originally
send as 3 patch series:
[PATCH 00/36] Convert DocBook documents to ReST
[PATCH 0/5] Convert more books to ReST
[PATCH 00/13] Get rid of DocBook
The lsm book was added as if it were a text file under
Documentation. The plan is to merge it with another file
under Documentation/security, after both this series and
a security Documentation patch series gets merged.
It also adjusts some Sphinx-pedantic errors/warnings on
some kernel-doc markups.
I also added some patches here to add PDF output for all
existing ReST books.
This updates the credentials API documentation to ReST markup and moves
it under the security subsection of kernel API documentation.
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Current limits with regards to processing program paths do not
really reflect today's needs anymore due to programs becoming
more complex and verifier smarter, keeping track of more data
such as const ALU operations, alignment tracking, spilling of
PTR_TO_MAP_VALUE_ADJ registers, and other features allowing for
smarter matching of what LLVM generates.
This also comes with the side-effect that we result in fewer
opportunities to prune search states and thus often need to do
more work to prove safety than in the past due to different
register states and stack layout where we mismatch. Generally,
it's quite hard to determine what caused a sudden increase in
complexity, it could be caused by something as trivial as a
single branch somewhere at the beginning of the program where
LLVM assigned a stack slot that is marked differently throughout
other branches and thus causing a mismatch, where verifier
then needs to prove safety for the whole rest of the program.
Subsequently, programs with even less than half the insn size
limit can get rejected. We noticed that while some programs
load fine under pre 4.11, they get rejected due to hitting
limits on more recent kernels. We saw that in the vast majority
of cases (90+%) pruning failed due to register mismatches. In
case of stack mismatches, majority of cases failed due to
different stack slot types (invalid, spill, misc) rather than
differences in spilled registers.
This patch makes pruning more aggressive by also adding markers
that sit at conditional jumps as well. Currently, we only mark
jump targets for pruning. For example in direct packet access,
these are usually error paths where we bail out. We found that
adding these markers, it can reduce number of processed insns
by up to 30%. Another option is to ignore reg->id in probing
PTR_TO_MAP_VALUE_OR_NULL registers, which can help pruning
slightly as well by up to 7% observed complexity reduction as
stand-alone. Meaning, if a previous path with register type
PTR_TO_MAP_VALUE_OR_NULL for map X was found to be safe, then
in the current state a PTR_TO_MAP_VALUE_OR_NULL register for
the same map X must be safe as well. Last but not least the
patch also adds a scheduling point and bumps the current limit
for instructions to be processed to a more adequate value.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thomas discovered a bug where the kprobe trace tests had a race
condition where the kprobe_optimizer called from a delayed work queue
that does the optimizing and "unoptimizing" of a kprobe, can try to
modify the text after it has been freed by the init code.
The kprobe trace selftest is a special case, and Thomas and myself
investigated to see if there's a chance that this could also be a bug
with module unloading, as the code is not obvious to how it handles
this. After adding lots of printks, I figured it out. Thomas suggested
that this should be commented so that others will not have to go
through this exercise again.
Link: http://lkml.kernel.org/r/20170516145835.3827d3aa@gandalf.local.home
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Enabling the tracer selftest triggers occasionally the warning in
text_poke(), which warns when the to be modified page is not marked
reserved.
The reason is that the tracer selftest installs kprobes on functions marked
__init for testing. These probes are removed after the tests, but that
removal schedules the delayed kprobes_optimizer work, which will do the
actual text poke. If the work is executed after the init text is freed,
then the warning triggers. The bug can be reproduced reliably when the work
delay is increased.
Flush the optimizer work and wait for the optimizing/unoptimizing lists to
become empty before returning from the kprobes tracer selftest. That
ensures that all operations which were queued due to the probes removal
have completed.
Link: http://lkml.kernel.org/r/20170516094802.76a468bb@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 6274de498 ("kprobes: Support delayed unoptimizing")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The kill_css() function may be called more than once under the condition
that the css was killed but not physically removed yet followed by the
removal of the cgroup that is hosting the css. This patch prevents any
harmm from being done when that happens.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v4.5+
This restores commit:
24b91e360e: ("nohz: Fix collision between tick and other hrtimers")
... which got reverted by commit:
558e8e27e7: ('Revert "nohz: Fix collision between tick and other hrtimers"')
... due to a regression where CPUs spuriously stopped ticking.
The bug happened when a tick fired too early past its expected expiration:
on IRQ exit the tick was scheduled again to the same deadline but skipped
reprogramming because ts->next_tick still kept in cache the deadline.
This has been fixed now with resetting ts->next_tick from the tick
itself. Extra care has also been taken to prevent from obsolete values
throughout CPU hotplug operations.
When the tick is stopped and an interrupt occurs afterward, we check on
that interrupt exit if the next tick needs to be rescheduled. If it
doesn't need any update, we don't want to do anything.
In order to check if the tick needs an update, we compare it against the
clockevent device deadline. Now that's a problem because the clockevent
device is at a lower level than the tick itself if it is implemented
on top of hrtimer.
Every hrtimer share this clockevent device. So comparing the next tick
deadline against the clockevent device deadline is wrong because the
device may be programmed for another hrtimer whose deadline collides
with the tick. As a result we may end up not reprogramming the tick
accidentally.
In a worst case scenario under full dynticks mode, the tick stops firing
as it is supposed to every 1hz, leaving /proc/stat stalled:
Task in a full dynticks CPU
----------------------------
* hrtimer A is queued 2 seconds ahead
* the tick is stopped, scheduled 1 second ahead
* tick fires 1 second later
* on tick exit, nohz schedules the tick 1 second ahead but sees
the clockevent device is already programmed to that deadline,
fooled by hrtimer A, the tick isn't rescheduled.
* hrtimer A is cancelled before its deadline
* tick never fires again until an interrupt happens...
In order to fix this, store the next tick deadline to the tick_sched
local structure and reuse that value later to check whether we need to
reprogram the clock after an interrupt.
On the other hand, ts->sleep_length still wants to know about the next
clock event and not just the tick, so we want to improve the related
comment to avoid confusion.
Reported-and-tested-by: Tim Wright <tim@binbash.co.uk>
Reported-and-tested-by: Pavel Machek <pavel@ucw.cz>
Reported-by: James Hartsock <hartsjc@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1492783255-5051-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
irq_set_chained_handler_and_data() sets up the chained interrupt and then
stores the handler data.
That's racy against an immediate interrupt which gets handled before the
store of the handler data happened. The handler will dereference a NULL
pointer and crash.
Cure it by storing handler data before installing the chained handler.
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
This book got converted from DocBook. Update its references to
point to the current location.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
There are a few issues on some kernel-doc markups that was
causing troubles with kernel-doc output on ReST format:
./kernel/futex.c:492: WARNING: Inline emphasis start-string without end-string.
./kernel/futex.c:1264: WARNING: Block quote ends without a blank line; unexpected unindent.
./kernel/futex.c:1721: WARNING: Block quote ends without a blank line; unexpected unindent.
./kernel/futex.c:2338: WARNING: Block quote ends without a blank line; unexpected unindent.
./kernel/futex.c:2426: WARNING: Block quote ends without a blank line; unexpected unindent.
./kernel/futex.c:2899: WARNING: Block quote ends without a blank line; unexpected unindent.
./kernel/futex.c:2972: WARNING: Block quote ends without a blank line; unexpected unindent.
Fix them.
No functional changes.
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Pull networking fixes from David Miller:
1) Track alignment in BPF verifier so that legitimate programs won't be
rejected on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures.
2) Make tail calls work properly in arm64 BPF JIT, from Deniel
Borkmann.
3) Make the configuration and semantics Generic XDP make more sense and
don't allow both generic XDP and a driver specific instance to be
active at the same time. Also from Daniel.
4) Don't crash on resume in xen-netfront, from Vitaly Kuznetsov.
5) Fix use-after-free in VRF driver, from Gao Feng.
6) Use netdev_alloc_skb_ip_align() to avoid unaligned IP headers in
qca_spi driver, from Stefan Wahren.
7) Always run cleanup routines in BPF samples when we get SIGTERM, from
Andy Gospodarek.
8) The mdio phy code should bring PHYs out of reset using the shared
GPIO lines before invoking bus->reset(). From Florian Fainelli.
9) Some USB descriptor access endian fixes in various drivers from
Johan Hovold.
10) Handle PAUSE advertisements properly in mlx5 driver, from Gal
Pressman.
11) Fix reversed test in mlx5e_setup_tc(), from Saeed Mahameed.
12) Cure netdev leak in AF_PACKET when using timestamping via control
messages. From Douglas Caetano dos Santos.
13) netcp doesn't support HWTSTAMP_FILTER_ALl, reject it. From Miroslav
Lichvar.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
ldmvsw: stop the clean timer at beginning of remove
ldmvsw: unregistering netdev before disable hardware
net: netcp: fix check of requested timestamping filter
ipv6: avoid dad-failures for addresses with NODAD
qed: Fix uninitialized data in aRFS infrastructure
mdio: mux: fix device_node_continue.cocci warnings
net/packet: fix missing net_device reference release
net/mlx4_core: Use min3 to select number of MSI-X vectors
macvlan: Fix performance issues with vlan tagged packets
net: stmmac: use correct pointer when printing normal descriptor ring
net/mlx5: Use underlay QPN from the root name space
net/mlx5e: IPoIB, Only support regular RQ for now
net/mlx5e: Fix setup TC ndo
net/mlx5e: Fix ethtool pause support and advertise reporting
net/mlx5e: Use the correct pause values for ethtool advertising
vmxnet3: ensure that adapter is in proper state during force_close
sfc: revert changes to NIC revision numbers
net: ch9200: add missing USB-descriptor endianness conversions
net: irda: irda-usb: fix firmware name on big-endian hosts
net: dsa: mv88e6xxx: add default case to switch
...
Currently, rq->leaf_cfs_rq_list is a traversal ordered list of all
live cfs_rqs which have ever been active on the CPU; unfortunately,
this makes update_blocked_averages() O(# total cgroups) which isn't
scalable at all.
This shows up as a small CPU consumption and scheduling latency
increase in the load balancing path in systems with CPU controller
enabled across most cgroups. In an edge case where temporary cgroups
were leaking, this caused the kernel to consume good several tens of
percents of CPU cycles running update_blocked_averages(), each run
taking multiple millisecs.
This patch fixes the issue by taking empty and fully decayed cfs_rqs
off the rq->leaf_cfs_rq_list.
Signed-off-by: Tejun Heo <tj@kernel.org>
[ Added cfs_rq_is_decayed() ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Chris Mason <clm@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170426004350.GB3222@wtj.duckdns.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In order to allow leaf_cfs_rq_list to remove entries switch the
bandwidth hotplug code over to the task_groups list.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170504133122.a6qjlj3hlblbjxux@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There's a discrepancy in naming between the sched_domain and
sched_group cpumask accessor. Since we're doing changes, fix it.
$ git grep sched_group_cpus | wc -l
28
$ git grep sched_domain_span | wc -l
38
Suggests changing sched_group_cpus() into sched_group_span():
for i in `git grep -l sched_group_cpus`
do
sed -ie 's/sched_group_cpus/sched_group_span/g' $i
done
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since sched_group_mask() is now an independent cpumask (it no longer
masks sched_group_cpus()), rename the thing.
Suggested-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While writing the comments, it occurred to me that:
sg_cpus & sg_mask == sg_mask
at least conceptually; the !overlap case sets the all 1s mask. If we
correct that we can simplify things and directly use sg_mask.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We want to attain:
sg_cpus() & sg_mask() == sg_mask()
for this to be so we must initialize sg_mask() to sg_cpus() for the
!overlap case (its currently cpumask_setall()).
Since the code makes my head hurt bad, rewrite it into a simpler form,
inspired by the now fixed overlap code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Try and describe what this code is about..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When building the overlapping groups we need to attach a consistent
sched_group_capacity structure. That is, all 'identical' sched_group's
should have the _same_ sched_group_capacity.
This can (once again) be demonstrated with a topology like:
node 0 1 2 3
0: 10 20 30 20
1: 20 10 20 30
2: 30 20 10 20
3: 20 30 20 10
But we need at least 2 CPUs per node for this to show up, after all,
if there is only one CPU per node, our CPU @i is per definition a
unique CPU that reaches this domain (aka balance-cpu).
Given the above NUMA topo and 2 CPUs per node:
[] CPU0 attaching sched-domain(s):
[] domain-0: span=0,4 level=DIE
[] groups: 0:{ span=0 }, 4:{ span=4 }
[] domain-1: span=0-1,3-5,7 level=NUMA
[] groups: 0:{ span=0,4 mask=0,4 cap=2048 }, 1:{ span=1,5 mask=1,5 cap=2048 }, 3:{ span=3,7 mask=3,7 cap=2048 }
[] domain-2: span=0-7 level=NUMA
[] groups: 0:{ span=0-1,3-5,7 mask=0,4 cap=6144 }, 2:{ span=1-3,5-7 mask=2,6 cap=6144 }
[] CPU1 attaching sched-domain(s):
[] domain-0: span=1,5 level=DIE
[] groups: 1:{ span=1 }, 5:{ span=5 }
[] domain-1: span=0-2,4-6 level=NUMA
[] groups: 1:{ span=1,5 mask=1,5 cap=2048 }, 2:{ span=2,6 mask=2,6 cap=2048 }, 4:{ span=0,4 mask=0,4 cap=2048 }
[] domain-2: span=0-7 level=NUMA
[] groups: 1:{ span=0-2,4-6 mask=1,5 cap=6144 }, 3:{ span=0,2-4,6-7 mask=3,7 cap=6144 }
Observe how CPU0-domain1-group0 and CPU1-domain1-group4 are the
'same' but have a different id (0 vs 4).
To fix this, use the group balance CPU to select the SGC. This means
we have to compute the full mask for each CPU and require a second
temporary mask to store the group mask in (it otherwise lives in the
SGC).
The fixed topology looks like:
[] CPU0 attaching sched-domain(s):
[] domain-0: span=0,4 level=DIE
[] groups: 0:{ span=0 }, 4:{ span=4 }
[] domain-1: span=0-1,3-5,7 level=NUMA
[] groups: 0:{ span=0,4 mask=0,4 cap=2048 }, 1:{ span=1,5 mask=1,5 cap=2048 }, 3:{ span=3,7 mask=3,7 cap=2048 }
[] domain-2: span=0-7 level=NUMA
[] groups: 0:{ span=0-1,3-5,7 mask=0,4 cap=6144 }, 2:{ span=1-3,5-7 mask=2,6 cap=6144 }
[] CPU1 attaching sched-domain(s):
[] domain-0: span=1,5 level=DIE
[] groups: 1:{ span=1 }, 5:{ span=5 }
[] domain-1: span=0-2,4-6 level=NUMA
[] groups: 1:{ span=1,5 mask=1,5 cap=2048 }, 2:{ span=2,6 mask=2,6 cap=2048 }, 0:{ span=0,4 mask=0,4 cap=2048 }
[] domain-2: span=0-7 level=NUMA
[] groups: 1:{ span=0-2,4-6 mask=1,5 cap=6144 }, 3:{ span=0,2-4,6-7 mask=3,7 cap=6144 }
Debugged-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: e3589f6c81 ("sched: Allow for overlapping sched_domain spans")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add sgc::id to easier spot domain construction issues.
Take the opportunity to slightly rework the group printing, because
adding more "(id: %d)" strings makes the entire thing very hard to
read. Also the individual groups are very hard to separate, so add
explicit visual grouping, which allows replacing all the "(%s: %d)"
format things with shorter "%s=%d" variants.
Then fix up some inconsistencies in surrounding prints for domains.
The end result looks like:
[] CPU0 attaching sched-domain(s):
[] domain-0: span=0,4 level=DIE
[] groups: 0:{ span=0 }, 4:{ span=4 }
[] domain-1: span=0-1,3-5,7 level=NUMA
[] groups: 0:{ span=0,4 mask=0,4 cap=2048 }, 1:{ span=1,5 mask=1,5 cap=2048 }, 3:{ span=3,7 mask=3,7 cap=2048 }
[] domain-2: span=0-7 level=NUMA
[] groups: 0:{ span=0-1,3-5,7 mask=0,4 cap=6144 }, 2:{ span=1-3,5-7 mask=2,6 cap=6144 }
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move the allocation of topology specific cpumasks into the topology
code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The point of sched_group_mask is to select those CPUs from
sched_group_cpus that can actually arrive at this balance domain.
The current code gets it wrong, as can be readily demonstrated with a
topology like:
node 0 1 2 3
0: 10 20 30 20
1: 20 10 20 30
2: 30 20 10 20
3: 20 30 20 10
Where (for example) domain 1 on CPU1 ends up with a mask that includes
CPU0:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 (mask: 1), 2, 0
[] domain 1: span 0-3 level NUMA
[] groups: 0-2 (mask: 0-2) (cpu_capacity: 3072), 0,2-3 (cpu_capacity: 3072)
This causes sched_balance_cpu() to compute the wrong CPU and
consequently should_we_balance() will terminate early resulting in
missed load-balance opportunities.
The fixed topology looks like:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 (mask: 1), 2, 0
[] domain 1: span 0-3 level NUMA
[] groups: 0-2 (mask: 1) (cpu_capacity: 3072), 0,2-3 (cpu_capacity: 3072)
(note: this relies on OVERLAP domains to always have children, this is
true because the regular topology domains are still here -- this is
before degenerate trimming)
Debugged-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e3589f6c81 ("sched: Allow for overlapping sched_domain spans")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Its an obsolete debug mechanism and future code wants to rely on
properties this undermines.
Namely, it would be good to assume that SD_OVERLAP domains have
children, but if we build the entire hierarchy with SD_OVERLAP this is
obviously false.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The group mask is always used in intersection with the group CPUs. So,
when building the group mask, we don't have to care about CPUs that are
not part of the group.
Signed-off-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lwang@redhat.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1492717903-5195-2-git-send-email-lvenanci@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We want sched_groups to be sibling child domains (or individual CPUs
when there are no child domains). Furthermore, since the first group
of a domain should include the CPU of that domain, the first group of
each domain should match the child domain.
Verify this is indeed so.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In order to determine the balance_cpu (for should_we_balance()) we need
the sched_group_mask() for overlapping domains.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Now that the first group will always be the previous domain of this
@cpu this can be simplified.
In fact, writing the code now removed should've been a big clue I was
doing it wrong :/
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When building the overlapping groups, we very obviously should start
with the previous domain of _this_ @cpu, not CPU-0.
This can be readily demonstrated with a topology like:
node 0 1 2 3
0: 10 20 30 20
1: 20 10 20 30
2: 30 20 10 20
3: 20 30 20 10
Where (for example) CPU1 ends up generating the following nonsensical groups:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 2 0
[] domain 1: span 0-3 level NUMA
[] groups: 1-3 (cpu_capacity = 3072) 0-1,3 (cpu_capacity = 3072)
Where the fact that domain 1 doesn't include a group with span 0-2 is
the obvious fail.
With patch this looks like:
[] CPU1 attaching sched-domain:
[] domain 0: span 0-2 level NUMA
[] groups: 1 0 2
[] domain 1: span 0-3 level NUMA
[] groups: 0-2 (cpu_capacity = 3072) 0,2-3 (cpu_capacity = 3072)
Debugged-by: Lauro Ramos Venancio <lvenanci@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e3589f6c81 ("sched: Allow for overlapping sched_domain spans")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
More users for for_each_cpu_wrap() have appeared. Promote the construct
to generic cpumask interface.
The implementation is slightly modified to reduce arguments.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Lauro Ramos Venancio <lvenanci@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lwang@redhat.com
Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
With our switch to stable delayed until late_initcall(), the most
likely cause of hitting mark_tsc_unstable() is the watchdog. The
watchdog typically only triggers when creative BIOS'es fiddle with the
TSC to hide SMI latency.
Since the watchdog can only detect TSC fiddling after the fact all TSC
clocks (including userspace GTOD) can already have reported funny
values.
The only way to fully avoid this, is manually marking the TSC unstable
at boot. Suggest people do this on their broken systems.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Core2 marks its TSC unstable in ACPI Processor Idle, which is probed
after sched_init_smp(). Luckily it appears both acpi_processor and
intel_idle (which has a similar check) are mandatory built-in.
This means we can delay switching to stable until after these drivers
have ran (if they were modules, this would be impossible).
Delay the stable switch to late_initcall() to allow these drivers to
mark TSC unstable and avoid difficult stable->unstable transitions.
Reported-by: Lofstedt, Marta <marta.lofstedt@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ville reported that on his Core2, which has TSC stop in idle, we would
always report very short idle durations. He tracked this down to
commit:
e93e59ce5b ("cpuidle: Replace ktime_get() with local_clock()")
which replaces ktime_get() with local_clock().
Add a sched_clock_idle_wakeup_event() call, which will re-sync the
clock with ktime_get_ns() when TSC is unstable and no-op otherwise.
Reported-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Fixes: e93e59ce5b ("cpuidle: Replace ktime_get() with local_clock()")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
2bacec8c31 ("sched: touch softlockup watchdog after idling")
introduced the touch_softlockup_watchdog_sched() call without
justification and I feel sched_clock management is not the right
place, it should only be concerned with producing semi coherent time.
If this causes watchdog thingies, we can find a better place.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The argument to sched_clock_idle_wakeup_event() has not been used in a
long time. Remove it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently we keep sched_clock_tick() active for stable TSC in order to
keep the per-CPU state semi up-to-date. The (obvious) problem is that
by the time we detect TSC is borked, our per-CPU state is also borked.
So hook into the clocksource watchdog and call a method after we've
found it to still be stable.
There's the obvious race where the TSC goes wonky between finding it
stable and us running the callback, but closing that is too much work
and not really worth it, since we're already detecting TSC wobbles
after the fact, so we cannot, per definition, fully avoid funny clock
values.
And since the watchdog runs less often than the tick, this is also an
optimization.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for not keeping the sched_clock_tick() active for
stable TSC, we need to explicitly initialize all per-CPU state
before switching back to unstable.
Note: this patch looses the __gtod_offset calculation; it will be
restored in the next one.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the current implementation of load/util_avg, we assume that the
ongoing time segment has fully elapsed, and util/load_sum is divided
by LOAD_AVG_MAX, even if part of the time segment still remains to
run. As a consequence, this remaining part is considered as idle time
and generates unexpected variations of util_avg of a busy CPU in the
range [1002..1024[ whereas util_avg should stay at 1023.
In order to keep the metric stable, we should not consider the ongoing
time segment when computing load/util_avg but only the segments that
have already fully elapsed. But to not consider the current time
segment adds unwanted latency in the load/util_avg responsivness
especially when the time is scaled instead of the contribution.
Instead of waiting for the current time segment to have fully elapsed
before accounting it in load/util_avg, we can already account the
elapsed part but change the range used to compute load/util_avg
accordingly.
At the very beginning of a new time segment, the past segments have
been decayed and the max value is LOAD_AVG_MAX*y. At the very end of
the current time segment, the max value becomes:
LOAD_AVG_MAX*y + 1024(us) (== LOAD_AVG_MAX)
In fact, the max value is:
LOAD_AVG_MAX*y + sa->period_contrib
at any time in the time segment.
Taking advantage of the fact that:
LOAD_AVG_MAX*y == LOAD_AVG_MAX-1024
the range becomes [0..LOAD_AVG_MAX-1024+sa->period_contrib].
As the elapsed part is already accounted in load/util_sum, we update
the max value according to the current position in the time segment
instead of removing its contribution.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Morten.Rasmussen@arm.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: pjt@google.com
Cc: yuyang.du@intel.com
Link: http://lkml.kernel.org/r/1493188076-2767-1-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I finally got around to creating trampolines for dynamically allocated
ftrace_ops with using synchronize_rcu_tasks(). For users of the ftrace
function hook callbacks, like perf, that allocate the ftrace_ops
descriptor via kmalloc() and friends, ftrace was not able to optimize
the functions being traced to use a trampoline because they would also
need to be allocated dynamically. The problem is that they cannot be
freed when CONFIG_PREEMPT is set, as there's no way to tell if a task
was preempted on the trampoline. That was before Paul McKenney
implemented synchronize_rcu_tasks() that would make sure all tasks
(except idle) have scheduled out or have entered user space.
While testing this, I triggered this bug:
BUG: unable to handle kernel paging request at ffffffffa0230077
...
RIP: 0010:0xffffffffa0230077
...
Call Trace:
schedule+0x5/0xe0
schedule_preempt_disabled+0x18/0x30
do_idle+0x172/0x220
What happened was that the idle task was preempted on the trampoline.
As synchronize_rcu_tasks() ignores the idle thread, there's nothing
that lets ftrace know that the idle task was preempted on a trampoline.
The idle task shouldn't need to ever enable preemption. The idle task
is simply a loop that calls schedule or places the cpu into idle mode.
In fact, having preemption enabled is inefficient, because it can
happen when idle is just about to call schedule anyway, which would
cause schedule to be called twice. Once for when the interrupt came in
and was returning back to normal context, and then again in the normal
path that the idle loop is running in, which would be pointless, as it
had already scheduled.
The only reason schedule_preempt_disable() enables preemption is to be
able to call sched_submit_work(), which requires preemption enabled. As
this is a nop when the task is in the RUNNING state, and idle is always
in the running state, there's no reason that idle needs to enable
preemption. But that means it cannot use schedule_preempt_disable() as
other callers of that function require calling sched_submit_work().
Adding a new function local to kernel/sched/ that allows idle to call
the scheduler without enabling preemption, fixes the
synchronize_rcu_tasks() issue, as well as removes the pointless spurious
schedule calls caused by interrupts happening in the brief window where
preemption is enabled just before it calls schedule.
Reviewed: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170414084809.3dacde2a@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fixing sparse warnings: 'symbol not declared. Should it be static?'
Signed-off-by: Pushkar Jambhlekar <pushkar.iit@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Imagine we have a pid namespace and a task from its parent's pid_ns,
which made setns() to the pid namespace. The task is doing fork(),
while the pid namespace's child reaper is dying. We have the race
between them:
Task from parent pid_ns Child reaper
copy_process() ..
alloc_pid() ..
.. zap_pid_ns_processes()
.. disable_pid_allocation()
.. read_lock(&tasklist_lock)
.. iterate over pids in pid_ns
.. kill tasks linked to pids
.. read_unlock(&tasklist_lock)
write_lock_irq(&tasklist_lock); ..
attach_pid(p, PIDTYPE_PID); ..
.. ..
So, just created task p won't receive SIGKILL signal,
and the pid namespace will be in contradictory state.
Only manual kill will help there, but does the userspace
care about this? I suppose, the most users just inject
a task into a pid namespace and wait a SIGCHLD from it.
The patch fixes the problem. It simply checks for
(pid_ns->nr_hashed & PIDNS_HASH_ADDING) in copy_process().
We do it under the tasklist_lock, and can't skip
PIDNS_HASH_ADDING as noted by Oleg:
"zap_pid_ns_processes() does disable_pid_allocation()
and then takes tasklist_lock to kill the whole namespace.
Given that copy_process() checks PIDNS_HASH_ADDING
under write_lock(tasklist) they can't race;
if copy_process() takes this lock first, the new child will
be killed, otherwise copy_process() can't miss
the change in ->nr_hashed."
If allocation is disabled, we just return -ENOMEM
like it's made for such cases in alloc_pid().
v2: Do not move disable_pid_allocation(), do not
introduce a new variable in copy_process() and simplify
the patch as suggested by Oleg Nesterov.
Account the problem with double irq enabling
found by Eric W. Biederman.
Fixes: c876ad7682 ("pidns: Stop pid allocation when init dies")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Mike Rapoport <rppt@linux.vnet.ibm.com>
CC: Michal Hocko <mhocko@suse.com>
CC: Andy Lutomirski <luto@kernel.org>
CC: "Eric W. Biederman" <ebiederm@xmission.com>
CC: Andrei Vagin <avagin@openvz.org>
CC: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Serge Hallyn <serge@hallyn.com>
Cc: stable@vger.kernel.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The code can potentially sleep for an indefinite amount of time in
zap_pid_ns_processes triggering the hung task timeout, and increasing
the system average. This is undesirable. Sleep with a task state of
TASK_INTERRUPTIBLE instead of TASK_UNINTERRUPTIBLE to remove these
undesirable side effects.
Apparently under heavy load this has been allowing Chrome to trigger
the hung time task timeout error and cause ChromeOS to reboot.
Reported-by: Vovo Yang <vovoy@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 6347e90091 ("pidns: guarantee that the pidns init will be the last pidns process reaped")
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
All uses of the current_fs_time() function have been replaced by other
time interfaces.
And, its use cases can be fulfilled by current_time() or ktime_get_*
variants.
Link: http://lkml.kernel.org/r/1491613030-11599-13-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf updates/fixes from Ingo Molnar:
"Mostly tooling updates, but also two kernel fixes: a call chain
handling robustness fix and an x86 PMU driver event definition fix"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/callchain: Force USER_DS when invoking perf_callchain_user()
tools build: Fixup sched_getcpu feature test
perf tests kmod-path: Don't fail if compressed modules aren't supported
perf annotate: Fix AArch64 comment char
perf tools: Fix spelling mistakes
perf/x86: Fix Broadwell-EP DRAM RAPL events
perf config: Refactor a duplicated code for obtaining config file name
perf symbols: Allow user probes on versioned symbols
perf symbols: Accept symbols starting at address 0
tools lib string: Adopt prefixcmp() from perf and subcmd
perf units: Move parse_tag_value() to units.[ch]
perf ui gtk: Move gtk .so name to the only place where it is used
perf tools: Move HAS_BOOL define to where perl headers are used
perf memswap: Split the byteswap memory range wrappers from util.[ch]
perf tools: Move event prototypes from util.h to event.h
perf buildid: Move prototypes from util.h to build-id.h
Pull stackprotector fixlet from Ingo Molnar:
"A single fix/enhancement to increase stackprotector canary randomness
on 64-bit kernels with very little cost"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
stackprotector: Increase the per-task stack canary's random range from 32 bits to 64 bits on 64-bit platforms
We must accumulate into reg->aux_off rather than use a plain assignment.
Add a test for this situation to test_align.
Reported-by: Alexei Starovoitov <ast@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new field, "prog_flags", and an initial flag value
BPF_F_STRICT_ALIGNMENT.
When set, the verifier will enforce strict pointer alignment
regardless of the setting of CONFIG_EFFICIENT_UNALIGNED_ACCESS.
The verifier, in this mode, will also use a fixed value of "2" in
place of NET_IP_ALIGN.
This facilitates test cases that will exercise and validate this part
of the verifier even when run on architectures where alignment doesn't
matter.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
If log_level > 1, do a state dump every instruction and emit it in
a more compact way (without a leading newline).
This will facilitate more sophisticated test cases which inspect the
verifier log for register state.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Currently if we add only constant values to pointers we can fully
validate the alignment, and properly check if we need to reject the
program on !CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS architectures.
However, once an unknown value is introduced we only allow byte sized
memory accesses which is too restrictive.
Add logic to track the known minimum alignment of register values,
and propagate this state into registers containing pointers.
The most common paradigm that makes use of this new logic is computing
the transport header using the IP header length field. For example:
struct ethhdr *ep = skb->data;
struct iphdr *iph = (struct iphdr *) (ep + 1);
struct tcphdr *th;
...
n = iph->ihl;
th = ((void *)iph + (n * 4));
port = th->dest;
The existing code will reject the load of th->dest because it cannot
validate that the alignment is at least 2 once "n * 4" is added the
the packet pointer.
In the new code, the register holding "n * 4" will have a reg->min_align
value of 4, because any value multiplied by 4 will be at least 4 byte
aligned. (actually, the eBPF code emitted by the compiler in this case
is most likely to use a shift left by 2, but the end result is identical)
At the critical addition:
th = ((void *)iph + (n * 4));
The register holding 'th' will start with reg->off value of 14. The
pointer addition will transform that reg into something that looks like:
reg->aux_off = 14
reg->aux_off_align = 4
Next, the verifier will look at the th->dest load, and it will see
a load offset of 2, and first check:
if (reg->aux_off_align % size)
which will pass because aux_off_align is 4. reg_off will be computed:
reg_off = reg->off;
...
reg_off += reg->aux_off;
plus we have off==2, and it will thus check:
if ((NET_IP_ALIGN + reg_off + off) % size != 0)
which evaluates to:
if ((NET_IP_ALIGN + 14 + 2) % size != 0)
On strict alignment architectures, NET_IP_ALIGN is 2, thus:
if ((2 + 14 + 2) % size != 0)
which passes.
These pointer transformations and checks work regardless of whether
the constant offset or the variable with known alignment is added
first to the pointer register.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
pointer to using cpumask_available(), which will do the check. This is
because cpumasks when not allocated are always set, and clang complains
about it.
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Merge tag 'trace-v4.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"This is a trivial patch that changes a check for a cpumask from a NULL
pointer to using cpumask_available(), which will do the check. This is
because cpumasks when not allocated are always set, and clang
complains about it"
* tag 'trace-v4.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Use cpumask_available() to check if cpumask variable may be used
Pull RCU updates from Ingo Molnar:
"The main changes are:
- Debloat RCU headers
- Parallelize SRCU callback handling (plus overlapping patches)
- Improve the performance of Tree SRCU on a CPU-hotplug stress test
- Documentation updates
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
rcu: Open-code the rcu_cblist_n_lazy_cbs() function
rcu: Open-code the rcu_cblist_n_cbs() function
rcu: Open-code the rcu_cblist_empty() function
rcu: Separately compile large rcu_segcblist functions
srcu: Debloat the <linux/rcu_segcblist.h> header
srcu: Adjust default auto-expediting holdoff
srcu: Specify auto-expedite holdoff time
srcu: Expedite first synchronize_srcu() when idle
srcu: Expedited grace periods with reduced memory contention
srcu: Make rcutorture writer stalls print SRCU GP state
srcu: Exact tracking of srcu_data structures containing callbacks
srcu: Make SRCU be built by default
srcu: Fix Kconfig botch when SRCU not selected
rcu: Make non-preemptive schedule be Tasks RCU quiescent state
srcu: Expedite srcu_schedule_cbs_snp() callback invocation
srcu: Parallelize callback handling
kvm: Move srcu_struct fields to end of struct kvm
rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
rcu: Use true/false in assignment to bool
rcu: Use bool value directly
...
- Add Intel Gemini Lake CPU IDs to the intel_idle and intel_rapl
drivers (David Box).
- Add a NULL pointer check to the cpuidle core to prevent it from
crashing on platforms with incomplete cpuidle configuration (Fei
Li).
- Fix DT-related documentation in the generic power domains (genpd)
framework and add a MAINTAINERS entry for DT-related material in
genpd (Viresh Kumar).
- Update the system suspend/resume infrastructure to improve the
handling of aborts of suspend transitions in progress in the
wakeup framework and rework the suspend-to-idle core loop to make
it possible to filter out spurious wakeup events (specifically the
ones coming from ACPI) without resuming all the way up to user
space every time (Rafael Wysocki).
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Merge tag 'pm-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
"These add new CPU IDs to a couple of drivers, fix a possible NULL
pointer dereference in the cpuidle core, update DT-related things in
the generic power domains framework and finally update the
suspend/resume infrastructure to improve the handling of wakeups from
suspend-to-idle.
Specifics:
- Add Intel Gemini Lake CPU IDs to the intel_idle and intel_rapl
drivers (David Box).
- Add a NULL pointer check to the cpuidle core to prevent it from
crashing on platforms with incomplete cpuidle configuration (Fei
Li).
- Fix DT-related documentation in the generic power domains (genpd)
framework and add a MAINTAINERS entry for DT-related material in
genpd (Viresh Kumar).
- Update the system suspend/resume infrastructure to improve the
handling of aborts of suspend transitions in progress in the wakeup
framework and rework the suspend-to-idle core loop to make it
possible to filter out spurious wakeup events (specifically the
ones coming from ACPI) without resuming all the way up to user
space every time (Rafael Wysocki)"
* tag 'pm-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle
PM / wakeup: Integrate mechanism to abort transitions in progress
x86/intel_idle: add Gemini Lake support
cpuidle: check dev before usage in cpuidle_use_deepest_state()
powercap: intel_rapl: Add support for Gemini Lake
PM / Domains: Add DT file to MAINTAINERS
PM / Domains: Fix DT example
Perf can generate and record a user callchain in response to a synchronous
request, such as a tracepoint firing. If this happens under set_fs(KERNEL_DS),
then we can end up walking the user stack (and dereferencing/saving whatever we
find there) without the protections usually afforded by checks such as
access_ok.
Rather than play whack-a-mole with each architecture's stack unwinding
implementation, fix the root of the problem by ensuring that we force USER_DS
when invoking perf_callchain_user from the perf core.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking fixes from David Miller:
1) Fix multiqueue in stmmac driver on PCI, from Andy Shevchenko.
2) cdc_ncm doesn't actually fully zero out the padding area is
allocates on TX, from Jim Baxter.
3) Don't leak map addresses in BPF verifier, from Daniel Borkmann.
4) If we randomize TCP timestamps, we have to do it everywhere
including SYN cookies. From Eric Dumazet.
5) Fix "ethtool -S" crash in aquantia driver, from Pavel Belous.
6) Fix allocation size for ntp filter bitmap in bnxt_en driver, from
Dan Carpenter.
7) Add missing memory allocation return value check to DSA loop driver,
from Christophe Jaillet.
8) Fix XDP leak on driver unload in qed driver, from Suddarsana Reddy
Kalluru.
9) Don't inherit MC list from parent inet connection sockets, another
syzkaller spotted gem. Fix from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits)
dccp/tcp: do not inherit mc_list from parent
qede: Split PF/VF ndos.
qed: Correct doorbell configuration for !4Kb pages
qed: Tell QM the number of tasks
qed: Fix VF removal sequence
qede: Fix XDP memory leak on unload
net/mlx4_core: Reduce harmless SRIOV error message to debug level
net/mlx4_en: Avoid adding steering rules with invalid ring
net/mlx4_en: Change the error print to debug print
drivers: net: wimax: i2400m: i2400m-usb: Use time_after for time comparison
DECnet: Use container_of() for embedded struct
Revert "ipv4: restore rt->fi for reference counting"
net: mdio-mux: bcm-iproc: call mdiobus_free() in error path
net: ethernet: ti: cpsw: adjust cpsw fifos depth for fullduplex flow control
ipv6: reorder ip6_route_dev_notifier after ipv6_dev_notf
net: cdc_ncm: Fix TX zero padding
stmmac: pci: split out common_default_data() helper
stmmac: pci: RX queue routing configuration
stmmac: pci: TX and RX queue priority configuration
stmmac: pci: set default number of rx and tx queues
...
* pm-domains:
PM / Domains: Add DT file to MAINTAINERS
PM / Domains: Fix DT example
* pm-cpuidle:
x86/intel_idle: add Gemini Lake support
cpuidle: check dev before usage in cpuidle_use_deepest_state()
* pm-sleep:
ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle
PM / wakeup: Integrate mechanism to abort transitions in progress
* powercap:
powercap: intel_rapl: Add support for Gemini Lake
Pull misc vfs updates from Al Viro:
"Assorted bits and pieces from various people. No common topic in this
pile, sorry"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs/affs: add rename exchange
fs/affs: add rename2 to prepare multiple methods
Make stat/lstat/fstatat pass AT_NO_AUTOMOUNT to vfs_statx()
fs: don't set *REFERENCED on single use objects
fs: compat: Remove warning from COMPATIBLE_IOCTL
remove pointless extern of atime_need_update_rcu()
fs: completely ignore unknown open flags
fs: add a VALID_OPEN_FLAGS
fs: remove _submit_bh()
fs: constify tree_descr arrays passed to simple_fill_super()
fs: drop duplicate header percpu-rwsem.h
fs/affs: bugfix: Write files greater than page size on OFS
fs/affs: bugfix: enable writes on OFS disks
fs/affs: remove node generation check
fs/affs: import amigaffs.h
fs/affs: bugfix: make symbolic links work again
The first one is just a switch from using strcpy() to strlcpy(). Someone
thought that it may cause an overflow bug, but since it only copies comms
into a pre-allocated array of TASK_COMM_LEN, and no comm should ever
be bigger than that, nor not end with a nul character, this change is more
of a safety precaution than fixing anything that is actually broken.
The other two changes are simply cleaning and optimizing some code.
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Merge tag 'trace-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull more tracing updates from Steven Rostedt:
"These are three simple changes.
The first one is just a switch from using strcpy() to strlcpy().
Someone thought that it may cause an overflow bug, but since it only
copies comms into a pre-allocated array of TASK_COMM_LEN, and no comm
should ever be bigger than that, nor not end with a nul character,
this change is more of a safety precaution than fixing anything that
is actually broken.
The other two changes are simply cleaning and optimizing some code"
* tag 'trace-v4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Simplify ftrace_match_record() even more
ftrace: Remove an unneeded condition
tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()
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Merge tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
- add framework for supporting PCIe devices in Endpoint mode (Kishon
Vijay Abraham I)
- use non-postable PCI config space mappings when possible (Lorenzo
Pieralisi)
- clean up and unify mmap of PCI BARs (David Woodhouse)
- export and unify Function Level Reset support (Christoph Hellwig)
- avoid FLR for Intel 82579 NICs (Sasha Neftin)
- add pci_request_irq() and pci_free_irq() helpers (Christoph Hellwig)
- short-circuit config access failures for disconnected devices (Keith
Busch)
- remove D3 sleep delay when possible (Adrian Hunter)
- freeze PME scan before suspending devices (Lukas Wunner)
- stop disabling MSI/MSI-X in pci_device_shutdown() (Prarit Bhargava)
- disable boot interrupt quirk for ASUS M2N-LR (Stefan Assmann)
- add arch-specific alignment control to improve device passthrough by
avoiding multiple BARs in a page (Yongji Xie)
- add sysfs sriov_drivers_autoprobe to control VF driver binding
(Bodong Wang)
- allow slots below PCI-to-PCIe "reverse bridges" (Bjorn Helgaas)
- fix crashes when unbinding host controllers that don't support
removal (Brian Norris)
- add driver for MicroSemi Switchtec management interface (Logan
Gunthorpe)
- add driver for Faraday Technology FTPCI100 host bridge (Linus
Walleij)
- add i.MX7D support (Andrey Smirnov)
- use generic MSI support for Aardvark (Thomas Petazzoni)
- make Rockchip driver modular (Brian Norris)
- advertise 128-byte Read Completion Boundary support for Rockchip
(Shawn Lin)
- advertise PCI_EXP_LNKSTA_SLC for Rockchip root port (Shawn Lin)
- convert atomic_t to refcount_t in HV driver (Elena Reshetova)
- add CPU IRQ affinity in HV driver (K. Y. Srinivasan)
- fix PCI bus removal in HV driver (Long Li)
- add support for ThunderX2 DMA alias topology (Jayachandran C)
- add ThunderX pass2.x 2nd node MCFG quirk (Tomasz Nowicki)
- add ITE 8893 bridge DMA alias quirk (Jarod Wilson)
- restrict Cavium ACS quirk only to CN81xx/CN83xx/CN88xx devices
(Manish Jaggi)
* tag 'pci-v4.12-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (146 commits)
PCI: Don't allow unbinding host controllers that aren't prepared
ARM: DRA7: clockdomain: Change the CLKTRCTRL of CM_PCIE_CLKSTCTRL to SW_WKUP
MAINTAINERS: Add PCI Endpoint maintainer
Documentation: PCI: Add userguide for PCI endpoint test function
tools: PCI: Add sample test script to invoke pcitest
tools: PCI: Add a userspace tool to test PCI endpoint
Documentation: misc-devices: Add Documentation for pci-endpoint-test driver
misc: Add host side PCI driver for PCI test function device
PCI: Add device IDs for DRA74x and DRA72x
dt-bindings: PCI: dra7xx: Add DT bindings to enable unaligned access
PCI: dwc: dra7xx: Workaround for errata id i870
dt-bindings: PCI: dra7xx: Add DT bindings for PCI dra7xx EP mode
PCI: dwc: dra7xx: Add EP mode support
PCI: dwc: dra7xx: Facilitate wrapper and MSI interrupts to be enabled independently
dt-bindings: PCI: Add DT bindings for PCI designware EP mode
PCI: dwc: designware: Add EP mode support
Documentation: PCI: Add binding documentation for pci-test endpoint function
ixgbe: Use pcie_flr() instead of duplicating it
IB/hfi1: Use pcie_flr() instead of duplicating it
PCI: imx6: Fix spelling mistake: "contol" -> "control"
...
Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver updates
and additions, tiny bugs fixed, and some core files split up to make
future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while. There will be a merge
conflict with include/linux/serdev.h coming from the bluetooth tree
merge, which we knew about, as we wanted some of the serdev changes to
go in through that tree. I'll send the expected merge result as a
follow-on message.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial updates from Greg KH:
"Here is the "big" TTY/Serial patch updates for 4.12-rc1
Not a lot of new things here, the normal number of serial driver
updates and additions, tiny bugs fixed, and some core files split up
to make future changes a bit easier for Nicolas's "tiny-tty" work.
All of these have been in linux-next for a while"
* tag 'tty-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (62 commits)
serial: small Makefile reordering
tty: split job control support into a file of its own
tty: move baudrate handling code to a file of its own
console: move console_init() out of tty_io.c
serial: 8250_early: Add earlycon support for Palmchip UART
tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44
vt: make mouse selection of non-ASCII consistent
vt: set mouse selection word-chars to gpm's default
imx-serial: Reduce RX DMA startup latency when opening for reading
serial: omap: suspend device on probe errors
serial: omap: fix runtime-pm handling on unbind
tty: serial: omap: add UPF_BOOT_AUTOCONF flag for DT init
serial: samsung: Remove useless spinlock
serial: samsung: Add missing checks for dma_map_single failure
serial: samsung: Use right device for DMA-mapping calls
serial: imx: setup DCEDTE early and ensure DCD and RI irqs to be off
tty: fix comment typo s/repsonsible/responsible/
tty: amba-pl011: Fix spurious TX interrupts
serial: xuartps: Enable clocks in the pm disable case also
serial: core: Re-use struct uart_port {name} field
...
This fixes the following clang warning:
kernel/trace/trace.c:3231:12: warning: address of array 'iter->started'
will always evaluate to 'true' [-Wpointer-bool-conversion]
if (iter->started)
Link: http://lkml.kernel.org/r/20170421234110.117075-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
struct timespec is not y2038 safe on 32 bit machines and needs to be
replaced by struct timespec64 in order to represent times beyond year
2038 on such machines.
Fix all the timestamp representation in struct trace_hwlat and all the
corresponding implementations.
Link: http://lkml.kernel.org/r/1491613030-11599-3-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_memory_* functions have moved to set_memory.h. Switch to this
explicitly.
Link: http://lkml.kernel.org/r/1488920133-27229-13-git-send-email-labbott@redhat.com
Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
set_memory_* functions have moved to set_memory.h. Switch to this
explicitly.
Link: http://lkml.kernel.org/r/1488920133-27229-12-git-send-email-labbott@redhat.com
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__vmalloc* allows users to provide gfp flags for the underlying
allocation. This API is quite popular
$ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l
77
The only problem is that many people are not aware that they really want
to give __GFP_HIGHMEM along with other flags because there is really no
reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages
which are mapped to the kernel vmalloc space. About half of users don't
use this flag, though. This signals that we make the API unnecessarily
too complex.
This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to
be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM
are simplified and drop the flag.
Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Cristopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
in_interrupt() semantics are confusing and wrong for most users as it
also returns true when bh is disabled. Thus we open coded a proper
check for interrupts in __sanitizer_cov_trace_pc() with a lengthy
explanatory comment.
Use the new in_task() predicate instead.
Link: http://lkml.kernel.org/r/20170321091026.139655-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: James Morse <james.morse@arm.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The elapsed time, user CPU time and system CPU time for the thread group
status request are presently left at zero. Fill these in.
[akpm@linux-foundation.org: run ktime_get_ns() a single time]
[akpm@linux-foundation.org: include linux/sched/cputime.h for task_cputime()]
Link: http://lkml.kernel.org/r/1488508424-12322-1-git-send-email-xiao.zhang@windriver.com
Signed-off-by: Zhang Xiao <xiao.zhang@windriver.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pid_ns_for_children set by a task is known only to the task itself, and
it's impossible to identify it from outside.
It's a big problem for checkpoint/restore software like CRIU, because it
can't correctly handle tasks, that do setns(CLONE_NEWPID) in proccess of
their work.
This patch solves the problem, and it exposes pid_ns_for_children to ns
directory in standard way with the name "pid_for_children":
~# ls /proc/5531/ns -l | grep pid
lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid -> pid:[4026531836]
lrwxrwxrwx 1 root root 0 Jan 14 16:38 pid_for_children -> pid:[4026532286]
Link: http://lkml.kernel.org/r/149201123914.6007.2187327078064239572.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Andrei Vagin <avagin@virtuozzo.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_pidmap() advances pid_namespace::last_pid. When first pid
allocation fails, then next created process will have pid 2 and
pid_ns_prepare_proc() won't be called. So, pid_namespace::proc_mnt will
never be initialized (not to mention that there won't be a child
reaper).
I saw crash stack of such case on kernel 3.10:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: proc_flush_task+0x8f/0x1b0
Call Trace:
release_task+0x3f/0x490
wait_consider_task.part.10+0x7ff/0xb00
do_wait+0x11f/0x280
SyS_wait4+0x7d/0x110
We may fix this by restore of last_pid in 0 or by prohibiting of futher
allocations. Since there was a similar issue in Oleg Nesterov's commit
314a8ad0f1 ("pidns: fix free_pid() to handle the first fork failure").
and it was fixed via prohibiting allocation, let's follow this way, and
do the same.
Link: http://lkml.kernel.org/r/149201021004.4863.6762095011554287922.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrei Vagin <avagin@virtuozzo.com>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Get rid of multiple definitions of append_elf_note() & final_note()
functions. Reuse these functions compiled under CONFIG_CRASH_CORE Also,
define Elf_Word and use it instead of generic u32 or the more specific
Elf64_Word.
Link: http://lkml.kernel.org/r/149035342324.6881.11667840929850361402.stgit@hbathini.in.ibm.com
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kexec/fadump: remove dependency with CONFIG_KEXEC and
reuse crashkernel parameter for fadump", v4.
Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.
This patchset removes dependency with CONFIG_KEXEC for crashkernel
parameter and vmcoreinfo related code as it can be reused without kexec
support. Also, crashkernel parameter is reused instead of
fadump_reserve_mem to reserve memory for fadump.
The first patch moves crashkernel parameter parsing and vmcoreinfo
related code under CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE. The
second patch reuses the definitions of append_elf_note() & final_note()
functions under CONFIG_CRASH_CORE in IA64 arch code. The third patch
removes dependency on CONFIG_KEXEC for firmware-assisted dump (fadump)
in powerpc. The next patch reuses crashkernel parameter for reserving
memory for fadump, instead of the fadump_reserve_mem parameter. This
has the advantage of using all syntaxes crashkernel parameter supports,
for fadump as well. The last patch updates fadump kernel documentation
about use of crashkernel parameter.
This patch (of 5):
Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.
But currently, code related to vmcoreinfo and parsing of crashkernel
parameter is built under CONFIG_KEXEC_CORE. This patch introduces
CONFIG_CRASH_CORE and moves the above mentioned code under this config,
allowing code reuse without dependency on CONFIG_KEXEC. There is no
functional change with this patch.
Link: http://lkml.kernel.org/r/149035338104.6881.4550894432615189948.stgit@hbathini.in.ibm.com
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using virtually mapped stack, kernel stacks are allocated via vmalloc.
In the current implementation, two stacks per cpu can be cached when
tasks are freed and the cached stacks are used again in task
duplications. But the cached stacks may remain unfreed even when cpu
are offline. By adding a cpu hotplug callback to free the cached stacks
when a cpu goes offline, the pages of the cached stacks are not wasted.
Link: http://lkml.kernel.org/r/1487076043-17802-1-git-send-email-hoeun.ryu@gmail.com
Signed-off-by: Hoeun Ryu <hoeun.ryu@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I was running my testcase which may block hundreds of threads on fs
locks, I got lockup due to output from debug_show_all_locks() added by
commit b2d4c2edb2 ("locking/hung_task: Show all locks").
For example, if 1000 threads were blocked in TASK_UNINTERRUPTIBLE state
and 500 out of 1000 threads hold some lock, debug_show_all_locks() from
for_each_process_thread() loop will report locks held by 500 threads for
1000 times. This is a too much noise.
In order to make sure rcu_lock_break() is called frequently, we should
avoid calling debug_show_all_locks() from for_each_process_thread() loop
because debug_show_all_locks() effectively calls for_each_process_thread()
loop. Let's defer calling debug_show_all_locks() till before panic() or
leaving for_each_process_thread() loop.
Link: http://lkml.kernel.org/r/1489296834-60436-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_proc_dointvec_jiffies_conv() uses LONG_MAX/HZ as the max value to
avoid overflow. But actually the *valp is int type, so it still causes
overflow.
For example,
echo 2147483647 > ./sys/net/ipv4/tcp_keepalive_time
Then,
cat ./sys/net/ipv4/tcp_keepalive_time
The output is "-1", it is not expected.
Now use INT_MAX/HZ as the max value instead LONG_MAX/HZ to fix it.
Link: http://lkml.kernel.org/r/1490109532-9228-1-git-send-email-fgao@ikuai8.com
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch fixes two things at once:
1) It checks the env->allow_ptr_leaks and only prints the map address to
the log if we have the privileges to do so, otherwise it just dumps 0
as we would when kptr_restrict is enabled on %pK. Given the latter is
off by default and not every distro sets it, I don't want to rely on
this, hence the 0 by default for unprivileged.
2) Printing of ldimm64 in the verifier log is currently broken in that
we don't print the full immediate, but only the 32 bit part of the
first insn part for ldimm64. Thus, fix this up as well; it's okay to
access, since we verified all ldimm64 earlier already (including just
constants) through replace_map_fd_with_map_ptr().
Fixes: 1be7f75d16 ("bpf: enable non-root eBPF programs")
Fixes: cbd3570086 ("bpf: verifier (add ability to receive verification log)")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, sugov_next_freq_shared() uses last_freq_update_time as a
reference to decide when to start considering CPU contributions as
stale.
However, since last_freq_update_time is set by the last CPU that issued
a frequency transition, this might cause problems in certain cases. In
practice, the detection of stale utilization values fails whenever the
CPU with such values was the last to update the policy. For example (and
please note again that the SCHED_CPUFREQ_RT flag is not the problem
here, but only the detection of after how much time that flag has to be
considered stale), suppose a policy with 2 CPUs:
CPU0 | CPU1
|
| RT task scheduled
| SCHED_CPUFREQ_RT is set
| CPU1->last_update = now
| freq transition to max
| last_freq_update_time = now
|
more than TICK_NSEC nsecs
|
a small CFS wakes up |
CPU0->last_update = now1 |
delta_ns(CPU0) < TICK_NSEC* |
CPU0's util is considered |
delta_ns(CPU1) = |
last_freq_update_time - |
CPU1->last_update = 0 |
< TICK_NSEC |
CPU1 is still considered |
CPU1->SCHED_CPUFREQ_RT is set |
we stay at max (until CPU1 |
exits from idle) |
* delta_ns is actually negative as now1 > last_freq_update_time
While last_freq_update_time is a sensible reference for rate limiting,
it doesn't seem to be useful for working around stale CPU states.
Fix the problem by always considering now (time) as the reference for
deciding when CPUs have stale contributions.
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state. However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up. In fact,
quite often they should just be discarded.
Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.
For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.
In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume. In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.
In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Highlights include:
- Larger virtual address space on 64-bit server CPUs. By default we use a 128TB
virtual address space, but a process can request access to the full 512TB by
passing a hint to mmap().
- Support for the new Power9 "XIVE" interrupt controller.
- TLB flushing optimisations for the radix MMU on Power9.
- Support for CAPI cards on Power9, using the "Coherent Accelerator Interface
Architecture 2.0".
- The ability to configure the mmap randomisation limits at build and runtime.
- Several small fixes and cleanups to the kprobes code, as well as support for
KPROBES_ON_FTRACE.
- Major improvements to handling of system reset interrupts, correctly treating
them as NMIs, giving them a dedicated stack and using a new hypervisor call
to trigger them, all of which should aid debugging and robustness.
Many fixes and other minor enhancements.
Thanks to:
Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan,
Aneesh Kumar K.V, Anshuman Khandual, Anton Blanchard, Balbir Singh, Ben
Hutchings, Benjamin Herrenschmidt, Bhupesh Sharma, Chris Packham, Christian
Zigotzky, Christophe Leroy, Christophe Lombard, Daniel Axtens, David Gibson,
Gautham R. Shenoy, Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli,
Hamish Martin, Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan,
Mahesh J Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew
R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran,
Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell Currey, Sukadev
Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C. Harding, Tyrel Datwyler,
Uma Krishnan, Vaibhav Jain, Vipin K Parashar, Yang Shi.
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Merge tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Highlights include:
- Larger virtual address space on 64-bit server CPUs. By default we
use a 128TB virtual address space, but a process can request access
to the full 512TB by passing a hint to mmap().
- Support for the new Power9 "XIVE" interrupt controller.
- TLB flushing optimisations for the radix MMU on Power9.
- Support for CAPI cards on Power9, using the "Coherent Accelerator
Interface Architecture 2.0".
- The ability to configure the mmap randomisation limits at build and
runtime.
- Several small fixes and cleanups to the kprobes code, as well as
support for KPROBES_ON_FTRACE.
- Major improvements to handling of system reset interrupts,
correctly treating them as NMIs, giving them a dedicated stack and
using a new hypervisor call to trigger them, all of which should
aid debugging and robustness.
- Many fixes and other minor enhancements.
Thanks to: Alastair D'Silva, Alexey Kardashevskiy, Alistair Popple,
Andrew Donnellan, Aneesh Kumar K.V, Anshuman Khandual, Anton
Blanchard, Balbir Singh, Ben Hutchings, Benjamin Herrenschmidt,
Bhupesh Sharma, Chris Packham, Christian Zigotzky, Christophe Leroy,
Christophe Lombard, Daniel Axtens, David Gibson, Gautham R. Shenoy,
Gavin Shan, Geert Uytterhoeven, Guilherme G. Piccoli, Hamish Martin,
Hari Bathini, Kees Cook, Laurent Dufour, Madhavan Srinivasan, Mahesh J
Salgaonkar, Mahesh Salgaonkar, Masami Hiramatsu, Matt Brown, Matthew
R. Ochs, Michael Neuling, Naveen N. Rao, Nicholas Piggin, Oliver
O'Halloran, Pan Xinhui, Paul Mackerras, Rashmica Gupta, Russell
Currey, Sukadev Bhattiprolu, Thadeu Lima de Souza Cascardo, Tobin C.
Harding, Tyrel Datwyler, Uma Krishnan, Vaibhav Jain, Vipin K Parashar,
Yang Shi"
* tag 'powerpc-4.12-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (214 commits)
powerpc/64s: Power9 has no LPCR[VRMASD] field so don't set it
powerpc/powernv: Fix TCE kill on NVLink2
powerpc/mm/radix: Drop support for CPUs without lockless tlbie
powerpc/book3s/mce: Move add_taint() later in virtual mode
powerpc/sysfs: Move #ifdef CONFIG_HOTPLUG_CPU out of the function body
powerpc/smp: Document irq enable/disable after migrating IRQs
powerpc/mpc52xx: Don't select user-visible RTAS_PROC
powerpc/powernv: Document cxl dependency on special case in pnv_eeh_reset()
powerpc/eeh: Clean up and document event handling functions
powerpc/eeh: Avoid use after free in eeh_handle_special_event()
cxl: Mask slice error interrupts after first occurrence
cxl: Route eeh events to all drivers in cxl_pci_error_detected()
cxl: Force context lock during EEH flow
powerpc/64: Allow CONFIG_RELOCATABLE if COMPILE_TEST
powerpc/xmon: Teach xmon oops about radix vectors
powerpc/mm/hash: Fix off-by-one in comment about kernel contexts ids
powerpc/pseries: Enable VFIO
powerpc/powernv: Fix iommu table size calculation hook for small tables
powerpc/powernv: Check kzalloc() return value in pnv_pci_table_alloc
powerpc: Add arch/powerpc/tools directory
...
Pull namespace updates from Eric Biederman:
"This is a set of small fixes that were mostly stumbled over during
more significant development. This proc fix and the fix to
posix-timers are the most significant of the lot.
There is a lot of good development going on but unfortunately it
didn't quite make the merge window"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Fix unbalanced hard link numbers
signal: Make kill_proc_info static
rlimit: Properly call security_task_setrlimit
signal: Remove unused definition of sig_user_definied
ia64: Remove unused IA64_TASK_SIGHAND_OFFSET and IA64_SIGHAND_SIGLOCK_OFFSET
ipc: Remove unused declaration of recompute_msgmni
posix-timers: Correct sanity check in posix_cpu_nsleep
sysctl: Remove dead register_sysctl_root
The stack canary is an 'unsigned long' and should be fully initialized to
random data rather than only 32 bits of random data.
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Arjan van Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170504133209.3053-1-danielmicay@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Dan Carpenter sent a patch to remove a check in ftrace_match_record()
because the logic of the code made the check redundant. I looked deeper into
the code, and made the following logic table, with the three variables and
the result of the original code.
modname mod_matches exclude_mod result
------- ----------- ----------- ------
0 0 0 return 0
0 0 1 func_match
0 1 * < cannot exist >
1 0 0 return 0
1 0 1 func_match
1 1 0 func_match
1 1 1 return 0
Notice that when mod_matches == exclude mod, the result is always to
return 0, and when mod_matches != exclude_mod, then the result is to test
the function. This means we only need test if mod_matches is equal to
exclude_mod.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
We know that "mod_matches" is true here so there is no need to check
again.
Link: http://lkml.kernel.org/r/20170331152130.GA4947@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().
Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org
Signed-off-by: Amey Telawane <ameyt@codeaurora.org>
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
