There is a race condition in SMP bootup code, which may result
in
WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
workqueue_cpu_up_callback()
or
kernel BUG at kernel/smpboot.c:135!
It can be triggered with a bit of luck in Linux guests running
on busy hosts.
CPU0 CPUn
==== ====
_cpu_up()
__cpu_up()
start_secondary()
set_cpu_online()
cpumask_set_cpu(cpu,
to_cpumask(cpu_online_bits));
cpu_notify(CPU_ONLINE)
<do stuff, see below>
cpumask_set_cpu(cpu,
to_cpumask(cpu_active_bits));
During the various CPU_ONLINE callbacks CPUn is online but not
active. Several things can go wrong at that point, depending on
the scheduling of tasks on CPU0.
Variant 1:
cpu_notify(CPU_ONLINE)
workqueue_cpu_up_callback()
rebind_workers()
set_cpus_allowed_ptr()
This call fails because it requires an active CPU; rebind_workers()
ends with a warning:
WARNING: CPU: 0 PID: 1 at kernel/workqueue.c:4418
workqueue_cpu_up_callback()
Variant 2:
cpu_notify(CPU_ONLINE)
smpboot_thread_call()
smpboot_unpark_threads()
..
__kthread_unpark()
__kthread_bind()
wake_up_state()
..
select_task_rq()
select_fallback_rq()
The ->wake_cpu of the unparked thread is not allowed, making a call
to select_fallback_rq() necessary. Then, select_fallback_rq() cannot
find an allowed, active CPU and promptly resets the allowed CPUs, so
that the task in question ends up on CPU0.
When those unparked tasks are eventually executed, they run
immediately into a BUG:
kernel BUG at kernel/smpboot.c:135!
Just changing the order in which the online/active bits are set
(and adding some memory barriers), would solve the two issues
above. However, it would change the order of operations back to
the one before commit 6acbfb9697 ("sched: Fix hotplug vs.
set_cpus_allowed_ptr()"), thus, reintroducing that particular
problem.
Going further back into history, we have at least the following
commits touching this topic:
- commit 2baab4e904 ("sched: Fix select_fallback_rq() vs cpu_active/cpu_online")
- commit 5fbd036b55 ("sched: Cleanup cpu_active madness")
Together, these give us the following non-working solutions:
- secondary CPU sets active before online, because active is assumed to
be a subset of online;
- secondary CPU sets online before active, because the primary CPU
assumes that an online CPU is also active;
- secondary CPU sets online and waits for primary CPU to set active,
because it might deadlock.
Commit 875ebe940d ("powerpc/smp: Wait until secondaries are
active & online") introduces an arch-specific solution to this
arch-independent problem.
Now, go for a more general solution without explicit waiting and
simply set active twice: once on the secondary CPU after online
was set and once on the primary CPU after online was seen.
set_cpus_allowed_ptr()")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <stable@vger.kernel.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Wilson <msw@amazon.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 6acbfb9697 ("sched: Fix hotplug vs. set_cpus_allowed_ptr()")
Link: http://lkml.kernel.org/r/1439408156-18840-1-git-send-email-jschoenh@amazon.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU cleanup from Paul E. McKenney:
"Privatize smp_mb__after_unlock_lock(). This commit moves the
definition of smp_mb__after_unlock_lock() to kernel/rcu/tree.h,
in recognition of the fact that RCU is the only thing using
this, that nothing else is likely to use it, and that it is
likely to go away completely."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull irq fixes from Thomas Gleixner:
"A series of small fixlets for a regression visible on OMAP devices
caused by the conversion of the OMAP interrupt chips to hierarchical
interrupt domains. Mostly one liners on the driver side plus a small
helper function in the core to avoid open coded mess in the drivers"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/crossbar: Restore set_wake functionality
irqchip/crossbar: Restore the mask on suspend behaviour
ARM: OMAP: wakeupgen: Restore the irq_set_type() mechanism
irqchip/crossbar: Restore the irq_set_type() mechanism
genirq: Introduce irq_chip_set_type_parent() helper
genirq: Don't return ENOSYS in irq_chip_retrigger_hierarchy
Pull timer fixes from Thomas Gleixner:
"Two minimalistic fixes for 4.2 regressions:
- Eric fixed a thinko in the timer_list base switching code caused by
the overhaul of the timer wheel. It can cause a cpu to see the
wrong base for a timer while we move the timer around.
- Guenter fixed a regression for IMX if booted w/o device tree, where
the timer interrupt is not initialized and therefor the machine
fails to boot"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/imx: Fix boot with non-DT systems
timer: Write timer->flags atomically
Commit 75e3b37d05 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
drops the return code of hrtimer_switch_to_hres(). While doing so, it also
drops the return statement itself on failure. This may cause a system hang.
Seen when running arm:multi_v7_defconfig in qemu with devicetree file
vexpress-v2p-ca9.
Fixes: 75e3b37d05 ("hrtimer: Drop return code of hrtimer_switch_to_hres()")
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/1440231047-16256-1-git-send-email-linux@roeck-us.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This helper is required for irq chips which do not implement a
irq_set_type callback and need to call down the irq domain hierarchy
for the actual trigger type change.
This helper is required to fix further wreckage caused by the
conversion of TI OMAP to hierarchical irq domains and therefor tagged
for stable.
[ tglx: Massaged changelog ]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <tony@atomide.com>
Cc: <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-3-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
irq_chip_retrigger_hierarchy() returns -ENOSYS if it was not able to
find at least one .irq_retrigger() callback implemented in the IRQ
domain hierarchy.
That's wrong, because check_irq_resend() expects a 0 return value from
the callback in case that the hardware assisted resend was not
possible. If the return value is non zero the core code assumes
hardware resend success and the software resend is not invoked.
This results in lost interrupts on platforms where none of the parent
irq chips in the hierarchy implements the retrigger callback.
This is observable on TI OMAP, where the hierarchy is:
ARM GIC <- OMAP wakeupgen <- TI Crossbar
Return 0 instead so the software resend mechanism gets invoked.
[ tglx: Massaged changelog ]
Fixes: 85f08c17de ('genirq: Introduce helper functions...')
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: <linux@arm.linux.org.uk>
Cc: <nsekhar@ti.com>
Cc: <jason@lakedaemon.net>
Cc: <balbi@ti.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: <tony@atomide.com>
Cc: stable@vger.kernel.org # 4.1
Link: http://lkml.kernel.org/r/1439554830-19502-2-git-send-email-grygorii.strashko@ti.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This allows cgroup subsystems to use a different name on the unified
hierarchy. cgroup_subsys->name is used on the unified hierarchy,
->legacy_name elsewhere. If ->legacy_name is not explicitly set, it's
automatically set to ->name and the userland visible behavior remains
unchanged.
v2: Make parse_cgroupfs_options() only consider ->legacy_name as mount
options are used only on legacy hierarchies. Suggested by Li
Zefan.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
It doesn't make sense to print subsystems on mount option or
/proc/PID/cgroup for the default hierarchy.
* cgroup.controllers file at the root of the default hierarchy lists
the currently attached controllers.
* The default hierarchy is catch-all for unmounted subsystems.
* The default hierarchy doesn't accept any mount options.
Suppress subsystem printing on mount options and /proc/PID/cgroup for
the default hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
The variable called "this_base" is confusing because its name suggests
it's of "struct hrtimer_clock_base" type, along with "base" and "new_base"
which doesn't help understanding this complicated function.
Make its name clearer and fix the misleading comment while at it.
[ tglx: Fixed the comment for real ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/1439907509-9553-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
lock_timer_base() cannot prevent the following :
CPU1 ( in __mod_timer()
timer->flags |= TIMER_MIGRATING;
spin_unlock(&base->lock);
base = new_base;
spin_lock(&base->lock);
// The next line clears TIMER_MIGRATING
timer->flags &= ~TIMER_BASEMASK;
CPU2 (in lock_timer_base())
see timer base is cpu0 base
spin_lock_irqsave(&base->lock, *flags);
if (timer->flags == tf)
return base; // oops, wrong base
timer->flags |= base->cpu // too late
We must write timer->flags in one go, otherwise we can fool other cpus.
Fixes: bc7a34b8b9 ("timer: Reduce timer migration overhead if disabled")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Christopherson <jon@jons.org>
Cc: David Miller <davem@davemloft.net>
Cc: xen-devel@lists.xen.org
Cc: david.vrabel@citrix.com
Cc: Sander Eikelenboom <linux@eikelenboom.it>
Link: http://lkml.kernel.org/r/1439831928.32680.11.camel@edumazet-glaptop2.roam.corp.google.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Pull cgroup fix from Tejun Heo:
"A fix for a subtle bug introduced back during 3.17 cycle which
interferes with setting configurations under specific conditions"
* 'for-4.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: use trialcs->mems_allowed as a temp variable
The conversion between struct timespec and jiffies is not year 2038
safe on 32bit systems. Introduce timespec64_to_jiffies() and
jiffies_to_timespec64() functions which use struct timespec64 to
make it ready for 2038 issue.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The current_kernel_time() is not year 2038 safe on 32bit systems
since it returns a timespec value. Introduce current_kernel_time64()
which returns a timespec64 value.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The weak update_persistent_clock64() calls update_persistent_clock(),
if the architecture defines an update_persistent_clock64() to replace
and remove its update_persistent_clock() version, when building the
kernel the linker will throw an undefined symbol error, that is, any
arch that switches to update_persistent_clock64() will have this issue.
To solve the issue, we add the common weak update_persistent_clock().
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Two issues were found on an IMX6 development board without an
enabled RTC device(resulting in the boot time and monotonic
time being initialized to 0).
Issue 1:exportfs -a generate:
"exportfs: /opt/nfs/arm does not support NFS export"
Issue 2:cat /proc/stat:
"btime 4294967236"
The same issues can be reproduced on x86 after running the
following code:
int main(void)
{
struct timeval val;
int ret;
val.tv_sec = 0;
val.tv_usec = 0;
ret = settimeofday(&val, NULL);
return 0;
}
Two issues are different symptoms of same problem:
The reason is a positive wall_to_monotonic pushes boot time back
to the time before Epoch, and getboottime will return negative
value.
In symptom 1:
negative boot time cause get_expiry() to overflow time_t
when input expire time is 2147483647, then cache_flush()
always clears entries just added in ip_map_parse.
In symptom 2:
show_stat() uses "unsigned long" to print negative btime
value returned by getboottime.
This patch fix the problem by prohibiting time from being set to a value which
would cause a negative boot time. As a result one can't set the CLOCK_REALTIME
time prior to (1970 + system uptime).
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Wang YanQing <udknight@gmail.com>
[jstultz: reworded commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
timespec_trunc() avoids rounding if granularity <= nanoseconds-per-jiffie
(or TICK_NSEC). This optimization assumes that:
1. current_kernel_time().tv_nsec is already rounded to TICK_NSEC (i.e.
with HZ=1000 you'd get 1000000, 2000000, 3000000... but never 1000001).
This is no longer true (probably since hrtimers introduced in 2.6.16).
2. TICK_NSEC is evenly divisible by all possible granularities. This may
be true for HZ=100, 250, 1000, but obviously not for HZ=300 /
TICK_NSEC=3333333 (introduced in 2.6.20).
Thus, sub-second portions of in-core file times are not rounded to on-disk
granularity. I.e. file times may change when the inode is re-read from disk
or when the file system is remounted.
This affects all file systems with file time granularities > 1 ns and < 1s,
e.g. CEPH (1000 ns), UDF (1000 ns), CIFS (100 ns), NTFS (100 ns) and FUSE
(configurable from user mode via struct fuse_init_out.time_gran).
Steps to reproduce with e.g. UDF:
$ dd if=/dev/zero of=udfdisk count=10000 && mkudffs udfdisk
$ mkdir udf && mount udfdisk udf
$ touch udf/test && stat -c %y udf/test
2015-06-09 10:22:56.130006767 +0200
$ umount udf && mount udfdisk udf
$ stat -c %y udf/test
2015-06-09 10:22:56.130006000 +0200
Remounting truncates the mtime to 1 µs.
Fix the rounding in timespec_trunc() and update the documentation.
timespec_trunc() is exclusively used to calculate inode's [acm]time (mostly
via current_fs_time()), and always with super_block.s_time_gran as second
argument. So this can safely be changed without side effects.
Note: This does _not_ fix the issue for FAT's 2 second mtime resolution,
as super_block.s_time_gran isn't prepared to handle different ctime /
mtime / atime resolutions nor resolutions > 1 second.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Karsten Blees <blees@dcon.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
I noticed for non-monotonic timers in timer_list, some of the
output looked a little confusing.
For example:
#1: <0000000000000000>, posix_timer_fn, S:01, hrtimer_start_range_ns, leap-a-day/2360
# expires at 1434412800000000000-1434412800000000000 nsecs [in 1434410725062375469 to 1434410725062375469 nsecs]
You'll note the relative time till the expiration "[in xxx to
yyy nsecs]" is incorrect. This is because its printing the delta
between CLOCK_MONOTONIC time to the CLOCK_REALTIME expiration.
This patch fixes this issue by adding the clock offset to the
"now" time which we use to calculate the delta.
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Pull locking fix from Ingo Molnar:
"A single fix for a locking self-test crash"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/pvqspinlock: Fix kernel panic in locking-selftest
Existing users of ioremap_cache() are mapping memory that is known in
advance to not have i/o side effects. These users are forced to cast
away the __iomem annotation, or otherwise neglect to fix the sparse
errors thrown when dereferencing pointers to this memory. Provide
memremap() as a non __iomem annotated ioremap_*() in the case when
ioremap is otherwise a pointer to cacheable memory. Empirically,
ioremap_<cacheable-type>() call sites are seeking memory-like semantics
(e.g. speculative reads, and prefetching permitted).
memremap() is a break from the ioremap implementation pattern of adding
a new memremap_<type>() for each mapping type and having silent
compatibility fall backs. Instead, the implementation defines flags
that are passed to the central memremap() and if a mapping type is not
supported by an arch memremap returns NULL.
We introduce a memremap prototype as a trivial wrapper of
ioremap_cache() and ioremap_wt(). Later, once all ioremap_cache() and
ioremap_wt() usage has been removed from drivers we teach archs to
implement arch_memremap() with the ability to strictly enforce the
mapping type.
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Move certificate handling out of the kernel/ directory and into a certs/
directory to get all the weird stuff in one place and move the generated
signing keys into this directory.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Conflicts:
drivers/net/ethernet/cavium/Kconfig
The cavium conflict was overlapping dependency
changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
The Intel build-bot detected a sparse warning with with a patch I posted a
couple of days ago that was accepted in the audit/next tree:
Subject: [linux-next:master 6689/6751] kernel/audit_watch.c:543:36: sparse: dereference of noderef expression
Date: Friday, August 07, 2015, 06:57:55 PM
From: kbuild test robot <fengguang.wu@intel.com>
tree: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: e6455bc5b91f41f842f30465c9193320f0568707
commit: 2e3a8aeb63e5335d4f837d453787c71bcb479796 [6689/6751] Merge remote- tracking branch 'audit/next'
sparse warnings: (new ones prefixed by >>)
>> kernel/audit_watch.c:543:36: sparse: dereference of noderef expression
kernel/audit_watch.c:544:28: sparse: dereference of noderef expression
34d99af5 Richard Guy Briggs 2015-08-05 541 int audit_exe_compare(struct task_struct *tsk, struct audit_fsnotify_mark *mark)
34d99af5 Richard Guy Briggs 2015-08-05 542 {
34d99af5 Richard Guy Briggs 2015-08-05 @543 unsigned long ino = tsk->mm- >exe_file->f_inode->i_ino;
34d99af5 Richard Guy Briggs 2015-08-05 544 dev_t dev = tsk->mm->exe_file- >f_inode->i_sb->s_dev;
:::::: The code at line 543 was first introduced by commit
:::::: 34d99af52a audit: implement audit by executable
tsk->mm->exe_file requires RCU access. The warning was reproduceable by adding
"C=1 CF=-D__CHECK_ENDIAN__" to the build command, and verified eliminated with
this patch.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
The code that places signals in signal queues computes the uids, gids,
and pids at the time the signals are enqueued. Which means that tasks
that share signal queues must be in the same pid and user namespaces.
Sharing signal handlers is fine, but bizarre.
So make the code in fork and userns_install clearer by only testing
for what is functionally necessary.
Also update the comment in unshare about unsharing a user namespace to
be a little more explicit and make a little more sense.
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In the logic in the initial commit of unshare made creating a new
thread group for a process, contingent upon creating a new memory
address space for that process. That is wrong. Two separate
processes in different thread groups can share a memory address space
and clone allows creation of such proceses.
This is significant because it was observed that mm_users > 1 does not
mean that a process is multi-threaded, as reading /proc/PID/maps
temporarily increments mm_users, which allows other processes to
(accidentally) interfere with unshare() calls.
Correct the check in check_unshare_flags() to test for
!thread_group_empty() for CLONE_THREAD, CLONE_SIGHAND, and CLONE_VM.
For sighand->count > 1 for CLONE_SIGHAND and CLONE_VM.
For !current_is_single_threaded instead of mm_users > 1 for CLONE_VM.
By using the correct checks in unshare this removes the possibility of
an accidental denial of service attack.
Additionally using the correct checks in unshare ensures that only an
explicit unshare(CLONE_VM) can possibly trigger the slow path of
current_is_single_threaded(). As an explict unshare(CLONE_VM) is
pointless it is not expected there are many applications that make
that call.
Cc: stable@vger.kernel.org
Fixes: b2e0d98705 userns: Implement unshare of the user namespace
Reported-by: Ricky Zhou <rickyz@chromium.org>
Reported-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
A PKCS#7 or CMS message can have per-signature authenticated attributes
that are digested as a lump and signed by the authorising key for that
signature. If such attributes exist, the content digest isn't itself
signed, but rather it is included in a special authattr which then
contributes to the signature.
Further, we already require the master message content type to be
pkcs7_signedData - but there's also a separate content type for the data
itself within the SignedData object and this must be repeated inside the
authattrs for each signer [RFC2315 9.2, RFC5652 11.1].
We should really validate the authattrs if they exist or forbid them
entirely as appropriate. To this end:
(1) Alter the PKCS#7 parser to reject any message that has more than one
signature where at least one signature has authattrs and at least one
that does not.
(2) Validate authattrs if they are present and strongly restrict them.
Only the following authattrs are permitted and all others are
rejected:
(a) contentType. This is checked to be an OID that matches the
content type in the SignedData object.
(b) messageDigest. This must match the crypto digest of the data.
(c) signingTime. If present, we check that this is a valid, parseable
UTCTime or GeneralTime and that the date it encodes fits within
the validity window of the matching X.509 cert.
(d) S/MIME capabilities. We don't check the contents.
(e) Authenticode SP Opus Info. We don't check the contents.
(f) Authenticode Statement Type. We don't check the contents.
The message is rejected if (a) or (b) are missing. If the message is
an Authenticode type, the message is rejected if (e) is missing; if
not Authenticode, the message is rejected if (d) - (f) are present.
The S/MIME capabilities authattr (d) unfortunately has to be allowed
to support kernels already signed by the pesign program. This only
affects kexec. sign-file suppresses them (CMS_NOSMIMECAP).
The message is also rejected if an authattr is given more than once or
if it contains more than one element in its set of values.
(3) Add a parameter to pkcs7_verify() to select one of the following
restrictions and pass in the appropriate option from the callers:
(*) VERIFYING_MODULE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
forbids authattrs. sign-file sets CMS_NOATTR. We could be more
flexible and permit authattrs optionally, but only permit minimal
content.
(*) VERIFYING_FIRMWARE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
requires authattrs. In future, this will require an attribute
holding the target firmware name in addition to the minimal set.
(*) VERIFYING_UNSPECIFIED_SIGNATURE
This requires that the SignedData content type be pkcs7-data but
allows either no authattrs or only permits the minimal set.
(*) VERIFYING_KEXEC_PE_SIGNATURE
This only supports the Authenticode SPC_INDIRECT_DATA content type
and requires at least an SpcSpOpusInfo authattr in addition to the
minimal set. It also permits an SPC_STATEMENT_TYPE authattr (and
an S/MIME capabilities authattr because the pesign program doesn't
remove these).
(*) VERIFYING_KEY_SIGNATURE
(*) VERIFYING_KEY_SELF_SIGNATURE
These are invalid in this context but are included for later use
when limiting the use of X.509 certs.
(4) The pkcs7_test key type is given a module parameter to select between
the above options for testing purposes. For example:
echo 1 >/sys/module/pkcs7_test_key/parameters/usage
keyctl padd pkcs7_test foo @s </tmp/stuff.pkcs7
will attempt to check the signature on stuff.pkcs7 as if it contains a
firmware blob (1 being VERIFYING_FIRMWARE_SIGNATURE).
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Fix up the dependencies somewhat too, while we're at it.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Pull RCU changes from Paul E. McKenney:
- The combination of tree geometry-initialization simplifications
and OS-jitter-reduction changes to expedited grace periods.
These two are stacked due to the large number of conflicts
that would otherwise result.
[ With one addition, a temporary commit to silence a lockdep false
positive. Additional changes to the expedited grace-period
primitives (queued for 4.4) remove the cause of this false
positive, and therefore include a revert of this temporary commit. ]
- Documentation updates.
- Torture-test updates.
- Miscellaneous fixes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The "dl_boosted" flag is set by comparing *absolute* deadlines
(c.f., rt_mutex_setprio()).
Signed-off-by: Andrea Parri <parri.andrea@gmail.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>
Link: http://lkml.kernel.org/r/1438782979-9057-2-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The comment is "misleading"; fix it by adapting a comment from
push_rt_tasks().
Signed-off-by: Andrea Parri <parri.andrea@gmail.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>
Link: http://lkml.kernel.org/r/1438782979-9057-1-git-send-email-parri.andrea@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change the calling context of sched_class::set_cpus_allowed() such
that we can assume the task is inactive.
This allows us to easily make changes that affect accounting done by
enqueue/dequeue. This does in fact completely remove
set_cpus_allowed_rt() and greatly reduces set_cpus_allowed_dl().
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: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.667516139@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Give every class a set_cpus_allowed() method, this enables some small
optimization in the RT,DL implementation by avoiding a double
cpumask_weight() call.
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: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.614517487@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Because sched_setscheduler() checks p->flags & PF_NO_SETAFFINITY
without locks, a caller might observe an old value and race with the
set_cpus_allowed_ptr() call from __kthread_bind() and effectively undo
it:
__kthread_bind()
do_set_cpus_allowed()
<SYSCALL>
sched_setaffinity()
if (p->flags & PF_NO_SETAFFINITIY)
set_cpus_allowed_ptr()
p->flags |= PF_NO_SETAFFINITY
Fix the bug by putting everything under the regular scheduler locks.
This also closes a hole in the serialization of task_struct::{nr_,}cpus_allowed.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: juri.lelli@arm.com
Cc: mgorman@suse.de
Cc: riel@redhat.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20150515154833.545640346@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Current code ensures that a task has a normalized vruntime when switching away
from the fair class, but it does not ensure the task has a non-normalized
vruntime when switching back to the fair class.
This is an example breaking this consistency:
1. a task is in fair class and !queued
2. changes its class to RT class (still !queued)
3. changes its class to fair class again (still !queued)
Signed-off-by: Byungchul Park <byungchul.park@lge.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>
Link: http://lkml.kernel.org/r/1439197375-27927-1-git-send-email-byungchul.park@lge.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Systems which have all nodes at a distance of at most 1 hop should be
identified as 'NUMA_DIRECT'.
However, the scheduler incorrectly identifies it as 'NUMA_BACKPLANE'.
This is because 'n' is assigned to sched_max_numa_distance but the
code (mis)interprets it to mean 'number of hops'.
Rik had actually used sched_domains_numa_levels for detecting a
'NUMA_DIRECT' topology:
http://marc.info/?l=linux-kernel&m=141279712429834&w=2
But that was changed when he removed the hops table in the
subsequent version:
http://marc.info/?l=linux-kernel&m=141353106106771&w=2
Fixing the issue here.
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rik van Riel <riel@redhat.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/1439256048-3748-1-git-send-email-Aravind.Gopalakrishnan@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The qrwlock implementation is slightly heavy in its use of memory
barriers, mainly through the use of _cmpxchg() and _return() atomics, which
imply full barrier semantics.
This patch modifies the qrwlock code to use the more relaxed atomic
routines so that we can reduce the unnecessary barrier overhead on
weakly-ordered architectures.
Signed-off-by: Will Deacon <will.deacon@arm.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>
Cc: Waiman.Long@hp.com
Cc: paulmck@linux.vnet.ibm.com
Link: http://lkml.kernel.org/r/1438880084-18856-7-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A question [1] was raised about the use of page::private in AUX buffer
allocations, so let's add a clarification about its intended use.
The private field and flag are used by perf's rb_alloc_aux() path to
tell the pmu driver the size of each high-order allocation, so that the
driver can program those appropriately into its hardware. This only
matters for PMUs that don't support hardware scatter tables. Otherwise,
every page in the buffer is just a page.
This patch adds a comment about the private field to the AUX buffer
allocation path.
[1] http://marc.info/?l=linux-kernel&m=143803696607968
Reported-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@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/1438063204-665-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I ran the perf fuzzer, which triggered some WARN()s which are due to
trying to stop/restart an event on the wrong CPU.
Use the normal IPI pattern to ensure we run the code on the correct CPU.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bad7192b84 ("perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If rb->aux_refcount is decremented to zero before rb->refcount,
__rb_free_aux() may be called twice resulting in a double free of
rb->aux_pages. Fix this by adding a check to __rb_free_aux().
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 57ffc5ca67 ("perf: Fix AUX buffer refcounting")
Link: http://lkml.kernel.org/r/1437953468.12842.17.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
By extending the filter rules by more generic fields
we can write triggers filters like
echo 'stacktrace if cpu == 1' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
or
echo 'stacktrace if comm == sshd' > \
/sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger
CPU and COMM are not part of struct trace_entry. We could add the two
new fields to ftrace_common_field list and fix up all depending
sides. But that looks pretty ugly. Another thing I would like to
avoid that the 'format' file contents changes.
All this can be avoided by introducing another list which contains
non field members of struct trace_entry.
Link: http://lkml.kernel.org/r/1439210146-24707-1-git-send-email-daniel.wagner@bmw-carit.de
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
region_is_ram() is used to prevent the establishment of aliased mappings
to physical "System RAM" with incompatible cache settings. However, it
uses "-1" to indicate both "unknown" memory ranges (ranges not described
by platform firmware) and "mixed" ranges (where the parameters describe
a range that partially overlaps "System RAM").
Fix this up by explicitly tracking the "unknown" vs "mixed" resource
cases and returning REGION_INTERSECTS, REGION_MIXED, or REGION_DISJOINT.
This re-write also adds support for detecting when the requested region
completely eclipses all of a resource. Note, the implementation treats
overlaps between "unknown" and the requested memory type as
REGION_INTERSECTS.
Finally, other memory types can be passed in by name, for now the only
usage "System RAM".
Suggested-by: Luis R. Rodriguez <mcgrof@suse.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The comment says it's using trialcs->mems_allowed as a temp variable but
it didn't match the code. Change the code to match the comment.
This fixes an issue when writing in cpuset.mems when a sub-directory
exists: we need to write several times for the information to persist:
| root@alban:/sys/fs/cgroup/cpuset# mkdir footest9
| root@alban:/sys/fs/cgroup/cpuset# cd footest9
| root@alban:/sys/fs/cgroup/cpuset/footest9# mkdir aa
| root@alban:/sys/fs/cgroup/cpuset/footest9# cat cpuset.mems
|
| root@alban:/sys/fs/cgroup/cpuset/footest9# echo 0 > cpuset.mems
| root@alban:/sys/fs/cgroup/cpuset/footest9# cat cpuset.mems
|
| root@alban:/sys/fs/cgroup/cpuset/footest9# echo 0 > cpuset.mems
| root@alban:/sys/fs/cgroup/cpuset/footest9# cat cpuset.mems
| 0
| root@alban:/sys/fs/cgroup/cpuset/footest9# cat aa/cpuset.mems
|
| root@alban:/sys/fs/cgroup/cpuset/footest9# echo 0 > aa/cpuset.mems
| root@alban:/sys/fs/cgroup/cpuset/footest9# cat aa/cpuset.mems
| 0
| root@alban:/sys/fs/cgroup/cpuset/footest9#
This should help to fix the following issue in Docker:
https://github.com/opencontainers/runc/issues/133
In some conditions, a Docker container needs to be started twice in
order to work.
Signed-off-by: Alban Crequy <alban@endocode.com>
Tested-by: Iago López Galeiras <iago@endocode.com>
Cc: <stable@vger.kernel.org> # 3.17+
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Migrate broadcast-hrtimer driver to the new 'set-state' interface
provided by clockevents core, the earlier 'set-mode' interface is marked
obsolete now.
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
According to the perf_event_map_fd and index, the function
bpf_perf_event_read() can convert the corresponding map
value to the pointer to struct perf_event and return the
Hardware PMU counter value.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce a new bpf map type 'BPF_MAP_TYPE_PERF_EVENT_ARRAY'.
This map only stores the pointer to struct perf_event. The
user space event FDs from perf_event_open() syscall are converted
to the pointer to struct perf_event and stored in map.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All the map backends are of generic nature. In order to avoid
adding much special code into the eBPF core, rewrite part of
the bpf_prog_array map code and make it more generic. So the
new perf_event_array map type can reuse most of code with
bpf_prog_array map and add fewer lines of special code.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch add three core perf APIs:
- perf_event_attrs(): export the struct perf_event_attr from struct
perf_event;
- perf_event_get(): get the struct perf_event from the given fd;
- perf_event_read_local(): read the events counters active on the
current CPU;
These APIs are needed when accessing events counters in eBPF programs.
The API perf_event_read_local() comes from Peter and I add the
corresponding SOB.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Let the user explicitly provide a file containing trusted keys, instead of
just automatically finding files matching *.x509 in the build tree and
trusting whatever we find. This really ought to be an *explicit*
configuration, and the build rules for dealing with the files were
fairly painful too.
Fix applied from James Morris that removes an '=' from a macro definition
in kernel/Makefile as this is a feature that only exists from GNU make 3.82
onwards.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
The current rule for generating signing_key.priv and signing_key.x509 is
a classic example of a bad rule which has a tendency to break parallel
make. When invoked to create *either* target, it generates the other
target as a side-effect that make didn't predict.
So let's switch to using a single file signing_key.pem which contains
both key and certificate. That matches what we do in the case of an
external key specified by CONFIG_MODULE_SIG_KEY anyway, so it's also
slightly cleaner.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Where an external PEM file or PKCS#11 URI is given, we can get the cert
from it for ourselves instead of making the user drop signing_key.x509
in place for us.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Extract the function that drives the PKCS#7 signature verification given a
data blob and a PKCS#7 blob out from the module signing code and lump it with
the system keyring code as it's generic. This makes it independent of module
config options and opens it to use by the firmware loader.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
system_keyring.c doesn't need to #include module-internal.h as it doesn't use
the one thing that exports. Remove the inclusion.
Signed-off-by: David Howells <dhowells@redhat.com>
Move to using PKCS#7 messages as module signatures because:
(1) We have to be able to support the use of X.509 certificates that don't
have a subjKeyId set. We're currently relying on this to look up the
X.509 certificate in the trusted keyring list.
(2) PKCS#7 message signed information blocks have a field that supplies the
data required to match with the X.509 certificate that signed it.
(3) The PKCS#7 certificate carries fields that specify the digest algorithm
used to generate the signature in a standardised way and the X.509
certificates specify the public key algorithm in a standardised way - so
we don't need our own methods of specifying these.
(4) We now have PKCS#7 message support in the kernel for signed kexec purposes
and we can make use of this.
To make this work, the old sign-file script has been replaced with a program
that needs compiling in a previous patch. The rules to build it are added
here.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
s,critiera,criteria,
While at it, add a comma, because it makes sense grammatically.
Signed-off-by: Frans Klaver <fransklaver@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
The s-Par visornic driver, currently in staging, processes a queue being
serviced by the an s-Par service partition. We can get a message that
something has happened with the Service Partition, when that happens, we
must not access the channel until we get a message that the service
partition is back again.
The visornic driver has a thread for processing the channel, when we get
the message, we need to be able to park the thread and then resume it
when the problem clears.
We can do this with kthread_park and unpark but they are not exported
from the kernel, this patch exports the needed functions.
Signed-off-by: David Kershner <david.kershner@unisys.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Weinberger <richard.weinberger@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function may copy the si_addr_lsb, si_lower and si_upper fields to
user mode when they haven't been initialized, which can leak kernel
stack data to user mode.
Just checking the value of si_code is insufficient because the same
si_code value is shared between multiple signals. This is solved by
checking the value of si_signo in addition to si_code.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function can leak kernel stack data when the user siginfo_t has a
positive si_code value. The top 16 bits of si_code descibe which fields
in the siginfo_t union are active, but they are treated inconsistently
between copy_siginfo_from_user32, copy_siginfo_to_user32 and
copy_siginfo_to_user.
copy_siginfo_from_user32 is called from rt_sigqueueinfo and
rt_tgsigqueueinfo in which the user has full control overthe top 16 bits
of si_code.
This fixes the following information leaks:
x86: 8 bytes leaked when sending a signal from a 32-bit process to
itself. This leak grows to 16 bytes if the process uses x32.
(si_code = __SI_CHLD)
x86: 100 bytes leaked when sending a signal from a 32-bit process to
a 64-bit process. (si_code = -1)
sparc: 4 bytes leaked when sending a signal from a 32-bit process to a
64-bit process. (si_code = any)
parsic and s390 have similar bugs, but they are not vulnerable because
rt_[tg]sigqueueinfo have checks that prevent sending a positive si_code
to a different process. These bugs are also fixed for consistency.
Signed-off-by: Amanieu d'Antras <amanieu@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Paul Mackerras <paulus@samba.org>
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>
This adds the ability audit the actions of a not-yet-running process.
This patch implements the ability to filter on the executable path. Instead of
just hard coding the ino and dev of the executable we care about at the moment
the rule is inserted into the kernel, use the new audit_fsnotify
infrastructure to manage this dynamically. This means that if the filename
does not yet exist but the containing directory does, or if the inode in
question is unlinked and creat'd (aka updated) the rule will just continue to
work. If the containing directory is moved or deleted or the filesystem is
unmounted, the rule is deleted automatically. A future enhancement would be to
have the rule survive across directory disruptions.
This is a heavily modified version of a patch originally submitted by Eric
Paris with some ideas from Peter Moody.
Cc: Peter Moody <peter@hda3.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: minor whitespace clean to satisfy ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
This is to be used to audit by executable path rules, but audit watches should
be able to share this code eventually.
At the moment the audit watch code is a lot more complex. That code only
creates one fsnotify watch per parent directory. That 'audit_parent' in
turn has a list of 'audit_watches' which contain the name, ino, dev of
the specific object we care about. This just creates one fsnotify watch
per object we care about. So if you watch 100 inodes in /etc this code
will create 100 fsnotify watches on /etc. The audit_watch code will
instead create 1 fsnotify watch on /etc (the audit_parent) and then 100
individual watches chained from that fsnotify mark.
We should be able to convert the audit_watch code to do one fsnotify
mark per watch and simplify things/remove a whole lot of code. After
that conversion we should be able to convert the audit_fsnotify code to
support that hierarchy if the optimization is necessary.
Move the access to the entry for audit_match_signal() to the beginning of
the audit_del_rule() function in case the entry found is the same one passed
in. This will enable it to be used by audit_autoremove_mark_rule(),
kill_rules() and audit_remove_parent_watches().
This is a heavily modified and merged version of two patches originally
submitted by Eric Paris.
Cc: Peter Moody <peter@hda3.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: added a space after a declaration to keep ./scripts/checkpatch happy]
Signed-off-by: Paul Moore <pmoore@redhat.com>
Clean up a number of places were casted magic numbers are used to represent
unset inode and device numbers in preparation for the audit by executable path
patch set.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: enclosed the _UNSET macros in parentheses for ./scripts/checkpatch]
Signed-off-by: Paul Moore <pmoore@redhat.com>
By copying BPF related operation to uprobe processing path, this patch
allow users attach BPF programs to uprobes like what they are already
doing on kprobes.
After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a
uprobe perf event. Which make it possible to profile user space programs
and kernel events together using BPF.
Because of this patch, CONFIG_BPF_EVENTS should be selected by
CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if
KPROBE_EVENT is not set.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
cpu_chain lost its __cpuinitdata annotation long ago in commit
5c113fbeed ("fix cpu_chain section mismatch..."). This and the global
__cpuinit annotation drop in v3.11 vanished the need to mark all users,
including transitive ones, with the __ref annotation. Just get rid of it
to not wrongly hide section mismatches.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move the access to the entry for audit_match_signal() to earlier in the
function in case the entry found is the same one passed in. This will enable
it to be used by audit_remove_mark_rule().
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: tweaked subject line as it no longer made sense after multiple revs]
Signed-off-by: Paul Moore <pmoore@redhat.com>
While cgroup subsystems can't be modules, blkcg supports dynamically
loadable policies which interact with cgroup core. Export
cgrp_dfl_root so that cgroup_on_dfl() can be used in those modules.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Hyper-V module needs to disable cpu hotplug (offlining) as there is no
support from hypervisor side to reassign already opened event channels
to a different CPU. Currently it is been done by altering
smp_ops.cpu_disable but it is hackish.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As a prerequisite to exporting cpu_hotplug_enable/cpu_hotplug_disable
functions to modules we need to convert cpu_hotplug_disabled to a counter
to properly support disable -> disable -> enable call sequences. E.g.
after Hyper-V vmbus module (which is supposed to be the first user of
exported cpu_hotplug_enable/cpu_hotplug_disable) did cpu_hotplug_disable()
hibernate path calls disable_nonboot_cpus() and if we hit an error in
_cpu_down() enable_nonboot_cpus() will be called on the failure path (thus
making cpu_hotplug_disabled = 0 and leaving cpu hotplug in 'enabled'
state). Same problem is possible if more than 1 module use
cpu_hotplug_disable/cpu_hotplug_enable on their load/unload paths. When
one of these modules is been unloaded it is logical to leave cpu hotplug
in 'disabled' state.
To support the change we need to increse cpu_hotplug_disabled counter
in disable_nonboot_cpus() unconditionally as all users of
disable_nonboot_cpus() are supposed to do enable_nonboot_cpus() in case
an error was returned.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As reported by the 0-Day testing service:
kernel/auditfilter.c: In function 'audit_rule_change':
>> kernel/auditfilter.c:864:6: warning: 'err' may be used uninit...
int err;
Cc: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
The audit watch parent count was imbalanced, adding an unnecessary layer of
watch parent references. Decrement the additional parent reference when a
watch is reused, already having a reference to the parent.
audit_find_parent() gets a reference to the parent, if the parent is
already known. This additional parental reference is not needed if the
watch is subsequently found by audit_add_to_parent(), and consumed if
the watch does not already exist, so we need to put the parent if the
watch is found, and do nothing if this new watch is added to the parent.
If the parent wasn't already known, it is created with a refcount of 1
and added to the audit_watch_group, then incremented by one to be
subsequently consumed by the newly created watch in
audit_add_to_parent().
The rule points to the watch, not to the parent, so the rule's refcount
gets bumped, not the parent's.
See LKML, 2015-07-16
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
The audit watch count was imbalanced, adding an unnecessary layer of watch
references. Only add the second reference when it is added to a parent.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Commit 37b1ef31a5 ("workqueue: move
flush_scheduled_work() to workqueue.h") moved the exported non GPL
flush_scheduled_work() from a function to an inline wrapper.
Unfortunately, it directly calls flush_workqueue() which is a GPL function.
This has the effect of changing the licensing requirement for this function
and makes it unavailable to non GPL modules.
See commit ad7b1f841f ("workqueue: Make
schedule_work() available again to non GPL modules") for precedent.
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
RCU is the only thing that uses smp_mb__after_unlock_lock(), and is
likely the only thing that ever will use it, so this commit makes this
macro private to RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
In a CONFIG_PREEMPT=y kernel, synchronize_rcu_expedited()
acquires the ->exp_funnel_mutex in rcu_preempt_state, then invokes
synchronize_sched_expedited, which acquires the ->exp_funnel_mutex in
rcu_sched_state. There can be no deadlock because rcu_preempt_state
->exp_funnel_mutex acquisition always precedes that of rcu_sched_state.
But lockdep does not know that, so it gives false-positive splats.
This commit therefore associates a separate lock_class_key structure
with the rcu_sched_state structure's ->exp_funnel_mutex, allowing
lockdep to see the lock ordering, avoiding the false positives.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, the PT driver zeroes out the status register every time before
starting the event. However, all the writable bits are already taken care
of in pt_handle_status() function, except the new PacketByteCnt field,
which in new versions of PT contains the number of packet bytes written
since the last sync (PSB) packet. Zeroing it out before enabling PT forces
a sync packet to be written. This means that, with the existing code, a
sync packet (PSB and PSBEND, 18 bytes in total) will be generated every
time a PT event is scheduled in.
To avoid these unnecessary syncs and save a WRMSR in the fast path, this
patch changes the default behavior to not clear PacketByteCnt field, so
that the sync packets will be generated with the period specified as
"psb_period" attribute config field. This has little impact on the trace
data as the other packets that are normally sent within PSB+ (between PSB
and PSBEND) have their own generation scenarios which do not depend on the
sync packets.
One exception where we do need to force PSB like this when tracing starts,
so that the decoder has a clear sync point in the trace. For this purpose
we aready have hw::itrace_started flag, which we are currently using to
output PERF_RECORD_ITRACE_START. This patch moves setting itrace_started
from perf core to the pmu::start, where it should still be 0 on the very
first run.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.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>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1438264104-16189-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Code on the kprobe blacklist doesn't want unexpected int3
exceptions. It probably doesn't want unexpected debug exceptions
either. Be safe: disallow breakpoints in nokprobes code.
On non-CONFIG_KPROBES kernels, there is no kprobe blacklist. In
that case, disallow kernel breakpoints entirely.
It will be particularly important to keep hw breakpoints out of the
entry and NMI code once we move debug exceptions off the IST stack.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported that the fasync signal stuff doesn't work proper for
inherited events. So fix that.
Installing fasync allocates memory and sets filp->f_flags |= FASYNC,
which upon the demise of the file descriptor ensures the allocation is
freed and state is updated.
Now for perf, we can have the events stick around for a while after the
original FD is dead because of references from child events. So we
cannot copy the fasync pointer around. We can however consistently use
the parent's fasync, as that will be updated.
Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho deMelo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It does not make much sense to call idr_preload with the same gfp mask
as the following idr_alloc, but this is what we do in cgroup_idr_alloc.
This patch fixes the idr_preload usage by making cgroup_idr_alloc call
idr_alloc w/o __GFP_WAIT. Since it is now safe to call cgroup_idr_alloc
with GFP_KERNEL, the patch also fixes all its callers appropriately.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The cfs_rq's load_avg is composed of runnable_load_avg and blocked_load_avg.
Before this series, sometimes the runnable_load_avg is used, and sometimes
the load_avg is used. Completely replacing all uses of runnable_load_avg
with load_avg may be too big a leap, i.e., the blocked_load_avg is concerned
to result in overrated load. Therefore, we get runnable_load_avg back.
The new cfs_rq's runnable_load_avg is improved to be updated with all of the
runnable sched_eneities at the same time, so the one sched_entity updated and
the others stale problem is solved.
Signed-off-by: Yuyang Du <yuyang.du@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: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan@linux.intel.com
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: fengguang.wu@intel.com
Cc: len.brown@intel.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: rafael.j.wysocki@intel.com
Cc: umgwanakikbuti@gmail.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1436918682-4971-7-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The idea of runnable load average (let runnable time contribute to weight)
was proposed by Paul Turner and Ben Segall, and it is still followed by
this rewrite. This rewrite aims to solve the following issues:
1. cfs_rq's load average (namely runnable_load_avg and blocked_load_avg) is
updated at the granularity of an entity at a time, which results in the
cfs_rq's load average is stale or partially updated: at any time, only
one entity is up to date, all other entities are effectively lagging
behind. This is undesirable.
To illustrate, if we have n runnable entities in the cfs_rq, as time
elapses, they certainly become outdated:
t0: cfs_rq { e1_old, e2_old, ..., en_old }
and when we update:
t1: update e1, then we have cfs_rq { e1_new, e2_old, ..., en_old }
t2: update e2, then we have cfs_rq { e1_old, e2_new, ..., en_old }
...
We solve this by combining all runnable entities' load averages together
in cfs_rq's avg, and update the cfs_rq's avg as a whole. This is based
on the fact that if we regard the update as a function, then:
w * update(e) = update(w * e) and
update(e1) + update(e2) = update(e1 + e2), then
w1 * update(e1) + w2 * update(e2) = update(w1 * e1 + w2 * e2)
therefore, by this rewrite, we have an entirely updated cfs_rq at the
time we update it:
t1: update cfs_rq { e1_new, e2_new, ..., en_new }
t2: update cfs_rq { e1_new, e2_new, ..., en_new }
...
2. cfs_rq's load average is different between top rq->cfs_rq and other
task_group's per CPU cfs_rqs in whether or not blocked_load_average
contributes to the load.
The basic idea behind runnable load average (the same for utilization)
is that the blocked state is taken into account as opposed to only
accounting for the currently runnable state. Therefore, the average
should include both the runnable/running and blocked load averages.
This rewrite does that.
In addition, we also combine runnable/running and blocked averages
of all entities into the cfs_rq's average, and update it together at
once. This is based on the fact that:
update(runnable) + update(blocked) = update(runnable + blocked)
This significantly reduces the code as we don't need to separately
maintain/update runnable/running load and blocked load.
3. How task_group entities' share is calculated is complex and imprecise.
We reduce the complexity in this rewrite to allow a very simple rule:
the task_group's load_avg is aggregated from its per CPU cfs_rqs's
load_avgs. Then group entity's weight is simply proportional to its
own cfs_rq's load_avg / task_group's load_avg. To illustrate,
if a task_group has { cfs_rq1, cfs_rq2, ..., cfs_rqn }, then,
task_group_avg = cfs_rq1_avg + cfs_rq2_avg + ... + cfs_rqn_avg, then
cfs_rqx's entity's share = cfs_rqx_avg / task_group_avg * task_group's share
To sum up, this rewrite in principle is equivalent to the current one, but
fixes the issues described above. Turns out, it significantly reduces the
code complexity and hence increases clarity and efficiency. In addition,
the new averages are more smooth/continuous (no spurious spikes and valleys)
and updated more consistently and quickly to reflect the load dynamics.
As a result, we have less load tracking overhead, better performance,
and especially better power efficiency due to more balanced load.
Signed-off-by: Yuyang Du <yuyang.du@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: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan@linux.intel.com
Cc: bsegall@google.com
Cc: dietmar.eggemann@arm.com
Cc: fengguang.wu@intel.com
Cc: len.brown@intel.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: rafael.j.wysocki@intel.com
Cc: umgwanakikbuti@gmail.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1436918682-4971-3-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cpu_stop_park() does cpu_stop_signal_done() but leaves the work on
stopper->works. The owner of this work can free/reuse this memory
right after that and corrupt the list, so if this CPU becomes online
again cpu_stopper_thread() will crash.
Signed-off-by: Oleg Nesterov <oleg@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: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: paulmck@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: viro@ZenIV.linux.org.uk
Link: http://lkml.kernel.org/r/20150630012958.GA23944@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cosmetic, but 'cpu_stop_fn_t' actually makes the code more readable and
it doesn't break cscope. And most of the declarations already use it.
Signed-off-by: Oleg Nesterov <oleg@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: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: paulmck@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: viro@ZenIV.linux.org.uk
Link: http://lkml.kernel.org/r/20150630012955.GA23937@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The only caller outside of stop_machine.c is _cpu_down(), it can use
stop_machine(). get_online_cpus() is fine under cpu_hotplug_begin().
Signed-off-by: Oleg Nesterov <oleg@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: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: paulmck@linux.vnet.ibm.com
Cc: riel@redhat.com
Cc: viro@ZenIV.linux.org.uk
Link: http://lkml.kernel.org/r/20150630012951.GA23934@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Josef Bacik reported that Facebook sees better performance with their
1:N load (1 dispatch/node, N workers/node) when carrying an old patch
to try very hard to wake to an idle CPU. While looking at wake_wide(),
I noticed that it doesn't pay attention to the wakeup of a many partner
waker, returning 1 only when waking one of its many partners.
Correct that, letting explicit domain flags override the heuristic.
While at it, adjust task_struct bits, we don't need a 64-bit counter.
Tested-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
[ Tidy things up. ]
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: kernel-team<Kernel-team@fb.com>
Cc: morten.rasmussen@arm.com
Cc: riel@redhat.com
Link: http://lkml.kernel.org/r/1436888390.7983.49.camel@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mathieu reported that since 317f394160 ("sched: Move the second half
of ttwu() to the remote cpu") trace_sched_wakeup() can happen out of
context of the waker.
This is a problem when you want to analyse wakeup paths because it is
now very hard to correlate the wakeup event to whoever issued the
wakeup.
OTOH trace_sched_wakeup() is issued at the point where we set
p->state = TASK_RUNNING, which is right were we hand the task off to
the scheduler, so this is an important point when looking at
scheduling behaviour, up to here its been the wakeup path everything
hereafter is due to scheduler policy.
To bridge this gap, introduce a second tracepoint: trace_sched_waking.
It is guaranteed to be called in the waker context.
Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Francis Giraldeau <francis.giraldeau@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.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>
Link: http://lkml.kernel.org/r/20150609091336.GQ3644@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While the current code guarantees monotonicity for stime and utime
independently of one another, it does not guarantee that the sum of
both is equal to the total time we started out with.
This confuses things (and peoples) who look at this sum, like top, and
will report >100% usage followed by a matching period of 0%.
Rework the code to provide both individual monotonicity and a coherent
sum.
Suggested-by: Fredrik Markstrom <fredrik.markstrom@gmail.com>
Reported-by: Fredrik Markstrom <fredrik.markstrom@gmail.com>
Tested-by: Fredrik Markstrom <fredrik.markstrom@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.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: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jason.low2@hp.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The unregister_sysctl_table() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
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/5597877E.3060503@users.sourceforge.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
'p' has been already queued at this point, so "!task_running(rq, p)"
and "p->nr_cpus_allowed > 1" imply that "has_pushable_dl_tasks(rq)"
is true, so it can be removed.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Juri Lelli <juri.lelli@gmail.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/1435995563-3723-2-git-send-email-xlpang@126.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
'p' has been already queued at this point, so "!task_running(rq, p)"
and "p->nr_cpus_allowed > 1" imply that "has_pushable_tasks(rq)" is
true, so it can be removed.
Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Juri Lelli <juri.lelli@gmail.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/1435995563-3723-1-git-send-email-xlpang@126.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In idle balancing where a CPU going idle pulls tasks from another CPU,
a livelock may happen if the CPU pulls all tasks from another, makes
it idle, and this iterates. So just avoid this.
Reported-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Ben Segall <bsegall@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Morten Rasmussen <morten.rasmussen@arm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150705221151.GF5197@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a little selftest that validates all combinations.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
There are various problems and short-comings with the current
static_key interface:
- static_key_{true,false}() read like a branch depending on the key
value, instead of the actual likely/unlikely branch depending on
init value.
- static_key_{true,false}() are, as stated above, tied to the
static_key init values STATIC_KEY_INIT_{TRUE,FALSE}.
- we're limited to the 2 (out of 4) possible options that compile to
a default NOP because that's what our arch_static_branch() assembly
emits.
So provide a new static_key interface:
DEFINE_STATIC_KEY_TRUE(name);
DEFINE_STATIC_KEY_FALSE(name);
Which define a key of different types with an initial true/false
value.
Then allow:
static_branch_likely()
static_branch_unlikely()
to take a key of either type and emit the right instruction for the
case.
This means adding a second arch_static_branch_jump() assembly helper
which emits a JMP per default.
In order to determine the right instruction for the right state,
encode the branch type in the LSB of jump_entry::key.
This is the final step in removing the naming confusion that has led to
a stream of avoidable bugs such as:
a833581e37 ("x86, perf: Fix static_key bug in load_mm_cr4()")
... but it also allows new static key combinations that will give us
performance enhancements in the subsequent patches.
Tested-by: Rabin Vincent <rabin@rab.in> # arm
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # ppc
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
Instead of spreading the branch_default logic all over the place,
concentrate it into the one jump_label_type() function.
This does mean we need to actually increment/decrement the enabled
count _before_ calling the update path, otherwise jump_label_type()
will not see the right state.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
Add two helpers to make it easier to treat the refcount as boolean.
Suggested-by: Jason Baron <jasonbaron0@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
Avoid some casting with a helper, also prepares the way for
overloading the LSB of jump_entry::key.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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>
Rename the JUMP_LABEL_TYPE_* macros to be JUMP_TYPE_* and move the
inline helpers into kernel/jump_label.c, since that's the only place
they're ever used.
Also rename the helpers where it's all about static keys.
This is the second step in removing the naming confusion that has led to
a stream of avoidable bugs such as:
a833581e37 ("x86, perf: Fix static_key bug in load_mm_cr4()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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 we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.
This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.
This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:
a833581e37 ("x86, perf: Fix static_key bug in load_mm_cr4()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Upcoming changes to static keys is interacting/conflicting with the following
pending TSC commits in tip:x86/asm:
4ea1636b04 x86/asm/tsc: Rename native_read_tsc() to rdtsc()
...
So merge it into the locking tree to have a smoother resolution.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For an over-committed guest with more vCPUs than physical CPUs
available, it is possible that a vCPU may be kicked twice before
getting the lock - once before it becomes queue head and once again
before it gets the lock. All these CPU kicking and halting (VMEXIT)
can be expensive and slow down system performance.
This patch adds a new vCPU state (vcpu_hashed) which enables the code
to delay CPU kicking until at unlock time. Once this state is set,
the new lock holder will set _Q_SLOW_VAL and fill in the hash table
on behalf of the halted queue head vCPU. The original vcpu_halted
state will be used by pv_wait_node() only to differentiate other
queue nodes from the qeue head.
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1436647018-49734-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, a reader will check first to make sure that the writer mode
byte is cleared before incrementing the reader count. That waiting is
not really necessary. It increases the latency in the reader/writer
to reader transition and reduces readers performance.
This patch eliminates that waiting. It also has the side effect
of reducing the chance of writer lock stealing and improving the
fairness of the lock. Using a locking microbenchmark, a 10-threads 5M
locking loop of mostly readers (RW ratio = 10,000:1) has the following
performance numbers in a Haswell-EX box:
Kernel Locking Rate (Kops/s)
------ ---------------------
4.1.1 15,063,081
4.1.1+patch 17,241,552 (+14.4%)
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1436459543-29126-2-git-send-email-Waiman.Long@hp.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we unlock in __pv_queued_spin_unlock(), a failed cmpxchg() on the lock
value indicates that we need to take the slow-path and unhash the
corresponding node blocked on the lock.
Since a failed cmpxchg() does not provide any memory-ordering guarantees,
it is possible that the node data could be read before the cmpxchg() on
weakly-ordered architectures and therefore return a stale value, leading
to hash corruption and/or a BUG().
This patch adds an smb_rmb() following the failed cmpxchg operation, so
that the unhashing is ordered after the lock has been checked.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
[ Added more comments]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <Waiman.Long@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steve Capper <Steve.Capper@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150713155830.GL2632@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Rename the on-stack variable to match the datastructure variable,
- place the cmpxchg back under the comment that explains it,
- clean up the WARN() statement to avoid superfluous conditionals
and line-breaks.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Conflicts:
arch/s390/net/bpf_jit_comp.c
drivers/net/ethernet/ti/netcp_ethss.c
net/bridge/br_multicast.c
net/ipv4/ip_fragment.c
All four conflicts were cases of simple overlapping
changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
The Linux kernel suspend path has traditionally invoked sys_sync()
before freezing user threads.
But sys_sync() can be expensive, and some user-space OS's do not want
the kernel to pay the cost of sys_sync() on every suspend -- preferring
invoke sync() from user-space if/when they want it.
So make sys_sync on suspend build-time optional.
The default is unchanged.
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The modify_ldt syscall exposes a large attack surface and is
unnecessary for modern userspace. Make it optional.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org <security@kernel.org>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/a605166a771c343fd64802dece77a903507333bd.1438291540.git.luto@kernel.org
[ Made MATH_EMULATION dependent on MODIFY_LDT_SYSCALL. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The xol_free_insn_slot()->waitqueue_active() check is buggy. We
need mb() after we set the conditon for wait_event(), or
xol_take_insn_slot() can miss the wakeup.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134036.GA4799@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change xol_add_vma() to use _install_special_mapping(), this way
we can name the vma installed by uprobes. Currently it looks
like private anonymous mapping, this is confusing and
complicates the debugging. With this change /proc/$pid/maps
reports "[uprobes]".
As a side effect this will cause core dumps to include the XOL vma
and I think this is good; this can help to debug the problem if
the app crashed because it was probed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134033.GA4796@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
install_special_mapping(pages) expects that "pages" is the zero-
terminated array while xol_add_vma() passes &area->page, this
means that special_mapping_fault() can wrongly use the next
member in xol_area (vaddr) as "struct page *".
Fortunately, this area is not expandable so pgoff != 0 isn't
possible (modulo bugs in special_mapping_vmops), but still this
does not look good.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134031.GA4789@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The previous change documents that cleanup_return_instances()
can't always detect the dead frames, the stack can grow. But
there is one special case which imho worth fixing:
arch_uretprobe_is_alive() can return true when the stack didn't
actually grow, but the next "call" insn uses the already
invalidated frame.
Test-case:
#include <stdio.h>
#include <setjmp.h>
jmp_buf jmp;
int nr = 1024;
void func_2(void)
{
if (--nr == 0)
return;
longjmp(jmp, 1);
}
void func_1(void)
{
setjmp(jmp);
func_2();
}
int main(void)
{
func_1();
return 0;
}
If you ret-probe func_1() and func_2() prepare_uretprobe() hits
the MAX_URETPROBE_DEPTH limit and "return" from func_2() is not
reported.
When we know that the new call is not chained, we can do the
more strict check. In this case "sp" points to the new ret-addr,
so every frame which uses the same "sp" must be dead. The only
complication is that arch_uretprobe_is_alive() needs to know was
it chained or not, so we add the new RP_CHECK_CHAIN_CALL enum
and change prepare_uretprobe() to pass RP_CHECK_CALL only if
!chained.
Note: arch_uretprobe_is_alive() could also re-read *sp and check
if this word is still trampoline_vaddr. This could obviously
improve the logic, but I would like to avoid another
copy_from_user() especially in the case when we can't avoid the
false "alive == T" positives.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134028.GA4786@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86 doesn't care (so far), but as Pratyush Anand pointed
out other architectures might want why arch_uretprobe_is_alive()
was called and use different checks depending on the context.
Add the new argument to distinguish 2 callers.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134026.GA4779@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change prepare_uretprobe() to flush the !arch_uretprobe_is_alive()
return_instance's. This is not needed correctness-wise, but can help
to avoid the failure caused by MAX_URETPROBE_DEPTH.
Note: in this case arch_uretprobe_is_alive() can be false
positive, the stack can grow after longjmp(). Unfortunately, the
kernel can't 100% solve this problem, but see the next patch.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134023.GA4776@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Test-case:
#include <stdio.h>
#include <setjmp.h>
jmp_buf jmp;
void func_2(void)
{
longjmp(jmp, 1);
}
void func_1(void)
{
if (setjmp(jmp))
return;
func_2();
printf("ERR!! I am running on the caller's stack\n");
}
int main(void)
{
func_1();
return 0;
}
fails if you probe func_1() and func_2() because
handle_trampoline() assumes that the probed function should must
return and hit the bp installed be prepare_uretprobe(). But in
this case func_2() does not return, so when func_1() returns the
kernel uses the no longer valid return_instance of func_2().
Change handle_trampoline() to unwind ->return_instances until we
know that the next chain is alive or NULL, this ensures that the
current chain is the last we need to report and free.
Alternatively, every return_instance could use unique
trampoline_vaddr, in this case we could use it as a key. And
this could solve the problem with sigaltstack() automatically.
But this approach needs more changes, and it puts the "hard"
limit on MAX_URETPROBE_DEPTH. Plus it can not solve another
problem partially fixed by the next patch.
Note: this change has no effect on !x86, the arch-agnostic
version of arch_uretprobe_is_alive() just returns "true".
TODO: as documented by the previous change, arch_uretprobe_is_alive()
can be fooled by sigaltstack/etc.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134021.GA4773@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the x86 specific version of arch_uretprobe_is_alive()
helper. It returns true if the stack frame mangled by
prepare_uretprobe() is still on stack. So if it returns false,
we know that the probed function has already returned.
We add the new return_instance->stack member and change the
generic code to initialize it in prepare_uretprobe, but it
should be equally useful for other architectures.
TODO: this assumes that the probed application can't use
multiple stacks (say sigaltstack). We will try to improve
this logic later.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134018.GA4766@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the new "weak" helper, arch_uretprobe_is_alive(), used by
the next patches. It should return true if this return_instance
is still valid. The arch agnostic version just always returns
true.
The patch exports "struct return_instance" for the architectures
which want to override this hook. We can also cleanup
prepare_uretprobe() if we pass the new return_instance to
arch_uretprobe_hijack_return_addr().
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134016.GA4762@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
No functional changes, preparation.
Add the new helper, find_next_ret_chain(), which finds the first
!chained entry and returns its ->next. Yes, it is suboptimal. We
probably want to turn ->chained into ->start_of_this_chain
pointer and avoid another loop. But this needs the boring
changes in dup_utask(), so lets do this later.
Change the main loop in handle_trampoline() to unwind the stack
until ri is equal to the pointer returned by this new helper.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134013.GA4755@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Turn the last pr_warn() in uprobes.c into uprobe_warn().
While at it:
- s/kzalloc/kmalloc, we initialize every member of 'ri'
- remove the pointless comment above the obvious code
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134010.GA4752@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. It doesn't make sense to continue if handle_trampoline()
fails, change handle_swbp() to always return after this call.
2. Turn pr_warn() into uprobe_warn(), and change
handle_trampoline() to send SIGILL on failure. It is pointless to
return to user mode with the corrupted instruction_pointer() which
we can't restore.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134008.GA4745@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We can simplify uprobe_free_utask() and handle_uretprobe_chain()
if we add a simple helper which does put_uprobe/kfree and
returns the ->next return_instance.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134006.GA4740@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cosmetic. Add the new trivial helper, get_uprobe(). It matches
put_uprobe() we already have and we can simplify a couple of its
users.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.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/20150721134003.GA4736@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
It is not uncommon (at least with the ARM stuff) to have a piece
of hardware that implements different flavours of "interrupts".
A typical example of this is the GICv3 ITS, which implements
standard PCI/MSI support, but also some form of "generic MSI".
So far, the PCI/MSI domain is registered using the ITS device_node,
so that irq_find_host can return it. On the contrary, the raw MSI
domain is not registered with an device_node, making it impossible
to be looked up by another subsystem (obviously, using the same
device_node twice would only result in confusion, as it is not
defined which one irq_find_host would return).
A solution to this is to "type" domains that may be aliasing, and
to be able to lookup an device_node that matches a given type.
For this, we introduce irq_find_matching_host() as a superset
of irq_find_host:
struct irq_domain *irq_find_matching_host(struct device_node *node,
enum irq_domain_bus_token bus_token);
where bus_token is the "type" we want to match the domain against
(so far, only DOMAIN_BUS_ANY is defined). This result in some
moderately invasive changes on the PPC side (which is the only
user of the .match method).
This has otherwise no functionnal change.
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Yijing Wang <wangyijing@huawei.com>
Cc: Ma Jun <majun258@huawei.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1438091186-10244-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The following warning is emitted for make xmldocs:
Warning(.//kernel/irq/chip.c:1009): No description found for parameter 'vcpu_info'
Warning(.//kernel/irq/chip.c:1009): Excess function parameter 'dest' description in 'irq_chip_set_vcpu_affinity_parent'
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Link: http://lkml.kernel.org/r/1438164576-5945-1-git-send-email-standby24x7@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Currently we have two different ways to signal an I/O error on a BIO:
(1) by clearing the BIO_UPTODATE flag
(2) by returning a Linux errno value to the bi_end_io callback
The first one has the drawback of only communicating a single possible
error (-EIO), and the second one has the drawback of not beeing persistent
when bios are queued up, and are not passed along from child to parent
bio in the ever more popular chaining scenario. Having both mechanisms
available has the additional drawback of utterly confusing driver authors
and introducing bugs where various I/O submitters only deal with one of
them, and the others have to add boilerplate code to deal with both kinds
of error returns.
So add a new bi_error field to store an errno value directly in struct
bio and remove the existing mechanisms to clean all this up.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
