task_will_free_mem() is wrong in many ways, and in particular the
SIGNAL_GROUP_COREDUMP check is not reliable: a task can participate in the
coredumping without SIGNAL_GROUP_COREDUMP bit set.
change zap_threads() paths to always set SIGNAL_GROUP_COREDUMP even if
other CLONE_VM processes can't react to SIGKILL. Fortunately, at least
oom-kill case if fine; it kills all tasks sharing the same mm, so it
should also kill the process which actually dumps the core.
The change in prepare_signal() is not strictly necessary, it just ensures
that the patch does not bring another subtle behavioural change. But it
reminds us that this SIGNAL_GROUP_EXIT/COREDUMP case needs more changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Kyle Walker <kwalker@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Stanislav Kozina <skozina@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is hardly possible to enumerate all problems with block_all_signals()
and unblock_all_signals(). Just for example,
1. block_all_signals(SIGSTOP/etc) simply can't help if the caller is
multithreaded. Another thread can dequeue the signal and force the
group stop.
2. Even is the caller is single-threaded, it will "stop" anyway. It
will not sleep, but it will spin in kernel space until SIGCONT or
SIGKILL.
And a lot more. In short, this interface doesn't work at all, at least
the last 10+ years.
Daniel said:
Yeah the only times I played around with the DRM_LOCK stuff was when
old drivers accidentally deadlocked - my impression is that the entire
DRM_LOCK thing was never really tested properly ;-) Hence I'm all for
purging where this leaks out of the drm subsystem.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Dave Airlie <airlied@redhat.com>
Cc: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following statement of ABI/testing/dev-kmsg is not quite right:
It is not possible to inject messages from userspace with the
facility number LOG_KERN (0), to make sure that the origin of the
messages can always be reliably determined.
Userland actually can inject messages with a facility of 0 by abusing the
fact that the facility is stored in a u8 data type. By using a facility
which is a multiple of 256 the assignment of msg->facility in log_store()
implicitly truncates it to 0, i.e. LOG_KERN, allowing users of /dev/kmsg
to spoof kernel messages as shown below:
The following call...
# printf '<%d>Kernel panic - not syncing: beer empty\n' 0 >/dev/kmsg
...leads to the following log entry (dmesg -x | tail -n 1):
user :emerg : [ 66.137758] Kernel panic - not syncing: beer empty
However, this call...
# printf '<%d>Kernel panic - not syncing: beer empty\n' 0x800 >/dev/kmsg
...leads to the slightly different log entry (note the kernel facility):
kern :emerg : [ 74.177343] Kernel panic - not syncing: beer empty
Fix that by limiting the user provided facility to 8 bit right from the
beginning and catch the truncation early.
Fixes: 7ff9554bb5 ("printk: convert byte-buffer to variable-length...")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Alex Elder <elder@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the param_free_charp() function from static to exported.
It is used by zswap in the next patch ("zswap: use charp for zswap param
strings").
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep. Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep. The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__GFP_WAIT has been used to identify atomic context in callers that hold
spinlocks or are in interrupts. They are expected to be high priority and
have access one of two watermarks lower than "min" which can be referred
to as the "atomic reserve". __GFP_HIGH users get access to the first
lower watermark and can be called the "high priority reserve".
Over time, callers had a requirement to not block when fallback options
were available. Some have abused __GFP_WAIT leading to a situation where
an optimisitic allocation with a fallback option can access atomic
reserves.
This patch uses __GFP_ATOMIC to identify callers that are truely atomic,
cannot sleep and have no alternative. High priority users continue to use
__GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and
are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify
callers that want to wake kswapd for background reclaim. __GFP_WAIT is
redefined as a caller that is willing to enter direct reclaim and wake
kswapd for background reclaim.
This patch then converts a number of sites
o __GFP_ATOMIC is used by callers that are high priority and have memory
pools for those requests. GFP_ATOMIC uses this flag.
o Callers that have a limited mempool to guarantee forward progress clear
__GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall
into this category where kswapd will still be woken but atomic reserves
are not used as there is a one-entry mempool to guarantee progress.
o Callers that are checking if they are non-blocking should use the
helper gfpflags_allow_blocking() where possible. This is because
checking for __GFP_WAIT as was done historically now can trigger false
positives. Some exceptions like dm-crypt.c exist where the code intent
is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to
flag manipulations.
o Callers that built their own GFP flags instead of starting with GFP_KERNEL
and friends now also need to specify __GFP_KSWAPD_RECLAIM.
The first key hazard to watch out for is callers that removed __GFP_WAIT
and was depending on access to atomic reserves for inconspicuous reasons.
In some cases it may be appropriate for them to use __GFP_HIGH.
The second key hazard is callers that assembled their own combination of
GFP flags instead of starting with something like GFP_KERNEL. They may
now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless
if it's missed in most cases as other activity will wake kswapd.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
stable tags to them. I searched through my INBOX just as the merge window
opened and found lots of patches to pull. I ran them through all my tests
and they were in linux-next for a few days.
Features added this release:
----------------------------
o Module globbing. You can now filter function tracing to several
modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)
o Tracer specific options are now visible even when the tracer is not
active. It was rather annoying that you can only see and modify tracer
options after enabling the tracer. Now they are in the options/ directory
even when the tracer is not active. Although they are still only visible
when the tracer is active in the trace_options file.
o Trace options are now per instance (although some of the tracer specific
options are global)
o New tracefs file: set_event_pid. If any pid is added to this file, then
all events in the instance will filter out events that are not part of
this pid. sched_switch and sched_wakeup events handle next and the wakee
pids.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQEcBAABAgAGBQJWPLQ5AAoJEKKk/i67LK/8CTYIAI1u8DE5QCzv3J0p54jVpNVR
J5FqEU3eXIzd6FS4JXD4nxCeMpUZAy21YnhlZpsnrbJJM5bc9bUsBCwiKKM+MuSZ
ztmy2sgYKkO0h/KUdhNgYJrzis3/Ojquyx9iAqK5ST/Fr+nKYx81akFKjNK53iur
RJRut45sSa8rv11LaL8sgJ6hAWQTc+YkybUdZ5xaMdJmZ6A61T7Y6VzTjbUexuvL
hntCfTjYLtVd8dbfknAnf3B7n/VOO3IFF85wr7ciYR5oEVfPrF8tHmJBlhHExPpX
kaXAiDDRY/UTg/5DQqnp4zmxJoR5BQ2l4pT5PwiLcnwhcphIDNYS8EYUmOYAWjU=
=TjOE
-----END PGP SIGNATURE-----
Merge tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracking updates from Steven Rostedt:
"Most of the changes are clean ups and small fixes. Some of them have
stable tags to them. I searched through my INBOX just as the merge
window opened and found lots of patches to pull. I ran them through
all my tests and they were in linux-next for a few days.
Features added this release:
----------------------------
- Module globbing. You can now filter function tracing to several
modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov)
- Tracer specific options are now visible even when the tracer is not
active. It was rather annoying that you can only see and modify
tracer options after enabling the tracer. Now they are in the
options/ directory even when the tracer is not active. Although
they are still only visible when the tracer is active in the
trace_options file.
- Trace options are now per instance (although some of the tracer
specific options are global)
- New tracefs file: set_event_pid. If any pid is added to this file,
then all events in the instance will filter out events that are not
part of this pid. sched_switch and sched_wakeup events handle next
and the wakee pids"
* tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits)
tracefs: Fix refcount imbalance in start_creating()
tracing: Put back comma for empty fields in boot string parsing
tracing: Apply tracer specific options from kernel command line.
tracing: Add some documentation about set_event_pid
ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark
tracing: Allow dumping traces without tracking trace started cpus
ring_buffer: Fix more races when terminating the producer in the benchmark
ring_buffer: Do no not complete benchmark reader too early
tracing: Remove redundant TP_ARGS redefining
tracing: Rename max_stack_lock to stack_trace_max_lock
tracing: Allow arch-specific stack tracer
recordmcount: arm64: Replace the ignored mcount call into nop
recordmcount: Fix endianness handling bug for nop_mcount
tracepoints: Fix documentation of RCU lockdep checks
tracing: ftrace_event_is_function() can return boolean
tracing: is_legal_op() can return boolean
ring-buffer: rb_event_is_commit() can return boolean
ring-buffer: rb_per_cpu_empty() can return boolean
ring_buffer: ring_buffer_empty{cpu}() can return boolean
ring-buffer: rb_is_reader_page() can return boolean
...
Currently tracing_init_dentry() returns -ENODEV when debugfs is not
configured in, which causes tracefs not populated with tracing files and
directories, so we will get an empty directory even after we manually
mount tracefs.
We can make tracing_init_dentry() return NULL if debugfs is not
configured in and can manually mount tracefs. But return -ENODEV
if debugfs is configured in but not initialized or failed to create
automount point as that would break backward compatibility with older
tools.
Link: http://lkml.kernel.org/r/1446797056-11683-1-git-send-email-hello.wjx@gmail.com
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Merge patch-bomb from Andrew Morton:
- inotify tweaks
- some ocfs2 updates (many more are awaiting review)
- various misc bits
- kernel/watchdog.c updates
- Some of mm. I have a huge number of MM patches this time and quite a
lot of it is quite difficult and much will be held over to next time.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
selftests: vm: add tests for lock on fault
mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage
mm: introduce VM_LOCKONFAULT
mm: mlock: add new mlock system call
mm: mlock: refactor mlock, munlock, and munlockall code
kasan: always taint kernel on report
mm, slub, kasan: enable user tracking by default with KASAN=y
kasan: use IS_ALIGNED in memory_is_poisoned_8()
kasan: Fix a type conversion error
lib: test_kasan: add some testcases
kasan: update reference to kasan prototype repo
kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile
kasan: various fixes in documentation
kasan: update log messages
kasan: accurately determine the type of the bad access
kasan: update reported bug types for kernel memory accesses
kasan: update reported bug types for not user nor kernel memory accesses
mm/kasan: prevent deadlock in kasan reporting
mm/kasan: don't use kasan shadow pointer in generic functions
mm/kasan: MODULE_VADDR is not available on all archs
...
The cost of faulting in all memory to be locked can be very high when
working with large mappings. If only portions of the mapping will be used
this can incur a high penalty for locking.
For the example of a large file, this is the usage pattern for a large
statical language model (probably applies to other statical or graphical
models as well). For the security example, any application transacting in
data that cannot be swapped out (credit card data, medical records, etc).
This patch introduces the ability to request that pages are not
pre-faulted, but are placed on the unevictable LRU when they are finally
faulted in. The VM_LOCKONFAULT flag will be used together with VM_LOCKED
and has no effect when set without VM_LOCKED. Setting the VM_LOCKONFAULT
flag for a VMA will cause pages faulted into that VMA to be added to the
unevictable LRU when they are faulted or if they are already present, but
will not cause any missing pages to be faulted in.
Exposing this new lock state means that we cannot overload the meaning of
the FOLL_POPULATE flag any longer. Prior to this patch it was used to
mean that the VMA for a fault was locked. This means we need the new
FOLL_MLOCK flag to communicate the locked state of a VMA. FOLL_POPULATE
will now only control if the VMA should be populated and in the case of
VM_LOCKONFAULT, it will not be set.
Signed-off-by: Eric B Munson <emunson@akamai.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the refactored mlock code, introduce a new system call for mlock.
The new call will allow the user to specify what lock states are being
added. mlock2 is trivial at the moment, but a follow on patch will add a
new mlock state making it useful.
Signed-off-by: Eric B Munson <emunson@akamai.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The oom killer takes task_lock() in a couple of places solely to protect
printing the task's comm.
A process's comm, including current's comm, may change due to
/proc/pid/comm or PR_SET_NAME.
The comm will always be NULL-terminated, so the worst race scenario would
only be during update. We can tolerate a comm being printed that is in
the middle of an update to avoid taking the lock.
Other locations in the kernel have already dropped task_lock() when
printing comm, so this is consistent.
Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Theoretically it is possible that the watchdog timer expires right at the
time when a user sets 'watchdog_thresh' to zero (note: this disables the
lockup detectors). In this scenario, the is_softlockup() function - which
is called by the timer - could produce a false positive.
Fix this by checking the current value of 'watchdog_thresh'.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
watchdog_{park|unpark}_threads() are now called in code paths that protect
themselves against CPU hotplug, so {get|put}_online_cpus() calls are
redundant and can be removed.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The handler functions for watchdog parameters in /proc/sys/kernel do not
protect themselves against races with CPU hotplug. Hence, theoretically
it is possible that a new watchdog thread is started on a hotplugged CPU
while a parameter is being modified, and the thread could thus use a
parameter value that is 'in transition'.
For example, if 'watchdog_thresh' is being set to zero (note: this
disables the lockup detectors) the thread would erroneously use the value
zero as the sample period.
To avoid such races and to keep the /proc handler code consistent,
call
{get|put}_online_cpus() in proc_watchdog_common()
{get|put}_online_cpus() in proc_watchdog_thresh()
{get|put}_online_cpus() in proc_watchdog_cpumask()
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The lockup detector suspend/resume interface that was introduced by
commit 8c073d27d7 ("watchdog: introduce watchdog_suspend() and
watchdog_resume()") does not protect itself against races with CPU
hotplug. Hence, theoretically it is possible that a new watchdog thread
is started on a hotplugged CPU while the lockup detector is suspended,
and the thread could thus interfere unexpectedly with the code that
requested to suspend the lockup detector.
Avoid the race by calling
get_online_cpus() in lockup_detector_suspend()
put_online_cpus() in lockup_detector_resume()
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The only way to enable a hardlockup to panic the machine is to set
'nmi_watchdog=panic' on the kernel command line.
This makes it awkward for end users and folks who want to run automate
tests (like myself).
Mimic the softlockup_panic knob and create a /proc/sys/kernel/hardlockup_panic
knob.
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In many cases of hardlockup reports, it's actually not possible to know
why it triggered, because the CPU that got stuck is usually waiting on a
resource (with IRQs disabled) in posession of some other CPU is holding.
IOW, we are often looking at the stacktrace of the victim and not the
actual offender.
Introduce sysctl / cmdline parameter that makes it possible to have
hardlockup detector perform all-CPU backtrace.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If kthread_park() returns an error, watchdog_park_threads() should not
blindly 'roll back' the already parked threads to the unparked state.
Instead leave it up to the callers to handle such errors appropriately in
their context. For example, it is redundant to unpark the threads if the
lockup detectors will soon be disabled by the callers anyway.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
update_watchdog_all_cpus() now passes errors from watchdog_park_threads()
up to functions in the call chain. This allows watchdog_enable_all_cpus()
and proc_watchdog_update() to handle such errors too.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move watchdog_disable_all_cpus() outside of the ifdef so that it is
available if CONFIG_SYSCTL is not defined. This is preparation for
"watchdog: implement error handling in update_watchdog_all_cpus() and
callers".
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The original watchdog_park_threads() function that was introduced by
commit 81a4beef91 ("watchdog: introduce watchdog_park_threads() and
watchdog_unpark_threads()") takes a very simple approach to handle
errors returned by kthread_park(): It attempts to roll back all watchdog
threads to the unparked state. However, this may be undesired behaviour
from the perspective of the caller which may want to handle errors as
appropriate in its specific context. Currently, there are two possible
call chains:
- watchdog suspend/resume interface
lockup_detector_suspend
watchdog_park_threads
- write to parameters in /proc/sys/kernel
proc_watchdog_update
watchdog_enable_all_cpus
update_watchdog_all_cpus
watchdog_park_threads
Instead of 'blindly' attempting to unpark the watchdog threads if a
kthread_park() call fails, the new approach is to disable the lockup
detectors in the above call chains. Failure becomes visible to the user
as follows:
- error messages from lockup_detector_suspend()
or watchdog_enable_all_cpus()
- the state that can be read from /proc/sys/kernel/watchdog_enabled
- the 'write' system call in the latter call chain returns an error
I did not experience kthread_park() failures in practice, I used some
instrumentation to fake error returns from kthread_park() in order to test
the patches.
This patch (of 5):
Restore the previous value of watchdog_thresh _and_ sample_period if
proc_watchdog_update() returns an error. The variables must be consistent
to avoid false positives of the lockup detectors.
Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make is_hardlockup return bool to improve readability due to this
particular function only using either one or zero as its return value.
No functional change.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
handling.
PPC: Mostly bug fixes.
ARM: No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite for
IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86: quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new component (in
virt/lib/) that connects VFIO and KVM together. The same infrastructure
will be used for ARM interrupt forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic interrupt
controller will have to wait for 4.5. These will let KVM expose Hyper-V
devices.
- nested virtualization now supports VPID (same as PCID but for vCPUs)
which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for clflushopt,
clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
userspace, which reduces the attack surface of the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten to not
require help from the hypervisor.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
iQEcBAABAgAGBQJWO2IQAAoJEL/70l94x66D/K0H/3AovAgYmJQToZlimsktMk6a
f2xhdIqfU5lIQQh5uNBCfL3o9o8H9Py1ym7aEw3fmztPHHJYc91oTatt2UEKhmEw
VtZHp/dFHt3hwaIdXmjRPEXiYctraKCyrhaUYdWmUYkoKi7lW5OL5h+S7frG2U6u
p/hFKnHRZfXHr6NSgIqvYkKqtnc+C0FWY696IZMzgCksOO8jB1xrxoSN3tANW3oJ
PDV+4og0fN/Fr1capJUFEc/fejREHneANvlKrLaa8ht0qJQutoczNADUiSFLcMPG
iHljXeDsv5eyjMtUuIL8+MPzcrIt/y4rY41ZPiKggxULrXc6H+JJL/e/zThZpXc=
=iv2z
-----END PGP SIGNATURE-----
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"First batch of KVM changes for 4.4.
s390:
A bunch of fixes and optimizations for interrupt and time handling.
PPC:
Mostly bug fixes.
ARM:
No big features, but many small fixes and prerequisites including:
- a number of fixes for the arch-timer
- introducing proper level-triggered semantics for the arch-timers
- a series of patches to synchronously halt a guest (prerequisite
for IRQ forwarding)
- some tracepoint improvements
- a tweak for the EL2 panic handlers
- some more VGIC cleanups getting rid of redundant state
x86:
Quite a few changes:
- support for VT-d posted interrupts (i.e. PCI devices can inject
interrupts directly into vCPUs). This introduces a new
component (in virt/lib/) that connects VFIO and KVM together.
The same infrastructure will be used for ARM interrupt
forwarding as well.
- more Hyper-V features, though the main one Hyper-V synthetic
interrupt controller will have to wait for 4.5. These will let
KVM expose Hyper-V devices.
- nested virtualization now supports VPID (same as PCID but for
vCPUs) which makes it quite a bit faster
- for future hardware that supports NVDIMM, there is support for
clflushopt, clwb, pcommit
- support for "split irqchip", i.e. LAPIC in kernel +
IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
the hypervisor
- obligatory smattering of SMM fixes
- on the guest side, stable scheduler clock support was rewritten
to not require help from the hypervisor"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
KVM: VMX: Fix commit which broke PML
KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
KVM: x86: allow RSM from 64-bit mode
KVM: VMX: fix SMEP and SMAP without EPT
KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
KVM: device assignment: remove pointless #ifdefs
KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
KVM: x86: zero apic_arb_prio on reset
drivers/hv: share Hyper-V SynIC constants with userspace
KVM: x86: handle SMBASE as physical address in RSM
KVM: x86: add read_phys to x86_emulate_ops
KVM: x86: removing unused variable
KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
KVM: arm/arm64: Optimize away redundant LR tracking
KVM: s390: use simple switch statement as multiplexer
KVM: s390: drop useless newline in debugging data
KVM: s390: SCA must not cross page boundaries
KVM: arm: Do not indent the arguments of DECLARE_BITMAP
...
Pull security subsystem update from James Morris:
"This is mostly maintenance updates across the subsystem, with a
notable update for TPM 2.0, and addition of Jarkko Sakkinen as a
maintainer of that"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits)
apparmor: clarify CRYPTO dependency
selinux: Use a kmem_cache for allocation struct file_security_struct
selinux: ioctl_has_perm should be static
selinux: use sprintf return value
selinux: use kstrdup() in security_get_bools()
selinux: use kmemdup in security_sid_to_context_core()
selinux: remove pointless cast in selinux_inode_setsecurity()
selinux: introduce security_context_str_to_sid
selinux: do not check open perm on ftruncate call
selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default
KEYS: Merge the type-specific data with the payload data
KEYS: Provide a script to extract a module signature
KEYS: Provide a script to extract the sys cert list from a vmlinux file
keys: Be more consistent in selection of union members used
certs: add .gitignore to stop git nagging about x509_certificate_list
KEYS: use kvfree() in add_key
Smack: limited capability for changing process label
TPM: remove unnecessary little endian conversion
vTPM: support little endian guests
char: Drop owner assignment from i2c_driver
...
Pull audit updates from Paul Moore:
"Seven audit patches for 4.4, but really only one of any significant
value, the remainder are trivial cleanups that are described well
enough in the patch descriptions.
The one significant patch is an attempt to make communication between
the kernel's audit subsystem and the userspace audit daemon a bit more
robust by retrying on certain transient error conditions. All in all,
it's a pretty small set of patches this time around with just fixes
and cleanups"
* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
audit: make audit_log_common_recv_msg() a void function
audit: removing unused variable
audit: fix comment block whitespace
audit: audit_tree_match can be boolean
audit: audit_string_contains_control can be boolean
audit: audit_dummy_context can be boolean
audit: try harder to send to auditd upon netlink failure
Pull cgroup updates from Tejun Heo:
"The cgroup core saw several significant updates this cycle:
- percpu_rwsem for threadgroup locking is reinstated. This was
temporarily dropped due to down_write latency issues. Oleg's
rework of percpu_rwsem which is scheduled to be merged in this
merge window resolves the issue.
- On the v2 hierarchy, when controllers are enabled and disabled, all
operations are atomic and can fail and revert cleanly. This allows
->can_attach() failure which is necessary for cpu RT slices.
- Tasks now stay associated with the original cgroups after exit
until released. This allows tracking resources held by zombies
(e.g. pids) and makes it easy to find out where zombies came from
on the v2 hierarchy. The pids controller was broken before these
changes as zombies escaped the limits; unfortunately, updating this
behavior required too many invasive changes and I don't think it's
a good idea to backport them, so the pids controller on 4.3, the
first version which included the pids controller, will stay broken
at least until I'm sure about the cgroup core changes.
- Optimization of a couple common tests using static_key"
* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
cgroup: fix race condition around termination check in css_task_iter_next()
blkcg: don't create "io.stat" on the root cgroup
cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
cgroup: replace error handling in cgroup_init() with WARN_ON()s
cgroup: add cgroup_subsys->free() method and use it to fix pids controller
cgroup: keep zombies associated with their original cgroups
cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
cgroup: don't hold css_set_rwsem across css task iteration
cgroup: reorganize css_task_iter functions
cgroup: factor out css_set_move_task()
cgroup: keep css_set and task lists in chronological order
cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
cgroup: make css_sets pin the associated cgroups
cgroup: relocate cgroup_[try]get/put()
cgroup: move check_for_release() invocation
cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
cgroup: make cgroup->nr_populated count the number of populated css_sets
cgroup: remove an unused parameter from cgroup_task_migrate()
cgroup: fix too early usage of static_branch_disable()
cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
...
Pull workqueue update from Tejun Heo:
"This pull request contains one patch to make an unbound worker pool
allocated from the NUMA node containing it if such node exists. As
unbound worker pools are node-affine by default, this makes most pools
allocated on the right node"
* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Allocate the unbound pool using local node memory
backend drivers to be unloaded.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
iQIcBAABAgAGBQJWN9nyAAoJEKurIx+X31iBlSQQALBEB5pwkCEBcJlXa1SL1uRN
WFOUhoNI6Rh1Wlsu6t0P9AhtotCHUeSRtF+Y05EXcytBb1EqsW90fk4m7VFDFuCp
drDYPJhNaFcvxDkt1PKKGRysGLXsCjr5szuApCFpYwg3FaxqddXTfFdZ7zdWaRb2
NkUd+aSElNr1avrulgyTqHjWFCP93bWMh6tFhUjCRjwmXDhxvHxLtlRUMtPlsgrC
nWuawkyrR31EJJoQ9lnvEQBjP6i5qSMfU+2o6nUm6/5LNe/m9iWDxmWakoa7p8e4
XArywFijO18byvjsvaJhUOLzLV0TT+PoL14m5U7JP0JA9mtpCYNvnb62CWmFulM2
Q75FGdfj2UQOnwMnaBpYPNC6S/ddLtl0iWGivgI3ja47xG9TGzEYmTrObt9LfVzd
kv1Nw/dNUY0fTb+n7rPBkpyHKO9ZQPQSebDOU7MJ61uuS/QB/sEbk2gU7HsV/Q68
ivOvy1zui9ggpPOuApqQTVi/OCHtb+TJep2+U5O8NR6DFY/bhQCH6g8mPaMKU5G0
6HF0kwx4h905VHWiP4I0EphmrDWVvpFMUgZoHgi3CCdmbm64+BPXYa6AiJ3I00Ed
FstB7pYuwsJ8jsYhxRVVSEW7vKZQ+jS5tzbLBjuTYe+KfBLFm7A5OdBHmhpXug0k
zw4kssZrm30mCpWR90ew
=liJx
-----END PGP SIGNATURE-----
Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull pstore updates from Tony Luck:
"Half dozen small cleanups plus change to allow pstore backend drivers
to be unloaded"
* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
pstore: fix code comment to match code
efi-pstore: fix kernel-doc argument name
pstore: Fix return type of pstore_is_mounted()
pstore: add pstore unregister
pstore: add a helper function pstore_register_kmsg
pstore: add vmalloc error check
Here's the "big" driver core updates for 4.4-rc1. Primarily a bunch of
debugfs updates, with a smattering of minor driver core fixes and
updates as well.
All have been in linux-next for a long time.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iEYEABECAAYFAlY6ePQACgkQMUfUDdst+ymNTgCgpP0CZw57GpwF/Hp2L/lMkVeo
Kx8AoKhEi4iqD5fdCQS9qTfomB+2/M6g
=g7ZO
-----END PGP SIGNATURE-----
Merge tag 'driver-core-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
"Here's the "big" driver core updates for 4.4-rc1. Primarily a bunch
of debugfs updates, with a smattering of minor driver core fixes and
updates as well.
All have been in linux-next for a long time"
* tag 'driver-core-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
debugfs: Add debugfs_create_ulong()
of: to support binding numa node to specified device in devicetree
debugfs: Add read-only/write-only bool file ops
debugfs: Add read-only/write-only size_t file ops
debugfs: Add read-only/write-only x64 file ops
debugfs: Consolidate file mode checks in debugfs_create_*()
Revert "mm: Check if section present during memory block (un)registering"
driver-core: platform: Provide helpers for multi-driver modules
mm: Check if section present during memory block (un)registering
devres: fix a for loop bounds check
CMA: fix CONFIG_CMA_SIZE_MBYTES overflow in 64bit
base/platform: assert that dev_pm_domain callbacks are called unconditionally
sysfs: correctly handle short reads on PREALLOC attrs.
base: soc: siplify ida usage
kobject: move EXPORT_SYMBOL() macros next to corresponding definitions
kobject: explain what kobject's sd field is
debugfs: document that debugfs_remove*() accepts NULL and error values
debugfs: Pass bool pointer to debugfs_create_bool()
ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'
Pull core block updates from Jens Axboe:
"This is the core block pull request for 4.4. I've got a few more
topic branches this time around, some of them will layer on top of the
core+drivers changes and will come in a separate round. So not a huge
chunk of changes in this round.
This pull request contains:
- Enable blk-mq page allocation tracking with kmemleak, from Catalin.
- Unused prototype removal in blk-mq from Christoph.
- Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
xchg()'s, from Davidlohr.
- A plug flush fix from Jeff.
- Also from Jeff, a fix that means we don't have to update shared tag
sets at init time unless we do a state change. This cuts down boot
times on thousands of devices a lot with scsi/blk-mq.
- blk-mq waitqueue barrier fix from Kosuke.
- Various fixes from Ming:
- Fixes for segment merging and splitting, and checks, for
the old core and blk-mq.
- Potential blk-mq speedup by marking ctx pending at the end
of a plug insertion batch in blk-mq.
- direct-io no page dirty on kernel direct reads.
- A WRITE_SYNC fix for mpage from Roman"
* 'for-4.4/core' of git://git.kernel.dk/linux-block:
blk-mq: avoid excessive boot delays with large lun counts
blktrace: re-write setting q->blk_trace
blk-mq: mark ctx as pending at batch in flush plug path
blk-mq: fix for trace_block_plug()
block: check bio_mergeable() early before merging
blk-mq: check bio_mergeable() early before merging
block: avoid to merge splitted bio
block: setup bi_phys_segments after splitting
block: fix plug list flushing for nomerge queues
blk-mq: remove unused blk_mq_clone_flush_request prototype
blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
block: kmemleak: Track the page allocations for struct request
- ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).
The most significant change is to allow the AML debugger to be
built into the kernel. On top of that there is an update related
to the NFIT table (the ACPI persistent memory interface)
and a few fixes and cleanups.
- ACPI CPPC2 (Collaborative Processor Performance Control v2)
support along with a cpufreq frontend (Ashwin Chaugule).
This can only be enabled on ARM64 at this point.
- New ACPI infrastructure for the early probing of IRQ chips and
clock sources (Marc Zyngier).
- Support for a new hierarchical properties extension of the ACPI
_DSD (Device Specific Data) device configuration object allowing
the kernel to handle hierarchical properties (provided by the
platform firmware this way) automatically and make them available
to device drivers via the generic device properties interface
(Rafael Wysocki).
- Generic device properties API extension to obtain an index of
certain string value in an array of strings, along the lines of
of_property_match_string(), but working for all of the supported
firmware node types, and support for the "dma-names" device
property based on it (Mika Westerberg).
- ACPI core fix to parse the MADT (Multiple APIC Description Table)
entries in the order expected by platform firmware (and mandated
by the specification) to avoid confusion on systems with more than
255 logical CPUs (Lukasz Anaczkowski).
- Consolidation of the ACPI-based handling of PCI host bridges
on x86 and ia64 (Jiang Liu).
- ACPI core fixes to ensure that the correct IRQ number is used to
represent the SCI (System Control Interrupt) in the cases when
it has been re-mapped (Chen Yu).
- New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).
- ACPI EC driver fixes (Lv Zheng).
- Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
Kosina, Rami Rosen, Rasmus Villemoes).
- New mechanism in the PM core allowing drivers to check if the
platform firmware is going to be involved in the upcoming system
suspend or if it has been involved in the suspend the system is
resuming from at the moment (Rafael Wysocki).
This should allow drivers to optimize their suspend/resume
handling in some cases and the changes include a couple of users
of it (the i8042 input driver, PCI PM).
- PCI PM fix to prevent runtime-suspended devices with PME enabled
from being resumed during system suspend even if they aren't
configured to wake up the system from sleep (Rafael Wysocki).
- New mechanism to report the number of a wakeup IRQ that woke up
the system from sleep last time (Alexandra Yates).
- Removal of unused interfaces from the generic power domains
framework and fixes related to latency measurements in that
code (Ulf Hansson, Daniel Lezcano).
- cpufreq core sysfs interface rework to make it handle CPUs that
share performance scaling settings (represented by a common
cpufreq policy object) more symmetrically (Viresh Kumar).
This should help to simplify the CPU offline/online handling among
other things.
- cpufreq core fixes and cleanups (Viresh Kumar).
- intel_pstate fixes related to the Turbo Activation Ratio (TAR)
mechanism on client platforms which causes the turbo P-states
range to vary depending on platform firmware settings (Srinivas
Pandruvada).
- intel_pstate sysfs interface fix (Prarit Bhargava).
- Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
Bhat, Luis de Bethencourt).
- cpuidle mvebu driver cleanups (Russell King).
- OPP (Operating Performance Points) framework code reorganization
to make it more maintainable (Viresh Kumar).
- Intel Broxton support for the RAPL (Running Average Power Limits)
power capping driver (Amy Wiles).
- Assorted power management code fixes and cleanups (Dan Carpenter,
Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
Villemoes).
/
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)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=1gaH
-----END PGP SIGNATURE-----
Merge tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI updates from Rafael Wysocki:
"Quite a new features are included this time.
First off, the Collaborative Processor Performance Control interface
(version 2) defined by ACPI will now be supported on ARM64 along with
a cpufreq frontend for CPU performance scaling.
Second, ACPI gets a new infrastructure for the early probing of IRQ
chips and clock sources (along the lines of the existing similar
mechanism for DT).
Next, the ACPI core and the generic device properties API will now
support a recently introduced hierarchical properties extension of the
_DSD (Device Specific Data) ACPI device configuration object. If the
ACPI platform firmware uses that extension to organize device
properties in a hierarchical way, the kernel will automatically handle
it and make those properties available to device drivers via the
generic device properties API.
It also will be possible to build the ACPICA's AML interpreter
debugger into the kernel now and use that to diagnose AML-related
problems more efficiently. In the future, this should make it
possible to single-step AML execution and do similar things.
Interesting stuff, although somewhat experimental at this point.
Finally, the PM core gets a new mechanism that can be used by device
drivers to distinguish between suspend-to-RAM (based on platform
firmware support) and suspend-to-idle (or other variants of system
suspend the platform firmware is not involved in) and possibly
optimize their device suspend/resume handling accordingly.
In addition to that, some existing features are re-organized quite
substantially.
First, the ACPI-based handling of PCI host bridges on x86 and ia64 is
unified and the common code goes into the ACPI core (so as to reduce
code duplication and eliminate non-essential differences between the
two architectures in that area).
Second, the Operating Performance Points (OPP) framework is
reorganized to make the code easier to find and follow.
Next, the cpufreq core's sysfs interface is reorganized to get rid of
the "primary CPU" concept for configurations in which the same
performance scaling settings are shared between multiple CPUs.
Finally, some interfaces that aren't necessary any more are dropped
from the generic power domains framework.
On top of the above we have some minor extensions, cleanups and bug
fixes in multiple places, as usual.
Specifics:
- ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng).
The most significant change is to allow the AML debugger to be
built into the kernel. On top of that there is an update related
to the NFIT table (the ACPI persistent memory interface) and a few
fixes and cleanups.
- ACPI CPPC2 (Collaborative Processor Performance Control v2) support
along with a cpufreq frontend (Ashwin Chaugule).
This can only be enabled on ARM64 at this point.
- New ACPI infrastructure for the early probing of IRQ chips and
clock sources (Marc Zyngier).
- Support for a new hierarchical properties extension of the ACPI
_DSD (Device Specific Data) device configuration object allowing
the kernel to handle hierarchical properties (provided by the
platform firmware this way) automatically and make them available
to device drivers via the generic device properties interface
(Rafael Wysocki).
- Generic device properties API extension to obtain an index of
certain string value in an array of strings, along the lines of
of_property_match_string(), but working for all of the supported
firmware node types, and support for the "dma-names" device
property based on it (Mika Westerberg).
- ACPI core fix to parse the MADT (Multiple APIC Description Table)
entries in the order expected by platform firmware (and mandated by
the specification) to avoid confusion on systems with more than 255
logical CPUs (Lukasz Anaczkowski).
- Consolidation of the ACPI-based handling of PCI host bridges on x86
and ia64 (Jiang Liu).
- ACPI core fixes to ensure that the correct IRQ number is used to
represent the SCI (System Control Interrupt) in the cases when it
has been re-mapped (Chen Yu).
- New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede).
- ACPI EC driver fixes (Lv Zheng).
- Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri
Kosina, Rami Rosen, Rasmus Villemoes).
- New mechanism in the PM core allowing drivers to check if the
platform firmware is going to be involved in the upcoming system
suspend or if it has been involved in the suspend the system is
resuming from at the moment (Rafael Wysocki).
This should allow drivers to optimize their suspend/resume handling
in some cases and the changes include a couple of users of it (the
i8042 input driver, PCI PM).
- PCI PM fix to prevent runtime-suspended devices with PME enabled
from being resumed during system suspend even if they aren't
configured to wake up the system from sleep (Rafael Wysocki).
- New mechanism to report the number of a wakeup IRQ that woke up the
system from sleep last time (Alexandra Yates).
- Removal of unused interfaces from the generic power domains
framework and fixes related to latency measurements in that code
(Ulf Hansson, Daniel Lezcano).
- cpufreq core sysfs interface rework to make it handle CPUs that
share performance scaling settings (represented by a common cpufreq
policy object) more symmetrically (Viresh Kumar).
This should help to simplify the CPU offline/online handling among
other things.
- cpufreq core fixes and cleanups (Viresh Kumar).
- intel_pstate fixes related to the Turbo Activation Ratio (TAR)
mechanism on client platforms which causes the turbo P-states range
to vary depending on platform firmware settings (Srinivas
Pandruvada).
- intel_pstate sysfs interface fix (Prarit Bhargava).
- Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes
and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G
Bhat, Luis de Bethencourt).
- cpuidle mvebu driver cleanups (Russell King).
- OPP (Operating Performance Points) framework code reorganization to
make it more maintainable (Viresh Kumar).
- Intel Broxton support for the RAPL (Running Average Power Limits)
power capping driver (Amy Wiles).
- Assorted power management code fixes and cleanups (Dan Carpenter,
Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus
Villemoes)"
* tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (108 commits)
cpufreq: postfix policy directory with the first CPU in related_cpus
cpufreq: create cpu/cpufreq/policyX directories
cpufreq: remove cpufreq_sysfs_{create|remove}_file()
cpufreq: create cpu/cpufreq at boot time
cpufreq: Use cpumask_copy instead of cpumask_or to copy a mask
cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate()
PM / Domains: Merge measurements for PM QoS device latencies
PM / Domains: Don't measure ->start|stop() latency in system PM callbacks
PM / clk: Fix broken build due to non-matching code and header #ifdefs
ACPI / Documentation: add copy_dsdt to ACPI format options
ACPI / sysfs: correctly check failing memory allocation
ACPI / video: Add a quirk to force native backlight on Lenovo IdeaPad S405
ACPI / CPPC: Fix potential memory leak
ACPI / CPPC: signedness bug in register_pcc_channel()
ACPI / PAD: power_saving_thread() is not freezable
ACPI / PM: Fix incorrect wakeup IRQ setting during suspend-to-idle
ACPI: Using correct irq when waiting for events
ACPI: Use correct IRQ when uninstalling ACPI interrupt handler
cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver
cpuidle: mvebu: clean up multiple platform drivers
...
- "genirq: Introduce generic irq migration for cpu hotunplugged" patch
merged from tip/irq/for-arm to allow the arm64-specific part to be
upstreamed via the arm64 tree
- CPU feature detection reworked to cope with heterogeneous systems
where CPUs may not have exactly the same features. The features
reported by the kernel via internal data structures or ELF_HWCAP are
delayed until all the CPUs are up (and before user space starts)
- Support for 16KB pages, with the additional bonus of a 36-bit VA
space, though the latter only depending on EXPERT
- Implement native {relaxed, acquire, release} atomics for arm64
- New ASID allocation algorithm which avoids IPI on roll-over, together
with TLB invalidation optimisations (using local vs global where
feasible)
- KASan support for arm64
- EFI_STUB clean-up and isolation for the kernel proper (required by
KASan)
- copy_{to,from,in}_user optimisations (sharing the memcpy template)
- perf: moving arm64 to the arm32/64 shared PMU framework
- L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware
- Support for the contiguous PTE hint on kernel mapping (16 consecutive
entries may be able to use a single TLB entry)
- Generic CONFIG_HZ now used on arm64
- defconfig updates
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=3six
-----END PGP SIGNATURE-----
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- "genirq: Introduce generic irq migration for cpu hotunplugged" patch
merged from tip/irq/for-arm to allow the arm64-specific part to be
upstreamed via the arm64 tree
- CPU feature detection reworked to cope with heterogeneous systems
where CPUs may not have exactly the same features. The features
reported by the kernel via internal data structures or ELF_HWCAP are
delayed until all the CPUs are up (and before user space starts)
- Support for 16KB pages, with the additional bonus of a 36-bit VA
space, though the latter only depending on EXPERT
- Implement native {relaxed, acquire, release} atomics for arm64
- New ASID allocation algorithm which avoids IPI on roll-over, together
with TLB invalidation optimisations (using local vs global where
feasible)
- KASan support for arm64
- EFI_STUB clean-up and isolation for the kernel proper (required by
KASan)
- copy_{to,from,in}_user optimisations (sharing the memcpy template)
- perf: moving arm64 to the arm32/64 shared PMU framework
- L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware
- Support for the contiguous PTE hint on kernel mapping (16 consecutive
entries may be able to use a single TLB entry)
- Generic CONFIG_HZ now used on arm64
- defconfig updates
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits)
arm64/efi: fix libstub build under CONFIG_MODVERSIONS
ARM64: Enable multi-core scheduler support by default
arm64/efi: move arm64 specific stub C code to libstub
arm64: page-align sections for DEBUG_RODATA
arm64: Fix build with CONFIG_ZONE_DMA=n
arm64: Fix compat register mappings
arm64: Increase the max granular size
arm64: remove bogus TASK_SIZE_64 check
arm64: make Timer Interrupt Frequency selectable
arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED
arm64: cachetype: fix definitions of ICACHEF_* flags
arm64: cpufeature: declare enable_cpu_capabilities as static
genirq: Make the cpuhotplug migration code less noisy
arm64: Constify hwcap name string arrays
arm64/kvm: Make use of the system wide safe values
arm64/debug: Make use of the system wide safe value
arm64: Move FP/ASIMD hwcap handling to common code
arm64/HWCAP: Use system wide safe values
arm64/capabilities: Make use of system wide safe value
arm64: Delay cpu feature capability checks
...
Regardless of the previous CPU a timer was on, add_timer_on()
currently simply sets timer->flags to the new CPU. As the caller must
be seeing the timer as idle, this is locally fine, but the timer
leaving the old base while unlocked can lead to race conditions as
follows.
Let's say timer was on cpu 0.
cpu 0 cpu 1
-----------------------------------------------------------------------------
del_timer(timer) succeeds
del_timer(timer)
lock_timer_base(timer) locks cpu_0_base
add_timer_on(timer, 1)
spin_lock(&cpu_1_base->lock)
timer->flags set to cpu_1_base
operates on @timer operates on @timer
This triggered with mod_delayed_work_on() which contains
"if (del_timer()) add_timer_on()" sequence eventually leading to the
following oops.
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff810ca6e9>] detach_if_pending+0x69/0x1a0
...
Workqueue: wqthrash wqthrash_workfunc [wqthrash]
task: ffff8800172ca680 ti: ffff8800172d0000 task.ti: ffff8800172d0000
RIP: 0010:[<ffffffff810ca6e9>] [<ffffffff810ca6e9>] detach_if_pending+0x69/0x1a0
...
Call Trace:
[<ffffffff810cb0b4>] del_timer+0x44/0x60
[<ffffffff8106e836>] try_to_grab_pending+0xb6/0x160
[<ffffffff8106e913>] mod_delayed_work_on+0x33/0x80
[<ffffffffa0000081>] wqthrash_workfunc+0x61/0x90 [wqthrash]
[<ffffffff8106dba8>] process_one_work+0x1e8/0x650
[<ffffffff8106e05e>] worker_thread+0x4e/0x450
[<ffffffff810746af>] kthread+0xef/0x110
[<ffffffff8185980f>] ret_from_fork+0x3f/0x70
Fix it by updating add_timer_on() to perform proper migration as
__mod_timer() does.
Reported-and-tested-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Worley <chris.worley@primarydata.com>
Cc: bfields@fieldses.org
Cc: Michael Skralivetsky <michael.skralivetsky@primarydata.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: kernel-team@fb.com
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20151029103113.2f893924@tlielax.poochiereds.net
Link: http://lkml.kernel.org/r/20151104171533.GI5749@mtj.duckdns.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull networking updates from David Miller:
Changes of note:
1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.
2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
David Ahern.
3) Allow the user to ask for the statistics to be filtered out of
ipv4/ipv6 address netlink dumps. From Sowmini Varadhan.
4) More work to pass the network namespace context around deep into
various packet path APIs, starting with the netfilter hooks. From
Eric W Biederman.
5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
Richter.
6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.
7) Support Very High Throughput in wireless MESH code, from Bob
Copeland.
8) Allow setting the ageing_time in switchdev/rocker. From Scott
Feldman.
9) Properly autoload L2TP type modules, from Stephen Hemminger.
10) Fix and enable offload features by default in 8139cp driver, from
David Woodhouse.
11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
Jiri Benc.
12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
Opstad.
13) Fix IPSEC flowcache overflows on large systems, from Steffen
Klassert.
14) Convert bridging to track VLANs using rhashtable entries rather than
a bitmap. From Nikolay Aleksandrov.
15) Make TCP listener handling completely lockless, this is a major
accomplishment. Incoming request sockets now live in the
established hash table just like any other socket too.
From Eric Dumazet.
15) Provide more bridging attributes to netlink, from Nikolay
Aleksandrov.
16) Use hash based algorithm for ipv4 multipath routing, this was very
long overdue. From Peter Nørlund.
17) Several y2038 cures, mostly avoiding timespec. From Arnd Bergmann.
18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.
19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet. This
influences the port binding selection logic used by SO_REUSEPORT.
20) Add ipv6 support to VRF, from David Ahern.
21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.
22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.
23) Implement RACK loss recovery in TCP, from Yuchung Cheng.
24) Support multipath routes in MPLS, from Roopa Prabhu.
25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
Dumazet.
26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
Sudarsana Kalluru.
27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
Sowa.
28) Support ipv6 geneve tunnels, from John W Linville.
29) Add flood control support to switchdev layer, from Ido Schimmel.
30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
Hannes Frederic Sowa.
31) Support persistent maps and progs in bpf, from Daniel Borkmann.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
sh_eth: use DMA barriers
switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
net: sched: kill dead code in sch_choke.c
irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
net: dsa: mv88e6xxx: include DSA ports in VLANs
net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
net/core: fix for_each_netdev_feature
vlan: Invoke driver vlan hooks only if device is present
arcnet/com20020: add LEDS_CLASS dependency
bpf, verifier: annotate verbose printer with __printf
dp83640: Only wait for timestamps for packets with timestamping enabled.
ptp: Change ptp_class to a proper bitmask
dp83640: Prune rx timestamp list before reading from it
dp83640: Delay scheduled work.
dp83640: Include hash in timestamp/packet matching
ipv6: fix tunnel error handling
net/mlx5e: Fix LSO vlan insertion
net/mlx5e: Re-eanble client vlan TX acceleration
net/mlx5e: Return error in case mlx5e_set_features() fails
net/mlx5e: Don't allow more than max supported channels
...
Variable rc in not required as it is just used for unchanged for return,
and return is always 0 in the function.
Signed-off-by: Saurabh Sengar <saurabh.truth@gmail.com>
[PM: fixed spelling errors in description]
Signed-off-by: Paul Moore <pmoore@redhat.com>
This patch makes audit_tree_match return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
[PM: tweaked the subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>
This patch makes audit_string_contains_control return bool to improve
readability due to this particular function only using either one or
zero as its return value.
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
[PM: tweaked subject line]
Signed-off-by: Paul Moore <pmoore@redhat.com>
There are several reports of the kernel losing contact with auditd when
it is, in fact, still running. When this happens, kernel syslogs show:
"audit: *NO* daemon at audit_pid=<pid>"
although auditd is still running, and is apparently happy, listening on
the netlink socket. The pid in the "*NO* daemon" message matches the pid
of the running auditd process. Restarting auditd solves this.
The problem appears to happen randomly, and doesn't seem to be strongly
correlated to the rate of audit events being logged. The problem
happens fairly regularly (every few days), but not yet reproduced to
order.
On production kernels, BUG_ON() is a no-op, so any error will trigger
this.
Commit 34eab0a7cd ("audit: prevent an older auditd shutdown from
orphaning a newer auditd startup") eliminates one possible cause. This
isn't the case here, since the PID in the error message and the PID of
the running auditd match.
The primary expected cause of error here is -ECONNREFUSED when the audit
daemon goes away, when netlink_getsockbyportid() can't find the auditd
portid entry in the netlink audit table (or there is no receive
function). If -EPERM is returned, that situation isn't likely to be
resolved in a timely fashion without administrator intervention. In
both cases, reset the audit_pid. This does not rule out a race
condition. SELinux is expected to return zero since this isn't an INET
or INET6 socket. Other LSMs may have other return codes. Log the error
code for better diagnosis in the future.
In the case of -ENOMEM, the situation could be temporary, based on local
or general availability of buffers. -EAGAIN should never happen since
the netlink audit (kernel) socket is set to MAX_SCHEDULE_TIMEOUT.
-ERESTARTSYS and -EINTR are not expected since this kernel thread is not
expected to receive signals. In these cases (or any other unexpected
ones for now), report the error and re-schedule the thread, retrying up
to 5 times.
v2:
Removed BUG_ON().
Moved comma in pr_*() statements.
Removed audit_strerror() text.
Reported-by: Vipin Rathor <v.rathor@gmail.com>
Reported-by: <ctcard@hotmail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: applied rgb's fixup patch to correct audit_log_lost() format issues]
Signed-off-by: Paul Moore <pmoore@redhat.com>
Both early_enable_events() and apply_trace_boot_options() parse a boot
string that may get parsed later on. They both use strsep() which converts a
comma into a nul character. To still allow the boot string to be parsed
again the same way, the nul character gets converted back to a comma after
the token is processed.
The problem is that these two functions check for an empty parameter (two
commas in a row ",,"), and continue the loop if the parameter is empty, but
fails to place the comma back. In this case, the second parsing will end at
this blank field, and not process fields afterward.
In most cases, users should not have an empty field, but if its going to be
checked, the code might as well be correct.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently, the trace_options parameter is only applied in
tracer_alloc_buffers() when global_trace.current_trace is nop_trace,
so a tracer specific option will not be applied even when the specific
tracer is also enabled from kernel command line. For example, the
'func_stack_trace' option can't be enabled with the following kernel
parameter:
ftrace=function ftrace_filter=kfree trace_options=func_stack_trace
We can enable tracer specific options by simply apply the options again
if the specific tracer is also supplied from command line and started
in register_tracer().
To make trace_boot_options_buf can be parsed again, a comma and a space
is put back if they were replaced by strsep and strstrip respectively.
Also make register_tracer() be __init to access the __init data, and
in fact register_tracer is only called from __init code.
Link: http://lkml.kernel.org/r/1446599669-9294-1-git-send-email-hello.wjx@gmail.com
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull scheduler changes from Ingo Molnar:
"The main changes in this cycle were:
- sched/fair load tracking fixes and cleanups (Byungchul Park)
- Make load tracking frequency scale invariant (Dietmar Eggemann)
- sched/deadline updates (Juri Lelli)
- stop machine fixes, cleanups and enhancements for bugs triggered by
CPU hotplug stress testing (Oleg Nesterov)
- scheduler preemption code rework: remove PREEMPT_ACTIVE and related
cleanups (Peter Zijlstra)
- Rework the sched_info::run_delay code to fix races (Peter Zijlstra)
- Optimize per entity utilization tracking (Peter Zijlstra)
- ... misc other fixes, cleanups and smaller updates"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
sched: Don't scan all-offline ->cpus_allowed twice if !CONFIG_CPUSETS
sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
sched: Start stopper early
stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark()
stop_machine: Change cpu_stop_queue_two_works() to rely on stopper->enabled
stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
sched/x86: Fix typo in __switch_to() comments
sched/core: Remove a parameter in the migrate_task_rq() function
sched/core: Drop unlikely behind BUG_ON()
sched/core: Fix task and run queue sched_info::run_delay inconsistencies
sched/numa: Fix task_tick_fair() from disabling numa_balancing
sched/core: Add preempt_count invariant check
sched/core: More notrace annotations
sched/core: Kill PREEMPT_ACTIVE
sched/core, sched/x86: Kill thread_info::saved_preempt_count
sched/core: Simplify preempt_count tests
sched/core: Robustify preemption leak checks
sched/core: Stop setting PREEMPT_ACTIVE
...
Pull RAS changes from Ingo Molnar:
"The main system reliability related changes were from x86, but also
some generic RAS changes:
- AMD MCE error injection subsystem enhancements. (Aravind
Gopalakrishnan)
- Fix MCE and CPU hotplug interaction bug. (Ashok Raj)
- kcrash bootup robustness fix. (Baoquan He)
- kcrash cleanups. (Borislav Petkov)
- x86 microcode driver rework: simplify it by unmodularizing it and
other cleanups. (Borislav Petkov)"
* 'ras-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
x86/mce: Add a default case to the switch in __mcheck_cpu_ancient_init()
x86/mce: Add a Scalable MCA vendor flags bit
MAINTAINERS: Unify the microcode driver section
x86/microcode/intel: Move #ifdef DEBUG inside the function
x86/microcode/amd: Remove maintainers from comments
x86/microcode: Remove modularization leftovers
x86/microcode: Merge the early microcode loader
x86/microcode: Unmodularize the microcode driver
x86/mce: Fix thermal throttling reporting after kexec
kexec/crash: Say which char is the unrecognized
x86/setup/crash: Check memblock_reserve() retval
x86/setup/crash: Cleanup some more
x86/setup/crash: Remove alignment variable
x86/setup: Cleanup crashkernel reservation functions
x86/amd_nb, EDAC: Rename amd_get_node_id()
x86/setup: Do not reserve crashkernel high memory if low reservation failed
x86/microcode/amd: Do not overwrite final patch levels
x86/microcode/amd: Extract current patch level read to a function
x86/ras/mce_amd_inj: Inject bank 4 errors on the NBC
x86/ras/mce_amd_inj: Trigger deferred and thresholding errors interrupts
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Improve accuracy of perf/sched clock on x86. (Adrian Hunter)
- Intel DS and BTS updates. (Alexander Shishkin)
- Intel cstate PMU support. (Kan Liang)
- Add group read support to perf_event_read(). (Peter Zijlstra)
- Branch call hardware sampling support, implemented on x86 and
PowerPC. (Stephane Eranian)
- Event groups transactional interface enhancements. (Sukadev
Bhattiprolu)
- Enable proper x86/intel/uncore PMU support on multi-segment PCI
systems. (Taku Izumi)
- ... misc fixes and cleanups.
The perf tooling team was very busy again with 200+ commits, the full
diff doesn't fit into lkml size limits. Here's an (incomplete) list
of the tooling highlights:
New features:
- Change the default event used in all tools (record/top): use the
most precise "cycles" hw counter available, i.e. when the user
doesn't specify any event, it will try using cycles:ppp, cycles:pp,
etc and fall back transparently until it finds a working counter.
(Arnaldo Carvalho de Melo)
- Integration of perf with eBPF that, given an eBPF .c source file
(or .o file built for the 'bpf' target with clang), will get it
automatically built, validated and loaded into the kernel via the
sys_bpf syscall, which can then be used and seen using 'perf trace'
and other tools.
(Wang Nan)
Various user interface improvements:
- Automatic pager invocation on long help output. (Namhyung Kim)
- Search for more options when passing args to -h, e.g.: (Arnaldo
Carvalho de Melo)
$ perf report -h interface
Usage: perf report [<options>]
--gtk Use the GTK2 interface
--stdio Use the stdio interface
--tui Use the TUI interface
- Show ordered command line options when -h is used or when an
unknown option is specified. (Arnaldo Carvalho de Melo)
- If options are passed after -h, show just its descriptions, not all
options. (Arnaldo Carvalho de Melo)
- Implement column based horizontal scrolling in the hists browser
(top, report), making it possible to use the TUI for things like
'perf mem report' where there are many more columns than can fit in
a terminal. (Arnaldo Carvalho de Melo)
- Enhance the error reporting of tracepoint event parsing, e.g.:
$ oldperf record -e sched:sched_switc usleep 1
event syntax error: 'sched:sched_switc'
\___ unknown tracepoint
Run 'perf list' for a list of valid events
Now we get the much nicer:
$ perf record -e sched:sched_switc ls
event syntax error: 'sched:sched_switc'
\___ can't access trace events
Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_switc
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
And after we have those mount point permissions fixed:
$ perf record -e sched:sched_switc ls
event syntax error: 'sched:sched_switc'
\___ unknown tracepoint
Error: File /sys/kernel/debug/tracing/events/sched/sched_switc not found.
Hint: Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
I.e. basically now the event parsing routing uses the strerror_open()
routines introduced by and used in 'perf trace' work. (Jiri Olsa)
- Fail properly when pattern matching fails to find a tracepoint,
i.e. '-e non:existent' was being correctly handled, with a proper
error message about that not being a valid event, but '-e
non:existent*' wasn't, fix it. (Jiri Olsa)
- Do event name substring search as last resort in 'perf list'.
(Arnaldo Carvalho de Melo)
E.g.:
# perf list clock
List of pre-defined events (to be used in -e):
cpu-clock [Software event]
task-clock [Software event]
uncore_cbox_0/clockticks/ [Kernel PMU event]
uncore_cbox_1/clockticks/ [Kernel PMU event]
kvm:kvm_pvclock_update [Tracepoint event]
kvm:kvm_update_master_clock [Tracepoint event]
power:clock_disable [Tracepoint event]
power:clock_enable [Tracepoint event]
power:clock_set_rate [Tracepoint event]
syscalls:sys_enter_clock_adjtime [Tracepoint event]
syscalls:sys_enter_clock_getres [Tracepoint event]
syscalls:sys_enter_clock_gettime [Tracepoint event]
syscalls:sys_enter_clock_nanosleep [Tracepoint event]
syscalls:sys_enter_clock_settime [Tracepoint event]
syscalls:sys_exit_clock_adjtime [Tracepoint event]
syscalls:sys_exit_clock_getres [Tracepoint event]
syscalls:sys_exit_clock_gettime [Tracepoint event]
syscalls:sys_exit_clock_nanosleep [Tracepoint event]
syscalls:sys_exit_clock_settime [Tracepoint event]
Intel PT hardware tracing enhancements:
- Accept a zero --itrace period, meaning "as often as possible". In
the case of Intel PT that is the same as a period of 1 and a unit
of 'instructions' (i.e. --itrace=i1i). (Adrian Hunter)
- Harmonize itrace's synthesized callchains with the existing
--max-stack tool option. (Adrian Hunter)
- Allow time to be displayed in nanoseconds in 'perf script'.
(Adrian Hunter)
- Fix potential infinite loop when handling Intel PT timestamps.
(Adrian Hunter)
- Slighly improve Intel PT debug logging. (Adrian Hunter)
- Warn when AUX data has been lost, just like when processing
PERF_RECORD_LOST. (Adrian Hunter)
- Further document export-to-postgresql.py script. (Adrian Hunter)
- Add option to synthesize branch stack from auxtrace data. (Adrian
Hunter)
Misc notable changes:
- Switch the default callchain output mode to 'graph,0.5,caller', to
make it look like the default for other tools, reducing the
learning curve for people used to 'caller' based viewing. (Arnaldo
Carvalho de Melo)
- various call chain usability enhancements. (Namhyung Kim)
- Introduce the 'P' event modifier, meaning 'max precision level,
please', i.e.:
$ perf record -e cycles:P usleep 1
Is now similar to:
$ perf record usleep 1
Useful, for instance, when specifying multiple events. (Jiri Olsa)
- Add 'socket' sort entry, to sort by the processor socket in 'perf
top' and 'perf report'. (Kan Liang)
- Introduce --socket-filter to 'perf report', for filtering by
processor socket. (Kan Liang)
- Add new "Zoom into Processor Socket" operation in the perf hists
browser, used in 'perf top' and 'perf report'. (Kan Liang)
- Allow probing on kmodules without DWARF. (Masami Hiramatsu)
- Fix 'perf probe -l' for probes added to kernel module functions.
(Masami Hiramatsu)
- Preparatory work for the 'perf stat record' feature that will allow
generating perf.data files with counting data in addition to the
sampling mode we have now (Jiri Olsa)
- Update libtraceevent KVM plugin. (Paolo Bonzini)
- ... plus lots of other enhancements that I failed to list properly,
by: Adrian Hunter, Alexander Shishkin, Andi Kleen, Andrzej Hajda,
Arnaldo Carvalho de Melo, Dima Kogan, Don Zickus, Geliang Tang, He
Kuang, Huaitong Han, Ingo Molnar, Jan Stancek, Jiri Olsa, Kan
Liang, Kirill Tkhai, Masami Hiramatsu, Matt Fleming, Namhyung Kim,
Paolo Bonzini, Peter Zijlstra, Rabin Vincent, Scott Wood, Stephane
Eranian, Sukadev Bhattiprolu, Taku Izumi, Vaishali Thakkar, Wang
Nan, Yang Shi and Yunlong Song"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (260 commits)
perf unwind: Pass symbol source to libunwind
tools build: Fix libiberty feature detection
perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
perf record: Add clang options for compiling BPF scripts
perf bpf: Attach eBPF filter to perf event
perf tools: Make sure fixdep is built before libbpf
perf script: Enable printing of branch stack
perf trace: Add cmd string table to decode sys_bpf first arg
perf bpf: Collect perf_evsel in BPF object files
perf tools: Load eBPF object into kernel
perf tools: Create probe points for BPF programs
perf tools: Enable passing bpf object file to --event
perf ebpf: Add the libbpf glue
perf tools: Make perf depend on libbpf
perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore
perf tools: Enable pre-event inherit setting by config terms
perf symbols: we can now read separate debug-info files based on a build ID
perf symbols: Fix type error when reading a build-id
perf tools: Search for more options when passing args to -h
perf stat: Cache aggregated map entries in extra cpumap
...
This seems to be a mis-reading of how alpha memory ordering works, and
is not backed up by the alpha architecture manual. The helper functions
don't do anything special on any other architectures, and the arguments
that support them being safe on other architectures also argue that they
are safe on alpha.
Basically, the "control dependency" is between a previous read and a
subsequent write that is dependent on the value read. Even if the
subsequent write is actually done speculatively, there is no way that
such a speculative write could be made visible to other cpu's until it
has been committed, which requires validating the speculation.
Note that most weakely ordered architectures (very much including alpha)
do not guarantee any ordering relationship between two loads that depend
on each other on a control dependency:
read A
if (val == 1)
read B
because the conditional may be predicted, and the "read B" may be
speculatively moved up to before reading the value A. So we require the
user to insert a smp_rmb() between the two accesses to be correct:
read A;
if (A == 1)
smp_rmb()
read B
Alpha is further special in that it can break that ordering even if the
*address* of B depends on the read of A, because the cacheline that is
read later may be stale unless you have a memory barrier in between the
pointer read and the read of the value behind a pointer:
read ptr
read offset(ptr)
whereas all other weakly ordered architectures guarantee that the data
dependency (as opposed to just a control dependency) will order the two
accesses. As a result, alpha needs a "smp_read_barrier_depends()" in
between those two reads for them to be ordered.
The coontrol dependency that "READ_ONCE_CTRL()" and "atomic_read_ctrl()"
had was a control dependency to a subsequent *write*, however, and
nobody can finalize such a subsequent write without having actually done
the read. And were you to write such a value to a "stale" cacheline
(the way the unordered reads came to be), that would seem to lose the
write entirely.
So the things that make alpha able to re-order reads even more
aggressively than other weak architectures do not seem to be relevant
for a subsequent write. Alpha memory ordering may be strange, but
there's no real indication that it is *that* strange.
Also, the alpha architecture reference manual very explicitly talks
about the definition of "Dependence Constraints" in section 5.6.1.7,
where a preceding read dominates a subsequent write.
Such a dependence constraint admittedly does not impose a BEFORE (alpha
architecture term for globally visible ordering), but it does guarantee
that there can be no "causal loop". I don't see how you could avoid
such a loop if another cpu could see the stored value and then impact
the value of the first read. Put another way: the read and the write
could not be seen as being out of order wrt other cpus.
So I do not see how these "x_ctrl()" functions can currently be necessary.
I may have to eat my words at some point, but in the absense of clear
proof that alpha actually needs this, or indeed even an explanation of
how alpha could _possibly_ need it, I do not believe these functions are
called for.
And if it turns out that alpha really _does_ need a barrier for this
case, that barrier still should not be "smp_read_barrier_depends()".
We'd have to make up some new speciality barrier just for alpha, along
with the documentation for why it really is necessary.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul E McKenney <paulmck@us.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull locking changes from Ingo Molnar:
"The main changes in this cycle were:
- More gradual enhancements to atomic ops: new atomic*_read_ctrl()
ops, synchronize atomic_{read,set}() ordering requirements between
architectures, add atomic_long_t bitops. (Peter Zijlstra)
- Add _{relaxed|acquire|release}() variants for inc/dec atomics and
use them in various locking primitives: mutex, rtmutex, mcs, rwsem.
This enables weakly ordered architectures (such as arm64) to make
use of more locking related optimizations. (Davidlohr Bueso)
- Implement atomic[64]_{inc,dec}_relaxed() on ARM. (Will Deacon)
- Futex kernel data cache footprint micro-optimization. (Rasmus
Villemoes)
- pvqspinlock runtime overhead micro-optimization. (Waiman Long)
- misc smaller fixlets"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ARM, locking/atomics: Implement _relaxed variants of atomic[64]_{inc,dec}
locking/rwsem: Use acquire/release semantics
locking/mcs: Use acquire/release semantics
locking/rtmutex: Use acquire/release semantics
locking/mutex: Use acquire/release semantics
locking/asm-generic: Add _{relaxed|acquire|release}() variants for inc/dec atomics
atomic: Implement atomic_read_ctrl()
atomic, arch: Audit atomic_{read,set}()
atomic: Add atomic_long_t bitops
futex: Force hot variables into a single cache line
locking/pvqspinlock: Kick the PV CPU unconditionally when _Q_SLOW_VAL
locking/osq: Relax atomic semantics
locking/qrwlock: Rename ->lock to ->wait_lock
locking/Documentation/lockstat: Fix typo - lokcing -> locking
locking/atomics, cmpxchg: Privatize the inclusion of asm/cmpxchg.h
Pull RCU changes from Ingo Molnar:
"The main changes in this cycle were:
- Improvements to expedited grace periods (Paul E McKenney)
- Performance improvements to and locktorture tests for percpu-rwsem
(Oleg Nesterov, Paul E McKenney)
- Torture-test changes (Paul E McKenney, Davidlohr Bueso)
- Documentation updates (Paul E McKenney)
- Miscellaneous fixes (Paul E McKenney, Boqun Feng, Oleg Nesterov,
Patrick Marlier)"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
fs/writeback, rcu: Don't use list_entry_rcu() for pointer offsetting in bdi_split_work_to_wbs()
rcu: Better hotplug handling for synchronize_sched_expedited()
rcu: Enable stall warnings for synchronize_rcu_expedited()
rcu: Add tasks to expedited stall-warning messages
rcu: Add online/offline info to expedited stall warning message
rcu: Consolidate expedited CPU selection
rcu: Prepare for consolidating expedited CPU selection
cpu: Remove try_get_online_cpus()
rcu: Stop excluding CPU hotplug in synchronize_sched_expedited()
rcu: Stop silencing lockdep false positive for expedited grace periods
rcu: Switch synchronize_sched_expedited() to IPI
locktorture: Fix module unwind when bad torture_type specified
torture: Forgive non-plural arguments
rcutorture: Fix unused-function warning for torturing_tasks()
rcutorture: Fix module unwind when bad torture_type specified
rcu_sync: Cleanup the CONFIG_PROVE_RCU checks
locking/percpu-rwsem: Clean up the lockdep annotations in percpu_down_read()
locking/percpu-rwsem: Fix the comments outdated by rcu_sync
locking/percpu-rwsem: Make use of the rcu_sync infrastructure
locking/percpu-rwsem: Make percpu_free_rwsem() after kzalloc() safe
...
Pull irq updates from Thomas Gleixner:
"The irq departement delivers:
- Rework the irqdomain core infrastructure to accomodate ACPI based
systems. This is required to support ARM64 without creating
artificial device tree nodes.
- Sanitize the ACPI based ARM GIC initialization by making use of the
new firmware independent irqdomain core
- Further improvements to the generic MSI management
- Generalize the irq migration on CPU hotplug
- Improvements to the threaded interrupt infrastructure
- Allow the migration of "chained" low level interrupt handlers
- Allow optional force masking of interrupts in disable_irq[_nosysnc]
- Support for two new interrupt chips - Sigh!
- A larger set of errata fixes for ARM gicv3
- The usual pile of fixes, updates, improvements and cleanups all
over the place"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits)
Document that IRQ_NONE should be returned when IRQ not actually handled
PCI/MSI: Allow the MSI domain to be device-specific
PCI: Add per-device MSI domain hook
of/irq: Use the msi-map property to provide device-specific MSI domain
of/irq: Split of_msi_map_rid to reuse msi-map lookup
irqchip/gic-v3-its: Parse new version of msi-parent property
PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing
of/irq: Add support code for multi-parent version of "msi-parent"
irqchip/gic-v3-its: Add handling of PCI requester id.
PCI/MSI: Add helper function pci_msi_domain_get_msi_rid().
of/irq: Add new function of_msi_map_rid()
Docs: dt: Add PCI MSI map bindings
irqchip/gic-v2m: Add support for multiple MSI frames
irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec
irqchip/mxs: Add Alphascale ASM9260 support
irqchip/mxs: Prepare driver for hardware with different offsets
irqchip/mxs: Panic if ioremap or domain creation fails
irqdomain: Documentation updates
irqdomain/msi: Use fwnode instead of of_node
...
Pull timer updates from Thomas Gleixner:
"The timer departement provides:
- More y2038 work in the area of ntp and pps.
- Optimization of posix cpu timers
- New time related selftests
- Some new clocksource drivers
- The usual pile of fixes, cleanups and improvements"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
timeconst: Update path in comment
timers/x86/hpet: Type adjustments
clocksource/drivers/armada-370-xp: Implement ARM delay timer
clocksource/drivers/tango_xtal: Add new timer for Tango SoCs
clocksource/drivers/imx: Allow timer irq affinity change
clocksource/drivers/exynos_mct: Use container_of() instead of this_cpu_ptr()
clocksource/drivers/h8300_*: Remove unneeded memset()s
clocksource/drivers/sh_cmt: Remove unneeded memset() in sh_cmt_setup()
clocksource/drivers/em_sti: Remove unneeded memset()s
clocksource/drivers/mediatek: Use GPT as sched clock source
clockevents/drivers/mtk: Fix spurious interrupt leading to crash
posix_cpu_timer: Reduce unnecessary sighand lock contention
posix_cpu_timer: Convert cputimer->running to bool
posix_cpu_timer: Check thread timers only when there are active thread timers
posix_cpu_timer: Optimize fastpath_timer_check()
timers, kselftest: Add 'adjtick' test to validate adjtimex() tick adjustments
timers: Use __fls in apply_slack()
clocksource: Remove return statement from void functions
net: sfc: avoid using timespec
ntp/pps: use y2038 safe types in pps_event_time
...
wake_up_process() has a memory barrier before doing anything, thus adding a
memory barrier before calling it is redundant.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
We don't init iter->started when dumping the ftrace buffer, and there's no
real need to do so - so allow skipping that check if the iter doesn't have
an initialized ->started cpumask.
Link: http://lkml.kernel.org/r/1441385156-27279-1-git-send-email-sasha.levin@oracle.com
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit b44754d826 ("ring_buffer: Allow to exit the ring
buffer benchmark immediately") added a hack into ring_buffer_producer()
that set @kill_test when kthread_should_stop() returned true. It improved
the situation a lot. It stopped the kthread in most cases because
the producer spent most of the time in the patched while cycle.
But there are still few possible races when kthread_should_stop()
is set outside of the cycle. Then we do not set @kill_test and
some other checks pass.
This patch adds a better fix. It renames @test_kill/TEST_KILL() into
a better descriptive @test_error/TEST_ERROR(). Also it introduces
break_test() function that checks for both @test_error and
kthread_should_stop().
The new function is used in the producer when the check for @test_error
is not enough. It is not used in the consumer because its state
is manipulated by the producer via the "reader_finish" variable.
Also we add a missing check into ring_buffer_producer_thread()
between setting TASK_INTERRUPTIBLE and calling schedule_timeout().
Otherwise, we might miss a wakeup from kthread_stop().
Link: http://lkml.kernel.org/r/1441629518-32712-3-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
It seems that complete(&read_done) might be called too early
in some situations.
1st scenario:
-------------
CPU0 CPU1
ring_buffer_producer_thread()
wake_up_process(consumer);
wait_for_completion(&read_start);
ring_buffer_consumer_thread()
complete(&read_start);
ring_buffer_producer()
# producing data in
# the do-while cycle
ring_buffer_consumer();
# reading data
# got error
# set kill_test = 1;
set_current_state(
TASK_INTERRUPTIBLE);
if (reader_finish) # false
schedule();
# producer still in the middle of
# do-while cycle
if (consumer && !(cnt % wakeup_interval))
wake_up_process(consumer);
# spurious wakeup
while (!reader_finish &&
!kill_test)
# leaving because
# kill_test == 1
reader_finish = 0;
complete(&read_done);
1st BANG: We might access uninitialized "read_done" if this is the
the first round.
# producer finally leaving
# the do-while cycle because kill_test == 1;
if (consumer) {
reader_finish = 1;
wake_up_process(consumer);
wait_for_completion(&read_done);
2nd BANG: This will never complete because consumer already did
the completion.
2nd scenario:
-------------
CPU0 CPU1
ring_buffer_producer_thread()
wake_up_process(consumer);
wait_for_completion(&read_start);
ring_buffer_consumer_thread()
complete(&read_start);
ring_buffer_producer()
# CPU3 removes the module <--- difference from
# and stops producer <--- the 1st scenario
if (kthread_should_stop())
kill_test = 1;
ring_buffer_consumer();
while (!reader_finish &&
!kill_test)
# kill_test == 1 => we never go
# into the top level while()
reader_finish = 0;
complete(&read_done);
# producer still in the middle of
# do-while cycle
if (consumer && !(cnt % wakeup_interval))
wake_up_process(consumer);
# spurious wakeup
while (!reader_finish &&
!kill_test)
# leaving because kill_test == 1
reader_finish = 0;
complete(&read_done);
BANG: We are in the same "bang" situations as in the 1st scenario.
Root of the problem:
--------------------
ring_buffer_consumer() must complete "read_done" only when "reader_finish"
variable is set. It must not be skipped due to other conditions.
Note that we still must keep the check for "reader_finish" in a loop
because there might be spurious wakeups as described in the
above scenarios.
Solution:
----------
The top level cycle in ring_buffer_consumer() will finish only when
"reader_finish" is set. The data will be read in "while-do" cycle
so that they are not read after an error (kill_test == 1)
or a spurious wake up.
In addition, "reader_finish" is manipulated by the producer thread.
Therefore we add READ_ONCE() to make sure that the fresh value is
read in each cycle. Also we add the corresponding barrier
to synchronize the sleep check.
Next we set the state back to TASK_RUNNING for the situation where we
did not sleep.
Just from paranoid reasons, we initialize both completions statically.
This is safer, in case there are other races that we are unaware of.
As a side effect we could remove the memory barrier from
ring_buffer_producer_thread(). IMHO, this was the reason for
the barrier. ring_buffer_reset() uses spin locks that should
provide the needed memory barrier for using the buffer.
Link: http://lkml.kernel.org/r/1441629518-32712-2-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
TP_ARGS is not used anywhere in trace.h nor trace_entries.h
Firstly, I left just #undef TP_ARGS and had no errors - remove it.
Link: http://lkml.kernel.org/r/1446576560-14085-1-git-send-email-0x7f454c46@gmail.com
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that max_stack_lock is a global variable, it requires a naming
convention that is unlikely to collide. Rename it to the same naming
convention that the other stack_trace variables have.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
A stack frame may be used in a different way depending on cpu architecture.
Thus it is not always appropriate to slurp the stack contents, as current
check_stack() does, in order to calcurate a stack index (height) at a given
function call. At least not on arm64.
In addition, there is a possibility that we will mistakenly detect a stale
stack frame which has not been overwritten.
This patch makes check_stack() a weak function so as to later implement
arch-specific version.
Link: http://lkml.kernel.org/r/1446182741-31019-5-git-send-email-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The verbose() printer dumps the verifier state to user space, so let gcc
take care to check calls to verbose() for (future) errors. make with W=1
correctly suggests: function might be possible candidate for 'gnu_printf'
format attribute [-Wsuggest-attribute=format].
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This work adds support for "persistent" eBPF maps/programs. The term
"persistent" is to be understood that maps/programs have a facility
that lets them survive process termination. This is desired by various
eBPF subsystem users.
Just to name one example: tc classifier/action. Whenever tc parses
the ELF object, extracts and loads maps/progs into the kernel, these
file descriptors will be out of reach after the tc instance exits.
So a subsequent tc invocation won't be able to access/relocate on this
resource, and therefore maps cannot easily be shared, f.e. between the
ingress and egress networking data path.
The current workaround is that Unix domain sockets (UDS) need to be
instrumented in order to pass the created eBPF map/program file
descriptors to a third party management daemon through UDS' socket
passing facility. This makes it a bit complicated to deploy shared
eBPF maps or programs (programs f.e. for tail calls) among various
processes.
We've been brainstorming on how we could tackle this issue and various
approches have been tried out so far, which can be read up further in
the below reference.
The architecture we eventually ended up with is a minimal file system
that can hold map/prog objects. The file system is a per mount namespace
singleton, and the default mount point is /sys/fs/bpf/. Any subsequent
mounts within a given namespace will point to the same instance. The
file system allows for creating a user-defined directory structure.
The objects for maps/progs are created/fetched through bpf(2) with
two new commands (BPF_OBJ_PIN/BPF_OBJ_GET). I.e. a bpf file descriptor
along with a pathname is being passed to bpf(2) that in turn creates
(we call it eBPF object pinning) the file system nodes. Only the pathname
is being passed to bpf(2) for getting a new BPF file descriptor to an
existing node. The user can use that to access maps and progs later on,
through bpf(2). Removal of file system nodes is being managed through
normal VFS functions such as unlink(2), etc. The file system code is
kept to a very minimum and can be further extended later on.
The next step I'm working on is to add dump eBPF map/prog commands
to bpf(2), so that a specification from a given file descriptor can
be retrieved. This can be used by things like CRIU but also applications
can inspect the meta data after calling BPF_OBJ_GET.
Big thanks also to Alexei and Hannes who significantly contributed
in the design discussion that eventually let us end up with this
architecture here.
Reference: https://lkml.org/lkml/2015/10/15/925
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently have duplicated cleanup code in bpf_prog_put() and
bpf_prog_put_rcu() cleanup paths. Back then we decided that it was
not worth it to make it a common helper called by both, but with
the recent addition of resource charging, we could have avoided
the fix in commit ac00737f4e ("bpf: Need to call bpf_prog_uncharge_memlock
from bpf_prog_put") if we would have had only a single, common path.
We can simplify it further by assigning aux->prog only once during
allocation time.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a bpf_map_get() function that we're going to use later on and
align/clean the remaining helpers a bit so that we have them a bit
more consistent:
- __bpf_map_get() and __bpf_prog_get() that both work on the fd
struct, check whether the descriptor is eBPF and return the
pointer to the map/prog stored in the private data.
Also, we can return f.file->private_data directly, the function
signature is enough of a documentation already.
- bpf_map_get() and bpf_prog_get() that both work on u32 user fd,
call their respective __bpf_map_get()/__bpf_prog_get() variants,
and take a reference.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since we're going to use anon_inode_getfd() invocations in more than just
the current places, make a helper function for both, so that we only need
to pass a map/prog pointer to the helper itself in order to get a fd. The
new helpers are called bpf_map_new_fd() and bpf_prog_new_fd().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make ftrace_event_is_function() return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-9-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make is_legal_op() return bool to improve readability due to this particular
function only using either one or zero as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-8-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make rb_event_is_commit() return bool to improve readability
due to this particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-7-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make rb_is_reader_page() return bool to improve readability due to this
particular function only using either true or false as its return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-4-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch makes report_latency return bool due to this
particular function only using either one or zero as its
return value.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-3-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch makes report_latency return bool to improve readability,
indicating whether this new latency should be reported/recorded.
No functional change.
Link: http://lkml.kernel.org/r/1443537816-5788-2-git-send-email-bywxiaobai@163.com
Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Update instancd_rmdir to use tracefs_remove_recursive instead of
debugfs_remove_recursive.This was left in the transition from debugfs
to tracefs.
Link: http://lkml.kernel.org/r/1445169490-18315-2-git-send-email-hello.wjx@gmail.com
Cc: stable@vger.kernel.org # 4.1+
Fixes: 8434dc9340 ("tracing: Convert the tracing facility over to use tracefs")
Signed-off-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There's no need to record the time tracepoints take when tracing is off.
This is because:
1) We cannot see these records since ring_buffer record is off at that
moment.
2) If tracing is off and benchmark tracepoint is enabled, the time
tracepoint takes is fewer than the same situation when tracing is on,
since the tracepoints need to be wrote into ring_buffer, it would
take more time. If turn on tracing at this moment, the average and
standard deviation cannot exactly present the time that tracepoints
take to write data into ring_buffer.
Link: http://lkml.kernel.org/r/1445947933-27955-1-git-send-email-zhang.chunyan@linaro.org
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
For the case where pids are already in set_event_pid, and one is added or
removed then each CPU should be checked to make sure that the new or old pid
is on or not on a CPU.
For example:
# echo 123 >> set_event_pid
or
# echo '!123' >> set_event_pid
Link: http://lkml.kernel.org/r/20151030061643.GA19480@cac
Suggested-by: Jiaxing Wang <hello.wjx@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* pm-sleep:
PM / hibernate: fix a comment typo
input: i8042: Avoid resetting controller on system suspend/resume
PM / PCI / ACPI: Kick devices that might have been reset by firmware
PM / sleep: Add flags to indicate platform firmware involvement
PM / sleep: Drop pm_request_idle() from pm_generic_complete()
PCI / PM: Avoid resuming more devices during system suspend
PM / wakeup: wakeup_source_create: use kstrdup_const
PM / sleep: Report interrupt that caused system wakeup
Pull memremap fix from Dan Williams:
"The new memremap() api introduced in the 4.3 cycle to unify/replace
ioremap_cache() and ioremap_wt() is mishandling the highmem case.
This patch has received a build success notification from a
0day-kbuild-robot run and has received an ack from Ard"
From the commit message:
"The impact of this bug is low for now since the pmem driver is the
only user of memremap(), but this is important to fix before more
conversions to memremap arrive in 4.4"
* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
memremap: fix highmem support
This is really about simplifying the double xchg patterns into
a single cmpxchg, with the same logic. Other than the immediate
cleanup, there are some subtleties this change deals with:
(i) While the load of the old bt is fully ordered wrt everything,
ie:
old_bt = xchg(&q->blk_trace, bt); [barrier]
if (old_bt)
(void) xchg(&q->blk_trace, old_bt); [barrier]
blk_trace could still be changed between the xchg and the old_bt
load. Note that this description is merely theoretical and afaict
very small, but doing everything in a single context with cmpxchg
closes this potential race.
(ii) Ordering guarantees are obviously kept with cmpxchg.
(iii) Gets rid of the hacky-by-nature (void)xchg pattern.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
eviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
css_task_iter_next() checked @it->cur_task before grabbing
css_set_lock and assumed that the result won't change afterwards;
however, tasks could leave the cgroup being iterated terminating the
iterator before css_task_lock is acquired. If this happens,
css_task_iter_next() tries to calculate the current task from NULL
cg_list pointer leading to the following oops.
BUG: unable to handle kernel paging request at fffffffffffff7d0
IP: [<ffffffff810d5f22>] css_task_iter_next+0x42/0x80
...
CPU: 4 PID: 6391 Comm: JobQDisp2 Not tainted 4.0.9-22_fbk4_rc3_81616_ge8d9cb6 #1
Hardware name: Quanta Freedom/Winterfell, BIOS F03_3B08 03/04/2014
task: ffff880868e46400 ti: ffff88083404c000 task.ti: ffff88083404c000
RIP: 0010:[<ffffffff810d5f22>] [<ffffffff810d5f22>] css_task_iter_next+0x42/0x80
RSP: 0018:ffff88083404fd28 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff88083404fd68 RCX: ffff8804697fb8b0
RDX: fffffffffffff7c0 RSI: ffff8803b7dff800 RDI: ffffffff822c0278
RBP: ffff88083404fd38 R08: 0000000000017160 R09: ffff88046f4070c0
R10: ffffffff810d61f7 R11: 0000000000000293 R12: ffff880863bf8400
R13: ffff88046b87fd80 R14: 0000000000000000 R15: ffff88083404fe58
FS: 00007fa0567e2700(0000) GS:ffff88046f900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffff7d0 CR3: 0000000469568000 CR4: 00000000001406e0
Stack:
0000000000000246 0000000000000000 ffff88083404fde8 ffffffff810d6248
ffff88083404fd68 0000000000000000 ffff8803b7dff800 000001ef000001ee
0000000000000000 0000000000000000 ffff880863bf8568 0000000000000000
Call Trace:
[<ffffffff810d6248>] cgroup_pidlist_start+0x258/0x550
[<ffffffff810cf66d>] cgroup_seqfile_start+0x1d/0x20
[<ffffffff8121f8ef>] kernfs_seq_start+0x5f/0xa0
[<ffffffff811cab76>] seq_read+0x166/0x380
[<ffffffff812200fd>] kernfs_fop_read+0x11d/0x180
[<ffffffff811a7398>] __vfs_read+0x18/0x50
[<ffffffff811a745d>] vfs_read+0x8d/0x150
[<ffffffff811a756f>] SyS_read+0x4f/0xb0
[<ffffffff818d4772>] system_call_fastpath+0x12/0x17
Fix it by moving the termination condition check inside css_set_lock.
@it->cur_task is now cleared after being put and @it->task_pos is
tested for termination instead of @it->cset_pos as they indicate the
same condition and @it->task_pos is what's being dereferenced.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Calvin Owens <calvinowens@fb.com>
Fixes: ed27b9f7a1 ("cgroup: don't hold css_set_rwsem across css task iteration")
Acked-by: Zefan Li <lizefan@huawei.com>
This patch adds support for dumping a process' (classic BPF) seccomp
filters via ptrace.
PTRACE_SECCOMP_GET_FILTER allows the tracer to dump the user's classic BPF
seccomp filters. addr should be an integer which represents the ith seccomp
filter (0 is the most recently installed filter). data should be a struct
sock_filter * with enough room for the ith filter, or NULL, in which case
the filter is not saved. The return value for this command is the number of
BPF instructions the program represents, or negative in the case of errors.
Command specific errors are ENOENT: which indicates that there is no ith
filter in this seccomp tree, and EMEDIUMTYPE, which indicates that the ith
filter was not installed as a classic BPF filter.
A caveat with this approach is that there is no way to get explicitly at
the heirarchy of seccomp filters, and users need to memcmp() filters to
decide which are inherited. This means that a task which installs two of
the same filter can potentially confuse users of this interface.
v2: * make save_orig const
* check that the orig_prog exists (not necessary right now, but when
grows eBPF support it will be)
* s/n/filter_off and make it an unsigned long to match ptrace
* count "down" the tree instead of "up" when passing a filter offset
v3: * don't take the current task's lock for inspecting its seccomp mode
* use a 0x42** constant for the ptrace command value
v4: * don't copy to userspace while holding spinlocks
v5: * add another condition to WARN_ON
v6: * rebase on net-next
Signed-off-by: Tycho Andersen <tycho.andersen@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
CC: Will Drewry <wad@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Pavel Emelyanov <xemul@parallels.com>
CC: Serge E. Hallyn <serge.hallyn@ubuntu.com>
CC: Alexei Starovoitov <ast@kernel.org>
CC: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
someone finally caught it thanks to Peter Z's additional checks.
Cheers,
Rusty.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=8AgP
-----END PGP SIGNATURE-----
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull module preemption fix from Rusty Russell:
"Turns out we should have always been disabling preemption here;
someone finally caught it thanks to Peter Z's additional checks"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
module: Fix locking in symbol_put_addr()
exported perf symbols are GPL only, mark eBPF helper functions
used in tracing as GPL only as well.
Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix safety checks for bpf_perf_event_read():
- only non-inherited events can be added to perf_event_array map
(do this check statically at map insertion time)
- dynamically check that event is local and !pmu->count
Otherwise buggy bpf program can cause kernel splat.
Also fix error path after perf_event_attrs()
and remove redundant 'extern'.
Fixes: 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently memremap checks if the range is "System RAM" and returns the
kernel linear address. This is broken for highmem platforms where a
range may be "System RAM", but is not part of the kernel linear mapping.
Fallback to ioremap_cache() in these cases, to let the arch code attempt
to handle it.
Note that ARM ioremap will WARN when attempting to remap ram, and in
that case the caller needs to be fixed. For this reason, existing
ioremap_cache() usages for ARM are already trained to avoid attempts to
remap ram.
The impact of this bug is low for now since the pmem driver is the only
user of memremap(), but this is important to fix before more conversions
to memremap arrive in 4.4.
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
p_start() and p_stop() are seq_file functions that match. Teach sparse to
know that rcu_read_lock_sched() that is taken by p_start() is released by
p_stop.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
My tests found that if a task is running but not filtered when set_event_pid
is modified, then it can still be traced.
Call on_each_cpu() to check if the current running task should be filtered
and update the per cpu flags of tr->data appropriately.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add the necessary hooks to use the pids loaded in set_event_pid to filter
all the events enabled in the tracing instance that match the pids listed.
Two probes are added to both sched_switch and sched_wakeup tracepoints to be
called before other probes are called and after the other probes are called.
The first is used to set the necessary flags to let the probes know to test
if they should be traced or not.
The sched_switch pre probe will set the "ignore_pid" flag if neither the
previous or next task has a matching pid.
The sched_switch probe will set the "ignore_pid" flag if the next task
does not match the matching pid.
The pre probe allows for probes tracing sched_switch to be traced if
necessary.
The sched_wakeup pre probe will set the "ignore_pid" flag if neither the
current task nor the wakee task has a matching pid.
The sched_wakeup post probe will set the "ignore_pid" flag if the current
task does not have a matching pid.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Create a tracing directory called set_event_pid, which currently has no
function, but will be used to filter all events for the tracing instance or
the pids that are added to the file.
The reason no functionality is added with this commit is that this commit
focuses on the creation and removal of the pids in a safe manner. And tests
can be made against this change to make sure things are correct before
hooking features to the list of pids.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
In order to guarantee that a probe will be called before other probes that
are attached to a tracepoint, there needs to be a mechanism to provide
priority of one probe over the others.
Adding a prio field to the struct tracepoint_func, which lets the probes be
sorted by the priority set in the structure. If no priority is specified,
then a priority of 10 is given (this is a macro, and perhaps may be changed
in the future).
Now probes may be added to affect other probes that are attached to a
tracepoint with a guaranteed order.
One use case would be to allow tracing of tracepoints be able to filter by
pid. A special (higher priority probe) may be added to the sched_switch
tracepoint and set the necessary flags of the other tracepoints to notify
them if they should be traced or not. In case a tracepoint is enabled at the
sched_switch tracepoint too, the order of the two are not random.
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull scheduler fixes from Ingo Molnar:
"Misc fixes all around the map: an instrumentation fix, a nohz
usability fix, a lockdep annotation fix and two task group scheduling
fixes"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/core: Add missing lockdep_unpin() annotations
sched/deadline: Fix migration of SCHED_DEADLINE tasks
nohz: Revert "nohz: Set isolcpus when nohz_full is set"
sched/fair: Update task group's load_avg after task migration
sched/fair: Fix overly small weight for interactive group entities
sched, tracing: Stop/start critical timings around the idle=poll idle loop
Merge fixes from Andrew Morton:
"9 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
ocfs2/dlm: unlock lockres spinlock before dlm_lockres_put
fault-inject: fix inverted interval/probability values in printk
lib/Kconfig.debug: disable -Wframe-larger-than warnings with KASAN=y
mm: make sendfile(2) killable
thp: use is_zero_pfn() only after pte_present() check
mailmap: update Javier Martinez Canillas' email
MAINTAINERS: add Sergey as zsmalloc reviewer
mm: cma: fix incorrect type conversion for size during dma allocation
kmod: don't run async usermode helper as a child of kworker thread
call_usermodehelper_exec_sync() does fork() + wait() with "unignored"
SIGCHLD. What we have missed is that this worker thread can have other
children previously forked by call_usermodehelper_exec_work() without
UMH_WAIT_PROC. If such a child exits in between it becomes a zombie
because auto-reaping only works if SIGCHLD is ignored, and nobody can
reap it (unless/until this worker thread exits too).
Change the !UMH_WAIT_PROC case to use CLONE_PARENT.
Note: this is only first step. All PF_KTHREAD tasks, even created by
kernel_thread() should have ->parent == kthreadd by default.
Fixes: bb304a5c6f ("kmod: handle UMH_WAIT_PROC from system unbound workqueue")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is an incremental fix for a patch previously pulled from tip
irq/for-arm.
* 'irq/for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Make the cpuhotplug migration code less noisy
pstore doesn't support unregistering yet. It was marked as TODO.
This patch adds some code to fix it:
1) Add functions to unregister kmsg/console/ftrace/pmsg.
2) Add a function to free compression buffer.
3) Unmap the memory and free it.
4) Add a function to unregister pstore filesystem.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Kees Cook <keescook@chromium.org>
[Removed __exit annotation from ramoops_remove(). Reported by Arnd Bergmann]
Signed-off-by: Tony Luck <tony.luck@intel.com>
This helper is used to send raw data from eBPF program into
special PERF_TYPE_SOFTWARE/PERF_COUNT_SW_BPF_OUTPUT perf_event.
User space needs to perf_event_open() it (either for one or all cpus) and
store FD into perf_event_array (similar to bpf_perf_event_read() helper)
before eBPF program can send data into it.
Today the programs triggered by kprobe collect the data and either store
it into the maps or print it via bpf_trace_printk() where latter is the debug
facility and not suitable to stream the data. This new helper replaces
such bpf_trace_printk() usage and allows programs to have dedicated
channel into user space for post-processing of the raw data collected.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
