Cm 12.1 new #3
Closed
Cm 12.1 new #3
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
upstream changes
Signed-off-by: tarun93 <tarunmyid@gmail.com> Conflicts: .gitignore
Thanks a lot: @TeamExodus, @TheCrazyLex, @AlmightyMegadeth00 Conflicts: Makefile
Conflicts: drivers/cpufreq/cpufreq_ondemand.c
simple_ondemands private data must be set to NULL, otherwise we would run into a NULL pointer in kgsl_devfreq_get_dev_status(). Signed-off-by: Paul Reioux <reioux@gmail.com> Signed-off-by: tarun93 <tarunmyid@gmail.com> Conflicts: drivers/devfreq/governor_simpleondemand.c Signed-off-by: tarun93 <tarunmyid@gmail.com>
Signed-off-by: Paul Reioux <reioux@gmail.com> Signed-off-by: tarun93 <tarunmyid@gmail.com>
If the target_freq is equal to freq we don't need to do some extra checks, we can just bail out. Signed-off-by: Blechd0se <alex.christ@hotmail.de> Signed-off-by: tarun93 <tarunmyid@gmail.com>
<4>[ 124.983957] ------------[ cut here ]------------ <4>[ 124.984381] WARNING: at arch/arm/mach-msm/msm-pm.c:837 msm_pm_wait_cpu_shu tdown+0x9c/0xb0() <4>[ 124.984661] CPU2 didn't collapse in 2 ms <4>[ 124.984869] [<c010e10c>] (unwind_backtrace+0x0/0x144) from [<c0a1c68c>] (d ump_stack+0x20/0x24) <4>[ 124.985170] [<c0a1c68c>] (dump_stack+0x20/0x24) from [<c019ab44>] (warn_sl owpath_common+0x58/0x70) <4>[ 124.985464] [<c019ab44>] (warn_slowpath_common+0x58/0x70) from [<c019abd8> ] (warn_slowpath_fmt+0x40/0x48) <4>[ 124.985943] [<c019abd8>] (warn_slowpath_fmt+0x40/0x48) from [<c0179d30>] ( msm_pm_wait_cpu_shutdown+0x9c/0xb0) <4>[ 124.986287] [<c0179d30>] (msm_pm_wait_cpu_shutdown+0x9c/0xb0) from [<c0126 750>] (platform_cpu_kill+0x38/0x48) <4>[ 124.986591] [<c0126750>] (platform_cpu_kill+0x38/0x48) from [<c010c6fc>] ( __cpu_die+0x4c/0x98) <4>[ 124.986778] [<c010c6fc>] (__cpu_die+0x4c/0x98) from [<c09ee9cc>] (_cpu_dow n+0xf8/0x2e0) <4>[ 124.987074] [<c09ee9cc>] (_cpu_down+0xf8/0x2e0) from [<c09eec58>] (cpu_dow n+0x34/0x50) <4>[ 124.987383] [<c09eec58>] (cpu_down+0x34/0x50) from [<c0194250>] (cpu_down_ work+0xc4/0xd8) <4>[ 124.987564] [<c0194250>] (cpu_down_work+0xc4/0xd8) from [<c01b4e44>] (proc ess_one_work+0x178/0x4f4) <4>[ 124.987861] [<c01b4e44>] (process_one_work+0x178/0x4f4) from [<c01b5540>] (worker_thread+0x174/0x448) <4>[ 124.988152] [<c01b5540>] (worker_thread+0x174/0x448) from [<c01bb8ac>] (kt hread+0xb4/0xc0) <4>[ 124.988450] [<c01bb8ac>] (kthread+0xb4/0xc0) from [<c0108060>] (kernel_thr ead_exit+0x0/0x8) <4>[ 124.988725] ---[ end trace 77427e632785e345 ]--- Signed-off-by: tarun93 <tarunmyid@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com> Signed-off-by: tarun93 <tarunmyid@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com> Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com> Signed-off-by: tarun93 <tarunmyid@gmail.com>
Signed-off-by: tarun93 <tarunmyid@gmail.com> Conflicts: .gitignore
This reverts commit 9538057f7389e444238690539a2188abc7e9a399.
Conflicts: block/Kconfig.iosched block/Makefile
Conflicts: arch/arm/configs/cyanogen_cancro_defconfig
Conflicts: drivers/cpufreq/Makefile include/linux/cpufreq.h Conflicts: arch/arm/configs/cyanogen_cancro_defconfig drivers/cpufreq/Kconfig drivers/cpufreq/Makefile include/linux/cpufreq.h
…e to a merge derp in 1.0 beta8 thx to @DespairFactor for original fix and again for this one!
- removed conditional calculation of proportional frequency indroduced in 1.0 beta8 to fix sometimes returning 0 in 'zz_target' (=pushing to policy->min) - removed some uneeded things in 'zz_get_next_freq' function - fixed extensively falling back to proportional freq because of missbehaving search optimization, this leads to a 'cleaner' scaling and rarely falling back to proportional freq only on limit switching - as it mistakenly wasn't enabled before: enable freq search optimization for ascending ordered freq tables
- introduced the possibility to turn off 'sleep mode' completely via tuneable 'disable_sleep_mode' NOTE: due to many reported issues (mostly device wakeup issues) related to more restrict suspend settings i decided to enable this new tuneable per default (=suspend restictions off) in upcoming versions. users who want to get the suspend restrictions back again can do this by setting this new tuneable to '0' via sysfs. devs can disable this (=suspend restrictions on like in previous versions) per default in source via macro 'DEF_DISABLE_SLEEP_MODE' - added resetting of 'music_state' and 'disable_sleep_mode' tuneable after a governor reload - corrected some documentation
- increase hotplug down block cycles by factor 10 in all settings to fix issues on some devices because of too aggressive down plugging
- schedule temp reading work only on core 0 to avoid re-scheduling on every governor reload during hotplugging - added canceling of temp reading work when leaving the governor
- add an alternative hook for screen on / off detection in the display pannel driver - sleeps ~0.1s sooner, wakes up ~1s later then autosleep - clean up source formatting a bit (Paul Reioux) Signed-off-by: Jean Francis Dominique S. Mabalot <jmabalot@google.com>
- fix hybrid-kernel mode cannot be set through sysfs kernel/power/powersuspend: new PM kernel driver for Android w/o early_suspend v1.4 (Yank555.lu) - add hybrid-kernel mode (autosleep and panel, first wins) - default to hybrid-kernel mode - harmonize debug message with my other stuff - include all 3 modes as default, so it's only commenting out to change kernel/power/powersuspend: new PM kernel driver for Android w/o early_suspend v1.3 (Yank555.lu) - fix stupid typo - add an alternative hook for screen on / off detection in the display panel driver (sleeps ~0.1s sooner, wakes up ~1s later then autosleep) kernel/power/powersuspend: new PM kernel driver for Android w/o early_suspend v1.2 (Yank555.lu) - make kernel / userspace mode switchable kernel/power/powersuspend: new PM kernel driver for Android w/o early_suspend v1.1 (Yank555.lu) - make powersuspend not depend on a userspace initiator anymore, but use a hook in autosleep instead. kernel/power/powersuspend: new PM kernel driver for Android w/o early_suspend (faux123) Android early_suspend/late_resume PM kernel driver framework has been deprecated by Google. This new powersuspend PM kernel driver is a replacement for it and existing early_suspend drivers can be easily adapted to use this new replacement driver Signed-off-by: Jean Francis Dominique S. Mabalot <jmabalot@google.com>
…Yank555.lu) - autosleep hook removed, not working on shamu - autosleep and hybrid modes removed - panel mode is now default - debug output switchable in defconfig Signed-off-by: Jean Francis Dominique S. Mabalot <jmabalot@google.com>
Signed-off-by: Jean Francis Dominique S. Mabalot <jmabalot@google.com>
qcom,mount-angle = <90>; //默认270相机倒置，90相机正常
3EleVen
pushed a commit
to Hybrid-Power/android_kernel_xiaomi_cancro
that referenced
this pull request
Jan 5, 2016
workqueue: change BUG_ON() to WARN_ON()
This BUG_ON() can be triggered if you call schedule_work() before
calling INIT_WORK(). It is a bug definitely, but it's nicer to just
print a stack trace and return.
Reported-by: Matt Renzelmann <mjr@cs.wisc.edu>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: Catch more locking problems with flush_work()
If a workqueue is flushed with flush_work() lockdep checking can
be circumvented. For example:
static DEFINE_MUTEX(mutex);
static void my_work(struct work_struct *w)
{
mutex_lock(&mutex);
mutex_unlock(&mutex);
}
static DECLARE_WORK(work, my_work);
static int __init start_test_module(void)
{
schedule_work(&work);
return 0;
}
module_init(start_test_module);
static void __exit stop_test_module(void)
{
mutex_lock(&mutex);
flush_work(&work);
mutex_unlock(&mutex);
}
module_exit(stop_test_module);
would not always print a warning when flush_work() was called.
In this trivial example nothing could go wrong since we are
guaranteed module_init() and module_exit() don't run concurrently,
but if the work item is schedule asynchronously we could have a
scenario where the work item is running just at the time flush_work()
is called resulting in a classic ABBA locking problem.
Add a lockdep hint by acquiring and releasing the work item
lockdep_map in flush_work() so that we always catch this
potential deadlock scenario.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
lockdep: fix oops in processing workqueue
Under memory load, on x86_64, with lockdep enabled, the workqueue's
process_one_work() has been seen to oops in __lock_acquire(), barfing
on a 0xffffffff00000000 pointer in the lockdep_map's class_cache[].
Because it's permissible to free a work_struct from its callout function,
the map used is an onstack copy of the map given in the work_struct: and
that copy is made without any locking.
Surprisingly, gcc (4.5.1 in Hugh's case) uses "rep movsl" rather than
"rep movsq" for that structure copy: which might race with a workqueue
user's wait_on_work() doing lock_map_acquire() on the source of the
copy, putting a pointer into the class_cache[], but only in time for
the top half of that pointer to be copied to the destination map.
Boom when process_one_work() subsequently does lock_map_acquire()
on its onstack copy of the lockdep_map.
Fix this, and a similar instance in call_timer_fn(), with a
lockdep_copy_map() function which additionally NULLs the class_cache[].
Note: this oops was actually seen on 3.4-next, where flush_work() newly
does the racing lock_map_acquire(); but Tejun points out that 3.4 and
earlier are already vulnerable to the same through wait_on_work().
* Patch orginally from Peter. Hugh modified it a bit and wrote the
description.
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Reported-by: Hugh Dickins <hughd@google.com>
LKML-Reference: <alpine.LSU.2.00.1205070951170.1544@eggly.anvils>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: perform cpu down operations from low priority cpu_notifier()
Currently, all workqueue cpu hotplug operations run off
CPU_PRI_WORKQUEUE which is higher than normal notifiers. This is to
ensure that workqueue is up and running while bringing up a CPU before
other notifiers try to use workqueue on the CPU.
Per-cpu workqueues are supposed to remain working and bound to the CPU
for normal CPU_DOWN_PREPARE notifiers. This holds mostly true even
with workqueue offlining running with higher priority because
workqueue CPU_DOWN_PREPARE only creates a bound trustee thread which
runs the per-cpu workqueue without concurrency management without
explicitly detaching the existing workers.
However, if the trustee needs to create new workers, it creates
unbound workers which may wander off to other CPUs while
CPU_DOWN_PREPARE notifiers are in progress. Furthermore, if the CPU
down is cancelled, the per-CPU workqueue may end up with workers which
aren't bound to the CPU.
While reliably reproducible with a convoluted artificial test-case
involving scheduling and flushing CPU burning work items from CPU down
notifiers, this isn't very likely to happen in the wild, and, even
when it happens, the effects are likely to be hidden by the following
successful CPU down.
Fix it by using different priorities for up and down notifiers - high
priority for up operations and low priority for down operations.
Workqueue cpu hotplug operations will soon go through further cleanup.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: drop CPU_DYING notifier operation
Workqueue used CPU_DYING notification to mark GCWQ_DISASSOCIATED.
This was necessary because workqueue's CPU_DOWN_PREPARE happened
before other DOWN_PREPARE notifiers and workqueue needed to stay
associated across the rest of DOWN_PREPARE.
After the previous patch, workqueue's DOWN_PREPARE happens after
others and can set GCWQ_DISASSOCIATED directly. Drop CPU_DYING and
let the trustee set GCWQ_DISASSOCIATED after disabling concurrency
management.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: ROGUE workers are UNBOUND workers
Currently, WORKER_UNBOUND is used to mark workers for the unbound
global_cwq and WORKER_ROGUE is used to mark workers for disassociated
per-cpu global_cwqs. Both are used to make the marked worker skip
concurrency management and the only place they make any difference is
in worker_enter_idle() where WORKER_ROGUE is used to skip scheduling
idle timer, which can easily be replaced with trustee state testing.
This patch replaces WORKER_ROGUE with WORKER_UNBOUND and drops
WORKER_ROGUE. This is to prepare for removing trustee and handling
disassociated global_cwqs as unbound.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: use mutex for global_cwq manager exclusion
POOL_MANAGING_WORKERS is used to ensure that at most one worker takes
the manager role at any given time on a given global_cwq. Trustee
later hitched on it to assume manager adding blocking wait for the
bit. As trustee already needed a custom wait mechanism, waiting for
MANAGING_WORKERS was rolled into the same mechanism.
Trustee is scheduled to be removed. This patch separates out
MANAGING_WORKERS wait into per-pool mutex. Workers use
mutex_trylock() to test for manager role and trustee uses mutex_lock()
to claim manager roles.
gcwq_claim/release_management() helpers are added to grab and release
manager roles of all pools on a global_cwq. gcwq_claim_management()
always grabs pool manager mutexes in ascending pool index order and
uses pool index as lockdep subclass.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: drop @bind from create_worker()
Currently, create_worker()'s callers are responsible for deciding
whether the newly created worker should be bound to the associated CPU
and create_worker() sets WORKER_UNBOUND only for the workers for the
unbound global_cwq. Creation during normal operation is always via
maybe_create_worker() and @bind is true. For workers created during
hotplug, @bind is false.
Normal operation path is planned to be used even while the CPU is
going through hotplug operations or offline and this static decision
won't work.
Drop @bind from create_worker() and decide whether to bind by looking
at GCWQ_DISASSOCIATED. create_worker() will also set WORKER_UNBOUND
autmatically if disassociated. To avoid flipping GCWQ_DISASSOCIATED
while create_worker() is in progress, the flag is now allowed to be
changed only while holding all manager_mutexes on the global_cwq.
This requires that GCWQ_DISASSOCIATED is not cleared behind trustee's
back. CPU_ONLINE no longer clears DISASSOCIATED before flushing
trustee, which clears DISASSOCIATED before rebinding remaining workers
if asked to release. For cases where trustee isn't around, CPU_ONLINE
clears DISASSOCIATED after flushing trustee. Also, now, first_idle
has UNBOUND set on creation which is explicitly cleared by CPU_ONLINE
while binding it. These convolutions will soon be removed by further
simplification of CPU hotplug path.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: reimplement CPU online rebinding to handle idle workers
Currently, if there are left workers when a CPU is being brough back
online, the trustee kills all idle workers and scheduled rebind_work
so that they re-bind to the CPU after the currently executing work is
finished. This works for busy workers because concurrency management
doesn't try to wake up them from scheduler callbacks, which require
the target task to be on the local run queue. The busy worker bumps
concurrency counter appropriately as it clears WORKER_UNBOUND from the
rebind work item and it's bound to the CPU before returning to the
idle state.
To reduce CPU on/offlining overhead (as many embedded systems use it
for powersaving) and simplify the code path, workqueue is planned to
be modified to retain idle workers across CPU on/offlining. This
patch reimplements CPU online rebinding such that it can also handle
idle workers.
As noted earlier, due to the local wakeup requirement, rebinding idle
workers is tricky. All idle workers must be re-bound before scheduler
callbacks are enabled. This is achieved by interlocking idle
re-binding. Idle workers are requested to re-bind and then hold until
all idle re-binding is complete so that no bound worker starts
executing work item. Only after all idle workers are re-bound and
parked, CPU_ONLINE proceeds to release them and queue rebind work item
to busy workers thus guaranteeing scheduler callbacks aren't invoked
until all idle workers are ready.
worker_rebind_fn() is renamed to busy_worker_rebind_fn() and
idle_worker_rebind() for idle workers is added. Rebinding logic is
moved to rebind_workers() and now called from CPU_ONLINE after
flushing trustee. While at it, add CPU sanity check in
worker_thread().
Note that now a worker may become idle or the manager between trustee
release and rebinding during CPU_ONLINE. As the previous patch
updated create_worker() so that it can be used by regular manager
while unbound and this patch implements idle re-binding, this is safe.
This prepares for removal of trustee and keeping idle workers across
CPU hotplugs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: don't butcher idle workers on an offline CPU
Currently, during CPU offlining, after all pending work items are
drained, the trustee butchers all workers. Also, on CPU onlining
failure, workqueue_cpu_callback() ensures that the first idle worker
is destroyed. Combined, these guarantee that an offline CPU doesn't
have any worker for it once all the lingering work items are finished.
This guarantee isn't really necessary and makes CPU on/offlining more
expensive than needs to be, especially for platforms which use CPU
hotplug for powersaving.
This patch lets offline CPUs removes idle worker butchering from the
trustee and let a CPU which failed onlining keep the created first
worker. The first worker is created if the CPU doesn't have any
during CPU_DOWN_PREPARE and started right away. If onlining succeeds,
the rebind_workers() call in CPU_ONLINE will rebind it like any other
workers. If onlining fails, the worker is left alone till the next
try.
This makes CPU hotplugs cheaper by allowing global_cwqs to keep
workers across them and simplifies code.
Note that trustee doesn't re-arm idle timer when it's done and thus
the disassociated global_cwq will keep all workers until it comes back
online. This will be improved by further patches.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: remove CPU offline trustee
With the previous changes, a disassociated global_cwq now can run as
an unbound one on its own - it can create workers as necessary to
drain remaining works after the CPU has been brought down and manage
the number of workers using the usual idle timer mechanism making
trustee completely redundant except for the actual unbinding
operation.
This patch removes the trustee and let a disassociated global_cwq
manage itself. Unbinding is moved to a work item (for CPU affinity)
which is scheduled and flushed from CPU_DONW_PREPARE.
This patch moves nr_running clearing outside gcwq and manager locks to
simplify the code. As nr_running is unused at the point, this is
safe.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: simplify CPU hotplug code
With trustee gone, CPU hotplug code can be simplified.
* gcwq_claim/release_management() now grab and release gcwq lock too
respectively and gained _and_lock and _and_unlock postfixes.
* All CPU hotplug logic was implemented in workqueue_cpu_callback()
which was called by workqueue_cpu_up/down_callback() for the correct
priority. This was because up and down paths shared a lot of logic,
which is no longer true. Remove workqueue_cpu_callback() and move
all hotplug logic into the two actual callbacks.
This patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
workqueue: fix spurious CPU locality WARN from process_one_work()
25511a4776 "workqueue: reimplement CPU online rebinding to handle idle
workers" added CPU locality sanity check in process_one_work(). It
triggers if a worker is executing on a different CPU without UNBOUND
or REBIND set.
This works for all normal workers but rescuers can trigger this
spuriously when they're serving the unbound or a disassociated
global_cwq - rescuers don't have either flag set and thus its
gcwq->cpu can be a different value including %WORK_CPU_UNBOUND.
Fix it by additionally testing %GCWQ_DISASSOCIATED.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
LKML-Refence: <20120721213656.GA7783@linux.vnet.ibm.com>
workqueue: reorder queueing functions so that _on() variants are on top
Currently, queue/schedule[_delayed]_work_on() are located below the
counterpart without the _on postifx even though the latter is usually
implemented using the former. Swap them.
This is cleanup and doesn't cause any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: make queueing functions return bool
All queueing functions return 1 on success, 0 if the work item was
already pending. Update them to return bool instead. This signifies
better that they don't return 0 / -errno.
This is cleanup and doesn't cause any functional difference.
While at it, fix comment opening for schedule_work_on().
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: add missing smp_wmb() in process_one_work()
WORK_STRUCT_PENDING is used to claim ownership of a work item and
process_one_work() releases it before starting execution. When
someone else grabs PENDING, all pre-release updates to the work item
should be visible and all updates made by the new owner should happen
afterwards.
Grabbing PENDING uses test_and_set_bit() and thus has a full barrier;
however, clearing doesn't have a matching wmb. Given the preceding
spin_unlock and use of clear_bit, I don't believe this can be a
problem on an actual machine and there hasn't been any related report
but it still is theretically possible for clear_pending to permeate
upwards and happen before work->entry update.
Add an explicit smp_wmb() before work_clear_pending().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: stable@vger.kernel.org
workqueue: disable irq while manipulating PENDING
Queueing operations use WORK_STRUCT_PENDING_BIT to synchronize access
to the target work item. They first try to claim the bit and proceed
with queueing only after that succeeds and there's a window between
PENDING being set and the actual queueing where the task can be
interrupted or preempted.
There's also a similar window in process_one_work() when clearing
PENDING. A work item is dequeued, gcwq->lock is released and then
PENDING is cleared and the worker might get interrupted or preempted
between releasing gcwq->lock and clearing PENDING.
cancel[_delayed]_work_sync() tries to claim or steal PENDING. The
function assumes that a work item with PENDING is either queued or in
the process of being [de]queued. In the latter case, it busy-loops
until either the work item loses PENDING or is queued. If canceling
coincides with the above described interrupts or preemptions, the
canceling task will busy-loop while the queueing or executing task is
preempted.
This patch keeps irq disabled across claiming PENDING and actual
queueing and moves PENDING clearing in process_one_work() inside
gcwq->lock so that busy looping from PENDING && !queued doesn't wait
for interrupted/preempted tasks. Note that, in process_one_work(),
setting last CPU and clearing PENDING got merged into single
operation.
This removes possible long busy-loops and will allow using
try_to_grab_pending() from bh and irq contexts.
v2: __queue_work() was testing preempt_count() to ensure that the
caller has disabled preemption. This triggers spuriously if
!CONFIG_PREEMPT_COUNT. Use preemptible() instead. Reported by
Fengguang Wu.
v3: Disable irq instead of preemption. IRQ will be disabled while
grabbing gcwq->lock later anyway and this allows using
try_to_grab_pending() from bh and irq contexts.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
workqueue: set delayed_work->timer function on initialization
delayed_work->timer.function is currently initialized during
queue_delayed_work_on(). Export delayed_work_timer_fn() and set
delayed_work timer function during delayed_work initialization
together with other fields.
This ensures the timer function is always valid on an initialized
delayed_work. This is to help mod_delayed_work() implementation.
To detect delayed_work users which diddle with the internal timer,
trigger WARN if timer function doesn't match on queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: unify local CPU queueing handling
Queueing functions have been using different methods to determine the
local CPU.
* queue_work() superflously uses get/put_cpu() to acquire and hold the
local CPU across queue_work_on().
* delayed_work_timer_fn() uses smp_processor_id().
* queue_delayed_work() calls queue_delayed_work_on() with -1 @cpu
which is interpreted as the local CPU.
* flush_delayed_work[_sync]() were using raw_smp_processor_id().
* __queue_work() interprets %WORK_CPU_UNBOUND as local CPU if the
target workqueue is bound one but nobody uses this.
This patch converts all functions to uniformly use %WORK_CPU_UNBOUND
to indicate local CPU and use the local binding feature of
__queue_work(). unlikely() is dropped from %WORK_CPU_UNBOUND handling
in __queue_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix zero @delay handling of queue_delayed_work_on()
If @delay is zero and the dealyed_work is idle, queue_delayed_work()
queues it for immediate execution; however, queue_delayed_work_on()
lacks this logic and always goes through timer regardless of @delay.
This patch moves 0 @delay handling logic from queue_delayed_work() to
queue_delayed_work_on() so that both functions behave the same.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: move try_to_grab_pending() upwards
try_to_grab_pending() will be used by to-be-implemented
mod_delayed_work[_on](). Move try_to_grab_pending() and related
functions above queueing functions.
This patch only moves functions around.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: introduce WORK_OFFQ_FLAG_*
Low WORK_STRUCT_FLAG_BITS bits of work_struct->data contain
WORK_STRUCT_FLAG_* and flush color. If the work item is queued, the
rest point to the cpu_workqueue with WORK_STRUCT_CWQ set; otherwise,
WORK_STRUCT_CWQ is clear and the bits contain the last CPU number -
either a real CPU number or one of WORK_CPU_*.
Scheduled addition of mod_delayed_work[_on]() requires an additional
flag, which is used only while a work item is off queue. There are
more than enough bits to represent off-queue CPU number on both 32 and
64bits. This patch introduces WORK_OFFQ_FLAG_* which occupy the lower
part of the @work->data high bits while off queue. This patch doesn't
define any actual OFFQ flag yet.
Off-queue CPU number is now shifted by WORK_OFFQ_CPU_SHIFT, which adds
the number of bits used by OFFQ flags to WORK_STRUCT_FLAG_SHIFT, to
make room for OFFQ flags.
To avoid shift width warning with large WORK_OFFQ_FLAG_BITS, ulong
cast is added to WORK_STRUCT_NO_CPU and, just in case, BUILD_BUG_ON()
to check that there are enough bits to accomodate off-queue CPU number
is added.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: factor out __queue_delayed_work() from queue_delayed_work_on()
This is to prepare for mod_delayed_work[_on]() and doesn't cause any
functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: reorganize try_to_grab_pending() and __cancel_timer_work()
* Use bool @is_dwork instead of @timer and let try_to_grab_pending()
use to_delayed_work() to determine the delayed_work address.
* Move timer handling from __cancel_work_timer() to
try_to_grab_pending().
* Make try_to_grab_pending() use -EAGAIN instead of -1 for
busy-looping and drop the ret local variable.
* Add proper function comment to try_to_grab_pending().
This makes the code a bit easier to understand and will ease further
changes. This patch doesn't make any functional change.
v2: Use @is_dwork instead of @timer.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: mark a work item being canceled as such
There can be two reasons try_to_grab_pending() can fail with -EAGAIN.
One is when someone else is queueing or deqeueing the work item. With
the previous patches, it is guaranteed that PENDING and queued state
will soon agree making it safe to busy-retry in this case.
The other is if multiple __cancel_work_timer() invocations are racing
one another. __cancel_work_timer() grabs PENDING and then waits for
running instances of the target work item on all CPUs while holding
PENDING and !queued. try_to_grab_pending() invoked from another task
will keep returning -EAGAIN while the current owner is waiting.
Not distinguishing the two cases is okay because __cancel_work_timer()
is the only user of try_to_grab_pending() and it invokes
wait_on_work() whenever grabbing fails. For the first case, busy
looping should be fine but wait_on_work() doesn't cause any critical
problem. For the latter case, the new contender usually waits for the
same condition as the current owner, so no unnecessarily extended
busy-looping happens. Combined, these make __cancel_work_timer()
technically correct even without irq protection while grabbing PENDING
or distinguishing the two different cases.
While the current code is technically correct, not distinguishing the
two cases makes it difficult to use try_to_grab_pending() for other
purposes than canceling because it's impossible to tell whether it's
safe to busy-retry grabbing.
This patch adds a mechanism to mark a work item being canceled.
try_to_grab_pending() now disables irq on success and returns -EAGAIN
to indicate that grabbing failed but PENDING and queued states are
gonna agree soon and it's safe to busy-loop. It returns -ENOENT if
the work item is being canceled and it may stay PENDING && !queued for
arbitrary amount of time.
__cancel_work_timer() is modified to mark the work canceling with
WORK_OFFQ_CANCELING after grabbing PENDING, thus making
try_to_grab_pending() fail with -ENOENT instead of -EAGAIN. Also, it
invokes wait_on_work() iff grabbing failed with -ENOENT. This isn't
necessary for correctness but makes it consistent with other future
users of try_to_grab_pending().
v2: try_to_grab_pending() was testing preempt_count() to ensure that
the caller has disabled preemption. This triggers spuriously if
!CONFIG_PREEMPT_COUNT. Use preemptible() instead. Reported by
Fengguang Wu.
v3: Updated so that try_to_grab_pending() disables irq on success
rather than requiring preemption disabled by the caller. This
makes busy-looping easier and will allow try_to_grap_pending() to
be used from bh/irq contexts.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
workqueue: implement mod_delayed_work[_on]()
Workqueue was lacking a mechanism to modify the timeout of an already
pending delayed_work. delayed_work users have been working around
this using several methods - using an explicit timer + work item,
messing directly with delayed_work->timer, and canceling before
re-queueing, all of which are error-prone and/or ugly.
This patch implements mod_delayed_work[_on]() which behaves similarly
to mod_timer() - if the delayed_work is idle, it's queued with the
given delay; otherwise, its timeout is modified to the new value.
Zero @delay guarantees immediate execution.
v2: Updated to reflect try_to_grab_pending() changes. Now safe to be
called from bh context.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
workqueue: fix CPU binding of flush_delayed_work[_sync]()
delayed_work encodes the workqueue to use and the last CPU in
delayed_work->work.data while it's on timer. The target CPU is
implicitly recorded as the CPU the timer is queued on and
delayed_work_timer_fn() queues delayed_work->work to the CPU it is
running on.
Unfortunately, this leaves flush_delayed_work[_sync]() no way to find
out which CPU the delayed_work was queued for when they try to
re-queue after killing the timer. Currently, it chooses the local CPU
flush is running on. This can unexpectedly move a delayed_work queued
on a specific CPU to another CPU and lead to subtle errors.
There isn't much point in trying to save several bytes in struct
delayed_work, which is already close to a hundred bytes on 64bit with
all debug options turned off. This patch adds delayed_work->cpu to
remember the CPU it's queued for.
Note that if the timer is migrated during CPU down, the work item
could be queued to the downed global_cwq after this change. As a
detached global_cwq behaves like an unbound one, this doesn't change
much for the delayed_work.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
workqueue: add missing wmb() in clear_work_data()
Any operation which clears PENDING should be preceded by a wmb to
guarantee that the next PENDING owner sees all the changes made before
PENDING release.
There are only two places where PENDING is cleared -
set_work_cpu_and_clear_pending() and clear_work_data(). The caller of
the former already does smp_wmb() but the latter doesn't have any.
Move the wmb above set_work_cpu_and_clear_pending() into it and add
one to clear_work_data().
There hasn't been any report related to this issue, and, given how
clear_work_data() is used, it is extremely unlikely to have caused any
actual problems on any architecture.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
workqueue: use enum value to set array size of pools in gcwq
Commit 3270476a6c0ce322354df8679652f060d66526dc ('workqueue: reimplement
WQ_HIGHPRI using a separate worker_pool') introduce separate worker_pool
for HIGHPRI. Although there is NR_WORKER_POOLS enum value which represent
size of pools, definition of worker_pool in gcwq doesn't use it.
Using it makes code robust and prevent future mistakes.
So change code to use this enum value.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: correct req_cpu in trace_workqueue_queue_work()
When we do tracing workqueue_queue_work(), it records requested cpu.
But, if !(@wq->flag & WQ_UNBOUND) and @cpu is WORK_CPU_UNBOUND,
requested cpu is changed as local cpu.
In case of @wq->flag & WQ_UNBOUND, above change is not occured,
therefore it is reasonable to correct it.
Use temporary local variable for storing requested cpu.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: change value of lcpu in __queue_delayed_work_on()
We assign cpu id into work struct's data field in __queue_delayed_work_on().
In current implementation, when work is come in first time,
current running cpu id is assigned.
If we do __queue_delayed_work_on() with CPU A on CPU B,
__queue_work() invoked in delayed_work_timer_fn() go into
the following sub-optimal path in case of WQ_NON_REENTRANT.
gcwq = get_gcwq(cpu);
if (wq->flags & WQ_NON_REENTRANT &&
(last_gcwq = get_work_gcwq(work)) && last_gcwq != gcwq) {
Change lcpu to @cpu and rechange lcpu to local cpu if lcpu is WORK_CPU_UNBOUND.
It is sufficient to prevent to go into sub-optimal path.
tj: Slightly rephrased the comment.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: introduce system_highpri_wq
Commit 3270476a6c0ce322354df8679652f060d66526dc ('workqueue: reimplement
WQ_HIGHPRI using a separate worker_pool') introduce separate worker pool
for HIGHPRI. When we handle busyworkers for gcwq, it can be normal worker
or highpri worker. But, we don't consider this difference in rebind_workers(),
we use just system_wq for highpri worker. It makes mismatch between
cwq->pool and worker->pool.
It doesn't make error in current implementation, but possible in the future.
Now, we introduce system_highpri_wq to use proper cwq for highpri workers
in rebind_workers(). Following patch fix this issue properly.
tj: Even apart from rebinding, having system_highpri_wq generally
makes sense.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: use system_highpri_wq for highpri workers in rebind_workers()
In rebind_workers(), we do inserting a work to rebind to cpu for busy workers.
Currently, in this case, we use only system_wq. This makes a possible
error situation as there is mismatch between cwq->pool and worker->pool.
To prevent this, we should use system_highpri_wq for highpri worker
to match theses. This implements it.
tj: Rephrased comment a bit.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: use system_highpri_wq for unbind_work
To speed cpu down processing up, use system_highpri_wq.
As scheduling priority of workers on it is higher than system_wq and
it is not contended by other normal works on this cpu, work on it
is processed faster than system_wq.
tj: CPU up/downs care quite a bit about latency these days. This
shouldn't hurt anything and makes sense.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix checkpatch issues
Fixed some checkpatch warnings.
tj: adapted to wq/for-3.7 and massaged pr_xxx() format strings a bit.
Signed-off-by: Valentin Ilie <valentin.ilie@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <1345326762-21747-1-git-send-email-valentin.ilie@gmail.com>
workqueue: make all workqueues non-reentrant
By default, each per-cpu part of a bound workqueue operates separately
and a work item may be executing concurrently on different CPUs. The
behavior avoids some cross-cpu traffic but leads to subtle weirdities
and not-so-subtle contortions in the API.
* There's no sane usefulness in allowing a single work item to be
executed concurrently on multiple CPUs. People just get the
behavior unintentionally and get surprised after learning about it.
Most either explicitly synchronize or use non-reentrant/ordered
workqueue but this is error-prone.
* flush_work() can't wait for multiple instances of the same work item
on different CPUs. If a work item is executing on cpu0 and then
queued on cpu1, flush_work() can only wait for the one on cpu1.
Unfortunately, work items can easily cross CPU boundaries
unintentionally when the queueing thread gets migrated. This means
that if multiple queuers compete, flush_work() can't even guarantee
that the instance queued right before it is finished before
returning.
* flush_work_sync() was added to work around some of the deficiencies
of flush_work(). In addition to the usual flushing, it ensures that
all currently executing instances are finished before returning.
This operation is expensive as it has to walk all CPUs and at the
same time fails to address competing queuer case.
Incorrectly using flush_work() when flush_work_sync() is necessary
is an easy error to make and can lead to bugs which are difficult to
reproduce.
* Similar problems exist for flush_delayed_work[_sync]().
Other than the cross-cpu access concern, there's no benefit in
allowing parallel execution and it's plain silly to have this level of
contortion for workqueue which is widely used from core code to
extremely obscure drivers.
This patch makes all workqueues non-reentrant. If a work item is
executing on a different CPU when queueing is requested, it is always
queued to that CPU. This guarantees that any given work item can be
executing on one CPU at maximum and if a work item is queued and
executing, both are on the same CPU.
The only behavior change which may affect workqueue users negatively
is that non-reentrancy overrides the affinity specified by
queue_work_on(). On a reentrant workqueue, the affinity specified by
queue_work_on() is always followed. Now, if the work item is
executing on one of the CPUs, the work item will be queued there
regardless of the requested affinity. I've reviewed all workqueue
users which request explicit affinity, and, fortunately, none seems to
be crazy enough to exploit parallel execution of the same work item.
This adds an additional busy_hash lookup if the work item was
previously queued on a different CPU. This shouldn't be noticeable
under any sane workload. Work item queueing isn't a very
high-frequency operation and they don't jump across CPUs all the time.
In a micro benchmark to exaggerate this difference - measuring the
time it takes for two work items to repeatedly jump between two CPUs a
number (10M) of times with busy_hash table densely populated, the
difference was around 3%.
While the overhead is measureable, it is only visible in pathological
cases and the difference isn't huge. This change brings much needed
sanity to workqueue and makes its behavior consistent with timer. I
think this is the right tradeoff to make.
This enables significant simplification of workqueue API.
Simplification patches will follow.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: gut flush[_delayed]_work_sync()
Now that all workqueues are non-reentrant, flush[_delayed]_work_sync()
are equivalent to flush[_delayed]_work(). Drop the separate
implementation and make them thin wrappers around
flush[_delayed]_work().
* start_flush_work() no longer takes @wait_executing as the only left
user - flush_work() - always sets it to %true.
* __cancel_work_timer() uses flush_work() instead of wait_on_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: gut system_nrt[_freezable]_wq()
Now that all workqueues are non-reentrant, system[_freezable]_wq() are
equivalent to system_nrt[_freezable]_wq(). Replace the latter with
wrappers around system[_freezable]_wq(). The wrapping goes through
inline functions so that __deprecated can be added easily.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: cosmetic whitespace updates for macro definitions
Consistently use the last tab position for '\' line continuation in
complex macro definitions. This is to help the following patches.
This patch is cosmetic.
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback()
workqueue_cpu_down_callback() is used only if HOTPLUG_CPU=y, so
hotcpu_notifier() fits better than cpu_notifier().
When HOTPLUG_CPU=y, hotcpu_notifier() and cpu_notifier() are the same.
When HOTPLUG_CPU=n, if we use cpu_notifier(),
workqueue_cpu_down_callback() will be called during boot to do
nothing, and the memory of workqueue_cpu_down_callback() and
gcwq_unbind_fn() will be discarded after boot.
If we use hotcpu_notifier(), we can avoid the no-op call of
workqueue_cpu_down_callback() and the memory of
workqueue_cpu_down_callback() and gcwq_unbind_fn() will be discard at
build time:
$ ls -l kernel/workqueue.o.cpu_notifier kernel/workqueue.o.hotcpu_notifier
-rw-rw-r-- 1 laijs laijs 484080 Sep 15 11:31 kernel/workqueue.o.cpu_notifier
-rw-rw-r-- 1 laijs laijs 478240 Sep 15 11:31 kernel/workqueue.o.hotcpu_notifier
$ size kernel/workqueue.o.cpu_notifier kernel/workqueue.o.hotcpu_notifier
text data bss dec hex filename
18513 2387 1221 22121 5669 kernel/workqueue.o.cpu_notifier
18082 2355 1221 21658 549a kernel/workqueue.o.hotcpu_notifier
tj: Updated description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: reimplement cancel_delayed_work() using try_to_grab_pending()
cancel_delayed_work() can't be called from IRQ handlers due to its use
of del_timer_sync() and can't cancel work items which are already
transferred from timer to worklist.
Also, unlike other flush and cancel functions, a canceled delayed_work
would still point to the last associated cpu_workqueue. If the
workqueue is destroyed afterwards and the work item is re-used on a
different workqueue, the queueing code can oops trying to dereference
already freed cpu_workqueue.
This patch reimplements cancel_delayed_work() using
try_to_grab_pending() and set_work_cpu_and_clear_pending(). This
allows the function to be called from IRQ handlers and makes its
behavior consistent with other flush / cancel functions.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
workqueue: UNBOUND -> REBIND morphing in rebind_workers() should be atomic
The compiler may compile the following code into TWO write/modify
instructions.
worker->flags &= ~WORKER_UNBOUND;
worker->flags |= WORKER_REBIND;
so the other CPU may temporarily see worker->flags which doesn't have
either WORKER_UNBOUND or WORKER_REBIND set and perform local wakeup
prematurely.
Fix it by using single explicit assignment via ACCESS_ONCE().
Because idle workers have another WORKER_NOT_RUNNING flag, this bug
doesn't exist for them; however, update it to use the same pattern for
consistency.
tj: Applied the change to idle workers too and updated comments and
patch description a bit.
Change-Id: I9b95f51d146c40c31ba028668d6f412bd74c6026
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
workqueue: move WORKER_REBIND clearing in rebind_workers() to the end of the function
This doesn't make any functional difference and is purely to help the
next patch to be simpler.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
workqueue: fix possible deadlock in idle worker rebinding
Currently, rebind_workers() and idle_worker_rebind() are two-way
interlocked. rebind_workers() waits for idle workers to finish
rebinding and rebound idle workers wait for rebind_workers() to finish
rebinding busy workers before proceeding.
Unfortunately, this isn't enough. The second wait from idle workers
is implemented as follows.
wait_event(gcwq->rebind_hold, !(worker->flags & WORKER_REBIND));
rebind_workers() clears WORKER_REBIND, wakes up the idle workers and
then returns. If CPU hotplug cycle happens again before one of the
idle workers finishes the above wait_event(), rebind_workers() will
repeat the first part of the handshake - set WORKER_REBIND again and
wait for the idle worker to finish rebinding - and this leads to
deadlock because the idle worker would be waiting for WORKER_REBIND to
clear.
This is fixed by adding another interlocking step at the end -
rebind_workers() now waits for all the idle workers to finish the
above WORKER_REBIND wait before returning. This ensures that all
rebinding steps are complete on all idle workers before the next
hotplug cycle can happen.
This problem was diagnosed by Lai Jiangshan who also posted a patch to
fix the issue, upon which this patch is based.
This is the minimal fix and further patches are scheduled for the next
merge window to simplify the CPU hotplug path.
Signed-off-by: Tejun Heo <tj@kernel.org>
Original-patch-by: Lai Jiangshan <laijs@cn.fujitsu.com>
LKML-Reference: <1346516916-1991-3-git-send-email-laijs@cn.fujitsu.com>
workqueue: restore POOL_MANAGING_WORKERS
This patch restores POOL_MANAGING_WORKERS which was replaced by
pool->manager_mutex by 6037315269 "workqueue: use mutex for global_cwq
manager exclusion".
There's a subtle idle worker depletion bug across CPU hotplug events
and we need to distinguish an actual manager and CPU hotplug
preventing management. POOL_MANAGING_WORKERS will be used for the
former and manager_mutex the later.
This patch just lays POOL_MANAGING_WORKERS on top of the existing
manager_mutex and doesn't introduce any synchronization changes. The
next patch will update it.
Note that this patch fixes a non-critical anomaly where
too_many_workers() may return %true spuriously while CPU hotplug is in
progress. While the issue could schedule idle timer spuriously, it
didn't trigger any actual misbehavior.
tj: Rewrote patch description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix possible idle worker depletion across CPU hotplug
To simplify both normal and CPU hotplug paths, worker management is
prevented while CPU hoplug is in progress. This is achieved by CPU
hotplug holding the same exclusion mechanism used by workers to ensure
there's only one manager per pool.
If someone else seems to be performing the manager role, workers
proceed to execute work items. CPU hotplug using the same mechanism
can lead to idle worker depletion because all workers could proceed to
execute work items while CPU hotplug is in progress and CPU hotplug
itself wouldn't actually perform the worker management duty - it
doesn't guarantee that there's an idle worker left when it releases
management.
This idle worker depletion, under extreme circumstances, can break
forward-progress guarantee and thus lead to deadlock.
This patch fixes the bug by using separate mechanisms for manager
exclusion among workers and hotplug exclusion. For manager exclusion,
POOL_MANAGING_WORKERS which was restored by the previous patch is
used. pool->manager_mutex is now only used for exclusion between the
elected manager and CPU hotplug. The elected manager won't proceed
without holding pool->manager_mutex.
This ensures that the worker which won the manager position can't skip
managing while CPU hotplug is in progress. It will block on
manager_mutex and perform management after CPU hotplug is complete.
Note that hotplug may happen while waiting for manager_mutex. A
manager isn't either on idle or busy list and thus the hoplug code
can't unbind/rebind it. Make the manager handle its own un/rebinding.
tj: Updated comment and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()
busy_worker_rebind_fn() didn't clear WORKER_REBIND if rebinding failed
(CPU is down again). This used to be okay because the flag wasn't
used for anything else.
However, after 25511a477 "workqueue: reimplement CPU online rebinding
to handle idle workers", WORKER_REBIND is also used to command idle
workers to rebind. If not cleared, the worker may confuse the next
CPU_UP cycle by having REBIND spuriously set or oops / get stuck by
prematurely calling idle_worker_rebind().
WARNING: at /work/os/wq/kernel/workqueue.c:1323 worker_thread+0x4cd/0x5
00()
Hardware name: Bochs
Modules linked in: test_wq(O-)
Pid: 33, comm: kworker/1:1 Tainted: G O 3.6.0-rc1-work+ #3
Call Trace:
[<ffffffff8109039f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff810903fa>] warn_slowpath_null+0x1a/0x20
[<ffffffff810b3f1d>] worker_thread+0x4cd/0x500
[<ffffffff810bc16e>] kthread+0xbe/0xd0
[<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
---[ end trace e977cf20f4661968 ]---
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff810b3db0>] worker_thread+0x360/0x500
PGD 0
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
Modules linked in: test_wq(O-)
CPU 0
Pid: 33, comm: kworker/1:1 Tainted: G W O 3.6.0-rc1-work+ #3 Bochs Bochs
RIP: 0010:[<ffffffff810b3db0>] [<ffffffff810b3db0>] worker_thread+0x360/0x500
RSP: 0018:ffff88001e1c9de0 EFLAGS: 00010086
RAX: 0000000000000000 RBX: ffff88001e633e00 RCX: 0000000000004140
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffff88001e1c9ea0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88001fc8d580
R13: ffff88001fc8d590 R14: ffff88001e633e20 R15: ffff88001e1c6900
FS: 0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000000 CR3: 00000000130e8000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process kworker/1:1 (pid: 33, threadinfo ffff88001e1c8000, task ffff88001e1c6900)
Stack:
ffff880000000000 ffff88001e1c9e40 0000000000000001 ffff88001e1c8010
ffff88001e519c78 ffff88001e1c9e58 ffff88001e1c6900 ffff88001e1c6900
ffff88001e1c6900 ffff88001e1c6900 ffff88001fc8d340 ffff88001fc8d340
Call Trace:
[<ffffffff810bc16e>] kthread+0xbe/0xd0
[<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10
Code: b1 00 f6 43 48 02 0f 85 91 01 00 00 48 8b 43 38 48 89 df 48 8b 00 48 89 45 90 e8 ac f0 ff ff 3c 01 0f 85 60 01 00 00 48 8b 53 50 <8b> 02 83 e8 01 85 c0 89 02 0f 84 3b 01 00 00 48 8b 43 38 48 8b
RIP [<ffffffff810b3db0>] worker_thread+0x360/0x500
RSP <ffff88001e1c9de0>
CR2: 0000000000000000
There was no reason to keep WORKER_REBIND on failure in the first
place - WORKER_UNBOUND is guaranteed to be set in such cases
preventing incorrectly activating concurrency management. Always
clear WORKER_REBIND.
tj: Updated comment and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: reimplement idle worker rebinding
Currently rebind_workers() uses rebinds idle workers synchronously
before proceeding to requesting busy workers to rebind. This is
necessary because all workers on @worker_pool->idle_list must be bound
before concurrency management local wake-ups from the busy workers
take place.
Unfortunately, the synchronous idle rebinding is quite complicated.
This patch reimplements idle rebinding to simplify the code path.
Rather than trying to make all idle workers bound before rebinding
busy workers, we simply remove all to-be-bound idle workers from the
idle list and let them add themselves back after completing rebinding
(successful or not).
As only workers which finished rebinding can on on the idle worker
list, the idle worker list is guaranteed to have only bound workers
unless CPU went down again and local wake-ups are safe.
After the change, @worker_pool->nr_idle may deviate than the actual
number of idle workers on @worker_pool->idle_list. More specifically,
nr_idle may be non-zero while ->idle_list is empty. All users of
->nr_idle and ->idle_list are audited. The only affected one is
too_many_workers() which is updated to check %false if ->idle_list is
empty regardless of ->nr_idle.
After this patch, rebind_workers() no longer performs the nasty
idle-rebind retries which require temporary release of gcwq->lock, and
both unbinding and rebinding are atomic w.r.t. global_cwq->lock.
worker->idle_rebind and global_cwq->rebind_hold are now unnecessary
and removed along with the definition of struct idle_rebind.
Changed from V1:
1) remove unlikely from too_many_workers(), ->idle_list can be empty
anytime, even before this patch, no reason to use unlikely.
2) fix a small rebasing mistake.
(which is from rebasing the orignal fixing patch to for-next)
3) add a lot of comments.
4) clear WORKER_REBIND unconditionaly in idle_worker_rebind()
tj: Updated comments and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: WORKER_REBIND is no longer necessary for busy rebinding
Because the old unbind/rebinding implementation wasn't atomic w.r.t.
GCWQ_DISASSOCIATED manipulation which is protected by
global_cwq->lock, we had to use two flags, WORKER_UNBOUND and
WORKER_REBIND, to avoid incorrectly losing all NOT_RUNNING bits with
back-to-back CPU hotplug operations; otherwise, completion of
rebinding while another unbinding is in progress could clear UNBIND
prematurely.
Now that both unbind/rebinding are atomic w.r.t. GCWQ_DISASSOCIATED,
there's no need to use two flags. Just one is enough. Don't use
WORKER_REBIND for busy rebinding.
tj: Updated description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: WORKER_REBIND is no longer necessary for idle rebinding
Now both worker destruction and idle rebinding remove the worker from
idle list while it's still idle, so list_empty(&worker->entry) can be
used to test whether either is pending and WORKER_DIE to distinguish
between the two instead making WORKER_REBIND unnecessary.
Use list_empty(&worker->entry) to determine whether destruction or
rebinding is pending. This simplifies worker state transitions.
WORKER_REBIND is not needed anymore. Remove it.
tj: Updated comments and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: rename manager_mutex to assoc_mutex
Now that manager_mutex's role has changed from synchronizing manager
role to excluding hotplug against manager, the name is misleading.
As it is protecting the CPU-association of the gcwq now, rename it to
assoc_mutex.
This patch is pure rename and doesn't introduce any functional change.
tj: Updated comments and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: use __cpuinit instead of __devinit for cpu callbacks
For workqueue hotplug callbacks, it makes less sense to use __devinit
which discards the memory after boot if !HOTPLUG. __cpuinit, which
discards the memory after boot if !HOTPLUG_CPU fits better.
tj: Updated description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: fix possible stall on try_to_grab_pending() of a delayed work item
Currently, when try_to_grab_pending() grabs a delayed work item, it
leaves its linked work items alone on the delayed_works. The linked
work items are always NO_COLOR and will cause future
cwq_activate_first_delayed() increase cwq->nr_active incorrectly, and
may cause the whole cwq to stall. For example,
state: cwq->max_active = 1, cwq->nr_active = 1
one work in cwq->pool, many in cwq->delayed_works.
step1: try_to_grab_pending() removes a work item from delayed_works
but leaves its NO_COLOR linked work items on it.
step2: Later on, cwq_activate_first_delayed() activates the linked
work item increasing ->nr_active.
step3: cwq->nr_active = 1, but all activated work items of the cwq are
NO_COLOR. When they finish, cwq->nr_active will not be
decreased due to NO_COLOR, and no further work items will be
activated from cwq->delayed_works. the cwq stalls.
Fix it by ensuring the target work item is activated before stealing
PENDING in try_to_grab_pending(). This ensures that all the linked
work items are activated without incorrectly bumping cwq->nr_active.
tj: Updated comment and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
workqueue: reimplement work_on_cpu() using system_wq
The existing work_on_cpu() implementation is hugely inefficient. It
creates a new kthread, execute that single function and then let the
kthread die on each invocation.
Now that system_wq can handle concurrent executions, there's no
advantage of doing this. Reimplement work_on_cpu() using system_wq
which makes it simpler and way more efficient.
stable: While this isn't a fix in itself, it's needed to fix a
workqueue related bug in cpufreq/powernow-k8. AFAICS, this
shouldn't break other existing users.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: stable@vger.kernel.org
workqueue: introduce cwq_set_max_active() helper for thaw_workqueues()
Using a helper instead of open code makes thaw_workqueues() clearer.
The helper will also be used by the next patch.
tj: Slight update to comment and description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: use cwq_set_max_active() helper for workqueue_set_max_active()
workqueue_set_max_active() may increase ->max_active without
activating delayed works and may make the activation order differ from
the queueing order. Both aren't strictly bugs but the resulting
behavior could be a bit odd.
To make things more consistent, use cwq_set_max_active() helper which
immediately makes use of the newly increased max_mactive if there are
delayed work items and also keeps the activation order.
tj: Slight update to description.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending()
e0aecdd874 ("workqueue: use irqsafe timer for delayed_work") made
try_to_grab_pending() safe to use from irq context but forgot to
remove WARN_ON_ONCE(in_irq()). Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
workqueue: cancel_delayed_work() should return %false if work item is idle
57b30ae77b ("workqueue: reimplement cancel_delayed_work() using
try_to_grab_pending()") made cancel_delayed_work() always return %true
unless someone else is also trying to cancel the work item, which is
broken - if the target work item is idle, the return value should be
%false.
try_to_grab_pending() indicates that the target work item was idle by
zero return value. Use it for return. Note that this brings
cancel_delayed_work() in line with __cancel_work_timer() in return
value handling.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <444a6439-b1a4-4740-9e7e-bc37267cfe73@default>
workqueue: exit rescuer_thread() as TASK_RUNNING
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again. In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.
PID: 18105 TASK: ffff8807fd412180 CPU: 5 COMMAND: "kdmflush"
#0 [ffff8808157e7670] schedule at ffffffff8143f489
#1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
#2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
#3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
#4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
#5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
#6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
#7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
#8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
#9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
[exception RIP: kernel_thread_helper]
RIP: ffffffff8144a5c0 RSP: ffff8808157e7f58 RFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8107af60 RDI: ffff8803ee491d18
RBP: 0000000000000000 R8: 0000000000000000 R9: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
workqueue: mod_delayed_work_on() shouldn't queue timer on 0 delay
8376fe22c7 ("workqueue: implement mod_delayed_work[_on]()")
implemented mod_delayed_work[_on]() using the improved
try_to_grab_pending(). The function is later used, among others, to
replace [__]candel_delayed_work() + queue_delayed_work() combinations.
Unfortunately, a delayed_work item w/ zero @delay is handled slightly
differently by mod_delayed_work_on() compared to
queue_delayed_work_on(). The latter skips timer altogether and
directly queues it using queue_work_on() while the former schedules
timer which will expire on the closest tick. This means, when @delay
is zero, that [__]cancel_delayed_work() + queue_delayed_work_on()
makes the target item immediately executable while
mod_delayed_work_on() may induce delay of upto a full tick.
This somewhat subtle difference breaks some of the converted users.
e.g. block queue plugging uses delayed_work for deferred processing
and uses mod_delayed_work_on() when the queue needs to be immediately
unplugged. The above problem manifested as noticeably higher number
of context switches under certain circumstances.
The difference in behavior was caused by missing special case handling
for 0 delay in mod_delayed_work_on() compared to
queue_delayed_work_on(). Joonsoo Kim posted a patch to add it -
("workqueue: optimize mod_delayed_work_on() when @delay == 0")[1].
The patch was queued for 3.8 but it was described as optimization and
I missed that it was a correctness issue.
As both queue_delayed_work_on() and mod_delayed_work_on() use
__queue_delayed_work() for queueing, it seems that the better approach
is to move the 0 delay special handling to the function instead of
duplicating it in mod_delayed_work_on().
Fix the problem by moving 0 delay special case handling from
queue_delayed_work_on() to __queue_delayed_work(). This replaces
Joonsoo's patch.
[1] http://thread.gmane.org/gmane.linux.kernel/1379011/focus=1379012
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Anders Kaseorg <andersk@MIT.EDU>
Reported-and-tested-by: Zlatko Calusic <zlatko.calusic@iskon.hr>
LKML-Reference: <alpine.DEB.2.00.1211280953350.26602@dr-wily.mit.edu>
LKML-Reference: <50A78AA9.5040904@iskon.hr>
Cc: Joonsoo Kim <js1304@gmail.com>
workqueue: trivial fix for return statement in work_busy()
Return type of work_busy() is unsigned int.
There is return statement returning boolean value, 'false' in work_busy().
It is not problem, because 'false' may be treated '0'.
However, fixing it would make code robust.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: add WARN_ON_ONCE() on CPU number to wq_worker_waking_up()
Recently, workqueue code has gone through some changes and we found
some bugs related to concurrency management operations happening on
the wrong CPU. When a worker is concurrency managed
(!WORKER_NOT_RUNNIG), it should be bound to its associated cpu and
woken up to that cpu. Add WARN_ON_ONCE() to verify this.
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s
8852aac25e ("workqueue: mod_delayed_work_on() shouldn't queue timer on
0 delay") unexpectedly uncovered a very nasty abuse of delayed_work in
megaraid - it allocated work_struct, casted it to delayed_work and
then pass that into queue_delayed_work().
Previously, this was okay because 0 @delay short-circuited to
queue_work() before doing anything with delayed_work. 8852aac25e
moved 0 @delay test into __queue_delayed_work() after sanity check on
delayed_work making megaraid trigger BUG_ON().
Although megaraid is already fixed by c1d390d8e6 ("megaraid: fix
BUG_ON() from incorrect use of delayed work"), this patch converts
BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s so that such
abusers, if there are more, trigger warning but don't crash the
machine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Xiaotian Feng <xtfeng@gmail.com>
wq
Change-Id: Ia3c507777a995f32bf6b40dc8318203e53134229
|
Hi there; This is an automated reply, to let you know CyanogenMod doesn't merge pull You can submit your change requests through our public review system, That review system is an installation of Google's Gerrit code review. Thanks! |
3EleVen
pushed a commit
to Hybrid-Power/android_kernel_xiaomi_cancro
that referenced
this pull request
Aug 31, 2016
Change-Id: Ib07ead1e23e816c96552254c049016825a164f2c
UPSTREAM: zram/zcomp: use GFP_NOIO to allocate streams
(cherry picked from commit 3d5fe03a3ea013060ebba2a811aeb0f23f56aefa)
We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations. That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.
Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.
An example:
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
(jbd2_handle){+.+.?.}, at: start_this_handle+0x4ca/0x555
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x8da/0x117b
lock_acquire+0x10c/0x1a7
start_this_handle+0x52d/0x555
jbd2__journal_start+0xb4/0x237
__ext4_journal_start_sb+0x108/0x17e
ext4_dirty_inode+0x32/0x61
__mark_inode_dirty+0x16b/0x60c
iput+0x11e/0x274
__dentry_kill+0x148/0x1b8
shrink_dentry_list+0x274/0x44a
prune_dcache_sb+0x4a/0x55
super_cache_scan+0xfc/0x176
shrink_slab.part.14.constprop.25+0x2a2/0x4d3
shrink_zone+0x74/0x140
kswapd+0x6b7/0x930
kthread+0x107/0x10f
ret_from_fork+0x3f/0x70
irq event stamp: 138297
hardirqs last enabled at (138297): debug_check_no_locks_freed+0x113/0x12f
hardirqs last disabled at (138296): debug_check_no_locks_freed+0x33/0x12f
softirqs last enabled at (137818): __do_softirq+0x2d3/0x3e9
softirqs last disabled at (137813): irq_exit+0x41/0x95
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(jbd2_handle);
<Interrupt>
lock(jbd2_handle);
*** DEADLOCK ***
5 locks held by git/20158:
#0: (sb_writers#7){.+.+.+}, at: [<ffffffff81155411>] mnt_want_write+0x24/0x4b
CyanogenMod#1: (&type->i_mutex_dir_key#2/1){+.+.+.}, at: [<ffffffff81145087>] lock_rename+0xd9/0xe3
CyanogenMod#2: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8114f8e2>] lock_two_nondirectories+0x3f/0x6b
CyanogenMod#3: (&sb->s_type->i_mutex_key#11/4){+.+.+.}, at: [<ffffffff8114f909>] lock_two_nondirectories+0x66/0x6b
CyanogenMod#4: (jbd2_handle){+.+.?.}, at: [<ffffffff811e31db>] start_this_handle+0x4ca/0x555
stack backtrace:
CPU: 2 PID: 20158 Comm: git Not tainted 4.1.0-rc7-next-20150615-dbg-00016-g8bdf555-dirty #211
Call Trace:
dump_stack+0x4c/0x6e
mark_lock+0x384/0x56d
mark_held_locks+0x5f/0x76
lockdep_trace_alloc+0xb2/0xb5
kmem_cache_alloc_trace+0x32/0x1e2
zcomp_strm_alloc+0x25/0x73 [zram]
zcomp_strm_multi_find+0xe7/0x173 [zram]
zcomp_strm_find+0xc/0xe [zram]
zram_bvec_rw+0x2ca/0x7e0 [zram]
zram_make_request+0x1fa/0x301 [zram]
generic_make_request+0x9c/0xdb
submit_bio+0xf7/0x120
ext4_io_submit+0x2e/0x43
ext4_bio_write_page+0x1b7/0x300
mpage_submit_page+0x60/0x77
mpage_map_and_submit_buffers+0x10f/0x21d
ext4_writepages+0xc8c/0xe1b
do_writepages+0x23/0x2c
__filemap_fdatawrite_range+0x84/0x8b
filemap_flush+0x1c/0x1e
ext4_alloc_da_blocks+0xb8/0x117
ext4_rename+0x132/0x6dc
? mark_held_locks+0x5f/0x76
ext4_rename2+0x29/0x2b
vfs_rename+0x540/0x636
SyS_renameat2+0x359/0x44d
SyS_rename+0x1e/0x20
entry_SYSCALL_64_fastpath+0x12/0x6f
[minchan@kernel.org: add stable mark]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UPSTREAM: zram: try vmalloc() after kmalloc()
(cherry picked from commit d913897abace843bba20249f3190167f7895e9c3)
When we're using LZ4 multi compression streams for zram swap, we found
out page allocation failure message in system running test. That was
not only once, but a few(2 - 5 times per test). Also, some failure
cases were continually occurring to try allocation order 3.
In order to make parallel compression private data, we should call
kzalloc() with order 2/3 in runtime(lzo/lz4). But if there is no order
2/3 size memory to allocate in that time, page allocation fails. This
patch makes to use vmalloc() as fallback of kmalloc(), this prevents
page alloc failure warning.
After using this, we never found warning message in running test, also
It could reduce process startup latency about 60-120ms in each case.
For reference a call trace :
Binder_1: page allocation failure: order:3, mode:0x10c0d0
CPU: 0 PID: 424 Comm: Binder_1 Tainted: GW 3.10.49-perf-g991d02b-dirty #20
Call trace:
dump_backtrace+0x0/0x270
show_stack+0x10/0x1c
dump_stack+0x1c/0x28
warn_alloc_failed+0xfc/0x11c
__alloc_pages_nodemask+0x724/0x7f0
__get_free_pages+0x14/0x5c
kmalloc_order_trace+0x38/0xd8
zcomp_lz4_create+0x2c/0x38
zcomp_strm_alloc+0x34/0x78
zcomp_strm_multi_find+0x124/0x1ec
zcomp_strm_find+0xc/0x18
zram_bvec_rw+0x2fc/0x780
zram_make_request+0x25c/0x2d4
generic_make_request+0x80/0xbc
submit_bio+0xa4/0x15c
__swap_writepage+0x218/0x230
swap_writepage+0x3c/0x4c
shrink_page_list+0x51c/0x8d0
shrink_inactive_list+0x3f8/0x60c
shrink_lruvec+0x33c/0x4cc
shrink_zone+0x3c/0x100
try_to_free_pages+0x2b8/0x54c
__alloc_pages_nodemask+0x514/0x7f0
__get_free_pages+0x14/0x5c
proc_info_read+0x50/0xe4
vfs_read+0xa0/0x12c
SyS_read+0x44/0x74
DMA: 3397*4kB (MC) 26*8kB (RC) 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB
0*512kB 0*1024kB 0*2048kB 0*4096kB = 13796kB
[minchan@kernel.org: change vmalloc gfp and adding comment about gfp]
[sergey.senozhatsky@gmail.com: tweak comments and styles]
Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UPSTREAM: zram: pass gfp from zcomp frontend to backend
(cherry picked from commit 75d8947a36d0c9aedd69118d1f14bf424005c7c2)
Each zcomp backend uses own gfp flag but it's pointless because the
context they could be called is driven by upper layer(ie, zcomp
frontend). As well, zcomp frondend could call them in different
context. One context(ie, zram init part) is it should be better to make
sure successful allocation other context(ie, further stream allocation
part for accelarating I/O speed) is just optional so let's pass gfp down
from driver (ie, zcomp frontend) like normal MM convention.
[sergey.senozhatsky@gmail.com: add missing __vmalloc zero and highmem gfps]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UPSTREAM: zram/zcomp: do not zero out zcomp private pages
(cherry picked from commit e02d238c9852a91b30da9ea32ce36d1416cdc683)
Do not __GFP_ZERO allocated zcomp ->private pages. We keep allocated
streams around and use them for read/write requests, so we supply a
zeroed out ->private to compression algorithm as a scratch buffer only
once -- the first time we use that stream. For the rest of IO requests
served by this stream ->private usually contains some temporarily data
from the previous requests.
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UPSTREAM: block: disable entropy contributions for nonrot devices
(cherry picked from commit b277da0a8a594308e17881f4926879bd5fca2a2d)
Clear QUEUE_FLAG_ADD_RANDOM in all block drivers that set
QUEUE_FLAG_NONROT.
Historically, all block devices have automatically made entropy
contributions. But as previously stated in commit e2e1a14 ("block: add
sysfs knob for turning off disk entropy contributions"):
- On SSD disks, the completion times aren't as random as they
are for rotational drives. So it's questionable whether they
should contribute to the random pool in the first place.
- Calling add_disk_randomness() has a lot of overhead.
There are more reliable sources for randomness than non-rotational block
devices. From a security perspective it is better to err on the side of
caution than to allow entropy contributions from unreliable "random"
sources.
Change-Id: I2a4f86bacee8786e2cb1a82d45156338f79d64e0
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Feb 19, 2017
The commit facd8b8 ("irq: Sanitize invoke_softirq") converted irq exit calls of do_softirq() to __do_softirq() on all architectures, assuming it was only used there for its irq disablement properties. But as a side effect, the softirqs processed in the end of the hardirq are always called on the inline current stack that is used by irq_exit() instead of the softirq stack provided by the archs that override do_softirq(). The result is mostly safe if the architecture runs irq_exit() on a separate irq stack because then softirqs are processed on that same stack that is near empty at this stage (assuming hardirq aren't nesting). Otherwise irq_exit() runs in the task stack and so does the softirq too. The interrupted call stack can be randomly deep already and the softirq can dig through it even further. To add insult to the injury, this softirq can be interrupted by a new hardirq, maximizing the chances for a stack overrun as reported in powerpc for example: do_IRQ: stack overflow: 1920 CPU: 0 PID: 1602 Comm: qemu-system-ppc Not tainted 3.10.4-300.1.fc19.ppc64p7 #1 Call Trace: [c0000000050a8740] .show_stack+0x130/0x200 (unreliable) [c0000000050a8810] .dump_stack+0x28/0x3c [c0000000050a8880] .do_IRQ+0x2b8/0x2c0 [c0000000050a8930] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .cp_start_xmit+0x3a4/0x820 [8139cp] LR = .cp_start_xmit+0x390/0x820 [8139cp] [c0000000050a8d40] .dev_hard_start_xmit+0x394/0x640 [c0000000050a8e00] .sch_direct_xmit+0x110/0x260 [c0000000050a8ea0] .dev_queue_xmit+0x260/0x630 [c0000000050a8f40] .br_dev_queue_push_xmit+0xc4/0x130 [bridge] [c0000000050a8fc0] .br_dev_xmit+0x198/0x270 [bridge] [c0000000050a9070] .dev_hard_start_xmit+0x394/0x640 [c0000000050a9130] .dev_queue_xmit+0x428/0x630 [c0000000050a91d0] .ip_finish_output+0x2a4/0x550 [c0000000050a9290] .ip_local_out+0x50/0x70 [c0000000050a9310] .ip_queue_xmit+0x148/0x420 [c0000000050a93b0] .tcp_transmit_skb+0x4e4/0xaf0 [c0000000050a94a0] .__tcp_ack_snd_check+0x7c/0xf0 [c0000000050a9520] .tcp_rcv_established+0x1e8/0x930 [c0000000050a95f0] .tcp_v4_do_rcv+0x21c/0x570 [c0000000050a96c0] .tcp_v4_rcv+0x734/0x930 [c0000000050a97a0] .ip_local_deliver_finish+0x184/0x360 [c0000000050a9840] .ip_rcv_finish+0x148/0x400 [c0000000050a98d0] .__netif_receive_skb_core+0x4f8/0xb00 [c0000000050a99d0] .netif_receive_skb+0x44/0x110 [c0000000050a9a70] .br_handle_frame_finish+0x2bc/0x3f0 [bridge] [c0000000050a9b20] .br_nf_pre_routing_finish+0x2ac/0x420 [bridge] [c0000000050a9bd0] .br_nf_pre_routing+0x4dc/0x7d0 [bridge] [c0000000050a9c70] .nf_iterate+0x114/0x130 [c0000000050a9d30] .nf_hook_slow+0xb4/0x1e0 [c0000000050a9e00] .br_handle_frame+0x290/0x330 [bridge] [c0000000050a9ea0] .__netif_receive_skb_core+0x34c/0xb00 [c0000000050a9fa0] .netif_receive_skb+0x44/0x110 [c0000000050aa040] .napi_gro_receive+0xe8/0x120 [c0000000050aa0c0] .cp_rx_poll+0x31c/0x590 [8139cp] [c0000000050aa1d0] .net_rx_action+0x1dc/0x310 [c0000000050aa2b0] .__do_softirq+0x158/0x330 [c0000000050aa3b0] .irq_exit+0xc8/0x110 [c0000000050aa430] .do_IRQ+0xdc/0x2c0 [c0000000050aa4e0] hardware_interrupt_common+0x154/0x180 --- Exception: 501 at .bad_range+0x1c/0x110 LR = .get_page_from_freelist+0x908/0xbb0 [c0000000050aa7d0] .list_del+0x18/0x50 (unreliable) [c0000000050aa850] .get_page_from_freelist+0x908/0xbb0 [c0000000050aa9e0] .__alloc_pages_nodemask+0x21c/0xae0 [c0000000050aaba0] .alloc_pages_vma+0xd0/0x210 [c0000000050aac60] .handle_pte_fault+0x814/0xb70 [c0000000050aad50] .__get_user_pages+0x1a4/0x640 [c0000000050aae60] .get_user_pages_fast+0xec/0x160 [c0000000050aaf10] .__gfn_to_pfn_memslot+0x3b0/0x430 [kvm] [c0000000050aafd0] .kvmppc_gfn_to_pfn+0x64/0x130 [kvm] [c0000000050ab070] .kvmppc_mmu_map_page+0x94/0x530 [kvm] [c0000000050ab190] .kvmppc_handle_pagefault+0x174/0x610 [kvm] [c0000000050ab270] .kvmppc_handle_exit_pr+0x464/0x9b0 [kvm] [c0000000050ab320] kvm_start_lightweight+0x1ec/0x1fc [kvm] [c0000000050ab4f0] .kvmppc_vcpu_run_pr+0x168/0x3b0 [kvm] [c0000000050ab9c0] .kvmppc_vcpu_run+0xc8/0xf0 [kvm] [c0000000050aba50] .kvm_arch_vcpu_ioctl_run+0x5c/0x1a0 [kvm] [c0000000050abae0] .kvm_vcpu_ioctl+0x478/0x730 [kvm] [c0000000050abc90] .do_vfs_ioctl+0x4ec/0x7c0 [c0000000050abd80] .SyS_ioctl+0xd4/0xf0 [c0000000050abe30] syscall_exit+0x0/0x98 Since this is a regression, this patch proposes a minimalistic and low-risk solution by blindly forcing the hardirq exit processing of softirqs on the softirq stack. This way we should reduce significantly the opportunities for task stack overflow dug by softirqs. Longer term solutions may involve extending the hardirq stack coverage to irq_exit(), etc... Reported-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: CyanogenMod#3.9.. <stable@vger.kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul Mackerras <paulus@au1.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Mar 26, 2017
Running fsx on tmpfs with concurrent memhog-swapoff-swapon, lots of
BUG: sleeping function called from invalid context at kernel/fork.c:606
in_atomic(): 0, irqs_disabled(): 0, pid: 1394, name: swapoff
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
followed by
================================================
[ BUG: lock held when returning to user space! ]
3.14.0-rc1 CyanogenMod#3 Not tainted
------------------------------------------------
swapoff/1394 is leaving the kernel with locks still held!
1 lock held by swapoff/1394:
#0: (rcu_read_lock){.+.+.+}, at: [<ffffffff812520a1>] radix_tree_locate_item+0x1f/0x2b6
after which the system recovered nicely.
Whoops, I long ago forgot the rcu_read_unlock() on one unlikely branch.
Fixes e504f3f ("tmpfs radix_tree: locate_item to speed up swapoff")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Apr 18, 2017
This fixes CVE-2016-8650. If mpi_powm() is given a zero exponent, it wants to immediately return either 1 or 0, depending on the modulus. However, if the result was initalised with zero limb space, no limbs space is allocated and a NULL-pointer exception ensues. Fix this by allocating a minimal amount of limb space for the result when the 0-exponent case when the result is 1 and not touching the limb space when the result is 0. This affects the use of RSA keys and X.509 certificates that carry them. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 PGD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 task: ffff8804011944c0 task.stack: ffff880401294000 RIP: 0010:[<ffffffff8138ce5d>] [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP: 0018:ffff880401297ad8 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0 RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0 RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000 R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50 FS: 00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0 Stack: ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8 Call Trace: [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e [<ffffffff81001c2b>] do_syscall_64+0x80/0x191 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25 Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f RIP [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP <ffff880401297ad8> CR2: 0000000000000000 ---[ end trace d82015255d4a5d8d ]--- Basically, this is a backport of a libgcrypt patch: http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526 Change-Id: Idc78371a3b7aa2dd54448846ba885ca2eda33364 Fixes: cdec9cb ("crypto: GnuPG based MPI lib - source files (part 1)") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> cc: linux-ima-devel@lists.sourceforge.net cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Nov 3, 2017
This fixes CVE-2016-8650. If mpi_powm() is given a zero exponent, it wants to immediately return either 1 or 0, depending on the modulus. However, if the result was initalised with zero limb space, no limbs space is allocated and a NULL-pointer exception ensues. Fix this by allocating a minimal amount of limb space for the result when the 0-exponent case when the result is 1 and not touching the limb space when the result is 0. This affects the use of RSA keys and X.509 certificates that carry them. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 PGD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278 Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014 task: ffff8804011944c0 task.stack: ffff880401294000 RIP: 0010:[<ffffffff8138ce5d>] [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP: 0018:ffff880401297ad8 EFLAGS: 00010212 RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0 RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0 RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000 R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50 FS: 00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0 Stack: ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8 Call Trace: [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e [<ffffffff81001c2b>] do_syscall_64+0x80/0x191 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25 Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f RIP [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6 RSP <ffff880401297ad8> CR2: 0000000000000000 ---[ end trace d82015255d4a5d8d ]--- Basically, this is a backport of a libgcrypt patch: http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526 Change-Id: Idc78371a3b7aa2dd54448846ba885ca2eda33364 Fixes: cdec9cb ("crypto: GnuPG based MPI lib - source files (part 1)") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> cc: linux-ima-devel@lists.sourceforge.net cc: stable@vger.kernel.org Signed-off-by: James Morris <james.l.morris@oracle.com>
DrRamm
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Nov 3, 2017
[ Upstream commit 120e9dabaf551c6dc03d3a10a1f026376cb1811c ] syszkaller team reported another problem in DCCP [1] Problem here is that the structure holding RTO timer (ccid2_hc_tx_rto_expire() handler) is freed too soon. We can not use del_timer_sync() to cancel the timer since this timer wants to grab socket lock (that would risk a dead lock) Solution is to defer the freeing of memory when all references to the socket were released. Socket timers do own a reference, so this should fix the issue. [1] ================================================================== BUG: KASAN: use-after-free in ccid2_hc_tx_rto_expire+0x51c/0x5c0 net/dccp/ccids/ccid2.c:144 Read of size 4 at addr ffff8801d2660540 by task kworker/u4:7/3365 CPU: 1 PID: 3365 Comm: kworker/u4:7 Not tainted 4.13.0-rc4+ CyanogenMod#3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_unbound call_usermodehelper_exec_work Call Trace: <IRQ> __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 ccid2_hc_tx_rto_expire+0x51c/0x5c0 net/dccp/ccids/ccid2.c:144 call_timer_fn+0x233/0x830 kernel/time/timer.c:1268 expire_timers kernel/time/timer.c:1307 [inline] __run_timers+0x7fd/0xb90 kernel/time/timer.c:1601 run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614 __do_softirq+0x2f5/0xba3 kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 [inline] irq_exit+0x1cc/0x200 kernel/softirq.c:405 exiting_irq arch/x86/include/asm/apic.h:638 [inline] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:1044 apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:702 RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:824 [inline] RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:267 [inline] RIP: 0010:_raw_write_unlock_irq+0x56/0x70 kernel/locking/spinlock.c:343 RSP: 0018:ffff8801cd50eaa8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000000 RBX: ffffffff85a090c0 RCX: 0000000000000006 RDX: 1ffffffff0b595f3 RSI: 1ffff1003962f989 RDI: ffffffff85acaf98 RBP: ffff8801cd50eab0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cc96ea60 R13: dffffc0000000000 R14: ffff8801cc96e4c0 R15: ffff8801cc96e4c0 </IRQ> release_task+0xe9e/0x1a40 kernel/exit.c:220 wait_task_zombie kernel/exit.c:1162 [inline] wait_consider_task+0x29b8/0x33c0 kernel/exit.c:1389 do_wait_thread kernel/exit.c:1452 [inline] do_wait+0x441/0xa90 kernel/exit.c:1523 kernel_wait4+0x1f5/0x370 kernel/exit.c:1665 SYSC_wait4+0x134/0x140 kernel/exit.c:1677 SyS_wait4+0x2c/0x40 kernel/exit.c:1673 call_usermodehelper_exec_sync kernel/kmod.c:286 [inline] call_usermodehelper_exec_work+0x1a0/0x2c0 kernel/kmod.c:323 process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2097 worker_thread+0x223/0x1860 kernel/workqueue.c:2231 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425 Allocated by task 21267: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc+0x127/0x750 mm/slab.c:3561 ccid_new+0x20e/0x390 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x140 net/dccp/feat.c:44 __dccp_feat_activate+0x142/0x2a0 net/dccp/feat.c:344 dccp_feat_activate_values+0x34e/0xa90 net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline] dccp_rcv_state_process+0xed1/0x1620 net/dccp/input.c:677 dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:679 sk_backlog_rcv include/net/sock.h:911 [inline] __release_sock+0x124/0x360 net/core/sock.c:2269 release_sock+0xa4/0x2a0 net/core/sock.c:2784 inet_wait_for_connect net/ipv4/af_inet.c:557 [inline] __inet_stream_connect+0x671/0xf00 net/ipv4/af_inet.c:643 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:682 SYSC_connect+0x204/0x470 net/socket.c:1642 SyS_connect+0x24/0x30 net/socket.c:1623 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 3049: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x77/0x280 mm/slab.c:3763 ccid_hc_tx_delete+0xc5/0x100 net/dccp/ccid.c:190 dccp_destroy_sock+0x1d1/0x2b0 net/dccp/proto.c:225 inet_csk_destroy_sock+0x166/0x3f0 net/ipv4/inet_connection_sock.c:833 dccp_done+0xb7/0xd0 net/dccp/proto.c:145 dccp_time_wait+0x13d/0x300 net/dccp/minisocks.c:72 dccp_rcv_reset+0x1d1/0x5b0 net/dccp/input.c:160 dccp_rcv_state_process+0x8fc/0x1620 net/dccp/input.c:663 dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:679 sk_backlog_rcv include/net/sock.h:911 [inline] __sk_receive_skb+0x33e/0xc00 net/core/sock.c:521 dccp_v4_rcv+0xef1/0x1c00 net/dccp/ipv4.c:871 ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216 NF_HOOK include/linux/netfilter.h:248 [inline] ip_local_deliver+0x1ce/0x6d0 net/ipv4/ip_input.c:257 dst_input include/net/dst.h:477 [inline] ip_rcv_finish+0x8db/0x19c0 net/ipv4/ip_input.c:397 NF_HOOK include/linux/netfilter.h:248 [inline] ip_rcv+0xc3f/0x17d0 net/ipv4/ip_input.c:488 __netif_receive_skb_core+0x19af/0x33d0 net/core/dev.c:4417 __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4455 process_backlog+0x203/0x740 net/core/dev.c:5130 napi_poll net/core/dev.c:5527 [inline] net_rx_action+0x792/0x1910 net/core/dev.c:5593 __do_softirq+0x2f5/0xba3 kernel/softirq.c:284 The buggy address belongs to the object at ffff8801d2660100 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 1088 bytes inside of 1240-byte region [ffff8801d2660100, ffff8801d26605d8) The buggy address belongs to the page: page:ffffea0007499800 count:1 mapcount:0 mapping:ffff8801d2660100 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801d2660100 0000000000000000 0000000100000005 raw: ffffea00075271a0 ffffea0007538820 ffff8801d3aef9c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d2660400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d2660480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d2660500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d2660580: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc ffff8801d2660600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
DrRamm
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Nov 10, 2017
commit 058ebd0eba3aff16b144eabf4510ed9510e1416e upstream.
Jiri managed to trigger this warning:
[] ======================================================
[] [ INFO: possible circular locking dependency detected ]
[] 3.10.0+ #228 Tainted: G W
[] -------------------------------------------------------
[] p/6613 is trying to acquire lock:
[] (rcu_node_0){..-...}, at: [<ffffffff810ca797>] rcu_read_unlock_special+0xa7/0x250
[]
[] but task is already holding lock:
[] (&ctx->lock){-.-...}, at: [<ffffffff810f2879>] perf_lock_task_context+0xd9/0x2c0
[]
[] which lock already depends on the new lock.
[]
[] the existing dependency chain (in reverse order) is:
[]
[] -> CyanogenMod#4 (&ctx->lock){-.-...}:
[] -> CyanogenMod#3 (&rq->lock){-.-.-.}:
[] -> CyanogenMod#2 (&p->pi_lock){-.-.-.}:
[] -> #1 (&rnp->nocb_gp_wq[1]){......}:
[] -> #0 (rcu_node_0){..-...}:
Paul was quick to explain that due to preemptible RCU we cannot call
rcu_read_unlock() while holding scheduler (or nested) locks when part
of the read side critical section was preemptible.
Therefore solve it by making the entire RCU read side non-preemptible.
Also pull out the retry from under the non-preempt to play nice with RT.
Change-Id: Ib93e3be618e05a483b73144994058c886fd780dc
Reported-by: Jiri Olsa <jolsa@redhat.com>
Helped-out-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Nov 10, 2017
commit 058ebd0eba3aff16b144eabf4510ed9510e1416e upstream.
Jiri managed to trigger this warning:
[] ======================================================
[] [ INFO: possible circular locking dependency detected ]
[] 3.10.0+ #228 Tainted: G W
[] -------------------------------------------------------
[] p/6613 is trying to acquire lock:
[] (rcu_node_0){..-...}, at: [<ffffffff810ca797>] rcu_read_unlock_special+0xa7/0x250
[]
[] but task is already holding lock:
[] (&ctx->lock){-.-...}, at: [<ffffffff810f2879>] perf_lock_task_context+0xd9/0x2c0
[]
[] which lock already depends on the new lock.
[]
[] the existing dependency chain (in reverse order) is:
[]
[] -> CyanogenMod#4 (&ctx->lock){-.-...}:
[] -> CyanogenMod#3 (&rq->lock){-.-.-.}:
[] -> CyanogenMod#2 (&p->pi_lock){-.-.-.}:
[] -> #1 (&rnp->nocb_gp_wq[1]){......}:
[] -> #0 (rcu_node_0){..-...}:
Paul was quick to explain that due to preemptible RCU we cannot call
rcu_read_unlock() while holding scheduler (or nested) locks when part
of the read side critical section was preemptible.
Therefore solve it by making the entire RCU read side non-preemptible.
Also pull out the retry from under the non-preempt to play nice with RT.
Change-Id: Ib93e3be618e05a483b73144994058c886fd780dc
Reported-by: Jiri Olsa <jolsa@redhat.com>
Helped-out-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 13, 2017
commit ecf5fc6e9654cd7a268c782a523f072b2f1959f9 upstream. Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e CyanogenMod#2 schedule_timeout at ffffffff815ae5e5 CyanogenMod#3 io_schedule_timeout at ffffffff815aad6a CyanogenMod#4 bit_wait_io at ffffffff815abfc6 CyanogenMod#5 __wait_on_bit at ffffffff815abda5 CyanogenMod#6 wait_on_page_bit at ffffffff8111fd4f CyanogenMod#7 shrink_page_list at ffffffff81135445 CyanogenMod#8 shrink_inactive_list at ffffffff81135845 CyanogenMod#9 shrink_lruvec at ffffffff81135ead CyanogenMod#10 shrink_zone at ffffffff811360c3 CyanogenMod#11 shrink_zones at ffffffff81136eff CyanogenMod#12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384 ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f4 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. [tytso@mit.edu: corrected the control flow] Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages") Reported-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [@nathanchance: Fixed conflicts due to 488cb10; omitted comment changes] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 13, 2017
commit 420902c9d086848a7548c83e0a49021514bd71b7 upstream.
If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can
deadlock our own worker - mount blocks kworker/3:2, sleeps forever more.
crash> ps|grep UN
715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2]
9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg
9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon
10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount
crash> bt ffff880220734d30
PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2"
#0 [ffff8802244c3c20] schedule at ffffffff8144584b
#1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3
CyanogenMod#2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5
CyanogenMod#3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs]
CyanogenMod#4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs]
CyanogenMod#5 [ffff8802244c3e08] process_one_work at ffffffff81073726
CyanogenMod#6 [ffff8802244c3e68] worker_thread at ffffffff81073eba
CyanogenMod#7 [ffff8802244c3ec8] kthread at ffffffff810782e0
CyanogenMod#8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064
crash> rd ffff8802244c3cc8 10
ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2."....
ffff8802244c3cd8: 0000000000000000 0000000000000286 ................
ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms ....
ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............
ffff8802244c3d08: 0000000000000000 0000000000000002 ................
crash> struct rt_mutex ffff880222e8f628
struct rt_mutex {
wait_lock = {
raw_lock = {
slock = 65537
}
},
wait_list = {
node_list = {
next = 0xffff8802244c3d48,
prev = 0xffff8802244c3d48
}
},
owner = 0xffff880222f22c71,
save_state = 0
}
crash> bt 0xffff880222f22c70
PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount"
#0 [ffff8802216a9868] schedule at ffffffff8144584b
#1 [ffff8802216a9910] schedule_timeout at ffffffff81446865
CyanogenMod#2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74
CyanogenMod#3 [ffff8802216a9a30] flush_work at ffffffff810712d3
CyanogenMod#4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463
CyanogenMod#5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba
CyanogenMod#6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632
CyanogenMod#7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c
CyanogenMod#8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs]
CyanogenMod#9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs]
RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202
RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0
RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0
RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001
R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e
R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20
ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b
Signed-off-by: Mike Galbraith <efault@gmx.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 13, 2017
commit 2bd624b4611ffee36422782d16e1c944d1351e98 upstream.
Commit 6664498280cf ("packet: call fanout_release, while UNREGISTERING a
netdev"), unfortunately, introduced the following issues.
1. calling mutex_lock(&fanout_mutex) (fanout_release()) from inside
rcu_read-side critical section. rcu_read_lock disables preemption, most often,
which prohibits calling sleeping functions.
[ ] include/linux/rcupdate.h:560 Illegal context switch in RCU read-side critical section!
[ ]
[ ] rcu_scheduler_active = 1, debug_locks = 0
[ ] 4 locks held by ovs-vswitchd/1969:
[ ] #0: (cb_lock){++++++}, at: [<ffffffff8158a6c9>] genl_rcv+0x19/0x40
[ ] #1: (ovs_mutex){+.+.+.}, at: [<ffffffffa04878ca>] ovs_vport_cmd_del+0x4a/0x100 [openvswitch]
[ ] CyanogenMod#2: (rtnl_mutex){+.+.+.}, at: [<ffffffff81564157>] rtnl_lock+0x17/0x20
[ ] CyanogenMod#3: (rcu_read_lock){......}, at: [<ffffffff81614165>] packet_notifier+0x5/0x3f0
[ ]
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff810c9077>] lockdep_rcu_suspicious+0x107/0x110
[ ] [<ffffffff810a2da7>] ___might_sleep+0x57/0x210
[ ] [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[ ] [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[ ] [<ffffffff810de93f>] ? vprintk_default+0x1f/0x30
[ ] [<ffffffff81186e88>] ? printk+0x4d/0x4f
[ ] [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0
2. calling mutex_lock(&fanout_mutex) inside spin_lock(&po->bind_lock).
"sleeping function called from invalid context"
[ ] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ ] in_atomic(): 1, irqs_disabled(): 0, pid: 1969, name: ovs-vswitchd
[ ] INFO: lockdep is turned off.
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff810a2f52>] ___might_sleep+0x202/0x210
[ ] [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[ ] [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[ ] [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0
3. calling dev_remove_pack(&fanout->prot_hook), from inside
spin_lock(&po->bind_lock) or rcu_read-side critical-section. dev_remove_pack()
-> synchronize_net(), which might sleep.
[ ] BUG: scheduling while atomic: ovs-vswitchd/1969/0x00000002
[ ] INFO: lockdep is turned off.
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff81186274>] __schedule_bug+0x64/0x73
[ ] [<ffffffff8162b8cb>] __schedule+0x6b/0xd10
[ ] [<ffffffff8162c5db>] schedule+0x6b/0x80
[ ] [<ffffffff81630b1d>] schedule_timeout+0x38d/0x410
[ ] [<ffffffff810ea3fd>] synchronize_sched_expedited+0x53d/0x810
[ ] [<ffffffff810ea6de>] synchronize_rcu_expedited+0xe/0x10
[ ] [<ffffffff8154eab5>] synchronize_net+0x35/0x50
[ ] [<ffffffff8154eae3>] dev_remove_pack+0x13/0x20
[ ] [<ffffffff8161077e>] fanout_release+0xbe/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0
4. fanout_release() races with calls from different CPU.
To fix the above problems, remove the call to fanout_release() under
rcu_read_lock(). Instead, call __dev_remove_pack(&fanout->prot_hook) and
netdev_run_todo will be happy that &dev->ptype_specific list is empty. In order
to achieve this, I moved dev_{add,remove}_pack() out of fanout_{add,release} to
__fanout_{link,unlink}. So, call to {,__}unregister_prot_hook() will make sure
fanout->prot_hook is removed as well.
[js] no rollover in 3.12
Fixes: 6664498280cf ("packet: call fanout_release, while UNREGISTERING a netdev")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 13, 2017
commit 3d46a44a0c01b15d385ccaae24b56f619613c256 upstream. PID: 614 TASK: ffff882a739da580 CPU: 3 COMMAND: "ocfs2dc" #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5 CyanogenMod#2 [ffff882ecc375af0] oops_end at ffffffff815091d8 CyanogenMod#3 [ffff882ecc375b20] die at ffffffff8101868b CyanogenMod#4 [ffff882ecc375b50] do_trap at ffffffff81508bb0 CyanogenMod#5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5 CyanogenMod#6 [ffff882ecc375c40] invalid_op at ffffffff815116fb [exception RIP: ocfs2_ci_checkpointed+208] RIP: ffffffffa0a7e940 RSP: ffff882ecc375cf0 RFLAGS: 00010002 RAX: 0000000000000001 RBX: 000000000000654b RCX: ffff8812dc83f1f8 RDX: 00000000000017d9 RSI: ffff8812dc83f1f8 RDI: ffffffffa0b2c318 RBP: ffff882ecc375d20 R8: ffff882ef6ecfa60 R9: ffff88301f272200 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffff R13: ffff8812dc83f4f0 R14: 0000000000000000 R15: ffff8812dc83f1f8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 CyanogenMod#7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2] CyanogenMod#8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2] CyanogenMod#9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2] assert is tripped because the tran is not checkpointed and the lock level is PR. Some time ago, chmod command had been executed. As result, the following call chain left the inode cluster lock in PR state, latter on causing the assert. system_call_fastpath -> my_chmod -> sys_chmod -> sys_fchmodat -> notify_change -> ocfs2_setattr -> posix_acl_chmod -> ocfs2_iop_set_acl -> ocfs2_set_acl -> ocfs2_acl_set_mode Here is how. 1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) 1120 { 1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do. .. 1258 if (!status && attr->ia_valid & ATTR_MODE) { 1259 status = posix_acl_chmod(inode, inode->i_mode); 519 posix_acl_chmod(struct inode *inode, umode_t mode) 520 { .. 539 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); 287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ... 288 { 289 return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL); 224 int ocfs2_set_acl(handle_t *handle, 225 struct inode *inode, ... 231 { .. 252 ret = ocfs2_acl_set_mode(inode, di_bh, 253 handle, mode); 168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ... 170 { 183 if (handle == NULL) { >>> BUG: inode lock not held in ex at this point <<< 184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), 185 OCFS2_INODE_UPDATE_CREDITS); ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach ocfs2_acl_set_mode.#181 and do trans, the inode cluster lock is not held in EX mode (it should be). How this could have happended? We are the lock master, were holding lock EX and have released it in ocfs2_setattr.#1247. Note that there are no holders of this lock at this point. Another node needs the lock in PR, and we downconvert from EX to PR. So the inode lock is PR when do the trans in ocfs2_acl_set_mode.#184. The trans stays in core (not flushed to disc). Now another node want the lock in EX, downconvert thread gets kicked (the one that tripped assert abovt), finds an unflushed trans but the lock is not EX (it is PR). If the lock was at EX, it would have flushed the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before downconverting (to NULL) for the request. ocfs2_setattr must not drop inode lock ex in this code path. If it does, takes it again before the trans, say in ocfs2_set_acl, another cluster node can get in between, execute another setattr, overwriting the one in progress on this node, resulting in a mode acl size combo that is a mix of the two. Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 13, 2017
commit d5afb6f9b6bb2c57bd0c05e76e12489dc0d037d9 upstream. The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b33d4b7 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ #234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 CyanogenMod#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] CyanogenMod#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] CyanogenMod#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 CyanogenMod#3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 CyanogenMod#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] CyanogenMod#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Dec 16, 2017
commit ecf5fc6e9654cd7a268c782a523f072b2f1959f9 upstream. Nikolay has reported a hang when a memcg reclaim got stuck with the following backtrace: PID: 18308 TASK: ffff883d7c9b0a30 CPU: 1 COMMAND: "rsync" #0 __schedule at ffffffff815ab152 #1 schedule at ffffffff815ab76e CyanogenMod#2 schedule_timeout at ffffffff815ae5e5 CyanogenMod#3 io_schedule_timeout at ffffffff815aad6a CyanogenMod#4 bit_wait_io at ffffffff815abfc6 CyanogenMod#5 __wait_on_bit at ffffffff815abda5 CyanogenMod#6 wait_on_page_bit at ffffffff8111fd4f CyanogenMod#7 shrink_page_list at ffffffff81135445 CyanogenMod#8 shrink_inactive_list at ffffffff81135845 CyanogenMod#9 shrink_lruvec at ffffffff81135ead CyanogenMod#10 shrink_zone at ffffffff811360c3 CyanogenMod#11 shrink_zones at ffffffff81136eff CyanogenMod#12 do_try_to_free_pages at ffffffff8113712f #13 try_to_free_mem_cgroup_pages at ffffffff811372be #14 try_charge at ffffffff81189423 #15 mem_cgroup_try_charge at ffffffff8118c6f5 #16 __add_to_page_cache_locked at ffffffff8112137d #17 add_to_page_cache_lru at ffffffff81121618 #18 pagecache_get_page at ffffffff8112170b #19 grow_dev_page at ffffffff811c8297 #20 __getblk_slow at ffffffff811c91d6 #21 __getblk_gfp at ffffffff811c92c1 #22 ext4_ext_grow_indepth at ffffffff8124565c #23 ext4_ext_create_new_leaf at ffffffff81246ca8 #24 ext4_ext_insert_extent at ffffffff81246f09 #25 ext4_ext_map_blocks at ffffffff8124a848 #26 ext4_map_blocks at ffffffff8121a5b7 #27 mpage_map_one_extent at ffffffff8121b1fa #28 mpage_map_and_submit_extent at ffffffff8121f07b #29 ext4_writepages at ffffffff8121f6d5 #30 do_writepages at ffffffff8112c490 #31 __filemap_fdatawrite_range at ffffffff81120199 #32 filemap_flush at ffffffff8112041c #33 ext4_alloc_da_blocks at ffffffff81219da1 #34 ext4_rename at ffffffff81229b91 #35 ext4_rename2 at ffffffff81229e32 #36 vfs_rename at ffffffff811a08a5 #37 SYSC_renameat2 at ffffffff811a3ffc #38 sys_renameat2 at ffffffff811a408e #39 sys_rename at ffffffff8119e51e #40 system_call_fastpath at ffffffff815afa89 Dave Chinner has properly pointed out that this is a deadlock in the reclaim code because ext4 doesn't submit pages which are marked by PG_writeback right away. The heuristic was introduced by commit e62e384 ("memcg: prevent OOM with too many dirty pages") and it was applied only when may_enter_fs was specified. The code has been changed by c3b94f4 ("memcg: further prevent OOM with too many dirty pages") which has removed the __GFP_FS restriction with a reasoning that we do not get into the fs code. But this is not sufficient apparently because the fs doesn't necessarily submit pages marked PG_writeback for IO right away. ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily submit the bio. Instead it tries to map more pages into the bio and mpage_map_one_extent might trigger memcg charge which might end up waiting on a page which is marked PG_writeback but hasn't been submitted yet so we would end up waiting for something that never finishes. Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2) before we go to wait on the writeback. The page fault path, which is the only path that triggers memcg oom killer since 3.12, shouldn't require GFP_NOFS and so we shouldn't reintroduce the premature OOM killer issue which was originally addressed by the heuristic. As per David Chinner the xfs is doing similar thing since 2.6.15 already so ext4 is not the only affected filesystem. Moreover he notes: : For example: IO completion might require unwritten extent conversion : which executes filesystem transactions and GFP_NOFS allocations. The : writeback flag on the pages can not be cleared until unwritten : extent conversion completes. Hence memory reclaim cannot wait on : page writeback to complete in GFP_NOFS context because it is not : safe to do so, memcg reclaim or otherwise. [tytso@mit.edu: corrected the control flow] Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages") Reported-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> [@nathanchance: Fixed conflicts due to 488cb10; omitted comment changes] Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Jan 21, 2018
commit 6f2e9f0 upstream. Now when we set the group inode free count, we don't have a proper group lock so that multiple threads may decrease the inode free count at the same time. And e2fsck will complain something like: Free inodes count wrong for group #1 (1, counted=0). Fix? no Free inodes count wrong for group CyanogenMod#2 (3, counted=0). Fix? no Directories count wrong for group CyanogenMod#2 (780, counted=779). Fix? no Free inodes count wrong for group CyanogenMod#3 (2272, counted=2273). Fix? no So this patch try to protect it with the ext4_lock_group. btw, it is found by xfstests test case 269 and the volume is mkfsed with the parameter "-O ^resize_inode,^uninit_bg,extent,meta_bg,flex_bg,ext_attr" and I have run it 100 times and the error in e2fsck doesn't show up again. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Jan 21, 2018
commit 6f2e9f0 upstream. Now when we set the group inode free count, we don't have a proper group lock so that multiple threads may decrease the inode free count at the same time. And e2fsck will complain something like: Free inodes count wrong for group #1 (1, counted=0). Fix? no Free inodes count wrong for group CyanogenMod#2 (3, counted=0). Fix? no Directories count wrong for group CyanogenMod#2 (780, counted=779). Fix? no Free inodes count wrong for group CyanogenMod#3 (2272, counted=2273). Fix? no So this patch try to protect it with the ext4_lock_group. btw, it is found by xfstests test case 269 and the volume is mkfsed with the parameter "-O ^resize_inode,^uninit_bg,extent,meta_bg,flex_bg,ext_attr" and I have run it 100 times and the error in e2fsck doesn't show up again. Signed-off-by: Tao Ma <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Mar 5, 2018
(cherry picked from commit 3d5fe03a3ea013060ebba2a811aeb0f23f56aefa)
We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations. That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.
Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.
An example:
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
(jbd2_handle){+.+.?.}, at: start_this_handle+0x4ca/0x555
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x8da/0x117b
lock_acquire+0x10c/0x1a7
start_this_handle+0x52d/0x555
jbd2__journal_start+0xb4/0x237
__ext4_journal_start_sb+0x108/0x17e
ext4_dirty_inode+0x32/0x61
__mark_inode_dirty+0x16b/0x60c
iput+0x11e/0x274
__dentry_kill+0x148/0x1b8
shrink_dentry_list+0x274/0x44a
prune_dcache_sb+0x4a/0x55
super_cache_scan+0xfc/0x176
shrink_slab.part.14.constprop.25+0x2a2/0x4d3
shrink_zone+0x74/0x140
kswapd+0x6b7/0x930
kthread+0x107/0x10f
ret_from_fork+0x3f/0x70
irq event stamp: 138297
hardirqs last enabled at (138297): debug_check_no_locks_freed+0x113/0x12f
hardirqs last disabled at (138296): debug_check_no_locks_freed+0x33/0x12f
softirqs last enabled at (137818): __do_softirq+0x2d3/0x3e9
softirqs last disabled at (137813): irq_exit+0x41/0x95
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(jbd2_handle);
<Interrupt>
lock(jbd2_handle);
*** DEADLOCK ***
5 locks held by git/20158:
#0: (sb_writers#7){.+.+.+}, at: [<ffffffff81155411>] mnt_want_write+0x24/0x4b
#1: (&type->i_mutex_dir_key#2/1){+.+.+.}, at: [<ffffffff81145087>] lock_rename+0xd9/0xe3
CyanogenMod#2: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8114f8e2>] lock_two_nondirectories+0x3f/0x6b
CyanogenMod#3: (&sb->s_type->i_mutex_key#11/4){+.+.+.}, at: [<ffffffff8114f909>] lock_two_nondirectories+0x66/0x6b
CyanogenMod#4: (jbd2_handle){+.+.?.}, at: [<ffffffff811e31db>] start_this_handle+0x4ca/0x555
stack backtrace:
CPU: 2 PID: 20158 Comm: git Not tainted 4.1.0-rc7-next-20150615-dbg-00016-g8bdf555-dirty #211
Call Trace:
dump_stack+0x4c/0x6e
mark_lock+0x384/0x56d
mark_held_locks+0x5f/0x76
lockdep_trace_alloc+0xb2/0xb5
kmem_cache_alloc_trace+0x32/0x1e2
zcomp_strm_alloc+0x25/0x73 [zram]
zcomp_strm_multi_find+0xe7/0x173 [zram]
zcomp_strm_find+0xc/0xe [zram]
zram_bvec_rw+0x2ca/0x7e0 [zram]
zram_make_request+0x1fa/0x301 [zram]
generic_make_request+0x9c/0xdb
submit_bio+0xf7/0x120
ext4_io_submit+0x2e/0x43
ext4_bio_write_page+0x1b7/0x300
mpage_submit_page+0x60/0x77
mpage_map_and_submit_buffers+0x10f/0x21d
ext4_writepages+0xc8c/0xe1b
do_writepages+0x23/0x2c
__filemap_fdatawrite_range+0x84/0x8b
filemap_flush+0x1c/0x1e
ext4_alloc_da_blocks+0xb8/0x117
ext4_rename+0x132/0x6dc
? mark_held_locks+0x5f/0x76
ext4_rename2+0x29/0x2b
vfs_rename+0x540/0x636
SyS_renameat2+0x359/0x44d
SyS_rename+0x1e/0x20
entry_SYSCALL_64_fastpath+0x12/0x6f
[minchan@kernel.org: add stable mark]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ShivamKumarJha
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Mar 16, 2018
(cherry picked from commit 3d5fe03a3ea013060ebba2a811aeb0f23f56aefa)
We can end up allocating a new compression stream with GFP_KERNEL from
within the IO path, which may result is nested (recursive) IO
operations. That can introduce problems if the IO path in question is a
reclaimer, holding some locks that will deadlock nested IOs.
Allocate streams and working memory using GFP_NOIO flag, forbidding
recursive IO and FS operations.
An example:
inconsistent {IN-RECLAIM_FS-W} -> {RECLAIM_FS-ON-W} usage.
git/20158 [HC0[0]:SC0[0]:HE1:SE1] takes:
(jbd2_handle){+.+.?.}, at: start_this_handle+0x4ca/0x555
{IN-RECLAIM_FS-W} state was registered at:
__lock_acquire+0x8da/0x117b
lock_acquire+0x10c/0x1a7
start_this_handle+0x52d/0x555
jbd2__journal_start+0xb4/0x237
__ext4_journal_start_sb+0x108/0x17e
ext4_dirty_inode+0x32/0x61
__mark_inode_dirty+0x16b/0x60c
iput+0x11e/0x274
__dentry_kill+0x148/0x1b8
shrink_dentry_list+0x274/0x44a
prune_dcache_sb+0x4a/0x55
super_cache_scan+0xfc/0x176
shrink_slab.part.14.constprop.25+0x2a2/0x4d3
shrink_zone+0x74/0x140
kswapd+0x6b7/0x930
kthread+0x107/0x10f
ret_from_fork+0x3f/0x70
irq event stamp: 138297
hardirqs last enabled at (138297): debug_check_no_locks_freed+0x113/0x12f
hardirqs last disabled at (138296): debug_check_no_locks_freed+0x33/0x12f
softirqs last enabled at (137818): __do_softirq+0x2d3/0x3e9
softirqs last disabled at (137813): irq_exit+0x41/0x95
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(jbd2_handle);
<Interrupt>
lock(jbd2_handle);
*** DEADLOCK ***
5 locks held by git/20158:
#0: (sb_writers#7){.+.+.+}, at: [<ffffffff81155411>] mnt_want_write+0x24/0x4b
#1: (&type->i_mutex_dir_key#2/1){+.+.+.}, at: [<ffffffff81145087>] lock_rename+0xd9/0xe3
CyanogenMod#2: (&sb->s_type->i_mutex_key#11){+.+.+.}, at: [<ffffffff8114f8e2>] lock_two_nondirectories+0x3f/0x6b
CyanogenMod#3: (&sb->s_type->i_mutex_key#11/4){+.+.+.}, at: [<ffffffff8114f909>] lock_two_nondirectories+0x66/0x6b
CyanogenMod#4: (jbd2_handle){+.+.?.}, at: [<ffffffff811e31db>] start_this_handle+0x4ca/0x555
stack backtrace:
CPU: 2 PID: 20158 Comm: git Not tainted 4.1.0-rc7-next-20150615-dbg-00016-g8bdf555-dirty #211
Call Trace:
dump_stack+0x4c/0x6e
mark_lock+0x384/0x56d
mark_held_locks+0x5f/0x76
lockdep_trace_alloc+0xb2/0xb5
kmem_cache_alloc_trace+0x32/0x1e2
zcomp_strm_alloc+0x25/0x73 [zram]
zcomp_strm_multi_find+0xe7/0x173 [zram]
zcomp_strm_find+0xc/0xe [zram]
zram_bvec_rw+0x2ca/0x7e0 [zram]
zram_make_request+0x1fa/0x301 [zram]
generic_make_request+0x9c/0xdb
submit_bio+0xf7/0x120
ext4_io_submit+0x2e/0x43
ext4_bio_write_page+0x1b7/0x300
mpage_submit_page+0x60/0x77
mpage_map_and_submit_buffers+0x10f/0x21d
ext4_writepages+0xc8c/0xe1b
do_writepages+0x23/0x2c
__filemap_fdatawrite_range+0x84/0x8b
filemap_flush+0x1c/0x1e
ext4_alloc_da_blocks+0xb8/0x117
ext4_rename+0x132/0x6dc
? mark_held_locks+0x5f/0x76
ext4_rename2+0x29/0x2b
vfs_rename+0x540/0x636
SyS_renameat2+0x359/0x44d
SyS_rename+0x1e/0x20
entry_SYSCALL_64_fastpath+0x12/0x6f
[minchan@kernel.org: add stable mark]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Kyeongdon Kim <kyeongdon.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DrRamm
pushed a commit
to ShivamKumarJha/android_kernel_xiaomi_cancro
that referenced
this pull request
Mar 21, 2018
The scenario is: 1. create lots of node blocks 2. sync 3. write lots of inline_data -> got panic due to no free space In that case, we should flush node blocks when writing inline_data in CyanogenMod#3, and trigger gc as well. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
No description provided.