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* Merge branch 'pm-sleep' into pm-for-linusRafael J. Wysocki2011-12-2513-366/+273
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-sleep: (51 commits) PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() PM / Sleep: Recommend [un]lock_system_sleep() over using pm_mutex directly PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep() PM / Sleep: Make [un]lock_system_sleep() generic PM / Sleep: Use the freezer_count() functions in [un]lock_system_sleep() APIs PM / Freezer: Remove the "userspace only" constraint from freezer[_do_not]_count() PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c with 'else' Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer PM / Sleep: Unify diagnostic messages from device suspend/resume ACPI / PM: Do not save/restore NVS on Asus K54C/K54HR PM / Hibernate: Remove deprecated hibernation test modes PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test path ... Conflicts: kernel/kmod.c
| * Merge branch 'master' into pm-sleepRafael J. Wysocki2011-12-2126-84/+467
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * master: (848 commits) SELinux: Fix RCU deref check warning in sel_netport_insert() binary_sysctl(): fix memory leak mm/vmalloc.c: remove static declaration of va from __get_vm_area_node ipmi_watchdog: restore settings when BMC reset oom: fix integer overflow of points in oom_badness memcg: keep root group unchanged if creation fails nilfs2: potential integer overflow in nilfs_ioctl_clean_segments() nilfs2: unbreak compat ioctl cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemask evm: prevent racing during tfm allocation evm: key must be set once during initialization mmc: vub300: fix type of firmware_rom_wait_states module parameter Revert "mmc: enable runtime PM by default" mmc: sdhci: remove "state" argument from sdhci_suspend_host x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT IB/qib: Correct sense on freectxts increment and decrement RDMA/cma: Verify private data length cgroups: fix a css_set not found bug in cgroup_attach_proc oprofile: Fix uninitialized memory access when writing to writing to oprofilefs Revert "xen/pv-on-hvm kexec: add xs_reset_watches to shutdown watches from old kernel" ... Conflicts: kernel/cgroup_freezer.c
| * | PM / Hibernate: Remove deprecated hibernation snapshot ioctlsSrivatsa S. Bhat2011-12-091-87/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | Several snapshot ioctls were marked for removal quite some time ago, since they were deprecated. Remove them. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()Srivatsa S. Bhat2011-12-091-1/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a144c6a (PM: Print a warning if firmware is requested when tasks are frozen) introduced usermodehelper_is_disabled() to warn and exit immediately if firmware is requested when usermodehelpers are disabled. However, it is racy. Consider the following scenario, currently used in drivers/base/firmware_class.c: ... if (usermodehelper_is_disabled()) goto out; /* Do actual work */ ... out: return err; Nothing prevents someone from disabling usermodehelpers just after the check in the 'if' condition, which means that it is quite possible to try doing the "actual work" with usermodehelpers disabled, leading to undesirable consequences. In particular, this race condition in _request_firmware() causes task freezing failures whenever suspend/hibernation is in progress because, it wrongly waits to get the firmware/microcode image from userspace when actually the usermodehelpers are disabled or userspace has been frozen. Some of the example scenarios that cause freezing failures due to this race are those that depend on userspace via request_firmware(), such as x86 microcode module initialization and microcode image reload. Previous discussions about this issue can be found at: http://thread.gmane.org/gmane.linux.kernel/1198291/focus=1200591 This patch adds proper synchronization to fix this issue. It is to be noted that this patchset fixes the freezing failures but doesn't remove the warnings. IOW, it does not attempt to add explicit synchronization to x86 microcode driver to avoid requesting microcode image at inopportune moments. Because, the warnings were introduced to highlight such cases, in the first place. And we need not silence the warnings, since we take care of the *real* problem (freezing failure) and hence, after that, the warnings are pretty harmless anyway. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()Srivatsa S. Bhat2011-12-085-22/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock() on 'pm_mutex', since the latter could lead to freezing failures. Hence convert all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs instead. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Reviewed-by: Simon Horman <horms@verge.net.au> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | PM / Hibernate: Replace unintuitive 'if' condition in kernel/power/user.c ↵Srivatsa S. Bhat2011-12-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | with 'else' In the snapshot_ioctl() function, under SNAPSHOT_FREEZE, the code below freeze_processes() is a bit unintuitive. Improve it by replacing the second 'if' condition with an 'else' clause. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | Merge branch 'pm-freezer' into pm-sleepRafael J. Wysocki2011-12-069-205/+196
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-freezer: (26 commits) Freezer / sunrpc / NFS: don't allow TASK_KILLABLE sleeps to block the freezer Freezer: fix more fallout from the thaw_process rename freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw ...
| | * \ Merge branch 'pm-freezer' of ↵Rafael J. Wysocki2011-11-239-205/+196
| | |\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into pm-freezer * 'pm-freezer' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc: (24 commits) freezer: fix wait_event_freezable/__thaw_task races freezer: kill unused set_freezable_with_signal() dmatest: don't use set_freezable_with_signal() usb_storage: don't use set_freezable_with_signal() freezer: remove unused @sig_only from freeze_task() freezer: use lock_task_sighand() in fake_signal_wake_up() freezer: restructure __refrigerator() freezer: fix set_freezable[_with_signal]() race freezer: remove should_send_signal() and update frozen() freezer: remove now unused TIF_FREEZE freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE cgroup_freezer: prepare for removal of TIF_FREEZE freezer: clean up freeze_processes() failure path freezer: kill PF_FREEZING freezer: test freezable conditions while holding freezer_lock freezer: make freezing indicate freeze condition in effect freezer: use dedicated lock instead of task_lock() + memory barrier freezer: don't distinguish nosig tasks on thaw freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasks freezer: rename thaw_process() to __thaw_task() and simplify the implementation ...
| | | * | freezer: kill unused set_freezable_with_signal()Tejun Heo2011-11-232-22/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no in-kernel user of set_freezable_with_signal() left. Mixing TIF_SIGPENDING with kernel threads can lead to nasty corner cases as kernel threads never travel signal delivery path on their own. e.g. the current implementation is buggy in the cancelation path of __thaw_task(). It calls recalc_sigpending_and_wake() in an attempt to clear TIF_SIGPENDING but the function never clears it regardless of sigpending state. This means that signallable freezable kthreads may continue executing with !freezing() && stuck TIF_SIGPENDING, which can be troublesome. This patch removes set_freezable_with_signal() along with PF_FREEZER_NOSIG and recalc_sigpending*() calls in freezer. User tasks get TIF_SIGPENDING, kernel tasks get woken up and the spurious sigpending is dealt with in the usual signal delivery path. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: remove unused @sig_only from freeze_task()Tejun Heo2011-11-213-18/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After "freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZE", freezing() returns authoritative answer on whether the current task should freeze or not and freeze_task() doesn't need or use @sig_only. Remove it. While at it, rewrite function comment for freeze_task() and rename @sig_only to @user_only in try_to_freeze_tasks(). This patch doesn't cause any functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: use lock_task_sighand() in fake_signal_wake_up()Tejun Heo2011-11-211-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cgroup_freezer calls freeze_task() without holding tasklist_lock and, if the task is exiting, its ->sighand may be gone by the time fake_signal_wake_up() is called. Use lock_task_sighand() instead of accessing ->sighand directly. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Paul Menage <paul@paulmenage.org>
| | | * | freezer: restructure __refrigerator()Tejun Heo2011-11-211-21/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If another freeze happens before all tasks leave FROZEN state after being thawed, the freezer can see the existing FROZEN and consider the tasks to be frozen but they can clear FROZEN without checking the new freezing(). Oleg suggested restructuring __refrigerator() such that there's single condition check section inside freezer_lock and sigpending is cleared afterwards, which fixes the problem and simplifies the code. Restructure accordingly. -v2: Frozen loop exited without releasing freezer_lock. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
| | | * | freezer: fix set_freezable[_with_signal]() raceTejun Heo2011-11-211-0/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A kthread doing set_freezable*() may race with on-going PM freeze and the freezer might think all tasks are frozen while the new freezable kthread is merrily proceeding to execute code paths which aren't supposed to be executing during PM freeze. Reimplement set_freezable[_with_signal]() using __set_freezable() such that freezable PF flags are modified under freezer_lock and try_to_freeze() is called afterwards. This eliminates race condition against freezing. Note: Separated out from larger patch to resolve fix order dependency Oleg pointed out. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: remove should_send_signal() and update frozen()Tejun Heo2011-11-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | should_send_signal() is only used in freezer.c. Exporting them only increases chance of abuse. Open code the two users and remove it. Update frozen() to return bool. Signed-off-by: Tejun Heo <tj@kernel.org>
| | | * | freezer: make freezing() test freeze conditions in effect instead of TIF_FREEZETejun Heo2011-11-214-28/+60
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using TIF_FREEZE for freezing worked when there was only single freezing condition (the PM one); however, now there is also the cgroup_freezer and single bit flag is getting clumsy. thaw_processes() is already testing whether cgroup freezing in in effect to avoid thawing tasks which were frozen by both PM and cgroup freezers. This is racy (nothing prevents race against cgroup freezing) and fragile. A much simpler way is to test actual freeze conditions from freezing() - ie. directly test whether PM or cgroup freezing is in effect. This patch adds variables to indicate whether and what type of freezing conditions are in effect and reimplements freezing() such that it directly tests whether any of the two freezing conditions is active and the task should freeze. On fast path, freezing() is still very cheap - it only tests system_freezing_cnt. This makes the clumsy dancing aroung TIF_FREEZE unnecessary and freeze/thaw operations more usual - updating state variables for the new state and nudging target tasks so that they notice the new state and comply. As long as the nudging happens after state update, it's race-free. * This allows use of freezing() in freeze_task(). Replace the open coded tests with freezing(). * p != current test is added to warning printing conditions in try_to_freeze_tasks() failure path. This is necessary as freezing() is now true for the task which initiated freezing too. -v2: Oleg pointed out that re-freezing FROZEN cgroup could increment system_freezing_cnt. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Paul Menage <paul@paulmenage.org> (for the cgroup portions)
| | | * | cgroup_freezer: prepare for removal of TIF_FREEZETejun Heo2011-11-212-28/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | TIF_FREEZE will be removed soon and freezing() will directly test whether any freezing condition is in effect. Make the following changes in preparation. * Rename cgroup_freezing_or_frozen() to cgroup_freezing() and make it return bool. * Make cgroup_freezing() access task_freezer() under rcu read lock instead of task_lock(). This makes the state dereferencing racy against task moving to another cgroup; however, it was already racy without this change as ->state dereference wasn't synchronized. This will be later dealt with using attach hooks. * freezer->state is now set before trying to push tasks into the target state. -v2: Oleg pointed out that freeze_change_state() was setting freeze->state incorrectly to CGROUP_FROZEN instead of CGROUP_FREEZING. Fixed. -v3: Matt pointed out that setting CGROUP_FROZEN used to always invoke try_to_freeze_cgroup() regardless of the current state. Patch updated such that the actual freeze/thaw operations are always performed on invocation. This shouldn't make any difference unless something is broken. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Paul Menage <paul@paulmenage.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: clean up freeze_processes() failure pathTejun Heo2011-11-215-45/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | freeze_processes() failure path is rather messy. Freezing is canceled for workqueues and tasks which aren't frozen yet but frozen tasks are left alone and should be thawed by the caller and of course some callers (xen and kexec) didn't do it. This patch updates __thaw_task() to handle cancelation correctly and makes freeze_processes() and freeze_kernel_threads() call thaw_processes() on failure instead so that the system is fully thawed on failure. Unnecessary [suspend_]thaw_processes() calls are removed from kernel/power/hibernate.c, suspend.c and user.c. While at it, restructure error checking if clause in suspend_prepare() to be less weird. -v2: Srivatsa spotted missing removal of suspend_thaw_processes() in suspend_prepare() and error in commit message. Updated. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
| | | * | freezer: kill PF_FREEZINGTejun Heo2011-11-211-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the previous changes, there's no meaningful difference between PF_FREEZING and PF_FROZEN. Remove PF_FREEZING and use PF_FROZEN instead in task_contributes_to_load(). Signed-off-by: Tejun Heo <tj@kernel.org>
| | | * | freezer: test freezable conditions while holding freezer_lockTejun Heo2011-11-212-16/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | try_to_freeze_tasks() and thaw_processes() use freezable() and frozen() as preliminary tests before initiating operations on a task. These are done without any synchronization and hinder with synchronization cleanup without any real performance benefits. In try_to_freeze_tasks(), open code self test and move PF_NOFREEZE and frozen() tests inside freezer_lock in freeze_task(). thaw_processes() can simply drop freezable() test as frozen() test in __thaw_task() is enough. Note: This used to be a part of larger patch to fix set_freezable() race. Separated out to satisfy ordering among dependent fixes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: make freezing indicate freeze condition in effectTejun Heo2011-11-213-20/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently freezing (TIF_FREEZE) and frozen (PF_FROZEN) states are interlocked - freezing is set to request freeze and when the task actually freezes, it clears freezing and sets frozen. This interlocking makes things more complex than necessary - freezing doesn't mean there's freezing condition in effect and frozen doesn't match the task actually entering and leaving frozen state (it's cleared by the thawing task). This patch makes freezing indicate that freeze condition is in effect. A task enters and stays frozen if freezing. This makes PF_FROZEN manipulation done only by the task itself and prevents wakeup from __thaw_task() leaking outside of refrigerator. The only place which needs to tell freezing && !frozen is try_to_freeze_task() to whine about tasks which don't enter frozen. It's updated to test the condition explicitly. With the change, frozen() state my linger after __thaw_task() until the task wakes up and exits fridge. This can trigger BUG_ON() in update_if_frozen(). Work it around by testing freezing() && frozen() instead of frozen(). -v2: Oleg pointed out missing re-check of freezing() when trying to clear FROZEN and possible spurious BUG_ON() trigger in update_if_frozen(). Both fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Menage <paul@paulmenage.org>
| | | * | freezer: use dedicated lock instead of task_lock() + memory barrierTejun Heo2011-11-212-49/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Freezer synchronization is needlessly complicated - it's by no means a hot path and the priority is staying unintrusive and safe. This patch makes it simply use a dedicated lock instead of piggy-backing on task_lock() and playing with memory barriers. On the failure path of try_to_freeze_tasks(), locking is moved from it to cancel_freezing(). This makes the frozen() test racy but the race here is a non-issue as the warning is printed for tasks which failed to enter frozen for 20 seconds and race on PF_FROZEN at the last moment doesn't change anything. This simplifies freezer implementation and eases further changes including some race fixes. Signed-off-by: Tejun Heo <tj@kernel.org>
| | | * | freezer: don't distinguish nosig tasks on thawTejun Heo2011-11-211-13/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no point in thawing nosig tasks before others. There's no ordering requirement between the two groups on thaw, which the staged thawing can't guarantee anyway. Simplify thaw_processes() by removing the distinction and collapsing thaw_tasks() into thaw_processes(). This will help further updates to freezer. Signed-off-by: Tejun Heo <tj@kernel.org>
| | | * | freezer: remove racy clear_freeze_flag() and set PF_NOFREEZE on dead tasksTejun Heo2011-11-212-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clear_freeze_flag() in exit_mm() is racy. Freezing can start afterwards. Remove it. Skipping freezer for exiting task will be properly implemented later. Also, freezable() was testing exit_state directly to make system freezer ignore dead tasks. Let the exiting task set PF_NOFREEZE after entering TASK_DEAD instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: rename thaw_process() to __thaw_task() and simplify the implementationTejun Heo2011-11-213-24/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | thaw_process() now has only internal users - system and cgroup freezers. Remove the unnecessary return value, rename, unexport and collapse __thaw_process() into it. This will help further updates to the freezer code. -v3: oom_kill grew a use of thaw_process() while this patch was pending. Convert it to use __thaw_task() for now. In the longer term, this should be handled by allowing tasks to die if killed even if it's frozen. -v2: minor style update as suggested by Matt. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Paul Menage <menage@google.com> Cc: Matt Helsley <matthltc@us.ibm.com>
| | | * | freezer: implement and use kthread_freezable_should_stop()Tejun Heo2011-11-212-2/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Writeback and thinkpad_acpi have been using thaw_process() to prevent deadlock between the freezer and kthread_stop(); unfortunately, this is inherently racy - nothing prevents freezing from happening between thaw_process() and kthread_stop(). This patch implements kthread_freezable_should_stop() which enters refrigerator if necessary but is guaranteed to return if kthread_stop() is invoked. Both thaw_process() users are converted to use the new function. Note that this deadlock condition exists for many of freezable kthreads. They need to be converted to use the new should_stop or freezable workqueue. Tested with synthetic test case. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br> Cc: Jens Axboe <axboe@kernel.dk> Cc: Oleg Nesterov <oleg@redhat.com>
| | | * | freezer: unexport refrigerator() and update try_to_freeze() slightlyTejun Heo2011-11-211-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no reason to export two functions for entering the refrigerator. Calling refrigerator() instead of try_to_freeze() doesn't save anything noticeable or removes any race condition. * Rename refrigerator() to __refrigerator() and make it return bool indicating whether it scheduled out for freezing. * Update try_to_freeze() to return bool and relay the return value of __refrigerator() if freezing(). * Convert all refrigerator() users to try_to_freeze(). * Update documentation accordingly. * While at it, add might_sleep() to try_to_freeze(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Samuel Ortiz <samuel@sortiz.org> Cc: Chris Mason <chris.mason@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jan Kara <jack@suse.cz> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Cc: Christoph Hellwig <hch@infradead.org>
| | | * | freezer: fix current->state restoration race in refrigerator()Tejun Heo2011-11-211-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | refrigerator() saves current->state before entering frozen state and restores it before returning using __set_current_state(); however, this is racy, for example, please consider the following sequence. set_current_state(TASK_INTERRUPTIBLE); try_to_freeze(); if (kthread_should_stop()) break; schedule(); If kthread_stop() races with ->state restoration, the restoration can restore ->state to TASK_INTERRUPTIBLE after kthread_stop() sets it to TASK_RUNNING but kthread_should_stop() may still see zero ->should_stop because there's no memory barrier between restoring TASK_INTERRUPTIBLE and kthread_should_stop() test. This isn't restricted to kthread_should_stop(). current->state is often used in memory barrier based synchronization and silently restoring it w/o mb breaks them. Use set_current_state() instead. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | PM / Hibernate: Remove deprecated hibernation test modesSrivatsa S. Bhat2011-12-061-29/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hibernation test modes 'test' and 'testproc' are deprecated, because the 'pm_test' framework offers much more fine-grained control for debugging suspend and hibernation related problems. So, remove the deprecated 'test' and 'testproc' hibernation test modes. Suggested-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | PM / Hibernate: Thaw processes in SNAPSHOT_CREATE_IMAGE ioctl test pathSrivatsa S. Bhat2011-12-063-4/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 2aede851ddf08666f68ffc17be446420e9d2a056 (PM / Hibernate: Freeze kernel threads after preallocating memory) moved the freezing of kernel threads to hibernation_snapshot() function. So now, if the call to hibernation_snapshot() returns early due to a successful hibernation test, the caller has to thaw processes to ensure that the system gets back to its original state. But in SNAPSHOT_CREATE_IMAGE hibernation ioctl, the caller does not thaw processes in case hibernation_snapshot() returned due to a successful freezer test. Fix this issue. But note we still send the value of 'in_suspend' (which is now 0) to userspace, because we are not in an error path per-se, and moreover, the value of in_suspend correctly depicts the situation here. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | PM / Hibernate: Enable usermodehelpers in software_resume() error pathSrivatsa S. Bhat2011-12-061-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the software_resume() function defined in kernel/power/hibernate.c, if the call to create_basic_memory_bitmaps() fails, the usermodehelpers are not enabled (which had been disabled in the previous step). Fix it. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | PM / Hibernate: Refactor and simplify hibernation_snapshot() codeSrivatsa S. Bhat2011-11-231-13/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The goto statements in hibernation_snapshot() are a bit complex. Refactor the code to remove some of them, thereby simplifying the implementation. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | | PM: Fix indentation and remove extraneous whitespaces in kernel/power/main.cSrivatsa S. Bhat2011-11-231-3/+3
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lack of proper indentation of the goto statement decreases the readability of code significantly. In fact, this made me look twice at the code to check whether it really does what it should be doing. Fix this. And in the same file, there are some extra whitespaces. Get rid of them too. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | | | Merge branch 'pm-misc' into pm-for-linusRafael J. Wysocki2011-12-252-6/+4
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | * pm-misc: CPU: Add right qualifiers for alloc_frozen_cpus() and cpu_hotplug_pm_sync_init() PM / Usermodehelper: Cleanup remnants of usermodehelper_pm_callback()
| * | | CPU: Add right qualifiers for alloc_frozen_cpus() and cpu_hotplug_pm_sync_init()Fenghua Yu2011-11-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add __init for functions alloc_frozen_cpus() and cpu_hotplug_pm_sync_init() because they are only called during boot time. Add static for function cpu_hotplug_pm_sync_init() because its scope is limited in this file only. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| * | | PM / Usermodehelper: Cleanup remnants of usermodehelper_pm_callback()Srivatsa S. Bhat2011-11-231-4/+2
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | usermodehelper_pm_callback() no longer exists in the kernel. There are 2 comments in kernel/kmod.c that still refer to it. Also, the patch that introduced usermodehelper_pm_callback(), #included two header files: <linux/notifier.h> and <linux/suspend.h>. But these are no longer necessary. This patch updates the comments as appropriate and removes the unnecessary header file inclusions. Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
* | | Merge branch 'for-3.2-fixes' of ↵Linus Torvalds2011-12-201-5/+0
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup * 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroups: fix a css_set not found bug in cgroup_attach_proc
| * | | cgroups: fix a css_set not found bug in cgroup_attach_procMandeep Singh Baines2011-12-191-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a BUG when migrating a PF_EXITING proc. Since css_set_prefetch() is not called for the PF_EXITING case, find_existing_css_set() will return NULL inside cgroup_task_migrate() causing a BUG. This bug is easy to reproduce. Create a zombie and echo its pid to cgroup.procs. $ cat zombie.c \#include <unistd.h> int main() { if (fork()) pause(); return 0; } $ We are hitting this bug pretty regularly on ChromeOS. This bug is already fixed by Tejun Heo's cgroup patchset which is targetted for the next merge window: https://lkml.org/lkml/2011/11/1/356 I've create a smaller patch here which just fixes this bug so that a fix can be merged into the current release and stable. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Downstream-Bug-Report: http://crosbug.com/23953 Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: containers@lists.linux-foundation.org Cc: cgroups@vger.kernel.org Cc: stable@kernel.org Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Menage <paul@paulmenage.org> Cc: Olof Johansson <olofj@chromium.org>
* | | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2011-12-201-3/+9
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: time/clocksource: Fix kernel-doc warnings rtc: m41t80: Workaround broken alarm functionality rtc: Expire alarms after the time is set.
| * | | | time/clocksource: Fix kernel-doc warningsKusanagi Kouichi2011-12-191-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix various KernelDoc build warnings. Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp> Cc: John Stultz <johnstul@us.ibm.com> Link: http://lkml.kernel.org/r/20111219091320.0D5AF6FC03D@msa105.auone-net.jp Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | binary_sysctl(): fix memory leakMichel Lespinasse2011-12-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | binary_sysctl() calls sysctl_getname() which allocates from names_cache slab usin __getname() The matching function to free the name is __putname(), and not putname() which should be used only to match getname() allocations. This is because when auditing is enabled, putname() calls audit_putname *instead* (not in addition) to __putname(). Then, if a syscall is in progress, audit_putname does not release the name - instead, it expects the name to get released when the syscall completes, but that will happen only if audit_getname() was called previously, i.e. if the name was allocated with getname() rather than the naked __getname(). So, __getname() followed by putname() ends up leaking memory. Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | cpusets: stall when updating mems_allowed for mempolicy or disjoint nodemaskDavid Rientjes2011-12-201-5/+24
| |/ / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Kernels where MAX_NUMNODES > BITS_PER_LONG may temporarily see an empty nodemask in a tsk's mempolicy if its previous nodemask is remapped onto a new set of allowed cpuset nodes where the two nodemasks, as a result of the remap, are now disjoint. c0ff7453bb5c ("cpuset,mm: fix no node to alloc memory when changing cpuset's mems") adds get_mems_allowed() to prevent the set of allowed nodes from changing for a thread. This causes any update to a set of allowed nodes to stall until put_mems_allowed() is called. This stall is unncessary, however, if at least one node remains unchanged in the update to the set of allowed nodes. This was addressed by 89e8a244b97e ("cpusets: avoid looping when storing to mems_allowed if one node remains set"), but it's still possible that an empty nodemask may be read from a mempolicy because the old nodemask may be remapped to the new nodemask during rebind. To prevent this, only avoid the stall if there is no mempolicy for the thread being changed. This is a temporary solution until all reads from mempolicy nodemasks can be guaranteed to not be empty without the get_mems_allowed() synchronization. Also moves the check for nodemask intersection inside task_lock() so that tsk->mems_allowed cannot change. This ensures that nothing can set this tsk's mems_allowed out from under us and also protects tsk->mempolicy. Reported-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Paul Menage <paul@paulmenage.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| | | |
| \ \ \
*-. \ \ \ Merge branches 'perf-urgent-for-linus' and 'sched-urgent-for-linus' of ↵Linus Torvalds2011-12-172-8/+14
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf events: Fix ring_buffer_wakeup() brown paperbag bug * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix select_idle_sibling() regression in selecting an idle SMT sibling MAINTAINERS: Update tip.git related git trees
| | * | | | sched: Fix select_idle_sibling() regression in selecting an idle SMT siblingPeter Zijlstra2011-12-161-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mike Galbraith reported that this recent commit: commit 4dcfe1025b513c2c1da5bf5586adb0e80148f612 Author: Peter Zijlstra <peterz@infradead.org> Date: Thu Nov 10 13:01:10 2011 +0100 sched: Avoid SMT siblings in select_idle_sibling() if possible stopped selecting an idle SMT sibling when there are no idle cores in a single socket system. Intent of the select_idle_sibling() was to fallback to an idle SMT sibling, if it fails to identify an idle core. But this fallback was not happening on systems where all the scheduler domains had `SD_SHARE_PKG_RESOURCES' flag set. Fix it. Slightly bigger patch of cleaning all these goto's etc is queued up for the next release. Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Link: http://lkml.kernel.org/r/1323978421.1984.244.camel@sbsiddha-desk.sc.intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | perf events: Fix ring_buffer_wakeup() brown paperbag bugWill Deacon2011-12-141-2/+6
|/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 10c6db11 ("perf: Fix loss of notification with multi-event") seems to unconditionally dereference event->rb in the wakeup handler, this is wrong, there might not be a buffer attached. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111213152651.GP20297@mudshark.cambridge.arm.com [ minor edits ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2011-12-092-3/+9
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Do no try to schedule task events if there are none lockdep, kmemcheck: Annotate ->lock in lockdep_init_map() perf header: Use event_name() to get an event name perf stat: Failure with "Operation not supported"
| * | | | | perf: Do no try to schedule task events if there are noneGleb Natapov2011-12-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_event_sched_in() shouldn't try to schedule task events if there are none otherwise task's ctx->is_active will be set and will not be cleared during sched_out. This will prevent newly added events from being scheduled into the task context. Fixes a boo-boo in commit 1d5f003f5a9 ("perf: Do not set task_ctx pointer in cpuctx if there are no events in the context"). Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111122140821.GF2557@redhat.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | | lockdep, kmemcheck: Annotate ->lock in lockdep_init_map()Yong Zhang2011-12-061-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit f59de89 ("lockdep: Clear whole lockdep_map on initialization"), lockdep_init_map() will clear all the struct. But it will break lock_set_class()/lock_set_subclass(). A typical race condition is like below: CPU A CPU B lock_set_subclass(lockA); lock_set_class(lockA); lockdep_init_map(lockA); /* lockA->name is cleared */ memset(lockA); __lock_acquire(lockA); /* lockA->class_cache[] is cleared */ register_lock_class(lockA); look_up_lock_class(lockA); WARN_ON_ONCE(class->name != lock->name); lock->name = name; So restore to what we have done before commit f59de89 but annotate ->lock with kmemcheck_mark_initialized() to suppress the kmemcheck warning reported in commit f59de89. Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Borislav Petkov <bp@alien8.de> Suggested-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20111109080451.GB8124@zhy Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | | | sys_getppid: add missing rcu_dereferenceMandeep Singh Baines2011-12-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to safely dereference current->real_parent inside an rcu_read_lock, we need an rcu_dereference. Signed-off-by: Mandeep Singh Baines <msb@chromium.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Pavel Emelyanov <xemul@openvz.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | printk: avoid double lock acquirePeter Zijlstra2011-12-091-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4f2a8d3cf5e ("printk: Fix console_sem vs logbuf_lock unlock race") introduced another silly bug where we would want to acquire an already held lock. Avoid this. Reported-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2011-12-081-1/+1
|\ \ \ \ \ \ | | |_|/ / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: alarmtimers: Fix time comparison ptp: Fix clock_getres() implementation
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