Searched hist:"8 cfe400ca54fd1ed96f962bea5f7e20b09b6d69f" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/kernel/ |
| H A D | freezer.c | diff 8cfe400ca54fd1ed96f962bea5f7e20b09b6d69f Fri Nov 26 16:07:27 CST 2010 Tejun Heo <tj@kernel.org> Freezer: Fix a race during freezing of TASK_STOPPED tasks
After calling freeze_task(), try_to_freeze_tasks() see whether the
task is stopped or traced and if so, considers it to be frozen;
however, nothing guarantees that either the task being frozen sees
TIF_FREEZE or the freezer sees TASK_STOPPED -> TASK_RUNNING
transition. The task being frozen may wake up and not see TIF_FREEZE
while the freezer fails to notice the transition and believes the task
is still stopped.
This patch fixes the race by making freeze_task() always go through
fake_signal_wake_up() for applicable tasks. The function goes through
the target task's scheduler lock and thus guarantees that either the
target sees TIF_FREEZE or try_to_freeze_task() sees TASK_RUNNING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
|
| /openbmc/linux/kernel/power/ |
| H A D | process.c | diff 8cfe400ca54fd1ed96f962bea5f7e20b09b6d69f Fri Nov 26 16:07:27 CST 2010 Tejun Heo <tj@kernel.org> Freezer: Fix a race during freezing of TASK_STOPPED tasks
After calling freeze_task(), try_to_freeze_tasks() see whether the
task is stopped or traced and if so, considers it to be frozen;
however, nothing guarantees that either the task being frozen sees
TIF_FREEZE or the freezer sees TASK_STOPPED -> TASK_RUNNING
transition. The task being frozen may wake up and not see TIF_FREEZE
while the freezer fails to notice the transition and believes the task
is still stopped.
This patch fixes the race by making freeze_task() always go through
fake_signal_wake_up() for applicable tasks. The function goes through
the target task's scheduler lock and thus guarantees that either the
target sees TIF_FREEZE or try_to_freeze_task() sees TASK_RUNNING.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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