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| author | Arnd Bergmann <arnd@arndb.de> | 2012-02-13 05:50:07 +0000 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2012-02-13 05:50:26 +0000 |
| commit | ffafe770a4160862476405a442d28ee48d2249ef (patch) | |
| tree | 5bb7d5913427c245c61dd5eb384321dff386f841 /kernel/exit.c | |
| parent | 0dcd627896fb87b2e78a1ed78e469591208cffcd (diff) | |
| parent | da911782be4c82dc1222aa0cb5bef28605d1e117 (diff) | |
| download | linux-ffafe770a4160862476405a442d28ee48d2249ef.tar.gz linux-ffafe770a4160862476405a442d28ee48d2249ef.tar.bz2 linux-ffafe770a4160862476405a442d28ee48d2249ef.zip | |
Merge branch 'v3.3-samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes
* 'v3.3-samsung-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung: (2 commits)
ARM: EXYNOS: Add cpu-offset property in gic device tree node
ARM: EXYNOS: Bring exynos4-dt up to date
Linux 3.3-rc3
This includes an update to the v3.3-rc3 release from v3.3-rc2
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 294b1709170d..4b4042f9bc6a 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -1038,6 +1038,22 @@ void do_exit(long code) if (tsk->nr_dirtied) __this_cpu_add(dirty_throttle_leaks, tsk->nr_dirtied); exit_rcu(); + + /* + * The setting of TASK_RUNNING by try_to_wake_up() may be delayed + * when the following two conditions become true. + * - There is race condition of mmap_sem (It is acquired by + * exit_mm()), and + * - SMI occurs before setting TASK_RUNINNG. + * (or hypervisor of virtual machine switches to other guest) + * As a result, we may become TASK_RUNNING after becoming TASK_DEAD + * + * To avoid it, we have to wait for releasing tsk->pi_lock which + * is held by try_to_wake_up() + */ + smp_mb(); + raw_spin_unlock_wait(&tsk->pi_lock); + /* causes final put_task_struct in finish_task_switch(). */ tsk->state = TASK_DEAD; tsk->flags |= PF_NOFREEZE; /* tell freezer to ignore us */ |