diff options
| author | Woody Lin <woodylin@google.com> | 2021-10-12 16:35:21 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-10-27 09:56:55 +0200 |
| commit | 96fe5061291d9e9734abf6bb187ef7532824522d (patch) | |
| tree | f7d921c1464cf0fbb19bb3a9811c5bca9528b8be /kernel | |
| parent | 96f0aebf29be25254fa585af43924e34aa21fd9a (diff) | |
sched/scs: Reset the shadow stack when idle_task_exit
[ Upstream commit 63acd42c0d4942f74710b11c38602fb14dea7320 ]
Commit f1a0a376ca0c ("sched/core: Initialize the idle task with
preemption disabled") removed the init_idle() call from
idle_thread_get(). This was the sole call-path on hotplug that resets
the Shadow Call Stack (scs) Stack Pointer (sp).
Not resetting the scs-sp leads to scs overflow after enough hotplug
cycles. Therefore add an explicit scs_task_reset() to the hotplug code
to make sure the scs-sp does get reset on hotplug.
Fixes: f1a0a376ca0c ("sched/core: Initialize the idle task with preemption disabled")
Signed-off-by: Woody Lin <woodylin@google.com>
[peterz: Changelog]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20211012083521.973587-1-woodylin@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 6db20a66e8e6..e4551d1736fa 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6677,6 +6677,7 @@ void idle_task_exit(void) finish_arch_post_lock_switch(); } + scs_task_reset(current); /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ } |