* [PATCH] mm,hwpoison: Don't call task_work_add when there is same work in the queue
@ 2021-07-09 9:28 yaozhenguo
0 siblings, 0 replies; only message in thread
From: yaozhenguo @ 2021-07-09 9:28 UTC (permalink / raw)
To: tony.luck, youquan.song; +Cc: linux-edac, linux-kernel, yaozhenguo, yaozhenguo
queue_task_work can be called more than once in one task before
this task work is running. it can lead to task->task_works becomes
an endless loop list and the task will never return to user mode.
Don't call task_work_add when there is same work in the queue.
Signed-off-by: yaozhenguo <yaozhenguo1@gmail.com>
---
arch/x86/kernel/cpu/mce/core.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 22791aa..62c67ad 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1299,7 +1299,9 @@ static void queue_task_work(struct mce *m, int kill_current_task)
else
current->mce_kill_me.func = kill_me_maybe;
- task_work_add(current, ¤t->mce_kill_me, TWA_RESUME);
+ /* Avoid endless loops in task_work_run */
+ if (READ_ONCE(current->task_works) != ¤t->mce_kill_me)
+ task_work_add(current, ¤t->mce_kill_me, TWA_RESUME);
}
/*
--
1.8.3.1
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