The patch titled
Subject: ipc/sem: do not sleep with a spin lock held
has been added to the -mm tree. Its filename is
ipc-sem-do-not-sleep-with-a-spin-lock-held.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/ipc-sem-do-not-sleep-with-a-spin-lock-held.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/ipc-sem-do-not-sleep-with-a-spin-lock-held.patch
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------------------------------------------------------
From: Minghao Chi <chi.minghao@xxxxxxxxxx>
Subject: ipc/sem: do not sleep with a spin lock held
We can't call kvfree() with a spin lock held, so defer it.
Link: https://lkml.kernel.org/r/20211223031207.556189-1-chi.minghao@xxxxxxxxxx
Fixes: fc37a3b8b438 ("[PATCH] ipc sem: use kvmalloc for sem_undo allocation")
Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
Signed-off-by: Minghao Chi <chi.minghao@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Yang Guang <cgel.zte@xxxxxxxxx>
Cc: Davidlohr Bueso <dbueso@xxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Bhaskar Chowdhury <unixbhaskar@xxxxxxxxx>
Cc: Vasily Averin <vvs@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/sem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/ipc/sem.c~ipc-sem-do-not-sleep-with-a-spin-lock-held
+++ a/ipc/sem.c
@@ -1964,6 +1964,7 @@ static struct sem_undo *find_alloc_undo(
*/
un = lookup_undo(ulp, semid);
if (un) {
+ spin_unlock(&ulp->lock);
kvfree(new);
goto success;
}
@@ -1976,9 +1977,8 @@ static struct sem_undo *find_alloc_undo(
ipc_assert_locked_object(&sma->sem_perm);
list_add(&new->list_id, &sma->list_id);
un = new;
-
-success:
spin_unlock(&ulp->lock);
+success:
sem_unlock(sma, -1);
out:
return un;
_
Patches currently in -mm which might be from chi.minghao@xxxxxxxxxx are
mm-remove-unneeded-variable.patch
selftests-vm-use-swap-to-make-code-cleaner.patch
fs-adfs-remove-unneeded-variable-make-code-cleaner.patch
ipc-sem-do-not-sleep-with-a-spin-lock-held.patch
