The patch titled
Subject: ipc, sem: prevent possible deadlock
has been added to the -mm tree. Its filename is
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch
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From: Davidlohr Bueso <davidlohr.bueso@xxxxxx>
Subject: ipc, sem: prevent possible deadlock
In semctl_main(), when cmd == GETALL, we're locking sma->sem_perm.lock
(through sem_lock_and_putref), yet after the conditional, we lock it
again. Unlock sma right after exiting the conditional.
Signed-off-by: Davidlohr Bueso <davidlohr.bueso@xxxxxx>
Reviewed-by: Rik van Riel <riel@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/sem.c | 1 +
1 file changed, 1 insertion(+)
diff -puN ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix ipc/sem.c
--- a/ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-fix
+++ a/ipc/sem.c
@@ -1115,6 +1115,7 @@ static int semctl_main(struct ipc_namesp
err = -EIDRM;
goto out_free;
}
+ sem_unlock(sma, -1);
}
sem_lock(sma, NULL, -1);
_
Patches currently in -mm which might be from davidlohr.bueso@xxxxxx are
lib-int_sqrtc-optimize-square-root-algorithm.patch
ipc-remove-bogus-lock-comment-for-ipc_checkid.patch
ipc-introduce-obtaining-a-lockless-ipc-object.patch
ipc-introduce-obtaining-a-lockless-ipc-object-fix.patch
ipc-introduce-lockless-pre_down-ipcctl.patch
ipcsem-do-not-hold-ipc-lock-more-than-necessary.patch
ipcsem-open-code-and-rename-sem_lock.patch
ipcsem-open-code-and-rename-sem_lock-fix.patch
ipcsem-have-only-one-list-in-struct-sem_queue.patch
ipcsem-fine-grained-locking-for-semtimedop.patch
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch
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