The patch titled
Subject: ipc,sem: fix locking in semctl_main
has been added to the -mm tree. Its filename is
ipcsem-fine-grained-locking-for-semtimedop-fix-locking-in-semctl_main.patch
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From: Rik van Riel <riel@xxxxxxxxxx>
Subject: ipc,sem: fix locking in semctl_main
Everywhere else in the code, we check sma->sem_perm.deleted under
the semaphore array lock, so we should do teh same here.
The easy fix is to simply not drop and re-take the lock, but keep
it locked.
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Davidlohr Bueso <davidlohr.bueso@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/sem.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff -puN ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-locking-in-semctl_main ipc/sem.c
--- a/ipc/sem.c~ipcsem-fine-grained-locking-for-semtimedop-fix-locking-in-semctl_main
+++ a/ipc/sem.c
@@ -1115,10 +1115,9 @@ static int semctl_main(struct ipc_namesp
err = -EIDRM;
goto out_free;
}
- sem_unlock(sma, -1);
- }
+ } else
+ sem_lock(sma, NULL, -1);
- sem_lock(sma, NULL, -1);
for (i = 0; i < sma->sem_nsems; i++)
sem_io[i] = sma->sem_base[i].semval;
sem_unlock(sma, -1);
_
Patches currently in -mm which might be from riel@xxxxxxxxxx are
linux-next.patch
mm-remove-free_area_cache-use-in-powerpc-architecture.patch
vmscan-minor-cleanup-for-kswapd.patch
mm-introduce-free_highmem_page-helper-to-free-highmem-pages-into-buddy-system.patch
mm-merging-memory-blocks-resets-mempolicy.patch
mm-remove-config_hotplug-ifdefs.patch
mm-thp-add-split-tail-pages-to-shrink-page-list-in-page-reclaim.patch
mm-remove-free_area_cache.patch
mm-add-vm-event-counters-for-balloon-pages-compaction.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-do-not-hold-ipc-lock-more-than-necessary-fix.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.patch
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch
ipcsem-fine-grained-locking-for-semtimedop-fix-locking-in-semctl_main.patch
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