The patch titled
Subject: ipc,sem: fix lockdep false positive
has been added to the -mm tree. Its filename is
ipcsem-fine-grained-locking-for-semtimedop-fix-fix.patch
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From: Rik van Riel <riel@xxxxxxxxxxx>
Subject: ipc,sem: fix lockdep false positive
When locking all the semaphores inside a sem_array, the kernel ends up
locking a large number of locks with identical lockdep status. This
trips up lockdep. Annotate the code to prevent such warnings.
Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Reported-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/sem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
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
@@ -227,7 +227,7 @@ static inline int sem_lock(struct sem_ar
spin_lock(&sma->sem_perm.lock);
for (i = 0; i < sma->sem_nsems; i++) {
struct sem *sem = sma->sem_base + i;
- spin_lock(&sem->lock);
+ spin_lock_nested(&sem->lock, SINGLE_DEPTH_NESTING);
}
locknum = -1;
}
@@ -426,7 +426,7 @@ static int newary(struct ipc_namespace *
for (i = 0; i < nsems; i++) {
INIT_LIST_HEAD(&sma->sem_base[i].sem_pending);
spin_lock_init(&sma->sem_base[i].lock);
- spin_lock(&sma->sem_base[i].lock);
+ spin_lock_nested(&sma->sem_base[i].lock, SINGLE_DEPTH_NESTING);
}
sma->complex_count = 0;
_
Patches currently in -mm which might be from riel@xxxxxxxxxxx are
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
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