From a71ae47a2cbfa542c69f695809124da4e4dd9e8f Mon Sep 17 00:00:00 2001
From: Christoph Lameter <cl@linux.com>
Date: Wed, 25 May 2011 09:47:43 -0500
Subject: [PATCH] slub: Fix double bit unlock in debug mode
Commit 442b06bcea23 ("slub: Remove node check in slab_free") added a
call to deactivate_slab() in the debug case in __slab_alloc(), which
unlocks the current slab used for allocation. Going to the label
'unlock_out' then does it again.
Also, in the debug case we do not need all the other processing that the
'unlock_out' path does. We always fall back to the slow path in the
debug case. So the tid update is useless.
Similarly, ALLOC_SLOWPATH would just be incremented for all allocations.
Also a pretty useless thing.
So simply restore irq flags and return the object.
Signed-off-by: Christoph Lameter <cl@linux.com>
Reported-and-bisected-by: James Morris <jmorris@namei.org>
Reported-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Jens Axboe <jaxboe@fusionio.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/slub.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/slub.c b/mm/slub.c
index 4ea7f1a22a94..4aad32d2e60d 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1884,7 +1884,8 @@ debug:
deactivate_slab(s, c);
c->page = NULL;
c->node = NUMA_NO_NODE;
- goto unlock_out;
+ local_irq_restore(flags);
+ return object;
}
/*
--
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