[PATCH] UBI: eliminate possible undefined behaviour
Artem Bityutskiy
dedekind at infradead.org
Thu Jul 23 11:46:23 EDT 2009
From: Phil Carmody <ext-phil.2.carmody at nokia.com>
The assignment to pos when rb is finally NULL is undefined behaviour.
Upon seeing that assignment, GCC may assume that rb is not NULL, and
the loop condition ``rb'' may be optimised away.
Signed-off-by: Phil Carmody <ext-phil.2.carmody at nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy at nokia.com>
---
drivers/mtd/ubi/ubi.h | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index 6a5fe96..c290f51 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -579,7 +579,8 @@ void ubi_do_get_volume_info(struct ubi_device *ubi, struct ubi_volume *vol,
for (rb = rb_first(root), \
pos = (rb ? container_of(rb, typeof(*pos), member) : NULL); \
rb; \
- rb = rb_next(rb), pos = container_of(rb, typeof(*pos), member))
+ rb = rb_next(rb), \
+ pos = (rb ? container_of(rb, typeof(*pos), member) : NULL))
/**
* ubi_zalloc_vid_hdr - allocate a volume identifier header object.
--
1.6.0.6
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