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authorAkinobu Mita <akinobu.mita@gmail.com>2011-08-07 18:30:38 +0900
committerPekka Enberg <penberg@kernel.org>2011-08-09 16:37:48 +0300
commitef62fb32b7b21731e41aea3c1e08bcdb407c9eb9 (patch)
treef508ace02d80e7b80791aff0ada407ae104de7e3 /mm
parent6fbabb20faed9c08f8b96de4182bd721cbd1cfcf (diff)
downloadlinux-linaro-precise-ef62fb32b7b21731e41aea3c1e08bcdb407c9eb9.tar.gz
slub: fix check_bytes() for slub debugging
The check_bytes() function is used by slub debugging. It returns a pointer to the first unmatching byte for a character in the given memory area. If the character for matching byte is greater than 0x80, check_bytes() doesn't work. Becuase 64-bit pattern is generated as below. value64 = value | value << 8 | value << 16 | value << 24; value64 = value64 | value64 << 32; The integer promotions are performed and sign-extended as the type of value is u8. The upper 32 bits of value64 is 0xffffffff in the first line, and the second line has no effect. This fixes the 64-bit pattern generation. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Matt Mackall <mpm@selenic.com> Reviewed-by: Marcin Slusarz <marcin.slusarz@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/slub.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 5436fe2fbf9..6da68597bde 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -701,7 +701,7 @@ static u8 *check_bytes(u8 *start, u8 value, unsigned int bytes)
return check_bytes8(start, value, bytes);
value64 = value | value << 8 | value << 16 | value << 24;
- value64 = value64 | value64 << 32;
+ value64 = (value64 & 0xffffffff) | value64 << 32;
prefix = 8 - ((unsigned long)start) % 8;
if (prefix) {