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authorJeff Mahoney <jeffm@suse.com>2010-03-17 10:55:51 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2010-07-05 11:08:42 -0700
commitae7aff994d0934d86a3278a65889f34629c778a7 (patch)
tree084f951dc181673cd9d29008c36a2a70a45ea54c
parent88102a584bf833892493a514430bcebd53d8f017 (diff)
downloadlwn-ae7aff994d0934d86a3278a65889f34629c778a7.tar.gz
lwn-ae7aff994d0934d86a3278a65889f34629c778a7.zip
powerpc: Fix handling of strncmp with zero len
commit 637a99022fb119b90fb281715d13172f0394fc12 upstream. Commit 0119536c, which added the assembly version of strncmp to powerpc, mentions that it adds two instructions to the version from boot/string.S to allow it to handle len=0. Unfortunately, it doesn't always return 0 when that is the case. The length is passed in r5, but the return value is passed back in r3. In certain cases, this will happen to work. Otherwise it will pass back the address of the first string as the return value. This patch lifts the len <= 0 handling code from memcpy to handle that case. Reported by: Christian_Sellars@symantec.com Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--arch/powerpc/lib/string.S4
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/powerpc/lib/string.S b/arch/powerpc/lib/string.S
index 64e2e499e32a..3ac0cd3a5373 100644
--- a/arch/powerpc/lib/string.S
+++ b/arch/powerpc/lib/string.S
@@ -71,7 +71,7 @@ _GLOBAL(strcmp)
_GLOBAL(strncmp)
PPC_LCMPI r5,0
- beqlr
+ ble- 2f
mtctr r5
addi r5,r3,-1
addi r4,r4,-1
@@ -82,6 +82,8 @@ _GLOBAL(strncmp)
beqlr 1
bdnzt eq,1b
blr
+2: li r3,0
+ blr
_GLOBAL(strlen)
addi r4,r3,-1