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authorJeff Mahoney <jeffm@suse.com>2010-03-17 10:55:51 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2010-04-07 18:00:39 +1000
commit637a99022fb119b90fb281715d13172f0394fc12 (patch)
treeecd77d0ce7499bb7af7b7a3cf508010552dcbb39
parent6d1bdd2afbed74b3adcf3a7aec49e430eeb6c5f3 (diff)
powerpc: Fix handling of strncmp with zero len
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> CC: <stable@kernel.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-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 64e2e499e32..3ac0cd3a537 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