[PATCH] csky: Fix ABIv2 memcmp() s1 alignment check

[Hanlin Song]

memcmp() saves the original s1 pointer in r3 and then clears r0 for the
return value. The following alignment check tests r0 instead of r3:

        mov     r3, r0
        movi    r0, 0
        ...
        andi    r13, r0, 3

As a result, the path for an unaligned s1 address is never taken, and
memcmp() may issue word loads from an unaligned s1 address.

Test r3 instead, which still holds the original s1 pointer.

Signed-off-by: Hanlin Song <pgeorge8929@xxxxxxxxx>
---
 arch/csky/abiv2/memcmp.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/csky/abiv2/memcmp.S b/arch/csky/abiv2/memcmp.S
index bf0d809f0..1c6ced74d 100644
--- a/arch/csky/abiv2/memcmp.S
+++ b/arch/csky/abiv2/memcmp.S
@@ -12,7 +12,7 @@ ENTRY(memcmp)
 	cmplti	r2, 4
 	bt	.L_compare_by_byte
 
-	andi	r13, r0, 3
+	andi	r13, r3, 3
 	movi	r19, 4
 
 	/* Test if s1 is not 4 bytes aligned.  */
-- 
2.25.1