From 20055a8bfaaa75f2cb9c23ecc8ab12b4abd8dc84 Mon Sep 17 00:00:00 2001
From: Santosh Sivaraj <santosh@fossix.org>
Date: Wed, 4 Sep 2019 03:13:58 +0530
Subject: [PATCH] powerpc/memcpy: Fix stack corruption for smaller sizes
References: bsc#1157774 ltc#182579
Patch-mainline: v5.4-rc1
Git-commit: 20055a8bfaaa75f2cb9c23ecc8ab12b4abd8dc84
For sizes lesser than 128 bytes, the code branches out early without saving
the stack frame, which when restored later drops frame of the caller.
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190903214359.23887-1-santosh@fossix.org
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
arch/powerpc/lib/memcpy_mcsafe_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/lib/memcpy_mcsafe_64.S b/arch/powerpc/lib/memcpy_mcsafe_64.S
index 949976dc115d..cb882d9a6d8a 100644
--- a/arch/powerpc/lib/memcpy_mcsafe_64.S
+++ b/arch/powerpc/lib/memcpy_mcsafe_64.S
@@ -84,7 +84,6 @@ err1; stw r0,0(r3)
3: sub r5,r5,r6
cmpldi r5,128
- blt 5f
mflr r0
stdu r1,-STACKFRAMESIZE(r1)
@@ -99,6 +98,7 @@ err1; stw r0,0(r3)
std r22,STK_REG(R22)(r1)
std r0,STACKFRAMESIZE+16(r1)
+ blt 5f
srdi r6,r5,7
mtctr r6
--
2.23.0