Commit 20055a8b authored Sep 04, 2019 by Santosh Sivaraj Committed by Michael Ellerman Sep 12, 2019

powerpc/memcpy: Fix stack corruption for smaller sizes

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

parent aa497d43

arch/powerpc/lib/memcpy_mcsafe_64.S

+1 −1

Original line number	Diff line number	Diff line
		@@ -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