[PATCH] powerpc32: don't adjust unmoved stack pointer in csum_partial_copy_generic() epilogue

From: Jason A. Donenfeld
Date: Wed Oct 14 2020 - 19:02:35 EST


A recent change to the checksum code removed usage of some extra
arguments, alongside with storage on the stack for those, and the stack
pointer no longer needed to be adjusted in the function prologue. But, a
left over subtraction wasn't removed in the function epilogue, causing
the function to return with the stack pointer moved 16 bytes away from
where it should have. This corrupted local state and lead to weird
crashes. This commit simply removes the leftover instruction from the
epilogue.

Fixes: 70d65cd555c5 ("ppc: propagate the calling conventions change down to csum_partial_copy_generic()")
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
---
arch/powerpc/lib/checksum_32.S | 1 -
1 file changed, 1 deletion(-)

diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index ec5cd2dede35..27d9070617df 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -236,7 +236,6 @@ _GLOBAL(csum_partial_copy_generic)
slwi r0,r0,8
adde r12,r12,r0
66: addze r3,r12
- addi r1,r1,16
beqlr+ cr7
rlwinm r3,r3,8,0,31 /* odd destination address: rotate one byte */
blr
--
2.28.0