From e6037a753e8e9a4146f7d94c32eb30a6717c9c70 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 15 Oct 2020 01:02:09 +0200
Subject: [PATCH] powerpc32: don't adjust unmoved stack pointer in
csum_partial_copy_generic() epilogue
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 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@zeniv.linux.org.uk>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
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
--
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