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Patch "powerpc/32: Fix again csum_partial_copy_generic()" has been added to the 4.7-stable tree

PATCH [email protected] 1 participant 1 message Sep 22, 2016

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This is a note to let you know that I've just added the patch titled

powerpc/32: Fix again csum_partial_copy_generic()

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
powerpc-32-fix-again-csum_partial_copy_generic.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From 8540571e01f973d321b0821f4f32ed6e9ae8263c Mon Sep 17 00:00:00 2001

From: Christophe Leroy <[email protected]>
Date: Fri, 26 Aug 2016 16:45:13 +0200
Subject: powerpc/32: Fix again csum_partial_copy_generic()

From: Christophe Leroy <[email protected]>

commit 8540571e01f973d321b0821f4f32ed6e9ae8263c upstream.

Commit 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()") introduced a bug when destination address is odd and len is lower than cacheline size.

In that case the resulting csum value doesn't have to be rotated one byte because the cache-aligned copy part is skipped so no alignment is performed.

Fixes 7aef4136566b0 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()")
---
 arch/powerpc/lib/checksum_32.S |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
arch/powerpc/lib/checksum_32.S +4 -3
@@ -127,18 +127,19 @@ _GLOBAL(csum_partial_copy_generic)
 	stw	r7,12(r1)
 	stw	r8,8(r1)
 
-	rlwinm	r0,r4,3,0x8
-	rlwnm	r6,r6,r0,0,31	/* odd destination address: rotate one byte */
-	cmplwi	cr7,r0,0	/* is destination address even ? */
 	addic	r12,r6,0
 	addi	r6,r4,-4
 	neg	r0,r4
 	addi	r4,r3,-4
 	andi.	r0,r0,CACHELINE_MASK	/* # bytes to start of cache line */
+	crset	4*cr7+eq
 	beq	58f
 
 	cmplw	0,r5,r0			/* is this more than total to do? */
 	blt	63f			/* if not much to do */
+	rlwinm	r7,r6,3,0x8
+	rlwnm	r12,r12,r7,0,31	/* odd destination address: rotate one byte */
+	cmplwi	cr7,r7,0	/* is destination address even ? */
 	andi.	r8,r0,3			/* get it word-aligned first */
 	mtctr	r8
 	beq+	61f

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/powerpc-sysdev-cpm-fix-gpio-save_regs-functions.patch queue-4.7/powerpc-32-fix-again-csum_partial_copy_generic.patch queue-4.7/powerpc-32-fix-csum_partial_copy_generic.patch