* [PATCH] powerpc/32: fix again csum_partial_copy_generic()
@ 2016-08-26 14:45 Christophe Leroy
2016-09-08 9:47 ` Michael Ellerman
0 siblings, 1 reply; 2+ messages in thread
From: Christophe Leroy @ 2016-08-26 14:45 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman, Scott Wood
Cc: linux-kernel, linuxppc-dev, Alessio Igor Bogani, Antoine Blangy, stable
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()")
Cc: stable@vger.kernel.org
Reported-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
---
arch/powerpc/lib/checksum_32.S | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index 0a57fe6..aa8214f 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -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
--
2.1.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: powerpc/32: fix again csum_partial_copy_generic()
2016-08-26 14:45 [PATCH] powerpc/32: fix again csum_partial_copy_generic() Christophe Leroy
@ 2016-09-08 9:47 ` Michael Ellerman
0 siblings, 0 replies; 2+ messages in thread
From: Michael Ellerman @ 2016-09-08 9:47 UTC (permalink / raw)
To: Christophe Leroy, Benjamin Herrenschmidt, Paul Mackerras, Scott Wood
Cc: Antoine Blangy, Alessio Igor Bogani, linuxppc-dev, linux-kernel, stable
On Fri, 2016-26-08 at 14:45:13 UTC, Christophe Leroy wrote:
> 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()")
> Cc: stable@vger.kernel.org
> Reported-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Tested-by: Alessio Igor Bogani <alessio.bogani@elettra.eu>
Applied to powerpc fixes, thanks.
https://git.kernel.org/powerpc/c/8540571e01f973d321b0821f4f
cheers
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