Commit 8540571e authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman

powerpc/32: Fix again csum_partial_copy_generic()

Commit 7aef4136 ("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: 7aef4136 ("powerpc32: rewrite csum_partial_copy_generic() based on copy_tofrom_user()")
Cc: stable@vger.kernel.org # v4.6+
Reported-by: default avatarAlessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Tested-by: default avatarAlessio Igor Bogani <alessio.bogani@elettra.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent caa58f80
......@@ -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
......
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