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sparc32: Fixed unaligned memory copying in function __csum_partial_copy_sparc_generic 

When we are in the label cc_dword_align, registers %o0 and %o1 have the same last 2 bits,
but it's not guaranteed one of them is zero. So we can get unaligned memory access
in label ccte. Example of parameters which lead to this:
%o0=0x7ff183e9, %o1=0x8e709e7d, %g1=3

With the parameters I had a memory corruption, when the additional 5 bytes were rewritten.
This patch corrects the error.

One comment to the patch. We don't care about the third bit in %o1, because cc_end_cruft
stores word or less.

Signed-off-by: Tkhai Kirill <tkhai@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tkhai Kirill 2011-05-10 02:31:41 +00:00 committed by David S. Miller
parent f486b3dc2d
commit b1054282d7
1 changed files with 9 additions and 3 deletions
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12
arch/sparc/lib/checksum_32.S
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@ -289,10 +289,16 @@ cc_end_cruft:
/* Also, handle the alignment code out of band. */
cc_dword_align:
cmp %g1, 6
bl,a ccte
cmp %g1, 16
bge 1f
srl %g1, 1, %o3
2: cmp %o3, 0
be,a ccte
andcc %g1, 0xf, %o3
andcc %o0, 0x1, %g0
andcc %o3, %o0, %g0 ! Check %o0 only (%o1 has the same last 2 bits)
be,a 2b
srl %o3, 1, %o3
1: andcc %o0, 0x1, %g0
bne ccslow
andcc %o0, 0x2, %g0
be 1f