From patchwork Mon May 9 19:55:55 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: SPARC32: Fixed unaligned memory copying in function __csum_partial_copy_sparc_generic Date: Mon, 09 May 2011 09:55:55 -0000 From: Tkhai Kirill X-Patchwork-Id: 94851 Message-Id: <772061304970955@web57.yandex.ru> To: David Miller Cc: sparclinux@vger.kernel.org, Tkhai Kirill , tkhai1@yandex.ru 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 they 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 --- -- To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html --- linux-2.6.38.5/arch/sparc/lib/checksum_32.S.orig 2011-05-06 22:54:25.000000000 +0400 +++ linux-2.6.38.5/arch/sparc/lib/checksum_32.S 2011-05-08 11:43:35.000000000 +0400 @@ -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,a 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