From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936767AbdJQQTk (ORCPT ); Tue, 17 Oct 2017 12:19:40 -0400 Received: from mga02.intel.com ([134.134.136.20]:43093 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934114AbdJQQTg (ORCPT ); Tue, 17 Oct 2017 12:19:36 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,391,1503385200"; d="scan'208";a="1231796377" Subject: Re: [PATCH 1/2] x86/crypto/sha256-mb: fix panic due to unaligned access To: Andrey Ryabinin , Herbert Xu Cc: "David S. Miller" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Linus Torvalds , Jeffrey Walton , Megha Dey , Andy Lutomirski , Josh Poimboeuf , linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20171016155131.10118-1-aryabinin@virtuozzo.com> From: Tim Chen Message-ID: <8e4b8f0a-bc36-ae0b-f85d-4a7def031fe9@linux.intel.com> Date: Tue, 17 Oct 2017 09:18:59 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <20171016155131.10118-1-aryabinin@virtuozzo.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/16/2017 08:51 AM, Andrey Ryabinin wrote: > struct sha256_ctx_mgr allocated in sha256_mb_mod_init() via kzalloc() > and later passed in sha256_mb_flusher_mgr_flush_avx2() function where > instructions vmovdqa used to access the struct. vmovdqa requires > 16-bytes aligned argument, but nothing guarantees that struct > sha256_ctx_mgr will have that alignment. Unaligned vmovdqa will > generate GP fault. > > Fix this by replacing vmovdqa with vmovdqu which doesn't have alignment > requirements. Using vmovdqu will be a bit slower if the structure is unaligned. However, flush is done on the non performance critical path so I don't expect this will be an issue to performance. Thanks. Tim Acked-by: Tim Chen > > Fixes: a377c6b1876e ("crypto: sha256-mb - submit/flush routines for AVX2") > Reported-by: Josh Poimboeuf > Signed-off-by: Andrey Ryabinin > Cc: > --- > arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S > index 8fe6338bcc84..16c4ccb1f154 100644 > --- a/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S > +++ b/arch/x86/crypto/sha256-mb/sha256_mb_mgr_flush_avx2.S > @@ -155,8 +155,8 @@ LABEL skip_ %I > .endr > > # Find min length > - vmovdqa _lens+0*16(state), %xmm0 > - vmovdqa _lens+1*16(state), %xmm1 > + vmovdqu _lens+0*16(state), %xmm0 > + vmovdqu _lens+1*16(state), %xmm1 > > vpminud %xmm1, %xmm0, %xmm2 # xmm2 has {D,C,B,A} > vpalignr $8, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,D,C} > @@ -176,8 +176,8 @@ LABEL skip_ %I > vpsubd %xmm2, %xmm0, %xmm0 > vpsubd %xmm2, %xmm1, %xmm1 > > - vmovdqa %xmm0, _lens+0*16(state) > - vmovdqa %xmm1, _lens+1*16(state) > + vmovdqu %xmm0, _lens+0*16(state) > + vmovdqu %xmm1, _lens+1*16(state) > > # "state" and "args" are the same address, arg1 > # len is arg2 > @@ -234,8 +234,8 @@ ENTRY(sha256_mb_mgr_get_comp_job_avx2) > jc .return_null > > # Find min length > - vmovdqa _lens(state), %xmm0 > - vmovdqa _lens+1*16(state), %xmm1 > + vmovdqu _lens(state), %xmm0 > + vmovdqu _lens+1*16(state), %xmm1 > > vpminud %xmm1, %xmm0, %xmm2 # xmm2 has {D,C,B,A} > vpalignr $8, %xmm2, %xmm3, %xmm3 # xmm3 has {x,x,D,C} >