From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BADF11BCA0F; Fri, 16 Aug 2024 13:45:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723815918; cv=none; b=SDwSWNCGGf9CcGF2sp92EEjM4R85vDemufqDkLNgdkcVlV0IQ0dVil/BAdDZ0Pt4osgSDDVQoOyOAoLlroQF7MButS62wumDiG2JLztDJGBOTz1DWn/wPdF2icsIl4TiUvXF3YJGUE2bBiiSXLo8o4ImFJpl4/oMg0xmdVGUy00= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723815918; c=relaxed/simple; bh=P2CiZHuj4n0wzBrGJeq7xdgx8UuuSPVLHbtVZzRm6cM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dXXeNoQV4Xwl2J3zjoRBOuOM2YEhZKbE3SHiyt9GdbZ+nkfL717cdv51h69A4Eo98Ofo8oAw1PKlgJ9YC8CXCaOimKBmrjxLkqhxVDjdxJ0yTKutJqkqNsQ0YAXDYVemNkuqk1SZVPvmK1nHEgbDN7lpxjB7bzSU0TnhGaeUmb8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rLVrfZ3R; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rLVrfZ3R" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF185C4AF09; Fri, 16 Aug 2024 13:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723815918; bh=P2CiZHuj4n0wzBrGJeq7xdgx8UuuSPVLHbtVZzRm6cM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rLVrfZ3RCQJY48FPpnHaSf248JkZQZNJFlsMdKa69x6kAZjmJs6VwIQYzGK5eewXG seav76X05XpPe01S3Wj43mBfTVsm18RCtDA3T0YiwOTkxrHwgo7DkWUzhHdCsmKIsN pH1+bhc93xNgWdGqWR8LdYoSnjB4gIvAOD2cHS0tEL3anMdTJdXYSGYxhwTS85SkgC fK1ya7EJoKmX5AnmJXNB4oM5yVZh2vRj33RKu4kMG/mSLgODNNhYM0Le9nYnJrY2Es fD2igF4fIySpwIKyX1SQnDDyHeG/iCtd4pwNFJ/5zkNIjGTjeVemkRGomHZyhD3APU Hs2MbuZLBCQIg== From: Alexey Gladkov To: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev Cc: "Alexey Gladkov (Intel)" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , "Kirill A. Shutemov" , Andrew Morton , Yuan Yao , Geert Uytterhoeven , Yuntao Wang , Kai Huang , Baoquan He , Oleg Nesterov , Tom Lendacky , Kevin Loughlin , Nikunj A Dadhania , cho@microsoft.com, decui@microsoft.com, John.Starks@microsoft.com Subject: [PATCH v3 06/10] x86/sev: Avoid crossing the page boundary Date: Fri, 16 Aug 2024 15:43:56 +0200 Message-ID: <56607a180717a4196738224c995fa2c16af44da2.1723807851.git.legion@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Alexey Gladkov (Intel)" Try to avoid crossing the page boundary to avoid side effects if the next page belongs to another VMA. Signed-off-by: Alexey Gladkov (Intel) --- arch/x86/coco/sev/core.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/x86/coco/sev/core.c b/arch/x86/coco/sev/core.c index 082d61d85dfc..b0e8e4264464 100644 --- a/arch/x86/coco/sev/core.c +++ b/arch/x86/coco/sev/core.c @@ -311,17 +311,16 @@ static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt, static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) { - char buffer[MAX_INSN_SIZE]; - int insn_bytes; + int ret; - insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer); - if (insn_bytes == 0) { + ret = insn_fetch_decode_from_user_inatomic(&ctxt->insn, ctxt->regs); + if (ret == -EFAULT) { /* Nothing could be copied */ ctxt->fi.vector = X86_TRAP_PF; ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER; ctxt->fi.cr2 = ctxt->regs->ip; return ES_EXCEPTION; - } else if (insn_bytes == -EINVAL) { + } else if (ret == -EINVAL) { /* Effective RIP could not be calculated */ ctxt->fi.vector = X86_TRAP_GP; ctxt->fi.error_code = 0; @@ -329,9 +328,6 @@ static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt) return ES_EXCEPTION; } - if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes)) - return ES_DECODE_FAILED; - if (ctxt->insn.immediate.got) return ES_OK; else -- 2.45.2