From patchwork Wed Feb 21 08:20:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 13565748 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 52856C48BC3 for ; Wed, 21 Feb 2024 15:40:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rcoWr-0007y1-4p; Wed, 21 Feb 2024 10:29:01 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rcoOM-0001Rw-Qw; Wed, 21 Feb 2024 10:20:14 -0500 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1rchvM-00035v-RH; Wed, 21 Feb 2024 03:25:54 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 8293D4F3F3; Wed, 21 Feb 2024 11:21:23 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id 4E03D860D2; Wed, 21 Feb 2024 11:21:02 +0300 (MSK) Received: (nullmailer pid 2142149 invoked by uid 1000); Wed, 21 Feb 2024 08:20:58 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Ziqiao Kong , Paolo Bonzini , Michael Tokarev Subject: [Stable-8.2.2 53/60] target/i386: Generate an illegal opcode exception on cmp instructions with lock prefix Date: Wed, 21 Feb 2024 11:20:41 +0300 Message-Id: <20240221082058.2141850-53-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Ziqiao Kong target/i386: As specified by Intel Manual Vol2 3-180, cmp instructions are not allowed to have lock prefix and a `UD` should be raised. Without this patch, s1->T0 will be uninitialized and used in the case OP_CMPL. Signed-off-by: Ziqiao Kong Message-ID: <20240215095015.570748-2-ziqiaokong@gmail.com> Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini (cherry picked from commit 99d0dcd7f102c07a510200d768cae65e5db25d23) Signed-off-by: Michael Tokarev diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 8fd49ff474..83c2b40480 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -1480,12 +1480,13 @@ static bool check_iopl(DisasContext *s) /* if d == OR_TMP0, it means memory operand (address in A0) */ static void gen_op(DisasContext *s1, int op, MemOp ot, int d) { + /* Invalid lock prefix when destination is not memory or OP_CMPL. */ + if ((d != OR_TMP0 || op == OP_CMPL) && s1->prefix & PREFIX_LOCK) { + gen_illegal_opcode(s1); + return; + } + if (d != OR_TMP0) { - if (s1->prefix & PREFIX_LOCK) { - /* Lock prefix when destination is not memory. */ - gen_illegal_opcode(s1); - return; - } gen_op_mov_v_reg(s1, ot, s1->T0, d); } else if (!(s1->prefix & PREFIX_LOCK)) { gen_op_ld_v(s1, ot, s1->T0, s1->A0);