From nobody Sat Sep 21 05:48:01 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1706024911359962.4031863663696; Tue, 23 Jan 2024 07:48:31 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1rSJ0G-0002pt-Rz; Tue, 23 Jan 2024 10:47:58 -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 1rSIzq-0002ne-9Y; Tue, 23 Jan 2024 10:47:32 -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 1rSIzl-0000gM-50; Tue, 23 Jan 2024 10:47:27 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 282BB4691F; Tue, 23 Jan 2024 18:47:50 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id D0A0769EAE; Tue, 23 Jan 2024 18:47:08 +0300 (MSK) Received: (nullmailer pid 3847900 invoked by uid 1000); Tue, 23 Jan 2024 15:47:08 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Richard Henderson , Michael Tokarev , Paolo Bonzini Subject: [Stable-8.2.1 40/54] target/i386: Do not re-compute new pc with CF_PCREL Date: Tue, 23 Jan 2024 18:46:41 +0300 Message-Id: <20240123154708.3847837-2-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1706024913629100003 Content-Type: text/plain; charset="utf-8" From: Richard Henderson With PCREL, we have a page-relative view of EIP, and an approximation of PC =3D EIP+CSBASE that is good enough to detect page crossings. If we try to recompute PC after masking EIP, we will mess up that approximation and write a corrupt value to EIP. We already handled masking properly for PCREL, so the fix in b5e0d5d2 was only needed for the !PCREL path. Cc: qemu-stable@nongnu.org Fixes: b5e0d5d22fbf ("target/i386: Fix 32-bit wrapping of pc/eip computatio= n") Reported-by: Michael Tokarev Signed-off-by: Richard Henderson Message-ID: <20240101230617.129349-1-richard.henderson@linaro.org> Signed-off-by: Paolo Bonzini (cherry picked from commit a58506b748b8988a95f4fa1a2420ac5c17038b30) Signed-off-by: Michael Tokarev diff --git a/target/i386/tcg/translate.c b/target/i386/tcg/translate.c index 037bc47e7c..e68375b19d 100644 --- a/target/i386/tcg/translate.c +++ b/target/i386/tcg/translate.c @@ -2845,10 +2845,6 @@ static void gen_jmp_rel(DisasContext *s, MemOp ot, i= nt diff, int tb_num) } } new_eip &=3D mask; - new_pc =3D new_eip + s->cs_base; - if (!CODE64(s)) { - new_pc =3D (uint32_t)new_pc; - } =20 gen_update_cc_op(s); set_cc_op(s, CC_OP_DYNAMIC); @@ -2864,6 +2860,8 @@ static void gen_jmp_rel(DisasContext *s, MemOp ot, in= t diff, int tb_num) tcg_gen_andi_tl(cpu_eip, cpu_eip, mask); use_goto_tb =3D false; } + } else if (!CODE64(s)) { + new_pc =3D (uint32_t)(new_eip + s->cs_base); } =20 if (use_goto_tb && translator_use_goto_tb(&s->base, new_pc)) { --=20 2.39.2