From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A3AFC6786F for ; Tue, 30 Oct 2018 06:55:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 33A752082D for ; Tue, 30 Oct 2018 06:55:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="BosEaZ6P" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 33A752082D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727417AbeJ3Pr4 (ORCPT ); Tue, 30 Oct 2018 11:47:56 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:39124 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727346AbeJ3Pr4 (ORCPT ); Tue, 30 Oct 2018 11:47:56 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9U6rUqV064220; Tue, 30 Oct 2018 06:55:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=mime-version : message-id : date : from : to : cc : subject : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=L3hPylc0rRV2wBjedQTZVcu/c0ihS12eOxda0ZXnqc8=; b=BosEaZ6PSB5vhvGhqEM2EUb110utZakCdSPkm3Zwq3yUYpOclo5BPjwOO0qmQvtGWeH9 Fn9uxPmS7hdeqlzRKR0vNnFQ4YxyLbdXlZQiTQ3JWRLg0rTMTRZKOX+JpTtPOh0Eywmd WYkX64kugMU+FIvI6dWO/1w3nbgb3gAlCc1hmD19ypako1eEPngo1r3lJydG1TZbQvri onHKCEt5RNFWcHc+vp65bjV60MN3kF7OVoZwFFFF0NcOntEhamjdqx+H2x3/fHsGTZpU JX462N69EbCgoGThA4qJQRwW9ihEHHHFURwOaW5bGQ84sKhpBISr60PisDA4HXTWjNMl 2g== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2120.oracle.com with ESMTP id 2ncgnqsxj1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Oct 2018 06:55:08 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9U6t7dp007285 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Oct 2018 06:55:07 GMT Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id w9U6t6lM008483; Tue, 30 Oct 2018 06:55:06 GMT MIME-Version: 1.0 Message-ID: Date: Mon, 29 Oct 2018 23:55:06 -0700 (PDT) From: Zhenzhong Duan To: Linux-Kernel Cc: , , , , Srinivas REDDY Eeda , , , Subject: [PATCH 3/3] kprobes/x86: Simplify indirect-jump check in retpoline X-Mailer: Zimbra on Oracle Beehive Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9061 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810300060 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since CONFIG_RETPOLINE hard depends on compiler support now, so replacing indirect-jump check with the range check is safe in that case. Signed-off-by: Zhenzhong Duan Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Borislav Petkov Cc: David Woodhouse Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Konrad Rzeszutek Wilk --- arch/x86/kernel/kprobes/opt.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c index 40b16b2..1136b29 100644 --- a/arch/x86/kernel/kprobes/opt.c +++ b/arch/x86/kernel/kprobes/opt.c @@ -203,6 +203,7 @@ static int copy_optimized_instructions(u8 *dest, u8 *sr= c, u8 *real) =09return len; } =20 +#ifndef CONFIG_RETPOLINE /* Check whether insn is indirect jump */ static int __insn_is_indirect_jump(struct insn *insn) { @@ -210,6 +211,7 @@ static int __insn_is_indirect_jump(struct insn *insn) =09=09(X86_MODRM_REG(insn->modrm.value) & 6) =3D=3D 4) || /* Jump */ =09=09insn->opcode.bytes[0] =3D=3D 0xea);=09/* Segment based jump */ } +#endif =20 /* Check whether insn jumps into specified address range */ static int insn_jump_into_range(struct insn *insn, unsigned long start, in= t len) @@ -240,20 +242,16 @@ static int insn_jump_into_range(struct insn *insn, un= signed long start, int len) =20 static int insn_is_indirect_jump(struct insn *insn) { -=09int ret =3D __insn_is_indirect_jump(insn); +=09int ret; =20 #ifdef CONFIG_RETPOLINE -=09/* -=09 * Jump to x86_indirect_thunk_* is treated as an indirect jump. -=09 * Note that even with CONFIG_RETPOLINE=3Dy, the kernel compiled with -=09 * older gcc may use indirect jump. So we add this check instead of -=09 * replace indirect-jump check. -=09 */ -=09if (!ret) +=09/* Jump to x86_indirect_thunk_* is treated as an indirect jump. */ =09=09ret =3D insn_jump_into_range(insn, =09=09=09=09(unsigned long)__indirect_thunk_start, =09=09=09=09(unsigned long)__indirect_thunk_end - =09=09=09=09(unsigned long)__indirect_thunk_start); +#else +=09=09ret =3D __insn_is_indirect_jump(insn); #endif =09return ret; } --=20 1.8.3.1