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=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 EF1B9C76195 for ; Thu, 18 Jul 2019 01:37:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D0D6A21850 for ; Thu, 18 Jul 2019 01:37:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387693AbfGRBh2 (ORCPT ); Wed, 17 Jul 2019 21:37:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52538 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733059AbfGRBhW (ORCPT ); Wed, 17 Jul 2019 21:37:22 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C9EB7C057E29; Thu, 18 Jul 2019 01:37:21 +0000 (UTC) Received: from treble.redhat.com (ovpn-122-211.rdu2.redhat.com [10.10.122.211]) by smtp.corp.redhat.com (Postfix) with ESMTP id B5A835D9CC; Thu, 18 Jul 2019 01:37:20 +0000 (UTC) From: Josh Poimboeuf To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Nick Desaulniers , Arnd Bergmann , Jann Horn , Randy Dunlap Subject: [PATCH v2 09/22] x86/uaccess: Remove redundant CLACs in getuser/putuser error paths Date: Wed, 17 Jul 2019 20:36:44 -0500 Message-Id: In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 18 Jul 2019 01:37:21 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The same getuser/putuser error paths are used regardless of whether AC is set. In non-exception failure cases, this results in an unnecessary CLAC. Fixes the following warnings: arch/x86/lib/getuser.o: warning: objtool: .altinstr_replacement+0x18: redundant UACCESS disable arch/x86/lib/putuser.o: warning: objtool: .altinstr_replacement+0x18: redundant UACCESS disable Signed-off-by: Josh Poimboeuf Acked-by: Peter Zijlstra (Intel) --- arch/x86/lib/getuser.S | 20 ++++++++++---------- arch/x86/lib/putuser.S | 29 ++++++++++++++++------------- 2 files changed, 26 insertions(+), 23 deletions(-) diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S index 74fdff968ea3..304f958c27b2 100644 --- a/arch/x86/lib/getuser.S +++ b/arch/x86/lib/getuser.S @@ -115,29 +115,29 @@ ENDPROC(__get_user_8) EXPORT_SYMBOL(__get_user_8) +bad_get_user_clac: + ASM_CLAC bad_get_user: xor %edx,%edx mov $(-EFAULT),%_ASM_AX - ASM_CLAC ret -END(bad_get_user) #ifdef CONFIG_X86_32 +bad_get_user_8_clac: + ASM_CLAC bad_get_user_8: xor %edx,%edx xor %ecx,%ecx mov $(-EFAULT),%_ASM_AX - ASM_CLAC ret -END(bad_get_user_8) #endif - _ASM_EXTABLE_UA(1b, bad_get_user) - _ASM_EXTABLE_UA(2b, bad_get_user) - _ASM_EXTABLE_UA(3b, bad_get_user) + _ASM_EXTABLE_UA(1b, bad_get_user_clac) + _ASM_EXTABLE_UA(2b, bad_get_user_clac) + _ASM_EXTABLE_UA(3b, bad_get_user_clac) #ifdef CONFIG_X86_64 - _ASM_EXTABLE_UA(4b, bad_get_user) + _ASM_EXTABLE_UA(4b, bad_get_user_clac) #else - _ASM_EXTABLE_UA(4b, bad_get_user_8) - _ASM_EXTABLE_UA(5b, bad_get_user_8) + _ASM_EXTABLE_UA(4b, bad_get_user_8_clac) + _ASM_EXTABLE_UA(5b, bad_get_user_8_clac) #endif diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S index d2e5c9c39601..14bf78341d3c 100644 --- a/arch/x86/lib/putuser.S +++ b/arch/x86/lib/putuser.S @@ -32,8 +32,6 @@ */ #define ENTER mov PER_CPU_VAR(current_task), %_ASM_BX -#define EXIT ASM_CLAC ; \ - ret .text ENTRY(__put_user_1) @@ -43,7 +41,8 @@ ENTRY(__put_user_1) ASM_STAC 1: movb %al,(%_ASM_CX) xor %eax,%eax - EXIT + ASM_CLAC + ret ENDPROC(__put_user_1) EXPORT_SYMBOL(__put_user_1) @@ -56,7 +55,8 @@ ENTRY(__put_user_2) ASM_STAC 2: movw %ax,(%_ASM_CX) xor %eax,%eax - EXIT + ASM_CLAC + ret ENDPROC(__put_user_2) EXPORT_SYMBOL(__put_user_2) @@ -69,7 +69,8 @@ ENTRY(__put_user_4) ASM_STAC 3: movl %eax,(%_ASM_CX) xor %eax,%eax - EXIT + ASM_CLAC + ret ENDPROC(__put_user_4) EXPORT_SYMBOL(__put_user_4) @@ -85,19 +86,21 @@ ENTRY(__put_user_8) 5: movl %edx,4(%_ASM_CX) #endif xor %eax,%eax - EXIT + ASM_CLAC + RET ENDPROC(__put_user_8) EXPORT_SYMBOL(__put_user_8) +bad_put_user_clac: + ASM_CLAC bad_put_user: movl $-EFAULT,%eax - EXIT -END(bad_put_user) + RET - _ASM_EXTABLE_UA(1b, bad_put_user) - _ASM_EXTABLE_UA(2b, bad_put_user) - _ASM_EXTABLE_UA(3b, bad_put_user) - _ASM_EXTABLE_UA(4b, bad_put_user) + _ASM_EXTABLE_UA(1b, bad_put_user_clac) + _ASM_EXTABLE_UA(2b, bad_put_user_clac) + _ASM_EXTABLE_UA(3b, bad_put_user_clac) + _ASM_EXTABLE_UA(4b, bad_put_user_clac) #ifdef CONFIG_X86_32 - _ASM_EXTABLE_UA(5b, bad_put_user) + _ASM_EXTABLE_UA(5b, bad_put_user_clac) #endif -- 2.20.1