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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4947FC433F5 for ; Thu, 4 Nov 2021 16:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3593561248 for ; Thu, 4 Nov 2021 16:56:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231944AbhKDQ71 (ORCPT ); Thu, 4 Nov 2021 12:59:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231642AbhKDQ7Y (ORCPT ); Thu, 4 Nov 2021 12:59:24 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A17CC061205 for ; Thu, 4 Nov 2021 09:56:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=FwAF+bJxnQgNc7Zbr4m4rMqVhiyCbHvCDahCzDGnf8Y=; b=ZNR4Iv4BVWxw0hfRQpCH435WiQ D8PxnDa9JDjGlVcQ/xbucr0bUdBVbJwb4/rmjJhen/kq5geYhp0TbHQYgrZV5oGAPo+F1WMyX+SON WCITcOFTiY5YeGeaK8ckwDt8+5LVStxi6nA85AeN9Z+xJcA9eJt5mMprC6nzJpL8zJUfaNZ/IFMOP +j3pz2iVHRIvP6/uJ//VPGEWRtyTvBuMzPwjEPM4N7DFVx26zCMWVoUM8mry+DLzg4bcyzVBy+1lF muZB0dQzPL0WO9ovQUySwPHcRygni9y5ZuEnXqUujnVp4XmoKjHih0cfjKeNwLKkBGVIpqmYkyr0S pk6qf8LQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mig2X-00EC7j-9m; Thu, 04 Nov 2021 16:56:37 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 55118301995; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 36AD62DD49FBD; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Message-ID: <20211104165525.107322937@infradead.org> User-Agent: quilt/0.66 Date: Thu, 04 Nov 2021 17:47:39 +0100 From: Peter Zijlstra To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, jpoimboe@redhat.com, mark.rutland@arm.com, dvyukov@google.com, seanjc@google.com, pbonzini@redhat.com, mbenes@suse.cz Subject: [RFC][PATCH 10/22] x86,uaccess: Remove .fixup usage References: <20211104164729.226550532@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For the !CC_AS_ASM_GOTO_OUTPUT (aka. the legacy codepath), remove the .fixup usage by employing both EX_TYPE_EFAULT_REG and EX_FLAG_CLR. Like was already done for X86_32's version of __get_user_asm_u64() use the "a" register for output, specifically so we can use CLR_AX. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/uaccess.h | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -351,24 +351,22 @@ do { \ "1: movl %[lowbits],%%eax\n" \ "2: movl %[highbits],%%edx\n" \ "3:\n" \ - ".section .fixup,\"ax\"\n" \ - "4: mov %[efault],%[errout]\n" \ - " xorl %%eax,%%eax\n" \ - " xorl %%edx,%%edx\n" \ - " jmp 3b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(1b, 4b) \ - _ASM_EXTABLE_UA(2b, 4b) \ + _ASM_EXTABLE_TYPE_REG(1b, 3b, EX_TYPE_EFAULT_REG | \ + EX_FLAG_CLR_AX_DX, \ + %[errout]) \ + _ASM_EXTABLE_TYPE_REG(2b, 3b, EX_TYPE_EFAULT_REG | \ + EX_FLAG_CLR_AX_DX, \ + %[errout]) \ : [errout] "=r" (retval), \ [output] "=&A"(x) \ : [lowbits] "m" (__m(__ptr)), \ [highbits] "m" __m(((u32 __user *)(__ptr)) + 1), \ - [efault] "i" (-EFAULT), "0" (retval)); \ + "0" (retval)); \ }) #else #define __get_user_asm_u64(x, ptr, retval) \ - __get_user_asm(x, ptr, retval, "q", "=r") + __get_user_asm(x, ptr, retval, "q", "=a") #endif #define __get_user_size(x, ptr, size, retval) \ @@ -379,14 +377,14 @@ do { \ __chk_user_ptr(ptr); \ switch (size) { \ case 1: \ - __get_user_asm(x_u8__, ptr, retval, "b", "=q"); \ + __get_user_asm(x_u8__, ptr, retval, "b", "=a"); \ (x) = x_u8__; \ break; \ case 2: \ - __get_user_asm(x, ptr, retval, "w", "=r"); \ + __get_user_asm(x, ptr, retval, "w", "=a"); \ break; \ case 4: \ - __get_user_asm(x, ptr, retval, "l", "=r"); \ + __get_user_asm(x, ptr, retval, "l", "=a"); \ break; \ case 8: \ __get_user_asm_u64(x, ptr, retval); \ @@ -400,16 +398,13 @@ do { \ asm volatile("\n" \ "1: mov"itype" %[umem],%[output]\n" \ "2:\n" \ - ".section .fixup,\"ax\"\n" \ - "3: mov %[efault],%[errout]\n" \ - " xorl %k[output],%k[output]\n" \ - " jmp 2b\n" \ - ".previous\n" \ - _ASM_EXTABLE_UA(1b, 3b) \ + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG | \ + EX_FLAG_CLR_AX, \ + %[errout]) \ : [errout] "=r" (err), \ [output] ltype(x) \ : [umem] "m" (__m(addr)), \ - [efault] "i" (-EFAULT), "0" (err)) + "0" (err)) #endif // CONFIG_CC_HAS_ASM_GOTO_OUTPUT