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 9DD40C433F5 for ; Thu, 4 Nov 2021 16:56:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C9BE61244 for ; Thu, 4 Nov 2021 16:56:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232001AbhKDQ7b (ORCPT ); Thu, 4 Nov 2021 12:59:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231623AbhKDQ7Y (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 898CEC061203 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=M2sJPN7yzSddDYUmRSPtpMqeTrheUq6cwIQIWZQ4aFA=; b=YMjlJ1EySp1w/0G93EeSsndIaZ fkfhlDKgclSNW2kdIS77D8ysMNUYtxldr1P40FMLZlHuRF+1ekktulTGOrl73X6Onhi1LRfZ9KlVm yJQ4fF92U8Swab8Mqcguecs/r5GDZo9jBtpGV+QvR3Rd1hu5/bs74FzMqARVlqyZWyrvHQe+Gli6t kw9t0YJ7kXQCb/w75tCF2hTFxuiGlDn8y4GGQIp2yTYSgPjtUyMnqXuM7nzXnNGMdkg5hw8No9LFe R710DhkMAkPLb//v5YjruxF/P6JJGvwtWtdk6ZRwtOt6EcXx303vUyPoMzSLajZPXHNzqr/P9G0AU l122MFpQ==; 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 1mig2W-00EC7g-OQ; Thu, 04 Nov 2021 16:56:36 +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 51F74300ECB; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 310BF2DD49FBB; Thu, 4 Nov 2021 17:56:35 +0100 (CET) Message-ID: <20211104165525.045702474@infradead.org> User-Agent: quilt/0.66 Date: Thu, 04 Nov 2021 17:47:38 +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 09/22] x86,futex: 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 Use the new EX_TYPE_IMM_REG to store -EFAULT into the designated 'ret' register, this removes the need for anonymous .fixup code. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/extable_fixup_types.h | 2 ++ arch/x86/include/asm/futex.h | 28 ++++++++-------------------- 2 files changed, 10 insertions(+), 20 deletions(-) --- a/arch/x86/include/asm/extable_fixup_types.h +++ b/arch/x86/include/asm/extable_fixup_types.h @@ -32,6 +32,8 @@ #define EX_TYPE_DEFAULT_MCE_SAFE 14 #define EX_TYPE_FAULT_MCE_SAFE 15 #define EX_TYPE_POP_SEG 16 + #define EX_TYPE_IMM_REG 17 /* reg := (long)imm */ +#define EX_TYPE_EFAULT_REG (EX_TYPE_IMM_REG | EX_TYPE_IMM(-EFAULT)) #endif --- a/arch/x86/include/asm/futex.h +++ b/arch/x86/include/asm/futex.h @@ -17,13 +17,9 @@ do { \ int oldval = 0, ret; \ asm volatile("1:\t" insn "\n" \ "2:\n" \ - "\t.section .fixup,\"ax\"\n" \ - "3:\tmov\t%3, %1\n" \ - "\tjmp\t2b\n" \ - "\t.previous\n" \ - _ASM_EXTABLE_UA(1b, 3b) \ + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %1) \ : "=r" (oldval), "=r" (ret), "+m" (*uaddr) \ - : "i" (-EFAULT), "0" (oparg), "1" (0)); \ + : "0" (oparg), "1" (0)); \ if (ret) \ goto label; \ *oval = oldval; \ @@ -39,15 +35,11 @@ do { \ "3:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \ "\tjnz\t2b\n" \ "4:\n" \ - "\t.section .fixup,\"ax\"\n" \ - "5:\tmov\t%5, %1\n" \ - "\tjmp\t4b\n" \ - "\t.previous\n" \ - _ASM_EXTABLE_UA(1b, 5b) \ - _ASM_EXTABLE_UA(3b, 5b) \ + _ASM_EXTABLE_TYPE_REG(1b, 4b, EX_TYPE_EFAULT_REG, %1) \ + _ASM_EXTABLE_TYPE_REG(3b, 4b, EX_TYPE_EFAULT_REG, %1) \ : "=&a" (oldval), "=&r" (ret), \ "+m" (*uaddr), "=&r" (tem) \ - : "r" (oparg), "i" (-EFAULT), "1" (0)); \ + : "r" (oparg), "1" (0)); \ if (ret) \ goto label; \ *oval = oldval; \ @@ -95,15 +87,11 @@ static inline int futex_atomic_cmpxchg_i if (!user_access_begin(uaddr, sizeof(u32))) return -EFAULT; asm volatile("\n" - "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" + "1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" "2:\n" - "\t.section .fixup, \"ax\"\n" - "3:\tmov %3, %0\n" - "\tjmp 2b\n" - "\t.previous\n" - _ASM_EXTABLE_UA(1b, 3b) + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %0) \ : "+r" (ret), "=a" (oldval), "+m" (*uaddr) - : "i" (-EFAULT), "r" (newval), "1" (oldval) + : "r" (newval), "1" (oldval) : "memory" ); user_access_end();