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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36928C433F5 for ; Sat, 4 Dec 2021 13:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1385114AbhLDNzI (ORCPT ); Sat, 4 Dec 2021 08:55:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233492AbhLDNzA (ORCPT ); Sat, 4 Dec 2021 08:55:00 -0500 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 20E10C061354 for ; Sat, 4 Dec 2021 05:51:35 -0800 (PST) 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=lLTh9Sg8ypRr+awXjTSLmh9JH82fVBGPW08NlmYtBTA=; b=eAYXSGiZEOPyY0NWICDbnBQnLd FPwPcpFG0EBlCiHY+9SEvAxq6oZkcJxE4jV8DPr+STgcokYQnpjimmPy0NivMTdNcthKhtn1Rgsnw huQi1jft3LnJ8tzO0/glo4T4hc8kXFPBztsys070bIcPLc7mlcgrWz2WXbZo5VT54gqJ8lO/pf9Jp +TMo75HV6bUM9RZpoytpD9nYtySnd1Bn+6xcLv+tKgPxtui8odYPBzaGfNxI0RGokhDAL1u7ba3Wq x/3i3h0CN0q4q8pU1/KW0QnBnX+miJv/NAXKYvB3YJrb78nx0N6MDsOG9eDhoSXW22iYxJ8o+FPtm vR2gp83A==; 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 1mtVRm-002CkV-65; Sat, 04 Dec 2021 13:51:26 +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 (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id C7E64300728; Sat, 4 Dec 2021 14:51:24 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 821682DD25627; Sat, 4 Dec 2021 14:51:24 +0100 (CET) Message-ID: <20211204134907.964635458@infradead.org> User-Agent: quilt/0.66 Date: Sat, 04 Dec 2021 14:43:41 +0100 From: Peter Zijlstra To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, keescook@chromium.org, hjl.tools@gmail.com, andrew.cooper3@citrix.com, mark.rutland@arm.com, will@kernel.org, ndesaulniers@google.com Subject: [PATCH v2 3/6] x86: Prepare inline-asm for straight-line-speculation References: <20211204134338.760603010@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 Replace all ret/retq instructions with ASM_RET in preparation of making it more than a single instruction. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/linkage.h | 4 ++++ arch/x86/include/asm/paravirt.h | 2 +- arch/x86/include/asm/qspinlock_paravirt.h | 4 ++-- arch/x86/kernel/alternative.c | 2 +- arch/x86/kernel/kprobes/core.c | 2 +- arch/x86/kernel/paravirt.c | 4 ++-- arch/x86/kvm/emulate.c | 4 ++-- arch/x86/lib/error-inject.c | 3 ++- samples/ftrace/ftrace-direct-modify.c | 4 ++-- samples/ftrace/ftrace-direct-too.c | 2 +- samples/ftrace/ftrace-direct.c | 2 +- 11 files changed, 19 insertions(+), 14 deletions(-) --- a/arch/x86/include/asm/linkage.h +++ b/arch/x86/include/asm/linkage.h @@ -18,6 +18,10 @@ #define __ALIGN_STR __stringify(__ALIGN) #endif +#else /* __ASSEMBLY__ */ + +#define ASM_RET "ret\n\t" + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_LINKAGE_H */ --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -671,7 +671,7 @@ bool __raw_callee_save___native_vcpu_is_ "call " #func ";" \ PV_RESTORE_ALL_CALLER_REGS \ FRAME_END \ - "ret;" \ + ASM_RET \ ".size " PV_THUNK_NAME(func) ", .-" PV_THUNK_NAME(func) ";" \ ".popsection") --- a/arch/x86/include/asm/qspinlock_paravirt.h +++ b/arch/x86/include/asm/qspinlock_paravirt.h @@ -48,7 +48,7 @@ asm (".pushsection .text;" "jne .slowpath;" "pop %rdx;" FRAME_END - "ret;" + ASM_RET ".slowpath: " "push %rsi;" "movzbl %al,%esi;" @@ -56,7 +56,7 @@ asm (".pushsection .text;" "pop %rsi;" "pop %rdx;" FRAME_END - "ret;" + ASM_RET ".size " PV_UNLOCK ", .-" PV_UNLOCK ";" ".popsection"); --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -714,7 +714,7 @@ asm ( " .type int3_magic, @function\n" "int3_magic:\n" " movl $1, (%" _ASM_ARG1 ")\n" -" ret\n" + ASM_RET " .size int3_magic, .-int3_magic\n" " .popsection\n" ); --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1051,7 +1051,7 @@ asm( " addl $4, %esp\n" " popfl\n" #endif - " ret\n" + ASM_RET ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(__kretprobe_trampoline); --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -41,7 +41,7 @@ extern void _paravirt_nop(void); asm (".pushsection .entry.text, \"ax\"\n" ".global _paravirt_nop\n" "_paravirt_nop:\n\t" - "ret\n\t" + ASM_RET ".size _paravirt_nop, . - _paravirt_nop\n\t" ".type _paravirt_nop, @function\n\t" ".popsection"); @@ -51,7 +51,7 @@ asm (".pushsection .entry.text, \"ax\"\n ".global paravirt_ret0\n" "paravirt_ret0:\n\t" "xor %" _ASM_AX ", %" _ASM_AX ";\n\t" - "ret\n\t" + ASM_RET ".size paravirt_ret0, . - paravirt_ret0\n\t" ".type paravirt_ret0, @function\n\t" ".popsection"); --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -315,7 +315,7 @@ static int fastop(struct x86_emulate_ctx __FOP_FUNC(#name) #define __FOP_RET(name) \ - "ret \n\t" \ + ASM_RET \ ".size " name ", .-" name "\n\t" #define FOP_RET(name) \ @@ -435,7 +435,7 @@ static int fastop(struct x86_emulate_ctx __FOP_RET(#op) asm(".pushsection .fixup, \"ax\"\n" - "kvm_fastop_exception: xor %esi, %esi; ret\n" + "kvm_fastop_exception: xor %esi, %esi; " ASM_RET ".popsection"); FOP_START(setcc) --- a/arch/x86/lib/error-inject.c +++ b/arch/x86/lib/error-inject.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include #include @@ -10,7 +11,7 @@ asm( ".type just_return_func, @function\n" ".globl just_return_func\n" "just_return_func:\n" - " ret\n" + ASM_RET ".size just_return_func, .-just_return_func\n" ); --- a/samples/ftrace/ftrace-direct-modify.c +++ b/samples/ftrace/ftrace-direct-modify.c @@ -31,7 +31,7 @@ asm ( " call my_direct_func1\n" " leave\n" " .size my_tramp1, .-my_tramp1\n" -" ret\n" + ASM_RET " .type my_tramp2, @function\n" " .globl my_tramp2\n" " my_tramp2:" @@ -39,7 +39,7 @@ asm ( " movq %rsp, %rbp\n" " call my_direct_func2\n" " leave\n" -" ret\n" + ASM_RET " .size my_tramp2, .-my_tramp2\n" " .popsection\n" ); --- a/samples/ftrace/ftrace-direct-too.c +++ b/samples/ftrace/ftrace-direct-too.c @@ -31,7 +31,7 @@ asm ( " popq %rsi\n" " popq %rdi\n" " leave\n" -" ret\n" + ASM_RET " .size my_tramp, .-my_tramp\n" " .popsection\n" ); --- a/samples/ftrace/ftrace-direct.c +++ b/samples/ftrace/ftrace-direct.c @@ -25,7 +25,7 @@ asm ( " call my_direct_func\n" " popq %rdi\n" " leave\n" -" ret\n" + ASM_RET " .size my_tramp, .-my_tramp\n" " .popsection\n" );