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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,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 2EBD2C433E1 for ; Tue, 19 May 2020 19:59:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15A3E20849 for ; Tue, 19 May 2020 19:59:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728425AbgEST7Q (ORCPT ); Tue, 19 May 2020 15:59:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728283AbgEST64 (ORCPT ); Tue, 19 May 2020 15:58:56 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90B41C08C5C1; Tue, 19 May 2020 12:58:56 -0700 (PDT) Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jb8O3-000075-FL; Tue, 19 May 2020 21:58:51 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id 13C7F1C0857; Tue, 19 May 2020 21:58:41 +0200 (CEST) Date: Tue, 19 May 2020 19:58:40 -0000 From: "tip-bot2 for Peter Zijlstra" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/entry] x86/entry: Make entry_64_compat.S objtool clean Cc: "Peter Zijlstra (Intel)" , Thomas Gleixner , Alexandre Chartre , Andy Lutomirski , x86 , LKML In-Reply-To: <20200505134341.272248024@linutronix.de> References: <20200505134341.272248024@linutronix.de> MIME-Version: 1.0 Message-ID: <158991832097.17951.17826399641705845911.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/entry branch of tip: Commit-ID: b5f7e5db3839c5e67af6544872f35e2d70359518 Gitweb: https://git.kernel.org/tip/b5f7e5db3839c5e67af6544872f35e2d70359518 Author: Peter Zijlstra AuthorDate: Tue, 12 May 2020 18:17:12 +02:00 Committer: Thomas Gleixner CommitterDate: Tue, 19 May 2020 16:03:52 +02:00 x86/entry: Make entry_64_compat.S objtool clean Currently entry_64_compat is exempt from objtool, but with vmlinux mode there is no hiding it. Make the following changes to make it pass: - change entry_SYSENTER_compat to STT_NOTYPE; it's not a function and doesn't have function type stack setup. - mark all STT_NOTYPE symbols with UNWIND_HINT_EMPTY; so we do validate them and don't treat them as unreachable. - don't abuse RSP as a temp register, this confuses objtool mightily as it (rightfully) thinks we're doing unspeakable things to the stack. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Reviewed-by: Alexandre Chartre Acked-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20200505134341.272248024@linutronix.de --- arch/x86/entry/Makefile | 2 -- arch/x86/entry/entry_64_compat.S | 25 ++++++++++++++++++++----- 2 files changed, 20 insertions(+), 7 deletions(-) diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile index cdf45ff..b7a5790 100644 --- a/arch/x86/entry/Makefile +++ b/arch/x86/entry/Makefile @@ -11,8 +11,6 @@ CFLAGS_REMOVE_common.o = $(CC_FLAGS_FTRACE) -fstack-protector -fstack-protector- CFLAGS_REMOVE_syscall_32.o = $(CC_FLAGS_FTRACE) -fstack-protector -fstack-protector-strong CFLAGS_REMOVE_syscall_64.o = $(CC_FLAGS_FTRACE) -fstack-protector -fstack-protector-strong -OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y - CFLAGS_syscall_64.o += $(call cc-option,-Wno-override-init,) CFLAGS_syscall_32.o += $(call cc-option,-Wno-override-init,) obj-y := entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S index 7c29ed8..0f974ae 100644 --- a/arch/x86/entry/entry_64_compat.S +++ b/arch/x86/entry/entry_64_compat.S @@ -46,12 +46,14 @@ * ebp user stack * 0(%ebp) arg6 */ -SYM_FUNC_START(entry_SYSENTER_compat) +SYM_CODE_START(entry_SYSENTER_compat) + UNWIND_HINT_EMPTY /* Interrupts are off on entry. */ SWAPGS - /* We are about to clobber %rsp anyway, clobbering here is OK */ - SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp + pushq %rax + SWITCH_TO_KERNEL_CR3 scratch_reg=%rax + popq %rax movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp @@ -104,6 +106,9 @@ SYM_FUNC_START(entry_SYSENTER_compat) xorl %r14d, %r14d /* nospec r14 */ pushq $0 /* pt_regs->r15 = 0 */ xorl %r15d, %r15d /* nospec r15 */ + + UNWIND_HINT_REGS + cld /* @@ -141,7 +146,7 @@ SYM_FUNC_START(entry_SYSENTER_compat) popfq jmp .Lsysenter_flags_fixed SYM_INNER_LABEL(__end_entry_SYSENTER_compat, SYM_L_GLOBAL) -SYM_FUNC_END(entry_SYSENTER_compat) +SYM_CODE_END(entry_SYSENTER_compat) /* * 32-bit SYSCALL entry. @@ -191,6 +196,7 @@ SYM_FUNC_END(entry_SYSENTER_compat) * 0(%esp) arg6 */ SYM_CODE_START(entry_SYSCALL_compat) + UNWIND_HINT_EMPTY /* Interrupts are off on entry. */ swapgs @@ -241,6 +247,8 @@ SYM_INNER_LABEL(entry_SYSCALL_compat_after_hwframe, SYM_L_GLOBAL) pushq $0 /* pt_regs->r15 = 0 */ xorl %r15d, %r15d /* nospec r15 */ + UNWIND_HINT_REGS + movq %rsp, %rdi call do_fast_syscall_32 /* XEN PV guests always use IRET path */ @@ -328,6 +336,7 @@ SYM_CODE_END(entry_SYSCALL_compat) * ebp arg6 */ SYM_CODE_START(entry_INT80_compat) + UNWIND_HINT_EMPTY /* * Interrupts are off on entry. */ @@ -349,8 +358,11 @@ SYM_CODE_START(entry_INT80_compat) /* Need to switch before accessing the thread stack. */ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi + /* In the Xen PV case we already run on the thread stack. */ - ALTERNATIVE "movq %rsp, %rdi", "jmp .Lint80_keep_stack", X86_FEATURE_XENPV + ALTERNATIVE "", "jmp .Lint80_keep_stack", X86_FEATURE_XENPV + + movq %rsp, %rdi movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp pushq 6*8(%rdi) /* regs->ss */ @@ -389,6 +401,9 @@ SYM_CODE_START(entry_INT80_compat) xorl %r14d, %r14d /* nospec r14 */ pushq %r15 /* pt_regs->r15 */ xorl %r15d, %r15d /* nospec r15 */ + + UNWIND_HINT_REGS + cld movq %rsp, %rdi