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=-12.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 76D57C43441 for ; Thu, 22 Nov 2018 10:10:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3316820684 for ; Thu, 22 Nov 2018 10:10:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3316820684 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393899AbeKVUtT (ORCPT ); Thu, 22 Nov 2018 15:49:19 -0500 Received: from terminus.zytor.com ([198.137.202.136]:41211 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390426AbeKVUtT (ORCPT ); Thu, 22 Nov 2018 15:49:19 -0500 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id wAMA9sWt3743618 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 22 Nov 2018 02:09:54 -0800 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id wAMA9svG3743615; Thu, 22 Nov 2018 02:09:54 -0800 Date: Thu, 22 Nov 2018 02:09:54 -0800 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Andy Lutomirski Message-ID: Cc: hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, dave.hansen@linux.intel.com, bp@alien8.de, tglx@linutronix.de, linux-kernel@vger.kernel.org, peterz@infradead.org, luto@kernel.org, yu-cheng.yu@intel.com, riel@surriel.com Reply-To: dave.hansen@linux.intel.com, bp@alien8.de, tglx@linutronix.de, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, yu-cheng.yu@intel.com, peterz@infradead.org, luto@kernel.org, riel@surriel.com In-Reply-To: <078f5b8ae6e8c79ff8ee7345b5c476c45003e5ac.1542841400.git.luto@kernel.org> References: <078f5b8ae6e8c79ff8ee7345b5c476c45003e5ac.1542841400.git.luto@kernel.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/mm] x86/fault: Remove sw_error_code Git-Commit-ID: 0ed32f1aa66ee758e6c8164f549f7ff9d399a20e X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 0ed32f1aa66ee758e6c8164f549f7ff9d399a20e Gitweb: https://git.kernel.org/tip/0ed32f1aa66ee758e6c8164f549f7ff9d399a20e Author: Andy Lutomirski AuthorDate: Wed, 21 Nov 2018 15:11:22 -0800 Committer: Ingo Molnar CommitDate: Thu, 22 Nov 2018 09:22:59 +0100 x86/fault: Remove sw_error_code All of the fault handling code now corrently checks user_mode(regs) as needed, and nothing depends on the X86_PF_USER bit being munged. Get rid of the sw_error code and use hw_error_code everywhere. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Rik van Riel Cc: Thomas Gleixner Cc: Yu-cheng Yu Link: http://lkml.kernel.org/r/078f5b8ae6e8c79ff8ee7345b5c476c45003e5ac.1542841400.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 50 +++++++++++--------------------------------------- 1 file changed, 11 insertions(+), 39 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index b898a38093a3..82881bc5feef 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -1217,7 +1217,6 @@ void do_user_addr_fault(struct pt_regs *regs, unsigned long hw_error_code, unsigned long address) { - unsigned long sw_error_code; struct vm_area_struct *vma; struct task_struct *tsk; struct mm_struct *mm; @@ -1262,13 +1261,6 @@ void do_user_addr_fault(struct pt_regs *regs, return; } - /* - * hw_error_code is literally the "page fault error code" passed to - * the kernel directly from the hardware. But, we will shortly be - * modifying it in software, so give it a new name. - */ - sw_error_code = hw_error_code; - /* * It's safe to allow irq's after cr2 has been saved and the * vmalloc fault has been handled. @@ -1278,26 +1270,6 @@ void do_user_addr_fault(struct pt_regs *regs, */ if (user_mode(regs)) { local_irq_enable(); - /* - * Up to this point, X86_PF_USER set in hw_error_code - * indicated a user-mode access. But, after this, - * X86_PF_USER in sw_error_code will indicate either - * that, *or* an implicit kernel(supervisor)-mode access - * which originated from user mode. - */ - if (!(hw_error_code & X86_PF_USER)) { - /* - * The CPU was in user mode, but the CPU says - * the fault was not a user-mode access. - * Must be an implicit kernel-mode access, - * which we do not expect to happen in the - * user address space. - */ - pr_warn_once("kernel-mode error from user-mode: %lx\n", - hw_error_code); - - sw_error_code |= X86_PF_USER; - } flags |= FAULT_FLAG_USER; } else { if (regs->flags & X86_EFLAGS_IF) @@ -1306,9 +1278,9 @@ void do_user_addr_fault(struct pt_regs *regs, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); - if (sw_error_code & X86_PF_WRITE) + if (hw_error_code & X86_PF_WRITE) flags |= FAULT_FLAG_WRITE; - if (sw_error_code & X86_PF_INSTR) + if (hw_error_code & X86_PF_INSTR) flags |= FAULT_FLAG_INSTRUCTION; #ifdef CONFIG_X86_64 @@ -1321,7 +1293,7 @@ void do_user_addr_fault(struct pt_regs *regs, * The vsyscall page does not have a "real" VMA, so do this * emulation before we go searching for VMAs. */ - if ((sw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) { + if ((hw_error_code & X86_PF_INSTR) && is_vsyscall_vaddr(address)) { if (emulate_vsyscall(regs, address)) return; } @@ -1345,7 +1317,7 @@ void do_user_addr_fault(struct pt_regs *regs, * Fault from code in kernel from * which we do not expect faults. */ - bad_area_nosemaphore(regs, sw_error_code, address); + bad_area_nosemaphore(regs, hw_error_code, address); return; } retry: @@ -1361,17 +1333,17 @@ retry: vma = find_vma(mm, address); if (unlikely(!vma)) { - bad_area(regs, sw_error_code, address); + bad_area(regs, hw_error_code, address); return; } if (likely(vma->vm_start <= address)) goto good_area; if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) { - bad_area(regs, sw_error_code, address); + bad_area(regs, hw_error_code, address); return; } if (unlikely(expand_stack(vma, address))) { - bad_area(regs, sw_error_code, address); + bad_area(regs, hw_error_code, address); return; } @@ -1380,8 +1352,8 @@ retry: * we can handle it.. */ good_area: - if (unlikely(access_error(sw_error_code, vma))) { - bad_area_access_error(regs, sw_error_code, address, vma); + if (unlikely(access_error(hw_error_code, vma))) { + bad_area_access_error(regs, hw_error_code, address, vma); return; } @@ -1420,13 +1392,13 @@ good_area: return; /* Not returning to user mode? Handle exceptions or die: */ - no_context(regs, sw_error_code, address, SIGBUS, BUS_ADRERR); + no_context(regs, hw_error_code, address, SIGBUS, BUS_ADRERR); return; } up_read(&mm->mmap_sem); if (unlikely(fault & VM_FAULT_ERROR)) { - mm_fault_error(regs, sw_error_code, address, fault); + mm_fault_error(regs, hw_error_code, address, fault); return; }