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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 61B2CC46476 for ; Fri, 7 Jun 2019 09:13:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41AD120B7C for ; Fri, 7 Jun 2019 09:13:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727625AbfFGJNQ (ORCPT ); Fri, 7 Jun 2019 05:13:16 -0400 Received: from foss.arm.com ([217.140.110.172]:36116 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726531AbfFGJNN (ORCPT ); Fri, 7 Jun 2019 05:13:13 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DE8AB344; Fri, 7 Jun 2019 02:13:12 -0700 (PDT) Received: from p8cg001049571a15.blr.arm.com (p8cg001049571a15.blr.arm.com [10.162.42.131]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C00033F96A; Fri, 7 Jun 2019 02:13:09 -0700 (PDT) From: Anshuman Khandual To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Anshuman Khandual , Catalin Marinas , Will Deacon , Mark Rutland , James Morse , Andrey Konovalov Subject: [PATCH V3 1/2] arm64/mm: Consolidate page fault information capture Date: Fri, 7 Jun 2019 14:43:05 +0530 Message-Id: <1559898786-28530-2-git-send-email-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1559898786-28530-1-git-send-email-anshuman.khandual@arm.com> References: <1559898786-28530-1-git-send-email-anshuman.khandual@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This consolidates page fault information capture and move them bit earlier. While here it also adds an wrapper is_write_abort(). It also saves some cycles by replacing multiple user_mode() calls into a single one earlier during the fault. Signed-off-by: Anshuman Khandual Cc: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: James Morse Cc: Andrey Konovalov --- arch/arm64/mm/fault.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 7c1c8f4..95cac4a 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -435,6 +435,15 @@ static bool is_el0_instruction_abort(unsigned int esr) return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_LOW; } +/* + * Note: not valid for EL1 DC IVAC, but we never use that such that it + * should fault. EL0 cannot issue DC IVAC (undef). + */ +static bool is_write_abort(unsigned int esr) +{ + return (esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM); +} + static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, struct pt_regs *regs) { @@ -443,6 +452,9 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, vm_fault_t fault, major = 0; unsigned long vm_flags = VM_READ | VM_WRITE; unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; + bool is_user = user_mode(regs); + bool is_el0_exec = is_el0_instruction_abort(esr); + bool is_write = is_write_abort(esr); if (notify_page_fault(regs, esr)) return 0; @@ -454,13 +466,13 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, if (faulthandler_disabled() || !mm) goto no_context; - if (user_mode(regs)) + if (is_user) mm_flags |= FAULT_FLAG_USER; - if (is_el0_instruction_abort(esr)) { + if (is_el0_exec) { vm_flags = VM_EXEC; mm_flags |= FAULT_FLAG_INSTRUCTION; - } else if ((esr & ESR_ELx_WNR) && !(esr & ESR_ELx_CM)) { + } else if (is_write) { vm_flags = VM_WRITE; mm_flags |= FAULT_FLAG_WRITE; } @@ -488,7 +500,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, * we can bug out early if this is from code which shouldn't. */ if (!down_read_trylock(&mm->mmap_sem)) { - if (!user_mode(regs) && !search_exception_tables(regs->pc)) + if (!is_user && !search_exception_tables(regs->pc)) goto no_context; retry: down_read(&mm->mmap_sem); @@ -499,7 +511,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, */ might_sleep(); #ifdef CONFIG_DEBUG_VM - if (!user_mode(regs) && !search_exception_tables(regs->pc)) { + if (!is_user && !search_exception_tables(regs->pc)) { up_read(&mm->mmap_sem); goto no_context; } @@ -517,7 +529,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, * in __lock_page_or_retry in mm/filemap.c. */ if (fatal_signal_pending(current)) { - if (!user_mode(regs)) + if (!is_user) goto no_context; return 0; } @@ -562,7 +574,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, * If we are in kernel mode at this point, we have no context to * handle this fault with. */ - if (!user_mode(regs)) + if (!is_user) goto no_context; if (fault & VM_FAULT_OOM) { -- 2.7.4