From patchwork Fri Jun 7 09:13:05 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anshuman Khandual X-Patchwork-Id: 10981139 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 52F2A15E6 for ; Fri, 7 Jun 2019 09:13:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4030B28B26 for ; Fri, 7 Jun 2019 09:13:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 346BF287A8; Fri, 7 Jun 2019 09:13:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id BE29228B26 for ; Fri, 7 Jun 2019 09:13:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=U9gxIqg8QV2baFtz7/HwDNfUeh0NDw9q9hz0JcZ88Rg=; b=MUeMZjXdJFJ2WXzPLKxh1Y8vqW OXRGYUu/yow4R0iw8on+nPnXcDTxB9vnRT7Lt13VevgRXIL//DON4Wko1OBYrV+wW2upk3aiMw/j3 A1mzCUVCYpMbg0qepuPBW7rfg91/kYI0cm6iYSRowTjwU84gZLhLQfTY2nKRH0yOdiVyhPl+c5wrM nshttDCPq2dhhYjp5dUBt7gDs735R1owLtInn/7NQvi62Rr53NW9w2RnnQBjonOCeAFJ/deIvrsUw DI1suAwUfvR2PW1dDa72kCL/Mm17dmjnt3zvmFVyHAt1UDi6c4LTu1u8P3TRsOIkZJqeW6pK1NUvr eNLzXtcA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hZAwC-0008OM-9Q; Fri, 07 Jun 2019 09:13:28 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hZAvx-0008DD-Lx for linux-arm-kernel@lists.infradead.org; Fri, 07 Jun 2019 09:13:15 +0000 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 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> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190607_021313_854137_F37079D4 X-CRM114-Status: GOOD ( 13.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Anshuman Khandual , Catalin Marinas , Will Deacon , James Morse , Andrey Konovalov MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Acked-by: Mark Rutland --- 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) {