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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 C1DB3C47083 for ; Wed, 2 Jun 2021 06:54:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A80B56135D for ; Wed, 2 Jun 2021 06:54:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230169AbhFBGzx (ORCPT ); Wed, 2 Jun 2021 02:55:53 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:3336 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230083AbhFBGzt (ORCPT ); Wed, 2 Jun 2021 02:55:49 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Fw04b1S1Sz19S7R; Wed, 2 Jun 2021 14:49:19 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 2 Jun 2021 14:53:47 +0800 Received: from localhost.localdomain.localdomain (10.175.113.25) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 2 Jun 2021 14:53:47 +0800 From: Kefeng Wang To: Russell King , CC: Catalin Marinas , , Andrew Morton , Jungseung Lee , Kefeng Wang Subject: [PATCH v2 3/7] ARM: mm: Cleanup access_error() Date: Wed, 2 Jun 2021 15:02:42 +0800 Message-ID: <20210602070246.83990-4-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210602070246.83990-1-wangkefeng.wang@huawei.com> References: <20210602070246.83990-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now the write fault check in do_page_fault() and access_error() twice, we can cleanup access_error(), and make the fault check and vma flags set into do_page_fault() directly, then pass the vma flags to __do_page_fault. No functional change. Signed-off-by: Kefeng Wang --- arch/arm/mm/fault.c | 38 ++++++++++++++------------------------ 1 file changed, 14 insertions(+), 24 deletions(-) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 249db395bdf0..9a6d74f6ea1d 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -183,26 +183,9 @@ void do_bad_area(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #define VM_FAULT_BADMAP 0x010000 #define VM_FAULT_BADACCESS 0x020000 -/* - * Check that the permissions on the VMA allow for the fault which occurred. - * If we encountered a write fault, we must have write permission, otherwise - * we allow any permission. - */ -static inline bool access_error(unsigned int fsr, struct vm_area_struct *vma) -{ - unsigned int mask = VM_ACCESS_FLAGS; - - if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) - mask = VM_WRITE; - if (fsr & FSR_LNX_PF) - mask = VM_EXEC; - - return vma->vm_flags & mask ? false : true; -} - static vm_fault_t __kprobes -__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, - unsigned int flags, struct pt_regs *regs) +__do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int flags, + unsigned long vma_flags, struct pt_regs *regs) { struct vm_area_struct *vma = find_vma(mm, addr); if (unlikely(!vma)) @@ -218,10 +201,10 @@ __do_page_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr, } /* - * Ok, we have a good vm_area for this - * memory access, so we can handle it. + * ok, we have a good vm_area for this memory access, check the + * permissions on the VMA allow for the fault which occurred. */ - if (access_error(fsr, vma)) + if (!(vma->vm_flags & vma_flags)) return VM_FAULT_BADACCESS; return handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); @@ -234,6 +217,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) int sig, code; vm_fault_t fault; unsigned int flags = FAULT_FLAG_DEFAULT; + unsigned long vm_flags = VM_ACCESS_FLAGS; if (kprobe_page_fault(regs, fsr)) return 0; @@ -252,8 +236,14 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (user_mode(regs)) flags |= FAULT_FLAG_USER; - if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) + + if ((fsr & FSR_WRITE) && !(fsr & FSR_CM)) { flags |= FAULT_FLAG_WRITE; + vm_flags = VM_WRITE; + } + + if (fsr & FSR_LNX_PF) + vm_flags = VM_EXEC; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); @@ -281,7 +271,7 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) #endif } - fault = __do_page_fault(mm, addr, fsr, flags, regs); + fault = __do_page_fault(mm, addr, flags, vm_flags, regs); /* If we need to retry but a fatal signal is pending, handle the * signal first. We do not need to release the mmap_lock because -- 2.26.2