From patchwork Mon Aug 21 12:30:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 1823621 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=patchwork.ozlabs.org) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1) server-digest SHA384) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RTspC58rGz1yYZ for ; Mon, 21 Aug 2023 22:52:51 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RTspC3LYDz3c0X for ; Mon, 21 Aug 2023 22:52:51 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=huawei.com (client-ip=45.249.212.188; helo=szxga02-in.huawei.com; envelope-from=wangkefeng.wang@huawei.com; receiver=lists.ozlabs.org) Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4RTsmv0yPsz3byH for ; Mon, 21 Aug 2023 22:51:43 +1000 (AEST) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RTsFF3Rj6zNnTN; Mon, 21 Aug 2023 20:27:45 +0800 (CST) Received: from localhost.localdomain (10.175.112.125) by dggpemm100001.china.huawei.com (7.185.36.93) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 21 Aug 2023 20:31:17 +0800 From: Kefeng Wang To: Andrew Morton , Subject: [PATCH rfc v2 05/10] powerpc: mm: use try_vma_locked_page_fault() Date: Mon, 21 Aug 2023 20:30:51 +0800 Message-ID: <20230821123056.2109942-6-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20230821123056.2109942-1-wangkefeng.wang@huawei.com> References: <20230821123056.2109942-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm100001.china.huawei.com (7.185.36.93) X-CFilter-Loop: Reflected X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kefeng Wang , x86@kernel.org, loongarch@lists.linux.dev, Peter Zijlstra , Catalin Marinas , Dave Hansen , "H . Peter Anvin" , WANG Xuerui , Will Deacon , Alexander Gordeev , linux-s390@vger.kernel.org, Huacai Chen , Russell King , willy@infradead.org, Ingo Molnar , Gerald Schaefer , Christian Borntraeger , Albert Ou , Vasily Gorbik , Heiko Carstens , Nicholas Piggin , Borislav Petkov , Andy Lutomirski , Paul Walmsley , Thomas Gleixner , surenb@google.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-ri scv@lists.infradead.org, Palmer Dabbelt , Sven Schnelle , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Use new try_vma_locked_page_fault() helper to simplify code. No functional change intended. Signed-off-by: Kefeng Wang --- arch/powerpc/mm/fault.c | 66 ++++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 34 deletions(-) diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index b1723094d464..52f9546e020e 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -391,6 +391,22 @@ static int page_fault_is_bad(unsigned long err) #define page_fault_is_bad(__err) ((__err) & DSISR_BAD_FAULT_32S) #endif +#ifdef CONFIG_PER_VMA_LOCK +bool arch_vma_access_error(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + int is_exec = TRAP(vmf->regs) == INTERRUPT_INST_STORAGE; + int is_write = page_fault_is_write(vmf->fault_code); + + if (unlikely(access_pkey_error(is_write, is_exec, + (vmf->fault_code & DSISR_KEYFAULT), vma))) + return true; + + if (unlikely(access_error(is_write, is_exec, vma))) + return true; + return false; +} +#endif + /* * For 600- and 800-family processors, the error_code parameter is DSISR * for a data fault, SRR1 for an instruction fault. @@ -407,12 +423,18 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, { struct vm_area_struct * vma; struct mm_struct *mm = current->mm; - unsigned int flags = FAULT_FLAG_DEFAULT; int is_exec = TRAP(regs) == INTERRUPT_INST_STORAGE; int is_user = user_mode(regs); int is_write = page_fault_is_write(error_code); vm_fault_t fault, major = 0; bool kprobe_fault = kprobe_page_fault(regs, 11); + struct vm_fault vmf = { + .real_address = address, + .fault_code = error_code, + .regs = regs, + .flags = FAULT_FLAG_DEFAULT, + }; + if (unlikely(debugger_fault_handler(regs) || kprobe_fault)) return 0; @@ -463,45 +485,21 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, * mmap_lock held */ if (is_user) - flags |= FAULT_FLAG_USER; + vmf.flags |= FAULT_FLAG_USER; if (is_write) - flags |= FAULT_FLAG_WRITE; + vmf.flags |= FAULT_FLAG_WRITE; if (is_exec) - flags |= FAULT_FLAG_INSTRUCTION; + vmf.flags |= FAULT_FLAG_INSTRUCTION; - if (!(flags & FAULT_FLAG_USER)) - goto lock_mmap; - - vma = lock_vma_under_rcu(mm, address); - if (!vma) - goto lock_mmap; - - if (unlikely(access_pkey_error(is_write, is_exec, - (error_code & DSISR_KEYFAULT), vma))) { - vma_end_read(vma); - goto lock_mmap; - } - - if (unlikely(access_error(is_write, is_exec, vma))) { - vma_end_read(vma); - goto lock_mmap; - } - - fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); - if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) - vma_end_read(vma); - - if (!(fault & VM_FAULT_RETRY)) { - count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + fault = try_vma_locked_page_fault(&vmf); + if (fault == VM_FAULT_NONE) + goto retry; + if (!(fault & VM_FAULT_RETRY)) goto done; - } - count_vm_vma_lock_event(VMA_LOCK_RETRY); if (fault_signal_pending(fault, regs)) return user_mode(regs) ? 0 : SIGBUS; -lock_mmap: - /* When running in the kernel we expect faults to occur only to * addresses in user space. All other faults represent errors in the * kernel and should generate an OOPS. Unfortunately, in the case of an @@ -528,7 +526,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, * make sure we exit gracefully rather than endlessly redo * the fault. */ - fault = handle_mm_fault(vma, address, flags, regs); + fault = handle_mm_fault(vma, address, vmf.flags, regs); major |= fault & VM_FAULT_MAJOR; @@ -544,7 +542,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, * case. */ if (unlikely(fault & VM_FAULT_RETRY)) { - flags |= FAULT_FLAG_TRIED; + vmf.flags |= FAULT_FLAG_TRIED; goto retry; }