From patchwork Mon Aug 21 12:30:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 1823625 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=112.213.38.117; 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 [112.213.38.117]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (secp384r1)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RTsrF0tD8z1yYZ for ; Mon, 21 Aug 2023 22:54:37 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RTsrF05nfz3djT for ; Mon, 21 Aug 2023 22:54:37 +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 4RTsnh1VYCz3dGQ for ; Mon, 21 Aug 2023 22:52:24 +1000 (AEST) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4RTsGr51ZwzVks7; Mon, 21 Aug 2023 20:29:08 +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 20:31:20 +0800 From: Kefeng Wang To: Andrew Morton , Subject: [PATCH rfc v2 07/10] ARM: mm: try VMA lock-based page fault handling first Date: Mon, 21 Aug 2023 20:30:53 +0800 Message-ID: <20230821123056.2109942-8-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" Attempt VMA lock-based page fault handling first, and fall back to the existing mmap_lock-based handling if that fails. Signed-off-by: Kefeng Wang --- arch/arm/Kconfig | 1 + arch/arm/mm/fault.c | 35 +++++++++++++++++++++++++---------- 2 files changed, 26 insertions(+), 10 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1a6a6eb48a15..8b6d4507ccee 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -34,6 +34,7 @@ config ARM select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7 select ARCH_SUPPORTS_ATOMIC_RMW select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE + select ARCH_SUPPORTS_PER_VMA_LOCK select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_USE_MEMTEST diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index fef62e4a9edd..d53bb028899a 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -242,8 +242,11 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) struct vm_area_struct *vma; int sig, code; vm_fault_t fault; - unsigned int flags = FAULT_FLAG_DEFAULT; - unsigned long vm_flags = VM_ACCESS_FLAGS; + struct vm_fault vmf = { + .real_address = addr, + .flags = FAULT_FLAG_DEFAULT, + .vm_flags = VM_ACCESS_FLAGS, + }; if (kprobe_page_fault(regs, fsr)) return 0; @@ -261,15 +264,15 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) goto no_context; if (user_mode(regs)) - flags |= FAULT_FLAG_USER; + vmf.flags |= FAULT_FLAG_USER; if (is_write_fault(fsr)) { - flags |= FAULT_FLAG_WRITE; - vm_flags = VM_WRITE; + vmf.flags |= FAULT_FLAG_WRITE; + vmf.vm_flags = VM_WRITE; } if (fsr & FSR_LNX_PF) { - vm_flags = VM_EXEC; + vmf.vm_flags = VM_EXEC; if (is_permission_fault(fsr) && !user_mode(regs)) die_kernel_fault("execution of memory", @@ -278,6 +281,18 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr); + fault = try_vma_locked_page_fault(&vmf); + if (fault == VM_FAULT_NONE) + goto retry; + if (!(fault & VM_FAULT_RETRY)) + goto done; + + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) + goto no_context; + return 0; + } + retry: vma = lock_mm_and_find_vma(mm, addr, regs); if (unlikely(!vma)) { @@ -289,10 +304,10 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) * ok, we have a good vm_area for this memory access, check the * permissions on the VMA allow for the fault which occurred. */ - if (!(vma->vm_flags & vm_flags)) + if (!(vma->vm_flags & vmf.vm_flags)) fault = VM_FAULT_BADACCESS; else - fault = handle_mm_fault(vma, addr & PAGE_MASK, flags, regs); + fault = handle_mm_fault(vma, addr & PAGE_MASK, vmf.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 @@ -310,13 +325,13 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs) if (!(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_RETRY) { - flags |= FAULT_FLAG_TRIED; + vmf.flags |= FAULT_FLAG_TRIED; goto retry; } } mmap_read_unlock(mm); - +done: /* * Handle the "normal" case first - VM_FAULT_MAJOR */