From patchwork Mon Aug 21 12:30:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 1823618 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 4RTslT45zyz1yYZ for ; Mon, 21 Aug 2023 22:50:29 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RTslT0xfYz3bmP for ; Mon, 21 Aug 2023 22:50:29 +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=45.249.212.187; helo=szxga01-in.huawei.com; envelope-from=wangkefeng.wang@huawei.com; receiver=lists.ozlabs.org) X-Greylist: delayed 1135 seconds by postgrey-1.37 at boromir; Mon, 21 Aug 2023 22:50:18 AEST Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 4RTslG1TYFz2yh2 for ; Mon, 21 Aug 2023 22:50:13 +1000 (AEST) Received: from dggpemm100001.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4RTsFC3r4rztShZ; Mon, 21 Aug 2023 20:27:43 +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 20:31:24 +0800 From: Kefeng Wang To: Andrew Morton , Subject: [PATCH rfc v2 10/10] loongarch: mm: try VMA lock-based page fault handling first Date: Mon, 21 Aug 2023 20:30:56 +0800 Message-ID: <20230821123056.2109942-11-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/loongarch/Kconfig | 1 + arch/loongarch/mm/fault.c | 37 +++++++++++++++++++++++++++++++------ 2 files changed, 32 insertions(+), 6 deletions(-) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 2b27b18a63af..6b821f621920 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -56,6 +56,7 @@ config LOONGARCH select ARCH_SUPPORTS_LTO_CLANG select ARCH_SUPPORTS_LTO_CLANG_THIN select ARCH_SUPPORTS_NUMA_BALANCING + select ARCH_SUPPORTS_PER_VMA_LOCK select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_CMPXCHG_LOCKREF select ARCH_USE_QUEUED_RWLOCKS diff --git a/arch/loongarch/mm/fault.c b/arch/loongarch/mm/fault.c index 2a45e9f3a485..f7ac3a14bb06 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -142,6 +142,13 @@ static inline bool access_error(unsigned int flags, struct pt_regs *regs, return false; } +#ifdef CONFIG_PER_VMA_LOCK +bool arch_vma_access_error(struct vm_area_struct *vma, struct vm_fault *vmf) +{ + return access_error(vmf->flags, vmf->regs, vmf->real_address, vma); +} +#endif + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate @@ -151,11 +158,15 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, unsigned long address) { int si_code = SEGV_MAPERR; - unsigned int flags = FAULT_FLAG_DEFAULT; struct task_struct *tsk = current; struct mm_struct *mm = tsk->mm; struct vm_area_struct *vma = NULL; vm_fault_t fault; + struct vm_fault vmf = { + .real_address = address, + .regs = regs, + .flags = FAULT_FLAG_DEFAULT, + }; if (kprobe_page_fault(regs, current->thread.trap_nr)) return; @@ -184,11 +195,24 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, goto bad_area_nosemaphore; if (user_mode(regs)) - flags |= FAULT_FLAG_USER; + vmf.flags |= FAULT_FLAG_USER; if (write) - flags |= FAULT_FLAG_WRITE; + vmf.flags |= FAULT_FLAG_WRITE; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + + 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)) + no_context(regs, write, address); + return; + } + retry: vma = lock_mm_and_find_vma(mm, address, regs); if (unlikely(!vma)) @@ -196,7 +220,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, si_code = SEGV_ACCERR; - if (access_error(flags, regs, vma)) + if (access_error(vmf.flags, regs, address, vma)) goto bad_area; /* @@ -204,7 +228,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, * 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); if (fault_signal_pending(fault, regs)) { if (!user_mode(regs)) @@ -217,7 +241,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, return; if (unlikely(fault & VM_FAULT_RETRY)) { - flags |= FAULT_FLAG_TRIED; + vmf.flags |= FAULT_FLAG_TRIED; /* * No need to mmap_read_unlock(mm) as we would @@ -229,6 +253,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, mmap_read_unlock(mm); +done: if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) do_out_of_memory(regs, write, address);