From patchwork Thu Jul 13 09:53:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kefeng Wang X-Patchwork-Id: 1807197 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=) 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 (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4R1qSH5DT4z20Ph for ; Thu, 13 Jul 2023 19:43:59 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4R1qSH4VDxz3dGY for ; Thu, 13 Jul 2023 19:43:59 +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) 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 4R1qNn4msxz3cHf for ; Thu, 13 Jul 2023 19:40:57 +1000 (AEST) Received: from dggpemm500001.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4R1qMR24J5zrRlb; Thu, 13 Jul 2023 17:39:47 +0800 (CST) 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 15.1.2507.27; Thu, 13 Jul 2023 17:40:22 +0800 From: Kefeng Wang To: , Andrew Morton , Subject: [PATCH rfc -next 01/10] mm: add a generic VMA lock-based page fault handler Date: Thu, 13 Jul 2023 17:53:29 +0800 Message-ID: <20230713095339.189715-2-wangkefeng.wang@huawei.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230713095339.189715-1-wangkefeng.wang@huawei.com> References: <20230713095339.189715-1-wangkefeng.wang@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.25] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpemm500001.china.huawei.com (7.185.36.107) 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 , WANG Xuerui , Will Deacon , Alexander Gordeev , linux-s390@vger.kernel.org, Huacai Chen , Russell King , Ingo Molnar , Gerald Schaefer , Christian Borntraeger , Albert Ou , Vasily Gorbik , Heiko Carstens , Nicholas Piggin , Borislav Petkov , Andy Lutomirski , Paul Walmsley , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@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" There are more and more architectures enabled ARCH_SUPPORTS_PER_VMA_LOCK, eg, x86, arm64, powerpc and s390, and riscv, those implementation are very similar which results in some duplicated codes, let's add a generic VMA lock-based page fault handler to eliminate them, and which also make it easy to support this feature on new architectures. Signed-off-by: Kefeng Wang --- include/linux/mm.h | 28 ++++++++++++++++++++++++++++ mm/memory.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 70 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index c7886784832b..cba1b7b19c9d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -633,6 +633,15 @@ static inline void vma_numab_state_init(struct vm_area_struct *vma) {} static inline void vma_numab_state_free(struct vm_area_struct *vma) {} #endif /* CONFIG_NUMA_BALANCING */ +struct vm_locked_fault { + struct mm_struct *mm; + unsigned long address; + unsigned int fault_flags; + unsigned long vm_flags; + struct pt_regs *regs; + unsigned long fault_code; +}; + #ifdef CONFIG_PER_VMA_LOCK /* * Try to read-lock a vma. The function is allowed to occasionally yield false @@ -733,6 +742,19 @@ static inline void assert_fault_locked(struct vm_fault *vmf) struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, unsigned long address); +#define VM_LOCKED_FAULT_INIT(_name, _mm, _address, _fault_flags, _vm_flags, _regs, _fault_code) \ + _name.mm = _mm; \ + _name.address = _address; \ + _name.fault_flags = _fault_flags; \ + _name.vm_flags = _vm_flags; \ + _name.regs = _regs; \ + _name.fault_code = _fault_code + +int __weak arch_vma_check_access(struct vm_area_struct *vma, + struct vm_locked_fault *vmlf); + +int try_vma_locked_page_fault(struct vm_locked_fault *vmlf, vm_fault_t *ret); + #else /* CONFIG_PER_VMA_LOCK */ static inline bool vma_start_read(struct vm_area_struct *vma) @@ -742,6 +764,12 @@ static inline void vma_start_write(struct vm_area_struct *vma) {} static inline void vma_assert_write_locked(struct vm_area_struct *vma) {} static inline void vma_mark_detached(struct vm_area_struct *vma, bool detached) {} +#define VM_LOCKED_FAULT_INIT(_name, _mm, _address, _fault_flags, _vm_flags, _regs, _fault_code) +static inline int try_vma_locked_page_fault(struct vm_locked_fault *vmlf, + vm_fault_t *ret) +{ + return -EINVAL; +} static inline void release_fault_lock(struct vm_fault *vmf) { diff --git a/mm/memory.c b/mm/memory.c index ad790394963a..d3f5d1270e7a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5449,6 +5449,48 @@ struct vm_area_struct *lock_vma_under_rcu(struct mm_struct *mm, count_vm_vma_lock_event(VMA_LOCK_ABORT); return NULL; } + +int __weak arch_vma_check_access(struct vm_area_struct *vma, + struct vm_locked_fault *vmlf) +{ + if (!(vma->vm_flags & vmlf->vm_flags)) + return -EINVAL; + return 0; +} + +int try_vma_locked_page_fault(struct vm_locked_fault *vmlf, vm_fault_t *ret) +{ + struct vm_area_struct *vma; + vm_fault_t fault; + + if (!(vmlf->fault_flags & FAULT_FLAG_USER)) + return -EINVAL; + + vma = lock_vma_under_rcu(vmlf->mm, vmlf->address); + if (!vma) + return -EINVAL; + + if (arch_vma_check_access(vma, vmlf)) { + vma_end_read(vma); + return -EINVAL; + } + + fault = handle_mm_fault(vma, vmlf->address, + vmlf->fault_flags | FAULT_FLAG_VMA_LOCK, + vmlf->regs); + *ret = fault; + + if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED))) + vma_end_read(vma); + + if ((fault & VM_FAULT_RETRY)) + count_vm_vma_lock_event(VMA_LOCK_RETRY); + else + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + + return 0; +} + #endif /* CONFIG_PER_VMA_LOCK */ #ifndef __PAGETABLE_P4D_FOLDED