From nobody Mon Feb 9 13:58:09 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C00ABC001B0 for ; Thu, 13 Jul 2023 09:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234491AbjGMJlZ (ORCPT ); Thu, 13 Jul 2023 05:41:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234379AbjGMJkx (ORCPT ); Thu, 13 Jul 2023 05:40:53 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B692C26B8; Thu, 13 Jul 2023 02:40:36 -0700 (PDT) Received: from dggpemm500001.china.huawei.com (unknown [172.30.72.53]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4R1qMg1LkQz18Lnh; Thu, 13 Jul 2023 17:39:59 +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 17:40:33 +0800 From: Kefeng Wang To: , Andrew Morton , CC: Russell King , Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , , , , , , , , Kefeng Wang Subject: [PATCH rfc -next 10/10] loongarch: mm: try VMA lock-based page fault handling first Date: Thu, 13 Jul 2023 17:53:38 +0800 Message-ID: <20230713095339.189715-11-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 Content-Transfer-Encoding: quoted-printable 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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 | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 397203e18800..afb0ccabab97 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -53,6 +53,7 @@ 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 cde2ea0119fa..7e54bc48813e 100644 --- a/arch/loongarch/mm/fault.c +++ b/arch/loongarch/mm/fault.c @@ -136,6 +136,17 @@ static inline bool access_error(unsigned int flags, st= ruct pt_regs *regs, return false; } =20 +#ifdef CONFIG_PER_VMA_LOCK +int arch_vma_check_access(struct vm_area_struct *vma, + struct vm_locked_fault *vmlf) +{ + if (unlikely(access_error(vmlf->fault_flags, vmlf->regs, vmlf->address, + vma))) + return -EINVAL; + return 0; +} +#endif + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate @@ -149,6 +160,7 @@ static void __kprobes __do_page_fault(struct pt_regs *r= egs, struct task_struct *tsk =3D current; struct mm_struct *mm =3D tsk->mm; struct vm_area_struct *vma =3D NULL; + struct vm_locked_fault vmlf; vm_fault_t fault; =20 if (kprobe_page_fault(regs, current->thread.trap_nr)) @@ -183,6 +195,19 @@ static void __kprobes __do_page_fault(struct pt_regs *= regs, flags |=3D FAULT_FLAG_WRITE; =20 perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + + VM_LOCKED_FAULT_INIT(vmlf, mm, address, flags, 0, regs, 0); + if (try_vma_locked_page_fault(&vmlf, &fault)) + goto retry; + else if (!(fault | VM_FAULT_RETRY)) + goto done; + + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) + no_context(regs, address); + return; + } + retry: vma =3D lock_mm_and_find_vma(mm, address, regs); if (unlikely(!vma)) @@ -223,6 +248,7 @@ static void __kprobes __do_page_fault(struct pt_regs *r= egs, =20 mmap_read_unlock(mm); =20 +done: if (unlikely(fault & VM_FAULT_ERROR)) { if (fault & VM_FAULT_OOM) { do_out_of_memory(regs, address); --=20 2.27.0