From mboxrd@z Thu Jan 1 00:00:00 1970 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 9C1B5C6379F for ; Mon, 9 Jan 2023 20:59:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237893AbjAIU7D (ORCPT ); Mon, 9 Jan 2023 15:59:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237751AbjAIU5r (ORCPT ); Mon, 9 Jan 2023 15:57:47 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77B3E8CD39 for ; Mon, 9 Jan 2023 12:55:10 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id z62-20020a623341000000b005809a4c70efso3995407pfz.0 for ; Mon, 09 Jan 2023 12:55:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=wQaK3IYB3deWxpAe9eNtEaAaK5GLZai42ZGvF8iLG5s=; b=rw20v86zZuVQYP+Ot38AI7CSNxJo3kS0fh4+Xzkg0ua9O1bePCbmIGXyRAOceAwONa J0TZdcxQSasqUL/oBe6wf7jLdD0R+p+Bu2MPqV1YykB1eqTKi0/qjL5rdUZIcmvdelEF RBoPMFMogBGK0PrycWwKvVRHJ+Ch4XmPWscy4TJxhfZ7irUJVjF6OWFk+4uiaZ5g0a9h xVEF8daEuEJDm1wmFyKFMZlgoKpmxoJhKWB0BV89iFmA1f0B2X0D/WawWhEeTcmbbuya u6sy1rh3eP2M76YM3K6bmEc6ANBDahY+/H9HaeO8ptCkobUJsiIXuerRnexRjBXA4ux5 pQew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=wQaK3IYB3deWxpAe9eNtEaAaK5GLZai42ZGvF8iLG5s=; b=yS23VSzCOwCFEsWSlB7spedhUrkZw2fVykti7K4ql6h2zk/cPMppoTcCxUEcwwks/m UmRkf85BqVCC4HROSkJlgExVZGvBIRg1+vT0757hc4xWxApXAyhmCDyOW9WUodby9Mep 2S/nEmYsm1nm6SU4AiyyHm1DzJPtEU5Rf5lRr7UdjiXrcpN1UtzG1/AFwxJy1wm49Da8 aW+rWR5s8JwB1xJ/bWQT+hqqh7iN50roquL2lTK3K++lDw5zcrx2llHa0yZtTyo2PqGs e4mGoevp+VIEz3GdUtSszs//aCinww2zEia0bKiNPRc6ahm+SFHHQa7zZvhLqgDwPCuf OOwg== X-Gm-Message-State: AFqh2kp6PaI9fLIUR1/gbzUPPYzUUNxdGCfqUSDX/OBvdGXUSSlUCbiz H5PdtYYnUoOQ8j0u8a79NwQYoMYkOeY= X-Google-Smtp-Source: AMrXdXslCGRX6fAYSmsr9gs68MBt+wxNt6fnptg7xXYf9+oinmXIkRDOo+t8kmB5UcEQZNFBtsxG/pDk5Sg= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:9393:6f7a:d410:55ca]) (user=surenb job=sendgmr) by 2002:a17:902:7583:b0:189:bee:65ee with SMTP id j3-20020a170902758300b001890bee65eemr3889654pll.107.1673297706216; Mon, 09 Jan 2023 12:55:06 -0800 (PST) Date: Mon, 9 Jan 2023 12:53:29 -0800 In-Reply-To: <20230109205336.3665937-1-surenb@google.com> Mime-Version: 1.0 References: <20230109205336.3665937-1-surenb@google.com> X-Mailer: git-send-email 2.39.0.314.g84b9a713c41-goog Message-ID: <20230109205336.3665937-35-surenb@google.com> Subject: [PATCH 34/41] x86/mm: try VMA lock-based page fault handling first From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, laurent.dufour@fr.ibm.com, paulmck@kernel.org, luto@kernel.org, songliubraving@fb.com, peterx@redhat.com, david@redhat.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, gurua@google.com, arjunroy@google.com, soheil@google.com, hughlynch@google.com, leewalsh@google.com, posk@google.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-kernel@vger.kernel.org, kernel-team@android.com, surenb@google.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Attempt VMA lock-based page fault handling first, and fall back to the existing mmap_lock-based handling if that fails. Signed-off-by: Suren Baghdasaryan --- arch/x86/Kconfig | 1 + arch/x86/mm/fault.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3604074a878b..3647f7bdb110 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -27,6 +27,7 @@ config X86_64 # Options that are inherently 64-bit kernel only: select ARCH_HAS_GIGANTIC_PAGE select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 + select ARCH_SUPPORTS_PER_VMA_LOCK select ARCH_USE_CMPXCHG_LOCKREF select HAVE_ARCH_SOFT_DIRTY select MODULES_USE_ELF_RELA diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7b0d4ab894c8..983266e7c49b 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -19,6 +19,7 @@ #include /* faulthandler_disabled() */ #include /* efi_crash_gracefully_on_page_fault()*/ #include +#include /* find_and_lock_vma() */ #include /* boot_cpu_has, ... */ #include /* dotraplinkage, ... */ @@ -1354,6 +1355,38 @@ void do_user_addr_fault(struct pt_regs *regs, } #endif +#ifdef CONFIG_PER_VMA_LOCK + if (!(flags & FAULT_FLAG_USER) || atomic_read(&mm->mm_users) == 1) + goto lock_mmap; + + vma = lock_vma_under_rcu(mm, address); + if (!vma) + goto lock_mmap; + + if (unlikely(access_error(error_code, vma))) { + vma_read_unlock(vma); + goto lock_mmap; + } + fault = handle_mm_fault(vma, address, flags | FAULT_FLAG_VMA_LOCK, regs); + vma_read_unlock(vma); + + if (!(fault & VM_FAULT_RETRY)) { + count_vm_vma_lock_event(VMA_LOCK_SUCCESS); + goto done; + } + count_vm_vma_lock_event(VMA_LOCK_RETRY); + + /* Quick path to respond to signals */ + if (fault_signal_pending(fault, regs)) { + if (!user_mode(regs)) + kernelmode_fixup_or_oops(regs, error_code, address, + SIGBUS, BUS_ADRERR, + ARCH_DEFAULT_PKEY); + return; + } +lock_mmap: +#endif /* CONFIG_PER_VMA_LOCK */ + /* * Kernel-mode access to the user address space should only occur * on well-defined single instructions listed in the exception @@ -1454,6 +1487,9 @@ void do_user_addr_fault(struct pt_regs *regs, } mmap_read_unlock(mm); +#ifdef CONFIG_PER_VMA_LOCK +done: +#endif if (likely(!(fault & VM_FAULT_ERROR))) return; -- 2.39.0