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 7F109C5479D for ; Mon, 9 Jan 2023 20:57:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237822AbjAIU5R (ORCPT ); Mon, 9 Jan 2023 15:57:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34804 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237745AbjAIU4I (ORCPT ); Mon, 9 Jan 2023 15:56:08 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0AD478B510 for ; Mon, 9 Jan 2023 12:54:40 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id z3-20020a170903018300b0018fb8ca1688so6973059plg.5 for ; Mon, 09 Jan 2023 12:54:40 -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=olOpibg5eXy7KG3cFGJtGZQRi2wnSYuvllMlsZALFjE=; b=pKSCW4f0d77MorxMhTYeMa3Bkvztzi2l/11p+8AD9JlAcd7O/4nLaK3tMdO/JZYFZO oqL+3k7pxb64mumhhSbnD+8oqAK9T+YZbtnVKYdyWwz1xTl0lxuCTGJlmjyD4W6tkdoJ ScE8xkE+709mZSvnfMafhqWZz0JUfC8PX8Gqgq4hVWAiFqsbly88nJnbf2OtvsEjRJ+V Bh1jSeLHcoArd7dhSosnJ19E8FECzKPk1IhOzNYJUOL7f9tKHCqrIEP0OXg1wGsfV/sX JopWIX7MNjYmVxKWpBhB8gnFt1KMXJN0MSlcK65fQjg6FKg5IorU4J4ePrdeGZ792swl N3JQ== 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=olOpibg5eXy7KG3cFGJtGZQRi2wnSYuvllMlsZALFjE=; b=Cse5lVDedKARQeb5dOg8SwyoAtu+QJQ4oB/2nBrSGg/s27leK0jzpr1QZE+41ziT0J hSqEKktydZ2zd0wYQcrKSTZpwEvq6QFW9QZU05o8ewxsulMXjpFOSUQVK3R5GAENo/ab q2SwEK81hyeZ0TLV7Z3TXeRrg49ANKQ3GRiwWcerOuxfMcnL81TSgaIeCLVRWMkTQP1z 87hdIRgCzYxN86Q65mVsL3YOeIMgKqHibIyodCNddG2gFRjmbhYPKg0Kq4wc24MrCrmc roPOYHT2bZAmLh/RhhcKh1UtZTy/TIGmOH6aUfjhwME3JsnkuR8NDdKHaJjHGHn8wST0 7RtA== X-Gm-Message-State: AFqh2kooJSGHSRf56ZYbaMJ7MtGrB9lNinD/ziV1TkqufYBRkkrST25p Jo3tHIxBfVwP8Hx2dm1X/TBNxYRD34A= X-Google-Smtp-Source: AMrXdXsFsv+WY6uB2QAxQKVey5zkUH2AXIcpYb3YNAv+Gej95uP4vEcIzk/UCgPyK193sduP1xpoK0p/ZF8= X-Received: from surenb-desktop.mtv.corp.google.com ([2620:15c:211:200:9393:6f7a:d410:55ca]) (user=surenb job=sendgmr) by 2002:a62:1501:0:b0:589:8362:c7ce with SMTP id 1-20020a621501000000b005898362c7cemr251559pfv.21.1673297679447; Mon, 09 Jan 2023 12:54:39 -0800 (PST) Date: Mon, 9 Jan 2023 12:53:18 -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: <20230109205336.3665937-24-surenb@google.com> Subject: [PATCH 23/41] mm: write-lock VMAs before removing them from VMA tree 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 Write-locking VMAs before isolating them ensures that page fault handlers don't operate on isolated VMAs. Signed-off-by: Suren Baghdasaryan --- mm/mmap.c | 2 ++ mm/nommu.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/mm/mmap.c b/mm/mmap.c index da1908730828..be289e0b693b 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -448,6 +448,7 @@ void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas) */ void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas) { + vma_write_lock(vma); trace_vma_mas_szero(mas->tree, vma->vm_start, vma->vm_end - 1); mas->index = vma->vm_start; mas->last = vma->vm_end - 1; @@ -2300,6 +2301,7 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma, static inline int munmap_sidetree(struct vm_area_struct *vma, struct ma_state *mas_detach) { + vma_write_lock(vma); mas_set_range(mas_detach, vma->vm_start, vma->vm_end - 1); if (mas_store_gfp(mas_detach, vma, GFP_KERNEL)) return -ENOMEM; diff --git a/mm/nommu.c b/mm/nommu.c index b3154357ced5..7ae91337ef14 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -552,6 +552,7 @@ void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas) void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas) { + vma_write_lock(vma); mas->index = vma->vm_start; mas->last = vma->vm_end - 1; mas_store_prealloc(mas, NULL); @@ -1551,6 +1552,10 @@ void exit_mmap(struct mm_struct *mm) mmap_write_lock(mm); for_each_vma(vmi, vma) { cleanup_vma_from_mm(vma); + /* + * No need to lock VMA because this is the only mm user and no + * page fault handled can race with it. + */ delete_vma(mm, vma); cond_resched(); } -- 2.39.0