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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0B2BDC43460 for ; Fri, 9 Apr 2021 16:22:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCDA261026 for ; Fri, 9 Apr 2021 16:22:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233395AbhDIQWc (ORCPT ); Fri, 9 Apr 2021 12:22:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232395AbhDIQWa (ORCPT ); Fri, 9 Apr 2021 12:22:30 -0400 Received: from mail-qk1-x729.google.com (mail-qk1-x729.google.com [IPv6:2607:f8b0:4864:20::729]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67674C061760 for ; Fri, 9 Apr 2021 09:22:17 -0700 (PDT) Received: by mail-qk1-x729.google.com with SMTP id q26so6370269qkm.6 for ; Fri, 09 Apr 2021 09:22:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=LPSR+SFooTaPgtBFedHf7Y31wtqhJOh5AqAapK2wyzs=; b=Q056bBDn7nbWunIqwgtUvNhy/EQyhNM6musYnQj7QpKC9MnxsY0qm7rHMSKR3wlLwF VxsdZFCvdQ9fTWUyEUR3SjENQ7y9DL/o82sAd385sro4Quk8mw1CAvc0/6fv8gxLtS0V aFyhjYa2+fANtrshg5ulm/gR2QV3RzKaIacy+FqTT4M0KLq1n7wV1C1NBytz8vbgByn0 Tt7V/5Cvn3y/72itgyTGQBE4y/pAbCz3FKu5UtR+jbAUJmOLxCvEfrYtw9bfL9LkP1EH yPVhSTzhuDRTzpD/R+B2Wj1/C276yeop31/JV2jlLQv7n/jN/tTxIOgIKA5zpI9MOXgC P8ZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=LPSR+SFooTaPgtBFedHf7Y31wtqhJOh5AqAapK2wyzs=; b=UdkQl6XB2Xglr+L13NHnz8wc4FltxGUrRvdHMQ3UiVW/pDQ59r0w6gQKwccZXbMtv+ rzrwccn3n+oGB/6zolGfL25ejYowDmexngBQAzHm7qVaQHlvpA5BRfvzs6hQwTX16p1G dzR3PL7JYjPsgJ7dyGOg6H2IXh8bvPrverwtraGhM30dMaOiNyELfpuw0eL5VL6ssnP7 cgX3b6Zzqlzpot+MLlR7y1BMmTlsiwUuxvgbkJc89WS0Udnmd5hF/YZZtEeVjARfewOA o7MJOJRswB++DJfK/5fcG7cNfY+d7xZItQ4uAnvdun3VYSRrIDmCVGwRH/CL+PxG97fi AJxg== X-Gm-Message-State: AOAM530ATE/fUYX4a3igSZk8Tsfk0e0RZ8Eu8N3OBc+mu8CI8B1SQ8y4 8GROTJsatD/nIX/N4sNsjTQ= X-Google-Smtp-Source: ABdhPJyV0BE86hD+1Lz1UISNzlxC1GNIuBKcE2RdCuH2q3ucvcY4bff6RxkyRVea7Of5FCyOz2hY0Q== X-Received: by 2002:a37:6288:: with SMTP id w130mr6932186qkb.70.1617985336747; Fri, 09 Apr 2021 09:22:16 -0700 (PDT) Received: from localhost.localdomain ([192.141.93.162]) by smtp.gmail.com with ESMTPSA id f13sm2205268qtg.2.2021.04.09.09.22.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Apr 2021 09:22:16 -0700 (PDT) From: Gonzalo Matias Juarez Tello To: linux-mm@kvack.org Cc: Gonzalo Matias Juarez Tello , Andrew Morton , linux-kernel@vger.kernel.org Subject: [PATCH] mm/mmap.c: logic of find_vma_intersection repeated in __do_munmap Date: Fri, 9 Apr 2021 13:21:26 -0300 Message-Id: <20210409162129.18313-1-gmjuareztello@gmail.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Logic of find_vma_intersection() (which is an inline fc) is repeated in __do_munmap(). Besides, prev is assigned a value before checking vma->vm_start >= end which might end up on a return statement making that assignment useless. Calling find_vma_intersection() checks that condition and returns NULL if no vma is found, hence only the !vma check is needed in __do_munmap(). Signed-off-by: Gonzalo Matias Juarez Tello --- mm/mmap.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 3f287599a7a3..59ceaa474a00 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2822,16 +2822,11 @@ int __do_munmap(struct mm_struct *mm, unsigned long start, size_t len, */ arch_unmap(mm, start, end); - /* Find the first overlapping VMA */ - vma = find_vma(mm, start); + /* Find the first overlapping VMA where start < vma->vm_end */ + vma = find_vma_intersection(mm, start, end); if (!vma) return 0; prev = vma->vm_prev; - /* we have start < vma->vm_end */ - - /* if it doesn't overlap, we have nothing.. */ - if (vma->vm_start >= end) - return 0; /* * If we need to split any vma, do it now to save pain later. -- 2.31.1