From patchwork Fri Apr 9 16:21:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gonzalo Matias Juarez Tello X-Patchwork-Id: 12194451 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=-13.5 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,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 98887C433B4 for ; Fri, 9 Apr 2021 16:22:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E5E4B61026 for ; Fri, 9 Apr 2021 16:22:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E5E4B61026 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5BBF46B006C; Fri, 9 Apr 2021 12:22:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 559ED6B006E; Fri, 9 Apr 2021 12:22:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3FA6A6B0070; Fri, 9 Apr 2021 12:22:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0128.hostedemail.com [216.40.44.128]) by kanga.kvack.org (Postfix) with ESMTP id 227696B006C for ; Fri, 9 Apr 2021 12:22:18 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id D0B04184B3548 for ; Fri, 9 Apr 2021 16:22:17 +0000 (UTC) X-FDA: 78013345914.36.38E516D Received: from mail-qk1-f175.google.com (mail-qk1-f175.google.com [209.85.222.175]) by imf27.hostedemail.com (Postfix) with ESMTP id E604480192EA for ; Fri, 9 Apr 2021 16:22:09 +0000 (UTC) Received: by mail-qk1-f175.google.com with SMTP id i9so6386309qka.2 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=l5fvkeP4CefiD86gp9w1Sc9cnVbeEDxLB89lWHzZ4hs4WRTgDsLV3Fx6DamBOJf/bT ZmP7lgANv1orp18B1UiJctvZOI4ogkvxwqTfR0Er4CXowiPHiAJareFSwd0TnZGvEpl+ XtVYIAUZVYB2Yr+BlO2C0CPdDu1IVmKIDPqOoacsvfqXSzwfZuX8khg96jo/puyKXOH5 3IHta2dJrdDCYyuTvvcFNd9y3fbmX6EJUrkH7N5svRm32fsdDgdPlW/lpv4Ftp+LOk3n ygShg6zUzn7sW+V0N8lltdrcJTeKNzj4LWVNkYuQeVzF1/orLAIU6XLcoHGEnPZirkhw Ecng== X-Gm-Message-State: AOAM530UApJ7qeWvskinT2K+eYQiaj6ovoo61S1VL80UQaNdFdNKlUda T+uHqopQoJGnLT3Nh4cXULL/BtWk9ag= 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 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: E604480192EA X-Stat-Signature: nyw8uonh4eemqsfcfyjbhfiwmjae4pas Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf27; identity=mailfrom; envelope-from=""; helo=mail-qk1-f175.google.com; client-ip=209.85.222.175 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617985329-827336 X-Bogosity: Ham, tests=bogofilter, spamicity=0.060112, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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.