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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 DA41FC47254 for ; Fri, 1 May 2020 01:53:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B91DD2074A for ; Fri, 1 May 2020 01:53:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OHcfllwj" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728090AbgEABxV (ORCPT ); Thu, 30 Apr 2020 21:53:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1728025AbgEABxS (ORCPT ); Thu, 30 Apr 2020 21:53:18 -0400 Received: from mail-ed1-x543.google.com (mail-ed1-x543.google.com [IPv6:2a00:1450:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 32F85C035494 for ; Thu, 30 Apr 2020 18:53:18 -0700 (PDT) Received: by mail-ed1-x543.google.com with SMTP id f12so6184970edn.12 for ; Thu, 30 Apr 2020 18:53:18 -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:in-reply-to:references; bh=L/eixiBO7KCR17cAG5IpTeBZCnCmuzeLdJS3OmBcd98=; b=OHcfllwjxxUFVat65zUUPNoQ+blqGZIuFQY+SiYeTzQySOJAGsJaSBgC/RoNSdkGxV D01pDAx4vQZvw2wc/bBohb/fhhJNztvgMx0d88aD6/mO+CJBwze+BPlV1Nh2tyvDyz+2 ClU7/DYC7B667QLAnGkXcLM+lVi19nDprnUybTb+YKrZREQ7nC6+Ni1PG7I6/z/uNQRr iFzzvs4QNHpUyT2P0LQ8MGq+N9ZrCAiOl289EmSCSOeK0vdHhmU5tLv9rGD76hJLNKXc oRLYklmIIz8z4sy3vGPSGQV+AR92ZX04nkEjVYq9WvQlmWMQyd8YfTJzWGMOLQVi3jk8 KwtA== 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:in-reply-to :references; bh=L/eixiBO7KCR17cAG5IpTeBZCnCmuzeLdJS3OmBcd98=; b=icVQ0QqcFg0S8fqXZEkj1BeQBLd4zj5K7CuPT21OcEw7QNeEz4cZU8c+PNRmG6jRgD uCkMZlO/GdBZRq86EkuVhNrMJz0EuHl3Gt0lhaddSrijHpFRNP8L2JJQA66vpWNmmR4d ie6Tdt/fXNL6EMcclFKYh+rgfV/DoTmHe+GedeCRzV/fdFDls5gecJbgbSbOjXyCM9ox 5XzhqDHRJ42qNkzUihXmNYLwTMwhOoc5erXHeZEjtX6NfxJ8p/112Ev8QSomrod/ySGa qMxYJdeFrQvOdbCPPg6Xd8UWIMVp9OpmieExvIOfeo9waK/CimWzvXcKeb/S1Qj1NwC4 t/YQ== X-Gm-Message-State: AGi0PuYb7OP+3RsGcblwgyX6qM1hRELYm0g/bmyO0qiv+0fHxsvxLzJg +pdcQtmmgNMoRVsyIS3t25k= X-Google-Smtp-Source: APiQypI6ocw5DBnFfrafoO2PU1kyqVt3eWL/xIIEWqyvGX1ib44xvQchsw21+chYGqWBRVj8xXX68g== X-Received: by 2002:a05:6402:887:: with SMTP id e7mr1745347edy.178.1588297996991; Thu, 30 Apr 2020 18:53:16 -0700 (PDT) Received: from localhost ([185.92.221.13]) by smtp.gmail.com with ESMTPSA id g1sm170066ejs.51.2020.04.30.18.53.16 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 30 Apr 2020 18:53:16 -0700 (PDT) From: Wei Yang To: akpm@linux-foundation.org, ying.huang@intel.com Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Wei Yang Subject: [PATCH 3/3] mm/swapfile.c: count won't be bigger than SWAP_MAP_MAX Date: Fri, 1 May 2020 01:52:59 +0000 Message-Id: <20200501015259.32237-3-richard.weiyang@gmail.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200501015259.32237-1-richard.weiyang@gmail.com> References: <20200501015259.32237-1-richard.weiyang@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When the condition is true, there are two possibilities: 1. count == SWAP_MAP_BAD 2. count == (SWAP_MAP_MAX & COUNT_CONTINUED) == SWAP_MAP_SHMEM The first case would be filtered by the first if in __swap_duplicate(). And the second case means this swap entry is for shmem. Since we never do another duplication for shmem swap entry. This won't happen neither. Signed-off-by: Wei Yang --- mm/swapfile.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/mm/swapfile.c b/mm/swapfile.c index 1a877d1d40e3..88dd2ad34aad 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3404,8 +3404,6 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage) if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX) count += usage; - else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX) - err = -EINVAL; else if (swap_count_continued(p, offset, count)) count = COUNT_CONTINUED; else -- 2.23.0