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=-9.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,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 3074AC31E40 for ; Fri, 9 Aug 2019 07:10:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04C73208C4 for ; Fri, 9 Aug 2019 07:10:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="pjebkB+W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405779AbfHIHKr (ORCPT ); Fri, 9 Aug 2019 03:10:47 -0400 Received: from mail-pl1-f193.google.com ([209.85.214.193]:42600 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405612AbfHIHKr (ORCPT ); Fri, 9 Aug 2019 03:10:47 -0400 Received: by mail-pl1-f193.google.com with SMTP id ay6so44646653plb.9 for ; Fri, 09 Aug 2019 00:10:46 -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=psT6ET5n53e8RWXSwxZ0SnD139vmrDzv09XLpcqNcnQ=; b=pjebkB+WzqjE25Hd/bEFmIqp+kxp6y1XWoDCJLV70ePRPKfYQflgh3R2/ZosY+woep 1RyphNqrG27xa2dWIUCKhaMzfrZhWKWtjT/NXDhkJog5YObgs5ffBcLpIC23OzBk1gI9 uEvveaQJFp3Z9tpGIuBRI4CXhgg45MrzJKnYZq3dlJROqFxxUpwUxZuB5VgO6m6LXAE3 vFIdvTUP593CIKKKzyYlYl2VtLcxYysUsBovjXNOetfBGrDbUQRj7TcBjPTzu7KLwnWN qNAMN0HK51n558r7MCutVeucUWx3LcSR2PLkRuq3l9F9Z5hGA1GWSyLSTcflPJ0WJ+O1 5bTw== 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=psT6ET5n53e8RWXSwxZ0SnD139vmrDzv09XLpcqNcnQ=; b=s8ES5OK+jqhQh+UZuk1SDlvkA9lejfL+ycMfL1t0XwWHKUXgiKVnEIseQjpdxcZzlD mvXiLhiN+n46chm13iKpkeik1bKVCDRtndd1ZIDXUb2Kw+jcfSKwNU2cWWghIX5cWrcO J9NpL/Y9hgYLa95YeBMxoF1kzFxv5Rsrjk1zna5iWELOxxm9O7ypC5iid/KVe8lFrh/W Ch8Hdp9um3zxSbtslBghw5WxtorCB5kuQmzYj0S721zoYXdrpEHLqzw2n2PagT05jpFw p2Hs1wlAsliFZP+Uohdlvhbgm+1uTr0DGoiK+w9lWWhGYxkL5XLpxNDfnE71pC37+rYa igvQ== X-Gm-Message-State: APjAAAW7Ehhfyda47v4xnmEPPoW1KtHk9xKsr2xdYdICaBEBMnBoFjh1 Qdl12JZRZL6bxI00JQ266qO08FQcBMxLlQ== X-Google-Smtp-Source: APXvYqykuGA1VV06c9nlUG2DUSHE5SeCVkb74qiTdK/x3XoXhHa5GsDLpA9I4sEjKvAn34pI+w9jnQ== X-Received: by 2002:a17:902:7288:: with SMTP id d8mr17686104pll.133.1565334646229; Fri, 09 Aug 2019 00:10:46 -0700 (PDT) Received: from suzukaze.ipads-lab.se.sjtu.edu.cn ([89.31.126.54]) by smtp.gmail.com with ESMTPSA id l17sm21794208pgj.44.2019.08.09.00.10.44 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 09 Aug 2019 00:10:45 -0700 (PDT) From: Chuhong Yuan Cc: linux-kernel@vger.kernel.org, Chuhong Yuan Subject: [PATCH v4 5/8] reboot: Replace strncmp with str_has_prefix Date: Fri, 9 Aug 2019 15:10:42 +0800 Message-Id: <20190809071042.17333-1-hslester96@gmail.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org strncmp(str, const, len) is error-prone because len is easy to have typo. The example is the hard-coded len has counting error or sizeof(const) forgets - 1. So we prefer using newly introduced str_has_prefix() to substitute such strncmp to make code better. Signed-off-by: Chuhong Yuan --- Changes in v4: - Eliminate assignments in if conditions. kernel/reboot.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/reboot.c b/kernel/reboot.c index c4d472b7f1b4..c79aaac43785 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -520,6 +520,8 @@ EXPORT_SYMBOL_GPL(orderly_reboot); static int __init reboot_setup(char *str) { + size_t len; + for (;;) { enum reboot_mode *mode; @@ -530,9 +532,10 @@ static int __init reboot_setup(char *str) */ reboot_default = 0; - if (!strncmp(str, "panic_", 6)) { + len = str_has_prefix(str, "panic_"); + if (len) { mode = &panic_reboot_mode; - str += 6; + str += len; } else { mode = &reboot_mode; } -- 2.20.1