From patchwork Fri Jul 12 11:20:58 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugeniu Rosca X-Patchwork-Id: 1131306 X-Patchwork-Delegate: trini@ti.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.denx.de (client-ip=81.169.180.215; helo=lists.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=de.adit-jv.com Received: from lists.denx.de (dione.denx.de [81.169.180.215]) by ozlabs.org (Postfix) with ESMTP id 45lVsT4TSmz9sDB for ; Fri, 12 Jul 2019 21:23:09 +1000 (AEST) Received: by lists.denx.de (Postfix, from userid 105) id 5B502C21C6A; Fri, 12 Jul 2019 11:22:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lists.denx.de X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=unavailable autolearn_force=no version=3.4.0 Received: from lists.denx.de (localhost [IPv6:::1]) by lists.denx.de (Postfix) with ESMTP id C1794C21DA6; Fri, 12 Jul 2019 11:22:37 +0000 (UTC) Received: by lists.denx.de (Postfix, from userid 105) id 4244AC21D9A; Fri, 12 Jul 2019 11:21:41 +0000 (UTC) Received: from smtp1.de.adit-jv.com (smtp1.de.adit-jv.com [93.241.18.167]) by lists.denx.de (Postfix) with ESMTPS id BA5E3C21DAF for ; Fri, 12 Jul 2019 11:21:37 +0000 (UTC) Received: from localhost (smtp1.de.adit-jv.com [127.0.0.1]) by smtp1.de.adit-jv.com (Postfix) with ESMTP id 9F17F3C00BA; Fri, 12 Jul 2019 13:21:37 +0200 (CEST) Received: from smtp1.de.adit-jv.com ([127.0.0.1]) by localhost (smtp1.de.adit-jv.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id JxeP9gSBqcX2; Fri, 12 Jul 2019 13:21:31 +0200 (CEST) Received: from HI2EXCH01.adit-jv.com (hi2exch01.adit-jv.com [10.72.92.24]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by smtp1.de.adit-jv.com (Postfix) with ESMTPS id 842623C001F; Fri, 12 Jul 2019 13:21:31 +0200 (CEST) Received: from vmlxhi-102.adit-jv.com (10.72.93.184) by HI2EXCH01.adit-jv.com (10.72.92.24) with Microsoft SMTP Server (TLS) id 14.3.439.0; Fri, 12 Jul 2019 13:21:30 +0200 From: Eugeniu Rosca To: , Sam Protsenko , Simon Glass , Igor Opaniuk , Tom Rini Date: Fri, 12 Jul 2019 13:20:58 +0200 Message-ID: <20190712112059.25558-5-erosca@de.adit-jv.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712112059.25558-1-erosca@de.adit-jv.com> References: <20190712112059.25558-1-erosca@de.adit-jv.com> MIME-Version: 1.0 X-Originating-IP: [10.72.93.184] Cc: Eugeniu Rosca , Eugeniu Rosca Subject: [U-Boot] [PATCH 4/5] cmd: bcb: Use strcmp() instead of strncmp() for string literals X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.18 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" Quote from https://patchwork.ozlabs.org/patch/1104244/#2210814: ----------8<----------- strncmp() is chosen for the sake of paranoid/defensive programming. Indeed, strncmp() is not really needed when comparing a variable with a string literal. We expect strcmp() to behave safely even if the string variable is not NUL-terminated. In the same scenario, Linux v5.2-rc7 uses both strcmp() and strncmp(), but the frequency of strcmp() is higher: $ git --version git version 2.22.0 $ (Linux 5.2-rc7) git grep -En 'strncmp\([^"]*"[[:alnum:]]+"' | wc -l 1066 $ (Linux 5.2-rc7) git grep -En 'strcmp\([^"]*"[[:alnum:]]+"' | wc -l 1968 A quick "strcmp vs strncmp" object size test shows that strcmp() generates smaller memory footprint (gcc-8, x86_64): $ (U-Boot) size cmd/bcb-strncmp.o cmd/bcb-strcmp.o text data bss dec hex filename 3373 400 2048 5821 16bd cmd/bcb-strncmp.o 3314 400 2048 5762 1682 cmd/bcb-strcmp.o So, overall, I agree to use strcmp() whenever variables are compared with string literals. ----------8<----------- Fixes: db7b7a05b267 ("cmd: Add 'bcb' command to read/modify/write BCB fields") Reported-by: Simon Glass Signed-off-by: Eugeniu Rosca Reviewed-by: Igor Opaniuk --- cmd/bcb.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/cmd/bcb.c b/cmd/bcb.c index 3b1c7434e287..c7138a5179a9 100644 --- a/cmd/bcb.c +++ b/cmd/bcb.c @@ -24,17 +24,17 @@ static struct bootloader_message bcb = { { 0 } }; static int bcb_cmd_get(char *cmd) { - if (!strncmp(cmd, "load", sizeof("load"))) + if (!strcmp(cmd, "load")) return BCB_CMD_LOAD; - if (!strncmp(cmd, "set", sizeof("set"))) + if (!strcmp(cmd, "set")) return BCB_CMD_FIELD_SET; - if (!strncmp(cmd, "clear", sizeof("clear"))) + if (!strcmp(cmd, "clear")) return BCB_CMD_FIELD_CLEAR; - if (!strncmp(cmd, "test", sizeof("test"))) + if (!strcmp(cmd, "test")) return BCB_CMD_FIELD_TEST; - if (!strncmp(cmd, "store", sizeof("store"))) + if (!strcmp(cmd, "store")) return BCB_CMD_STORE; - if (!strncmp(cmd, "dump", sizeof("dump"))) + if (!strcmp(cmd, "dump")) return BCB_CMD_FIELD_DUMP; else return -1; @@ -85,21 +85,21 @@ err: static int bcb_field_get(char *name, char **field, int *size) { - if (!strncmp(name, "command", sizeof("command"))) { - *field = bcb.command; - *size = sizeof(bcb.command); - } else if (!strncmp(name, "status", sizeof("status"))) { - *field = bcb.status; - *size = sizeof(bcb.status); - } else if (!strncmp(name, "recovery", sizeof("recovery"))) { - *field = bcb.recovery; - *size = sizeof(bcb.recovery); - } else if (!strncmp(name, "stage", sizeof("stage"))) { - *field = bcb.stage; - *size = sizeof(bcb.stage); - } else if (!strncmp(name, "reserved", sizeof("reserved"))) { - *field = bcb.reserved; - *size = sizeof(bcb.reserved); + if (!strcmp(name, "command")) { + *fieldp = bcb.command; + *sizep = sizeof(bcb.command); + } else if (!strcmp(name, "status")) { + *fieldp = bcb.status; + *sizep = sizeof(bcb.status); + } else if (!strcmp(name, "recovery")) { + *fieldp = bcb.recovery; + *sizep = sizeof(bcb.recovery); + } else if (!strcmp(name, "stage")) { + *fieldp = bcb.stage; + *sizep = sizeof(bcb.stage); + } else if (!strcmp(name, "reserved")) { + *fieldp = bcb.reserved; + *sizep = sizeof(bcb.reserved); } else { printf("Error: Unknown bcb field '%s'\n", name); return -1;