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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94ED3C25B08 for ; Wed, 17 Aug 2022 20:03:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241677AbiHQUDw (ORCPT ); Wed, 17 Aug 2022 16:03:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232057AbiHQUDr (ORCPT ); Wed, 17 Aug 2022 16:03:47 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ECD5B1F623 for ; Wed, 17 Aug 2022 13:03:45 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A5C65B81F61 for ; Wed, 17 Aug 2022 20:03:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CBB2FC4347C; Wed, 17 Aug 2022 20:03:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660766623; bh=wv0Zebl3/M8/sl1p7uqmjBF5ITW2e0LsrTBPWFRbNuA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IybX3rRa0kAATdNa9CEutWHHd6nJNB/y5T4vkHUm4SCBxsG8J6o2lnKb5ITB9GZwT WOunqvHZDReF98jHFUrT4omATeTvB3UCsg/rZDPxcxrrDrtzAcum1B8j4gTkqj0NLe en9O7rOnvqqyggowmKPE4BeGmXuDlKMcTntGHaJ3PwQamtksLtjybpR/aPxmhpwVMg pA2qJizPk36y4j50+h95mxHjC0e9BVblhawKMwatNS0D4RpoUMf6u6kUMoXnrzZfTH 6NXMp7SKRpNPotFkq14UcIQPtJFT6KTkDsDWLgb0zPPUVkbS/L4c+4E5yToxy65t3j CT26aaydcxB2A== From: =?UTF-8?q?Marek=20Beh=C3=BAn?= To: Vinod Koul , Kishon Vijay Abraham I , Linux Phy , Kees Cook , Andy Shevchenko Cc: Daniel Scally , Gregory Clement , Heikki Krogerus , Sakari Ailus , linux-kernel@vger.kernel.org, pali@kernel.org, josef.schlehofer@nic.cz, =?UTF-8?q?Marek=20Beh=C3=BAn?= Subject: [PATCH linux-phy v2 1/4] string.h: Add str_has_proper_prefix() Date: Wed, 17 Aug 2022 22:03:32 +0200 Message-Id: <20220817200335.911-2-kabel@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220817200335.911-1-kabel@kernel.org> References: <20220817200335.911-1-kabel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add str_has_proper_prefix(), similar to str_has_prefix(), but requires that the prefix is proper: the string itself must be longer than the prefix. Signed-off-by: Marek Behún --- Andy, Kees, could you ack this if it is ok? --- include/linux/string.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index 61ec7e4f6311..375f51b9182c 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -316,4 +316,22 @@ static __always_inline size_t str_has_prefix(const char *str, const char *prefix return strncmp(str, prefix, len) == 0 ? len : 0; } +/** + * str_has_proper_prefix - Test if a string has a proper prefix + * @str: The string to test + * @prefix: The string to see if @str starts with + * + * This is like str_has_prefix(), but fails if the strings are equal. + * + * Returns: + * * strlen(@prefix) if @str starts with @prefix and they aren't equal + * * 0 otherwise + */ +static __always_inline size_t str_has_proper_prefix(const char *str, + const char *prefix) +{ + size_t len = strlen(prefix); + return strncmp(str, prefix, len) == 0 && len != strlen(str) ? len : 0; +} + #endif /* _LINUX_STRING_H_ */ -- 2.35.1