From patchwork Thu Feb 16 11:42:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 13142975 X-Patchwork-Delegate: kuba@kernel.org 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 8FD3BC61DA4 for ; Thu, 16 Feb 2023 11:42:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230227AbjBPLmK (ORCPT ); Thu, 16 Feb 2023 06:42:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230063AbjBPLmI (ORCPT ); Thu, 16 Feb 2023 06:42:08 -0500 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CA3701F488; Thu, 16 Feb 2023 03:42:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1676547726; x=1708083726; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=FfCAalj2Nee1CcJLc+LGlUXcvI9FY2hBGzZJL2n+MEo=; b=mw3oNVc5RgBteAH7PI08t5I/AveePF5vQim6KoKMLITrr0hkCjsgV5sz bktGZBxTUDAjbZVBdScT/19Q8AZgtRQx2lbx+2avgvsoGXyLOcOisg5eV sNlvUikl2CGIyWKlhGCxu3oZicZFHaPxIkzrSUH/kIA2vaF7FWNUje1Ya /IaA+9ieNAvkyM8M0fzxniXvDsfzgWJ/RgvSRk7Mlt59eh5/j5P+obJBF eAxNAMemOZqr+Kg+6xjcz195vVP/oC8WShX7to8doECbydSAMRvtFw4sG 4FLSUQ/NWewh+cf78qKFhYFgsqjhHIGyMku5t1XbyI53ocXXjqh3napdt g==; X-IronPort-AV: E=McAfee;i="6500,9779,10622"; a="359124747" X-IronPort-AV: E=Sophos;i="5.97,302,1669104000"; d="scan'208";a="359124747" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Feb 2023 03:42:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10622"; a="999003914" X-IronPort-AV: E=Sophos;i="5.97,302,1669104000"; d="scan'208";a="999003914" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga005.fm.intel.com with ESMTP; 16 Feb 2023 03:42:00 -0800 Received: by black.fi.intel.com (Postfix, from userid 1003) id 199DC1C5; Thu, 16 Feb 2023 13:42:41 +0200 (EET) From: Andy Shevchenko To: Andy Shevchenko , Kees Cook , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, netdev@vger.kernel.org Cc: Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andy Shevchenko , Eric Dumazet , Jakub Kicinski , Paolo Abeni Subject: [PATCH net-next v1 2/2] dns: use memscan() instead of open coded variant Date: Thu, 16 Feb 2023 13:42:34 +0200 Message-Id: <20230216114234.36343-2-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230216114234.36343-1-andriy.shevchenko@linux.intel.com> References: <20230216114234.36343-1-andriy.shevchenko@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org memscan() is a standard API to provide an equivalent to memchr(foo, $CHAR, end - foo) ?: end so use it. Memory footprint (x86_64): Function old new delta dns_resolver_preparse 1429 1393 -36 Total: Before=3229, After=3193, chg -1.11% Signed-off-by: Andy Shevchenko --- net/dns_resolver/dns_key.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c index 01e54b46ae0b..835be6e2dd83 100644 --- a/net/dns_resolver/dns_key.c +++ b/net/dns_resolver/dns_key.c @@ -134,8 +134,8 @@ dns_resolver_preparse(struct key_preparsed_payload *prep) /* deal with any options embedded in the data */ end = data + datalen; - opt = memchr(data, '#', datalen); - if (!opt) { + opt = memscan(data, '#', datalen); + if (opt == end) { /* no options: the entire data is the result */ kdebug("no options"); result_len = datalen; @@ -150,7 +150,7 @@ dns_resolver_preparse(struct key_preparsed_payload *prep) const char *eq; char optval[128]; - next_opt = memchr(opt, '#', end - opt) ?: end; + next_opt = memscan(opt, '#', end - opt); opt_len = next_opt - opt; if (opt_len <= 0 || opt_len > sizeof(optval)) { pr_warn_ratelimited("Invalid option length (%d) for dns_resolver key\n", @@ -158,16 +158,10 @@ dns_resolver_preparse(struct key_preparsed_payload *prep) return -EINVAL; } - eq = memchr(opt, '=', opt_len); - if (eq) { - opt_nlen = eq - opt; - eq++; - memcpy(optval, eq, next_opt - eq); - optval[next_opt - eq] = '\0'; - } else { - opt_nlen = opt_len; - optval[0] = '\0'; - } + eq = memscan(opt, '=', opt_len); + opt_nlen = eq - opt; + memcpy(optval, eq, next_opt - eq); + optval[next_opt - eq] = '\0'; kdebug("option '%*.*s' val '%s'", opt_nlen, opt_nlen, opt, optval);