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 6BB6DC433FE for ; Wed, 16 Mar 2022 12:24:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355637AbiCPM0H (ORCPT ); Wed, 16 Mar 2022 08:26:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355659AbiCPM0G (ORCPT ); Wed, 16 Mar 2022 08:26:06 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A73DF4D9D1; Wed, 16 Mar 2022 05:24:52 -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 35ACBB81AE4; Wed, 16 Mar 2022 12:24:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D55B6C340E9; Wed, 16 Mar 2022 12:24:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647433489; bh=5dSI2Vb07oF19cImCiHaEFsIdyzJFr+m3f7S16flnS8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aOWBF80J2Jw1aJVgipMGQy2wkRkhslV1XC/JRAtHKHvpas1hSDUN/U3eLzG7qxLiX l9C+cmSQzokSiBAMaoAbNdCFJD5fw6m//qcCx10ovyLDwWNRZ0m/dGrcNnoidkYD0c n6hYqsbifn3b2rh2CAUX6ZcazCXGVrJqi+zd23xjG9I+xHaat/UNOiArvmQ39E14sH +abunun5WS10lecjwQBFGIM9Q7B7ii7aX3iTj5KiRvnyv3mpDnSHBxlpfJyq/uWU6o wCdZ/flnd1D4sYCK7PwIMP7hskdOTOqV/BUQaHJ+KqTCcLQFVMtTYjBx2qQ3ieGgBq dGJm+cx77hVVg== From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt Subject: [PATCHv3 bpf-next 02/13] kallsyms: Skip the name search for empty string Date: Wed, 16 Mar 2022 13:24:08 +0100 Message-Id: <20220316122419.933957-3-jolsa@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220316122419.933957-1-jolsa@kernel.org> References: <20220316122419.933957-1-jolsa@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When kallsyms_lookup_name is called with empty string, it will do futile search for it through all the symbols. Skipping the search for empty string. Signed-off-by: Jiri Olsa --- kernel/kallsyms.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 951c93216fc4..79f2eb617a62 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -212,6 +212,10 @@ unsigned long kallsyms_lookup_name(const char *name) unsigned long i; unsigned int off; + /* Skip the search for empty string. */ + if (!*name) + return 0; + for (i = 0, off = 0; i < kallsyms_num_syms; i++) { off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf)); -- 2.35.1