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=-8.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 EEFB7ECE564 for ; Wed, 19 Sep 2018 22:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A302F21522 for ; Wed, 19 Sep 2018 22:05:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=rasmusvillemoes.dk header.i=@rasmusvillemoes.dk header.b="c2KQl4m9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A302F21522 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rasmusvillemoes.dk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387424AbeITDo7 (ORCPT ); Wed, 19 Sep 2018 23:44:59 -0400 Received: from mail-ed1-f68.google.com ([209.85.208.68]:45618 "EHLO mail-ed1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733235AbeITDo6 (ORCPT ); Wed, 19 Sep 2018 23:44:58 -0400 Received: by mail-ed1-f68.google.com with SMTP id p52-v6so6145310eda.12 for ; Wed, 19 Sep 2018 15:05:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rasmusvillemoes.dk; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=2MpIPnUj7X7v5PFxUqTacXruO6RjfNepRmP1LhcK5GE=; b=c2KQl4m9pu4Ee8AtyT884SlCOxGHmdm5V8mK5pxjICzXyF5Lm8YzJRKSvN6Iqt9i1/ z7jWv9Yk1ZW+dk1wKcvWMEv4KN2IgZs2hleDGI9IlEoRcWh7f9tUl/E2ImFP8CNdTfp+ IH2wWoJUYaXr9Ho8jMEdhMP/adiuLHOvwasSU= 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:in-reply-to :references; bh=2MpIPnUj7X7v5PFxUqTacXruO6RjfNepRmP1LhcK5GE=; b=ZLx5DHVvUDOZI9K16BVW0709aAz+DPfm0CbMC2P/losy40N0NX5g5A2D7Hd0/AIn6U hb5OxaQwm9Y/dsUuRI+csY14Qxn0bUXTEUb6D/Vw1ne5k8eXD7cXM8tvOyu3+Jb6BGfn VgKBvhLLvpjbkl7smdsp2y80PdiJzzNgUkdEU4goba5GyTKglmmYZLMr/Mb7PfhWMhiD vFmStGLqJSBgDyCjuHZWpmawU17AqjTWA1pwvWtxA10QKh1AZ6YIWRJYL4yCJwOtf+93 Fe/OxrGp8AZjN49Lf5QnhXXp3gqUT202wYL6R6IV6lTikweIwMWJNc1m00odrsGbdIiW F1LQ== X-Gm-Message-State: APzg51DSJen1LPDrtR2fvlLUTyMu98exwwYT890gHVF66CQ4+2xQfFgL tIHu+ohHpSCfOKHBIHvniLpRWg== X-Google-Smtp-Source: ANB0VdYDPu5L+c77merVhVncMVWlWZSGOdknbiUJkqtmBAdVyM3lgo6/SI88E7yiuvl1O64IP0VGPQ== X-Received: by 2002:aa7:c441:: with SMTP id n1-v6mr58724142edr.55.1537394701077; Wed, 19 Sep 2018 15:05:01 -0700 (PDT) Received: from prevas-ravi.waoo.dk (dhcp-5-186-115-161.cgn.ip.fibianet.dk. [5.186.115.161]) by smtp.gmail.com with ESMTPSA id a9-v6sm2798edi.26.2018.09.19.15.05.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 19 Sep 2018 15:05:00 -0700 (PDT) From: Rasmus Villemoes To: Jason Baron , Andrew Morton Cc: linux-kernel@vger.kernel.org, Rasmus Villemoes Subject: [PATCH 09/22] dynamic_debug: use pointer comparison in ddebug_remove_module Date: Thu, 20 Sep 2018 00:04:31 +0200 Message-Id: <20180919220444.23190-10-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20180919220444.23190-1-linux@rasmusvillemoes.dk> References: <20180919220444.23190-1-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now that we store the passed-in string directly in ddebug_add_module, we can use pointer equality instead of strcmp. This is a little more efficient, but more importantly, this also makes the code somewhat more correct: Currently, if one loads and then unloads a module whose name happens to match the KBUILD_MODNAME of some built-in functionality (which need not even be modular at all), all of their dynamic debug entries vanish along with those of the actual module. For example, loading and unloading a core.ko hides all pr_debugs from drivers/base/core.c and other built-in files called core.c (incidentally, there is an in-tree module whose name is core, but I just tested this with an out-of-tree trivial one). Signed-off-by: Rasmus Villemoes --- lib/dynamic_debug.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 2155e0e23530..ab81155f928d 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -929,9 +929,10 @@ int ddebug_remove_module(const char *mod_name) mutex_lock(&ddebug_lock); list_for_each_entry_safe(dt, nextdt, &ddebug_tables, link) { - if (!strcmp(dt->mod_name, mod_name)) { + if (dt->mod_name == mod_name) { ddebug_table_free(dt); ret = 0; + break; } } mutex_unlock(&ddebug_lock); -- 2.16.4