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 F26C8C77B7A for ; Mon, 29 May 2023 09:23:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231500AbjE2JX0 (ORCPT ); Mon, 29 May 2023 05:23:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229572AbjE2JXX (ORCPT ); Mon, 29 May 2023 05:23:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D6DFEAC; Mon, 29 May 2023 02:23:22 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 7402162247; Mon, 29 May 2023 09:23:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02F23C4339B; Mon, 29 May 2023 09:23:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685352201; bh=GWbhfro7mScT3pUdsUQtz4ZAPeagy5Rb6k2c8ZAI6OQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=dIOU/xaGwkDyKcwyDocIkiVQbENBQUi7g8WqE5qVwhsQEKDXoKJAnOaqRk5026r0M 6oyFDRIKaqfaBYUw5znjcIqLKg5YqJ7kQG15fkIxk29lHxmPMgWriZOU1HpjRvc1xP K1Ieza6rVH1Q9zHLYYzJeQ+pcW5U1cpYDq6KtrH45561axeaGeA7l6d1Jn4P4flXoh g8PvuHzoF6Agw4qkKi1ijOvsDhq57VDhV6atWntw/7r6SU2zWDcX28ARQWofVWdB0p 3LahSss88sxsVsd2diXJijydgrAi6UZFgzu3pzXw30uPOKtqzRlIDjUgoyTUlH3HSA w78SZsz40txaA== Date: Mon, 29 May 2023 18:23:19 +0900 From: Masami Hiramatsu (Google) To: sunliming Cc: rostedt@goodmis.org, beaub@linux.microsoft.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH V3] tracing/user_events: Prevent same name but different args event Message-Id: <20230529182319.5b3dff8afcf50922eb46099f@kernel.org> In-Reply-To: <20230529032100.286534-1-sunliming@kylinos.cn> References: <20230529032100.286534-1-sunliming@kylinos.cn> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 29 May 2023 11:21:00 +0800 sunliming wrote: > User processes register name_args for events. If the same name but different > args event are registered. The trace outputs of second event are printed > as the first event. This is incorrect. > > Return EADDRINUSE back to the user process if the same name but different args > event has being registered. > > Signed-off-by: sunliming Looks good to me. Reviewed-by: Masami Hiramatsu (Google) Thank you, > --- > kernel/trace/trace_events_user.c | 36 +++++++++++++++---- > .../selftests/user_events/ftrace_test.c | 6 ++++ > 2 files changed, 36 insertions(+), 6 deletions(-) > > diff --git a/kernel/trace/trace_events_user.c b/kernel/trace/trace_events_user.c > index b1ecd7677642..e90161294698 100644 > --- a/kernel/trace/trace_events_user.c > +++ b/kernel/trace/trace_events_user.c > @@ -1753,6 +1753,8 @@ static int user_event_parse(struct user_event_group *group, char *name, > int ret; > u32 key; > struct user_event *user; > + int argc = 0; > + char **argv; > > /* Prevent dyn_event from racing */ > mutex_lock(&event_mutex); > @@ -1760,13 +1762,35 @@ static int user_event_parse(struct user_event_group *group, char *name, > mutex_unlock(&event_mutex); > > if (user) { > - *newuser = user; > - /* > - * Name is allocated by caller, free it since it already exists. > - * Caller only worries about failure cases for freeing. > - */ > - kfree(name); > + if (args) { > + argv = argv_split(GFP_KERNEL, args, &argc); > + if (!argv) { > + ret = -ENOMEM; > + goto error; > + } > + > + ret = user_fields_match(user, argc, (const char **)argv); > + argv_free(argv); > + > + } else > + ret = list_empty(&user->fields); > + > + if (ret) { > + *newuser = user; > + /* > + * Name is allocated by caller, free it since it already exists. > + * Caller only worries about failure cases for freeing. > + */ > + kfree(name); > + } else { > + ret = -EADDRINUSE; > + goto error; > + } > + > return 0; > +error: > + refcount_dec(&user->refcnt); > + return ret; > } > > user = kzalloc(sizeof(*user), GFP_KERNEL_ACCOUNT); > diff --git a/tools/testing/selftests/user_events/ftrace_test.c b/tools/testing/selftests/user_events/ftrace_test.c > index 7c99cef94a65..6e8c4b47281c 100644 > --- a/tools/testing/selftests/user_events/ftrace_test.c > +++ b/tools/testing/selftests/user_events/ftrace_test.c > @@ -228,6 +228,12 @@ TEST_F(user, register_events) { > ASSERT_EQ(0, ioctl(self->data_fd, DIAG_IOCSREG, ®)); > ASSERT_EQ(0, reg.write_index); > > + /* Multiple registers to same name but different args should fail */ > + reg.enable_bit = 29; > + reg.name_args = (__u64)"__test_event u32 field1;"; > + ASSERT_EQ(-1, ioctl(self->data_fd, DIAG_IOCSREG, ®)); > + ASSERT_EQ(EADDRINUSE, errno); > + > /* Ensure disabled */ > self->enable_fd = open(enable_file, O_RDWR); > ASSERT_NE(-1, self->enable_fd); > -- > 2.25.1 > -- Masami Hiramatsu (Google)