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 58935C77B7A for ; Tue, 30 May 2023 18:10:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232007AbjE3SKW (ORCPT ); Tue, 30 May 2023 14:10:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48476 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230234AbjE3SKU (ORCPT ); Tue, 30 May 2023 14:10:20 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 10F26A1; Tue, 30 May 2023 11:10:17 -0700 (PDT) Received: from W11-BEAU-MD.localdomain (unknown [76.135.27.212]) by linux.microsoft.com (Postfix) with ESMTPSA id 5104620FC3D5; Tue, 30 May 2023 11:10:16 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 5104620FC3D5 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1685470216; bh=BAU3e+yvd1iAQiR6QyNHK9pkl071iekAm5ZOtk3PffY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QOC2gH2MYjzTCleG+SWvBrdiBFRYBw9fdbIEfXxzhV9tySwPMOdSAXpYy04r5ytlD nfLhBwgf/8spsDleloffYuV8Xg2H10cZYYGJX3xNyzrNkvyUQ1KP28cOY2e/K7Igp+ w9GTh5A+/cF67UFNogFGDlxV1FPdVQCxBPYzAXlM= Date: Tue, 30 May 2023 11:10:11 -0700 From: Beau Belgrave To: Masami Hiramatsu Cc: sunliming , rostedt@goodmis.org, 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: <20230530181011.GA225@W11-BEAU-MD.localdomain> References: <20230529032100.286534-1-sunliming@kylinos.cn> <20230529182319.5b3dff8afcf50922eb46099f@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230529182319.5b3dff8afcf50922eb46099f@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Mon, May 29, 2023 at 06:23:19PM +0900, Masami Hiramatsu wrote: > 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, > This also looks good to me, thank you for your patch! Acked-by: Beau Belgrave Thanks, -Beau > > --- > > 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)