From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754927Ab3EIObs (ORCPT ); Thu, 9 May 2013 10:31:48 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:11972 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751222Ab3EIObr (ORCPT ); Thu, 9 May 2013 10:31:47 -0400 X-Authority-Analysis: v=2.0 cv=DKcNElxb c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=OF0BmyLs-1YA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=meVymXHHAAAA:8 a=Kfn0_i_Y4z8A:10 a=3nbZYyFuAAAA:8 a=pGLkceISAAAA:8 a=20KFwNOVAAAA:8 a=QyXUC8HyAAAA:8 a=0P8YjRj644Lh5uG7nk8A:9 a=QEXdDO2ut3YA:10 a=EvKJbDF4Ut8A:10 a=jeBq3FmKZ4MA:10 a=MSl-tDqOz04A:10 a=jEp0ucaQiEUA:10 a=dGJ0OcVc7YAA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 74.67.115.198 Message-ID: <1368109905.7373.99.camel@gandalf.local.home> Subject: Re: [PATCH 01/11] [BUGFIX] tracing: Return 0 if event_enable_func succeeded From: Steven Rostedt To: Masami Hiramatsu Cc: linux-kernel@vger.kernel.org, Srikar Dronamraju , Frederic Weisbecker , yrl.pp-manager.tt@hitachi.com, Oleg Nesterov , Ingo Molnar , Tom Zanussi Date: Thu, 09 May 2013 10:31:45 -0400 In-Reply-To: <20130509054413.30398.55650.stgit@mhiramat-M0-7522> References: <20130509054405.30398.73831.stgit@mhiramat-M0-7522> <20130509054413.30398.55650.stgit@mhiramat-M0-7522> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4-2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2013-05-09 at 14:44 +0900, Masami Hiramatsu wrote: > Return 0 instead of the number of activated ftrace if > event_enable_func succeeded and return an error code if failed, > beacuse 0 is success code at caller (ftrace_regex_write). > > Without this fix, writing enable_event trigger on set_ftrace_filter > always doesn't work, since event_enable_func returns 1 to > ftrace_regex_write, it consumes 1 byte and pass input string > without the first character again. This makes event_enable_func > fail and disables event entry. > > Signed-off-by: Masami Hiramatsu > Cc: Steven Rostedt > Cc: Frederic Weisbecker > Cc: Ingo Molnar > Cc: Tom Zanussi > --- > kernel/trace/trace_events.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 53582e9..44ac836 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -2061,8 +2061,11 @@ event_enable_func(struct ftrace_hash *hash, > if (ret < 0) > goto out_put; > ret = register_ftrace_function_probe(glob, ops, data); > - if (!ret) > + if (!ret) { > + ret = -ENOENT; > goto out_disable; > + } else > + ret = 0; I think you meant: if (ret < 0) goto out_disable; ret = 0; Otherwise, I don't see how you fixed anything, as you still return error if ret is something other than zero. Or am I missing something? -- Steve > out: > mutex_unlock(&event_mutex); > return ret;