From: Steven Rostedt <rostedt@goodmis.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-kernel@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Tzvetomir Stoyanov" <tz.stoyanov@gmail.com>,
Tom Zanussi <zanussi@kernel.org>,
linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH v6 7/7] tracing: Add a probe that attaches to trace events
Date: Thu, 19 Aug 2021 00:10:05 -0400 [thread overview]
Message-ID: <20210819001005.712e542a@oasis.local.home> (raw)
In-Reply-To: <20210819000342.615e68c7@oasis.local.home>
On Thu, 19 Aug 2021 00:03:42 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> Probably. I noticed that it was updated under the dyn_event_ops_mutex,
> and thought that was enough protection. But I now see the lockdep
> assert on the event_mutex in the other functions.
Anyway, here's the new version:
static bool find_event_probe(const char *group, const char *event)
{
struct trace_eprobe *ep;
struct dyn_event *ev;
bool ret = false;
/*
* Must grab the event_mutex to prevent the list from being modified
* by other probes. But the event_probe being only created via the
* dynamic_events file, is only added under the dyn_event_ops_mutex,
* which is currently held. There is no race between this check and
* adding the new probe.
*/
mutex_lock(&event_mutex);
for_each_dyn_event(ev) {
if (ev->ops != &eprobe_dyn_event_ops)
continue;
ep = to_trace_eprobe(ev);
if (strcmp(ep->tp.event->class.system, group) == 0 &&
strcmp(ep->tp.event->call.name, event) == 0) {
ret = true;
break;
}
}
mutex_lock(&event_mutex);
return ret;
}
-- Steve
next prev parent reply other threads:[~2021-08-19 4:10 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-17 3:42 [PATCH v6 0/7] tracing: Creation of event probe Steven Rostedt
2021-08-17 3:42 ` [PATCH v6 1/7] tracing: Add DYNAMIC flag for dynamic events Steven Rostedt
2021-08-18 8:15 ` Masami Hiramatsu
2021-08-17 3:42 ` [PATCH v6 2/7] tracing: Have dynamic events have a ref counter Steven Rostedt
2021-08-18 16:14 ` Masami Hiramatsu
2021-08-17 3:42 ` [PATCH v6 3/7] tracing/probe: Have traceprobe_parse_probe_arg() take a const arg Steven Rostedt
2021-08-18 16:16 ` Masami Hiramatsu
2021-08-17 3:42 ` [PATCH v6 4/7] tracing/probes: Allow for dot delimiter as well as slash for system names Steven Rostedt
2021-08-18 10:57 ` Masami Hiramatsu
2021-08-17 3:43 ` [PATCH v6 5/7] tracing/probes: Use struct_size() instead of defining custom macros Steven Rostedt
2021-08-18 11:08 ` Masami Hiramatsu
2021-08-17 3:43 ` [PATCH v6 6/7] tracing/probe: Change traceprobe_set_print_fmt() to take a type Steven Rostedt
2021-08-18 16:19 ` Masami Hiramatsu
2021-08-17 3:43 ` [PATCH v6 7/7] tracing: Add a probe that attaches to trace events Steven Rostedt
2021-08-19 2:29 ` Masami Hiramatsu
2021-08-19 3:37 ` Steven Rostedt
2021-08-19 3:56 ` Masami Hiramatsu
2021-08-19 4:03 ` Steven Rostedt
2021-08-19 4:10 ` Steven Rostedt [this message]
2021-08-19 4:28 ` Masami Hiramatsu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210819001005.712e542a@oasis.local.home \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-devel@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=tz.stoyanov@gmail.com \
--cc=zanussi@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).