[PATCH v6 4/7] tracing/probes: Allow for dot delimiter as well as slash for system names

Steven Rostedt
2021-08-17T03:50:41Z

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

Kprobe and uprobe events can add a "system" to the events that are created
via the kprobe_events and uprobe_events files respectively. If they do not
include a "system" in the name, then the default "kprobes" or "uprobes" is
used. The current notation to specify a system for one of these probe
events is to add a '/' delimiter in the name, where the content before the
'/' will be the system to use, and the content after will be the event
name.

echo 'p:my_system/my_event' > kprobe_events

But this is inconsistent with the way histogram triggers separate their
system / event names. The histogram triggers use a '.' delimiter, which
can be confusing.

To allow this to be more consistent, as well as keep backward
compatibility, allow the kprobe and uprobe events to denote a system name
with either a '/' or a '.'.

That is:

echo 'p:my_system/my_event' > kprobe_events

is equivalent to:

echo 'p:my_system.my_event' > kprobe_events

Link: https://lore.kernel.org/linux-trace-devel/20210813004448.51c7de69ce432d338f4d226b@kernel.org/

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace_probe.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index ef717b373443..0916a9964719 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -233,6 +233,9 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
int len;

slash = strchr(event, '/');
+ if (!slash)
+ slash = strchr(event, '.');
+
if (slash) {
if (slash == event) {
trace_probe_log_err(offset, NO_GROUP_NAME);
--
2.30.2