From: Tom Zanussi <tom.zanussi@linux.intel.com>
Date: Thu, 26 Apr 2018 20:04:48 -0500
Subject: tracing: Add field parsing hist error for hist triggers
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git
Git-commit: 9c026feb8878f82709ec494f34b523c41bfdc12a
Patch-mainline: Queued in subsystem maintainer repository
References: SLE Realtime Extension
[ commit 5ec432d7bf9dd3b4a2b84f8974e3adb71f45fb1d ]
If the user specifies a nonexistent field for a hist trigger, the
current code correctly flags that as an error, but doesn't tell the
user what happened.
Fix this by invoking hist_err() with an appropriate message when
nonexistent fields are specified.
Before:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
-su: echo: write error: Invalid argument
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
After:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
-su: echo: write error: Invalid argument
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
ERROR: Couldn't find field: pid
Last command: keys=pid:ts0=common_timestamp.usecs
Link: http://lkml.kernel.org/r/fdc8746969d16906120f162b99dd71c741e0b62c.1524790601.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
---
kernel/trace/trace_events_hist.c | 1 +
1 file changed, 1 insertion(+)
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2481,6 +2481,7 @@ parse_field(struct hist_trigger_data *hi
else {
field = trace_find_event_field(file->event_call, field_name);
if (!field || !field->size) {
+ hist_err("Couldn't find field: ", field_name);
field = ERR_PTR(-EINVAL);
goto out;
}