[51/54] tracing: Add field modifier parsing hist error for hist triggers
diff mbox series

Message ID TY1PR01MB1692F0B83268006EB0CEB7FE96090@TY1PR01MB1692.jpnprd01.prod.outlook.com
State New
Headers show
Series
  • Untitled series #12773
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Commit Message

Motai.Hirotaka@aj.MitsubishiElectric.co.jp Aug. 29, 2018, 12:17 p.m. UTC
If the user specifies an invalid field modifier 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
invalid modifiers are specified.

Before:

  # echo 'hist:keys=pid:ts0=common_timestamp.junkusecs' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
  -su: echo: write error: Invalid argument
  # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist

After:

  # echo 'hist:keys=pid:ts0=common_timestamp.junkusecs' >> /sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
  -su: echo: write error: Invalid argument
  # cat /sys/kernel/debug/tracing/events/sched/sched_wakeup/hist
  ERROR: Invalid field modifier: junkusecs
    Last command: keys=pid:ts0=common_timestamp.junkusecs

Link: http://lkml.kernel.org/r/b043c59fa79acd06a5f14a1d44dee9e5a3cd1248.1524790601.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit dcf234577cd31fa16874e828b90659166ad6b80d)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
---
 kernel/trace/trace_events_hist.c | 1 +
 1 file changed, 1 insertion(+)

Patch
diff mbox series

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index f231fa2a..b9061ed5 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2461,16 +2461,17 @@  parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
 			*flags |= HIST_FIELD_FL_EXECNAME;
 		else if (strcmp(modifier, "syscall") == 0)
 			*flags |= HIST_FIELD_FL_SYSCALL;
 		else if (strcmp(modifier, "log2") == 0)
 			*flags |= HIST_FIELD_FL_LOG2;
 		else if (strcmp(modifier, "usecs") == 0)
 			*flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
 		else {
+			hist_err("Invalid field modifier: ", modifier);
 			field = ERR_PTR(-EINVAL);
 			goto out;
 		}
 	}
 
 	if (strcmp(field_name, "common_timestamp") == 0) {
 		*flags |= HIST_FIELD_FL_TIMESTAMP;
 		hist_data->enable_timestamps = true;