4.14.40-rt31-rc1 stable review patch.
If anyone has any objections, please let me know.
------------------
From: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
[ commit dcf234577cd31fa16874e828b90659166ad6b80d ]
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@xxxxxxxxxxxxxxx
Signed-off-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 37db86145c8b..b8fee11b5be9 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2466,6 +2466,7 @@ parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
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;
}
--
2.17.0
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