[PATCH 5/6] tracing: Add field parsing trace event errors for hist triggers

Tom Zanussi
2018-04-12T15:15:22Z

Log errors to the tracing/events/error_log for nonexistent fields and
modifiers specified in hist triggers.

Also screen out variable references, which shouldn't be looked up as
fields.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
---
kernel/trace/trace_events_hist.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 08424ff..d223fd6 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2461,6 +2461,7 @@ static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
else if (strcmp(modifier, "usecs") == 0)
*flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
else {
+ log_err("Invalid field modifier: %s", modifier);
field = ERR_PTR(-EINVAL);
goto out;
}
@@ -2476,6 +2477,7 @@ static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
else {
field = trace_find_event_field(file->event_call, field_name);
if (!field || !field->size) {
+ log_err("Couldn't find field: %s", field_name);
field = ERR_PTR(-EINVAL);
goto out;
}
@@ -2553,6 +2555,11 @@ static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
} else
str = s;

+ if (is_var_ref(str)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
field = parse_field(hist_data, file, str, flags);
if (IS_ERR(field)) {
ret = PTR_ERR(field);
--
1.9.3