[PATCH v2 3/4] tracing: Check that number of vals matches number of synth event fields

From: Tom Zanussi
Date: Fri Feb 14 2020 - 17:57:05 EST


Commit 7276531d4036('tracing: Consolidate trace() functions')
inadvertently dropped the synth_event_trace() and
synth_event_trace_array() checks that verify the number of values
passed in matches the number of fields in the synthetic event being
traced, so add them back.

Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/trace/trace_events_hist.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 913760d2d505..95d4c871f87b 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1885,6 +1885,11 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
return ret;
}

+ if (n_vals != state.event->n_fields) {
+ ret = -EINVAL;
+ goto out;
+ }
+
va_start(args, n_vals);
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
u64 val;
@@ -1921,7 +1926,7 @@ int synth_event_trace(struct trace_event_file *file, unsigned int n_vals, ...)
}
}
va_end(args);
-
+out:
__synth_event_trace_end(&state);

return ret;
@@ -1960,6 +1965,11 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
return ret;
}

+ if (n_vals != state.event->n_fields) {
+ ret = -EINVAL;
+ goto out;
+ }
+
for (i = 0, n_u64 = 0; i < state.event->n_fields; i++) {
if (state.event->fields[i]->is_string) {
char *str_val = (char *)(long)vals[i];
@@ -1991,7 +2001,7 @@ int synth_event_trace_array(struct trace_event_file *file, u64 *vals,
n_u64++;
}
}
-
+out:
__synth_event_trace_end(&state);

return ret;
--
2.14.1