tracing: Fix parse_synth_field() error handling
synth_field_size() returns either a positive size or an error (zero or
a negative value). However, the existing code assumes the only error
value is 0. It doesn't handle negative error codes, as it assigns
directly to field->size (a size_t; unsigned), thereby interpreting the
error code as a valid size instead.
Do the test before assignment to field->size.
[ axelrasmussen@google.com: changelog addition, first paragraph above ]
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index a9cd779..fa8a998 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -465,6 +465,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
struct synth_field *field;
const char *prefix = NULL, *field_type = argv[0], *field_name, *array;
int len, ret = 0;
+ ssize_t size;
if (field_type[0] == ';')
field_type++;
@@ -520,11 +521,12 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
field->type[len - 1] = '\0';
}
- field->size = synth_field_size(field->type);
- if (!field->size) {
+ size = synth_field_size(field->type);
+ if (size <= 0) {
ret = -EINVAL;
goto free;
}
+ field->size = size;
if (synth_field_is_string(field->type))
field->is_string = true;
