tracing/filters: clean up filter_add_subsystem_pred()
Impact: cleanup, memory leak fix
This patch cleans up filter_add_subsystem_pred():
- searches for the field before creating a copy of the pred
- fixes memory leak in the case a predicate isn't applied
- if -ENOMEM, makes sure there's no longer a reference to the
pred so the caller can free the half-finished filter
- changes the confusing i == MAX_FILTER_PRED - 1 comparison
previously remarked upon
This affects only per-subsystem event filtering.
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: =?ISO-8859-1?Q?Fr=E9d=E9ric?= Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1237796808.7527.40.camel@charm-linux>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 19f61dd..fdab30d 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -585,6 +585,7 @@
}
if (filter_add_subsystem_pred(system, pred)) {
+ filter_free_subsystem_preds(system);
filter_free_pred(pred);
return -EINVAL;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index fd01d80..4117c2e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -318,22 +318,39 @@
system->preds[i] = pred;
break;
}
- if (i == MAX_FILTER_PRED - 1)
- return -EINVAL;
}
+ if (i == MAX_FILTER_PRED)
+ return -EINVAL;
+
events_for_each(call) {
+ int err;
+
if (!call->name || !call->regfunc)
continue;
- if (!strcmp(call->system, system->name)) {
- event_pred = copy_pred(pred);
- if (event_pred)
- filter_add_pred(call, event_pred);
- }
+ if (strcmp(call->system, system->name))
+ continue;
+
+ if (!find_event_field(call, pred->field_name))
+ continue;
+
+ event_pred = copy_pred(pred);
+ if (!event_pred)
+ goto oom;
+
+ err = filter_add_pred(call, event_pred);
+ if (err)
+ filter_free_pred(event_pred);
+ if (err == -ENOMEM)
+ goto oom;
}
return 0;
+
+oom:
+ system->preds[i] = NULL;
+ return -ENOMEM;
}
int filter_parse(char **pbuf, struct filter_pred *pred)