tracing: add per-subsystem filtering

[safe/jmp/linux-2.6] / kernel / trace / trace_events_filter.c

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 8e8c5fa..1ab20ce 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -181,6 +181,27 @@ void filter_free_preds(struct ftrace_event_call *call)
        }
 }
 
+void filter_free_subsystem_preds(struct event_subsystem *system)
+{
+       struct ftrace_event_call *call = __start_ftrace_events;
+       int i;
+
+       if (system->preds) {
+               for (i = 0; i < MAX_FILTER_PRED; i++)
+                       filter_free_pred(system->preds[i]);
+               kfree(system->preds);
+               system->preds = NULL;
+       }
+
+       events_for_each(call) {
+               if (!call->name || !call->regfunc)
+                       continue;
+
+               if (!strcmp(call->system, system->name))
+                       filter_free_preds(call);
+       }
+}
+
 static int __filter_add_pred(struct ftrace_event_call *call,
                             struct filter_pred *pred)
 {
@@ -250,6 +271,65 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
        return __filter_add_pred(call, pred);
 }
 
+static struct filter_pred *copy_pred(struct filter_pred *pred)
+{
+       struct filter_pred *new_pred = kmalloc(sizeof(*pred), GFP_KERNEL);
+       if (!new_pred)
+               return NULL;
+
+       memcpy(new_pred, pred, sizeof(*pred));
+       if (pred->str_val) {
+               new_pred->str_val = kstrdup(pred->str_val, GFP_KERNEL);
+               new_pred->field_name = kstrdup(pred->field_name, GFP_KERNEL);
+               if (!new_pred->str_val) {
+                       kfree(new_pred);
+                       return NULL;
+               }
+       }
+
+       return new_pred;
+}
+
+int filter_add_subsystem_pred(struct event_subsystem *system,
+                             struct filter_pred *pred)
+{
+       struct ftrace_event_call *call = __start_ftrace_events;
+       struct filter_pred *event_pred;
+       int i;
+
+       if (system->preds && !pred->compound)
+               filter_free_subsystem_preds(system);
+
+       if (!system->preds) {
+               system->preds = kzalloc(MAX_FILTER_PRED * sizeof(pred),
+                                       GFP_KERNEL);
+               if (!system->preds)
+                       return -ENOMEM;
+       }
+
+       for (i = 0; i < MAX_FILTER_PRED; i++) {
+               if (!system->preds[i]) {
+                       system->preds[i] = pred;
+                       break;
+               }
+               if (i == MAX_FILTER_PRED - 1)
+                       return -EINVAL;
+       }
+
+       events_for_each(call) {
+               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);
+               }
+       }
+
+       return 0;
+}
+
 int filter_parse(char **pbuf, struct filter_pred *pred)
 {
        char *tmp, *tok, *val_str = NULL;