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Commit c4cff064 authored by Tom Zanussi's avatar Tom Zanussi Committed by Ingo Molnar
Browse files

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: default avatarTom 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: default avatarIngo Molnar <mingo@elte.hu>
parent ee6cdabc

kernel/trace/trace_events.c

+1 −0
Original line number Diff line number Diff line
@@ -585,6 +585,7 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt, 
	}



	if (filter_add_subsystem_pred(system, pred)) {

		filter_free_subsystem_preds(system);

		filter_free_pred(pred);

		return -EINVAL;

	}

kernel/trace/trace_events_filter.c

+24 −7
Original line number Diff line number Diff line
@@ -318,22 +318,39 @@ int filter_add_subsystem_pred(struct event_subsystem *system, 
			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)) {

		if (strcmp(call->system, system->name))

			continue;



		if (!find_event_field(call, pred->field_name))

			continue;



		event_pred = copy_pred(pred);

			if (event_pred)

				filter_add_pred(call, event_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)