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tracing/filters: clean up filter_add_subsystem_pred()

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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>
This commit is contained in:
Tom Zanussi
2009-03-23 03:26:48 -05:00
committed by Ingo Molnar
parent ee6cdabc82
commit c4cff064be
2 changed files with 25 additions and 7 deletions
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1
kernel/trace/trace_events.c
View File

@@ -585,6 +585,7 @@ subsystem_filter_write(struct file *filp, const char __user *ubuf, size_t cnt,
} }
if (filter_add_subsystem_pred(system, pred)) { if (filter_add_subsystem_pred(system, pred)) {
filter_free_subsystem_preds(system);
filter_free_pred(pred); filter_free_pred(pred);
return -EINVAL; return -EINVAL;
} }

29
kernel/trace/trace_events_filter.c
View File

@@ -318,22 +318,39 @@ int filter_add_subsystem_pred(struct event_subsystem *system,
system->preds[i] = pred; system->preds[i] = pred;
break; break;
} }
if (i == MAX_FILTER_PRED - 1)
return -EINVAL;
} }
if (i == MAX_FILTER_PRED)
return -EINVAL;
events_for_each(call) { events_for_each(call) {
int err;
if (!call->name || !call->regfunc) if (!call->name || !call->regfunc)
continue; 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); event_pred = copy_pred(pred);
if (event_pred) if (!event_pred)
filter_add_pred(call, 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; return 0;
oom:
system->preds[i] = NULL;
return -ENOMEM;
} }
int filter_parse(char **pbuf, struct filter_pred *pred) int filter_parse(char **pbuf, struct filter_pred *pred)