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-rw-r--r--include/linux/perf_event.h2
-rw-r--r--kernel/events/core.c42
2 files changed, 30 insertions, 14 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 5c58e93c130c..000fdb211c7d 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -482,6 +482,7 @@ struct perf_addr_filter {
* @list: list of filters for this event
* @lock: spinlock that serializes accesses to the @list and event's
* (and its children's) filter generations.
+ * @nr_file_filters: number of file-based filters
*
* A child event will use parent's @list (and therefore @lock), so they are
* bundled together; see perf_event_addr_filters().
@@ -489,6 +490,7 @@ struct perf_addr_filter {
struct perf_addr_filters_head {
struct list_head list;
raw_spinlock_t lock;
+ unsigned int nr_file_filters;
};
/**
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1730995c31ec..a8664247b3e4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8090,6 +8090,9 @@ static void perf_event_addr_filters_apply(struct perf_event *event)
if (task == TASK_TOMBSTONE)
return;
+ if (!ifh->nr_file_filters)
+ return;
+
mm = get_task_mm(event->ctx->task);
if (!mm)
goto restart;
@@ -8268,6 +8271,18 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
if (!filename)
goto fail;
+ /*
+ * For now, we only support file-based filters
+ * in per-task events; doing so for CPU-wide
+ * events requires additional context switching
+ * trickery, since same object code will be
+ * mapped at different virtual addresses in
+ * different processes.
+ */
+ ret = -EOPNOTSUPP;
+ if (!event->ctx->task)
+ goto fail_free_name;
+
/* look up the path and grab its inode */
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
@@ -8283,6 +8298,8 @@ perf_event_parse_addr_filter(struct perf_event *event, char *fstr,
!S_ISREG(filter->inode->i_mode))
/* free_filters_list() will iput() */
goto fail;
+
+ event->addr_filters.nr_file_filters++;
}
/* ready to consume more filters */
@@ -8322,24 +8339,13 @@ perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
if (WARN_ON_ONCE(event->parent))
return -EINVAL;
- /*
- * For now, we only support filtering in per-task events; doing so
- * for CPU-wide events requires additional context switching trickery,
- * since same object code will be mapped at different virtual
- * addresses in different processes.
- */
- if (!event->ctx->task)
- return -EOPNOTSUPP;
-
ret = perf_event_parse_addr_filter(event, filter_str, &filters);
if (ret)
- return ret;
+ goto fail_clear_files;
ret = event->pmu->addr_filters_validate(&filters);
- if (ret) {
- free_filters_list(&filters);
- return ret;
- }
+ if (ret)
+ goto fail_free_filters;
/* remove existing filters, if any */
perf_addr_filters_splice(event, &filters);
@@ -8348,6 +8354,14 @@ perf_event_set_addr_filter(struct perf_event *event, char *filter_str)
perf_event_for_each_child(event, perf_event_addr_filters_apply);
return ret;
+
+fail_free_filters:
+ free_filters_list(&filters);
+
+fail_clear_files:
+ event->addr_filters.nr_file_filters = 0;
+
+ return ret;
}
static int perf_event_set_filter(struct perf_event *event, void __user *arg)