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Diffstat (limited to 'kernel/trace/trace_events.c')
-rw-r--r--kernel/trace/trace_events.c43
1 files changed, 28 insertions, 15 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f8af4a15c3a8..0a7348b90ba5 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -969,26 +969,38 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
}
}
-static void remove_event_file_dir(struct trace_event_file *file)
+void event_file_get(struct trace_event_file *file)
{
- struct dentry *dir = file->dir;
- struct dentry *child;
+ atomic_inc(&file->ref);
+}
- if (dir) {
- spin_lock(&dir->d_lock); /* probably unneeded */
- list_for_each_entry(child, &dir->d_subdirs, d_child) {
- if (d_really_is_positive(child)) /* probably unneeded */
- d_inode(child)->i_private = NULL;
- }
- spin_unlock(&dir->d_lock);
+void event_file_put(struct trace_event_file *file)
+{
+ if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
+ if (file->flags & EVENT_FILE_FL_FREED)
+ kmem_cache_free(file_cachep, file);
+ return;
+ }
- tracefs_remove(dir);
+ if (atomic_dec_and_test(&file->ref)) {
+ /* Count should only go to zero when it is freed */
+ if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
+ return;
+ kmem_cache_free(file_cachep, file);
}
+}
+
+static void remove_event_file_dir(struct trace_event_file *file)
+{
+ struct dentry *dir = file->dir;
+
+ tracefs_remove(dir);
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
- kmem_cache_free(file_cachep, file);
+ file->flags |= EVENT_FILE_FL_FREED;
+ event_file_put(file);
}
/*
@@ -1361,7 +1373,7 @@ event_enable_read(struct file *filp, char __user *ubuf, size_t cnt,
flags = file->flags;
mutex_unlock(&event_mutex);
- if (!file)
+ if (!file || flags & EVENT_FILE_FL_FREED)
return -ENODEV;
if (flags & EVENT_FILE_FL_ENABLED &&
@@ -1399,7 +1411,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt,
ret = -ENODEV;
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (likely(file))
+ if (likely(file && !(file->flags & EVENT_FILE_FL_FREED)))
ret = ftrace_event_enable_disable(file, val);
mutex_unlock(&event_mutex);
break;
@@ -1668,7 +1680,7 @@ event_filter_read(struct file *filp, char __user *ubuf, size_t cnt,
mutex_lock(&event_mutex);
file = event_file_data(filp);
- if (file)
+ if (file && !(file->flags & EVENT_FILE_FL_FREED))
print_event_filter(file, s);
mutex_unlock(&event_mutex);
@@ -2784,6 +2796,7 @@ trace_create_new_event(struct trace_event_call *call,
atomic_set(&file->tm_ref, 0);
INIT_LIST_HEAD(&file->triggers);
list_add(&file->list, &tr->events);
+ event_file_get(file);
return file;
}