diff options
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 3bcb9df93342..19332200c457 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -345,11 +345,59 @@ static struct dentry *event_trace_events_dir(void) return d_events; } +struct event_subsystem { + struct list_head list; + const char *name; + struct dentry *entry; +}; + +static LIST_HEAD(event_subsystems); + +static struct dentry * +event_subsystem_dir(const char *name, struct dentry *d_events) +{ + struct event_subsystem *system; + + /* First see if we did not already create this dir */ + list_for_each_entry(system, &event_subsystems, list) { + if (strcmp(system->name, name) == 0) + return system->entry; + } + + /* need to create new entry */ + system = kmalloc(sizeof(*system), GFP_KERNEL); + if (!system) { + pr_warning("No memory to create event subsystem %s\n", + name); + return d_events; + } + + system->entry = debugfs_create_dir(name, d_events); + if (!system->entry) { + pr_warning("Could not create event subsystem %s\n", + name); + kfree(system); + return d_events; + } + + system->name = name; + list_add(&system->list, &event_subsystems); + + return system->entry; +} + static int event_create_dir(struct ftrace_event_call *call, struct dentry *d_events) { struct dentry *entry; + /* + * If the trace point header did not define TRACE_SYSTEM + * then the system would be called "TRACE_SYSTEM". + */ + if (strcmp(call->system, "TRACE_SYSTEM") != 0) + d_events = event_subsystem_dir(call->system, d_events); + call->dir = debugfs_create_dir(call->name, d_events); if (!call->dir) { pr_warning("Could not create debugfs " |