Merge branch 'tracing/urgent' into tracing/core
[linux-2.6.git] / kernel / trace / trace_events.c
index 8c91b7c8f04731e488bb1131538d378176c8d1bf..5e9ffc33f6db7b0e0d992b2de0ce52f380c33476 100644 (file)
@@ -232,10 +232,9 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
                   size_t cnt, loff_t *ppos)
 {
        struct trace_parser parser;
-       size_t read = 0;
-       ssize_t ret;
+       ssize_t read, ret;
 
-       if (!cnt || cnt < 0)
+       if (!cnt)
                return 0;
 
        ret = tracing_update_buffers();
@@ -247,7 +246,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 
        read = trace_get_user(&parser, ubuf, cnt, ppos);
 
-       if (trace_parser_loaded((&parser))) {
+       if (read >= 0 && trace_parser_loaded((&parser))) {
                int set = 1;
 
                if (*parser.buffer == '!')
@@ -271,42 +270,32 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct list_head *list = m->private;
-       struct ftrace_event_call *call;
+       struct ftrace_event_call *call = v;
 
        (*pos)++;
 
-       for (;;) {
-               if (list == &ftrace_events)
-                       return NULL;
-
-               call = list_entry(list, struct ftrace_event_call, list);
-
+       list_for_each_entry_continue(call, &ftrace_events, list) {
                /*
                 * The ftrace subsystem is for showing formats only.
                 * They can not be enabled or disabled via the event files.
                 */
                if (call->regfunc)
-                       break;
-
-               list = list->next;
+                       return call;
        }
 
-       m->private = list->next;
-
-       return call;
+       return NULL;
 }
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
-       struct ftrace_event_call *call = NULL;
+       struct ftrace_event_call *call;
        loff_t l;
 
        mutex_lock(&event_mutex);
 
-       m->private = ftrace_events.next;
+       call = list_entry(&ftrace_events, struct ftrace_event_call, list);
        for (l = 0; l <= *pos; ) {
-               call = t_next(m, NULL, &l);
+               call = t_next(m, call, &l);
                if (!call)
                        break;
        }
@@ -316,37 +305,28 @@ static void *t_start(struct seq_file *m, loff_t *pos)
 static void *
 s_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct list_head *list = m->private;
-       struct ftrace_event_call *call;
+       struct ftrace_event_call *call = v;
 
        (*pos)++;
 
- retry:
-       if (list == &ftrace_events)
-               return NULL;
-
-       call = list_entry(list, struct ftrace_event_call, list);
-
-       if (!call->enabled) {
-               list = list->next;
-               goto retry;
+       list_for_each_entry_continue(call, &ftrace_events, list) {
+               if (call->enabled)
+                       return call;
        }
 
-       m->private = list->next;
-
-       return call;
+       return NULL;
 }
 
 static void *s_start(struct seq_file *m, loff_t *pos)
 {
-       struct ftrace_event_call *call = NULL;
+       struct ftrace_event_call *call;
        loff_t l;
 
        mutex_lock(&event_mutex);
 
-       m->private = ftrace_events.next;
+       call = list_entry(&ftrace_events, struct ftrace_event_call, list);
        for (l = 0; l <= *pos; ) {
-               call = s_next(m, NULL, &l);
+               call = s_next(m, call, &l);
                if (!call)
                        break;
        }