Merge tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "A few updates and fixes:

   - move the suppressing of the __builtin_return_address >0 warning to
     the tracing directory only.

   - metag recordmcount fix for newer glibc's

   - two tracing histogram fixes that were reported by KASAN"

* tag 'trace-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix use-after-free in hist_register_trigger()
  tracing: Fix use-after-free in hist_unreg_all/hist_enable_unreg_all
  Makefile: Mute warning for __builtin_return_address(>0) for tracing only
  ftrace/recordmcount: Work around for addition of metag magic but not relocations

2 files changed, 11 insertions, 7 deletions

diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 979e7bfbde7a..d0a1617b52b4 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -1,4 +1,8 @@
 
+# We are fully aware of the dangers of __builtin_return_address()
+FRAME_CFLAGS := $(call cc-disable-warning,frame-address)
+KBUILD_CFLAGS += $(FRAME_CFLAGS)
+
 # Do not instrument the tracer itself:
 
 ifdef CONFIG_FUNCTION_TRACER
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 0c05b8a99806..f3a960ed75a1 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1441,6 +1441,9 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
                 goto out;
         }
 
+        if (hist_data->attrs->pause)
+                data->paused = true;
+
         if (named_data) {
                 destroy_hist_data(data->private_data);
                 data->private_data = named_data->private_data;
@@ -1448,9 +1451,6 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
                 data->ops = &event_hist_trigger_named_ops;
         }
 
-        if (hist_data->attrs->pause)
-                data->paused = true;
-
         if (data->ops->init) {
                 ret = data->ops->init(data->ops, data);
                 if (ret < 0)
@@ -1500,9 +1500,9 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
 
 static void hist_unreg_all(struct trace_event_file *file)
 {
-        struct event_trigger_data *test;
+        struct event_trigger_data *test, *n;
 
-        list_for_each_entry_rcu(test, &file->triggers, list) {
+        list_for_each_entry_safe(test, n, &file->triggers, list) {
                 if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
                         list_del_rcu(&test->list);
                         trace_event_trigger_enable_disable(file, 0);
@@ -1699,9 +1699,9 @@ hist_enable_get_trigger_ops(char *cmd, char *param)
 
 static void hist_enable_unreg_all(struct trace_event_file *file)
 {
-        struct event_trigger_data *test;
+        struct event_trigger_data *test, *n;
 
-        list_for_each_entry_rcu(test, &file->triggers, list) {
+        list_for_each_entry_safe(test, n, &file->triggers, list) {
                 if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
                         list_del_rcu(&test->list);
                         update_cond_flag(file);