Merge tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Oleg Nesterov has been working hard in closing all the holes that can
  lead to race conditions between deleting an event and accessing an
  event debugfs file.  This included a fix to the debugfs system (acked
  by Greg Kroah-Hartman).  We think that all the holes have been patched
  and hopefully we don't find more.  I haven't marked all of them for
  stable because I need to examine them more to figure out how far back
  some of the changes need to go.

  Along the way, some other fixes have been made.  Alexander Z Lam fixed
  some logic where the wrong buffer was being modifed.

  Andrew Vagin found a possible corruption for machines that actually
  allocate cpumask, as a reference to one was being zeroed out by
  mistake.

  Dhaval Giani found a bad prototype when tracing is not configured.

  And I not only had some changes to help Oleg, but also finally fixed a
  long standing bug that Dave Jones and others have been hitting, where
  a module unload and reload can cause the function tracing accounting
  to get screwed up"

* tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix reset of time stamps during trace_clock changes
  tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer
  tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set
  tracing: Fix fields of struct trace_iterator that are zeroed by mistake
  tracing/uprobes: Fail to unregister if probe event files are in use
  tracing/kprobes: Fail to unregister if probe event files are in use
  tracing: Add comment to describe special break case in probe_remove_event_call()
  tracing: trace_remove_event_call() should fail if call/file is in use
  debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)
  ftrace: Check module functions being traced on reload
  ftrace: Consolidate some duplicate code for updating ftrace ops
  tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private
  tracing: Introduce remove_event_file_dir()
  tracing: Change f_start() to take event_mutex and verify i_private != NULL
  tracing: Change event_filter_read/write to verify i_private != NULL
  tracing: Change event_enable/disable_read() to verify i_private != NULL
  tracing: Turn event/id->i_private into call->event.type

1 files changed, 14 insertions, 13 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 882ec1dd151..496f94d5769 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -243,20 +243,25 @@ int filter_current_check_discard(struct ring_buffer *buffer,
 }
 EXPORT_SYMBOL_GPL(filter_current_check_discard);
 
-cycle_t ftrace_now(int cpu)
+cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu)
 {
 	u64 ts;
 
 	/* Early boot up does not have a buffer yet */
-	if (!global_trace.trace_buffer.buffer)
+	if (!buf->buffer)
 		return trace_clock_local();
 
-	ts = ring_buffer_time_stamp(global_trace.trace_buffer.buffer, cpu);
-	ring_buffer_normalize_time_stamp(global_trace.trace_buffer.buffer, cpu, &ts);
+	ts = ring_buffer_time_stamp(buf->buffer, cpu);
+	ring_buffer_normalize_time_stamp(buf->buffer, cpu, &ts);
 
 	return ts;
 }
 
+cycle_t ftrace_now(int cpu)
+{
+	return buffer_ftrace_now(&global_trace.trace_buffer, cpu);
+}
+
 /**
  * tracing_is_enabled - Show if global_trace has been disabled
  *
@@ -1211,7 +1216,7 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
 	/* Make sure all commits have finished */
 	synchronize_sched();
 
-	buf->time_start = ftrace_now(buf->cpu);
+	buf->time_start = buffer_ftrace_now(buf, buf->cpu);
 
 	for_each_online_cpu(cpu)
 		ring_buffer_reset_cpu(buffer, cpu);
@@ -1219,11 +1224,6 @@ void tracing_reset_online_cpus(struct trace_buffer *buf)
 	ring_buffer_record_enable(buffer);
 }
 
-void tracing_reset_current(int cpu)
-{
-	tracing_reset(&global_trace.trace_buffer, cpu);
-}
-
 /* Must have trace_types_lock held */
 void tracing_reset_all_online_cpus(void)
 {
@@ -4151,6 +4151,7 @@ waitagain:
 	memset(&iter->seq, 0,
 	       sizeof(struct trace_iterator) -
 	       offsetof(struct trace_iterator, seq));
+	cpumask_clear(iter->started);
 	iter->pos = -1;
 
 	trace_event_read_lock();
@@ -4468,7 +4469,7 @@ tracing_free_buffer_release(struct inode *inode, struct file *filp)
 
 	/* disable tracing ? */
 	if (trace_flags & TRACE_ITER_STOP_ON_FREE)
-		tracing_off();
+		tracer_tracing_off(tr);
 	/* resize the ring buffer to 0 */
 	tracing_resize_ring_buffer(tr, 0, RING_BUFFER_ALL_CPUS);
 
@@ -4633,12 +4634,12 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf,
 	 * New clock may not be consistent with the previous clock.
 	 * Reset the buffer so that it doesn't have incomparable timestamps.
 	 */
-	tracing_reset_online_cpus(&global_trace.trace_buffer);
+	tracing_reset_online_cpus(&tr->trace_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
 	if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
 		ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
-	tracing_reset_online_cpus(&global_trace.max_buffer);
+	tracing_reset_online_cpus(&tr->max_buffer);
 #endif
 
 	mutex_unlock(&trace_types_lock);