Merge branch 'trace/ftrace/urgent' into trace/ftrace/core

Needed 099ed151 "tracing: Remove ftrace_stop/start() from
 reading the trace file" for the removal of ftrace_start/stop().

kernel/events/uprobes.c

@@ -846,7 +846,7 @@ static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *u
 {
 	int err;
 
-	if (!consumer_del(uprobe, uc))	/* WARN? */
+	if (WARN_ON(!consumer_del(uprobe, uc)))
 		return;
 
 	err = register_for_each_vma(uprobe, NULL);
@@ -927,7 +927,7 @@ int uprobe_apply(struct inode *inode, loff_t offset,
 	int ret = -ENOENT;
 
 	uprobe = find_uprobe(inode, offset);
-	if (!uprobe)
+	if (WARN_ON(!uprobe))
 		return ret;
 
 	down_write(&uprobe->register_rwsem);
@@ -952,7 +952,7 @@ void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consume
 	struct uprobe *uprobe;
 
 	uprobe = find_uprobe(inode, offset);
-	if (!uprobe)
+	if (WARN_ON(!uprobe))
 		return;
 
 	down_write(&uprobe->register_rwsem);

kernel/trace/trace.c

@@ -1372,7 +1372,6 @@ void tracing_start(void)
 
 	arch_spin_unlock(&global_trace.max_lock);
 
-	ftrace_start();
  out:
 	raw_spin_unlock_irqrestore(&global_trace.start_lock, flags);
 }
@@ -1419,7 +1418,6 @@ void tracing_stop(void)
 	struct ring_buffer *buffer;
 	unsigned long flags;
 
-	ftrace_stop();
 	raw_spin_lock_irqsave(&global_trace.start_lock, flags);
 	if (global_trace.stop_count++)
 		goto out;

kernel/trace/trace_uprobe.c

@@ -893,6 +893,9 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
 	int ret;
 
 	if (file) {
+		if (tu->tp.flags & TP_FLAG_PROFILE)
+			return -EINTR;
+
 		link = kmalloc(sizeof(*link), GFP_KERNEL);
 		if (!link)
 			return -ENOMEM;
@@ -901,29 +904,40 @@ probe_event_enable(struct trace_uprobe *tu, struct ftrace_event_file *file,
 		list_add_tail_rcu(&link->list, &tu->tp.files);
 
 		tu->tp.flags |= TP_FLAG_TRACE;
-	} else
-		tu->tp.flags |= TP_FLAG_PROFILE;
+	} else {
+		if (tu->tp.flags & TP_FLAG_TRACE)
+			return -EINTR;
 
-	ret = uprobe_buffer_enable();
-	if (ret < 0)
-		return ret;
+		tu->tp.flags |= TP_FLAG_PROFILE;
+	}
 
 	WARN_ON(!uprobe_filter_is_empty(&tu->filter));
 
 	if (enabled)
 		return 0;
 
+	ret = uprobe_buffer_enable();
+	if (ret)
+		goto err_flags;
+
 	tu->consumer.filter = filter;
 	ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
-	if (ret) {
-		if (file) {
-			list_del(&link->list);
-			kfree(link);
-			tu->tp.flags &= ~TP_FLAG_TRACE;
-		} else
-			tu->tp.flags &= ~TP_FLAG_PROFILE;
-	}
+	if (ret)
+		goto err_buffer;
 
+	return 0;
+
+ err_buffer:
+	uprobe_buffer_disable();
+
+ err_flags:
+	if (file) {
+		list_del(&link->list);
+		kfree(link);
+		tu->tp.flags &= ~TP_FLAG_TRACE;
+	} else {
+		tu->tp.flags &= ~TP_FLAG_PROFILE;
+	}
 	return ret;
 }
 
@@ -1201,12 +1215,6 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 
 	current->utask->vaddr = (unsigned long) &udd;
 
-#ifdef CONFIG_PERF_EVENTS
-	if ((tu->tp.flags & TP_FLAG_TRACE) == 0 &&
-	    !uprobe_perf_filter(&tu->consumer, 0, current->mm))
-		return UPROBE_HANDLER_REMOVE;
-#endif
-
 	if (WARN_ON_ONCE(!uprobe_cpu_buffer))
 		return 0;