1 files changed, 107 insertions, 3 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 5360b7aec57a..73e67b68c53b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4020,11 +4020,17 @@ static int tracing_open(struct inode *inode, struct file *file)
 	/* If this file was open for write, then erase contents */
 	if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
 		int cpu = tracing_get_cpu(inode);
+		struct trace_buffer *trace_buf = &tr->trace_buffer;
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+		if (tr->current_trace->print_max)
+			trace_buf = &tr->max_buffer;
+#endif
 
 		if (cpu == RING_BUFFER_ALL_CPUS)
-			tracing_reset_online_cpus(&tr->trace_buffer);
+			tracing_reset_online_cpus(trace_buf);
 		else
-			tracing_reset(&tr->trace_buffer, cpu);
+			tracing_reset(trace_buf, cpu);
 	}
 
 	if (file->f_mode & FMODE_READ) {
@@ -5358,6 +5364,13 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf)
 	if (t == tr->current_trace)
 		goto out;
 
+	/* Some tracers won't work on kernel command line */
+	if (system_state < SYSTEM_RUNNING && t->noboot) {
+		pr_warn("Tracer '%s' is not allowed on command line, ignored\n",
+			t->name);
+		goto out;
+	}
+
 	/* Some tracers are only allowed for the top level buffer */
 	if (!trace_ok_for_array(t, tr)) {
 		ret = -EINVAL;
@@ -5667,7 +5680,7 @@ static int tracing_wait_pipe(struct file *filp)
 		 *
 		 * iter->pos will be 0 if we haven't read anything.
 		 */
-		if (!tracing_is_on() && iter->pos)
+		if (!tracer_tracing_is_on(iter->tr) && iter->pos)
 			break;
 
 		mutex_unlock(&iter->mutex);
@@ -7674,6 +7687,7 @@ static int instance_mkdir(const char *name)
 	struct trace_array *tr;
 	int ret;
 
+	mutex_lock(&event_mutex);
 	mutex_lock(&trace_types_lock);
 
 	ret = -EEXIST;
@@ -7729,6 +7743,7 @@ static int instance_mkdir(const char *name)
 	list_add(&tr->list, &ftrace_trace_arrays);
 
 	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 
 	return 0;
 
@@ -7740,6 +7755,7 @@ static int instance_mkdir(const char *name)
 
  out_unlock:
 	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 
 	return ret;
 
@@ -7752,6 +7768,7 @@ static int instance_rmdir(const char *name)
 	int ret;
 	int i;
 
+	mutex_lock(&event_mutex);
 	mutex_lock(&trace_types_lock);
 
 	ret = -ENODEV;
@@ -7797,6 +7814,7 @@ static int instance_rmdir(const char *name)
 
  out_unlock:
 	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 
 	return ret;
 }
@@ -8263,6 +8281,92 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 }
 EXPORT_SYMBOL_GPL(ftrace_dump);
 
+int trace_run_command(const char *buf, int (*createfn)(int, char **))
+{
+	char **argv;
+	int argc, ret;
+
+	argc = 0;
+	ret = 0;
+	argv = argv_split(GFP_KERNEL, buf, &argc);
+	if (!argv)
+		return -ENOMEM;
+
+	if (argc)
+		ret = createfn(argc, argv);
+
+	argv_free(argv);
+
+	return ret;
+}
+
+#define WRITE_BUFSIZE  4096
+
+ssize_t trace_parse_run_command(struct file *file, const char __user *buffer,
+				size_t count, loff_t *ppos,
+				int (*createfn)(int, char **))
+{
+	char *kbuf, *buf, *tmp;
+	int ret = 0;
+	size_t done = 0;
+	size_t size;
+
+	kbuf = kmalloc(WRITE_BUFSIZE, GFP_KERNEL);
+	if (!kbuf)
+		return -ENOMEM;
+
+	while (done < count) {
+		size = count - done;
+
+		if (size >= WRITE_BUFSIZE)
+			size = WRITE_BUFSIZE - 1;
+
+		if (copy_from_user(kbuf, buffer + done, size)) {
+			ret = -EFAULT;
+			goto out;
+		}
+		kbuf[size] = '\0';
+		buf = kbuf;
+		do {
+			tmp = strchr(buf, '\n');
+			if (tmp) {
+				*tmp = '\0';
+				size = tmp - buf + 1;
+			} else {
+				size = strlen(buf);
+				if (done + size < count) {
+					if (buf != kbuf)
+						break;
+					/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
+					pr_warn("Line length is too long: Should be less than %d\n",
+						WRITE_BUFSIZE - 2);
+					ret = -EINVAL;
+					goto out;
+				}
+			}
+			done += size;
+
+			/* Remove comments */
+			tmp = strchr(buf, '#');
+
+			if (tmp)
+				*tmp = '\0';
+
+			ret = trace_run_command(buf, createfn);
+			if (ret)
+				goto out;
+			buf += size;
+
+		} while (done < count);
+	}
+	ret = done;
+
+out:
+	kfree(kbuf);
+
+	return ret;
+}
+
 __init static int tracer_alloc_buffers(void)
 {
 	int ring_buf_size;