1 files changed, 131 insertions, 11 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 42b9355033d4..73e67b68c53b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1702,6 +1702,9 @@ void tracing_reset_all_online_cpus(void)
 	struct trace_array *tr;
 
 	list_for_each_entry(tr, &ftrace_trace_arrays, list) {
+		if (!tr->clear_trace)
+			continue;
+		tr->clear_trace = false;
 		tracing_reset_online_cpus(&tr->trace_buffer);
 #ifdef CONFIG_TRACER_MAX_TRACE
 		tracing_reset_online_cpus(&tr->max_buffer);
@@ -2799,11 +2802,17 @@ static char *get_trace_buf(void)
 	if (!buffer || buffer->nesting >= 4)
 		return NULL;
 
-	return &buffer->buffer[buffer->nesting++][0];
+	buffer->nesting++;
+
+	/* Interrupts must see nesting incremented before we use the buffer */
+	barrier();
+	return &buffer->buffer[buffer->nesting][0];
 }
 
 static void put_trace_buf(void)
 {
+	/* Don't let the decrement of nesting leak before this */
+	barrier();
 	this_cpu_dec(trace_percpu_buffer->nesting);
 }
 
@@ -4011,11 +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) {
@@ -5349,6 +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;
@@ -5658,7 +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);
@@ -6220,7 +6242,7 @@ static int tracing_set_clock(struct trace_array *tr, const char *clockstr)
 	tracing_reset_online_cpus(&tr->trace_buffer);
 
 #ifdef CONFIG_TRACER_MAX_TRACE
-	if (tr->flags & TRACE_ARRAY_FL_GLOBAL && tr->max_buffer.buffer)
+	if (tr->max_buffer.buffer)
 		ring_buffer_set_clock(tr->max_buffer.buffer, trace_clocks[i].func);
 	tracing_reset_online_cpus(&tr->max_buffer);
 #endif
@@ -6598,7 +6620,7 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 {
 	struct ftrace_buffer_info *info = filp->private_data;
 	struct trace_iterator *iter = &info->iter;
-	ssize_t ret;
+	ssize_t ret = 0;
 	ssize_t size;
 
 	if (!count)
@@ -6612,10 +6634,15 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 	if (!info->spare) {
 		info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
 							  iter->cpu_file);
-		info->spare_cpu = iter->cpu_file;
+		if (IS_ERR(info->spare)) {
+			ret = PTR_ERR(info->spare);
+			info->spare = NULL;
+		} else {
+			info->spare_cpu = iter->cpu_file;
+		}
 	}
 	if (!info->spare)
-		return -ENOMEM;
+		return ret;
 
 	/* Do we have previous read data to read? */
 	if (info->read < PAGE_SIZE)
@@ -6790,8 +6817,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
 		ref->ref = 1;
 		ref->buffer = iter->trace_buffer->buffer;
 		ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file);
-		if (!ref->page) {
-			ret = -ENOMEM;
+		if (IS_ERR(ref->page)) {
+			ret = PTR_ERR(ref->page);
+			ref->page = NULL;
 			kfree(ref);
 			break;
 		}
@@ -7659,6 +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;
@@ -7714,6 +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;
 
@@ -7725,6 +7755,7 @@ static int instance_mkdir(const char *name)
 
  out_unlock:
 	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 
 	return ret;
 
@@ -7737,6 +7768,7 @@ static int instance_rmdir(const char *name)
 	int ret;
 	int i;
 
+	mutex_lock(&event_mutex);
 	mutex_lock(&trace_types_lock);
 
 	ret = -ENODEV;
@@ -7782,6 +7814,7 @@ static int instance_rmdir(const char *name)
 
  out_unlock:
 	mutex_unlock(&trace_types_lock);
+	mutex_unlock(&event_mutex);
 
 	return ret;
 }
@@ -8248,6 +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;
@@ -8293,6 +8412,7 @@ __init static int tracer_alloc_buffers(void)
 	if (ret < 0)
 		goto out_free_cpumask;
 	/* Used for event triggers */
+	ret = -ENOMEM;
 	temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
 	if (!temp_buffer)
 		goto out_rm_hp_state;
@@ -8407,4 +8527,4 @@ __init static int clear_boot_tracer(void)
 }
 
 fs_initcall(tracer_init_tracefs);
-late_initcall(clear_boot_tracer);
+late_initcall_sync(clear_boot_tracer);