1 files changed, 43 insertions, 2 deletions

diff --git a/drivers/android/binderfs.c b/drivers/android/binderfs.c
index 55c5adb87585..e54c99bc995f 100644
--- a/drivers/android/binderfs.c
+++ b/drivers/android/binderfs.c
@@ -51,18 +51,27 @@ static DEFINE_IDA(binderfs_minors);
 /**
  * binderfs_mount_opts - mount options for binderfs
  * @max: maximum number of allocatable binderfs binder devices
+ * @stats_mode: enable binder stats in binderfs.
  */
 struct binderfs_mount_opts {
 	int max;
+	int stats_mode;
 };
 
 enum {
 	Opt_max,
+	Opt_stats_mode,
 	Opt_err
 };
 
+enum binderfs_stats_mode {
+	STATS_NONE,
+	STATS_GLOBAL,
+};
+
 static const match_table_t tokens = {
 	{ Opt_max, "max=%d" },
+	{ Opt_stats_mode, "stats=%s" },
 	{ Opt_err, NULL     }
 };
 
@@ -290,8 +299,9 @@ static void binderfs_evict_inode(struct inode *inode)
 static int binderfs_parse_mount_opts(char *data,
 				     struct binderfs_mount_opts *opts)
 {
-	char *p;
+	char *p, *stats;
 	opts->max = BINDERFS_MAX_MINOR;
+	opts->stats_mode = STATS_NONE;
 
 	while ((p = strsep(&data, ",")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
@@ -311,6 +321,22 @@ static int binderfs_parse_mount_opts(char *data,
 
 			opts->max = max_devices;
 			break;
+		case Opt_stats_mode:
+			if (!capable(CAP_SYS_ADMIN))
+				return -EINVAL;
+
+			stats = match_strdup(&args[0]);
+			if (!stats)
+				return -ENOMEM;
+
+			if (strcmp(stats, "global") != 0) {
+				kfree(stats);
+				return -EINVAL;
+			}
+
+			opts->stats_mode = STATS_GLOBAL;
+			kfree(stats);
+			break;
 		default:
 			pr_err("Invalid mount options\n");
 			return -EINVAL;
@@ -322,8 +348,21 @@ static int binderfs_parse_mount_opts(char *data,
 
 static int binderfs_remount(struct super_block *sb, int *flags, char *data)
 {
+	int prev_stats_mode, ret;
 	struct binderfs_info *info = sb->s_fs_info;
-	return binderfs_parse_mount_opts(data, &info->mount_opts);
+
+	prev_stats_mode = info->mount_opts.stats_mode;
+	ret = binderfs_parse_mount_opts(data, &info->mount_opts);
+	if (ret)
+		return ret;
+
+	if (prev_stats_mode != info->mount_opts.stats_mode) {
+		pr_err("Binderfs stats mode cannot be changed during a remount\n");
+		info->mount_opts.stats_mode = prev_stats_mode;
+		return -EINVAL;
+	}
+
+	return 0;
 }
 
 static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root)
@@ -333,6 +372,8 @@ static int binderfs_show_mount_opts(struct seq_file *seq, struct dentry *root)
 	info = root->d_sb->s_fs_info;
 	if (info->mount_opts.max <= BINDERFS_MAX_MINOR)
 		seq_printf(seq, ",max=%d", info->mount_opts.max);
+	if (info->mount_opts.stats_mode == STATS_GLOBAL)
+		seq_printf(seq, ",stats=global");
 
 	return 0;
 }