1 files changed, 25 insertions, 4 deletions

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index cfd9dce1ce0b..d412a1ddc12f 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -46,6 +46,17 @@
 struct fb_info *registered_fb[FB_MAX] __read_mostly;
 int num_registered_fb __read_mostly;
 
+int lock_fb_info(struct fb_info *info)
+{
+	mutex_lock(&info->lock);
+	if (!info->fbops) {
+		mutex_unlock(&info->lock);
+		return 0;
+	}
+	return 1;
+}
+EXPORT_SYMBOL(lock_fb_info);
+
 /*
  * Helpers
  */
@@ -1086,13 +1097,11 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 			return -EINVAL;
 		con2fb.framebuffer = -1;
 		event.data = &con2fb;
-
 		if (!lock_fb_info(info))
 			return -ENODEV;
 		event.info = info;
 		fb_notifier_call_chain(FB_EVENT_GET_CONSOLE_MAP, &event);
 		unlock_fb_info(info);
-
 		ret = copy_to_user(argp, &con2fb, sizeof(con2fb)) ? -EFAULT : 0;
 		break;
 	case FBIOPUT_CON2FBMAP:
@@ -1112,8 +1121,7 @@ static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
 		if (!lock_fb_info(info))
 			return -ENODEV;
 		event.info = info;
-		ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP,
-					      &event);
+		ret = fb_notifier_call_chain(FB_EVENT_SET_CONSOLE_MAP, &event);
 		unlock_fb_info(info);
 		break;
 	case FBIOBLANK:
@@ -1519,7 +1527,10 @@ register_framebuffer(struct fb_info *fb_info)
 	registered_fb[i] = fb_info;
 
 	event.info = fb_info;
+	if (!lock_fb_info(fb_info))
+		return -ENODEV;
 	fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
+	unlock_fb_info(fb_info);
 	return 0;
 }
 
@@ -1553,8 +1564,12 @@ unregister_framebuffer(struct fb_info *fb_info)
 		goto done;
 	}
 
+
+	if (!lock_fb_info(fb_info))
+		return -ENODEV;
 	event.info = fb_info;
 	ret = fb_notifier_call_chain(FB_EVENT_FB_UNBIND, &event);
+	unlock_fb_info(fb_info);
 
 	if (ret) {
 		ret = -EINVAL;
@@ -1588,6 +1603,8 @@ void fb_set_suspend(struct fb_info *info, int state)
 {
 	struct fb_event event;
 
+	if (!lock_fb_info(info))
+		return;
 	event.info = info;
 	if (state) {
 		fb_notifier_call_chain(FB_EVENT_SUSPEND, &event);
@@ -1596,6 +1613,7 @@ void fb_set_suspend(struct fb_info *info, int state)
 		info->state = FBINFO_STATE_RUNNING;
 		fb_notifier_call_chain(FB_EVENT_RESUME, &event);
 	}
+	unlock_fb_info(info);
 }
 
 /**
@@ -1665,8 +1683,11 @@ int fb_new_modelist(struct fb_info *info)
 	err = 1;
 
 	if (!list_empty(&info->modelist)) {
+		if (!lock_fb_info(info))
+			return -ENODEV;
 		event.info = info;
 		err = fb_notifier_call_chain(FB_EVENT_NEW_MODELIST, &event);
+		unlock_fb_info(info);
 	}
 
 	return err;