fbdev: fbmem: implement error handling in fbmem_init()

fbmem_init() ignores all errors, while fbmem_exit() does not
check if deallocating resources are valid.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

1 files changed, 17 insertions, 3 deletions

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 4e73b6f6b1c0..76c1ad96fb37 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1854,17 +1854,31 @@ EXPORT_SYMBOL(fb_set_suspend);
 static int __init
 fbmem_init(void)
 {
-        proc_create("fb", 0, NULL, &fb_proc_fops);
+        int ret;
+
+        if (!proc_create("fb", 0, NULL, &fb_proc_fops))
+                return -ENOMEM;
 
-        if (register_chrdev(FB_MAJOR,"fb",&fb_fops))
+        ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
+        if (ret) {
                 printk("unable to get major %d for fb devs\n", FB_MAJOR);
+                goto err_chrdev;
+        }
 
         fb_class = class_create(THIS_MODULE, "graphics");
         if (IS_ERR(fb_class)) {
-                printk(KERN_WARNING "Unable to create fb class; errno = %ld\n", PTR_ERR(fb_class));
+                ret = PTR_ERR(fb_class);
+                pr_warn("Unable to create fb class; errno = %d\n", ret);
                 fb_class = NULL;
+                goto err_class;
         }
         return 0;
+
+err_class:
+        unregister_chrdev(FB_MAJOR, "fb");
+err_chrdev:
+        remove_proc_entry("fb", NULL);
+        return ret;
 }
 
 #ifdef MODULE