char_dev: order /proc/devices by major number

[people/ms/linux.git] / fs / char_dev.c

diff --git a/fs/char_dev.c b/fs/char_dev.c
index c9d18362e89de0a060f96ae8e41cc05543c9dc6f..ebcc8fb3fa6641363e302082aacd92812142e6b1 100644 (file)
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -28,6 +28,8 @@ static struct kobj_map *cdev_map;
 
 static DEFINE_MUTEX(chrdevs_lock);
 
+#define CHRDEV_MAJOR_HASH_SIZE 255
+
 static struct char_device_struct {
        struct char_device_struct *next;
        unsigned int major;
@@ -49,12 +51,12 @@ void chrdev_show(struct seq_file *f, off_t offset)
 {
        struct char_device_struct *cd;
 
-       if (offset < CHRDEV_MAJOR_HASH_SIZE) {
-               mutex_lock(&chrdevs_lock);
-               for (cd = chrdevs[offset]; cd; cd = cd->next)
+       mutex_lock(&chrdevs_lock);
+       for (cd = chrdevs[major_to_index(offset)]; cd; cd = cd->next) {
+               if (cd->major == offset)
                        seq_printf(f, "%3d %s\n", cd->major, cd->name);
-               mutex_unlock(&chrdevs_lock);
        }
+       mutex_unlock(&chrdevs_lock);
 }
 
 #endif /* CONFIG_PROC_FS */
@@ -117,6 +119,13 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
                major = ret;
        }
 
+       if (major >= CHRDEV_MAJOR_MAX) {
+               pr_err("CHRDEV \"%s\" major requested (%d) is greater than the maximum (%d)\n",
+                      name, major, CHRDEV_MAJOR_MAX);
+               ret = -EINVAL;
+               goto out;
+       }
+
        cd->major = major;
        cd->baseminor = baseminor;
        cd->minorct = minorct;