From 4ae717da8d18839487485f6ae608b8542790fdd3 Mon Sep 17 00:00:00 2001 From: Thadeu Lima de Souza Cascardo Date: Mon, 14 Dec 2009 18:00:30 -0800 Subject: drivers/char/misc.c: clear allocation bit in minor bitmap when device register fails If there's a failure creating the device (because there's already one with the same name, for example), the current implementation does not clear the bit for the allocated minor and that number is lost for future allocations. Second, the test currently in misc_deregister is broken, since it does not test for the 0 minor. Signed-off-by: Thadeu Lima de Souza Cascardo Cc: "H. Peter Anvin" Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/misc.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/misc.c b/drivers/char/misc.c index 281edefffa0b..a3a02f6303c8 100644 --- a/drivers/char/misc.c +++ b/drivers/char/misc.c @@ -214,6 +214,9 @@ int misc_register(struct miscdevice * misc) misc->this_device = device_create(misc_class, misc->parent, dev, misc, "%s", misc->name); if (IS_ERR(misc->this_device)) { + int i = misc->minor; + if (i < DYNAMIC_MINORS && i >= 0) + misc_minors[i>>3] &= ~(1 << (i & 7)); err = PTR_ERR(misc->this_device); goto out; } @@ -248,9 +251,8 @@ int misc_deregister(struct miscdevice *misc) mutex_lock(&misc_mtx); list_del(&misc->list); device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor)); - if (i < DYNAMIC_MINORS && i>0) { - misc_minors[i>>3] &= ~(1 << (misc->minor & 7)); - } + if (i < DYNAMIC_MINORS && i >= 0) + misc_minors[i>>3] &= ~(1 << (i & 7)); mutex_unlock(&misc_mtx); return 0; } -- cgit v1.2.3