Commit aa715284 authored Jun 25, 2009 by Thomas Gleixner

futex: request only one page from get_user_pages()



Yanmin noticed that fault_in_user_writeable() requests 4 pages instead
of one.

That's the result of blindly trusting Linus' proposal :) I even looked
up the prototype to verify the correctness: the argument in question
is confusingly enough named "len" while in reality it means number of
pages.

Pointed-out-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 28d0325c

kernel/futex.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -299,7 +299,7 @@ void put_futex_key(int fshared, union futex_key *key)
	static int fault_in_user_writeable(u32 __user *uaddr)		static int fault_in_user_writeable(u32 __user *uaddr)
	{		{
	int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,		int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,
	sizeof(*uaddr), 1, 0, NULL, NULL);		1, 1, 0, NULL, NULL);
	return ret < 0 ? ret : 0;		return ret < 0 ? ret : 0;
	}		}