selinux: remove obsolete read buffer limit from sel_read_bool

On Tue, 2009-05-19 at 00:05 -0400, Eamon Walsh wrote:
> Recent versions of coreutils have bumped the read buffer size from 4K to
> 32K in several of the utilities.
>
> This means that "cat /selinux/booleans/xserver_object_manager" no longer
> works, it returns "Invalid argument" on F11.  getsebool works fine.
>
> sel_read_bool has a check for "count > PAGE_SIZE" that doesn't seem to
> be present in the other read functions.  Maybe it could be removed?

Yes, that check is obsoleted by the conversion of those functions to
using simple_read_from_buffer(), which will reduce count if necessary to
what is available in the buffer.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>

security/selinux/selinuxfs.c

@@ -803,10 +803,6 @@ static ssize_t sel_read_bool(struct file *filep, char __user *buf,
 		goto out;
 	}
 
-	if (count > PAGE_SIZE) {
-		ret = -EINVAL;
-		goto out;
-	}
 	page = (char *)get_zeroed_page(GFP_KERNEL);
 	if (!page) {
 		ret = -ENOMEM;