[deliverable/linux.git] / arch / x86 / lib / usercopy.c

/*
 * User address space access functions.
 *
 *  For licencing details see kernel-base/COPYING
 */

#include <linux/highmem.h>
#include <linux/module.h>

#include <asm/word-at-a-time.h>
#include <linux/sched.h>

/*
 * We rely on the nested NMI work to allow atomic faults from the NMI path; the
 * nested NMI paths are careful to preserve CR2.
 */
unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
{
	unsigned long ret;

	if (__range_not_ok(from, n, TASK_SIZE))
		return n;

	/*
	 * Even though this function is typically called from NMI/IRQ context
	 * disable pagefaults so that its behaviour is consistent even when
	 * called form other contexts.
	 */
	pagefault_disable();
	ret = __copy_from_user_inatomic(to, from, n);
	pagefault_enable();

	return ret;
}
EXPORT_SYMBOL_GPL(copy_from_user_nmi);
Commit	Line	Data
1ac2e6ca RR	1	/*
	2	* User address space access functions.
	3	*
	4	* For licencing details see kernel-base/COPYING
	5	*/
	6
	7	#include <linux/highmem.h>
	8	#include <linux/module.h>
	9
92ae03f2	10	#include <asm/word-at-a-time.h>
db0dc75d	11	#include <linux/sched.h>
92ae03f2	12
1ac2e6ca	13	/*
e00b12e6 PZ	14	* We rely on the nested NMI work to allow atomic faults from the NMI path; the
e00b12e6 PZ	15	* nested NMI paths are careful to preserve CR2.
1ac2e6ca RR	16	*/
	17	unsigned long
	18	copy_from_user_nmi(void to, const void __user from, unsigned long n)
	19	{
e00b12e6	20	unsigned long ret;
1ac2e6ca	21
25f42985	22	if (__range_not_ok(from, n, TASK_SIZE))
ebf2d268	23	return n;
e00b12e6 PZ	24
	25	/*
	26	* Even though this function is typically called from NMI/IRQ context
	27	* disable pagefaults so that its behaviour is consistent even when
	28	* called form other contexts.
	29	*/
	30	pagefault_disable();
	31	ret = __copy_from_user_inatomic(to, from, n);
	32	pagefault_enable();
	33
0a196848	34	return ret;
1ac2e6ca RR	35	}
1ac2e6ca RR	36	EXPORT_SYMBOL_GPL(copy_from_user_nmi);