[mirror_ubuntu-bionic-kernel.git] / arch / x86 / lib / usercopy.c

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

#include <linux/uaccess.h>
#include <linux/export.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
beba3a20	7	#include <linux/uaccess.h>
e683014c	8	#include <linux/export.h>
1ac2e6ca RR	9
1ac2e6ca RR	10	/*
e00b12e6 PZ	11	* We rely on the nested NMI work to allow atomic faults from the NMI path; the
e00b12e6 PZ	12	* nested NMI paths are careful to preserve CR2.
1ac2e6ca RR	13	*/
	14	unsigned long
	15	copy_from_user_nmi(void to, const void __user from, unsigned long n)
	16	{
e00b12e6	17	unsigned long ret;
1ac2e6ca	18
25f42985	19	if (__range_not_ok(from, n, TASK_SIZE))
ebf2d268	20	return n;
e00b12e6 PZ	21
	22	/*
	23	* Even though this function is typically called from NMI/IRQ context
	24	* disable pagefaults so that its behaviour is consistent even when
	25	* called form other contexts.
	26	*/
	27	pagefault_disable();
	28	ret = __copy_from_user_inatomic(to, from, n);
	29	pagefault_enable();
	30
0a196848	31	return ret;
1ac2e6ca RR	32	}
1ac2e6ca RR	33	EXPORT_SYMBOL_GPL(copy_from_user_nmi);