[mirror_ubuntu-eoan-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>

#include <asm/tlbflush.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;

	if (!nmi_uaccess_okay())
		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	9
4012e77a AL	10	#include <asm/tlbflush.h>
4012e77a AL	11
1ac2e6ca	12	/*
e00b12e6 PZ	13	* We rely on the nested NMI work to allow atomic faults from the NMI path; the
e00b12e6 PZ	14	* nested NMI paths are careful to preserve CR2.
1ac2e6ca RR	15	*/
	16	unsigned long
	17	copy_from_user_nmi(void to, const void __user from, unsigned long n)
	18	{
e00b12e6	19	unsigned long ret;
1ac2e6ca	20
25f42985	21	if (__range_not_ok(from, n, TASK_SIZE))
ebf2d268	22	return n;
e00b12e6	23
4012e77a AL	24	if (!nmi_uaccess_okay())
	25	return n;
	26
e00b12e6 PZ	27	/*
	28	* Even though this function is typically called from NMI/IRQ context
	29	* disable pagefaults so that its behaviour is consistent even when
	30	* called form other contexts.
	31	*/
	32	pagefault_disable();
	33	ret = __copy_from_user_inatomic(to, from, n);
	34	pagefault_enable();
	35
0a196848	36	return ret;
1ac2e6ca RR	37	}
1ac2e6ca RR	38	EXPORT_SYMBOL_GPL(copy_from_user_nmi);