1 /* 2 * User address space access functions. 3 * 4 * For licencing details see kernel-base/COPYING 5 */ 6 7 #include <linux/uaccess.h> 8 #include <linux/export.h> 9 10 /* 11 * We rely on the nested NMI work to allow atomic faults from the NMI path; the 12 * nested NMI paths are careful to preserve CR2. 13 */ 14 unsigned long 15 copy_from_user_nmi(void *to, const void __user *from, unsigned long n) 16 { 17 unsigned long ret; 18 19 if (__range_not_ok(from, n, TASK_SIZE)) 20 return n; 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 31 return ret; 32 } 33 EXPORT_SYMBOL_GPL(copy_from_user_nmi); 34