xref: /openbmc/linux/lib/usercopy.c (revision 8ee90c5c)
1 #include <linux/uaccess.h>
2 
3 /* out-of-line parts */
4 
5 #ifndef INLINE_COPY_FROM_USER
6 unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
7 {
8 	unsigned long res = n;
9 	might_fault();
10 	if (likely(access_ok(VERIFY_READ, from, n))) {
11 		kasan_check_write(to, n);
12 		res = raw_copy_from_user(to, from, n);
13 	}
14 	if (unlikely(res))
15 		memset(to + (n - res), 0, res);
16 	return res;
17 }
18 EXPORT_SYMBOL(_copy_from_user);
19 #endif
20 
21 #ifndef INLINE_COPY_TO_USER
22 unsigned long _copy_to_user(void *to, const void __user *from, unsigned long n)
23 {
24 	might_fault();
25 	if (likely(access_ok(VERIFY_WRITE, to, n))) {
26 		kasan_check_read(from, n);
27 		n = raw_copy_to_user(to, from, n);
28 	}
29 	return n;
30 }
31 EXPORT_SYMBOL(_copy_to_user);
32 #endif
33