xref: /openbmc/linux/lib/usercopy.c (revision 6d99a79c)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/uaccess.h>
3 
4 /* out-of-line parts */
5 
6 #ifndef INLINE_COPY_FROM_USER
7 unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
8 {
9 	unsigned long res = n;
10 	might_fault();
11 	if (likely(access_ok(VERIFY_READ, from, n))) {
12 		kasan_check_write(to, n);
13 		res = raw_copy_from_user(to, from, n);
14 	}
15 	if (unlikely(res))
16 		memset(to + (n - res), 0, res);
17 	return res;
18 }
19 EXPORT_SYMBOL(_copy_from_user);
20 #endif
21 
22 #ifndef INLINE_COPY_TO_USER
23 unsigned long _copy_to_user(void __user *to, const void *from, unsigned long n)
24 {
25 	might_fault();
26 	if (likely(access_ok(VERIFY_WRITE, to, n))) {
27 		kasan_check_read(from, n);
28 		n = raw_copy_to_user(to, from, n);
29 	}
30 	return n;
31 }
32 EXPORT_SYMBOL(_copy_to_user);
33 #endif
34