xref: /openbmc/linux/lib/usercopy.c (revision f2f4bf5a)
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(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(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