linux/lib/usercopy.c
Al Viro d597580d37 generic ...copy_..._user primitives
provide raw_copy_..._user() and select ARCH_HAS_RAW_COPY_USER to use those.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 18:22:11 -04:00

27 lines
629 B
C

#include <linux/uaccess.h>
/* out-of-line parts */
#ifndef INLINE_COPY_FROM_USER
unsigned long _copy_from_user(void *to, const void __user *from, unsigned long n)
{
unsigned long res = n;
if (likely(access_ok(VERIFY_READ, from, n)))
res = raw_copy_from_user(to, from, n);
if (unlikely(res))
memset(to + (n - res), 0, res);
return res;
}
EXPORT_SYMBOL(_copy_from_user);
#endif
#ifndef INLINE_COPY_TO_USER
unsigned long _copy_to_user(void *to, const void __user *from, unsigned long n)
{
if (likely(access_ok(VERIFY_WRITE, to, n)))
n = raw_copy_to_user(to, from, n);
return n;
}
EXPORT_SYMBOL(_copy_to_user);
#endif