LXR linux/lib/usercopy.c

   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
   7unsigned 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}
  19EXPORT_SYMBOL(_copy_from_user);
  20#endif
  21
  22#ifndef INLINE_COPY_TO_USER
  23unsigned 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}
  32EXPORT_SYMBOL(_copy_to_user);
  33#endif
  34