linux-stable/lib/usercopy.c
Christophe Leroy a0e94598e6 Fix misannotated out-of-line _copy_to_user()
Destination is a kernel pointer and source - a userland one
in _copy_from_user(); _copy_to_user() is the other way round.

Fixes: d597580d37 ("generic ...copy_..._user primitives")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-12-11 09:35:11 -05:00

33 lines
764 B
C

// SPDX-License-Identifier: GPL-2.0
#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;
might_fault();
if (likely(access_ok(VERIFY_READ, from, n))) {
kasan_check_write(to, 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 __user *to, const void *from, unsigned long n)
{
might_fault();
if (likely(access_ok(VERIFY_WRITE, to, n))) {
kasan_check_read(from, n);
n = raw_copy_to_user(to, from, n);
}
return n;
}
EXPORT_SYMBOL(_copy_to_user);
#endif