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cris: don't rely upon __copy_user_zeroing() zeroing the tail 

we want to get rid of it; unfortunately, it's tangled as hell, so
it'll take many steps, more's the pity.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2017-03-19 15:07:21 -04:00
parent a8be34459c
commit 07f78b3089
1 changed files with 9 additions and 7 deletions
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16
arch/cris/include/asm/uaccess.h
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@ -338,14 +338,16 @@ static inline size_t clear_user(void __user *to, size_t n)
static inline size_t copy_from_user(void *to, const void __user *from, size_t n)
{
if (unlikely(!access_ok(VERIFY_READ, from, n))) {
memset(to, 0, n);
return n;
size_t res = n;
if (likely(access_ok(VERIFY_READ, from, n))) {
if (__builtin_constant_p(n))
res = __constant_copy_from_user(to, from, n);
else
res = __copy_user_zeroing(to, from, n);
}
if (__builtin_constant_p(n))
return __constant_copy_from_user(to, from, n);
else
return __copy_user_zeroing(to, from, n);
if (unlikely(res))
memset(to + n - res , 0, res);
return res;
}
static inline size_t copy_to_user(void __user *to, const void *from, size_t n)