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ppc32: fix copy_from_user()

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should clear on access_ok() failures.  Also remove the useless
range truncation logics.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-08-21 19:16:26 -04:00
parent aace880fee
commit 224264657b
1 changed files with 2 additions and 23 deletions
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25
arch/powerpc/include/asm/uaccess.h
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@ -308,40 +308,23 @@ extern unsigned long __copy_tofrom_user(void __user *to,
static inline unsigned long copy_from_user(void *to,
const void __user *from, unsigned long n)
{
unsigned long over;
if (access_ok(VERIFY_READ, from, n)) {
if (likely(access_ok(VERIFY_READ, from, n))) {
if (!__builtin_constant_p(n))
check_object_size(to, n, false);
return __copy_tofrom_user((__force void __user *)to, from, n);
}
if ((unsigned long)from < TASK_SIZE) {
over = (unsigned long)from + n - TASK_SIZE;
if (!__builtin_constant_p(n - over))
check_object_size(to, n - over, false);
return __copy_tofrom_user((__force void __user *)to, from,
n - over) + over;
}
memset(to, 0, n);
return n;
}
static inline unsigned long copy_to_user(void __user *to,
const void *from, unsigned long n)
{
unsigned long over;
if (access_ok(VERIFY_WRITE, to, n)) {
if (!__builtin_constant_p(n))
check_object_size(from, n, true);
return __copy_tofrom_user(to, (__force void __user *)from, n);
}
if ((unsigned long)to < TASK_SIZE) {
over = (unsigned long)to + n - TASK_SIZE;
if (!__builtin_constant_p(n))
check_object_size(from, n - over, true);
return __copy_tofrom_user(to, (__force void __user *)from,
n - over) + over;
}
return n;
}
@ -439,10 +422,6 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size)
might_fault();
if (likely(access_ok(VERIFY_WRITE, addr, size)))
return __clear_user(addr, size);
if ((unsigned long)addr < TASK_SIZE) {
unsigned long over = (unsigned long)addr + size - TASK_SIZE;
return __clear_user(addr, size - over) + over;
}
return size;
}