ppc32: fix copy_from_user()
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>
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index c1dc6c1..c2ce5dd 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -308,40 +308,23 @@
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 @@
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;
}