blob: e683113b9d1be86d61d2145c1239fb46dfff273b [file] [log] [blame]
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 21 Aug 2016 19:16:26 -0400
Subject: ppc32: fix copy_from_user()
commit 224264657b8b228f949b42346e09ed8c90136a8e upstream.
should clear on access_ok() failures. Also remove the useless
range truncation logics.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16: no calls to check_object_size()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -323,30 +323,17 @@ extern unsigned long __copy_tofrom_user(
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)))
return __copy_tofrom_user((__force void __user *)to, from, n);
- if ((unsigned long)from < TASK_SIZE) {
- over = (unsigned long)from + n - TASK_SIZE;
- 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))
return __copy_tofrom_user(to, (__force void __user *)from, n);
- if ((unsigned long)to < TASK_SIZE) {
- over = (unsigned long)to + n - TASK_SIZE;
- return __copy_tofrom_user(to, (__force void __user *)from,
- n - over) + over;
- }
return n;
}
@@ -437,10 +424,6 @@ static inline unsigned long clear_user(v
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;
}