lkml.org 
[lkml]   [2016]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 116/118] ppc32: fix copy_from_user()
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@zeniv.linux.org.uk>

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/powerpc/include/asm/uaccess.h | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)

--- 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;
}


\
 
 \ /
  Last update: 2016-09-23 00:04    [W:0.262 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site