From: Christoph Hellwig
Sent: 14 February 2022 17:01
On Mon, Feb 14, 2022 at 05:34:41PM +0100, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>
The get_user()/put_user() functions are meant to check for
access_ok(), while the __get_user()/__put_user() functions
don't.
This broke in 4.19 for nds32, when it gained an extraneous
check in __get_user(), but lost the check it needs in
__put_user().
Can we follow the lead of MIPS (which this was originally copied
from I think) and kill the pointless __get/put_user_check wrapper
that just obsfucate the code?
Is it possible to make all these architectures fall back to
a common definition somewhere?
Maybe they need to define ACCESS_OK_USER_LIMIT - which can be
different from TASK_SIZE.
There'll be a few special cases, but most architectures have
kernel addresses above userspace ones.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
