Re: [PATCH v3 08/26] compat_ioctl: add compat_ptr_ioctl()
From: Arnd Bergmann
Date: Wed Apr 17 2019 - 17:35:07 EST
On Wed, Apr 17, 2019 at 11:19 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> On Tue, Apr 16, 2019 at 10:19:46PM +0200, Arnd Bergmann wrote:
> > Many drivers have ioctl() handlers that are completely compatible between
> > 32-bit and 64-bit architectures, except for the argument that is passed
> > down from user space and may have to be passed through compat_ptr()
> > in order to become a valid 64-bit pointer.
> >
> > Using ".compat_ptr = compat_ptr_ioctl" in file operations should let
> > us simplify a lot of those drivers to avoid #ifdef checks, and convert
> > additional drivers that don't have proper compat handling yet.
>
> You forgot to mention that it even gets the previous commit to build ;-)
> IOW, that needs to be reordered.
Right. I had reordered the series multiple times and got this part wrong
in the end.
Arnd