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Date:   Sat, 4 Jul 2020 14:25:17 +0200
From:   Oscar Carter <oscar.carter@gmx.com>
To:     Kees Cook <keescook@chromium.org>
Cc:     Oscar Carter <oscar.carter@gmx.com>,
        Heiko Carstens <heiko.carstens@de.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Christian Borntraeger <borntraeger@de.ibm.com>,
        kernel-hardening@lists.openwall.com, linux-s390@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drivers/s390/char/tty3270: Remove function callback casts
Message-ID: <20200704122517.GB3143@ubuntu>
References: <20200627125417.18887-1-oscar.carter@gmx.com>
 <202006270853.C40CA89806@keescook>
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On Sat, Jun 27, 2020 at 09:10:56AM -0700, Kees Cook wrote:
> On Sat, Jun 27, 2020 at 02:54:17PM +0200, Oscar Carter wrote:
> > In an effort to enable -Wcast-function-type in the top-level Makefile =
to
> > support Control Flow Integrity builds, remove all the function callbac=
k
> > casts.
> >
> > To do this modify the function prototypes accordingly.
> >
> > Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
>
> Oh yes, the tasklets! I'd love to see this fixed correctly. (Which is to
> say, modernize the API.) Romain hasn't had time to continue the work:
> https://lore.kernel.org/kernel-hardening/20190929163028.9665-1-romain.pe=
rier@gmail.com/
>
> Is this something you'd want to tackle?

Yes, of course. It will be a pleasure to work on this. But without forgett=
ing
the work to remove all the function cast mismatches.

> > ---
> >  drivers/s390/char/tty3270.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/s390/char/tty3270.c b/drivers/s390/char/tty3270.c
> > index 98d7fc152e32..aec996de44d9 100644
> > --- a/drivers/s390/char/tty3270.c
> > +++ b/drivers/s390/char/tty3270.c
> > @@ -556,8 +556,9 @@ tty3270_scroll_backward(struct kbd_data *kbd)
> >   * Pass input line to tty.
> >   */
> >  static void
> > -tty3270_read_tasklet(struct raw3270_request *rrq)
> > +tty3270_read_tasklet(unsigned long data)
> >  {
> > +	struct raw3270_request *rrq =3D (struct raw3270_request *)data;
>
> Regardless, this is correct as far as fixing the prototype.
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
> --
> Kees Cook

Regards,
Oscar Carter