[PATCH][RFC] Delete export of tty.h to userspace.

[PATCH][RFC] Delete export of tty.h to userspace.

[Robert P. J. Day]

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>

---

  given that the entire contents of include/linux/tty.h is contained
within an "#ifdef __KERNEL__", it seems pointless to export it to
userspace, unless there's some kind of need for that header file to
exist in userspace, even if it's empty.

  a quick grep shows that nothing under /usr/include references any
file of the name "tty.h" in any way.  thoughts?



 diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index 4ff0f57..63de91a 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -328,7 +327,6 @@ unifdef-y += sysctl.h
 unifdef-y += tcp.h
 unifdef-y += time.h
 unifdef-y += timex.h
-unifdef-y += tty.h
 unifdef-y += types.h
 unifdef-y += udf_fs_i.h
 unifdef-y += udp.h
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Jiri Slaby]

Robert P. J. Day napsal(a):
> Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
> 
> ---
> 
>   given that the entire contents of include/linux/tty.h is contained
> within an "#ifdef __KERNEL__", it seems pointless to export it to
> userspace, unless there's some kind of need for that header file to
> exist in userspace, even if it's empty.
> 
>   a quick grep shows that nothing under /usr/include references any
> file of the name "tty.h" in any way.  thoughts?

If we decide to remove the file, I would rather go through deprecation of the
file with filing an entry in feature-remove-schedule. There still seems to be
some users of the file.

With deprecation done with sth. like
#ifndef __KERNEL__
#warning Don't include this file from userspace, it's emtpy.
#endif

>  diff --git a/include/linux/Kbuild b/include/linux/Kbuild
> index 4ff0f57..63de91a 100644
> --- a/include/linux/Kbuild
> +++ b/include/linux/Kbuild
> @@ -328,7 +327,6 @@ unifdef-y += sysctl.h
>  unifdef-y += tcp.h
>  unifdef-y += time.h
>  unifdef-y += timex.h
> -unifdef-y += tty.h
>  unifdef-y += types.h
>  unifdef-y += udf_fs_i.h
>  unifdef-y += udp.h


-- 
Jiri Slaby (jirislaby@gmail.com)
Faculty of Informatics, Masaryk University

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Robert P. J. Day]

On Wed, 18 Jul 2007, Jiri Slaby wrote:

> Robert P. J. Day napsal(a):
> > Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
> >
> > ---
> >
> >   given that the entire contents of include/linux/tty.h is contained
> > within an "#ifdef __KERNEL__", it seems pointless to export it to
> > userspace, unless there's some kind of need for that header file to
> > exist in userspace, even if it's empty.
> >
> >   a quick grep shows that nothing under /usr/include references any
> > file of the name "tty.h" in any way.  thoughts?
>
> If we decide to remove the file, I would rather go through
> deprecation of the file with filing an entry in
> feature-remove-schedule. There still seems to be some users of the
> file.

i'm curious -- how did you determine that?

> With deprecation done with sth. like
> #ifndef __KERNEL__
> #warning Don't include this file from userspace, it's emtpy.
> #endif

yes, that makes sense.  i can do that.

rday
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Karel Zak]

On Wed, Jul 18, 2007 at 04:33:12PM -0400, Robert P. J. Day wrote:
> On Wed, 18 Jul 2007, Jiri Slaby wrote:
> 
> > Robert P. J. Day napsal(a):
> > >   given that the entire contents of include/linux/tty.h is contained
> > > within an "#ifdef __KERNEL__", it seems pointless to export it to
> > > userspace, unless there's some kind of need for that header file to
> > > exist in userspace, even if it's empty.
> > >
> > >   a quick grep shows that nothing under /usr/include references any
> > > file of the name "tty.h" in any way.  thoughts?
> >
> > If we decide to remove the file, I would rather go through
> > deprecation of the file with filing an entry in
> > feature-remove-schedule. There still seems to be some users of the
> > file.
> 
> i'm curious -- how did you determine that?

 $ grep "tty.h" util-linux/sys-utils/cytune.c
 #include <linux/tty.h>

 ... I'll fix it in util-linux-ng.


    Karel

-- 
 Karel Zak  <kzak@redhat.com>

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Robert P. J. Day]

On Thu, 19 Jul 2007, Karel Zak wrote:

> On Wed, Jul 18, 2007 at 04:33:12PM -0400, Robert P. J. Day wrote:
> > On Wed, 18 Jul 2007, Jiri Slaby wrote:
> >
> > > Robert P. J. Day napsal(a):
> > > >   given that the entire contents of include/linux/tty.h is contained
> > > > within an "#ifdef __KERNEL__", it seems pointless to export it to
> > > > userspace, unless there's some kind of need for that header file to
> > > > exist in userspace, even if it's empty.
> > > >
> > > >   a quick grep shows that nothing under /usr/include references any
> > > > file of the name "tty.h" in any way.  thoughts?
> > >
> > > If we decide to remove the file, I would rather go through
> > > deprecation of the file with filing an entry in
> > > feature-remove-schedule. There still seems to be some users of the
> > > file.
> >
> > i'm curious -- how did you determine that?
>
>  $ grep "tty.h" util-linux/sys-utils/cytune.c
>  #include <linux/tty.h>
>
>  ... I'll fix it in util-linux-ng.

so you're saying you'll drop that include from util-linux, is that it?
but it's still a good plan to generate a warning whenever userspace
includes that file, so i'll submit a quick patch to generate that,
based on jiri's suggestion.

rday
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Christoph Hellwig]

On Thu, Jul 19, 2007 at 07:17:07AM -0400, Robert P. J. Day wrote:
> so you're saying you'll drop that include from util-linux, is that it?
> but it's still a good plan to generate a warning whenever userspace
> includes that file, so i'll submit a quick patch to generate that,
> based on jiri's suggestion.

Not exporting it at all gives an error which is a lot better.  Just look
at all the warnings most userspace spews, they'd never even notice it
otherwise.

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Robert P. J. Day]

On Thu, 19 Jul 2007, Christoph Hellwig wrote:

> On Thu, Jul 19, 2007 at 07:17:07AM -0400, Robert P. J. Day wrote:
> > so you're saying you'll drop that include from util-linux, is that
> > it? but it's still a good plan to generate a warning whenever
> > userspace includes that file, so i'll submit a quick patch to
> > generate that, based on jiri's suggestion.
>
> Not exporting it at all gives an error which is a lot better.  Just
> look at all the warnings most userspace spews, they'd never even
> notice it otherwise.

i'm fine either way, i just didn't want to gratuitously break
userspace.  someone higher up the food chain is welcome to make the
decision here.

rday
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Jiri Slaby]

Christoph Hellwig napsal(a):
> On Thu, Jul 19, 2007 at 07:17:07AM -0400, Robert P. J. Day wrote:
>> so you're saying you'll drop that include from util-linux, is that it?
>> but it's still a good plan to generate a warning whenever userspace
>> includes that file, so i'll submit a quick patch to generate that,
>> based on jiri's suggestion.
> 
> Not exporting it at all gives an error which is a lot better.  Just look
> at all the warnings most userspace spews, they'd never even notice it
> otherwise.

Not directly responding to this, but keeping CCs. I though of the removal one
more time and there is one more issue (maybe). Every exported kernel header,
which includes this file outside #ifdef __KERNEL__ #endif will be broken in
userspace. Are you sure, there are no such includes?

-- 
Jiri Slaby (jirislaby@gmail.com)
Faculty of Informatics, Masaryk University

Re: [PATCH][RFC] Delete export of tty.h to userspace.

[Robert P. J. Day]

On Thu, 19 Jul 2007, Jiri Slaby wrote:

> Christoph Hellwig napsal(a):
> > On Thu, Jul 19, 2007 at 07:17:07AM -0400, Robert P. J. Day wrote:
> >> so you're saying you'll drop that include from util-linux, is
> >> that it? but it's still a good plan to generate a warning
> >> whenever userspace includes that file, so i'll submit a quick
> >> patch to generate that, based on jiri's suggestion.
> >
> > Not exporting it at all gives an error which is a lot better.
> > Just look at all the warnings most userspace spews, they'd never
> > even notice it otherwise.
>
> Not directly responding to this, but keeping CCs. I though of the
> removal one more time and there is one more issue (maybe). Every
> exported kernel header, which includes this file outside #ifdef
> __KERNEL__ #endif will be broken in userspace. Are you sure, there
> are no such includes?

yes, i checked the output from "make headers_install" as my first test
before proposing this.  there's nothing anywhere in that output that
includes tty.h.  that is, as long as i didn't screw up somewhere along
the way.

rday
-- 
========================================================================
Robert P. J. Day
Linux Consulting, Training and Annoying Kernel Pedantry
Waterloo, Ontario, CANADA

http://fsdev.net/wiki/index.php?title=Main_Page
========================================================================