* [PATCH] Fix KDFONTOP 32bit compatibility layer
@ 2012-01-28 23:28 Samuel Thibault
2012-01-31 16:35 ` Arnd Bergmann
0 siblings, 1 reply; 3+ messages in thread
From: Samuel Thibault @ 2012-01-28 23:28 UTC (permalink / raw)
To: linux-kernel, Arnd Bergmann, Greg Kroah-Hartman, Andrew Morton,
Arthur Taylor, Jiri Slaby, Jiri Olsa
KDFONTOP(GET) currently fails with EIO when being run in a 32bit
userland with a 64bit kernel if the font width is not 8. This is because
the compatibility layer introduced by e9216651 forces the addition of
the KD_FONT_FLAG_OLD flag, which makes con_font_get return EIO in such
case. This flag should *not* be set for KDFONTOP, since it's actually
the whole point of this flag (see comment in con_font_set for instance).
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
index 5e096f4..65447c5 100644
--- a/drivers/tty/vt/vt_ioctl.c
+++ b/drivers/tty/vt/vt_ioctl.c
@@ -1463,7 +1463,6 @@ compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
if (!perm && op->op != KD_FONT_OP_GET)
return -EPERM;
op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
- op->flags |= KD_FONT_FLAG_OLD;
i = con_font_op(vc, op);
if (i)
return i;
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] Fix KDFONTOP 32bit compatibility layer
2012-01-28 23:28 [PATCH] Fix KDFONTOP 32bit compatibility layer Samuel Thibault
@ 2012-01-31 16:35 ` Arnd Bergmann
2012-01-31 19:15 ` Andrew Morton
0 siblings, 1 reply; 3+ messages in thread
From: Arnd Bergmann @ 2012-01-31 16:35 UTC (permalink / raw)
To: Samuel Thibault
Cc: linux-kernel, Greg Kroah-Hartman, Andrew Morton, Arthur Taylor,
Jiri Slaby, Jiri Olsa
On Saturday 28 January 2012, Samuel Thibault wrote:
> KDFONTOP(GET) currently fails with EIO when being run in a 32bit
> userland with a 64bit kernel if the font width is not 8. This is because
> the compatibility layer introduced by e9216651 forces the addition of
> the KD_FONT_FLAG_OLD flag, which makes con_font_get return EIO in such
> case. This flag should not be set for KDFONTOP, since it's actually
> the whole point of this flag (see comment in con_font_set for instance).
>
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Hmm, this flag was not introduced in the patch you cite, it used to
live in fs/compat_ioctl.c before that, since before the start of the
git history. It seems to date back on the original sparc64 implementation
of do_kdfontop_ioctl that was written by Eddie Dost in 1998.
> diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> index 5e096f4..65447c5 100644
> --- a/drivers/tty/vt/vt_ioctl.c
> +++ b/drivers/tty/vt/vt_ioctl.c
> @@ -1463,7 +1463,6 @@ compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
> if (!perm && op->op != KD_FONT_OP_GET)
> return -EPERM;
> op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
> - op->flags |= KD_FONT_FLAG_OLD;
> i = con_font_op(vc, op);
> if (i)
> return i;
>From all I can tell, the patch looks correct, but please update the
description so you don't blame my innocent patch ;-)
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Fix KDFONTOP 32bit compatibility layer
2012-01-31 16:35 ` Arnd Bergmann
@ 2012-01-31 19:15 ` Andrew Morton
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Morton @ 2012-01-31 19:15 UTC (permalink / raw)
To: Arnd Bergmann
Cc: Samuel Thibault, linux-kernel, Greg Kroah-Hartman, Arthur Taylor,
Jiri Slaby, Jiri Olsa
On Tue, 31 Jan 2012 16:35:36 +0000
Arnd Bergmann <arnd@arndb.de> wrote:
> On Saturday 28 January 2012, Samuel Thibault wrote:
> > KDFONTOP(GET) currently fails with EIO when being run in a 32bit
> > userland with a 64bit kernel if the font width is not 8. This is because
> > the compatibility layer introduced by e9216651 forces the addition of
> > the KD_FONT_FLAG_OLD flag, which makes con_font_get return EIO in such
> > case. This flag should not be set for KDFONTOP, since it's actually
> > the whole point of this flag (see comment in con_font_set for instance).
> >
> > Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
>
> Hmm, this flag was not introduced in the patch you cite, it used to
> live in fs/compat_ioctl.c before that, since before the start of the
> git history. It seems to date back on the original sparc64 implementation
> of do_kdfontop_ioctl that was written by Eddie Dost in 1998.
>
> > diff --git a/drivers/tty/vt/vt_ioctl.c b/drivers/tty/vt/vt_ioctl.c
> > index 5e096f4..65447c5 100644
> > --- a/drivers/tty/vt/vt_ioctl.c
> > +++ b/drivers/tty/vt/vt_ioctl.c
> > @@ -1463,7 +1463,6 @@ compat_kdfontop_ioctl(struct compat_console_font_op __user *fontop,
> > if (!perm && op->op != KD_FONT_OP_GET)
> > return -EPERM;
> > op->data = compat_ptr(((struct compat_console_font_op *)op)->data);
> > - op->flags |= KD_FONT_FLAG_OLD;
> > i = con_font_op(vc, op);
> > if (i)
> > return i;
>
> From all I can tell, the patch looks correct, but please update the
> description so you don't blame my innocent patch ;-)
>
> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Yes, we should note the fact that at least one kernel bug isn't your
fault ;)
I changed the changelog to
: KDFONTOP(GET) currently fails with EIO when being run in a 32bit userland
: with a 64bit kernel if the font width is not 8.
:
: This is because of the setting of the KD_FONT_FLAG_OLD flag, which makes
: con_font_get return EIO in such case.
:
: This flag should *not* be set for KDFONTOP, since it's actually the whole
: point of this flag (see comment in con_font_set for instance).
:
: Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
: Reviewed-by: Arnd Bergmann <arnd@arndb.de>
: Cc: Greg Kroah-Hartman <gregkh@suse.de>
: Cc: Arthur Taylor <art@ified.ca>
: Cc: Jiri Slaby <jslaby@suse.cz>
: Cc: Jiri Olsa <jolsa@redhat.com>
: Cc: <stable@vger.kernel.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-01-28 23:28 [PATCH] Fix KDFONTOP 32bit compatibility layer Samuel Thibault
2012-01-31 16:35 ` Arnd Bergmann
2012-01-31 19:15 ` Andrew Morton
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