Messages in this thread Patch in this message | | | Date | Tue, 31 Jan 2012 11:15:53 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] Fix KDFONTOP 32bit compatibility layer |
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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>
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