2008-06-11 13:48:46

by Jiri Bohac

[permalink] [raw]
Subject: [PATCH] console keyboard mapping broken by 04c71976

Hi,

the Czech (and I believe many other) console keyboard maps are
broken since 04c71976.

To make old (non-unicode - the majority distributed with the kbd
package) keymaps work, the keyboard mapping in the kernel uses a
trick. It uses the translation tables loaded with the console
font to translate the 8-bit values to unicode values.

So with the currently available keymaps when using unicode in
the console you end up with:

- kbd->kbdmode set to VC_UNICODE, to send UTF-8 sequences to the
terminal
- most letters, icluding non-latin1, defined as type=KT_LETTER in the
keymap, with an 8-bit value, which only has its correct meaning
when translated using conv_8bit_to_uni().

04c71976 changes k_self() to:
static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
{
unsigned int uni;
if (kbd->kbdmode == VC_UNICODE)
uni = value;
else
uni = conv_8bit_to_uni(value);
k_unicode(vc, uni, up_flag);
}

It wrongly assumes, that when the keyboard is in the VC_UNICODE
mode, value is already the correct unicode value. This is only
true for latin1.

I think we need to always convert the value with
conv_8bit_to_uni(), as we did before 04c71976.

The following patch fixes the problem for me:

diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 7f7e798..16492b7 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -678,10 +678,7 @@ static void k_deadunicode(struct vc_data *vc, unsigned int value, char up_flag)
static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
{
unsigned int uni;
- if (kbd->kbdmode == VC_UNICODE)
- uni = value;
- else
- uni = conv_8bit_to_uni(value);
+ uni = conv_8bit_to_uni(value);
k_unicode(vc, uni, up_flag);
}

As far as I can see, it will affect latin1 users that now get
their keymaps working even without loading the "trivial" console
map (so the conversion will not do anything) but I think they
needed to do that before 04c71976, so they probably still do
without even knowing, right?

Samuel, any comments?

--
Jiri Bohac <[email protected]>
SUSE Labs, SUSE CZ


2008-06-11 14:13:12

by Samuel Thibault

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976

Err, at quick look it looks to me rather like a bug kbd, which doesn't
cope with the console being in unicode mode. Which distribution are you
using?

In unicode mode, k_self is really meant to hold unicode values (there is
no other way to provide an arbitrary unicode value in keyboard maps),
and thus kbd should translate KT_LETTER's value from the map file's
encoding (set by the charset directive) to unicode.

Samuel

2008-06-11 15:10:38

by Jiri Bohac

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976

On Wed, Jun 11, 2008 at 03:03:04PM +0100, Samuel Thibault wrote:
> Err, at quick look it looks to me rather like a bug kbd, which doesn't
> cope with the console being in unicode mode. Which distribution are you
> using?
>
> In unicode mode, k_self is really meant to hold unicode values (there is
> no other way to provide an arbitrary unicode value in keyboard maps),
> and thus kbd should translate KT_LETTER's value from the map file's
> encoding (set by the charset directive) to unicode.

I am actually hunting down a bug this causes in openSUSE. We use
kbd-1.12. kbd does not translate anything to unicode - there is
no space for that in the 8 bits the keycode uses for the value.
The kernel needs to take care for the conversion.

I'll demonstrate the problem on tracing kbd_keycode() in
drivers/char/keyboard.c when the key "2" (keycode 3) is pressed.
The expected result is the letter letter "e" with a caron [CARON]
accent, code 0xec in iso-8859-2 [88592].

The keysym for this key in the Czech keyboard is set to 0xbec
by a call to KDSKBENT, which stores it as 0xfbec in the map.

...
type = KTYP(keysym); // 0xfb
...
type -= 0xf0; // 0xb
if (type == KT_LETTER) { // true
type = KT_LATIN; // 0

...
(*k_handler[type])(vc, keysym & 0xff, !down);
// calls k_self, note there is really no space for a
// full unicode representation ;-)

So, we need to perform the conversion in k_self (or later). Your
patch removed it from k_unicode, but only does it in k_self when
the keyboard mode is not VC_UNICODE.

[CARON]: http://en.wikipedia.org/wiki/Caron
[88592]: http://en.wikipedia.org/wiki/Iso-8859-2

Regards,

--
Jiri Bohac <[email protected]>
SUSE Labs, SUSE CZ

2008-06-11 15:24:19

by Samuel Thibault

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976

Jiri Bohac, le Wed 11 Jun 2008 17:10:28 +0200, a ?crit :
> ...
> type = KTYP(keysym); // 0xfb
> ...
> type -= 0xf0; // 0xb
> if (type == KT_LETTER) { // true
> type = KT_LATIN; // 0
>
> ...
> (*k_handler[type])(vc, keysym & 0xff, !down);
> // calls k_self, note there is really no space for a
> // full unicode representation ;-)

Ah, right, my too-quick look mistook your case with the (type < 0xf0)
case, which does have room for unicode.

Well, in my tests it _was_ working with latin2. I'll dig more this
evening.

Samuel

2008-06-12 01:25:42

by Samuel Thibault

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976


Ok, a closer look agrees with the patch, but no need to keep the uni
variable then, here is an updated patch. Thanks!

From: Jiri Bohac <[email protected]>
Signed-off-by: Samuel Thibault <[email protected]>

diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 7f7e798..16492b7 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -678,10 +678,5 @@
static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
{
- unsigned int uni;
- if (kbd->kbdmode == VC_UNICODE)
- uni = value;
- else
- uni = conv_8bit_to_uni(value);
- k_unicode(vc, uni, up_flag);
+ k_unicode(vc, conv_8bit_to_uni(value), up_flag);
}

2008-06-12 01:27:47

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976

On Thu, 12 Jun 2008 02:18:32 +0100 Samuel Thibault <[email protected]> wrote:

>
> Ok, a closer look agrees with the patch, but no need to keep the uni
> variable then, here is an updated patch. Thanks!
>
> From: Jiri Bohac <[email protected]>
> Signed-off-by: Samuel Thibault <[email protected]>
>
> diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
> index 7f7e798..16492b7 100644
> --- a/drivers/char/keyboard.c
> +++ b/drivers/char/keyboard.c
> @@ -678,10 +678,5 @@
> static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
> {
> - unsigned int uni;
> - if (kbd->kbdmode == VC_UNICODE)
> - uni = value;
> - else
> - uni = conv_8bit_to_uni(value);
> - k_unicode(vc, uni, up_flag);
> + k_unicode(vc, conv_8bit_to_uni(value), up_flag);
> }

Is this ready to be applied? If so, please send a changelog.

btw, the From: line shold be right at the top of the changelog.

Thanks.

2008-06-12 01:36:30

by Samuel Thibault

[permalink] [raw]
Subject: Re: [PATCH] console keyboard mapping broken by 04c71976

Andrew Morton, le Wed 11 Jun 2008 18:27:06 -0700, a ?crit :
> Is this ready to be applied? If so, please send a changelog.

Ah, right, there was no changelog.



From: Jiri Bohac <[email protected]>

Several console keyboard maps are broken since 04c71976, because that
changeset made k_self consider the value as a latin1 character when in
Unicode mode, which is wrong; k_self should still take the console map
into account.

Signed-off-by: Samuel Thibault <[email protected]>

diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index 7f7e798..16492b7 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -678,10 +678,5 @@
static void k_self(struct vc_data *vc, unsigned char value, char up_flag)
{
- unsigned int uni;
- if (kbd->kbdmode == VC_UNICODE)
- uni = value;
- else
- uni = conv_8bit_to_uni(value);
- k_unicode(vc, uni, up_flag);
+ k_unicode(vc, conv_8bit_to_uni(value), up_flag);
}