unicode diacritics support

There have been issues with non-latin1 diacritics and unicode.
http://bugzilla.kernel.org/show_bug.cgi?id=7746

Git 759448f459234bfcf34b82471f0dba77a9aca498 `Kernel utf-8 handling'
partly resolved it by adding conversion between diacritics and
unicode. The patch below goes further by just turning diacritics into
unicode, hence providing better future support. The kbd support can be
fetched from
http://bugzilla.kernel.org/attachment.cgi?id=12313

This was tested in all of latin1, latin9, latin2 and unicode with french
and czech dead keys.

Turn the kernel accent_table into unicode, and extend ioctls KDGKBDIACR
and KDSKBDIACR into their equivalents KDGKBDIACRUC and KDSKBDIACR.

New function int conv_uni_to_8bit(u32 uni) for converting unicode into 8bit
_input_.  No, we don't want to store the translation, as it is potentially
sparse and large.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jan Engelhardt <jengelh@gmx.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 86 insertions, 19 deletions

diff --git a/drivers/char/consolemap.c b/drivers/char/consolemap.c
index 163f3fce3f84..6b104e45a322 100644
--- a/drivers/char/consolemap.c
+++ b/drivers/char/consolemap.c
@@ -669,19 +669,29 @@ void con_protect_unimap(struct vc_data *vc, int rdonly)
                 p->readonly = rdonly;
 }
 
+/*
+ * Always use USER_MAP. These functions are used by the keyboard,
+ * which shouldn't be affected by G0/G1 switching, etc.
+ * If the user map still contains default values, i.e. the
+ * direct-to-font mapping, then assume user is using Latin1.
+ */
 /* may be called during an interrupt */
 u32 conv_8bit_to_uni(unsigned char c)
 {
-        /*
-         * Always use USER_MAP. This function is used by the keyboard,
-         * which shouldn't be affected by G0/G1 switching, etc.
-         * If the user map still contains default values, i.e. the
-         * direct-to-font mapping, then assume user is using Latin1.
-         */
         unsigned short uni = translations[USER_MAP][c];
         return uni == (0xf000 | c) ? c : uni;
 }
 
+int conv_uni_to_8bit(u32 uni)
+{
+        int c;
+        for (c = 0; c < 0x100; c++)
+                if (translations[USER_MAP][c] == uni ||
+                   (translations[USER_MAP][c] == (c | 0xf000) && uni == c))
+                        return c;
+        return -1;
+}
+
 int
 conv_uni_to_pc(struct vc_data *conp, long ucs) 
 {
diff --git a/drivers/char/defkeymap.c_shipped b/drivers/char/defkeymap.c_shipped
index 453a2f1ffa15..0aa419a61767 100644
--- a/drivers/char/defkeymap.c_shipped
+++ b/drivers/char/defkeymap.c_shipped
@@ -222,7 +222,7 @@ char *func_table[MAX_NR_FUNC] = {
         NULL,
 };
 
-struct kbdiacr accent_table[MAX_DIACR] = {
+struct kbdiacruc accent_table[MAX_DIACR] = {
         {'`', 'A', '\300'},     {'`', 'a', '\340'},
         {'\'', 'A', '\301'},    {'\'', 'a', '\341'},
         {'^', 'A', '\302'},     {'^', 'a', '\342'},
diff --git a/drivers/char/keyboard.c b/drivers/char/keyboard.c
index d95f316afb5a..5ae2a3250c50 100644
--- a/drivers/char/keyboard.c
+++ b/drivers/char/keyboard.c
@@ -38,6 +38,7 @@
 #include <linux/kbd_kern.h>
 #include <linux/kbd_diacr.h>
 #include <linux/vt_kern.h>
+#include <linux/consolemap.h>
 #include <linux/sysrq.h>
 #include <linux/input.h>
 #include <linux/reboot.h>
@@ -403,9 +404,12 @@ static unsigned int handle_diacr(struct vc_data *vc, unsigned int ch)
                 return d;
 
         if (kbd->kbdmode == VC_UNICODE)
-                to_utf8(vc, conv_8bit_to_uni(d));
-        else if (d < 0x100)
-                put_queue(vc, d);
+                to_utf8(vc, d);
+        else {
+                int c = conv_uni_to_8bit(d);
+                if (c != -1)
+                        put_queue(vc, c);
+        }
 
         return ch;
 }
@@ -417,9 +421,12 @@ static void fn_enter(struct vc_data *vc)
 {
         if (diacr) {
                 if (kbd->kbdmode == VC_UNICODE)
-                        to_utf8(vc, conv_8bit_to_uni(diacr));
-                else if (diacr < 0x100)
-                        put_queue(vc, diacr);
+                        to_utf8(vc, diacr);
+                else {
+                        int c = conv_uni_to_8bit(diacr);
+                        if (c != -1)
+                                put_queue(vc, c);
+                }
                 diacr = 0;
         }
         put_queue(vc, 13);
@@ -627,9 +634,12 @@ static void k_unicode(struct vc_data *vc, unsigned int value, char up_flag)
                 return;
         }
         if (kbd->kbdmode == VC_UNICODE)
-                to_utf8(vc, conv_8bit_to_uni(value));
-        else if (value < 0x100)
-                put_queue(vc, value);
+                to_utf8(vc, value);
+        else {
+                int c = conv_uni_to_8bit(value);
+                if (c != -1)
+                        put_queue(vc, c);
+        }
 }
 
 /*
@@ -646,7 +656,12 @@ 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)
 {
-        k_unicode(vc, value, 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);
 }
 
 static void k_dead2(struct vc_data *vc, unsigned char value, char up_flag)
diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index f69a8258095c..6c7384afff13 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -23,6 +23,7 @@
 #include <linux/major.h>
 #include <linux/fs.h>
 #include <linux/console.h>
+#include <linux/consolemap.h>
 #include <linux/signal.h>
 #include <linux/timex.h>
 
@@ -582,10 +583,27 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
         case KDGKBDIACR:
         {
                 struct kbdiacrs __user *a = up;
+                struct kbdiacr diacr;
+                int i;
 
                 if (put_user(accent_table_size, &a->kb_cnt))
                         return -EFAULT;
-                if (copy_to_user(a->kbdiacr, accent_table, accent_table_size*sizeof(struct kbdiacr)))
+                for (i = 0; i < accent_table_size; i++) {
+                        diacr.diacr = conv_uni_to_8bit(accent_table[i].diacr);
+                        diacr.base = conv_uni_to_8bit(accent_table[i].base);
+                        diacr.result = conv_uni_to_8bit(accent_table[i].result);
+                        if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
+                                return -EFAULT;
+                }
+                return 0;
+        }
+        case KDGKBDIACRUC:
+        {
+                struct kbdiacrsuc __user *a = up;
+
+                if (put_user(accent_table_size, &a->kb_cnt))
+                        return -EFAULT;
+                if (copy_to_user(a->kbdiacruc, accent_table, accent_table_size*sizeof(struct kbdiacruc)))
                         return -EFAULT;
                 return 0;
         }
@@ -593,6 +611,30 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
         case KDSKBDIACR:
         {
                 struct kbdiacrs __user *a = up;
+                struct kbdiacr diacr;
+                unsigned int ct;
+                int i;
+
+                if (!perm)
+                        return -EPERM;
+                if (get_user(ct,&a->kb_cnt))
+                        return -EFAULT;
+                if (ct >= MAX_DIACR)
+                        return -EINVAL;
+                accent_table_size = ct;
+                for (i = 0; i < ct; i++) {
+                        if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
+                                return -EFAULT;
+                        accent_table[i].diacr = conv_8bit_to_uni(diacr.diacr);
+                        accent_table[i].base = conv_8bit_to_uni(diacr.base);
+                        accent_table[i].result = conv_8bit_to_uni(diacr.result);
+                }
+                return 0;
+        }
+
+        case KDSKBDIACRUC:
+        {
+                struct kbdiacrsuc __user *a = up;
                 unsigned int ct;
 
                 if (!perm)
@@ -602,7 +644,7 @@ int vt_ioctl(struct tty_struct *tty, struct file * file,
                 if (ct >= MAX_DIACR)
                         return -EINVAL;
                 accent_table_size = ct;
-                if (copy_from_user(accent_table, a->kbdiacr, ct*sizeof(struct kbdiacr)))
+                if (copy_from_user(accent_table, a->kbdiacruc, ct*sizeof(struct kbdiacruc)))
                         return -EFAULT;
                 return 0;
         }