loadkmap: explain what happens with K_ALLOCATED key value

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/console-tools/loadkmap.c b/console-tools/loadkmap.c
index bcffe16..66ec3b0 100644 (file)
--- a/console-tools/loadkmap.c
+++ b/console-tools/loadkmap.c
@@ -48,6 +48,7 @@ int loadkmap_main(int argc UNUSED_PARAM, char **argv)
        if (argv[1])
                bb_show_usage();
 /* bb_warn_ignoring_args(argv[1]); */
+
        fd = get_console_fd_or_die();
 /* or maybe:
        opt = getopt32(argv, "C:", &tty_name);
@@ -61,14 +62,24 @@ int loadkmap_main(int argc UNUSED_PARAM, char **argv)
        xread(STDIN_FILENO, flags, MAX_NR_KEYMAPS);
 
        for (i = 0; i < MAX_NR_KEYMAPS; i++) {
-               if (flags[i] == 1) {
-                       xread(STDIN_FILENO, ibuff, NR_KEYS * sizeof(uint16_t));
-                       for (j = 0; j < NR_KEYS; j++) {
-                               ke.kb_index = j;
-                               ke.kb_table = i;
-                               ke.kb_value = ibuff[j];
-                               ioctl(fd, KDSKBENT, &ke);
-                       }
+               if (flags[i] != 1)
+                       continue;
+               xread(STDIN_FILENO, ibuff, NR_KEYS * sizeof(uint16_t));
+               for (j = 0; j < NR_KEYS; j++) {
+                       ke.kb_index = j;
+                       ke.kb_table = i;
+                       ke.kb_value = ibuff[j];
+                       /*
+                        * Note: table[idx:0] can contain special value
+                        * K_ALLOCATED (marks allocated tables in kernel).
+                        * dumpkmap saves the value as-is; but attempts
+                        * to load it here fail, since it isn't a valid
+                        * key value: it is K(KT_SPEC,126) == 2<<8 + 126,
+                        * whereas last valid KT_SPEC is
+                        * K_BARENUMLOCK == K(KT_SPEC,19).
+                        * So far we just ignore these errors:
+                        */
+                       ioctl(fd, KDSKBENT, &ke);
                }
        }