gistfile1.patch

diff --git a/src/libkfont/kdfontop.c b/src/libkfont/kdfontop.c
index 1eadbebb..cada3f95 100644
--- a/src/libkfont/kdfontop.c
+++ b/src/libkfont/kdfontop.c
@@ -21,11 +21,29 @@
 #include "compat/linux-kd.h"
 #endif

+static int
+is_kd_text(struct kfont_context *ctx, int fd)
+{
+       unsigned int kd_mode;
+
+       if (ioctl(fd, KDGETMODE, &kd_mode)) {
+               KFONT_ERR(ctx, "ioctl(KDGETMODE): %m");
+               return 0;
+       }
+
+       return (kd_mode == KD_TEXT);
+}
+
 int
 kfont_restore_font(struct kfont_context *ctx, int fd)
 {
        struct console_font_op cfo;

+       if (!is_kd_text(ctx, fd)) {
+               KFONT_ERR(ctx, _("Console is not in text mode"));
+               return -1;
+       }
+
        cfo.op = KD_FONT_OP_SET_DEFAULT;

        if (ioctl(fd, KDFONTOP, &cfo)) {
@@ -60,6 +78,11 @@ get_font_kdfontop(struct kfont_context *ctx, int consolefd,
 {
        struct console_font_op cfo;

+       if (!is_kd_text(ctx, consolefd)) {
+               KFONT_ERR(ctx, _("Console is not in text mode"));
+               return -1;
+       }
+
        cfo.op = KD_FONT_OP_GET;
        cfo.flags = 0;
        cfo.width = 32;
@@ -162,6 +185,11 @@ put_font_kdfontop(struct kfont_context *ctx, int consolefd, unsigned char *buf,
 {
        struct console_font_op cfo;

+       if (!is_kd_text(ctx, consolefd)) {
+               KFONT_ERR(ctx, _("Console is not in text mode"));
+               return -1;
+       }
+
        if (vpitch == 32 && width <= 32)
                cfo.op        = KD_FONT_OP_SET;
        else {