cttyhack: handle multiple consoles found in sysfs

If multiple consoles are found from the sysfs file, cttyhack fails:

cttyhack: can't open '/dev/tty0 ttyS0': No such file or directory

In such cases take the last one as the kernel will use that one for
/dev/console.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/shell/cttyhack.c b/shell/cttyhack.c
index 6ff867413..f9b59c263 100644
--- a/shell/cttyhack.c
+++ b/shell/cttyhack.c
@@ -123,15 +123,22 @@ int cttyhack_main(int argc UNUSED_PARAM, char **argv)
                          * TIOCGSERIAL check, which assumes that all
                          * serial lines follow /dev/ttySn convention -
                          * which is not always the case.
-                         * Therefore, we use this methos first:
+                         * Therefore, we use this method first:
                          */
                         int s = open_read_close("/sys/class/tty/console/active",
                                 console + 5, sizeof(console) - 5);
                         if (s > 0) {
-                                /* found active console via sysfs (Linux 2.6.38+)
-                                 * sysfs string looks like "ttyS0\n" so zap the newline:
+                                char *last;
+                                /* Found active console via sysfs (Linux 2.6.38+).
+                                 * It looks like "[tty0 ]ttyS0\n" so zap the newline:
                                  */
                                 console[4 + s] = '\0';
+                                /* If there are multiple consoles,
+                                 * take the last one:
+                                 */
+                                last = strrchr(console + 5, ' ');
+                                if (last)
+                                        overlapping_strcpy(console + 5, last + 1);
                                 break;
                         }