switch-root: reopen /dev/console before we switch root

src/core/main.c

@@ -164,16 +164,11 @@ _noreturn_ static void crash(int sig) {
                 sa.sa_flags = SA_NOCLDSTOP|SA_NOCLDWAIT|SA_RESTART;
                 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 
-                if ((pid = fork()) < 0)
+                pid = fork();
+                if (pid < 0)
                         log_error("Failed to fork off crash shell: %s", strerror(errno));
                 else if (pid == 0) {
-                        int fd, r;
-
-                        if ((fd = acquire_terminal("/dev/console", false, true, true, (usec_t) -1)) < 0)
-                                log_error("Failed to acquire terminal: %s", strerror(-fd));
-                        else if ((r = make_stdio(fd)) < 0)
-                                log_error("Failed to duplicate terminal fd: %s", strerror(-r));
-
+                        make_console_stdio();
                         execl("/bin/sh", "/bin/sh", NULL);
 
                         log_error("execl() failed: %s", strerror(errno));
@@ -1677,6 +1672,9 @@ finish:
                  * rebooted while we do that */
                 watchdog_close(true);
 
+                /* Reopen the console */
+                make_console_stdio();
+
                 if (switch_root_dir) {
                         r = switch_root(switch_root_dir);
                         if (r < 0)

src/core/shutdown.c

@@ -267,9 +267,10 @@ static int prepare_new_root(void) {
 }
 
 static int pivot_to_new_root(void) {
-        int fd;
-
-        chdir("/run/initramfs");
+        if (chdir("/run/initramfs") < 0) {
+                log_error("Failed to change directory to /run/initramfs: %m");
+                return -errno;
+        }
 
         /*
           In case some evil process made "/" MS_SHARED
@@ -288,19 +289,12 @@ static int pivot_to_new_root(void) {
         }
 
         chroot(".");
+
+        setsid();
+        make_console_stdio();
+
         log_info("Successfully changed into root pivot.");
 
-        fd = open("/dev/console", O_RDWR);
-        if (fd < 0)
-                log_error("Failed to open /dev/console: %m");
-        else {
-                make_stdio(fd);
-
-                /* Initialize the controlling terminal */
-                setsid();
-                ioctl(STDIN_FILENO, TIOCSCTTY, NULL);
-        }
-
         return 0;
 }