Fix chroot, leave console alone if -c not specified, and yank debug code.

(I still haven't set up a test environment to confirm this works...)

1 files changed, 16 insertions, 11 deletions

diff --git a/util-linux/switch_root.c b/util-linux/switch_root.c
index 242699560..0c86eec08 100644
--- a/util-linux/switch_root.c
+++ b/util-linux/switch_root.c
@@ -56,17 +56,17 @@ static void delete_contents(char *directory)
                         closedir(dir);
                         
                         // Directory should now be empty.  Zap it.
-                        printf("rmdir %s\n",directory); // rmdir(directory);
+                        rmdir(directory);
                 }
                 
         // It wasn't a directory.  Zap it.
                 
-        } else printf("unlink %s\n",directory); //unlink(directory);
+        } else unlink(directory);
 }
 
 int switch_root_main(int argc, char *argv[])
 {
-        char *newroot, *console="/dev/console";
+        char *newroot, *console=NULL;
         struct stat st1, st2;
         struct statfs stfs;
 
@@ -98,19 +98,24 @@ int switch_root_main(int argc, char *argv[])
         }
 
         // Zap everything out of rootdev
+
         delete_contents("/");
         
-        // Overmount / with newdir
+        // Overmount / with newdir and chroot into it.  The chdir is needed to
+        // recalculate "." and ".." links.
 
-        if (mount(".", "/", NULL, MS_MOVE, NULL) || chdir("/"))
+        if (mount(".", "/", NULL, MS_MOVE, NULL) || chroot(".") || chdir("/"))
                 bb_error_msg_and_die("moving root");
         
-        // Reopen stdin/stdout/stderr to /dev/console
-        close(0);
-        if(open(console, O_RDWR) < 0)
-                bb_error_msg_and_die("Bad console '%s'",console);
-        dup2(0, 1);
-        dup2(0, 2);
+        // If a new console specified, redirect stdin/stdout/stderr to that.
+
+        if (console) {
+                close(0);
+                if(open(console, O_RDWR) < 0)
+                        bb_error_msg_and_die("Bad console '%s'",console);
+                dup2(0, 1);
+                dup2(0, 2);
+        }
 
         // Exec real init.  (This is why we must be pid 1.)
         execv(argv[optind],argv+optind+1);