2 files changed, 18 insertions, 0 deletions

diff --git a/init/Config.in b/init/Config.in
index 521f8fe1d..a3584aaf5 100644
--- a/init/Config.in
+++ b/init/Config.in
@@ -43,6 +43,17 @@ config CONFIG_FEATURE_INIT_SWAPON
           If the system has less than one megabyte of total memory, init
           will run '/sbin/swapon -a' to add swap memory.
 
+config CONFIG_FEATURE_INIT_SCTTY
+        bool "  Support running commands with a controlling-tty?"
+        default n
+        depends on CONFIG_INIT
+        help
+          If this option is enabled a command starting with hyphen (-)
+          is run in its own session (setsid(2)) and possibly with a
+          controlling tty (TIOCSCTTY).  This is not the traditional init
+          behavour, but is often what you want in an embedded system where
+          the console is only accessed during development or for maintenance.
+
 config CONFIG_FEATURE_EXTRA_QUIET
         bool "  Should init be _extra_ quiet on boot?"
         default y
diff --git a/init/init.c b/init/init.c
index 8687b106c..0f49a45d8 100644
--- a/init/init.c
+++ b/init/init.c
@@ -577,6 +577,13 @@ static pid_t run(const struct init_action *a)
                                 cmd[0][0] = '-';
                                 strcpy(cmd[0] + 1, s);
                         }
+#ifdef CONFIG_FEATURE_INIT_SCTTY
+                        /* Establish this process as session leader and
+                         * (attempt) to make the tty (if any) a controlling tty.
+                         */
+                        (void) setsid();
+                        (void) ioctl(0, TIOCSCTTY, 0/*don't steal it*/);
+#endif
                 }
 
 #if !defined(__UCLIBC__) || defined(__ARCH_HAS_MMU__)