From e206a4de4c700230f3dc9fdaa101c6f4432e1c27 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sat, 22 Oct 2011 08:19:42 +0200 Subject: [PATCH] getty: add O_NONBLOCK to open which is used to drop ctty Signed-off-by: Denys Vlasenko --- loginutils/getty.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/loginutils/getty.c b/loginutils/getty.c index 230846008..3496f0284 100644 --- a/loginutils/getty.c +++ b/loginutils/getty.c @@ -556,10 +556,12 @@ int getty_main(int argc UNUSED_PARAM, char **argv) * In this case (setsid failed) we may still have ctty, * and it may be different from tty we need to control! * If we still have ctty, on Linux ioctl(TIOCSCTTY) - * (which we are going to call a bit later) always fails. - * Try to drop ctty now to prevent that. + * (which we are going to use a bit later) always fails - + * even if we try to take ctty which is already ours! + * Try to drop old ctty now to prevent that. + * Use O_NONBLOCK: old ctty may be a serial line. */ - fd = open("/dev/tty", O_RDWR); + fd = open("/dev/tty", O_RDWR | O_NONBLOCK); if (fd >= 0) { ioctl(fd, TIOCNOTTY); close(fd);