getty: add O_NONBLOCK to open which is used to drop ctty

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2011-10-22 08:19:42 +02:00
parent a241069004
commit e206a4de4c

View File

@ -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);