Re: [TTY] exclusive mode question

From: Frederik Deweerdt
Date: Thu Jun 09 2005 - 05:43:32 EST


Le 09/06/05 11:59 +0200, moreau francis écrivit:
>
> --- Frederik Deweerdt <dev.deweerdt@xxxxxxxxxxx> a écrit :
>
> > I've just greped and I found :
> >
> > if (!retval && test_bit(TTY_EXCLUSIVE, &tty->flags) &&
> > !capable(CAP_SYS_ADMIN))
> > retval = -EBUSY;
> > in drivers/char/tty_io.c:tty_open
> >
> > Which sources are you looking at?
> >
>
> same source code but if another process has previously open the tty, how does
> this source code detect it ?
>
Sorry I misunderstood your question, there's no check on previous opens:
from man tty_ioctl:

TIOCEXCL void
Put the tty into exclusive mode. No _further_ open(2) operations on the terminal are permitted.
(They will fail with EBUSY, except for root.)

Emphasis mine.
Regards,
Frederik Deweerdt
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