From 25c4ad6ea52fc5451193dc98fc5ab04b1f509302 Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Tue, 20 Dec 2022 20:26:36 +0900 Subject: [PATCH] Cygwin: pinfo: Align CTTY behavior to the statement of POSIX. POSIX states "A terminal may be the controlling terminal for at most one session." https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap11.html However, in cygwin, multiple sessions could be associated with the same TTY. This patch aligns CTTY behavior to the statement of POSIX. Reviewed-by: Corinna Vinschen Signed-off-by: Takashi Yano --- winsup/cygwin/fhandler/termios.cc | 6 ++++- winsup/cygwin/mm/cygheap.cc | 2 ++ winsup/cygwin/pinfo.cc | 38 ++++++++++++++++++------------- 3 files changed, 29 insertions(+), 17 deletions(-) diff --git a/winsup/cygwin/fhandler/termios.cc b/winsup/cygwin/fhandler/termios.cc index fe4dfd13e..f94e20ff6 100644 --- a/winsup/cygwin/fhandler/termios.cc +++ b/winsup/cygwin/fhandler/termios.cc @@ -737,7 +737,11 @@ fhandler_termios::ioctl (int cmd, void *varg) } myself->ctty = -1; - myself->set_ctty (this, 0); + if (!myself->set_ctty (this, 0)) + { + set_errno (EPERM); + return -1; + } return 0; } diff --git a/winsup/cygwin/mm/cygheap.cc b/winsup/cygwin/mm/cygheap.cc index a305570df..72861d8d7 100644 --- a/winsup/cygwin/mm/cygheap.cc +++ b/winsup/cygwin/mm/cygheap.cc @@ -127,6 +127,8 @@ void init_cygheap::close_ctty () { debug_printf ("closing cygheap->ctty %p", cygheap->ctty); + if (cygheap->ctty->tc ()->getsid () == pid) + cygheap->ctty->tc ()->setsid (0); /* Release CTTY ownership */ cygheap->ctty->close_with_arch (); cygheap->ctty = NULL; } diff --git a/winsup/cygwin/pinfo.cc b/winsup/cygwin/pinfo.cc index e086ab9a8..586a4204d 100644 --- a/winsup/cygwin/pinfo.cc +++ b/winsup/cygwin/pinfo.cc @@ -530,24 +530,30 @@ _pinfo::set_ctty (fhandler_termios *fh, int flags) debug_printf ("old %s, ctty device number %y, tc.ntty device number %y flags & O_NOCTTY %y", __ctty (), ctty, tc.ntty, flags & O_NOCTTY); if (fh && (ctty <= 0 || ctty == tc.ntty) && !(flags & O_NOCTTY)) { - ctty = tc.ntty; - if (cygheap->ctty != fh->archetype) + if (tc.getsid () && tc.getsid () != sid) + ; /* Do nothing if another session is associated with the TTY. */ + else { - debug_printf ("cygheap->ctty %p, archetype %p", cygheap->ctty, fh->archetype); - if (!cygheap->ctty) - syscall_printf ("ctty was NULL"); - else + ctty = tc.ntty; + if (cygheap->ctty != fh->archetype) { - syscall_printf ("ctty %p, usecount %d", cygheap->ctty, - cygheap->ctty->archetype_usecount (0)); - cygheap->ctty->close (); - } - cygheap->ctty = (fhandler_termios *) fh->archetype; - if (cygheap->ctty) - { - fh->archetype_usecount (1); - /* guard ctty fh */ - report_tty_counts (cygheap->ctty, "ctty", ""); + debug_printf ("cygheap->ctty %p, archetype %p", + cygheap->ctty, fh->archetype); + if (!cygheap->ctty) + syscall_printf ("ctty was NULL"); + else + { + syscall_printf ("ctty %p, usecount %d", cygheap->ctty, + cygheap->ctty->archetype_usecount (0)); + cygheap->ctty->close (); + } + cygheap->ctty = (fhandler_termios *) fh->archetype; + if (cygheap->ctty) + { + fh->archetype_usecount (1); + /* guard ctty fh */ + report_tty_counts (cygheap->ctty, "ctty", ""); + } } }