There was a long-standing issue that pseudo console ownership could
not hand over from the process whose ctty is /dev/cons* rather than
/dev/pty*. This problem happens when a cygwin app starts non-cygwin
app in a pty, then the non-cygwin app starts multiple cygwin apps,
and the non-cygwin app ends before the second cygwin apps end.
In this case, the stub process of the non-cygwin app hands over the
ownership of pcon to one of the second cygwin apps, however, this
app does not hand over the ownership of pcon to another second
cygwin app. This is due to the fact that the hand-over feature is
implemented only in fhandler_pty_slave but not in fhandler_console.
With this patch, the second cygwin apps check if their console device
is inside a pseudo console, and if so, it tries to hand over the
ownership of the pseudo console to anther process that is attached
to the same pseudo console.
Addresses: https://cygwin.com/pipermail/cygwin/2024-February/255388.html
Fixes: 253352e796 ("Cygwin: pty: Allow multiple apps to enable pseudo console simultaneously.")
Reported-by: lmari Lauhakangas <ilmari.lauhakangas@libreoffice.org>, Hossein Nourikhah <hossein@libreoffice.org>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
While st_rdev returned by fstat() for /dev/tty should be FH_TTY,
the current cygwin1.dll returns FH_PTYS+minor or FH_CONS+minor.
Similarly, fstat() does not return correct value for /dev/console,
/dev/conout, /dev/conin or /dev/ptmx.
This patch fixes the issue by:
1) Introduce dev_referred_via in fhandler_termios.
2) Add new argument, which has dev_t value referred by open(),
for constructors of fhandler_pty_slave and fhandler_pty_master to
set the value of dev_referred_via.
3) Set st_rdev using dev_referred_via in fhandler_termios::fstat()
if it is available.
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
This patch replaces ctty constants with more descriptive macros
(CTTY_UNINITIALIZED and CTTY_RELEASED) rather than -1 and -2 as
well as checking sign with CTTY_IS_VALID().
Fixes: 3b7df69aaa (Cygwin: ctty: Add comments for the special values: -1 and -2.)
Suggested-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
The commit 25c4ad6ea5 did not fix the CTTY behavior enough. For
example, in the following test case, TTY will be associated as
a CTTY on the second open() call even though the TTY is already
CTTY of another session. This patch fixes the issue.
#include <unistd.h>
#include <sys/fcntl.h>
int main()
{
if (fork () == 0) {
char *tty = ttyname(0);
int fd;
setsid();
fd = open(tty, O_RDWR);
close(fd);
fd = open(tty, O_RDWR);
usleep (60000000L);
}
return 0;
}
Fixes: 25c4ad6ea5 ("Cygwin: pinfo: Align CTTY behavior to the
statement of POSIX.")
Reviewed-by: Corinna Vinschen <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
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 <corinna@vinschen.de>
Signed-off-by: Takashi Yano <takashi.yano@nifty.ne.jp>
Only required for Windows 7.
This in turn allows to drop the helper_pid and related
methods from fhandler_pty_common.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
- The codes related to pty and console in spawn.cc have been moved
into the new class fhandler_termios::spawn_worker, and make spawn.cc
call them. The functionality has not been changed at all.
Takashi Yano
Corinna Vinschen