Fix regressions in return events of poll() on TTYs.

As pointed out, POLLHUP should be generated, even if it hasn't been
specified on input. It is also not allowed to return both POLLOUT and
POLLHUP

Fix regressions in return events of poll() on TTYs.

As pointed out, POLLHUP should be generated, even if it hasn't been
specified on input. It is also not allowed to return both POLLOUT and
POLLHUP at the same time.

Reported by: jilles
Approved by: re (kib)

show more ...

- MFC

Add FIONWRITE support to TTYs.

TTYs already supported TIOCOUTQ, but FIONWRITE seems to be a more
generic name for this.

Approved by: re (kib)

Improve my last commit: use a separate condvar to serialize.

The advantage of using a separate condvar is that we can just use
cv_signal(9) instead of cv_broadcast(9). It makes no sense to wake up
m

Improve my last commit: use a separate condvar to serialize.

The advantage of using a separate condvar is that we can just use
cv_signal(9) instead of cv_broadcast(9). It makes no sense to wake up
multiple threads. It also makes the TTY code easier to understand.
t_dcdwait sounds totally unrelated.

show more ...

Use dcdwait to block threads to serialize writes.

I suspect the usage of bgwait causes a lot of spurious wakeups when
threads are blocked in the background, because they will be woken up
each time a

Use dcdwait to block threads to serialize writes.

I suspect the usage of bgwait causes a lot of spurious wakeups when
threads are blocked in the background, because they will be woken up
each time a write() call is performed.

Also wakeup dcdwait when the TTY is abandoned.

show more ...

Improve nested jail awareness of devfs by handling credentials.

Now that we start to use credentials on character devices more often
(because of MPSAFE TTY), move the prison-checks that are in place

Improve nested jail awareness of devfs by handling credentials.

Now that we start to use credentials on character devices more often
(because of MPSAFE TTY), move the prison-checks that are in place in the
TTY code into devfs.

Instead of strictly comparing the prisons, use the more common
prison_check() function to compare credentials. This means that
pseudo-terminals are only visible in devfs by processes within the same
jail and parent jails.

Even though regular users in parent jails can now interact with
pseudo-terminals from child jails, this seems to be the right approach.
These processes are also capable of interacting with the jailed
processes anyway, through signals for example.

Reviewed by: kib, rwatson (older version)

show more ...

Perform some more cleanups to in-kernel session handling.

The code that was in place in exit1() was mainly based on code from the
old TTY layer. The main reason behind this, was because at one momen

Perform some more cleanups to in-kernel session handling.

The code that was in place in exit1() was mainly based on code from the
old TTY layer. The main reason behind this, was because at one moment I
ran a system that had two TTY layers in place at the same time. It is
now sufficient to do the following:

- Remove references from the session structure to the TTY vnode and the
session leader.

- If we have a controlling TTY and the session used by the TTY is equal
to our session, send the SIGHUP.

- If we have a vnode to the controlling TTY which has not been revoked,
revoke it.

While there, change sys/kern/tty.c to use s_ttyp in the comparison
instead of s_ttyvp. It should not make any difference, because s_ttyvp
can only become null when the session leader already left, but it's
nicer to compare against the proper value.

show more ...

Make tcsetsid(3) work on revoked TTYs.

Right now the only way to make tcsetsid(3)/TIOCSCTTY work, is by
ensuring the session leader is dead. This means that an application that
catches SIGHUPs and p

Make tcsetsid(3) work on revoked TTYs.

Right now the only way to make tcsetsid(3)/TIOCSCTTY work, is by
ensuring the session leader is dead. This means that an application that
catches SIGHUPs and performs a sleep prevents us from assigning a new
session leader.

Change the code to make it work on revoked TTYs as well. This allows us
to change init(8) to make the shutdown script run in a more clean
environment.

show more ...

Revert my previous change, because it reintroduces an old regression.

Because our rc scripts also open the /etc/ttyv* nodes, it revokes the
console, preventing startup messages from being displayed.

Revert my previous change, because it reintroduces an old regression.

Because our rc scripts also open the /etc/ttyv* nodes, it revokes the
console, preventing startup messages from being displayed.

I really have to think about this. Maybe we should just give the console
its own TTY and let it build on top of other TTYs. I'm still not sure
what to do with input handling there.

show more ...

Prevent yet another staircase effect bug in the console device.

Even though I thought I fixed the staircase issue (and I was no longer
able to reproduce it), I got some reports of the issue still be

Prevent yet another staircase effect bug in the console device.

Even though I thought I fixed the staircase issue (and I was no longer
able to reproduce it), I got some reports of the issue still being
there. It turns out the staircase effect still occurred when
/dev/console was kept open while killing the getty on the same TTY
(ttyv0).

For some reason I can't figure out how the old TTY code dealt with that,
so I assume the issue has always been there. I only exposed it more by
merging consolectl with ttyv0, which means that the issue was present,
even on systems without a serial console.

I'm now marking the console device as being closed when closing the
regular TTY device node. This means that when the getty shuts down,
init(8) will open /dev/console, which means the termios attributes will
always be reset in this case.

show more ...

- Merge from HEAD

Adapt vfs kqfilter to the shared vnode lock used by zfs write vop. Use
vnode interlock to protect the knote fields [1]. The locking assumes
that shared vnode lock is held, thus we get exclusive acces

Adapt vfs kqfilter to the shared vnode lock used by zfs write vop. Use
vnode interlock to protect the knote fields [1]. The locking assumes
that shared vnode lock is held, thus we get exclusive access to knote
either by exclusive vnode lock protection, or by shared vnode lock +
vnode interlock.

Do not use kl_locked() method to assert either lock ownership or the
fact that curthread does not own the lock. For shared locks, ownership
is not recorded, e.g. VOP_ISLOCKED can return LK_SHARED for the shared
lock not owned by curthread, causing false positives in kqueue subsystem
assertions about knlist lock.

Remove kl_locked method from knlist lock vector, and add two separate
assertion methods kl_assert_locked and kl_assert_unlocked, that are
supposed to use proper asserts. Change knlist_init accordingly.

Add convenience function knlist_init_mtx to reduce number of arguments
for typical knlist initialization.

Submitted by: jhb [1]
Noted by: jhb [2]
Reviewed by: jhb
Tested by: rnoland

show more ...

Do not dereference vp->v_rdev without holding any of dev_mtx or vnode
lock. Use code similar to devfs_fp_check(), but inlined to feet other
checks performed by ttyhook_register().

Reviewed by: ed

Last minute TTY API change: remove mutex argument from tty_alloc().

I don't want people to override the mutex when allocating a TTY. It has
to be there, to keep drivers like syscons happy. So I'm cr

Last minute TTY API change: remove mutex argument from tty_alloc().

I don't want people to override the mutex when allocating a TTY. It has
to be there, to keep drivers like syscons happy. So I'm creating a
tty_alloc_mutex() which can be used in those cases. tty_alloc_mutex()
should eventually be removed.

The advantage of this approach, is that we can just remove a function,
without breaking the regular API in the future.

show more ...

Get rid of M_TEMP.

Merge from HEAD

Block when initially opening a TTY multiple times.

In the original MPSAFE TTY code, I changed the behaviour by returning
EBUSY. I thought this made more sense, because it's basically a race to
see w

Block when initially opening a TTY multiple times.

In the original MPSAFE TTY code, I changed the behaviour by returning
EBUSY. I thought this made more sense, because it's basically a race to
see who gets the TTY first.

It turns out this is not a good change, because it also causes EBUSY to
be returned when another process is closing the TTY. This can happen
during startup, when /etc/rc (or one of its children) is still busy
draining its data and /sbin/init is attempting to open the TTY to spawn
a getty.

Reported by: bz
Tested by: bz

show more ...

- Implement a lockless file descriptor lookup algorithm in
fget_unlocked().
- Save old file descriptor tables created on expansion until
the entire descriptor table is freed so that pointers m

- Implement a lockless file descriptor lookup algorithm in
fget_unlocked().
- Save old file descriptor tables created on expansion until
the entire descriptor table is freed so that pointers may be
followed without regard for expanders.
- Mark the file zone as NOFREE so we may attempt to reference
potentially freed files.
- Convert several fget_locked() users to fget_unlocked(). This
requires us to manage reference counts explicitly but reduces
locking overhead in the common case.

show more ...

Merge from HEAD

Remove unneeded check for SESS_LEADER().

We perform the same check ~10 lines above.

- Merge from HEAD

Fix tty_wait_background() to comply with standards.

It turns out my handling of SIGTTOU and SIGTTIN didn't entirely comply
to the standards. It is true that in the SIGTTOU case we should not
return

Fix tty_wait_background() to comply with standards.

It turns out my handling of SIGTTOU and SIGTTIN didn't entirely comply
to the standards. It is true that in the SIGTTOU case we should not
return EIO when the signal is ignored/blocked, but in the SIGTTIN case
we must.

See also: POSIX issue 7 section 11.1.4

show more ...

Update the projects tree to a newer FreeBSD current.

Improve my previous changes to the TTY code: also remove memcpy().

It's better to just use internal language constructs, because it is
likely the compiler has a better opinion on whether to perform

Improve my previous changes to the TTY code: also remove memcpy().

It's better to just use internal language constructs, because it is
likely the compiler has a better opinion on whether to perform inlining,
which is very likely to happen to struct winsize.

Submitted by: Christoph Mallon <christoph mallon gmx de>

show more ...

Replace bcopy() calls inside the TTY layer with memcpy()/strlcpy().

In all these cases the buffers never overlap. Program names are also
likely to be shorter, so use a regular strlcpy() to copy p_co

Replace bcopy() calls inside the TTY layer with memcpy()/strlcpy().

In all these cases the buffers never overlap. Program names are also
likely to be shorter, so use a regular strlcpy() to copy p_comm.

show more ...