user/sven/linux.git/include/linux/tty.h, branch v4.4.25

Fix OpenSSH pty regression on close

2016-06-01T19:15:52Z

commit 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa upstream. OpenSSH expects the (non-blocking) read() of pty master to return EAGAIN only if it has received all of the slave-side output after it has received SIGCHLD. This used to work on pre-3.12 kernels. This fix effectively forces non-blocking read() and poll() to block for parallel i/o to complete for all ttys. It also unwinds these changes: 1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12 tty: Fix pty master read() after slave closes 2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73 pty, n_tty: Simplify input processing on final close 3) 1a48632ffed61352a7810ce089dc5a8bcd505a60 pty: Fix input race when closing Inspired by analysis and patch from Marc Aurele La France Reported-by: Volth Reported-by: Marc Aurele La France BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52 BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492 Signed-off-by: Brian Bloniarz Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Fix GPF in flush_to_ldisc(), part 2

2016-04-12T16:08:49Z

commit f33798deecbd59a2955f40ac0ae2bc7dff54c069 upstream. commit 9ce119f318ba ("tty: Fix GPF in flush_to_ldisc()") fixed a GPF caused by a line discipline which does not define a receive_buf() method. However, the vt driver (and speakup driver also) pushes selection data directly to the line discipline receive_buf() method via tty_ldisc_receive_buf(). Fix the same problem in tty_ldisc_receive_buf(). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Wait interruptibly for tty lock on reopen

2016-02-17T20:31:02Z

commit 0bfd464d3fdd5bb322f9cace4cc47f1796545cf7 upstream. Allow a signal to interrupt the wait for a tty reopen; eg., if the tty has starting final close and is waiting for the device to drain. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: audit: Fix audit source

2015-11-21T00:19:54Z

The data to audit/record is in the 'from' buffer (ie., the input read buffer). Fixes: 72586c6061ab ("n_tty: Fix auditing support for cannonical mode") Cc: stable # 4.1+ Cc: Miloslav Trmač Signed-off-by: Peter Hurley Acked-by: Laura Abbott Signed-off-by: Greg Kroah-Hartman

tty: Abstract tty buffer work

2015-10-18T04:32:21Z

Introduce API functions to restart and cancel tty buffer work, rather than manipulate buffer work directly. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Combine SIGTTOU/SIGTTIN handling

2015-10-18T04:30:49Z

The job_control() check in n_tty_read() has nearly identical purpose and results as tty_check_change(). Both functions' purpose is to determine if the current task's pgrp is the foreground pgrp for the tty, and if not, to signal the current pgrp. Introduce __tty_check_change() which takes the signal to send and performs the shared operations for job control() and tty_check_change(). Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove wait_event_interruptible_tty()

2015-10-18T04:11:29Z

In-tree users of wait_event_interruptible_tty() have been removed; remove. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove tty_port::close_wait

2015-10-18T04:11:29Z

With the removal of tty_wait_until_sent_from_close(), tty drivers no longer wait during open for parallel closes to complete (instead, the tty core waits before calling the driver open() method). Thus, the close_wait waitqueue is no longer used for waiting. Remove struct tty_port::close_wait. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: Remove tty_wait_until_sent_from_close()

2015-10-18T04:11:29Z

tty_wait_until_sent_from_close() drops the tty lock while waiting for the tty driver to finish sending previously accepted data (ie., data remaining in its write buffer and transmit fifo). tty_wait_until_sent_from_close() was added by commit a57a7bf3fc7e ("TTY: define tty_wait_until_sent_from_close") to prevent the entire tty subsystem from being unable to open new ttys while waiting for one tty to close while output drained. However, since commit 0911261d4cb6 ("tty: Don't take tty_mutex for tty count changes"), holding a tty lock while closing does not prevent other ttys from being opened/closed/hung up, but only prevents lifetime event changes for the tty under lock. Holding the tty lock while waiting for output to drain does prevent parallel non-blocking opens (O_NONBLOCK) from advancing or returning while the tty lock is held. However, all parallel opens _already_ block even if the tty lock is dropped while closing and the parallel open advances. Blocking in open has been in mainline since at least 2.6.29 (see tty_port_block_til_ready(); note the test for O_NONBLOCK is _after_ the wait while ASYNC_CLOSING). IOW, before this patch a non-blocking open will sleep anyway for the _entire_ duration of a parallel hardware shutdown, and when it wakes, the error return will cause a release of its tty, and it will restart with a fresh attempt to open. Similarly with a blocking open that is already waiting; when it's woken, the hardware shutdown has already completed to ASYNC_INITIALIZED is not set, which forces a release and restart as well. So, holding the tty lock across the _entire_ close (which is what this patch does), even while waiting for output to drain, is equivalent to the current outcome wrt parallel opens. Cc: Alan Cox Cc: David Laight CC: Arnd Bergmann CC: Karsten Keil CC: linuxppc-dev@lists.ozlabs.org Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

tty: core: Add tty_debug() for printk(KERN_DEBUG) messages

2015-07-24T01:37:31Z

Introduce tty_debug() macro to output uniform debug information for tty core debug messages (function name and tty name). Note: printk(KERN_DEBUG) is retained here over pr_debug() since messages can be enabled in non-DEBUG builds. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman