Commit graph

316 commits

Author SHA1 Message Date
Greg Kroah-Hartman
dd9f611442 tty: make tty_release_redirect() static
No one calls this outside of the tty_io.c file, so mark this static and
do not export the symbol anymore.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-11-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:28:30 +02:00
Greg Kroah-Hartman
98602c010c tty: create internal tty.h file
There are a number of functions and #defines in include/linux/tty.h that
do not belong there as they are private to the tty core code.

Create an initial drivers/tty/tty.h file and copy the odd "tty logging"
macros into it to seed the file with some initial things that we know
nothing outside of the tty core should be calling.

Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:22:17 +02:00
Johan Hovold
885c77d528 tty: refactor TIOCSSERIAL handling
Factor out the deprecated serial flags handling and tty-operation check
shared with the compat TIOCSSERIAL handler.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
1b7bc6b10a tty: use pr_warn_ratelimited() for deprecated serial flags
Use pr_warn_ratelimited() when warning about deprecated serial flags
instead of open coding.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Johan Hovold
1b8b20868a tty: fix return value for unsupported ioctls
Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Fix up the TIOCMGET, TIOCMSET and TIOCGICOUNT helpers which returned
-EINVAL when a tty driver did not implement the corresponding
operations.

Note that the TIOCMGET and TIOCMSET helpers predate git and do not get a
corresponding Fixes tag below.

Fixes: d281da7ff6 ("tty: Make tiocgicount a handler")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210407095208.31838-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-10 10:36:34 +02:00
Greg Kroah-Hartman
280def1e1c Merge 5.12-rc3 into tty-next
Resolves a merge issue with:
	drivers/tty/hvc/hvcs.c
and we want the tty/serial fixes from 5.12-rc3 in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-15 08:43:49 +01:00
Jiri Slaby
a846dcf9d7 tty: localise ptychar and make it const
ptychar was not const, so mark it as such. And move this variable to the
only place where it's used.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-36-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:09 +01:00
Jiri Slaby
a872ab4d6d tty: let tty_unregister_driver return void
Now that noone checks the return value, switch the return type of
tty_unregister_driver to void. We can do that as we always return zero.

Generally, drivers are not allowed to call tty_unregister_driver while
there are open devices.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-35-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:09 +01:00
Greg Kroah-Hartman
c776b77a27 Revert "drivers:tty:pty: Fix a race causing data loss on close"
This reverts commit 33d4ae9885.

Pierre-Louis writes:

	Our SOF/audio CI shows an across-the-board regression when we try v5.12-rc1,
	specifically on pause/resume tests with an interactive terminal running 'aplay
	-i' commands managed by expect to simulate the user pressing the space bar to
	pause/unpause. It turns out the processes are not longer killed and the audio
	devices remain busy (see publicly available test results listed below).

	git bisect points to commit 33d4ae9885 ("drivers:tty:pty: Fix a race
	causing data loss on close"). Reverting the patch fixes the issue on all test
	devices.

	Further analysis with Corey Minyard points to a problem where a slave tty will
	not get a SIGHUP when the master is closed.

So revert this for now:

Reported-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/00154592-c5ee-aaba-956e-b265473b53bc@linux.intel.com
Cc: Corey Minyard <cminyard@mvista.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Mark Brown <broonie@kernel.org>,
Fixes: 33d4ae9885 ("drivers:tty:pty: Fix a race causing data loss on close")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:27:56 +01:00
Linus Torvalds
e4286926ab TTY/Serial driver changes for 5.12-rc1
Here is the big set of tty/serial driver changes for 5.12-rc1.
 
 Nothing huge, just lots of good cleanups and additions:
 	- Your n_tty line discipline cleanups
 	- vt core cleanups and reworks to make the code more "modern"
 	- stm32 driver additions
 	- tty led support added to the tty core and led layer
 	- minor serial driver fixups and additions
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 5.12-rc1.

  Nothing huge, just lots of good cleanups and additions:

   - n_tty line discipline cleanups

   - vt core cleanups and reworks to make the code more "modern"

   - stm32 driver additions

   - tty led support added to the tty core and led layer

   - minor serial driver fixups and additions

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (54 commits)
  serial: core: Remove BUG_ON(in_interrupt()) check
  vt_ioctl: Remove in_interrupt() check
  dt-bindings: serial: imx: Switch to my personal address
  vt: keyboard, use new API for keyboard_tasklet
  serial: stm32: improve platform_get_irq condition handling in init_port
  serial: ifx6x60: Remove driver for deprecated platform
  tty: fix up iterate_tty_read() EOVERFLOW handling
  tty: fix up hung_up_tty_read() conversion
  tty: fix up hung_up_tty_write() conversion
  tty: teach the n_tty ICANON case about the new "cookie continuations" too
  tty: teach n_tty line discipline about the new "cookie continuations"
  tty: clean up legacy leftovers from n_tty line discipline
  tty: implement read_iter
  tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
  serial: remove sirf prima/atlas driver
  serial: mxs-auart: Remove <asm/cacheflush.h>
  serial: mxs-auart: Remove serial_mxs_probe_dt()
  serial: fsl_lpuart: Use of_device_get_match_data()
  dt-bindings: serial: renesas,hscif: Add r8a779a0 support
  tty: serial: Drop unused efm32 serial driver
  ...
2021-02-20 21:28:04 -08:00
Linus Torvalds
3342ff2698 tty: protect tty_write from odd low-level tty disciplines
Al root-caused a new warning from syzbot to the ttyprintk tty driver
returning a write count larger than the data the tty layer actually gave
it.  Which confused the tty write code mightily, and with the new
iov_iter based code, caused a WARNING in iov_iter_revert().

syzbot correctly bisected the source of the new warning to commit
9bb48c82ac ("tty: implement write_iter"), but the oddity goes back
much further, it just didn't get caught by anything before.

Reported-by: syzbot+3d2c27c2b7dc2a94814d@syzkaller.appspotmail.com
Fixes: 9bb48c82ac ("tty: implement write_iter")
Debugged-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-02-20 21:15:00 -08:00
Linus Torvalds
a9cbbb80e3 tty: avoid using vfs_iocb_iter_write() for redirected console writes
It turns out that the vfs_iocb_iter_{read,write}() functions are
entirely broken, and don't actually use the passed-in file pointer for
IO - only for the preparatory work (permission checking and for the
write_iter function lookup).

That worked fine for overlayfs, which always builds the new iocb with
the same file pointer that it passes in, but in the general case it ends
up doing nonsensical things (and could cause an iterator call that
doesn't even match the passed-in file pointer).

This subtly broke the tty conversion to write_iter in commit
9bb48c82ac ("tty: implement write_iter"), because the console
redirection didn't actually end up redirecting anything, since the
passed-in file pointer was basically ignored, and the actual write was
done with the original non-redirected console tty after all.

The main visible effect of this is that the console messages were no
longer logged to /var/log/boot.log during graphical boot.

Fix the issue by simply not using the vfs write "helper" function at
all, and just redirecting the write entirely internally to the tty
layer.  Do the target writability permission checks when actually
registering the target tty with TIOCCONS instead of at write time.

Fixes: 9bb48c82ac ("tty: implement write_iter")
Reported-and-tested-by: Hans de Goede <hdegoede@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-29 13:12:17 -08:00
Sami Tolvanen
9f12e37cae Commit 9bb48c82ac ("tty: implement write_iter") converted the tty
layer to use write_iter. Fix the redirected_tty_write declaration
also in n_tty and change the comparisons to use write_iter instead of
write.

[ Also moved the declaration of redirected_tty_write() to the proper
  location in a header file. The reason for the bug was the bogus extern
  declaration in n_tty.c silently not matching the changed definition in
  tty_io.c, and because it wasn't in a shared header file, there was no
  cross-checking of the declaration.

  Sami noticed because Clang's Control Flow Integrity checking ended up
  incidentally noticing the inconsistent declaration.    - Linus ]

Fixes: 9bb48c82ac ("tty: implement write_iter")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-25 12:08:07 -08:00
Linus Torvalds
17749851eb tty: fix up hung_up_tty_write() conversion
In commit "tty: implement write_iter", I left the write_iter conversion
of the hung up tty case alone, because I incorrectly thought it didn't
matter.

Jiri showed me the errors of my ways, and pointed out the problems with
that incomplete conversion.  Fix it all up.

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22 11:01:55 +01:00
Linus Torvalds
e71a8d5cf4 tty: fix up iterate_tty_read() EOVERFLOW handling
When I converted the tty_ldisc_ops 'read()' function to take a kernel
pointer, I was a bit too aggressive about the ldisc returning EOVERFLOW.

Yes, we want to have EOVERFLOW override any partially read data (because
the whole point is that the buffer was too small for the whole packet,
and we don't want to see partial packets), but it shouldn't override a
previous EFAULT.

And in fact, it really is just EOVERFLOW that is special and should
throw away any partially read data, not "any error".  Admittedly
EOVERFLOW is currently the only one that can happen for a continuation
read - and if the first read iteration returns an error we won't have this issue.

So this is more of a technicality, but let's just make the intent very
explicit, and re-organize the error handling a bit so that this is all
clearer.

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22 10:53:10 +01:00
Linus Torvalds
ddc5fda745 tty: fix up hung_up_tty_read() conversion
In commit "tty: implement read_iter", I left the read_iter conversion of
the hung up tty case alone, because I incorrectly thought it didn't
matter.

Jiri showed me the errors of my ways, and pointed out the problems with
that incomplete conversion.  Fix it all up.

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22 10:53:07 +01:00
Linus Torvalds
c7135bbe5a tty: fix up hung_up_tty_write() conversion
In commit "tty: implement write_iter", I left the write_iter conversion
of the hung up tty case alone, because I incorrectly thought it didn't
matter.

Jiri showed me the errors of my ways, and pointed out the problems with
that incomplete conversion.  Fix it all up.

Reported-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/CAHk-=wh+-rGsa=xruEWdg_fJViFG8rN9bpLrfLz=_yBYh2tBhA@mail.gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-22 10:52:43 +01:00
Greg Kroah-Hartman
3cfade53c7 Merge branch 'tty-splice' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into tty-next
Fixes both the "splice/sendfile to a tty" and "splice/sendfile from a
tty" regression from 5.10.

* 'tty-splice' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux:
  tty: teach the n_tty ICANON case about the new "cookie continuations" too
  tty: teach n_tty line discipline about the new "cookie continuations"
  tty: clean up legacy leftovers from n_tty line discipline
  tty: implement read_iter
  tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
  tty: implement write_iter
2021-01-21 09:40:55 +01:00
Greg Kroah-Hartman
494e63ee9c Merge 9bb48c82ac ("tty: implement write_iter") into tty-linus
We want the single "splice/sendfile to a tty" regression fix into
tty-linus so it can get into 5.11-final, while the larger patch series
fixing "splice/sendfile from a tty" should wait for 5.12-rc1 so that we
get more testing.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-21 09:38:37 +01:00
Linus Torvalds
9bb48c82ac tty: implement write_iter
This makes the tty layer use the .write_iter() function instead of the
traditional .write() functionality.

That allows writev(), but more importantly also makes it possible to
enable .splice_write() for ttys, reinstating the "splice to tty"
functionality that was lost in commit 36e2c7421f ("fs: don't allow
splice read/write without explicit ops").

Fixes: 36e2c7421f ("fs: don't allow splice read/write without explicit ops")
Reported-by: Oliver Giles <ohw.giles@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20 16:48:47 -08:00
Linus Torvalds
dd78b0c483 tty: implement read_iter
Now that the ldisc read() function takes kernel pointers, it's fairly
straightforward to make the tty file operations use .read_iter() instead
of .read().

That automatically gives us vread() and friends, and also makes it
possible to do .splice_read() on ttys again.

Fixes: 36e2c7421f ("fs: don't allow splice read/write without explicit ops")
Reported-by: Oliver Giles <ohw.giles@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20 16:48:47 -08:00
Linus Torvalds
3b830a9c34 tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
The tty line discipline .read() function was passed the final user
pointer destination as an argument, which doesn't match the 'write()'
function, and makes it very inconvenient to do a splice method for
ttys.

This is a conversion to use a kernel buffer instead.

NOTE! It does this by passing the tty line discipline ->read() function
an additional "cookie" to fill in, and an offset into the cookie data.

The line discipline can fill in the cookie data with its own private
information, and then the reader will repeat the read until either the
cookie is cleared or it runs out of data.

The only real user of this is N_HDLC, which can use this to handle big
packets, even if the kernel buffer is smaller than the whole packet.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-01-20 16:48:47 -08:00
Corey Minyard
33d4ae9885 drivers:tty:pty: Fix a race causing data loss on close
Remove the tty_vhangup() from the pty code and just release the
redirect.  The tty_vhangup() results in data loss and data out of order
issues.

If you write to a pty master an immediately close the pty master, the
receiver might get a chunk of data dropped, but then receive some later
data.  That's obviously something rather unexpected for a user.  It
certainly confused my test program.

It turns out that tty_vhangup() on the slave pty gets called from
pty_close(), and that causes the data on the slave side to be flushed,
but due to races more data can be copied into the slave side's buffer
after that.  Consider the following sequence:

thread1          thread2         thread3
-------          -------         -------
 |                |-write data into buffer,
 |                | n_tty buffer is filled
 |                | along with other buffers
 |                |-pty_close(master)
 |                |--tty_vhangup(slave)
 |                |---tty_ldisc_hangup()
 |                |----n_tty_flush_buffer()
 |                |-----reset_buffer_flags()
 |-n_tty_read()   |
 |--up_read(&tty->termios_rwsem);
 |                |------down_read(&tty->termios_rwsem)
 |                |------clear n_tty buffer contents
 |                |------up_read(&tty->termios_rwsem)
 |--tty_buffer_flush_work()       |
 |--schedules work calling        |
 |  flush_to_ldisc()              |
 |                                |-flush_to_ldisc()
 |                                |--receive_buf()
 |                                |---tty_port_default_receive_buf()
 |                                |----tty_ldisc_receive_buf()
 |                                |-----n_tty_receive_buf2()
 |                                |------n_tty_receive_buf_common()
 |                                |-------down_read(&tty->termios_rwsem)
 |                                |-------__receive_buf()
 |                                |       copies data into n_tty buffer
 |                                |-------up_read(&tty->termios_rwsem)
 |--down_read(&tty->termios_rwsem)
 |--copy buffer data to user

>From this sequence, you can see that thread2 writes to the buffer then
only clears the part of the buffer in n_tty.  The n_tty receive buffer
code then copies more data into the n_tty buffer.

But part of the vhangup, releasing the redirect, is still required to
avoid issues with consoles running on pty slaves.  So do that.
As far as I can tell, that is all that should be required.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Link: https://lore.kernel.org/r/20201124004902.1398477-3-minyard@acm.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07 16:30:55 +01:00
Corey Minyard
f446776ebf tty: Export redirect release
This will be required by the pty code when it removes tty_vhangup() on
master close.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Link: https://lore.kernel.org/r/20201124004902.1398477-2-minyard@acm.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-07 16:30:55 +01:00
Uwe Kleine-König
d20c219c73 tty: new helper function tty_get_icount()
For a given struct tty_struct this yields the corresponding statistics
about sent and received characters (and some more) which is needed to
implement an LED trigger for tty devices.

The new function is then used to simplify tty_tiocgicount().

Reviewed-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201218104246.591315-3-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28 16:09:29 +01:00
Uwe Kleine-König
4ea3cd65e0 tty: rename tty_kopen() and add new function tty_kopen_shared()
Introduce a new function tty_kopen_shared() that yields a struct
tty_struct. The semantic difference to tty_kopen() is that the tty is
expected to be used already. So rename tty_kopen() to
tty_kopen_exclusive() for clearness, adapt the single user and put the
common code in a new static helper function.

tty_kopen_shared is to be used to implement an LED trigger for tty
devices in one of the next patches.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20201218104246.591315-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-28 16:09:11 +01:00
Greg Kroah-Hartman
ba3b8bb126 Merge 5.10-rc7 into tty-next
We want the tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-07 10:19:31 +01:00
Jann Horn
c8bcd9c5be tty: Fix ->session locking
Currently, locking of ->session is very inconsistent; most places
protect it using the legacy tty mutex, but disassociate_ctty(),
__do_SAK(), tiocspgrp() and tiocgsid() don't.
Two of the writers hold the ctrl_lock (because they already need it for
->pgrp), but __proc_set_tty() doesn't do that yet.

On a PREEMPT=y system, an unprivileged user can theoretically abuse
this broken locking to read 4 bytes of freed memory via TIOCGSID if
tiocgsid() is preempted long enough at the right point. (Other things
might also go wrong, especially if root-only ioctls are involved; I'm
not sure about that.)

Change the locking on ->session such that:

 - tty_lock() is held by all writers: By making disassociate_ctty()
   hold it. This should be fine because the same lock can already be
   taken through the call to tty_vhangup_session().
   The tricky part is that we need to shorten the area covered by
   siglock to be able to take tty_lock() without ugly retry logic; as
   far as I can tell, this should be fine, since nothing in the
   signal_struct is touched in the `if (tty)` branch.
 - ctrl_lock is held by all writers: By changing __proc_set_tty() to
   hold the lock a little longer.
 - All readers that aren't holding tty_lock() hold ctrl_lock: By
   adding locking to tiocgsid() and __do_SAK(), and expanding the area
   covered by ctrl_lock in tiocspgrp().

Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-04 17:39:58 +01:00
Greg Kroah-Hartman
9b085d6e88 Merge 5.10-rc3 into tty-next
We need the TTY/vt/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-09 10:37:10 +01:00
Matthias Reichl
4466d6d2f8 tty: fix crash in release_tty if tty->port is not set
Commit 2ae0b31e0f ("tty: don't crash in tty_init_dev when missing
tty_port") didn't fully prevent the crash as the cleanup path in
tty_init_dev() calls release_tty() which dereferences tty->port
without checking it for non-null.

Add tty->port checks to release_tty to avoid the kernel crash.

Fixes: 2ae0b31e0f ("tty: don't crash in tty_init_dev when missing tty_port")
Signed-off-by: Matthias Reichl <hias@horus.com>
Link: https://lore.kernel.org/r/20201105123432.4448-1-hias@horus.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06 17:24:49 +01:00
Lee Jones
08aa5042d2 tty: tty_io: Fix some kernel-doc issues
Demote non-conformant headers and supply some missing descriptions.

Fixes the following W=1 kernel build warning(s):

 drivers/tty/tty_io.c:218: warning: Function parameter or member 'file' not described in 'tty_free_file'
 drivers/tty/tty_io.c:566: warning: Function parameter or member 'exit_session' not described in '__tty_hangup'
 drivers/tty/tty_io.c:1077: warning: Function parameter or member 'tty' not described in 'tty_send_xchar'
 drivers/tty/tty_io.c:1077: warning: Function parameter or member 'ch' not described in 'tty_send_xchar'
 drivers/tty/tty_io.c:1155: warning: Function parameter or member 'file' not described in 'tty_driver_lookup_tty'
 drivers/tty/tty_io.c:1508: warning: Function parameter or member 'tty' not described in 'release_tty'
 drivers/tty/tty_io.c:1508: warning: Function parameter or member 'idx' not described in 'release_tty'
 drivers/tty/tty_io.c:2973: warning: Function parameter or member 'driver' not described in 'alloc_tty_struct'
 drivers/tty/tty_io.c:2973: warning: Function parameter or member 'idx' not described in 'alloc_tty_struct'

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Nick Holloway <alfie@dcs.warwick.ac.uk>
Cc: -- <julian@uhunix.uhcc.hawaii.edu>
Cc: Marko Kohtala <Marko.Kohtala@hut.fi>
Cc: Bill Hawes <whawes@star.net>
Cc: "C. Scott Ananian" <cananian@alumni.princeton.edu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Andrew Morton <andrewm@uow.edu.eu>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104193549.4026187-13-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06 10:49:27 +01:00
Lee Jones
aec51036a1 tty: tty_io: Move 'tty_sysctl_init's prototype to shared space
Fixes the following W=1 kernel build warning(s):

 drivers/tty/tty_ldisc.c:883:6: warning: no previous prototype for ‘tty_sysctl_init’ [-Wmissing-prototypes]
 883 | void tty_sysctl_init(void)
 | ^~~~~~~~~~~~~~~

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Nick Holloway <alfie@dcs.warwick.ac.uk>
Cc: -- <julian@uhunix.uhcc.hawaii.edu>
Cc: Marko Kohtala <Marko.Kohtala@hut.fi>
Cc: Bill Hawes <whawes@star.net>
Cc: "C. Scott Ananian" <cananian@alumni.princeton.edu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Andrew Morton <andrewm@uow.edu.eu>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20201104193549.4026187-5-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-11-06 10:49:27 +01:00
Jiri Slaby
fa44195455 tty: fix kernel-doc
With W=1, the kernel-doc checker complains quite a lot in the tty layer.
Over the time, many documented parameters were renamed, removed or
switched from tty to tty_port and similar. Some were mistyped in the doc
too.

So fix all these in the tty core. (But do not add the missing ones which
the checker complains about too. Not now.) The rest in the tty layer
will follow in the next patches.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200818085655.12071-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-18 13:51:18 +02:00
Gustavo A. R. Silva
a32418919d tty: Use the preferred form for passing the size of a structure type
Use the preferred form for passing the size of a structure type. The
alternative form where the structure type is spelled out hurts
readability and introduces an opportunity for a bug when the object
type is changed but the corresponding object identifier to which the
sizeof operator is applied is not.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/b04dd8cdd67bd6ffde3fd12940aeef35fdb824a6.1595543280.git.gustavoars@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 17:07:59 +02:00
Gustavo A. R. Silva
52b52e9189 tty: Fix identation issues in struct serial_struct32
Fix the following checkpatch.pl warnings together with all the
identation issues in struct serial_struct32:

ERROR: code indent should use tabs where possible
+        char    reserved_char;$

WARNING: please, no spaces at the start of a line
+        char    reserved_char;$

ERROR: code indent should use tabs where possible
+        compat_int_t    reserved;$

WARNING: please, no spaces at the start of a line
+        compat_int_t    reserved;$

Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/77576843397aeab0af8aa0423a9768f3ca8dedfb.1595543280.git.gustavoars@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 17:07:58 +02:00
Gustavo A. R. Silva
e5b9f4b1dc tty: Avoid the use of one-element arrays
One-element arrays are being deprecated[1]. Replace the one-element arrays
with simple value types 'char reserved_char' and 'compat_int_t reserved'[2],
once it seems these are just placeholders for alignment.

[1] https://github.com/KSPP/linux/issues/79
[2] https://github.com/KSPP/linux/issues/86

Tested-by: kernel test robot <lkp@intel.com>
Link: https://github.com/GustavoARSilva/linux-hardening/blob/master/cii/0-day/tty-20200716.md
Acked-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/f49bf0e27eaac396c96d21392c8c284f9f5ef52a.1595543280.git.gustavoars@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 17:07:58 +02:00
Eric Biggers
6e622cd8bd tty: fix compat TIOCGSERIAL checking wrong function ptr
Commit 7765435030 ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
checking for the presence of the ->set_serial function pointer rather
than ->get_serial.  This appears to be a copy-and-paste error, since
->get_serial is the function pointer that is called as well as the
pointer that is checked by the non-compat version of TIOCGSERIAL.

Fix this by checking the correct function pointer.

Fixes: 7765435030 ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-3-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 13:15:13 +01:00
Eric Biggers
17329563a9 tty: fix compat TIOCGSERIAL leaking uninitialized memory
Commit 7765435030 ("take compat TIOC[SG]SERIAL treatment into
tty_compat_ioctl()") changed the compat version of TIOCGSERIAL to start
copying a whole 'serial_struct32' to userspace rather than individual
fields, but failed to initialize all padding and fields -- namely the
hole after the 'iomem_reg_shift' field, and the 'reserved' field.

Fix this by initializing the struct to zero.

[v2: use sizeof, and convert the adjacent line for consistency.]

Reported-by: syzbot+8da9175e28eadcb203ce@syzkaller.appspotmail.com
Fixes: 7765435030 ("take compat TIOC[SG]SERIAL treatment into tty_compat_ioctl()")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200224182044.234553-2-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 13:15:13 +01:00
Eric Biggers
ed069827ca tty: drop outdated comments about release_tty() locking
The current version of the TTY code unlocks the tty_struct(s) before
release_tty() rather than after.  Moreover, tty_unlock_pair() no longer
exists.  Thus, remove the outdated comments regarding tty_unlock_pair().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224073359.292795-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 13:08:45 +01:00
Uwe Kleine-König
f1d31743a1 tty: drop useless variable initialisation in tty_kopen()
The driver variable is assigned to unconditionally and not used before.
So there is no need to explicitly initialize it at the start of
tty_kopen().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20191217075040.8020-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17 14:42:45 +01:00
Linus Torvalds
537bd0a159 TTY/Serial patches for 5.5-rc1
Here is the "big" tty and serial driver patches for 5.5-rc1.  It's a bit
 later in the merge window than normal as I wanted to make sure some
 last-minute patches applied to it were all sane.  They seem to be :)
 
 There's a lot of little stuff in here, for the tty core, and for lots of
 serial drivers:
 	- reverts of uartlite serial driver patches that were wrong
 	- msm-serial driver fixes
 	- serial core updates and fixes
 	- tty core fixes
 	- serial driver dma mapping api changes
 	- lots of other tiny fixes and updates for serial drivers
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the "big" tty and serial driver patches for 5.5-rc1.

  It's a bit later in the merge window than normal as I wanted to make
  sure some last-minute patches applied to it were all sane. They seem
  to be :)

  There's a lot of little stuff in here, for the tty core, and for lots
  of serial drivers:

   - reverts of uartlite serial driver patches that were wrong

   - msm-serial driver fixes

   - serial core updates and fixes

   - tty core fixes

   - serial driver dma mapping api changes

   - lots of other tiny fixes and updates for serial drivers

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (58 commits)
  Revert "serial/8250: Add support for NI-Serial PXI/PXIe+485 devices"
  vcs: prevent write access to vcsu devices
  tty: vt: keyboard: reject invalid keycodes
  tty: don't crash in tty_init_dev when missing tty_port
  serial: stm32: fix clearing interrupt error flags
  tty: Fix Kconfig indentation, continued
  serial: serial_core: Perform NULL checks for break_ctl ops
  tty: remove unused argument from tty_open_by_driver()
  tty: Fix Kconfig indentation
  {tty: serial, nand: onenand}: samsung: rename to fix build warning
  serial: ifx6x60: add missed pm_runtime_disable
  serial: pl011: Fix DMA ->flush_buffer()
  Revert "serial-uartlite: Move the uart register"
  Revert "serial-uartlite: Add get serial id if not provided"
  Revert "serial-uartlite: Do not use static struct uart_driver out of probe()"
  Revert "serial-uartlite: Add runtime support"
  Revert "serial-uartlite: Change logic how console_port is setup"
  Revert "serial-uartlite: Use allocated structure instead of static ones"
  tty: serial: msm_serial: Use dma_request_chan() directly for channel request
  tty: serial: tegra: Use dma_request_chan() directly for channel request
  ...
2019-12-03 14:09:14 -08:00
Jiri Slaby
2ae0b31e0f tty: don't crash in tty_init_dev when missing tty_port
We currently warn the user when tty->port is not set in tty_init_dev
yet. The warning says that the kernel will crash later. And it really
will only few lines below at:
tty->port->itty = tty;

So be nice and avoid the crash -- return an error instead. And update
the warning.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/20191122101721.7222-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-22 11:38:38 +01:00
Sudip Mukherjee
14ce384844 tty: remove unused argument from tty_open_by_driver()
The argument 'inode' passed to tty_open_by_driver() was not being used.
Remove the extra argument.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/20191120151709.14148-1-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20 16:39:51 +01:00
Arnd Bergmann
b7aff093e9 tty: handle compat PPP ioctls
Multiple tty devices are have tty devices that handle the
PPPIOCGUNIT and PPPIOCGCHAN ioctls. To avoid adding a compat_ioctl
handler to each of those, add it directly in tty_compat_ioctl
so we can remove the calls from fs/compat_ioctl.c.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:47 +02:00
Arnd Bergmann
c7dc504e2f compat_ioctl: move SIOCOUTQ out of compat_ioctl.c
All users of this call are in socket or tty code, so handling
it there means we can avoid the table entry in fs/compat_ioctl.c.

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: netdev@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-10-23 17:23:46 +02:00
Suzuki K Poulose
4495dfdd61 drivers: Introduce device lookup variants by device type
Add a helper to match a device by its type and provide wrappers
for {bus/class/driver}_find_device() APIs.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Harald Freudenberger <freude@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-usb@vger.kernel.org
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20190723221838.12024-5-suzuki.poulose@arm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-30 13:07:42 +02:00
Lin Yi
8c8af41d24 tty: tty_io: fix driver refcount imbalance on error path
tty_lookup_driver take a reference to the struct tty_driver, but forget
to release it on the error path, lead to a memory leak.
add a tty_driver_kref_put before error return.

Signed-off-by: Lin Yi <teroincn@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24 10:09:12 +02:00
Johan Hovold
8daa89e099 tty: update obsolete termios comment
Update an obsolete comment referring to the termios_locked structure
which was removed over a decade ago by commit fe6e29fdb1 ("tty:
simplify ktermios allocation").

While at it, fix the "Thus" typo.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 11:58:56 +02:00
Greg Kroah-Hartman
0eae4686a1 Revert "tty: pty: Fix race condition between release_one_tty and pty_write"
This reverts commit b9ca5f8560 as 0-day
shows it has a circular locking dependency.

Fixes: b9ca5f8560 ("tty: pty: Fix race condition between release_one_tty and pty_write")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Sahara <keun-o.park@darkmatter.ae>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-29 15:47:40 +01:00
Sahara
b9ca5f8560 tty: pty: Fix race condition between release_one_tty and pty_write
Especially when a linked tty is used such as pty, the linked tty
port's buf works have not been cancelled while master tty port's
buf work has been cancelled. Since release_one_tty and flush_to_ldisc
run in workqueue threads separately, when pty_cleanup happens and
link tty port is freed, flush_to_ldisc tries to access freed port
and port->itty, eventually it causes a panic.
This patch utilizes the magic value with holding the tty_mutex to
check if the tty->link is valid.

Fixes: 2b022ab754 ("pty: cancel pty slave port buf's work in tty_release")
Signed-off-by: Sahara <keun-o.park@darkmatter.ae>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-28 01:28:23 +09:00