linux-toradex.git/drivers/tty/n_hdlc.c, branch v6.4-rc3

tty: n_hdlc: remove HDLC_MAGIC

2022-09-22T14:12:34+00:00

According to Greg, in the context of magic numbers as defined in
magic-number.rst, "the tty layer should not need this and I'll gladly
take patches"

Acked-by: Jiri Slaby 
Signed-off-by: Ahelenia Ziemiańska 
Ref: https://lore.kernel.org/linux-doc/YyMlovoskUcHLEb7@kroah.com/
Link: https://lore.kernel.org/r/c31d228302da3f426cebf6fcff855181a5590a66.1663288066.git.nabijaczleweli@nabijaczleweli.xyz
Signed-off-by: Greg Kroah-Hartman

termios: get rid of stray asm/termios.h include in n_hdlc.c

2022-08-30T12:25:02+00:00

that's the only one outside of include/uapi/linux/termios.h and it's
not even needed there - we have linux/tty.h already pulled and that
pulls linux/termios.h

Normally I would not consider that a sufficient reason, but there's a
plenty of linux/tty.h users, and this is the only one that follows that
with asm/termios.h.  The situation with termios.h is genuinely convoluted,
and this complicates it for no good reason.

Signed-off-by: Al Viro 
Link: https://lore.kernel.org/r/20220821010239.1554132-2-viro@zeniv.linux.org.uk
Signed-off-by: Greg Kroah-Hartman

Merge 5.16-rc6 into tty-next

2021-12-20T09:00:30+00:00

We need the tty/serial fixes in here as well.

Signed-off-by: Greg Kroah-Hartman

tty: n_hdlc: make n_hdlc_tty_wakeup() asynchronous

2021-12-15T20:50:39+00:00

syzbot is reporting that an unprivileged user who logged in from tty
console can crash the system using a reproducer shown below [1], for
n_hdlc_tty_wakeup() is synchronously calling n_hdlc_send_frames().

----------
  #include 
  #include 

  int main(int argc, char *argv[])
  {
    const int disc = 0xd;

    ioctl(1, TIOCSETD, &disc);
    while (1) {
      ioctl(1, TCXONC, 0);
      write(1, "", 1);
      ioctl(1, TCXONC, 1); /* Kernel panic - not syncing: scheduling while atomic */
    }
  }
----------

Linus suspected that "struct tty_ldisc"->ops->write_wakeup() must not
sleep, and Jiri confirmed it from include/linux/tty_ldisc.h. Thus, defer
n_hdlc_send_frames() from n_hdlc_tty_wakeup() to a WQ context like
net/nfc/nci/uart.c does.

Link: https://syzkaller.appspot.com/bug?extid=5f47a8cea6a12b77a876 [1]
Reported-by: syzbot 
Cc: stable 
Analyzed-by: Fabio M. De Francesco 
Suggested-by: Linus Torvalds 
Confirmed-by: Jiri Slaby 
Reviewed-by: Fabio M. De Francesco 
Signed-off-by: Tetsuo Handa 
Link: https://lore.kernel.org/r/40de8b7e-a3be-4486-4e33-1b1d1da452f8@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman

tty: remove file from tty_ldisc_ops::ioctl and compat_ioctl

2021-11-25T17:36:27+00:00

After the previous patches, noone needs 'file' parameter in neither
ioctl hook from tty_ldisc_ops. So remove 'file' from both of them.

Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Cc: Wolfgang Grandegger 
Cc: Marc Kleine-Budde 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Andreas Koensgen 
Cc: Paul Mackerras 
Acked-by: Krzysztof Kozlowski  [NFC]
Acked-by: Dmitry Torokhov 
Acked-by: Marc Kleine-Budde 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211122094529.24171-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: remove file from n_tty_ioctl_helper

2021-09-22T14:59:13+00:00

After the previous patch, there are no users of 'file' in
n_tty_ioctl_helper. So remove it also from there.

Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Krzysztof Kozlowski 
Acked-by: Krzysztof Kozlowski 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210914091134.17426-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: n_hdlc: Fix a little doc-rot in n_hdlc_tty_read()

2021-05-20T15:06:17+00:00

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

 drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'kbuf' not described in 'n_hdlc_tty_read'
 drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'cookie' not described in 'n_hdlc_tty_read'
 drivers/tty/n_hdlc.c:421: warning: Function parameter or member 'offset' not described in 'n_hdlc_tty_read'
 drivers/tty/n_hdlc.c:421: warning: Excess function parameter 'buf' description in 'n_hdlc_tty_read'

Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Cc: Paul Fulghum 
Cc: Michael Callahan 
Cc: Al Longyear 
Cc: Paul Mackerras 
Signed-off-by: Lee Jones 
Link: https://lore.kernel.org/r/20210520121906.3468725-9-lee.jones@linaro.org
Signed-off-by: Greg Kroah-Hartman

tty: no checking of tty_unregister_ldisc

2021-05-13T14:57:17+00:00

tty_unregister_ldisc now returns 0 = success. No need to check the
return value. In fact, the users only warned if an error occured and
didn't do anything useful anyway -- the ldisc module was unloaded in any
case.

Signed-off-by: Jiri Slaby 
Cc: William Hubbs 
Cc: Chris Brannon 
Cc: Kirk Reiser 
Cc: Samuel Thibault 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Cc: Arnd Bergmann 
Cc: Wolfgang Grandegger 
Cc: Marc Kleine-Budde 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Andreas Koensgen 
Cc: Paul Mackerras 
Cc: Rodolfo Giometti 
Cc: Peter Ujfalusi 
Cc: Liam Girdwood 
Cc: Mark Brown 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Link: https://lore.kernel.org/r/20210505091928.22010-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: make tty_ldisc_ops a param in tty_unregister_ldisc

2021-05-13T14:57:16+00:00

Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting
struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids
checking of the ldisc number bounds in tty_unregister_ldisc.

Signed-off-by: Jiri Slaby 
Cc: William Hubbs 
Cc: Chris Brannon 
Cc: Kirk Reiser 
Cc: Samuel Thibault 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Cc: Dmitry Torokhov 
Cc: Arnd Bergmann 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Wolfgang Grandegger 
Cc: Marc Kleine-Budde 
Cc: Andreas Koensgen 
Cc: Paul Mackerras 
Cc: Rodolfo Giometti 
Cc: Peter Ujfalusi 
Cc: Liam Girdwood 
Cc: Mark Brown 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: set tty_ldisc_ops::num statically

2021-05-13T14:57:16+00:00

There is no reason to pass the ldisc number to tty_register_ldisc
separately. Just set it in the already defined tty_ldisc_ops in all the
ldiscs.

This simplifies tty_register_ldisc a bit too (no need to set the num
member there).

Signed-off-by: Jiri Slaby 
Cc: William Hubbs 
Cc: Chris Brannon 
Cc: Kirk Reiser 
Cc: Samuel Thibault 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Cc: Luiz Augusto von Dentz 
Cc: Dmitry Torokhov 
Cc: Arnd Bergmann 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Wolfgang Grandegger 
Cc: Marc Kleine-Budde 
Cc: Andreas Koensgen 
Cc: Paul Mackerras 
Cc: Rodolfo Giometti 
Cc: Peter Ujfalusi 
Cc: Liam Girdwood 
Cc: Mark Brown 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman