kernel/linux.git/drivers/char/ttyprintk.c, branch v6.1.168

char: ttyprintk: register console

2022-04-22T14:24:47+00:00

Register a console in the ttyprintk driver so that it can be selected for /dev/console with console=ttyprintk on the kernel command line, similar to other console drivers. Signed-off-by: Vincent Whitchurch Link: https://lore.kernel.org/r/20220215141750.92808-1-vincent.whitchurch@axis.com Signed-off-by: Greg Kroah-Hartman

tty: drop put_tty_driver

2021-07-27T10:17:21+00:00

put_tty_driver() is an alias for tty_driver_kref_put(). There is no need for two exported identical functions, therefore switch all users of old put_tty_driver() to new tty_driver_kref_put() and remove the former for good. Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Geert Uytterhoeven Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Chris Zankel Cc: Max Filippov Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Samuel Iglesias Gonsalvez Cc: Jens Taprogge Cc: Karsten Keil Cc: Scott Branden Cc: Ulf Hansson Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: David Lin Cc: Johan Hovold Cc: Alex Elder Cc: Jiri Slaby Cc: Laurentiu Tudor Cc: Jiri Kosina Cc: David Sterba Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Oliver Neukum Cc: Felipe Balbi Cc: Mathias Nyman Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Acked-by: Alex Elder Acked-by: Christian Borntraeger Acked-by: Max Filippov Acked-by: David Sterba Acked-by: Samuel Iglesias Gonsálvez Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20210723074317.32690-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

ttyprintk: remove redundant initialization of variable i

2021-05-27T12:19:50+00:00

The variable i is being initialized with a value that is never read, it is being updated later on. The assignment is redundant and can be removed. Signed-off-by: Colin Ian King Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210518182126.140978-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman

ttyprintk: Removed unnecessary TTY ioctl callback

2021-05-13T16:29:12+00:00

It turns-out, that TIOCCONS is completely handled in tty_io.c, so the current local ioctl callback is of no real use. Signed-off-by: Samo Pogačnik Link: https://lore.kernel.org/r/1502946c760b1aae3ad9cffcf4ea3b9f37206585.camel@t-2.net Signed-off-by: Greg Kroah-Hartman

ttyprintk: Add TTY port shutdown callback

2021-05-13T16:29:12+00:00

By adding the TTY port shutdown callback, the final buffer flush has been moved from tpk_close() to tpk_port_shutdown(). This enables buffer flush upon close and hangup as well. The change also removes the specific 'buf == NULL' handling in tpk_printk(), which became useless. Signed-off-by: Samo Pogačnik Link: https://lore.kernel.org/r/f236ea26520fbef176fefec2e06a43548f63fa9c.camel@t-2.net Signed-off-by: Greg Kroah-Hartman

tty: make tty_operations::write_room return uint

2021-05-13T15:03:20+00:00

Line disciplines expect a positive value or zero returned from tty->ops->write_room (invoked by tty_write_room). So make this assumption explicit by using unsigned int as a return value. Both of tty->ops->write_room and tty_write_room. Signed-off-by: Jiri Slaby Acked-by: Laurentiu Tudor Acked-by: Alex Elder Acked-by: Max Filippov # xtensa Acked-by: David Sterba Acked-By: Anton Ivanov Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Jeff Dike Cc: Richard Weinberger Cc: Chris Zankel Cc: Arnd Bergmann Cc: Samuel Iglesias Gonsalvez Cc: Jens Taprogge Cc: Karsten Keil Cc: Scott Branden Cc: Ulf Hansson Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: David Lin Cc: Johan Hovold Cc: Jiri Kosina Cc: Shawn Guo Cc: Sascha Hauer Cc: Oliver Neukum Cc: Felipe Balbi Cc: Mathias Nyman Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

ttyprintk: Add TTY hangup callback.

2021-04-22T10:01:26+00:00

syzbot is reporting hung task due to flood of tty_warn(tty, "%s: tty->count = 1 port count = %d\n", __func__, port->count); message [1], for ioctl(TIOCVHANGUP) prevents tty_port_close() from decrementing port->count due to tty_hung_up_p() == true. ---------- #include #include #include #include #include int main(int argc, char *argv[]) { int i; int fd[10]; for (i = 0; i < 10; i++) fd[i] = open("/dev/ttyprintk", O_WRONLY); ioctl(fd[0], TIOCVHANGUP); for (i = 0; i < 10; i++) close(fd[i]); close(open("/dev/ttyprintk", O_WRONLY)); return 0; } ---------- When TTY hangup happens, port->count needs to be reset via "struct tty_operations"->hangup callback. [1] https://syzkaller.appspot.com/bug?id=39ea6caa479af471183997376dc7e90bc7d64a6a Reported-by: syzbot Reported-by: syzbot Tested-by: syzbot Signed-off-by: Tetsuo Handa Fixes: 24b4b67d17c308aa ("add ttyprintk driver") Link: https://lore.kernel.org/r/17e0652d-89b7-c8c0-fb53-e7566ac9add4@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman

ttyprintk: remove redundant initialization of variable ret

2020-07-10T12:50:51+00:00

The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Link: https://lore.kernel.org/r/20200611153108.927614-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman

ttyprintk: fix a potential deadlock in interrupt context issue

2020-01-14T13:37:54+00:00

tpk_write()/tpk_close() could be interrupted when holding a mutex, then in timer handler tpk_write() may be called again trying to acquire same mutex, lead to deadlock. Google syzbot reported this issue with CONFIG_DEBUG_ATOMIC_SLEEP enabled: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:938 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 0, name: swapper/1 1 lock held by swapper/1/0: ... Call Trace: dump_stack+0x197/0x210 ___might_sleep.cold+0x1fb/0x23e __might_sleep+0x95/0x190 __mutex_lock+0xc5/0x13c0 mutex_lock_nested+0x16/0x20 tpk_write+0x5d/0x340 resync_tnc+0x1b6/0x320 call_timer_fn+0x1ac/0x780 run_timer_softirq+0x6c3/0x1790 __do_softirq+0x262/0x98c irq_exit+0x19b/0x1e0 smp_apic_timer_interrupt+0x1a3/0x610 apic_timer_interrupt+0xf/0x20 See link https://syzkaller.appspot.com/bug?extid=2eeef62ee31f9460ad65 for more details. Fix it by using spinlock in process context instead of mutex and having interrupt disabled in critical section. Reported-by: syzbot+2eeef62ee31f9460ad65@syzkaller.appspotmail.com Signed-off-by: Zhenzhong Duan Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200113034842.435-1-zhenzhong.duan@gmail.com Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 402

2019-06-05T15:37:13+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the smems of the gnu general public license as published by the free software foundation version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 5 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Armijn Hemel Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190111.946565886@linutronix.de Signed-off-by: Greg Kroah-Hartman