kernel/linux.git/drivers/tty/pty.c, branch v6.1.168

tty: Make ->set_termios() old ktermios const

2022-08-30T12:22:35+00:00

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-9-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

tty: use new tty_insert_flip_string_and_push_buffer() in pty_write()

2022-07-08T13:16:28+00:00

There is a race in pty_write(). pty_write() can be called in parallel with e.g. ioctl(TIOCSTI) or ioctl(TCXONC) which also inserts chars to the buffer. Provided, tty_flip_buffer_push() in pty_write() is called outside the lock, it can commit inconsistent tail. This can lead to out of bounds writes and other issues. See the Link below. To fix this, we have to introduce a new helper called tty_insert_flip_string_and_push_buffer(). It does both tty_insert_flip_string() and tty_flip_buffer_commit() under the port lock. It also calls queue_work(), but outside the lock. See 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) for the reasons. Keep the helper internal-only (in drivers' tty.h). It is not intended to be used widely. Link: https://seclists.org/oss-sec/2022/q2/155 Fixes: 71a174b39f10 (pty: do tty_flip_buffer_push without port->lock in pty_write) Cc: 一只狗 Cc: Dan Carpenter Suggested-by: Hillf Danton Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220707082558.9250-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: pty: correct function name pty_resize()

2021-05-20T14:33:06+00:00

Fix the following make W=1 kernel build warning: drivers/tty/pty.c:307: warning: expecting prototype for pty_do_resize(). Prototype was for pty_resize() instead Reviewed-by: Jiri Slaby Signed-off-by: Yang Yingliang Link: https://lore.kernel.org/r/20210518045353.611017-1-yangyingliang@huawei.com Signed-off-by: Greg Kroah-Hartman

tty: pty: remove redundant initialization of variable fd

2021-05-20T14:32:59+00:00

The variable fd is being initialized with a value that is never read, it is being updated later on. The assignment is redundant and can be removed. Reviewed-by: Jiri Slaby Signed-off-by: Colin Ian King Addresses-Coverity: ("Unused value") Link: https://lore.kernel.org/r/20210513221833.137672-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman

tty: remove tty_operations::chars_in_buffer for non-buffering

2021-05-13T16:29:11+00:00

The only user of tty_ops::chars_in_buffer is tty_chars_in_buffer. And it considers tty_ops::chars_in_buffer optional. In case it's NULL, zero is returned. So remove all those chars_in_buffer from tty_ops which return zero. (Zero means such driver doesn't buffer.) Signed-off-by: Jiri Slaby Cc: Richard Henderson Acked-by: Max Filippov # xtensa Cc: Ivan Kokshaysky Cc: Matt Turner Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Chris Zankel Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Link: https://lore.kernel.org/r/20210505091928.22010-26-jslaby@suse.cz 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

tty: cumulate and document tty_struct::ctrl* members

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

Group the ctrl members under a single struct called ctrl. The new struct contains 'pgrp', 'session', 'pktstatus', and 'packet'. 'pktstatus' and 'packet' used to be bits in a bitfield. The struct also contains the lock protecting them to share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::ctrl_unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. Add a kerneldoc comment for this grouped members. Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: Jakub Kicinski Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20210505091928.22010-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: cumulate and document tty_struct::flow* members

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

Group the flow flags under a single struct called flow. The new struct contains 'stopped' and 'tco_stopped' bools which used to be bits in a bitfield. The struct also contains the lock protecting them to potentially share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. This is also the perfect time to start the documentation of tty_struct where all this lives. So we start by documenting what these bools actually serve for. And why we do all the alignment dances. Only the few up-to-date information from the Theodore's comment made it into this new Kerneldoc comment. Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Jonathan Corbet Cc: Arnd Bergmann Cc: Ulf Hansson Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Shawn Guo Cc: Sascha Hauer Cc: Vineet Gupta Cc: "Maciej W. Rozycki" Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

tty: create internal tty.h file

2021-04-15T08:22:17+00:00

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 Cc: Jiri Slaby Link: https://lore.kernel.org/r/20210408125134.3016837-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

tty: pty: Add a blank line after declarations

2021-04-02T14:12:35+00:00

Add a blank line after declarations, reported by checkpatch.pl. Signed-off-by: Xiaofei Tan Link: https://lore.kernel.org/r/1617351990-5189-1-git-send-email-tanxiaofei@huawei.com Signed-off-by: Greg Kroah-Hartman