linux-stable.git/drivers/tty/tty_ioctl.c, branch linux-5.17.y

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: remove file from tty_mode_ioctl

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

The only user of 'file' parameter in tty_mode_ioctl is a BUG_ON check.
Provided it never crashed for anyone, it's an overkill to pass the
parameter to tty_mode_ioctl only for this check.

If we wanted to check 'file' there, we should handle it in more graceful
way anyway. Not by a BUG == crash.

Cc: Wolfgang Grandegger 
Cc: Marc Kleine-Budde 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Andreas Koensgen 
Cc: Paul Mackerras 
Acked-by: Marc Kleine-Budde 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210914091134.17426-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: make tty_get_{char,frame}_size available

2021-06-15T12:03:26+00:00

Many tty drivers contain code to compute bits count depending on termios
cflags. So extract this code from serial core to two separate tty helper
functions:
* tty_get_char_size -- only size of a character, without flags,
* tty_get_frame_size -- complete size of a frame including flags.

In the next patch, calls to these new functions replace many copies of
this code.

Note that we accept only cflag as a parameter. That's because some
callers like pch_uart_startup or sunsab_console_setup don't have at hand
termios which we could pass around.

Cc: Joe Perches 
Cc: Johan Hovold 
Reviewed-by: Andy Shevchenko 
Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210610090247.2593-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: remove unused tty_throttle

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

The last user was removed in commit e91e52e42814 (n_tty: Fix stuck
throttled driver) in 2013. So remove exported tty_throttle completely.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210510065923.5112-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: make tty_operations::chars_in_buffer return uint

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

tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.

Signed-off-by: Jiri Slaby 
Acked-By: Anton Ivanov 
Acked-by: David Sterba 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Arnd Bergmann 
Cc: Samuel Iglesias Gonsalvez 
Cc: Jens Taprogge 
Cc: Karsten Keil 
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 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/20210505091928.22010-27-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::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: move some tty-only functions to drivers/tty/tty.h

2021-04-15T08:30:18+00:00

The flow change and restricted_tty_write() logic is internal to the tty
core only, so move it out of the include/linux/tty.h file.

Cc: Jiri Slaby 
Link: https://lore.kernel.org/r/20210408125134.3016837-12-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

tty: fix return value for unsupported termiox ioctls

2021-04-10T08:36:34+00:00

Drivers should return -ENOTTY ("Inappropriate I/O control operation")
when an ioctl isn't supported, while -EINVAL is used for invalid
arguments.

Support for termiox was added by commit 1d65b4a088de ("tty: Add
termiox") in 2008 but no driver support ever followed and it was
recently ripped out by commit e0efb3168d34 ("tty: Remove dead termiox
code").

Fix the return value for the unsupported termiox ioctls, which have
always returned -EINVAL, by explicitly returning -ENOTTY rather than
removing them completely and falling back to the default unrecognised-
ioctl handling.

Fixes: 1d65b4a088de ("tty: Add termiox")
Signed-off-by: Johan Hovold 
Link: https://lore.kernel.org/r/20210407095208.31838-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman

tty: cleanup tty_chars_in_buffer

2021-03-10T08:34:09+00:00

There is no need for 'else' when the 'if' part already returned. This
makes tty_chars_in_buffer similar to tty_write_room too.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210302062214.29627-42-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman