linux-stable.git/drivers/tty/tty_io.c, branch v6.0

tty: fix typos in comments

2022-06-10T11:32:52+00:00

Spelling mistakes (triple letters) in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall 
Link: https://lore.kernel.org/r/20220521111145.81697-95-Julia.Lawall@inria.fr
Signed-off-by: Greg Kroah-Hartman

memcg: enable accounting for tty-related objects

2022-03-22T22:57:04+00:00

At each login the user forces the kernel to create a new terminal and
allocate up to ~1Kb memory for the tty-related structures.

By default it's allowed to create up to 4096 ptys with 1024 reserve for
initial mount namespace only and the settings are controlled by host
admin.

Though this default is not enough for hosters with thousands of
containers per node.  Host admin can be forced to increase it up to
NR_UNIX98_PTY_MAX = 1<<20.

By default container is restricted by pty mount_opt.max = 1024, but
admin inside container can change it via remount.  As a result, one
container can consume almost all allowed ptys and allocate up to 1Gb of
unaccounted memory.

It is not enough per-se to trigger OOM on host, however anyway, it
allows to significantly exceed the assigned memcg limit and leads to
troubles on the over-committed node.

It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.

Link: https://lkml.kernel.org/r/5d4bca06-7d4f-a905-e518-12981ebca1b3@virtuozzo.com
Signed-off-by: Vasily Averin 
Cc: Michal Hocko 
Cc: Shakeel Butt 
Cc: Johannes Weiner 
Cc: Vladimir Davydov 
Cc: Roman Gushchin 
Cc: Greg Kroah-Hartman 
Cc: Jiri Slaby 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tty: tty_io: Switch to vmalloc() fallback in case of TTY_NO_WRITE_SPLIT

2021-12-21T08:18:44+00:00

When TTY_NO_WRITE_SPLIT is set and 64 KiB chunks are used, allow
vmalloc() fallback. Supply __GFP_RETRY_MAYFAIL to make kmalloc()
preferable over vmalloc() since we may want a better performance.

Note, both current users copy data to another buffer anyway, so
the type of our allocation doesn't affect their expectations.

Signed-off-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20211220133250.3070-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman

tty: add kernel-doc for tty_standard_install

2021-11-26T15:27:43+00:00

It is the only missing exported function which is not documented. Fix
it.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211126081611.11001-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: add kernel-doc for more tty_driver functions

2021-11-26T15:27:43+00:00

The only documented function for tty_driver structure
allocation/registration was __tty_alloc_driver(). Fix highlighting in
that comment.

And add kernel-doc headers to all tty_driver_kref_put(),
tty_register_driver(), and tty_unregister_driver() -- i.e. the main
ones. More to follow later.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211126081611.11001-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: reformat kernel-doc in tty_io.c

2021-11-26T15:27:43+00:00

Kernel-doc is a bit strict about some formatting. So fix these:
1) When there is a tab in comments, it thinks the line is a continuation
   one. So the description of the functions end up as descriptions of
   the last parameter described. Remove the tabs.

2) Remove newlines before parameters description and after the comments.
   This was not wrong per se, only inconsistent with the rest of the
   file.

3) Add periods to the end of sentences where appropriate.

4) Add "()" to function names and "%" to constants, so that they are
   properly highlighted.

By the above, this patch also unifies these docs with the other
kernel-doc's in this file.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211126081611.11001-13-jslaby@suse.cz
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: clean up whitespace in __do_SAK()

2021-11-25T17:31:32+00:00

Remove spaces before the 'i' variable declaration and wrap parameters of
group_send_sig_info().

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211118071911.12059-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: remove tty NULL check from __do_SAK()

2021-11-25T17:31:32+00:00

Both do_SAK_work() and vc_SAK() provide a valid tty to __do_SAK(), so
remove the check.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211118071911.12059-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

tty: remove TTY_SOFT_SAK part from __do_SAK()

2021-11-25T17:31:32+00:00

Remove the TTY_SOFT_SAK part. It is never defined, so this is only
confusing.

It was actually never defined since its introduction in
0.99.14g.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20211118071911.12059-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman