License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 17:07:57 +03:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2005-04-17 02:20:36 +04:00
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#ifndef _LINUX_TTY_H
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#define _LINUX_TTY_H
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2011-05-24 12:43:03 +04:00
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#include <linux/fs.h>
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#include <linux/major.h>
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#include <linux/termios.h>
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#include <linux/workqueue.h>
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#include <linux/tty_driver.h>
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#include <linux/tty_ldisc.h>
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#include <linux/mutex.h>
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2012-09-04 19:35:08 +04:00
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#include <linux/tty_flags.h>
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2018-04-13 20:44:18 +03:00
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#include <linux/seq_file.h>
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2012-10-13 13:46:48 +04:00
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#include <uapi/linux/tty.h>
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2013-06-15 17:14:23 +04:00
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#include <linux/rwsem.h>
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2013-06-15 17:36:06 +04:00
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#include <linux/llist.h>
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2011-05-24 12:43:03 +04:00
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2015-01-17 23:42:04 +03:00
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/*
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* Lock subclasses for tty locks
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*
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* TTY_LOCK_NORMAL is for normal ttys and master ptys.
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* TTY_LOCK_SLAVE is for slave ptys only.
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*
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* Lock subclasses are necessary for handling nested locking with pty pairs.
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* tty locks which use nested locking:
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*
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* legacy_mutex - Nested tty locks are necessary for releasing pty pairs.
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* The stable lock order is master pty first, then slave pty.
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2015-01-17 23:42:06 +03:00
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* termios_rwsem - The stable lock order is tty_buffer lock->termios_rwsem.
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* Subclassing this lock enables the slave pty to hold its
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* termios_rwsem when claiming the master tty_buffer lock.
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2015-01-17 23:42:05 +03:00
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* tty_buffer lock - slave ptys can claim nested buffer lock when handling
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* signal chars. The stable lock order is slave pty, then
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* master.
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2015-01-17 23:42:04 +03:00
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*/
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enum {
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TTY_LOCK_NORMAL = 0,
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TTY_LOCK_SLAVE,
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};
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2011-05-24 12:43:03 +04:00
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/*
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* (Note: the *_driver.minor_start values 1, 64, 128, 192 are
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* hardcoded at present.)
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*/
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#define NR_UNIX98_PTY_DEFAULT 4096 /* Default maximum for Unix98 ptys */
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2012-01-05 13:06:11 +04:00
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#define NR_UNIX98_PTY_RESERVE 1024 /* Default reserve for main devpts */
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2011-05-24 12:43:03 +04:00
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#define NR_UNIX98_PTY_MAX (1 << MINORBITS) /* Absolute limit */
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2005-04-17 02:20:36 +04:00
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/*
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* This character is the same as _POSIX_VDISABLE: it cannot be used as
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* a c_cc[] character, but indicates that a particular special character
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* isn't in use (eg VINTR has no character etc)
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*/
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#define __DISABLED_CHAR '\0'
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[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
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struct tty_buffer {
|
2013-06-15 17:36:06 +04:00
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union {
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struct tty_buffer *next;
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struct llist_node free;
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};
|
[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
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int used;
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int size;
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2006-02-10 12:51:14 +03:00
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int commit;
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int read;
|
2013-12-09 18:23:52 +04:00
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int flags;
|
[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
|
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|
/* Data points here */
|
2020-05-04 19:16:37 +03:00
|
|
|
unsigned long data[];
|
[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
|
|
|
};
|
|
|
|
|
|
2013-12-09 18:23:52 +04:00
|
|
|
/* Values for .flags field of tty_buffer */
|
|
|
|
|
#define TTYB_NORMAL 1 /* buffer has no flags buffer */
|
|
|
|
|
|
2013-06-15 17:36:01 +04:00
|
|
|
static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
|
|
|
|
|
{
|
|
|
|
|
return ((unsigned char *)b->data) + ofs;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
|
|
|
|
|
{
|
|
|
|
|
return (char *)char_buf_ptr(b, ofs) + b->size;
|
|
|
|
|
}
|
|
|
|
|
|
[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
|
|
|
struct tty_bufhead {
|
2013-06-15 17:36:12 +04:00
|
|
|
struct tty_buffer *head; /* Queue head */
|
2011-03-23 02:17:32 +03:00
|
|
|
struct work_struct work;
|
2013-06-15 17:36:15 +04:00
|
|
|
struct mutex lock;
|
|
|
|
|
atomic_t priority;
|
2013-06-15 17:36:07 +04:00
|
|
|
struct tty_buffer sentinel;
|
2013-06-15 17:36:06 +04:00
|
|
|
struct llist_head free; /* Free queue head */
|
2013-11-22 21:09:56 +04:00
|
|
|
atomic_t mem_used; /* In-use buffers excluding free list */
|
2013-11-22 21:09:55 +04:00
|
|
|
int mem_limit;
|
2013-06-15 17:36:12 +04:00
|
|
|
struct tty_buffer *tail; /* Active buffer */
|
2005-04-17 02:20:36 +04:00
|
|
|
};
|
|
|
|
|
/*
|
|
|
|
|
* When a break, frame error, or parity error happens, these codes are
|
|
|
|
|
* stuffed into the flags buffer.
|
|
|
|
|
*/
|
|
|
|
|
#define TTY_NORMAL 0
|
|
|
|
|
#define TTY_BREAK 1
|
|
|
|
|
#define TTY_FRAME 2
|
|
|
|
|
#define TTY_PARITY 3
|
|
|
|
|
#define TTY_OVERRUN 4
|
|
|
|
|
|
2012-07-14 18:31:47 +04:00
|
|
|
#define INTR_CHAR(tty) ((tty)->termios.c_cc[VINTR])
|
|
|
|
|
#define QUIT_CHAR(tty) ((tty)->termios.c_cc[VQUIT])
|
|
|
|
|
#define ERASE_CHAR(tty) ((tty)->termios.c_cc[VERASE])
|
|
|
|
|
#define KILL_CHAR(tty) ((tty)->termios.c_cc[VKILL])
|
|
|
|
|
#define EOF_CHAR(tty) ((tty)->termios.c_cc[VEOF])
|
|
|
|
|
#define TIME_CHAR(tty) ((tty)->termios.c_cc[VTIME])
|
|
|
|
|
#define MIN_CHAR(tty) ((tty)->termios.c_cc[VMIN])
|
|
|
|
|
#define SWTC_CHAR(tty) ((tty)->termios.c_cc[VSWTC])
|
|
|
|
|
#define START_CHAR(tty) ((tty)->termios.c_cc[VSTART])
|
|
|
|
|
#define STOP_CHAR(tty) ((tty)->termios.c_cc[VSTOP])
|
|
|
|
|
#define SUSP_CHAR(tty) ((tty)->termios.c_cc[VSUSP])
|
|
|
|
|
#define EOL_CHAR(tty) ((tty)->termios.c_cc[VEOL])
|
|
|
|
|
#define REPRINT_CHAR(tty) ((tty)->termios.c_cc[VREPRINT])
|
|
|
|
|
#define DISCARD_CHAR(tty) ((tty)->termios.c_cc[VDISCARD])
|
|
|
|
|
#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])
|
|
|
|
|
#define LNEXT_CHAR(tty) ((tty)->termios.c_cc[VLNEXT])
|
|
|
|
|
#define EOL2_CHAR(tty) ((tty)->termios.c_cc[VEOL2])
|
2005-04-17 02:20:36 +04:00
|
|
|
|
2012-07-14 18:31:47 +04:00
|
|
|
#define _I_FLAG(tty, f) ((tty)->termios.c_iflag & (f))
|
|
|
|
|
#define _O_FLAG(tty, f) ((tty)->termios.c_oflag & (f))
|
|
|
|
|
#define _C_FLAG(tty, f) ((tty)->termios.c_cflag & (f))
|
|
|
|
|
#define _L_FLAG(tty, f) ((tty)->termios.c_lflag & (f))
|
2008-07-17 00:54:54 +04:00
|
|
|
|
|
|
|
|
#define I_IGNBRK(tty) _I_FLAG((tty), IGNBRK)
|
|
|
|
|
#define I_BRKINT(tty) _I_FLAG((tty), BRKINT)
|
|
|
|
|
#define I_IGNPAR(tty) _I_FLAG((tty), IGNPAR)
|
|
|
|
|
#define I_PARMRK(tty) _I_FLAG((tty), PARMRK)
|
|
|
|
|
#define I_INPCK(tty) _I_FLAG((tty), INPCK)
|
|
|
|
|
#define I_ISTRIP(tty) _I_FLAG((tty), ISTRIP)
|
|
|
|
|
#define I_INLCR(tty) _I_FLAG((tty), INLCR)
|
|
|
|
|
#define I_IGNCR(tty) _I_FLAG((tty), IGNCR)
|
|
|
|
|
#define I_ICRNL(tty) _I_FLAG((tty), ICRNL)
|
|
|
|
|
#define I_IUCLC(tty) _I_FLAG((tty), IUCLC)
|
|
|
|
|
#define I_IXON(tty) _I_FLAG((tty), IXON)
|
|
|
|
|
#define I_IXANY(tty) _I_FLAG((tty), IXANY)
|
|
|
|
|
#define I_IXOFF(tty) _I_FLAG((tty), IXOFF)
|
|
|
|
|
#define I_IMAXBEL(tty) _I_FLAG((tty), IMAXBEL)
|
|
|
|
|
#define I_IUTF8(tty) _I_FLAG((tty), IUTF8)
|
|
|
|
|
|
|
|
|
|
#define O_OPOST(tty) _O_FLAG((tty), OPOST)
|
|
|
|
|
#define O_OLCUC(tty) _O_FLAG((tty), OLCUC)
|
|
|
|
|
#define O_ONLCR(tty) _O_FLAG((tty), ONLCR)
|
|
|
|
|
#define O_OCRNL(tty) _O_FLAG((tty), OCRNL)
|
|
|
|
|
#define O_ONOCR(tty) _O_FLAG((tty), ONOCR)
|
|
|
|
|
#define O_ONLRET(tty) _O_FLAG((tty), ONLRET)
|
|
|
|
|
#define O_OFILL(tty) _O_FLAG((tty), OFILL)
|
|
|
|
|
#define O_OFDEL(tty) _O_FLAG((tty), OFDEL)
|
|
|
|
|
#define O_NLDLY(tty) _O_FLAG((tty), NLDLY)
|
|
|
|
|
#define O_CRDLY(tty) _O_FLAG((tty), CRDLY)
|
|
|
|
|
#define O_TABDLY(tty) _O_FLAG((tty), TABDLY)
|
|
|
|
|
#define O_BSDLY(tty) _O_FLAG((tty), BSDLY)
|
|
|
|
|
#define O_VTDLY(tty) _O_FLAG((tty), VTDLY)
|
|
|
|
|
#define O_FFDLY(tty) _O_FLAG((tty), FFDLY)
|
|
|
|
|
|
|
|
|
|
#define C_BAUD(tty) _C_FLAG((tty), CBAUD)
|
|
|
|
|
#define C_CSIZE(tty) _C_FLAG((tty), CSIZE)
|
|
|
|
|
#define C_CSTOPB(tty) _C_FLAG((tty), CSTOPB)
|
|
|
|
|
#define C_CREAD(tty) _C_FLAG((tty), CREAD)
|
|
|
|
|
#define C_PARENB(tty) _C_FLAG((tty), PARENB)
|
|
|
|
|
#define C_PARODD(tty) _C_FLAG((tty), PARODD)
|
|
|
|
|
#define C_HUPCL(tty) _C_FLAG((tty), HUPCL)
|
|
|
|
|
#define C_CLOCAL(tty) _C_FLAG((tty), CLOCAL)
|
|
|
|
|
#define C_CIBAUD(tty) _C_FLAG((tty), CIBAUD)
|
|
|
|
|
#define C_CRTSCTS(tty) _C_FLAG((tty), CRTSCTS)
|
2013-12-29 22:23:16 +04:00
|
|
|
#define C_CMSPAR(tty) _C_FLAG((tty), CMSPAR)
|
2008-07-17 00:54:54 +04:00
|
|
|
|
|
|
|
|
#define L_ISIG(tty) _L_FLAG((tty), ISIG)
|
|
|
|
|
#define L_ICANON(tty) _L_FLAG((tty), ICANON)
|
|
|
|
|
#define L_XCASE(tty) _L_FLAG((tty), XCASE)
|
|
|
|
|
#define L_ECHO(tty) _L_FLAG((tty), ECHO)
|
|
|
|
|
#define L_ECHOE(tty) _L_FLAG((tty), ECHOE)
|
|
|
|
|
#define L_ECHOK(tty) _L_FLAG((tty), ECHOK)
|
|
|
|
|
#define L_ECHONL(tty) _L_FLAG((tty), ECHONL)
|
|
|
|
|
#define L_NOFLSH(tty) _L_FLAG((tty), NOFLSH)
|
|
|
|
|
#define L_TOSTOP(tty) _L_FLAG((tty), TOSTOP)
|
|
|
|
|
#define L_ECHOCTL(tty) _L_FLAG((tty), ECHOCTL)
|
|
|
|
|
#define L_ECHOPRT(tty) _L_FLAG((tty), ECHOPRT)
|
|
|
|
|
#define L_ECHOKE(tty) _L_FLAG((tty), ECHOKE)
|
|
|
|
|
#define L_FLUSHO(tty) _L_FLAG((tty), FLUSHO)
|
|
|
|
|
#define L_PENDIN(tty) _L_FLAG((tty), PENDIN)
|
|
|
|
|
#define L_IEXTEN(tty) _L_FLAG((tty), IEXTEN)
|
tty: Add EXTPROC support for LINEMODE
This patch is against the 2.6.34 source.
Paraphrased from the 1989 BSD patch by David Borman @ cray.com:
These are the changes needed for the kernel to support
LINEMODE in the server.
There is a new bit in the termios local flag word, EXTPROC.
When this bit is set, several aspects of the terminal driver
are disabled. Input line editing, character echo, and mapping
of signals are all disabled. This allows the telnetd to turn
off these functions when in linemode, but still keep track of
what state the user wants the terminal to be in.
New ioctl:
TIOCSIG Generate a signal to processes in the
current process group of the pty.
There is a new mode for packet driver, the TIOCPKT_IOCTL bit.
When packet mode is turned on in the pty, and the EXTPROC bit
is set, then whenever the state of the pty is changed, the
next read on the master side of the pty will have the TIOCPKT_IOCTL
bit set. This allows the process on the server side of the pty
to know when the state of the terminal has changed; it can then
issue the appropriate ioctl to retrieve the new state.
Since the original BSD patches accompanied the source code for telnet
I've left that reference here, but obviously the feature is useful for
any remote terminal protocol, including ssh.
The corresponding feature has existed in the BSD tty driver since 1989.
For historical reference, a good copy of the relevant files can be found
here:
http://anonsvn.mit.edu/viewvc/krb5/trunk/src/appl/telnet/?pathrev=17741
Signed-off-by: Howard Chu <hyc@symas.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22 21:14:49 +04:00
|
|
|
#define L_EXTPROC(tty) _L_FLAG((tty), EXTPROC)
|
2005-04-17 02:20:36 +04:00
|
|
|
|
|
|
|
|
struct device;
|
Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
|
|
|
struct signal_struct;
|
2008-07-17 00:53:41 +04:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Port level information. Each device keeps its own port level information
|
|
|
|
|
* so provide a common structure for those ports wanting to use common support
|
|
|
|
|
* routines.
|
|
|
|
|
*
|
|
|
|
|
* The tty port has a different lifetime to the tty so must be kept apart.
|
|
|
|
|
* In addition be careful as tty -> port mappings are valid for the life
|
|
|
|
|
* of the tty object but in many cases port -> tty mappings are valid only
|
|
|
|
|
* until a hangup so don't use the wrong path.
|
|
|
|
|
*/
|
2008-07-17 00:54:54 +04:00
|
|
|
|
2009-01-02 16:45:05 +03:00
|
|
|
struct tty_port;
|
|
|
|
|
|
|
|
|
|
struct tty_port_operations {
|
|
|
|
|
/* Return 1 if the carrier is raised */
|
|
|
|
|
int (*carrier_raised)(struct tty_port *port);
|
2009-09-20 00:13:20 +04:00
|
|
|
/* Control the DTR line */
|
2009-06-11 15:24:17 +04:00
|
|
|
void (*dtr_rts)(struct tty_port *port, int raise);
|
2009-09-20 00:13:20 +04:00
|
|
|
/* Called when the last close completes or a hangup finishes
|
2009-10-06 19:06:11 +04:00
|
|
|
IFF the port was initialized. Do not use to free resources. Called
|
|
|
|
|
under the port mutex to serialize against activate/shutdowns */
|
2009-09-20 00:13:20 +04:00
|
|
|
void (*shutdown)(struct tty_port *port);
|
2009-10-06 19:06:11 +04:00
|
|
|
/* Called under the port mutex from tty_port_open, serialized using
|
|
|
|
|
the port mutex */
|
|
|
|
|
/* FIXME: long term getting the tty argument *out* of this would be
|
|
|
|
|
good for consoles */
|
|
|
|
|
int (*activate)(struct tty_port *port, struct tty_struct *tty);
|
2009-11-30 16:17:14 +03:00
|
|
|
/* Called on the final put of a port */
|
|
|
|
|
void (*destruct)(struct tty_port *port);
|
2009-01-02 16:45:05 +03:00
|
|
|
};
|
2017-02-02 22:48:05 +03:00
|
|
|
|
|
|
|
|
struct tty_port_client_operations {
|
|
|
|
|
int (*receive_buf)(struct tty_port *port, const unsigned char *, const unsigned char *, size_t);
|
|
|
|
|
void (*write_wakeup)(struct tty_port *port);
|
|
|
|
|
};
|
|
|
|
|
|
2020-02-10 17:57:30 +03:00
|
|
|
extern const struct tty_port_client_operations tty_port_default_client_ops;
|
|
|
|
|
|
2008-07-17 00:53:41 +04:00
|
|
|
struct tty_port {
|
2012-10-19 00:26:47 +04:00
|
|
|
struct tty_bufhead buf; /* Locked internally */
|
2008-07-17 00:53:41 +04:00
|
|
|
struct tty_struct *tty; /* Back pointer */
|
2012-10-19 00:26:46 +04:00
|
|
|
struct tty_struct *itty; /* internal back ptr */
|
2009-01-02 16:45:05 +03:00
|
|
|
const struct tty_port_operations *ops; /* Port operations */
|
2017-02-02 22:48:05 +03:00
|
|
|
const struct tty_port_client_operations *client_ops; /* Port client operations */
|
2008-10-13 13:39:46 +04:00
|
|
|
spinlock_t lock; /* Lock protecting tty field */
|
2008-07-17 00:53:41 +04:00
|
|
|
int blocked_open; /* Waiting to open */
|
|
|
|
|
int count; /* Usage count */
|
|
|
|
|
wait_queue_head_t open_wait; /* Open waiters */
|
2009-09-20 00:13:31 +04:00
|
|
|
wait_queue_head_t delta_msr_wait; /* Modem status change */
|
2016-04-10 03:53:20 +03:00
|
|
|
unsigned long flags; /* User TTY flags ASYNC_ */
|
|
|
|
|
unsigned long iflags; /* Internal flags TTY_PORT_ */
|
2013-01-03 18:53:05 +04:00
|
|
|
unsigned char console:1, /* port is a console */
|
tty: Fix low_latency BUG
The user-settable knob, low_latency, has been the source of
several BUG reports which stem from flush_to_ldisc() running
in interrupt context. Since 3.12, which added several sleeping
locks (termios_rwsem and buf->lock) to the input processing path,
the frequency of these BUG reports has increased.
Note that changes in 3.12 did not introduce this regression;
sleeping locks were first added to the input processing path
with the removal of the BKL from N_TTY in commit
a88a69c91256418c5907c2f1f8a0ec0a36f9e6cc,
'n_tty: Fix loss of echoed characters and remove bkl from n_tty'
and later in commit 38db89799bdf11625a831c5af33938dcb11908b6,
'tty: throttling race fix'. Since those changes, executing
flush_to_ldisc() in interrupt_context (ie, low_latency set), is unsafe.
However, since most devices do not validate if the low_latency
setting is appropriate for the context (process or interrupt) in
which they receive data, some reports are due to misconfiguration.
Further, serial dma devices for which dma fails, resort to
interrupt receiving as a backup without resetting low_latency.
Historically, low_latency was used to force wake-up the reading
process rather than wait for the next scheduler tick. The
effect was to trim multiple milliseconds of latency from
when the process would receive new data.
Recent tests [1] have shown that the reading process now receives
data with only 10's of microseconds latency without low_latency set.
Remove the low_latency rx steering from tty_flip_buffer_push();
however, leave the knob as an optional hint to drivers that can
tune their rx fifos and such like. Cleanup stale code comments
regarding low_latency.
[1] https://lkml.org/lkml/2014/2/20/434
"Yay.. thats an annoying historical pain in the butt gone."
-- Alan Cox
Reported-by: Beat Bolli <bbolli@ewanet.ch>
Reported-by: Pavel Roskin <proski@gnu.org>
Acked-by: David Sterba <dsterba@suse.cz>
Cc: Grant Edwards <grant.b.edwards@gmail.com>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Hal Murray <murray+fedora@ip-64-139-1-69.sjc.megapath.net>
Cc: <stable@vger.kernel.org> # 3.12.x+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-22 16:31:21 +04:00
|
|
|
low_latency:1; /* optional: tune for latency */
|
2008-07-17 00:53:41 +04:00
|
|
|
struct mutex mutex; /* Locking */
|
2009-11-30 16:16:41 +03:00
|
|
|
struct mutex buf_mutex; /* Buffer alloc lock */
|
2008-07-17 00:53:41 +04:00
|
|
|
unsigned char *xmit_buf; /* Optional buffer */
|
2009-09-20 00:13:28 +04:00
|
|
|
unsigned int close_delay; /* Close port delay */
|
|
|
|
|
unsigned int closing_wait; /* Delay for output */
|
2009-06-11 15:25:25 +04:00
|
|
|
int drain_delay; /* Set to zero if no pure time
|
|
|
|
|
based drain is needed else
|
|
|
|
|
set to size of fifo */
|
2009-11-30 16:17:14 +03:00
|
|
|
struct kref kref; /* Ref counter */
|
2017-02-02 22:48:05 +03:00
|
|
|
void *client_data;
|
2008-07-17 00:53:41 +04:00
|
|
|
};
|
|
|
|
|
|
2016-04-10 03:53:20 +03:00
|
|
|
/* tty_port::iflags bits -- use atomic bit ops */
|
|
|
|
|
#define TTY_PORT_INITIALIZED 0 /* device is initialized */
|
|
|
|
|
#define TTY_PORT_SUSPENDED 1 /* device is suspended */
|
|
|
|
|
#define TTY_PORT_ACTIVE 2 /* device is open */
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* uart drivers: use the uart_port::status field and the UPSTAT_* defines
|
|
|
|
|
* for s/w-based flow control steering and carrier detection status
|
|
|
|
|
*/
|
|
|
|
|
#define TTY_PORT_CTS_FLOW 3 /* h/w flow control enabled */
|
|
|
|
|
#define TTY_PORT_CHECK_CD 4 /* carrier detect enabled */
|
2017-07-20 10:22:36 +03:00
|
|
|
#define TTY_PORT_KOPENED 5 /* device exclusively opened by
|
|
|
|
|
kernel */
|
2016-04-10 03:53:20 +03:00
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
/*
|
|
|
|
|
* Where all of the state associated with a tty is kept while the tty
|
|
|
|
|
* is open. Since the termios state should be kept even if the tty
|
|
|
|
|
* has been closed --- for things like the baud rate, etc --- it is
|
|
|
|
|
* not stored here, but rather a pointer to the real state is stored
|
|
|
|
|
* here. Possible the winsize structure should have the same
|
|
|
|
|
* treatment, but (1) the default 80x24 is usually right and (2) it's
|
|
|
|
|
* most often used by a windowing system, which will set the correct
|
|
|
|
|
* size each time the window is created or resized anyway.
|
|
|
|
|
* - TYT, 9/14/92
|
|
|
|
|
*/
|
2008-04-30 11:54:13 +04:00
|
|
|
|
|
|
|
|
struct tty_operations;
|
|
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
struct tty_struct {
|
|
|
|
|
int magic;
|
2008-10-13 13:37:26 +04:00
|
|
|
struct kref kref;
|
2010-08-09 18:22:49 +04:00
|
|
|
struct device *dev;
|
2005-04-17 02:20:36 +04:00
|
|
|
struct tty_driver *driver;
|
2008-04-30 11:54:13 +04:00
|
|
|
const struct tty_operations *ops;
|
2005-04-17 02:20:36 +04:00
|
|
|
int index;
|
2009-06-11 15:50:12 +04:00
|
|
|
|
|
|
|
|
/* Protects ldisc changes: Lock tty not pty */
|
2013-06-15 15:04:48 +04:00
|
|
|
struct ld_semaphore ldisc_sem;
|
2009-06-11 15:50:12 +04:00
|
|
|
struct tty_ldisc *ldisc;
|
|
|
|
|
|
2012-10-19 00:26:42 +04:00
|
|
|
struct mutex atomic_write_lock;
|
2012-08-08 19:30:13 +04:00
|
|
|
struct mutex legacy_mutex;
|
2013-06-15 17:14:31 +04:00
|
|
|
struct mutex throttle_mutex;
|
2013-06-15 17:14:23 +04:00
|
|
|
struct rw_semaphore termios_rwsem;
|
tty: Fix lock order in tty_do_resize()
Commits 6a1c0680cf3ba94356ecd58833e1540c93472a57 and
9356b535fcb71db494fc434acceb79f56d15bda2, respectively
'tty: Convert termios_mutex to termios_rwsem' and
'n_tty: Access termios values safely'
introduced a circular lock dependency with console_lock and
termios_rwsem.
The lockdep report [1] shows that n_tty_write() will attempt
to claim console_lock while holding the termios_rwsem, whereas
tty_do_resize() may already hold the console_lock while
claiming the termios_rwsem.
Since n_tty_write() and tty_do_resize() do not contend
over the same data -- the tty->winsize structure -- correct
the lock dependency by introducing a new lock which
specifically serializes access to tty->winsize only.
[1] Lockdep report
======================================================
[ INFO: possible circular locking dependency detected ]
3.10.0-0+tip-xeon+lockdep #0+tip Not tainted
-------------------------------------------------------
modprobe/277 is trying to acquire lock:
(&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0
but task is already holding lock:
((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 ((fb_notifier_list).rwsem){.+.+.+}:
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff8175b797>] down_read+0x47/0x5c
[<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
-> #1 (console_lock){+.+.+.}:
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff810430a7>] console_lock+0x77/0x80
[<ffffffff8146b2a1>] con_flush_chars+0x31/0x50
[<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0
[<ffffffff814541b9>] tty_write+0x159/0x2e0
[<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0
[<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0
[<ffffffff811abec5>] SyS_write+0x55/0xa0
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
-> #0 (&tty->termios_rwsem){++++..}:
[<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff8175b724>] down_write+0x44/0x70
[<ffffffff81452656>] tty_do_resize+0x36/0xe0
[<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0
[<ffffffff8146c99f>] vc_resize+0x1f/0x30
[<ffffffff813e4535>] fbcon_init+0x385/0x5a0
[<ffffffff8146a4bc>] visual_init+0xbc/0x120
[<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320
[<ffffffff8146cfa1>] do_take_over_console+0x61/0x70
[<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0
[<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820
[<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110
[<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Chain exists of:
&tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock((fb_notifier_list).rwsem);
lock(console_lock);
lock((fb_notifier_list).rwsem);
lock(&tty->termios_rwsem);
*** DEADLOCK ***
7 locks held by modprobe/277:
#0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0
#1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0
#2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm]
#3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320
#4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60
#5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320
#6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
stack backtrace:
CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip
Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012
ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8
ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8
ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007
Call Trace:
[<ffffffff81755f19>] dump_stack+0x19/0x1b
[<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c
[<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30
[<ffffffff810b775e>] ? mark_held_locks+0xae/0x120
[<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff81452656>] ? tty_do_resize+0x36/0xe0
[<ffffffff8175b724>] down_write+0x44/0x70
[<ffffffff81452656>] ? tty_do_resize+0x36/0xe0
[<ffffffff81452656>] tty_do_resize+0x36/0xe0
[<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0
[<ffffffff8146c99f>] vc_resize+0x1f/0x30
[<ffffffff813e4535>] fbcon_init+0x385/0x5a0
[<ffffffff8146a4bc>] visual_init+0xbc/0x120
[<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320
[<ffffffff8146cfa1>] do_take_over_console+0x61/0x70
[<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0
[<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820
[<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110
[<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0
[<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290
[<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0
[<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 00:43:51 +04:00
|
|
|
struct mutex winsize_mutex;
|
2008-04-30 11:53:29 +04:00
|
|
|
spinlock_t ctrl_lock;
|
2014-09-10 23:06:31 +04:00
|
|
|
spinlock_t flow_lock;
|
2013-06-15 17:14:23 +04:00
|
|
|
/* Termios values are protected by the termios rwsem */
|
2012-07-14 18:31:47 +04:00
|
|
|
struct ktermios termios, termios_locked;
|
2005-04-17 02:20:36 +04:00
|
|
|
char name[64];
|
2008-04-30 11:53:30 +04:00
|
|
|
struct pid *pgrp; /* Protected by ctrl lock */
|
tty: Fix ->session locking
Currently, locking of ->session is very inconsistent; most places
protect it using the legacy tty mutex, but disassociate_ctty(),
__do_SAK(), tiocspgrp() and tiocgsid() don't.
Two of the writers hold the ctrl_lock (because they already need it for
->pgrp), but __proc_set_tty() doesn't do that yet.
On a PREEMPT=y system, an unprivileged user can theoretically abuse
this broken locking to read 4 bytes of freed memory via TIOCGSID if
tiocgsid() is preempted long enough at the right point. (Other things
might also go wrong, especially if root-only ioctls are involved; I'm
not sure about that.)
Change the locking on ->session such that:
- tty_lock() is held by all writers: By making disassociate_ctty()
hold it. This should be fine because the same lock can already be
taken through the call to tty_vhangup_session().
The tricky part is that we need to shorten the area covered by
siglock to be able to take tty_lock() without ugly retry logic; as
far as I can tell, this should be fine, since nothing in the
signal_struct is touched in the `if (tty)` branch.
- ctrl_lock is held by all writers: By changing __proc_set_tty() to
hold the lock a little longer.
- All readers that aren't holding tty_lock() hold ctrl_lock: By
adding locking to tiocgsid() and __do_SAK(), and expanding the area
covered by ctrl_lock in tiocspgrp().
Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-03 04:25:05 +03:00
|
|
|
/*
|
|
|
|
|
* Writes protected by both ctrl lock and legacy mutex, readers must use
|
|
|
|
|
* at least one of them.
|
|
|
|
|
*/
|
2007-02-12 11:53:00 +03:00
|
|
|
struct pid *session;
|
2005-04-17 02:20:36 +04:00
|
|
|
unsigned long flags;
|
|
|
|
|
int count;
|
tty: Fix lock order in tty_do_resize()
Commits 6a1c0680cf3ba94356ecd58833e1540c93472a57 and
9356b535fcb71db494fc434acceb79f56d15bda2, respectively
'tty: Convert termios_mutex to termios_rwsem' and
'n_tty: Access termios values safely'
introduced a circular lock dependency with console_lock and
termios_rwsem.
The lockdep report [1] shows that n_tty_write() will attempt
to claim console_lock while holding the termios_rwsem, whereas
tty_do_resize() may already hold the console_lock while
claiming the termios_rwsem.
Since n_tty_write() and tty_do_resize() do not contend
over the same data -- the tty->winsize structure -- correct
the lock dependency by introducing a new lock which
specifically serializes access to tty->winsize only.
[1] Lockdep report
======================================================
[ INFO: possible circular locking dependency detected ]
3.10.0-0+tip-xeon+lockdep #0+tip Not tainted
-------------------------------------------------------
modprobe/277 is trying to acquire lock:
(&tty->termios_rwsem){++++..}, at: [<ffffffff81452656>] tty_do_resize+0x36/0xe0
but task is already holding lock:
((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 ((fb_notifier_list).rwsem){.+.+.+}:
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff8175b797>] down_read+0x47/0x5c
[<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
-> #1 (console_lock){+.+.+.}:
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff810430a7>] console_lock+0x77/0x80
[<ffffffff8146b2a1>] con_flush_chars+0x31/0x50
[<ffffffff8145780c>] n_tty_write+0x1ec/0x4d0
[<ffffffff814541b9>] tty_write+0x159/0x2e0
[<ffffffff814543f5>] redirected_tty_write+0xb5/0xc0
[<ffffffff811ab9d5>] vfs_write+0xc5/0x1f0
[<ffffffff811abec5>] SyS_write+0x55/0xa0
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
-> #0 (&tty->termios_rwsem){++++..}:
[<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff8175b724>] down_write+0x44/0x70
[<ffffffff81452656>] tty_do_resize+0x36/0xe0
[<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0
[<ffffffff8146c99f>] vc_resize+0x1f/0x30
[<ffffffff813e4535>] fbcon_init+0x385/0x5a0
[<ffffffff8146a4bc>] visual_init+0xbc/0x120
[<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320
[<ffffffff8146cfa1>] do_take_over_console+0x61/0x70
[<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0
[<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820
[<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110
[<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
other info that might help us debug this:
Chain exists of:
&tty->termios_rwsem --> console_lock --> (fb_notifier_list).rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock((fb_notifier_list).rwsem);
lock(console_lock);
lock((fb_notifier_list).rwsem);
lock(&tty->termios_rwsem);
*** DEADLOCK ***
7 locks held by modprobe/277:
#0: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b5b>] __driver_attach+0x5b/0xb0
#1: (&__lockdep_no_validate__){......}, at: [<ffffffff81497b69>] __driver_attach+0x69/0xb0
#2: (drm_global_mutex){+.+.+.}, at: [<ffffffffa008a6dd>] drm_get_pci_dev+0xbd/0x2a0 [drm]
#3: (registration_lock){+.+.+.}, at: [<ffffffff813d93f5>] register_framebuffer+0x25/0x320
#4: (&fb_info->lock){+.+.+.}, at: [<ffffffff813d8116>] lock_fb_info+0x26/0x60
#5: (console_lock){+.+.+.}, at: [<ffffffff813d95a4>] register_framebuffer+0x1d4/0x320
#6: ((fb_notifier_list).rwsem){.+.+.+}, at: [<ffffffff8107aac6>] __blocking_notifier_call_chain+0x56/0xc0
stack backtrace:
CPU: 0 PID: 277 Comm: modprobe Not tainted 3.10.0-0+tip-xeon+lockdep #0+tip
Hardware name: Dell Inc. Precision WorkStation T5400 /0RW203, BIOS A11 04/30/2012
ffffffff8213e5e0 ffff8802aa2fb298 ffffffff81755f19 ffff8802aa2fb2e8
ffffffff8174f506 ffff8802aa2fa000 ffff8802aa2fb378 ffff8802aa2ea8e8
ffff8802aa2ea910 ffff8802aa2ea8e8 0000000000000006 0000000000000007
Call Trace:
[<ffffffff81755f19>] dump_stack+0x19/0x1b
[<ffffffff8174f506>] print_circular_bug+0x1fb/0x20c
[<ffffffff810b65c3>] __lock_acquire+0x1c43/0x1d30
[<ffffffff810b775e>] ? mark_held_locks+0xae/0x120
[<ffffffff810b78d5>] ? trace_hardirqs_on_caller+0x105/0x1d0
[<ffffffff810b6d62>] lock_acquire+0x92/0x1f0
[<ffffffff81452656>] ? tty_do_resize+0x36/0xe0
[<ffffffff8175b724>] down_write+0x44/0x70
[<ffffffff81452656>] ? tty_do_resize+0x36/0xe0
[<ffffffff81452656>] tty_do_resize+0x36/0xe0
[<ffffffff8146c841>] vc_do_resize+0x3e1/0x4c0
[<ffffffff8146c99f>] vc_resize+0x1f/0x30
[<ffffffff813e4535>] fbcon_init+0x385/0x5a0
[<ffffffff8146a4bc>] visual_init+0xbc/0x120
[<ffffffff8146cd13>] do_bind_con_driver+0x163/0x320
[<ffffffff8146cfa1>] do_take_over_console+0x61/0x70
[<ffffffff813e2b93>] do_fbcon_takeover+0x63/0xc0
[<ffffffff813e67a5>] fbcon_event_notify+0x715/0x820
[<ffffffff81762f9d>] notifier_call_chain+0x5d/0x110
[<ffffffff8107aadc>] __blocking_notifier_call_chain+0x6c/0xc0
[<ffffffff8107ab46>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff813d7c0b>] fb_notifier_call_chain+0x1b/0x20
[<ffffffff813d95b2>] register_framebuffer+0x1e2/0x320
[<ffffffffa01043e1>] drm_fb_helper_initial_config+0x371/0x540 [drm_kms_helper]
[<ffffffff8173cbcb>] ? kmemleak_alloc+0x5b/0xc0
[<ffffffff81198874>] ? kmem_cache_alloc_trace+0x104/0x290
[<ffffffffa01035e1>] ? drm_fb_helper_single_add_all_connectors+0x81/0xf0 [drm_kms_helper]
[<ffffffffa01bcb05>] nouveau_fbcon_init+0x105/0x140 [nouveau]
[<ffffffffa01ad0af>] nouveau_drm_load+0x43f/0x610 [nouveau]
[<ffffffffa008a79e>] drm_get_pci_dev+0x17e/0x2a0 [drm]
[<ffffffffa01ad4da>] nouveau_drm_probe+0x25a/0x2a0 [nouveau]
[<ffffffff8175f162>] ? _raw_spin_unlock_irqrestore+0x42/0x80
[<ffffffff813b13db>] local_pci_probe+0x4b/0x80
[<ffffffff813b1701>] pci_device_probe+0x111/0x120
[<ffffffff814977eb>] driver_probe_device+0x8b/0x3a0
[<ffffffff81497bab>] __driver_attach+0xab/0xb0
[<ffffffff81497b00>] ? driver_probe_device+0x3a0/0x3a0
[<ffffffff814956ad>] bus_for_each_dev+0x5d/0xa0
[<ffffffff814971fe>] driver_attach+0x1e/0x20
[<ffffffff81496cc1>] bus_add_driver+0x111/0x290
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffff814982b7>] driver_register+0x77/0x170
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffff813b0454>] __pci_register_driver+0x64/0x70
[<ffffffffa008a9da>] drm_pci_init+0x11a/0x130 [drm]
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffffa022a000>] ? 0xffffffffa0229fff
[<ffffffffa022a04d>] nouveau_drm_init+0x4d/0x1000 [nouveau]
[<ffffffff810002ea>] do_one_initcall+0xea/0x1a0
[<ffffffff810c54cb>] load_module+0x123b/0x1bf0
[<ffffffff81399a50>] ? ddebug_proc_open+0xb0/0xb0
[<ffffffff813855ae>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[<ffffffff810c5f57>] SyS_init_module+0xd7/0x120
[<ffffffff817677c2>] system_call_fastpath+0x16/0x1b
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-25 00:43:51 +04:00
|
|
|
struct winsize winsize; /* winsize_mutex */
|
2014-09-10 23:06:33 +04:00
|
|
|
unsigned long stopped:1, /* flow_lock */
|
|
|
|
|
flow_stopped:1,
|
2014-09-24 14:26:21 +04:00
|
|
|
unused:BITS_PER_LONG - 2;
|
2014-09-10 23:06:30 +04:00
|
|
|
int hw_stopped;
|
tty: Workaround Alpha non-atomic byte storage in tty_struct
The Alpha EV4/EV5 cpus can corrupt adjacent byte and short data because
those cpus use RMW to store byte and short data. Thus, concurrent adjacent
byte stores could become corrupted, if serialized by a different lock.
tty_struct uses different locks to protect certain fields within the
structure, and thus is vulnerable to byte stores which are not atomic.
Merge the ->ctrl_status byte and packet mode bit, both protected by the
->ctrl_lock, into an unsigned long.
The padding bits are necessary to force the compiler to allocate the
type specified; otherwise, gcc will ignore the type specifier and
allocate the minimum number of bytes required to store the bitfield.
In turn, this would allow Alpha EV4/EV5 cpus to corrupt adjacent byte
or short storage (because those cpus use RMW to store byte and short data).
gcc versions < 4.7.2 will also corrupt storage adjacent to bitfields
smaller than unsigned long on ia64, ppc64, hppa64, and sparc64, thus
requiring more than unsigned int storage (which would otherwise be
sufficient to fix the Alpha non-atomic storage problem).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-10 23:06:36 +04:00
|
|
|
unsigned long ctrl_status:8, /* ctrl_lock */
|
|
|
|
|
packet:1,
|
2014-09-24 14:26:21 +04:00
|
|
|
unused_ctrl:BITS_PER_LONG - 9;
|
[PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.
This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.
When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.
For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).
Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.
The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.
I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.
Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real. That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.
Description:
tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification]. It
does now also return the number of chars inserted
There are also
tty_buffer_request_room(tty, len)
which asks for a buffer block of the length requested and returns the space
found. This improves efficiency with hardware that knows how much to
transfer.
and tty_insert_flip_string_flags(tty, str, flags, len)
to insert a string of characters and flags
For a smart interface the usual code is
len = tty_request_buffer_room(tty, amount_hardware_says);
tty_insert_flip_string(tty, buffer_from_card, len);
More description!
At the moment tty buffers are attached directly to the tty. This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)
I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers. This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.
So far so good. Lots of drivers reference tty->flip.*. Several of them also
call directly and unsafely into function pointers it provides. This will all
break. Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.
At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say
int tty_buffer_request_room(tty, size)
Try and ensure at least size bytes are available, returns actual room (may be
zero). At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative. (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space. The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.
int tty_insert_flip_char(tty, ch, flag)
As before insert a character if there is room. Now returns 1 for success, 0
for failure.
int tty_insert_flip_string(tty, str, len)
Insert a block of non error characters. Returns the number inserted.
int tty_prepare_flip_string(tty, strptr, len)
Adjust the buffer to allow len characters to be added. Returns a buffer
pointer in strptr and the length available. This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 07:54:13 +03:00
|
|
|
unsigned int receive_room; /* Bytes free for queue */
|
2013-03-06 17:20:52 +04:00
|
|
|
int flow_change;
|
2005-04-17 02:20:36 +04:00
|
|
|
|
|
|
|
|
struct tty_struct *link;
|
|
|
|
|
struct fasync_struct *fasync;
|
|
|
|
|
wait_queue_head_t write_wait;
|
|
|
|
|
wait_queue_head_t read_wait;
|
|
|
|
|
struct work_struct hangup_work;
|
|
|
|
|
void *disc_data;
|
|
|
|
|
void *driver_data;
|
2016-01-10 08:35:23 +03:00
|
|
|
spinlock_t files_lock; /* protects tty_files list */
|
2005-04-17 02:20:36 +04:00
|
|
|
struct list_head tty_files;
|
|
|
|
|
|
|
|
|
|
#define N_TTY_BUF_SIZE 4096
|
2008-07-17 00:53:41 +04:00
|
|
|
|
2014-11-05 20:40:04 +03:00
|
|
|
int closing;
|
2005-04-17 02:20:36 +04:00
|
|
|
unsigned char *write_buf;
|
|
|
|
|
int write_cnt;
|
|
|
|
|
/* If the tty has a pending do_SAK, queue it here - akpm */
|
|
|
|
|
struct work_struct SAK_work;
|
2008-07-17 00:53:41 +04:00
|
|
|
struct tty_port *port;
|
2016-10-28 11:22:25 +03:00
|
|
|
} __randomize_layout;
|
2005-04-17 02:20:36 +04:00
|
|
|
|
tty: fix fu_list abuse
tty: fix fu_list abuse
tty code abuses fu_list, which causes a bug in remount,ro handling.
If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".
Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.
The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.
[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]
Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-17 22:37:36 +04:00
|
|
|
/* Each of a tty's open files has private_data pointing to tty_file_private */
|
|
|
|
|
struct tty_file_private {
|
|
|
|
|
struct tty_struct *tty;
|
|
|
|
|
struct file *file;
|
|
|
|
|
struct list_head list;
|
|
|
|
|
};
|
|
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
/* tty magic number */
|
|
|
|
|
#define TTY_MAGIC 0x5401
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* These bits are used in the flags field of the tty structure.
|
2008-07-17 00:54:54 +04:00
|
|
|
*
|
2005-04-17 02:20:36 +04:00
|
|
|
* So that interrupts won't be able to mess up the queues,
|
|
|
|
|
* copy_to_cooked must be atomic with respect to itself, as must
|
|
|
|
|
* tty->write. Thus, you must use the inline functions set_bit() and
|
|
|
|
|
* clear_bit() to make things atomic.
|
|
|
|
|
*/
|
|
|
|
|
#define TTY_THROTTLED 0 /* Call unthrottle() at threshold min */
|
2008-07-17 00:54:54 +04:00
|
|
|
#define TTY_IO_ERROR 1 /* Cause an I/O error (may be no ldisc too) */
|
2005-04-17 02:20:36 +04:00
|
|
|
#define TTY_OTHER_CLOSED 2 /* Other side (if any) has closed */
|
|
|
|
|
#define TTY_EXCLUSIVE 3 /* Exclusive open mode */
|
|
|
|
|
#define TTY_DO_WRITE_WAKEUP 5 /* Call write_wakeup after queuing new */
|
2009-06-11 15:50:12 +04:00
|
|
|
#define TTY_LDISC_OPEN 11 /* Line discipline is open */
|
2005-04-17 02:20:36 +04:00
|
|
|
#define TTY_PTY_LOCK 16 /* pty private */
|
|
|
|
|
#define TTY_NO_WRITE_SPLIT 17 /* Preserve write boundaries to driver */
|
|
|
|
|
#define TTY_HUPPED 18 /* Post driver->hangup() */
|
tty: make n_tty_read() always abort if hangup is in progress
A tty is hung up by __tty_hangup() setting file->f_op to
hung_up_tty_fops, which is skipped on ttys whose write operation isn't
tty_write(). This means that, for example, /dev/console whose write
op is redirected_tty_write() is never actually marked hung up.
Because n_tty_read() uses the hung up status to decide whether to
abort the waiting readers, the lack of hung-up marking can lead to the
following scenario.
1. A session contains two processes. The leader and its child. The
child ignores SIGHUP.
2. The leader exits and starts disassociating from the controlling
terminal (/dev/console).
3. __tty_hangup() skips setting f_op to hung_up_tty_fops.
4. SIGHUP is delivered and ignored.
5. tty_ldisc_hangup() is invoked. It wakes up the waits which should
clear the read lockers of tty->ldisc_sem.
6. The reader wakes up but because tty_hung_up_p() is false, it
doesn't abort and goes back to sleep while read-holding
tty->ldisc_sem.
7. The leader progresses to tty_ldisc_lock() in tty_ldisc_hangup()
and is now stuck in D sleep indefinitely waiting for
tty->ldisc_sem.
The following is Alan's explanation on why some ttys aren't hung up.
http://lkml.kernel.org/r/20171101170908.6ad08580@alans-desktop
1. It broke the serial consoles because they would hang up and close
down the hardware. With tty_port that *should* be fixable properly
for any cases remaining.
2. The console layer was (and still is) completely broken and doens't
refcount properly. So if you turn on console hangups it breaks (as
indeed does freeing consoles and half a dozen other things).
As neither can be fixed quickly, this patch works around the problem
by introducing a new flag, TTY_HUPPING, which is used solely to tell
n_tty_read() that hang-up is in progress for the console and the
readers should be aborted regardless of the hung-up status of the
device.
The following is a sample hung task warning caused by this issue.
INFO: task agetty:2662 blocked for more than 120 seconds.
Not tainted 4.11.3-dbg-tty-lockup-02478-gfd6c7ee-dirty #28
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
0 2662 1 0x00000086
Call Trace:
__schedule+0x267/0x890
schedule+0x36/0x80
schedule_timeout+0x23c/0x2e0
ldsem_down_write+0xce/0x1f6
tty_ldisc_lock+0x16/0x30
tty_ldisc_hangup+0xb3/0x1b0
__tty_hangup+0x300/0x410
disassociate_ctty+0x6c/0x290
do_exit+0x7ef/0xb00
do_group_exit+0x3f/0xa0
get_signal+0x1b3/0x5d0
do_signal+0x28/0x660
exit_to_usermode_loop+0x46/0x86
do_syscall_64+0x9c/0xb0
entry_SYSCALL64_slow_path+0x25/0x25
The following is the repro. Run "$PROG /dev/console". The parent
process hangs in D state.
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/ioctl.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <time.h>
#include <termios.h>
int main(int argc, char **argv)
{
struct sigaction sact = { .sa_handler = SIG_IGN };
struct timespec ts1s = { .tv_sec = 1 };
pid_t pid;
int fd;
if (argc < 2) {
fprintf(stderr, "test-hung-tty /dev/$TTY\n");
return 1;
}
/* fork a child to ensure that it isn't already the session leader */
pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (pid > 0) {
/* top parent, wait for everyone */
while (waitpid(-1, NULL, 0) >= 0)
;
if (errno != ECHILD)
perror("waitpid");
return 0;
}
/* new session, start a new session and set the controlling tty */
if (setsid() < 0) {
perror("setsid");
return 1;
}
fd = open(argv[1], O_RDWR);
if (fd < 0) {
perror("open");
return 1;
}
if (ioctl(fd, TIOCSCTTY, 1) < 0) {
perror("ioctl");
return 1;
}
/* fork a child, sleep a bit and exit */
pid = fork();
if (pid < 0) {
perror("fork");
return 1;
}
if (pid > 0) {
nanosleep(&ts1s, NULL);
printf("Session leader exiting\n");
exit(0);
}
/*
* The child ignores SIGHUP and keeps reading from the controlling
* tty. Because SIGHUP is ignored, the child doesn't get killed on
* parent exit and the bug in n_tty makes the read(2) block the
* parent's control terminal hangup attempt. The parent ends up in
* D sleep until the child is explicitly killed.
*/
sigaction(SIGHUP, &sact, NULL);
printf("Child reading tty\n");
while (1) {
char buf[1024];
if (read(fd, buf, sizeof(buf)) < 0) {
perror("read");
return 1;
}
}
return 0;
}
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alan Cox <alan@llwyncelyn.cymru>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-13 18:38:08 +03:00
|
|
|
#define TTY_HUPPING 19 /* Hangup in progress */
|
2018-11-01 03:24:48 +03:00
|
|
|
#define TTY_LDISC_CHANGING 20 /* Change pending - non-block IO */
|
2013-03-12 00:44:21 +04:00
|
|
|
#define TTY_LDISC_HALTED 22 /* Line discipline is halted */
|
2005-04-17 02:20:36 +04:00
|
|
|
|
2013-03-06 17:20:52 +04:00
|
|
|
/* Values for tty->flow_change */
|
|
|
|
|
#define TTY_THROTTLE_SAFE 1
|
|
|
|
|
#define TTY_UNTHROTTLE_SAFE 2
|
|
|
|
|
|
|
|
|
|
static inline void __tty_set_flow_change(struct tty_struct *tty, int val)
|
|
|
|
|
{
|
|
|
|
|
tty->flow_change = val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_set_flow_change(struct tty_struct *tty, int val)
|
|
|
|
|
{
|
|
|
|
|
tty->flow_change = val;
|
|
|
|
|
smp_mb();
|
|
|
|
|
}
|
|
|
|
|
|
2018-11-01 03:24:48 +03:00
|
|
|
static inline bool tty_io_nonblock(struct tty_struct *tty, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
return file->f_flags & O_NONBLOCK ||
|
|
|
|
|
test_bit(TTY_LDISC_CHANGING, &tty->flags);
|
|
|
|
|
}
|
|
|
|
|
|
2016-04-10 03:06:48 +03:00
|
|
|
static inline bool tty_io_error(struct tty_struct *tty)
|
|
|
|
|
{
|
|
|
|
|
return test_bit(TTY_IO_ERROR, &tty->flags);
|
|
|
|
|
}
|
|
|
|
|
|
2016-04-10 03:11:36 +03:00
|
|
|
static inline bool tty_throttled(struct tty_struct *tty)
|
|
|
|
|
{
|
|
|
|
|
return test_bit(TTY_THROTTLED, &tty->flags);
|
|
|
|
|
}
|
|
|
|
|
|
2013-01-18 10:44:22 +04:00
|
|
|
#ifdef CONFIG_TTY
|
|
|
|
|
extern void tty_kref_put(struct tty_struct *tty);
|
|
|
|
|
extern struct pid *tty_get_pgrp(struct tty_struct *tty);
|
|
|
|
|
extern void tty_vhangup_self(void);
|
|
|
|
|
extern void disassociate_ctty(int priv);
|
|
|
|
|
extern dev_t tty_devnum(struct tty_struct *tty);
|
|
|
|
|
extern void proc_clear_tty(struct task_struct *p);
|
|
|
|
|
extern struct tty_struct *get_current_tty(void);
|
|
|
|
|
/* tty_io.c */
|
|
|
|
|
extern int __init tty_init(void);
|
2016-04-27 12:56:04 +03:00
|
|
|
extern const char *tty_name(const struct tty_struct *tty);
|
2017-07-20 10:22:36 +03:00
|
|
|
extern struct tty_struct *tty_kopen(dev_t device);
|
|
|
|
|
extern void tty_kclose(struct tty_struct *tty);
|
2017-06-25 21:40:00 +03:00
|
|
|
extern int tty_dev_name_to_number(const char *name, dev_t *number);
|
2018-01-23 10:46:34 +03:00
|
|
|
extern int tty_ldisc_lock(struct tty_struct *tty, unsigned long timeout);
|
|
|
|
|
extern void tty_ldisc_unlock(struct tty_struct *tty);
|
2021-01-25 22:09:25 +03:00
|
|
|
extern ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
|
2013-01-18 10:44:22 +04:00
|
|
|
#else
|
|
|
|
|
static inline void tty_kref_put(struct tty_struct *tty)
|
|
|
|
|
{ }
|
|
|
|
|
static inline struct pid *tty_get_pgrp(struct tty_struct *tty)
|
|
|
|
|
{ return NULL; }
|
|
|
|
|
static inline void tty_vhangup_self(void)
|
|
|
|
|
{ }
|
|
|
|
|
static inline void disassociate_ctty(int priv)
|
|
|
|
|
{ }
|
|
|
|
|
static inline dev_t tty_devnum(struct tty_struct *tty)
|
|
|
|
|
{ return 0; }
|
|
|
|
|
static inline void proc_clear_tty(struct task_struct *p)
|
|
|
|
|
{ }
|
|
|
|
|
static inline struct tty_struct *get_current_tty(void)
|
|
|
|
|
{ return NULL; }
|
|
|
|
|
/* tty_io.c */
|
|
|
|
|
static inline int __init tty_init(void)
|
|
|
|
|
{ return 0; }
|
2016-04-27 12:56:04 +03:00
|
|
|
static inline const char *tty_name(const struct tty_struct *tty)
|
|
|
|
|
{ return "(none)"; }
|
2017-07-20 10:22:36 +03:00
|
|
|
static inline struct tty_struct *tty_kopen(dev_t device)
|
|
|
|
|
{ return ERR_PTR(-ENODEV); }
|
|
|
|
|
static inline void tty_kclose(struct tty_struct *tty)
|
|
|
|
|
{ }
|
2017-06-25 21:40:00 +03:00
|
|
|
static inline int tty_dev_name_to_number(const char *name, dev_t *number)
|
|
|
|
|
{ return -ENOTSUPP; }
|
2013-01-18 10:44:22 +04:00
|
|
|
#endif
|
|
|
|
|
|
2006-12-08 13:38:44 +03:00
|
|
|
extern struct ktermios tty_std_termios;
|
2005-04-17 02:20:36 +04:00
|
|
|
|
|
|
|
|
extern int vcs_init(void);
|
|
|
|
|
|
2008-10-13 13:41:42 +04:00
|
|
|
extern struct class *tty_class;
|
|
|
|
|
|
2008-10-13 13:37:26 +04:00
|
|
|
/**
|
|
|
|
|
* tty_kref_get - get a tty reference
|
|
|
|
|
* @tty: tty device
|
|
|
|
|
*
|
|
|
|
|
* Return a new reference to a tty object. The caller must hold
|
|
|
|
|
* sufficient locks/counts to ensure that their existing reference cannot
|
|
|
|
|
* go away
|
|
|
|
|
*/
|
|
|
|
|
|
2008-11-25 10:58:11 +03:00
|
|
|
static inline struct tty_struct *tty_kref_get(struct tty_struct *tty)
|
2008-10-13 13:37:26 +04:00
|
|
|
{
|
|
|
|
|
if (tty)
|
|
|
|
|
kref_get(&tty->kref);
|
|
|
|
|
return tty;
|
|
|
|
|
}
|
|
|
|
|
|
2015-11-08 21:01:12 +03:00
|
|
|
extern const char *tty_driver_name(const struct tty_struct *tty);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern void tty_wait_until_sent(struct tty_struct *tty, long timeout);
|
2015-10-11 03:28:42 +03:00
|
|
|
extern int __tty_check_change(struct tty_struct *tty, int sig);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern int tty_check_change(struct tty_struct *tty);
|
2014-09-10 23:06:31 +04:00
|
|
|
extern void __stop_tty(struct tty_struct *tty);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern void stop_tty(struct tty_struct *tty);
|
2014-09-10 23:06:31 +04:00
|
|
|
extern void __start_tty(struct tty_struct *tty);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern void start_tty(struct tty_struct *tty);
|
2005-04-17 02:20:36 +04:00
|
|
|
extern int tty_register_driver(struct tty_driver *driver);
|
|
|
|
|
extern int tty_unregister_driver(struct tty_driver *driver);
|
2006-08-08 09:19:37 +04:00
|
|
|
extern struct device *tty_register_device(struct tty_driver *driver,
|
|
|
|
|
unsigned index, struct device *dev);
|
2012-09-06 05:17:18 +04:00
|
|
|
extern struct device *tty_register_device_attr(struct tty_driver *driver,
|
|
|
|
|
unsigned index, struct device *device,
|
|
|
|
|
void *drvdata,
|
|
|
|
|
const struct attribute_group **attr_grp);
|
2005-04-17 02:20:36 +04:00
|
|
|
extern void tty_unregister_device(struct tty_driver *driver, unsigned index);
|
|
|
|
|
extern void tty_write_message(struct tty_struct *tty, char *msg);
|
2014-09-10 23:06:34 +04:00
|
|
|
extern int tty_send_xchar(struct tty_struct *tty, char ch);
|
2008-04-30 11:54:13 +04:00
|
|
|
extern int tty_put_char(struct tty_struct *tty, unsigned char c);
|
|
|
|
|
extern int tty_chars_in_buffer(struct tty_struct *tty);
|
|
|
|
|
extern int tty_write_room(struct tty_struct *tty);
|
|
|
|
|
extern void tty_driver_flush_buffer(struct tty_struct *tty);
|
2008-04-30 11:54:18 +04:00
|
|
|
extern void tty_throttle(struct tty_struct *tty);
|
|
|
|
|
extern void tty_unthrottle(struct tty_struct *tty);
|
2013-03-06 17:20:52 +04:00
|
|
|
extern int tty_throttle_safe(struct tty_struct *tty);
|
|
|
|
|
extern int tty_unthrottle_safe(struct tty_struct *tty);
|
2009-01-02 16:43:17 +03:00
|
|
|
extern int tty_do_resize(struct tty_struct *tty, struct winsize *ws);
|
2007-02-12 11:52:58 +03:00
|
|
|
extern int is_current_pgrp_orphaned(void);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern void tty_hangup(struct tty_struct *tty);
|
|
|
|
|
extern void tty_vhangup(struct tty_struct *tty);
|
2017-04-13 01:37:16 +03:00
|
|
|
extern void tty_vhangup_session(struct tty_struct *tty);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern int tty_hung_up_p(struct file *filp);
|
2005-04-17 02:20:36 +04:00
|
|
|
extern void do_SAK(struct tty_struct *tty);
|
2007-02-10 12:44:34 +03:00
|
|
|
extern void __do_SAK(struct tty_struct *tty);
|
2017-04-13 01:37:16 +03:00
|
|
|
extern void tty_open_proc_set_tty(struct file *filp, struct tty_struct *tty);
|
|
|
|
|
extern int tty_signal_session_leader(struct tty_struct *tty, int exit_session);
|
|
|
|
|
extern void session_clear_tty(struct pid *session);
|
2007-05-08 11:26:56 +04:00
|
|
|
extern void no_tty(void);
|
2012-10-19 00:26:47 +04:00
|
|
|
extern void tty_buffer_free_all(struct tty_port *port);
|
2014-11-05 20:13:09 +03:00
|
|
|
extern void tty_buffer_flush(struct tty_struct *tty, struct tty_ldisc *ld);
|
2012-10-19 00:26:47 +04:00
|
|
|
extern void tty_buffer_init(struct tty_port *port);
|
2015-01-17 23:42:05 +03:00
|
|
|
extern void tty_buffer_set_lock_subclass(struct tty_port *port);
|
2015-10-17 23:36:23 +03:00
|
|
|
extern bool tty_buffer_restart_work(struct tty_port *port);
|
|
|
|
|
extern bool tty_buffer_cancel_work(struct tty_port *port);
|
2016-03-07 00:16:30 +03:00
|
|
|
extern void tty_buffer_flush_work(struct tty_port *port);
|
2006-12-08 13:38:44 +03:00
|
|
|
extern speed_t tty_termios_baud_rate(struct ktermios *termios);
|
|
|
|
|
extern speed_t tty_termios_input_baud_rate(struct ktermios *termios);
|
2008-07-17 00:54:54 +04:00
|
|
|
extern void tty_termios_encode_baud_rate(struct ktermios *termios,
|
|
|
|
|
speed_t ibaud, speed_t obaud);
|
|
|
|
|
extern void tty_encode_baud_rate(struct tty_struct *tty,
|
|
|
|
|
speed_t ibaud, speed_t obaud);
|
2013-03-07 16:12:27 +04:00
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* tty_get_baud_rate - get tty bit rates
|
|
|
|
|
* @tty: tty to query
|
|
|
|
|
*
|
|
|
|
|
* Returns the baud rate as an integer for this terminal. The
|
|
|
|
|
* termios lock must be held by the caller and the terminal bit
|
|
|
|
|
* flags may be updated.
|
|
|
|
|
*
|
|
|
|
|
* Locking: none
|
|
|
|
|
*/
|
|
|
|
|
static inline speed_t tty_get_baud_rate(struct tty_struct *tty)
|
|
|
|
|
{
|
|
|
|
|
return tty_termios_baud_rate(&tty->termios);
|
|
|
|
|
}
|
|
|
|
|
|
2007-10-17 10:30:07 +04:00
|
|
|
extern void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old);
|
2018-05-21 14:08:44 +03:00
|
|
|
extern int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b);
|
2015-04-10 16:13:05 +03:00
|
|
|
extern int tty_set_termios(struct tty_struct *tty, struct ktermios *kt);
|
2005-04-17 02:20:36 +04:00
|
|
|
|
|
|
|
|
extern struct tty_ldisc *tty_ldisc_ref(struct tty_struct *);
|
|
|
|
|
extern void tty_ldisc_deref(struct tty_ldisc *);
|
|
|
|
|
extern struct tty_ldisc *tty_ldisc_ref_wait(struct tty_struct *);
|
tty: Destroy ldisc instance on hangup
Currently, when the tty is hungup, the ldisc is re-instanced; ie., the
current instance is destroyed and a new instance is created. The purpose
of this design was to guarantee a valid, open ldisc for the lifetime of
the tty.
However, now that tty buffers are owned by and have lifetime equivalent
to the tty_port (since v3.10), any data received immediately after the
ldisc is re-instanced may cause continued driver i/o operations
concurrently with the driver's hangup() operation. For drivers that
shutdown h/w on hangup, this is unexpected and usually bad. For example,
the serial core may free the xmit buffer page concurrently with an
in-progress write() operation (triggered by echo).
With the existing stable and robust ldisc reference handling, the
cleaned-up tty_reopen(), the straggling unsafe ldisc use cleaned up, and
the preparation to properly handle a NULL tty->ldisc, the ldisc instance
can be destroyed and only re-instanced when the tty is re-opened.
If the tty was opened as /dev/console or /dev/tty0, the original behavior
of re-instancing the ldisc is retained (the 'reinit' parameter to
tty_ldisc_hangup() is true). This is required since those file descriptors
are never hungup.
This patch has neglible impact on userspace; the tty file_operations ptr
is changed to point to the hungup file operations _before_ the ldisc
instance is destroyed, so only racing file operations might now retrieve
a NULL ldisc reference (which is simply handled as if the hungup file
operation had been called instead -- see "tty: Prepare for destroying
line discipline on hangup").
This resolves a long-standing FIXME and several crash reports.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-11 09:41:06 +03:00
|
|
|
extern void tty_ldisc_hangup(struct tty_struct *tty, bool reset);
|
|
|
|
|
extern int tty_ldisc_reinit(struct tty_struct *tty, int disc);
|
2018-04-13 20:44:18 +03:00
|
|
|
extern const struct seq_operations tty_ldiscs_seq_ops;
|
2005-04-17 02:20:36 +04:00
|
|
|
|
|
|
|
|
extern void tty_wakeup(struct tty_struct *tty);
|
|
|
|
|
extern void tty_ldisc_flush(struct tty_struct *tty);
|
|
|
|
|
|
2008-04-30 11:53:29 +04:00
|
|
|
extern long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
|
2007-11-07 12:24:56 +03:00
|
|
|
extern int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
|
|
|
|
|
unsigned int cmd, unsigned long arg);
|
2017-04-13 01:37:16 +03:00
|
|
|
extern long tty_jobctrl_ioctl(struct tty_struct *tty, struct tty_struct *real_tty,
|
|
|
|
|
struct file *file, unsigned int cmd, unsigned long arg);
|
2007-11-07 12:24:56 +03:00
|
|
|
extern int tty_perform_flush(struct tty_struct *tty, unsigned long arg);
|
2008-10-13 13:41:42 +04:00
|
|
|
extern void tty_default_fops(struct file_operations *fops);
|
2014-07-10 23:01:22 +04:00
|
|
|
extern struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx);
|
2011-10-12 13:32:43 +04:00
|
|
|
extern int tty_alloc_file(struct file *file);
|
|
|
|
|
extern void tty_add_file(struct tty_struct *tty, struct file *file);
|
|
|
|
|
extern void tty_free_file(struct file *file);
|
2012-01-05 13:04:21 +04:00
|
|
|
extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
|
2017-01-17 01:54:28 +03:00
|
|
|
extern void tty_release_struct(struct tty_struct *tty, int idx);
|
2009-11-30 16:18:29 +03:00
|
|
|
extern int tty_release(struct inode *inode, struct file *filp);
|
2016-01-10 08:13:48 +03:00
|
|
|
extern void tty_init_termios(struct tty_struct *tty);
|
2018-12-04 19:00:36 +03:00
|
|
|
extern void tty_save_termios(struct tty_struct *tty);
|
2012-01-31 00:14:28 +04:00
|
|
|
extern int tty_standard_install(struct tty_driver *driver,
|
|
|
|
|
struct tty_struct *tty);
|
2006-12-08 13:36:04 +03:00
|
|
|
|
2006-03-23 14:00:31 +03:00
|
|
|
extern struct mutex tty_mutex;
|
2005-04-17 02:20:36 +04:00
|
|
|
|
2007-07-16 10:39:43 +04:00
|
|
|
#define tty_is_writelocked(tty) (mutex_is_locked(&tty->atomic_write_lock))
|
|
|
|
|
|
2008-07-17 00:53:41 +04:00
|
|
|
extern void tty_port_init(struct tty_port *port);
|
2012-08-07 23:47:50 +04:00
|
|
|
extern void tty_port_link_device(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index);
|
2012-06-04 15:35:37 +04:00
|
|
|
extern struct device *tty_port_register_device(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index,
|
|
|
|
|
struct device *device);
|
2012-09-07 01:17:47 +04:00
|
|
|
extern struct device *tty_port_register_device_attr(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index,
|
|
|
|
|
struct device *device, void *drvdata,
|
|
|
|
|
const struct attribute_group **attr_grp);
|
2017-05-18 18:33:00 +03:00
|
|
|
extern struct device *tty_port_register_device_serdev(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index,
|
|
|
|
|
struct device *device);
|
|
|
|
|
extern struct device *tty_port_register_device_attr_serdev(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index,
|
|
|
|
|
struct device *device, void *drvdata,
|
|
|
|
|
const struct attribute_group **attr_grp);
|
|
|
|
|
extern void tty_port_unregister_device(struct tty_port *port,
|
|
|
|
|
struct tty_driver *driver, unsigned index);
|
2008-07-17 00:53:41 +04:00
|
|
|
extern int tty_port_alloc_xmit_buf(struct tty_port *port);
|
|
|
|
|
extern void tty_port_free_xmit_buf(struct tty_port *port);
|
2012-11-15 12:49:54 +04:00
|
|
|
extern void tty_port_destroy(struct tty_port *port);
|
2009-11-30 16:17:14 +03:00
|
|
|
extern void tty_port_put(struct tty_port *port);
|
|
|
|
|
|
2010-01-16 04:01:11 +03:00
|
|
|
static inline struct tty_port *tty_port_get(struct tty_port *port)
|
2009-11-30 16:17:14 +03:00
|
|
|
{
|
2014-02-10 05:59:04 +04:00
|
|
|
if (port && kref_get_unless_zero(&port->kref))
|
|
|
|
|
return port;
|
|
|
|
|
return NULL;
|
2009-11-30 16:17:14 +03:00
|
|
|
}
|
|
|
|
|
|
2012-08-23 06:13:36 +04:00
|
|
|
/* If the cts flow control is enabled, return true. */
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_cts_enabled(const struct tty_port *port)
|
2012-08-23 06:13:36 +04:00
|
|
|
{
|
2016-04-10 03:53:21 +03:00
|
|
|
return test_bit(TTY_PORT_CTS_FLOW, &port->iflags);
|
2012-08-23 06:13:36 +04:00
|
|
|
}
|
|
|
|
|
|
2016-04-10 03:53:21 +03:00
|
|
|
static inline void tty_port_set_cts_flow(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_CTS_FLOW, &port->iflags, val);
|
2016-04-10 03:53:21 +03:00
|
|
|
}
|
|
|
|
|
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_active(const struct tty_port *port)
|
2016-04-10 03:53:22 +03:00
|
|
|
{
|
|
|
|
|
return test_bit(TTY_PORT_ACTIVE, &port->iflags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_port_set_active(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_ACTIVE, &port->iflags, val);
|
2016-04-10 03:53:22 +03:00
|
|
|
}
|
2016-04-10 03:53:21 +03:00
|
|
|
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_check_carrier(const struct tty_port *port)
|
2016-04-10 03:53:23 +03:00
|
|
|
{
|
|
|
|
|
return test_bit(TTY_PORT_CHECK_CD, &port->iflags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_port_set_check_carrier(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_CHECK_CD, &port->iflags, val);
|
2016-04-10 03:53:23 +03:00
|
|
|
}
|
|
|
|
|
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_suspended(const struct tty_port *port)
|
2016-04-10 03:53:24 +03:00
|
|
|
{
|
|
|
|
|
return test_bit(TTY_PORT_SUSPENDED, &port->iflags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_port_set_suspended(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_SUSPENDED, &port->iflags, val);
|
2016-04-10 03:53:24 +03:00
|
|
|
}
|
|
|
|
|
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_initialized(const struct tty_port *port)
|
2016-04-10 03:53:25 +03:00
|
|
|
{
|
|
|
|
|
return test_bit(TTY_PORT_INITIALIZED, &port->iflags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_port_set_initialized(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_INITIALIZED, &port->iflags, val);
|
2012-08-23 06:13:36 +04:00
|
|
|
}
|
|
|
|
|
|
2020-12-02 14:39:37 +03:00
|
|
|
static inline bool tty_port_kopened(const struct tty_port *port)
|
2017-07-20 10:22:36 +03:00
|
|
|
{
|
|
|
|
|
return test_bit(TTY_PORT_KOPENED, &port->iflags);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void tty_port_set_kopened(struct tty_port *port, bool val)
|
|
|
|
|
{
|
2020-12-02 14:39:36 +03:00
|
|
|
assign_bit(TTY_PORT_KOPENED, &port->iflags, val);
|
2017-07-20 10:22:36 +03:00
|
|
|
}
|
|
|
|
|
|
2008-10-13 13:39:46 +04:00
|
|
|
extern struct tty_struct *tty_port_tty_get(struct tty_port *port);
|
|
|
|
|
extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);
|
2009-01-02 16:45:05 +03:00
|
|
|
extern int tty_port_carrier_raised(struct tty_port *port);
|
2009-01-02 16:45:19 +03:00
|
|
|
extern void tty_port_raise_dtr_rts(struct tty_port *port);
|
2009-06-11 15:24:17 +04:00
|
|
|
extern void tty_port_lower_dtr_rts(struct tty_port *port);
|
2009-01-02 16:45:26 +03:00
|
|
|
extern void tty_port_hangup(struct tty_port *port);
|
2013-03-07 16:12:30 +04:00
|
|
|
extern void tty_port_tty_hangup(struct tty_port *port, bool check_clocal);
|
2013-03-07 16:12:29 +04:00
|
|
|
extern void tty_port_tty_wakeup(struct tty_port *port);
|
2009-01-02 16:46:10 +03:00
|
|
|
extern int tty_port_block_til_ready(struct tty_port *port,
|
|
|
|
|
struct tty_struct *tty, struct file *filp);
|
2009-01-02 16:46:50 +03:00
|
|
|
extern int tty_port_close_start(struct tty_port *port,
|
|
|
|
|
struct tty_struct *tty, struct file *filp);
|
|
|
|
|
extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);
|
2009-09-20 00:13:20 +04:00
|
|
|
extern void tty_port_close(struct tty_port *port,
|
|
|
|
|
struct tty_struct *tty, struct file *filp);
|
2012-06-04 15:35:32 +04:00
|
|
|
extern int tty_port_install(struct tty_port *port, struct tty_driver *driver,
|
|
|
|
|
struct tty_struct *tty);
|
2009-10-06 19:06:11 +04:00
|
|
|
extern int tty_port_open(struct tty_port *port,
|
|
|
|
|
struct tty_struct *tty, struct file *filp);
|
2010-01-16 04:01:11 +03:00
|
|
|
static inline int tty_port_users(struct tty_port *port)
|
2009-09-20 00:13:32 +04:00
|
|
|
{
|
|
|
|
|
return port->count + port->blocked_open;
|
|
|
|
|
}
|
|
|
|
|
|
2008-07-22 14:16:55 +04:00
|
|
|
extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);
|
|
|
|
|
extern int tty_unregister_ldisc(int disc);
|
2016-01-11 09:41:04 +03:00
|
|
|
extern int tty_set_ldisc(struct tty_struct *tty, int disc);
|
2008-07-22 14:16:55 +04:00
|
|
|
extern int tty_ldisc_setup(struct tty_struct *tty, struct tty_struct *o_tty);
|
2014-11-05 20:12:58 +03:00
|
|
|
extern void tty_ldisc_release(struct tty_struct *tty);
|
2018-04-05 13:40:16 +03:00
|
|
|
extern int __must_check tty_ldisc_init(struct tty_struct *tty);
|
2011-03-23 12:48:35 +03:00
|
|
|
extern void tty_ldisc_deinit(struct tty_struct *tty);
|
2017-01-17 01:54:31 +03:00
|
|
|
extern int tty_ldisc_receive_buf(struct tty_ldisc *ld, const unsigned char *p,
|
2016-01-11 07:36:13 +03:00
|
|
|
char *f, int count);
|
2020-11-04 22:35:17 +03:00
|
|
|
extern void tty_sysctl_init(void);
|
2007-07-16 10:39:43 +04:00
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
/* n_tty.c */
|
2010-03-11 02:23:46 +03:00
|
|
|
extern void n_tty_inherit_ops(struct tty_ldisc_ops *ops);
|
2017-04-13 01:37:14 +03:00
|
|
|
#ifdef CONFIG_TTY
|
2016-01-10 08:35:19 +03:00
|
|
|
extern void __init n_tty_init(void);
|
2017-04-13 01:37:14 +03:00
|
|
|
#else
|
|
|
|
|
static inline void n_tty_init(void) { }
|
|
|
|
|
#endif
|
2005-04-17 02:20:36 +04:00
|
|
|
|
Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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/* tty_audit.c */
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#ifdef CONFIG_AUDIT
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2015-11-08 16:52:31 +03:00
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extern void tty_audit_add_data(struct tty_struct *tty, const void *data,
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2016-01-10 09:55:27 +03:00
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size_t size);
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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extern void tty_audit_exit(void);
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extern void tty_audit_fork(struct signal_struct *sig);
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2008-12-09 12:23:33 +03:00
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extern void tty_audit_tiocsti(struct tty_struct *tty, char ch);
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2016-01-10 09:55:31 +03:00
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extern int tty_audit_push(void);
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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#else
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2015-11-08 16:52:31 +03:00
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static inline void tty_audit_add_data(struct tty_struct *tty, const void *data,
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2016-01-10 09:55:27 +03:00
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size_t size)
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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{
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}
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2008-12-09 12:23:33 +03:00
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static inline void tty_audit_tiocsti(struct tty_struct *tty, char ch)
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{
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}
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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static inline void tty_audit_exit(void)
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{
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}
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static inline void tty_audit_fork(struct signal_struct *sig)
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{
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}
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2016-01-10 09:55:31 +03:00
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static inline int tty_audit_push(void)
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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{
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2009-12-09 17:19:31 +03:00
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return 0;
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Audit: add TTY input auditing
Add TTY input auditing, used to audit system administrator's actions. This is
required by various security standards such as DCID 6/3 and PCI to provide
non-repudiation of administrator's actions and to allow a review of past
actions if the administrator seems to overstep their duties or if the system
becomes misconfigured for unknown reasons. These requirements do not make it
necessary to audit TTY output as well.
Compared to an user-space keylogger, this approach records TTY input using the
audit subsystem, correlated with other audit events, and it is completely
transparent to the user-space application (e.g. the console ioctls still
work).
TTY input auditing works on a higher level than auditing all system calls
within the session, which would produce an overwhelming amount of mostly
useless audit events.
Add an "audit_tty" attribute, inherited across fork (). Data read from TTYs
by process with the attribute is sent to the audit subsystem by the kernel.
The audit netlink interface is extended to allow modifying the audit_tty
attribute, and to allow sending explanatory audit events from user-space (for
example, a shell might send an event containing the final command, after the
interactive command-line editing and history expansion is performed, which
might be difficult to decipher from the TTY input alone).
Because the "audit_tty" attribute is inherited across fork (), it would be set
e.g. for sshd restarted within an audited session. To prevent this, the
audit_tty attribute is cleared when a process with no open TTY file
descriptors (e.g. after daemon startup) opens a TTY.
See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
more detailed rationale document for an older version of this patch.
[akpm@linux-foundation.org: build fix]
Signed-off-by: Miloslav Trmac <mitr@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Fulghum <paulkf@microgate.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-16 10:40:56 +04:00
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}
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#endif
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2005-04-17 02:20:36 +04:00
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/* tty_ioctl.c */
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2008-10-13 13:44:17 +04:00
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extern int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
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2005-04-17 02:20:36 +04:00
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unsigned int cmd, unsigned long arg);
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/* vt.c */
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2011-02-14 19:27:22 +03:00
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extern int vt_ioctl(struct tty_struct *tty,
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2005-04-17 02:20:36 +04:00
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unsigned int cmd, unsigned long arg);
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2011-02-17 23:02:51 +03:00
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extern long vt_compat_ioctl(struct tty_struct *tty,
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2009-08-06 17:09:28 +04:00
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unsigned int cmd, unsigned long arg);
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2010-08-06 23:40:30 +04:00
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/* tty_mutex.c */
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2010-06-02 00:53:01 +04:00
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/* functions for preparation of BKL removal */
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2016-01-10 08:13:51 +03:00
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extern void tty_lock(struct tty_struct *tty);
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2016-01-10 08:13:44 +03:00
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extern int tty_lock_interruptible(struct tty_struct *tty);
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2016-01-10 08:13:51 +03:00
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extern void tty_unlock(struct tty_struct *tty);
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extern void tty_lock_slave(struct tty_struct *tty);
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extern void tty_unlock_slave(struct tty_struct *tty);
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2014-11-05 20:13:02 +03:00
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extern void tty_set_lock_subclass(struct tty_struct *tty);
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2010-06-02 00:53:05 +04:00
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2013-04-12 05:29:19 +04:00
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#ifdef CONFIG_PROC_FS
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extern void proc_tty_register_driver(struct tty_driver *);
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extern void proc_tty_unregister_driver(struct tty_driver *);
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#else
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static inline void proc_tty_register_driver(struct tty_driver *d) {}
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static inline void proc_tty_unregister_driver(struct tty_driver *d) {}
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#endif
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2010-06-02 00:53:05 +04:00
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2015-11-08 21:01:13 +03:00
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#define tty_msg(fn, tty, f, ...) \
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fn("%s %s: " f, tty_driver_name(tty), tty_name(tty), ##__VA_ARGS__)
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2015-11-08 21:01:19 +03:00
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#define tty_debug(tty, f, ...) tty_msg(pr_debug, tty, f, ##__VA_ARGS__)
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2015-11-08 21:01:13 +03:00
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#define tty_info(tty, f, ...) tty_msg(pr_info, tty, f, ##__VA_ARGS__)
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#define tty_notice(tty, f, ...) tty_msg(pr_notice, tty, f, ##__VA_ARGS__)
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#define tty_warn(tty, f, ...) tty_msg(pr_warn, tty, f, ##__VA_ARGS__)
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#define tty_err(tty, f, ...) tty_msg(pr_err, tty, f, ##__VA_ARGS__)
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#define tty_info_ratelimited(tty, f, ...) \
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tty_msg(pr_info_ratelimited, tty, f, ##__VA_ARGS__)
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2015-07-13 05:49:08 +03:00
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2005-04-17 02:20:36 +04:00
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#endif
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