11 Jun, 2009
4 commits
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There are several pretty much unfixable races in the old ldisc code, especially
with respect to pty behaviour and also to hangup. It's easier to rewrite the
code than simply try and patch it up.This patch
- splits the ldisc from the tty (so we will be able to refcount it more cleanly
later)
- introduces a mutex lock for ldisc changing on an active device
- fixes the complete mess that hangup caused
- implements hopefully correct setldisc/close/hangup lockingThere are still some problems around pty pairs that have always been there but
at least it is now possible to understand the code and fix further problems.This fixes the following known bugs
- hang up can leak ldisc references
- hang up may not call open/close on ldisc in a matched way
- pty/tty pairs can deadlock during an ldisc change
- reading the ldisc proc files can cause every ldisc to be loadedand probably a few other of the mysterious ldisc race reports.
I'm sure it also adds the odd new one.
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Before trying to tackle the ldisc bugs the code needs to be a good deal
more readable, so do the simple extractions of routines first.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
We need this for devices that cannot flush and wait, but which do not order
data and modem events. Without it we will hang up before all the data
clears the hardware. Needed for the USB changes.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Some drivers implement this internally, others miss it out. Push the
behaviour into the core code as that way everyone will do it consistently.Update the dtr rts method to raise or lower depending upon flags. Having a
single method in this style fits most of the implementations more cleanly than
two funtions.We need this in place before we tackle the USB side
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds
03 Jan, 2009
8 commits
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Again this is a lot of common code we can unify
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Start sucking more commonality out of the drivers into a single piece of
core code.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
This helps set the basis for moving block_til_ready into common code. We also
introduce a tty_port_hangup helper as this will also be generally needed.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
This moves another per device special out of what should be shared open
wait paths into private methodsSigned-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
This is the first step to generalising the various pieces of waiting logic
duplicated in all sorts of serial drivers.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
We have special case logic for resizing pty/tty pairs. We also have a per
driver resize method so for the pty case we should use it.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Fixes the loss of echoed (and other ldisc-generated characters) when
the tty is stopped or when the driver output buffer is full (happens
frequently for input during continuous program output, such as ^C)
and removes the Big Kernel Lock from the N_TTY line discipline.Adds an "echo buffer" to the N_TTY line discipline that handles all
ldisc-generated output (including echoed characters). Along with the
loss of characters, this also fixes the associated loss of sync between
tty output and the ldisc state when characters cannot be immediately
written to the tty driver.The echo buffer stores (in addition to characters) state operations that need
to be done at the time of character output (like management of the column
position). This allows echo to cooperate correctly with program output,
since the ldisc state remains consistent with actual characters written.Since the echo buffer code now isolates the tty column state code
to the process_out* and process_echoes functions, we can remove the
Big Kernel Lock (BKL) and replace it with mutex locks.Highlights are:
* Handles echo (and other ldisc output) when tty driver buffer is full
- continuous program output can block echo
* Saves echo when tty is in stopped state (e.g. ^S)
- (e.g.: ^Q will correctly cause held characters to be released for output)
* Control character pairs (e.g. "^C") are treated atomically and not
split up by interleaved program output
* Line discipline state is kept consistent with characters sent to
the tty driver
* Remove the big kernel lock (BKL) from N_TTY line disciplineSigned-off-by: Joe Peterson
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds
29 Dec, 2008
1 commit
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…el/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
sched, trace: update trace_sched_wakeup()
tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
Revert "x86: disable X86_PTRACE_BTS"
ring-buffer: prevent false positive warning
ring-buffer: fix dangling commit race
ftrace: enable format arguments checking
x86, bts: memory accounting
x86, bts: add fork and exit handling
ftrace: introduce tracing_reset_online_cpus() helper
tracing: fix warnings in kernel/trace/trace_sched_switch.c
tracing: fix warning in kernel/trace/trace.c
tracing/ring-buffer: remove unused ring_buffer size
trace: fix task state printout
ftrace: add not to regex on filtering functions
trace: better use of stack_trace_enabled for boot up code
trace: add a way to enable or disable the stack tracer
x86: entry_64 - introduce FTRACE_ frame macro v2
tracing/ftrace: add the printk-msg-only option
tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
x86, bts: correctly report invalid bts records
...Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
09 Dec, 2008
1 commit
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AUDIT_TTY records currently log all data read by processes marked for
TTY input auditing, even if the data was "pushed back" using the TIOCSTI
ioctl, not typed by the user.This patch records all TIOCSTI calls to disambiguate the input. It
generates one audit message per character pushed back; considering
TIOCSTI is used very rarely, this simple solution is probably good
enough. (The only program I could find that uses TIOCSTI is mailx/nail
in "header editing" mode, e.g. using the ~h escape. mailx is used very
rarely, and the escapes are used even rarer.)Signed-Off-By: Miloslav Trmac
Signed-off-by: Al Viro
Signed-off-by: James Morris
25 Nov, 2008
1 commit
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Stephen Rothwell reported tht this warning started triggering in
linux-next:In file included from init/main.c:27:
include/linux/tty.h: In function ‘tty_kref_get’:
include/linux/tty.h:330: warning: ‘______f’ is static but declared in inline function ‘tty_kref_get’ which is not staticWhich gcc emits for 'extern inline' functions that nevertheless define
static variables. Change it to 'static inline', which is the norm
in the kernel anyway.Reported-by: Stephen Rothwell
Signed-off-by: Ingo Molnar
14 Oct, 2008
11 commits
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Move the set up on ldisc change into the ldisc
Move the INQ/OUTQ cases into the driver not in shared ioctl code where it
gives bogus answers for other ldisc valuesSigned-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
The majority of the remaining init_dev code is pty special cases. We
refactor this code into the driver->install method.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Original suggestion and proposal from Sukadev Bhattiprolu.
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Carry on pushing code out of tty_io when it belongs to other drivers. I'm
not 100% happy with some of this and it will be worth revisiting some of the
exports later when the restructuring work is done.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Right now there are various drivers that try to use tty->count to know when
they get the final close. Aristeau Rozanski showed while debugging the vt
sysfs race that this isn't entirely safe.Instead of driver side tricks to work around this introduce a shutdown which
is called when the tty is being destructed. This also means that the shutdown
method is tied into the refcounting.Use this to rework the console close/sysfs logic.
Remove lots of special case code from the tty core code. The pty code can now
have a shutdown() method that replaces the special case hackery in the tree
free up paths.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
We now have the infrastructure to sort this out but rather than teaching
the syscall tty lock rules we move the hard work into a tty helperSigned-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.Contains two err->dev_err changes merged together to fix clashes in the
-next tree.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
We need a way to describe the various additional modes and flow control
features that random weird hardware shows up and software such as wine
wants to emulate as Windows supports them.TCGETX/TCSETX and the termiox ioctl are a SYS5 extension that we might as
well adopt. This patches adds the structures and the basic ioctl interfaces
when the TCGETX etc defines are added for an architecture. Drivers wishing
to use this stuff need to add new methods.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Introduce a kref to the tty structure and use it to protect the tty->signal
tty references. For now we don't introduce it for anything else.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Add a new line discipline for "pulse per second" devices connected to
a serial port.Signed-off-by: Rodolfo Giometti
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
The two are basically independent chunks of code so lets split them up for
readability and sanity. It also makes the API boundaries much clearer.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds
16 Aug, 2008
1 commit
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This moves it to being a tty operation. That removes special cases and now
also means that resize can be picked up by um and other non vt consoles
which may have a resize operation.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds
23 Jul, 2008
1 commit
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Signed-off-by: Alan Cox
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Linus Torvalds
21 Jul, 2008
4 commits
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Move more bits into the tty_port structure
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Coding style clean up and white space tidy
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Every tty driver has its own concept of a port structure and because
they all differ we cannot extract commonality. Begin fixing this by
creating a structure drivers can elect to use so that over time we can
push fields into this and create commonality and then introduce common
methods.Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds -
Move the line disciplines towards a conventional ->ops arrangement. For
the moment the actual 'tty_ldisc' struct in the tty is kept as part of
the tty struct but this can then be changed if it turns out that when it
all settles down we want to refcount ldiscs separately to the tty.Pull the ldisc code out of /proc and put it with our ldisc code.
Signed-off-by: Alan Cox
Signed-off-by: Linus Torvalds
07 Jun, 2008
1 commit
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Although if people have questions about ARCnet, perhaps it's _better_
for them to be mailing dwmw2@cam.ac.uk about it...Signed-off-by: David Woodhouse
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Apr, 2008
5 commits
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Something Arjan suggested which allows us to clean up the code nicely
Signed-off-by: Alan Cox
Cc: Arjan van de Ven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Operations are now a shared const function block as with most other Linux
objects- Introduce wrappers for some optional functions to get consistent behaviour
- Wrap put_char which used to be patched by the tty layer
- Document which functions are needed/optional
- Make put_char report success/fail
- Cache the driver->ops pointer in the tty as tty->ops
- Remove various surplus lock calls we no longer need
- Remove proc_write method as noted by Alexey Dobriyan
- Introduce some missing sanity checks where certain driver/ldisc
combinations would oops as they didn't check needed methods were present[akpm@linux-foundation.org: fix fs/compat_ioctl.c build]
[akpm@linux-foundation.org: fix isicom]
[akpm@linux-foundation.org: fix arch/ia64/hp/sim/simserial.c build]
[akpm@linux-foundation.org: fix kgdb]
Signed-off-by: Alan Cox
Acked-by: Greg Kroah-Hartman
Cc: Jason Wessel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This fixes the last couple of pid struct locking failures I know about.
[oleg@tv-sign.ru: clean up do_task_stat()]
Signed-off-by: Alan Cox
Signed-off-by: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Historically tty->pgrp and friends were pid_t and the code "knew" they were
safe. The change to pid structs opened up a few races and the removal of the
BKL in places made them quite hittable. We put tty->pgrp under the ctrl_lock
for the tty.Signed-off-by: Alan Cox
Cc: Oleg Nesterov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- Push the BKL down into the line disciplines
- Switch the tty layer to unlocked_ioctl
- Introduce a new ctrl_lock spin lock for the control bits
- Eliminate much of the lock_kernel use in n_tty
- Prepare to (but don't yet) call the drivers with the lock dropped
on the paths that historically held the lockBKL now primarily protects open/close/ldisc change in the tty layer
[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox
Signed-off-by: Jiri Slaby
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Apr, 2008
2 commits
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Remove the code that automatically disables TTY input auditing in processes
that open TTYs when they have no other TTY open; this heuristic was
intended to automatically handle daemons, but it has false positives (e.g.
with sshd) that make it impossible to control TTY input auditing from a PAM
module. With this patch, TTY input auditing is controlled from user-space
only.On the other hand, not even for daemons does it make sense to audit "input"
from PTY masters; this data was produced by a program writing to the PTY
slave, and does not represent data entered by the user.Signed-off-by: Miloslav Trmac
Cc: Al Viro
Cc: David Woodhouse
Signed-off-by: Andrew Morton
Signed-off-by: Al Viro -
Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages. This patch adds that information to netlink messages
so we can audit who sent netlink messages.Signed-off-by: Eric Paris
Signed-off-by: Al Viro
