The tty code should be in its own subdirectory and not in the char
driver with all of the cruft that is currently there.
Based on work done by Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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For historical reference, a good copy of the relevant files can be found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>
something-bility is spelled as something-blity
so a grep for 'blit' would find these lines
this is so trivial that I didn't split it by subsystem / copy
additional maintainers - all changes are to comments
The only purpose is to get fewer false positives when grepping
around the kernel sources.
Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT
This will make hardirq.h inclusion cheaper for every PREEMPT=n config
(which includes allmodconfig/allyesconfig, BTW)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If TCGETX is not defined, we end up with this warning:
drivers/char/tty_ioctl.c: In function ‘tty_mode_ioctl’:
drivers/char/tty_ioctl.c:950: warning: unused variable ‘ktermx’
Since the variable is only used in one case statement, push it down to
the local case scope.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Although this doesn't cause any problems it could potentially do so for
future mmap using devices. No real work is needed to sort it out so untangle
it before it causes problems
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The tty throttling code can race due to the lock drops. It takes very high
loads but this has been observed and verified by Rob Duncan.
The basic problem is that on an SMP box we can go
CPU #1 CPU #2
need to throttle ?
suppose we should buffer space cleared
are we throttled
yes ? - unthrottle
call throttle method
This changeet take the termios lock to protect against this. The termios
lock isn't the initial obvious candidate but many implementations of throttle
methods already need to poke around their own termios structures (and nobody
really locks them against a racing change of flow control).
This does mean that anyone who is setting tty->low_latency = 1 and then
calling tty_flip_buffer_push from their unthrottle method is going to end up
collapsing in a pile of locks. However we've removed all the known bogus
users of low_latency = 1 and such use isn't safe anyway for other reasons so
catching it would be an improvement.
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you issue an ioctl to flush a tty as the line discipline is changing or
otherwise unplugged you can get a crash. The bug is very old but the rest
of the BKL lock dropping and some very "good" luck on Ingo's part caught
an example.
Use the correct ldisc_ref form so that we wait for the ldisc change to
complete and then flush
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 values
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves us towards sanity and should mean our termios locking is now
complete and comprehensive.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The termios settings ioctls on a pty should affect the bound tty side not
the pty. The SOFTCAR ioctls use the wrong device file.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noted that the 'struct tty_struct *real_tty' is not used in this
function, so I removed the code about 'real_tty'.
Signed-off-by: Gustavo Fernando Padovan <gustavo@las.ic.unicamp.br>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Something Arjan suggested which allows us to clean up the code nicely
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- 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 <alan@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Stop drivers calling their own flush method indirectly, it obfuscates code
and it will change soon anyway
- A few more lock_kernel paths temporarily needed in some driver internal
waiting code
- Remove private put_char method that does a write call for one char - we
have that anyway
- Most but not yet all of the termios copy under lock fixing (some has other
dependencies to follow)
- Note a few locking bugs in drivers found in the process
- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
fix the termios locking
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
First cut at moving the soft carrier handling knowledge entirely into the core
code. One or two drivers still needed to snoop these functions to track
CLOCAL internally. Instead make TIOCSSOFTCAR generate the same driver calls
as other termios ioctls changing the clocal flag. This allows us to remove
any driver knowledge and special casing. Also while we are at it we can fix
the error handling.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function still depends on the big kernel lock in some cases. Push
locking into the function ready for removal of the BKL from ioctl call paths.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- 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 lock
BKL now primarily protects open/close/ldisc change in the tty layer
[jirislaby@gmail.com: a couple of fixes]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleaning out all the incorrect 'no change made' checks for termios
settings showed up a problem with the PL2303. The hardware here seems to
lose sync and bits if you tell it to make no changes. This shows up with
a real world application.
To fix this the driver check for meaningful hardware changes is restored
but doing the tests correctly and as a tty layer function so it doesn't
get duplicated wrongly everywhere if other drivers turn out to need it.
Signed-off-by: Alan Cox <alan@redhat.com>
Tested-by: Mirko Parthey <mirko.parthey@informatik.tu-chemnitz.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 5a52bd4a2d introduced a subtle logic
change in tty_wait_until_sent(). The original version would only error out
of the 'do { ... } while (timeout)' loop if signal_pending() evaluated to
true; a timeout or break due to an empty buffer would fall out of the loop
and into the tty->driver->wait_until_sent handling. The current
implementation will error out on either a pending signal or an empty
buffer, falling through to the tty->driver->wait_until_sent handling only
on a timeout.
The ->wait_until_sent() will not be reached if the buffer empties before
timeout jiffies have elapsed. This behavior differs from that prior to commit
5a52bd4a2d.
I turned this up while using a little serial download utility to bootstrap an
ARM-based eval board. The util worked fine on 2.6.22.x, but consistently
failed on 2.6.23.x. Once I'd determined that, I narrowed things down with git
bisect, and found the above difference in logic in tty_wait_until_sent() by
inspection.
This change reverts the logic flow in tty_wait_until_sent() to match that
prior to the aforementioned commit.
Signed-off-by: Cory T. Tusar <ctusar@videon-central.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Miller noted various cases where line disciplines for things like
ppp go poking around in termios themselves in ways that broke with the
new termios code. Rather than have them all learning about termios
internals provide proper methods for this
- tty_mode_ioctl()
This handles all the terminal mode handling for speed/carrier
etc and none of the methods are ldisc dependant so they can be called
by any user
- tty_perform_flush()
This extracts the flush functionality and enables pppd the ppp
layer to share it cleanly.
The existing n_tty_ioctl code is refactored in this patch to provide
the new functions and to call them itself appropriately. This patch
has no (intended) behaviour changes and simply prepares for the other
fixes.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
The tty_termios_encode_baud_rate() function as defined by tty_ioctl.c has a
problem with the baud_table within. The comparison operators are reversed
and as a result this table's entries never match and BOTHER is always used.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds three new functions (or in one case to be more exact makes it
always available)
tty_termios_copy_hw
Copies all the hardware settings from one termios structure to the other.
This is intended for drivers that support little or no hardware setting
tty_termios_encode_baud_rate
Allows you to set the input and output baud rate in a termios structure. A
driver is supposed to set the resulting baud rate from a request so most
will want to use this function to set the resulting input and output rates
to match the hardware values. Internally it knows about keeping Bxxx
encoding when possible to maximise compatibility.
tty_encode_baud_rate
As above but for the tty's own current termios structure
I suspect this will initially need some tweaking as it gets enabled by
driver patches over the next few mm cycles so consider this lot -mm only
for the moment so it can stabilize and end up neat before it goes to base.
I've tried not to break any obscure architectures - if you get a speed you
can't represent the code will print warnings on non updated termios systems
but not break.
Once this is merged and seems sane I've got a growing pile of driver
updates to use it - notably for USB serial drivers.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add Guards around TIOCSLCKTRMIOS and TIOCGLCKTRMIOS.
Several architectures are still broken. Put temporary-for-2.6.23 ifdef guards
around the offending code.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by:: Linus Torvalds <torvalds@linux-foundation.org>
I ran into a few problems.
n_tty_ioctl() for instance:
drivers/char/tty_ioctl.c:799: error: $,1rxstruct termios$,1ry has no
member named $,1rxc_ispeed$,1ry
This is calling the copy interface that is supposed to be using
a termios2 when the new interfaces are defined, however:
case TIOCGLCKTRMIOS:
if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
return -EFAULT;
return 0;
This is going to write over the end of the userspace
structure by a few bytes, and wasn't caught by you yet
because the i386 implementation is simply copy_to_user()
which does zero type checking.
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tty_ioctl, little whitespace cleanup
the point is to make
while (++i < n_baud_table);
clear and assign it to the do { } loop
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Without this a tty write could block if a previous blocking tty write was
in progress on the same tty and blocked by a line discipline or hardware
event. Originally found and reported by Dave Johnson.
Signed-off-by: Alan Cox <alan@redhat.com>
Acked-by: Dave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mostly so people can see the work in progress. This enhances the encode
function which isn't currently used in the base tree but is when using some of
the testing tty patches.
This resolves a problem with some hardware where applications got confusing
information from the tty ioctls. Correct but confusing.
In some situations asking for, say, 9600 baud actually gets you 9595 baud or
similar near-miss values. With the old code this meant that a request for
B9600 got a return of BOTHER, 9595 which programs interpreted as a failure.
The new code now works on the following basis
- If you ask for specific rate via BOTHER, you get a precise return
- If you ask for a standard Bfoo rate and the result is close you get a Bfoo
return
- If you ask for a standard Bfoo rate and get something way off you get a
BOTHER/rate return
This seems to fix up the cases I've found where this broke compatibility.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Having split out the user and kernel structures it turns out that some non
glibc C libraries pull their termios struct from the kernel headers
directly or indirectly. This means we must keep "struct termios" as the
library sees it correct for the old ioctls. Not a big problem just shuffle
the names and ifdef around a bit
[akpm@osdl.org: build fix]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the grungy swap all the occurrences in the right places patch that
goes with the updates. At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs
If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.
If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)
Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia
[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the core of the switch to the new framework. I've split it from the
driver patches which are mostly search/replace and would encourage people to
give this one a good hard stare.
The references to BOTHER and ISHIFT are the termios values that must be
defined by a platform once it wants to turn on "new style" ioctl support. The
code patches here ensure that providing
1. The termios overlays the ktermios in memory
2. The only new kernel only fields are c_ispeed/c_ospeed (or none)
the existing behaviour is retained. This is true for the patches at this
point in time.
Future patches will define BOTHER, ISHIFT and enable newer termios structures
for each architecture, and once they are all done some of the ifdefs also
vanish.
[akpm@osdl.org: warning fix]
[akpm@osdl.org: IRDA fix]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If you send a priority character (as is done for flow control) then the tty
driver can either have its own method for "jumping the queue" or the characrer
can be queued normally. In the latter case we call the write method but
without the atomic_write_lock taken elsewhere.
Make this consistent. Note that the send_xchar method if implemented remains
outside of the lock as it can jump ahead of a current write so must not be
locked out by it.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
[akpm@osdl.org: fix]
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Doesn't fix them but does show up some interesting areas that need review
and fixing.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We add a check of the return value of tty_ldisc_ref(), which
is checked 7 out of 8 times, e.g.:
149 ld = tty_ldisc_ref(tty);
150 if (ld != NULL) {
151 if (ld->set_termios)
152 (ld->set_termios)(tty, &old_termios);
153 tty_ldisc_deref(ld);
154 }
This defect was found automatically by Coverity Prevent, a static analysis
tool.
(akpm: presumably `ld' is never NULL. Oh well)
Signed-off-by: Zaur Kambarov <zkambarov@coverity.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Greg Kroah-Hartman