The WARN_ON() that was added to tty_reopen can be triggered in the specific
case of a hangup occurring during a re-open of a tty which is not in the
middle of being otherwise closed.

In that case however the WARN() is bogus as we don't hold the neccessary
locks to make a correct decision.

The case we should be checking is "if the ldisc is not changing and reopen
is occuring". We could drop the WARN_ON but for the moment the debug is more
valuable even if it means taking a mutex as it will find any other cases.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The pty code has always been buggy on its ldisc handling. The recent
changes made the window for the race much bigger. Pending fixing it
properly which is not at all trivial, at least make the race small again so
we don't disrupt other dev work.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus 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: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Gold star for the kmemleak detector.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

.ko is normally not included in Kconfig help, make it consistent.
Signed-off-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

If the device fills less than 4 bytes of our random buffer, we'll
BUG_ON.  It's nicer to handle the case where it partially fills the
buffer (the protocol doesn't explicitly bad that).
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)

Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

This file is no longer annotated for false positives but the kmemleak.h
include was still present.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NAlan Cox <alan.cox@linux.intel.com>

Now that kmem_cache_init() happens before console_init(), we should use
kzalloc() and not the bootmem allocator.
Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>

There are allocations for which the main pointer cannot be found but
they are not memory leaks. This patch fixes some of them. For more
information on false positives, see Documentation/kmemleak.txt.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

In moxa.c there are 32 minor numbers reserved for each device. The
number of ports actually available per device is stored in
moxa_board_conf->numPorts. This number is not considered in moxa_open().
Opening a port that is not available results in a kernel oops.
This patch adds a test to moxa_open() that prevents opening unavailable
ports.
Signed-off-by: NDirk Eibach <eibach@gdsys.de>
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use prepare_to_wait and finish_wait instead of add_wait_queue and
remove_wait_queue.

This avoids us setting a task state.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use wait_event instead of sleep_on in tty_block_til_ready.

Wait for ASYNC_CLOSING flag being 0.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NLinus 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: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The Blackfin JTAG interface has a 4 byte generic data field (EMUDAT).  With
a little creative thinking, we can turn this into a TTY device.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Having cleaned up the allocators we might as well remove the inline helpers
for some of it

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Long long ago a 4K kmalloc allocated two pages so the tty layer used the
page allocator, except on some machines where the page size was huge. This was
removed from the core tty layer with the tty buffer re-implementation but not
from tty_audit or the n_tty ldisc.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We have a tty_ldisc file now so put tty_ldisc_flush in the right place
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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 locking

There 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 loaded

and probably a few other of the mysterious ldisc race reports.

I'm sure it also adds the odd new one.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Costantino Leandro found a bug in tty_find_polling_driver and provided a
patch that fixed the crash but not the underlying bug. This fixes the
underlying bug where the list walk corrupts the values it is using on a
match but then reuses them if the open fails.
Signed-off-by: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We fixed the globals, so now fix the comment
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus 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: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch from ASYNC_* to ASYNCB_*, because test_bit expects
bit number, not mask.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch from ASYNC_* to ASYNCB_*, because {test,set}_bit expect
bit number, not mask.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Set up ports right after FW load so that we won't allocate maximal
(64) ports when we use few.

Also remove reading of nports in irq context, since we know it from
initialisation now.

This also fixes a tty ports unregistration on some fail paths and for
Ze which registered 64 and unregistered real port count.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove ugly macros and add inlines instead of them. This improves
readability and type checking a much.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Store HW version locally to not read it all the time in interrupts
and alike.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove ugly all-over-the-code casts of ctl_addr to 9060 space.
Add an union to the cyclades_card structure, which contains
a pointer to both 9050 and 9060 spaces.

The 9050 space layout is unknown, so let it still as a void
__iomem pointer.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add receive programmed IO mode to reduce receive latency
when using low data rates. The receive FIFO trigger
level of 128 bytes used in DMA mode creates excessive latency
when operating at low data rates. PIO mode is selected when user
application requests data in blocks of less than 128 bytes.
Signed-off-by: NPaul Fulghum <paulkf@microgate.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NAlan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No need to check if dev_id is NULL, it never is.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't reset the PLX chip after FW load, which effectively kills
the FW, so that user had to boot manually.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>