The tty_port can be released in two cases: when we get a HUP in the
functions rfcomm_tty_hangup() and rfcomm_dev_state_change(). Or when the
user releases the device in rfcomm_release_dev().

In these cases we set the flag RFCOMM_TTY_RELEASED so that no other
function can get a reference to the tty_port.
The use of !test_and_set_bit(RFCOMM_TTY_RELEASED) ensures that the
'initial' tty_port reference is only dropped once.

The rfcomm_dev_del function is removed becase it isn't used anymore.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Implement .activate, .shutdown and .carrier_raised methods of tty_port
to manage the dlc, moving the code from rfcomm_tty_install() and
rfcomm_tty_cleanup() functions.

At the same time the tty .open()/.close() and .hangup() methods are
changed to use the tty_port helpers that properly call the
aforementioned tty_port methods.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Move the tty_struct initialization from rfcomm_tty_open() to
rfcomm_tty_install() and do the same for the cleanup moving the code from
rfcomm_tty_close() to rfcomm_tty_cleanup().

Add also extra error handling in rfcomm_tty_install() because, unlike
.open()/.close(), .cleanup() is not called if .install() fails.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The current code removes the device from the device list in several
places. Do it only in the destructor instead and in the error path of
rfcomm_add_dev() if the device couldn't be initialized.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

In net/bluetooth/rfcomm/tty.c the struct tty_struct is used without
taking references. This may lead to a use-after-free of the rfcomm tty.

Fix this by taking references properly, using the tty_port_* helpers
when possible.

The raw assignments of dev->port.tty in rfcomm_tty_open/close are
addressed in the later commit 'rfcomm: Implement .activate, .shutdown
and .carrier_raised methods'.
Signed-off-by: NGianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

tty_insert_flip_string this time.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Instead of old unsafe batostr function use %pMR print specifier
for printing Bluetooth addresses in sprintf and seq_printf
statements.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

Instead of old unsafe batostr function use %pMR print specifier
for printing Bluetooth addresses in debug and error statements.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

The RFCOMM code fails to initialize the two padding bytes of struct
rfcomm_dev_list_req inserted for alignment before copying it to
userland. Additionally there are two padding bytes in each instance of
struct rfcomm_dev_info. The ioctl() that for disclosures two bytes plus
dev_num times two bytes uninitialized kernel heap memory.

Allocate the memory using kzalloc() to fix this issue.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently we have no way to assign tty->port while performing tty
installation. There are two ways to provide the link tty_struct =>
tty_port. Either by calling tty_port_install from tty->ops->install or
tty_port_register_device called instead of tty_register_device when
the device is being set up after connected.

In this patch we modify most of the drivers to do the latter. When the
drivers use tty_register_device and we have tty_port already, we
switch to tty_port_register_device. So we have the tty_struct =>
tty_port link for free for those.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The termios and other changes mean the other protections needed on the driver
tty arrays should be adequate. Turn it all back on.

This contains pieces folded in from the fixes made to the original patches

| From: Geert Uytterhoeven <geert@linux-m68k.org>	(fix m68k)
| From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
| From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
| From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This will let us sort out a whole pile of tty related races. The
alternative would be to keep points and refcount the termios objects.
However
1. They are tiny anyway
2. Many devices don't use the stored copies
3. We can remove a pty special case
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I sent GregKH this after the pre-requisites. He dropped the pre-requesites
for good reason and unfortunately then applied this patch. Without this
reverted you get random kernel memory corruption which will make bisecting
anything between it and the properly applied patches a complete sod.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The termios and other changes mean the other protections needed on the driver
tty arrays should be adequate. Turn it all back on.

This contains pieces folded in from the fixes made to the original patches

| From: Geert Uytterhoeven <geert@linux-m68k.org>	(fix m68k)
| From: Paul Gortmaker <paul.gortmaker@windriver.com>	(fix cris)
| From: Jiri Kosina <jkosina@suze.cz>			(lockdep)
| From: Eric Dumazet <eric.dumazet@gmail.com>		(lockdep)
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Most of the include were unnecessary or already included by some other
header.
Replace module.h by export.h where possible.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Only obvious cases were left as inline, mostly oneline functions.
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This reverts the tty layer change to use per-tty locking, because it's
not correct yet, and fixing it will require some more deep surgery.

The main revert is d29f3ef3 ("tty_lock: Localise the lock"), but
there are several smaller commits that built upon it, they also get
reverted here. The list of reverted commits is:

  fde86d31 - tty: add lockdep annotations
  8f6576ad - tty: fix ldisc lock inversion trace
  d3ca8b64 - pty: Fix lock inversion
  b1d679af - tty: drop the pty lock during hangup
  abcefe5f - tty/amiserial: Add missing argument for tty_unlock()
  fd11b42e - cris: fix missing tty arg in wait_event_interruptible_tty call
  d29f3ef3 - tty_lock: Localise the lock

The revert had a trivial conflict in the 68360serial.c staging driver
that got removed in the meantime.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In each remaining case the tty_lock is associated with a specific tty. This
means we can now lock on a per tty basis. We do need tty_lock_pair() for
the pty case. Uglier but still a step in the right direction.

[fixed up calls in 3 missing drivers - gregkh]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This means converting an atomic counter to a counter protected by
lock. This is the first step needed to convert the rest of the code to
the tty_port helpers.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

tty_wakeup is safe to be called from all contexts. No need to schedule
a work for that. Let us call it directly like in other drivers.

This allows us to kill another member of rfcomm_dev structure.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Switch the refcounting from manual atomic plays with refcounter to the
one offered by tty_port.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

And use tty from there.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All num, magic and owner are set by alloc_tty_driver. No need to
re-set them on each allocation site.

pti driver sets something different to what it passes to
alloc_tty_driver. It is not a bug, since we don't use the lines
parameter in any way. Anyway this is fixed, and now we do the right
thing.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

+ src/net/bluetooth/rfcomm/tty.c: warning: 'p' is used uninitialized in this
       function:  => 218
+ src/net/bluetooth/rfcomm/tty.c: warning: 'p' may be used uninitialized in
       this function:  => 218
Signed-off-by: NLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

We now run in process context, no need to disable interrupts.
Calls from the tty layer also run in process context.

rw_lock was converted to spinlock, we have more writers than readers in
this case.
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

When all items in the list have the same type there is no much of a point
to use list_for_each except if you want to use the list pointer itself.
Signed-off-by: NLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Remove old tasklets and replace by workqueue. To avoid reentrancy (which
tasklets always avoid) we use the system_nrt_wq.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Forward error codes from tty core to the rfcomm_init caller instead of using
generic -1 errors.
Signed-off-by: NDavid Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Only oddities here are a couple of drivers that bogusly called the ldisc
helpers instead of returning -ENOIOCTLCMD. Fix the bug and the rest goes
away.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NVladislav P <vladisslav@inbox.ru>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Remove extra spaces, assignments in if statement, zeroing static
variables, extra braces. Fix includes.
Signed-off-by: NAndrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

Again basically cut and paste

Convert the main driver set to use the hooks for GICOUNT
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The Bluetooth core uses the the BD_ADDR in the opposite order from the
human readable order. So we are changing batostr() to print in the
correct order and then removing some baswap(), as they are not needed
anymore.
Acked-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

rfcomm_cleanup_ttys() is also called from rfcomm_init(), so it can't
have __exit.
Reported-by: NMat Martineau <mathewm@codeaurora.org>
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Those annotation save memory and space on the binary. __init code is
discarded just after execute and __exit code is discarded if the module
is built into the kernel image or unload of modules is not allowed.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch removes from net/ (but not any netfilter files)
all the unnecessary return; statements that precede the
last closing brace of void functions.

It does not remove the returns that are immediately
preceded by a label as gcc doesn't like that.

Done via:
$ grep -rP --include=*.[ch] -l "return;\n}" net/ | \
  xargs perl -i -e 'local $/ ; while (<>) { s/\n[ \t\n]+return;\n}/\n}/g; print; }'
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

struct tty_operations::proc_fops took it's place and there is one less
create_proc_read_entry() user now!
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>