The skb truesize of a 12-byte payload with a 10-byte head/tail
reserve is 768 bytes. Consequently, even with 40 tx_credits, at
most 6 packets could be queued at any one time:
40 tx_credits * 127-byte mtu < 768-byte truesize * 7
This error could also cause the tx queue to apparently stall if
credit flow control is disabled (where tx_credits is fixed at 5),
or if the receiver only granted a limited number of tx credits
(eg., less than 7).
Instead, track the outstanding number of queued packets not yet sent
in wmem_alloc and allow for a maximum of 40 queued packets. Report
the space avail for a single write() as the mtu * number of packets
left before reaching the maximum.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Compute the amount of space available for a single write()
within rfcomm_room(); clamp to 0 for negative values. Note
this patch does not change the result of the computation.
Report the amount of room returned in the debug printk.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The tty driver api design prefers no-fail writes if the driver
write_room() method has previously indicated space is available
to accept writes. Since this is trivially possible for the
RFCOMM tty driver, do so.
Introduce rfcomm_dlc_send_noerror(), which queues but does not
schedule the krfcomm thread if the dlc is not yet connected
(and thus does not error based on the connection state).
The mtu size test is also unnecessary since the caller already
chunks the written data into mtu size.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If rfcomm_dlc_open() fails, set tty into error state which returns
-EIO from reads and writes.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If RFCOMM tty device registration fails, cleanup by releasing
the tty_port reference to trigger rfcomm_dev destruction
(rather than open-coding it).
The dlc reference release is moved into rfcomm_dev_add(),
which ensures cleanup in both error paths -- ie., if
__rfcomm_dev_add() fails or if tty_port_register_device() fails.
Fixes releasing the module reference if device registration fails.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Move rfcomm_dev allocation and initialization into new function,
__rfcomm_dev_add(), to simplify resource release in error handling.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
At least two different race conditions exist with multiple concurrent
RFCOMMCREATEDEV and RFCOMMRELEASEDEV ioctls:
* Multiple concurrent RFCOMMCREATEDEVs with RFCOMM_REUSE_DLC can
mistakenly share the same DLC.
* RFCOMMRELEASEDEV can destruct the rfcomm_dev still being
constructed by RFCOMMCREATEDEV.
Introduce rfcomm_ioctl_mutex to serialize these add/remove operations.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Functions which search lists for matching id's are more
commonly named *_lookup, which is the convention in the
bluetooth core as well.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The RFCOMM tty device is parented to the acl link device when
the dlc state_change(BT_CONNECTED) notification is received.
However, if the dlc from the RFCOMM socket is being reused
(RFCOMM_REUSE_DLC is set), then the dlc may already be connected,
and no notification will occur.
Instead, always parent the RFCOMM tty device to the acl link
device at registration time. If the acl link device is not available
(eg, because the dlc is not connected) then the tty will remain
unparented until the BT_CONNECTED notification is received.
Fixes regression with ModemManager when the rfcomm device is
created with the flag RFCOMM_REUSE_DLC.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Accessing the results of hci_conn_hash_lookup_ba() is unsafe without
holding the hci_dev_lock() during the lookup. For example:
CPU 0 | CPU 1
hci_conn_hash_lookup_ba | hci_conn_del
rcu_read_lock | hci_conn_hash_del
list_for_each_entry_rcu | list_del_rcu
if (.....) | synchronize_rcu
rcu_read_unlock |
| hci_conn_del_sysfs
| hci_dev_put
| hci_conn_put
| put_device (last reference)
| bt_link_release
| kfree(conn)
return p << just freed |
Even if a hci_conn reference were taken (via hci_conn_get), would
not guarantee the lifetime of the sysfs device, but only safe
access to the in-memory structure.
Ensure the hci_conn device stays valid while the rfcomm device
is reparented; rename rfcomm_get_device() to rfcomm_reparent_device()
and perform the reparenting within the function while holding the
hci_dev_lock.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Only one session/channel combination may be in use at any one
time. However, the failure does not occur until the tty is
opened (in rfcomm_dlc_open()).
Because these settings are actually bound at rfcomm device
creation (via RFCOMMCREATEDEV ioctl), validate and fail before
creating the rfcomm tty device.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
RFCOMM tty device teardown can race with new tty device registration
for the same device id:
CPU 0 | CPU 1
rfcomm_dev_add | rfcomm_dev_destruct
| spin_lock
| list_del <== dev_id no longer used
| spin_unlock
spin_lock | .
[search rfcomm_dev_list] | .
[dev_id not in use] | .
[initialize new rfcomm_dev] | .
spin_unlock | .
| .
tty_port_register_device | tty_unregister_device
Don't remove rfcomm_dev from the device list until after tty device
unregistration has completed.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When RFCOMM_RELEASE_ONHUP is set, the rfcomm tty driver 'takes over'
the initial rfcomm_dev reference created by the RFCOMMCREATEDEV ioctl.
The assumption is that the rfcomm tty driver will release the
rfcomm_dev reference when the tty is freed (in rfcomm_tty_cleanup()).
However, if the tty is never opened, the 'take over' never occurs,
so when RFCOMMRELEASEDEV ioctl is called, the reference is not
released.
Track the state of the reference 'take over' so that the release
is guaranteed by either the RFCOMMRELEASEDEV ioctl or the rfcomm tty
driver.
Note that the synchronous hangup in rfcomm_release_dev() ensures
that rfcomm_tty_install() cannot race with the RFCOMMRELEASEDEV ioctl.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
No logic prevents an rfcomm_dev from being released multiple
times. For example, if the rfcomm_dev ref count is large due
to pending tx, then multiple RFCOMMRELEASEDEV ioctls may
mistakenly release the rfcomm_dev too many times. Note that
concurrent ioctls are not required to create this condition.
Introduce RFCOMM_DEV_RELEASED status bit which guarantees the
rfcomm_dev can only be released once.
NB: Since the flags are exported to userspace, introduce the status
field to track state for which userspace should not be aware.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When enumerating RFCOMM devices in the rfcomm_dev_list, holding
the rfcomm_dev_lock only guarantees the existence of the enumerated
rfcomm_dev in memory, and not safe access to its state. Testing
the device state (such as RFCOMM_TTY_RELEASED) does not guarantee
the device will remain in that state for the subsequent access
to the rfcomm_dev's fields, nor guarantee that teardown has not
commenced.
Obtain an rfcomm_dev reference for the duration of rfcomm_dev
access.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
rfcomm_dev_get() can return a rfcomm_dev reference for a
device for which destruction may be commencing. This can happen
on tty destruction, which calls rfcomm_tty_cleanup(), the last
port reference may have been released but RFCOMM_TTY_RELEASED
was not set. The following race is also possible:
CPU 0 | CPU 1
| rfcomm_release_dev
rfcomm_dev_get | .
spin_lock | .
dev = __rfcomm_dev_get | .
if dev | .
if test_bit(TTY_RELEASED) | .
| !test_and_set_bit(TTY_RELEASED)
| tty_port_put <<<< last reference
else |
tty_port_get |
The reference acquire is bogus because destruction will commence
with the release of the last reference.
Ignore the external state change of TTY_RELEASED and instead rely
on the reference acquire itself to determine if the reference is
valid.
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This reverts commit e228b63390.
This is the third of a 3-patch revert, together with
Revert "Bluetooth: Remove rfcomm_carrier_raised()" and
Revert "Bluetooth: Always wait for a connection on RFCOMM open()".
Commit 4a2fb3ecc7,
"Bluetooth: Always wait for a connection on RFCOMM open()" open-codes
blocking on tty open(), rather than using the default behavior
implemented by the tty port.
The reasons for reverting that patch are detailed in that changelog;
this patch restores required functionality for that revert.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This reverts commit 4a2fb3ecc7.
This is the second of a 3-patch revert, together with
Revert "Bluetooth: Remove rfcomm_carrier_raised()" and
Revert "Bluetooth: Move rfcomm_get_device() before rfcomm_dev_activate()".
Before commit cad348a17e,
Bluetooth: Implement .activate, .shutdown and .carrier_raised methods,
tty_port_block_til_ready() was open-coded in rfcomm_tty_install() as
part of the RFCOMM tty open().
Unfortunately, it did not implement non-blocking open nor CLOCAL open,
but rather always blocked for carrier. This is not the expected or
typical behavior for ttys, and prevents several common terminal
programming idioms from working (eg., opening in non-blocking
mode to initialize desired termios settings then re-opening for
connection).
Commit cad348a17e,
Bluetooth: Implement .activate, .shutdown and .carrier_raised methods,
added the necessary tty_port methods to use the default tty_port_open().
However, this triggered two important user-space regressions.
The first regression involves the complicated mechanism for reparenting
the rfcomm tty device to the ACL link device which represents an
open link to a specific bluetooth host. This regression causes ModemManager
to conclude the rfcomm tty device does not front a modem so it makes
no attempt to initialize an attached modem. This regression is
caused by the lack of a device_move() if the dlc is already open (and
not specifically related to the open-coded block_til_ready()).
A more appropriate solution is submitted in
"Bluetooth: Fix unsafe RFCOMM device parenting" and
"Bluetooth: Fix RFCOMM parent device for reused dlc"
The second regression involves "rfcomm bind" and wvdial (a ppp dialer).
rfcomm bind creates a device node for a /dev/rfcomm<n>. wvdial opens
that device in non-blocking mode (because it expects the connection
to have already been established). In addition, subsequent writes
to the rfcomm tty device fail (because the link is not yet connected;
rfcomm connection begins with the actual tty open()).
However, restoring the original behavior (in the patch which
this reverts) was undesirable.
Firstly, the original reporter notes that a trivial userspace
"workaround" already exists: rfcomm connect, which creates the
device node and establishes the expected connection.
Secondly, the failed writes occur because the rfcomm tty driver
does not buffer writes to an unconnected device; this contrasts with
the dozen of other tty drivers (in fact, all of them) that do just
that. The submitted patch "Bluetooth: Don't fail RFCOMM tty writes"
corrects this.
Thirdly, it was a long-standing bug to block on non-blocking open,
which is re-fixed by revert.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This reverts commit f86772af6a.
This is the first of a 3-patch revert, together with
Revert "Bluetooth: Always wait for a connection on RFCOMM open()" and
Revert "Bluetooth: Move rfcomm_get_device() before rfcomm_dev_activate()".
Commit 4a2fb3ecc7,
"Bluetooth: Always wait for a connection on RFCOMM open()" open-codes
blocking on tty open(), rather than using the default behavior
implemented by the tty port.
The reasons for reverting that patch are detailed in that changelog;
this patch restores required functionality for that revert.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Tested-By: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Remove the rfcomm_carrier_raised() definition as that function isn't
used anymore.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes two regressions introduced with the recent rfcomm tty
rework.
The current code uses the carrier_raised() method to wait for the
bluetooth connection when a process opens the tty.
However processes may open the port with the O_NONBLOCK flag or set the
CLOCAL termios flag: in these cases the open() syscall returns
immediately without waiting for the bluetooth connection to
complete.
This behaviour confuses userspace which expects an established bluetooth
connection.
The patch restores the old behaviour by waiting for the connection in
rfcomm_dev_activate() and removes carrier_raised() from the tty_port ops.
As a side effect the new code also fixes the case in which the rfcomm
tty device is created with the flag RFCOMM_REUSE_DLC: the old code
didn't call device_move() and ModemManager skipped the detection
probe. Now device_move() is always called inside rfcomm_dev_activate().
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reported-by: Andrey Vihrov <andrey.vihrov@gmail.com>
Reported-by: Beson Chow <blc+bluez@mail.vanade.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This is a preparatory patch which moves the rfcomm_get_device()
definition before rfcomm_dev_activate() where it will be used.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes a userspace regression introduced by the commit
29cd718b.
If the rfcomm device was created with the flag RFCOMM_RELEASE_ONHUP the
user space expects that the tty_port is released as soon as the last
process closes the tty.
The current code attempts to release the port in the function
rfcomm_dev_state_change(). However it won't get a reference to the
relevant tty to send a HUP: at that point the tty is already destroyed
and therefore NULL.
This patch fixes the regression by taking over the tty refcount in the
tty install method(). This way the tty_port is automatically released as
soon as the tty is destroyed.
As a consequence the check for RFCOMM_RELEASE_ONHUP flag in the hangup()
method is now redundant. Instead we have to be careful with the reference
counting in the rfcomm_release_dev() function.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reported-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the dlc is closed, rfcomm_dev_state_change() tries to release the
port in the case it cannot get a reference to the tty. However this is
racy and not even needed.
Infact as Peter Hurley points out:
1. Only consider dlcs that are 'stolen' from a connected socket, ie.
reused. Allocated dlcs cannot have been closed prior to port
activate and so for these dlcs a tty reference will always be avail
in rfcomm_dev_state_change() -- except for the conditions covered by
#2b below.
2. If a tty was at some point previously created for this rfcomm, then
either
(a) the tty reference is still avail, so rfcomm_dev_state_change()
will perform a hangup. So nothing to do, or,
(b) the tty reference is no longer avail, and the tty_port will be
destroyed by the last tty_port_put() in rfcomm_tty_cleanup.
Again, no action required.
3. Prior to obtaining the dlc lock in rfcomm_dev_add(),
rfcomm_dev_state_change() will not 'see' a rfcomm_dev so nothing to
do here.
4. After releasing the dlc lock in rfcomm_dev_add(),
rfcomm_dev_state_change() will 'see' an incomplete rfcomm_dev if a
tty reference could not be obtained. Again, the best thing to do here
is nothing. Any future attempted open() will block on
rfcomm_dev_carrier_raised(). The unconnected device will exist until
released by ioctl(RFCOMMRELEASEDEV).
The patch removes the aforementioned code and uses the
tty_port_tty_hangup() helper to hangup the tty.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In rfcomm_tty_cleanup we purge the dlc->tx_queue which may contain
socket buffers referencing the tty_port and thus preventing the tty_port
destruction.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
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: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo 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: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo 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: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo 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: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo 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: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo 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: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg 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: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg 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: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo 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: Mathias 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: David 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: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This handles the merge issue in:
arch/um/drivers/line.c
arch/um/drivers/line.h
And resolves the duplicate patches that were in both trees do to the
tty-next branch not getting merged into 3.6-rc1.
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Only obvious cases were left as inline, mostly oneline functions.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel 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 d29f3ef39b ("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:
fde86d3108 - tty: add lockdep annotations
8f6576ad47 - tty: fix ldisc lock inversion trace
d3ca8b64b9 - pty: Fix lock inversion
b1d679afd7 - tty: drop the pty lock during hangup
abcefe5fc3 - tty/amiserial: Add missing argument for tty_unlock()
fd11b42e35 - cris: fix missing tty arg in wait_event_interruptible_tty call
d29f3ef39b - 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: Linus 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: Alan Cox <alan@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg 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: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg 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: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch the refcounting from manual atomic plays with refcounter to the
one offered by tty_port.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley