Commit graph

254,637 commits

Author SHA1 Message Date
Gustavo F. Padovan
554f05bb8a Bluetooth: move l2cap_sock_release() to l2cap_sock.c
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan
65390587c7 Bluetooth: move l2cap_sock_ops to l2cap_sock.c
First step to move all l2cap_sock_ops function to l2cap_sock.c

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan
bb58f747e5 Bluetooth: Initial work for L2CAP split.
This patch tries to do the minimal to move l2cap_sock_create() and its
dependencies to l2cap_sock.c. It create a API to initialize and cleanup
the L2CAP sockets from l2cap_core.c through l2cap_init_sockets() and
l2cap_cleanup_sockets().

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:30 -02:00
Gustavo F. Padovan
0a708f8fc4 Bluetooth: Rename l2cap.c to l2cap_core.c
In a preparation to the the L2CAP code split in many files.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:43:15 -02:00
Rogério Brito
84f0e17f78 Bluetooth: ath3k: Avoid duplication of code
In commit 86e09287e4, to reduce memory
usage, the functions of the ath3k module were rewritten to release the
firmware blob after it has been loaded (successfully or not).

The resuting code has some redundancy and the compiler can potentially
produce better code if we omit a function call that is unconditionally
executed in

,----
|     if (ath3k_load_firmware(udev, firmware)) {
|             release_firmware(firmware);
|             return -EIO;
|     }
|     release_firmware(firmware);
|
|     return 0;
| }
`----

It may also be argued that the rewritten code becomes easier to read,
and also to see the code coverage of the snippet in question.

Signed-off-by: Rogério Brito <rbrito@ime.usp.br>
Cc: Alexander Holler <holler@ahsoftware.de>
Cc: "Gustavo F. Padovan" <padovan@profusion.mobi>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:08 -02:00
Andrei Emeltchenko
d37f50e190 Bluetooth: fix crash by disabling tasklet in sock accept
Crash can happen when tasklet handling connect/disconnect requests
preempts socket accept. Can be reproduced with "l2test -r" on one
side and several "l2test -c -b 1000 -i hci0 -P 10 <bdaddr>" on the
other side.

disable taskets in socket accept and change lock_sock and release_sock
to bh_lock_sock and bh_unlock_sock since we have to use spinlocks and
there is no need to mark sock as owned by user.

...
[ 3555.897247] Unable to handle kernel NULL pointer dereference at virtual
address 000000bc
[ 3555.915039] pgd = cab9c000
[ 3555.917785] [000000bc] *pgd=8bf3d031, *pte=00000000, *ppte=00000000
[ 3555.928314] Internal error: Oops: 17 [#1] PREEMPT
[ 3555.999786] CPU: 0    Not tainted  (2.6.32.21-13874-g67918ef #65)
...
[ 3556.005981] PC is at bt_accept_unlink+0x20/0x58 [bluetooth]
[ 3556.011627] LR is at bt_accept_dequeue+0x3c/0xe8 [bluetooth]
...
[ 3556.161285] [<bf0007fc>] (bt_accept_unlink+0x20/0x58 [bluetooth]) from
[<bf000870>] (bt_accept_dequeue+0x3c/0xe8 [bluetooth])
[ 3556.172729] [<bf000870>] (bt_accept_dequeue+0x3c/0xe8 [bluetooth]) from
[<bf324df8>] (l2cap_sock_accept+0x100/0x15c [l2cap])
[ 3556.184082] [<bf324df8>] (l2cap_sock_accept+0x100/0x15c [l2cap]) from
[<c026a0a8>] (sys_accept4+0x120/0x1e0)
[ 3556.193969] [<c026a0a8>] (sys_accept4+0x120/0x1e0) from [<c002c9a0>]
(ret_fast_syscall+0x0/0x2c)
[ 3556.202819] Code: e5813000 e5901164 e580c160 e580c15c (e1d13bbc)
...

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:08 -02:00
Andrei Emeltchenko
5a08ecceda Bluetooth: Do not use assignments in IF conditions
Fix checkpatch warnings concerning assignments in if conditions.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:08 -02:00
Johan Hedberg
17fa4b9dff Bluetooth: Add set_io_capability management command
This patch adds a new set_io_capability management command which is used
to set the IO capability for Secure Simple Pairing (SSP) as well as the
Security Manager Protocol (SMP). The value is per hci_dev and each
hci_conn object inherits it upon creation.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:08 -02:00
Johan Hedberg
980e1a537f Bluetooth: Add support for PIN code handling in the management interface
This patch adds the necessary commands and events needed to communicate
PIN code related actions between the kernel and userspace. This includes
a pin_code_request event as well as pin_code_reply and
pin_code_negative_reply commands.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
a38528f111 Bluetooth: Create common cmd_complete function for mgmt.c
A lot of management code needs to generate command complete events so it
makes sense to have a helper function for this.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
2784eb41b1 Bluetooth: Add get_connections managment interface command
This patch adds a get_connections command to the management interface.
With this command userspace can get the current list of connected
devices. Typically this command would only be used once when enumerating
existing adapters. After that the connected and disconnected events are
used to track connections.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
17d5c04cb5 Bluetooth: Add support for connect failed management event
This patch add a new connect failed management event to track failures
in connecting to remote devices. It is particularly useful for security
mode 3 scenarios when we don't have a connected state while pairing but
still need to detect when the connect attempt failed.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
8962ee74be Bluetooth: Add disconnect managment command
This patch adds a disconnect command to the managment interface. Using
this command user space is able to force the disconnection of connected
devices. The command maps directly to the Disconnect HCI command.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
f7520543ab Bluetooth: Add connected/disconnected management events
This patch adds connected and disconnected managment events to track the
connection status to remote devices. The events map directly to
successful connection complete and disconnection complete HCI events for
ACL links.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
55ed8ca10f Bluetooth: Implement link key handling for the management interface
This patch adds a management commands to feed the kernel with all stored
link keys as well as remove specific ones or all of them. Once the
load_keys command has been called the kernel takes over link key
replies. A new_key event is also added to inform userspace of newly
created link keys that should be stored permanently.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:07 -02:00
Johan Hedberg
1aff6f0949 Bluetooth: Add class of device control to the management interface
This patch adds the possibility for user space to fully control the
Class of Device value of local adapters. To control the service class
bits each UUID that's added comes with a service class "hint" which acts
as a mask of bits that the UUID needs to have enabled. The
set_service_cache management command is used to make sure we queue up
all UUID changes as user space initializes its drivers and then send a
single HCI_Write_Class_of_Device command when initialization is
complete.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
d5859e22cd Bluetooth: Implement a more complete adapter initialization sequence
Using the managment interface means that user space doesn't need to do
any HCI command sending at all. This patch moves the remaining
initialization commands from user space to the kernel side. The patch
makes use of the new feature of __hci_request which allows the request
to be dynamically modified while it is ongoing (something that is needed
to react appropriately to the local features and the version of the
adapter).

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
d835060036 Bluetooth: Remove page timeout setting from HCI init sequence
User space should set the page timeout so there's no need to explicitly
set it in the HCI init sequence. Even if user space fails to set it the
controller default value will be used.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
b0916ea0d9 Bluetooth: Add controller side link key clearing to hci_init_req
The controller may have link keys in its own memory and these keys could
be used for secure connections. However, since the interface to access
these keys doesn't provide information about the key types (which would
be needed to infer the level of security each key provides) using these
keys is rather useless. Therefore, simply clear the controller side list
in the initialization procedure.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
a5040efa20 Bluetooth: Add special handling with __hci_request and HCI_INIT
To support a more dynamic HCI initialization sequence the __hci_request
behavior requires some more changes. Particularly, the init sequence
should be able to have conditionals in it (sending some HCI commands
depending on the outcome of a previous command) instead of being a fixed
list as it is right now.

The reasons for these additional requirements are the moving all
previously user space driven initialization commands to the kernel side
as well as the support the Low Energy controllers.

To fulfull these requirements the init sequence is made the only special
case for multi-command requests and req_last_cmd is renamed to
init_last_cmd. The hci_send_cmd function is changed to update
init_last_cmd as long as the HCI_INIT flag is set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
03b555e119 Bluetooth: Reject pairing requests when in non-pairable mode
This patch adds the necessary logic to act accordingly when the
HCI_PAIRABLE flag is not set. In that case PIN code replies as well as
Secure Simple Pairing requests without a NoBonding requirement need to
be rejected.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
930e13363f Bluetooth: Implement debugfs support for listing UUIDs
This patch adds a debugfs entry to list the UUIDs that have been
registered through the management interface.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:06 -02:00
Johan Hedberg
2aeb9a1ae0 Bluetooth: Implement UUID handling through the management interface
This patch adds methods to the management interface for userspace to
notify the kernel of which services have been registered for specific
adapters. This information is needed for setting the appropriate Class
of Device value as well as the Extended Inquiry Response value. This
patch doesn't actually implement setting of these values but just
provides the storage of the UUIDs so the needed functionality can be
built on top of it.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
c542a06c29 Bluetooth: Implement set_pairable managment command
This patch implements a new set_pairable management command to control
the pairable state of local adapters. The state is represented using a
new HCI_PAIRABLE flag in the hci_dev struct.

For backwards compatibility with older user space versions the
HCI_PAIRABLE flag gets automatically set when the existence of an
adapter is reported to user space through legacy methods and the
HCI_MGMT flag is not set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
053f0211d3 Bluetooth: Add send_mode_rsp convenience function for mgmt.c
Several management commands have similar responses but they are not
always sent asynchronously. To enable synchronous sending (from the
managment command handler function) a send_mode_rsp function is added.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
ebc99feba7 Bluetooth: Add flag to track managment controlled adapters
This patch adds a HCI_MGMT flag to track adapters which are under the
control of the management interface. This is needed to make sure that
new kernels will work with old user space versions. I.e. behaviour which
could break old user space versions (but is needed by the management
interface) should not be exhibited when the HCI_MGMT flag is not set.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
72a734ec1a Bluetooth: Unify mode related management messages to a single struct
The powered, connectable and discoverable messages all have the same
format. By using a single struct for all of them a lot of code can be
simplified and reused.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
9fbcbb455d Bluetooth: Add set_connectable management command
This patch adds a set_connectable command as well as a corresponding
event to the management interface. It's mainly useful for setting an
adapter as connectable from a non-initialized state as well as setting
an already initialized adapter as non-connectable (mostly useful for
qualification purposes).

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:05 -02:00
Johan Hedberg
73f22f6238 Bluetooth: Add support for set_discoverable management command
This patch adds a set_discoverable command to the management interface
as well as the corresponding event. The command is used to control the
discoverable state of adapters.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg
eec8d2bcc8 Bluetooth: Add support for set_powered management command
This patch adds a set_powered command to the management interface
through which the powered state of local adapters can be controlled.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg
5add6af8fc Bluetooth: Add support for management powered event
This patch adds support for the powered event that's used to indicate to
userspace when the powered state of a local adapter changes.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Johan Hedberg
ab81cbf99c Bluetooth: Implement automatic setup procedure for local adapters
This patch implements automatic initialization of basic information
about newly registered Bluetooth adapters. E.g. the address and features
are always needed so it makes sense for the kernel to automatically
power on adapters and read this information. A new HCI_SETUP flag is
added to track this state.

In order to not consume unnecessary amounts of power if there isn't a
user space available that could switch the adapter back off, a timer is
added to do this automatically as long as no Bluetooth user space seems
to be present. A new HCI_AUTO_OFF flag is added that user space needs to
clear to avoid the automatic power off.

Additionally, the management interface index_added event is moved to the
end of the HCI_SETUP stage so a user space supporting the managment
inteface has all the necessary information available for fetching when
it gets notified of a new adapter. The HCI_DEV_REG event is kept in the
same place as before since existing HCI raw socket based user space
versions depend on seeing the kernels initialization sequence
(hci_init_req) to determine when the adapter is ready for use.

Signed-off-by: Johan Hedberg <johan.hedberg@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Gustavo F. Padovan
7990681c40 Bluetooth: Fix setting of MTU for ERTM and Streaming Mode
The desired MTU should be sent in an Config_Req for all modes.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Andrei Emeltchenko
e702112ff6 Bluetooth: Use non-flushable by default L2CAP data packets
Modification of Nick Pelly <npelly@google.com> patch.

With Bluetooth 2.1 ACL packets can be flushable or non-flushable. This commit
makes ACL data packets non-flushable by default on compatible chipsets, and
adds the BT_FLUSHABLE socket option to explicitly request flushable ACL
data packets for a given L2CAP socket. This is useful for A2DP data which can
be safely discarded if it can not be delivered within a short time (while
other ACL data should not be discarded).

Note that making ACL data flushable has no effect unless the automatic flush
timeout for that ACL link is changed from its default of 0 (infinite).

Default packet types (for compatible chipsets):
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..00 .... .... .... = PB Flag: First Non-automatically Flushable Packet (0)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet

After setting BT_FLUSHABLE
(sock.setsockopt(274 /*SOL_BLUETOOTH*/, 8 /* BT_FLUSHABLE */, 1 /* flush */))
Frame 34: 13 bytes on wire (104 bits), 13 bytes captured (104 bits)
Bluetooth HCI H4
Bluetooth HCI ACL Packet
    .... 0000 0000 0010 = Connection Handle: 0x0002
    ..10 .... .... .... = PB Flag: First Automatically Flushable Packet (2)
    00.. .... .... .... = BC Flag: Point-To-Point (0)
    Data Total Length: 8
Bluetooth L2CAP Packet

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Jesper Juhl
b2c60d42db Bluetooth: Fix failure to release lock in read_index_list()
If alloc_skb() fails in read_index_list() we'll return -ENOMEM without
releasing 'hci_dev_list_lock'.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
2011-02-08 01:40:04 -02:00
Gustavo F. Padovan
80f5585a29 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/padovan/bluetooth-2.6 into wireless 2011-02-08 01:38:50 -02:00
Ian Munsie
ae07f551c4 tracing/syscalls: Early terminate search for sys_ni_syscall
Many system calls are unimplemented and mapped to sys_ni_syscall, but at
boot ftrace would still search through every syscall metadata entry for
a match which wouldn't be there.

This patch adds causes the search to terminate early if the system call
is not mapped.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-7-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:30:14 -05:00
Ian Munsie
b2d5549681 tracing/syscalls: Allow arch specific syscall symbol matching
Some architectures have unusual symbol names and the generic code to
match the symbol name with the function name for the syscall metadata
will fail. For example, symbols on PPC64 start with a period and the
generic code will fail to match them.

This patch moves the match logic out into a separate function which an
arch can override by defining ARCH_HAS_SYSCALL_MATCH_SYM_NAME in
asm/ftrace.h and implementing arch_syscall_match_sym_name.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-5-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:29:03 -05:00
Ian Munsie
c763ba06bd tracing/syscalls: Make arch_syscall_addr weak
Some architectures use non-trivial system call tables and will not work
with the generic arch_syscall_addr code. For example, PowerPC64 uses a
table of twin long longs.

This patch makes the generic arch_syscall_addr weak to allow
architectures with non-trivial system call tables to override it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-4-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:26:22 -05:00
Ian Munsie
3773b389b6 tracing/syscalls: Convert redundant syscall_nr checks into WARN_ON
With the ftrace events now checking if the syscall_nr is valid upon
initialisation it should no longer be possible to register or unregister
a syscall event without a valid syscall_nr since they should not be
created. This adds a WARN_ON_ONCE in the register and unregister
functions to locate potential regressions in the future.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-3-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:25:52 -05:00
Ian Munsie
ba976970c7 tracing/syscalls: Don't add events for unmapped syscalls
FTRACE_SYSCALLS would create events for each and every system call, even
if it had failed to map the system call's name with it's number. This
resulted in a number of events being created that would not behave as
expected.

This could happen, for example, on architectures who's symbol names are
unusual and will not match the system call name. It could also happen
with system calls which were mapped to sys_ni_syscall.

This patch changes the default system call number in the metadata to -1.
If the system call name from the metadata is not successfully mapped to
a system call number during boot, than the event initialisation routine
will now return an error, preventing the event from being created.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
LKML-Reference: <1296703645-18718-2-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 21:24:44 -05:00
Steven Rostedt
4defe682d8 tracing/filter: Remove synchronize_sched() from __alloc_preds()
Because the filters are processed first and then activated
(added to the call), we no longer need to worry about the preds
of the filter in __alloc_preds() being used. As the filter that
is allocating preds is not activated yet.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt
75b8e98263 tracing/filter: Swap entire filter of events
When creating a new filter, instead of allocating the filter to the
event call first and then processing the filter, it is easier to
process a temporary filter and then just swap it with the call filter.
By doing this, it simplifies the code.

A filter is allocated and processed, when it is done, it is
swapped with the call filter, synchronize_sched() is called to make
sure all callers are done with the old filter (filters are called
with premption disabled), and then the old filter is freed.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt
bf93f9ed3a tracing/filter: Increase the max preds to 2^14
Now that the filter logic does not require to save the pred results
on the stack, we can increase the max number of preds we allow.
As the preds are index by a short value, and we use the MSBs as flags
we can increase the max preds to 2^14 (16384) which should be way
more than enough.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt
4a3d27e98a tracing/filter: Move MAX_FILTER_PRED to local tracing directory
The MAX_FILTER_PRED is only needed by the kernel/trace/*.c files.
Move it to kernel/trace/trace.h.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:20 -05:00
Steven Rostedt
43cd414552 tracing/filter: Optimize filter by folding the tree
There are many cases that a filter will contain multiple ORs or
ANDs together near the leafs. Walking up and down the tree to get
to the next compare can be a waste.

If there are several ORs or ANDs together, fold them into a single
pred and allocate an array of the conditions that they check.
This will speed up the filter by linearly walking an array
and can still break out if a short circuit condition is met.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:19 -05:00
Steven Rostedt
ec126cac23 tracing/filter: Check the created pred tree
Since the filter walks a tree to determine if a match is made or not,
if the tree was incorrectly created, it could cause an infinite loop.

Add a check to walk the entire tree before assigning it as a filter
to make sure the tree is correct.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:19 -05:00
Steven Rostedt
5571927418 tracing/filter: Optimize short ciruit check
The test if we should break out early for OR and AND operations
can be optimized by comparing the current result with
  (pred->op == OP_OR)

That is if the result is true and the op is an OP_OR, or
if the result is false and the op is not an OP_OR (thus an OP_AND)
we can break out early in either case. Otherwise we continue
processing.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:19 -05:00
Steven Rostedt
61e9dea20e tracing/filter: Use a tree instead of stack for filter_match_preds()
Currently the filter_match_preds() requires a stack to push
and pop the preds to determine if the filter matches the record or not.
This has two drawbacks:

1) It requires a stack to store state information. As this is done
   in fast paths we can't allocate the storage for this stack, and
   we can't use a global as it must be re-entrant. The stack is stored
   on the kernel stack and this greatly limits how many preds we
   may allow.

2) All conditions are calculated even when a short circuit exists.
   a || b  will always calculate a and b even though a was determined
   to be true.

Using a tree we can walk a constant structure that will save
the state as we go. The algorithm is simply:

  pred = root;
  do {
	switch (move) {
	case MOVE_DOWN:
		if (OR or AND) {
			pred = left;
			continue;
		}
		if (pred == root)
			break;
		match = pred->fn();
		pred = pred->parent;
		move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT;
		continue;

	case MOVE_UP_FROM_LEFT:
		/* Only OR or AND can be a parent */
		if (match && OR || !match && AND) {
			/* short circuit */
			if (pred == root)
				break;
			pred = pred->parent;
			move = left child ?
				MOVE_UP_FROM_LEFT :
				MOVE_UP_FROM_RIGHT;
			continue;
		}
		pred = pred->right;
		move = MOVE_DOWN;
		continue;

	case MOVE_UP_FROM_RIGHT:
		if (pred == root)
			break;
		pred = pred->parent;
		move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT;
		continue;
	}
	done = 1;
  } while (!done);

This way there's no strict limit to how many preds we allow
and it also will short circuit the logical operations when possible.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:19 -05:00
Steven Rostedt
f76690afd0 tracing/filter: Free pred array on disabling of filter
When a filter is disabled, free the preds.

Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-02-07 20:56:18 -05:00