[ Upstream commit e04480920d ]
syzbot is hitting might_sleep() warning at hci_sock_dev_event() due to
calling lock_sock() with rw spinlock held [1].
It seems that history of this locking problem is a trial and error.
Commit b40df5743e ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to
lock_sock() as an attempt to fix lockdep warning.
Then, commit 4ce61d1c7a ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix the
sleep in atomic context warning.
Then, commit 4b5dd696f8 ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().
Then, commit e305509e67 ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.
This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately
reclaims resources as soon as returning from
hci_sock_dev_event(HCI_DEV_UNREG).
But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.
Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_cleanup_dev() which is called by bt_host_release() when all
references to this unregistered device (which is a kobject) are gone.
Since hci_sock_dev_event(HCI_DEV_UNREG) no longer resets
hci_pi(sk)->hdev, we need to check whether this device was unregistered
and return an error based on HCI_UNREGISTER flag. There might be subtle
behavioral difference in "monitor the hdev" functionality; please report
if you found something went wrong due to this patch.
Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: e305509e67 ("Bluetooth: use correct lock to prevent UAF of hdev object")
Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 5c4c8c9544 upstream.
hci_chan can be created in 2 places: hci_loglink_complete_evt() if
it is an AMP hci_chan, or l2cap_conn_add() otherwise. In theory,
Only AMP hci_chan should be removed by a call to
hci_disconn_loglink_complete_evt(). However, the controller might mess
up, call that function, and destroy an hci_chan which is not initiated
by hci_loglink_complete_evt().
This patch adds a verification that the destroyed hci_chan must have
been init'd by hci_loglink_complete_evt().
Example crash call trace:
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xe3/0x144 lib/dump_stack.c:118
print_address_description+0x67/0x22a mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report+0x251/0x28f mm/kasan/report.c:396
hci_send_acl+0x3b/0x56e net/bluetooth/hci_core.c:4072
l2cap_send_cmd+0x5af/0x5c2 net/bluetooth/l2cap_core.c:877
l2cap_send_move_chan_cfm_icid+0x8e/0xb1 net/bluetooth/l2cap_core.c:4661
l2cap_move_fail net/bluetooth/l2cap_core.c:5146 [inline]
l2cap_move_channel_rsp net/bluetooth/l2cap_core.c:5185 [inline]
l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:5464 [inline]
l2cap_sig_channel net/bluetooth/l2cap_core.c:5799 [inline]
l2cap_recv_frame+0x1d12/0x51aa net/bluetooth/l2cap_core.c:7023
l2cap_recv_acldata+0x2ea/0x693 net/bluetooth/l2cap_core.c:7596
hci_acldata_packet net/bluetooth/hci_core.c:4606 [inline]
hci_rx_work+0x2bd/0x45e net/bluetooth/hci_core.c:4796
process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175
worker_thread+0x4fc/0x670 kernel/workqueue.c:2321
kthread+0x2f0/0x304 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
Allocated by task 38:
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0x8d/0x9a mm/kasan/kasan.c:553
kmem_cache_alloc_trace+0x102/0x129 mm/slub.c:2787
kmalloc include/linux/slab.h:515 [inline]
kzalloc include/linux/slab.h:709 [inline]
hci_chan_create+0x86/0x26d net/bluetooth/hci_conn.c:1674
l2cap_conn_add.part.0+0x1c/0x814 net/bluetooth/l2cap_core.c:7062
l2cap_conn_add net/bluetooth/l2cap_core.c:7059 [inline]
l2cap_connect_cfm+0x134/0x852 net/bluetooth/l2cap_core.c:7381
hci_connect_cfm+0x9d/0x122 include/net/bluetooth/hci_core.h:1404
hci_remote_ext_features_evt net/bluetooth/hci_event.c:4161 [inline]
hci_event_packet+0x463f/0x72fa net/bluetooth/hci_event.c:5981
hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791
process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175
worker_thread+0x4fc/0x670 kernel/workqueue.c:2321
kthread+0x2f0/0x304 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
Freed by task 1732:
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free mm/kasan/kasan.c:521 [inline]
__kasan_slab_free+0x106/0x128 mm/kasan/kasan.c:493
slab_free_hook mm/slub.c:1409 [inline]
slab_free_freelist_hook+0xaa/0xf6 mm/slub.c:1436
slab_free mm/slub.c:3009 [inline]
kfree+0x182/0x21e mm/slub.c:3972
hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4891 [inline]
hci_event_packet+0x6a1c/0x72fa net/bluetooth/hci_event.c:6050
hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791
process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175
worker_thread+0x4fc/0x670 kernel/workqueue.c:2321
kthread+0x2f0/0x304 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415
The buggy address belongs to the object at ffff8881d7af9180
which belongs to the cache kmalloc-128 of size 128
The buggy address is located 24 bytes inside of
128-byte region [ffff8881d7af9180, ffff8881d7af9200)
The buggy address belongs to the page:
page:ffffea00075ebe40 count:1 mapcount:0 mapping:ffff8881da403200 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 dead000000000100 dead000000000200 ffff8881da403200
raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881d7af9080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
ffff8881d7af9100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8881d7af9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881d7af9200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881d7af9280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reported-by: syzbot+98228e7407314d2d4ba2@syzkaller.appspotmail.com
Reviewed-by: Alain Michaud <alainm@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: George Kennedy <george.kennedy@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 339ddaa626 upstream.
Starting with the upgrade to v5.8-rc3, I've noticed I wasn't able to
connect to my Bluetooth headset properly anymore. While connecting to
the device would eventually succeed, bluetoothd seemed to be confused
about the current connection state where the state was flapping hence
and forth. Bisecting this issue led to commit 3ca44c16b0 (Bluetooth:
Consolidate encryption handling in hci_encrypt_cfm, 2020-05-19), which
refactored `hci_encrypt_cfm` to also handle updating the connection
state.
The commit in question changed the code to call `hci_connect_cfm` inside
`hci_encrypt_cfm` and to change the connection state. But with the
conversion, we now only update the connection state if a status was set
already. In fact, the reverse should be true: the status should be
updated if no status is yet set. So let's fix the isuse by reversing the
condition.
Fixes: 3ca44c16b0 ("Bluetooth: Consolidate encryption handling in hci_encrypt_cfm")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3ca44c16b0 upstream.
This makes hci_encrypt_cfm calls hci_connect_cfm in case the connection
state is BT_CONFIG so callers don't have to check the state.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: Hans-Christian Noren Egtvedt <hegtvedt@cisco.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f19425641c upstream.
Only sockets will have the chan->data set to an actual sk, channels
like A2MP would have its own data which would likely cause a crash when
calling sk_filter, in order to fix this a new callback has been
introduced so channels can implement their own filtering if necessary.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 745f5c5f2a which is
commit d5bb334a8e upstream.
Lots of people have reported issues with this patch, and as there does
not seem to be a fix going into Linus's kernel tree any time soon,
revert the commit in the stable trees so as to get people's machines
working properly again.
Reported-by: Vasily Khoruzhick <anarsoul@gmail.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Cc: Jeremy Cline <jeremy@jcline.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In case of using BT_ERR and BT_INFO, convert to bt_dev_err and
bt_dev_info when possible. This allows for controller specific
reporting.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Change-Id: I3cd472bf3ce8e797b112c36227884ee2d80b6394
The hci_get_route() API is used to look up local HCI devices, however
so far it has been incapable of dealing with anything else than the
public address of HCI devices. This completely breaks with LE-only HCI
devices that do not come with a public address, but use a static
random address instead.
This patch exteds the hci_get_route() API with a src_type parameter
that's used for comparing with the right address of each HCI device.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch enables prepending appearance value to scan response data.
It also adds support for setting appearance value through mgmt command.
If currently advertised instance has apperance flag set it is expired
immediately.
Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>
Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
While the subsystem version information are purely informational,
increase the minor number due to the addition of user channel and
management control monitoring suppport. It is helpful for debugging
purposes to see the version numbers change.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This command is used to retrieve the current state and basic
information of a controller. It is typically used right after
getting the response to the Read Controller Index List command
or an Index Added event (or its extended counterparts).
When any of the values in the EIR_Data field changes, the event
Extended Controller Information Changed will be used to inform
clients about the updated information.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Michał Narajowski <michal.narajowski@codecoup.pl>
Instead of keeping a version string around, use version and revision
numbers and then stringify them for use as module parameter.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Instead of hiding everything behind a general managment events flag,
introduce indivdual flags that allow fine control over which events are
send to a given management channel.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This adds support for tracing all management commands and events via the
monitor interface.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This sends new notifications to the monitor support whenever a
management channel has been opened or closed. This allows tracing of
control channels really easily.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The mgmt version information will be also needed for the control
changell tracing feature. This provides a helper to pack them.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
To further allow unique identification and tracking of control socket,
store cookie and comm information when binding the socket.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Commit 5177a83827 ("Bluetooth: Add debugfs fields for hardware and
firmware info") introduced hci_set_hw_info() and hci_set_fw_info().
These functions use kvasprintf_const() but are not marked with a
__printf attribute. Adding such an attribute helps detecting issues
related to printf-formatting at build time.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The led_trigger field in hci_dev should be conditional based on if
CONFIG_BT_LEDS is set or not.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Some Bluetooth controllers allow for reading hardware and firmware
related vendor specific infos. If they are available, then they can be
exposed via debugfs now.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The protoypes for hci_recv_frame and hci_recv_diag are in the wrong
location in the header file. Move them close to all the other hci_dev
related exported functions.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The HCI_BREDR naming is confusing since it actually stands for Primary
Bluetooth Controller. Which is a term that has been used in the latest
standard. However from a legacy point of view there only really have
been Basic Rate (BR) and Enhanced Data Rate (EDR). Recent versions of
Bluetooth introduced Low Energy (LE) and made this terminology a little
bit confused since Dual Mode Controllers include BR/EDR and LE. To
simplify this the name HCI_PRIMARY stands for the Primary Controller
which can be a single mode or dual mode controller.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Introduce a limited privacy mode indicated by value 0x02 to the mgmt
Set Privacy command.
With value 0x02 the kernel will use privacy mode with a resolvable
private address. In case the controller is bondable and discoverable
the identity address will be used.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Add support for LED triggers to the Bluetooth subsystem and add kernel
config symbol BT_LEDS for it.
For now one trigger for indicating "HCI is powered up" is supported.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Having proper defines makes the code a bit readable, it also avoids
duplicating hard-coded values since these are also needed when
auto-allocating PSM values (in a subsequent patch).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch implements the mgmt Start Limited Discovery command. Most
of existing Start Discovery code is reused since the only difference
is the presence of a 'limited' flag as part of the discovery state.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To make the EIR parsing helper more general purpose, make it return
the found data and its length rather than just saying whether the data
was present or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This flag just tells us whether hdev->adv_instances is empty or not.
We can equally well use the list_empty() function to get this
information.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The request to update HCI during power on is always coming either from
hdev->req_workqueue or through an ioctl, so it's safe to use
hci_req_sync for it. This way we also eliminate potential races with
incoming mgmt commands or other actions while powering on.
Part of this refactoring is the splitting of mgmt_powered() into
mgmt_power_on() and __mgmt_power_off() functions. The main reason is
the different requirements as far as hdev locking is concerned, as
highlighted with the __ prefix of the power off API.
Since the power on in the case of clearing the AUTO_OFF flag cannot be
done synchronously in the set_powered mgmt handler, the hci_power_on
work callback is extended to cover this (which also simplifies the
set_powered helper a lot).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since the other discoverable changes are behind req_workqueue now it
only makes sense to move the discoverable timeout there as well.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The discoverable mode is intrinsically linked with the connectable
mode e.g. through sharing the same HCI command (Write Scan Enable) for
BR/EDR. It makes therefore sense to move it to hci_request.c and run
the changes through the same hdev->req_workqueue.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This way the connectable changes are synchronized against each other,
which helps avoid potential races. The connectable mode is also linked
together with LE advertising which makes is more convenient to have it
behind the same workqueue.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This paves the way for eventually performing advertising changes
through the hdev->req_workqueue. Some new APIs need to be exposed from
mgmt.c to hci_request.c and vice-versa, but many of them will go away
once hdev->req_workqueue gets used.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since Add/Remove Device perform the page scan updates independently
from the HCI command completion we've introduced a potential race when
multiple mgmt commands are queued. Doing the page scan updates through
the req_workqueue ensures that the state changes are performed in a
race-free manner.
At the same time, to make the request helper more widely usable,
extend it to also cover Inquiry Scan changes since those are behind
the same HCI command. This is also reflected in the new name of the
API as well as the work struct name.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Get Advertising Size Information command allows to retrieve size
information for advertising data and scan response data fields depending
on the selected flags. This is useful if applications want to know the
available size ahead of time.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The hci_connect_le_scan() is (as the name implies) a master/central
role API, so it makes no sense in passing a role parameter to it. At
the same time this patch also fixes the direct advertising support for
LE L2CAP sockets where we now call the more appropriate hci_le_connect()
API if slave/peripheral role is desired.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since discovery also deals with LE scanning it makes sense to move it
behind the same req_workqueue as other LE scanning changes. This also
simplifies the logic since we do many of the actions in a synchronous
manner.
Part of this refactoring is moving hci_req_stop_discovery() to
hci_request.c. At the same time the function receives support for
properly handling the STOPPING state since that's the state we'll be
in when stopping through the req_workqueue.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since discovery also deals with LE scanning it makes sense to move it
behind the same req_workqueue as other LE scanning changes. This also
simplifies the logic since we do many of the actions in a synchronous
manner.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To avoid any risks of races, place also these LE scan modification
work callbacks behind the same work queue as the other LE scan
changes.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In some cases it may be important to get the exact HCI status rather
than the converted HCI-to-errno value. Add an optional return
parameter to the hci_req_sync() API to allow for this. Since there are
no good HCI translation candidates for cancelation and timeout, use
the "unknown" status code for those cases.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Instead of firing off a simple async request queue all background scan
updates through req_workqueue and use hci_req_sync() there to ensure
that no two updates overlap with each other.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The hci_conn_params_clear_all() function is only called from
hci_unregister_dev() at which point it's completely futile to try to
do any LE scanning updates. Simply remove this unnecessary function
call. At the same time we can make the function static since it's only
accessed from within the same c-file.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To enable controller specific logging, the userspace daemon has to have
the ability to log per controller. To facilitate this support, provide
a dedicated logging channel. Messages in this channel will be included
in the monitor queue and with that also forwarded to monitoring tools
along with the actual hardware traces.
All messages from the logging channel are timestamped and with that
allow an easy correlation between userspace messages and hardware
events. This will increase the ability to debug problems faster.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
