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Back in the days when the direct I/O ->end_io callback could be called
from interrupt context for AIO we needed a structure to hand off to the
workqueue, and reused the ioend structure for this purpose. These days
->end_io is always called from user or workqueue context, which allows us
to avoid this memory allocation and simplify the code significantly.
[dchinner: removed now unused xfs_finish_ioend_sync() function after
Brian Foster did an initial review. ]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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Change kmem_free to use kvfree() generic function, remove the
duplicated code.
Signed-off-by: Yalin Wang <yalin.wang@sonymobile.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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This logic is duplicated in xfs_file_fallocate and xfs_ioc_space, and
we'll need another copy of it for pNFS block support.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"One more week's worth of fixes. Worth pointing out here are:
- A patch fixing detaching of iommu registrations when a device is
removed -- earlier the ops pointer wasn't managed properly
- Another set of Renesas boards get the same GIC setup fixup as
others have in previous -rcs
- Serial port aliases fixups for sunxi. We did the same to tegra but
we caught that in time before the merge window due to more machines
being affected. Here it took longer for anyone to notice.
- A couple more DT tweaks on sunxi
- A follow-up patch for the mvebu coherency disabling in last -rc
batch"
* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
arm: dma-mapping: Set DMA IOMMU ops in arm_iommu_attach_device()
ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled
ARM: sunxi: dt: Fix aliases
ARM: dts: sun4i: Add simplefb node with de_fe0-de_be0-lcd0-hdmi pipeline
ARM: dts: sun6i: ippo-q8h-v5: Fix serial0 alias
ARM: dts: sunxi: Fix usb-phy support for sun4i/sun5i
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Pull input layer updates from Dmitry Torokhov:
"Just a few quirks for PS/2 this time"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: elantech - add more Fujtisu notebooks to force crc_enabled
Input: i8042 - add noloop quirk for Medion Akoya E7225 (MD98857)
Input: synaptics - adjust min/max for Lenovo ThinkPad X1 Carbon 2nd
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Olivier Sobrie says:
====================
hso: fix some problems in the disconnect path
These patches attempt to fix some problems I observed when the hso
device is disconnected.
Several patches of this serie are fixing crashes or memleaks when a
hso device is disconnected.
This serie of patches is based on v3.18.
changes in v2:
- Last patch of the serie dropped since another patch fix the issue.
See http://marc.info/?l=linux-usb&m=142186699418489 for more info.
- Added an extra patch avoiding name conflicts for the rfkill interface.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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By using only the usb interface number for the rfkill name, we might
have a name conflicts in case two similar hso devices are connected.
In this patch, the name of the hso rfkill interface embed the value
of a counter that is incremented each time a new rfkill interface is
added.
Suggested-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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For hso serial devices, two cancel_work_sync were missing in the
disconnect method.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The serial_table is used to map the minor number of the usb serial device
to its associated context. The table is updated in the probe method and
in hso_serial_ref_free() which is called either from the tty cleanup
method or from the usb disconnect method.
This patch ensures that the serial_table is updated in the disconnect
method and no more from the cleanup method to avoid the following
potential race condition.
- hso_disconnect() is called for usb interface "x". Because the serial
port was open and because the cleanup method of the tty_port hasn't
been called yet, hso_serial_ref_free() is not run.
- hso_probe() is called and fails for a new hso serial usb interface
"y". The function hso_free_interface() is called and iterates
over the element of serial_table to find the device associated to
the usb interface context.
If the usb interface context of usb interface "y" has been created
at the same place as for usb interface "x", then the cleanup
functions are called for usb interfaces "x" and "y" and
hso_serial_ref_free() is called for both interfaces.
- release_tty() is called for serial port linked to usb interface "x"
and possibly crash because the tty_port structure contained in the
hso_device structure has been freed.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The function hso_serial_common_free() is called either by the cleanup
method of the tty or by the usb disconnect method.
In the former case, the usb_disconnect() has been already called
and the sysfs group associated to the device has been removed.
By calling tty_unregister directly from the usb_disconnect() method,
we avoid a warning due to the removal of the sysfs group of the usb
device.
Example of warning:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 778 at fs/sysfs/group.c:225 sysfs_remove_group+0x50/0x94()
sysfs group c0645a88 not found for kobject 'ttyHS5'
Modules linked in:
CPU: 0 PID: 778 Comm: kworker/0:3 Tainted: G W 3.18.0+ #105
Workqueue: events release_one_tty
[<c000dfe4>] (unwind_backtrace) from [<c000c014>] (show_stack+0x14/0x1c)
[<c000c014>] (show_stack) from [<c0016bac>] (warn_slowpath_common+0x5c/0x7c)
[<c0016bac>] (warn_slowpath_common) from [<c0016c60>] (warn_slowpath_fmt+0x30/0x40)
[<c0016c60>] (warn_slowpath_fmt) from [<c00ddd14>] (sysfs_remove_group+0x50/0x94)
[<c00ddd14>] (sysfs_remove_group) from [<c0221e44>] (device_del+0x30/0x190)
[<c0221e44>] (device_del) from [<c0221fb0>] (device_unregister+0xc/0x18)
[<c0221fb0>] (device_unregister) from [<c0221fec>] (device_destroy+0x30/0x3c)
[<c0221fec>] (device_destroy) from [<c01fe1dc>] (tty_unregister_device+0x2c/0x5c)
[<c01fe1dc>] (tty_unregister_device) from [<c029a428>] (hso_serial_common_free+0x2c/0x88)
[<c029a428>] (hso_serial_common_free) from [<c029a4c0>] (hso_serial_ref_free+0x3c/0xb8)
[<c029a4c0>] (hso_serial_ref_free) from [<c01ff430>] (release_one_tty+0x30/0x84)
[<c01ff430>] (release_one_tty) from [<c00271d4>] (process_one_work+0x21c/0x3c8)
[<c00271d4>] (process_one_work) from [<c0027758>] (worker_thread+0x3d8/0x560)
[<c0027758>] (worker_thread) from [<c002be4c>] (kthread+0xc0/0xcc)
[<c002be4c>] (kthread) from [<c0009630>] (ret_from_fork+0x14/0x24)
---[ end trace cb88537fdc8fa208 ]---
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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There is no need for a dedicated reset work in the hso driver since
there is already a reset work foreseen in usb_interface that does
the same.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In other functions of the driver, variables of type "struct hso_serial"
are denoted by "serial" and variables of type "struct hso_device" are
denoted by "hso_dev". This patch makes the hso_free_interface()
consistent with these notations.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Simply remove the useless extra tab.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When the rfkill interface was created, a buffer containing the name
of the rfkill node was allocated. This buffer was never freed when the
device disappears.
To fix the problem, we put the name given to rfkill_alloc() in
the hso_net structure.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In the disconnect path, tx_buffer should freed like tx_data to avoid
a memory leak when the device disconnects.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When the device disappear, the function hso_disconnect() is called to
perform cleanup. In the cleanup function, hso_free_interface() calls
tty_port_tty_hangup() in view of scheduling a work to hang up the tty if
needed. If the port was not open then hso_serial_ref_free() is called
directly to cleanup everything. Otherwise, hso_serial_ref_free() is called
when the last fd associated to the port is closed.
For each open port, tty_release() will call the close method,
hso_serial_close(), which drops the last kref and call
hso_serial_ref_free() which unregisters, destroys the tty port
and finally frees the structure in which the tty_port structure
is included. Later, in tty_release(), more precisely when release_tty()
is called, the tty_port previously freed is accessed to cancel
the tty buf workqueue and it leads to a crash.
In view of avoiding this crash, we add a cleanup method that is called
at the end of the hangup process and we drop the last kref in this
function when all the ports have been closed, when tty_port is no
more needed and when it is safe to free the structure containing the
tty_port structure.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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No timer related function is used in this driver.
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Commit 8eb23b9f35aa ("sched: Debug nested sleeps") added code to report
on nested sleep conditions, which we generally want to avoid because the
inner sleeping operation can re-set the thread state to TASK_RUNNING,
but that will then cause the outer sleep loop not actually sleep when it
calls schedule.
However, that's actually valid traditional behavior, with the inner
sleep being some fairly rare case (like taking a sleeping lock that
normally doesn't actually need to sleep).
And the debug code would actually change the state of the task to
TASK_RUNNING internally, which makes that kind of traditional and
working code not work at all, because now the nested sleep doesn't just
sometimes cause the outer one to not block, but will cause it to happen
every time.
In particular, it will cause the cardbus kernel daemon (pccardd) to
basically busy-loop doing scheduling, converting a laptop into a heater,
as reported by Bruno Prémont. But there may be other legacy uses of
that nested sleep model in other drivers that are also likely to never
get converted to the new model.
This fixes both cases:
- don't set TASK_RUNNING when the nested condition happens (note: even
if WARN_ONCE() only _warns_ once, the return value isn't whether the
warning happened, but whether the condition for the warning was true.
So despite the warning only happening once, the "if (WARN_ON(..))"
would trigger for every nested sleep.
- in the cases where we knowingly disable the warning by using
"sched_annotate_sleep()", don't change the task state (that is used
for all core scheduling decisions), instead use '->task_state_change'
that is used for the debugging decision itself.
(Credit for the second part of the fix goes to Oleg Nesterov: "Can't we
avoid this subtle change in behaviour DEBUG_ATOMIC_SLEEP adds?" with the
suggested change to use 'task_state_change' as part of the test)
Reported-and-bisected-by: Bruno Prémont <bonbons@linux-vserver.org>
Tested-by: Rafael J Wysocki <rjw@rjwysocki.net>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Cc: Ilya Dryomov <ilya.dryomov@inktank.com>,
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>,
Cc: Davidlohr Bueso <dave@stgolabs.net>,
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add two more Fujitsu LIFEBOOK models that also ship with the Elantech
touchpad and don't work with crc_disabled to the quirk list.
Signed-off-by: Rainer Koenig <Rainer.Koenig@ts.fujitsu.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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Some devices are not fast enough to differentiate between a fast-moving
contact and a new contact. This problem cannot be fully resolved because
information is truly missing, but it is possible to safe-guard against
obvious mistakes by restricting movement with a maximum displacement.
The new problem formulation for dmax > 0 cannot benefit from the speedup
for positive definite matrices, but since the convergence is faster, the
result is about the same. For a handful of contacts, the latency difference
is truly negligible.
Suggested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Henrik Rydberg <rydberg@bitmath.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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This is a I2C driver, so it's wrong to use platform prefix for the
modalias. We have all needed i2c aliases coming form MODULE_DEVICE_TABLE,
so let's remove the wrong and unneeded drv2667-haptics modalias.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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This is a I2C driver, so it's wrong to use platform prefix for the
modalias. We have all needed i2c aliases coming form MODULE_DEVICE_TABLE,
so let's remove the wrong and unneeded drv260x-haptics modalias.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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This is a I2C driver, so it's wrong to use platform prefix for the
modalias. We have all needed i2c aliases coming form MODULE_DEVICE_TABLE,
so let's remove the wrong and unneeded cap11xx modalias.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Daniel Mack <linux@zonque.org>
Reviewed-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes
Merge "Third Round of Renesas ARM Based SoC Fixes for v3.19" from Simon Horman:
* Instantiate GIC from C board code in legacy builds on r8a7790 and r8a73a4
* tag 'renesas-soc-fixes3-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
Signed-off-by: Olof Johansson <olof@lixom.net>
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Use the chanel hw_value and not the center frequency when
building channel array for scan_config_cmd.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Enable EBS on one shot scans if supported by FW.
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Reviewed-by: Alexander Bondar <alexander.bondar@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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When iwl_mvm_power_update_mac() is called, we have already added the
mac context, so if this call fails we should remove the mac.
CC: <stable@vger.kernel.org> [3.15+]
Fixes: commit e5e7aa8e2561 ('iwlwifi: mvm: refactor power code')
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Last EBS status wasn't set to success in the initialization, which
caused the first scan to be without EBS. Fix that.
When EBS is not enabled by the driver, the FW still sends ebs_status success,
which can override EBS failure state. Consider only EBS failures, to avoid
such override. Last_ebs_success is set back to true upon disconnection.
Last_ebs_success wasn't set in umac scan abort flow, fix that too.
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: David Spinadel <david.spinadel@intel.com>
Reviewed-by: Alexander Bondar <alexander.bondar@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Different queue can have different behavior. While it can be
unacceptable for a certain queue to be stuck for 2 seconds
(e.g. the command queue), it can happen that another queue
will stay stuck for even longer (a queue servicing a power
saving client in GO).
The op_mode can even make the timeout be a function of the
listen interval.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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This watchdog allows to monitor the transmit queues. When a
queue doesn't progress for a too long time, a timer fires
and then, debug data can be collected.
This watchdog has never been enabled on dvm controlled
devices, so don't enable it there.
In order to have it running on mvm controlled devices, we
need to fix a small issue in the transport layer: mvm
controlled devices use the shadow registers optimization.
In this case, the watchdog wasn't running at all, even if
enabled by the module parameter. Fix that on the way.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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During out-of-channel activities (e.g. scan) TDLS ch-switch responses from
a peer are kept in FW. These packets arrive only after the out-of-channel
activity is complete, which can be in the order of several seconds.
Since TDLS ch-sw has no dialog-token-like mechanism for distinguishing
sessions, use the GP2 time of the incoming ch-switch response to discern
validity. For this purpose record the GP2 time of an outgoing TDLS ch-sw
request and compare to the Rx time of the ch-sw response.
The methods works in practice since the GP2 time of FW-deferred Rx is
accurate and contains the real Rx timestamp.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Add a response-received state and add more limits on allowed requests
in each state of the connection. Previously ch-switch requests from
other peers could interrupt an outgoing active ch-switch. Also stale
packets from the current peer could disrupt the channel switch state.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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The base address of the scheduler in the device's memory
(SRAM) comes from two different sources. The periphery
register and the alive notification from the firmware.
We have a check in iwl_pcie_tx_start that ensures that
they are the same.
When we resume from WoWLAN, the firmware may have crashed
for whatever reason. In that case, the whole device may be
reset which means that the periphery register will hold a
meaningless value. When we come to compare
trans_pcie->scd_base_addr (which really holds the value we
had when we loaded the WoWLAN firmware upon suspend) and
the current value of the register, we don't see a match
unsurprisingly.
Trick the check to avoid a loud yet harmless WARN.
Note that when the WoWLAN has crashed, we will see that
in iwl_trans_pcie_d3_resume which will let the op_mode
know. Once the op_mode is informed that the WowLAN firmware
has crashed, it can't do much besides resetting the whole
device.
CC: <stable@vger.kernel.org>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Some devices have 31 TFD queues. Don't enable it yet since
there are still issues with it, but at least prepare the
code for it. There was a bug in the read pointer assignment,
fix that. Also, move the inline functions to iwl-scd.h which
is the right place.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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In certain testing scenarios we'd like to force a decision
between STBC/BFER/SISO. In the normal scenario this decision
is done by the FW. Enable this option vis debugfs.
Signed-off-by: Eyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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VHT Beamformer (BFER) will be used if the peer supports it
and there's a benefit to use it vs. STBC or SISO.
The driver now tells the FW whether BFER and/or STBC are
allowed but the FW will make the decision to use either
or stick to SISO on its own.
BFER is limited to a single remote peer. The driver takes
care of ensuring this to the FW and prioritizes with which
peer BFER will be used.
Signed-off-by: Eyal Shapira <eyalx.shapira@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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Printing all the scratch data of the TFDs of that queue is
useless and stuffed the kernel log with data. Remove that.
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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We don't really need to use different mac colors when adding mac
contexts, because they're not used anywhere. In fact, the firmware
doesn't accept 255 as a valid color, so we get into a SYSASSERT 0x3401
when we reach that.
Remove the color increment to use always zero and avoid reaching 255.
CC: <stable@vger.kernel.org> [3.10+]
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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There's really no reason to pad out the field with spaces at the
end of the line - they're practically invisible there anyway.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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If we don't want to restart the firmware, don't reprobe either in case
of a failure during reconfiguration. This allows us to debug failures
in the reconfig flow as well.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
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We used to optimize rescheduling and audit on syscall exit. Now
that the full slow path is reasonably fast, remove these
optimizations. Syscall exit auditing is now handled exclusively by
syscall_trace_leave.
This adds something like 10ns to the previously optimized paths on
my computer, presumably due mostly to SAVE_REST / RESTORE_REST.
I think that we should eventually replace both the syscall and
non-paranoid interrupt exit slow paths with a pair of C functions
along the lines of the syscall entry hooks.
Link: http://lkml.kernel.org/r/22f2aa4a0361707a5cfb1de9d45260b39965dead.1421453410.git.luto@amacapital.net
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
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The x86_64 entry code currently jumps through complex and
inconsistent hoops to try to minimize the impact of syscall exit
work. For a true fast-path syscall, almost nothing needs to be
done, so returning is just a check for exit work and sysret. For a
full slow-path return from a syscall, the C exit hook is invoked if
needed and we join the iret path.
Using iret to return to userspace is very slow, so the entry code
has accumulated various special cases to try to do certain forms of
exit work without invoking iret. This is error-prone, since it
duplicates assembly code paths, and it's dangerous, since sysret
can malfunction in interesting ways if used carelessly. It's
also inefficient, since a lot of useful cases aren't optimized
and therefore force an iret out of a combination of paranoia and
the fact that no one has bothered to write even more asm code
to avoid it.
I would argue that this approach is backwards. Rather than trying
to avoid the iret path, we should instead try to make the iret path
fast. Under a specific set of conditions, iret is unnecessary. In
particular, if RIP==RCX, RFLAGS==R11, RIP is canonical, RF is not
set, and both SS and CS are as expected, then
movq 32(%rsp),%rsp;sysret does the same thing as iret. This set of
conditions is nearly always satisfied on return from syscalls, and
it can even occasionally be satisfied on return from an irq.
Even with the careful checks for sysret applicability, this cuts
nearly 80ns off of the overhead from syscalls with unoptimized exit
work. This includes tracing and context tracking, and any return
that invokes KVM's user return notifier. For example, the cost of
getpid with CONFIG_CONTEXT_TRACKING_FORCE=y drops from ~360ns to
~280ns on my computer.
This may allow the removal and even eventual conversion to C
of a respectable amount of exit asm.
This may require further tweaking to give the full benefit on Xen.
It may be worthwhile to adjust signal delivery and exec to try hit
the sysret path.
This does not optimize returns to 32-bit userspace. Making the same
optimization for CS == __USER32_CS is conceptually straightforward,
but it will require some tedious code to handle the differences
between sysretl and sysexitl.
Link: http://lkml.kernel.org/r/71428f63e681e1b4aa1a781e3ef7c27f027d1103.1421453410.git.luto@amacapital.net
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
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context_tracking_user_exit() has no effect if in_interrupt() returns true,
so ist_enter() didn't work. Fix it by calling exception_enter(), and thus
context_tracking_user_exit(), before incrementing the preempt count.
This also adds an assertion that will catch the problem reliably if
CONFIG_PROVE_RCU=y to help prevent the bug from being reintroduced.
Link: http://lkml.kernel.org/r/261ebee6aee55a4724746d0d7024697013c40a08.1422709102.git.luto@amacapital.net
Fixes: 959274753857 x86, traps: Track entry into and exit from IST context
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
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When using Secure Connections Only mode, then only P-256 OOB data is
valid and should be provided. In case userspace provides P-192 and P-256
OOB data, then the P-192 values will be set to zero. However the present
value of the IO capability exchange still mentioned that both values
would be available. Fix this by telling the controller clearly that only
the P-256 OOB data is present.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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Use of this function ended with commits 3e58c868db1d ("staging: line6:
drop midi_mask_receive") and af89d2897a71 ("staging: line6: drop
midi_mask_transmit".)
[Removed the corresponding line in midibuf.h, too -- tiwai]
Signed-off-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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This function has not been used since merging the driver into the kernel
(and a good while before that.)
[Removed the corresponding line in midibuf.h, too -- tiwai]
Signed-off-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
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For debugging purposes it is good to know which OOB data is actually
currently loaded for each controller. So expose that list via debugfs.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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When the Hardware Error event is send by the controller, the Bluetooth
core stores the error code. Expose it via debugfs so it can be retrieved
later on.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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To allow easier debugging when debug keys are generated, provide debugfs
entry for checking the setting of debug keys usage.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
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