Core can be accessed via PCIe on X86 platform.
This patch also allows the driver to be used as module.
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This way we do not need to transverse the device tree manually and we
support hot plugged devices.
Also Implement remove callback so the driver can be unloaded
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Instead of calculating the register offset per call, pre-calculate it on
probe time.
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Intel Quark X1000 provides a total of 16 GPIOs. The GPIOs are split between
the legacy I/O bridge and the GPIO controller.
GPIO-SCH is the GPIO pins on legacy bridge for Intel Quark SoC.
Intel Quark X1000 has 2 GPIOs powered by the core power well and 6 from
the suspend power well.
This piece of work is derived from Dan O'Donovan's initial work for Quark
X1000 enabling.
Signed-off-by: Chang Rebecca Swee Fun <rebecca.swee.fun.chang@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
semtech has two series of sx150x gpio expanders: sx150x-456 and
sx150x-789.
The current gpio-150x driver in linux only support sx1508 and
sx1509.
We added sx1506 support code into this driver.
Signed-off-by: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The sx150x gpio driver used a loop to set liner irq map for gpio pins.
Now we use the irq domain to rebuild this irq mappig and make sure the
codes are still compatible to old users.
this patch also adds IRQF_ONESHOT flag to fix the IRQ flooding issues.
Signed-off-by: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
[Make Kconfig select GPIOLIB_IRQCHIP]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Fix attribute-creation race with userspace by using the default group
to create also the contingent gpio device attributes.
Fixes: d8f388d8dc ("gpio: sysfs interface")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The gpio device attributes were never destroyed when the gpio was
unexported (or on export failures).
Use device_create_with_groups() to create the default device attributes
of the gpio class device. Note that this also fixes the
attribute-creation race with userspace for these attributes.
Remove contingent attributes in export error path and on unexport.
Fixes: d8f388d8dc ("gpio: sysfs interface")
Cc: stable <stable@vger.kernel.org> # v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The gpio-chip device attributes were never destroyed when the device was
removed.
Fix by using device_create_with_groups() to create the device attributes
of the chip class device.
Note that this also fixes the attribute-creation race with userspace.
Fixes: d8f388d8dc ("gpio: sysfs interface")
Cc: stable <stable@vger.kernel.org> # v2.6.27+
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add MLB+ 3-pin mode pin group to R8A7791 PFC driver.
Based on original patch by Andrey Gusakov <andrey.gusakov@cogentembedded.com>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The R8A7791 manual sometimes calls the signal MLB_CLK and sometimes MLB_CK; the
latter can only be encountered in the PFC section and is probably just a typo
(this signal is always called MLB_CLK in the R8A7790 manual). Fix occurences
of MLB_CK throughout the R8A7791 PFC driver.
Based on original patch by Andrey Gusakov <andrey.gusakov@cogentembedded.com>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
We should not touch the packet after a netif_rx: it might
get freed behind our back.
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Recent Leaf firmware versions (>= 3.1.557) do not allow to send
commands for non-existing channels. If a command is sent for a
non-existing channel, the firmware crashes.
Reported-by: Christopher Storah <Christopher.Storah@invetech.com.au>
Signed-off-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Flooding the Kvaser CAN to USB dongle with multiple reads and
writes in very high frequency (*), closing the CAN channel while
all the transmissions are on (#), opening the device again (@),
then sending a small number of packets would make the driver
enter an almost infinite loop of:
[....]
[15959.853988] kvaser_usb 4-3:1.0 can0: cannot find free context
[15959.853990] kvaser_usb 4-3:1.0 can0: cannot find free context
[15959.853991] kvaser_usb 4-3:1.0 can0: cannot find free context
[15959.853993] kvaser_usb 4-3:1.0 can0: cannot find free context
[15959.853994] kvaser_usb 4-3:1.0 can0: cannot find free context
[15959.853995] kvaser_usb 4-3:1.0 can0: cannot find free context
[....]
_dragging the whole system down_ in the process due to the
excessive logging output.
Initially, this has caused random panics in the kernel due to a
buggy error recovery path. That got fixed in an earlier commit.(%)
This patch aims at solving the root cause. -->
16 tx URBs and contexts are allocated per CAN channel per USB
device. Such URBs are protected by:
a) A simple atomic counter, up to a value of MAX_TX_URBS (16)
b) A flag in each URB context, stating if it's free
c) The fact that ndo_start_xmit calls are themselves protected
by the networking layers higher above
After grabbing one of the tx URBs, if the driver noticed that all
of them are now taken, it stops the netif transmission queue.
Such queue is worken up again only if an acknowedgment was received
from the firmware on one of our earlier-sent frames.
Meanwhile, upon channel close (#), the driver sends a CMD_STOP_CHIP
to the firmware, effectively closing all further communication. In
the high traffic case, the atomic counter remains at MAX_TX_URBS,
and all the URB contexts remain marked as active. While opening
the channel again (@), it cannot send any further frames since no
more free tx URB contexts are available.
Reset all tx URB contexts upon CAN channel close.
(*) 50 parallel instances of `cangen0 -g 0 -ix`
(#) `ifconfig can0 down`
(@) `ifconfig can0 up`
(%) "can: kvaser_usb: Don't free packets when tight on URBs"
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Flooding the Kvaser CAN to USB dongle with multiple reads and
writes in high frequency caused seemingly-random panics in the
kernel.
On further inspection, it seems the driver erroneously freed the
to-be-transmitted packet upon getting tight on URBs and returning
NETDEV_TX_BUSY, leading to invalid memory writes and double frees
at a later point in time.
Note:
Finding no more URBs/transmit-contexts and returning NETDEV_TX_BUSY
is a driver bug in and out of itself: it means that our start/stop
queue flow control is broken.
This patch only fixes the (buggy) error handling code; the root
cause shall be fixed in a later commit.
Acked-by: Olivier Sobrie <olivier@sobrie.be>
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
use of regmap_read() and regmap_write() in c_can_hw_raminit_syscon()
is not safe as the RAMINIT register can be shared between different drivers
at least for TI SoCs.
To make the modification atomic we switch to using regmap_update_bits().
regmap_update_bits() skips writing to the register if it's read content is the
same as what is going to be written. This causes an issue for us when we
need to clear the DONE bit with the initial condition START:0, DONE:1 as
DONE bit must be written with 1 to clear it.
So we defer the clearing of DONE bit to later when we set the START bit.
There we are sure that START bit is changed from 0 to 1 so the write of
1 to already set DONE bit will happen.
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
During the CAN FD standardization process within the ISO it turned out that
the failure detection capability has to be improved.
The CAN in Automation organization (CiA) defined the already implemented CAN
FD controllers as 'non-ISO' and the upcoming improved CAN FD controllers as
'ISO' compliant. See at http://www.can-cia.com/index.php?id=1937
Finally there will be three types of CAN FD controllers in the future:
1. ISO compliant (fixed)
2. non-ISO compliant (fixed, like the M_CAN IP v3.0.1 in m_can.c)
3. ISO/non-ISO CAN FD controllers (switchable, like the PEAK USB FD)
So the current M_CAN driver for the M_CAN IP v3.0.1 has to expose its non-ISO
implementation by setting the CAN_CTRLMODE_FD_NON_ISO ctrlmode at startup.
As this bit cannot be switched at configuration time CAN_CTRLMODE_FD_NON_ISO
must not be set in ctrlmode_supported of the current M_CAN driver.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
When changing flags in the CAN drivers ctrlmode the provided new content has to
be checked whether the bits are allowed to be changed. The bits that are to be
changed are given as a bitfield in cm->mask. Therefore checking against
cm->flags is wrong as the content can hold any kind of values.
The iproute2 tool sets the bits in cm->mask and cm->flags depending on the
detected command line options. To be robust against bogus user space
applications additionally sanitize the provided flags with the provided mask.
Cc: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The linux-can upstream git repositories are now hosted on kernel.org, update
MAINTAINERS accordingly.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The comparing of chan->src should always be done against the local
identity address, represented by hcon->src and hcon->src_type. This
patch modifies l2cap_global_fixed_chan() to take the full hci_conn so
that we can easily compare against hcon->src and hcon->src_type.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The current bdaddr_type() usage in l2cap_core.c is a bit funny in that
it's always passed a hci_conn + a hci_conn member. Because of this only
the hci_conn is really needed. Since the second parameter is always
either hcon->src_type or hcon->dst type this patch adds two helper
functions for each purpose: bdaddr_src_type() and bdaddr_dst_type().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In soc_new_compress() when rtd->dai_link->dynamic is set, we create the pcm
substreams with this call:
ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
1, 0, &be_pcm);
which passes 0 as capture_count leading to
be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream
being NULL, hence when trying to set rtd a few lines below we get an oops.
Fix by using rtd->dai_link->dpcm_playback and rtd->dai_link->dpcm_capture as
playback_count and capture_count to snd_pcm_new_internal().
Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
The arm64 kernel builds fine without the libgcc. Actually it should not
be used at all in the kernel. The following are the reasons indicated
by Russell King:
Although libgcc is part of the compiler, libgcc is built with the
expectation that it will be running in userland - it expects to link
to a libc. That's why you can't build libgcc without having the glibc
headers around.
[...]
Meanwhile, having the kernel build the compiler support functions that
it needs ensures that (a) we know what compiler support functions are
being used, (b) we know the implementation of those support functions
are sane for use in the kernel, (c) we can build them with appropriate
compiler flags for best performance, and (d) we remove an unnecessary
dependency on the build toolchain.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
While the code is correct and functions well, it's still
a bit misleading to add the reference operator in from of
the buf argument.
This patch simply removes that operator in order to make
use of buf slightly better to the eyes.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Since we can compose gadgets from many functions, there is the problem
related to gadget breakage while FunctionFS daemon being closed. FFS
function is userspace code so there is no way to know when it will close
files (it doesn't matter what is the reason of this situation, it can
be daemon logic, program breakage, process kill or any other). So when
we have another function in gadget which, for example, sends some amount
of data, does some software update or implements some real-time functionality,
we may want to keep the gadget connected despite FFS function is no longer
functional.
We can't just remove one of functions from gadget since it has been
enumerated, so the only way to keep entire gadget working is to make
broken FFS function deactivated but still visible to host. For this
purpose this patch introduces "no_disconnect" mode. It can be enabled
by setting mount option "no_disconnect=1", and results with defering
function disconnect to the moment of reopen ep0 file or filesystem
unmount. After closing all endpoint files, FunctionFS is set to state
FFS_DEACTIVATED.
When ffs->state == FFS_DEACTIVATED:
- function is still bound and visible to host,
- setup requests are automatically stalled,
- transfers on other endpoints are refused,
- epfiles, except ep0, are deleted from the filesystem,
- opening ep0 causes the function to be closed, and then FunctionFS
is ready for descriptors and string write,
- altsetting change causes the function to be closed - we want to keep
function alive until another functions are potentialy used, altsetting
change means that another configuration is being selected or USB cable
was unplugged, which indicates that we don't need to stay longer in
FFS_DEACTIVATED state
- unmounting of the FunctionFS instance causes the function to be closed.
Tested-by: David Cohen <david.a.cohen@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Removing a few items that are not needed anymore and
adding separate function for quirks.
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
There is nothing specific being done in the suspend and
resume callbacks that is not already taken care of in PCI
driver core, so dropping the functions.
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
None of the PCI platforms need the NOP transceivers, and
since we can now live without the PHYs, removing
registration of the platform devices for them.
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
drivers/usb/gadget/function/uvc_configfs.c:46:28: sparse: symbol 'to_uvcg_control_header' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:138:25: sparse: symbol 'uvcg_control_header_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:164:6: sparse: symbol 'uvcg_control_header_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:721:20: sparse: symbol 'to_uvcg_format' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:798:30: sparse: symbol 'to_uvcg_streaming_header' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:950:25: sparse: symbol 'uvcg_streaming_header_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:976:6: sparse: symbol 'uvcg_streaming_header_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1020:19: sparse: symbol 'to_uvcg_frame' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1265:25: sparse: symbol 'uvcg_frame_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1315:6: sparse: symbol 'uvcg_frame_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1338:26: sparse: symbol 'to_uvcg_uncompressed' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1548:25: sparse: symbol 'uvcg_uncompressed_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1586:6: sparse: symbol 'uvcg_uncompressed_drop' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1610:19: sparse: symbol 'to_uvcg_mjpeg' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1761:25: sparse: symbol 'uvcg_mjpeg_type' was not declared. Should it be static?
drivers/usb/gadget/function/uvc_configfs.c:1793:6: sparse: symbol 'uvcg_mjpeg_drop' was not declared. Should it be static?
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This makes examples more platform independent and more compatible with
USB standard, as endpoint addresses in given interface may differ
between hardware platforms or even between configurations in single
USB device.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Since we call gaudio_cleanup at f_audio_free, the f_uac1_opts
doesn't need to use gaudio any more.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
If the first queue created was failed on DQM then PQM should
unregister the process from DQM.
Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
According to v4l2 dt document, we add:
a camera host: ISI port.
a i2c camera sensor: ov2640 port.
to sama5d3xmb.dtsi.
The ov2640 node defines the pinctrls, clocks and refer to isi port.
The ISI node also has a reference to the ov2640 port.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
For sama5d3xmb board, the pins: pinctrl_isi_pck_as_mck is pck1, and
used to provide MCK for camera sensor.
We change its name to: pinctrl_pck1_as_isi_mck.
As we want camera sensor instead of ISI to configure the pck1 (ISI_MCK) pin.
So we remove this pinctrl from ISI DT node. It will be added in sensor's
DT node.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
For sama5d3xmb board, the pins: pinctrl_isi_{power,reset} is used to
power-down or reset camera sensor.
So we should let camera sensor instead of ISI to configure the pins.
This patch will change pinctrl name from pinctrl_isi_{power,reset} to
pinctrl_sensor_{power,reset}. And remove these two pinctrl from ISI's
DT node. We will add these two pinctrl to sensor's DT node.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
The mck is decided by the board design, move it to mb related
dtsi file.
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
The ISI has 12 data lines, add the missing two data lines.
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
As the ISI has 12 data lines, however we only use 8 data lines with
sensor module. So, split the data line into two groups which make
it can be choosed depends on the hardware design.
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Josh Wu <josh.wu@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
These rates are treated the same as 160 MHz in the spec, so
it makes no sense to distinguish them. As no driver uses them
yet, this is also not a problem, just remove them.
In the userspace API the field remains reserved to preserve
API and ABI.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
These rates are treated the same as 160 MHz in the spec,
so it makes no sense to distinguish them. As no driver
uses them yet, this is also not a problem, just remove
them.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Commit 90cee759f0 ("MIPS: ELF: Set FP mode according to .MIPS.abiflags")
introduced checking of the .MIPS.abiflags ELF section but did so through
the native sized "elfhdr" and "elf_phdr" structures regardless whether the
ELF was actually 32-bit or 64-bit. This produces wrong results when trying
to use a 64-bit kernel to load o32 ELF files.
Change the uses of the generic elf structures to their 32-bit versions.
Since the code bails out on any 64-bit cases, this is OK until they are
implemented.
Fixes: 90cee759f0 ("MIPS: ELF: Set FP mode according to .MIPS.abiflags")
Signed-off-by: James Cowgill <James.Cowgill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Reviewed-by: Maciej W. Rozycki <macro@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/8932/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 5f893b2639 "tracing: Move enabling tracepoints to just after
rcu_init()" broke the enabling of system call events from the command
line. The reason was that the enabling of command line trace events
was moved before PID 1 started, and the syscall tracepoints require
that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the
swapper task (pid 0) is not part of that. Since the swapper task is the
only task that is running at this early in boot, no task gets the
flag set, and the tracepoint never gets reached.
Instead of setting the swapper task flag (there should be no reason to
do that), re-enabled trace events again after the init thread (PID 1)
has been started. It requires disabling all command line events and
re-enabling them, as just enabling them again will not reset the logic
to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will
be fooled into thinking that it was already set, and wont try setting
it again. For this reason, we must first disable it and re-enable it.
Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
trace_init() calls init_ftrace_syscalls() and then calls trace_event_init()
which also calls init_ftrace_syscalls(). It makes more sense to only
call it from trace_event_init().
Calling it twice wastes memory, as it allocates the syscall events twice,
and loses the first copy of it.
Link: http://lkml.kernel.org/r/54AF53BD.5070303@huawei.com
Link: http://lkml.kernel.org/r/20150115040505.930398632@goodmis.org
Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If the function graph tracer traces a jprobe callback, the system will
crash. This can easily be demonstrated by compiling the jprobe
sample module that is in the kernel tree, loading it and running the
function graph tracer.
# modprobe jprobe_example.ko
# echo function_graph > /sys/kernel/debug/tracing/current_tracer
# ls
The first two commands end up in a nice crash after the first fork.
(do_fork has a jprobe attached to it, so "ls" just triggers that fork)
The problem is caused by the jprobe_return() that all jprobe callbacks
must end with. The way jprobes works is that the function a jprobe
is attached to has a breakpoint placed at the start of it (or it uses
ftrace if fentry is supported). The breakpoint handler (or ftrace callback)
will copy the stack frame and change the ip address to return to the
jprobe handler instead of the function. The jprobe handler must end
with jprobe_return() which swaps the stack and does an int3 (breakpoint).
This breakpoint handler will then put back the saved stack frame,
simulate the instruction at the beginning of the function it added
a breakpoint to, and then continue on.
For function tracing to work, it hijakes the return address from the
stack frame, and replaces it with a hook function that will trace
the end of the call. This hook function will restore the return
address of the function call.
If the function tracer traces the jprobe handler, the hook function
for that handler will not be called, and its saved return address
will be used for the next function. This will result in a kernel crash.
To solve this, pause function tracing before the jprobe handler is called
and unpause it before it returns back to the function it probed.
Some other updates:
Used a variable "saved_sp" to hold kcb->jprobe_saved_sp. This makes the
code look a bit cleaner and easier to understand (various tries to fix
this bug required this change).
Note, if fentry is being used, jprobes will change the ip address before
the function graph tracer runs and it will not be able to trace the
function that the jprobe is probing.
Link: http://lkml.kernel.org/r/20150114154329.552437962@goodmis.org
Cc: stable@vger.kernel.org # 2.6.30+
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
