The I2C core framework provides a simplified probe framework from commit
b8a1a4cd5a ("i2c: Provide a temporary .probe_new() call-back type").
This driver does not utilise the i2c_device_id table in the probe, so we can
easily convert it to utilise the simplified i2c driver registration.
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The I2C core framework provides a simplified probe framework from commit
b8a1a4cd5a ("i2c: Provide a temporary .probe_new() call-back type").
Convert the ADV748x to utilise this simplified i2c driver registration.
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Each iteration of for_each_available_child_of_node puts the previous
node, but in the case of a goto from the middle of the loop, there is
no put, thus causing a memory leak. Hence add an of_node_put before the
goto in four places.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Each iteration of for_each_child_of_node puts the previous node, but in
the case of a goto from the middle of the loop, there is no put, thus
causing a memory leak. Hence add an of_node_put before the goto in two
places.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Acked-by: Houlong Wei <houlong.wei@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move PCIe config space capability search API to common DesignWare file
as this can be used by both host and EP mode drivers.
Signed-off-by: Vidya Sagar <vidyaos@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
When support for the IPMMU is not enabled, the FDP driver may be
probe-deferred multiple times, causing several messages to be printed
like:
rcar_fdp1 fe940000.fdp1: FCP not found (-517)
rcar_fdp1 fe944000.fdp1: FCP not found (-517)
Fix this by reducing the message level to debug level, as is done in the
VSP1 driver.
Fixes: 4710b752e0 ("[media] v4l: Add Renesas R-Car FDP1 Driver")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
No need to check a retval after we assigned a constant to it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
No need to check a retval after we assigned a constant to it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
No need to check a retval after we assigned a constant to it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
No need to check a retval after we assigned a constant to it.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move away from the to-be-removed i2c_new_dummy() to
i2c_new_dummy_device(). So, we now get an ERRPTR which we use in error
handling by printing the error code. To keep the rest of the driver
logic as is, internally a NULL ptr is still kept.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
i2c_new_dummy() can fail returning a NULL pointer. This is not checked
and the returned pointer is blindly used. Convert to
devm_i2c_new_dummy_client() which returns an ERR_PTR and also add a
validity check. Using devm_* here also fixes a leak because the dummy
client was not released in the probe error path.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
After commit c223da6893 ("can: xilinx_can: Add support for CANFD FD
frames") the driver is updating the FSR IRI index multiple times (i.e in
xcanfd_rx() and xcan_rx_fifo_get_next_frame()), It should be updated
once per RX packet. This patch fixes this issue, also this patch removes
the unnecessary fsr register checks in xcanfd_rx() API.
Fixes: c223da6 ("can: xilinx_can: Add support for CANFD FD frames")
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>
Reviewed-by: Shubhrajyoti Datta <Shubhrajyoti.datta@xilinx.com>
Signed-off-by: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Move from i2c_new_dummy() to i2c_new_dummy_device(), so we now get an
ERRPTR which we use in error handling.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
When can clock is provided from the clock wizard, clock wizard driver
may not be available when can driver probes resulting to the error
message "Device clock not found error".
As this error message is not very userful to the end user, skip printing
it in the case of deferred probe.
Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: Appana Durga Kedareswara rao <appana.durga.rao@xilinx.com>
Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
of_get_next_child() increments the reference count of the returning
device_node. Decrement it in the check if we are using the old or the
new DTB.
Fixes: ba1f1f70c2 ("[media] media: mtk-mdp: Fix mdp device tree")
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Houlong Wei <houlong.wei@mediatek.com>
[hverkuil-cisco@xs4all.nl: use node instead of parent as temp variable]
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Some of DesignWare core's DBI registers (a.k.a configuration space
registers) are write-protected with a lock without enabling which they
are read-only by default.
These write-protected registers are implementation specific. Tegra194's
BAR-0 register which is at offset 0x10 in the configuration space is an
example. Current implementation in dw_pcie_setup_rc() API attempts to
unlock those write-protected registers whenever they are updated and
lock them back again for writing.
Group all write-protected registers writes so that locking and unlocking
is performed once to avoid bloating the code with multiple unlock/lock
sequences for all those write-protected registers.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Scale and rotation are currently not implemented, so it makes no sense to
set chroma size for it.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Currently the xilinx_can xcan_chip_start() function, called from
.ndo_open() and via CAN_MODE_START (bus-off restart), waits for the SR
register to show the wanted operating state, with a 1 sec timeout.
However, that register bit will only be set once the HW has observed 11
consecutive recessive bits (BusIdle) on the bus.
If the bus will not see the 11 bits (e.g. it is stuck dominant), the
function will timeout and return an error. If this was done as part of a
scheduled restart from bus-off, the interface will stay in bus-off state
forever even if the bus recovers later.
According to M_CAN and FLEXCAN documentation they also wait for 11
consecutive recessive bits, but their drivers do not seem to wait for
that.
To make the behavior consistent, modify xilinx_can to also not wait for
the synchronization to complete.
The only way for users to know for sure that the bus has been joined
successfully is to see successfully received or transmitted frames. That
does not seem optimal, but it is consistent with other drivers and we
should have a properly working restart-ms with xilinx_can.
Tested on ZynqMP with Xilinx CAN-FD 1.0.
Fixes: b1201e44f5 ("can: xilinx CAN controller support")
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Tested-by: Appana Durga Kedareswara Rao <appana.durga.rao@xilinx.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This array is just duplicated capture buffer queue. Remove it and adjust
code to look into capture buffer queue instead.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Acked-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Tegra PCIe rootports don't generate MSI interrupts for PME and AER events.
Since PCIe spec (Ref: r4.0 sec 7.7.1.2 and 7.7.2.2) doesn't support using
a mix of INTx and MSI/MSI-X, MSI needs to be disabled to avoid root ports
service drivers registering their respective ISRs with MSI interrupt and
to let only INTx be used for all events.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Add #defines only for the Data Link Feature and Physical Layer 16.0 GT/s
features as defined in PCIe spec r4.0, sec 7.7.4 for Data Link Feature and
sec 7.7.5 for Physical Layer 16.0 GT/s.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
This reverts commit b6c61a6c37.
The requested pixelformat is being propagated from the capture to the
tpg in the sensor.
This was a bad design choice, as we start having the following issues:
* We set a pixelformat in the capture;
* We set matching media bus formats in the subdevices pads;
* Link validate looks fine (sizes matches, media bus formats matches);
* Issue: if some of the subdevice doesn't know how to generate the
requested pixelformat in the capture, then stream_on fails. This is bad
because capture says it supports that pixelformat, everything looks
fine, but it is not, and there is no way to find it out through the
links.
This patch was implemented so we could request any pixelformat from the
pipeline regardeless of the media bus format configured between pads.
Not all pixelformat can be mapped into a media bus code (e.g.
multiplanar formats), so with this patch we could request those
pixelformats from the tpg.
Solution: map pixelformats to media bus codes as before, and implement
conversions to other pixelformats in the capture to support multiplanar.
So first step to this solution is to revert this patch.
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Lucas A. M. Magalhaes <lucmaga@gmail.com>
Tested-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Fixes gcc '-Wunused-but-set-variable' warning:
drivers/net/can/ti_hecc.c: In function 'ti_hecc_mailbox_read':
drivers/net/can/ti_hecc.c:533:12: warning:
variable 'mbx_mask' set but not used [-Wunused-but-set-variable]
It is never used so can be removed.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This reverts commit 3c1b9ac753.
Required to Revert "media: vimc: propagate pixel format in the stream"
which introduced the stream object in the vimc_ent_device struct.
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Lucas A. M. Magalhaes <lucmaga@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The image stride was adjusted when it was written to hardware and not
when configuring the format. Calculate the correct stride value and
report it to userspace.
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This patch adds two blank lines in ti_hecc_mailbox_read() to improve the
readability of the function.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch changes the multiple assignments of HECC_TX_MASK in
ti_hecc_start() into two single ones.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Remove including <linux/version.h> that don't need it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Remove including <linux/version.h> that don't need it.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
To set the duty cycle to zero (i.e. pwm_stop), the trigger value shall
be equal to the top value.
This is achieved by reading the value of the top bit field from the pwm
register and then writing back this value to the trigger and top bit
fields.
Addresses-Coverity: ("Logically dead code")
Reported-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Christer Beskow <chbe@kvaser.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Convert omap_vout to the vb2 framework. After this change
'v4l2-compliance -s' passes all tests.
As usual, this vb2 conversion is a 'big bang' patch and hard to read.
Tested on a Pandaboard and a Beagle XM board.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This patch fixes the following v4l2-compliance failures:
- FIELD_ANY could be returned, which is not allowed.
- JPEG colorspace was set instead of SRGB.
- No control events.
- Empty bus_info in QUERYCAP.
- Overlay format handling wasn't zeroing bitmap/clips and
didn't return the chromakey correctly.
- G_FBUF didn't fill in many of the v4l2_framebuffer values.
Now also return the base address of the corresponding
framebuffer that this overlays.
- Missing ENUM/G/S_OUTPUT ioctls.
- ROTATE/VFLIP controls were added when the HW didn't support them.
With these changes 'v4l2-compliance' passes all non-streaming tests.
Tested on a Pandaboard and a Beagle XM board.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Since the "last_dissection" map holds only the flow keys for the most
recent packet, there is a small race in the skb-less flow dissector
tests if a new packet comes between transmitting the test packet, and
reading its keys from the map. If this happens, the test packet keys
will be overwritten and the test will fail.
Changing the "last_dissection" map to a hash map, keyed on the
source/dest port pair resolves this issue. Additionally, let's clear the
last test results from the map between tests to prevent previous test
cases from interfering with the following test cases.
Fixes: 0905beec9f ("selftests/bpf: run flow dissector tests in skb-less mode")
Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
The G700 suffers from the same issue than the G502:
when plugging it in, the driver tries to contact it but it fails.
This timeout is problematic as it introduce a delay in the boot,
and having only the mouse event node means that the hardware
macros keys can not be relayed to the userspace.
Link: https://github.com/libratbag/libratbag/issues/797
Fixes: 91cf9a98ae ("HID: logitech-hidpp: make .probe usbhid capable")
Cc: stable@vger.kernel.org # v5.2
Reviewed-by: Filipe Laíns <lains@archlinux.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
This partially reverts commit 27fc32fd94.
It turns out that the G502 has some issues with hid-logitech-hidpp:
when plugging it in, the driver tries to contact it but it fails.
So the driver bails out leaving only the mouse event node available.
This timeout is problematic as it introduce a delay in the boot,
and having only the mouse event node means that the hardware
macros keys can not be relayed to the userspace.
Filipe and I just gave a shot at the following devices:
G403 Wireless (0xC082)
G703 (0xC087)
G703 Hero (0xC090)
G903 (0xC086)
G903 Hero (0xC091)
G Pro (0xC088)
Reverting the devices we are not sure that works flawlessly.
Reviewed-by: Filipe Laíns <lains@archlinux.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
bpftool requires libelf, and zlib for decompressing /proc/config.gz.
zlib is a transitive dependency via libelf, and became mandatory since
elfutils 0.165 (Jan 2016). The feature check of libelf is already done
in the elfdep target of tools/lib/bpf/Makefile, pulled in by bpftool via
a dependency on libbpf.a. Add a similar feature check for zlib.
Suggested-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Peter Wu <peter@lekensteyn.nl>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Make .BTF section allocated and expose its contents through sysfs.
/sys/kernel/btf directory is created to contain all the BTFs present
inside kernel. Currently there is only kernel's main BTF, represented as
/sys/kernel/btf/kernel file. Once kernel modules' BTFs are supported,
each module will expose its BTF as /sys/kernel/btf/<module-name> file.
Current approach relies on a few pieces coming together:
1. pahole is used to take almost final vmlinux image (modulo .BTF and
kallsyms) and generate .BTF section by converting DWARF info into
BTF. This section is not allocated and not mapped to any segment,
though, so is not yet accessible from inside kernel at runtime.
2. objcopy dumps .BTF contents into binary file and subsequently
convert binary file into linkable object file with automatically
generated symbols _binary__btf_kernel_bin_start and
_binary__btf_kernel_bin_end, pointing to start and end, respectively,
of BTF raw data.
3. final vmlinux image is generated by linking this object file (and
kallsyms, if necessary). sysfs_btf.c then creates
/sys/kernel/btf/kernel file and exposes embedded BTF contents through
it. This allows, e.g., libbpf and bpftool access BTF info at
well-known location, without resorting to searching for vmlinux image
on disk (location of which is not standardized and vmlinux image
might not be even available in some scenarios, e.g., inside qemu
during testing).
Alternative approach using .incbin assembler directive to embed BTF
contents directly was attempted but didn't work, because sysfs_proc.o is
not re-compiled during link-vmlinux.sh stage. This is required, though,
to update embedded BTF data (initially empty data is embedded, then
pahole generates BTF info and we need to regenerate sysfs_btf.o with
updated contents, but it's too late at that point).
If BTF couldn't be generated due to missing or too old pahole,
sysfs_btf.c handles that gracefully by detecting that
_binary__btf_kernel_bin_start (weak symbol) is 0 and not creating
/sys/kernel/btf at all.
v2->v3:
- added Documentation/ABI/testing/sysfs-kernel-btf (Greg K-H);
- created proper kobject (btf_kobj) for btf directory (Greg K-H);
- undo v2 change of reusing vmlinux, as it causes extra kallsyms pass
due to initially missing __binary__btf_kernel_bin_{start/end} symbols;
v1->v2:
- allow kallsyms stage to re-use vmlinux generated by gen_btf();
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Kieran Bingham