64 Commits

Author SHA1 Message Date
Thomas Weißschuh
a707f85d47 HID: bpf: constify parameter rdesc of call_hid_bpf_rdesc_fixup()
The parameter is never modified, so mark it as const.
Also inline the return statement to avoid a type mismatch error.

This is a prerequisite for constification changes in the HID core.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://patch.msgid.link/20240803-hid-const-fixup-v2-1-f53d7a7b29d8@weissschuh.net
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-08-27 16:18:51 +02:00
Benjamin Tissoires
acd34cfc48 HID: bpf: prevent the same struct_ops to be attached more than once
If the struct_ops is already attached, we should bail out or we will
end up in various locks and pointer issues while unregistering.

Link: https://patch.msgid.link/20240723-fix-6-11-bpf-v1-3-b9d770346784@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-24 18:27:21 +02:00
Arnd Bergmann
bacc15e010 hid: bpf: add BPF_JIT dependency
The module does not do anything when the JIT is disabled, but instead
causes a warning:

In file included from include/linux/bpf_verifier.h:7,
                 from drivers/hid/bpf/hid_bpf_struct_ops.c:10:
drivers/hid/bpf/hid_bpf_struct_ops.c: In function 'hid_bpf_struct_ops_init':
include/linux/bpf.h:1853:50: error: statement with no effect [-Werror=unused-value]
 1853 | #define register_bpf_struct_ops(st_ops, type) ({ (void *)(st_ops); 0; })
      |                                                  ^~~~~~~~~~~~~~~~
drivers/hid/bpf/hid_bpf_struct_ops.c:305:16: note: in expansion of macro 'register_bpf_struct_ops'
  305 |         return register_bpf_struct_ops(&bpf_hid_bpf_ops, hid_bpf_ops);
      |                ^~~~~~~~~~~~~~~~~~~~~~~

Add a Kconfig dependency to only allow building the HID-BPF support
when a JIT is enabled.

Fixes: ebc0d8093e8c ("HID: bpf: implement HID-BPF through bpf_struct_ops")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/96a00b6f-eb81-4c67-8c4b-6b1f3f045034@app.fastmail.com
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-22 16:52:05 +02:00
Linus Torvalds
6e504d2c61 for-linus-2024071601
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Merge tag 'for-linus-2024071601' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid

Pull HID updates from Benjamin Tissoires:

 - rewrite of the HID-BPF internal implementation to use bpf struct_ops
   instead of a tracing endpoint (Benjamin Tissoires)

 - add two new HID-BPF hooks to be able to intercept userspace calls
   targeting a HID device and filtering them (Benjamin Tissoires)

 - add support for various new devices through HID-BPF filters (Benjamin
   Tissoires)

 - add support for the magic keyboard backlight (Orlando Chamberlain)

 - add the missing MODULE_DESCRIPTION() macros in HID drivers (Jeff
   Johnson)

 - use of kvzalloc in case memory gets too fragmented (Hailong Liu)

 - retrieve the device firmware node in the child HID device (Danny
   Kaehn)

 - some hid-uclogic improvements (José Expósito)

 - some more typos, trivial fixes, kernel doctext and unused functions
   cleanups

* tag 'for-linus-2024071601' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (60 commits)
  HID: hid-steam: Fix typo in goto label
  HID: mcp2221: Remove unnecessary semicolon
  HID: Fix spelling mistakes "Kensigton" -> "Kensington"
  HID: add more missing MODULE_DESCRIPTION() macros
  HID: samples: fix the 2 struct_ops definitions
  HID: fix for amples in for-6.11/bpf
  HID: apple: Add support for magic keyboard backlight on T2 Macs
  HID: bpf: Thrustmaster TCA Yoke Boeing joystick fix
  HID: bpf: Add Huion Dial 2 bpf fixup
  HID: bpf: Add support for the XP-PEN Deco Mini 4
  HID: bpf: move the BIT() macro to hid_bpf_helpers.h
  HID: bpf: add a driver for the Huion Inspiroy 2S (H641P)
  HID: bpf: Add a HID report composition helper macros
  HID: bpf: doc fixes for hid_hw_request() hooks
  HID: bpf: doc fixes for hid_hw_request() hooks
  HID: bpf: fix gcc warning and unify __u64 into u64
  selftests/hid: ensure CKI can compile our new tests on old kernels
  selftests/hid: add an infinite loop test for hid_bpf_try_input_report
  selftests/hid: add another test for injecting an event from an event hook
  HID: bpf: allow hid_device_event hooks to inject input reports on self
  ...
2024-07-17 17:28:31 -07:00
Benjamin Tissoires
f58e7f404d HID: bpf: Thrustmaster TCA Yoke Boeing joystick fix
This joystick's original HID descriptor is wrong & it shows a
ABS_MISC axis in Linux that doesn't exist on the hardware.

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/82
Signed-off-by: K S Iyer <kumar.s.iyer65@gmail.com>
Link: https://patch.msgid.link/20240627-import-bpf-v1-6-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:44 +02:00
Benjamin Tissoires
9b52d81115 HID: bpf: Add Huion Dial 2 bpf fixup
Pretty much similar to the Inspiroy 2, but with 2 wheels and 8 buttons.

This bpf also works in both normal and vendor mode. If the device is
switched into vendor mode by huion-switcher, a udev property is set
which is then retrieved by this bpf object. This allows to hide the now
unused normal collections.

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/103
Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/104
Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/111
Link: https://patch.msgid.link/20240627-import-bpf-v1-5-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:39 +02:00
Benjamin Tissoires
f03741540d HID: bpf: Add support for the XP-PEN Deco Mini 4
The XP-PEN Deco Mini 4 is a UGEE device with a frame with 6 buttons.
Its pen has 2 buttons and supports pressure reporting.

Fix their report descriptors and transform the frame button events to
support it.

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/88
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://patch.msgid.link/20240627-import-bpf-v1-4-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:37 +02:00
Benjamin Tissoires
c4015aa7d8 HID: bpf: move the BIT() macro to hid_bpf_helpers.h
This macro can be useful in mopre than one place

Link: 7970a9c17a
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Link: https://patch.msgid.link/20240627-import-bpf-v1-3-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:33 +02:00
Benjamin Tissoires
09c555faed HID: bpf: add a driver for the Huion Inspiroy 2S (H641P)
This is a a driver for the Huion Inspiroy 2S in both modes (firmware mode
and tablet mode). This device has 6 buttons and a wheel, all of which
send key combinations (see the comments for the defaults). Luckily the
device is quite limited in that it only supports one button down at a
time, so with this BPF we can simply remap the 8 possible report IDs to
our own custom-built report descriptor.

If the device is in tablet mode (e.g. using huion-switcher it sends
everything through the vendor report instead). This BPF program converts
both, depending which devices you attach to you get both. Or if you
attach to all hid devices you get a duplicate device but it'll work
either way.

This BPF should be mostly compatible for the M and L as well though they
have more buttons so the rdescs will need some minor rework.

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/85
Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/109
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://patch.msgid.link/20240627-import-bpf-v1-2-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:23 +02:00
Benjamin Tissoires
8a89db5187 HID: bpf: Add a HID report composition helper macros
These macros make it slightly easier and more modular to create
a HID report descriptor from scratch. Since they carry the annotation
we don't need to comment it and they cannot get stale.

For comparison, before we had this:

        0x15, 0x00,                    //   Logical Minimum (0)
        0x25, 0x01,                    //   Logical Maximum (1)
        0x95, 0x04,                    //   Report Count (4)
        0x75, 0x01,                    //   Report Size (1)

Now we can write this as:
        LogicalRange_i8(0, 1)
        ReportCount(4)
        ReportSize(1)

Because these macros are for creating new report descriptors,
some bits aren't directly exposed. e.g in the example above:
there is a logical range as one macro that sets both min and max.
There is seldom a good use case for skipping either anyway.

These macros will need to be expanded over time.

For Usage Pages and Usage IDs, we use a tool to parse the HUT JSON
(attached to the HUT 1.5 PDF [1]) and generate all #defines for all
usage pages and usages in the form:

 #define UsagePage_Foo_Bar
 #define Usage_FB_SomeOrOther

Where the FB is simply the acronym based on the capital letters in the
Usage Page name or the first three letters, whichever makes slightly
more sense.

[1] https://usb.org/document-library/hid-usage-tables-15

Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/92
Link: https://gitlab.freedesktop.org/libevdev/udev-hid-bpf/-/merge_requests/96
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://patch.msgid.link/20240627-import-bpf-v1-1-0dbcda4a5b1f@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:18 +02:00
Benjamin Tissoires
c79de517a2 HID: bpf: doc fixes for hid_hw_request() hooks
We had the following errors while doing make htmldocs:

Documentation/hid/hid-bpf:185: include/linux/hid_bpf.h:167:
	ERROR: Unexpected indentation.

Also ensure consistency with the rest of the __u64 vs u64.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 9286675a2aed ("HID: bpf: add HID-BPF hooks for hid_hw_output_report")
Link: https://patch.msgid.link/20240701-fix-cki-v2-4-20564e2e1393@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:16 +02:00
Benjamin Tissoires
762ced1630 HID: bpf: fix gcc warning and unify __u64 into u64
I've got multiple reports of:
error: cast from pointer to integer of different size
[-Werror=pointer-to-int-cast].

Let's use the same trick than kernel/bpf/helpers.c to shut up that warning.

Even if we were on an architecture with addresses on more than 64 bits,
this isn't much of an issue as the address is not used as a pointer,
but as an hash and the caller is not supposed to go back to the kernel
address ever.

And while we change those, make sure we use u64 instead of __u64 for
consistency

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406280633.OPB5uIFj-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282304.UydSVncq-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202406282242.Fk738zzy-lkp@intel.com/
Reported-by: Mirsad Todorovac <mtodorovac69@gmail.com>
Fixes: 67eccf151d76 ("HID: add source argument to HID low level functions")
Link: https://patch.msgid.link/20240701-fix-cki-v2-2-20564e2e1393@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-07-01 14:48:11 +02:00
Benjamin Tissoires
9acbb7ba45 HID: bpf: allow hid_device_event hooks to inject input reports on self
This is the same logic than hid_hw_raw_request or hid_hw_output_report:
we can allow hid_bpf_try_input_report to be called from a hook on
hid_input_report if we ensure that the call can not be made twice in a
row.

There is one extra subtlety in which there is a lock in hid_input_report.
But given that we can detect if we are already in the hook, we can notify
hid_input_report to not take the lock. This is done by checking if
ctx_kern data is valid or null, and if it is equal to the dedicated
incoming data buffer.

In order to have more control on whether the lock needs to be taken or not
we introduce a new kfunc for it: hid_bpf_try_input_report()

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-11-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:48 +02:00
Benjamin Tissoires
fa03f398a8 HID: bpf: make hid_bpf_input_report() sleep until the device is ready
hid_bpf_input_report() is already marked to be used in sleepable context
only. So instead of hammering with timers the device to hopefully get
an available slot where the device is not sending events, we can make
that kfunc wait for the current event to be terminated before it goes in.

This allows to work with the following pseudo code:

in struct_ops/hid_device_event:
  - schedule a bpf_wq, which calls hid_bpf_input_report()
  - once this struct_ops function terminates, hid_bpf_input_report()
    immediately starts before the next event

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-9-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:48 +02:00
Benjamin Tissoires
3ac83fcd6e selftests/hid: add tests for hid_hw_output_report HID-BPF hooks
We add 3 new tests:
- first, we make sure we can prevent the output_report to happen
- second, we make sure that we can detect that a given hidraw client
  was actually doing the request, and for that client only, call ourself
  hid_bpf_hw_output_report(), returning a custom value
- last, we ensure that we can not loop between hooks for
  hid_hw_output_report() and manual calls to hid_bpf_hw_output_report()
  from that same hook

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-8-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:48 +02:00
Benjamin Tissoires
9286675a2a HID: bpf: add HID-BPF hooks for hid_hw_output_report
Same story than hid_hw_raw_requests:

This allows to intercept and prevent or change the behavior of
hid_hw_output_report() from a bpf program.

The intent is to solve a couple of use case:
  - firewalling a HID device: a firewall can monitor who opens the hidraw
    nodes and then prevent or allow access to write operations on that
    hidraw node.
  - change the behavior of a device and emulate a new HID feature request

The hook is allowed to be run as sleepable so it can itself call
hid_hw_output_report(), which allows to "convert" one feature request into
another or even call the feature request on a different HID device on the
same physical device.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-7-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:45 +02:00
Benjamin Tissoires
75839101ce HID: bpf: prevent infinite recursions with hid_hw_raw_requests hooks
When we attach a sleepable hook to hid_hw_raw_requests, we can (and in
many cases should) call ourself hid_bpf_raw_request(), to actually fetch
data from the device itself.

However, this means that we might enter an infinite loop between
hid_hw_raw_requests hooks and hid_bpf_hw_request() call.

To prevent that, if a hid_bpf_hw_request() call is emitted, we prevent
any new call of this kfunc by storing the information in the context.
This way we can always trace/monitor/filter the incoming bpf requests,
while preventing those loops to happen.

I don't think exposing "from_bpf" is very interesting because while
writing such a bpf program, you need to match at least the report number
and/or the source of the call. So a blind "if there is a
hid_hw_raw_request() call, I'm emitting another one" makes no real
sense.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-5-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:12 +02:00
Benjamin Tissoires
8bd0488b5e HID: bpf: add HID-BPF hooks for hid_hw_raw_requests
This allows to intercept and prevent or change the behavior of
hid_hw_raw_request() from a bpf program.

The intent is to solve a couple of use case:
- firewalling a HID device: a firewall can monitor who opens the hidraw
  nodes and then prevent or allow access to write operations on that
  hidraw node.
- change the behavior of a device and emulate a new HID feature request

The hook is allowed to be run as sleepable so it can itself call
hid_bpf_hw_request(), which allows to "convert" one feature request into
another or even call the feature request on a different HID device on the
same physical device.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-4-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 11:00:07 +02:00
Benjamin Tissoires
6cd735f0e5 HID: bpf: protect HID-BPF prog_list access by a SRCU
We want to add sleepable callbacks for hid_hw_raw_request() and
hid_hw_output_report(), but we can not use a plain RCU for those.

Prepare for a SRCU so we can extend HID-BPF.

This changes a little bit how hid_bpf_device_init() behaves, as it may
now fail, so there is a tiny hid-core.c change to accommodate for this.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-3-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 10:58:22 +02:00
Benjamin Tissoires
67eccf151d HID: add source argument to HID low level functions
This allows to know who actually sent what when we process the request
to the device.
This will be useful for a BPF firewall program to allow or not requests
coming from a dedicated hidraw node client.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-2-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 10:58:19 +02:00
Benjamin Tissoires
ebae0b2a6f HID: bpf: fix dispatch_hid_bpf_device_event uninitialized ret value
Looks like if a bpf program gets inserted and then removed,
hdev->bpf.device_data is then allocated, but the loop iterating
over the bpf program is never assigning ret.

This is a problem and also revealed another bug in which only the last
value of ret was checked. This effectively meant than only the last
program in the chain could change the size of the incoming buffer.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/all/00f7b624-219f-4a05-a7ad-5335f15a41c7@moroto.mountain
Fixes: 4a86220e046d ("HID: bpf: remove tracing HID-BPF capability")
Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-1-cfd60fb6c79f@kernel.org
Acked-by: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 10:58:00 +02:00
Luis Felipe Hernandez
9e16bada92 hid: bpf: Fix grammar
* spelling fix: XBox -> Xbox, lowercase 'b' as per Microsoft branding
* rephrase: paddle -> paddles, the controller itself has more than one paddle
* rephrase: replace usage of "those" in favor of explicitly making reference
  to the paddles
* grammatical fix: report -> reports, use present tense verb.
* spelling fix: interpret
* consistency: capitalize the first word in bullet points

Signed-off-by: Luis Felipe Hernandez <luis.hernandez093@gmail.com>
Link: https://patch.msgid.link/20240625105553.50830-1-luis.hernandez093@gmail.com
[bentiss: renamed the file into Xbox, not XBox]
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-27 09:21:40 +02:00
Benjamin Tissoires
33c0fb85b5 HID: bpf: make part of struct hid_device writable
It is useful to change the name, the phys and/or the uniq of a
struct hid_device during .rdesc_fixup().

For example, hid-uclogic.ko changes the uniq to store the firmware version
to differentiate between 2 devices sharing the same PID. In the same
way, changing the device name is useful when the device export 3 nodes,
all with the same name.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-16-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:21 +02:00
Benjamin Tissoires
f1a5fb6c7c HID: bpf: rework hid_bpf_ops_btf_struct_access
The idea is to provide a list of stucts and their editable fields.

Currently no functional changes are introduced here, we will add some
more writeable fields in the next patch.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-15-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:21 +02:00
Benjamin Tissoires
bd0747543b bpf: allow bpf helpers to be used into HID-BPF struct_ops
Without this helpers like bpf_printk() or bpf_map_update() are not
available, making anything but change of bytes impossible to do.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-14-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:21 +02:00
Benjamin Tissoires
c94ae2189a HID: bpf: error on warnings when compiling bpf objects
There is no real reasons to paper over warnings for such small programs.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-13-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:20 +02:00
Benjamin Tissoires
26ba1e0a98 HID: bpf: Artist24: remove unused variable
warning: unused variable ‘tilt’ [-Wunused-variable]

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-12-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:20 +02:00
Benjamin Tissoires
4a86220e04 HID: bpf: remove tracing HID-BPF capability
We can now rely on struct_ops as we cleared the users in-tree.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-8-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:20 +02:00
Benjamin Tissoires
50fe0fc6e2 HID: bpf: convert in-tree fixes into struct_ops
Very mechanical:
- Change HID_BPF_DEVICE_EVENT and HID_BPF_RDESC_FIXUP #defines
- add a matching SEC(".struct_ops.link")
- in ArtistPro16Gen2 make the 2 functions static and have a new one
  calling them

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-7-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:20 +02:00
Benjamin Tissoires
df67602fb8 HID: bpf: add defines for HID-BPF SEC in in-tree bpf fixes
We are going to switch over struct_ops, so instead of having to manually
replace all fields one by one, let's have a common place to change it.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-6-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:20 +02:00
Benjamin Tissoires
ebc0d8093e HID: bpf: implement HID-BPF through bpf_struct_ops
We do this implementation in several steps to not have the CI failing:
- first (this patch), we add struct_ops while keeping the existing infra
  available
- then we change the selftests, the examples and the existing in-tree
  HID-BPF programs
- then we remove the existing trace points making old HID-BPF obsolete

There are a few advantages of struct_ops over tracing:
- compatibility with sleepable programs (for hid_hw_raw_request() in
  a later patch)
- a lot simpler in the kernel: it's a simple rcu protected list
- we can add more parameters to the function called without much trouble
- the "attach" is now generic through BPF-core: the caller just needs to
  set hid_id and flags before calling __load().
- all the BPF tough part is not handled in BPF-core through generic
  processing
- hid_bpf_ctx is now only writable where it needs be

Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-3-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:20:16 +02:00
Benjamin Tissoires
99b40bf805 HID: bpf: add hid_get/put_device() helpers
no code change, but this way we reduce code duplication and we
can export it later.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-2-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:13:22 +02:00
Benjamin Tissoires
146a06a0d2 HID: rename struct hid_bpf_ops into hid_ops
Those operations are the ones from HID, not HID-BPF, and I'd like to
reuse hid_bpf_ops as the user facing struct_ops API.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-1-6ac6ade58329@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-06-14 11:13:22 +02:00
Benjamin Tissoires
0cd1465cac HID: bpf: add in-tree HID-BPF fix for the Raptor Mach 2
This device is already fixed by "HID: do not assume HAT Switch
logical max < 8", but for people without the fix already, having the
HID-BPF locally can fix the device while they wait for their
distribution to update.

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-9-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:19 +02:00
Benjamin Tissoires
9f1bf4c225 HID: bpf: add in-tree HID-BPF fix for the Huion Kamvas Pro 19
This tablets gets a lot of things wrong:
- the secondary button is reported through Secondary Tip Switch
- the third button is reported through Invert

Fortunately, before entering eraser mode, (so Invert = 1),
the tablet always sends an out-of-proximity event.
So we can detect that single event and:
- if there was none but the invert bit was toggled: this is the
  third button
- if there was this out-of-proximity event, we are entering
  eraser mode, and we will until the next out-of-proximity.

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-8-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:16 +02:00
Benjamin Tissoires
1c046d09c6 HID: bpf: add in-tree HID-BPF fix for the XBox Elite 2 over Bluetooth
When using the XBox Wireless Controller Elite 2 over Bluetooth,
the device exports the paddle on the back of the device as a single
bitfield value of usage "Assign Selection".

The kernel doesn't process those usages properly and report KEY_UNKNOWN
for it.

SDL doesn't know how to interprete that KEY_UNKNOWN and thus ignores the
paddles.

Given that over USB the kernel uses BTN_TRIGGER_HAPPY[5-8], we
can tweak the report descriptor to make the kernel interprete it properly:
- we need an application collection of gamepad (so we have to close the
  current Consumer Control one)
- we need to change the usage to be buttons from 0x15 to 0x18

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-7-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:12 +02:00
Benjamin Tissoires
d9e7897392 HID: bpf: add in-tree HID-BPF fix for the Wacom ArtPen
This pen is compatible with multiple Wacom tablets, but we only add support
for the Intuos Pro 2 M, as this is the one our user reported the bug
against.

We can not generically add all compatible Wacom tablets as we are
writing the offsets by hand.

The point of this HID-BPF program is to work around a firmware limitation
where the pressure is repeated every other report.
Given that we know this will happen, we can change the first new pressure
information with the mean compared to the previous one. This way we
smooth the incoming pressure without losing information.

Cc: Ping Cheng <pinglinux@gmail.com>
Cc: Jason Gerecke <killertofu@gmail.com>
Cc: Aaron Armstrong Skomra <skomra@gmail.com>
Cc: Joshua Dickens <Joshua@joshua-dickens.com>
Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-6-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:07 +02:00
Benjamin Tissoires
0bc8f89f40 HID: bpf: add in-tree HID-BPF fix for the IOGear Kaliber Gaming MMOmentum mouse
Allows to export more than 5 buttons on this 12 buttons mouse.

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-5-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:04 +02:00
Benjamin Tissoires
4e6d2a297d HID: bpf: add in-tree HID-BPF fix for the HP Elite Presenter Mouse
Duplicate of commit 0db117359e47 ("HID: add quirk for 03f0:464a HP Elite
Presenter Mouse"), but in a slightly better way.

This time we actually change the application collection, making clearer
for userspace what the second mouse is.

Note that having both hid-quirks fix and this HID-BPF fix is not a
problem at all.

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-4-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:39:00 +02:00
Benjamin Tissoires
e0599675a3 HID: bpf: add in-tree HID-BPF fix for the XPPen Artist 16
Same problem than the Artist 24: the second button on the pen is treated
like an eraser.
But the problem is even worse this time. There is an actual eraser at
the tail of the pen.

The compensation of the coordinates was done by Martin

Signed-off-by: Martin Sivak <mars@montik.net>
Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-3-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:38:57 +02:00
Benjamin Tissoires
04b3e5ab05 HID: bpf: add first in-tree HID-BPF fix for the XPPen Artist 24
This commit adds a fix for XPPen Artist 24 where the second button on
the pen is used as an eraser.

It's a "feature" from Microsoft, but it turns out that it's actually
painful for artists. So we ship here a HID-BPF program that turns this
second button into an actual button.

Note that the HID-BPF program is not directly loaded by the kernel itself
but by udev-hid-bpf[0]. But having the sources here allows us to also
integrate tests into tools/testing/selftests/hid to ensure the HID-BPF
program are actually tested.

[0] https://gitlab.freedesktop.org/libevdev/udev-hid-bpf

Link: https://lore.kernel.org/r/20240410-bpf_sources-v1-2-a8bf16033ef8@kernel.org
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-05-07 15:38:53 +02:00
Benjamin Tissoires
b912cf0420 HID: bpf: fix hid_bpf_input_report() when hid-core is not ready
Reported by linux-next:
After merging the hid tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

x86_64-linux-gnu-ld: vmlinux.o: in function `hid_bpf_input_report':
(.text+0x1c75181): undefined reference to `hid_input_report'

Caused by commit 9be50ac30a83 ("HID: bpf: allow to inject HID event
from BPF")

I just forgot to put the indirection in place.

Link: https://lore.kernel.org/linux-kernel/20240411105131.7830f966@canb.auug.org.au/
Fixes: 9be50ac30a83 ("HID: bpf: allow to inject HID event from BPF")
Link: https://lore.kernel.org/r/20240411-fix-hid-bpf-v1-1-4ae913031a8c@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-04-11 16:02:01 +02:00
Benjamin Tissoires
685dadafbd HID: bpf: allow to use bpf_timer_set_sleepable_cb() in tracing callbacks.
Export the sleepable kfuncs we have on HID-BPF in tracing bpf programs,
but with the condition of being used in a sleepable context.
This allows to use the bpf_timer when used in a sleepable context
through bpf_timer_set_sleepable_cb() and initiate work from a device event.

Link: https://lore.kernel.org/r/20240315-b4-hid-bpf-new-funcs-v4-7-079c282469d3@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-04-10 16:38:37 +02:00
Benjamin Tissoires
9be50ac30a HID: bpf: allow to inject HID event from BPF
It can be interesting to inject events from BPF as if the event were
to come from the device.
For example, some multitouch devices do not all the time send a proximity
out event, and we might want to send it for the physical device.

Compared to uhid, we can now inject events on any physical device, not
just uhid virtual ones.

Link: https://lore.kernel.org/r/20240315-b4-hid-bpf-new-funcs-v4-5-079c282469d3@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-04-10 16:38:11 +02:00
Benjamin Tissoires
5599f80196 HID: bpf: export hid_hw_output_report as a BPF kfunc
We currently only export hid_hw_raw_request() as a BPF kfunc.
However, some devices require an explicit write on the Output Report
instead of the use of the control channel.

So also export hid_hw_output_report to BPF

Link: https://lore.kernel.org/r/20240315-b4-hid-bpf-new-funcs-v4-2-079c282469d3@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-04-10 16:37:14 +02:00
Benjamin Tissoires
4171954f56 HID: bpf/dispatch: regroup kfuncs definitions
No code change, just move down the hid_bpf_get_data() kfunc definition
so we have only one block of __bpf_kfunc_start/end_defs()

Link: https://lore.kernel.org/r/20240315-b4-hid-bpf-new-funcs-v4-1-079c282469d3@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-04-10 16:35:25 +02:00
Jakub Kicinski
4b2765ae41 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-02-29

We've added 119 non-merge commits during the last 32 day(s) which contain
a total of 150 files changed, 3589 insertions(+), 995 deletions(-).

The main changes are:

1) Extend the BPF verifier to enable static subprog calls in spin lock
   critical sections, from Kumar Kartikeya Dwivedi.

2) Fix confusing and incorrect inference of PTR_TO_CTX argument type
   in BPF global subprogs, from Andrii Nakryiko.

3) Larger batch of riscv BPF JIT improvements and enabling inlining
   of the bpf_kptr_xchg() for RV64, from Pu Lehui.

4) Allow skeleton users to change the values of the fields in struct_ops
   maps at runtime, from Kui-Feng Lee.

5) Extend the verifier's capabilities of tracking scalars when they
   are spilled to stack, especially when the spill or fill is narrowing,
   from Maxim Mikityanskiy & Eduard Zingerman.

6) Various BPF selftest improvements to fix errors under gcc BPF backend,
   from Jose E. Marchesi.

7) Avoid module loading failure when the module trying to register
   a struct_ops has its BTF section stripped, from Geliang Tang.

8) Annotate all kfuncs in .BTF_ids section which eventually allows
   for automatic kfunc prototype generation from bpftool, from Daniel Xu.

9) Several updates to the instruction-set.rst IETF standardization
   document, from Dave Thaler.

10) Shrink the size of struct bpf_map resp. bpf_array,
    from Alexei Starovoitov.

11) Initial small subset of BPF verifier prepwork for sleepable bpf_timer,
    from Benjamin Tissoires.

12) Fix bpftool to be more portable to musl libc by using POSIX's
    basename(), from Arnaldo Carvalho de Melo.

13) Add libbpf support to gcc in CORE macro definitions,
    from Cupertino Miranda.

14) Remove a duplicate type check in perf_event_bpf_event,
    from Florian Lehner.

15) Fix bpf_spin_{un,}lock BPF helpers to actually annotate them
    with notrace correctly, from Yonghong Song.

16) Replace the deprecated bpf_lpm_trie_key 0-length array with flexible
    array to fix build warnings, from Kees Cook.

17) Fix resolve_btfids cross-compilation to non host-native endianness,
    from Viktor Malik.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (119 commits)
  selftests/bpf: Test if shadow types work correctly.
  bpftool: Add an example for struct_ops map and shadow type.
  bpftool: Generated shadow variables for struct_ops maps.
  libbpf: Convert st_ops->data to shadow type.
  libbpf: Set btf_value_type_id of struct bpf_map for struct_ops.
  bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
  bpf, arm64: use bpf_prog_pack for memory management
  arm64: patching: implement text_poke API
  bpf, arm64: support exceptions
  arm64: stacktrace: Implement arch_bpf_stack_walk() for the BPF JIT
  bpf: add is_async_callback_calling_insn() helper
  bpf: introduce in_sleepable() helper
  bpf: allow more maps in sleepable bpf programs
  selftests/bpf: Test case for lacking CFI stub functions.
  bpf: Check cfi_stubs before registering a struct_ops type.
  bpf: Clarify batch lookup/lookup_and_delete semantics
  bpf, docs: specify which BPF_ABS and BPF_IND fields were zero
  bpf, docs: Fix typos in instruction-set.rst
  selftests/bpf: update tcp_custom_syncookie to use scalar packet offset
  bpf: Shrink size of struct bpf_map/bpf_array.
  ...
====================

Link: https://lore.kernel.org/r/20240301001625.8800-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-02 20:50:59 -08:00
Daniel Xu
6f3189f38a bpf: treewide: Annotate BPF kfuncs in BTF
This commit marks kfuncs as such inside the .BTF_ids section. The upshot
of these annotations is that we'll be able to automatically generate
kfunc prototypes for downstream users. The process is as follows:

1. In source, use BTF_KFUNCS_START/END macro pair to mark kfuncs
2. During build, pahole injects into BTF a "bpf_kfunc" BTF_DECL_TAG for
   each function inside BTF_KFUNCS sets
3. At runtime, vmlinux or module BTF is made available in sysfs
4. At runtime, bpftool (or similar) can look at provided BTF and
   generate appropriate prototypes for functions with "bpf_kfunc" tag

To ensure future kfunc are similarly tagged, we now also return error
inside kfunc registration for untagged kfuncs. For vmlinux kfuncs,
we also WARN(), as initcall machinery does not handle errors.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/e55150ceecbf0a5d961e608941165c0bee7bc943.1706491398.git.dxu@dxuuu.xyz
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-31 20:40:56 -08:00
Benjamin Tissoires
764ad6b027 HID: bpf: use __bpf_kfunc instead of noinline
Follow the docs at Documentation/bpf/kfuncs.rst:
- declare the function with `__bpf_kfunc`
- disables missing prototype warnings, which allows to remove them from
  include/linux/hid-bpf.h

Removing the prototypes is not an issue because we currently have to
redeclare them when writing the BPF program. They will eventually be
generated by bpftool directly AFAIU.

Link: https://lore.kernel.org/r/20240124-b4-hid-bpf-fixes-v2-3-052520b1e5e6@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-01-31 10:27:08 +01:00
Benjamin Tissoires
89be8aa5b0 HID: bpf: actually free hdev memory after attaching a HID-BPF program
Turns out that I got my reference counts wrong and each successful
bus_find_device() actually calls get_device(), and we need to manually
call put_device().

Ensure each bus_find_device() gets a matching put_device() when releasing
the bpf programs and fix all the error paths.

Cc: <stable@vger.kernel.org>
Fixes: f5c27da4e3c8 ("HID: initial BPF implementation")
Link: https://lore.kernel.org/r/20240124-b4-hid-bpf-fixes-v2-2-052520b1e5e6@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
2024-01-31 10:27:05 +01:00