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: ebc0d8093e ("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>
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Merge tag 'for-linus-2023022201' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid
Pull HID updates from Benjamin Tissoires:
- HID-BPF infrastructure: this allows to start using HID-BPF. Note that
the mechanism to ship HID-BPF program through the kernel tree is
still not implemented yet (but is planned).
This should be a no-op for 99% of users. Also we are gaining
kselftests for the HID tree (Benjamin Tissoires)
- Some UAF fixes in workers when using uhid (Pietro Borrello & Benjamin
Tissoires)
- Constify hid_ll_driver (Thomas Weißschuh)
- Allow more custom IIO sensors through HID (Philipp Jungkamp)
- Logitech HID++ fixes for scroll wheel, protocol and debug (Bastien
Nocera)
- Some new device support: Steam Deck (Vicki Pfau), UClogic (José
Expósito), Logitech G923 Xbox Edition steering wheel (Walt Holman),
EVision keyboards (Philippe Valembois)
- other assorted code cleanups and fixes
* tag 'for-linus-2023022201' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (99 commits)
HID: mcp-2221: prevent UAF in delayed work
hid: bigben_probe(): validate report count
HID: asus: use spinlock to safely schedule workers
HID: asus: use spinlock to protect concurrent accesses
HID: bigben: use spinlock to safely schedule workers
HID: bigben_worker() remove unneeded check on report_field
HID: bigben: use spinlock to protect concurrent accesses
HID: logitech-hidpp: Add myself to authors
HID: logitech-hidpp: Retry commands when device is busy
HID: logitech-hidpp: Add more debug statements
HID: Add support for Logitech G923 Xbox Edition steering wheel
HID: logitech-hidpp: Add Signature M650
HID: logitech-hidpp: Remove HIDPP_QUIRK_NO_HIDINPUT quirk
HID: logitech-hidpp: Don't restart communication if not necessary
HID: logitech-hidpp: Add constants for HID++ 2.0 error codes
Revert "HID: logitech-hidpp: add a module parameter to keep firmware gestures"
HID: logitech-hidpp: Hard-code HID++ 1.0 fast scroll support
HID: i2c-hid: goodix: Add mainboard-vddio-supply
dt-bindings: HID: i2c-hid: goodix: Add mainboard-vddio-supply
HID: i2c-hid: goodix: Stop tying the reset line to the regulator
...
Declare an entry point that can use fmod_ret BPF programs, and
also an API to access and change the incoming data.
A simpler implementation would consist in just calling
hid_bpf_device_event() for any incoming event and let users deal
with the fact that they will be called for any event of any device.
The goal of HID-BPF is to partially replace drivers, so this situation
can be problematic because we might have programs which will step on
each other toes.
For that, we add a new API hid_bpf_attach_prog() that can be called
from a syscall and we manually deal with a jump table in hid-bpf.
Whenever we add a program to the jump table (in other words, when we
attach a program to a HID device), we keep the number of time we added
this program in the jump table so we can release it whenever there are
no other users.
HID devices have an RCU protected list of available programs in the
jump table, and those programs are called one after the other thanks
to bpf_tail_call().
To achieve the detection of users losing their fds on the programs we
attached, we add 2 tracing facilities on bpf_prog_release() (for when
a fd is closed) and bpf_free_inode() (for when a pinned program gets
unpinned).
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
