Commit 33c0fb85 authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

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: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent f1a5fb6c

drivers/hid/bpf/hid_bpf_struct_ops.c

+3 −0
Original line number Diff line number Diff line
@@ -74,6 +74,9 @@ static int hid_bpf_ops_btf_struct_access(struct bpf_verifier_log *log, 


	const struct hid_bpf_offset_write_range write_ranges[] = {

		WRITE_RANGE(hid_bpf_ctx, retval, false),

		WRITE_RANGE(hid_device, name, true),

		WRITE_RANGE(hid_device, uniq, true),

		WRITE_RANGE(hid_device, phys, true),

	};

#undef WRITE_RANGE

	const struct btf_type *state = NULL;

include/linux/hid_bpf.h

+1 −1
Original line number Diff line number Diff line
@@ -43,7 +43,7 @@ struct hid_device; 
 * ``hid`` and ``allocated_size`` are read-only, ``size`` and ``retval`` are read-write.

 */

struct hid_bpf_ctx {

	const struct hid_device *hid;

	struct hid_device *hid;

	__u32 allocated_size;

	union {

		__s32 retval;