tools/testing/selftests/hid/progs/hid.c

File Facts

System

Linux kernel

Corpus path

tools/testing/selftests/hid/progs/hid.c

Extension

.c

Size

13977 bytes

Lines

601

Domain

Support Tooling And Documentation

Bucket

tools

Inferred role

Support Tooling And Documentation: implementation source

Status

source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

• Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• hid_bpf_helpers.h

Detected Declarations

• struct attach_prog_args
• struct hid_hw_request_syscall_args
• struct elem
• function BPF_PROG
• function __hid_subprog_first_event
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function hid_user_raw_request
• function hid_user_output_report
• function hid_user_input_report
• function sleepable
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG
• function wq_cb_sleepable
• function test_inject_input_report_callback
• function BPF_PROG
• function BPF_PROG
• function BPF_PROG

Annotated Snippet

struct attach_prog_args {
	int prog_fd;
	unsigned int hid;
	int retval;
	int insert_head;
};

__u64 callback_check = 52;
__u64 callback2_check = 52;

SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);

	if (!rw_data)
		return 0; /* EPERM check */

	callback_check = rw_data[1];

	rw_data[2] = rw_data[1] + 5;

	return hid_ctx->size;
}

SEC(".struct_ops.link")
struct hid_bpf_ops first_event = {
	.hid_device_event = (void *)hid_first_event,
	.hid_id = 2,
};

int __hid_subprog_first_event(struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);

	if (!rw_data)
		return 0; /* EPERM check */

	rw_data[2] = rw_data[1] + 5;

	return hid_ctx->size;
}

SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_subprog_first_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
	return __hid_subprog_first_event(hid_ctx, type);
}

SEC(".struct_ops.link")
struct hid_bpf_ops subprog_first_event = {
	.hid_device_event = (void *)hid_subprog_first_event,
	.hid_id = 2,
};

SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_second_event, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 4 /* size */);

	if (!rw_data)
		return 0; /* EPERM check */

	rw_data[3] = rw_data[2] + 5;

	return hid_ctx->size;
}

SEC(".struct_ops.link")
struct hid_bpf_ops second_event = {
	.hid_device_event = (void *)hid_second_event,
};

SEC("?struct_ops/hid_device_event")
int BPF_PROG(hid_change_report_id, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)
{
	__u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);

	if (!rw_data)
		return 0; /* EPERM check */

	rw_data[0] = 2;

	return 9;
}

SEC(".struct_ops.link")
struct hid_bpf_ops change_report_id = {
	.hid_device_event = (void *)hid_change_report_id,
};

Annotation

• Immediate include surface: `hid_bpf_helpers.h`.
• Detected declarations: `struct attach_prog_args`, `struct hid_hw_request_syscall_args`, `struct elem`, `function BPF_PROG`, `function __hid_subprog_first_event`, `function BPF_PROG`, `function BPF_PROG`, `function BPF_PROG`, `function hid_user_raw_request`, `function hid_user_output_report`.
• Atlas domain: Support Tooling And Documentation / tools.
• Implementation status: source implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.