Commit 05b3b8f1 authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

selftests/hid: add subprog call test 

I got a weird verifier error with a subprog once, so let's have a test
for it.

Link: https://lore.kernel.org/r/20240608-hid_bpf_struct_ops-v3-9-6ac6ade58329@kernel.org


Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent 4a86220e

tools/testing/selftests/hid/hid_bpf.c

+41 −0
Original line number Diff line number Diff line
@@ -638,6 +638,47 @@ TEST_F(hid_bpf, raw_event) 
	ASSERT_EQ(buf[2], 52);

}



/*

 * Attach hid_first_event to the given uhid device,

 * retrieve and open the matching hidraw node,

 * inject one event in the uhid device,

 * check that the program sees it and can change the data

 */

TEST_F(hid_bpf, subprog_raw_event)

{

	const struct test_program progs[] = {

		{ .name = "hid_subprog_first_event" },

	};

	__u8 buf[10] = {0};

	int err;



	LOAD_PROGRAMS(progs);



	/* inject one event */

	buf[0] = 1;

	buf[1] = 42;

	uhid_send_event(_metadata, self->uhid_fd, buf, 6);



	/* read the data from hidraw */

	memset(buf, 0, sizeof(buf));

	err = read(self->hidraw_fd, buf, sizeof(buf));

	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");

	ASSERT_EQ(buf[0], 1);

	ASSERT_EQ(buf[2], 47);



	/* inject another event */

	memset(buf, 0, sizeof(buf));

	buf[0] = 1;

	buf[1] = 47;

	uhid_send_event(_metadata, self->uhid_fd, buf, 6);



	/* read the data from hidraw */

	memset(buf, 0, sizeof(buf));

	err = read(self->hidraw_fd, buf, sizeof(buf));

	ASSERT_EQ(err, 6) TH_LOG("read_hidraw");

	ASSERT_EQ(buf[2], 52);

}



/*

 * Ensures that we can attach/detach programs

 */

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

+24 −0
Original line number Diff line number Diff line
@@ -35,6 +35,30 @@ struct hid_bpf_ops 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)

{