Commit 62f2e1a0 authored by Benjamin Tissoires's avatar Benjamin Tissoires
Browse files

selftests/hid: add another test for injecting an event from an event hook 

Similar to test_multiply_events_wq: we receive one event and inject a
new one. But given that this time we are already in the event hook, we
can use hid_bpf_try_input_report() directly as this function will not
sleep.

Note that the injected event gets processed before the original one this
way.

Link: https://patch.msgid.link/20240626-hid_hw_req_bpf-v2-12-cfd60fb6c79f@kernel.org


Acked-by: default avatarJiri Kosina <jkosina@suse.com>
Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
parent 9acbb7ba

tools/testing/selftests/hid/hid_bpf.c

+36 −0
Original line number Diff line number Diff line
@@ -1168,6 +1168,42 @@ TEST_F(hid_bpf, test_multiply_events_wq) 
	ASSERT_EQ(buf[1], 3);

}



/*

 * Attach hid_multiply_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 add extra data

 */

TEST_F(hid_bpf, test_multiply_events)

{

	const struct test_program progs[] = {

		{ .name = "hid_test_multiply_events" },

	};

	__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, 9) TH_LOG("read_hidraw");

	ASSERT_EQ(buf[0], 2);

	ASSERT_EQ(buf[1], 47);



	/* read the data from hidraw */

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

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

	ASSERT_EQ(err, 9) TH_LOG("read_hidraw");

	ASSERT_EQ(buf[0], 2);

	ASSERT_EQ(buf[1], 52);

}



/*

 * Attach hid_insert{0,1,2} to the given uhid device,

 * retrieve and open the matching hidraw node,

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

+39 −0
Original line number Diff line number Diff line
@@ -522,3 +522,42 @@ SEC(".struct_ops.link") 
struct hid_bpf_ops test_multiply_events_wq = {

	.hid_device_event = (void *)hid_test_multiply_events_wq,

};



SEC("?struct_ops/hid_device_event")

int BPF_PROG(hid_test_multiply_events, struct hid_bpf_ctx *hid_ctx, enum hid_report_type type)

{

	__u8 *data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 9 /* size */);

	__u8 buf[9];

	int ret;



	if (!data)

		return 0; /* EPERM check */



	if (data[0] != 1)

		return 0;



	/*

	 * we have to use an intermediate buffer as hid_bpf_input_report

	 * will memset data to \0

	 */

	__builtin_memcpy(buf, data, sizeof(buf));



	buf[0] = 2;

	buf[1] += 5;

	ret = hid_bpf_try_input_report(hid_ctx, HID_INPUT_REPORT, buf, sizeof(buf));

	if (ret < 0)

		return ret;



	/*

	 * In real world we should reset the original buffer as data might be garbage now,

	 * but it actually now has the content of 'buf'

	 */

	data[1] += 5;



	return 9;

}



SEC(".struct_ops.link")

struct hid_bpf_ops test_multiply_events = {

	.hid_device_event = (void *)hid_test_multiply_events,

};

tools/testing/selftests/hid/progs/hid_bpf_helpers.h

+4 −0
Original line number Diff line number Diff line
@@ -89,6 +89,10 @@ extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx, 
				enum hid_report_type type,

				__u8 *data,

				size_t buf__sz) __ksym;

extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,

				    enum hid_report_type type,

				    __u8 *data,

				    size_t buf__sz) __ksym;



/* bpf_wq implementation */

extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;