[PATCH RFC bpf-next v2 06/10] selftests/hid: Add test for hid_bpf_hw_output_report

From: Benjamin Tissoires
Date: Wed Feb 14 2024 - 12:21:32 EST


This time we need to ensure uhid receives it, thus the new mutex and
condition.

Signed-off-by: Benjamin Tissoires <bentiss@xxxxxxxxxx>

---

no changes in v2
---
tools/testing/selftests/hid/hid_bpf.c | 63 ++++++++++++++++++++++
tools/testing/selftests/hid/progs/hid.c | 24 +++++++++
.../testing/selftests/hid/progs/hid_bpf_helpers.h | 2 +
3 files changed, 89 insertions(+)

diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 2cf96f818f25..8332014838b0 100644
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -16,6 +16,11 @@

#define SHOW_UHID_DEBUG 0

+#define min(a, b) \
+ ({ __typeof__(a) _a = (a); \
+ __typeof__(b) _b = (b); \
+ _a < _b ? _a : _b; })
+
static unsigned char rdesc[] = {
0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
0x09, 0x21, /* Usage (Vendor Usage 0x21) */
@@ -111,6 +116,10 @@ struct hid_hw_request_syscall_args {
static pthread_mutex_t uhid_started_mtx = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t uhid_started = PTHREAD_COND_INITIALIZER;

+static pthread_mutex_t uhid_output_mtx = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t uhid_output_cond = PTHREAD_COND_INITIALIZER;
+static unsigned char output_report[10];
+
/* no need to protect uhid_stopped, only one thread accesses it */
static bool uhid_stopped;

@@ -205,6 +214,13 @@ static int uhid_event(struct __test_metadata *_metadata, int fd)
break;
case UHID_OUTPUT:
UHID_LOG("UHID_OUTPUT from uhid-dev");
+
+ pthread_mutex_lock(&uhid_output_mtx);
+ memcpy(output_report,
+ ev.u.output.data,
+ min(ev.u.output.size, sizeof(output_report)));
+ pthread_cond_signal(&uhid_output_cond);
+ pthread_mutex_unlock(&uhid_output_mtx);
break;
case UHID_GET_REPORT:
UHID_LOG("UHID_GET_REPORT from uhid-dev");
@@ -733,6 +749,53 @@ TEST_F(hid_bpf, test_hid_change_report)
ASSERT_EQ(buf[2], 0) TH_LOG("leftovers_from_previous_test");
}

+/*
+ * Call hid_bpf_hw_output_report against the given uhid device,
+ * check that the program is called and does the expected.
+ */
+TEST_F(hid_bpf, test_hid_user_output_report_call)
+{
+ struct hid_hw_request_syscall_args args = {
+ .retval = -1,
+ .size = 10,
+ };
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattrs,
+ .ctx_in = &args,
+ .ctx_size_in = sizeof(args),
+ );
+ int err, cond_err, prog_fd;
+ struct timespec time_to_wait;
+
+ LOAD_BPF;
+
+ args.hid = self->hid_id;
+ args.data[0] = 1; /* report ID */
+ args.data[1] = 2; /* report ID */
+ args.data[2] = 42; /* report ID */
+
+ prog_fd = bpf_program__fd(self->skel->progs.hid_user_output_report);
+
+ pthread_mutex_lock(&uhid_output_mtx);
+
+ memset(output_report, 0, sizeof(output_report));
+ clock_gettime(CLOCK_REALTIME, &time_to_wait);
+ time_to_wait.tv_sec += 2;
+
+ err = bpf_prog_test_run_opts(prog_fd, &tattrs);
+ cond_err = pthread_cond_timedwait(&uhid_output_cond, &uhid_output_mtx, &time_to_wait);
+
+ ASSERT_OK(err) TH_LOG("error while calling bpf_prog_test_run_opts");
+ ASSERT_OK(cond_err) TH_LOG("error while calling waiting for the condition");
+
+ ASSERT_EQ(args.retval, 3);
+
+ ASSERT_EQ(output_report[0], 1);
+ ASSERT_EQ(output_report[1], 2);
+ ASSERT_EQ(output_report[2], 42);
+
+ pthread_mutex_unlock(&uhid_output_mtx);
+}
+
/*
* Attach hid_user_raw_request to the given uhid device,
* call the bpf program from userspace
diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c
index 1e558826b809..2c2b679a83b1 100644
--- a/tools/testing/selftests/hid/progs/hid.c
+++ b/tools/testing/selftests/hid/progs/hid.c
@@ -101,6 +101,30 @@ int hid_user_raw_request(struct hid_hw_request_syscall_args *args)
return 0;
}

+SEC("syscall")
+int hid_user_output_report(struct hid_hw_request_syscall_args *args)
+{
+ struct hid_bpf_ctx *ctx;
+ const size_t size = args->size;
+ int i, ret = 0;
+
+ if (size > sizeof(args->data))
+ return -7; /* -E2BIG */
+
+ ctx = hid_bpf_allocate_context(args->hid);
+ if (!ctx)
+ return -1; /* EPERM check */
+
+ ret = hid_bpf_hw_output_report(ctx,
+ args->data,
+ size);
+ args->retval = ret;
+
+ hid_bpf_release_context(ctx);
+
+ return 0;
+}
+
static const __u8 rdesc[] = {
0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */
0x09, 0x32, /* USAGE (Z) */
diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
index 65e657ac1198..50c6a0d5765e 100644
--- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
+++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
@@ -94,5 +94,7 @@ extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
size_t buf__sz,
enum hid_report_type type,
enum hid_class_request reqtype) __ksym;
+extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
+ __u8 *buf, size_t buf__sz) __ksym;

#endif /* __HID_BPF_HELPERS_H */

--
2.43.0