@@ -875,6 +875,89 @@ TEST_F(hid_bpf, test_hid_user_raw_request_call)
ASSERT_EQ(args.data[1], 2);
}
+static __u8 workload_data;
+
+static int handle_event(void *ctx, void *data, size_t data_sz)
+{
+ const __u8 *e = data;
+
+ workload_data = *e;
+
+ return 0;
+}
+
+TEST_F(hid_bpf, test_hid_schedule_work_defer_events_2)
+{
+ 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),
+ );
+ const struct test_program progs[] = {
+ { .name = "hid_defer_bpf_timer" },
+ };
+ struct ring_buffer *rb = NULL;
+ __u8 buf[10] = {0};
+ int prog_fd, err;
+
+ LOAD_PROGRAMS(progs);
+
+ /* Set up ring buffer polling */
+ rb = ring_buffer__new(bpf_map__fd(self->skel->maps.rb), handle_event, NULL, NULL);
+ ASSERT_OK_PTR(rb) TH_LOG("Failed to create ring buffer");
+ ASSERT_EQ(workload_data, 0);
+
+ args.hid = self->hid_id;
+ prog_fd = bpf_program__fd(self->skel->progs.hid_setup_timer);
+
+ err = bpf_prog_test_run_opts(prog_fd, &tattrs);
+
+ ASSERT_OK(err) TH_LOG("error while calling bpf_prog_test_run_opts");
+
+ /* check that there is no data to read from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, -1) TH_LOG("read_hidraw");
+
+ /* inject one event */
+ buf[0] = 1;
+ buf[1] = 47;
+ buf[2] = 50;
+ uhid_send_event(_metadata, self->uhid_fd, buf, 6);
+
+ err = ring_buffer__poll(rb, 100 /* timeout, ms */);
+ ASSERT_EQ(err, 1) TH_LOG("error while calling ring_buffer__poll");
+ ASSERT_EQ(workload_data, 3);
+
+ /* 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], 2);
+ ASSERT_EQ(buf[1], 3);
+ ASSERT_EQ(buf[2], 4) TH_LOG("leftovers_from_previous_test");
+
+ err = ring_buffer__poll(rb, 100 /* timeout, ms */);
+ ASSERT_EQ(err, 1) TH_LOG("error while calling ring_buffer__poll");
+ ASSERT_EQ(workload_data, 4);
+
+ /* 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], 2);
+ ASSERT_EQ(buf[1], 4);
+ ASSERT_EQ(buf[2], 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(self->hidraw_fd, buf, sizeof(buf));
+ ASSERT_EQ(err, -1) TH_LOG("read_hidraw");
+}
+
/*
* Attach hid_insert{0,1,2} to the given uhid device,
* retrieve and open the matching hidraw node,
@@ -250,3 +250,155 @@ int BPF_PROG(hid_test_insert3, struct hid_bpf_ctx *hid_ctx)
return 0;
}
+
+struct test_report {
+ __u8 data[6];
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_QUEUE);
+ __uint(max_entries, 8);
+ __type(value, struct test_report);
+} queue SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+ __uint(max_entries, 8);
+} rb SEC(".maps");
+
+struct elem {
+ struct bpf_timer t;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __uint(max_entries, 1024);
+ __type(key, u32);
+ __type(value, struct elem);
+} timer_map SEC(".maps");
+
+/* callback for timer_map timers */
+
+static int timer_cb1(void *map, int *key, struct bpf_timer *timer)
+{
+ struct hid_bpf_ctx *hid_ctx;
+ struct test_report buf;
+ __u8 *rb_elem;
+ int err;
+ int i, ret = 0;
+
+ /* do not pop the event, it'll be done in hid_offload_test() when
+ * notifying user space, this also allows to retry sending it
+ * if hid_bpf_input_report fails
+ */
+ if (bpf_map_peek_elem(&queue, &buf))
+ return 0;
+
+ hid_ctx = hid_bpf_allocate_context(*key);
+ if (!hid_ctx)
+ return 0; /* EPERM check */
+
+ buf.data[0] = 2;
+
+ /* re-inject the modified event into the HID stack */
+ err = hid_bpf_input_report(hid_ctx, HID_INPUT_REPORT, buf.data, sizeof(buf.data));
+ if (err == -16 /* -EBUSY */) {
+ /*
+ * This happens when we schedule the work with a 0 delay:
+ * the thread immediately starts but the current input
+ * processing hasn't finished yet. So the semaphore is
+ * already taken, and hid_input_report returns -EBUSY
+ */
+ /* schedule another attempt */
+ bpf_timer_start(timer, 0, BPF_F_TIMER_SLEEPABLE);
+
+ goto out;
+ }
+
+ if (bpf_map_pop_elem(&queue, &buf))
+ goto out;
+
+ rb_elem = bpf_ringbuf_reserve(&rb, sizeof(*rb_elem), 0);
+ if (!rb_elem)
+ goto out;
+
+ *rb_elem = buf.data[1];
+
+ bpf_ringbuf_submit(rb_elem, 0);
+
+ /* call ourself once again until there is no more events in the queue */
+ bpf_timer_start(timer, 0, BPF_F_TIMER_SLEEPABLE);
+
+ out:
+ hid_bpf_release_context(hid_ctx);
+ return 0;
+}
+
+#define CLOCK_MONOTONIC 1
+
+SEC("?fmod_ret/hid_bpf_device_event")
+int BPF_PROG(hid_defer_bpf_timer, struct hid_bpf_ctx *hctx)
+{
+ __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4 /* size */);
+ struct test_report buf = {
+ .data = {2, 3, 4, 5, 6, 7},
+ };
+ struct bpf_timer *timer;
+ int key = hctx->hid->id;
+ struct elem init = {};
+
+ if (!data)
+ return 0; /* EPERM check */
+
+ /* Only schedule a delayed work when reportID is 1, otherwise
+ * simply forward it to hidraw
+ */
+ if (data[0] != 1)
+ return 0;
+
+ bpf_map_push_elem(&queue, &buf, BPF_ANY);
+ buf.data[0] = 2;
+ buf.data[1] = 4;
+ buf.data[2] = 6;
+ bpf_map_push_elem(&queue, &buf, BPF_ANY);
+
+ timer = bpf_map_lookup_elem(&timer_map, &key);
+ if (!timer)
+ return 3;
+
+ bpf_timer_set_sleepable_cb(timer, timer_cb1);
+
+ if (bpf_timer_start(timer, 0, BPF_F_TIMER_SLEEPABLE) != 0)
+ return 2;
+
+ return -1; /* discard the event */
+}
+
+SEC("syscall")
+int hid_setup_timer(struct hid_hw_request_syscall_args *args)
+{
+ struct hid_bpf_ctx *ctx;
+ struct bpf_timer *timer;
+ struct elem init = {};
+ int key = args->hid;
+ int i, ret = 0;
+
+ ctx = hid_bpf_allocate_context(args->hid);
+ if (!ctx)
+ return -1; /* EPERM check */
+
+ bpf_map_update_elem(&timer_map, &key, &init, 0);
+
+ timer = bpf_map_lookup_elem(&timer_map, &key);
+ if (!timer) {
+ hid_bpf_release_context(ctx);
+ return 1;
+ }
+
+ bpf_timer_init(timer, &timer_map, CLOCK_MONOTONIC);
+
+ hid_bpf_release_context(ctx);
+
+ return 0;
+}
+
@@ -100,5 +100,7 @@ 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 bpf_timer_set_sleepable_cb(struct bpf_timer *timer,
+ int (callback_fn)(void *map, int *key, struct bpf_timer *timer)) __ksym;
#endif /* __HID_BPF_HELPERS_H */