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: Jiri Kosina <jkosina@suse.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>

diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 31637b3b8db557d573c4c7dcb86787c302a133c8..36bbad8e0f9f2374dbad2965aa1f9ae603680144 100644 (file)
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -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,

diff --git a/tools/testing/selftests/hid/progs/hid.c b/tools/testing/selftests/hid/progs/hid.c
index f539a7a223cf88ddc20d58e90c76e9138e3f3671..46feeb91d1d5de35b84f01c91b4eb333ae5052d3 100644 (file)
--- a/tools/testing/selftests/hid/progs/hid.c
+++ b/tools/testing/selftests/hid/progs/hid.c
@@ -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,
+};

diff --git a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
index 8014383846d211eecf27977f6579e49e65e1b699..c72e44321764c9251b4ded6783c6cf6c72c3b7ea 100644 (file)
--- a/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
+++ b/tools/testing/selftests/hid/progs/hid_bpf_helpers.h
@@ -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;