selftests: hid: prepare tests for HID_BPF API change

We plan on changing the return value of hid_bpf_attach_prog().
Instead of returning an error code, it will return an fd to a bpf_link.
This bpf_link is responsible for the binding between the bpf program and
the hid device.

Add a fallback mechanism to not break bisections by pinning the program
when we run this test against the non changed kernel.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/tools/testing/selftests/hid/hid_bpf.c b/tools/testing/selftests/hid/hid_bpf.c
index 3b204a15e44be8bed2843624cbed401bbcd6b433..9a262fe99b32b1215cdecd79f2a7af7377a0de4d 100644 (file)
--- a/tools/testing/selftests/hid/hid_bpf.c
+++ b/tools/testing/selftests/hid/hid_bpf.c
@@ -444,13 +444,21 @@ FIXTURE(hid_bpf) {
        int hid_id;
        pthread_t tid;
        struct hid *skel;
+       int hid_links[3]; /* max number of programs loaded in a single test */
 };
 static void detach_bpf(FIXTURE_DATA(hid_bpf) * self)
 {
+       int i;
+
        if (self->hidraw_fd)
                close(self->hidraw_fd);
        self->hidraw_fd = 0;
 
+       for (i = 0; i < ARRAY_SIZE(self->hid_links); i++) {
+               if (self->hid_links[i])
+                       close(self->hid_links[i]);
+       }
+
        hid__destroy(self->skel);
        self->skel = NULL;
 }
@@ -512,6 +520,9 @@ static void load_programs(const struct test_program programs[],
                            .ctx_size_in = sizeof(args),
        );
 
+       ASSERT_LE(progs_count, ARRAY_SIZE(self->hid_links))
+               TH_LOG("too many programs are to be loaded");
+
        /* open the bpf file */
        self->skel = hid__open();
        ASSERT_OK_PTR(self->skel) TEARDOWN_LOG("Error while calling hid__open");
@@ -543,7 +554,10 @@ static void load_programs(const struct test_program programs[],
                args.hid = self->hid_id;
                args.insert_head = programs[i].insert_head;
                err = bpf_prog_test_run_opts(attach_fd, &tattr);
-               ASSERT_OK(args.retval) TH_LOG("attach_hid(%s): %d", programs[i].name, args.retval);
+               ASSERT_GE(args.retval, 0)
+                       TH_LOG("attach_hid(%s): %d", programs[i].name, args.retval);
+
+               self->hid_links[i] = args.retval;
        }
 
        self->hidraw_fd = open_hidraw(self->dev_id);
@@ -619,10 +633,17 @@ TEST_F(hid_bpf, test_attach_detach)
                { .name = "hid_second_event" },
        };
        __u8 buf[10] = {0};
-       int err;
+       int err, link;
 
        LOAD_PROGRAMS(progs);
 
+       link = self->hid_links[0];
+       /* we might not be using the new code path where hid_bpf_attach_prog()
+        * returns a link.
+        */
+       if (!link)
+               link = bpf_program__fd(self->skel->progs.hid_first_event);
+
        /* inject one event */
        buf[0] = 1;
        buf[1] = 42;
@@ -640,8 +661,8 @@ TEST_F(hid_bpf, test_attach_detach)
 
        /* pin the first program and immediately unpin it */
 #define PIN_PATH "/sys/fs/bpf/hid_first_event"
-       err = bpf_program__pin(self->skel->progs.hid_first_event, PIN_PATH);
-       ASSERT_OK(err) TH_LOG("error while calling bpf_program__pin");
+       err = bpf_obj_pin(link, PIN_PATH);
+       ASSERT_OK(err) TH_LOG("error while calling bpf_obj_pin");
        remove(PIN_PATH);
 #undef PIN_PATH
        usleep(100000);