[PATCH bpf-next v7 14/24] selftests/bpf: add tests for the HID-bpf initial implementation

Benjamin Tissoires
2022-07-21T15:39:44Z

The test is pretty basic:
- create a virtual uhid device that no userspace will like (to not mess
up the running system)
- attach a BPF prog to it
- open the matching hidraw node
- inject one event and check:
* that the BPF program can do something on the event stream
* can modify the event stream
- add another test where we attach/detach BPF programs to see if we get
errors

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

no changes in v7

no changes in v6

changes in v5:
- use of the HID device system id instead of fd
- attach to HID device with the new API
- add attach/detach test

changes in v4:
- manually retrieve the hidraw node from the sysfs (we can't get it for
free from BPF)
- use the new API

changes in v3:
- squashed "hid: rely on uhid event to know if a test device is ready"
into this one
- add selftests bpf VM config changes
- s/hidraw_ino/hidraw_number/

changes in v2:
- split the series by bpf/libbpf/hid/selftests and samples
---
tools/testing/selftests/bpf/config | 3 +
tools/testing/selftests/bpf/prog_tests/hid.c | 669 +++++++++++++++++++
tools/testing/selftests/bpf/progs/hid.c | 45 ++
3 files changed, 717 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/hid.c
create mode 100644 tools/testing/selftests/bpf/progs/hid.c

diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index c69c119f4bb7..0709b68000f0 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -63,3 +63,6 @@ CONFIG_NETFILTER_XT_MATCH_STATE=y
CONFIG_IP_NF_FILTER=y
CONFIG_IP_NF_TARGET_SYNPROXY=y
CONFIG_IP_NF_RAW=y
+CONFIG_HID=y
+CONFIG_HIDRAW=y
+CONFIG_UHID=y
diff --git a/tools/testing/selftests/bpf/prog_tests/hid.c b/tools/testing/selftests/bpf/prog_tests/hid.c
new file mode 100644
index 000000000000..719d220c8d86
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/hid.c
@@ -0,0 +1,669 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Red Hat */
+#include <test_progs.h>
+#include <testing_helpers.h>
+#include "hid.skel.h"
+
+#include <fcntl.h>
+#include <fnmatch.h>
+#include <dirent.h>
+#include <poll.h>
+#include <stdbool.h>
+#include <linux/uhid.h>
+
+static unsigned char rdesc[] = {
+ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
+ 0x09, 0x21, /* Usage (Vendor Usage 0x21) */
+ 0xa1, 0x01, /* COLLECTION (Application) */
+ 0x09, 0x01, /* Usage (Vendor Usage 0x01) */
+ 0xa1, 0x00, /* COLLECTION (Physical) */
+ 0x85, 0x01, /* REPORT_ID (1) */
+ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
+ 0x19, 0x01, /* USAGE_MINIMUM (1) */
+ 0x29, 0x03, /* USAGE_MAXIMUM (3) */
+ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */
+ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */
+ 0x95, 0x03, /* REPORT_COUNT (3) */
+ 0x75, 0x01, /* REPORT_SIZE (1) */
+ 0x81, 0x02, /* INPUT (Data,Var,Abs) */
+ 0x95, 0x01, /* REPORT_COUNT (1) */
+ 0x75, 0x05, /* REPORT_SIZE (5) */
+ 0x81, 0x01, /* INPUT (Cnst,Var,Abs) */
+ 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */
+ 0x09, 0x30, /* USAGE (X) */
+ 0x09, 0x31, /* USAGE (Y) */
+ 0x15, 0x81, /* LOGICAL_MINIMUM (-127) */
+ 0x25, 0x7f, /* LOGICAL_MAXIMUM (127) */
+ 0x75, 0x10, /* REPORT_SIZE (16) */
+ 0x95, 0x02, /* REPORT_COUNT (2) */
+ 0x81, 0x06, /* INPUT (Data,Var,Rel) */
+
+ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
+ 0x19, 0x01, /* USAGE_MINIMUM (1) */
+ 0x29, 0x03, /* USAGE_MAXIMUM (3) */
+ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */
+ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */
+ 0x95, 0x03, /* REPORT_COUNT (3) */
+ 0x75, 0x01, /* REPORT_SIZE (1) */
+ 0x91, 0x02, /* Output (Data,Var,Abs) */
+ 0x95, 0x01, /* REPORT_COUNT (1) */
+ 0x75, 0x05, /* REPORT_SIZE (5) */
+ 0x91, 0x01, /* Output (Cnst,Var,Abs) */
+
+ 0x06, 0x00, 0xff, /* Usage Page (Vendor Defined Page 1) */
+ 0x19, 0x06, /* USAGE_MINIMUM (6) */
+ 0x29, 0x08, /* USAGE_MAXIMUM (8) */
+ 0x15, 0x00, /* LOGICAL_MINIMUM (0) */
+ 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */
+ 0x95, 0x03, /* REPORT_COUNT (3) */
+ 0x75, 0x01, /* REPORT_SIZE (1) */
+ 0xb1, 0x02, /* Feature (Data,Var,Abs) */
+ 0x95, 0x01, /* REPORT_COUNT (1) */
+ 0x75, 0x05, /* REPORT_SIZE (5) */
+ 0x91, 0x01, /* Output (Cnst,Var,Abs) */
+
+ 0xc0, /* END_COLLECTION */
+ 0xc0, /* END_COLLECTION */
+};
+
+struct attach_prog_args {
+ int prog_fd;
+ unsigned int hid;
+ int retval;
+};
+
+static pthread_mutex_t uhid_started_mtx = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t uhid_started = PTHREAD_COND_INITIALIZER;
+
+/* no need to protect uhid_stopped, only one thread accesses it */
+static bool uhid_stopped;
+
+static int uhid_write(int fd, const struct uhid_event *ev)
+{
+ ssize_t ret;
+
+ ret = write(fd, ev, sizeof(*ev));
+ if (ret < 0) {
+ fprintf(stderr, "Cannot write to uhid: %m\n");
+ return -errno;
+ } else if (ret != sizeof(*ev)) {
+ fprintf(stderr, "Wrong size written to uhid: %zd != %zu\n",
+ ret, sizeof(ev));
+ return -EFAULT;
+ } else {
+ return 0;
+ }
+}
+
+static int create(int fd, int rand_nb)
+{
+ struct uhid_event ev;
+ char buf[25];
+
+ sprintf(buf, "test-uhid-device-%d", rand_nb);
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_CREATE;
+ strcpy((char *)ev.u.create.name, buf);
+ ev.u.create.rd_data = rdesc;
+ ev.u.create.rd_size = sizeof(rdesc);
+ ev.u.create.bus = BUS_USB;
+ ev.u.create.vendor = 0x0001;
+ ev.u.create.product = 0x0a37;
+ ev.u.create.version = 0;
+ ev.u.create.country = 0;
+
+ sprintf(buf, "%d", rand_nb);
+ strcpy((char *)ev.u.create.phys, buf);
+
+ return uhid_write(fd, &ev);
+}
+
+static void destroy(int fd)
+{
+ struct uhid_event ev;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_DESTROY;
+
+ uhid_write(fd, &ev);
+}
+
+static int uhid_event(int fd)
+{
+ struct uhid_event ev;
+ ssize_t ret;
+
+ memset(&ev, 0, sizeof(ev));
+ ret = read(fd, &ev, sizeof(ev));
+ if (ret == 0) {
+ fprintf(stderr, "Read HUP on uhid-cdev\n");
+ return -EFAULT;
+ } else if (ret < 0) {
+ fprintf(stderr, "Cannot read uhid-cdev: %m\n");
+ return -errno;
+ } else if (ret != sizeof(ev)) {
+ fprintf(stderr, "Invalid size read from uhid-dev: %zd != %zu\n",
+ ret, sizeof(ev));
+ return -EFAULT;
+ }
+
+ switch (ev.type) {
+ case UHID_START:
+ pthread_mutex_lock(&uhid_started_mtx);
+ pthread_cond_signal(&uhid_started);
+ pthread_mutex_unlock(&uhid_started_mtx);
+
+ fprintf(stderr, "UHID_START from uhid-dev\n");
+ break;
+ case UHID_STOP:
+ uhid_stopped = true;
+
+ fprintf(stderr, "UHID_STOP from uhid-dev\n");
+ break;
+ case UHID_OPEN:
+ fprintf(stderr, "UHID_OPEN from uhid-dev\n");
+ break;
+ case UHID_CLOSE:
+ fprintf(stderr, "UHID_CLOSE from uhid-dev\n");
+ break;
+ case UHID_OUTPUT:
+ fprintf(stderr, "UHID_OUTPUT from uhid-dev\n");
+ break;
+ case UHID_GET_REPORT:
+ fprintf(stderr, "UHID_GET_REPORT from uhid-dev\n");
+ break;
+ case UHID_SET_REPORT:
+ fprintf(stderr, "UHID_SET_REPORT from uhid-dev\n");
+ break;
+ default:
+ fprintf(stderr, "Invalid event from uhid-dev: %u\n", ev.type);
+ }
+
+ return 0;
+}
+
+static void *read_uhid_events_thread(void *arg)
+{
+ int fd = *(int *)arg;
+ struct pollfd pfds[1];
+ int ret = 0;
+
+ pfds[0].fd = fd;
+ pfds[0].events = POLLIN;
+
+ uhid_stopped = false;
+
+ while (!uhid_stopped) {
+ ret = poll(pfds, 1, 100);
+ if (ret < 0) {
+ fprintf(stderr, "Cannot poll for fds: %m\n");
+ break;
+ }
+ if (pfds[0].revents & POLLIN) {
+ ret = uhid_event(fd);
+ if (ret)
+ break;
+ }
+ }
+
+ return (void *)(long)ret;
+}
+
+static int uhid_start_listener(pthread_t *tid, int uhid_fd)
+{
+ int fd = uhid_fd;
+
+ pthread_mutex_lock(&uhid_started_mtx);
+ if (CHECK_FAIL(pthread_create(tid, NULL, read_uhid_events_thread,
+ (void *)&fd))) {
+ pthread_mutex_unlock(&uhid_started_mtx);
+ close(fd);
+ return -EIO;
+ }
+ pthread_cond_wait(&uhid_started, &uhid_started_mtx);
+ pthread_mutex_unlock(&uhid_started_mtx);
+
+ return 0;
+}
+
+static int send_event(int fd, u8 *buf, size_t size)
+{
+ struct uhid_event ev;
+
+ if (size > sizeof(ev.u.input.data))
+ return -E2BIG;
+
+ memset(&ev, 0, sizeof(ev));
+ ev.type = UHID_INPUT2;
+ ev.u.input2.size = size;
+
+ memcpy(ev.u.input2.data, buf, size);
+
+ return uhid_write(fd, &ev);
+}
+
+static int setup_uhid(int rand_nb)
+{
+ int fd;
+ const char *path = "/dev/uhid";
+ int ret;
+
+ fd = open(path, O_RDWR | O_CLOEXEC);
+ if (!ASSERT_GE(fd, 0, "open uhid-cdev"))
+ return -EPERM;
+
+ ret = create(fd, rand_nb);
+ if (!ASSERT_OK(ret, "create uhid device")) {
+ close(fd);
+ return -EPERM;
+ }
+
+ return fd;
+}
+
+static bool match_sysfs_device(int dev_id, const char *workdir, struct dirent *dir)
+{
+ const char *target = "0003:0001:0A37.*";
+ char phys[512];
+ char uevent[1024];
+ char temp[512];
+ int fd, nread;
+ bool found = false;
+
+ if (fnmatch(target, dir->d_name, 0))
+ return false;
+
+ /* we found the correct VID/PID, now check for phys */
+ sprintf(uevent, "%s/%s/uevent", workdir, dir->d_name);
+
+ fd = open(uevent, O_RDONLY | O_NONBLOCK);
+ if (fd < 0)
+ return false;
+
+ sprintf(phys, "PHYS=%d", dev_id);
+
+ nread = read(fd, temp, ARRAY_SIZE(temp));
+ if (nread > 0 && (strstr(temp, phys)) != NULL)
+ found = true;
+
+ close(fd);
+
+ return found;
+}
+
+static int get_hid_id(int dev_id)
+{
+ const char *workdir = "/sys/devices/virtual/misc/uhid";
+ const char *str_id;
+ DIR *d;
+ struct dirent *dir;
+ int found = -1;
+
+ /* it would be nice to be able to use nftw, but the no_alu32 target doesn't support it */
+
+ d = opendir(workdir);
+ if (d) {
+ while ((dir = readdir(d)) != NULL) {
+ if (!match_sysfs_device(dev_id, workdir, dir))
+ continue;
+
+ str_id = dir->d_name + sizeof("0003:0001:0A37.");
+ found = (int)strtol(str_id, NULL, 16);
+
+ break;
+ }
+ closedir(d);
+ }
+
+ return found;
+}
+
+static int get_hidraw(int dev_id)
+{
+ const char *workdir = "/sys/devices/virtual/misc/uhid";
+ char sysfs[1024];
+ DIR *d, *subd;
+ struct dirent *dir, *subdir;
+ int i, found = -1;
+
+ /* retry 5 times in case the system is loaded */
+ for (i = 5; i > 0; i--) {
+ usleep(10);
+ d = opendir(workdir);
+
+ if (!d)
+ continue;
+
+ while ((dir = readdir(d)) != NULL) {
+ if (!match_sysfs_device(dev_id, workdir, dir))
+ continue;
+
+ sprintf(sysfs, "%s/%s/hidraw", workdir, dir->d_name);
+
+ subd = opendir(sysfs);
+ if (!subd)
+ continue;
+
+ while ((subdir = readdir(subd)) != NULL) {
+ if (fnmatch("hidraw*", subdir->d_name, 0))
+ continue;
+
+ found = atoi(subdir->d_name + strlen("hidraw"));
+ }
+
+ closedir(subd);
+
+ if (found > 0)
+ break;
+ }
+ closedir(d);
+ }
+
+ return found;
+}
+
+static int open_hidraw(int dev_id)
+{
+ int hidraw_number;
+ char hidraw_path[64] = { 0 };
+
+ hidraw_number = get_hidraw(dev_id);
+ if (hidraw_number < 0)
+ return hidraw_number;
+
+ /* open hidraw node to check the other side of the pipe */
+ sprintf(hidraw_path, "/dev/hidraw%d", hidraw_number);
+ return open(hidraw_path, O_RDWR | O_NONBLOCK);
+}
+
+struct test_params {
+ struct hid *skel;
+ int hidraw_fd;
+};
+
+static int prep_test(int dev_id, const char *prog_name, struct test_params *test_data)
+{
+ struct hid *hid_skel = NULL;
+ struct bpf_program *prog = NULL;
+ char buf[64] = {0};
+ int hidraw_fd = -1;
+ int hid_id, attach_fd, err = -EINVAL;
+ struct attach_prog_args args = {
+ .retval = -1,
+ };
+ DECLARE_LIBBPF_OPTS(bpf_test_run_opts, tattr,
+ .ctx_in = &args,
+ .ctx_size_in = sizeof(args),
+ );
+
+ /* locate the uevent file of the created device */
+ hid_id = get_hid_id(dev_id);
+ if (!ASSERT_GE(hid_id, 0, "locate uhid device id"))
+ goto cleanup;
+
+ args.hid = hid_id;
+
+ hid_skel = hid__open();
+ if (!ASSERT_OK_PTR(hid_skel, "hid_skel_open"))
+ goto cleanup;
+
+ prog = bpf_object__find_program_by_name(*hid_skel->skeleton->obj, prog_name);
+ if (!ASSERT_OK_PTR(prog, "find_prog_by_name"))
+ goto cleanup;
+
+ bpf_program__set_autoload(prog, true);
+
+ err = hid__load(hid_skel);
+ if (!ASSERT_OK(err, "hid_skel_load"))
+ goto cleanup;
+
+ attach_fd = bpf_program__fd(hid_skel->progs.attach_prog);
+ if (!ASSERT_GE(attach_fd, 0, "locate attach_prog")) {
+ err = attach_fd;
+ goto cleanup;
+ }
+
+ args.prog_fd = bpf_program__fd(prog);
+ err = bpf_prog_test_run_opts(attach_fd, &tattr);
+ snprintf(buf, sizeof(buf), "attach_hid(%s)", prog_name);
+ if (!ASSERT_EQ(args.retval, 0, buf))
+ goto cleanup;
+
+ hidraw_fd = open_hidraw(dev_id);
+ if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw"))
+ goto cleanup;
+
+ test_data->skel = hid_skel;
+ test_data->hidraw_fd = hidraw_fd;
+
+ return 0;
+
+ cleanup:
+ if (hidraw_fd >= 0)
+ close(hidraw_fd);
+
+ hid__destroy(hid_skel);
+
+ memset(test_data, 0, sizeof(*test_data));
+
+ return err;
+}
+
+static void cleanup_test(struct test_params *test_data)
+{
+ if (!test_data)
+ return;
+
+ if (test_data->hidraw_fd)
+ close(test_data->hidraw_fd);
+
+ hid__destroy(test_data->skel);
+
+ memset(test_data, 0, sizeof(*test_data));
+}
+
+/*
+ * Attach hid_first_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 change the data
+ */
+static int test_hid_raw_event(int uhid_fd, int dev_id)
+{
+ struct hid *hid_skel = NULL;
+ struct test_params params;
+ int err, hidraw_fd = -1;
+ u8 buf[10] = {0};
+ int ret = -1;
+
+ err = prep_test(dev_id, "hid_first_event", &params);
+ if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)"))
+ goto cleanup;
+
+ hid_skel = params.skel;
+ hidraw_fd = params.hidraw_fd;
+
+ /* check that the program is correctly loaded */
+ ASSERT_EQ(hid_skel->data->callback_check, 52, "callback_check1");
+ ASSERT_EQ(hid_skel->data->callback2_check, 52, "callback2_check1");
+
+ /* inject one event */
+ buf[0] = 1;
+ buf[1] = 42;
+ send_event(uhid_fd, buf, 6);
+
+ /* check that hid_first_event() was executed */
+ ASSERT_EQ(hid_skel->data->callback_check, 42, "callback_check1");
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[0], 1, "hid_first_event"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 47, "hid_first_event"))
+ goto cleanup;
+
+ /* inject another event */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = 1;
+ buf[1] = 47;
+ send_event(uhid_fd, buf, 6);
+
+ /* check that hid_first_event() was executed */
+ ASSERT_EQ(hid_skel->data->callback_check, 47, "callback_check1");
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 52, "hid_first_event"))
+ goto cleanup;
+
+ ret = 0;
+
+cleanup:
+ cleanup_test(&params);
+
+ return ret;
+}
+
+/*
+ * Ensures that we can attach/detach programs
+ */
+static int test_attach_detach(int uhid_fd, int dev_id)
+{
+ struct test_params params;
+ int err, hidraw_fd = -1;
+ u8 buf[10] = {0};
+ int ret = -1;
+
+ err = prep_test(dev_id, "hid_first_event", &params);
+ if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)"))
+ goto cleanup;
+
+ /* inject one event */
+ buf[0] = 1;
+ buf[1] = 42;
+ send_event(uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(params.hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw_with_bpf"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[0], 1, "hid_first_event"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 47, "hid_first_event"))
+ goto cleanup;
+
+ /* pin the program and immediately unpin it */
+#define PIN_PATH "/sys/fs/bpf/hid_first_event"
+ bpf_program__pin(params.skel->progs.hid_first_event, PIN_PATH);
+ remove(PIN_PATH);
+#undef PIN_PATH
+ usleep(100000);
+
+ /* detach the program */
+ cleanup_test(&params);
+
+ hidraw_fd = open_hidraw(dev_id);
+ if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw"))
+ goto cleanup;
+
+ /* inject another event */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = 1;
+ buf[1] = 47;
+ send_event(uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw_no_bpf"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[0], 1, "event_no_bpf"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[1], 47, "event_no_bpf"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 0, "event_no_bpf"))
+ goto cleanup;
+
+ /* re-attach our program */
+
+ err = prep_test(dev_id, "hid_first_event", &params);
+ if (!ASSERT_EQ(err, 0, "prep_test(hid_first_event)"))
+ goto cleanup;
+
+ /* inject one event */
+ memset(buf, 0, sizeof(buf));
+ buf[0] = 1;
+ buf[1] = 42;
+ send_event(uhid_fd, buf, 6);
+
+ /* read the data from hidraw */
+ memset(buf, 0, sizeof(buf));
+ err = read(params.hidraw_fd, buf, sizeof(buf));
+ if (!ASSERT_EQ(err, 6, "read_hidraw"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[0], 1, "hid_first_event"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 47, "hid_first_event"))
+ goto cleanup;
+
+ ret = 0;
+
+cleanup:
+ if (hidraw_fd >= 0)
+ close(hidraw_fd);
+
+ cleanup_test(&params);
+
+ return ret;
+}
+
+void serial_test_hid_bpf(void)
+{
+ int err, uhid_fd;
+ void *uhid_err;
+ time_t t;
+ pthread_t tid;
+ int dev_id;
+
+ /* initialize random number generator */
+ srand((unsigned int)time(&t));
+
+ dev_id = rand() % 1024;
+
+ uhid_fd = setup_uhid(dev_id);
+ if (!ASSERT_GE(uhid_fd, 0, "setup uhid"))
+ return;
+
+ err = uhid_start_listener(&tid, uhid_fd);
+ ASSERT_OK(err, "uhid_start_listener");
+
+ /* start the tests! */
+ err = test_hid_raw_event(uhid_fd, dev_id);
+ ASSERT_OK(err, "hid");
+ err = test_attach_detach(uhid_fd, dev_id);
+ ASSERT_OK(err, "hid_attach_detach");
+
+ destroy(uhid_fd);
+
+ pthread_join(tid, &uhid_err);
+ err = (int)(long)uhid_err;
+ CHECK_FAIL(err);
+}
diff --git a/tools/testing/selftests/bpf/progs/hid.c b/tools/testing/selftests/bpf/progs/hid.c
new file mode 100644
index 000000000000..fc0a4241643a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/hid.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Red hat */
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+char _license[] SEC("license") = "GPL";
+
+extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
+ unsigned int offset,
+ const size_t __sz) __ksym;
+extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym;
+
+struct attach_prog_args {
+ int prog_fd;
+ unsigned int hid;
+ int retval;
+};
+
+__u64 callback_check = 52;
+__u64 callback2_check = 52;
+
+SEC("?fmod_ret/hid_bpf_device_event")
+int BPF_PROG(hid_first_event, struct hid_bpf_ctx *hid_ctx)
+{
+ __u8 *rw_data = hid_bpf_get_data(hid_ctx, 0 /* offset */, 3 /* size */);
+
+ if (!rw_data)
+ return 0; /* EPERM check */
+
+ callback_check = rw_data[1];
+
+ rw_data[2] = rw_data[1] + 5;
+
+ return 0;
+}
+
+SEC("syscall")
+int attach_prog(struct attach_prog_args *ctx)
+{
+ ctx->retval = hid_bpf_attach_prog(ctx->hid,
+ ctx->prog_fd,
+ 0);
+ return 0;
+}
--
2.36.1