[PATCH bpf-next v2 27/28] selftests/bpf: Add a test for BPF_F_INSERT_HEAD

Benjamin Tissoires
2022-03-04T17:36:16Z

Insert 3 programs to check that we are doing the correct thing:
'2', '1', '3' are inserted, but '1' is supposed to be executed first.

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

---

new in v2
---
tools/testing/selftests/bpf/prog_tests/hid.c | 90 ++++++++++++++++++--
tools/testing/selftests/bpf/progs/hid.c | 36 ++++++++
2 files changed, 121 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/hid.c b/tools/testing/selftests/bpf/prog_tests/hid.c
index a2bab6a799a1..f7fec748a0b9 100644
--- a/tools/testing/selftests/bpf/prog_tests/hid.c
+++ b/tools/testing/selftests/bpf/prog_tests/hid.c
@@ -353,7 +353,7 @@ static int test_hid_raw_event(struct hid *hid_skel, int uhid_fd, int sysfs_fd)

/* attach the first program */
hid_skel->links.hid_first_event =
- bpf_program__attach_hid(hid_skel->progs.hid_first_event, sysfs_fd);
+ bpf_program__attach_hid(hid_skel->progs.hid_first_event, sysfs_fd, 0);
if (!ASSERT_OK_PTR(hid_skel->links.hid_first_event,
"attach_hid(hid_first_event)"))
return PTR_ERR(hid_skel->links.hid_first_event);
@@ -429,7 +429,7 @@ static int test_hid_set_get_data(struct hid *hid_skel, int uhid_fd, int sysfs_fd

/* attach hid_set_get_data program */
hid_skel->links.hid_set_get_data =
- bpf_program__attach_hid(hid_skel->progs.hid_set_get_data, sysfs_fd);
+ bpf_program__attach_hid(hid_skel->progs.hid_set_get_data, sysfs_fd, 0);
if (!ASSERT_OK_PTR(hid_skel->links.hid_set_get_data,
"attach_hid(hid_set_get_data)"))
return PTR_ERR(hid_skel->links.hid_set_get_data);
@@ -498,7 +498,7 @@ static int test_hid_user_call(struct hid *hid_skel, int uhid_fd, int sysfs_fd)
);

/* attach hid_user program */
- hid_skel->links.hid_user = bpf_program__attach_hid(hid_skel->progs.hid_user, sysfs_fd);
+ hid_skel->links.hid_user = bpf_program__attach_hid(hid_skel->progs.hid_user, sysfs_fd, 0);
if (!ASSERT_OK_PTR(hid_skel->links.hid_user,
"attach_hid(hid_user)"))
return PTR_ERR(hid_skel->links.hid_user);
@@ -552,7 +552,7 @@ static int test_hid_user_raw_request_call(struct hid *hid_skel, int uhid_fd, int

/* attach hid_user_raw_request program */
hid_skel->links.hid_user_raw_request =
- bpf_program__attach_hid(hid_skel->progs.hid_user_raw_request, sysfs_fd);
+ bpf_program__attach_hid(hid_skel->progs.hid_user_raw_request, sysfs_fd, 0);
if (!ASSERT_OK_PTR(hid_skel->links.hid_user_raw_request,
"attach_hid(hid_user_raw_request)"))
return PTR_ERR(hid_skel->links.hid_user_raw_request);
@@ -582,6 +582,83 @@ static int test_hid_user_raw_request_call(struct hid *hid_skel, int uhid_fd, int
return ret;
}

+/*
+ * Attach hid_insert{0,1,2} to the given uhid device,
+ * retrieve and open the matching hidraw node,
+ * inject one event in the uhid device,
+ * check that the programs have been inserted in the correct order.
+ */
+static int test_hid_attach_flags(struct hid *hid_skel, int uhid_fd, int sysfs_fd)
+{
+ int err, hidraw_ino, hidraw_fd = -1;
+ char hidraw_path[64] = {0};
+ u8 buf[10] = {0};
+ int ret = -1;
+
+ /* attach hid_test_insert2 program */
+ hid_skel->links.hid_test_insert2 =
+ bpf_program__attach_hid(hid_skel->progs.hid_test_insert2, sysfs_fd, 0);
+ if (!ASSERT_OK_PTR(hid_skel->links.hid_test_insert2,
+ "attach_hid(hid_test_insert2)"))
+ return PTR_ERR(hid_skel->links.hid_test_insert2);
+
+ /* then attach hid_test_insert1 program before the previous*/
+ hid_skel->links.hid_test_insert1 =
+ bpf_program__attach_hid(hid_skel->progs.hid_test_insert1,
+ sysfs_fd,
+ BPF_F_INSERT_HEAD);
+ if (!ASSERT_OK_PTR(hid_skel->links.hid_test_insert1,
+ "attach_hid(hid_test_insert1)"))
+ return PTR_ERR(hid_skel->links.hid_test_insert1);
+
+ /* finally attach hid_test_insert3 at the end */
+ hid_skel->links.hid_test_insert3 =
+ bpf_program__attach_hid(hid_skel->progs.hid_test_insert3, sysfs_fd, 0);
+ if (!ASSERT_OK_PTR(hid_skel->links.hid_test_insert3,
+ "attach_hid(hid_test_insert3)"))
+ return PTR_ERR(hid_skel->links.hid_test_insert3);
+
+ hidraw_ino = get_hidraw(hid_skel->links.hid_test_insert1);
+ if (!ASSERT_GE(hidraw_ino, 0, "get_hidraw"))
+ goto cleanup;
+
+ /* open hidraw node to check the other side of the pipe */
+ sprintf(hidraw_path, "/dev/hidraw%d", hidraw_ino);
+ hidraw_fd = open(hidraw_path, O_RDWR | O_NONBLOCK);
+
+ if (!ASSERT_GE(hidraw_fd, 0, "open_hidraw"))
+ goto cleanup;
+
+ /* inject one event */
+ buf[0] = 1;
+ 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"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[1], 1, "hid_test_insert1"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[2], 2, "hid_test_insert2"))
+ goto cleanup;
+
+ if (!ASSERT_EQ(buf[3], 3, "hid_test_insert3"))
+ goto cleanup;
+
+ ret = 0;
+
+cleanup:
+ if (hidraw_fd >= 0)
+ close(hidraw_fd);
+
+ hid__detach(hid_skel);
+
+ return ret;
+}
+
/*
* Attach hid_rdesc_fixup to the given uhid device,
* retrieve and open the matching hidraw node,
@@ -598,7 +675,7 @@ static int test_rdesc_fixup(struct hid *hid_skel, int uhid_fd, int sysfs_fd)

/* attach the program */
hid_skel->links.hid_rdesc_fixup =
- bpf_program__attach_hid(hid_skel->progs.hid_rdesc_fixup, sysfs_fd);
+ bpf_program__attach_hid(hid_skel->progs.hid_rdesc_fixup, sysfs_fd, 0);
if (!ASSERT_OK_PTR(hid_skel->links.hid_rdesc_fixup,
"attach_hid(hid_rdesc_fixup)"))
return PTR_ERR(hid_skel->links.hid_rdesc_fixup);
@@ -695,6 +772,9 @@ void serial_test_hid_bpf(void)
err = test_hid_user_raw_request_call(hid_skel, uhid_fd, sysfs_fd);
ASSERT_OK(err, "hid_user_raw_request");

+ err = test_hid_attach_flags(hid_skel, uhid_fd, sysfs_fd);
+ ASSERT_OK(err, "hid_user_raw_request");
+
err = test_rdesc_fixup(hid_skel, uhid_fd, sysfs_fd);
ASSERT_OK(err, "hid_rdesc_fixup");

diff --git a/tools/testing/selftests/bpf/progs/hid.c b/tools/testing/selftests/bpf/progs/hid.c
index ea011ff9e752..40161aa8cb6e 100644
--- a/tools/testing/selftests/bpf/progs/hid.c
+++ b/tools/testing/selftests/bpf/progs/hid.c
@@ -178,3 +178,39 @@ int hid_user_raw_request(struct hid_bpf_ctx *ctx)

return ret;
}
+
+SEC("hid/device_event")
+int hid_test_insert1(struct hid_bpf_ctx *ctx)
+{
+ /* we need to be run first */
+ if (ctx->data[2] || ctx->data[3])
+ return -1;
+
+ ctx->data[1] = 1;
+
+ return 0;
+}
+
+SEC("hid/device_event")
+int hid_test_insert2(struct hid_bpf_ctx *ctx)
+{
+ /* after insert0 and before insert2 */
+ if (!ctx->data[1] || ctx->data[3])
+ return -1;
+
+ ctx->data[2] = 2;
+
+ return 0;
+}
+
+SEC("hid/device_event")
+int hid_test_insert3(struct hid_bpf_ctx *ctx)
+{
+ /* at the end */
+ if (!ctx->data[1] || !ctx->data[2])
+ return -1;
+
+ ctx->data[3] = 3;
+
+ return 0;
+}
--
2.35.1