aboutsummaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/bpf/prog_tests/tailcalls.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/tailcalls.c')
-rw-r--r--tools/testing/selftests/bpf/prog_tests/tailcalls.c487
1 files changed, 487 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
new file mode 100644
index 000000000000..bb8fe646dd9f
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <test_progs.h>
+
+/* test_tailcall_1 checks basic functionality by patching multiple locations
+ * in a single program for a single tail call slot with nop->jmp, jmp->nop
+ * and jmp->jmp rewrites. Also checks for nop->nop.
+ */
+static void test_tailcall_1(void)
+{
+ int err, map_fd, prog_fd, main_fd, i, j;
+ struct bpf_map *prog_array;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ __u32 retval, duration;
+ char prog_name[32];
+ char buff[128] = {};
+
+ err = bpf_prog_load("tailcall1.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(main_fd < 0))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (CHECK_FAIL(!prog_array))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (CHECK_FAIL(map_fd < 0))
+ goto out;
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != i, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ j = bpf_map__def(prog_array)->max_entries - 1 - i;
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", j);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ j = bpf_map__def(prog_array)->max_entries - 1 - i;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != j, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err >= 0 || errno != ENOENT))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+ }
+
+out:
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_2 checks that patching multiple programs for a single
+ * tail call slot works. It also jumps through several programs and tests
+ * the tail call limit counter.
+ */
+static void test_tailcall_2(void)
+{
+ int err, map_fd, prog_fd, main_fd, i;
+ struct bpf_map *prog_array;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ __u32 retval, duration;
+ char prog_name[32];
+ char buff[128] = {};
+
+ err = bpf_prog_load("tailcall2.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(main_fd < 0))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (CHECK_FAIL(!prog_array))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (CHECK_FAIL(map_fd < 0))
+ goto out;
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 2, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ i = 2;
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ i = 0;
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+out:
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_3 checks that the count value of the tail call limit
+ * enforcement matches with expectations.
+ */
+static void test_tailcall_3(void)
+{
+ int err, map_fd, prog_fd, main_fd, data_fd, i, val;
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ __u32 retval, duration;
+ char buff[128] = {};
+
+ err = bpf_prog_load("tailcall3.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(main_fd < 0))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (CHECK_FAIL(!prog_array))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (CHECK_FAIL(map_fd < 0))
+ goto out;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier/0");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ i = 0;
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 1, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+
+ data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
+ if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
+ return;
+
+ data_fd = bpf_map__fd(data_map);
+ if (CHECK_FAIL(map_fd < 0))
+ return;
+
+ i = 0;
+ err = bpf_map_lookup_elem(data_fd, &i, &val);
+ CHECK(err || val != 33, "tailcall count", "err %d errno %d count %d\n",
+ err, errno, val);
+
+ i = 0;
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n",
+ err, errno, retval);
+out:
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_4 checks that the kernel properly selects indirect jump
+ * for the case where the key is not known. Latter is passed via global
+ * data to select different targets we can compare return value of.
+ */
+static void test_tailcall_4(void)
+{
+ int err, map_fd, prog_fd, main_fd, data_fd, i;
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ __u32 retval, duration;
+ static const int zero = 0;
+ char buff[128] = {};
+ char prog_name[32];
+
+ err = bpf_prog_load("tailcall4.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(main_fd < 0))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (CHECK_FAIL(!prog_array))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (CHECK_FAIL(map_fd < 0))
+ goto out;
+
+ data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
+ if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
+ return;
+
+ data_fd = bpf_map__fd(data_map);
+ if (CHECK_FAIL(map_fd < 0))
+ return;
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != i, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+ }
+out:
+ bpf_object__close(obj);
+}
+
+/* test_tailcall_5 probes similarly to test_tailcall_4 that the kernel generates
+ * an indirect jump when the keys are const but different from different branches.
+ */
+static void test_tailcall_5(void)
+{
+ int err, map_fd, prog_fd, main_fd, data_fd, i, key[] = { 1111, 1234, 5678 };
+ struct bpf_map *prog_array, *data_map;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ __u32 retval, duration;
+ static const int zero = 0;
+ char buff[128] = {};
+ char prog_name[32];
+
+ err = bpf_prog_load("tailcall5.o", BPF_PROG_TYPE_SCHED_CLS, &obj,
+ &prog_fd);
+ if (CHECK_FAIL(err))
+ return;
+
+ prog = bpf_object__find_program_by_title(obj, "classifier");
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ main_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(main_fd < 0))
+ goto out;
+
+ prog_array = bpf_object__find_map_by_name(obj, "jmp_table");
+ if (CHECK_FAIL(!prog_array))
+ goto out;
+
+ map_fd = bpf_map__fd(prog_array);
+ if (CHECK_FAIL(map_fd < 0))
+ goto out;
+
+ data_map = bpf_object__find_map_by_name(obj, "tailcall.bss");
+ if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map)))
+ return;
+
+ data_fd = bpf_map__fd(data_map);
+ if (CHECK_FAIL(map_fd < 0))
+ return;
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ snprintf(prog_name, sizeof(prog_name), "classifier/%i", i);
+
+ prog = bpf_object__find_program_by_title(obj, prog_name);
+ if (CHECK_FAIL(!prog))
+ goto out;
+
+ prog_fd = bpf_program__fd(prog);
+ if (CHECK_FAIL(prog_fd < 0))
+ goto out;
+
+ err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != i, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+ }
+
+ for (i = 0; i < bpf_map__def(prog_array)->max_entries; i++) {
+ err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_map_delete_elem(map_fd, &i);
+ if (CHECK_FAIL(err))
+ goto out;
+
+ err = bpf_prog_test_run(main_fd, 1, buff, sizeof(buff), 0,
+ &duration, &retval, NULL);
+ CHECK(err || retval != 3, "tailcall",
+ "err %d errno %d retval %d\n", err, errno, retval);
+ }
+out:
+ bpf_object__close(obj);
+}
+
+void test_tailcalls(void)
+{
+ if (test__start_subtest("tailcall_1"))
+ test_tailcall_1();
+ if (test__start_subtest("tailcall_2"))
+ test_tailcall_2();
+ if (test__start_subtest("tailcall_3"))
+ test_tailcall_3();
+ if (test__start_subtest("tailcall_4"))
+ test_tailcall_4();
+ if (test__start_subtest("tailcall_5"))
+ test_tailcall_5();
+}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.