diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/tailcalls.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/tailcalls.c | 913 |
1 files changed, 913 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 000000000..09c189761 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c @@ -0,0 +1,913 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <network_helpers.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; + char prog_name[32]; + char buff[128] = {}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall1.bpf.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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__max_entries(prog_array); i++) { + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, i, "tailcall retval"); + + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + } + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall retval"); + + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_OK(topts.retval, "tailcall retval"); + + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + j = bpf_map__max_entries(prog_array) - 1 - i; + snprintf(prog_name, sizeof(prog_name), "classifier_%d", j); + + prog = bpf_object__find_program_by_name(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__max_entries(prog_array); i++) { + j = bpf_map__max_entries(prog_array) - 1 - i; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, j, "tailcall retval"); + + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + } + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall retval"); + + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err >= 0 || errno != ENOENT)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall 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; + char prog_name[32]; + char buff[128] = {}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall2.bpf.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 2, "tailcall retval"); + + i = 2; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 1, "tailcall retval"); + + i = 0; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall retval"); +out: + bpf_object__close(obj); +} + +static void test_tailcall_count(const char *which) +{ + 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; + char buff[128] = {}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load(which, BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 1, "tailcall retval"); + + data_map = bpf_object__find_map_by_name(obj, "tailcall.bss"); + if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map))) + goto out; + + data_fd = bpf_map__fd(data_map); + if (CHECK_FAIL(data_fd < 0)) + goto out; + + i = 0; + err = bpf_map_lookup_elem(data_fd, &i, &val); + ASSERT_OK(err, "tailcall count"); + ASSERT_EQ(val, 33, "tailcall count"); + + i = 0; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_OK(topts.retval, "tailcall retval"); +out: + bpf_object__close(obj); +} + +/* test_tailcall_3 checks that the count value of the tail call limit + * enforcement matches with expectations. JIT uses direct jump. + */ +static void test_tailcall_3(void) +{ + test_tailcall_count("tailcall3.bpf.o"); +} + +/* test_tailcall_6 checks that the count value of the tail call limit + * enforcement matches with expectations. JIT uses indirect jump. + */ +static void test_tailcall_6(void) +{ + test_tailcall_count("tailcall6.bpf.o"); +} + +/* 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; + static const int zero = 0; + char buff[128] = {}; + char prog_name[32]; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall4.bpf.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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))) + goto out; + + data_fd = bpf_map__fd(data_map); + if (CHECK_FAIL(data_fd < 0)) + goto out; + + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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__max_entries(prog_array); i++) { + err = bpf_map_update_elem(data_fd, &zero, &i, BPF_ANY); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, i, "tailcall retval"); + } + + for (i = 0; i < bpf_map__max_entries(prog_array); 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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall 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; + static const int zero = 0; + char buff[128] = {}; + char prog_name[32]; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall5.bpf.o", BPF_PROG_TYPE_SCHED_CLS, &obj, + &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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))) + goto out; + + data_fd = bpf_map__fd(data_map); + if (CHECK_FAIL(data_fd < 0)) + goto out; + + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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__max_entries(prog_array); i++) { + err = bpf_map_update_elem(data_fd, &zero, &key[i], BPF_ANY); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, i, "tailcall retval"); + } + + for (i = 0; i < bpf_map__max_entries(prog_array); 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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 3, "tailcall retval"); + } +out: + bpf_object__close(obj); +} + +/* test_tailcall_bpf2bpf_1 purpose is to make sure that tailcalls are working + * correctly in correlation with BPF subprograms + */ +static void test_tailcall_bpf2bpf_1(void) +{ + int err, map_fd, prog_fd, main_fd, i; + struct bpf_map *prog_array; + struct bpf_program *prog; + struct bpf_object *obj; + char prog_name[32]; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall_bpf2bpf1.bpf.o", BPF_PROG_TYPE_SCHED_CLS, + &obj, &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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; + + /* nop -> jmp */ + for (i = 0; i < bpf_map__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 1, "tailcall retval"); + + /* jmp -> nop, call subprog that will do tailcall */ + i = 1; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_OK(topts.retval, "tailcall retval"); + + /* make sure that subprog can access ctx and entry prog that + * called this subprog can properly return + */ + i = 0; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, sizeof(pkt_v4) * 2, "tailcall retval"); +out: + bpf_object__close(obj); +} + +/* test_tailcall_bpf2bpf_2 checks that the count value of the tail call limit + * enforcement matches with expectations when tailcall is preceded with + * bpf2bpf call. + */ +static void test_tailcall_bpf2bpf_2(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; + char buff[128] = {}; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = buff, + .data_size_in = sizeof(buff), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall_bpf2bpf2.bpf.o", BPF_PROG_TYPE_SCHED_CLS, + &obj, &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, 1, "tailcall retval"); + + data_map = bpf_object__find_map_by_name(obj, "tailcall.bss"); + if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map))) + goto out; + + data_fd = bpf_map__fd(data_map); + if (CHECK_FAIL(data_fd < 0)) + goto out; + + i = 0; + err = bpf_map_lookup_elem(data_fd, &i, &val); + ASSERT_OK(err, "tailcall count"); + ASSERT_EQ(val, 33, "tailcall count"); + + i = 0; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_OK(topts.retval, "tailcall retval"); +out: + bpf_object__close(obj); +} + +/* test_tailcall_bpf2bpf_3 checks that non-trivial amount of stack (up to + * 256 bytes) can be used within bpf subprograms that have the tailcalls + * in them + */ +static void test_tailcall_bpf2bpf_3(void) +{ + int err, map_fd, prog_fd, main_fd, i; + struct bpf_map *prog_array; + struct bpf_program *prog; + struct bpf_object *obj; + char prog_name[32]; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall_bpf2bpf3.bpf.o", BPF_PROG_TYPE_SCHED_CLS, + &obj, &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, sizeof(pkt_v4) * 3, "tailcall retval"); + + i = 1; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, sizeof(pkt_v4), "tailcall retval"); + + i = 0; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, sizeof(pkt_v4) * 2, "tailcall retval"); +out: + bpf_object__close(obj); +} + +#include "tailcall_bpf2bpf4.skel.h" + +/* test_tailcall_bpf2bpf_4 checks that tailcall counter is correctly preserved + * across tailcalls combined with bpf2bpf calls. for making sure that tailcall + * counter behaves correctly, bpf program will go through following flow: + * + * entry -> entry_subprog -> tailcall0 -> bpf_func0 -> subprog0 -> + * -> tailcall1 -> bpf_func1 -> subprog1 -> tailcall2 -> bpf_func2 -> + * subprog2 [here bump global counter] --------^ + * + * We go through first two tailcalls and start counting from the subprog2 where + * the loop begins. At the end of the test make sure that the global counter is + * equal to 31, because tailcall counter includes the first two tailcalls + * whereas global counter is incremented only on loop presented on flow above. + * + * The noise parameter is used to insert bpf_map_update calls into the logic + * to force verifier to patch instructions. This allows us to ensure jump + * logic remains correct with instruction movement. + */ +static void test_tailcall_bpf2bpf_4(bool noise) +{ + int err, map_fd, prog_fd, main_fd, data_fd, i; + struct tailcall_bpf2bpf4__bss val; + struct bpf_map *prog_array, *data_map; + struct bpf_program *prog; + struct bpf_object *obj; + char prog_name[32]; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + err = bpf_prog_test_load("tailcall_bpf2bpf4.bpf.o", BPF_PROG_TYPE_SCHED_CLS, + &obj, &prog_fd); + if (CHECK_FAIL(err)) + return; + + prog = bpf_object__find_program_by_name(obj, "entry"); + 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__max_entries(prog_array); i++) { + snprintf(prog_name, sizeof(prog_name), "classifier_%d", i); + + prog = bpf_object__find_program_by_name(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; + } + + data_map = bpf_object__find_map_by_name(obj, "tailcall.bss"); + if (CHECK_FAIL(!data_map || !bpf_map__is_internal(data_map))) + goto out; + + data_fd = bpf_map__fd(data_map); + if (CHECK_FAIL(data_fd < 0)) + goto out; + + i = 0; + val.noise = noise; + val.count = 0; + err = bpf_map_update_elem(data_fd, &i, &val, BPF_ANY); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "tailcall"); + ASSERT_EQ(topts.retval, sizeof(pkt_v4) * 3, "tailcall retval"); + + i = 0; + err = bpf_map_lookup_elem(data_fd, &i, &val); + ASSERT_OK(err, "tailcall count"); + ASSERT_EQ(val.count, 31, "tailcall count"); + +out: + bpf_object__close(obj); +} + +#include "tailcall_bpf2bpf6.skel.h" + +/* Tail call counting works even when there is data on stack which is + * not aligned to 8 bytes. + */ +static void test_tailcall_bpf2bpf_6(void) +{ + struct tailcall_bpf2bpf6 *obj; + int err, map_fd, prog_fd, main_fd, data_fd, i, val; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = &pkt_v4, + .data_size_in = sizeof(pkt_v4), + .repeat = 1, + ); + + obj = tailcall_bpf2bpf6__open_and_load(); + if (!ASSERT_OK_PTR(obj, "open and load")) + return; + + main_fd = bpf_program__fd(obj->progs.entry); + if (!ASSERT_GE(main_fd, 0, "entry prog fd")) + goto out; + + map_fd = bpf_map__fd(obj->maps.jmp_table); + if (!ASSERT_GE(map_fd, 0, "jmp_table map fd")) + goto out; + + prog_fd = bpf_program__fd(obj->progs.classifier_0); + if (!ASSERT_GE(prog_fd, 0, "classifier_0 prog fd")) + goto out; + + i = 0; + err = bpf_map_update_elem(map_fd, &i, &prog_fd, BPF_ANY); + if (!ASSERT_OK(err, "jmp_table map update")) + goto out; + + err = bpf_prog_test_run_opts(main_fd, &topts); + ASSERT_OK(err, "entry prog test run"); + ASSERT_EQ(topts.retval, 0, "tailcall retval"); + + data_fd = bpf_map__fd(obj->maps.bss); + if (!ASSERT_GE(data_fd, 0, "bss map fd")) + goto out; + + i = 0; + err = bpf_map_lookup_elem(data_fd, &i, &val); + ASSERT_OK(err, "bss map lookup"); + ASSERT_EQ(val, 1, "done flag is set"); + +out: + tailcall_bpf2bpf6__destroy(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(); + if (test__start_subtest("tailcall_6")) + test_tailcall_6(); + if (test__start_subtest("tailcall_bpf2bpf_1")) + test_tailcall_bpf2bpf_1(); + if (test__start_subtest("tailcall_bpf2bpf_2")) + test_tailcall_bpf2bpf_2(); + if (test__start_subtest("tailcall_bpf2bpf_3")) + test_tailcall_bpf2bpf_3(); + if (test__start_subtest("tailcall_bpf2bpf_4")) + test_tailcall_bpf2bpf_4(false); + if (test__start_subtest("tailcall_bpf2bpf_5")) + test_tailcall_bpf2bpf_4(true); + if (test__start_subtest("tailcall_bpf2bpf_6")) + test_tailcall_bpf2bpf_6(); +} |