diff options
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/tailcalls.c')
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/tailcalls.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/tailcalls.c b/tools/testing/selftests/bpf/prog_tests/tailcalls.c index bb8fe646dd9f..ee27d68d2a1c 100644 --- a/tools/testing/selftests/bpf/prog_tests/tailcalls.c +++ b/tools/testing/selftests/bpf/prog_tests/tailcalls.c @@ -1,5 +1,6 @@ // 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 @@ -472,6 +473,329 @@ 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; + __u32 retval, duration; + char prog_name[32]; + + err = bpf_prog_load("tailcall_bpf2bpf1.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; + + /* nop -> jmp */ + 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, &pkt_v4, sizeof(pkt_v4), 0, + 0, &retval, &duration); + CHECK(err || retval != 1, "tailcall", + "err %d errno %d retval %d\n", err, errno, 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(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0, + 0, &retval, &duration); + CHECK(err || retval != 0, "tailcall", "err %d errno %d retval %d\n", + err, errno, 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(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0, + 0, &retval, &duration); + CHECK(err || retval != sizeof(pkt_v4) * 2, + "tailcall", "err %d errno %d retval %d\n", + err, errno, 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; + __u32 retval, duration; + char buff[128] = {}; + + err = bpf_prog_load("tailcall_bpf2bpf2.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_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; + __u32 retval, duration; + char prog_name[32]; + + err = bpf_prog_load("tailcall_bpf2bpf3.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, &pkt_v4, sizeof(pkt_v4), 0, + &duration, &retval, NULL); + CHECK(err || retval != sizeof(pkt_v4) * 3, + "tailcall", "err %d errno %d retval %d\n", + err, errno, retval); + + i = 1; + err = bpf_map_delete_elem(map_fd, &i); + if (CHECK_FAIL(err)) + goto out; + + err = bpf_prog_test_run(main_fd, 1, &pkt_v4, sizeof(pkt_v4), 0, + &duration, &retval, NULL); + CHECK(err || retval != sizeof(pkt_v4), + "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, &pkt_v4, sizeof(pkt_v4), 0, + &duration, &retval, NULL); + CHECK(err || retval != sizeof(pkt_v4) * 2, + "tailcall", "err %d errno %d retval %d\n", + err, errno, retval); +out: + bpf_object__close(obj); +} + +/* 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. + */ +static void test_tailcall_bpf2bpf_4(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 prog_name[32]; + + err = bpf_prog_load("tailcall_bpf2bpf4.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, &pkt_v4, sizeof(pkt_v4), 0, + &duration, &retval, NULL); + CHECK(err || retval != sizeof(pkt_v4) * 3, "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 != 31, "tailcall count", "err %d errno %d count %d\n", + err, errno, val); + +out: + bpf_object__close(obj); +} + void test_tailcalls(void) { if (test__start_subtest("tailcall_1")) @@ -484,4 +808,12 @@ void test_tailcalls(void) test_tailcall_4(); if (test__start_subtest("tailcall_5")) test_tailcall_5(); + 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(); } |