diff options
Diffstat (limited to 'tools/testing/selftests/bpf/test_loader.c')
-rw-r--r-- | tools/testing/selftests/bpf/test_loader.c | 707 |
1 files changed, 707 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c new file mode 100644 index 0000000000..b4edd84549 --- /dev/null +++ b/tools/testing/selftests/bpf/test_loader.c @@ -0,0 +1,707 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2022 Meta Platforms, Inc. and affiliates. */ +#include <linux/capability.h> +#include <stdlib.h> +#include <test_progs.h> +#include <bpf/btf.h> + +#include "autoconf_helper.h" +#include "unpriv_helpers.h" +#include "cap_helpers.h" + +#define str_has_pfx(str, pfx) \ + (strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0) + +#define TEST_LOADER_LOG_BUF_SZ 1048576 + +#define TEST_TAG_EXPECT_FAILURE "comment:test_expect_failure" +#define TEST_TAG_EXPECT_SUCCESS "comment:test_expect_success" +#define TEST_TAG_EXPECT_MSG_PFX "comment:test_expect_msg=" +#define TEST_TAG_EXPECT_FAILURE_UNPRIV "comment:test_expect_failure_unpriv" +#define TEST_TAG_EXPECT_SUCCESS_UNPRIV "comment:test_expect_success_unpriv" +#define TEST_TAG_EXPECT_MSG_PFX_UNPRIV "comment:test_expect_msg_unpriv=" +#define TEST_TAG_LOG_LEVEL_PFX "comment:test_log_level=" +#define TEST_TAG_PROG_FLAGS_PFX "comment:test_prog_flags=" +#define TEST_TAG_DESCRIPTION_PFX "comment:test_description=" +#define TEST_TAG_RETVAL_PFX "comment:test_retval=" +#define TEST_TAG_RETVAL_PFX_UNPRIV "comment:test_retval_unpriv=" +#define TEST_TAG_AUXILIARY "comment:test_auxiliary" +#define TEST_TAG_AUXILIARY_UNPRIV "comment:test_auxiliary_unpriv" + +/* Warning: duplicated in bpf_misc.h */ +#define POINTER_VALUE 0xcafe4all +#define TEST_DATA_LEN 64 + +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +#define EFFICIENT_UNALIGNED_ACCESS 1 +#else +#define EFFICIENT_UNALIGNED_ACCESS 0 +#endif + +static int sysctl_unpriv_disabled = -1; + +enum mode { + PRIV = 1, + UNPRIV = 2 +}; + +struct test_subspec { + char *name; + bool expect_failure; + const char **expect_msgs; + size_t expect_msg_cnt; + int retval; + bool execute; +}; + +struct test_spec { + const char *prog_name; + struct test_subspec priv; + struct test_subspec unpriv; + int log_level; + int prog_flags; + int mode_mask; + bool auxiliary; + bool valid; +}; + +static int tester_init(struct test_loader *tester) +{ + if (!tester->log_buf) { + tester->log_buf_sz = TEST_LOADER_LOG_BUF_SZ; + tester->log_buf = malloc(tester->log_buf_sz); + if (!ASSERT_OK_PTR(tester->log_buf, "tester_log_buf")) + return -ENOMEM; + } + + return 0; +} + +void test_loader_fini(struct test_loader *tester) +{ + if (!tester) + return; + + free(tester->log_buf); +} + +static void free_test_spec(struct test_spec *spec) +{ + free(spec->priv.name); + free(spec->unpriv.name); + free(spec->priv.expect_msgs); + free(spec->unpriv.expect_msgs); + + spec->priv.name = NULL; + spec->unpriv.name = NULL; + spec->priv.expect_msgs = NULL; + spec->unpriv.expect_msgs = NULL; +} + +static int push_msg(const char *msg, struct test_subspec *subspec) +{ + void *tmp; + + tmp = realloc(subspec->expect_msgs, (1 + subspec->expect_msg_cnt) * sizeof(void *)); + if (!tmp) { + ASSERT_FAIL("failed to realloc memory for messages\n"); + return -ENOMEM; + } + subspec->expect_msgs = tmp; + subspec->expect_msgs[subspec->expect_msg_cnt++] = msg; + + return 0; +} + +static int parse_int(const char *str, int *val, const char *name) +{ + char *end; + long tmp; + + errno = 0; + if (str_has_pfx(str, "0x")) + tmp = strtol(str + 2, &end, 16); + else + tmp = strtol(str, &end, 10); + if (errno || end[0] != '\0') { + PRINT_FAIL("failed to parse %s from '%s'\n", name, str); + return -EINVAL; + } + *val = tmp; + return 0; +} + +static int parse_retval(const char *str, int *val, const char *name) +{ + struct { + char *name; + int val; + } named_values[] = { + { "INT_MIN" , INT_MIN }, + { "POINTER_VALUE", POINTER_VALUE }, + { "TEST_DATA_LEN", TEST_DATA_LEN }, + }; + int i; + + for (i = 0; i < ARRAY_SIZE(named_values); ++i) { + if (strcmp(str, named_values[i].name) != 0) + continue; + *val = named_values[i].val; + return 0; + } + + return parse_int(str, val, name); +} + +/* Uses btf_decl_tag attributes to describe the expected test + * behavior, see bpf_misc.h for detailed description of each attribute + * and attribute combinations. + */ +static int parse_test_spec(struct test_loader *tester, + struct bpf_object *obj, + struct bpf_program *prog, + struct test_spec *spec) +{ + const char *description = NULL; + bool has_unpriv_result = false; + bool has_unpriv_retval = false; + int func_id, i, err = 0; + struct btf *btf; + + memset(spec, 0, sizeof(*spec)); + + spec->prog_name = bpf_program__name(prog); + + btf = bpf_object__btf(obj); + if (!btf) { + ASSERT_FAIL("BPF object has no BTF"); + return -EINVAL; + } + + func_id = btf__find_by_name_kind(btf, spec->prog_name, BTF_KIND_FUNC); + if (func_id < 0) { + ASSERT_FAIL("failed to find FUNC BTF type for '%s'", spec->prog_name); + return -EINVAL; + } + + for (i = 1; i < btf__type_cnt(btf); i++) { + const char *s, *val, *msg; + const struct btf_type *t; + int tmp; + + t = btf__type_by_id(btf, i); + if (!btf_is_decl_tag(t)) + continue; + + if (t->type != func_id || btf_decl_tag(t)->component_idx != -1) + continue; + + s = btf__str_by_offset(btf, t->name_off); + if (str_has_pfx(s, TEST_TAG_DESCRIPTION_PFX)) { + description = s + sizeof(TEST_TAG_DESCRIPTION_PFX) - 1; + } else if (strcmp(s, TEST_TAG_EXPECT_FAILURE) == 0) { + spec->priv.expect_failure = true; + spec->mode_mask |= PRIV; + } else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS) == 0) { + spec->priv.expect_failure = false; + spec->mode_mask |= PRIV; + } else if (strcmp(s, TEST_TAG_EXPECT_FAILURE_UNPRIV) == 0) { + spec->unpriv.expect_failure = true; + spec->mode_mask |= UNPRIV; + has_unpriv_result = true; + } else if (strcmp(s, TEST_TAG_EXPECT_SUCCESS_UNPRIV) == 0) { + spec->unpriv.expect_failure = false; + spec->mode_mask |= UNPRIV; + has_unpriv_result = true; + } else if (strcmp(s, TEST_TAG_AUXILIARY) == 0) { + spec->auxiliary = true; + spec->mode_mask |= PRIV; + } else if (strcmp(s, TEST_TAG_AUXILIARY_UNPRIV) == 0) { + spec->auxiliary = true; + spec->mode_mask |= UNPRIV; + } else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX)) { + msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX) - 1; + err = push_msg(msg, &spec->priv); + if (err) + goto cleanup; + spec->mode_mask |= PRIV; + } else if (str_has_pfx(s, TEST_TAG_EXPECT_MSG_PFX_UNPRIV)) { + msg = s + sizeof(TEST_TAG_EXPECT_MSG_PFX_UNPRIV) - 1; + err = push_msg(msg, &spec->unpriv); + if (err) + goto cleanup; + spec->mode_mask |= UNPRIV; + } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX)) { + val = s + sizeof(TEST_TAG_RETVAL_PFX) - 1; + err = parse_retval(val, &spec->priv.retval, "__retval"); + if (err) + goto cleanup; + spec->priv.execute = true; + spec->mode_mask |= PRIV; + } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV)) { + val = s + sizeof(TEST_TAG_RETVAL_PFX_UNPRIV) - 1; + err = parse_retval(val, &spec->unpriv.retval, "__retval_unpriv"); + if (err) + goto cleanup; + spec->mode_mask |= UNPRIV; + spec->unpriv.execute = true; + has_unpriv_retval = true; + } else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) { + val = s + sizeof(TEST_TAG_LOG_LEVEL_PFX) - 1; + err = parse_int(val, &spec->log_level, "test log level"); + if (err) + goto cleanup; + } else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) { + val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1; + if (strcmp(val, "BPF_F_STRICT_ALIGNMENT") == 0) { + spec->prog_flags |= BPF_F_STRICT_ALIGNMENT; + } else if (strcmp(val, "BPF_F_ANY_ALIGNMENT") == 0) { + spec->prog_flags |= BPF_F_ANY_ALIGNMENT; + } else if (strcmp(val, "BPF_F_TEST_RND_HI32") == 0) { + spec->prog_flags |= BPF_F_TEST_RND_HI32; + } else if (strcmp(val, "BPF_F_TEST_STATE_FREQ") == 0) { + spec->prog_flags |= BPF_F_TEST_STATE_FREQ; + } else if (strcmp(val, "BPF_F_SLEEPABLE") == 0) { + spec->prog_flags |= BPF_F_SLEEPABLE; + } else if (strcmp(val, "BPF_F_XDP_HAS_FRAGS") == 0) { + spec->prog_flags |= BPF_F_XDP_HAS_FRAGS; + } else /* assume numeric value */ { + err = parse_int(val, &tmp, "test prog flags"); + if (err) + goto cleanup; + spec->prog_flags |= tmp; + } + } + } + + if (spec->mode_mask == 0) + spec->mode_mask = PRIV; + + if (!description) + description = spec->prog_name; + + if (spec->mode_mask & PRIV) { + spec->priv.name = strdup(description); + if (!spec->priv.name) { + PRINT_FAIL("failed to allocate memory for priv.name\n"); + err = -ENOMEM; + goto cleanup; + } + } + + if (spec->mode_mask & UNPRIV) { + int descr_len = strlen(description); + const char *suffix = " @unpriv"; + char *name; + + name = malloc(descr_len + strlen(suffix) + 1); + if (!name) { + PRINT_FAIL("failed to allocate memory for unpriv.name\n"); + err = -ENOMEM; + goto cleanup; + } + + strcpy(name, description); + strcpy(&name[descr_len], suffix); + spec->unpriv.name = name; + } + + if (spec->mode_mask & (PRIV | UNPRIV)) { + if (!has_unpriv_result) + spec->unpriv.expect_failure = spec->priv.expect_failure; + + if (!has_unpriv_retval) { + spec->unpriv.retval = spec->priv.retval; + spec->unpriv.execute = spec->priv.execute; + } + + if (!spec->unpriv.expect_msgs) { + size_t sz = spec->priv.expect_msg_cnt * sizeof(void *); + + spec->unpriv.expect_msgs = malloc(sz); + if (!spec->unpriv.expect_msgs) { + PRINT_FAIL("failed to allocate memory for unpriv.expect_msgs\n"); + err = -ENOMEM; + goto cleanup; + } + memcpy(spec->unpriv.expect_msgs, spec->priv.expect_msgs, sz); + spec->unpriv.expect_msg_cnt = spec->priv.expect_msg_cnt; + } + } + + spec->valid = true; + + return 0; + +cleanup: + free_test_spec(spec); + return err; +} + +static void prepare_case(struct test_loader *tester, + struct test_spec *spec, + struct bpf_object *obj, + struct bpf_program *prog) +{ + int min_log_level = 0, prog_flags; + + if (env.verbosity > VERBOSE_NONE) + min_log_level = 1; + if (env.verbosity > VERBOSE_VERY) + min_log_level = 2; + + bpf_program__set_log_buf(prog, tester->log_buf, tester->log_buf_sz); + + /* Make sure we set at least minimal log level, unless test requires + * even higher level already. Make sure to preserve independent log + * level 4 (verifier stats), though. + */ + if ((spec->log_level & 3) < min_log_level) + bpf_program__set_log_level(prog, (spec->log_level & 4) | min_log_level); + else + bpf_program__set_log_level(prog, spec->log_level); + + prog_flags = bpf_program__flags(prog); + bpf_program__set_flags(prog, prog_flags | spec->prog_flags); + + tester->log_buf[0] = '\0'; + tester->next_match_pos = 0; +} + +static void emit_verifier_log(const char *log_buf, bool force) +{ + if (!force && env.verbosity == VERBOSE_NONE) + return; + fprintf(stdout, "VERIFIER LOG:\n=============\n%s=============\n", log_buf); +} + +static void validate_case(struct test_loader *tester, + struct test_subspec *subspec, + struct bpf_object *obj, + struct bpf_program *prog, + int load_err) +{ + int i, j; + + for (i = 0; i < subspec->expect_msg_cnt; i++) { + char *match; + const char *expect_msg; + + expect_msg = subspec->expect_msgs[i]; + + match = strstr(tester->log_buf + tester->next_match_pos, expect_msg); + if (!ASSERT_OK_PTR(match, "expect_msg")) { + /* if we are in verbose mode, we've already emitted log */ + if (env.verbosity == VERBOSE_NONE) + emit_verifier_log(tester->log_buf, true /*force*/); + for (j = 0; j < i; j++) + fprintf(stderr, + "MATCHED MSG: '%s'\n", subspec->expect_msgs[j]); + fprintf(stderr, "EXPECTED MSG: '%s'\n", expect_msg); + return; + } + + tester->next_match_pos = match - tester->log_buf + strlen(expect_msg); + } +} + +struct cap_state { + __u64 old_caps; + bool initialized; +}; + +static int drop_capabilities(struct cap_state *caps) +{ + const __u64 caps_to_drop = (1ULL << CAP_SYS_ADMIN | 1ULL << CAP_NET_ADMIN | + 1ULL << CAP_PERFMON | 1ULL << CAP_BPF); + int err; + + err = cap_disable_effective(caps_to_drop, &caps->old_caps); + if (err) { + PRINT_FAIL("failed to drop capabilities: %i, %s\n", err, strerror(err)); + return err; + } + + caps->initialized = true; + return 0; +} + +static int restore_capabilities(struct cap_state *caps) +{ + int err; + + if (!caps->initialized) + return 0; + + err = cap_enable_effective(caps->old_caps, NULL); + if (err) + PRINT_FAIL("failed to restore capabilities: %i, %s\n", err, strerror(err)); + caps->initialized = false; + return err; +} + +static bool can_execute_unpriv(struct test_loader *tester, struct test_spec *spec) +{ + if (sysctl_unpriv_disabled < 0) + sysctl_unpriv_disabled = get_unpriv_disabled() ? 1 : 0; + if (sysctl_unpriv_disabled) + return false; + if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS) + return false; + return true; +} + +static bool is_unpriv_capable_map(struct bpf_map *map) +{ + enum bpf_map_type type; + __u32 flags; + + type = bpf_map__type(map); + + switch (type) { + case BPF_MAP_TYPE_HASH: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_HASH_OF_MAPS: + flags = bpf_map__map_flags(map); + return !(flags & BPF_F_ZERO_SEED); + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: + case BPF_MAP_TYPE_ARRAY: + case BPF_MAP_TYPE_RINGBUF: + case BPF_MAP_TYPE_PROG_ARRAY: + case BPF_MAP_TYPE_CGROUP_ARRAY: + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_USER_RINGBUF: + case BPF_MAP_TYPE_ARRAY_OF_MAPS: + case BPF_MAP_TYPE_CGROUP_STORAGE: + case BPF_MAP_TYPE_PERF_EVENT_ARRAY: + return true; + default: + return false; + } +} + +static int do_prog_test_run(int fd_prog, int *retval) +{ + __u8 tmp_out[TEST_DATA_LEN << 2] = {}; + __u8 tmp_in[TEST_DATA_LEN] = {}; + int err, saved_errno; + LIBBPF_OPTS(bpf_test_run_opts, topts, + .data_in = tmp_in, + .data_size_in = sizeof(tmp_in), + .data_out = tmp_out, + .data_size_out = sizeof(tmp_out), + .repeat = 1, + ); + + err = bpf_prog_test_run_opts(fd_prog, &topts); + saved_errno = errno; + + if (err) { + PRINT_FAIL("FAIL: Unexpected bpf_prog_test_run error: %d (%s) ", + saved_errno, strerror(saved_errno)); + return err; + } + + ASSERT_OK(0, "bpf_prog_test_run"); + *retval = topts.retval; + + return 0; +} + +static bool should_do_test_run(struct test_spec *spec, struct test_subspec *subspec) +{ + if (!subspec->execute) + return false; + + if (subspec->expect_failure) + return false; + + if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS) { + if (env.verbosity != VERBOSE_NONE) + printf("alignment prevents execution\n"); + return false; + } + + return true; +} + +/* this function is forced noinline and has short generic name to look better + * in test_progs output (in case of a failure) + */ +static noinline +void run_subtest(struct test_loader *tester, + struct bpf_object_open_opts *open_opts, + const void *obj_bytes, + size_t obj_byte_cnt, + struct test_spec *specs, + struct test_spec *spec, + bool unpriv) +{ + struct test_subspec *subspec = unpriv ? &spec->unpriv : &spec->priv; + struct bpf_program *tprog, *tprog_iter; + struct test_spec *spec_iter; + struct cap_state caps = {}; + struct bpf_object *tobj; + struct bpf_map *map; + int retval, err, i; + bool should_load; + + if (!test__start_subtest(subspec->name)) + return; + + if (unpriv) { + if (!can_execute_unpriv(tester, spec)) { + test__skip(); + test__end_subtest(); + return; + } + if (drop_capabilities(&caps)) { + test__end_subtest(); + return; + } + } + + tobj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, open_opts); + if (!ASSERT_OK_PTR(tobj, "obj_open_mem")) /* shouldn't happen */ + goto subtest_cleanup; + + i = 0; + bpf_object__for_each_program(tprog_iter, tobj) { + spec_iter = &specs[i++]; + should_load = false; + + if (spec_iter->valid) { + if (strcmp(bpf_program__name(tprog_iter), spec->prog_name) == 0) { + tprog = tprog_iter; + should_load = true; + } + + if (spec_iter->auxiliary && + spec_iter->mode_mask & (unpriv ? UNPRIV : PRIV)) + should_load = true; + } + + bpf_program__set_autoload(tprog_iter, should_load); + } + + prepare_case(tester, spec, tobj, tprog); + + /* By default bpf_object__load() automatically creates all + * maps declared in the skeleton. Some map types are only + * allowed in priv mode. Disable autoload for such maps in + * unpriv mode. + */ + bpf_object__for_each_map(map, tobj) + bpf_map__set_autocreate(map, !unpriv || is_unpriv_capable_map(map)); + + err = bpf_object__load(tobj); + if (subspec->expect_failure) { + if (!ASSERT_ERR(err, "unexpected_load_success")) { + emit_verifier_log(tester->log_buf, false /*force*/); + goto tobj_cleanup; + } + } else { + if (!ASSERT_OK(err, "unexpected_load_failure")) { + emit_verifier_log(tester->log_buf, true /*force*/); + goto tobj_cleanup; + } + } + + emit_verifier_log(tester->log_buf, false /*force*/); + validate_case(tester, subspec, tobj, tprog, err); + + if (should_do_test_run(spec, subspec)) { + /* For some reason test_verifier executes programs + * with all capabilities restored. Do the same here. + */ + if (restore_capabilities(&caps)) + goto tobj_cleanup; + + if (tester->pre_execution_cb) { + err = tester->pre_execution_cb(tobj); + if (err) { + PRINT_FAIL("pre_execution_cb failed: %d\n", err); + goto tobj_cleanup; + } + } + + do_prog_test_run(bpf_program__fd(tprog), &retval); + if (retval != subspec->retval && subspec->retval != POINTER_VALUE) { + PRINT_FAIL("Unexpected retval: %d != %d\n", retval, subspec->retval); + goto tobj_cleanup; + } + } + +tobj_cleanup: + bpf_object__close(tobj); +subtest_cleanup: + test__end_subtest(); + restore_capabilities(&caps); +} + +static void process_subtest(struct test_loader *tester, + const char *skel_name, + skel_elf_bytes_fn elf_bytes_factory) +{ + LIBBPF_OPTS(bpf_object_open_opts, open_opts, .object_name = skel_name); + struct test_spec *specs = NULL; + struct bpf_object *obj = NULL; + struct bpf_program *prog; + const void *obj_bytes; + int err, i, nr_progs; + size_t obj_byte_cnt; + + if (tester_init(tester) < 0) + return; /* failed to initialize tester */ + + obj_bytes = elf_bytes_factory(&obj_byte_cnt); + obj = bpf_object__open_mem(obj_bytes, obj_byte_cnt, &open_opts); + if (!ASSERT_OK_PTR(obj, "obj_open_mem")) + return; + + nr_progs = 0; + bpf_object__for_each_program(prog, obj) + ++nr_progs; + + specs = calloc(nr_progs, sizeof(struct test_spec)); + if (!ASSERT_OK_PTR(specs, "Can't alloc specs array")) + return; + + i = 0; + bpf_object__for_each_program(prog, obj) { + /* ignore tests for which we can't derive test specification */ + err = parse_test_spec(tester, obj, prog, &specs[i++]); + if (err) + PRINT_FAIL("Can't parse test spec for program '%s'\n", + bpf_program__name(prog)); + } + + i = 0; + bpf_object__for_each_program(prog, obj) { + struct test_spec *spec = &specs[i++]; + + if (!spec->valid || spec->auxiliary) + continue; + + if (spec->mode_mask & PRIV) + run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt, + specs, spec, false); + if (spec->mode_mask & UNPRIV) + run_subtest(tester, &open_opts, obj_bytes, obj_byte_cnt, + specs, spec, true); + + } + + for (i = 0; i < nr_progs; ++i) + free_test_spec(&specs[i]); + free(specs); + bpf_object__close(obj); +} + +void test_loader__run_subtests(struct test_loader *tester, + const char *skel_name, + skel_elf_bytes_fn elf_bytes_factory) +{ + /* see comment in run_subtest() for why we do this function nesting */ + process_subtest(tester, skel_name, elf_bytes_factory); +} |