From 765a34130ea506fafefe179bdfa47da296016d92 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 27 Jun 2022 14:15:14 -0700 Subject: libbpf: remove deprecated low-level APIs Drop low-level APIs as well as high-level (and very confusingly named) BPF object loading bpf_prog_load_xattr() and bpf_prog_load_deprecated() APIs. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220627211527.2245459-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 174 ++-------------------------------------------------- 1 file changed, 4 insertions(+), 170 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 240186aac8e6..2f3495d80d69 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -233,11 +233,10 @@ alloc_zero_tailing_info(const void *orecord, __u32 cnt, return info; } -DEFAULT_VERSION(bpf_prog_load_v0_6_0, bpf_prog_load, LIBBPF_0.6.0) -int bpf_prog_load_v0_6_0(enum bpf_prog_type prog_type, - const char *prog_name, const char *license, - const struct bpf_insn *insns, size_t insn_cnt, - const struct bpf_prog_load_opts *opts) +int bpf_prog_load(enum bpf_prog_type prog_type, + const char *prog_name, const char *license, + const struct bpf_insn *insns, size_t insn_cnt, + const struct bpf_prog_load_opts *opts) { void *finfo = NULL, *linfo = NULL; const char *func_info, *line_info; @@ -384,94 +383,6 @@ done: return libbpf_err_errno(fd); } -__attribute__((alias("bpf_load_program_xattr2"))) -int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, - char *log_buf, size_t log_buf_sz); - -static int bpf_load_program_xattr2(const struct bpf_load_program_attr *load_attr, - char *log_buf, size_t log_buf_sz) -{ - LIBBPF_OPTS(bpf_prog_load_opts, p); - - if (!load_attr || !log_buf != !log_buf_sz) - return libbpf_err(-EINVAL); - - p.expected_attach_type = load_attr->expected_attach_type; - switch (load_attr->prog_type) { - case BPF_PROG_TYPE_STRUCT_OPS: - case BPF_PROG_TYPE_LSM: - p.attach_btf_id = load_attr->attach_btf_id; - break; - case BPF_PROG_TYPE_TRACING: - case BPF_PROG_TYPE_EXT: - p.attach_btf_id = load_attr->attach_btf_id; - p.attach_prog_fd = load_attr->attach_prog_fd; - break; - default: - p.prog_ifindex = load_attr->prog_ifindex; - p.kern_version = load_attr->kern_version; - } - p.log_level = load_attr->log_level; - p.log_buf = log_buf; - p.log_size = log_buf_sz; - p.prog_btf_fd = load_attr->prog_btf_fd; - p.func_info_rec_size = load_attr->func_info_rec_size; - p.func_info_cnt = load_attr->func_info_cnt; - p.func_info = load_attr->func_info; - p.line_info_rec_size = load_attr->line_info_rec_size; - p.line_info_cnt = load_attr->line_info_cnt; - p.line_info = load_attr->line_info; - p.prog_flags = load_attr->prog_flags; - - return bpf_prog_load(load_attr->prog_type, load_attr->name, load_attr->license, - load_attr->insns, load_attr->insns_cnt, &p); -} - -int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t insns_cnt, const char *license, - __u32 kern_version, char *log_buf, - size_t log_buf_sz) -{ - struct bpf_load_program_attr load_attr; - - memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); - load_attr.prog_type = type; - load_attr.expected_attach_type = 0; - load_attr.name = NULL; - load_attr.insns = insns; - load_attr.insns_cnt = insns_cnt; - load_attr.license = license; - load_attr.kern_version = kern_version; - - return bpf_load_program_xattr2(&load_attr, log_buf, log_buf_sz); -} - -int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, - size_t insns_cnt, __u32 prog_flags, const char *license, - __u32 kern_version, char *log_buf, size_t log_buf_sz, - int log_level) -{ - union bpf_attr attr; - int fd; - - bump_rlimit_memlock(); - - memset(&attr, 0, sizeof(attr)); - attr.prog_type = type; - attr.insn_cnt = (__u32)insns_cnt; - attr.insns = ptr_to_u64(insns); - attr.license = ptr_to_u64(license); - attr.log_buf = ptr_to_u64(log_buf); - attr.log_size = log_buf_sz; - attr.log_level = log_level; - log_buf[0] = 0; - attr.kern_version = kern_version; - attr.prog_flags = prog_flags; - - fd = sys_bpf_prog_load(&attr, sizeof(attr), PROG_LOAD_ATTEMPTS); - return libbpf_err_errno(fd); -} - int bpf_map_update_elem(int fd, const void *key, const void *value, __u64 flags) { @@ -910,62 +821,6 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, return libbpf_err_errno(ret); } -int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, - void *data_out, __u32 *size_out, __u32 *retval, - __u32 *duration) -{ - union bpf_attr attr; - int ret; - - memset(&attr, 0, sizeof(attr)); - attr.test.prog_fd = prog_fd; - attr.test.data_in = ptr_to_u64(data); - attr.test.data_out = ptr_to_u64(data_out); - attr.test.data_size_in = size; - attr.test.repeat = repeat; - - ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); - - if (size_out) - *size_out = attr.test.data_size_out; - if (retval) - *retval = attr.test.retval; - if (duration) - *duration = attr.test.duration; - - return libbpf_err_errno(ret); -} - -int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) -{ - union bpf_attr attr; - int ret; - - if (!test_attr->data_out && test_attr->data_size_out > 0) - return libbpf_err(-EINVAL); - - memset(&attr, 0, sizeof(attr)); - attr.test.prog_fd = test_attr->prog_fd; - attr.test.data_in = ptr_to_u64(test_attr->data_in); - attr.test.data_out = ptr_to_u64(test_attr->data_out); - attr.test.data_size_in = test_attr->data_size_in; - attr.test.data_size_out = test_attr->data_size_out; - attr.test.ctx_in = ptr_to_u64(test_attr->ctx_in); - attr.test.ctx_out = ptr_to_u64(test_attr->ctx_out); - attr.test.ctx_size_in = test_attr->ctx_size_in; - attr.test.ctx_size_out = test_attr->ctx_size_out; - attr.test.repeat = test_attr->repeat; - - ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); - - test_attr->data_size_out = attr.test.data_size_out; - test_attr->ctx_size_out = attr.test.ctx_size_out; - test_attr->retval = attr.test.retval; - test_attr->duration = attr.test.duration; - - return libbpf_err_errno(ret); -} - int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts) { union bpf_attr attr; @@ -1162,27 +1017,6 @@ int bpf_btf_load(const void *btf_data, size_t btf_size, const struct bpf_btf_loa return libbpf_err_errno(fd); } -int bpf_load_btf(const void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, bool do_log) -{ - LIBBPF_OPTS(bpf_btf_load_opts, opts); - int fd; - -retry: - if (do_log && log_buf && log_buf_size) { - opts.log_buf = log_buf; - opts.log_size = log_buf_size; - opts.log_level = 1; - } - - fd = bpf_btf_load(btf, btf_size, &opts); - if (fd < 0 && !do_log && log_buf && log_buf_size) { - do_log = true; - goto retry; - } - - return libbpf_err_errno(fd); -} - int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, __u64 *probe_addr) -- cgit From bd054102a8c7f36ff03446cc41822601180241f3 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Mon, 27 Jun 2022 14:15:26 -0700 Subject: libbpf: enforce strict libbpf 1.0 behaviors Remove support for legacy features and behaviors that previously had to be disabled by calling libbpf_set_strict_mode(): - legacy BPF map definitions are not supported now; - RLIMIT_MEMLOCK auto-setting, if necessary, is always on (but see libbpf_set_memlock_rlim()); - program name is used for program pinning (instead of section name); - cleaned up error returning logic; - entry BPF programs should have SEC() always. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220627211527.2245459-15-andrii@kernel.org Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 4 - tools/lib/bpf/libbpf.c | 212 ++-------------------------------------- tools/lib/bpf/libbpf.h | 34 ------- tools/lib/bpf/libbpf_internal.h | 24 +---- tools/lib/bpf/libbpf_legacy.h | 24 +++++ 5 files changed, 37 insertions(+), 261 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 2f3495d80d69..6d848b02c1e0 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -147,10 +147,6 @@ int bump_rlimit_memlock(void) { struct rlimit rlim; - /* this the default in libbpf 1.0, but for now user has to opt-in explicitly */ - if (!(libbpf_mode & LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK)) - return 0; - /* if kernel supports memcg-based accounting, skip bumping RLIMIT_MEMLOCK */ if (memlock_bumped || kernel_supports(NULL, FEAT_MEMCG_ACCOUNT)) return 0; diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index ae58cf2898ad..e994797bcd48 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -278,12 +278,9 @@ static inline __u64 ptr_to_u64(const void *ptr) return (__u64) (unsigned long) ptr; } -/* this goes away in libbpf 1.0 */ -enum libbpf_strict_mode libbpf_mode = LIBBPF_STRICT_NONE; - int libbpf_set_strict_mode(enum libbpf_strict_mode mode) { - libbpf_mode = mode; + /* as of v1.0 libbpf_set_strict_mode() is a no-op */ return 0; } @@ -367,9 +364,10 @@ struct bpf_sec_def { * linux/filter.h. */ struct bpf_program { - const struct bpf_sec_def *sec_def; + char *name; char *sec_name; size_t sec_idx; + const struct bpf_sec_def *sec_def; /* this program's instruction offset (in number of instructions) * within its containing ELF section */ @@ -389,12 +387,6 @@ struct bpf_program { */ size_t sub_insn_off; - char *name; - /* name with / replaced by _; makes recursive pinning - * in bpf_object__pin_programs easier - */ - char *pin_name; - /* instructions that belong to BPF program; insns[0] is located at * sec_insn_off instruction within its ELF section in ELF file, so * when mapping ELF file instruction index to the local instruction, @@ -695,7 +687,6 @@ static void bpf_program__exit(struct bpf_program *prog) bpf_program__unload(prog); zfree(&prog->name); zfree(&prog->sec_name); - zfree(&prog->pin_name); zfree(&prog->insns); zfree(&prog->reloc_desc); @@ -704,26 +695,6 @@ static void bpf_program__exit(struct bpf_program *prog) prog->sec_idx = -1; } -static char *__bpf_program__pin_name(struct bpf_program *prog) -{ - char *name, *p; - - if (libbpf_mode & LIBBPF_STRICT_SEC_NAME) - name = strdup(prog->name); - else - name = strdup(prog->sec_name); - - if (!name) - return NULL; - - p = name; - - while ((p = strchr(p, '/'))) - *p = '_'; - - return name; -} - static bool insn_is_subprog_call(const struct bpf_insn *insn) { return BPF_CLASS(insn->code) == BPF_JMP && @@ -790,10 +761,6 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, if (!prog->name) goto errout; - prog->pin_name = __bpf_program__pin_name(prog); - if (!prog->pin_name) - goto errout; - prog->insns = malloc(insn_data_sz); if (!prog->insns) goto errout; @@ -2007,143 +1974,6 @@ static int bpf_object__init_kconfig_map(struct bpf_object *obj) return 0; } -static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict) -{ - Elf_Data *symbols = obj->efile.symbols; - int i, map_def_sz = 0, nr_maps = 0, nr_syms; - Elf_Data *data = NULL; - Elf_Scn *scn; - - if (obj->efile.maps_shndx < 0) - return 0; - - if (libbpf_mode & LIBBPF_STRICT_MAP_DEFINITIONS) { - pr_warn("legacy map definitions in SEC(\"maps\") are not supported\n"); - return -EOPNOTSUPP; - } - - if (!symbols) - return -EINVAL; - - scn = elf_sec_by_idx(obj, obj->efile.maps_shndx); - data = elf_sec_data(obj, scn); - if (!scn || !data) { - pr_warn("elf: failed to get legacy map definitions for %s\n", - obj->path); - return -EINVAL; - } - - /* - * Count number of maps. Each map has a name. - * Array of maps is not supported: only the first element is - * considered. - * - * TODO: Detect array of map and report error. - */ - nr_syms = symbols->d_size / sizeof(Elf64_Sym); - for (i = 0; i < nr_syms; i++) { - Elf64_Sym *sym = elf_sym_by_idx(obj, i); - - if (sym->st_shndx != obj->efile.maps_shndx) - continue; - if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION) - continue; - nr_maps++; - } - /* Assume equally sized map definitions */ - pr_debug("elf: found %d legacy map definitions (%zd bytes) in %s\n", - nr_maps, data->d_size, obj->path); - - if (!data->d_size || nr_maps == 0 || (data->d_size % nr_maps) != 0) { - pr_warn("elf: unable to determine legacy map definition size in %s\n", - obj->path); - return -EINVAL; - } - map_def_sz = data->d_size / nr_maps; - - /* Fill obj->maps using data in "maps" section. */ - for (i = 0; i < nr_syms; i++) { - Elf64_Sym *sym = elf_sym_by_idx(obj, i); - const char *map_name; - struct bpf_map_def *def; - struct bpf_map *map; - - if (sym->st_shndx != obj->efile.maps_shndx) - continue; - if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION) - continue; - - map = bpf_object__add_map(obj); - if (IS_ERR(map)) - return PTR_ERR(map); - - map_name = elf_sym_str(obj, sym->st_name); - if (!map_name) { - pr_warn("failed to get map #%d name sym string for obj %s\n", - i, obj->path); - return -LIBBPF_ERRNO__FORMAT; - } - - pr_warn("map '%s' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead\n", map_name); - - if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) { - pr_warn("map '%s' (legacy): static maps are not supported\n", map_name); - return -ENOTSUP; - } - - map->libbpf_type = LIBBPF_MAP_UNSPEC; - map->sec_idx = sym->st_shndx; - map->sec_offset = sym->st_value; - pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n", - map_name, map->sec_idx, map->sec_offset); - if (sym->st_value + map_def_sz > data->d_size) { - pr_warn("corrupted maps section in %s: last map \"%s\" too small\n", - obj->path, map_name); - return -EINVAL; - } - - map->name = strdup(map_name); - if (!map->name) { - pr_warn("map '%s': failed to alloc map name\n", map_name); - return -ENOMEM; - } - pr_debug("map %d is \"%s\"\n", i, map->name); - def = (struct bpf_map_def *)(data->d_buf + sym->st_value); - /* - * If the definition of the map in the object file fits in - * bpf_map_def, copy it. Any extra fields in our version - * of bpf_map_def will default to zero as a result of the - * calloc above. - */ - if (map_def_sz <= sizeof(struct bpf_map_def)) { - memcpy(&map->def, def, map_def_sz); - } else { - /* - * Here the map structure being read is bigger than what - * we expect, truncate if the excess bits are all zero. - * If they are not zero, reject this map as - * incompatible. - */ - char *b; - - for (b = ((char *)def) + sizeof(struct bpf_map_def); - b < ((char *)def) + map_def_sz; b++) { - if (*b != 0) { - pr_warn("maps section in %s: \"%s\" has unrecognized, non-zero options\n", - obj->path, map_name); - if (strict) - return -EINVAL; - } - } - memcpy(&map->def, def, sizeof(struct bpf_map_def)); - } - - /* btf info may not exist but fill it in if it does exist */ - (void) bpf_map_find_btf_info(obj, map); - } - return 0; -} - const struct btf_type * skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id) { @@ -2700,12 +2530,11 @@ static int bpf_object__init_maps(struct bpf_object *obj, { const char *pin_root_path; bool strict; - int err; + int err = 0; strict = !OPTS_GET(opts, relaxed_maps, false); pin_root_path = OPTS_GET(opts, pin_root_path, NULL); - err = bpf_object__init_user_maps(obj, strict); err = err ?: bpf_object__init_user_btf_maps(obj, strict, pin_root_path); err = err ?: bpf_object__init_global_data_maps(obj); err = err ?: bpf_object__init_kconfig_map(obj); @@ -3979,28 +3808,8 @@ static int bpf_object__collect_externs(struct bpf_object *obj) return 0; } -static bool prog_is_subprog(const struct bpf_object *obj, - const struct bpf_program *prog) -{ - /* For legacy reasons, libbpf supports an entry-point BPF programs - * without SEC() attribute, i.e., those in the .text section. But if - * there are 2 or more such programs in the .text section, they all - * must be subprograms called from entry-point BPF programs in - * designated SEC()'tions, otherwise there is no way to distinguish - * which of those programs should be loaded vs which are a subprogram. - * Similarly, if there is a function/program in .text and at least one - * other BPF program with custom SEC() attribute, then we just assume - * .text programs are subprograms (even if they are not called from - * other programs), because libbpf never explicitly supported mixing - * SEC()-designated BPF programs and .text entry-point BPF programs. - * - * In libbpf 1.0 strict mode, we always consider .text - * programs to be subprograms. - */ - - if (libbpf_mode & LIBBPF_STRICT_SEC_NAME) - return prog->sec_idx == obj->efile.text_shndx; - +static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog) +{ return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1; } @@ -8163,8 +7972,7 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path) char buf[PATH_MAX]; int len; - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); + len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name); if (len < 0) { err = -EINVAL; goto err_unpin_programs; @@ -8185,8 +7993,7 @@ err_unpin_programs: char buf[PATH_MAX]; int len; - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); + len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name); if (len < 0) continue; else if (len >= PATH_MAX) @@ -8210,8 +8017,7 @@ int bpf_object__unpin_programs(struct bpf_object *obj, const char *path) char buf[PATH_MAX]; int len; - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); + len = snprintf(buf, PATH_MAX, "%s/%s", path, prog->name); if (len < 0) return libbpf_err(-EINVAL); else if (len >= PATH_MAX) diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5eb3145b8945..e4d5353f757b 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -886,40 +886,6 @@ LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map, const void *cur_key, void *next_key, size_t key_sz); -/** - * @brief **libbpf_get_error()** extracts the error code from the passed - * pointer - * @param ptr pointer returned from libbpf API function - * @return error code; or 0 if no error occured - * - * Many libbpf API functions which return pointers have logic to encode error - * codes as pointers, and do not return NULL. Meaning **libbpf_get_error()** - * should be used on the return value from these functions immediately after - * calling the API function, with no intervening calls that could clobber the - * `errno` variable. Consult the individual functions documentation to verify - * if this logic applies should be used. - * - * For these API functions, if `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` - * is enabled, NULL is returned on error instead. - * - * If ptr is NULL, then errno should be already set by the failing - * API, because libbpf never returns NULL on success and it now always - * sets errno on error. - * - * Example usage: - * - * struct perf_buffer *pb; - * - * pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES, &opts); - * err = libbpf_get_error(pb); - * if (err) { - * pb = NULL; - * fprintf(stderr, "failed to open perf buffer: %d\n", err); - * goto cleanup; - * } - */ -LIBBPF_API long libbpf_get_error(const void *ptr); - struct bpf_xdp_set_link_opts { size_t sz; int old_fd; diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index a1ad145ffa74..9cd7829cbe41 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -15,7 +15,6 @@ #include #include #include -#include "libbpf_legacy.h" #include "relo_core.h" /* make sure libbpf doesn't use kernel-only integer typedefs */ @@ -478,8 +477,6 @@ int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void __s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name, __u32 kind); -extern enum libbpf_strict_mode libbpf_mode; - typedef int (*kallsyms_cb_t)(unsigned long long sym_addr, char sym_type, const char *sym_name, void *ctx); @@ -498,12 +495,8 @@ static inline int libbpf_err(int ret) */ static inline int libbpf_err_errno(int ret) { - if (libbpf_mode & LIBBPF_STRICT_DIRECT_ERRS) - /* errno is already assumed to be set on error */ - return ret < 0 ? -errno : ret; - - /* legacy: on error return -1 directly and don't touch errno */ - return ret; + /* errno is already assumed to be set on error */ + return ret < 0 ? -errno : ret; } /* handle error for pointer-returning APIs, err is assumed to be < 0 always */ @@ -511,12 +504,7 @@ static inline void *libbpf_err_ptr(int err) { /* set errno on error, this doesn't break anything */ errno = -err; - - if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) - return NULL; - - /* legacy: encode err as ptr */ - return ERR_PTR(err); + return NULL; } /* handle pointer-returning APIs' error handling */ @@ -526,11 +514,7 @@ static inline void *libbpf_ptr(void *ret) if (IS_ERR(ret)) errno = -PTR_ERR(ret); - if (libbpf_mode & LIBBPF_STRICT_CLEAN_PTRS) - return IS_ERR(ret) ? NULL : ret; - - /* legacy: pass-through original pointer */ - return ret; + return IS_ERR(ret) ? NULL : ret; } static inline bool str_is_empty(const char *s) diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h index d7bcbd01f66f..863f49df8bf4 100644 --- a/tools/lib/bpf/libbpf_legacy.h +++ b/tools/lib/bpf/libbpf_legacy.h @@ -20,6 +20,11 @@ extern "C" { #endif +/* As of libbpf 1.0 libbpf_set_strict_mode() and enum libbpf_struct_mode have + * no effect. But they are left in libbpf_legacy.h so that applications that + * prepared for libbpf 1.0 before final release by using + * libbpf_set_strict_mode() still work with libbpf 1.0+ without any changes. + */ enum libbpf_strict_mode { /* Turn on all supported strict features of libbpf to simulate libbpf * v1.0 behavior. @@ -88,6 +93,25 @@ enum libbpf_strict_mode { LIBBPF_API int libbpf_set_strict_mode(enum libbpf_strict_mode mode); +/** + * @brief **libbpf_get_error()** extracts the error code from the passed + * pointer + * @param ptr pointer returned from libbpf API function + * @return error code; or 0 if no error occured + * + * Note, as of libbpf 1.0 this function is not necessary and not recommended + * to be used. Libbpf doesn't return error code embedded into the pointer + * itself. Instead, NULL is returned on error and error code is passed through + * thread-local errno variable. **libbpf_get_error()** is just returning -errno + * value if it receives NULL, which is correct only if errno hasn't been + * modified between libbpf API call and corresponding **libbpf_get_error()** + * call. Prefer to check return for NULL and use errno directly. + * + * This API is left in libbpf 1.0 to allow applications that were 1.0-ready + * before final libbpf 1.0 without needing to change them. + */ +LIBBPF_API long libbpf_get_error(const void *ptr); + #define DECLARE_LIBBPF_OPTS LIBBPF_OPTS /* "Discouraged" APIs which don't follow consistent libbpf naming patterns. -- cgit From a4b2f3cf699f8ec3964722e7ef3f37f809701172 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Tue, 28 Jun 2022 10:43:12 -0700 Subject: libbpf: implement bpf_prog_query_opts Implement bpf_prog_query_opts as a more expendable version of bpf_prog_query. Expose new prog_attach_flags and attach_btf_func_id as well: * prog_attach_flags is a per-program attach_type; relevant only for lsm cgroup program which might have different attach_flags per attach_btf_id * attach_btf_func_id is a new field expose for prog_query which specifies real btf function id for lsm cgroup attachments Acked-by: Martin KaFai Lau Acked-by: Andrii Nakryiko Signed-off-by: Stanislav Fomichev Link: https://lore.kernel.org/r/20220628174314.1216643-10-sdf@google.com Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 38 +++++++++++++++++++++++++++++++------- tools/lib/bpf/bpf.h | 15 +++++++++++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 47 insertions(+), 7 deletions(-) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 6d848b02c1e0..5eb0df90eb2b 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -795,24 +795,48 @@ int bpf_iter_create(int link_fd) return libbpf_err_errno(fd); } -int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, - __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) +int bpf_prog_query_opts(int target_fd, + enum bpf_attach_type type, + struct bpf_prog_query_opts *opts) { union bpf_attr attr; int ret; + if (!OPTS_VALID(opts, bpf_prog_query_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, sizeof(attr)); + attr.query.target_fd = target_fd; attr.query.attach_type = type; - attr.query.query_flags = query_flags; - attr.query.prog_cnt = *prog_cnt; - attr.query.prog_ids = ptr_to_u64(prog_ids); + attr.query.query_flags = OPTS_GET(opts, query_flags, 0); + attr.query.prog_cnt = OPTS_GET(opts, prog_cnt, 0); + attr.query.prog_ids = ptr_to_u64(OPTS_GET(opts, prog_ids, NULL)); + attr.query.prog_attach_flags = ptr_to_u64(OPTS_GET(opts, prog_attach_flags, NULL)); ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr)); + OPTS_SET(opts, attach_flags, attr.query.attach_flags); + OPTS_SET(opts, prog_cnt, attr.query.prog_cnt); + + return libbpf_err_errno(ret); +} + +int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, + __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) +{ + LIBBPF_OPTS(bpf_prog_query_opts, opts); + int ret; + + opts.query_flags = query_flags; + opts.prog_ids = prog_ids; + opts.prog_cnt = *prog_cnt; + + ret = bpf_prog_query_opts(target_fd, type, &opts); + if (attach_flags) - *attach_flags = attr.query.attach_flags; - *prog_cnt = attr.query.prog_cnt; + *attach_flags = opts.attach_flags; + *prog_cnt = opts.prog_cnt; return libbpf_err_errno(ret); } diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index af7baf5da74d..88a7cc4bd76f 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -359,9 +359,24 @@ LIBBPF_API int bpf_map_get_fd_by_id(__u32 id); LIBBPF_API int bpf_btf_get_fd_by_id(__u32 id); LIBBPF_API int bpf_link_get_fd_by_id(__u32 id); LIBBPF_API int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len); + +struct bpf_prog_query_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + __u32 query_flags; + __u32 attach_flags; /* output argument */ + __u32 *prog_ids; + __u32 prog_cnt; /* input+output argument */ + __u32 *prog_attach_flags; +}; +#define bpf_prog_query_opts__last_field prog_attach_flags + +LIBBPF_API int bpf_prog_query_opts(int target_fd, + enum bpf_attach_type type, + struct bpf_prog_query_opts *opts); LIBBPF_API int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt); + LIBBPF_API int bpf_raw_tracepoint_open(const char *name, int prog_fd); LIBBPF_API int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type, diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 43c6697a6d27..94b589ecfeaa 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -355,6 +355,7 @@ LIBBPF_0.8.0 { LIBBPF_1.0.0 { global: + bpf_prog_query_opts; btf__add_enum64; btf__add_enum64_value; libbpf_bpf_attach_type_str; -- cgit From 395fc4fa33e98944384d0d6c8b3ecd9fb4b50d00 Mon Sep 17 00:00:00 2001 From: Joe Burton Date: Fri, 29 Jul 2022 20:27:27 +0000 Subject: libbpf: Add bpf_obj_get_opts() Add an extensible variant of bpf_obj_get() capable of setting the `file_flags` parameter. This parameter is needed to enable unprivileged access to BPF maps. Without a method like this, users must manually make the syscall. Signed-off-by: Joe Burton Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220729202727.3311806-1-jevburton.kernel@gmail.com --- tools/lib/bpf/bpf.c | 9 +++++++++ tools/lib/bpf/bpf.h | 11 +++++++++++ tools/lib/bpf/libbpf.map | 1 + 3 files changed, 21 insertions(+) (limited to 'tools/lib/bpf/bpf.c') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 5eb0df90eb2b..efcc06dafbd9 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -578,12 +578,21 @@ int bpf_obj_pin(int fd, const char *pathname) } int bpf_obj_get(const char *pathname) +{ + return bpf_obj_get_opts(pathname, NULL); +} + +int bpf_obj_get_opts(const char *pathname, const struct bpf_obj_get_opts *opts) { union bpf_attr attr; int fd; + if (!OPTS_VALID(opts, bpf_obj_get_opts)) + return libbpf_err(-EINVAL); + memset(&attr, 0, sizeof(attr)); attr.pathname = ptr_to_u64((void *)pathname); + attr.file_flags = OPTS_GET(opts, file_flags, 0); fd = sys_bpf_fd(BPF_OBJ_GET, &attr, sizeof(attr)); return libbpf_err_errno(fd); diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index 88a7cc4bd76f..9c50beabdd14 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -270,8 +270,19 @@ LIBBPF_API int bpf_map_update_batch(int fd, const void *keys, const void *values __u32 *count, const struct bpf_map_batch_opts *opts); +struct bpf_obj_get_opts { + size_t sz; /* size of this struct for forward/backward compatibility */ + + __u32 file_flags; + + size_t :0; +}; +#define bpf_obj_get_opts__last_field file_flags + LIBBPF_API int bpf_obj_pin(int fd, const char *pathname); LIBBPF_API int bpf_obj_get(const char *pathname); +LIBBPF_API int bpf_obj_get_opts(const char *pathname, + const struct bpf_obj_get_opts *opts); struct bpf_prog_attach_opts { size_t sz; /* size of this struct for forward/backward compatibility */ diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 0625adb9e888..119e6e1ea7f1 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -355,6 +355,7 @@ LIBBPF_0.8.0 { LIBBPF_1.0.0 { global: + bpf_obj_get_opts; bpf_prog_query_opts; bpf_program__attach_ksyscall; btf__add_enum64; -- cgit