diff options
Diffstat (limited to 'tools/lib/bpf/libbpf.c')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 154 |
1 files changed, 125 insertions, 29 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 96ef18cfeffb..7132c6bdec02 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -189,6 +189,7 @@ struct bpf_program { enum bpf_attach_type expected_attach_type; __u32 attach_btf_id; + __u32 attach_prog_fd; void *func_info; __u32 func_info_rec_size; __u32 func_info_cnt; @@ -3683,8 +3684,13 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.insns = insns; load_attr.insns_cnt = insns_cnt; load_attr.license = license; - load_attr.kern_version = kern_version; - load_attr.prog_ifindex = prog->prog_ifindex; + if (prog->type == BPF_PROG_TYPE_TRACING) { + load_attr.attach_prog_fd = prog->attach_prog_fd; + load_attr.attach_btf_id = prog->attach_btf_id; + } else { + load_attr.kern_version = kern_version; + load_attr.prog_ifindex = prog->prog_ifindex; + } /* if .BTF.ext was loaded, kernel supports associated BTF for prog */ if (prog->obj->btf_ext) btf_fd = bpf_object__btf_fd(prog->obj); @@ -3699,7 +3705,6 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt, load_attr.line_info_cnt = prog->line_info_cnt; load_attr.log_level = prog->log_level; load_attr.prog_flags = prog->prog_flags; - load_attr.attach_btf_id = prog->attach_btf_id; retry_load: log_buf = malloc(log_buf_size); @@ -3856,8 +3861,9 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) return 0; } -static int libbpf_attach_btf_id_by_name(const char *name, __u32 *btf_id); - +static int libbpf_find_attach_btf_id(const char *name, + enum bpf_attach_type attach_type, + __u32 attach_prog_fd); static struct bpf_object * __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, struct bpf_object_open_opts *opts) @@ -3868,6 +3874,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, const char *obj_name; char tmp_name[64]; bool relaxed_maps; + __u32 attach_prog_fd; int err; if (elf_version(EV_CURRENT) == EV_NONE) { @@ -3898,6 +3905,7 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false); relaxed_maps = OPTS_GET(opts, relaxed_maps, false); pin_root_path = OPTS_GET(opts, pin_root_path, NULL); + attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0); CHECK_ERR(bpf_object__elf_init(obj), err, out); CHECK_ERR(bpf_object__check_endianness(obj), err, out); @@ -3910,7 +3918,6 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, bpf_object__for_each_program(prog, obj) { enum bpf_prog_type prog_type; enum bpf_attach_type attach_type; - __u32 btf_id; err = libbpf_prog_type_by_name(prog->section_name, &prog_type, &attach_type); @@ -3923,10 +3930,13 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz, bpf_program__set_type(prog, prog_type); bpf_program__set_expected_attach_type(prog, attach_type); if (prog_type == BPF_PROG_TYPE_TRACING) { - err = libbpf_attach_btf_id_by_name(prog->section_name, &btf_id); - if (err) + err = libbpf_find_attach_btf_id(prog->section_name, + attach_type, + attach_prog_fd); + if (err <= 0) goto out; - prog->attach_btf_id = btf_id; + prog->attach_btf_id = err; + prog->attach_prog_fd = attach_prog_fd; } } @@ -4935,6 +4945,10 @@ static const struct { BPF_PROG_SEC("raw_tp/", BPF_PROG_TYPE_RAW_TRACEPOINT), BPF_PROG_BTF("tp_btf/", BPF_PROG_TYPE_TRACING, BPF_TRACE_RAW_TP), + BPF_PROG_BTF("fentry/", BPF_PROG_TYPE_TRACING, + BPF_TRACE_FENTRY), + BPF_PROG_BTF("fexit/", BPF_PROG_TYPE_TRACING, + BPF_TRACE_FEXIT), BPF_PROG_SEC("xdp", BPF_PROG_TYPE_XDP), BPF_PROG_SEC("perf_event", BPF_PROG_TYPE_PERF_EVENT), BPF_PROG_SEC("lwt_in", BPF_PROG_TYPE_LWT_IN), @@ -5052,43 +5066,94 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, } #define BTF_PREFIX "btf_trace_" -static int libbpf_attach_btf_id_by_name(const char *name, __u32 *btf_id) +int libbpf_find_vmlinux_btf_id(const char *name, + enum bpf_attach_type attach_type) { struct btf *btf = bpf_core_find_kernel_btf(); - char raw_tp_btf_name[128] = BTF_PREFIX; - char *dst = raw_tp_btf_name + sizeof(BTF_PREFIX) - 1; - int ret, i, err = -EINVAL; + char raw_tp_btf[128] = BTF_PREFIX; + char *dst = raw_tp_btf + sizeof(BTF_PREFIX) - 1; + const char *btf_name; + int err = -EINVAL; + u32 kind; if (IS_ERR(btf)) { pr_warn("vmlinux BTF is not found\n"); return -EINVAL; } - if (!name) + if (attach_type == BPF_TRACE_RAW_TP) { + /* prepend "btf_trace_" prefix per kernel convention */ + strncat(dst, name, sizeof(raw_tp_btf) - sizeof(BTF_PREFIX)); + btf_name = raw_tp_btf; + kind = BTF_KIND_TYPEDEF; + } else { + btf_name = name; + kind = BTF_KIND_FUNC; + } + err = btf__find_by_name_kind(btf, btf_name, kind); + btf__free(btf); + return err; +} + +static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) +{ + struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info *info; + struct btf *btf = NULL; + int err = -EINVAL; + + info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0); + if (IS_ERR_OR_NULL(info_linear)) { + pr_warn("failed get_prog_info_linear for FD %d\n", + attach_prog_fd); + return -EINVAL; + } + info = &info_linear->info; + if (!info->btf_id) { + pr_warn("The target program doesn't have BTF\n"); + goto out; + } + if (btf__get_from_id(info->btf_id, &btf)) { + pr_warn("Failed to get BTF of the program\n"); goto out; + } + err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC); + btf__free(btf); + if (err <= 0) { + pr_warn("%s is not found in prog's BTF\n", name); + goto out; + } +out: + free(info_linear); + return err; +} + +static int libbpf_find_attach_btf_id(const char *name, + enum bpf_attach_type attach_type, + __u32 attach_prog_fd) +{ + int i, err; + + if (!name) + return -EINVAL; for (i = 0; i < ARRAY_SIZE(section_names); i++) { if (!section_names[i].is_attach_btf) continue; if (strncmp(name, section_names[i].sec, section_names[i].len)) continue; - /* prepend "btf_trace_" prefix per kernel convention */ - strncat(dst, name + section_names[i].len, - sizeof(raw_tp_btf_name) - sizeof(BTF_PREFIX)); - ret = btf__find_by_name(btf, raw_tp_btf_name); - if (ret <= 0) { - pr_warn("%s is not found in vmlinux BTF\n", dst); - goto out; - } - *btf_id = ret; - err = 0; - goto out; + if (attach_prog_fd) + err = libbpf_find_prog_btf_id(name + section_names[i].len, + attach_prog_fd); + else + err = libbpf_find_vmlinux_btf_id(name + section_names[i].len, + attach_type); + if (err <= 0) + pr_warn("%s is not found in vmlinux BTF\n", name); + return err; } pr_warn("failed to identify btf_id based on ELF section name '%s'\n", name); - err = -ESRCH; -out: - btf__free(btf); - return err; + return -ESRCH; } int libbpf_attach_type_by_name(const char *name, @@ -5716,6 +5781,37 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog, return (struct bpf_link *)link; } +struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog) +{ + char errmsg[STRERR_BUFSIZE]; + struct bpf_link_fd *link; + int prog_fd, pfd; + + prog_fd = bpf_program__fd(prog); + if (prog_fd < 0) { + pr_warn("program '%s': can't attach before loaded\n", + bpf_program__title(prog, false)); + return ERR_PTR(-EINVAL); + } + + link = malloc(sizeof(*link)); + if (!link) + return ERR_PTR(-ENOMEM); + link->link.destroy = &bpf_link__destroy_fd; + + pfd = bpf_raw_tracepoint_open(NULL, prog_fd); + if (pfd < 0) { + pfd = -errno; + free(link); + pr_warn("program '%s': failed to attach to trace: %s\n", + bpf_program__title(prog, false), + libbpf_strerror_r(pfd, errmsg, sizeof(errmsg))); + return ERR_PTR(pfd); + } + link->fd = pfd; + return (struct bpf_link *)link; +} + enum bpf_perf_event_ret bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, |