lib/bpf/usdt.c

271 	struct usdt_manager *man;
281 	man = calloc(1, sizeof(*man));
282 	if (!man)
285 	man->specs_map = specs_map;
286 	man->ip_to_spec_id_map = ip_to_spec_id_map;
292 	man->has_bpf_cookie = kernel_supports(obj, FEAT_BPF_COOKIE);
298 	man->has_sema_refcnt = faccessat(AT_FDCWD, ref_ctr_sysfs_path, F_OK, AT_EACCESS) == 0;
304 	man->has_uprobe_multi = kernel_supports(obj, FEAT_UPROBE_MULTI_LINK);
311 	man->has_uprobe_syscall = kernel_supports(obj, FEAT_UPROBE_SYSCALL);
312 	return man;
315 void usdt_manager_free(struct usdt_manager *man)
317 	if (IS_ERR_OR_NULL(man))
320 	free(man->free_spec_ids);
321 	free(man);
615 static int collect_usdt_targets(struct usdt_manager *man, struct elf_fd *elf_fd, const char *path,
727 		if (ehdr.e_type == ET_DYN && !man->has_bpf_cookie) {
775 			if (!man->has_sema_refcnt) {
821 		if (man->has_uprobe_syscall && has_nop_combo(elf_fd->fd, usdt_rel_ip)) {
874 	struct usdt_manager *man = usdt_link->usdt_man;
889 		if (!man->has_bpf_cookie) {
891 			(void)bpf_map_delete_elem(bpf_map__fd(man->ip_to_spec_id_map),
899 	if (!man->free_spec_ids) {
901 		man->free_spec_ids = usdt_link->spec_ids;
902 		man->free_spec_cnt = usdt_link->spec_cnt;
906 		size_t new_cnt = man->free_spec_cnt + usdt_link->spec_cnt;
909 		new_free_ids = libbpf_reallocarray(man->free_spec_ids, new_cnt,
921 			memcpy(new_free_ids + man->free_spec_cnt, usdt_link->spec_ids,
923 			man->free_spec_ids = new_free_ids;
924 			man->free_spec_cnt = new_cnt;
950 static int allocate_spec_id(struct usdt_manager *man, struct hashmap *specs_hash,
974 	if (man->free_spec_cnt) {
975 		*spec_id = man->free_spec_ids[man->free_spec_cnt - 1];
982 		man->free_spec_cnt--;
985 		if (man->next_free_spec_id >= bpf_map__max_entries(man->specs_map))
988 		*spec_id = man->next_free_spec_id;
995 		man->next_free_spec_id++;
1005 struct bpf_link *usdt_manager_attach_usdt(struct usdt_manager *man, const struct bpf_program *prog,
1020 	spec_map_fd = bpf_map__fd(man->specs_map);
1021 	ip_map_fd = bpf_map__fd(man->ip_to_spec_id_map);
1040 	err = collect_usdt_targets(man, &elf_fd, path, pid, usdt_provider, usdt_name,
1059 	link->usdt_man = man;
1063 	if (man->has_uprobe_multi) {
1094 		err = allocate_spec_id(man, specs_hash, link, target, &spec_id, &is_new);
1104 		if (!man->has_bpf_cookie &&
1118 		if (man->has_uprobe_multi) {
1124 			opts.bpf_cookie = man->has_bpf_cookie ? spec_id : 0;
1140 	if (man->has_uprobe_multi) {