diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 4249 |
1 files changed, 2434 insertions, 1815 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7f10dd501a52..184ce1684dcd 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -31,7 +31,6 @@ #include <linux/bpf.h> #include <linux/btf.h> #include <linux/filter.h> -#include <linux/list.h> #include <linux/limits.h> #include <linux/perf_event.h> #include <linux/ring_buffer.h> @@ -72,6 +71,136 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj); static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog); +static const char * const attach_type_name[] = { + [BPF_CGROUP_INET_INGRESS] = "cgroup_inet_ingress", + [BPF_CGROUP_INET_EGRESS] = "cgroup_inet_egress", + [BPF_CGROUP_INET_SOCK_CREATE] = "cgroup_inet_sock_create", + [BPF_CGROUP_INET_SOCK_RELEASE] = "cgroup_inet_sock_release", + [BPF_CGROUP_SOCK_OPS] = "cgroup_sock_ops", + [BPF_CGROUP_DEVICE] = "cgroup_device", + [BPF_CGROUP_INET4_BIND] = "cgroup_inet4_bind", + [BPF_CGROUP_INET6_BIND] = "cgroup_inet6_bind", + [BPF_CGROUP_INET4_CONNECT] = "cgroup_inet4_connect", + [BPF_CGROUP_INET6_CONNECT] = "cgroup_inet6_connect", + [BPF_CGROUP_INET4_POST_BIND] = "cgroup_inet4_post_bind", + [BPF_CGROUP_INET6_POST_BIND] = "cgroup_inet6_post_bind", + [BPF_CGROUP_INET4_GETPEERNAME] = "cgroup_inet4_getpeername", + [BPF_CGROUP_INET6_GETPEERNAME] = "cgroup_inet6_getpeername", + [BPF_CGROUP_INET4_GETSOCKNAME] = "cgroup_inet4_getsockname", + [BPF_CGROUP_INET6_GETSOCKNAME] = "cgroup_inet6_getsockname", + [BPF_CGROUP_UDP4_SENDMSG] = "cgroup_udp4_sendmsg", + [BPF_CGROUP_UDP6_SENDMSG] = "cgroup_udp6_sendmsg", + [BPF_CGROUP_SYSCTL] = "cgroup_sysctl", + [BPF_CGROUP_UDP4_RECVMSG] = "cgroup_udp4_recvmsg", + [BPF_CGROUP_UDP6_RECVMSG] = "cgroup_udp6_recvmsg", + [BPF_CGROUP_GETSOCKOPT] = "cgroup_getsockopt", + [BPF_CGROUP_SETSOCKOPT] = "cgroup_setsockopt", + [BPF_SK_SKB_STREAM_PARSER] = "sk_skb_stream_parser", + [BPF_SK_SKB_STREAM_VERDICT] = "sk_skb_stream_verdict", + [BPF_SK_SKB_VERDICT] = "sk_skb_verdict", + [BPF_SK_MSG_VERDICT] = "sk_msg_verdict", + [BPF_LIRC_MODE2] = "lirc_mode2", + [BPF_FLOW_DISSECTOR] = "flow_dissector", + [BPF_TRACE_RAW_TP] = "trace_raw_tp", + [BPF_TRACE_FENTRY] = "trace_fentry", + [BPF_TRACE_FEXIT] = "trace_fexit", + [BPF_MODIFY_RETURN] = "modify_return", + [BPF_LSM_MAC] = "lsm_mac", + [BPF_LSM_CGROUP] = "lsm_cgroup", + [BPF_SK_LOOKUP] = "sk_lookup", + [BPF_TRACE_ITER] = "trace_iter", + [BPF_XDP_DEVMAP] = "xdp_devmap", + [BPF_XDP_CPUMAP] = "xdp_cpumap", + [BPF_XDP] = "xdp", + [BPF_SK_REUSEPORT_SELECT] = "sk_reuseport_select", + [BPF_SK_REUSEPORT_SELECT_OR_MIGRATE] = "sk_reuseport_select_or_migrate", + [BPF_PERF_EVENT] = "perf_event", + [BPF_TRACE_KPROBE_MULTI] = "trace_kprobe_multi", +}; + +static const char * const link_type_name[] = { + [BPF_LINK_TYPE_UNSPEC] = "unspec", + [BPF_LINK_TYPE_RAW_TRACEPOINT] = "raw_tracepoint", + [BPF_LINK_TYPE_TRACING] = "tracing", + [BPF_LINK_TYPE_CGROUP] = "cgroup", + [BPF_LINK_TYPE_ITER] = "iter", + [BPF_LINK_TYPE_NETNS] = "netns", + [BPF_LINK_TYPE_XDP] = "xdp", + [BPF_LINK_TYPE_PERF_EVENT] = "perf_event", + [BPF_LINK_TYPE_KPROBE_MULTI] = "kprobe_multi", + [BPF_LINK_TYPE_STRUCT_OPS] = "struct_ops", +}; + +static const char * const map_type_name[] = { + [BPF_MAP_TYPE_UNSPEC] = "unspec", + [BPF_MAP_TYPE_HASH] = "hash", + [BPF_MAP_TYPE_ARRAY] = "array", + [BPF_MAP_TYPE_PROG_ARRAY] = "prog_array", + [BPF_MAP_TYPE_PERF_EVENT_ARRAY] = "perf_event_array", + [BPF_MAP_TYPE_PERCPU_HASH] = "percpu_hash", + [BPF_MAP_TYPE_PERCPU_ARRAY] = "percpu_array", + [BPF_MAP_TYPE_STACK_TRACE] = "stack_trace", + [BPF_MAP_TYPE_CGROUP_ARRAY] = "cgroup_array", + [BPF_MAP_TYPE_LRU_HASH] = "lru_hash", + [BPF_MAP_TYPE_LRU_PERCPU_HASH] = "lru_percpu_hash", + [BPF_MAP_TYPE_LPM_TRIE] = "lpm_trie", + [BPF_MAP_TYPE_ARRAY_OF_MAPS] = "array_of_maps", + [BPF_MAP_TYPE_HASH_OF_MAPS] = "hash_of_maps", + [BPF_MAP_TYPE_DEVMAP] = "devmap", + [BPF_MAP_TYPE_DEVMAP_HASH] = "devmap_hash", + [BPF_MAP_TYPE_SOCKMAP] = "sockmap", + [BPF_MAP_TYPE_CPUMAP] = "cpumap", + [BPF_MAP_TYPE_XSKMAP] = "xskmap", + [BPF_MAP_TYPE_SOCKHASH] = "sockhash", + [BPF_MAP_TYPE_CGROUP_STORAGE] = "cgroup_storage", + [BPF_MAP_TYPE_REUSEPORT_SOCKARRAY] = "reuseport_sockarray", + [BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE] = "percpu_cgroup_storage", + [BPF_MAP_TYPE_QUEUE] = "queue", + [BPF_MAP_TYPE_STACK] = "stack", + [BPF_MAP_TYPE_SK_STORAGE] = "sk_storage", + [BPF_MAP_TYPE_STRUCT_OPS] = "struct_ops", + [BPF_MAP_TYPE_RINGBUF] = "ringbuf", + [BPF_MAP_TYPE_INODE_STORAGE] = "inode_storage", + [BPF_MAP_TYPE_TASK_STORAGE] = "task_storage", + [BPF_MAP_TYPE_BLOOM_FILTER] = "bloom_filter", + [BPF_MAP_TYPE_USER_RINGBUF] = "user_ringbuf", +}; + +static const char * const prog_type_name[] = { + [BPF_PROG_TYPE_UNSPEC] = "unspec", + [BPF_PROG_TYPE_SOCKET_FILTER] = "socket_filter", + [BPF_PROG_TYPE_KPROBE] = "kprobe", + [BPF_PROG_TYPE_SCHED_CLS] = "sched_cls", + [BPF_PROG_TYPE_SCHED_ACT] = "sched_act", + [BPF_PROG_TYPE_TRACEPOINT] = "tracepoint", + [BPF_PROG_TYPE_XDP] = "xdp", + [BPF_PROG_TYPE_PERF_EVENT] = "perf_event", + [BPF_PROG_TYPE_CGROUP_SKB] = "cgroup_skb", + [BPF_PROG_TYPE_CGROUP_SOCK] = "cgroup_sock", + [BPF_PROG_TYPE_LWT_IN] = "lwt_in", + [BPF_PROG_TYPE_LWT_OUT] = "lwt_out", + [BPF_PROG_TYPE_LWT_XMIT] = "lwt_xmit", + [BPF_PROG_TYPE_SOCK_OPS] = "sock_ops", + [BPF_PROG_TYPE_SK_SKB] = "sk_skb", + [BPF_PROG_TYPE_CGROUP_DEVICE] = "cgroup_device", + [BPF_PROG_TYPE_SK_MSG] = "sk_msg", + [BPF_PROG_TYPE_RAW_TRACEPOINT] = "raw_tracepoint", + [BPF_PROG_TYPE_CGROUP_SOCK_ADDR] = "cgroup_sock_addr", + [BPF_PROG_TYPE_LWT_SEG6LOCAL] = "lwt_seg6local", + [BPF_PROG_TYPE_LIRC_MODE2] = "lirc_mode2", + [BPF_PROG_TYPE_SK_REUSEPORT] = "sk_reuseport", + [BPF_PROG_TYPE_FLOW_DISSECTOR] = "flow_dissector", + [BPF_PROG_TYPE_CGROUP_SYSCTL] = "cgroup_sysctl", + [BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE] = "raw_tracepoint_writable", + [BPF_PROG_TYPE_CGROUP_SOCKOPT] = "cgroup_sockopt", + [BPF_PROG_TYPE_TRACING] = "tracing", + [BPF_PROG_TYPE_STRUCT_OPS] = "struct_ops", + [BPF_PROG_TYPE_EXT] = "ext", + [BPF_PROG_TYPE_LSM] = "lsm", + [BPF_PROG_TYPE_SK_LOOKUP] = "sk_lookup", + [BPF_PROG_TYPE_SYSCALL] = "syscall", +}; + static int __base_pr(enum libbpf_print_level level, const char *format, va_list args) { @@ -95,13 +224,18 @@ __printf(2, 3) void libbpf_print(enum libbpf_print_level level, const char *format, ...) { va_list args; + int old_errno; if (!__libbpf_pr) return; + old_errno = errno; + va_start(args, format); __libbpf_pr(level, format, args); va_end(args); + + errno = old_errno; } static void pr_perm_msg(int err) @@ -151,20 +285,9 @@ 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_STRICT_LAST is the last power-of-2 value used + 1, so to - * get all possible values we compensate last +1, and then (2*x - 1) - * to get the bit mask - */ - if (mode != LIBBPF_STRICT_ALL - && (mode & ~((__LIBBPF_STRICT_LAST - 1) * 2 - 1))) - return errno = EINVAL, -EINVAL; - - libbpf_mode = mode; + /* as of v1.0 libbpf_set_strict_mode() is a no-op */ return 0; } @@ -209,12 +332,6 @@ struct reloc_desc { }; }; -struct bpf_sec_def; - -typedef int (*init_fn_t)(struct bpf_program *prog, long cookie); -typedef int (*preload_fn_t)(struct bpf_program *prog, struct bpf_prog_load_opts *opts, long cookie); -typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long cookie); - /* stored as sec_def->cookie for all libbpf-supported SEC()s */ enum sec_def_flags { SEC_NONE = 0, @@ -233,19 +350,20 @@ enum sec_def_flags { SEC_ATTACH_BTF = 4, /* BPF program type allows sleeping/blocking in kernel */ SEC_SLEEPABLE = 8, - /* allow non-strict prefix matching */ - SEC_SLOPPY_PFX = 16, + /* BPF program support non-linear XDP buffer */ + SEC_XDP_FRAGS = 16, }; struct bpf_sec_def { - const char *sec; + char *sec; enum bpf_prog_type prog_type; enum bpf_attach_type expected_attach_type; long cookie; + int handler_id; - init_fn_t init_fn; - preload_fn_t preload_fn; - attach_fn_t attach_fn; + libbpf_prog_setup_fn_t prog_setup_fn; + libbpf_prog_prepare_load_fn_t prog_prepare_load_fn; + libbpf_prog_attach_fn_t prog_attach_fn; }; /* @@ -253,9 +371,10 @@ 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 */ @@ -275,12 +394,6 @@ 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, @@ -301,24 +414,20 @@ struct bpf_program { size_t log_size; __u32 log_level; - struct { - int nr; - int *fds; - } instances; - bpf_program_prep_t preprocessor; - struct bpf_object *obj; - void *priv; - bpf_program_clear_priv_t clear_priv; - bool load; + int fd; + bool autoload; + bool autoattach; bool mark_btf_static; enum bpf_prog_type type; enum bpf_attach_type expected_attach_type; + int prog_ifindex; __u32 attach_btf_obj_fd; __u32 attach_btf_id; __u32 attach_prog_fd; + void *func_info; __u32 func_info_rec_size; __u32 func_info_cnt; @@ -365,7 +474,16 @@ enum libbpf_map_type { LIBBPF_MAP_KCONFIG, }; +struct bpf_map_def { + unsigned int type; + unsigned int key_size; + unsigned int value_size; + unsigned int max_entries; + unsigned int map_flags; +}; + struct bpf_map { + struct bpf_object *obj; char *name; /* real_name is defined for special internal maps (.rodata*, * .data*, .bss, .kconfig) and preserves their original ELF section @@ -384,8 +502,6 @@ struct bpf_map { __u32 btf_key_type_id; __u32 btf_value_type_id; __u32 btf_vmlinux_value_type_id; - void *priv; - bpf_map_clear_priv_t clear_priv; enum libbpf_map_type libbpf_type; void *mmaped; struct bpf_struct_ops *st_ops; @@ -395,7 +511,7 @@ struct bpf_map { char *pin_path; bool pinned; bool reused; - bool skipped; + bool autocreate; __u64 map_extra; }; @@ -448,8 +564,6 @@ struct extern_desc { }; }; -static LIST_HEAD(bpf_objects_list); - struct module_btf { struct btf *btf; char *name; @@ -484,7 +598,6 @@ struct elf_state { size_t strtabidx; struct elf_sec_desc *secs; int sec_cnt; - int maps_shndx; int btf_maps_shndx; __u32 btf_maps_sec_btf_id; int text_shndx; @@ -492,6 +605,8 @@ struct elf_state { int st_ops_shndx; }; +struct usdt_manager; + struct bpf_object { char name[BPF_OBJ_NAME_LEN]; char license[64]; @@ -516,12 +631,6 @@ struct bpf_object { /* Information when doing ELF related work. Only valid if efile.elf is not NULL */ struct elf_state efile; - /* - * All loaded bpf_object are linked in a list, which is - * hidden to caller. bpf_objects__<func> handlers deal with - * all objects. - */ - struct list_head list; struct btf *btf; struct btf_ext *btf_ext; @@ -547,13 +656,12 @@ struct bpf_object { size_t log_size; __u32 log_level; - void *priv; - bpf_object_clear_priv_t clear_priv; - int *fd_array; size_t fd_array_cap; size_t fd_array_cnt; + struct usdt_manager *usdt_man; + char path[]; }; @@ -569,25 +677,10 @@ static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx); void bpf_program__unload(struct bpf_program *prog) { - int i; - if (!prog) return; - /* - * If the object is opened but the program was never loaded, - * it is possible that prog->instances.nr == -1. - */ - if (prog->instances.nr > 0) { - for (i = 0; i < prog->instances.nr; i++) - zclose(prog->instances.fds[i]); - } else if (prog->instances.nr != -1) { - pr_warn("Internal error: instances.nr is %d\n", - prog->instances.nr); - } - - prog->instances.nr = -1; - zfree(&prog->instances.fds); + zclose(prog->fd); zfree(&prog->func_info); zfree(&prog->line_info); @@ -598,16 +691,9 @@ static void bpf_program__exit(struct bpf_program *prog) if (!prog) return; - if (prog->clear_priv) - prog->clear_priv(prog, prog->priv); - - prog->priv = NULL; - prog->clear_priv = NULL; - bpf_program__unload(prog); zfree(&prog->name); zfree(&prog->sec_name); - zfree(&prog->pin_name); zfree(&prog->insns); zfree(&prog->reloc_desc); @@ -616,26 +702,6 @@ 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 && @@ -677,10 +743,21 @@ bpf_object__init_prog(struct bpf_object *obj, struct bpf_program *prog, prog->insns_cnt = prog->sec_insn_cnt; prog->type = BPF_PROG_TYPE_UNSPEC; - prog->load = true; + prog->fd = -1; + + /* libbpf's convention for SEC("?abc...") is that it's just like + * SEC("abc...") but the corresponding bpf_program starts out with + * autoload set to false. + */ + if (sec_name[0] == '?') { + prog->autoload = false; + /* from now on forget there was ? in section name */ + sec_name++; + } else { + prog->autoload = true; + } - prog->instances.fds = NULL; - prog->instances.nr = -1; + prog->autoattach = true; /* inherit object's log_level */ prog->log_level = obj->log_level; @@ -693,10 +770,6 @@ 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; @@ -811,7 +884,7 @@ __u32 get_kernel_version(void) __u32 major, minor, patch; struct utsname info; - if (access(ubuntu_kver_file, R_OK) == 0) { + if (faccessat(AT_FDCWD, ubuntu_kver_file, R_OK, AT_EACCESS) == 0) { FILE *f; f = fopen(ubuntu_kver_file, "r"); @@ -1178,7 +1251,6 @@ static struct bpf_object *bpf_object__new(const char *path, size_t obj_buf_sz, const char *obj_name) { - bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST); struct bpf_object *obj; char *end; @@ -1208,7 +1280,6 @@ static struct bpf_object *bpf_object__new(const char *path, */ obj->efile.obj_buf = obj_buf; obj->efile.obj_buf_sz = obj_buf_sz; - obj->efile.maps_shndx = -1; obj->efile.btf_maps_shndx = -1; obj->efile.st_ops_shndx = -1; obj->kconfig_map_idx = -1; @@ -1216,9 +1287,6 @@ static struct bpf_object *bpf_object__new(const char *path, obj->kern_version = get_kernel_version(); obj->loaded = false; - INIT_LIST_HEAD(&obj->list); - if (!strict) - list_add(&obj->list, &bpf_objects_list); return obj; } @@ -1227,10 +1295,8 @@ static void bpf_object__elf_finish(struct bpf_object *obj) if (!obj->efile.elf) return; - if (obj->efile.elf) { - elf_end(obj->efile.elf); - obj->efile.elf = NULL; - } + elf_end(obj->efile.elf); + obj->efile.elf = NULL; obj->efile.symbols = NULL; obj->efile.st_ops_data = NULL; @@ -1253,10 +1319,7 @@ static int bpf_object__elf_init(struct bpf_object *obj) } if (obj->efile.obj_buf_sz > 0) { - /* - * obj_buf should have been validated by - * bpf_object__open_buffer(). - */ + /* obj_buf should have been validated by bpf_object__open_mem(). */ elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz); } else { obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC); @@ -1378,22 +1441,20 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type) static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size) { - int ret = -ENOENT; Elf_Data *data; Elf_Scn *scn; - *size = 0; if (!name) return -EINVAL; scn = elf_sec_by_name(obj, name); data = elf_sec_data(obj, scn); if (data) { - ret = 0; /* found it */ *size = data->d_size; + return 0; /* found it */ } - return *size ? 0 : ret; + return -ENOENT; } static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off) @@ -1408,8 +1469,11 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _ for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) { Elf64_Sym *sym = elf_sym_by_idx(obj, si); - if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL || - ELF64_ST_TYPE(sym->st_info) != STT_OBJECT) + if (ELF64_ST_TYPE(sym->st_info) != STT_OBJECT) + continue; + + if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL && + ELF64_ST_BIND(sym->st_info) != STB_WEAK) continue; sname = elf_sym_str(obj, sym->st_name); @@ -1428,36 +1492,21 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj) { - struct bpf_map *new_maps; - size_t new_cap; - int i; - - if (obj->nr_maps < obj->maps_cap) - return &obj->maps[obj->nr_maps++]; - - new_cap = max((size_t)4, obj->maps_cap * 3 / 2); - new_maps = libbpf_reallocarray(obj->maps, new_cap, sizeof(*obj->maps)); - if (!new_maps) { - pr_warn("alloc maps for object failed\n"); - return ERR_PTR(-ENOMEM); - } + struct bpf_map *map; + int err; - obj->maps_cap = new_cap; - obj->maps = new_maps; + err = libbpf_ensure_mem((void **)&obj->maps, &obj->maps_cap, + sizeof(*obj->maps), obj->nr_maps + 1); + if (err) + return ERR_PTR(err); - /* zero out new maps */ - memset(obj->maps + obj->nr_maps, 0, - (obj->maps_cap - obj->nr_maps) * sizeof(*obj->maps)); - /* - * fill all fd with -1 so won't close incorrect fd (fd=0 is stdin) - * when failure (zclose won't close negative fd)). - */ - for (i = obj->nr_maps; i < obj->maps_cap; i++) { - obj->maps[i].fd = -1; - obj->maps[i].inner_map_fd = -1; - } + map = &obj->maps[obj->nr_maps++]; + map->obj = obj; + map->fd = -1; + map->inner_map_fd = -1; + map->autocreate = true; - return &obj->maps[obj->nr_maps++]; + return map; } static size_t bpf_map_mmap_sz(const struct bpf_map *map) @@ -1529,6 +1578,9 @@ static char *internal_map_name(struct bpf_object *obj, const char *real_name) } static int +bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map); + +static int bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, const char *real_name, int sec_idx, void *data, size_t data_sz) { @@ -1575,6 +1627,9 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type, return err; } + /* failures are fine because of maps like .rodata.str1.1 */ + (void) bpf_map_find_btf_info(obj, map); + if (data) memcpy(map->mmaped, data, data_sz); @@ -1594,6 +1649,10 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj) for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) { sec_desc = &obj->efile.secs[sec_idx]; + /* Skip recognized sections with size 0. */ + if (!sec_desc->data || sec_desc->data->d_size == 0) + continue; + switch (sec_desc->sec_type) { case SEC_DATA: sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx)); @@ -1646,7 +1705,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, switch (ext->kcfg.type) { case KCFG_BOOL: if (value == 'm') { - pr_warn("extern (kcfg) %s=%c should be tristate or char\n", + pr_warn("extern (kcfg) '%s': value '%c' implies tristate or char type\n", ext->name, value); return -EINVAL; } @@ -1667,7 +1726,7 @@ static int set_kcfg_value_tri(struct extern_desc *ext, void *ext_val, case KCFG_INT: case KCFG_CHAR_ARR: default: - pr_warn("extern (kcfg) %s=%c should be bool, tristate, or char\n", + pr_warn("extern (kcfg) '%s': value '%c' implies bool, tristate, or char type\n", ext->name, value); return -EINVAL; } @@ -1681,7 +1740,8 @@ static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, size_t len; if (ext->kcfg.type != KCFG_CHAR_ARR) { - pr_warn("extern (kcfg) %s=%s should be char array\n", ext->name, value); + pr_warn("extern (kcfg) '%s': value '%s' implies char array type\n", + ext->name, value); return -EINVAL; } @@ -1695,7 +1755,7 @@ static int set_kcfg_value_str(struct extern_desc *ext, char *ext_val, /* strip quotes */ len -= 2; if (len >= ext->kcfg.sz) { - pr_warn("extern (kcfg) '%s': long string config %s of (%zu bytes) truncated to %d bytes\n", + pr_warn("extern (kcfg) '%s': long string '%s' of (%zu bytes) truncated to %d bytes\n", ext->name, value, len, ext->kcfg.sz - 1); len = ext->kcfg.sz - 1; } @@ -1752,13 +1812,20 @@ static bool is_kcfg_value_in_range(const struct extern_desc *ext, __u64 v) static int set_kcfg_value_num(struct extern_desc *ext, void *ext_val, __u64 value) { - if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { - pr_warn("extern (kcfg) %s=%llu should be integer\n", + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR && + ext->kcfg.type != KCFG_BOOL) { + pr_warn("extern (kcfg) '%s': value '%llu' implies integer, char, or boolean type\n", + ext->name, (unsigned long long)value); + return -EINVAL; + } + if (ext->kcfg.type == KCFG_BOOL && value > 1) { + pr_warn("extern (kcfg) '%s': value '%llu' isn't boolean compatible\n", ext->name, (unsigned long long)value); return -EINVAL; + } if (!is_kcfg_value_in_range(ext, value)) { - pr_warn("extern (kcfg) %s=%llu value doesn't fit in %d bytes\n", + pr_warn("extern (kcfg) '%s': value '%llu' doesn't fit in %d bytes\n", ext->name, (unsigned long long)value, ext->kcfg.sz); return -ERANGE; } @@ -1822,16 +1889,19 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj, /* assume integer */ err = parse_u64(value, &num); if (err) { - pr_warn("extern (kcfg) %s=%s should be integer\n", - ext->name, value); + pr_warn("extern (kcfg) '%s': value '%s' isn't a valid integer\n", ext->name, value); return err; } + if (ext->kcfg.type != KCFG_INT && ext->kcfg.type != KCFG_CHAR) { + pr_warn("extern (kcfg) '%s': value '%s' implies integer type\n", ext->name, value); + return -EINVAL; + } err = set_kcfg_value_num(ext, ext_val, num); break; } if (err) return err; - pr_debug("extern (kcfg) %s=%s\n", ext->name, value); + pr_debug("extern (kcfg) '%s': set to %s\n", ext->name, value); return 0; } @@ -1927,133 +1997,6 @@ 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 (!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; - } - - 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)); - } - } - return 0; -} - const struct btf_type * skip_mods_and_typedefs(const struct btf *btf, __u32 id, __u32 *res_id) { @@ -2107,6 +2050,7 @@ static const char *__btf_kind_str(__u16 kind) case BTF_KIND_FLOAT: return "float"; case BTF_KIND_DECL_TAG: return "decl_tag"; case BTF_KIND_TYPE_TAG: return "type_tag"; + case BTF_KIND_ENUM64: return "enum64"; default: return "unknown"; } } @@ -2153,23 +2097,41 @@ static bool get_map_field_int(const char *map_name, const struct btf *btf, return true; } +static int pathname_concat(char *buf, size_t buf_sz, const char *path, const char *name) +{ + int len; + + len = snprintf(buf, buf_sz, "%s/%s", path, name); + if (len < 0) + return -EINVAL; + if (len >= buf_sz) + return -ENAMETOOLONG; + + return 0; +} + static int build_map_pin_path(struct bpf_map *map, const char *path) { char buf[PATH_MAX]; - int len; + int err; if (!path) path = "/sys/fs/bpf"; - len = snprintf(buf, PATH_MAX, "%s/%s", path, bpf_map__name(map)); - if (len < 0) - return -EINVAL; - else if (len >= PATH_MAX) - return -ENAMETOOLONG; + err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); + if (err) + return err; return bpf_map__set_pin_path(map, buf); } +/* should match definition in bpf_helpers.h */ +enum libbpf_pin_type { + LIBBPF_PIN_NONE, + /* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */ + LIBBPF_PIN_BY_NAME, +}; + int parse_btf_map_def(const char *map_name, struct btf *btf, const struct btf_type *def_t, bool strict, struct btf_map_def *map_def, struct btf_map_def *inner_def) @@ -2391,6 +2353,43 @@ int parse_btf_map_def(const char *map_name, struct btf *btf, return 0; } +static size_t adjust_ringbuf_sz(size_t sz) +{ + __u32 page_sz = sysconf(_SC_PAGE_SIZE); + __u32 mul; + + /* if user forgot to set any size, make sure they see error */ + if (sz == 0) + return 0; + /* Kernel expects BPF_MAP_TYPE_RINGBUF's max_entries to be + * a power-of-2 multiple of kernel's page size. If user diligently + * satisified these conditions, pass the size through. + */ + if ((sz % page_sz) == 0 && is_pow_of_2(sz / page_sz)) + return sz; + + /* Otherwise find closest (page_sz * power_of_2) product bigger than + * user-set size to satisfy both user size request and kernel + * requirements and substitute correct max_entries for map creation. + */ + for (mul = 1; mul <= UINT_MAX / page_sz; mul <<= 1) { + if (mul * page_sz > sz) + return mul * page_sz; + } + + /* if it's impossible to satisfy the conditions (i.e., user size is + * very close to UINT_MAX but is not a power-of-2 multiple of + * page_size) then just return original size and let kernel reject it + */ + return sz; +} + +static bool map_is_ringbuf(const struct bpf_map *map) +{ + return map->def.type == BPF_MAP_TYPE_RINGBUF || + map->def.type == BPF_MAP_TYPE_USER_RINGBUF; +} + static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def) { map->def.type = def->map_type; @@ -2404,6 +2403,10 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def map->btf_key_type_id = def->key_type_id; map->btf_value_type_id = def->value_type_id; + /* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ + if (map_is_ringbuf(map)) + map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries); + if (def->parts & MAP_DEF_MAP_TYPE) pr_debug("map '%s': found type = %u.\n", map->name, def->map_type); @@ -2538,6 +2541,10 @@ static int bpf_object__init_user_btf_map(struct bpf_object *obj, fill_map_from_def(map->inner_map, &inner_def); } + err = bpf_map_find_btf_info(obj, map); + if (err) + return err; + return 0; } @@ -2598,12 +2605,11 @@ 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); @@ -2631,12 +2637,13 @@ static bool btf_needs_sanitization(struct bpf_object *obj) bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG); + bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64); return !has_func || !has_datasec || !has_func_global || !has_float || - !has_decl_tag || !has_type_tag; + !has_decl_tag || !has_type_tag || !has_enum64; } -static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) +static int bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) { bool has_func_global = kernel_supports(obj, FEAT_BTF_GLOBAL_FUNC); bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC); @@ -2644,6 +2651,8 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) bool has_func = kernel_supports(obj, FEAT_BTF_FUNC); bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG); bool has_type_tag = kernel_supports(obj, FEAT_BTF_TYPE_TAG); + bool has_enum64 = kernel_supports(obj, FEAT_BTF_ENUM64); + int enum64_placeholder_id = 0; struct btf_type *t; int i, j, vlen; @@ -2706,8 +2715,32 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf) /* replace TYPE_TAG with a CONST */ t->name_off = 0; t->info = BTF_INFO_ENC(BTF_KIND_CONST, 0, 0); - } + } else if (!has_enum64 && btf_is_enum(t)) { + /* clear the kflag */ + t->info = btf_type_info(btf_kind(t), btf_vlen(t), false); + } else if (!has_enum64 && btf_is_enum64(t)) { + /* replace ENUM64 with a union */ + struct btf_member *m; + + if (enum64_placeholder_id == 0) { + enum64_placeholder_id = btf__add_int(btf, "enum64_placeholder", 1, 0); + if (enum64_placeholder_id < 0) + return enum64_placeholder_id; + + t = (struct btf_type *)btf__type_by_id(btf, i); + } + + m = btf_members(t); + vlen = btf_vlen(t); + t->info = BTF_INFO_ENC(BTF_KIND_UNION, 0, vlen); + for (j = 0; j < vlen; j++, m++) { + m->type = enum64_placeholder_id; + m->offset = 0; + } + } } + + return 0; } static bool libbpf_needs_btf(const struct bpf_object *obj) @@ -2740,6 +2773,9 @@ static int bpf_object__init_btf(struct bpf_object *obj, btf__set_pointer_size(obj->btf, 8); } if (btf_ext_data) { + struct btf_ext_info *ext_segs[3]; + int seg_num, sec_num; + if (!obj->btf) { pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n", BTF_EXT_ELF_SEC, BTF_ELF_SEC); @@ -2753,6 +2789,43 @@ static int bpf_object__init_btf(struct bpf_object *obj, obj->btf_ext = NULL; goto out; } + + /* setup .BTF.ext to ELF section mapping */ + ext_segs[0] = &obj->btf_ext->func_info; + ext_segs[1] = &obj->btf_ext->line_info; + ext_segs[2] = &obj->btf_ext->core_relo_info; + for (seg_num = 0; seg_num < ARRAY_SIZE(ext_segs); seg_num++) { + struct btf_ext_info *seg = ext_segs[seg_num]; + const struct btf_ext_info_sec *sec; + const char *sec_name; + Elf_Scn *scn; + + if (seg->sec_cnt == 0) + continue; + + seg->sec_idxs = calloc(seg->sec_cnt, sizeof(*seg->sec_idxs)); + if (!seg->sec_idxs) { + err = -ENOMEM; + goto out; + } + + sec_num = 0; + for_each_btf_ext_sec(seg, sec) { + /* preventively increment index to avoid doing + * this before every continue below + */ + sec_num++; + + sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); + if (str_is_empty(sec_name)) + continue; + scn = elf_sec_by_name(obj, sec_name); + if (!scn) + continue; + + seg->sec_idxs[sec_num - 1] = elf_ndxscn(scn); + } + } } out: if (err && libbpf_needs_btf(obj)) { @@ -2792,7 +2865,7 @@ static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf, goto sort_vars; ret = find_elf_sec_sz(obj, name, &size); - if (ret || !size || (t->size && t->size != size)) { + if (ret || !size) { pr_debug("Invalid size for section %s: %u bytes\n", name, size); return -ENOENT; } @@ -2854,11 +2927,6 @@ static int btf_finalize_data(struct bpf_object *obj, struct btf *btf) return libbpf_err(err); } -int btf__finalize_data(struct bpf_object *obj, struct btf *btf) -{ - return btf_finalize_data(obj, btf); -} - static int bpf_object__finalize_btf(struct bpf_object *obj) { int err; @@ -2911,7 +2979,7 @@ static bool obj_needs_vmlinux_btf(const struct bpf_object *obj) } bpf_object__for_each_program(prog, obj) { - if (!prog->load) + if (!prog->autoload) continue; if (prog_needs_vmlinux_btf(prog)) return true; @@ -3005,7 +3073,9 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj) /* enforce 8-byte pointers for BPF-targeted BTFs */ btf__set_pointer_size(obj->btf, 8); - bpf_object__sanitize_btf(obj, kern_btf); + err = bpf_object__sanitize_btf(obj, kern_btf); + if (err) + return err; } if (obj->gen_loader) { @@ -3317,7 +3387,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj) if (err) return err; } else if (strcmp(name, "maps") == 0) { - obj->efile.maps_shndx = idx; + pr_warn("elf: legacy map definitions in 'maps' section are not supported by libbpf v1.0+\n"); + return -ENOTSUP; } else if (strcmp(name, MAPS_ELF_SEC) == 0) { obj->efile.btf_maps_shndx = idx; } else if (strcmp(name, BTF_ELF_SEC) == 0) { @@ -3512,6 +3583,10 @@ static enum kcfg_type find_kcfg_type(const struct btf *btf, int id, if (strcmp(name, "libbpf_tristate")) return KCFG_UNKNOWN; return KCFG_TRISTATE; + case BTF_KIND_ENUM64: + if (strcmp(name, "libbpf_tristate")) + return KCFG_UNKNOWN; + return KCFG_TRISTATE; case BTF_KIND_ARRAY: if (btf_array(t)->nelems == 0) return KCFG_UNKNOWN; @@ -3687,7 +3762,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj) ext->kcfg.type = find_kcfg_type(obj->btf, t->type, &ext->kcfg.is_signed); if (ext->kcfg.type == KCFG_UNKNOWN) { - pr_warn("extern (kcfg) '%s' type is unsupported\n", ext_name); + pr_warn("extern (kcfg) '%s': type is unsupported\n", ext_name); return -ENOTSUP; } } else if (strcmp(sec_name, KSYMS_SEC) == 0) { @@ -3809,34 +3884,8 @@ static int bpf_object__collect_externs(struct bpf_object *obj) return 0; } -struct bpf_program * -bpf_object__find_program_by_title(const struct bpf_object *obj, - const char *title) +static bool prog_is_subprog(const struct bpf_object *obj, const struct bpf_program *prog) { - struct bpf_program *pos; - - bpf_object__for_each_program(pos, obj) { - if (pos->sec_name && !strcmp(pos->sec_name, title)) - return pos; - } - return errno = ENOENT, NULL; -} - -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. - */ return prog->sec_idx == obj->efile.text_shndx && obj->nr_programs > 1; } @@ -3871,8 +3920,7 @@ static bool bpf_object__shndx_is_data(const struct bpf_object *obj, static bool bpf_object__shndx_is_maps(const struct bpf_object *obj, int shndx) { - return shndx == obj->efile.maps_shndx || - shndx == obj->efile.btf_maps_shndx; + return shndx == obj->efile.btf_maps_shndx; } static enum libbpf_map_type @@ -4177,35 +4225,31 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Dat static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map) { - struct bpf_map_def *def = &map->def; - __u32 key_type_id = 0, value_type_id = 0; - int ret; + int id; + + if (!obj->btf) + return -ENOENT; /* if it's BTF-defined map, we don't need to search for type IDs. * For struct_ops map, it does not need btf_key_type_id and * btf_value_type_id. */ - if (map->sec_idx == obj->efile.btf_maps_shndx || - bpf_map__is_struct_ops(map)) + if (map->sec_idx == obj->efile.btf_maps_shndx || bpf_map__is_struct_ops(map)) return 0; - if (!bpf_map__is_internal(map)) { - ret = btf__get_map_kv_tids(obj->btf, map->name, def->key_size, - def->value_size, &key_type_id, - &value_type_id); - } else { - /* - * LLVM annotates global data differently in BTF, that is, - * only as '.data', '.bss' or '.rodata'. - */ - ret = btf__find_by_name(obj->btf, map->real_name); - } - if (ret < 0) - return ret; + /* + * LLVM annotates global data differently in BTF, that is, + * only as '.data', '.bss' or '.rodata'. + */ + if (!bpf_map__is_internal(map)) + return -ENOENT; + + id = btf__find_by_name(obj->btf, map->real_name); + if (id < 0) + return id; - map->btf_key_type_id = key_type_id; - map->btf_value_type_id = bpf_map__is_internal(map) ? - ret : value_type_id; + map->btf_key_type_id = 0; + map->btf_value_type_id = id; return 0; } @@ -4245,20 +4289,40 @@ static int bpf_get_map_info_from_fdinfo(int fd, struct bpf_map_info *info) return 0; } +bool bpf_map__autocreate(const struct bpf_map *map) +{ + return map->autocreate; +} + +int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate) +{ + if (map->obj->loaded) + return libbpf_err(-EBUSY); + + map->autocreate = autocreate; + return 0; +} + int bpf_map__reuse_fd(struct bpf_map *map, int fd) { - struct bpf_map_info info = {}; - __u32 len = sizeof(info); + struct bpf_map_info info; + __u32 len = sizeof(info), name_len; int new_fd, err; char *new_name; + memset(&info, 0, len); err = bpf_obj_get_info_by_fd(fd, &info, &len); if (err && errno == EINVAL) err = bpf_get_map_info_from_fdinfo(fd, &info); if (err) return libbpf_err(err); - new_name = strdup(info.name); + name_len = strlen(info.name); + if (name_len == BPF_OBJ_NAME_LEN - 1 && strncmp(map->name, info.name, name_len) == 0) + new_name = strdup(map->name); + else + new_name = strdup(info.name); + if (!new_name) return libbpf_err(-errno); @@ -4317,18 +4381,16 @@ struct bpf_map *bpf_map__inner_map(struct bpf_map *map) int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries) { - if (map->fd >= 0) + if (map->obj->loaded) return libbpf_err(-EBUSY); + map->def.max_entries = max_entries; - return 0; -} -int bpf_map__resize(struct bpf_map *map, __u32 max_entries) -{ - if (!map || !max_entries) - return libbpf_err(-EINVAL); + /* auto-adjust BPF ringbuf map max_entries to be a multiple of page size */ + if (map_is_ringbuf(map)) + map->def.max_entries = adjust_ringbuf_sz(map->def.max_entries); - return bpf_map__set_max_entries(map, max_entries); + return 0; } static int @@ -4375,14 +4437,23 @@ static int probe_fd(int fd) static int probe_kern_prog_name(void) { + const size_t attr_sz = offsetofend(union bpf_attr, prog_name); struct bpf_insn insns[] = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), }; - int ret, insn_cnt = ARRAY_SIZE(insns); + union bpf_attr attr; + int ret; + + memset(&attr, 0, attr_sz); + attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER; + attr.license = ptr_to_u64("GPL"); + attr.insns = ptr_to_u64(insns); + attr.insn_cnt = (__u32)ARRAY_SIZE(insns); + libbpf_strlcpy(attr.prog_name, "libbpf_nametest", sizeof(attr.prog_name)); /* make sure loading with name works */ - ret = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "test", "GPL", insns, insn_cnt, NULL); + ret = sys_bpf_prog_load(&attr, attr_sz, PROG_LOAD_ATTEMPTS); return probe_fd(ret); } @@ -4397,7 +4468,7 @@ static int probe_kern_global_data(void) }; int ret, map, insn_cnt = ARRAY_SIZE(insns); - map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL); + map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_global", sizeof(int), 32, 1, NULL); if (map < 0) { ret = -errno; cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg)); @@ -4530,7 +4601,7 @@ static int probe_kern_array_mmap(void) LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_MMAPABLE); int fd; - fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), sizeof(int), 1, &opts); + fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_mmap", sizeof(int), sizeof(int), 1, &opts); return probe_fd(fd); } @@ -4564,7 +4635,7 @@ static int probe_kern_probe_read_kernel(void) }; int fd, insn_cnt = ARRAY_SIZE(insns); - fd = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL); + fd = bpf_prog_load(BPF_PROG_TYPE_TRACEPOINT, NULL, "GPL", insns, insn_cnt, NULL); return probe_fd(fd); } @@ -4577,7 +4648,7 @@ static int probe_prog_bind_map(void) }; int ret, map, prog, insn_cnt = ARRAY_SIZE(insns); - map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(int), 32, 1, NULL); + map = bpf_map_create(BPF_MAP_TYPE_ARRAY, "libbpf_det_bind", sizeof(int), 32, 1, NULL); if (map < 0) { ret = -errno; cp = libbpf_strerror_r(ret, errmsg, sizeof(errmsg)); @@ -4655,6 +4726,31 @@ static int probe_perf_link(void) return link_fd < 0 && err == -EBADF; } +static int probe_kern_bpf_cookie(void) +{ + struct bpf_insn insns[] = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_get_attach_cookie), + BPF_EXIT_INSN(), + }; + int ret, insn_cnt = ARRAY_SIZE(insns); + + ret = bpf_prog_load(BPF_PROG_TYPE_KPROBE, NULL, "GPL", insns, insn_cnt, NULL); + return probe_fd(ret); +} + +static int probe_kern_btf_enum64(void) +{ + static const char strs[] = "\0enum64"; + __u32 types[] = { + BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_ENUM64, 0, 0), 8), + }; + + return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types), + strs, sizeof(strs))); +} + +static int probe_kern_syscall_wrapper(void); + enum kern_feature_result { FEAT_UNKNOWN = 0, FEAT_SUPPORTED = 1, @@ -4717,6 +4813,15 @@ static struct kern_feature_desc { [FEAT_MEMCG_ACCOUNT] = { "memcg-based memory accounting", probe_memcg_account, }, + [FEAT_BPF_COOKIE] = { + "BPF cookie support", probe_kern_bpf_cookie, + }, + [FEAT_BTF_ENUM64] = { + "BTF_KIND_ENUM64 support", probe_kern_btf_enum64, + }, + [FEAT_SYSCALL_WRAPPER] = { + "Kernel using syscall wrapper", probe_kern_syscall_wrapper, + }, }; bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) @@ -4747,13 +4852,12 @@ bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id) static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd) { - struct bpf_map_info map_info = {}; + struct bpf_map_info map_info; char msg[STRERR_BUFSIZE]; - __u32 map_info_len; + __u32 map_info_len = sizeof(map_info); int err; - map_info_len = sizeof(map_info); - + memset(&map_info, 0, map_info_len); err = bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len); if (err && errno == EINVAL) err = bpf_get_map_info_from_fdinfo(map_fd, &map_info); @@ -4800,8 +4904,8 @@ bpf_object__reuse_map(struct bpf_map *map) } err = bpf_map__reuse_fd(map, pin_fd); + close(pin_fd); if (err) { - close(pin_fd); return err; } map->pinned = true; @@ -4854,7 +4958,6 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b LIBBPF_OPTS(bpf_map_create_opts, create_attr); struct bpf_map_def *def = &map->def; const char *map_name = NULL; - __u32 max_entries; int err = 0; if (kernel_supports(obj, FEAT_PROG_NAME)) @@ -4864,25 +4967,10 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b create_attr.numa_node = map->numa_node; create_attr.map_extra = map->map_extra; - if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) { - int nr_cpus; - - nr_cpus = libbpf_num_possible_cpus(); - if (nr_cpus < 0) { - pr_warn("map '%s': failed to determine number of system CPUs: %d\n", - map->name, nr_cpus); - return nr_cpus; - } - pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus); - max_entries = nr_cpus; - } else { - max_entries = def->max_entries; - } - if (bpf_map__is_struct_ops(map)) create_attr.btf_vmlinux_value_type_id = map->btf_vmlinux_value_type_id; - if (obj->btf && btf__fd(obj->btf) >= 0 && !bpf_map_find_btf_info(obj, map)) { + if (obj->btf && btf__fd(obj->btf) >= 0) { create_attr.btf_fd = btf__fd(obj->btf); create_attr.btf_key_type_id = map->btf_key_type_id; create_attr.btf_value_type_id = map->btf_value_type_id; @@ -4916,7 +5004,6 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b case BPF_MAP_TYPE_SOCKHASH: case BPF_MAP_TYPE_QUEUE: case BPF_MAP_TYPE_STACK: - case BPF_MAP_TYPE_RINGBUF: create_attr.btf_fd = 0; create_attr.btf_key_type_id = 0; create_attr.btf_value_type_id = 0; @@ -4928,7 +5015,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b if (obj->gen_loader) { bpf_gen__map_create(obj->gen_loader, def->type, map_name, - def->key_size, def->value_size, max_entries, + def->key_size, def->value_size, def->max_entries, &create_attr, is_inner ? -1 : map - obj->maps); /* Pretend to have valid FD to pass various fd >= 0 checks. * This fd == 0 will not be used with any syscall and will be reset to -1 eventually. @@ -4937,7 +5024,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b } else { map->fd = bpf_map_create(def->type, map_name, def->key_size, def->value_size, - max_entries, &create_attr); + def->max_entries, &create_attr); } if (map->fd < 0 && (create_attr.btf_key_type_id || create_attr.btf_value_type_id)) { @@ -4954,7 +5041,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b map->btf_value_type_id = 0; map->fd = bpf_map_create(def->type, map_name, def->key_size, def->value_size, - max_entries, &create_attr); + def->max_entries, &create_attr); } err = map->fd < 0 ? -errno : 0; @@ -5058,6 +5145,24 @@ static int bpf_object_init_prog_arrays(struct bpf_object *obj) return 0; } +static int map_set_def_max_entries(struct bpf_map *map) +{ + if (map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !map->def.max_entries) { + int nr_cpus; + + nr_cpus = libbpf_num_possible_cpus(); + if (nr_cpus < 0) { + pr_warn("map '%s': failed to determine number of system CPUs: %d\n", + map->name, nr_cpus); + return nr_cpus; + } + pr_debug("map '%s': setting size to %d\n", map->name, nr_cpus); + map->def.max_entries = nr_cpus; + } + + return 0; +} + static int bpf_object__create_maps(struct bpf_object *obj) { @@ -5084,12 +5189,18 @@ bpf_object__create_maps(struct bpf_object *obj) * bpf_object loading will succeed just fine even on old * kernels. */ - if (bpf_map__is_internal(map) && - !kernel_supports(obj, FEAT_GLOBAL_DATA)) { - map->skipped = true; + if (bpf_map__is_internal(map) && !kernel_supports(obj, FEAT_GLOBAL_DATA)) + map->autocreate = false; + + if (!map->autocreate) { + pr_debug("map '%s': skipped auto-creating...\n", map->name); continue; } + err = map_set_def_max_entries(map); + if (err) + goto err_out; + retried = false; retry: if (map->pin_path) { @@ -5185,18 +5296,21 @@ size_t bpf_core_essential_name_len(const char *name) return n; } -static void bpf_core_free_cands(struct bpf_core_cand_list *cands) +void bpf_core_free_cands(struct bpf_core_cand_list *cands) { + if (!cands) + return; + free(cands->cands); free(cands); } -static int bpf_core_add_cands(struct bpf_core_cand *local_cand, - size_t local_essent_len, - const struct btf *targ_btf, - const char *targ_btf_name, - int targ_start_id, - struct bpf_core_cand_list *cands) +int bpf_core_add_cands(struct bpf_core_cand *local_cand, + size_t local_essent_len, + const struct btf *targ_btf, + const char *targ_btf_name, + int targ_start_id, + struct bpf_core_cand_list *cands) { struct bpf_core_cand *new_cands, *cand; const struct btf_type *t, *local_t; @@ -5210,7 +5324,7 @@ static int bpf_core_add_cands(struct bpf_core_cand *local_cand, n = btf__type_cnt(targ_btf); for (i = targ_start_id; i < n; i++) { t = btf__type_by_id(targ_btf, i); - if (btf_kind(t) != btf_kind(local_t)) + if (!btf_kind_core_compat(t, local_t)) continue; targ_name = btf__name_by_offset(targ_btf, t->name_off); @@ -5418,76 +5532,13 @@ err_out: int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id, const struct btf *targ_btf, __u32 targ_id) { - const struct btf_type *local_type, *targ_type; - int depth = 32; /* max recursion depth */ - - /* caller made sure that names match (ignoring flavor suffix) */ - local_type = btf__type_by_id(local_btf, local_id); - targ_type = btf__type_by_id(targ_btf, targ_id); - if (btf_kind(local_type) != btf_kind(targ_type)) - return 0; - -recur: - depth--; - if (depth < 0) - return -EINVAL; - - local_type = skip_mods_and_typedefs(local_btf, local_id, &local_id); - targ_type = skip_mods_and_typedefs(targ_btf, targ_id, &targ_id); - if (!local_type || !targ_type) - return -EINVAL; - - if (btf_kind(local_type) != btf_kind(targ_type)) - return 0; - - switch (btf_kind(local_type)) { - case BTF_KIND_UNKN: - case BTF_KIND_STRUCT: - case BTF_KIND_UNION: - case BTF_KIND_ENUM: - case BTF_KIND_FWD: - return 1; - case BTF_KIND_INT: - /* just reject deprecated bitfield-like integers; all other - * integers are by default compatible between each other - */ - return btf_int_offset(local_type) == 0 && btf_int_offset(targ_type) == 0; - case BTF_KIND_PTR: - local_id = local_type->type; - targ_id = targ_type->type; - goto recur; - case BTF_KIND_ARRAY: - local_id = btf_array(local_type)->type; - targ_id = btf_array(targ_type)->type; - goto recur; - case BTF_KIND_FUNC_PROTO: { - struct btf_param *local_p = btf_params(local_type); - struct btf_param *targ_p = btf_params(targ_type); - __u16 local_vlen = btf_vlen(local_type); - __u16 targ_vlen = btf_vlen(targ_type); - int i, err; - - if (local_vlen != targ_vlen) - return 0; - - for (i = 0; i < local_vlen; i++, local_p++, targ_p++) { - skip_mods_and_typedefs(local_btf, local_p->type, &local_id); - skip_mods_and_typedefs(targ_btf, targ_p->type, &targ_id); - err = bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id); - if (err <= 0) - return err; - } + return __bpf_core_types_are_compat(local_btf, local_id, targ_btf, targ_id, 32); +} - /* tail recurse for return type check */ - skip_mods_and_typedefs(local_btf, local_type->type, &local_id); - skip_mods_and_typedefs(targ_btf, targ_type->type, &targ_id); - goto recur; - } - default: - pr_warn("unexpected kind %s relocated, local [%d], target [%d]\n", - btf_kind_str(local_type), local_id, targ_id); - return 0; - } +int bpf_core_types_match(const struct btf *local_btf, __u32 local_id, + const struct btf *targ_btf, __u32 targ_id) +{ + return __bpf_core_types_match(local_btf, local_id, targ_btf, targ_id, false, 32); } static size_t bpf_core_hash_fn(const void *key, void *ctx) @@ -5523,11 +5574,28 @@ static int record_relo_core(struct bpf_program *prog, return 0; } -static int bpf_core_apply_relo(struct bpf_program *prog, - const struct bpf_core_relo *relo, - int relo_idx, - const struct btf *local_btf, - struct hashmap *cand_cache) +static const struct bpf_core_relo *find_relo_core(struct bpf_program *prog, int insn_idx) +{ + struct reloc_desc *relo; + int i; + + for (i = 0; i < prog->nr_reloc; i++) { + relo = &prog->reloc_desc[i]; + if (relo->type != RELO_CORE || relo->insn_idx != insn_idx) + continue; + + return relo->core_relo; + } + + return NULL; +} + +static int bpf_core_resolve_relo(struct bpf_program *prog, + const struct bpf_core_relo *relo, + int relo_idx, + const struct btf *local_btf, + struct hashmap *cand_cache, + struct bpf_core_relo_res *targ_res) { struct bpf_core_spec specs_scratch[3] = {}; const void *type_key = u32_as_hash_key(relo->type_id); @@ -5536,20 +5604,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog, const struct btf_type *local_type; const char *local_name; __u32 local_id = relo->type_id; - struct bpf_insn *insn; - int insn_idx, err; - - if (relo->insn_off % BPF_INSN_SZ) - return -EINVAL; - insn_idx = relo->insn_off / BPF_INSN_SZ; - /* adjust insn_idx from section frame of reference to the local - * program's frame of reference; (sub-)program code is not yet - * relocated, so it's enough to just subtract in-section offset - */ - insn_idx = insn_idx - prog->sec_insn_off; - if (insn_idx >= prog->insns_cnt) - return -EINVAL; - insn = &prog->insns[insn_idx]; + int err; local_type = btf__type_by_id(local_btf, local_id); if (!local_type) @@ -5559,15 +5614,6 @@ static int bpf_core_apply_relo(struct bpf_program *prog, if (!local_name) return -EINVAL; - if (prog->obj->gen_loader) { - const char *spec_str = btf__name_by_offset(local_btf, relo->access_str_off); - - pr_debug("record_relo_core: prog %td insn[%d] %s %s %s final insn_idx %d\n", - prog - prog->obj->programs, relo->insn_off / 8, - btf_kind_str(local_type), local_name, spec_str, insn_idx); - return record_relo_core(prog, relo, insn_idx); - } - if (relo->kind != BPF_CORE_TYPE_ID_LOCAL && !hashmap__find(cand_cache, type_key, (void **)&cands)) { cands = bpf_core_find_cands(prog->obj, local_btf, local_id); @@ -5584,21 +5630,23 @@ static int bpf_core_apply_relo(struct bpf_program *prog, } } - return bpf_core_apply_relo_insn(prog_name, insn, insn_idx, relo, - relo_idx, local_btf, cands, specs_scratch); + return bpf_core_calc_relo_insn(prog_name, relo, relo_idx, local_btf, cands, specs_scratch, + targ_res); } static int bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) { const struct btf_ext_info_sec *sec; + struct bpf_core_relo_res targ_res; const struct bpf_core_relo *rec; const struct btf_ext_info *seg; struct hashmap_entry *entry; struct hashmap *cand_cache = NULL; struct bpf_program *prog; + struct bpf_insn *insn; const char *sec_name; - int i, err = 0, insn_idx, sec_idx; + int i, err = 0, insn_idx, sec_idx, sec_num; if (obj->btf_ext->core_relo_info.len == 0) return 0; @@ -5619,54 +5667,75 @@ bpf_object__relocate_core(struct bpf_object *obj, const char *targ_btf_path) } seg = &obj->btf_ext->core_relo_info; + sec_num = 0; for_each_btf_ext_sec(seg, sec) { + sec_idx = seg->sec_idxs[sec_num]; + sec_num++; + sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); if (str_is_empty(sec_name)) { err = -EINVAL; goto out; } - /* bpf_object's ELF is gone by now so it's not easy to find - * section index by section name, but we can find *any* - * bpf_program within desired section name and use it's - * prog->sec_idx to do a proper search by section index and - * instruction offset - */ - prog = NULL; - for (i = 0; i < obj->nr_programs; i++) { - prog = &obj->programs[i]; - if (strcmp(prog->sec_name, sec_name) == 0) - break; - } - if (!prog) { - pr_warn("sec '%s': failed to find a BPF program\n", sec_name); - return -ENOENT; - } - sec_idx = prog->sec_idx; - pr_debug("sec '%s': found %d CO-RE relocations\n", - sec_name, sec->num_info); + pr_debug("sec '%s': found %d CO-RE relocations\n", sec_name, sec->num_info); for_each_btf_ext_rec(seg, sec, i, rec) { + if (rec->insn_off % BPF_INSN_SZ) + return -EINVAL; insn_idx = rec->insn_off / BPF_INSN_SZ; prog = find_prog_by_sec_insn(obj, sec_idx, insn_idx); if (!prog) { - pr_warn("sec '%s': failed to find program at insn #%d for CO-RE offset relocation #%d\n", - sec_name, insn_idx, i); - err = -EINVAL; - goto out; + /* When __weak subprog is "overridden" by another instance + * of the subprog from a different object file, linker still + * appends all the .BTF.ext info that used to belong to that + * eliminated subprogram. + * This is similar to what x86-64 linker does for relocations. + * So just ignore such relocations just like we ignore + * subprog instructions when discovering subprograms. + */ + pr_debug("sec '%s': skipping CO-RE relocation #%d for insn #%d belonging to eliminated weak subprogram\n", + sec_name, i, insn_idx); + continue; } /* no need to apply CO-RE relocation if the program is * not going to be loaded */ - if (!prog->load) + if (!prog->autoload) continue; - err = bpf_core_apply_relo(prog, rec, i, obj->btf, cand_cache); + /* adjust insn_idx from section frame of reference to the local + * program's frame of reference; (sub-)program code is not yet + * relocated, so it's enough to just subtract in-section offset + */ + insn_idx = insn_idx - prog->sec_insn_off; + if (insn_idx >= prog->insns_cnt) + return -EINVAL; + insn = &prog->insns[insn_idx]; + + err = record_relo_core(prog, rec, insn_idx); + if (err) { + pr_warn("prog '%s': relo #%d: failed to record relocation: %d\n", + prog->name, i, err); + goto out; + } + + if (prog->obj->gen_loader) + continue; + + err = bpf_core_resolve_relo(prog, rec, i, obj->btf, cand_cache, &targ_res); if (err) { pr_warn("prog '%s': relo #%d: failed to relocate: %d\n", prog->name, i, err); goto out; } + + err = bpf_core_patch_insn(prog->name, insn, insn_idx, rec, i, &targ_res); + if (err) { + pr_warn("prog '%s': relo #%d: failed to patch insn #%u: %d\n", + prog->name, i, insn_idx, err); + goto out; + } } } @@ -5684,6 +5753,36 @@ out: return err; } +/* base map load ldimm64 special constant, used also for log fixup logic */ +#define MAP_LDIMM64_POISON_BASE 2001000000 +#define MAP_LDIMM64_POISON_PFX "200100" + +static void poison_map_ldimm64(struct bpf_program *prog, int relo_idx, + int insn_idx, struct bpf_insn *insn, + int map_idx, const struct bpf_map *map) +{ + int i; + + pr_debug("prog '%s': relo #%d: poisoning insn #%d that loads map #%d '%s'\n", + prog->name, relo_idx, insn_idx, map_idx, map->name); + + /* we turn single ldimm64 into two identical invalid calls */ + for (i = 0; i < 2; i++) { + insn->code = BPF_JMP | BPF_CALL; + insn->dst_reg = 0; + insn->src_reg = 0; + insn->off = 0; + /* if this instruction is reachable (not a dead code), + * verifier will complain with something like: + * invalid func unknown#2001000123 + * where lower 123 is map index into obj->maps[] array + */ + insn->imm = MAP_LDIMM64_POISON_BASE + map_idx; + + insn++; + } +} + /* Relocate data references within program code: * - map references; * - global variable references; @@ -5697,33 +5796,35 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog) for (i = 0; i < prog->nr_reloc; i++) { struct reloc_desc *relo = &prog->reloc_desc[i]; struct bpf_insn *insn = &prog->insns[relo->insn_idx]; + const struct bpf_map *map; struct extern_desc *ext; switch (relo->type) { case RELO_LD64: + map = &obj->maps[relo->map_idx]; if (obj->gen_loader) { insn[0].src_reg = BPF_PSEUDO_MAP_IDX; insn[0].imm = relo->map_idx; - } else { + } else if (map->autocreate) { insn[0].src_reg = BPF_PSEUDO_MAP_FD; - insn[0].imm = obj->maps[relo->map_idx].fd; + insn[0].imm = map->fd; + } else { + poison_map_ldimm64(prog, i, relo->insn_idx, insn, + relo->map_idx, map); } break; case RELO_DATA: + map = &obj->maps[relo->map_idx]; insn[1].imm = insn[0].imm + relo->sym_off; if (obj->gen_loader) { insn[0].src_reg = BPF_PSEUDO_MAP_IDX_VALUE; insn[0].imm = relo->map_idx; - } else { - const struct bpf_map *map = &obj->maps[relo->map_idx]; - - if (map->skipped) { - pr_warn("prog '%s': relo #%d: kernel doesn't support global data\n", - prog->name, i); - return -ENOTSUP; - } + } else if (map->autocreate) { insn[0].src_reg = BPF_PSEUDO_MAP_VALUE; - insn[0].imm = obj->maps[relo->map_idx].fd; + insn[0].imm = map->fd; + } else { + poison_map_ldimm64(prog, i, relo->insn_idx, insn, + relo->map_idx, map); } break; case RELO_EXTERN_VAR: @@ -5793,14 +5894,13 @@ static int adjust_prog_btf_ext_info(const struct bpf_object *obj, void *rec, *rec_end, *new_prog_info; const struct btf_ext_info_sec *sec; size_t old_sz, new_sz; - const char *sec_name; - int i, off_adj; + int i, sec_num, sec_idx, off_adj; + sec_num = 0; for_each_btf_ext_sec(ext_info, sec) { - sec_name = btf__name_by_offset(obj->btf, sec->sec_name_off); - if (!sec_name) - return -EINVAL; - if (strcmp(sec_name, prog->sec_name) != 0) + sec_idx = ext_info->sec_idxs[sec_num]; + sec_num++; + if (prog->sec_idx != sec_idx) continue; for_each_btf_ext_rec(ext_info, sec, i, rec) { @@ -6195,7 +6295,6 @@ bpf_object__relocate_calls(struct bpf_object *obj, struct bpf_program *prog) if (err) return err; - return 0; } @@ -6256,8 +6355,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) err); return err; } - if (obj->gen_loader) - bpf_object__sort_relos(obj); + bpf_object__sort_relos(obj); } /* Before relocating calls pre-process relocations and mark @@ -6293,7 +6391,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) */ if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) + if (!prog->autoload) continue; err = bpf_object__relocate_calls(obj, prog); @@ -6308,7 +6406,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) + if (!prog->autoload) continue; err = bpf_object__relocate_data(obj, prog); if (err) { @@ -6317,8 +6415,7 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path) return err; } } - if (!obj->gen_loader) - bpf_object__free_relocs(obj); + return 0; } @@ -6549,9 +6646,9 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name, int *btf_obj_fd, int *btf_type_id); -/* this is called as prog->sec_def->preload_fn for libbpf-supported sec_defs */ -static int libbpf_preload_prog(struct bpf_program *prog, - struct bpf_prog_load_opts *opts, long cookie) +/* this is called as prog->sec_def->prog_prepare_load_fn for libbpf-supported sec_defs */ +static int libbpf_prepare_prog_load(struct bpf_program *prog, + struct bpf_prog_load_opts *opts, long cookie) { enum sec_def_flags def = cookie; @@ -6562,13 +6659,30 @@ static int libbpf_preload_prog(struct bpf_program *prog, if (def & SEC_SLEEPABLE) opts->prog_flags |= BPF_F_SLEEPABLE; - if ((prog->type == BPF_PROG_TYPE_TRACING || - prog->type == BPF_PROG_TYPE_LSM || - prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) { + if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_FRAGS)) + opts->prog_flags |= BPF_F_XDP_HAS_FRAGS; + + if ((def & SEC_ATTACH_BTF) && !prog->attach_btf_id) { int btf_obj_fd = 0, btf_type_id = 0, err; const char *attach_name; - attach_name = strchr(prog->sec_name, '/') + 1; + attach_name = strchr(prog->sec_name, '/'); + if (!attach_name) { + /* if BPF program is annotated with just SEC("fentry") + * (or similar) without declaratively specifying + * target, then it is expected that target will be + * specified with bpf_program__set_attach_target() at + * runtime before BPF object load step. If not, then + * there is nothing to load into the kernel as BPF + * verifier won't be able to validate BPF program + * correctness anyways. + */ + pr_warn("prog '%s': no BTF-based attach target is specified, use bpf_program__set_attach_target()\n", + prog->name); + return -EINVAL; + } + attach_name++; /* skip over / */ + err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id); if (err) return err; @@ -6588,10 +6702,11 @@ static int libbpf_preload_prog(struct bpf_program *prog, return 0; } -static int bpf_object_load_prog_instance(struct bpf_object *obj, struct bpf_program *prog, - struct bpf_insn *insns, int insns_cnt, - const char *license, __u32 kern_version, - int *prog_fd) +static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz); + +static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog, + struct bpf_insn *insns, int insns_cnt, + const char *license, __u32 kern_version, int *prog_fd) { LIBBPF_OPTS(bpf_prog_load_opts, load_attr); const char *prog_name = NULL; @@ -6640,13 +6755,15 @@ static int bpf_object_load_prog_instance(struct bpf_object *obj, struct bpf_prog load_attr.fd_array = obj->fd_array; /* adjust load_attr if sec_def provides custom preload callback */ - if (prog->sec_def && prog->sec_def->preload_fn) { - err = prog->sec_def->preload_fn(prog, &load_attr, prog->sec_def->cookie); + if (prog->sec_def && prog->sec_def->prog_prepare_load_fn) { + err = prog->sec_def->prog_prepare_load_fn(prog, &load_attr, prog->sec_def->cookie); if (err < 0) { pr_warn("prog '%s': failed to prepare load attributes: %d\n", prog->name, err); return err; } + insns = prog->insns; + insns_cnt = prog->insns_cnt; } if (obj->gen_loader) { @@ -6658,7 +6775,7 @@ static int bpf_object_load_prog_instance(struct bpf_object *obj, struct bpf_prog } retry_load: - /* if log_level is zero, we don't request logs initiallly even if + /* if log_level is zero, we don't request logs initially even if * custom log_buf is specified; if the program load fails, then we'll * bump log_level to 1 and use either custom log_buf or we'll allocate * our own and retry the load to get details on what failed @@ -6734,6 +6851,10 @@ retry_load: goto retry_load; ret = -errno; + + /* post-process verifier log to improve error descriptions */ + fixup_verifier_log(prog, log_buf, log_buf_size); + cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg)); pr_warn("prog '%s': BPF program load failed: %s\n", prog->name, cp); pr_perm_msg(ret); @@ -6742,10 +6863,6 @@ retry_load: pr_warn("prog '%s': -- BEGIN PROG LOAD LOG --\n%s-- END PROG LOAD LOG --\n", prog->name, log_buf); } - if (insns_cnt >= BPF_MAXINSNS) { - pr_warn("prog '%s': program too large (%d insns), at most %d insns\n", - prog->name, insns_cnt, BPF_MAXINSNS); - } out: if (own_log_buf) @@ -6753,6 +6870,169 @@ out: return ret; } +static char *find_prev_line(char *buf, char *cur) +{ + char *p; + + if (cur == buf) /* end of a log buf */ + return NULL; + + p = cur - 1; + while (p - 1 >= buf && *(p - 1) != '\n') + p--; + + return p; +} + +static void patch_log(char *buf, size_t buf_sz, size_t log_sz, + char *orig, size_t orig_sz, const char *patch) +{ + /* size of the remaining log content to the right from the to-be-replaced part */ + size_t rem_sz = (buf + log_sz) - (orig + orig_sz); + size_t patch_sz = strlen(patch); + + if (patch_sz != orig_sz) { + /* If patch line(s) are longer than original piece of verifier log, + * shift log contents by (patch_sz - orig_sz) bytes to the right + * starting from after to-be-replaced part of the log. + * + * If patch line(s) are shorter than original piece of verifier log, + * shift log contents by (orig_sz - patch_sz) bytes to the left + * starting from after to-be-replaced part of the log + * + * We need to be careful about not overflowing available + * buf_sz capacity. If that's the case, we'll truncate the end + * of the original log, as necessary. + */ + if (patch_sz > orig_sz) { + if (orig + patch_sz >= buf + buf_sz) { + /* patch is big enough to cover remaining space completely */ + patch_sz -= (orig + patch_sz) - (buf + buf_sz) + 1; + rem_sz = 0; + } else if (patch_sz - orig_sz > buf_sz - log_sz) { + /* patch causes part of remaining log to be truncated */ + rem_sz -= (patch_sz - orig_sz) - (buf_sz - log_sz); + } + } + /* shift remaining log to the right by calculated amount */ + memmove(orig + patch_sz, orig + orig_sz, rem_sz); + } + + memcpy(orig, patch, patch_sz); +} + +static void fixup_log_failed_core_relo(struct bpf_program *prog, + char *buf, size_t buf_sz, size_t log_sz, + char *line1, char *line2, char *line3) +{ + /* Expected log for failed and not properly guarded CO-RE relocation: + * line1 -> 123: (85) call unknown#195896080 + * line2 -> invalid func unknown#195896080 + * line3 -> <anything else or end of buffer> + * + * "123" is the index of the instruction that was poisoned. We extract + * instruction index to find corresponding CO-RE relocation and + * replace this part of the log with more relevant information about + * failed CO-RE relocation. + */ + const struct bpf_core_relo *relo; + struct bpf_core_spec spec; + char patch[512], spec_buf[256]; + int insn_idx, err, spec_len; + + if (sscanf(line1, "%d: (%*d) call unknown#195896080\n", &insn_idx) != 1) + return; + + relo = find_relo_core(prog, insn_idx); + if (!relo) + return; + + err = bpf_core_parse_spec(prog->name, prog->obj->btf, relo, &spec); + if (err) + return; + + spec_len = bpf_core_format_spec(spec_buf, sizeof(spec_buf), &spec); + snprintf(patch, sizeof(patch), + "%d: <invalid CO-RE relocation>\n" + "failed to resolve CO-RE relocation %s%s\n", + insn_idx, spec_buf, spec_len >= sizeof(spec_buf) ? "..." : ""); + + patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch); +} + +static void fixup_log_missing_map_load(struct bpf_program *prog, + char *buf, size_t buf_sz, size_t log_sz, + char *line1, char *line2, char *line3) +{ + /* Expected log for failed and not properly guarded CO-RE relocation: + * line1 -> 123: (85) call unknown#2001000345 + * line2 -> invalid func unknown#2001000345 + * line3 -> <anything else or end of buffer> + * + * "123" is the index of the instruction that was poisoned. + * "345" in "2001000345" are map index in obj->maps to fetch map name. + */ + struct bpf_object *obj = prog->obj; + const struct bpf_map *map; + int insn_idx, map_idx; + char patch[128]; + + if (sscanf(line1, "%d: (%*d) call unknown#%d\n", &insn_idx, &map_idx) != 2) + return; + + map_idx -= MAP_LDIMM64_POISON_BASE; + if (map_idx < 0 || map_idx >= obj->nr_maps) + return; + map = &obj->maps[map_idx]; + + snprintf(patch, sizeof(patch), + "%d: <invalid BPF map reference>\n" + "BPF map '%s' is referenced but wasn't created\n", + insn_idx, map->name); + + patch_log(buf, buf_sz, log_sz, line1, line3 - line1, patch); +} + +static void fixup_verifier_log(struct bpf_program *prog, char *buf, size_t buf_sz) +{ + /* look for familiar error patterns in last N lines of the log */ + const size_t max_last_line_cnt = 10; + char *prev_line, *cur_line, *next_line; + size_t log_sz; + int i; + + if (!buf) + return; + + log_sz = strlen(buf) + 1; + next_line = buf + log_sz - 1; + + for (i = 0; i < max_last_line_cnt; i++, next_line = cur_line) { + cur_line = find_prev_line(buf, next_line); + if (!cur_line) + return; + + /* failed CO-RE relocation case */ + if (str_has_pfx(cur_line, "invalid func unknown#195896080\n")) { + prev_line = find_prev_line(buf, cur_line); + if (!prev_line) + continue; + + fixup_log_failed_core_relo(prog, buf, buf_sz, log_sz, + prev_line, cur_line, next_line); + return; + } else if (str_has_pfx(cur_line, "invalid func unknown#"MAP_LDIMM64_POISON_PFX)) { + prev_line = find_prev_line(buf, cur_line); + if (!prev_line) + continue; + + fixup_log_missing_map_load(prog, buf, buf_sz, log_sz, + prev_line, cur_line, next_line); + return; + } + } +} + static int bpf_program_record_relos(struct bpf_program *prog) { struct bpf_object *obj = prog->obj; @@ -6793,93 +7073,6 @@ static int bpf_program_record_relos(struct bpf_program *prog) return 0; } -static int bpf_object_load_prog(struct bpf_object *obj, struct bpf_program *prog, - const char *license, __u32 kern_ver) -{ - int err = 0, fd, i; - - if (obj->loaded) { - pr_warn("prog '%s': can't load after object was loaded\n", prog->name); - return libbpf_err(-EINVAL); - } - - if (prog->instances.nr < 0 || !prog->instances.fds) { - if (prog->preprocessor) { - pr_warn("Internal error: can't load program '%s'\n", - prog->name); - return libbpf_err(-LIBBPF_ERRNO__INTERNAL); - } - - prog->instances.fds = malloc(sizeof(int)); - if (!prog->instances.fds) { - pr_warn("Not enough memory for BPF fds\n"); - return libbpf_err(-ENOMEM); - } - prog->instances.nr = 1; - prog->instances.fds[0] = -1; - } - - if (!prog->preprocessor) { - if (prog->instances.nr != 1) { - pr_warn("prog '%s': inconsistent nr(%d) != 1\n", - prog->name, prog->instances.nr); - } - if (obj->gen_loader) - bpf_program_record_relos(prog); - err = bpf_object_load_prog_instance(obj, prog, - prog->insns, prog->insns_cnt, - license, kern_ver, &fd); - if (!err) - prog->instances.fds[0] = fd; - goto out; - } - - for (i = 0; i < prog->instances.nr; i++) { - struct bpf_prog_prep_result result; - bpf_program_prep_t preprocessor = prog->preprocessor; - - memset(&result, 0, sizeof(result)); - err = preprocessor(prog, i, prog->insns, - prog->insns_cnt, &result); - if (err) { - pr_warn("Preprocessing the %dth instance of program '%s' failed\n", - i, prog->name); - goto out; - } - - if (!result.new_insn_ptr || !result.new_insn_cnt) { - pr_debug("Skip loading the %dth instance of program '%s'\n", - i, prog->name); - prog->instances.fds[i] = -1; - if (result.pfd) - *result.pfd = -1; - continue; - } - - err = bpf_object_load_prog_instance(obj, prog, - result.new_insn_ptr, result.new_insn_cnt, - license, kern_ver, &fd); - if (err) { - pr_warn("Loading the %dth instance of program '%s' failed\n", - i, prog->name); - goto out; - } - - if (result.pfd) - *result.pfd = fd; - prog->instances.fds[i] = fd; - } -out: - if (err) - pr_warn("failed to load program '%s'\n", prog->name); - return libbpf_err(err); -} - -int bpf_program__load(struct bpf_program *prog, const char *license, __u32 kern_ver) -{ - return bpf_object_load_prog(prog->obj, prog, license, kern_ver); -} - static int bpf_object__load_progs(struct bpf_object *obj, int log_level) { @@ -6898,17 +7091,24 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level) prog = &obj->programs[i]; if (prog_is_subprog(obj, prog)) continue; - if (!prog->load) { + if (!prog->autoload) { pr_debug("prog '%s': skipped loading\n", prog->name); continue; } prog->log_level |= log_level; - err = bpf_object_load_prog(obj, prog, obj->license, obj->kern_version); - if (err) + + if (obj->gen_loader) + bpf_program_record_relos(prog); + + err = bpf_object_load_prog(obj, prog, prog->insns, prog->insns_cnt, + obj->license, obj->kern_version, &prog->fd); + if (err) { + pr_warn("prog '%s': failed to load: %d\n", prog->name, err); return err; + } } - if (obj->gen_loader) - bpf_object__free_relocs(obj); + + bpf_object__free_relocs(obj); return 0; } @@ -6928,21 +7128,14 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object continue; } - bpf_program__set_type(prog, prog->sec_def->prog_type); - bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type); - -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wdeprecated-declarations" - if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING || - prog->sec_def->prog_type == BPF_PROG_TYPE_EXT) - prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0); -#pragma GCC diagnostic pop + prog->type = prog->sec_def->prog_type; + prog->expected_attach_type = prog->sec_def->expected_attach_type; /* sec_def can have custom callback which should be called * after bpf_program is initialized to adjust its properties */ - if (prog->sec_def->init_fn) { - err = prog->sec_def->init_fn(prog, prog->sec_def->cookie); + if (prog->sec_def->prog_setup_fn) { + err = prog->sec_def->prog_setup_fn(prog, prog->sec_def->cookie); if (err < 0) { pr_warn("prog '%s': failed to initialize: %d\n", prog->name, err); @@ -7043,36 +7236,6 @@ out: return ERR_PTR(err); } -static struct bpf_object * -__bpf_object__open_xattr(struct bpf_object_open_attr *attr, int flags) -{ - DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, - .relaxed_maps = flags & MAPS_RELAX_COMPAT, - ); - - /* param validation */ - if (!attr->file) - return NULL; - - pr_debug("loading %s\n", attr->file); - return bpf_object_open(attr->file, NULL, 0, &opts); -} - -struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr) -{ - return libbpf_ptr(__bpf_object__open_xattr(attr, 0)); -} - -struct bpf_object *bpf_object__open(const char *path) -{ - struct bpf_object_open_attr attr = { - .file = path, - .prog_type = BPF_PROG_TYPE_UNSPEC, - }; - - return libbpf_ptr(__bpf_object__open_xattr(&attr, 0)); -} - struct bpf_object * bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts) { @@ -7084,6 +7247,11 @@ bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts) return libbpf_ptr(bpf_object_open(path, NULL, 0, opts)); } +struct bpf_object *bpf_object__open(const char *path) +{ + return bpf_object__open_file(path, NULL); +} + struct bpf_object * bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, const struct bpf_object_open_opts *opts) @@ -7094,23 +7262,6 @@ bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz, return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, opts)); } -struct bpf_object * -bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz, - const char *name) -{ - DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, - .object_name = name, - /* wrong default, but backwards-compatible */ - .relaxed_maps = true, - ); - - /* returning NULL is wrong, but backwards-compatible */ - if (!obj_buf || obj_buf_sz == 0) - return errno = EINVAL, NULL; - - return libbpf_ptr(bpf_object_open(NULL, obj_buf, obj_buf_sz, &opts)); -} - static int bpf_object_unload(struct bpf_object *obj) { size_t i; @@ -7130,8 +7281,6 @@ static int bpf_object_unload(struct bpf_object *obj) return 0; } -int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload"))); - static int bpf_object__sanitize_maps(struct bpf_object *obj) { struct bpf_map *m; @@ -7146,12 +7295,10 @@ static int bpf_object__sanitize_maps(struct bpf_object *obj) return 0; } -static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +int libbpf_kallsyms_parse(kallsyms_cb_t cb, void *ctx) { char sym_type, sym_name[500]; unsigned long long sym_addr; - const struct btf_type *t; - struct extern_desc *ext; int ret, err = 0; FILE *f; @@ -7170,35 +7317,51 @@ static int bpf_object__read_kallsyms_file(struct bpf_object *obj) if (ret != 3) { pr_warn("failed to read kallsyms entry: %d\n", ret); err = -EINVAL; - goto out; + break; } - ext = find_extern_by_name(obj, sym_name); - if (!ext || ext->type != EXT_KSYM) - continue; - - t = btf__type_by_id(obj->btf, ext->btf_id); - if (!btf_is_var(t)) - continue; - - if (ext->is_set && ext->ksym.addr != sym_addr) { - pr_warn("extern (ksym) '%s' resolution is ambiguous: 0x%llx or 0x%llx\n", - sym_name, ext->ksym.addr, sym_addr); - err = -EINVAL; - goto out; - } - if (!ext->is_set) { - ext->is_set = true; - ext->ksym.addr = sym_addr; - pr_debug("extern (ksym) %s=0x%llx\n", sym_name, sym_addr); - } + err = cb(sym_addr, sym_type, sym_name, ctx); + if (err) + break; } -out: fclose(f); return err; } +static int kallsyms_cb(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx) +{ + struct bpf_object *obj = ctx; + const struct btf_type *t; + struct extern_desc *ext; + + ext = find_extern_by_name(obj, sym_name); + if (!ext || ext->type != EXT_KSYM) + return 0; + + t = btf__type_by_id(obj->btf, ext->btf_id); + if (!btf_is_var(t)) + return 0; + + if (ext->is_set && ext->ksym.addr != sym_addr) { + pr_warn("extern (ksym) '%s': resolution is ambiguous: 0x%llx or 0x%llx\n", + sym_name, ext->ksym.addr, sym_addr); + return -EINVAL; + } + if (!ext->is_set) { + ext->is_set = true; + ext->ksym.addr = sym_addr; + pr_debug("extern (ksym) '%s': set to 0x%llx\n", sym_name, sym_addr); + } + return 0; +} + +static int bpf_object__read_kallsyms_file(struct bpf_object *obj) +{ + return libbpf_kallsyms_parse(kallsyms_cb, obj); +} + static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name, __u16 kind, struct btf **res_btf, struct module_btf **res_mod_btf) @@ -7393,28 +7556,52 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, for (i = 0; i < obj->nr_extern; i++) { ext = &obj->externs[i]; - if (ext->type == EXT_KCFG && - strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { - void *ext_val = kcfg_data + ext->kcfg.data_off; - __u32 kver = get_kernel_version(); + if (ext->type == EXT_KSYM) { + if (ext->ksym.type_id) + need_vmlinux_btf = true; + else + need_kallsyms = true; + continue; + } else if (ext->type == EXT_KCFG) { + void *ext_ptr = kcfg_data + ext->kcfg.data_off; + __u64 value = 0; - if (!kver) { - pr_warn("failed to get kernel version\n"); + /* Kconfig externs need actual /proc/config.gz */ + if (str_has_pfx(ext->name, "CONFIG_")) { + need_config = true; + continue; + } + + /* Virtual kcfg externs are customly handled by libbpf */ + if (strcmp(ext->name, "LINUX_KERNEL_VERSION") == 0) { + value = get_kernel_version(); + if (!value) { + pr_warn("extern (kcfg) '%s': failed to get kernel version\n", ext->name); + return -EINVAL; + } + } else if (strcmp(ext->name, "LINUX_HAS_BPF_COOKIE") == 0) { + value = kernel_supports(obj, FEAT_BPF_COOKIE); + } else if (strcmp(ext->name, "LINUX_HAS_SYSCALL_WRAPPER") == 0) { + value = kernel_supports(obj, FEAT_SYSCALL_WRAPPER); + } else if (!str_has_pfx(ext->name, "LINUX_") || !ext->is_weak) { + /* Currently libbpf supports only CONFIG_ and LINUX_ prefixed + * __kconfig externs, where LINUX_ ones are virtual and filled out + * customly by libbpf (their values don't come from Kconfig). + * If LINUX_xxx variable is not recognized by libbpf, but is marked + * __weak, it defaults to zero value, just like for CONFIG_xxx + * externs. + */ + pr_warn("extern (kcfg) '%s': unrecognized virtual extern\n", ext->name); return -EINVAL; } - err = set_kcfg_value_num(ext, ext_val, kver); + + err = set_kcfg_value_num(ext, ext_ptr, value); if (err) return err; - pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver); - } else if (ext->type == EXT_KCFG && str_has_pfx(ext->name, "CONFIG_")) { - need_config = true; - } else if (ext->type == EXT_KSYM) { - if (ext->ksym.type_id) - need_vmlinux_btf = true; - else - need_kallsyms = true; + pr_debug("extern (kcfg) '%s': set to 0x%llx\n", + ext->name, (long long)value); } else { - pr_warn("unrecognized extern '%s'\n", ext->name); + pr_warn("extern '%s': unrecognized extern kind\n", ext->name); return -EINVAL; } } @@ -7450,10 +7637,10 @@ static int bpf_object__resolve_externs(struct bpf_object *obj, ext = &obj->externs[i]; if (!ext->is_set && !ext->is_weak) { - pr_warn("extern %s (strong) not resolved\n", ext->name); + pr_warn("extern '%s' (strong): not resolved\n", ext->name); return -ESRCH; } else if (!ext->is_set) { - pr_debug("extern %s (weak) not resolved, defaulting to zero\n", + pr_debug("extern '%s' (weak): not resolved, defaulting to zero\n", ext->name); } } @@ -7529,11 +7716,6 @@ out: return libbpf_err(err); } -int bpf_object__load_xattr(struct bpf_object_load_attr *attr) -{ - return bpf_object_load(attr->obj, attr->log_level, attr->target_btf_path); -} - int bpf_object__load(struct bpf_object *obj) { return bpf_object_load(obj, 0, NULL); @@ -7591,11 +7773,16 @@ static int check_path(const char *path) return err; } -static int bpf_program_pin_instance(struct bpf_program *prog, const char *path, int instance) +int bpf_program__pin(struct bpf_program *prog, const char *path) { char *cp, errmsg[STRERR_BUFSIZE]; int err; + if (prog->fd < 0) { + pr_warn("prog '%s': can't pin program that wasn't loaded\n", prog->name); + return libbpf_err(-EINVAL); + } + err = make_parent_dir(path); if (err) return libbpf_err(err); @@ -7604,170 +7791,35 @@ static int bpf_program_pin_instance(struct bpf_program *prog, const char *path, if (err) return libbpf_err(err); - if (prog == NULL) { - pr_warn("invalid program pointer\n"); - return libbpf_err(-EINVAL); - } - - if (instance < 0 || instance >= prog->instances.nr) { - pr_warn("invalid prog instance %d of prog %s (max %d)\n", - instance, prog->name, prog->instances.nr); - return libbpf_err(-EINVAL); - } - - if (bpf_obj_pin(prog->instances.fds[instance], path)) { + if (bpf_obj_pin(prog->fd, path)) { err = -errno; cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg)); - pr_warn("failed to pin program: %s\n", cp); + pr_warn("prog '%s': failed to pin at '%s': %s\n", prog->name, path, cp); return libbpf_err(err); } - pr_debug("pinned program '%s'\n", path); + pr_debug("prog '%s': pinned at '%s'\n", prog->name, path); return 0; } -static int bpf_program_unpin_instance(struct bpf_program *prog, const char *path, int instance) +int bpf_program__unpin(struct bpf_program *prog, const char *path) { int err; - err = check_path(path); - if (err) - return libbpf_err(err); - - if (prog == NULL) { - pr_warn("invalid program pointer\n"); - return libbpf_err(-EINVAL); - } - - if (instance < 0 || instance >= prog->instances.nr) { - pr_warn("invalid prog instance %d of prog %s (max %d)\n", - instance, prog->name, prog->instances.nr); - return libbpf_err(-EINVAL); - } - - err = unlink(path); - if (err != 0) - return libbpf_err(-errno); - - pr_debug("unpinned program '%s'\n", path); - - return 0; -} - -__attribute__((alias("bpf_program_pin_instance"))) -int bpf_object__pin_instance(struct bpf_program *prog, const char *path, int instance); - -__attribute__((alias("bpf_program_unpin_instance"))) -int bpf_program__unpin_instance(struct bpf_program *prog, const char *path, int instance); - -int bpf_program__pin(struct bpf_program *prog, const char *path) -{ - int i, err; - - err = make_parent_dir(path); - if (err) - return libbpf_err(err); - - err = check_path(path); - if (err) - return libbpf_err(err); - - if (prog == NULL) { - pr_warn("invalid program pointer\n"); - return libbpf_err(-EINVAL); - } - - if (prog->instances.nr <= 0) { - pr_warn("no instances of prog %s to pin\n", prog->name); + if (prog->fd < 0) { + pr_warn("prog '%s': can't unpin program that wasn't loaded\n", prog->name); return libbpf_err(-EINVAL); } - if (prog->instances.nr == 1) { - /* don't create subdirs when pinning single instance */ - return bpf_program_pin_instance(prog, path, 0); - } - - for (i = 0; i < prog->instances.nr; i++) { - char buf[PATH_MAX]; - int len; - - len = snprintf(buf, PATH_MAX, "%s/%d", path, i); - if (len < 0) { - err = -EINVAL; - goto err_unpin; - } else if (len >= PATH_MAX) { - err = -ENAMETOOLONG; - goto err_unpin; - } - - err = bpf_program_pin_instance(prog, buf, i); - if (err) - goto err_unpin; - } - - return 0; - -err_unpin: - for (i = i - 1; i >= 0; i--) { - char buf[PATH_MAX]; - int len; - - len = snprintf(buf, PATH_MAX, "%s/%d", path, i); - if (len < 0) - continue; - else if (len >= PATH_MAX) - continue; - - bpf_program_unpin_instance(prog, buf, i); - } - - rmdir(path); - - return libbpf_err(err); -} - -int bpf_program__unpin(struct bpf_program *prog, const char *path) -{ - int i, err; - err = check_path(path); if (err) return libbpf_err(err); - if (prog == NULL) { - pr_warn("invalid program pointer\n"); - return libbpf_err(-EINVAL); - } - - if (prog->instances.nr <= 0) { - pr_warn("no instances of prog %s to pin\n", prog->name); - return libbpf_err(-EINVAL); - } - - if (prog->instances.nr == 1) { - /* don't create subdirs when pinning single instance */ - return bpf_program_unpin_instance(prog, path, 0); - } - - for (i = 0; i < prog->instances.nr; i++) { - char buf[PATH_MAX]; - int len; - - len = snprintf(buf, PATH_MAX, "%s/%d", path, i); - if (len < 0) - return libbpf_err(-EINVAL); - else if (len >= PATH_MAX) - return libbpf_err(-ENAMETOOLONG); - - err = bpf_program_unpin_instance(prog, buf, i); - if (err) - return err; - } - - err = rmdir(path); + err = unlink(path); if (err) return libbpf_err(-errno); + pr_debug("prog '%s': unpinned from '%s'\n", prog->name, path); return 0; } @@ -7883,10 +7935,8 @@ int bpf_map__set_pin_path(struct bpf_map *map, const char *path) return 0; } -const char *bpf_map__get_pin_path(const struct bpf_map *map) -{ - return map->pin_path; -} +__alias(bpf_map__pin_path) +const char *bpf_map__get_pin_path(const struct bpf_map *map); const char *bpf_map__pin_path(const struct bpf_map *map) { @@ -7925,21 +7975,13 @@ int bpf_object__pin_maps(struct bpf_object *obj, const char *path) char *pin_path = NULL; char buf[PATH_MAX]; - if (map->skipped) + if (!map->autocreate) continue; if (path) { - int len; - - len = snprintf(buf, PATH_MAX, "%s/%s", path, - bpf_map__name(map)); - if (len < 0) { - err = -EINVAL; - goto err_unpin_maps; - } else if (len >= PATH_MAX) { - err = -ENAMETOOLONG; + err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); + if (err) goto err_unpin_maps; - } sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { @@ -7977,14 +8019,9 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path) char buf[PATH_MAX]; if (path) { - int len; - - len = snprintf(buf, PATH_MAX, "%s/%s", path, - bpf_map__name(map)); - if (len < 0) - return libbpf_err(-EINVAL); - else if (len >= PATH_MAX) - return libbpf_err(-ENAMETOOLONG); + err = pathname_concat(buf, sizeof(buf), path, bpf_map__name(map)); + if (err) + return libbpf_err(err); sanitize_pin_path(buf); pin_path = buf; } else if (!map->pin_path) { @@ -8002,6 +8039,7 @@ int bpf_object__unpin_maps(struct bpf_object *obj, const char *path) int bpf_object__pin_programs(struct bpf_object *obj, const char *path) { struct bpf_program *prog; + char buf[PATH_MAX]; int err; if (!obj) @@ -8013,18 +8051,9 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path) } bpf_object__for_each_program(prog, obj) { - char buf[PATH_MAX]; - int len; - - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); - if (len < 0) { - err = -EINVAL; - goto err_unpin_programs; - } else if (len >= PATH_MAX) { - err = -ENAMETOOLONG; + err = pathname_concat(buf, sizeof(buf), path, prog->name); + if (err) goto err_unpin_programs; - } err = bpf_program__pin(prog, buf); if (err) @@ -8035,14 +8064,7 @@ int bpf_object__pin_programs(struct bpf_object *obj, const char *path) err_unpin_programs: while ((prog = bpf_object__prev_program(obj, prog))) { - char buf[PATH_MAX]; - int len; - - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); - if (len < 0) - continue; - else if (len >= PATH_MAX) + if (pathname_concat(buf, sizeof(buf), path, prog->name)) continue; bpf_program__unpin(prog, buf); @@ -8061,14 +8083,10 @@ int bpf_object__unpin_programs(struct bpf_object *obj, const char *path) bpf_object__for_each_program(prog, obj) { char buf[PATH_MAX]; - int len; - len = snprintf(buf, PATH_MAX, "%s/%s", path, - prog->pin_name); - if (len < 0) - return libbpf_err(-EINVAL); - else if (len >= PATH_MAX) - return libbpf_err(-ENAMETOOLONG); + err = pathname_concat(buf, sizeof(buf), path, prog->name); + if (err) + return libbpf_err(err); err = bpf_program__unpin(prog, buf); if (err) @@ -8097,11 +8115,6 @@ int bpf_object__pin(struct bpf_object *obj, const char *path) static void bpf_map__destroy(struct bpf_map *map) { - if (map->clear_priv) - map->clear_priv(map, map->priv); - map->priv = NULL; - map->clear_priv = NULL; - if (map->inner_map) { bpf_map__destroy(map->inner_map); zfree(&map->inner_map); @@ -8137,8 +8150,8 @@ void bpf_object__close(struct bpf_object *obj) if (IS_ERR_OR_NULL(obj)) return; - if (obj->clear_priv) - obj->clear_priv(obj, obj->priv); + usdt_manager_free(obj->usdt_man); + obj->usdt_man = NULL; bpf_gen__free(obj->gen_loader); bpf_object__elf_finish(obj); @@ -8163,33 +8176,9 @@ void bpf_object__close(struct bpf_object *obj) } zfree(&obj->programs); - list_del(&obj->list); free(obj); } -struct bpf_object * -bpf_object__next(struct bpf_object *prev) -{ - struct bpf_object *next; - bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST); - - if (strict) - return NULL; - - if (!prev) - next = list_first_entry(&bpf_objects_list, - struct bpf_object, - list); - else - next = list_next_entry(prev, list); - - /* Empty list is noticed here so don't need checking on entry. */ - if (&next->list == &bpf_objects_list) - return NULL; - - return next; -} - const char *bpf_object__name(const struct bpf_object *obj) { return obj ? obj->name : libbpf_err_ptr(-EINVAL); @@ -8220,22 +8209,6 @@ int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version) return 0; } -int bpf_object__set_priv(struct bpf_object *obj, void *priv, - bpf_object_clear_priv_t clear_priv) -{ - if (obj->priv && obj->clear_priv) - obj->clear_priv(obj, obj->priv); - - obj->priv = priv; - obj->clear_priv = clear_priv; - return 0; -} - -void *bpf_object__priv(const struct bpf_object *obj) -{ - return obj ? obj->priv : libbpf_err_ptr(-EINVAL); -} - int bpf_object__gen_loader(struct bpf_object *obj, struct gen_loader_opts *opts) { struct bpf_gen *gen; @@ -8279,12 +8252,6 @@ __bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj, } struct bpf_program * -bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj) -{ - return bpf_object__next_program(obj, prev); -} - -struct bpf_program * bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev) { struct bpf_program *prog = prev; @@ -8297,12 +8264,6 @@ bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev) } struct bpf_program * -bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj) -{ - return bpf_object__prev_program(obj, next); -} - -struct bpf_program * bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *next) { struct bpf_program *prog = next; @@ -8314,22 +8275,6 @@ bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *next) return prog; } -int bpf_program__set_priv(struct bpf_program *prog, void *priv, - bpf_program_clear_priv_t clear_priv) -{ - if (prog->priv && prog->clear_priv) - prog->clear_priv(prog, prog->priv); - - prog->priv = priv; - prog->clear_priv = clear_priv; - return 0; -} - -void *bpf_program__priv(const struct bpf_program *prog) -{ - return prog ? prog->priv : libbpf_err_ptr(-EINVAL); -} - void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex) { prog->prog_ifindex = ifindex; @@ -8345,25 +8290,9 @@ const char *bpf_program__section_name(const struct bpf_program *prog) return prog->sec_name; } -const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy) -{ - const char *title; - - title = prog->sec_name; - if (needs_copy) { - title = strdup(title); - if (!title) { - pr_warn("failed to strdup program title\n"); - return libbpf_err_ptr(-ENOMEM); - } - } - - return title; -} - bool bpf_program__autoload(const struct bpf_program *prog) { - return prog->load; + return prog->autoload; } int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) @@ -8371,20 +8300,18 @@ int bpf_program__set_autoload(struct bpf_program *prog, bool autoload) if (prog->obj->loaded) return libbpf_err(-EINVAL); - prog->load = autoload; + prog->autoload = autoload; return 0; } -static int bpf_program_nth_fd(const struct bpf_program *prog, int n); - -int bpf_program__fd(const struct bpf_program *prog) +bool bpf_program__autoattach(const struct bpf_program *prog) { - return bpf_program_nth_fd(prog, 0); + return prog->autoattach; } -size_t bpf_program__size(const struct bpf_program *prog) +void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach) { - return prog->insns_cnt * BPF_INSN_SZ; + prog->autoattach = autoattach; } const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog) @@ -8397,114 +8324,70 @@ size_t bpf_program__insn_cnt(const struct bpf_program *prog) return prog->insns_cnt; } -int bpf_program__set_prep(struct bpf_program *prog, int nr_instances, - bpf_program_prep_t prep) +int bpf_program__set_insns(struct bpf_program *prog, + struct bpf_insn *new_insns, size_t new_insn_cnt) { - int *instances_fds; - - if (nr_instances <= 0 || !prep) - return libbpf_err(-EINVAL); + struct bpf_insn *insns; - if (prog->instances.nr > 0 || prog->instances.fds) { - pr_warn("Can't set pre-processor after loading\n"); - return libbpf_err(-EINVAL); - } + if (prog->obj->loaded) + return -EBUSY; - instances_fds = malloc(sizeof(int) * nr_instances); - if (!instances_fds) { - pr_warn("alloc memory failed for fds\n"); - return libbpf_err(-ENOMEM); + insns = libbpf_reallocarray(prog->insns, new_insn_cnt, sizeof(*insns)); + if (!insns) { + pr_warn("prog '%s': failed to realloc prog code\n", prog->name); + return -ENOMEM; } + memcpy(insns, new_insns, new_insn_cnt * sizeof(*insns)); - /* fill all fd with -1 */ - memset(instances_fds, -1, sizeof(int) * nr_instances); - - prog->instances.nr = nr_instances; - prog->instances.fds = instances_fds; - prog->preprocessor = prep; + prog->insns = insns; + prog->insns_cnt = new_insn_cnt; return 0; } -__attribute__((alias("bpf_program_nth_fd"))) -int bpf_program__nth_fd(const struct bpf_program *prog, int n); - -static int bpf_program_nth_fd(const struct bpf_program *prog, int n) +int bpf_program__fd(const struct bpf_program *prog) { - int fd; - if (!prog) return libbpf_err(-EINVAL); - if (n >= prog->instances.nr || n < 0) { - pr_warn("Can't get the %dth fd from program %s: only %d instances\n", - n, prog->name, prog->instances.nr); - return libbpf_err(-EINVAL); - } - - fd = prog->instances.fds[n]; - if (fd < 0) { - pr_warn("%dth instance of program '%s' is invalid\n", - n, prog->name); + if (prog->fd < 0) return libbpf_err(-ENOENT); - } - return fd; + return prog->fd; } -enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog) +__alias(bpf_program__type) +enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog); + +enum bpf_prog_type bpf_program__type(const struct bpf_program *prog) { return prog->type; } -void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) +int bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->type = type; + return 0; } -static bool bpf_program__is_type(const struct bpf_program *prog, - enum bpf_prog_type type) -{ - return prog ? (prog->type == type) : false; -} - -#define BPF_PROG_TYPE_FNS(NAME, TYPE) \ -int bpf_program__set_##NAME(struct bpf_program *prog) \ -{ \ - if (!prog) \ - return libbpf_err(-EINVAL); \ - bpf_program__set_type(prog, TYPE); \ - return 0; \ -} \ - \ -bool bpf_program__is_##NAME(const struct bpf_program *prog) \ -{ \ - return bpf_program__is_type(prog, TYPE); \ -} \ - -BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER); -BPF_PROG_TYPE_FNS(lsm, BPF_PROG_TYPE_LSM); -BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE); -BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS); -BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT); -BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT); -BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT); -BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP); -BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT); -BPF_PROG_TYPE_FNS(tracing, BPF_PROG_TYPE_TRACING); -BPF_PROG_TYPE_FNS(struct_ops, BPF_PROG_TYPE_STRUCT_OPS); -BPF_PROG_TYPE_FNS(extension, BPF_PROG_TYPE_EXT); -BPF_PROG_TYPE_FNS(sk_lookup, BPF_PROG_TYPE_SK_LOOKUP); - -enum bpf_attach_type -bpf_program__get_expected_attach_type(const struct bpf_program *prog) +__alias(bpf_program__expected_attach_type) +enum bpf_attach_type bpf_program__get_expected_attach_type(const struct bpf_program *prog); + +enum bpf_attach_type bpf_program__expected_attach_type(const struct bpf_program *prog) { return prog->expected_attach_type; } -void bpf_program__set_expected_attach_type(struct bpf_program *prog, +int bpf_program__set_expected_attach_type(struct bpf_program *prog, enum bpf_attach_type type) { + if (prog->obj->loaded) + return libbpf_err(-EBUSY); + prog->expected_attach_type = type; + return 0; } __u32 bpf_program__flags(const struct bpf_program *prog) @@ -8556,148 +8439,256 @@ int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log } #define SEC_DEF(sec_pfx, ptype, atype, flags, ...) { \ - .sec = sec_pfx, \ + .sec = (char *)sec_pfx, \ .prog_type = BPF_PROG_TYPE_##ptype, \ .expected_attach_type = atype, \ .cookie = (long)(flags), \ - .preload_fn = libbpf_preload_prog, \ + .prog_prepare_load_fn = libbpf_prepare_prog_load, \ __VA_ARGS__ \ } -static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie); -static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie); -static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie); -static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie); -static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie); -static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie); +static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link); +static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link); static const struct bpf_sec_def section_defs[] = { - SEC_DEF("socket", SOCKET_FILTER, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("sk_reuseport/migrate", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("kprobe/", KPROBE, 0, SEC_NONE, attach_kprobe), - SEC_DEF("uprobe/", KPROBE, 0, SEC_NONE), - SEC_DEF("kretprobe/", KPROBE, 0, SEC_NONE, attach_kprobe), - SEC_DEF("uretprobe/", KPROBE, 0, SEC_NONE), + SEC_DEF("socket", SOCKET_FILTER, 0, SEC_NONE), + SEC_DEF("sk_reuseport/migrate", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE), + SEC_DEF("sk_reuseport", SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE), + SEC_DEF("kprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), + SEC_DEF("uprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), + SEC_DEF("uprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), + SEC_DEF("kretprobe+", KPROBE, 0, SEC_NONE, attach_kprobe), + SEC_DEF("uretprobe+", KPROBE, 0, SEC_NONE, attach_uprobe), + SEC_DEF("uretprobe.s+", KPROBE, 0, SEC_SLEEPABLE, attach_uprobe), + SEC_DEF("kprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("kretprobe.multi+", KPROBE, BPF_TRACE_KPROBE_MULTI, SEC_NONE, attach_kprobe_multi), + SEC_DEF("ksyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), + SEC_DEF("kretsyscall+", KPROBE, 0, SEC_NONE, attach_ksyscall), + SEC_DEF("usdt+", KPROBE, 0, SEC_NONE, attach_usdt), SEC_DEF("tc", SCHED_CLS, 0, SEC_NONE), - SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("action", SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("tracepoint/", TRACEPOINT, 0, SEC_NONE, attach_tp), - SEC_DEF("tp/", TRACEPOINT, 0, SEC_NONE, attach_tp), - SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), - SEC_DEF("raw_tp/", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), - SEC_DEF("raw_tracepoint.w/", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), - SEC_DEF("raw_tp.w/", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), - SEC_DEF("tp_btf/", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace), - SEC_DEF("fentry/", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace), - SEC_DEF("fmod_ret/", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace), - SEC_DEF("fexit/", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace), - SEC_DEF("fentry.s/", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), - SEC_DEF("fmod_ret.s/", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), - SEC_DEF("fexit.s/", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), - SEC_DEF("freplace/", EXT, 0, SEC_ATTACH_BTF, attach_trace), - SEC_DEF("lsm/", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm), - SEC_DEF("lsm.s/", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm), - SEC_DEF("iter/", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter), + SEC_DEF("classifier", SCHED_CLS, 0, SEC_NONE), + SEC_DEF("action", SCHED_ACT, 0, SEC_NONE), + SEC_DEF("tracepoint+", TRACEPOINT, 0, SEC_NONE, attach_tp), + SEC_DEF("tp+", TRACEPOINT, 0, SEC_NONE, attach_tp), + SEC_DEF("raw_tracepoint+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), + SEC_DEF("raw_tp+", RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp), + SEC_DEF("raw_tracepoint.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), + SEC_DEF("raw_tp.w+", RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp), + SEC_DEF("tp_btf+", TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace), + SEC_DEF("fentry+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace), + SEC_DEF("fmod_ret+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace), + SEC_DEF("fexit+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace), + SEC_DEF("fentry.s+", TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), + SEC_DEF("fmod_ret.s+", TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), + SEC_DEF("fexit.s+", TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace), + SEC_DEF("freplace+", EXT, 0, SEC_ATTACH_BTF, attach_trace), + SEC_DEF("lsm+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm), + SEC_DEF("lsm.s+", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm), + SEC_DEF("lsm_cgroup+", LSM, BPF_LSM_CGROUP, SEC_ATTACH_BTF), + SEC_DEF("iter+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter), + SEC_DEF("iter.s+", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_iter), SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE), - SEC_DEF("xdp_devmap/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE), - SEC_DEF("xdp_cpumap/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE), - SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("lwt_out", LWT_OUT, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("lwt_xmit", LWT_XMIT, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("lwt_seg6local", LWT_SEG6LOCAL, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup_skb/ingress", CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("cgroup_skb/egress", CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/skb", CGROUP_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sock_create", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sock_release", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sock", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/post_bind4", CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/post_bind6", CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/dev", CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("sockops", SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("sk_skb/stream_parser", SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("sk_skb", SK_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX), - SEC_DEF("sk_msg", SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("lirc_mode2", LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("flow_dissector", FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/bind4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/bind6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/connect4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/connect6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sendmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sendmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/recvmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/recvmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/getpeername4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/getpeername6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/getsockname4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/getsockname6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/sysctl", CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/getsockopt", CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), - SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX), + SEC_DEF("xdp.frags/devmap", XDP, BPF_XDP_DEVMAP, SEC_XDP_FRAGS), + SEC_DEF("xdp/devmap", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE), + SEC_DEF("xdp.frags/cpumap", XDP, BPF_XDP_CPUMAP, SEC_XDP_FRAGS), + SEC_DEF("xdp/cpumap", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE), + SEC_DEF("xdp.frags", XDP, BPF_XDP, SEC_XDP_FRAGS), + SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT), + SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE), + SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE), + SEC_DEF("lwt_out", LWT_OUT, 0, SEC_NONE), + SEC_DEF("lwt_xmit", LWT_XMIT, 0, SEC_NONE), + SEC_DEF("lwt_seg6local", LWT_SEG6LOCAL, 0, SEC_NONE), + SEC_DEF("sockops", SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT), + SEC_DEF("sk_skb/stream_parser", SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT), + SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT), + SEC_DEF("sk_skb", SK_SKB, 0, SEC_NONE), + SEC_DEF("sk_msg", SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT), + SEC_DEF("lirc_mode2", LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT), + SEC_DEF("flow_dissector", FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT), + SEC_DEF("cgroup_skb/ingress", CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT), + SEC_DEF("cgroup_skb/egress", CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT), + SEC_DEF("cgroup/skb", CGROUP_SKB, 0, SEC_NONE), + SEC_DEF("cgroup/sock_create", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE), + SEC_DEF("cgroup/sock_release", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE), + SEC_DEF("cgroup/sock", CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT), + SEC_DEF("cgroup/post_bind4", CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE), + SEC_DEF("cgroup/post_bind6", CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE), + SEC_DEF("cgroup/bind4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE), + SEC_DEF("cgroup/bind6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE), + SEC_DEF("cgroup/connect4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE), + SEC_DEF("cgroup/connect6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE), + SEC_DEF("cgroup/sendmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/sendmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/recvmsg4", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/recvmsg6", CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE), + SEC_DEF("cgroup/getpeername4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/getpeername6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/getsockname4", CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/getsockname6", CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE), + SEC_DEF("cgroup/sysctl", CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE), + SEC_DEF("cgroup/getsockopt", CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE), + SEC_DEF("cgroup/setsockopt", CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE), + SEC_DEF("cgroup/dev", CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT), SEC_DEF("struct_ops+", STRUCT_OPS, 0, SEC_NONE), - SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE | SEC_SLOPPY_PFX), + SEC_DEF("sk_lookup", SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE), }; -#define MAX_TYPE_NAME_SIZE 32 +static size_t custom_sec_def_cnt; +static struct bpf_sec_def *custom_sec_defs; +static struct bpf_sec_def custom_fallback_def; +static bool has_custom_fallback_def; -static const struct bpf_sec_def *find_sec_def(const char *sec_name) +static int last_custom_sec_def_handler_id; + +int libbpf_register_prog_handler(const char *sec, + enum bpf_prog_type prog_type, + enum bpf_attach_type exp_attach_type, + const struct libbpf_prog_handler_opts *opts) { - const struct bpf_sec_def *sec_def; - enum sec_def_flags sec_flags; - int i, n = ARRAY_SIZE(section_defs), len; - bool strict = libbpf_mode & LIBBPF_STRICT_SEC_NAME; + struct bpf_sec_def *sec_def; - for (i = 0; i < n; i++) { - sec_def = §ion_defs[i]; - sec_flags = sec_def->cookie; - len = strlen(sec_def->sec); + if (!OPTS_VALID(opts, libbpf_prog_handler_opts)) + return libbpf_err(-EINVAL); - /* "type/" always has to have proper SEC("type/extras") form */ - if (sec_def->sec[len - 1] == '/') { - if (str_has_pfx(sec_name, sec_def->sec)) - return sec_def; - continue; - } + if (last_custom_sec_def_handler_id == INT_MAX) /* prevent overflow */ + return libbpf_err(-E2BIG); - /* "type+" means it can be either exact SEC("type") or - * well-formed SEC("type/extras") with proper '/' separator - */ - if (sec_def->sec[len - 1] == '+') { - len--; - /* not even a prefix */ - if (strncmp(sec_name, sec_def->sec, len) != 0) - continue; - /* exact match or has '/' separator */ - if (sec_name[len] == '\0' || sec_name[len] == '/') - return sec_def; - continue; - } + if (sec) { + sec_def = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt + 1, + sizeof(*sec_def)); + if (!sec_def) + return libbpf_err(-ENOMEM); - /* SEC_SLOPPY_PFX definitions are allowed to be just prefix - * matches, unless strict section name mode - * (LIBBPF_STRICT_SEC_NAME) is enabled, in which case the - * match has to be exact. - */ - if ((sec_flags & SEC_SLOPPY_PFX) && !strict) { - if (str_has_pfx(sec_name, sec_def->sec)) - return sec_def; - continue; - } + custom_sec_defs = sec_def; + sec_def = &custom_sec_defs[custom_sec_def_cnt]; + } else { + if (has_custom_fallback_def) + return libbpf_err(-EBUSY); - /* Definitions not marked SEC_SLOPPY_PFX (e.g., - * SEC("syscall")) are exact matches in both modes. - */ - if (strcmp(sec_name, sec_def->sec) == 0) + sec_def = &custom_fallback_def; + } + + sec_def->sec = sec ? strdup(sec) : NULL; + if (sec && !sec_def->sec) + return libbpf_err(-ENOMEM); + + sec_def->prog_type = prog_type; + sec_def->expected_attach_type = exp_attach_type; + sec_def->cookie = OPTS_GET(opts, cookie, 0); + + sec_def->prog_setup_fn = OPTS_GET(opts, prog_setup_fn, NULL); + sec_def->prog_prepare_load_fn = OPTS_GET(opts, prog_prepare_load_fn, NULL); + sec_def->prog_attach_fn = OPTS_GET(opts, prog_attach_fn, NULL); + + sec_def->handler_id = ++last_custom_sec_def_handler_id; + + if (sec) + custom_sec_def_cnt++; + else + has_custom_fallback_def = true; + + return sec_def->handler_id; +} + +int libbpf_unregister_prog_handler(int handler_id) +{ + struct bpf_sec_def *sec_defs; + int i; + + if (handler_id <= 0) + return libbpf_err(-EINVAL); + + if (has_custom_fallback_def && custom_fallback_def.handler_id == handler_id) { + memset(&custom_fallback_def, 0, sizeof(custom_fallback_def)); + has_custom_fallback_def = false; + return 0; + } + + for (i = 0; i < custom_sec_def_cnt; i++) { + if (custom_sec_defs[i].handler_id == handler_id) + break; + } + + if (i == custom_sec_def_cnt) + return libbpf_err(-ENOENT); + + free(custom_sec_defs[i].sec); + for (i = i + 1; i < custom_sec_def_cnt; i++) + custom_sec_defs[i - 1] = custom_sec_defs[i]; + custom_sec_def_cnt--; + + /* try to shrink the array, but it's ok if we couldn't */ + sec_defs = libbpf_reallocarray(custom_sec_defs, custom_sec_def_cnt, sizeof(*sec_defs)); + if (sec_defs) + custom_sec_defs = sec_defs; + + return 0; +} + +static bool sec_def_matches(const struct bpf_sec_def *sec_def, const char *sec_name) +{ + size_t len = strlen(sec_def->sec); + + /* "type/" always has to have proper SEC("type/extras") form */ + if (sec_def->sec[len - 1] == '/') { + if (str_has_pfx(sec_name, sec_def->sec)) + return true; + return false; + } + + /* "type+" means it can be either exact SEC("type") or + * well-formed SEC("type/extras") with proper '/' separator + */ + if (sec_def->sec[len - 1] == '+') { + len--; + /* not even a prefix */ + if (strncmp(sec_name, sec_def->sec, len) != 0) + return false; + /* exact match or has '/' separator */ + if (sec_name[len] == '\0' || sec_name[len] == '/') + return true; + return false; + } + + return strcmp(sec_name, sec_def->sec) == 0; +} + +static const struct bpf_sec_def *find_sec_def(const char *sec_name) +{ + const struct bpf_sec_def *sec_def; + int i, n; + + n = custom_sec_def_cnt; + for (i = 0; i < n; i++) { + sec_def = &custom_sec_defs[i]; + if (sec_def_matches(sec_def, sec_name)) + return sec_def; + } + + n = ARRAY_SIZE(section_defs); + for (i = 0; i < n; i++) { + sec_def = §ion_defs[i]; + if (sec_def_matches(sec_def, sec_name)) return sec_def; } + + if (has_custom_fallback_def) + return &custom_fallback_def; + return NULL; } +#define MAX_TYPE_NAME_SIZE 32 + static char *libbpf_get_type_names(bool attach_type) { int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE; @@ -8713,7 +8704,7 @@ static char *libbpf_get_type_names(bool attach_type) const struct bpf_sec_def *sec_def = §ion_defs[i]; if (attach_type) { - if (sec_def->preload_fn != libbpf_preload_prog) + if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load) continue; if (!(sec_def->cookie & SEC_ATTACHABLE)) @@ -8757,6 +8748,38 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type, return libbpf_err(-ESRCH); } +const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t) +{ + if (t < 0 || t >= ARRAY_SIZE(attach_type_name)) + return NULL; + + return attach_type_name[t]; +} + +const char *libbpf_bpf_link_type_str(enum bpf_link_type t) +{ + if (t < 0 || t >= ARRAY_SIZE(link_type_name)) + return NULL; + + return link_type_name[t]; +} + +const char *libbpf_bpf_map_type_str(enum bpf_map_type t) +{ + if (t < 0 || t >= ARRAY_SIZE(map_type_name)) + return NULL; + + return map_type_name[t]; +} + +const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t) +{ + if (t < 0 || t >= ARRAY_SIZE(prog_type_name)) + return NULL; + + return prog_type_name[t]; +} + static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj, size_t offset) { @@ -8907,6 +8930,7 @@ void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type, *kind = BTF_KIND_TYPEDEF; break; case BPF_LSM_MAC: + case BPF_LSM_CGROUP: *prefix = BTF_LSM_PREFIX; *kind = BTF_KIND_FUNC; break; @@ -8970,11 +8994,12 @@ int libbpf_find_vmlinux_btf_id(const char *name, static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd) { - struct bpf_prog_info info = {}; + struct bpf_prog_info info; __u32 info_len = sizeof(info); struct btf *btf; int err; + memset(&info, 0, info_len); err = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len); if (err) { pr_warn("failed bpf_obj_get_info_by_fd for FD %d: %d\n", @@ -9048,11 +9073,15 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attac int err = 0; /* BPF program's BTF ID */ - if (attach_prog_fd) { + if (prog->type == BPF_PROG_TYPE_EXT || attach_prog_fd) { + if (!attach_prog_fd) { + pr_warn("prog '%s': attach program FD is not set\n", prog->name); + return -EINVAL; + } err = libbpf_find_prog_btf_id(attach_name, attach_prog_fd); if (err < 0) { - pr_warn("failed to find BPF program (FD %d) BTF ID for '%s': %d\n", - attach_prog_fd, attach_name, err); + pr_warn("prog '%s': failed to find BPF program (FD %d) BTF ID for '%s': %d\n", + prog->name, attach_prog_fd, attach_name, err); return err; } *btf_obj_fd = 0; @@ -9069,7 +9098,8 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attac err = find_kernel_btf_id(prog->obj, attach_name, attach_type, btf_obj_fd, btf_type_id); } if (err) { - pr_warn("failed to find kernel BTF type ID of '%s': %d\n", attach_name, err); + pr_warn("prog '%s': failed to find kernel BTF type ID of '%s': %d\n", + prog->name, attach_name, err); return err; } return 0; @@ -9096,7 +9126,7 @@ int libbpf_attach_type_by_name(const char *name, return libbpf_err(-EINVAL); } - if (sec_def->preload_fn != libbpf_preload_prog) + if (sec_def->prog_prepare_load_fn != libbpf_prepare_prog_load) return libbpf_err(-EINVAL); if (!(sec_def->cookie & SEC_ATTACHABLE)) return libbpf_err(-EINVAL); @@ -9110,11 +9140,6 @@ int bpf_map__fd(const struct bpf_map *map) return map ? map->fd : libbpf_err(-EINVAL); } -const struct bpf_map_def *bpf_map__def(const struct bpf_map *map) -{ - return map ? &map->def : libbpf_err_ptr(-EINVAL); -} - static bool map_uses_real_name(const struct bpf_map *map) { /* Since libbpf started to support custom .data.* and .rodata.* maps, @@ -9229,27 +9254,6 @@ __u32 bpf_map__btf_value_type_id(const struct bpf_map *map) return map ? map->btf_value_type_id : 0; } -int bpf_map__set_priv(struct bpf_map *map, void *priv, - bpf_map_clear_priv_t clear_priv) -{ - if (!map) - return libbpf_err(-EINVAL); - - if (map->priv) { - if (map->clear_priv) - map->clear_priv(map, map->priv); - } - - map->priv = priv; - map->clear_priv = clear_priv; - return 0; -} - -void *bpf_map__priv(const struct bpf_map *map) -{ - return map ? map->priv : libbpf_err_ptr(-EINVAL); -} - int bpf_map__set_initial_value(struct bpf_map *map, const void *data, size_t size) { @@ -9269,11 +9273,6 @@ const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize) return map->mmaped; } -bool bpf_map__is_offload_neutral(const struct bpf_map *map) -{ - return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY; -} - bool bpf_map__is_internal(const struct bpf_map *map) { return map->libbpf_type != LIBBPF_MAP_UNSPEC; @@ -9335,12 +9334,6 @@ __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i) } struct bpf_map * -bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj) -{ - return bpf_object__next_map(obj, prev); -} - -struct bpf_map * bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev) { if (prev == NULL) @@ -9350,12 +9343,6 @@ bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev) } struct bpf_map * -bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj) -{ - return bpf_object__prev_map(obj, next); -} - -struct bpf_map * bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next) { if (next == NULL) { @@ -9400,126 +9387,126 @@ bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name) return bpf_map__fd(bpf_object__find_map_by_name(obj, name)); } -struct bpf_map * -bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset) +static int validate_map_op(const struct bpf_map *map, size_t key_sz, + size_t value_sz, bool check_value_sz) { - return libbpf_err_ptr(-ENOTSUP); + if (map->fd <= 0) + return -ENOENT; + + if (map->def.key_size != key_sz) { + pr_warn("map '%s': unexpected key size %zu provided, expected %u\n", + map->name, key_sz, map->def.key_size); + return -EINVAL; + } + + if (!check_value_sz) + return 0; + + switch (map->def.type) { + case BPF_MAP_TYPE_PERCPU_ARRAY: + case BPF_MAP_TYPE_PERCPU_HASH: + case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: { + int num_cpu = libbpf_num_possible_cpus(); + size_t elem_sz = roundup(map->def.value_size, 8); + + if (value_sz != num_cpu * elem_sz) { + pr_warn("map '%s': unexpected value size %zu provided for per-CPU map, expected %d * %zu = %zd\n", + map->name, value_sz, num_cpu, elem_sz, num_cpu * elem_sz); + return -EINVAL; + } + break; + } + default: + if (map->def.value_size != value_sz) { + pr_warn("map '%s': unexpected value size %zu provided, expected %u\n", + map->name, value_sz, map->def.value_size); + return -EINVAL; + } + break; + } + return 0; } -long libbpf_get_error(const void *ptr) +int bpf_map__lookup_elem(const struct bpf_map *map, + const void *key, size_t key_sz, + void *value, size_t value_sz, __u64 flags) { - if (!IS_ERR_OR_NULL(ptr)) - return 0; + int err; - if (IS_ERR(ptr)) - errno = -PTR_ERR(ptr); + err = validate_map_op(map, key_sz, value_sz, true); + if (err) + return libbpf_err(err); - /* If ptr == 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. So no extra errno handling for ptr == NULL - * case. - */ - return -errno; + return bpf_map_lookup_elem_flags(map->fd, key, value, flags); } -__attribute__((alias("bpf_prog_load_xattr2"))) -int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr, - struct bpf_object **pobj, int *prog_fd); - -static int bpf_prog_load_xattr2(const struct bpf_prog_load_attr *attr, - struct bpf_object **pobj, int *prog_fd) +int bpf_map__update_elem(const struct bpf_map *map, + const void *key, size_t key_sz, + const void *value, size_t value_sz, __u64 flags) { - struct bpf_object_open_attr open_attr = {}; - struct bpf_program *prog, *first_prog = NULL; - struct bpf_object *obj; - struct bpf_map *map; int err; - if (!attr) - return libbpf_err(-EINVAL); - if (!attr->file) - return libbpf_err(-EINVAL); + err = validate_map_op(map, key_sz, value_sz, true); + if (err) + return libbpf_err(err); - open_attr.file = attr->file; - open_attr.prog_type = attr->prog_type; + return bpf_map_update_elem(map->fd, key, value, flags); +} - obj = bpf_object__open_xattr(&open_attr); - err = libbpf_get_error(obj); +int bpf_map__delete_elem(const struct bpf_map *map, + const void *key, size_t key_sz, __u64 flags) +{ + int err; + + err = validate_map_op(map, key_sz, 0, false /* check_value_sz */); if (err) - return libbpf_err(-ENOENT); + return libbpf_err(err); - bpf_object__for_each_program(prog, obj) { - enum bpf_attach_type attach_type = attr->expected_attach_type; - /* - * to preserve backwards compatibility, bpf_prog_load treats - * attr->prog_type, if specified, as an override to whatever - * bpf_object__open guessed - */ - if (attr->prog_type != BPF_PROG_TYPE_UNSPEC) { - bpf_program__set_type(prog, attr->prog_type); - bpf_program__set_expected_attach_type(prog, - attach_type); - } - if (bpf_program__get_type(prog) == BPF_PROG_TYPE_UNSPEC) { - /* - * we haven't guessed from section name and user - * didn't provide a fallback type, too bad... - */ - bpf_object__close(obj); - return libbpf_err(-EINVAL); - } + return bpf_map_delete_elem_flags(map->fd, key, flags); +} - prog->prog_ifindex = attr->ifindex; - prog->log_level = attr->log_level; - prog->prog_flags |= attr->prog_flags; - if (!first_prog) - first_prog = prog; - } +int bpf_map__lookup_and_delete_elem(const struct bpf_map *map, + const void *key, size_t key_sz, + void *value, size_t value_sz, __u64 flags) +{ + int err; - bpf_object__for_each_map(map, obj) { - if (!bpf_map__is_offload_neutral(map)) - map->map_ifindex = attr->ifindex; - } + err = validate_map_op(map, key_sz, value_sz, true); + if (err) + return libbpf_err(err); - if (!first_prog) { - pr_warn("object file doesn't contain bpf program\n"); - bpf_object__close(obj); - return libbpf_err(-ENOENT); - } + return bpf_map_lookup_and_delete_elem_flags(map->fd, key, value, flags); +} - err = bpf_object__load(obj); - if (err) { - bpf_object__close(obj); +int bpf_map__get_next_key(const struct bpf_map *map, + const void *cur_key, void *next_key, size_t key_sz) +{ + int err; + + err = validate_map_op(map, key_sz, 0, false /* check_value_sz */); + if (err) return libbpf_err(err); - } - *pobj = obj; - *prog_fd = bpf_program__fd(first_prog); - return 0; + return bpf_map_get_next_key(map->fd, cur_key, next_key); } -COMPAT_VERSION(bpf_prog_load_deprecated, bpf_prog_load, LIBBPF_0.0.1) -int bpf_prog_load_deprecated(const char *file, enum bpf_prog_type type, - struct bpf_object **pobj, int *prog_fd) +long libbpf_get_error(const void *ptr) { - struct bpf_prog_load_attr attr; + if (!IS_ERR_OR_NULL(ptr)) + return 0; - memset(&attr, 0, sizeof(struct bpf_prog_load_attr)); - attr.file = file; - attr.prog_type = type; - attr.expected_attach_type = 0; + if (IS_ERR(ptr)) + errno = -PTR_ERR(ptr); - return bpf_prog_load_xattr2(&attr, pobj, prog_fd); + /* If ptr == 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. So no extra errno handling for ptr == NULL + * case. + */ + return -errno; } -struct bpf_link { - int (*detach)(struct bpf_link *link); - void (*dealloc)(struct bpf_link *link); - char *pin_path; /* NULL, if not pinned */ - int fd; /* hook FD, -1 if not applicable */ - bool disconnected; -}; - /* Replace link's underlying BPF program with the new one */ int bpf_link__update_program(struct bpf_link *link, struct bpf_program *prog) { @@ -9845,13 +9832,16 @@ static int determine_uprobe_retprobe_bit(void) static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, uint64_t offset, int pid, size_t ref_ctr_off) { - struct perf_event_attr attr = {}; + const size_t attr_sz = sizeof(struct perf_event_attr); + struct perf_event_attr attr; char errmsg[STRERR_BUFSIZE]; - int type, pfd, err; + int type, pfd; if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS)) return -EINVAL; + memset(&attr, 0, attr_sz); + type = uprobe ? determine_uprobe_perf_type() : determine_kprobe_perf_type(); if (type < 0) { @@ -9872,7 +9862,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, } attr.config |= 1 << bit; } - attr.size = sizeof(attr); + attr.size = attr_sz; attr.type = type; attr.config |= (__u64)ref_ctr_off << PERF_UPROBE_REF_CTR_OFFSET_SHIFT; attr.config1 = ptr_to_u64(name); /* kprobe_func or uprobe_path */ @@ -9883,14 +9873,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, pid < 0 ? -1 : pid /* pid */, pid == -1 ? 0 : -1 /* cpu */, -1 /* group_fd */, PERF_FLAG_FD_CLOEXEC); - if (pfd < 0) { - err = -errno; - pr_warn("%s perf_event_open() failed: %s\n", - uprobe ? "uprobe" : "kprobe", - libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - return err; - } - return pfd; + return pfd >= 0 ? pfd : -errno; } static int append_to_file(const char *file, const char *fmt, ...) @@ -9913,6 +9896,34 @@ static int append_to_file(const char *file, const char *fmt, ...) return err; } +#define DEBUGFS "/sys/kernel/debug/tracing" +#define TRACEFS "/sys/kernel/tracing" + +static bool use_debugfs(void) +{ + static int has_debugfs = -1; + + if (has_debugfs < 0) + has_debugfs = faccessat(AT_FDCWD, DEBUGFS, F_OK, AT_EACCESS) == 0; + + return has_debugfs == 1; +} + +static const char *tracefs_path(void) +{ + return use_debugfs() ? DEBUGFS : TRACEFS; +} + +static const char *tracefs_kprobe_events(void) +{ + return use_debugfs() ? DEBUGFS"/kprobe_events" : TRACEFS"/kprobe_events"; +} + +static const char *tracefs_uprobe_events(void) +{ + return use_debugfs() ? DEBUGFS"/uprobe_events" : TRACEFS"/uprobe_events"; +} + static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, const char *kfunc_name, size_t offset) { @@ -9925,9 +9936,7 @@ static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz, static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; - - return append_to_file(file, "%c:%s/%s %s+0x%zx", + return append_to_file(tracefs_kprobe_events(), "%c:%s/%s %s+0x%zx", retprobe ? 'r' : 'p', retprobe ? "kretprobes" : "kprobes", probe_name, kfunc_name, offset); @@ -9935,18 +9944,16 @@ static int add_kprobe_event_legacy(const char *probe_name, bool retprobe, static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/kprobe_events"; - - return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name); + return append_to_file(tracefs_kprobe_events(), "-:%s/%s", + retprobe ? "kretprobes" : "kprobes", probe_name); } static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe) { char file[256]; - snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - retprobe ? "kretprobes" : "kprobes", probe_name); + snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), retprobe ? "kretprobes" : "kprobes", probe_name); return parse_uint_from_file(file, "%d\n"); } @@ -9954,7 +9961,8 @@ static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retpro static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe, const char *kfunc_name, size_t offset, int pid) { - struct perf_event_attr attr = {}; + const size_t attr_sz = sizeof(struct perf_event_attr); + struct perf_event_attr attr; char errmsg[STRERR_BUFSIZE]; int type, pfd, err; @@ -9967,12 +9975,15 @@ static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe, } type = determine_kprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { + err = type; pr_warn("failed to determine legacy kprobe event id for '%s+0x%zx': %s\n", kfunc_name, offset, - libbpf_strerror_r(type, errmsg, sizeof(errmsg))); - return type; + libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + goto err_clean_legacy; } - attr.size = sizeof(attr); + + memset(&attr, 0, attr_sz); + attr.size = attr_sz; attr.config = type; attr.type = PERF_TYPE_TRACEPOINT; @@ -9984,9 +9995,72 @@ static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe, err = -errno; pr_warn("legacy kprobe perf_event_open() failed: %s\n", libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - return err; + goto err_clean_legacy; } return pfd; + +err_clean_legacy: + /* Clear the newly added legacy kprobe_event */ + remove_kprobe_event_legacy(probe_name, retprobe); + return err; +} + +static const char *arch_specific_syscall_pfx(void) +{ +#if defined(__x86_64__) + return "x64"; +#elif defined(__i386__) + return "ia32"; +#elif defined(__s390x__) + return "s390x"; +#elif defined(__s390__) + return "s390"; +#elif defined(__arm__) + return "arm"; +#elif defined(__aarch64__) + return "arm64"; +#elif defined(__mips__) + return "mips"; +#elif defined(__riscv) + return "riscv"; +#elif defined(__powerpc__) + return "powerpc"; +#elif defined(__powerpc64__) + return "powerpc64"; +#else + return NULL; +#endif +} + +static int probe_kern_syscall_wrapper(void) +{ + char syscall_name[64]; + const char *ksys_pfx; + + ksys_pfx = arch_specific_syscall_pfx(); + if (!ksys_pfx) + return 0; + + snprintf(syscall_name, sizeof(syscall_name), "__%s_sys_bpf", ksys_pfx); + + if (determine_kprobe_perf_type() >= 0) { + int pfd; + + pfd = perf_event_open_probe(false, false, syscall_name, 0, getpid(), 0); + if (pfd >= 0) + close(pfd); + + return pfd >= 0 ? 1 : 0; + } else { /* legacy mode */ + char probe_name[128]; + + gen_kprobe_legacy_event_name(probe_name, sizeof(probe_name), syscall_name, 0); + if (add_kprobe_event_legacy(probe_name, false, syscall_name, 0) < 0) + return 0; + + (void)remove_kprobe_event_legacy(probe_name, false); + return 1; + } } struct bpf_link * @@ -10043,7 +10117,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, prog->name, retprobe ? "kretprobe" : "kprobe", func_name, offset, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - goto err_out; + goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); @@ -10054,6 +10128,10 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog, } return link; + +err_clean_legacy: + if (legacy) + remove_kprobe_event_legacy(legacy_probe, retprobe); err_out: free(legacy_probe); return libbpf_err_ptr(err); @@ -10070,14 +10148,180 @@ struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog, return bpf_program__attach_kprobe_opts(prog, func_name, &opts); } -static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie) +struct bpf_link *bpf_program__attach_ksyscall(const struct bpf_program *prog, + const char *syscall_name, + const struct bpf_ksyscall_opts *opts) +{ + LIBBPF_OPTS(bpf_kprobe_opts, kprobe_opts); + char func_name[128]; + + if (!OPTS_VALID(opts, bpf_ksyscall_opts)) + return libbpf_err_ptr(-EINVAL); + + if (kernel_supports(prog->obj, FEAT_SYSCALL_WRAPPER)) { + /* arch_specific_syscall_pfx() should never return NULL here + * because it is guarded by kernel_supports(). However, since + * compiler does not know that we have an explicit conditional + * as well. + */ + snprintf(func_name, sizeof(func_name), "__%s_sys_%s", + arch_specific_syscall_pfx() ? : "", syscall_name); + } else { + snprintf(func_name, sizeof(func_name), "__se_sys_%s", syscall_name); + } + + kprobe_opts.retprobe = OPTS_GET(opts, retprobe, false); + kprobe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + + return bpf_program__attach_kprobe_opts(prog, func_name, &kprobe_opts); +} + +/* Adapted from perf/util/string.c */ +static bool glob_match(const char *str, const char *pat) +{ + while (*str && *pat && *pat != '*') { + if (*pat == '?') { /* Matches any single character */ + str++; + pat++; + continue; + } + if (*str != *pat) + return false; + str++; + pat++; + } + /* Check wild card */ + if (*pat == '*') { + while (*pat == '*') + pat++; + if (!*pat) /* Tail wild card matches all */ + return true; + while (*str) + if (glob_match(str++, pat)) + return true; + } + return !*str && !*pat; +} + +struct kprobe_multi_resolve { + const char *pattern; + unsigned long *addrs; + size_t cap; + size_t cnt; +}; + +static int +resolve_kprobe_multi_cb(unsigned long long sym_addr, char sym_type, + const char *sym_name, void *ctx) +{ + struct kprobe_multi_resolve *res = ctx; + int err; + + if (!glob_match(sym_name, res->pattern)) + return 0; + + err = libbpf_ensure_mem((void **) &res->addrs, &res->cap, sizeof(unsigned long), + res->cnt + 1); + if (err) + return err; + + res->addrs[res->cnt++] = (unsigned long) sym_addr; + return 0; +} + +struct bpf_link * +bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog, + const char *pattern, + const struct bpf_kprobe_multi_opts *opts) +{ + LIBBPF_OPTS(bpf_link_create_opts, lopts); + struct kprobe_multi_resolve res = { + .pattern = pattern, + }; + struct bpf_link *link = NULL; + char errmsg[STRERR_BUFSIZE]; + const unsigned long *addrs; + int err, link_fd, prog_fd; + const __u64 *cookies; + const char **syms; + bool retprobe; + size_t cnt; + + if (!OPTS_VALID(opts, bpf_kprobe_multi_opts)) + return libbpf_err_ptr(-EINVAL); + + syms = OPTS_GET(opts, syms, false); + addrs = OPTS_GET(opts, addrs, false); + cnt = OPTS_GET(opts, cnt, false); + cookies = OPTS_GET(opts, cookies, false); + + if (!pattern && !addrs && !syms) + return libbpf_err_ptr(-EINVAL); + if (pattern && (addrs || syms || cookies || cnt)) + return libbpf_err_ptr(-EINVAL); + if (!pattern && !cnt) + return libbpf_err_ptr(-EINVAL); + if (addrs && syms) + return libbpf_err_ptr(-EINVAL); + + if (pattern) { + err = libbpf_kallsyms_parse(resolve_kprobe_multi_cb, &res); + if (err) + goto error; + if (!res.cnt) { + err = -ENOENT; + goto error; + } + addrs = res.addrs; + cnt = res.cnt; + } + + retprobe = OPTS_GET(opts, retprobe, false); + + lopts.kprobe_multi.syms = syms; + lopts.kprobe_multi.addrs = addrs; + lopts.kprobe_multi.cookies = cookies; + lopts.kprobe_multi.cnt = cnt; + lopts.kprobe_multi.flags = retprobe ? BPF_F_KPROBE_MULTI_RETURN : 0; + + link = calloc(1, sizeof(*link)); + if (!link) { + err = -ENOMEM; + goto error; + } + link->detach = &bpf_link__detach_fd; + + prog_fd = bpf_program__fd(prog); + link_fd = bpf_link_create(prog_fd, 0, BPF_TRACE_KPROBE_MULTI, &lopts); + if (link_fd < 0) { + err = -errno; + pr_warn("prog '%s': failed to attach: %s\n", + prog->name, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); + goto error; + } + link->fd = link_fd; + free(res.addrs); + return link; + +error: + free(link); + free(res.addrs); + return libbpf_err_ptr(err); +} + +static int attach_kprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link) { DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts); unsigned long offset = 0; - struct bpf_link *link; const char *func_name; char *func; - int n, err; + int n; + + *link = NULL; + + /* no auto-attach for SEC("kprobe") and SEC("kretprobe") */ + if (strcmp(prog->sec_name, "kprobe") == 0 || strcmp(prog->sec_name, "kretprobe") == 0) + return 0; opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe/"); if (opts.retprobe) @@ -10087,21 +10331,71 @@ static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cooki n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset); if (n < 1) { - err = -EINVAL; pr_warn("kprobe name is invalid: %s\n", func_name); - return libbpf_err_ptr(err); + return -EINVAL; } if (opts.retprobe && offset != 0) { free(func); - err = -EINVAL; pr_warn("kretprobes do not support offset specification\n"); - return libbpf_err_ptr(err); + return -EINVAL; } opts.offset = offset; - link = bpf_program__attach_kprobe_opts(prog, func, &opts); + *link = bpf_program__attach_kprobe_opts(prog, func, &opts); free(func); - return link; + return libbpf_get_error(*link); +} + +static int attach_ksyscall(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_ksyscall_opts, opts); + const char *syscall_name; + + *link = NULL; + + /* no auto-attach for SEC("ksyscall") and SEC("kretsyscall") */ + if (strcmp(prog->sec_name, "ksyscall") == 0 || strcmp(prog->sec_name, "kretsyscall") == 0) + return 0; + + opts.retprobe = str_has_pfx(prog->sec_name, "kretsyscall/"); + if (opts.retprobe) + syscall_name = prog->sec_name + sizeof("kretsyscall/") - 1; + else + syscall_name = prog->sec_name + sizeof("ksyscall/") - 1; + + *link = bpf_program__attach_ksyscall(prog, syscall_name, &opts); + return *link ? 0 : -errno; +} + +static int attach_kprobe_multi(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + LIBBPF_OPTS(bpf_kprobe_multi_opts, opts); + const char *spec; + char *pattern; + int n; + + *link = NULL; + + /* no auto-attach for SEC("kprobe.multi") and SEC("kretprobe.multi") */ + if (strcmp(prog->sec_name, "kprobe.multi") == 0 || + strcmp(prog->sec_name, "kretprobe.multi") == 0) + return 0; + + opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe.multi/"); + if (opts.retprobe) + spec = prog->sec_name + sizeof("kretprobe.multi/") - 1; + else + spec = prog->sec_name + sizeof("kprobe.multi/") - 1; + + n = sscanf(spec, "%m[a-zA-Z0-9_.*?]", &pattern); + if (n < 1) { + pr_warn("kprobe multi pattern is invalid: %s\n", pattern); + return -EINVAL; + } + + *link = bpf_program__attach_kprobe_multi_opts(prog, pattern, &opts); + free(pattern); + return libbpf_get_error(*link); } static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, @@ -10121,9 +10415,7 @@ static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz, static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; - - return append_to_file(file, "%c:%s/%s %s:0x%zx", + return append_to_file(tracefs_uprobe_events(), "%c:%s/%s %s:0x%zx", retprobe ? 'r' : 'p', retprobe ? "uretprobes" : "uprobes", probe_name, binary_path, offset); @@ -10131,18 +10423,16 @@ static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe, static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe) { - const char *file = "/sys/kernel/debug/tracing/uprobe_events"; - - return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name); + return append_to_file(tracefs_uprobe_events(), "-:%s/%s", + retprobe ? "uretprobes" : "uprobes", probe_name); } static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe) { char file[512]; - snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - retprobe ? "uretprobes" : "uprobes", probe_name); + snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), retprobe ? "uretprobes" : "uprobes", probe_name); return parse_uint_from_file(file, "%d\n"); } @@ -10150,6 +10440,7 @@ static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retpro static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, const char *binary_path, size_t offset, int pid) { + const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_event_attr attr; int type, pfd, err; @@ -10161,13 +10452,14 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, } type = determine_uprobe_perf_type_legacy(probe_name, retprobe); if (type < 0) { + err = type; pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n", binary_path, offset, err); - return type; + goto err_clean_legacy; } - memset(&attr, 0, sizeof(attr)); - attr.size = sizeof(attr); + memset(&attr, 0, attr_sz); + attr.size = attr_sz; attr.config = type; attr.type = PERF_TYPE_TRACEPOINT; @@ -10178,9 +10470,264 @@ static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe, if (pfd < 0) { err = -errno; pr_warn("legacy uprobe perf_event_open() failed: %d\n", err); - return err; + goto err_clean_legacy; } return pfd; + +err_clean_legacy: + /* Clear the newly added legacy uprobe_event */ + remove_uprobe_event_legacy(probe_name, retprobe); + return err; +} + +/* Return next ELF section of sh_type after scn, or first of that type if scn is NULL. */ +static Elf_Scn *elf_find_next_scn_by_type(Elf *elf, int sh_type, Elf_Scn *scn) +{ + while ((scn = elf_nextscn(elf, scn)) != NULL) { + GElf_Shdr sh; + + if (!gelf_getshdr(scn, &sh)) + continue; + if (sh.sh_type == sh_type) + return scn; + } + return NULL; +} + +/* Find offset of function name in object specified by path. "name" matches + * symbol name or name@@LIB for library functions. + */ +static long elf_find_func_offset(const char *binary_path, const char *name) +{ + int fd, i, sh_types[2] = { SHT_DYNSYM, SHT_SYMTAB }; + bool is_shared_lib, is_name_qualified; + char errmsg[STRERR_BUFSIZE]; + long ret = -ENOENT; + size_t name_len; + GElf_Ehdr ehdr; + Elf *elf; + + fd = open(binary_path, O_RDONLY | O_CLOEXEC); + if (fd < 0) { + ret = -errno; + pr_warn("failed to open %s: %s\n", binary_path, + libbpf_strerror_r(ret, errmsg, sizeof(errmsg))); + return ret; + } + elf = elf_begin(fd, ELF_C_READ_MMAP, NULL); + if (!elf) { + pr_warn("elf: could not read elf from %s: %s\n", binary_path, elf_errmsg(-1)); + close(fd); + return -LIBBPF_ERRNO__FORMAT; + } + if (!gelf_getehdr(elf, &ehdr)) { + pr_warn("elf: failed to get ehdr from %s: %s\n", binary_path, elf_errmsg(-1)); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } + /* for shared lib case, we do not need to calculate relative offset */ + is_shared_lib = ehdr.e_type == ET_DYN; + + name_len = strlen(name); + /* Does name specify "@@LIB"? */ + is_name_qualified = strstr(name, "@@") != NULL; + + /* Search SHT_DYNSYM, SHT_SYMTAB for symbol. This search order is used because if + * a binary is stripped, it may only have SHT_DYNSYM, and a fully-statically + * linked binary may not have SHT_DYMSYM, so absence of a section should not be + * reported as a warning/error. + */ + for (i = 0; i < ARRAY_SIZE(sh_types); i++) { + size_t nr_syms, strtabidx, idx; + Elf_Data *symbols = NULL; + Elf_Scn *scn = NULL; + int last_bind = -1; + const char *sname; + GElf_Shdr sh; + + scn = elf_find_next_scn_by_type(elf, sh_types[i], NULL); + if (!scn) { + pr_debug("elf: failed to find symbol table ELF sections in '%s'\n", + binary_path); + continue; + } + if (!gelf_getshdr(scn, &sh)) + continue; + strtabidx = sh.sh_link; + symbols = elf_getdata(scn, 0); + if (!symbols) { + pr_warn("elf: failed to get symbols for symtab section in '%s': %s\n", + binary_path, elf_errmsg(-1)); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } + nr_syms = symbols->d_size / sh.sh_entsize; + + for (idx = 0; idx < nr_syms; idx++) { + int curr_bind; + GElf_Sym sym; + Elf_Scn *sym_scn; + GElf_Shdr sym_sh; + + if (!gelf_getsym(symbols, idx, &sym)) + continue; + + if (GELF_ST_TYPE(sym.st_info) != STT_FUNC) + continue; + + sname = elf_strptr(elf, strtabidx, sym.st_name); + if (!sname) + continue; + + curr_bind = GELF_ST_BIND(sym.st_info); + + /* User can specify func, func@@LIB or func@@LIB_VERSION. */ + if (strncmp(sname, name, name_len) != 0) + continue; + /* ...but we don't want a search for "foo" to match 'foo2" also, so any + * additional characters in sname should be of the form "@@LIB". + */ + if (!is_name_qualified && sname[name_len] != '\0' && sname[name_len] != '@') + continue; + + if (ret >= 0) { + /* handle multiple matches */ + if (last_bind != STB_WEAK && curr_bind != STB_WEAK) { + /* Only accept one non-weak bind. */ + pr_warn("elf: ambiguous match for '%s', '%s' in '%s'\n", + sname, name, binary_path); + ret = -LIBBPF_ERRNO__FORMAT; + goto out; + } else if (curr_bind == STB_WEAK) { + /* already have a non-weak bind, and + * this is a weak bind, so ignore. + */ + continue; + } + } + + /* Transform symbol's virtual address (absolute for + * binaries and relative for shared libs) into file + * offset, which is what kernel is expecting for + * uprobe/uretprobe attachment. + * See Documentation/trace/uprobetracer.rst for more + * details. + * This is done by looking up symbol's containing + * section's header and using it's virtual address + * (sh_addr) and corresponding file offset (sh_offset) + * to transform sym.st_value (virtual address) into + * desired final file offset. + */ + sym_scn = elf_getscn(elf, sym.st_shndx); + if (!sym_scn) + continue; + if (!gelf_getshdr(sym_scn, &sym_sh)) + continue; + + ret = sym.st_value - sym_sh.sh_addr + sym_sh.sh_offset; + last_bind = curr_bind; + } + if (ret > 0) + break; + } + + if (ret > 0) { + pr_debug("elf: symbol address match for '%s' in '%s': 0x%lx\n", name, binary_path, + ret); + } else { + if (ret == 0) { + pr_warn("elf: '%s' is 0 in symtab for '%s': %s\n", name, binary_path, + is_shared_lib ? "should not be 0 in a shared library" : + "try using shared library path instead"); + ret = -ENOENT; + } else { + pr_warn("elf: failed to find symbol '%s' in '%s'\n", name, binary_path); + } + } +out: + elf_end(elf); + close(fd); + return ret; +} + +static const char *arch_specific_lib_paths(void) +{ + /* + * Based on https://packages.debian.org/sid/libc6. + * + * Assume that the traced program is built for the same architecture + * as libbpf, which should cover the vast majority of cases. + */ +#if defined(__x86_64__) + return "/lib/x86_64-linux-gnu"; +#elif defined(__i386__) + return "/lib/i386-linux-gnu"; +#elif defined(__s390x__) + return "/lib/s390x-linux-gnu"; +#elif defined(__s390__) + return "/lib/s390-linux-gnu"; +#elif defined(__arm__) && defined(__SOFTFP__) + return "/lib/arm-linux-gnueabi"; +#elif defined(__arm__) && !defined(__SOFTFP__) + return "/lib/arm-linux-gnueabihf"; +#elif defined(__aarch64__) + return "/lib/aarch64-linux-gnu"; +#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 64 + return "/lib/mips64el-linux-gnuabi64"; +#elif defined(__mips__) && defined(__MIPSEL__) && _MIPS_SZLONG == 32 + return "/lib/mipsel-linux-gnu"; +#elif defined(__powerpc64__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + return "/lib/powerpc64le-linux-gnu"; +#elif defined(__sparc__) && defined(__arch64__) + return "/lib/sparc64-linux-gnu"; +#elif defined(__riscv) && __riscv_xlen == 64 + return "/lib/riscv64-linux-gnu"; +#else + return NULL; +#endif +} + +/* Get full path to program/shared library. */ +static int resolve_full_path(const char *file, char *result, size_t result_sz) +{ + const char *search_paths[3] = {}; + int i, perm; + + if (str_has_sfx(file, ".so") || strstr(file, ".so.")) { + search_paths[0] = getenv("LD_LIBRARY_PATH"); + search_paths[1] = "/usr/lib64:/usr/lib"; + search_paths[2] = arch_specific_lib_paths(); + perm = R_OK; + } else { + search_paths[0] = getenv("PATH"); + search_paths[1] = "/usr/bin:/usr/sbin"; + perm = R_OK | X_OK; + } + + for (i = 0; i < ARRAY_SIZE(search_paths); i++) { + const char *s; + + if (!search_paths[i]) + continue; + for (s = search_paths[i]; s != NULL; s = strchr(s, ':')) { + char *next_path; + int seg_len; + + if (s[0] == ':') + s++; + next_path = strchr(s, ':'); + seg_len = next_path ? next_path - s : strlen(s); + if (!seg_len) + continue; + snprintf(result, result_sz, "%.*s/%s", seg_len, s, file); + /* ensure it has required permissions */ + if (faccessat(AT_FDCWD, result, perm, AT_EACCESS) < 0) + continue; + pr_debug("resolved '%s' to '%s'\n", file, result); + return 0; + } + } + return -ENOENT; } LIBBPF_API struct bpf_link * @@ -10190,10 +10737,12 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, { DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts); char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL; + char full_binary_path[PATH_MAX]; struct bpf_link *link; size_t ref_ctr_off; int pfd, err; bool retprobe, legacy; + const char *func_name; if (!OPTS_VALID(opts, bpf_uprobe_opts)) return libbpf_err_ptr(-EINVAL); @@ -10202,12 +10751,35 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0); pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0); + if (!binary_path) + return libbpf_err_ptr(-EINVAL); + + if (!strchr(binary_path, '/')) { + err = resolve_full_path(binary_path, full_binary_path, + sizeof(full_binary_path)); + if (err) { + pr_warn("prog '%s': failed to resolve full path for '%s': %d\n", + prog->name, binary_path, err); + return libbpf_err_ptr(err); + } + binary_path = full_binary_path; + } + func_name = OPTS_GET(opts, func_name, NULL); + if (func_name) { + long sym_off; + + sym_off = elf_find_func_offset(binary_path, func_name); + if (sym_off < 0) + return libbpf_err_ptr(sym_off); + func_offset += sym_off; + } + legacy = determine_uprobe_perf_type() < 0; if (!legacy) { pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path, func_offset, pid, ref_ctr_off); } else { - char probe_name[512]; + char probe_name[PATH_MAX + 64]; if (ref_ctr_off) return libbpf_err_ptr(-EINVAL); @@ -10239,7 +10811,7 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, prog->name, retprobe ? "uretprobe" : "uprobe", binary_path, func_offset, libbpf_strerror_r(err, errmsg, sizeof(errmsg))); - goto err_out; + goto err_clean_legacy; } if (legacy) { struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link); @@ -10249,10 +10821,68 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid, perf_link->legacy_is_retprobe = retprobe; } return link; + +err_clean_legacy: + if (legacy) + remove_uprobe_event_legacy(legacy_probe, retprobe); err_out: free(legacy_probe); return libbpf_err_ptr(err); +} + +/* Format of u[ret]probe section definition supporting auto-attach: + * u[ret]probe/binary:function[+offset] + * + * binary can be an absolute/relative path or a filename; the latter is resolved to a + * full binary path via bpf_program__attach_uprobe_opts. + * + * Specifying uprobe+ ensures we carry out strict matching; either "uprobe" must be + * specified (and auto-attach is not possible) or the above format is specified for + * auto-attach. + */ +static int attach_uprobe(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, opts); + char *probe_type = NULL, *binary_path = NULL, *func_name = NULL; + int n, ret = -EINVAL; + long offset = 0; + *link = NULL; + + n = sscanf(prog->sec_name, "%m[^/]/%m[^:]:%m[a-zA-Z0-9_.]+%li", + &probe_type, &binary_path, &func_name, &offset); + switch (n) { + case 1: + /* handle SEC("u[ret]probe") - format is valid, but auto-attach is impossible. */ + ret = 0; + break; + case 2: + pr_warn("prog '%s': section '%s' missing ':function[+offset]' specification\n", + prog->name, prog->sec_name); + break; + case 3: + case 4: + opts.retprobe = strcmp(probe_type, "uretprobe") == 0 || + strcmp(probe_type, "uretprobe.s") == 0; + if (opts.retprobe && offset != 0) { + pr_warn("prog '%s': uretprobes do not support offset specification\n", + prog->name); + break; + } + opts.func_name = func_name; + *link = bpf_program__attach_uprobe_opts(prog, -1, binary_path, offset, &opts); + ret = libbpf_get_error(*link); + break; + default: + pr_warn("prog '%s': invalid format of section definition '%s'\n", prog->name, + prog->sec_name); + break; + } + free(probe_type); + free(binary_path); + free(func_name); + + return ret; } struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog, @@ -10265,15 +10895,96 @@ struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog, return bpf_program__attach_uprobe_opts(prog, pid, binary_path, func_offset, &opts); } +struct bpf_link *bpf_program__attach_usdt(const struct bpf_program *prog, + pid_t pid, const char *binary_path, + const char *usdt_provider, const char *usdt_name, + const struct bpf_usdt_opts *opts) +{ + char resolved_path[512]; + struct bpf_object *obj = prog->obj; + struct bpf_link *link; + __u64 usdt_cookie; + int err; + + if (!OPTS_VALID(opts, bpf_uprobe_opts)) + return libbpf_err_ptr(-EINVAL); + + if (bpf_program__fd(prog) < 0) { + pr_warn("prog '%s': can't attach BPF program w/o FD (did you load it?)\n", + prog->name); + return libbpf_err_ptr(-EINVAL); + } + + if (!binary_path) + return libbpf_err_ptr(-EINVAL); + + if (!strchr(binary_path, '/')) { + err = resolve_full_path(binary_path, resolved_path, sizeof(resolved_path)); + if (err) { + pr_warn("prog '%s': failed to resolve full path for '%s': %d\n", + prog->name, binary_path, err); + return libbpf_err_ptr(err); + } + binary_path = resolved_path; + } + + /* USDT manager is instantiated lazily on first USDT attach. It will + * be destroyed together with BPF object in bpf_object__close(). + */ + if (IS_ERR(obj->usdt_man)) + return libbpf_ptr(obj->usdt_man); + if (!obj->usdt_man) { + obj->usdt_man = usdt_manager_new(obj); + if (IS_ERR(obj->usdt_man)) + return libbpf_ptr(obj->usdt_man); + } + + usdt_cookie = OPTS_GET(opts, usdt_cookie, 0); + link = usdt_manager_attach_usdt(obj->usdt_man, prog, pid, binary_path, + usdt_provider, usdt_name, usdt_cookie); + err = libbpf_get_error(link); + if (err) + return libbpf_err_ptr(err); + return link; +} + +static int attach_usdt(const struct bpf_program *prog, long cookie, struct bpf_link **link) +{ + char *path = NULL, *provider = NULL, *name = NULL; + const char *sec_name; + int n, err; + + sec_name = bpf_program__section_name(prog); + if (strcmp(sec_name, "usdt") == 0) { + /* no auto-attach for just SEC("usdt") */ + *link = NULL; + return 0; + } + + n = sscanf(sec_name, "usdt/%m[^:]:%m[^:]:%m[^:]", &path, &provider, &name); + if (n != 3) { + pr_warn("invalid section '%s', expected SEC(\"usdt/<path>:<provider>:<name>\")\n", + sec_name); + err = -EINVAL; + } else { + *link = bpf_program__attach_usdt(prog, -1 /* any process */, path, + provider, name, NULL); + err = libbpf_get_error(*link); + } + free(path); + free(provider); + free(name); + return err; +} + static int determine_tracepoint_id(const char *tp_category, const char *tp_name) { char file[PATH_MAX]; int ret; - ret = snprintf(file, sizeof(file), - "/sys/kernel/debug/tracing/events/%s/%s/id", - tp_category, tp_name); + ret = snprintf(file, sizeof(file), "%s/events/%s/%s/id", + tracefs_path(), tp_category, tp_name); if (ret < 0) return -errno; if (ret >= sizeof(file)) { @@ -10287,7 +10998,8 @@ static int determine_tracepoint_id(const char *tp_category, static int perf_event_open_tracepoint(const char *tp_category, const char *tp_name) { - struct perf_event_attr attr = {}; + const size_t attr_sz = sizeof(struct perf_event_attr); + struct perf_event_attr attr; char errmsg[STRERR_BUFSIZE]; int tp_id, pfd, err; @@ -10299,8 +11011,9 @@ static int perf_event_open_tracepoint(const char *tp_category, return tp_id; } + memset(&attr, 0, attr_sz); attr.type = PERF_TYPE_TRACEPOINT; - attr.size = sizeof(attr); + attr.size = attr_sz; attr.config = tp_id; pfd = syscall(__NR_perf_event_open, &attr, -1 /* pid */, 0 /* cpu */, @@ -10356,14 +11069,19 @@ struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog, return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL); } -static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie) +static int attach_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link) { char *sec_name, *tp_cat, *tp_name; - struct bpf_link *link; + + *link = NULL; + + /* no auto-attach for SEC("tp") or SEC("tracepoint") */ + if (strcmp(prog->sec_name, "tp") == 0 || strcmp(prog->sec_name, "tracepoint") == 0) + return 0; sec_name = strdup(prog->sec_name); if (!sec_name) - return libbpf_err_ptr(-ENOMEM); + return -ENOMEM; /* extract "tp/<category>/<name>" or "tracepoint/<category>/<name>" */ if (str_has_pfx(prog->sec_name, "tp/")) @@ -10373,14 +11091,14 @@ static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie) tp_name = strchr(tp_cat, '/'); if (!tp_name) { free(sec_name); - return libbpf_err_ptr(-EINVAL); + return -EINVAL; } *tp_name = '\0'; tp_name++; - link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name); + *link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name); free(sec_name); - return link; + return libbpf_get_error(*link); } struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *prog, @@ -10413,39 +11131,59 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr return link; } -static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie) +static int attach_raw_tp(const struct bpf_program *prog, long cookie, struct bpf_link **link) { static const char *const prefixes[] = { - "raw_tp/", - "raw_tracepoint/", - "raw_tp.w/", - "raw_tracepoint.w/", + "raw_tp", + "raw_tracepoint", + "raw_tp.w", + "raw_tracepoint.w", }; size_t i; const char *tp_name = NULL; + *link = NULL; + for (i = 0; i < ARRAY_SIZE(prefixes); i++) { - if (str_has_pfx(prog->sec_name, prefixes[i])) { - tp_name = prog->sec_name + strlen(prefixes[i]); - break; - } + size_t pfx_len; + + if (!str_has_pfx(prog->sec_name, prefixes[i])) + continue; + + pfx_len = strlen(prefixes[i]); + /* no auto-attach case of, e.g., SEC("raw_tp") */ + if (prog->sec_name[pfx_len] == '\0') + return 0; + + if (prog->sec_name[pfx_len] != '/') + continue; + + tp_name = prog->sec_name + pfx_len + 1; + break; } + if (!tp_name) { pr_warn("prog '%s': invalid section name '%s'\n", prog->name, prog->sec_name); - return libbpf_err_ptr(-EINVAL); + return -EINVAL; } - return bpf_program__attach_raw_tracepoint(prog, tp_name); + *link = bpf_program__attach_raw_tracepoint(prog, tp_name); + return libbpf_get_error(link); } /* Common logic for all BPF program types that attach to a btf_id */ -static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog) +static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog, + const struct bpf_trace_opts *opts) { + LIBBPF_OPTS(bpf_link_create_opts, link_opts); char errmsg[STRERR_BUFSIZE]; struct bpf_link *link; int prog_fd, pfd; + if (!OPTS_VALID(opts, bpf_trace_opts)) + return libbpf_err_ptr(-EINVAL); + prog_fd = bpf_program__fd(prog); if (prog_fd < 0) { pr_warn("prog '%s': can't attach before loaded\n", prog->name); @@ -10457,7 +11195,9 @@ static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *pro return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd; - pfd = bpf_raw_tracepoint_open(NULL, prog_fd); + /* libbpf is smart enough to redirect to BPF_RAW_TRACEPOINT_OPEN on old kernels */ + link_opts.tracing.cookie = OPTS_GET(opts, cookie, 0); + pfd = bpf_link_create(prog_fd, 0, bpf_program__expected_attach_type(prog), &link_opts); if (pfd < 0) { pfd = -errno; free(link); @@ -10466,27 +11206,35 @@ static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *pro return libbpf_err_ptr(pfd); } link->fd = pfd; - return (struct bpf_link *)link; + return link; } struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog) { - return bpf_program__attach_btf_id(prog); + return bpf_program__attach_btf_id(prog, NULL); +} + +struct bpf_link *bpf_program__attach_trace_opts(const struct bpf_program *prog, + const struct bpf_trace_opts *opts) +{ + return bpf_program__attach_btf_id(prog, opts); } struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog) { - return bpf_program__attach_btf_id(prog); + return bpf_program__attach_btf_id(prog, NULL); } -static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie) +static int attach_trace(const struct bpf_program *prog, long cookie, struct bpf_link **link) { - return bpf_program__attach_trace(prog); + *link = bpf_program__attach_trace(prog); + return libbpf_get_error(*link); } -static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie) +static int attach_lsm(const struct bpf_program *prog, long cookie, struct bpf_link **link) { - return bpf_program__attach_lsm(prog); + *link = bpf_program__attach_lsm(prog); + return libbpf_get_error(*link); } static struct bpf_link * @@ -10511,7 +11259,7 @@ bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id return libbpf_err_ptr(-ENOMEM); link->detach = &bpf_link__detach_fd; - attach_type = bpf_program__get_expected_attach_type(prog); + attach_type = bpf_program__expected_attach_type(prog); link_fd = bpf_link_create(prog_fd, target_fd, attach_type, &opts); if (link_fd < 0) { link_fd = -errno; @@ -10615,17 +11363,33 @@ bpf_program__attach_iter(const struct bpf_program *prog, return link; } -static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie) +static int attach_iter(const struct bpf_program *prog, long cookie, struct bpf_link **link) { - return bpf_program__attach_iter(prog, NULL); + *link = bpf_program__attach_iter(prog, NULL); + return libbpf_get_error(*link); } struct bpf_link *bpf_program__attach(const struct bpf_program *prog) { - if (!prog->sec_def || !prog->sec_def->attach_fn) - return libbpf_err_ptr(-ESRCH); + struct bpf_link *link = NULL; + int err; + + if (!prog->sec_def || !prog->sec_def->prog_attach_fn) + return libbpf_err_ptr(-EOPNOTSUPP); + + err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, &link); + if (err) + return libbpf_err_ptr(err); + + /* When calling bpf_program__attach() explicitly, auto-attach support + * is expected to work, so NULL returned link is considered an error. + * This is different for skeleton's attach, see comment in + * bpf_object__attach_skeleton(). + */ + if (!link) + return libbpf_err_ptr(-EOPNOTSUPP); - return prog->sec_def->attach_fn(prog, prog->sec_def->cookie); + return link; } static int bpf_link__detach_struct_ops(struct bpf_link *link) @@ -10679,6 +11443,9 @@ struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map) return link; } +typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(struct perf_event_header *hdr, + void *private_data); + static enum bpf_perf_event_ret perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, void **copy_mem, size_t *copy_size, @@ -10727,12 +11494,6 @@ perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size, return libbpf_err(ret); } -__attribute__((alias("perf_event_read_simple"))) -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, - bpf_perf_event_print_t fn, void *private_data); - struct perf_buffer; struct perf_buffer_params { @@ -10866,19 +11627,21 @@ error: static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, struct perf_buffer_params *p); -DEFAULT_VERSION(perf_buffer__new_v0_6_0, perf_buffer__new, LIBBPF_0.6.0) -struct perf_buffer *perf_buffer__new_v0_6_0(int map_fd, size_t page_cnt, - perf_buffer_sample_fn sample_cb, - perf_buffer_lost_fn lost_cb, - void *ctx, - const struct perf_buffer_opts *opts) +struct perf_buffer *perf_buffer__new(int map_fd, size_t page_cnt, + perf_buffer_sample_fn sample_cb, + perf_buffer_lost_fn lost_cb, + void *ctx, + const struct perf_buffer_opts *opts) { + const size_t attr_sz = sizeof(struct perf_event_attr); struct perf_buffer_params p = {}; - struct perf_event_attr attr = {}; + struct perf_event_attr attr; if (!OPTS_VALID(opts, perf_buffer_opts)) return libbpf_err_ptr(-EINVAL); + memset(&attr, 0, attr_sz); + attr.size = attr_sz; attr.config = PERF_COUNT_SW_BPF_OUTPUT; attr.type = PERF_TYPE_SOFTWARE; attr.sample_type = PERF_SAMPLE_RAW; @@ -10893,26 +11656,14 @@ struct perf_buffer *perf_buffer__new_v0_6_0(int map_fd, size_t page_cnt, return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p)); } -COMPAT_VERSION(perf_buffer__new_deprecated, perf_buffer__new, LIBBPF_0.0.4) -struct perf_buffer *perf_buffer__new_deprecated(int map_fd, size_t page_cnt, - const struct perf_buffer_opts *opts) -{ - return perf_buffer__new_v0_6_0(map_fd, page_cnt, - opts ? opts->sample_cb : NULL, - opts ? opts->lost_cb : NULL, - opts ? opts->ctx : NULL, - NULL); -} - -DEFAULT_VERSION(perf_buffer__new_raw_v0_6_0, perf_buffer__new_raw, LIBBPF_0.6.0) -struct perf_buffer *perf_buffer__new_raw_v0_6_0(int map_fd, size_t page_cnt, - struct perf_event_attr *attr, - perf_buffer_event_fn event_cb, void *ctx, - const struct perf_buffer_raw_opts *opts) +struct perf_buffer *perf_buffer__new_raw(int map_fd, size_t page_cnt, + struct perf_event_attr *attr, + perf_buffer_event_fn event_cb, void *ctx, + const struct perf_buffer_raw_opts *opts) { struct perf_buffer_params p = {}; - if (page_cnt == 0 || !attr) + if (!attr) return libbpf_err_ptr(-EINVAL); if (!OPTS_VALID(opts, perf_buffer_raw_opts)) @@ -10928,20 +11679,6 @@ struct perf_buffer *perf_buffer__new_raw_v0_6_0(int map_fd, size_t page_cnt, return libbpf_ptr(__perf_buffer__new(map_fd, page_cnt, &p)); } -COMPAT_VERSION(perf_buffer__new_raw_deprecated, perf_buffer__new_raw, LIBBPF_0.0.4) -struct perf_buffer *perf_buffer__new_raw_deprecated(int map_fd, size_t page_cnt, - const struct perf_buffer_raw_opts *opts) -{ - LIBBPF_OPTS(perf_buffer_raw_opts, inner_opts, - .cpu_cnt = opts->cpu_cnt, - .cpus = opts->cpus, - .map_keys = opts->map_keys, - ); - - return perf_buffer__new_raw_v0_6_0(map_fd, page_cnt, opts->attr, - opts->event_cb, opts->ctx, &inner_opts); -} - static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, struct perf_buffer_params *p) { @@ -10953,7 +11690,7 @@ static struct perf_buffer *__perf_buffer__new(int map_fd, size_t page_cnt, __u32 map_info_len; int err, i, j, n; - if (page_cnt & (page_cnt - 1)) { + if (page_cnt == 0 || (page_cnt & (page_cnt - 1))) { pr_warn("page count should be power of two, but is %zu\n", page_cnt); return ERR_PTR(-EINVAL); @@ -11202,6 +11939,22 @@ int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx) return cpu_buf->fd; } +int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf, size_t *buf_size) +{ + struct perf_cpu_buf *cpu_buf; + + if (buf_idx >= pb->cpu_cnt) + return libbpf_err(-EINVAL); + + cpu_buf = pb->cpu_bufs[buf_idx]; + if (!cpu_buf) + return libbpf_err(-ENOENT); + + *buf = cpu_buf->base; + *buf_size = pb->mmap_size; + return 0; +} + /* * Consume data from perf ring buffer corresponding to slot *buf_idx* in * PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to @@ -11243,254 +11996,6 @@ int perf_buffer__consume(struct perf_buffer *pb) return 0; } -struct bpf_prog_info_array_desc { - int array_offset; /* e.g. offset of jited_prog_insns */ - int count_offset; /* e.g. offset of jited_prog_len */ - int size_offset; /* > 0: offset of rec size, - * < 0: fix size of -size_offset - */ -}; - -static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = { - [BPF_PROG_INFO_JITED_INSNS] = { - offsetof(struct bpf_prog_info, jited_prog_insns), - offsetof(struct bpf_prog_info, jited_prog_len), - -1, - }, - [BPF_PROG_INFO_XLATED_INSNS] = { - offsetof(struct bpf_prog_info, xlated_prog_insns), - offsetof(struct bpf_prog_info, xlated_prog_len), - -1, - }, - [BPF_PROG_INFO_MAP_IDS] = { - offsetof(struct bpf_prog_info, map_ids), - offsetof(struct bpf_prog_info, nr_map_ids), - -(int)sizeof(__u32), - }, - [BPF_PROG_INFO_JITED_KSYMS] = { - offsetof(struct bpf_prog_info, jited_ksyms), - offsetof(struct bpf_prog_info, nr_jited_ksyms), - -(int)sizeof(__u64), - }, - [BPF_PROG_INFO_JITED_FUNC_LENS] = { - offsetof(struct bpf_prog_info, jited_func_lens), - offsetof(struct bpf_prog_info, nr_jited_func_lens), - -(int)sizeof(__u32), - }, - [BPF_PROG_INFO_FUNC_INFO] = { - offsetof(struct bpf_prog_info, func_info), - offsetof(struct bpf_prog_info, nr_func_info), - offsetof(struct bpf_prog_info, func_info_rec_size), - }, - [BPF_PROG_INFO_LINE_INFO] = { - offsetof(struct bpf_prog_info, line_info), - offsetof(struct bpf_prog_info, nr_line_info), - offsetof(struct bpf_prog_info, line_info_rec_size), - }, - [BPF_PROG_INFO_JITED_LINE_INFO] = { - offsetof(struct bpf_prog_info, jited_line_info), - offsetof(struct bpf_prog_info, nr_jited_line_info), - offsetof(struct bpf_prog_info, jited_line_info_rec_size), - }, - [BPF_PROG_INFO_PROG_TAGS] = { - offsetof(struct bpf_prog_info, prog_tags), - offsetof(struct bpf_prog_info, nr_prog_tags), - -(int)sizeof(__u8) * BPF_TAG_SIZE, - }, - -}; - -static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, - int offset) -{ - __u32 *array = (__u32 *)info; - - if (offset >= 0) - return array[offset / sizeof(__u32)]; - return -(int)offset; -} - -static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, - int offset) -{ - __u64 *array = (__u64 *)info; - - if (offset >= 0) - return array[offset / sizeof(__u64)]; - return -(int)offset; -} - -static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset, - __u32 val) -{ - __u32 *array = (__u32 *)info; - - if (offset >= 0) - array[offset / sizeof(__u32)] = val; -} - -static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset, - __u64 val) -{ - __u64 *array = (__u64 *)info; - - if (offset >= 0) - array[offset / sizeof(__u64)] = val; -} - -struct bpf_prog_info_linear * -bpf_program__get_prog_info_linear(int fd, __u64 arrays) -{ - struct bpf_prog_info_linear *info_linear; - struct bpf_prog_info info = {}; - __u32 info_len = sizeof(info); - __u32 data_len = 0; - int i, err; - void *ptr; - - if (arrays >> BPF_PROG_INFO_LAST_ARRAY) - return libbpf_err_ptr(-EINVAL); - - /* step 1: get array dimensions */ - err = bpf_obj_get_info_by_fd(fd, &info, &info_len); - if (err) { - pr_debug("can't get prog info: %s", strerror(errno)); - return libbpf_err_ptr(-EFAULT); - } - - /* step 2: calculate total size of all arrays */ - for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { - bool include_array = (arrays & (1UL << i)) > 0; - struct bpf_prog_info_array_desc *desc; - __u32 count, size; - - desc = bpf_prog_info_array_desc + i; - - /* kernel is too old to support this field */ - if (info_len < desc->array_offset + sizeof(__u32) || - info_len < desc->count_offset + sizeof(__u32) || - (desc->size_offset > 0 && info_len < desc->size_offset)) - include_array = false; - - if (!include_array) { - arrays &= ~(1UL << i); /* clear the bit */ - continue; - } - - count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); - size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); - - data_len += count * size; - } - - /* step 3: allocate continuous memory */ - data_len = roundup(data_len, sizeof(__u64)); - info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len); - if (!info_linear) - return libbpf_err_ptr(-ENOMEM); - - /* step 4: fill data to info_linear->info */ - info_linear->arrays = arrays; - memset(&info_linear->info, 0, sizeof(info)); - ptr = info_linear->data; - - for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { - struct bpf_prog_info_array_desc *desc; - __u32 count, size; - - if ((arrays & (1UL << i)) == 0) - continue; - - desc = bpf_prog_info_array_desc + i; - count = bpf_prog_info_read_offset_u32(&info, desc->count_offset); - size = bpf_prog_info_read_offset_u32(&info, desc->size_offset); - bpf_prog_info_set_offset_u32(&info_linear->info, - desc->count_offset, count); - bpf_prog_info_set_offset_u32(&info_linear->info, - desc->size_offset, size); - bpf_prog_info_set_offset_u64(&info_linear->info, - desc->array_offset, - ptr_to_u64(ptr)); - ptr += count * size; - } - - /* step 5: call syscall again to get required arrays */ - err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len); - if (err) { - pr_debug("can't get prog info: %s", strerror(errno)); - free(info_linear); - return libbpf_err_ptr(-EFAULT); - } - - /* step 6: verify the data */ - for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { - struct bpf_prog_info_array_desc *desc; - __u32 v1, v2; - - if ((arrays & (1UL << i)) == 0) - continue; - - desc = bpf_prog_info_array_desc + i; - v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset); - v2 = bpf_prog_info_read_offset_u32(&info_linear->info, - desc->count_offset); - if (v1 != v2) - pr_warn("%s: mismatch in element count\n", __func__); - - v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset); - v2 = bpf_prog_info_read_offset_u32(&info_linear->info, - desc->size_offset); - if (v1 != v2) - pr_warn("%s: mismatch in rec size\n", __func__); - } - - /* step 7: update info_len and data_len */ - info_linear->info_len = sizeof(struct bpf_prog_info); - info_linear->data_len = data_len; - - return info_linear; -} - -void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear) -{ - int i; - - for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { - struct bpf_prog_info_array_desc *desc; - __u64 addr, offs; - - if ((info_linear->arrays & (1UL << i)) == 0) - continue; - - desc = bpf_prog_info_array_desc + i; - addr = bpf_prog_info_read_offset_u64(&info_linear->info, - desc->array_offset); - offs = addr - ptr_to_u64(info_linear->data); - bpf_prog_info_set_offset_u64(&info_linear->info, - desc->array_offset, offs); - } -} - -void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear) -{ - int i; - - for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) { - struct bpf_prog_info_array_desc *desc; - __u64 addr, offs; - - if ((info_linear->arrays & (1UL << i)) == 0) - continue; - - desc = bpf_prog_info_array_desc + i; - offs = bpf_prog_info_read_offset_u64(&info_linear->info, - desc->array_offset); - addr = offs + ptr_to_u64(info_linear->data); - bpf_prog_info_set_offset_u64(&info_linear->info, - desc->array_offset, addr); - } -} - int bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd, const char *attach_func_name) @@ -11640,6 +12145,49 @@ int libbpf_num_possible_cpus(void) return tmp_cpus; } +static int populate_skeleton_maps(const struct bpf_object *obj, + struct bpf_map_skeleton *maps, + size_t map_cnt) +{ + int i; + + for (i = 0; i < map_cnt; i++) { + struct bpf_map **map = maps[i].map; + const char *name = maps[i].name; + void **mmaped = maps[i].mmaped; + + *map = bpf_object__find_map_by_name(obj, name); + if (!*map) { + pr_warn("failed to find skeleton map '%s'\n", name); + return -ESRCH; + } + + /* externs shouldn't be pre-setup from user code */ + if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG) + *mmaped = (*map)->mmaped; + } + return 0; +} + +static int populate_skeleton_progs(const struct bpf_object *obj, + struct bpf_prog_skeleton *progs, + size_t prog_cnt) +{ + int i; + + for (i = 0; i < prog_cnt; i++) { + struct bpf_program **prog = progs[i].prog; + const char *name = progs[i].name; + + *prog = bpf_object__find_program_by_name(obj, name); + if (!*prog) { + pr_warn("failed to find skeleton program '%s'\n", name); + return -ESRCH; + } + } + return 0; +} + int bpf_object__open_skeleton(struct bpf_object_skeleton *s, const struct bpf_object_open_opts *opts) { @@ -11647,7 +12195,7 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s, .object_name = s->name, ); struct bpf_object *obj; - int i, err; + int err; /* Attempt to preserve opts->object_name, unless overriden by user * explicitly. Overwriting object name for skeletons is discouraged, @@ -11670,37 +12218,91 @@ int bpf_object__open_skeleton(struct bpf_object_skeleton *s, } *s->obj = obj; + err = populate_skeleton_maps(obj, s->maps, s->map_cnt); + if (err) { + pr_warn("failed to populate skeleton maps for '%s': %d\n", s->name, err); + return libbpf_err(err); + } - for (i = 0; i < s->map_cnt; i++) { - struct bpf_map **map = s->maps[i].map; - const char *name = s->maps[i].name; - void **mmaped = s->maps[i].mmaped; + err = populate_skeleton_progs(obj, s->progs, s->prog_cnt); + if (err) { + pr_warn("failed to populate skeleton progs for '%s': %d\n", s->name, err); + return libbpf_err(err); + } - *map = bpf_object__find_map_by_name(obj, name); - if (!*map) { - pr_warn("failed to find skeleton map '%s'\n", name); - return libbpf_err(-ESRCH); - } + return 0; +} - /* externs shouldn't be pre-setup from user code */ - if (mmaped && (*map)->libbpf_type != LIBBPF_MAP_KCONFIG) - *mmaped = (*map)->mmaped; +int bpf_object__open_subskeleton(struct bpf_object_subskeleton *s) +{ + int err, len, var_idx, i; + const char *var_name; + const struct bpf_map *map; + struct btf *btf; + __u32 map_type_id; + const struct btf_type *map_type, *var_type; + const struct bpf_var_skeleton *var_skel; + struct btf_var_secinfo *var; + + if (!s->obj) + return libbpf_err(-EINVAL); + + btf = bpf_object__btf(s->obj); + if (!btf) { + pr_warn("subskeletons require BTF at runtime (object %s)\n", + bpf_object__name(s->obj)); + return libbpf_err(-errno); } - for (i = 0; i < s->prog_cnt; i++) { - struct bpf_program **prog = s->progs[i].prog; - const char *name = s->progs[i].name; + err = populate_skeleton_maps(s->obj, s->maps, s->map_cnt); + if (err) { + pr_warn("failed to populate subskeleton maps: %d\n", err); + return libbpf_err(err); + } - *prog = bpf_object__find_program_by_name(obj, name); - if (!*prog) { - pr_warn("failed to find skeleton program '%s'\n", name); - return libbpf_err(-ESRCH); - } + err = populate_skeleton_progs(s->obj, s->progs, s->prog_cnt); + if (err) { + pr_warn("failed to populate subskeleton maps: %d\n", err); + return libbpf_err(err); } + for (var_idx = 0; var_idx < s->var_cnt; var_idx++) { + var_skel = &s->vars[var_idx]; + map = *var_skel->map; + map_type_id = bpf_map__btf_value_type_id(map); + map_type = btf__type_by_id(btf, map_type_id); + + if (!btf_is_datasec(map_type)) { + pr_warn("type for map '%1$s' is not a datasec: %2$s", + bpf_map__name(map), + __btf_kind_str(btf_kind(map_type))); + return libbpf_err(-EINVAL); + } + + len = btf_vlen(map_type); + var = btf_var_secinfos(map_type); + for (i = 0; i < len; i++, var++) { + var_type = btf__type_by_id(btf, var->type); + var_name = btf__name_by_offset(btf, var_type->name_off); + if (strcmp(var_name, var_skel->name) == 0) { + *var_skel->addr = map->mmaped + var->offset; + break; + } + } + } return 0; } +void bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s) +{ + if (!s) + return; + free(s->maps); + free(s->progs); + free(s->vars); + free(s); +} + int bpf_object__load_skeleton(struct bpf_object_skeleton *s) { int i, err; @@ -11762,20 +12364,34 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s) struct bpf_program *prog = *s->progs[i].prog; struct bpf_link **link = s->progs[i].link; - if (!prog->load) + if (!prog->autoload || !prog->autoattach) continue; /* auto-attaching not supported for this program */ - if (!prog->sec_def || !prog->sec_def->attach_fn) + if (!prog->sec_def || !prog->sec_def->prog_attach_fn) continue; - *link = bpf_program__attach(prog); - err = libbpf_get_error(*link); + /* if user already set the link manually, don't attempt auto-attach */ + if (*link) + continue; + + err = prog->sec_def->prog_attach_fn(prog, prog->sec_def->cookie, link); if (err) { - pr_warn("failed to auto-attach program '%s': %d\n", + pr_warn("prog '%s': failed to auto-attach: %d\n", bpf_program__name(prog), err); return libbpf_err(err); } + + /* It's possible that for some SEC() definitions auto-attach + * is supported in some cases (e.g., if definition completely + * specifies target information), but is not in other cases. + * SEC("uprobe") is one such case. If user specified target + * binary and function name, such BPF program can be + * auto-attached. But if not, it shouldn't trigger skeleton's + * attach to fail. It should just be skipped. + * attach_fn signals such case with returning 0 (no error) and + * setting link to NULL. + */ } return 0; @@ -11795,6 +12411,9 @@ void bpf_object__detach_skeleton(struct bpf_object_skeleton *s) void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s) { + if (!s) + return; + if (s->progs) bpf_object__detach_skeleton(s); if (s->obj) |