samples/bpf/bpf_load.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <stdio.h>
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <fcntl.h>
   6 #include <libelf.h>
   7 #include <gelf.h>
   8 #include <errno.h>
   9 #include <unistd.h>
  10 #include <string.h>
  11 #include <stdbool.h>
  12 #include <stdlib.h>
  13 #include <linux/bpf.h>
  14 #include <linux/filter.h>
  15 #include <linux/perf_event.h>
  16 #include <linux/netlink.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/types.h>
  19 #include <sys/types.h>
  20 #include <sys/socket.h>
  21 #include <sys/syscall.h>
  22 #include <sys/ioctl.h>
  23 #include <sys/mman.h>
  24 #include <poll.h>
  25 #include <ctype.h>
  26 #include <assert.h>
  27 #include <bpf/bpf.h>
  28 #include "bpf_load.h"
  29 #include "perf-sys.h"
  30
  31 #define DEBUGFS "/sys/kernel/debug/tracing/"
  32
  33 static char license[128];
  34 static int kern_version;
  35 static bool processed_sec[128];
  36 char bpf_log_buf[BPF_LOG_BUF_SIZE];
  37 int map_fd[MAX_MAPS];
  38 int prog_fd[MAX_PROGS];
  39 int event_fd[MAX_PROGS];
  40 int prog_cnt;
  41 int prog_array_fd = -1;
  42
  43 struct bpf_map_data map_data[MAX_MAPS];
  44 int map_data_count = 0;
  45
  46 static int populate_prog_array(const char *event, int prog_fd)
  47 {
  48         int ind = atoi(event), err;
  49
  50         err = bpf_map_update_elem(prog_array_fd, &ind, &prog_fd, BPF_ANY);
  51         if (err < 0) {
  52                 printf("failed to store prog_fd in prog_array\n");
  53                 return -1;
  54         }
  55         return 0;
  56 }
  57
  58 static int write_kprobe_events(const char *val)
  59 {
  60         int fd, ret, flags;
  61
  62         if (val == NULL)
  63                 return -1;
  64         else if (val[0] == '\0')
  65                 flags = O_WRONLY | O_TRUNC;
  66         else
  67                 flags = O_WRONLY | O_APPEND;
  68
  69         fd = open("/sys/kernel/debug/tracing/kprobe_events", flags);
  70
  71         ret = write(fd, val, strlen(val));
  72         close(fd);
  73
  74         return ret;
  75 }
  76
  77 static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
  78 {
  79         bool is_socket = strncmp(event, "socket", 6) == 0;
  80         bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
  81         bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
  82         bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
  83         bool is_raw_tracepoint = strncmp(event, "raw_tracepoint/", 15) == 0;
  84         bool is_xdp = strncmp(event, "xdp", 3) == 0;
  85         bool is_perf_event = strncmp(event, "perf_event", 10) == 0;
  86         bool is_cgroup_skb = strncmp(event, "cgroup/skb", 10) == 0;
  87         bool is_cgroup_sk = strncmp(event, "cgroup/sock", 11) == 0;
  88         bool is_sockops = strncmp(event, "sockops", 7) == 0;
  89         bool is_sk_skb = strncmp(event, "sk_skb", 6) == 0;
  90         bool is_sk_msg = strncmp(event, "sk_msg", 6) == 0;
  91         size_t insns_cnt = size / sizeof(struct bpf_insn);
  92         enum bpf_prog_type prog_type;
  93         char buf[256];
  94         int fd, efd, err, id;
  95         struct perf_event_attr attr = {};
  96
  97         attr.type = PERF_TYPE_TRACEPOINT;
  98         attr.sample_type = PERF_SAMPLE_RAW;
  99         attr.sample_period = 1;
 100         attr.wakeup_events = 1;
 101
 102         if (is_socket) {
 103                 prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
 104         } else if (is_kprobe || is_kretprobe) {
 105                 prog_type = BPF_PROG_TYPE_KPROBE;
 106         } else if (is_tracepoint) {
 107                 prog_type = BPF_PROG_TYPE_TRACEPOINT;
 108         } else if (is_raw_tracepoint) {
 109                 prog_type = BPF_PROG_TYPE_RAW_TRACEPOINT;
 110         } else if (is_xdp) {
 111                 prog_type = BPF_PROG_TYPE_XDP;
 112         } else if (is_perf_event) {
 113                 prog_type = BPF_PROG_TYPE_PERF_EVENT;
 114         } else if (is_cgroup_skb) {
 115                 prog_type = BPF_PROG_TYPE_CGROUP_SKB;
 116         } else if (is_cgroup_sk) {
 117                 prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
 118         } else if (is_sockops) {
 119                 prog_type = BPF_PROG_TYPE_SOCK_OPS;
 120         } else if (is_sk_skb) {
 121                 prog_type = BPF_PROG_TYPE_SK_SKB;
 122         } else if (is_sk_msg) {
 123                 prog_type = BPF_PROG_TYPE_SK_MSG;
 124         } else {
 125                 printf("Unknown event '%s'\n", event);
 126                 return -1;
 127         }
 128
 129         if (prog_cnt == MAX_PROGS)
 130                 return -1;
 131
 132         fd = bpf_load_program(prog_type, prog, insns_cnt, license, kern_version,
 133                               bpf_log_buf, BPF_LOG_BUF_SIZE);
 134         if (fd < 0) {
 135                 printf("bpf_load_program() err=%d\n%s", errno, bpf_log_buf);
 136                 return -1;
 137         }
 138
 139         prog_fd[prog_cnt++] = fd;
 140
 141         if (is_xdp || is_perf_event || is_cgroup_skb || is_cgroup_sk)
 142                 return 0;
 143
 144         if (is_socket || is_sockops || is_sk_skb || is_sk_msg) {
 145                 if (is_socket)
 146                         event += 6;
 147                 else
 148                         event += 7;
 149                 if (*event != '/')
 150                         return 0;
 151                 event++;
 152                 if (!isdigit(*event)) {
 153                         printf("invalid prog number\n");
 154                         return -1;
 155                 }
 156                 return populate_prog_array(event, fd);
 157         }
 158
 159         if (is_raw_tracepoint) {
 160                 efd = bpf_raw_tracepoint_open(event + 15, fd);
 161                 if (efd < 0) {
 162                         printf("tracepoint %s %s\n", event + 15, strerror(errno));
 163                         return -1;
 164                 }
 165                 event_fd[prog_cnt - 1] = efd;
 166                 return 0;
 167         }
 168
 169         if (is_kprobe || is_kretprobe) {
 170                 bool need_normal_check = true;
 171                 const char *event_prefix = "";
 172
 173                 if (is_kprobe)
 174                         event += 7;
 175                 else
 176                         event += 10;
 177
 178                 if (*event == 0) {
 179                         printf("event name cannot be empty\n");
 180                         return -1;
 181                 }
 182
 183                 if (isdigit(*event))
 184                         return populate_prog_array(event, fd);
 185
 186 #ifdef __x86_64__
 187                 if (strncmp(event, "sys_", 4) == 0) {
 188                         snprintf(buf, sizeof(buf), "%c:__x64_%s __x64_%s",
 189                                 is_kprobe ? 'p' : 'r', event, event);
 190                         err = write_kprobe_events(buf);
 191                         if (err >= 0) {
 192                                 need_normal_check = false;
 193                                 event_prefix = "__x64_";
 194                         }
 195                 }
 196 #endif
 197                 if (need_normal_check) {
 198                         snprintf(buf, sizeof(buf), "%c:%s %s",
 199                                 is_kprobe ? 'p' : 'r', event, event);
 200                         err = write_kprobe_events(buf);
 201                         if (err < 0) {
 202                                 printf("failed to create kprobe '%s' error '%s'\n",
 203                                        event, strerror(errno));
 204                                 return -1;
 205                         }
 206                 }
 207
 208                 strcpy(buf, DEBUGFS);
 209                 strcat(buf, "events/kprobes/");
 210                 strcat(buf, event_prefix);
 211                 strcat(buf, event);
 212                 strcat(buf, "/id");
 213         } else if (is_tracepoint) {
 214                 event += 11;
 215
 216                 if (*event == 0) {
 217                         printf("event name cannot be empty\n");
 218                         return -1;
 219                 }
 220                 strcpy(buf, DEBUGFS);
 221                 strcat(buf, "events/");
 222                 strcat(buf, event);
 223                 strcat(buf, "/id");
 224         }
 225
 226         efd = open(buf, O_RDONLY, 0);
 227         if (efd < 0) {
 228                 printf("failed to open event %s\n", event);
 229                 return -1;
 230         }
 231
 232         err = read(efd, buf, sizeof(buf));
 233         if (err < 0 || err >= sizeof(buf)) {
 234                 printf("read from '%s' failed '%s'\n", event, strerror(errno));
 235                 return -1;
 236         }
 237
 238         close(efd);
 239
 240         buf[err] = 0;
 241         id = atoi(buf);
 242         attr.config = id;
 243
 244         efd = sys_perf_event_open(&attr, -1/*pid*/, 0/*cpu*/, -1/*group_fd*/, 0);
 245         if (efd < 0) {
 246                 printf("event %d fd %d err %s\n", id, efd, strerror(errno));
 247                 return -1;
 248         }
 249         event_fd[prog_cnt - 1] = efd;
 250         err = ioctl(efd, PERF_EVENT_IOC_ENABLE, 0);
 251         if (err < 0) {
 252                 printf("ioctl PERF_EVENT_IOC_ENABLE failed err %s\n",
 253                        strerror(errno));
 254                 return -1;
 255         }
 256         err = ioctl(efd, PERF_EVENT_IOC_SET_BPF, fd);
 257         if (err < 0) {
 258                 printf("ioctl PERF_EVENT_IOC_SET_BPF failed err %s\n",
 259                        strerror(errno));
 260                 return -1;
 261         }
 262
 263         return 0;
 264 }
 265
 266 static int load_maps(struct bpf_map_data *maps, int nr_maps,
 267                      fixup_map_cb fixup_map)
 268 {
 269         int i, numa_node;
 270
 271         for (i = 0; i < nr_maps; i++) {
 272                 if (fixup_map) {
 273                         fixup_map(&maps[i], i);
 274                         /* Allow userspace to assign map FD prior to creation */
 275                         if (maps[i].fd != -1) {
 276                                 map_fd[i] = maps[i].fd;
 277                                 continue;
 278                         }
 279                 }
 280
 281                 numa_node = maps[i].def.map_flags & BPF_F_NUMA_NODE ?
 282                         maps[i].def.numa_node : -1;
 283
 284                 if (maps[i].def.type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
 285                     maps[i].def.type == BPF_MAP_TYPE_HASH_OF_MAPS) {
 286                         int inner_map_fd = map_fd[maps[i].def.inner_map_idx];
 287
 288                         map_fd[i] = bpf_create_map_in_map_node(maps[i].def.type,
 289                                                         maps[i].name,
 290                                                         maps[i].def.key_size,
 291                                                         inner_map_fd,
 292                                                         maps[i].def.max_entries,
 293                                                         maps[i].def.map_flags,
 294                                                         numa_node);
 295                 } else {
 296                         map_fd[i] = bpf_create_map_node(maps[i].def.type,
 297                                                         maps[i].name,
 298                                                         maps[i].def.key_size,
 299                                                         maps[i].def.value_size,
 300                                                         maps[i].def.max_entries,
 301                                                         maps[i].def.map_flags,
 302                                                         numa_node);
 303                 }
 304                 if (map_fd[i] < 0) {
 305                         printf("failed to create a map: %d %s\n",
 306                                errno, strerror(errno));
 307                         return 1;
 308                 }
 309                 maps[i].fd = map_fd[i];
 310
 311                 if (maps[i].def.type == BPF_MAP_TYPE_PROG_ARRAY)
 312                         prog_array_fd = map_fd[i];
 313         }
 314         return 0;
 315 }
 316
 317 static int get_sec(Elf *elf, int i, GElf_Ehdr *ehdr, char **shname,
 318                    GElf_Shdr *shdr, Elf_Data **data)
 319 {
 320         Elf_Scn *scn;
 321
 322         scn = elf_getscn(elf, i);
 323         if (!scn)
 324                 return 1;
 325
 326         if (gelf_getshdr(scn, shdr) != shdr)
 327                 return 2;
 328
 329         *shname = elf_strptr(elf, ehdr->e_shstrndx, shdr->sh_name);
 330         if (!*shname || !shdr->sh_size)
 331                 return 3;
 332
 333         *data = elf_getdata(scn, 0);
 334         if (!*data || elf_getdata(scn, *data) != NULL)
 335                 return 4;
 336
 337         return 0;
 338 }
 339
 340 static int parse_relo_and_apply(Elf_Data *data, Elf_Data *symbols,
 341                                 GElf_Shdr *shdr, struct bpf_insn *insn,
 342                                 struct bpf_map_data *maps, int nr_maps)
 343 {
 344         int i, nrels;
 345
 346         nrels = shdr->sh_size / shdr->sh_entsize;
 347
 348         for (i = 0; i < nrels; i++) {
 349                 GElf_Sym sym;
 350                 GElf_Rel rel;
 351                 unsigned int insn_idx;
 352                 bool match = false;
 353                 int j, map_idx;
 354
 355                 gelf_getrel(data, i, &rel);
 356
 357                 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
 358
 359                 gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym);
 360
 361                 if (insn[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
 362                         printf("invalid relo for insn[%d].code 0x%x\n",
 363                                insn_idx, insn[insn_idx].code);
 364                         return 1;
 365                 }
 366                 insn[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
 367
 368                 /* Match FD relocation against recorded map_data[] offset */
 369                 for (map_idx = 0; map_idx < nr_maps; map_idx++) {
 370                         if (maps[map_idx].elf_offset == sym.st_value) {
 371                                 match = true;
 372                                 break;
 373                         }
 374                 }
 375                 if (match) {
 376                         insn[insn_idx].imm = maps[map_idx].fd;
 377                 } else {
 378                         printf("invalid relo for insn[%d] no map_data match\n",
 379                                insn_idx);
 380                         return 1;
 381                 }
 382         }
 383
 384         return 0;
 385 }
 386
 387 static int cmp_symbols(const void *l, const void *r)
 388 {
 389         const GElf_Sym *lsym = (const GElf_Sym *)l;
 390         const GElf_Sym *rsym = (const GElf_Sym *)r;
 391
 392         if (lsym->st_value < rsym->st_value)
 393                 return -1;
 394         else if (lsym->st_value > rsym->st_value)
 395                 return 1;
 396         else
 397                 return 0;
 398 }
 399
 400 static int load_elf_maps_section(struct bpf_map_data *maps, int maps_shndx,
 401                                  Elf *elf, Elf_Data *symbols, int strtabidx)
 402 {
 403         int map_sz_elf, map_sz_copy;
 404         bool validate_zero = false;
 405         Elf_Data *data_maps;
 406         int i, nr_maps;
 407         GElf_Sym *sym;
 408         Elf_Scn *scn;
 409         int copy_sz;
 410
 411         if (maps_shndx < 0)
 412                 return -EINVAL;
 413         if (!symbols)
 414                 return -EINVAL;
 415
 416         /* Get data for maps section via elf index */
 417         scn = elf_getscn(elf, maps_shndx);
 418         if (scn)
 419                 data_maps = elf_getdata(scn, NULL);
 420         if (!scn || !data_maps) {
 421                 printf("Failed to get Elf_Data from maps section %d\n",
 422                        maps_shndx);
 423                 return -EINVAL;
 424         }
 425
 426         /* For each map get corrosponding symbol table entry */
 427         sym = calloc(MAX_MAPS+1, sizeof(GElf_Sym));
 428         for (i = 0, nr_maps = 0; i < symbols->d_size / sizeof(GElf_Sym); i++) {
 429                 assert(nr_maps < MAX_MAPS+1);
 430                 if (!gelf_getsym(symbols, i, &sym[nr_maps]))
 431                         continue;
 432                 if (sym[nr_maps].st_shndx != maps_shndx)
 433                         continue;
 434                 /* Only increment iif maps section */
 435                 nr_maps++;
 436         }
 437
 438         /* Align to map_fd[] order, via sort on offset in sym.st_value */
 439         qsort(sym, nr_maps, sizeof(GElf_Sym), cmp_symbols);
 440
 441         /* Keeping compatible with ELF maps section changes
 442          * ------------------------------------------------
 443          * The program size of struct bpf_load_map_def is known by loader
 444          * code, but struct stored in ELF file can be different.
 445          *
 446          * Unfortunately sym[i].st_size is zero.  To calculate the
 447          * struct size stored in the ELF file, assume all struct have
 448          * the same size, and simply divide with number of map
 449          * symbols.
 450          */
 451         map_sz_elf = data_maps->d_size / nr_maps;
 452         map_sz_copy = sizeof(struct bpf_load_map_def);
 453         if (map_sz_elf < map_sz_copy) {
 454                 /*
 455                  * Backward compat, loading older ELF file with
 456                  * smaller struct, keeping remaining bytes zero.
 457                  */
 458                 map_sz_copy = map_sz_elf;
 459         } else if (map_sz_elf > map_sz_copy) {
 460                 /*
 461                  * Forward compat, loading newer ELF file with larger
 462                  * struct with unknown features. Assume zero means
 463                  * feature not used.  Thus, validate rest of struct
 464                  * data is zero.
 465                  */
 466                 validate_zero = true;
 467         }
 468
 469         /* Memcpy relevant part of ELF maps data to loader maps */
 470         for (i = 0; i < nr_maps; i++) {
 471                 struct bpf_load_map_def *def;
 472                 unsigned char *addr, *end;
 473                 const char *map_name;
 474                 size_t offset;
 475
 476                 map_name = elf_strptr(elf, strtabidx, sym[i].st_name);
 477                 maps[i].name = strdup(map_name);
 478                 if (!maps[i].name) {
 479                         printf("strdup(%s): %s(%d)\n", map_name,
 480                                strerror(errno), errno);
 481                         free(sym);
 482                         return -errno;
 483                 }
 484
 485                 /* Symbol value is offset into ELF maps section data area */
 486                 offset = sym[i].st_value;
 487                 def = (struct bpf_load_map_def *)(data_maps->d_buf + offset);
 488                 maps[i].elf_offset = offset;
 489                 memset(&maps[i].def, 0, sizeof(struct bpf_load_map_def));
 490                 memcpy(&maps[i].def, def, map_sz_copy);
 491
 492                 /* Verify no newer features were requested */
 493                 if (validate_zero) {
 494                         addr = (unsigned char*) def + map_sz_copy;
 495                         end  = (unsigned char*) def + map_sz_elf;
 496                         for (; addr < end; addr++) {
 497                                 if (*addr != 0) {
 498                                         free(sym);
 499                                         return -EFBIG;
 500                                 }
 501                         }
 502                 }
 503         }
 504
 505         free(sym);
 506         return nr_maps;
 507 }
 508
 509 static int do_load_bpf_file(const char *path, fixup_map_cb fixup_map)
 510 {
 511         int fd, i, ret, maps_shndx = -1, strtabidx = -1;
 512         Elf *elf;
 513         GElf_Ehdr ehdr;
 514         GElf_Shdr shdr, shdr_prog;
 515         Elf_Data *data, *data_prog, *data_maps = NULL, *symbols = NULL;
 516         char *shname, *shname_prog;
 517         int nr_maps = 0;
 518
 519         /* reset global variables */
 520         kern_version = 0;
 521         memset(license, 0, sizeof(license));
 522         memset(processed_sec, 0, sizeof(processed_sec));
 523
 524         if (elf_version(EV_CURRENT) == EV_NONE)
 525                 return 1;
 526
 527         fd = open(path, O_RDONLY, 0);
 528         if (fd < 0)
 529                 return 1;
 530
 531         elf = elf_begin(fd, ELF_C_READ, NULL);
 532
 533         if (!elf)
 534                 return 1;
 535
 536         if (gelf_getehdr(elf, &ehdr) != &ehdr)
 537                 return 1;
 538
 539         /* clear all kprobes */
 540         i = write_kprobe_events("");
 541
 542         /* scan over all elf sections to get license and map info */
 543         for (i = 1; i < ehdr.e_shnum; i++) {
 544
 545                 if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
 546                         continue;
 547
 548                 if (0) /* helpful for llvm debugging */
 549                         printf("section %d:%s data %p size %zd link %d flags %d\n",
 550                                i, shname, data->d_buf, data->d_size,
 551                                shdr.sh_link, (int) shdr.sh_flags);
 552
 553                 if (strcmp(shname, "license") == 0) {
 554                         processed_sec[i] = true;
 555                         memcpy(license, data->d_buf, data->d_size);
 556                 } else if (strcmp(shname, "version") == 0) {
 557                         processed_sec[i] = true;
 558                         if (data->d_size != sizeof(int)) {
 559                                 printf("invalid size of version section %zd\n",
 560                                        data->d_size);
 561                                 return 1;
 562                         }
 563                         memcpy(&kern_version, data->d_buf, sizeof(int));
 564                 } else if (strcmp(shname, "maps") == 0) {
 565                         int j;
 566
 567                         maps_shndx = i;
 568                         data_maps = data;
 569                         for (j = 0; j < MAX_MAPS; j++)
 570                                 map_data[j].fd = -1;
 571                 } else if (shdr.sh_type == SHT_SYMTAB) {
 572                         strtabidx = shdr.sh_link;
 573                         symbols = data;
 574                 }
 575         }
 576
 577         ret = 1;
 578
 579         if (!symbols) {
 580                 printf("missing SHT_SYMTAB section\n");
 581                 goto done;
 582         }
 583
 584         if (data_maps) {
 585                 nr_maps = load_elf_maps_section(map_data, maps_shndx,
 586                                                 elf, symbols, strtabidx);
 587                 if (nr_maps < 0) {
 588                         printf("Error: Failed loading ELF maps (errno:%d):%s\n",
 589                                nr_maps, strerror(-nr_maps));
 590                         goto done;
 591                 }
 592                 if (load_maps(map_data, nr_maps, fixup_map))
 593                         goto done;
 594                 map_data_count = nr_maps;
 595
 596                 processed_sec[maps_shndx] = true;
 597         }
 598
 599         /* process all relo sections, and rewrite bpf insns for maps */
 600         for (i = 1; i < ehdr.e_shnum; i++) {
 601                 if (processed_sec[i])
 602                         continue;
 603
 604                 if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
 605                         continue;
 606
 607                 if (shdr.sh_type == SHT_REL) {
 608                         struct bpf_insn *insns;
 609
 610                         /* locate prog sec that need map fixup (relocations) */
 611                         if (get_sec(elf, shdr.sh_info, &ehdr, &shname_prog,
 612                                     &shdr_prog, &data_prog))
 613                                 continue;
 614
 615                         if (shdr_prog.sh_type != SHT_PROGBITS ||
 616                             !(shdr_prog.sh_flags & SHF_EXECINSTR))
 617                                 continue;
 618
 619                         insns = (struct bpf_insn *) data_prog->d_buf;
 620                         processed_sec[i] = true; /* relo section */
 621
 622                         if (parse_relo_and_apply(data, symbols, &shdr, insns,
 623                                                  map_data, nr_maps))
 624                                 continue;
 625                 }
 626         }
 627
 628         /* load programs */
 629         for (i = 1; i < ehdr.e_shnum; i++) {
 630
 631                 if (processed_sec[i])
 632                         continue;
 633
 634                 if (get_sec(elf, i, &ehdr, &shname, &shdr, &data))
 635                         continue;
 636
 637                 if (memcmp(shname, "kprobe/", 7) == 0 ||
 638                     memcmp(shname, "kretprobe/", 10) == 0 ||
 639                     memcmp(shname, "tracepoint/", 11) == 0 ||
 640                     memcmp(shname, "raw_tracepoint/", 15) == 0 ||
 641                     memcmp(shname, "xdp", 3) == 0 ||
 642                     memcmp(shname, "perf_event", 10) == 0 ||
 643                     memcmp(shname, "socket", 6) == 0 ||
 644                     memcmp(shname, "cgroup/", 7) == 0 ||
 645                     memcmp(shname, "sockops", 7) == 0 ||
 646                     memcmp(shname, "sk_skb", 6) == 0 ||
 647                     memcmp(shname, "sk_msg", 6) == 0) {
 648                         ret = load_and_attach(shname, data->d_buf,
 649                                               data->d_size);
 650                         if (ret != 0)
 651                                 goto done;
 652                 }
 653         }
 654
 655 done:
 656         close(fd);
 657         return ret;
 658 }
 659
 660 int load_bpf_file(char *path)
 661 {
 662         return do_load_bpf_file(path, NULL);
 663 }
 664
 665 int load_bpf_file_fixup_map(const char *path, fixup_map_cb fixup_map)
 666 {
 667         return do_load_bpf_file(path, fixup_map);
 668 }
 669
 670 void read_trace_pipe(void)
 671 {
 672         int trace_fd;
 673
 674         trace_fd = open(DEBUGFS "trace_pipe", O_RDONLY, 0);
 675         if (trace_fd < 0)
 676                 return;
 677
 678         while (1) {
 679                 static char buf[4096];
 680                 ssize_t sz;
 681
 682                 sz = read(trace_fd, buf, sizeof(buf) - 1);
 683                 if (sz > 0) {
 684                         buf[sz] = 0;
 685                         puts(buf);
 686                 }
 687         }
 688 }