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