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