tools/lib/bpf/libbpf.c

   1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
   2
   3 /*
   4  * Common eBPF ELF object loading operations.
   5  *
   6  * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
   7  * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   8  * Copyright (C) 2015 Huawei Inc.
   9  * Copyright (C) 2017 Nicira, Inc.
  10  * Copyright (C) 2019 Isovalent, Inc.
  11  */
  12
  13 #ifndef _GNU_SOURCE
  14 #define _GNU_SOURCE
  15 #endif
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include <stdarg.h>
  19 #include <libgen.h>
  20 #include <inttypes.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <fcntl.h>
  24 #include <errno.h>
  25 #include <asm/unistd.h>
  26 #include <linux/err.h>
  27 #include <linux/kernel.h>
  28 #include <linux/bpf.h>
  29 #include <linux/btf.h>
  30 #include <linux/filter.h>
  31 #include <linux/list.h>
  32 #include <linux/limits.h>
  33 #include <linux/perf_event.h>
  34 #include <linux/ring_buffer.h>
  35 #include <sys/stat.h>
  36 #include <sys/types.h>
  37 #include <sys/vfs.h>
  38 #include <tools/libc_compat.h>
  39 #include <libelf.h>
  40 #include <gelf.h>
  41
  42 #include "libbpf.h"
  43 #include "bpf.h"
  44 #include "btf.h"
  45 #include "str_error.h"
  46 #include "libbpf_util.h"
  47
  48 #ifndef EM_BPF
  49 #define EM_BPF 247
  50 #endif
  51
  52 #ifndef BPF_FS_MAGIC
  53 #define BPF_FS_MAGIC            0xcafe4a11
  54 #endif
  55
  56 /* vsprintf() in __base_pr() uses nonliteral format string. It may break
  57  * compilation if user enables corresponding warning. Disable it explicitly.
  58  */
  59 #pragma GCC diagnostic ignored "-Wformat-nonliteral"
  60
  61 #define __printf(a, b)  __attribute__((format(printf, a, b)))
  62
  63 static int __base_pr(enum libbpf_print_level level, const char *format,
  64                      va_list args)
  65 {
  66         if (level == LIBBPF_DEBUG)
  67                 return 0;
  68
  69         return vfprintf(stderr, format, args);
  70 }
  71
  72 static libbpf_print_fn_t __libbpf_pr = __base_pr;
  73
  74 void libbpf_set_print(libbpf_print_fn_t fn)
  75 {
  76         __libbpf_pr = fn;
  77 }
  78
  79 __printf(2, 3)
  80 void libbpf_print(enum libbpf_print_level level, const char *format, ...)
  81 {
  82         va_list args;
  83
  84         if (!__libbpf_pr)
  85                 return;
  86
  87         va_start(args, format);
  88         __libbpf_pr(level, format, args);
  89         va_end(args);
  90 }
  91
  92 #define STRERR_BUFSIZE  128
  93
  94 #define CHECK_ERR(action, err, out) do {        \
  95         err = action;                   \
  96         if (err)                        \
  97                 goto out;               \
  98 } while(0)
  99
 100
 101 /* Copied from tools/perf/util/util.h */
 102 #ifndef zfree
 103 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
 104 #endif
 105
 106 #ifndef zclose
 107 # define zclose(fd) ({                  \
 108         int ___err = 0;                 \
 109         if ((fd) >= 0)                  \
 110                 ___err = close((fd));   \
 111         fd = -1;                        \
 112         ___err; })
 113 #endif
 114
 115 #ifdef HAVE_LIBELF_MMAP_SUPPORT
 116 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ_MMAP
 117 #else
 118 # define LIBBPF_ELF_C_READ_MMAP ELF_C_READ
 119 #endif
 120
 121 static inline __u64 ptr_to_u64(const void *ptr)
 122 {
 123         return (__u64) (unsigned long) ptr;
 124 }
 125
 126 struct bpf_capabilities {
 127         /* v4.14: kernel support for program & map names. */
 128         __u32 name:1;
 129 };
 130
 131 /*
 132  * bpf_prog should be a better name but it has been used in
 133  * linux/filter.h.
 134  */
 135 struct bpf_program {
 136         /* Index in elf obj file, for relocation use. */
 137         int idx;
 138         char *name;
 139         int prog_ifindex;
 140         char *section_name;
 141         /* section_name with / replaced by _; makes recursive pinning
 142          * in bpf_object__pin_programs easier
 143          */
 144         char *pin_name;
 145         struct bpf_insn *insns;
 146         size_t insns_cnt, main_prog_cnt;
 147         enum bpf_prog_type type;
 148
 149         struct reloc_desc {
 150                 enum {
 151                         RELO_LD64,
 152                         RELO_CALL,
 153                         RELO_DATA,
 154                 } type;
 155                 int insn_idx;
 156                 union {
 157                         int map_idx;
 158                         int text_off;
 159                 };
 160         } *reloc_desc;
 161         int nr_reloc;
 162         int log_level;
 163
 164         struct {
 165                 int nr;
 166                 int *fds;
 167         } instances;
 168         bpf_program_prep_t preprocessor;
 169
 170         struct bpf_object *obj;
 171         void *priv;
 172         bpf_program_clear_priv_t clear_priv;
 173
 174         enum bpf_attach_type expected_attach_type;
 175         int btf_fd;
 176         void *func_info;
 177         __u32 func_info_rec_size;
 178         __u32 func_info_cnt;
 179
 180         struct bpf_capabilities *caps;
 181
 182         void *line_info;
 183         __u32 line_info_rec_size;
 184         __u32 line_info_cnt;
 185 };
 186
 187 enum libbpf_map_type {
 188         LIBBPF_MAP_UNSPEC,
 189         LIBBPF_MAP_DATA,
 190         LIBBPF_MAP_BSS,
 191         LIBBPF_MAP_RODATA,
 192 };
 193
 194 static const char * const libbpf_type_to_btf_name[] = {
 195         [LIBBPF_MAP_DATA]       = ".data",
 196         [LIBBPF_MAP_BSS]        = ".bss",
 197         [LIBBPF_MAP_RODATA]     = ".rodata",
 198 };
 199
 200 struct bpf_map {
 201         int fd;
 202         char *name;
 203         size_t offset;
 204         int map_ifindex;
 205         int inner_map_fd;
 206         struct bpf_map_def def;
 207         __u32 btf_key_type_id;
 208         __u32 btf_value_type_id;
 209         void *priv;
 210         bpf_map_clear_priv_t clear_priv;
 211         enum libbpf_map_type libbpf_type;
 212 };
 213
 214 struct bpf_secdata {
 215         void *rodata;
 216         void *data;
 217 };
 218
 219 static LIST_HEAD(bpf_objects_list);
 220
 221 struct bpf_object {
 222         char name[BPF_OBJ_NAME_LEN];
 223         char license[64];
 224         __u32 kern_version;
 225
 226         struct bpf_program *programs;
 227         size_t nr_programs;
 228         struct bpf_map *maps;
 229         size_t nr_maps;
 230         struct bpf_secdata sections;
 231
 232         bool loaded;
 233         bool has_pseudo_calls;
 234
 235         /*
 236          * Information when doing elf related work. Only valid if fd
 237          * is valid.
 238          */
 239         struct {
 240                 int fd;
 241                 void *obj_buf;
 242                 size_t obj_buf_sz;
 243                 Elf *elf;
 244                 GElf_Ehdr ehdr;
 245                 Elf_Data *symbols;
 246                 Elf_Data *data;
 247                 Elf_Data *rodata;
 248                 Elf_Data *bss;
 249                 size_t strtabidx;
 250                 struct {
 251                         GElf_Shdr shdr;
 252                         Elf_Data *data;
 253                 } *reloc;
 254                 int nr_reloc;
 255                 int maps_shndx;
 256                 int text_shndx;
 257                 int data_shndx;
 258                 int rodata_shndx;
 259                 int bss_shndx;
 260         } efile;
 261         /*
 262          * All loaded bpf_object is linked in a list, which is
 263          * hidden to caller. bpf_objects__<func> handlers deal with
 264          * all objects.
 265          */
 266         struct list_head list;
 267
 268         struct btf *btf;
 269         struct btf_ext *btf_ext;
 270
 271         void *priv;
 272         bpf_object_clear_priv_t clear_priv;
 273
 274         struct bpf_capabilities caps;
 275
 276         char path[];
 277 };
 278 #define obj_elf_valid(o)        ((o)->efile.elf)
 279
 280 void bpf_program__unload(struct bpf_program *prog)
 281 {
 282         int i;
 283
 284         if (!prog)
 285                 return;
 286
 287         /*
 288          * If the object is opened but the program was never loaded,
 289          * it is possible that prog->instances.nr == -1.
 290          */
 291         if (prog->instances.nr > 0) {
 292                 for (i = 0; i < prog->instances.nr; i++)
 293                         zclose(prog->instances.fds[i]);
 294         } else if (prog->instances.nr != -1) {
 295                 pr_warning("Internal error: instances.nr is %d\n",
 296                            prog->instances.nr);
 297         }
 298
 299         prog->instances.nr = -1;
 300         zfree(&prog->instances.fds);
 301
 302         zclose(prog->btf_fd);
 303         zfree(&prog->func_info);
 304         zfree(&prog->line_info);
 305 }
 306
 307 static void bpf_program__exit(struct bpf_program *prog)
 308 {
 309         if (!prog)
 310                 return;
 311
 312         if (prog->clear_priv)
 313                 prog->clear_priv(prog, prog->priv);
 314
 315         prog->priv = NULL;
 316         prog->clear_priv = NULL;
 317
 318         bpf_program__unload(prog);
 319         zfree(&prog->name);
 320         zfree(&prog->section_name);
 321         zfree(&prog->pin_name);
 322         zfree(&prog->insns);
 323         zfree(&prog->reloc_desc);
 324
 325         prog->nr_reloc = 0;
 326         prog->insns_cnt = 0;
 327         prog->idx = -1;
 328 }
 329
 330 static char *__bpf_program__pin_name(struct bpf_program *prog)
 331 {
 332         char *name, *p;
 333
 334         name = p = strdup(prog->section_name);
 335         while ((p = strchr(p, '/')))
 336                 *p = '_';
 337
 338         return name;
 339 }
 340
 341 static int
 342 bpf_program__init(void *data, size_t size, char *section_name, int idx,
 343                   struct bpf_program *prog)
 344 {
 345         if (size < sizeof(struct bpf_insn)) {
 346                 pr_warning("corrupted section '%s'\n", section_name);
 347                 return -EINVAL;
 348         }
 349
 350         memset(prog, 0, sizeof(*prog));
 351
 352         prog->section_name = strdup(section_name);
 353         if (!prog->section_name) {
 354                 pr_warning("failed to alloc name for prog under section(%d) %s\n",
 355                            idx, section_name);
 356                 goto errout;
 357         }
 358
 359         prog->pin_name = __bpf_program__pin_name(prog);
 360         if (!prog->pin_name) {
 361                 pr_warning("failed to alloc pin name for prog under section(%d) %s\n",
 362                            idx, section_name);
 363                 goto errout;
 364         }
 365
 366         prog->insns = malloc(size);
 367         if (!prog->insns) {
 368                 pr_warning("failed to alloc insns for prog under section %s\n",
 369                            section_name);
 370                 goto errout;
 371         }
 372         prog->insns_cnt = size / sizeof(struct bpf_insn);
 373         memcpy(prog->insns, data,
 374                prog->insns_cnt * sizeof(struct bpf_insn));
 375         prog->idx = idx;
 376         prog->instances.fds = NULL;
 377         prog->instances.nr = -1;
 378         prog->type = BPF_PROG_TYPE_UNSPEC;
 379         prog->btf_fd = -1;
 380
 381         return 0;
 382 errout:
 383         bpf_program__exit(prog);
 384         return -ENOMEM;
 385 }
 386
 387 static int
 388 bpf_object__add_program(struct bpf_object *obj, void *data, size_t size,
 389                         char *section_name, int idx)
 390 {
 391         struct bpf_program prog, *progs;
 392         int nr_progs, err;
 393
 394         err = bpf_program__init(data, size, section_name, idx, &prog);
 395         if (err)
 396                 return err;
 397
 398         prog.caps = &obj->caps;
 399         progs = obj->programs;
 400         nr_progs = obj->nr_programs;
 401
 402         progs = reallocarray(progs, nr_progs + 1, sizeof(progs[0]));
 403         if (!progs) {
 404                 /*
 405                  * In this case the original obj->programs
 406                  * is still valid, so don't need special treat for
 407                  * bpf_close_object().
 408                  */
 409                 pr_warning("failed to alloc a new program under section '%s'\n",
 410                            section_name);
 411                 bpf_program__exit(&prog);
 412                 return -ENOMEM;
 413         }
 414
 415         pr_debug("found program %s\n", prog.section_name);
 416         obj->programs = progs;
 417         obj->nr_programs = nr_progs + 1;
 418         prog.obj = obj;
 419         progs[nr_progs] = prog;
 420         return 0;
 421 }
 422
 423 static int
 424 bpf_object__init_prog_names(struct bpf_object *obj)
 425 {
 426         Elf_Data *symbols = obj->efile.symbols;
 427         struct bpf_program *prog;
 428         size_t pi, si;
 429
 430         for (pi = 0; pi < obj->nr_programs; pi++) {
 431                 const char *name = NULL;
 432
 433                 prog = &obj->programs[pi];
 434
 435                 for (si = 0; si < symbols->d_size / sizeof(GElf_Sym) && !name;
 436                      si++) {
 437                         GElf_Sym sym;
 438
 439                         if (!gelf_getsym(symbols, si, &sym))
 440                                 continue;
 441                         if (sym.st_shndx != prog->idx)
 442                                 continue;
 443                         if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
 444                                 continue;
 445
 446                         name = elf_strptr(obj->efile.elf,
 447                                           obj->efile.strtabidx,
 448                                           sym.st_name);
 449                         if (!name) {
 450                                 pr_warning("failed to get sym name string for prog %s\n",
 451                                            prog->section_name);
 452                                 return -LIBBPF_ERRNO__LIBELF;
 453                         }
 454                 }
 455
 456                 if (!name && prog->idx == obj->efile.text_shndx)
 457                         name = ".text";
 458
 459                 if (!name) {
 460                         pr_warning("failed to find sym for prog %s\n",
 461                                    prog->section_name);
 462                         return -EINVAL;
 463                 }
 464
 465                 prog->name = strdup(name);
 466                 if (!prog->name) {
 467                         pr_warning("failed to allocate memory for prog sym %s\n",
 468                                    name);
 469                         return -ENOMEM;
 470                 }
 471         }
 472
 473         return 0;
 474 }
 475
 476 static struct bpf_object *bpf_object__new(const char *path,
 477                                           void *obj_buf,
 478                                           size_t obj_buf_sz)
 479 {
 480         struct bpf_object *obj;
 481         char *end;
 482
 483         obj = calloc(1, sizeof(struct bpf_object) + strlen(path) + 1);
 484         if (!obj) {
 485                 pr_warning("alloc memory failed for %s\n", path);
 486                 return ERR_PTR(-ENOMEM);
 487         }
 488
 489         strcpy(obj->path, path);
 490         /* Using basename() GNU version which doesn't modify arg. */
 491         strncpy(obj->name, basename((void *)path),
 492                 sizeof(obj->name) - 1);
 493         end = strchr(obj->name, '.');
 494         if (end)
 495                 *end = 0;
 496
 497         obj->efile.fd = -1;
 498         /*
 499          * Caller of this function should also calls
 500          * bpf_object__elf_finish() after data collection to return
 501          * obj_buf to user. If not, we should duplicate the buffer to
 502          * avoid user freeing them before elf finish.
 503          */
 504         obj->efile.obj_buf = obj_buf;
 505         obj->efile.obj_buf_sz = obj_buf_sz;
 506         obj->efile.maps_shndx = -1;
 507         obj->efile.data_shndx = -1;
 508         obj->efile.rodata_shndx = -1;
 509         obj->efile.bss_shndx = -1;
 510
 511         obj->loaded = false;
 512
 513         INIT_LIST_HEAD(&obj->list);
 514         list_add(&obj->list, &bpf_objects_list);
 515         return obj;
 516 }
 517
 518 static void bpf_object__elf_finish(struct bpf_object *obj)
 519 {
 520         if (!obj_elf_valid(obj))
 521                 return;
 522
 523         if (obj->efile.elf) {
 524                 elf_end(obj->efile.elf);
 525                 obj->efile.elf = NULL;
 526         }
 527         obj->efile.symbols = NULL;
 528         obj->efile.data = NULL;
 529         obj->efile.rodata = NULL;
 530         obj->efile.bss = NULL;
 531
 532         zfree(&obj->efile.reloc);
 533         obj->efile.nr_reloc = 0;
 534         zclose(obj->efile.fd);
 535         obj->efile.obj_buf = NULL;
 536         obj->efile.obj_buf_sz = 0;
 537 }
 538
 539 static int bpf_object__elf_init(struct bpf_object *obj)
 540 {
 541         int err = 0;
 542         GElf_Ehdr *ep;
 543
 544         if (obj_elf_valid(obj)) {
 545                 pr_warning("elf init: internal error\n");
 546                 return -LIBBPF_ERRNO__LIBELF;
 547         }
 548
 549         if (obj->efile.obj_buf_sz > 0) {
 550                 /*
 551                  * obj_buf should have been validated by
 552                  * bpf_object__open_buffer().
 553                  */
 554                 obj->efile.elf = elf_memory(obj->efile.obj_buf,
 555                                             obj->efile.obj_buf_sz);
 556         } else {
 557                 obj->efile.fd = open(obj->path, O_RDONLY);
 558                 if (obj->efile.fd < 0) {
 559                         char errmsg[STRERR_BUFSIZE];
 560                         char *cp = libbpf_strerror_r(errno, errmsg,
 561                                                      sizeof(errmsg));
 562
 563                         pr_warning("failed to open %s: %s\n", obj->path, cp);
 564                         return -errno;
 565                 }
 566
 567                 obj->efile.elf = elf_begin(obj->efile.fd,
 568                                 LIBBPF_ELF_C_READ_MMAP,
 569                                 NULL);
 570         }
 571
 572         if (!obj->efile.elf) {
 573                 pr_warning("failed to open %s as ELF file\n",
 574                                 obj->path);
 575                 err = -LIBBPF_ERRNO__LIBELF;
 576                 goto errout;
 577         }
 578
 579         if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
 580                 pr_warning("failed to get EHDR from %s\n",
 581                                 obj->path);
 582                 err = -LIBBPF_ERRNO__FORMAT;
 583                 goto errout;
 584         }
 585         ep = &obj->efile.ehdr;
 586
 587         /* Old LLVM set e_machine to EM_NONE */
 588         if ((ep->e_type != ET_REL) || (ep->e_machine && (ep->e_machine != EM_BPF))) {
 589                 pr_warning("%s is not an eBPF object file\n",
 590                         obj->path);
 591                 err = -LIBBPF_ERRNO__FORMAT;
 592                 goto errout;
 593         }
 594
 595         return 0;
 596 errout:
 597         bpf_object__elf_finish(obj);
 598         return err;
 599 }
 600
 601 static int
 602 bpf_object__check_endianness(struct bpf_object *obj)
 603 {
 604         static unsigned int const endian = 1;
 605
 606         switch (obj->efile.ehdr.e_ident[EI_DATA]) {
 607         case ELFDATA2LSB:
 608                 /* We are big endian, BPF obj is little endian. */
 609                 if (*(unsigned char const *)&endian != 1)
 610                         goto mismatch;
 611                 break;
 612
 613         case ELFDATA2MSB:
 614                 /* We are little endian, BPF obj is big endian. */
 615                 if (*(unsigned char const *)&endian != 0)
 616                         goto mismatch;
 617                 break;
 618         default:
 619                 return -LIBBPF_ERRNO__ENDIAN;
 620         }
 621
 622         return 0;
 623
 624 mismatch:
 625         pr_warning("Error: endianness mismatch.\n");
 626         return -LIBBPF_ERRNO__ENDIAN;
 627 }
 628
 629 static int
 630 bpf_object__init_license(struct bpf_object *obj,
 631                          void *data, size_t size)
 632 {
 633         memcpy(obj->license, data,
 634                min(size, sizeof(obj->license) - 1));
 635         pr_debug("license of %s is %s\n", obj->path, obj->license);
 636         return 0;
 637 }
 638
 639 static int
 640 bpf_object__init_kversion(struct bpf_object *obj,
 641                           void *data, size_t size)
 642 {
 643         __u32 kver;
 644
 645         if (size != sizeof(kver)) {
 646                 pr_warning("invalid kver section in %s\n", obj->path);
 647                 return -LIBBPF_ERRNO__FORMAT;
 648         }
 649         memcpy(&kver, data, sizeof(kver));
 650         obj->kern_version = kver;
 651         pr_debug("kernel version of %s is %x\n", obj->path,
 652                  obj->kern_version);
 653         return 0;
 654 }
 655
 656 static int compare_bpf_map(const void *_a, const void *_b)
 657 {
 658         const struct bpf_map *a = _a;
 659         const struct bpf_map *b = _b;
 660
 661         return a->offset - b->offset;
 662 }
 663
 664 static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 665 {
 666         if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||
 667             type == BPF_MAP_TYPE_HASH_OF_MAPS)
 668                 return true;
 669         return false;
 670 }
 671
 672 static int bpf_object_search_section_size(const struct bpf_object *obj,
 673                                           const char *name, size_t *d_size)
 674 {
 675         const GElf_Ehdr *ep = &obj->efile.ehdr;
 676         Elf *elf = obj->efile.elf;
 677         Elf_Scn *scn = NULL;
 678         int idx = 0;
 679
 680         while ((scn = elf_nextscn(elf, scn)) != NULL) {
 681                 const char *sec_name;
 682                 Elf_Data *data;
 683                 GElf_Shdr sh;
 684
 685                 idx++;
 686                 if (gelf_getshdr(scn, &sh) != &sh) {
 687                         pr_warning("failed to get section(%d) header from %s\n",
 688                                    idx, obj->path);
 689                         return -EIO;
 690                 }
 691
 692                 sec_name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
 693                 if (!sec_name) {
 694                         pr_warning("failed to get section(%d) name from %s\n",
 695                                    idx, obj->path);
 696                         return -EIO;
 697                 }
 698
 699                 if (strcmp(name, sec_name))
 700                         continue;
 701
 702                 data = elf_getdata(scn, 0);
 703                 if (!data) {
 704                         pr_warning("failed to get section(%d) data from %s(%s)\n",
 705                                    idx, name, obj->path);
 706                         return -EIO;
 707                 }
 708
 709                 *d_size = data->d_size;
 710                 return 0;
 711         }
 712
 713         return -ENOENT;
 714 }
 715
 716 int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 717                              __u32 *size)
 718 {
 719         int ret = -ENOENT;
 720         size_t d_size;
 721
 722         *size = 0;
 723         if (!name) {
 724                 return -EINVAL;
 725         } else if (!strcmp(name, ".data")) {
 726                 if (obj->efile.data)
 727                         *size = obj->efile.data->d_size;
 728         } else if (!strcmp(name, ".bss")) {
 729                 if (obj->efile.bss)
 730                         *size = obj->efile.bss->d_size;
 731         } else if (!strcmp(name, ".rodata")) {
 732                 if (obj->efile.rodata)
 733                         *size = obj->efile.rodata->d_size;
 734         } else {
 735                 ret = bpf_object_search_section_size(obj, name, &d_size);
 736                 if (!ret)
 737                         *size = d_size;
 738         }
 739
 740         return *size ? 0 : ret;
 741 }
 742
 743 int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
 744                                 __u32 *off)
 745 {
 746         Elf_Data *symbols = obj->efile.symbols;
 747         const char *sname;
 748         size_t si;
 749
 750         if (!name || !off)
 751                 return -EINVAL;
 752
 753         for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
 754                 GElf_Sym sym;
 755
 756                 if (!gelf_getsym(symbols, si, &sym))
 757                         continue;
 758                 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
 759                     GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
 760                         continue;
 761
 762                 sname = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
 763                                    sym.st_name);
 764                 if (!sname) {
 765                         pr_warning("failed to get sym name string for var %s\n",
 766                                    name);
 767                         return -EIO;
 768                 }
 769                 if (strcmp(name, sname) == 0) {
 770                         *off = sym.st_value;
 771                         return 0;
 772                 }
 773         }
 774
 775         return -ENOENT;
 776 }
 777
 778 static bool bpf_object__has_maps(const struct bpf_object *obj)
 779 {
 780         return obj->efile.maps_shndx >= 0 ||
 781                obj->efile.data_shndx >= 0 ||
 782                obj->efile.rodata_shndx >= 0 ||
 783                obj->efile.bss_shndx >= 0;
 784 }
 785
 786 static int
 787 bpf_object__init_internal_map(struct bpf_object *obj, struct bpf_map *map,
 788                               enum libbpf_map_type type, Elf_Data *data,
 789                               void **data_buff)
 790 {
 791         struct bpf_map_def *def = &map->def;
 792         char map_name[BPF_OBJ_NAME_LEN];
 793
 794         map->libbpf_type = type;
 795         map->offset = ~(typeof(map->offset))0;
 796         snprintf(map_name, sizeof(map_name), "%.8s%.7s", obj->name,
 797                  libbpf_type_to_btf_name[type]);
 798         map->name = strdup(map_name);
 799         if (!map->name) {
 800                 pr_warning("failed to alloc map name\n");
 801                 return -ENOMEM;
 802         }
 803
 804         def->type = BPF_MAP_TYPE_ARRAY;
 805         def->key_size = sizeof(int);
 806         def->value_size = data->d_size;
 807         def->max_entries = 1;
 808         def->map_flags = type == LIBBPF_MAP_RODATA ?
 809                          BPF_F_RDONLY_PROG : 0;
 810         if (data_buff) {
 811                 *data_buff = malloc(data->d_size);
 812                 if (!*data_buff) {
 813                         zfree(&map->name);
 814                         pr_warning("failed to alloc map content buffer\n");
 815                         return -ENOMEM;
 816                 }
 817                 memcpy(*data_buff, data->d_buf, data->d_size);
 818         }
 819
 820         pr_debug("map %ld is \"%s\"\n", map - obj->maps, map->name);
 821         return 0;
 822 }
 823
 824 static int
 825 bpf_object__init_maps(struct bpf_object *obj, int flags)
 826 {
 827         int i, map_idx, map_def_sz, nr_syms, nr_maps = 0, nr_maps_glob = 0;
 828         bool strict = !(flags & MAPS_RELAX_COMPAT);
 829         Elf_Data *symbols = obj->efile.symbols;
 830         Elf_Data *data = NULL;
 831         int ret = 0;
 832
 833         if (!symbols)
 834                 return -EINVAL;
 835         nr_syms = symbols->d_size / sizeof(GElf_Sym);
 836
 837         if (obj->efile.maps_shndx >= 0) {
 838                 Elf_Scn *scn = elf_getscn(obj->efile.elf,
 839                                           obj->efile.maps_shndx);
 840
 841                 if (scn)
 842                         data = elf_getdata(scn, NULL);
 843                 if (!scn || !data) {
 844                         pr_warning("failed to get Elf_Data from map section %d\n",
 845                                    obj->efile.maps_shndx);
 846                         return -EINVAL;
 847                 }
 848         }
 849
 850         /*
 851          * Count number of maps. Each map has a name.
 852          * Array of maps is not supported: only the first element is
 853          * considered.
 854          *
 855          * TODO: Detect array of map and report error.
 856          */
 857         if (obj->efile.data_shndx >= 0)
 858                 nr_maps_glob++;
 859         if (obj->efile.rodata_shndx >= 0)
 860                 nr_maps_glob++;
 861         if (obj->efile.bss_shndx >= 0)
 862                 nr_maps_glob++;
 863         for (i = 0; data && i < nr_syms; i++) {
 864                 GElf_Sym sym;
 865
 866                 if (!gelf_getsym(symbols, i, &sym))
 867                         continue;
 868                 if (sym.st_shndx != obj->efile.maps_shndx)
 869                         continue;
 870                 nr_maps++;
 871         }
 872
 873         /* Alloc obj->maps and fill nr_maps. */
 874         pr_debug("maps in %s: %d maps in %zd bytes\n", obj->path,
 875                  nr_maps, data->d_size);
 876         if (!nr_maps && !nr_maps_glob)
 877                 return 0;
 878
 879         /* Assume equally sized map definitions */
 880         if (data) {
 881                 map_def_sz = data->d_size / nr_maps;
 882                 if (!data->d_size || (data->d_size % nr_maps) != 0) {
 883                         pr_warning("unable to determine map definition size "
 884                                    "section %s, %d maps in %zd bytes\n",
 885                                    obj->path, nr_maps, data->d_size);
 886                         return -EINVAL;
 887                 }
 888         }
 889
 890         nr_maps += nr_maps_glob;
 891         obj->maps = calloc(nr_maps, sizeof(obj->maps[0]));
 892         if (!obj->maps) {
 893                 pr_warning("alloc maps for object failed\n");
 894                 return -ENOMEM;
 895         }
 896         obj->nr_maps = nr_maps;
 897
 898         for (i = 0; i < nr_maps; i++) {
 899                 /*
 900                  * fill all fd with -1 so won't close incorrect
 901                  * fd (fd=0 is stdin) when failure (zclose won't close
 902                  * negative fd)).
 903                  */
 904                 obj->maps[i].fd = -1;
 905                 obj->maps[i].inner_map_fd = -1;
 906         }
 907
 908         /*
 909          * Fill obj->maps using data in "maps" section.
 910          */
 911         for (i = 0, map_idx = 0; data && i < nr_syms; i++) {
 912                 GElf_Sym sym;
 913                 const char *map_name;
 914                 struct bpf_map_def *def;
 915
 916                 if (!gelf_getsym(symbols, i, &sym))
 917                         continue;
 918                 if (sym.st_shndx != obj->efile.maps_shndx)
 919                         continue;
 920
 921                 map_name = elf_strptr(obj->efile.elf,
 922                                       obj->efile.strtabidx,
 923                                       sym.st_name);
 924
 925                 obj->maps[map_idx].libbpf_type = LIBBPF_MAP_UNSPEC;
 926                 obj->maps[map_idx].offset = sym.st_value;
 927                 if (sym.st_value + map_def_sz > data->d_size) {
 928                         pr_warning("corrupted maps section in %s: last map \"%s\" too small\n",
 929                                    obj->path, map_name);
 930                         return -EINVAL;
 931                 }
 932
 933                 obj->maps[map_idx].name = strdup(map_name);
 934                 if (!obj->maps[map_idx].name) {
 935                         pr_warning("failed to alloc map name\n");
 936                         return -ENOMEM;
 937                 }
 938                 pr_debug("map %d is \"%s\"\n", map_idx,
 939                          obj->maps[map_idx].name);
 940                 def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
 941                 /*
 942                  * If the definition of the map in the object file fits in
 943                  * bpf_map_def, copy it.  Any extra fields in our version
 944                  * of bpf_map_def will default to zero as a result of the
 945                  * calloc above.
 946                  */
 947                 if (map_def_sz <= sizeof(struct bpf_map_def)) {
 948                         memcpy(&obj->maps[map_idx].def, def, map_def_sz);
 949                 } else {
 950                         /*
 951                          * Here the map structure being read is bigger than what
 952                          * we expect, truncate if the excess bits are all zero.
 953                          * If they are not zero, reject this map as
 954                          * incompatible.
 955                          */
 956                         char *b;
 957                         for (b = ((char *)def) + sizeof(struct bpf_map_def);
 958                              b < ((char *)def) + map_def_sz; b++) {
 959                                 if (*b != 0) {
 960                                         pr_warning("maps section in %s: \"%s\" "
 961                                                    "has unrecognized, non-zero "
 962                                                    "options\n",
 963                                                    obj->path, map_name);
 964                                         if (strict)
 965                                                 return -EINVAL;
 966                                 }
 967                         }
 968                         memcpy(&obj->maps[map_idx].def, def,
 969                                sizeof(struct bpf_map_def));
 970                 }
 971                 map_idx++;
 972         }
 973
 974         /*
 975          * Populate rest of obj->maps with libbpf internal maps.
 976          */
 977         if (obj->efile.data_shndx >= 0)
 978                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 979                                                     LIBBPF_MAP_DATA,
 980                                                     obj->efile.data,
 981                                                     &obj->sections.data);
 982         if (!ret && obj->efile.rodata_shndx >= 0)
 983                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 984                                                     LIBBPF_MAP_RODATA,
 985                                                     obj->efile.rodata,
 986                                                     &obj->sections.rodata);
 987         if (!ret && obj->efile.bss_shndx >= 0)
 988                 ret = bpf_object__init_internal_map(obj, &obj->maps[map_idx++],
 989                                                     LIBBPF_MAP_BSS,
 990                                                     obj->efile.bss, NULL);
 991         if (!ret)
 992                 qsort(obj->maps, obj->nr_maps, sizeof(obj->maps[0]),
 993                       compare_bpf_map);
 994         return ret;
 995 }
 996
 997 static bool section_have_execinstr(struct bpf_object *obj, int idx)
 998 {
 999         Elf_Scn *scn;
1000         GElf_Shdr sh;
1001
1002         scn = elf_getscn(obj->efile.elf, idx);
1003         if (!scn)
1004                 return false;
1005
1006         if (gelf_getshdr(scn, &sh) != &sh)
1007                 return false;
1008
1009         if (sh.sh_flags & SHF_EXECINSTR)
1010                 return true;
1011
1012         return false;
1013 }
1014
1015 static int bpf_object__elf_collect(struct bpf_object *obj, int flags)
1016 {
1017         Elf *elf = obj->efile.elf;
1018         GElf_Ehdr *ep = &obj->efile.ehdr;
1019         Elf_Data *btf_ext_data = NULL;
1020         Elf_Data *btf_data = NULL;
1021         Elf_Scn *scn = NULL;
1022         int idx = 0, err = 0;
1023
1024         /* Elf is corrupted/truncated, avoid calling elf_strptr. */
1025         if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL)) {
1026                 pr_warning("failed to get e_shstrndx from %s\n",
1027                            obj->path);
1028                 return -LIBBPF_ERRNO__FORMAT;
1029         }
1030
1031         while ((scn = elf_nextscn(elf, scn)) != NULL) {
1032                 char *name;
1033                 GElf_Shdr sh;
1034                 Elf_Data *data;
1035
1036                 idx++;
1037                 if (gelf_getshdr(scn, &sh) != &sh) {
1038                         pr_warning("failed to get section(%d) header from %s\n",
1039                                    idx, obj->path);
1040                         err = -LIBBPF_ERRNO__FORMAT;
1041                         goto out;
1042                 }
1043
1044                 name = elf_strptr(elf, ep->e_shstrndx, sh.sh_name);
1045                 if (!name) {
1046                         pr_warning("failed to get section(%d) name from %s\n",
1047                                    idx, obj->path);
1048                         err = -LIBBPF_ERRNO__FORMAT;
1049                         goto out;
1050                 }
1051
1052                 data = elf_getdata(scn, 0);
1053                 if (!data) {
1054                         pr_warning("failed to get section(%d) data from %s(%s)\n",
1055                                    idx, name, obj->path);
1056                         err = -LIBBPF_ERRNO__FORMAT;
1057                         goto out;
1058                 }
1059                 pr_debug("section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
1060                          idx, name, (unsigned long)data->d_size,
1061                          (int)sh.sh_link, (unsigned long)sh.sh_flags,
1062                          (int)sh.sh_type);
1063
1064                 if (strcmp(name, "license") == 0) {
1065                         err = bpf_object__init_license(obj,
1066                                                        data->d_buf,
1067                                                        data->d_size);
1068                 } else if (strcmp(name, "version") == 0) {
1069                         err = bpf_object__init_kversion(obj,
1070                                                         data->d_buf,
1071                                                         data->d_size);
1072                 } else if (strcmp(name, "maps") == 0) {
1073                         obj->efile.maps_shndx = idx;
1074                 } else if (strcmp(name, BTF_ELF_SEC) == 0) {
1075                         btf_data = data;
1076                 } else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
1077                         btf_ext_data = data;
1078                 } else if (sh.sh_type == SHT_SYMTAB) {
1079                         if (obj->efile.symbols) {
1080                                 pr_warning("bpf: multiple SYMTAB in %s\n",
1081                                            obj->path);
1082                                 err = -LIBBPF_ERRNO__FORMAT;
1083                         } else {
1084                                 obj->efile.symbols = data;
1085                                 obj->efile.strtabidx = sh.sh_link;
1086                         }
1087                 } else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
1088                         if (sh.sh_flags & SHF_EXECINSTR) {
1089                                 if (strcmp(name, ".text") == 0)
1090                                         obj->efile.text_shndx = idx;
1091                                 err = bpf_object__add_program(obj, data->d_buf,
1092                                                               data->d_size, name, idx);
1093                                 if (err) {
1094                                         char errmsg[STRERR_BUFSIZE];
1095                                         char *cp = libbpf_strerror_r(-err, errmsg,
1096                                                                      sizeof(errmsg));
1097
1098                                         pr_warning("failed to alloc program %s (%s): %s",
1099                                                    name, obj->path, cp);
1100                                 }
1101                         } else if (strcmp(name, ".data") == 0) {
1102                                 obj->efile.data = data;
1103                                 obj->efile.data_shndx = idx;
1104                         } else if (strcmp(name, ".rodata") == 0) {
1105                                 obj->efile.rodata = data;
1106                                 obj->efile.rodata_shndx = idx;
1107                         } else {
1108                                 pr_debug("skip section(%d) %s\n", idx, name);
1109                         }
1110                 } else if (sh.sh_type == SHT_REL) {
1111                         void *reloc = obj->efile.reloc;
1112                         int nr_reloc = obj->efile.nr_reloc + 1;
1113                         int sec = sh.sh_info; /* points to other section */
1114
1115                         /* Only do relo for section with exec instructions */
1116                         if (!section_have_execinstr(obj, sec)) {
1117                                 pr_debug("skip relo %s(%d) for section(%d)\n",
1118                                          name, idx, sec);
1119                                 continue;
1120                         }
1121
1122                         reloc = reallocarray(reloc, nr_reloc,
1123                                              sizeof(*obj->efile.reloc));
1124                         if (!reloc) {
1125                                 pr_warning("realloc failed\n");
1126                                 err = -ENOMEM;
1127                         } else {
1128                                 int n = nr_reloc - 1;
1129
1130                                 obj->efile.reloc = reloc;
1131                                 obj->efile.nr_reloc = nr_reloc;
1132
1133                                 obj->efile.reloc[n].shdr = sh;
1134                                 obj->efile.reloc[n].data = data;
1135                         }
1136                 } else if (sh.sh_type == SHT_NOBITS && strcmp(name, ".bss") == 0) {
1137                         obj->efile.bss = data;
1138                         obj->efile.bss_shndx = idx;
1139                 } else {
1140                         pr_debug("skip section(%d) %s\n", idx, name);
1141                 }
1142                 if (err)
1143                         goto out;
1144         }
1145
1146         if (!obj->efile.strtabidx || obj->efile.strtabidx >= idx) {
1147                 pr_warning("Corrupted ELF file: index of strtab invalid\n");
1148                 return LIBBPF_ERRNO__FORMAT;
1149         }
1150         if (btf_data) {
1151                 obj->btf = btf__new(btf_data->d_buf, btf_data->d_size);
1152                 if (IS_ERR(obj->btf)) {
1153                         pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
1154                                    BTF_ELF_SEC, PTR_ERR(obj->btf));
1155                         obj->btf = NULL;
1156                 } else {
1157                         err = btf__finalize_data(obj, obj->btf);
1158                         if (!err)
1159                                 err = btf__load(obj->btf);
1160                         if (err) {
1161                                 pr_warning("Error finalizing and loading %s into kernel: %d. Ignored and continue.\n",
1162                                            BTF_ELF_SEC, err);
1163                                 btf__free(obj->btf);
1164                                 obj->btf = NULL;
1165                                 err = 0;
1166                         }
1167                 }
1168         }
1169         if (btf_ext_data) {
1170                 if (!obj->btf) {
1171                         pr_debug("Ignore ELF section %s because its depending ELF section %s is not found.\n",
1172                                  BTF_EXT_ELF_SEC, BTF_ELF_SEC);
1173                 } else {
1174                         obj->btf_ext = btf_ext__new(btf_ext_data->d_buf,
1175                                                     btf_ext_data->d_size);
1176                         if (IS_ERR(obj->btf_ext)) {
1177                                 pr_warning("Error loading ELF section %s: %ld. Ignored and continue.\n",
1178                                            BTF_EXT_ELF_SEC,
1179                                            PTR_ERR(obj->btf_ext));
1180                                 obj->btf_ext = NULL;
1181                         }
1182                 }
1183         }
1184         if (bpf_object__has_maps(obj)) {
1185                 err = bpf_object__init_maps(obj, flags);
1186                 if (err)
1187                         goto out;
1188         }
1189         err = bpf_object__init_prog_names(obj);
1190 out:
1191         return err;
1192 }
1193
1194 static struct bpf_program *
1195 bpf_object__find_prog_by_idx(struct bpf_object *obj, int idx)
1196 {
1197         struct bpf_program *prog;
1198         size_t i;
1199
1200         for (i = 0; i < obj->nr_programs; i++) {
1201                 prog = &obj->programs[i];
1202                 if (prog->idx == idx)
1203                         return prog;
1204         }
1205         return NULL;
1206 }
1207
1208 struct bpf_program *
1209 bpf_object__find_program_by_title(struct bpf_object *obj, const char *title)
1210 {
1211         struct bpf_program *pos;
1212
1213         bpf_object__for_each_program(pos, obj) {
1214                 if (pos->section_name && !strcmp(pos->section_name, title))
1215                         return pos;
1216         }
1217         return NULL;
1218 }
1219
1220 static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
1221                                       int shndx)
1222 {
1223         return shndx == obj->efile.data_shndx ||
1224                shndx == obj->efile.bss_shndx ||
1225                shndx == obj->efile.rodata_shndx;
1226 }
1227
1228 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
1229                                       int shndx)
1230 {
1231         return shndx == obj->efile.maps_shndx;
1232 }
1233
1234 static bool bpf_object__relo_in_known_section(const struct bpf_object *obj,
1235                                               int shndx)
1236 {
1237         return shndx == obj->efile.text_shndx ||
1238                bpf_object__shndx_is_maps(obj, shndx) ||
1239                bpf_object__shndx_is_data(obj, shndx);
1240 }
1241
1242 static enum libbpf_map_type
1243 bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
1244 {
1245         if (shndx == obj->efile.data_shndx)
1246                 return LIBBPF_MAP_DATA;
1247         else if (shndx == obj->efile.bss_shndx)
1248                 return LIBBPF_MAP_BSS;
1249         else if (shndx == obj->efile.rodata_shndx)
1250                 return LIBBPF_MAP_RODATA;
1251         else
1252                 return LIBBPF_MAP_UNSPEC;
1253 }
1254
1255 static int
1256 bpf_program__collect_reloc(struct bpf_program *prog, GElf_Shdr *shdr,
1257                            Elf_Data *data, struct bpf_object *obj)
1258 {
1259         Elf_Data *symbols = obj->efile.symbols;
1260         struct bpf_map *maps = obj->maps;
1261         size_t nr_maps = obj->nr_maps;
1262         int i, nrels;
1263
1264         pr_debug("collecting relocating info for: '%s'\n",
1265                  prog->section_name);
1266         nrels = shdr->sh_size / shdr->sh_entsize;
1267
1268         prog->reloc_desc = malloc(sizeof(*prog->reloc_desc) * nrels);
1269         if (!prog->reloc_desc) {
1270                 pr_warning("failed to alloc memory in relocation\n");
1271                 return -ENOMEM;
1272         }
1273         prog->nr_reloc = nrels;
1274
1275         for (i = 0; i < nrels; i++) {
1276                 GElf_Sym sym;
1277                 GElf_Rel rel;
1278                 unsigned int insn_idx;
1279                 unsigned int shdr_idx;
1280                 struct bpf_insn *insns = prog->insns;
1281                 enum libbpf_map_type type;
1282                 const char *name;
1283                 size_t map_idx;
1284
1285                 if (!gelf_getrel(data, i, &rel)) {
1286                         pr_warning("relocation: failed to get %d reloc\n", i);
1287                         return -LIBBPF_ERRNO__FORMAT;
1288                 }
1289
1290                 if (!gelf_getsym(symbols,
1291                                  GELF_R_SYM(rel.r_info),
1292                                  &sym)) {
1293                         pr_warning("relocation: symbol %"PRIx64" not found\n",
1294                                    GELF_R_SYM(rel.r_info));
1295                         return -LIBBPF_ERRNO__FORMAT;
1296                 }
1297
1298                 name = elf_strptr(obj->efile.elf, obj->efile.strtabidx,
1299                                   sym.st_name) ? : "<?>";
1300
1301                 pr_debug("relo for %lld value %lld name %d (\'%s\')\n",
1302                          (long long) (rel.r_info >> 32),
1303                          (long long) sym.st_value, sym.st_name, name);
1304
1305                 shdr_idx = sym.st_shndx;
1306                 if (!bpf_object__relo_in_known_section(obj, shdr_idx)) {
1307                         pr_warning("Program '%s' contains unrecognized relo data pointing to section %u\n",
1308                                    prog->section_name, shdr_idx);
1309                         return -LIBBPF_ERRNO__RELOC;
1310                 }
1311
1312                 insn_idx = rel.r_offset / sizeof(struct bpf_insn);
1313                 pr_debug("relocation: insn_idx=%u\n", insn_idx);
1314
1315                 if (insns[insn_idx].code == (BPF_JMP | BPF_CALL)) {
1316                         if (insns[insn_idx].src_reg != BPF_PSEUDO_CALL) {
1317                                 pr_warning("incorrect bpf_call opcode\n");
1318                                 return -LIBBPF_ERRNO__RELOC;
1319                         }
1320                         prog->reloc_desc[i].type = RELO_CALL;
1321                         prog->reloc_desc[i].insn_idx = insn_idx;
1322                         prog->reloc_desc[i].text_off = sym.st_value;
1323                         obj->has_pseudo_calls = true;
1324                         continue;
1325                 }
1326
1327                 if (insns[insn_idx].code != (BPF_LD | BPF_IMM | BPF_DW)) {
1328                         pr_warning("bpf: relocation: invalid relo for insns[%d].code 0x%x\n",
1329                                    insn_idx, insns[insn_idx].code);
1330                         return -LIBBPF_ERRNO__RELOC;
1331                 }
1332
1333                 if (bpf_object__shndx_is_maps(obj, shdr_idx) ||
1334                     bpf_object__shndx_is_data(obj, shdr_idx)) {
1335                         type = bpf_object__section_to_libbpf_map_type(obj, shdr_idx);
1336                         if (type != LIBBPF_MAP_UNSPEC &&
1337                             GELF_ST_BIND(sym.st_info) == STB_GLOBAL) {
1338                                 pr_warning("bpf: relocation: not yet supported relo for non-static global \'%s\' variable found in insns[%d].code 0x%x\n",
1339                                            name, insn_idx, insns[insn_idx].code);
1340                                 return -LIBBPF_ERRNO__RELOC;
1341                         }
1342
1343                         for (map_idx = 0; map_idx < nr_maps; map_idx++) {
1344                                 if (maps[map_idx].libbpf_type != type)
1345                                         continue;
1346                                 if (type != LIBBPF_MAP_UNSPEC ||
1347                                     (type == LIBBPF_MAP_UNSPEC &&
1348                                      maps[map_idx].offset == sym.st_value)) {
1349                                         pr_debug("relocation: find map %zd (%s) for insn %u\n",
1350                                                  map_idx, maps[map_idx].name, insn_idx);
1351                                         break;
1352                                 }
1353                         }
1354
1355                         if (map_idx >= nr_maps) {
1356                                 pr_warning("bpf relocation: map_idx %d large than %d\n",
1357                                            (int)map_idx, (int)nr_maps - 1);
1358                                 return -LIBBPF_ERRNO__RELOC;
1359                         }
1360
1361                         prog->reloc_desc[i].type = type != LIBBPF_MAP_UNSPEC ?
1362                                                    RELO_DATA : RELO_LD64;
1363                         prog->reloc_desc[i].insn_idx = insn_idx;
1364                         prog->reloc_desc[i].map_idx = map_idx;
1365                 }
1366         }
1367         return 0;
1368 }
1369
1370 static int bpf_map_find_btf_info(struct bpf_map *map, const struct btf *btf)
1371 {
1372         struct bpf_map_def *def = &map->def;
1373         __u32 key_type_id = 0, value_type_id = 0;
1374         int ret;
1375
1376         if (!bpf_map__is_internal(map)) {
1377                 ret = btf__get_map_kv_tids(btf, map->name, def->key_size,
1378                                            def->value_size, &key_type_id,
1379                                            &value_type_id);
1380         } else {
1381                 /*
1382                  * LLVM annotates global data differently in BTF, that is,
1383                  * only as '.data', '.bss' or '.rodata'.
1384                  */
1385                 ret = btf__find_by_name(btf,
1386                                 libbpf_type_to_btf_name[map->libbpf_type]);
1387         }
1388         if (ret < 0)
1389                 return ret;
1390
1391         map->btf_key_type_id = key_type_id;
1392         map->btf_value_type_id = bpf_map__is_internal(map) ?
1393                                  ret : value_type_id;
1394         return 0;
1395 }
1396
1397 int bpf_map__reuse_fd(struct bpf_map *map, int fd)
1398 {
1399         struct bpf_map_info info = {};
1400         __u32 len = sizeof(info);
1401         int new_fd, err;
1402         char *new_name;
1403
1404         err = bpf_obj_get_info_by_fd(fd, &info, &len);
1405         if (err)
1406                 return err;
1407
1408         new_name = strdup(info.name);
1409         if (!new_name)
1410                 return -errno;
1411
1412         new_fd = open("/", O_RDONLY | O_CLOEXEC);
1413         if (new_fd < 0)
1414                 goto err_free_new_name;
1415
1416         new_fd = dup3(fd, new_fd, O_CLOEXEC);
1417         if (new_fd < 0)
1418                 goto err_close_new_fd;
1419
1420         err = zclose(map->fd);
1421         if (err)
1422                 goto err_close_new_fd;
1423         free(map->name);
1424
1425         map->fd = new_fd;
1426         map->name = new_name;
1427         map->def.type = info.type;
1428         map->def.key_size = info.key_size;
1429         map->def.value_size = info.value_size;
1430         map->def.max_entries = info.max_entries;
1431         map->def.map_flags = info.map_flags;
1432         map->btf_key_type_id = info.btf_key_type_id;
1433         map->btf_value_type_id = info.btf_value_type_id;
1434
1435         return 0;
1436
1437 err_close_new_fd:
1438         close(new_fd);
1439 err_free_new_name:
1440         free(new_name);
1441         return -errno;
1442 }
1443
1444 int bpf_map__resize(struct bpf_map *map, __u32 max_entries)
1445 {
1446         if (!map || !max_entries)
1447                 return -EINVAL;
1448
1449         /* If map already created, its attributes can't be changed. */
1450         if (map->fd >= 0)
1451                 return -EBUSY;
1452
1453         map->def.max_entries = max_entries;
1454
1455         return 0;
1456 }
1457
1458 static int
1459 bpf_object__probe_name(struct bpf_object *obj)
1460 {
1461         struct bpf_load_program_attr attr;
1462         char *cp, errmsg[STRERR_BUFSIZE];
1463         struct bpf_insn insns[] = {
1464                 BPF_MOV64_IMM(BPF_REG_0, 0),
1465                 BPF_EXIT_INSN(),
1466         };
1467         int ret;
1468
1469         /* make sure basic loading works */
1470
1471         memset(&attr, 0, sizeof(attr));
1472         attr.prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
1473         attr.insns = insns;
1474         attr.insns_cnt = ARRAY_SIZE(insns);
1475         attr.license = "GPL";
1476
1477         ret = bpf_load_program_xattr(&attr, NULL, 0);
1478         if (ret < 0) {
1479                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1480                 pr_warning("Error in %s():%s(%d). Couldn't load basic 'r0 = 0' BPF program.\n",
1481                            __func__, cp, errno);
1482                 return -errno;
1483         }
1484         close(ret);
1485
1486         /* now try the same program, but with the name */
1487
1488         attr.name = "test";
1489         ret = bpf_load_program_xattr(&attr, NULL, 0);
1490         if (ret >= 0) {
1491                 obj->caps.name = 1;
1492                 close(ret);
1493         }
1494
1495         return 0;
1496 }
1497
1498 static int
1499 bpf_object__probe_caps(struct bpf_object *obj)
1500 {
1501         return bpf_object__probe_name(obj);
1502 }
1503
1504 static int
1505 bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
1506 {
1507         char *cp, errmsg[STRERR_BUFSIZE];
1508         int err, zero = 0;
1509         __u8 *data;
1510
1511         /* Nothing to do here since kernel already zero-initializes .bss map. */
1512         if (map->libbpf_type == LIBBPF_MAP_BSS)
1513                 return 0;
1514
1515         data = map->libbpf_type == LIBBPF_MAP_DATA ?
1516                obj->sections.data : obj->sections.rodata;
1517
1518         err = bpf_map_update_elem(map->fd, &zero, data, 0);
1519         /* Freeze .rodata map as read-only from syscall side. */
1520         if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
1521                 err = bpf_map_freeze(map->fd);
1522                 if (err) {
1523                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1524                         pr_warning("Error freezing map(%s) as read-only: %s\n",
1525                                    map->name, cp);
1526                         err = 0;
1527                 }
1528         }
1529         return err;
1530 }
1531
1532 static int
1533 bpf_object__create_maps(struct bpf_object *obj)
1534 {
1535         struct bpf_create_map_attr create_attr = {};
1536         unsigned int i;
1537         int err;
1538
1539         for (i = 0; i < obj->nr_maps; i++) {
1540                 struct bpf_map *map = &obj->maps[i];
1541                 struct bpf_map_def *def = &map->def;
1542                 char *cp, errmsg[STRERR_BUFSIZE];
1543                 int *pfd = &map->fd;
1544
1545                 if (map->fd >= 0) {
1546                         pr_debug("skip map create (preset) %s: fd=%d\n",
1547                                  map->name, map->fd);
1548                         continue;
1549                 }
1550
1551                 if (obj->caps.name)
1552                         create_attr.name = map->name;
1553                 create_attr.map_ifindex = map->map_ifindex;
1554                 create_attr.map_type = def->type;
1555                 create_attr.map_flags = def->map_flags;
1556                 create_attr.key_size = def->key_size;
1557                 create_attr.value_size = def->value_size;
1558                 create_attr.max_entries = def->max_entries;
1559                 create_attr.btf_fd = 0;
1560                 create_attr.btf_key_type_id = 0;
1561                 create_attr.btf_value_type_id = 0;
1562                 if (bpf_map_type__is_map_in_map(def->type) &&
1563                     map->inner_map_fd >= 0)
1564                         create_attr.inner_map_fd = map->inner_map_fd;
1565
1566                 if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) {
1567                         create_attr.btf_fd = btf__fd(obj->btf);
1568                         create_attr.btf_key_type_id = map->btf_key_type_id;
1569                         create_attr.btf_value_type_id = map->btf_value_type_id;
1570                 }
1571
1572                 *pfd = bpf_create_map_xattr(&create_attr);
1573                 if (*pfd < 0 && create_attr.btf_key_type_id) {
1574                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1575                         pr_warning("Error in bpf_create_map_xattr(%s):%s(%d). Retrying without BTF.\n",
1576                                    map->name, cp, errno);
1577                         create_attr.btf_fd = 0;
1578                         create_attr.btf_key_type_id = 0;
1579                         create_attr.btf_value_type_id = 0;
1580                         map->btf_key_type_id = 0;
1581                         map->btf_value_type_id = 0;
1582                         *pfd = bpf_create_map_xattr(&create_attr);
1583                 }
1584
1585                 if (*pfd < 0) {
1586                         size_t j;
1587
1588                         err = *pfd;
1589 err_out:
1590                         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1591                         pr_warning("failed to create map (name: '%s'): %s\n",
1592                                    map->name, cp);
1593                         for (j = 0; j < i; j++)
1594                                 zclose(obj->maps[j].fd);
1595                         return err;
1596                 }
1597
1598                 if (bpf_map__is_internal(map)) {
1599                         err = bpf_object__populate_internal_map(obj, map);
1600                         if (err < 0) {
1601                                 zclose(*pfd);
1602                                 goto err_out;
1603                         }
1604                 }
1605
1606                 pr_debug("create map %s: fd=%d\n", map->name, *pfd);
1607         }
1608
1609         return 0;
1610 }
1611
1612 static int
1613 check_btf_ext_reloc_err(struct bpf_program *prog, int err,
1614                         void *btf_prog_info, const char *info_name)
1615 {
1616         if (err != -ENOENT) {
1617                 pr_warning("Error in loading %s for sec %s.\n",
1618                            info_name, prog->section_name);
1619                 return err;
1620         }
1621
1622         /* err == -ENOENT (i.e. prog->section_name not found in btf_ext) */
1623
1624         if (btf_prog_info) {
1625                 /*
1626                  * Some info has already been found but has problem
1627                  * in the last btf_ext reloc.  Must have to error
1628                  * out.
1629                  */
1630                 pr_warning("Error in relocating %s for sec %s.\n",
1631                            info_name, prog->section_name);
1632                 return err;
1633         }
1634
1635         /*
1636          * Have problem loading the very first info.  Ignore
1637          * the rest.
1638          */
1639         pr_warning("Cannot find %s for main program sec %s. Ignore all %s.\n",
1640                    info_name, prog->section_name, info_name);
1641         return 0;
1642 }
1643
1644 static int
1645 bpf_program_reloc_btf_ext(struct bpf_program *prog, struct bpf_object *obj,
1646                           const char *section_name,  __u32 insn_offset)
1647 {
1648         int err;
1649
1650         if (!insn_offset || prog->func_info) {
1651                 /*
1652                  * !insn_offset => main program
1653                  *
1654                  * For sub prog, the main program's func_info has to
1655                  * be loaded first (i.e. prog->func_info != NULL)
1656                  */
1657                 err = btf_ext__reloc_func_info(obj->btf, obj->btf_ext,
1658                                                section_name, insn_offset,
1659                                                &prog->func_info,
1660                                                &prog->func_info_cnt);
1661                 if (err)
1662                         return check_btf_ext_reloc_err(prog, err,
1663                                                        prog->func_info,
1664                                                        "bpf_func_info");
1665
1666                 prog->func_info_rec_size = btf_ext__func_info_rec_size(obj->btf_ext);
1667         }
1668
1669         if (!insn_offset || prog->line_info) {
1670                 err = btf_ext__reloc_line_info(obj->btf, obj->btf_ext,
1671                                                section_name, insn_offset,
1672                                                &prog->line_info,
1673                                                &prog->line_info_cnt);
1674                 if (err)
1675                         return check_btf_ext_reloc_err(prog, err,
1676                                                        prog->line_info,
1677                                                        "bpf_line_info");
1678
1679                 prog->line_info_rec_size = btf_ext__line_info_rec_size(obj->btf_ext);
1680         }
1681
1682         if (!insn_offset)
1683                 prog->btf_fd = btf__fd(obj->btf);
1684
1685         return 0;
1686 }
1687
1688 static int
1689 bpf_program__reloc_text(struct bpf_program *prog, struct bpf_object *obj,
1690                         struct reloc_desc *relo)
1691 {
1692         struct bpf_insn *insn, *new_insn;
1693         struct bpf_program *text;
1694         size_t new_cnt;
1695         int err;
1696
1697         if (relo->type != RELO_CALL)
1698                 return -LIBBPF_ERRNO__RELOC;
1699
1700         if (prog->idx == obj->efile.text_shndx) {
1701                 pr_warning("relo in .text insn %d into off %d\n",
1702                            relo->insn_idx, relo->text_off);
1703                 return -LIBBPF_ERRNO__RELOC;
1704         }
1705
1706         if (prog->main_prog_cnt == 0) {
1707                 text = bpf_object__find_prog_by_idx(obj, obj->efile.text_shndx);
1708                 if (!text) {
1709                         pr_warning("no .text section found yet relo into text exist\n");
1710                         return -LIBBPF_ERRNO__RELOC;
1711                 }
1712                 new_cnt = prog->insns_cnt + text->insns_cnt;
1713                 new_insn = reallocarray(prog->insns, new_cnt, sizeof(*insn));
1714                 if (!new_insn) {
1715                         pr_warning("oom in prog realloc\n");
1716                         return -ENOMEM;
1717                 }
1718
1719                 if (obj->btf_ext) {
1720                         err = bpf_program_reloc_btf_ext(prog, obj,
1721                                                         text->section_name,
1722                                                         prog->insns_cnt);
1723                         if (err)
1724                                 return err;
1725                 }
1726
1727                 memcpy(new_insn + prog->insns_cnt, text->insns,
1728                        text->insns_cnt * sizeof(*insn));
1729                 prog->insns = new_insn;
1730                 prog->main_prog_cnt = prog->insns_cnt;
1731                 prog->insns_cnt = new_cnt;
1732                 pr_debug("added %zd insn from %s to prog %s\n",
1733                          text->insns_cnt, text->section_name,
1734                          prog->section_name);
1735         }
1736         insn = &prog->insns[relo->insn_idx];
1737         insn->imm += prog->main_prog_cnt - relo->insn_idx;
1738         return 0;
1739 }
1740
1741 static int
1742 bpf_program__relocate(struct bpf_program *prog, struct bpf_object *obj)
1743 {
1744         int i, err;
1745
1746         if (!prog)
1747                 return 0;
1748
1749         if (obj->btf_ext) {
1750                 err = bpf_program_reloc_btf_ext(prog, obj,
1751                                                 prog->section_name, 0);
1752                 if (err)
1753                         return err;
1754         }
1755
1756         if (!prog->reloc_desc)
1757                 return 0;
1758
1759         for (i = 0; i < prog->nr_reloc; i++) {
1760                 if (prog->reloc_desc[i].type == RELO_LD64 ||
1761                     prog->reloc_desc[i].type == RELO_DATA) {
1762                         bool relo_data = prog->reloc_desc[i].type == RELO_DATA;
1763                         struct bpf_insn *insns = prog->insns;
1764                         int insn_idx, map_idx;
1765
1766                         insn_idx = prog->reloc_desc[i].insn_idx;
1767                         map_idx = prog->reloc_desc[i].map_idx;
1768
1769                         if (insn_idx + 1 >= (int)prog->insns_cnt) {
1770                                 pr_warning("relocation out of range: '%s'\n",
1771                                            prog->section_name);
1772                                 return -LIBBPF_ERRNO__RELOC;
1773                         }
1774
1775                         if (!relo_data) {
1776                                 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_FD;
1777                         } else {
1778                                 insns[insn_idx].src_reg = BPF_PSEUDO_MAP_VALUE;
1779                                 insns[insn_idx + 1].imm = insns[insn_idx].imm;
1780                         }
1781                         insns[insn_idx].imm = obj->maps[map_idx].fd;
1782                 } else if (prog->reloc_desc[i].type == RELO_CALL) {
1783                         err = bpf_program__reloc_text(prog, obj,
1784                                                       &prog->reloc_desc[i]);
1785                         if (err)
1786                                 return err;
1787                 }
1788         }
1789
1790         zfree(&prog->reloc_desc);
1791         prog->nr_reloc = 0;
1792         return 0;
1793 }
1794
1795
1796 static int
1797 bpf_object__relocate(struct bpf_object *obj)
1798 {
1799         struct bpf_program *prog;
1800         size_t i;
1801         int err;
1802
1803         for (i = 0; i < obj->nr_programs; i++) {
1804                 prog = &obj->programs[i];
1805
1806                 err = bpf_program__relocate(prog, obj);
1807                 if (err) {
1808                         pr_warning("failed to relocate '%s'\n",
1809                                    prog->section_name);
1810                         return err;
1811                 }
1812         }
1813         return 0;
1814 }
1815
1816 static int bpf_object__collect_reloc(struct bpf_object *obj)
1817 {
1818         int i, err;
1819
1820         if (!obj_elf_valid(obj)) {
1821                 pr_warning("Internal error: elf object is closed\n");
1822                 return -LIBBPF_ERRNO__INTERNAL;
1823         }
1824
1825         for (i = 0; i < obj->efile.nr_reloc; i++) {
1826                 GElf_Shdr *shdr = &obj->efile.reloc[i].shdr;
1827                 Elf_Data *data = obj->efile.reloc[i].data;
1828                 int idx = shdr->sh_info;
1829                 struct bpf_program *prog;
1830
1831                 if (shdr->sh_type != SHT_REL) {
1832                         pr_warning("internal error at %d\n", __LINE__);
1833                         return -LIBBPF_ERRNO__INTERNAL;
1834                 }
1835
1836                 prog = bpf_object__find_prog_by_idx(obj, idx);
1837                 if (!prog) {
1838                         pr_warning("relocation failed: no section(%d)\n", idx);
1839                         return -LIBBPF_ERRNO__RELOC;
1840                 }
1841
1842                 err = bpf_program__collect_reloc(prog,
1843                                                  shdr, data,
1844                                                  obj);
1845                 if (err)
1846                         return err;
1847         }
1848         return 0;
1849 }
1850
1851 static int
1852 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
1853              char *license, __u32 kern_version, int *pfd)
1854 {
1855         struct bpf_load_program_attr load_attr;
1856         char *cp, errmsg[STRERR_BUFSIZE];
1857         int log_buf_size = BPF_LOG_BUF_SIZE;
1858         char *log_buf;
1859         int ret;
1860
1861         memset(&load_attr, 0, sizeof(struct bpf_load_program_attr));
1862         load_attr.prog_type = prog->type;
1863         load_attr.expected_attach_type = prog->expected_attach_type;
1864         if (prog->caps->name)
1865                 load_attr.name = prog->name;
1866         load_attr.insns = insns;
1867         load_attr.insns_cnt = insns_cnt;
1868         load_attr.license = license;
1869         load_attr.kern_version = kern_version;
1870         load_attr.prog_ifindex = prog->prog_ifindex;
1871         load_attr.prog_btf_fd = prog->btf_fd >= 0 ? prog->btf_fd : 0;
1872         load_attr.func_info = prog->func_info;
1873         load_attr.func_info_rec_size = prog->func_info_rec_size;
1874         load_attr.func_info_cnt = prog->func_info_cnt;
1875         load_attr.line_info = prog->line_info;
1876         load_attr.line_info_rec_size = prog->line_info_rec_size;
1877         load_attr.line_info_cnt = prog->line_info_cnt;
1878         load_attr.log_level = prog->log_level;
1879         if (!load_attr.insns || !load_attr.insns_cnt)
1880                 return -EINVAL;
1881
1882 retry_load:
1883         log_buf = malloc(log_buf_size);
1884         if (!log_buf)
1885                 pr_warning("Alloc log buffer for bpf loader error, continue without log\n");
1886
1887         ret = bpf_load_program_xattr(&load_attr, log_buf, log_buf_size);
1888
1889         if (ret >= 0) {
1890                 if (load_attr.log_level)
1891                         pr_debug("verifier log:\n%s", log_buf);
1892                 *pfd = ret;
1893                 ret = 0;
1894                 goto out;
1895         }
1896
1897         if (errno == ENOSPC) {
1898                 log_buf_size <<= 1;
1899                 free(log_buf);
1900                 goto retry_load;
1901         }
1902         ret = -LIBBPF_ERRNO__LOAD;
1903         cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
1904         pr_warning("load bpf program failed: %s\n", cp);
1905
1906         if (log_buf && log_buf[0] != '\0') {
1907                 ret = -LIBBPF_ERRNO__VERIFY;
1908                 pr_warning("-- BEGIN DUMP LOG ---\n");
1909                 pr_warning("\n%s\n", log_buf);
1910                 pr_warning("-- END LOG --\n");
1911         } else if (load_attr.insns_cnt >= BPF_MAXINSNS) {
1912                 pr_warning("Program too large (%zu insns), at most %d insns\n",
1913                            load_attr.insns_cnt, BPF_MAXINSNS);
1914                 ret = -LIBBPF_ERRNO__PROG2BIG;
1915         } else {
1916                 /* Wrong program type? */
1917                 if (load_attr.prog_type != BPF_PROG_TYPE_KPROBE) {
1918                         int fd;
1919
1920                         load_attr.prog_type = BPF_PROG_TYPE_KPROBE;
1921                         load_attr.expected_attach_type = 0;
1922                         fd = bpf_load_program_xattr(&load_attr, NULL, 0);
1923                         if (fd >= 0) {
1924                                 close(fd);
1925                                 ret = -LIBBPF_ERRNO__PROGTYPE;
1926                                 goto out;
1927                         }
1928                 }
1929
1930                 if (log_buf)
1931                         ret = -LIBBPF_ERRNO__KVER;
1932         }
1933
1934 out:
1935         free(log_buf);
1936         return ret;
1937 }
1938
1939 int
1940 bpf_program__load(struct bpf_program *prog,
1941                   char *license, __u32 kern_version)
1942 {
1943         int err = 0, fd, i;
1944
1945         if (prog->instances.nr < 0 || !prog->instances.fds) {
1946                 if (prog->preprocessor) {
1947                         pr_warning("Internal error: can't load program '%s'\n",
1948                                    prog->section_name);
1949                         return -LIBBPF_ERRNO__INTERNAL;
1950                 }
1951
1952                 prog->instances.fds = malloc(sizeof(int));
1953                 if (!prog->instances.fds) {
1954                         pr_warning("Not enough memory for BPF fds\n");
1955                         return -ENOMEM;
1956                 }
1957                 prog->instances.nr = 1;
1958                 prog->instances.fds[0] = -1;
1959         }
1960
1961         if (!prog->preprocessor) {
1962                 if (prog->instances.nr != 1) {
1963                         pr_warning("Program '%s' is inconsistent: nr(%d) != 1\n",
1964                                    prog->section_name, prog->instances.nr);
1965                 }
1966                 err = load_program(prog, prog->insns, prog->insns_cnt,
1967                                    license, kern_version, &fd);
1968                 if (!err)
1969                         prog->instances.fds[0] = fd;
1970                 goto out;
1971         }
1972
1973         for (i = 0; i < prog->instances.nr; i++) {
1974                 struct bpf_prog_prep_result result;
1975                 bpf_program_prep_t preprocessor = prog->preprocessor;
1976
1977                 memset(&result, 0, sizeof(result));
1978                 err = preprocessor(prog, i, prog->insns,
1979                                    prog->insns_cnt, &result);
1980                 if (err) {
1981                         pr_warning("Preprocessing the %dth instance of program '%s' failed\n",
1982                                    i, prog->section_name);
1983                         goto out;
1984                 }
1985
1986                 if (!result.new_insn_ptr || !result.new_insn_cnt) {
1987                         pr_debug("Skip loading the %dth instance of program '%s'\n",
1988                                  i, prog->section_name);
1989                         prog->instances.fds[i] = -1;
1990                         if (result.pfd)
1991                                 *result.pfd = -1;
1992                         continue;
1993                 }
1994
1995                 err = load_program(prog, result.new_insn_ptr,
1996                                    result.new_insn_cnt,
1997                                    license, kern_version, &fd);
1998
1999                 if (err) {
2000                         pr_warning("Loading the %dth instance of program '%s' failed\n",
2001                                         i, prog->section_name);
2002                         goto out;
2003                 }
2004
2005                 if (result.pfd)
2006                         *result.pfd = fd;
2007                 prog->instances.fds[i] = fd;
2008         }
2009 out:
2010         if (err)
2011                 pr_warning("failed to load program '%s'\n",
2012                            prog->section_name);
2013         zfree(&prog->insns);
2014         prog->insns_cnt = 0;
2015         return err;
2016 }
2017
2018 static bool bpf_program__is_function_storage(struct bpf_program *prog,
2019                                              struct bpf_object *obj)
2020 {
2021         return prog->idx == obj->efile.text_shndx && obj->has_pseudo_calls;
2022 }
2023
2024 static int
2025 bpf_object__load_progs(struct bpf_object *obj)
2026 {
2027         size_t i;
2028         int err;
2029
2030         for (i = 0; i < obj->nr_programs; i++) {
2031                 if (bpf_program__is_function_storage(&obj->programs[i], obj))
2032                         continue;
2033                 err = bpf_program__load(&obj->programs[i],
2034                                         obj->license,
2035                                         obj->kern_version);
2036                 if (err)
2037                         return err;
2038         }
2039         return 0;
2040 }
2041
2042 static bool bpf_prog_type__needs_kver(enum bpf_prog_type type)
2043 {
2044         switch (type) {
2045         case BPF_PROG_TYPE_SOCKET_FILTER:
2046         case BPF_PROG_TYPE_SCHED_CLS:
2047         case BPF_PROG_TYPE_SCHED_ACT:
2048         case BPF_PROG_TYPE_XDP:
2049         case BPF_PROG_TYPE_CGROUP_SKB:
2050         case BPF_PROG_TYPE_CGROUP_SOCK:
2051         case BPF_PROG_TYPE_LWT_IN:
2052         case BPF_PROG_TYPE_LWT_OUT:
2053         case BPF_PROG_TYPE_LWT_XMIT:
2054         case BPF_PROG_TYPE_LWT_SEG6LOCAL:
2055         case BPF_PROG_TYPE_SOCK_OPS:
2056         case BPF_PROG_TYPE_SK_SKB:
2057         case BPF_PROG_TYPE_CGROUP_DEVICE:
2058         case BPF_PROG_TYPE_SK_MSG:
2059         case BPF_PROG_TYPE_CGROUP_SOCK_ADDR:
2060         case BPF_PROG_TYPE_LIRC_MODE2:
2061         case BPF_PROG_TYPE_SK_REUSEPORT:
2062         case BPF_PROG_TYPE_FLOW_DISSECTOR:
2063         case BPF_PROG_TYPE_UNSPEC:
2064         case BPF_PROG_TYPE_TRACEPOINT:
2065         case BPF_PROG_TYPE_RAW_TRACEPOINT:
2066         case BPF_PROG_TYPE_PERF_EVENT:
2067                 return false;
2068         case BPF_PROG_TYPE_KPROBE:
2069         default:
2070                 return true;
2071         }
2072 }
2073
2074 static int bpf_object__validate(struct bpf_object *obj, bool needs_kver)
2075 {
2076         if (needs_kver && obj->kern_version == 0) {
2077                 pr_warning("%s doesn't provide kernel version\n",
2078                            obj->path);
2079                 return -LIBBPF_ERRNO__KVERSION;
2080         }
2081         return 0;
2082 }
2083
2084 static struct bpf_object *
2085 __bpf_object__open(const char *path, void *obj_buf, size_t obj_buf_sz,
2086                    bool needs_kver, int flags)
2087 {
2088         struct bpf_object *obj;
2089         int err;
2090
2091         if (elf_version(EV_CURRENT) == EV_NONE) {
2092                 pr_warning("failed to init libelf for %s\n", path);
2093                 return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
2094         }
2095
2096         obj = bpf_object__new(path, obj_buf, obj_buf_sz);
2097         if (IS_ERR(obj))
2098                 return obj;
2099
2100         CHECK_ERR(bpf_object__elf_init(obj), err, out);
2101         CHECK_ERR(bpf_object__check_endianness(obj), err, out);
2102         CHECK_ERR(bpf_object__elf_collect(obj, flags), err, out);
2103         CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
2104         CHECK_ERR(bpf_object__validate(obj, needs_kver), err, out);
2105
2106         bpf_object__elf_finish(obj);
2107         return obj;
2108 out:
2109         bpf_object__close(obj);
2110         return ERR_PTR(err);
2111 }
2112
2113 struct bpf_object *__bpf_object__open_xattr(struct bpf_object_open_attr *attr,
2114                                             int flags)
2115 {
2116         /* param validation */
2117         if (!attr->file)
2118                 return NULL;
2119
2120         pr_debug("loading %s\n", attr->file);
2121
2122         return __bpf_object__open(attr->file, NULL, 0,
2123                                   bpf_prog_type__needs_kver(attr->prog_type),
2124                                   flags);
2125 }
2126
2127 struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr)
2128 {
2129         return __bpf_object__open_xattr(attr, 0);
2130 }
2131
2132 struct bpf_object *bpf_object__open(const char *path)
2133 {
2134         struct bpf_object_open_attr attr = {
2135                 .file           = path,
2136                 .prog_type      = BPF_PROG_TYPE_UNSPEC,
2137         };
2138
2139         return bpf_object__open_xattr(&attr);
2140 }
2141
2142 struct bpf_object *bpf_object__open_buffer(void *obj_buf,
2143                                            size_t obj_buf_sz,
2144                                            const char *name)
2145 {
2146         char tmp_name[64];
2147
2148         /* param validation */
2149         if (!obj_buf || obj_buf_sz <= 0)
2150                 return NULL;
2151
2152         if (!name) {
2153                 snprintf(tmp_name, sizeof(tmp_name), "%lx-%lx",
2154                          (unsigned long)obj_buf,
2155                          (unsigned long)obj_buf_sz);
2156                 tmp_name[sizeof(tmp_name) - 1] = '\0';
2157                 name = tmp_name;
2158         }
2159         pr_debug("loading object '%s' from buffer\n",
2160                  name);
2161
2162         return __bpf_object__open(name, obj_buf, obj_buf_sz, true, true);
2163 }
2164
2165 int bpf_object__unload(struct bpf_object *obj)
2166 {
2167         size_t i;
2168
2169         if (!obj)
2170                 return -EINVAL;
2171
2172         for (i = 0; i < obj->nr_maps; i++)
2173                 zclose(obj->maps[i].fd);
2174
2175         for (i = 0; i < obj->nr_programs; i++)
2176                 bpf_program__unload(&obj->programs[i]);
2177
2178         return 0;
2179 }
2180
2181 int bpf_object__load(struct bpf_object *obj)
2182 {
2183         int err;
2184
2185         if (!obj)
2186                 return -EINVAL;
2187
2188         if (obj->loaded) {
2189                 pr_warning("object should not be loaded twice\n");
2190                 return -EINVAL;
2191         }
2192
2193         obj->loaded = true;
2194
2195         CHECK_ERR(bpf_object__probe_caps(obj), err, out);
2196         CHECK_ERR(bpf_object__create_maps(obj), err, out);
2197         CHECK_ERR(bpf_object__relocate(obj), err, out);
2198         CHECK_ERR(bpf_object__load_progs(obj), err, out);
2199
2200         return 0;
2201 out:
2202         bpf_object__unload(obj);
2203         pr_warning("failed to load object '%s'\n", obj->path);
2204         return err;
2205 }
2206
2207 static int check_path(const char *path)
2208 {
2209         char *cp, errmsg[STRERR_BUFSIZE];
2210         struct statfs st_fs;
2211         char *dname, *dir;
2212         int err = 0;
2213
2214         if (path == NULL)
2215                 return -EINVAL;
2216
2217         dname = strdup(path);
2218         if (dname == NULL)
2219                 return -ENOMEM;
2220
2221         dir = dirname(dname);
2222         if (statfs(dir, &st_fs)) {
2223                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2224                 pr_warning("failed to statfs %s: %s\n", dir, cp);
2225                 err = -errno;
2226         }
2227         free(dname);
2228
2229         if (!err && st_fs.f_type != BPF_FS_MAGIC) {
2230                 pr_warning("specified path %s is not on BPF FS\n", path);
2231                 err = -EINVAL;
2232         }
2233
2234         return err;
2235 }
2236
2237 int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
2238                               int instance)
2239 {
2240         char *cp, errmsg[STRERR_BUFSIZE];
2241         int err;
2242
2243         err = check_path(path);
2244         if (err)
2245                 return err;
2246
2247         if (prog == NULL) {
2248                 pr_warning("invalid program pointer\n");
2249                 return -EINVAL;
2250         }
2251
2252         if (instance < 0 || instance >= prog->instances.nr) {
2253                 pr_warning("invalid prog instance %d of prog %s (max %d)\n",
2254                            instance, prog->section_name, prog->instances.nr);
2255                 return -EINVAL;
2256         }
2257
2258         if (bpf_obj_pin(prog->instances.fds[instance], path)) {
2259                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2260                 pr_warning("failed to pin program: %s\n", cp);
2261                 return -errno;
2262         }
2263         pr_debug("pinned program '%s'\n", path);
2264
2265         return 0;
2266 }
2267
2268 int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
2269                                 int instance)
2270 {
2271         int err;
2272
2273         err = check_path(path);
2274         if (err)
2275                 return err;
2276
2277         if (prog == NULL) {
2278                 pr_warning("invalid program pointer\n");
2279                 return -EINVAL;
2280         }
2281
2282         if (instance < 0 || instance >= prog->instances.nr) {
2283                 pr_warning("invalid prog instance %d of prog %s (max %d)\n",
2284                            instance, prog->section_name, prog->instances.nr);
2285                 return -EINVAL;
2286         }
2287
2288         err = unlink(path);
2289         if (err != 0)
2290                 return -errno;
2291         pr_debug("unpinned program '%s'\n", path);
2292
2293         return 0;
2294 }
2295
2296 static int make_dir(const char *path)
2297 {
2298         char *cp, errmsg[STRERR_BUFSIZE];
2299         int err = 0;
2300
2301         if (mkdir(path, 0700) && errno != EEXIST)
2302                 err = -errno;
2303
2304         if (err) {
2305                 cp = libbpf_strerror_r(-err, errmsg, sizeof(errmsg));
2306                 pr_warning("failed to mkdir %s: %s\n", path, cp);
2307         }
2308         return err;
2309 }
2310
2311 int bpf_program__pin(struct bpf_program *prog, const char *path)
2312 {
2313         int i, err;
2314
2315         err = check_path(path);
2316         if (err)
2317                 return err;
2318
2319         if (prog == NULL) {
2320                 pr_warning("invalid program pointer\n");
2321                 return -EINVAL;
2322         }
2323
2324         if (prog->instances.nr <= 0) {
2325                 pr_warning("no instances of prog %s to pin\n",
2326                            prog->section_name);
2327                 return -EINVAL;
2328         }
2329
2330         if (prog->instances.nr == 1) {
2331                 /* don't create subdirs when pinning single instance */
2332                 return bpf_program__pin_instance(prog, path, 0);
2333         }
2334
2335         err = make_dir(path);
2336         if (err)
2337                 return err;
2338
2339         for (i = 0; i < prog->instances.nr; i++) {
2340                 char buf[PATH_MAX];
2341                 int len;
2342
2343                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2344                 if (len < 0) {
2345                         err = -EINVAL;
2346                         goto err_unpin;
2347                 } else if (len >= PATH_MAX) {
2348                         err = -ENAMETOOLONG;
2349                         goto err_unpin;
2350                 }
2351
2352                 err = bpf_program__pin_instance(prog, buf, i);
2353                 if (err)
2354                         goto err_unpin;
2355         }
2356
2357         return 0;
2358
2359 err_unpin:
2360         for (i = i - 1; i >= 0; i--) {
2361                 char buf[PATH_MAX];
2362                 int len;
2363
2364                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2365                 if (len < 0)
2366                         continue;
2367                 else if (len >= PATH_MAX)
2368                         continue;
2369
2370                 bpf_program__unpin_instance(prog, buf, i);
2371         }
2372
2373         rmdir(path);
2374
2375         return err;
2376 }
2377
2378 int bpf_program__unpin(struct bpf_program *prog, const char *path)
2379 {
2380         int i, err;
2381
2382         err = check_path(path);
2383         if (err)
2384                 return err;
2385
2386         if (prog == NULL) {
2387                 pr_warning("invalid program pointer\n");
2388                 return -EINVAL;
2389         }
2390
2391         if (prog->instances.nr <= 0) {
2392                 pr_warning("no instances of prog %s to pin\n",
2393                            prog->section_name);
2394                 return -EINVAL;
2395         }
2396
2397         if (prog->instances.nr == 1) {
2398                 /* don't create subdirs when pinning single instance */
2399                 return bpf_program__unpin_instance(prog, path, 0);
2400         }
2401
2402         for (i = 0; i < prog->instances.nr; i++) {
2403                 char buf[PATH_MAX];
2404                 int len;
2405
2406                 len = snprintf(buf, PATH_MAX, "%s/%d", path, i);
2407                 if (len < 0)
2408                         return -EINVAL;
2409                 else if (len >= PATH_MAX)
2410                         return -ENAMETOOLONG;
2411
2412                 err = bpf_program__unpin_instance(prog, buf, i);
2413                 if (err)
2414                         return err;
2415         }
2416
2417         err = rmdir(path);
2418         if (err)
2419                 return -errno;
2420
2421         return 0;
2422 }
2423
2424 int bpf_map__pin(struct bpf_map *map, const char *path)
2425 {
2426         char *cp, errmsg[STRERR_BUFSIZE];
2427         int err;
2428
2429         err = check_path(path);
2430         if (err)
2431                 return err;
2432
2433         if (map == NULL) {
2434                 pr_warning("invalid map pointer\n");
2435                 return -EINVAL;
2436         }
2437
2438         if (bpf_obj_pin(map->fd, path)) {
2439                 cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
2440                 pr_warning("failed to pin map: %s\n", cp);
2441                 return -errno;
2442         }
2443
2444         pr_debug("pinned map '%s'\n", path);
2445
2446         return 0;
2447 }
2448
2449 int bpf_map__unpin(struct bpf_map *map, const char *path)
2450 {
2451         int err;
2452
2453         err = check_path(path);
2454         if (err)
2455                 return err;
2456
2457         if (map == NULL) {
2458                 pr_warning("invalid map pointer\n");
2459                 return -EINVAL;
2460         }
2461
2462         err = unlink(path);
2463         if (err != 0)
2464                 return -errno;
2465         pr_debug("unpinned map '%s'\n", path);
2466
2467         return 0;
2468 }
2469
2470 int bpf_object__pin_maps(struct bpf_object *obj, const char *path)
2471 {
2472         struct bpf_map *map;
2473         int err;
2474
2475         if (!obj)
2476                 return -ENOENT;
2477
2478         if (!obj->loaded) {
2479                 pr_warning("object not yet loaded; load it first\n");
2480                 return -ENOENT;
2481         }
2482
2483         err = make_dir(path);
2484         if (err)
2485                 return err;
2486
2487         bpf_object__for_each_map(map, obj) {
2488                 char buf[PATH_MAX];
2489                 int len;
2490
2491                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2492                                bpf_map__name(map));
2493                 if (len < 0) {
2494                         err = -EINVAL;
2495                         goto err_unpin_maps;
2496                 } else if (len >= PATH_MAX) {
2497                         err = -ENAMETOOLONG;
2498                         goto err_unpin_maps;
2499                 }
2500
2501                 err = bpf_map__pin(map, buf);
2502                 if (err)
2503                         goto err_unpin_maps;
2504         }
2505
2506         return 0;
2507
2508 err_unpin_maps:
2509         while ((map = bpf_map__prev(map, obj))) {
2510                 char buf[PATH_MAX];
2511                 int len;
2512
2513                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2514                                bpf_map__name(map));
2515                 if (len < 0)
2516                         continue;
2517                 else if (len >= PATH_MAX)
2518                         continue;
2519
2520                 bpf_map__unpin(map, buf);
2521         }
2522
2523         return err;
2524 }
2525
2526 int bpf_object__unpin_maps(struct bpf_object *obj, const char *path)
2527 {
2528         struct bpf_map *map;
2529         int err;
2530
2531         if (!obj)
2532                 return -ENOENT;
2533
2534         bpf_object__for_each_map(map, obj) {
2535                 char buf[PATH_MAX];
2536                 int len;
2537
2538                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2539                                bpf_map__name(map));
2540                 if (len < 0)
2541                         return -EINVAL;
2542                 else if (len >= PATH_MAX)
2543                         return -ENAMETOOLONG;
2544
2545                 err = bpf_map__unpin(map, buf);
2546                 if (err)
2547                         return err;
2548         }
2549
2550         return 0;
2551 }
2552
2553 int bpf_object__pin_programs(struct bpf_object *obj, const char *path)
2554 {
2555         struct bpf_program *prog;
2556         int err;
2557
2558         if (!obj)
2559                 return -ENOENT;
2560
2561         if (!obj->loaded) {
2562                 pr_warning("object not yet loaded; load it first\n");
2563                 return -ENOENT;
2564         }
2565
2566         err = make_dir(path);
2567         if (err)
2568                 return err;
2569
2570         bpf_object__for_each_program(prog, obj) {
2571                 char buf[PATH_MAX];
2572                 int len;
2573
2574                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2575                                prog->pin_name);
2576                 if (len < 0) {
2577                         err = -EINVAL;
2578                         goto err_unpin_programs;
2579                 } else if (len >= PATH_MAX) {
2580                         err = -ENAMETOOLONG;
2581                         goto err_unpin_programs;
2582                 }
2583
2584                 err = bpf_program__pin(prog, buf);
2585                 if (err)
2586                         goto err_unpin_programs;
2587         }
2588
2589         return 0;
2590
2591 err_unpin_programs:
2592         while ((prog = bpf_program__prev(prog, obj))) {
2593                 char buf[PATH_MAX];
2594                 int len;
2595
2596                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2597                                prog->pin_name);
2598                 if (len < 0)
2599                         continue;
2600                 else if (len >= PATH_MAX)
2601                         continue;
2602
2603                 bpf_program__unpin(prog, buf);
2604         }
2605
2606         return err;
2607 }
2608
2609 int bpf_object__unpin_programs(struct bpf_object *obj, const char *path)
2610 {
2611         struct bpf_program *prog;
2612         int err;
2613
2614         if (!obj)
2615                 return -ENOENT;
2616
2617         bpf_object__for_each_program(prog, obj) {
2618                 char buf[PATH_MAX];
2619                 int len;
2620
2621                 len = snprintf(buf, PATH_MAX, "%s/%s", path,
2622                                prog->pin_name);
2623                 if (len < 0)
2624                         return -EINVAL;
2625                 else if (len >= PATH_MAX)
2626                         return -ENAMETOOLONG;
2627
2628                 err = bpf_program__unpin(prog, buf);
2629                 if (err)
2630                         return err;
2631         }
2632
2633         return 0;
2634 }
2635
2636 int bpf_object__pin(struct bpf_object *obj, const char *path)
2637 {
2638         int err;
2639
2640         err = bpf_object__pin_maps(obj, path);
2641         if (err)
2642                 return err;
2643
2644         err = bpf_object__pin_programs(obj, path);
2645         if (err) {
2646                 bpf_object__unpin_maps(obj, path);
2647                 return err;
2648         }
2649
2650         return 0;
2651 }
2652
2653 void bpf_object__close(struct bpf_object *obj)
2654 {
2655         size_t i;
2656
2657         if (!obj)
2658                 return;
2659
2660         if (obj->clear_priv)
2661                 obj->clear_priv(obj, obj->priv);
2662
2663         bpf_object__elf_finish(obj);
2664         bpf_object__unload(obj);
2665         btf__free(obj->btf);
2666         btf_ext__free(obj->btf_ext);
2667
2668         for (i = 0; i < obj->nr_maps; i++) {
2669                 zfree(&obj->maps[i].name);
2670                 if (obj->maps[i].clear_priv)
2671                         obj->maps[i].clear_priv(&obj->maps[i],
2672                                                 obj->maps[i].priv);
2673                 obj->maps[i].priv = NULL;
2674                 obj->maps[i].clear_priv = NULL;
2675         }
2676
2677         zfree(&obj->sections.rodata);
2678         zfree(&obj->sections.data);
2679         zfree(&obj->maps);
2680         obj->nr_maps = 0;
2681
2682         if (obj->programs && obj->nr_programs) {
2683                 for (i = 0; i < obj->nr_programs; i++)
2684                         bpf_program__exit(&obj->programs[i]);
2685         }
2686         zfree(&obj->programs);
2687
2688         list_del(&obj->list);
2689         free(obj);
2690 }
2691
2692 struct bpf_object *
2693 bpf_object__next(struct bpf_object *prev)
2694 {
2695         struct bpf_object *next;
2696
2697         if (!prev)
2698                 next = list_first_entry(&bpf_objects_list,
2699                                         struct bpf_object,
2700                                         list);
2701         else
2702                 next = list_next_entry(prev, list);
2703
2704         /* Empty list is noticed here so don't need checking on entry. */
2705         if (&next->list == &bpf_objects_list)
2706                 return NULL;
2707
2708         return next;
2709 }
2710
2711 const char *bpf_object__name(struct bpf_object *obj)
2712 {
2713         return obj ? obj->path : ERR_PTR(-EINVAL);
2714 }
2715
2716 unsigned int bpf_object__kversion(struct bpf_object *obj)
2717 {
2718         return obj ? obj->kern_version : 0;
2719 }
2720
2721 struct btf *bpf_object__btf(struct bpf_object *obj)
2722 {
2723         return obj ? obj->btf : NULL;
2724 }
2725
2726 int bpf_object__btf_fd(const struct bpf_object *obj)
2727 {
2728         return obj->btf ? btf__fd(obj->btf) : -1;
2729 }
2730
2731 int bpf_object__set_priv(struct bpf_object *obj, void *priv,
2732                          bpf_object_clear_priv_t clear_priv)
2733 {
2734         if (obj->priv && obj->clear_priv)
2735                 obj->clear_priv(obj, obj->priv);
2736
2737         obj->priv = priv;
2738         obj->clear_priv = clear_priv;
2739         return 0;
2740 }
2741
2742 void *bpf_object__priv(struct bpf_object *obj)
2743 {
2744         return obj ? obj->priv : ERR_PTR(-EINVAL);
2745 }
2746
2747 static struct bpf_program *
2748 __bpf_program__iter(struct bpf_program *p, struct bpf_object *obj, bool forward)
2749 {
2750         size_t nr_programs = obj->nr_programs;
2751         ssize_t idx;
2752
2753         if (!nr_programs)
2754                 return NULL;
2755
2756         if (!p)
2757                 /* Iter from the beginning */
2758                 return forward ? &obj->programs[0] :
2759                         &obj->programs[nr_programs - 1];
2760
2761         if (p->obj != obj) {
2762                 pr_warning("error: program handler doesn't match object\n");
2763                 return NULL;
2764         }
2765
2766         idx = (p - obj->programs) + (forward ? 1 : -1);
2767         if (idx >= obj->nr_programs || idx < 0)
2768                 return NULL;
2769         return &obj->programs[idx];
2770 }
2771
2772 struct bpf_program *
2773 bpf_program__next(struct bpf_program *prev, struct bpf_object *obj)
2774 {
2775         struct bpf_program *prog = prev;
2776
2777         do {
2778                 prog = __bpf_program__iter(prog, obj, true);
2779         } while (prog && bpf_program__is_function_storage(prog, obj));
2780
2781         return prog;
2782 }
2783
2784 struct bpf_program *
2785 bpf_program__prev(struct bpf_program *next, struct bpf_object *obj)
2786 {
2787         struct bpf_program *prog = next;
2788
2789         do {
2790                 prog = __bpf_program__iter(prog, obj, false);
2791         } while (prog && bpf_program__is_function_storage(prog, obj));
2792
2793         return prog;
2794 }
2795
2796 int bpf_program__set_priv(struct bpf_program *prog, void *priv,
2797                           bpf_program_clear_priv_t clear_priv)
2798 {
2799         if (prog->priv && prog->clear_priv)
2800                 prog->clear_priv(prog, prog->priv);
2801
2802         prog->priv = priv;
2803         prog->clear_priv = clear_priv;
2804         return 0;
2805 }
2806
2807 void *bpf_program__priv(struct bpf_program *prog)
2808 {
2809         return prog ? prog->priv : ERR_PTR(-EINVAL);
2810 }
2811
2812 void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex)
2813 {
2814         prog->prog_ifindex = ifindex;
2815 }
2816
2817 const char *bpf_program__title(struct bpf_program *prog, bool needs_copy)
2818 {
2819         const char *title;
2820
2821         title = prog->section_name;
2822         if (needs_copy) {
2823                 title = strdup(title);
2824                 if (!title) {
2825                         pr_warning("failed to strdup program title\n");
2826                         return ERR_PTR(-ENOMEM);
2827                 }
2828         }
2829
2830         return title;
2831 }
2832
2833 int bpf_program__fd(struct bpf_program *prog)
2834 {
2835         return bpf_program__nth_fd(prog, 0);
2836 }
2837
2838 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
2839                           bpf_program_prep_t prep)
2840 {
2841         int *instances_fds;
2842
2843         if (nr_instances <= 0 || !prep)
2844                 return -EINVAL;
2845
2846         if (prog->instances.nr > 0 || prog->instances.fds) {
2847                 pr_warning("Can't set pre-processor after loading\n");
2848                 return -EINVAL;
2849         }
2850
2851         instances_fds = malloc(sizeof(int) * nr_instances);
2852         if (!instances_fds) {
2853                 pr_warning("alloc memory failed for fds\n");
2854                 return -ENOMEM;
2855         }
2856
2857         /* fill all fd with -1 */
2858         memset(instances_fds, -1, sizeof(int) * nr_instances);
2859
2860         prog->instances.nr = nr_instances;
2861         prog->instances.fds = instances_fds;
2862         prog->preprocessor = prep;
2863         return 0;
2864 }
2865
2866 int bpf_program__nth_fd(struct bpf_program *prog, int n)
2867 {
2868         int fd;
2869
2870         if (!prog)
2871                 return -EINVAL;
2872
2873         if (n >= prog->instances.nr || n < 0) {
2874                 pr_warning("Can't get the %dth fd from program %s: only %d instances\n",
2875                            n, prog->section_name, prog->instances.nr);
2876                 return -EINVAL;
2877         }
2878
2879         fd = prog->instances.fds[n];
2880         if (fd < 0) {
2881                 pr_warning("%dth instance of program '%s' is invalid\n",
2882                            n, prog->section_name);
2883                 return -ENOENT;
2884         }
2885
2886         return fd;
2887 }
2888
2889 void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type)
2890 {
2891         prog->type = type;
2892 }
2893
2894 static bool bpf_program__is_type(struct bpf_program *prog,
2895                                  enum bpf_prog_type type)
2896 {
2897         return prog ? (prog->type == type) : false;
2898 }
2899
2900 #define BPF_PROG_TYPE_FNS(NAME, TYPE)                   \
2901 int bpf_program__set_##NAME(struct bpf_program *prog)   \
2902 {                                                       \
2903         if (!prog)                                      \
2904                 return -EINVAL;                         \
2905         bpf_program__set_type(prog, TYPE);              \
2906         return 0;                                       \
2907 }                                                       \
2908                                                         \
2909 bool bpf_program__is_##NAME(struct bpf_program *prog)   \
2910 {                                                       \
2911         return bpf_program__is_type(prog, TYPE);        \
2912 }                                                       \
2913
2914 BPF_PROG_TYPE_FNS(socket_filter, BPF_PROG_TYPE_SOCKET_FILTER);
2915 BPF_PROG_TYPE_FNS(kprobe, BPF_PROG_TYPE_KPROBE);
2916 BPF_PROG_TYPE_FNS(sched_cls, BPF_PROG_TYPE_SCHED_CLS);
2917 BPF_PROG_TYPE_FNS(sched_act, BPF_PROG_TYPE_SCHED_ACT);
2918 BPF_PROG_TYPE_FNS(tracepoint, BPF_PROG_TYPE_TRACEPOINT);
2919 BPF_PROG_TYPE_FNS(raw_tracepoint, BPF_PROG_TYPE_RAW_TRACEPOINT);
2920 BPF_PROG_TYPE_FNS(xdp, BPF_PROG_TYPE_XDP);
2921 BPF_PROG_TYPE_FNS(perf_event, BPF_PROG_TYPE_PERF_EVENT);
2922
2923 void bpf_program__set_expected_attach_type(struct bpf_program *prog,
2924                                            enum bpf_attach_type type)
2925 {
2926         prog->expected_attach_type = type;
2927 }
2928
2929 #define BPF_PROG_SEC_IMPL(string, ptype, eatype, is_attachable, atype) \
2930         { string, sizeof(string) - 1, ptype, eatype, is_attachable, atype }
2931
2932 /* Programs that can NOT be attached. */
2933 #define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0)
2934
2935 /* Programs that can be attached. */
2936 #define BPF_APROG_SEC(string, ptype, atype) \
2937         BPF_PROG_SEC_IMPL(string, ptype, 0, 1, atype)
2938
2939 /* Programs that must specify expected attach type at load time. */
2940 #define BPF_EAPROG_SEC(string, ptype, eatype) \
2941         BPF_PROG_SEC_IMPL(string, ptype, eatype, 1, eatype)
2942
2943 /* Programs that can be attached but attach type can't be identified by section
2944  * name. Kept for backward compatibility.
2945  */
2946 #define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
2947
2948 static const struct {
2949         const char *sec;
2950         size_t len;
2951         enum bpf_prog_type prog_type;
2952         enum bpf_attach_type expected_attach_type;
2953         int is_attachable;
2954         enum bpf_attach_type attach_type;
2955 } section_names[] = {
2956         BPF_PROG_SEC("socket",                  BPF_PROG_TYPE_SOCKET_FILTER),
2957         BPF_PROG_SEC("kprobe/",                 BPF_PROG_TYPE_KPROBE),
2958         BPF_PROG_SEC("kretprobe/",              BPF_PROG_TYPE_KPROBE),
2959         BPF_PROG_SEC("classifier",              BPF_PROG_TYPE_SCHED_CLS),
2960         BPF_PROG_SEC("action",                  BPF_PROG_TYPE_SCHED_ACT),
2961         BPF_PROG_SEC("tracepoint/",             BPF_PROG_TYPE_TRACEPOINT),
2962         BPF_PROG_SEC("raw_tracepoint/",         BPF_PROG_TYPE_RAW_TRACEPOINT),
2963         BPF_PROG_SEC("xdp",                     BPF_PROG_TYPE_XDP),
2964         BPF_PROG_SEC("perf_event",              BPF_PROG_TYPE_PERF_EVENT),
2965         BPF_PROG_SEC("lwt_in",                  BPF_PROG_TYPE_LWT_IN),
2966         BPF_PROG_SEC("lwt_out",                 BPF_PROG_TYPE_LWT_OUT),
2967         BPF_PROG_SEC("lwt_xmit",                BPF_PROG_TYPE_LWT_XMIT),
2968         BPF_PROG_SEC("lwt_seg6local",           BPF_PROG_TYPE_LWT_SEG6LOCAL),
2969         BPF_APROG_SEC("cgroup_skb/ingress",     BPF_PROG_TYPE_CGROUP_SKB,
2970                                                 BPF_CGROUP_INET_INGRESS),
2971         BPF_APROG_SEC("cgroup_skb/egress",      BPF_PROG_TYPE_CGROUP_SKB,
2972                                                 BPF_CGROUP_INET_EGRESS),
2973         BPF_APROG_COMPAT("cgroup/skb",          BPF_PROG_TYPE_CGROUP_SKB),
2974         BPF_APROG_SEC("cgroup/sock",            BPF_PROG_TYPE_CGROUP_SOCK,
2975                                                 BPF_CGROUP_INET_SOCK_CREATE),
2976         BPF_EAPROG_SEC("cgroup/post_bind4",     BPF_PROG_TYPE_CGROUP_SOCK,
2977                                                 BPF_CGROUP_INET4_POST_BIND),
2978         BPF_EAPROG_SEC("cgroup/post_bind6",     BPF_PROG_TYPE_CGROUP_SOCK,
2979                                                 BPF_CGROUP_INET6_POST_BIND),
2980         BPF_APROG_SEC("cgroup/dev",             BPF_PROG_TYPE_CGROUP_DEVICE,
2981                                                 BPF_CGROUP_DEVICE),
2982         BPF_APROG_SEC("sockops",                BPF_PROG_TYPE_SOCK_OPS,
2983                                                 BPF_CGROUP_SOCK_OPS),
2984         BPF_APROG_SEC("sk_skb/stream_parser",   BPF_PROG_TYPE_SK_SKB,
2985                                                 BPF_SK_SKB_STREAM_PARSER),
2986         BPF_APROG_SEC("sk_skb/stream_verdict",  BPF_PROG_TYPE_SK_SKB,
2987                                                 BPF_SK_SKB_STREAM_VERDICT),
2988         BPF_APROG_COMPAT("sk_skb",              BPF_PROG_TYPE_SK_SKB),
2989         BPF_APROG_SEC("sk_msg",                 BPF_PROG_TYPE_SK_MSG,
2990                                                 BPF_SK_MSG_VERDICT),
2991         BPF_APROG_SEC("lirc_mode2",             BPF_PROG_TYPE_LIRC_MODE2,
2992                                                 BPF_LIRC_MODE2),
2993         BPF_APROG_SEC("flow_dissector",         BPF_PROG_TYPE_FLOW_DISSECTOR,
2994                                                 BPF_FLOW_DISSECTOR),
2995         BPF_EAPROG_SEC("cgroup/bind4",          BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
2996                                                 BPF_CGROUP_INET4_BIND),
2997         BPF_EAPROG_SEC("cgroup/bind6",          BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
2998                                                 BPF_CGROUP_INET6_BIND),
2999         BPF_EAPROG_SEC("cgroup/connect4",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3000                                                 BPF_CGROUP_INET4_CONNECT),
3001         BPF_EAPROG_SEC("cgroup/connect6",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3002                                                 BPF_CGROUP_INET6_CONNECT),
3003         BPF_EAPROG_SEC("cgroup/sendmsg4",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3004                                                 BPF_CGROUP_UDP4_SENDMSG),
3005         BPF_EAPROG_SEC("cgroup/sendmsg6",       BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
3006                                                 BPF_CGROUP_UDP6_SENDMSG),
3007 };
3008
3009 #undef BPF_PROG_SEC_IMPL
3010 #undef BPF_PROG_SEC
3011 #undef BPF_APROG_SEC
3012 #undef BPF_EAPROG_SEC
3013 #undef BPF_APROG_COMPAT
3014
3015 #define MAX_TYPE_NAME_SIZE 32
3016
3017 static char *libbpf_get_type_names(bool attach_type)
3018 {
3019         int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE;
3020         char *buf;
3021
3022         buf = malloc(len);
3023         if (!buf)
3024                 return NULL;
3025
3026         buf[0] = '\0';
3027         /* Forge string buf with all available names */
3028         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3029                 if (attach_type && !section_names[i].is_attachable)
3030                         continue;
3031
3032                 if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) {
3033                         free(buf);
3034                         return NULL;
3035                 }
3036                 strcat(buf, " ");
3037                 strcat(buf, section_names[i].sec);
3038         }
3039
3040         return buf;
3041 }
3042
3043 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
3044                              enum bpf_attach_type *expected_attach_type)
3045 {
3046         char *type_names;
3047         int i;
3048
3049         if (!name)
3050                 return -EINVAL;
3051
3052         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3053                 if (strncmp(name, section_names[i].sec, section_names[i].len))
3054                         continue;
3055                 *prog_type = section_names[i].prog_type;
3056                 *expected_attach_type = section_names[i].expected_attach_type;
3057                 return 0;
3058         }
3059         pr_warning("failed to guess program type based on ELF section name '%s'\n", name);
3060         type_names = libbpf_get_type_names(false);
3061         if (type_names != NULL) {
3062                 pr_info("supported section(type) names are:%s\n", type_names);
3063                 free(type_names);
3064         }
3065
3066         return -EINVAL;
3067 }
3068
3069 int libbpf_attach_type_by_name(const char *name,
3070                                enum bpf_attach_type *attach_type)
3071 {
3072         char *type_names;
3073         int i;
3074
3075         if (!name)
3076                 return -EINVAL;
3077
3078         for (i = 0; i < ARRAY_SIZE(section_names); i++) {
3079                 if (strncmp(name, section_names[i].sec, section_names[i].len))
3080                         continue;
3081                 if (!section_names[i].is_attachable)
3082                         return -EINVAL;
3083                 *attach_type = section_names[i].attach_type;
3084                 return 0;
3085         }
3086         pr_warning("failed to guess attach type based on ELF section name '%s'\n", name);
3087         type_names = libbpf_get_type_names(true);
3088         if (type_names != NULL) {
3089                 pr_info("attachable section(type) names are:%s\n", type_names);
3090                 free(type_names);
3091         }
3092
3093         return -EINVAL;
3094 }
3095
3096 static int
3097 bpf_program__identify_section(struct bpf_program *prog,
3098                               enum bpf_prog_type *prog_type,
3099                               enum bpf_attach_type *expected_attach_type)
3100 {
3101         return libbpf_prog_type_by_name(prog->section_name, prog_type,
3102                                         expected_attach_type);
3103 }
3104
3105 int bpf_map__fd(struct bpf_map *map)
3106 {
3107         return map ? map->fd : -EINVAL;
3108 }
3109
3110 const struct bpf_map_def *bpf_map__def(struct bpf_map *map)
3111 {
3112         return map ? &map->def : ERR_PTR(-EINVAL);
3113 }
3114
3115 const char *bpf_map__name(struct bpf_map *map)
3116 {
3117         return map ? map->name : NULL;
3118 }
3119
3120 __u32 bpf_map__btf_key_type_id(const struct bpf_map *map)
3121 {
3122         return map ? map->btf_key_type_id : 0;
3123 }
3124
3125 __u32 bpf_map__btf_value_type_id(const struct bpf_map *map)
3126 {
3127         return map ? map->btf_value_type_id : 0;
3128 }
3129
3130 int bpf_map__set_priv(struct bpf_map *map, void *priv,
3131                      bpf_map_clear_priv_t clear_priv)
3132 {
3133         if (!map)
3134                 return -EINVAL;
3135
3136         if (map->priv) {
3137                 if (map->clear_priv)
3138                         map->clear_priv(map, map->priv);
3139         }
3140
3141         map->priv = priv;
3142         map->clear_priv = clear_priv;
3143         return 0;
3144 }
3145
3146 void *bpf_map__priv(struct bpf_map *map)
3147 {
3148         return map ? map->priv : ERR_PTR(-EINVAL);
3149 }
3150
3151 bool bpf_map__is_offload_neutral(struct bpf_map *map)
3152 {
3153         return map->def.type == BPF_MAP_TYPE_PERF_EVENT_ARRAY;
3154 }
3155
3156 bool bpf_map__is_internal(struct bpf_map *map)
3157 {
3158         return map->libbpf_type != LIBBPF_MAP_UNSPEC;
3159 }
3160
3161 void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex)
3162 {
3163         map->map_ifindex = ifindex;
3164 }
3165
3166 int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)
3167 {
3168         if (!bpf_map_type__is_map_in_map(map->def.type)) {
3169                 pr_warning("error: unsupported map type\n");
3170                 return -EINVAL;
3171         }
3172         if (map->inner_map_fd != -1) {
3173                 pr_warning("error: inner_map_fd already specified\n");
3174                 return -EINVAL;
3175         }
3176         map->inner_map_fd = fd;
3177         return 0;
3178 }
3179
3180 static struct bpf_map *
3181 __bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i)
3182 {
3183         ssize_t idx;
3184         struct bpf_map *s, *e;
3185
3186         if (!obj || !obj->maps)
3187                 return NULL;
3188
3189         s = obj->maps;
3190         e = obj->maps + obj->nr_maps;
3191
3192         if ((m < s) || (m >= e)) {
3193                 pr_warning("error in %s: map handler doesn't belong to object\n",
3194                            __func__);
3195                 return NULL;
3196         }
3197
3198         idx = (m - obj->maps) + i;
3199         if (idx >= obj->nr_maps || idx < 0)
3200                 return NULL;
3201         return &obj->maps[idx];
3202 }
3203
3204 struct bpf_map *
3205 bpf_map__next(struct bpf_map *prev, struct bpf_object *obj)
3206 {
3207         if (prev == NULL)
3208                 return obj->maps;
3209
3210         return __bpf_map__iter(prev, obj, 1);
3211 }
3212
3213 struct bpf_map *
3214 bpf_map__prev(struct bpf_map *next, struct bpf_object *obj)
3215 {
3216         if (next == NULL) {
3217                 if (!obj->nr_maps)
3218                         return NULL;
3219                 return obj->maps + obj->nr_maps - 1;
3220         }
3221
3222         return __bpf_map__iter(next, obj, -1);
3223 }
3224
3225 struct bpf_map *
3226 bpf_object__find_map_by_name(struct bpf_object *obj, const char *name)
3227 {
3228         struct bpf_map *pos;
3229
3230         bpf_object__for_each_map(pos, obj) {
3231                 if (pos->name && !strcmp(pos->name, name))
3232                         return pos;
3233         }
3234         return NULL;
3235 }
3236
3237 int
3238 bpf_object__find_map_fd_by_name(struct bpf_object *obj, const char *name)
3239 {
3240         return bpf_map__fd(bpf_object__find_map_by_name(obj, name));
3241 }
3242
3243 struct bpf_map *
3244 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset)
3245 {
3246         int i;
3247
3248         for (i = 0; i < obj->nr_maps; i++) {
3249                 if (obj->maps[i].offset == offset)
3250                         return &obj->maps[i];
3251         }
3252         return ERR_PTR(-ENOENT);
3253 }
3254
3255 long libbpf_get_error(const void *ptr)
3256 {
3257         if (IS_ERR(ptr))
3258                 return PTR_ERR(ptr);
3259         return 0;
3260 }
3261
3262 int bpf_prog_load(const char *file, enum bpf_prog_type type,
3263                   struct bpf_object **pobj, int *prog_fd)
3264 {
3265         struct bpf_prog_load_attr attr;
3266
3267         memset(&attr, 0, sizeof(struct bpf_prog_load_attr));
3268         attr.file = file;
3269         attr.prog_type = type;
3270         attr.expected_attach_type = 0;
3271
3272         return bpf_prog_load_xattr(&attr, pobj, prog_fd);
3273 }
3274
3275 int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
3276                         struct bpf_object **pobj, int *prog_fd)
3277 {
3278         struct bpf_object_open_attr open_attr = {
3279                 .file           = attr->file,
3280                 .prog_type      = attr->prog_type,
3281         };
3282         struct bpf_program *prog, *first_prog = NULL;
3283         enum bpf_attach_type expected_attach_type;
3284         enum bpf_prog_type prog_type;
3285         struct bpf_object *obj;
3286         struct bpf_map *map;
3287         int err;
3288
3289         if (!attr)
3290                 return -EINVAL;
3291         if (!attr->file)
3292                 return -EINVAL;
3293
3294         obj = bpf_object__open_xattr(&open_attr);
3295         if (IS_ERR_OR_NULL(obj))
3296                 return -ENOENT;
3297
3298         bpf_object__for_each_program(prog, obj) {
3299                 /*
3300                  * If type is not specified, try to guess it based on
3301                  * section name.
3302                  */
3303                 prog_type = attr->prog_type;
3304                 prog->prog_ifindex = attr->ifindex;
3305                 expected_attach_type = attr->expected_attach_type;
3306                 if (prog_type == BPF_PROG_TYPE_UNSPEC) {
3307                         err = bpf_program__identify_section(prog, &prog_type,
3308                                                             &expected_attach_type);
3309                         if (err < 0) {
3310                                 bpf_object__close(obj);
3311                                 return -EINVAL;
3312                         }
3313                 }
3314
3315                 bpf_program__set_type(prog, prog_type);
3316                 bpf_program__set_expected_attach_type(prog,
3317                                                       expected_attach_type);
3318
3319                 prog->log_level = attr->log_level;
3320                 if (!first_prog)
3321                         first_prog = prog;
3322         }
3323
3324         bpf_object__for_each_map(map, obj) {
3325                 if (!bpf_map__is_offload_neutral(map))
3326                         map->map_ifindex = attr->ifindex;
3327         }
3328
3329         if (!first_prog) {
3330                 pr_warning("object file doesn't contain bpf program\n");
3331                 bpf_object__close(obj);
3332                 return -ENOENT;
3333         }
3334
3335         err = bpf_object__load(obj);
3336         if (err) {
3337                 bpf_object__close(obj);
3338                 return -EINVAL;
3339         }
3340
3341         *pobj = obj;
3342         *prog_fd = bpf_program__fd(first_prog);
3343         return 0;
3344 }
3345
3346 enum bpf_perf_event_ret
3347 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
3348                            void **copy_mem, size_t *copy_size,
3349                            bpf_perf_event_print_t fn, void *private_data)
3350 {
3351         struct perf_event_mmap_page *header = mmap_mem;
3352         __u64 data_head = ring_buffer_read_head(header);
3353         __u64 data_tail = header->data_tail;
3354         void *base = ((__u8 *)header) + page_size;
3355         int ret = LIBBPF_PERF_EVENT_CONT;
3356         struct perf_event_header *ehdr;
3357         size_t ehdr_size;
3358
3359         while (data_head != data_tail) {
3360                 ehdr = base + (data_tail & (mmap_size - 1));
3361                 ehdr_size = ehdr->size;
3362
3363                 if (((void *)ehdr) + ehdr_size > base + mmap_size) {
3364                         void *copy_start = ehdr;
3365                         size_t len_first = base + mmap_size - copy_start;
3366                         size_t len_secnd = ehdr_size - len_first;
3367
3368                         if (*copy_size < ehdr_size) {
3369                                 free(*copy_mem);
3370                                 *copy_mem = malloc(ehdr_size);
3371                                 if (!*copy_mem) {
3372                                         *copy_size = 0;
3373                                         ret = LIBBPF_PERF_EVENT_ERROR;
3374                                         break;
3375                                 }
3376                                 *copy_size = ehdr_size;
3377                         }
3378
3379                         memcpy(*copy_mem, copy_start, len_first);
3380                         memcpy(*copy_mem + len_first, base, len_secnd);
3381                         ehdr = *copy_mem;
3382                 }
3383
3384                 ret = fn(ehdr, private_data);
3385                 data_tail += ehdr_size;
3386                 if (ret != LIBBPF_PERF_EVENT_CONT)
3387                         break;
3388         }
3389
3390         ring_buffer_write_tail(header, data_tail);
3391         return ret;
3392 }
3393
3394 struct bpf_prog_info_array_desc {
3395         int     array_offset;   /* e.g. offset of jited_prog_insns */
3396         int     count_offset;   /* e.g. offset of jited_prog_len */
3397         int     size_offset;    /* > 0: offset of rec size,
3398                                  * < 0: fix size of -size_offset
3399                                  */
3400 };
3401
3402 static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
3403         [BPF_PROG_INFO_JITED_INSNS] = {
3404                 offsetof(struct bpf_prog_info, jited_prog_insns),
3405                 offsetof(struct bpf_prog_info, jited_prog_len),
3406                 -1,
3407         },
3408         [BPF_PROG_INFO_XLATED_INSNS] = {
3409                 offsetof(struct bpf_prog_info, xlated_prog_insns),
3410                 offsetof(struct bpf_prog_info, xlated_prog_len),
3411                 -1,
3412         },
3413         [BPF_PROG_INFO_MAP_IDS] = {
3414                 offsetof(struct bpf_prog_info, map_ids),
3415                 offsetof(struct bpf_prog_info, nr_map_ids),
3416                 -(int)sizeof(__u32),
3417         },
3418         [BPF_PROG_INFO_JITED_KSYMS] = {
3419                 offsetof(struct bpf_prog_info, jited_ksyms),
3420                 offsetof(struct bpf_prog_info, nr_jited_ksyms),
3421                 -(int)sizeof(__u64),
3422         },
3423         [BPF_PROG_INFO_JITED_FUNC_LENS] = {
3424                 offsetof(struct bpf_prog_info, jited_func_lens),
3425                 offsetof(struct bpf_prog_info, nr_jited_func_lens),
3426                 -(int)sizeof(__u32),
3427         },
3428         [BPF_PROG_INFO_FUNC_INFO] = {
3429                 offsetof(struct bpf_prog_info, func_info),
3430                 offsetof(struct bpf_prog_info, nr_func_info),
3431                 offsetof(struct bpf_prog_info, func_info_rec_size),
3432         },
3433         [BPF_PROG_INFO_LINE_INFO] = {
3434                 offsetof(struct bpf_prog_info, line_info),
3435                 offsetof(struct bpf_prog_info, nr_line_info),
3436                 offsetof(struct bpf_prog_info, line_info_rec_size),
3437         },
3438         [BPF_PROG_INFO_JITED_LINE_INFO] = {
3439                 offsetof(struct bpf_prog_info, jited_line_info),
3440                 offsetof(struct bpf_prog_info, nr_jited_line_info),
3441                 offsetof(struct bpf_prog_info, jited_line_info_rec_size),
3442         },
3443         [BPF_PROG_INFO_PROG_TAGS] = {
3444                 offsetof(struct bpf_prog_info, prog_tags),
3445                 offsetof(struct bpf_prog_info, nr_prog_tags),
3446                 -(int)sizeof(__u8) * BPF_TAG_SIZE,
3447         },
3448
3449 };
3450
3451 static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info, int offset)
3452 {
3453         __u32 *array = (__u32 *)info;
3454
3455         if (offset >= 0)
3456                 return array[offset / sizeof(__u32)];
3457         return -(int)offset;
3458 }
3459
3460 static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info, int offset)
3461 {
3462         __u64 *array = (__u64 *)info;
3463
3464         if (offset >= 0)
3465                 return array[offset / sizeof(__u64)];
3466         return -(int)offset;
3467 }
3468
3469 static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
3470                                          __u32 val)
3471 {
3472         __u32 *array = (__u32 *)info;
3473
3474         if (offset >= 0)
3475                 array[offset / sizeof(__u32)] = val;
3476 }
3477
3478 static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
3479                                          __u64 val)
3480 {
3481         __u64 *array = (__u64 *)info;
3482
3483         if (offset >= 0)
3484                 array[offset / sizeof(__u64)] = val;
3485 }
3486
3487 struct bpf_prog_info_linear *
3488 bpf_program__get_prog_info_linear(int fd, __u64 arrays)
3489 {
3490         struct bpf_prog_info_linear *info_linear;
3491         struct bpf_prog_info info = {};
3492         __u32 info_len = sizeof(info);
3493         __u32 data_len = 0;
3494         int i, err;
3495         void *ptr;
3496
3497         if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
3498                 return ERR_PTR(-EINVAL);
3499
3500         /* step 1: get array dimensions */
3501         err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
3502         if (err) {
3503                 pr_debug("can't get prog info: %s", strerror(errno));
3504                 return ERR_PTR(-EFAULT);
3505         }
3506
3507         /* step 2: calculate total size of all arrays */
3508         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3509                 bool include_array = (arrays & (1UL << i)) > 0;
3510                 struct bpf_prog_info_array_desc *desc;
3511                 __u32 count, size;
3512
3513                 desc = bpf_prog_info_array_desc + i;
3514
3515                 /* kernel is too old to support this field */
3516                 if (info_len < desc->array_offset + sizeof(__u32) ||
3517                     info_len < desc->count_offset + sizeof(__u32) ||
3518                     (desc->size_offset > 0 && info_len < desc->size_offset))
3519                         include_array = false;
3520
3521                 if (!include_array) {
3522                         arrays &= ~(1UL << i);  /* clear the bit */
3523                         continue;
3524                 }
3525
3526                 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3527                 size  = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3528
3529                 data_len += count * size;
3530         }
3531
3532         /* step 3: allocate continuous memory */
3533         data_len = roundup(data_len, sizeof(__u64));
3534         info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
3535         if (!info_linear)
3536                 return ERR_PTR(-ENOMEM);
3537
3538         /* step 4: fill data to info_linear->info */
3539         info_linear->arrays = arrays;
3540         memset(&info_linear->info, 0, sizeof(info));
3541         ptr = info_linear->data;
3542
3543         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3544                 struct bpf_prog_info_array_desc *desc;
3545                 __u32 count, size;
3546
3547                 if ((arrays & (1UL << i)) == 0)
3548                         continue;
3549
3550                 desc  = bpf_prog_info_array_desc + i;
3551                 count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3552                 size  = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3553                 bpf_prog_info_set_offset_u32(&info_linear->info,
3554                                              desc->count_offset, count);
3555                 bpf_prog_info_set_offset_u32(&info_linear->info,
3556                                              desc->size_offset, size);
3557                 bpf_prog_info_set_offset_u64(&info_linear->info,
3558                                              desc->array_offset,
3559                                              ptr_to_u64(ptr));
3560                 ptr += count * size;
3561         }
3562
3563         /* step 5: call syscall again to get required arrays */
3564         err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
3565         if (err) {
3566                 pr_debug("can't get prog info: %s", strerror(errno));
3567                 free(info_linear);
3568                 return ERR_PTR(-EFAULT);
3569         }
3570
3571         /* step 6: verify the data */
3572         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3573                 struct bpf_prog_info_array_desc *desc;
3574                 __u32 v1, v2;
3575
3576                 if ((arrays & (1UL << i)) == 0)
3577                         continue;
3578
3579                 desc = bpf_prog_info_array_desc + i;
3580                 v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
3581                 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
3582                                                    desc->count_offset);
3583                 if (v1 != v2)
3584                         pr_warning("%s: mismatch in element count\n", __func__);
3585
3586                 v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
3587                 v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
3588                                                    desc->size_offset);
3589                 if (v1 != v2)
3590                         pr_warning("%s: mismatch in rec size\n", __func__);
3591         }
3592
3593         /* step 7: update info_len and data_len */
3594         info_linear->info_len = sizeof(struct bpf_prog_info);
3595         info_linear->data_len = data_len;
3596
3597         return info_linear;
3598 }
3599
3600 void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
3601 {
3602         int i;
3603
3604         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3605                 struct bpf_prog_info_array_desc *desc;
3606                 __u64 addr, offs;
3607
3608                 if ((info_linear->arrays & (1UL << i)) == 0)
3609                         continue;
3610
3611                 desc = bpf_prog_info_array_desc + i;
3612                 addr = bpf_prog_info_read_offset_u64(&info_linear->info,
3613                                                      desc->array_offset);
3614                 offs = addr - ptr_to_u64(info_linear->data);
3615                 bpf_prog_info_set_offset_u64(&info_linear->info,
3616                                              desc->array_offset, offs);
3617         }
3618 }
3619
3620 void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
3621 {
3622         int i;
3623
3624         for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
3625                 struct bpf_prog_info_array_desc *desc;
3626                 __u64 addr, offs;
3627
3628                 if ((info_linear->arrays & (1UL << i)) == 0)
3629                         continue;
3630
3631                 desc = bpf_prog_info_array_desc + i;
3632                 offs = bpf_prog_info_read_offset_u64(&info_linear->info,
3633                                                      desc->array_offset);
3634                 addr = offs + ptr_to_u64(info_linear->data);
3635                 bpf_prog_info_set_offset_u64(&info_linear->info,
3636                                              desc->array_offset, addr);
3637         }
3638 }