scripts/mod/modpost.c

   1 /* Postprocess module symbol versions
   2  *
   3  * Copyright 2003       Kai Germaschewski
   4  * Copyright 2002-2004  Rusty Russell, IBM Corporation
   5  * Copyright 2006-2008  Sam Ravnborg
   6  * Based in part on module-init-tools/depmod.c,file2alias
   7  *
   8  * This software may be used and distributed according to the terms
   9  * of the GNU General Public License, incorporated herein by reference.
  10  *
  11  * Usage: modpost vmlinux module1.o module2.o ...
  12  */
  13
  14 #define _GNU_SOURCE
  15 #include <elf.h>
  16 #include <fnmatch.h>
  17 #include <stdio.h>
  18 #include <ctype.h>
  19 #include <string.h>
  20 #include <limits.h>
  21 #include <stdbool.h>
  22 #include <errno.h>
  23 #include "modpost.h"
  24 #include "../../include/linux/license.h"
  25 #include "../../include/linux/module_symbol.h"
  26
  27 static bool module_enabled;
  28 /* Are we using CONFIG_MODVERSIONS? */
  29 static bool modversions;
  30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  31 static bool all_versions;
  32 /* If we are modposting external module set to 1 */
  33 static bool external_module;
  34 /* Only warn about unresolved symbols */
  35 static bool warn_unresolved;
  36
  37 static int sec_mismatch_count;
  38 static bool sec_mismatch_warn_only = true;
  39 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  40 static bool trim_unused_exports;
  41
  42 /* ignore missing files */
  43 static bool ignore_missing_files;
  44 /* If set to 1, only warn (instead of error) about missing ns imports */
  45 static bool allow_missing_ns_imports;
  46
  47 static bool error_occurred;
  48
  49 static bool extra_warn;
  50
  51 /*
  52  * Cut off the warnings when there are too many. This typically occurs when
  53  * vmlinux is missing. ('make modules' without building vmlinux.)
  54  */
  55 #define MAX_UNRESOLVED_REPORTS  10
  56 static unsigned int nr_unresolved;
  57
  58 /* In kernel, this size is defined in linux/module.h;
  59  * here we use Elf_Addr instead of long for covering cross-compile
  60  */
  61
  62 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  63
  64 void __attribute__((format(printf, 2, 3)))
  65 modpost_log(enum loglevel loglevel, const char *fmt, ...)
  66 {
  67         va_list arglist;
  68
  69         switch (loglevel) {
  70         case LOG_WARN:
  71                 fprintf(stderr, "WARNING: ");
  72                 break;
  73         case LOG_ERROR:
  74                 fprintf(stderr, "ERROR: ");
  75                 break;
  76         case LOG_FATAL:
  77                 fprintf(stderr, "FATAL: ");
  78                 break;
  79         default: /* invalid loglevel, ignore */
  80                 break;
  81         }
  82
  83         fprintf(stderr, "modpost: ");
  84
  85         va_start(arglist, fmt);
  86         vfprintf(stderr, fmt, arglist);
  87         va_end(arglist);
  88
  89         if (loglevel == LOG_FATAL)
  90                 exit(1);
  91         if (loglevel == LOG_ERROR)
  92                 error_occurred = true;
  93 }
  94
  95 static inline bool strends(const char *str, const char *postfix)
  96 {
  97         if (strlen(str) < strlen(postfix))
  98                 return false;
  99
 100         return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
 101 }
 102
 103 void *do_nofail(void *ptr, const char *expr)
 104 {
 105         if (!ptr)
 106                 fatal("Memory allocation failure: %s.\n", expr);
 107
 108         return ptr;
 109 }
 110
 111 char *read_text_file(const char *filename)
 112 {
 113         struct stat st;
 114         size_t nbytes;
 115         int fd;
 116         char *buf;
 117
 118         fd = open(filename, O_RDONLY);
 119         if (fd < 0) {
 120                 perror(filename);
 121                 exit(1);
 122         }
 123
 124         if (fstat(fd, &st) < 0) {
 125                 perror(filename);
 126                 exit(1);
 127         }
 128
 129         buf = NOFAIL(malloc(st.st_size + 1));
 130
 131         nbytes = st.st_size;
 132
 133         while (nbytes) {
 134                 ssize_t bytes_read;
 135
 136                 bytes_read = read(fd, buf, nbytes);
 137                 if (bytes_read < 0) {
 138                         perror(filename);
 139                         exit(1);
 140                 }
 141
 142                 nbytes -= bytes_read;
 143         }
 144         buf[st.st_size] = '\0';
 145
 146         close(fd);
 147
 148         return buf;
 149 }
 150
 151 char *get_line(char **stringp)
 152 {
 153         char *orig = *stringp, *next;
 154
 155         /* do not return the unwanted extra line at EOF */
 156         if (!orig || *orig == '\0')
 157                 return NULL;
 158
 159         /* don't use strsep here, it is not available everywhere */
 160         next = strchr(orig, '\n');
 161         if (next)
 162                 *next++ = '\0';
 163
 164         *stringp = next;
 165
 166         return orig;
 167 }
 168
 169 /* A list of all modules we processed */
 170 LIST_HEAD(modules);
 171
 172 static struct module *find_module(const char *modname)
 173 {
 174         struct module *mod;
 175
 176         list_for_each_entry(mod, &modules, list) {
 177                 if (strcmp(mod->name, modname) == 0)
 178                         return mod;
 179         }
 180         return NULL;
 181 }
 182
 183 static struct module *new_module(const char *name, size_t namelen)
 184 {
 185         struct module *mod;
 186
 187         mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
 188         memset(mod, 0, sizeof(*mod));
 189
 190         INIT_LIST_HEAD(&mod->exported_symbols);
 191         INIT_LIST_HEAD(&mod->unresolved_symbols);
 192         INIT_LIST_HEAD(&mod->missing_namespaces);
 193         INIT_LIST_HEAD(&mod->imported_namespaces);
 194
 195         memcpy(mod->name, name, namelen);
 196         mod->name[namelen] = '\0';
 197         mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 198
 199         /*
 200          * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 201          * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 202          * modpost will exit wiht error anyway.
 203          */
 204         mod->is_gpl_compatible = true;
 205
 206         list_add_tail(&mod->list, &modules);
 207
 208         return mod;
 209 }
 210
 211 /* A hash of all exported symbols,
 212  * struct symbol is also used for lists of unresolved symbols */
 213
 214 #define SYMBOL_HASH_SIZE 1024
 215
 216 struct symbol {
 217         struct symbol *next;
 218         struct list_head list;  /* link to module::exported_symbols or module::unresolved_symbols */
 219         struct module *module;
 220         char *namespace;
 221         unsigned int crc;
 222         bool crc_valid;
 223         bool weak;
 224         bool is_func;
 225         bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
 226         bool used;              /* there exists a user of this symbol */
 227         char name[];
 228 };
 229
 230 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 231
 232 /* This is based on the hash algorithm from gdbm, via tdb */
 233 static inline unsigned int tdb_hash(const char *name)
 234 {
 235         unsigned value; /* Used to compute the hash value.  */
 236         unsigned   i;   /* Used to cycle through random values. */
 237
 238         /* Set the initial value from the key size. */
 239         for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 240                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 241
 242         return (1103515243 * value + 12345);
 243 }
 244
 245 /**
 246  * Allocate a new symbols for use in the hash of exported symbols or
 247  * the list of unresolved symbols per module
 248  **/
 249 static struct symbol *alloc_symbol(const char *name)
 250 {
 251         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 252
 253         memset(s, 0, sizeof(*s));
 254         strcpy(s->name, name);
 255
 256         return s;
 257 }
 258
 259 /* For the hash of exported symbols */
 260 static void hash_add_symbol(struct symbol *sym)
 261 {
 262         unsigned int hash;
 263
 264         hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
 265         sym->next = symbolhash[hash];
 266         symbolhash[hash] = sym;
 267 }
 268
 269 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 270 {
 271         struct symbol *sym;
 272
 273         sym = alloc_symbol(name);
 274         sym->weak = weak;
 275
 276         list_add_tail(&sym->list, &mod->unresolved_symbols);
 277 }
 278
 279 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 280 {
 281         struct symbol *s;
 282
 283         /* For our purposes, .foo matches foo.  PPC64 needs this. */
 284         if (name[0] == '.')
 285                 name++;
 286
 287         for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 288                 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 289                         return s;
 290         }
 291         return NULL;
 292 }
 293
 294 static struct symbol *find_symbol(const char *name)
 295 {
 296         return sym_find_with_module(name, NULL);
 297 }
 298
 299 struct namespace_list {
 300         struct list_head list;
 301         char namespace[];
 302 };
 303
 304 static bool contains_namespace(struct list_head *head, const char *namespace)
 305 {
 306         struct namespace_list *list;
 307
 308         /*
 309          * The default namespace is null string "", which is always implicitly
 310          * contained.
 311          */
 312         if (!namespace[0])
 313                 return true;
 314
 315         list_for_each_entry(list, head, list) {
 316                 if (!strcmp(list->namespace, namespace))
 317                         return true;
 318         }
 319
 320         return false;
 321 }
 322
 323 static void add_namespace(struct list_head *head, const char *namespace)
 324 {
 325         struct namespace_list *ns_entry;
 326
 327         if (!contains_namespace(head, namespace)) {
 328                 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 329                                          strlen(namespace) + 1));
 330                 strcpy(ns_entry->namespace, namespace);
 331                 list_add_tail(&ns_entry->list, head);
 332         }
 333 }
 334
 335 static void *sym_get_data_by_offset(const struct elf_info *info,
 336                                     unsigned int secindex, unsigned long offset)
 337 {
 338         Elf_Shdr *sechdr = &info->sechdrs[secindex];
 339
 340         return (void *)info->hdr + sechdr->sh_offset + offset;
 341 }
 342
 343 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 344 {
 345         return sym_get_data_by_offset(info, get_secindex(info, sym),
 346                                       sym->st_value);
 347 }
 348
 349 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 350 {
 351         return sym_get_data_by_offset(info, info->secindex_strings,
 352                                       sechdr->sh_name);
 353 }
 354
 355 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 356 {
 357         /*
 358          * If sym->st_shndx is a special section index, there is no
 359          * corresponding section header.
 360          * Return "" if the index is out of range of info->sechdrs[] array.
 361          */
 362         if (secindex >= info->num_sections)
 363                 return "";
 364
 365         return sech_name(info, &info->sechdrs[secindex]);
 366 }
 367
 368 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 369
 370 static struct symbol *sym_add_exported(const char *name, struct module *mod,
 371                                        bool gpl_only, const char *namespace)
 372 {
 373         struct symbol *s = find_symbol(name);
 374
 375         if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 376                 error("%s: '%s' exported twice. Previous export was in %s%s\n",
 377                       mod->name, name, s->module->name,
 378                       s->module->is_vmlinux ? "" : ".ko");
 379         }
 380
 381         s = alloc_symbol(name);
 382         s->module = mod;
 383         s->is_gpl_only = gpl_only;
 384         s->namespace = NOFAIL(strdup(namespace));
 385         list_add_tail(&s->list, &mod->exported_symbols);
 386         hash_add_symbol(s);
 387
 388         return s;
 389 }
 390
 391 static void sym_set_crc(struct symbol *sym, unsigned int crc)
 392 {
 393         sym->crc = crc;
 394         sym->crc_valid = true;
 395 }
 396
 397 static void *grab_file(const char *filename, size_t *size)
 398 {
 399         struct stat st;
 400         void *map = MAP_FAILED;
 401         int fd;
 402
 403         fd = open(filename, O_RDONLY);
 404         if (fd < 0)
 405                 return NULL;
 406         if (fstat(fd, &st))
 407                 goto failed;
 408
 409         *size = st.st_size;
 410         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 411
 412 failed:
 413         close(fd);
 414         if (map == MAP_FAILED)
 415                 return NULL;
 416         return map;
 417 }
 418
 419 static void release_file(void *file, size_t size)
 420 {
 421         munmap(file, size);
 422 }
 423
 424 static int parse_elf(struct elf_info *info, const char *filename)
 425 {
 426         unsigned int i;
 427         Elf_Ehdr *hdr;
 428         Elf_Shdr *sechdrs;
 429         Elf_Sym  *sym;
 430         const char *secstrings;
 431         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 432
 433         hdr = grab_file(filename, &info->size);
 434         if (!hdr) {
 435                 if (ignore_missing_files) {
 436                         fprintf(stderr, "%s: %s (ignored)\n", filename,
 437                                 strerror(errno));
 438                         return 0;
 439                 }
 440                 perror(filename);
 441                 exit(1);
 442         }
 443         info->hdr = hdr;
 444         if (info->size < sizeof(*hdr)) {
 445                 /* file too small, assume this is an empty .o file */
 446                 return 0;
 447         }
 448         /* Is this a valid ELF file? */
 449         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 450             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 451             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 452             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 453                 /* Not an ELF file - silently ignore it */
 454                 return 0;
 455         }
 456         /* Fix endianness in ELF header */
 457         hdr->e_type      = TO_NATIVE(hdr->e_type);
 458         hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 459         hdr->e_version   = TO_NATIVE(hdr->e_version);
 460         hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 461         hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 462         hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 463         hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 464         hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 465         hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 466         hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 467         hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 468         hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 469         hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 470         sechdrs = (void *)hdr + hdr->e_shoff;
 471         info->sechdrs = sechdrs;
 472
 473         /* modpost only works for relocatable objects */
 474         if (hdr->e_type != ET_REL)
 475                 fatal("%s: not relocatable object.", filename);
 476
 477         /* Check if file offset is correct */
 478         if (hdr->e_shoff > info->size) {
 479                 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 480                       (unsigned long)hdr->e_shoff, filename, info->size);
 481                 return 0;
 482         }
 483
 484         if (hdr->e_shnum == SHN_UNDEF) {
 485                 /*
 486                  * There are more than 64k sections,
 487                  * read count from .sh_size.
 488                  */
 489                 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 490         }
 491         else {
 492                 info->num_sections = hdr->e_shnum;
 493         }
 494         if (hdr->e_shstrndx == SHN_XINDEX) {
 495                 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 496         }
 497         else {
 498                 info->secindex_strings = hdr->e_shstrndx;
 499         }
 500
 501         /* Fix endianness in section headers */
 502         for (i = 0; i < info->num_sections; i++) {
 503                 sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 504                 sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 505                 sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 506                 sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 507                 sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 508                 sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 509                 sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 510                 sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 511                 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 512                 sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 513         }
 514         /* Find symbol table. */
 515         secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 516         for (i = 1; i < info->num_sections; i++) {
 517                 const char *secname;
 518                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 519
 520                 if (!nobits && sechdrs[i].sh_offset > info->size) {
 521                         fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 522                               filename, (unsigned long)sechdrs[i].sh_offset,
 523                               sizeof(*hdr));
 524                         return 0;
 525                 }
 526                 secname = secstrings + sechdrs[i].sh_name;
 527                 if (strcmp(secname, ".modinfo") == 0) {
 528                         if (nobits)
 529                                 fatal("%s has NOBITS .modinfo\n", filename);
 530                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 531                         info->modinfo_len = sechdrs[i].sh_size;
 532                 } else if (!strcmp(secname, ".export_symbol")) {
 533                         info->export_symbol_secndx = i;
 534                 }
 535
 536                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 537                         unsigned int sh_link_idx;
 538                         symtab_idx = i;
 539                         info->symtab_start = (void *)hdr +
 540                             sechdrs[i].sh_offset;
 541                         info->symtab_stop  = (void *)hdr +
 542                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 543                         sh_link_idx = sechdrs[i].sh_link;
 544                         info->strtab       = (void *)hdr +
 545                             sechdrs[sh_link_idx].sh_offset;
 546                 }
 547
 548                 /* 32bit section no. table? ("more than 64k sections") */
 549                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 550                         symtab_shndx_idx = i;
 551                         info->symtab_shndx_start = (void *)hdr +
 552                             sechdrs[i].sh_offset;
 553                         info->symtab_shndx_stop  = (void *)hdr +
 554                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 555                 }
 556         }
 557         if (!info->symtab_start)
 558                 fatal("%s has no symtab?\n", filename);
 559
 560         /* Fix endianness in symbols */
 561         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 562                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
 563                 sym->st_name  = TO_NATIVE(sym->st_name);
 564                 sym->st_value = TO_NATIVE(sym->st_value);
 565                 sym->st_size  = TO_NATIVE(sym->st_size);
 566         }
 567
 568         if (symtab_shndx_idx != ~0U) {
 569                 Elf32_Word *p;
 570                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 571                         fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 572                               filename, sechdrs[symtab_shndx_idx].sh_link,
 573                               symtab_idx);
 574                 /* Fix endianness */
 575                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 576                      p++)
 577                         *p = TO_NATIVE(*p);
 578         }
 579
 580         return 1;
 581 }
 582
 583 static void parse_elf_finish(struct elf_info *info)
 584 {
 585         release_file(info->hdr, info->size);
 586 }
 587
 588 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 589 {
 590         /* ignore __this_module, it will be resolved shortly */
 591         if (strcmp(symname, "__this_module") == 0)
 592                 return 1;
 593         /* ignore global offset table */
 594         if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 595                 return 1;
 596         if (info->hdr->e_machine == EM_PPC)
 597                 /* Special register function linked on all modules during final link of .ko */
 598                 if (strstarts(symname, "_restgpr_") ||
 599                     strstarts(symname, "_savegpr_") ||
 600                     strstarts(symname, "_rest32gpr_") ||
 601                     strstarts(symname, "_save32gpr_") ||
 602                     strstarts(symname, "_restvr_") ||
 603                     strstarts(symname, "_savevr_"))
 604                         return 1;
 605         if (info->hdr->e_machine == EM_PPC64)
 606                 /* Special register function linked on all modules during final link of .ko */
 607                 if (strstarts(symname, "_restgpr0_") ||
 608                     strstarts(symname, "_savegpr0_") ||
 609                     strstarts(symname, "_restvr_") ||
 610                     strstarts(symname, "_savevr_") ||
 611                     strcmp(symname, ".TOC.") == 0)
 612                         return 1;
 613
 614         if (info->hdr->e_machine == EM_S390)
 615                 /* Expoline thunks are linked on all kernel modules during final link of .ko */
 616                 if (strstarts(symname, "__s390_indirect_jump_r"))
 617                         return 1;
 618         /* Do not ignore this symbol */
 619         return 0;
 620 }
 621
 622 static void handle_symbol(struct module *mod, struct elf_info *info,
 623                           const Elf_Sym *sym, const char *symname)
 624 {
 625         switch (sym->st_shndx) {
 626         case SHN_COMMON:
 627                 if (strstarts(symname, "__gnu_lto_")) {
 628                         /* Should warn here, but modpost runs before the linker */
 629                 } else
 630                         warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 631                 break;
 632         case SHN_UNDEF:
 633                 /* undefined symbol */
 634                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 635                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
 636                         break;
 637                 if (ignore_undef_symbol(info, symname))
 638                         break;
 639                 if (info->hdr->e_machine == EM_SPARC ||
 640                     info->hdr->e_machine == EM_SPARCV9) {
 641                         /* Ignore register directives. */
 642                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 643                                 break;
 644                         if (symname[0] == '.') {
 645                                 char *munged = NOFAIL(strdup(symname));
 646                                 munged[0] = '_';
 647                                 munged[1] = toupper(munged[1]);
 648                                 symname = munged;
 649                         }
 650                 }
 651
 652                 sym_add_unresolved(symname, mod,
 653                                    ELF_ST_BIND(sym->st_info) == STB_WEAK);
 654                 break;
 655         default:
 656                 if (strcmp(symname, "init_module") == 0)
 657                         mod->has_init = true;
 658                 if (strcmp(symname, "cleanup_module") == 0)
 659                         mod->has_cleanup = true;
 660                 break;
 661         }
 662 }
 663
 664 /**
 665  * Parse tag=value strings from .modinfo section
 666  **/
 667 static char *next_string(char *string, unsigned long *secsize)
 668 {
 669         /* Skip non-zero chars */
 670         while (string[0]) {
 671                 string++;
 672                 if ((*secsize)-- <= 1)
 673                         return NULL;
 674         }
 675
 676         /* Skip any zero padding. */
 677         while (!string[0]) {
 678                 string++;
 679                 if ((*secsize)-- <= 1)
 680                         return NULL;
 681         }
 682         return string;
 683 }
 684
 685 static char *get_next_modinfo(struct elf_info *info, const char *tag,
 686                               char *prev)
 687 {
 688         char *p;
 689         unsigned int taglen = strlen(tag);
 690         char *modinfo = info->modinfo;
 691         unsigned long size = info->modinfo_len;
 692
 693         if (prev) {
 694                 size -= prev - modinfo;
 695                 modinfo = next_string(prev, &size);
 696         }
 697
 698         for (p = modinfo; p; p = next_string(p, &size)) {
 699                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 700                         return p + taglen + 1;
 701         }
 702         return NULL;
 703 }
 704
 705 static char *get_modinfo(struct elf_info *info, const char *tag)
 706
 707 {
 708         return get_next_modinfo(info, tag, NULL);
 709 }
 710
 711 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 712 {
 713         if (sym)
 714                 return elf->strtab + sym->st_name;
 715         else
 716                 return "(unknown)";
 717 }
 718
 719 /*
 720  * Check whether the 'string' argument matches one of the 'patterns',
 721  * an array of shell wildcard patterns (glob).
 722  *
 723  * Return true is there is a match.
 724  */
 725 static bool match(const char *string, const char *const patterns[])
 726 {
 727         const char *pattern;
 728
 729         while ((pattern = *patterns++)) {
 730                 if (!fnmatch(pattern, string, 0))
 731                         return true;
 732         }
 733
 734         return false;
 735 }
 736
 737 /* useful to pass patterns to match() directly */
 738 #define PATTERNS(...) \
 739         ({ \
 740                 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 741                 patterns; \
 742         })
 743
 744 /* sections that we do not want to do full section mismatch check on */
 745 static const char *const section_white_list[] =
 746 {
 747         ".comment*",
 748         ".debug*",
 749         ".zdebug*",             /* Compressed debug sections. */
 750         ".GCC.command.line",    /* record-gcc-switches */
 751         ".mdebug*",        /* alpha, score, mips etc. */
 752         ".pdr",            /* alpha, score, mips etc. */
 753         ".stab*",
 754         ".note*",
 755         ".got*",
 756         ".toc*",
 757         ".xt.prop",                              /* xtensa */
 758         ".xt.lit",         /* xtensa */
 759         ".arcextmap*",                  /* arc */
 760         ".gnu.linkonce.arcext*",        /* arc : modules */
 761         ".cmem*",                       /* EZchip */
 762         ".fmt_slot*",                   /* EZchip */
 763         ".gnu.lto*",
 764         ".discard.*",
 765         ".llvm.call-graph-profile",     /* call graph */
 766         NULL
 767 };
 768
 769 /*
 770  * This is used to find sections missing the SHF_ALLOC flag.
 771  * The cause of this is often a section specified in assembler
 772  * without "ax" / "aw".
 773  */
 774 static void check_section(const char *modname, struct elf_info *elf,
 775                           Elf_Shdr *sechdr)
 776 {
 777         const char *sec = sech_name(elf, sechdr);
 778
 779         if (sechdr->sh_type == SHT_PROGBITS &&
 780             !(sechdr->sh_flags & SHF_ALLOC) &&
 781             !match(sec, section_white_list)) {
 782                 warn("%s (%s): unexpected non-allocatable section.\n"
 783                      "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 784                      "Note that for example <linux/init.h> contains\n"
 785                      "section definitions for use in .S files.\n\n",
 786                      modname, sec);
 787         }
 788 }
 789
 790
 791
 792 #define ALL_INIT_DATA_SECTIONS \
 793         ".init.setup", ".init.rodata", ".meminit.rodata", \
 794         ".init.data", ".meminit.data"
 795 #define ALL_EXIT_DATA_SECTIONS \
 796         ".exit.data", ".memexit.data"
 797
 798 #define ALL_INIT_TEXT_SECTIONS \
 799         ".init.text", ".meminit.text"
 800 #define ALL_EXIT_TEXT_SECTIONS \
 801         ".exit.text", ".memexit.text"
 802
 803 #define ALL_PCI_INIT_SECTIONS   \
 804         ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 805         ".pci_fixup_enable", ".pci_fixup_resume", \
 806         ".pci_fixup_resume_early", ".pci_fixup_suspend"
 807
 808 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
 809 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
 810
 811 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 812 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 813
 814 #define DATA_SECTIONS ".data", ".data.rel"
 815 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 816                 ".kprobes.text", ".cpuidle.text", ".noinstr.text"
 817 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 818                 ".fixup", ".entry.text", ".exception.text", \
 819                 ".coldtext", ".softirqentry.text"
 820
 821 #define INIT_SECTIONS      ".init.*"
 822 #define MEM_INIT_SECTIONS  ".meminit.*"
 823
 824 #define EXIT_SECTIONS      ".exit.*"
 825 #define MEM_EXIT_SECTIONS  ".memexit.*"
 826
 827 #define ALL_TEXT_SECTIONS  ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
 828                 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 829
 830 enum mismatch {
 831         TEXT_TO_ANY_INIT,
 832         DATA_TO_ANY_INIT,
 833         TEXTDATA_TO_ANY_EXIT,
 834         XXXINIT_TO_SOME_INIT,
 835         XXXEXIT_TO_SOME_EXIT,
 836         ANY_INIT_TO_ANY_EXIT,
 837         ANY_EXIT_TO_ANY_INIT,
 838         EXTABLE_TO_NON_TEXT,
 839 };
 840
 841 /**
 842  * Describe how to match sections on different criteria:
 843  *
 844  * @fromsec: Array of sections to be matched.
 845  *
 846  * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 847  * this array is forbidden (black-list).  Can be empty.
 848  *
 849  * @good_tosec: Relocations applied to a section in @fromsec must be
 850  * targeting sections in this array (white-list).  Can be empty.
 851  *
 852  * @mismatch: Type of mismatch.
 853  */
 854 struct sectioncheck {
 855         const char *fromsec[20];
 856         const char *bad_tosec[20];
 857         const char *good_tosec[20];
 858         enum mismatch mismatch;
 859 };
 860
 861 static const struct sectioncheck sectioncheck[] = {
 862 /* Do not reference init/exit code/data from
 863  * normal code and data
 864  */
 865 {
 866         .fromsec = { TEXT_SECTIONS, NULL },
 867         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 868         .mismatch = TEXT_TO_ANY_INIT,
 869 },
 870 {
 871         .fromsec = { DATA_SECTIONS, NULL },
 872         .bad_tosec = { ALL_XXXINIT_SECTIONS, INIT_SECTIONS, NULL },
 873         .mismatch = DATA_TO_ANY_INIT,
 874 },
 875 {
 876         .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 877         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 878         .mismatch = TEXTDATA_TO_ANY_EXIT,
 879 },
 880 /* Do not reference init code/data from meminit code/data */
 881 {
 882         .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 883         .bad_tosec = { INIT_SECTIONS, NULL },
 884         .mismatch = XXXINIT_TO_SOME_INIT,
 885 },
 886 /* Do not reference exit code/data from memexit code/data */
 887 {
 888         .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
 889         .bad_tosec = { EXIT_SECTIONS, NULL },
 890         .mismatch = XXXEXIT_TO_SOME_EXIT,
 891 },
 892 /* Do not use exit code/data from init code */
 893 {
 894         .fromsec = { ALL_INIT_SECTIONS, NULL },
 895         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 896         .mismatch = ANY_INIT_TO_ANY_EXIT,
 897 },
 898 /* Do not use init code/data from exit code */
 899 {
 900         .fromsec = { ALL_EXIT_SECTIONS, NULL },
 901         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 902         .mismatch = ANY_EXIT_TO_ANY_INIT,
 903 },
 904 {
 905         .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 906         .bad_tosec = { INIT_SECTIONS, NULL },
 907         .mismatch = ANY_INIT_TO_ANY_EXIT,
 908 },
 909 {
 910         .fromsec = { "__ex_table", NULL },
 911         /* If you're adding any new black-listed sections in here, consider
 912          * adding a special 'printer' for them in scripts/check_extable.
 913          */
 914         .bad_tosec = { ".altinstr_replacement", NULL },
 915         .good_tosec = {ALL_TEXT_SECTIONS , NULL},
 916         .mismatch = EXTABLE_TO_NON_TEXT,
 917 }
 918 };
 919
 920 static const struct sectioncheck *section_mismatch(
 921                 const char *fromsec, const char *tosec)
 922 {
 923         int i;
 924
 925         /*
 926          * The target section could be the SHT_NUL section when we're
 927          * handling relocations to un-resolved symbols, trying to match it
 928          * doesn't make much sense and causes build failures on parisc
 929          * architectures.
 930          */
 931         if (*tosec == '\0')
 932                 return NULL;
 933
 934         for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 935                 const struct sectioncheck *check = &sectioncheck[i];
 936
 937                 if (match(fromsec, check->fromsec)) {
 938                         if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 939                                 return check;
 940                         if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 941                                 return check;
 942                 }
 943         }
 944         return NULL;
 945 }
 946
 947 /**
 948  * Whitelist to allow certain references to pass with no warning.
 949  *
 950  * Pattern 1:
 951  *   If a module parameter is declared __initdata and permissions=0
 952  *   then this is legal despite the warning generated.
 953  *   We cannot see value of permissions here, so just ignore
 954  *   this pattern.
 955  *   The pattern is identified by:
 956  *   tosec   = .init.data
 957  *   fromsec = .data*
 958  *   atsym   =__param*
 959  *
 960  * Pattern 1a:
 961  *   module_param_call() ops can refer to __init set function if permissions=0
 962  *   The pattern is identified by:
 963  *   tosec   = .init.text
 964  *   fromsec = .data*
 965  *   atsym   = __param_ops_*
 966  *
 967  * Pattern 3:
 968  *   Whitelist all references from .head.text to any init section
 969  *
 970  * Pattern 4:
 971  *   Some symbols belong to init section but still it is ok to reference
 972  *   these from non-init sections as these symbols don't have any memory
 973  *   allocated for them and symbol address and value are same. So even
 974  *   if init section is freed, its ok to reference those symbols.
 975  *   For ex. symbols marking the init section boundaries.
 976  *   This pattern is identified by
 977  *   refsymname = __init_begin, _sinittext, _einittext
 978  *
 979  * Pattern 5:
 980  *   GCC may optimize static inlines when fed constant arg(s) resulting
 981  *   in functions like cpumask_empty() -- generating an associated symbol
 982  *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 983  *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 984  *   meaningless section warning.  May need to add isra symbols too...
 985  *   This pattern is identified by
 986  *   tosec   = init section
 987  *   fromsec = text section
 988  *   refsymname = *.constprop.*
 989  *
 990  **/
 991 static int secref_whitelist(const char *fromsec, const char *fromsym,
 992                             const char *tosec, const char *tosym)
 993 {
 994         /* Check for pattern 1 */
 995         if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 996             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 997             strstarts(fromsym, "__param"))
 998                 return 0;
 999
1000         /* Check for pattern 1a */
1001         if (strcmp(tosec, ".init.text") == 0 &&
1002             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1003             strstarts(fromsym, "__param_ops_"))
1004                 return 0;
1005
1006         /* symbols in data sections that may refer to any init/exit sections */
1007         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1008             match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
1009             match(fromsym, PATTERNS("*_template", // scsi uses *_template a lot
1010                                     "*_timer", // arm uses ops structures named _timer a lot
1011                                     "*_sht", // scsi also used *_sht to some extent
1012                                     "*_ops",
1013                                     "*_probe",
1014                                     "*_probe_one",
1015                                     "*_console")))
1016                 return 0;
1017
1018         /* symbols in data sections that may refer to meminit/exit sections */
1019         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
1020             match(tosec, PATTERNS(ALL_XXXINIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
1021             match(fromsym, PATTERNS("*driver")))
1022                 return 0;
1023
1024         /* Check for pattern 3 */
1025         if (strstarts(fromsec, ".head.text") &&
1026             match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
1027                 return 0;
1028
1029         /* Check for pattern 4 */
1030         if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
1031                 return 0;
1032
1033         /* Check for pattern 5 */
1034         if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
1035             match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
1036             match(fromsym, PATTERNS("*.constprop.*")))
1037                 return 0;
1038
1039         return 1;
1040 }
1041
1042 /*
1043  * If there's no name there, ignore it; likewise, ignore it if it's
1044  * one of the magic symbols emitted used by current tools.
1045  *
1046  * Otherwise if find_symbols_between() returns those symbols, they'll
1047  * fail the whitelist tests and cause lots of false alarms ... fixable
1048  * only by merging __exit and __init sections into __text, bloating
1049  * the kernel (which is especially evil on embedded platforms).
1050  */
1051 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1052 {
1053         const char *name = elf->strtab + sym->st_name;
1054
1055         if (!name || !strlen(name))
1056                 return 0;
1057         return !is_mapping_symbol(name);
1058 }
1059
1060 /* Look up the nearest symbol based on the section and the address */
1061 static Elf_Sym *find_nearest_sym(struct elf_info *elf, Elf_Addr addr,
1062                                  unsigned int secndx, bool allow_negative,
1063                                  Elf_Addr min_distance)
1064 {
1065         Elf_Sym *sym;
1066         Elf_Sym *near = NULL;
1067         Elf_Addr sym_addr, distance;
1068         bool is_arm = (elf->hdr->e_machine == EM_ARM);
1069
1070         for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1071                 if (get_secindex(elf, sym) != secndx)
1072                         continue;
1073                 if (!is_valid_name(elf, sym))
1074                         continue;
1075
1076                 sym_addr = sym->st_value;
1077
1078                 /*
1079                  * For ARM Thumb instruction, the bit 0 of st_value is set
1080                  * if the symbol is STT_FUNC type. Mask it to get the address.
1081                  */
1082                 if (is_arm && ELF_ST_TYPE(sym->st_info) == STT_FUNC)
1083                          sym_addr &= ~1;
1084
1085                 if (addr >= sym_addr)
1086                         distance = addr - sym_addr;
1087                 else if (allow_negative)
1088                         distance = sym_addr - addr;
1089                 else
1090                         continue;
1091
1092                 if (distance <= min_distance) {
1093                         min_distance = distance;
1094                         near = sym;
1095                 }
1096
1097                 if (min_distance == 0)
1098                         break;
1099         }
1100         return near;
1101 }
1102
1103 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1104                              unsigned int secndx)
1105 {
1106         return find_nearest_sym(elf, addr, secndx, false, ~0);
1107 }
1108
1109 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1110 {
1111         /* If the supplied symbol has a valid name, return it */
1112         if (is_valid_name(elf, sym))
1113                 return sym;
1114
1115         /*
1116          * Strive to find a better symbol name, but the resulting name may not
1117          * match the symbol referenced in the original code.
1118          */
1119         return find_nearest_sym(elf, addr, get_secindex(elf, sym), true, 20);
1120 }
1121
1122 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1123 {
1124         if (secndx >= elf->num_sections)
1125                 return false;
1126
1127         return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1128 }
1129
1130 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1131                                      const struct sectioncheck* const mismatch,
1132                                      Elf_Sym *tsym,
1133                                      unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1134                                      const char *tosec, Elf_Addr taddr)
1135 {
1136         Elf_Sym *from;
1137         const char *tosym;
1138         const char *fromsym;
1139
1140         from = find_fromsym(elf, faddr, fsecndx);
1141         fromsym = sym_name(elf, from);
1142
1143         tsym = find_tosym(elf, taddr, tsym);
1144         tosym = sym_name(elf, tsym);
1145
1146         /* check whitelist - we may ignore it */
1147         if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1148                 return;
1149
1150         sec_mismatch_count++;
1151
1152         warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1153              modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec);
1154
1155         if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1156                 if (match(tosec, mismatch->bad_tosec))
1157                         fatal("The relocation at %s+0x%lx references\n"
1158                               "section \"%s\" which is black-listed.\n"
1159                               "Something is seriously wrong and should be fixed.\n"
1160                               "You might get more information about where this is\n"
1161                               "coming from by using scripts/check_extable.sh %s\n",
1162                               fromsec, (long)faddr, tosec, modname);
1163                 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1164                         warn("The relocation at %s+0x%lx references\n"
1165                              "section \"%s\" which is not in the list of\n"
1166                              "authorized sections.  If you're adding a new section\n"
1167                              "and/or if this reference is valid, add \"%s\" to the\n"
1168                              "list of authorized sections to jump to on fault.\n"
1169                              "This can be achieved by adding \"%s\" to\n"
1170                              "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1171                              fromsec, (long)faddr, tosec, tosec, tosec);
1172                 else
1173                         error("%s+0x%lx references non-executable section '%s'\n",
1174                               fromsec, (long)faddr, tosec);
1175         }
1176 }
1177
1178 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1179                                 Elf_Addr faddr, const char *secname,
1180                                 Elf_Sym *sym)
1181 {
1182         static const char *prefix = "__export_symbol_";
1183         const char *label_name, *name, *data;
1184         Elf_Sym *label;
1185         struct symbol *s;
1186         bool is_gpl;
1187
1188         label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1189         label_name = sym_name(elf, label);
1190
1191         if (!strstarts(label_name, prefix)) {
1192                 error("%s: .export_symbol section contains strange symbol '%s'\n",
1193                       mod->name, label_name);
1194                 return;
1195         }
1196
1197         if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1198             ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1199                 error("%s: local symbol '%s' was exported\n", mod->name,
1200                       label_name + strlen(prefix));
1201                 return;
1202         }
1203
1204         name = sym_name(elf, sym);
1205         if (strcmp(label_name + strlen(prefix), name)) {
1206                 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1207                       mod->name, name);
1208                 return;
1209         }
1210
1211         data = sym_get_data(elf, label);        /* license */
1212         if (!strcmp(data, "GPL")) {
1213                 is_gpl = true;
1214         } else if (!strcmp(data, "")) {
1215                 is_gpl = false;
1216         } else {
1217                 error("%s: unknown license '%s' was specified for '%s'\n",
1218                       mod->name, data, name);
1219                 return;
1220         }
1221
1222         data += strlen(data) + 1;       /* namespace */
1223         s = sym_add_exported(name, mod, is_gpl, data);
1224
1225         /*
1226          * We need to be aware whether we are exporting a function or
1227          * a data on some architectures.
1228          */
1229         s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1230
1231         if (match(secname, PATTERNS(INIT_SECTIONS)))
1232                 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1233                      mod->name, name);
1234         else if (match(secname, PATTERNS(EXIT_SECTIONS)))
1235                 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1236                      mod->name, name);
1237 }
1238
1239 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1240                                    Elf_Sym *sym,
1241                                    unsigned int fsecndx, const char *fromsec,
1242                                    Elf_Addr faddr, Elf_Addr taddr)
1243 {
1244         const char *tosec = sec_name(elf, get_secindex(elf, sym));
1245         const struct sectioncheck *mismatch;
1246
1247         if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1248                 check_export_symbol(mod, elf, faddr, tosec, sym);
1249                 return;
1250         }
1251
1252         mismatch = section_mismatch(fromsec, tosec);
1253         if (!mismatch)
1254                 return;
1255
1256         default_mismatch_handler(mod->name, elf, mismatch, sym,
1257                                  fsecndx, fromsec, faddr,
1258                                  tosec, taddr);
1259 }
1260
1261 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1262 {
1263         switch (r_type) {
1264         case R_386_32:
1265                 return TO_NATIVE(*location);
1266         case R_386_PC32:
1267                 return TO_NATIVE(*location) + 4;
1268         }
1269
1270         return (Elf_Addr)(-1);
1271 }
1272
1273 #ifndef R_ARM_CALL
1274 #define R_ARM_CALL      28
1275 #endif
1276 #ifndef R_ARM_JUMP24
1277 #define R_ARM_JUMP24    29
1278 #endif
1279
1280 #ifndef R_ARM_THM_CALL
1281 #define R_ARM_THM_CALL          10
1282 #endif
1283 #ifndef R_ARM_THM_JUMP24
1284 #define R_ARM_THM_JUMP24        30
1285 #endif
1286
1287 #ifndef R_ARM_MOVW_ABS_NC
1288 #define R_ARM_MOVW_ABS_NC       43
1289 #endif
1290
1291 #ifndef R_ARM_MOVT_ABS
1292 #define R_ARM_MOVT_ABS          44
1293 #endif
1294
1295 #ifndef R_ARM_THM_MOVW_ABS_NC
1296 #define R_ARM_THM_MOVW_ABS_NC   47
1297 #endif
1298
1299 #ifndef R_ARM_THM_MOVT_ABS
1300 #define R_ARM_THM_MOVT_ABS      48
1301 #endif
1302
1303 #ifndef R_ARM_THM_JUMP19
1304 #define R_ARM_THM_JUMP19        51
1305 #endif
1306
1307 static int32_t sign_extend32(int32_t value, int index)
1308 {
1309         uint8_t shift = 31 - index;
1310
1311         return (int32_t)(value << shift) >> shift;
1312 }
1313
1314 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1315 {
1316         uint32_t inst, upper, lower, sign, j1, j2;
1317         int32_t offset;
1318
1319         switch (r_type) {
1320         case R_ARM_ABS32:
1321         case R_ARM_REL32:
1322                 inst = TO_NATIVE(*(uint32_t *)loc);
1323                 return inst + sym->st_value;
1324         case R_ARM_MOVW_ABS_NC:
1325         case R_ARM_MOVT_ABS:
1326                 inst = TO_NATIVE(*(uint32_t *)loc);
1327                 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1328                                        15);
1329                 return offset + sym->st_value;
1330         case R_ARM_PC24:
1331         case R_ARM_CALL:
1332         case R_ARM_JUMP24:
1333                 inst = TO_NATIVE(*(uint32_t *)loc);
1334                 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1335                 return offset + sym->st_value + 8;
1336         case R_ARM_THM_MOVW_ABS_NC:
1337         case R_ARM_THM_MOVT_ABS:
1338                 upper = TO_NATIVE(*(uint16_t *)loc);
1339                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1340                 offset = sign_extend32(((upper & 0x000f) << 12) |
1341                                        ((upper & 0x0400) << 1) |
1342                                        ((lower & 0x7000) >> 4) |
1343                                        (lower & 0x00ff),
1344                                        15);
1345                 return offset + sym->st_value;
1346         case R_ARM_THM_JUMP19:
1347                 /*
1348                  * Encoding T3:
1349                  * S     = upper[10]
1350                  * imm6  = upper[5:0]
1351                  * J1    = lower[13]
1352                  * J2    = lower[11]
1353                  * imm11 = lower[10:0]
1354                  * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1355                  */
1356                 upper = TO_NATIVE(*(uint16_t *)loc);
1357                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1358
1359                 sign = (upper >> 10) & 1;
1360                 j1 = (lower >> 13) & 1;
1361                 j2 = (lower >> 11) & 1;
1362                 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1363                                        ((upper & 0x03f) << 12) |
1364                                        ((lower & 0x07ff) << 1),
1365                                        20);
1366                 return offset + sym->st_value + 4;
1367         case R_ARM_THM_CALL:
1368         case R_ARM_THM_JUMP24:
1369                 /*
1370                  * Encoding T4:
1371                  * S     = upper[10]
1372                  * imm10 = upper[9:0]
1373                  * J1    = lower[13]
1374                  * J2    = lower[11]
1375                  * imm11 = lower[10:0]
1376                  * I1    = NOT(J1 XOR S)
1377                  * I2    = NOT(J2 XOR S)
1378                  * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1379                  */
1380                 upper = TO_NATIVE(*(uint16_t *)loc);
1381                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1382
1383                 sign = (upper >> 10) & 1;
1384                 j1 = (lower >> 13) & 1;
1385                 j2 = (lower >> 11) & 1;
1386                 offset = sign_extend32((sign << 24) |
1387                                        ((~(j1 ^ sign) & 1) << 23) |
1388                                        ((~(j2 ^ sign) & 1) << 22) |
1389                                        ((upper & 0x03ff) << 12) |
1390                                        ((lower & 0x07ff) << 1),
1391                                        24);
1392                 return offset + sym->st_value + 4;
1393         }
1394
1395         return (Elf_Addr)(-1);
1396 }
1397
1398 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1399 {
1400         uint32_t inst;
1401
1402         inst = TO_NATIVE(*location);
1403         switch (r_type) {
1404         case R_MIPS_LO16:
1405                 return inst & 0xffff;
1406         case R_MIPS_26:
1407                 return (inst & 0x03ffffff) << 2;
1408         case R_MIPS_32:
1409                 return inst;
1410         }
1411         return (Elf_Addr)(-1);
1412 }
1413
1414 #ifndef EM_RISCV
1415 #define EM_RISCV                243
1416 #endif
1417
1418 #ifndef R_RISCV_SUB32
1419 #define R_RISCV_SUB32           39
1420 #endif
1421
1422 #ifndef EM_LOONGARCH
1423 #define EM_LOONGARCH            258
1424 #endif
1425
1426 #ifndef R_LARCH_SUB32
1427 #define R_LARCH_SUB32           55
1428 #endif
1429
1430 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1431                                  unsigned int *r_type, unsigned int *r_sym)
1432 {
1433         typedef struct {
1434                 Elf64_Word    r_sym;    /* Symbol index */
1435                 unsigned char r_ssym;   /* Special symbol for 2nd relocation */
1436                 unsigned char r_type3;  /* 3rd relocation type */
1437                 unsigned char r_type2;  /* 2nd relocation type */
1438                 unsigned char r_type;   /* 1st relocation type */
1439         } Elf64_Mips_R_Info;
1440
1441         bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1442
1443         if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1444                 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1445
1446                 *r_type = mips64_r_info->r_type;
1447                 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1448                 return;
1449         }
1450
1451         if (is_64bit) {
1452                 Elf64_Xword r_info64 = r_info;
1453
1454                 r_info = TO_NATIVE(r_info64);
1455         } else {
1456                 Elf32_Word r_info32 = r_info;
1457
1458                 r_info = TO_NATIVE(r_info32);
1459         }
1460
1461         *r_type = ELF_R_TYPE(r_info);
1462         *r_sym = ELF_R_SYM(r_info);
1463 }
1464
1465 static void section_rela(struct module *mod, struct elf_info *elf,
1466                          Elf_Shdr *sechdr)
1467 {
1468         Elf_Rela *rela;
1469         unsigned int fsecndx = sechdr->sh_info;
1470         const char *fromsec = sec_name(elf, fsecndx);
1471         Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1472         Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1473
1474         /* if from section (name) is know good then skip it */
1475         if (match(fromsec, section_white_list))
1476                 return;
1477
1478         for (rela = start; rela < stop; rela++) {
1479                 Elf_Addr taddr, r_offset;
1480                 unsigned int r_type, r_sym;
1481
1482                 r_offset = TO_NATIVE(rela->r_offset);
1483                 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1484
1485                 taddr = TO_NATIVE(rela->r_addend);
1486
1487                 switch (elf->hdr->e_machine) {
1488                 case EM_RISCV:
1489                         if (!strcmp("__ex_table", fromsec) &&
1490                             r_type == R_RISCV_SUB32)
1491                                 continue;
1492                         break;
1493                 case EM_LOONGARCH:
1494                         if (!strcmp("__ex_table", fromsec) &&
1495                             r_type == R_LARCH_SUB32)
1496                                 continue;
1497                         break;
1498                 }
1499
1500                 check_section_mismatch(mod, elf, elf->symtab_start + r_sym,
1501                                        fsecndx, fromsec, r_offset, taddr);
1502         }
1503 }
1504
1505 static void section_rel(struct module *mod, struct elf_info *elf,
1506                         Elf_Shdr *sechdr)
1507 {
1508         Elf_Rel *rel;
1509         unsigned int fsecndx = sechdr->sh_info;
1510         const char *fromsec = sec_name(elf, fsecndx);
1511         Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1512         Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1513
1514         /* if from section (name) is know good then skip it */
1515         if (match(fromsec, section_white_list))
1516                 return;
1517
1518         for (rel = start; rel < stop; rel++) {
1519                 Elf_Sym *tsym;
1520                 Elf_Addr taddr = 0, r_offset;
1521                 unsigned int r_type, r_sym;
1522                 void *loc;
1523
1524                 r_offset = TO_NATIVE(rel->r_offset);
1525                 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1526
1527                 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1528                 tsym = elf->symtab_start + r_sym;
1529
1530                 switch (elf->hdr->e_machine) {
1531                 case EM_386:
1532                         taddr = addend_386_rel(loc, r_type);
1533                         break;
1534                 case EM_ARM:
1535                         taddr = addend_arm_rel(loc, tsym, r_type);
1536                         break;
1537                 case EM_MIPS:
1538                         taddr = addend_mips_rel(loc, r_type);
1539                         break;
1540                 default:
1541                         fatal("Please add code to calculate addend for this architecture\n");
1542                 }
1543
1544                 check_section_mismatch(mod, elf, tsym,
1545                                        fsecndx, fromsec, r_offset, taddr);
1546         }
1547 }
1548
1549 /**
1550  * A module includes a number of sections that are discarded
1551  * either when loaded or when used as built-in.
1552  * For loaded modules all functions marked __init and all data
1553  * marked __initdata will be discarded when the module has been initialized.
1554  * Likewise for modules used built-in the sections marked __exit
1555  * are discarded because __exit marked function are supposed to be called
1556  * only when a module is unloaded which never happens for built-in modules.
1557  * The check_sec_ref() function traverses all relocation records
1558  * to find all references to a section that reference a section that will
1559  * be discarded and warns about it.
1560  **/
1561 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1562 {
1563         int i;
1564         Elf_Shdr *sechdrs = elf->sechdrs;
1565
1566         /* Walk through all sections */
1567         for (i = 0; i < elf->num_sections; i++) {
1568                 check_section(mod->name, elf, &elf->sechdrs[i]);
1569                 /* We want to process only relocation sections and not .init */
1570                 if (sechdrs[i].sh_type == SHT_RELA)
1571                         section_rela(mod, elf, &elf->sechdrs[i]);
1572                 else if (sechdrs[i].sh_type == SHT_REL)
1573                         section_rel(mod, elf, &elf->sechdrs[i]);
1574         }
1575 }
1576
1577 static char *remove_dot(char *s)
1578 {
1579         size_t n = strcspn(s, ".");
1580
1581         if (n && s[n]) {
1582                 size_t m = strspn(s + n + 1, "0123456789");
1583                 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1584                         s[n] = 0;
1585         }
1586         return s;
1587 }
1588
1589 /*
1590  * The CRCs are recorded in .*.cmd files in the form of:
1591  * #SYMVER <name> <crc>
1592  */
1593 static void extract_crcs_for_object(const char *object, struct module *mod)
1594 {
1595         char cmd_file[PATH_MAX];
1596         char *buf, *p;
1597         const char *base;
1598         int dirlen, ret;
1599
1600         base = strrchr(object, '/');
1601         if (base) {
1602                 base++;
1603                 dirlen = base - object;
1604         } else {
1605                 dirlen = 0;
1606                 base = object;
1607         }
1608
1609         ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1610                        dirlen, object, base);
1611         if (ret >= sizeof(cmd_file)) {
1612                 error("%s: too long path was truncated\n", cmd_file);
1613                 return;
1614         }
1615
1616         buf = read_text_file(cmd_file);
1617         p = buf;
1618
1619         while ((p = strstr(p, "\n#SYMVER "))) {
1620                 char *name;
1621                 size_t namelen;
1622                 unsigned int crc;
1623                 struct symbol *sym;
1624
1625                 name = p + strlen("\n#SYMVER ");
1626
1627                 p = strchr(name, ' ');
1628                 if (!p)
1629                         break;
1630
1631                 namelen = p - name;
1632                 p++;
1633
1634                 if (!isdigit(*p))
1635                         continue;       /* skip this line */
1636
1637                 crc = strtoul(p, &p, 0);
1638                 if (*p != '\n')
1639                         continue;       /* skip this line */
1640
1641                 name[namelen] = '\0';
1642
1643                 /*
1644                  * sym_find_with_module() may return NULL here.
1645                  * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1646                  * Since commit e1327a127703, genksyms calculates CRCs of all
1647                  * symbols, including trimmed ones. Ignore orphan CRCs.
1648                  */
1649                 sym = sym_find_with_module(name, mod);
1650                 if (sym)
1651                         sym_set_crc(sym, crc);
1652         }
1653
1654         free(buf);
1655 }
1656
1657 /*
1658  * The symbol versions (CRC) are recorded in the .*.cmd files.
1659  * Parse them to retrieve CRCs for the current module.
1660  */
1661 static void mod_set_crcs(struct module *mod)
1662 {
1663         char objlist[PATH_MAX];
1664         char *buf, *p, *obj;
1665         int ret;
1666
1667         if (mod->is_vmlinux) {
1668                 strcpy(objlist, ".vmlinux.objs");
1669         } else {
1670                 /* objects for a module are listed in the *.mod file. */
1671                 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1672                 if (ret >= sizeof(objlist)) {
1673                         error("%s: too long path was truncated\n", objlist);
1674                         return;
1675                 }
1676         }
1677
1678         buf = read_text_file(objlist);
1679         p = buf;
1680
1681         while ((obj = strsep(&p, "\n")) && obj[0])
1682                 extract_crcs_for_object(obj, mod);
1683
1684         free(buf);
1685 }
1686
1687 static void read_symbols(const char *modname)
1688 {
1689         const char *symname;
1690         char *version;
1691         char *license;
1692         char *namespace;
1693         struct module *mod;
1694         struct elf_info info = { };
1695         Elf_Sym *sym;
1696
1697         if (!parse_elf(&info, modname))
1698                 return;
1699
1700         if (!strends(modname, ".o")) {
1701                 error("%s: filename must be suffixed with .o\n", modname);
1702                 return;
1703         }
1704
1705         /* strip trailing .o */
1706         mod = new_module(modname, strlen(modname) - strlen(".o"));
1707
1708         if (!mod->is_vmlinux) {
1709                 license = get_modinfo(&info, "license");
1710                 if (!license)
1711                         error("missing MODULE_LICENSE() in %s\n", modname);
1712                 while (license) {
1713                         if (!license_is_gpl_compatible(license)) {
1714                                 mod->is_gpl_compatible = false;
1715                                 break;
1716                         }
1717                         license = get_next_modinfo(&info, "license", license);
1718                 }
1719
1720                 namespace = get_modinfo(&info, "import_ns");
1721                 while (namespace) {
1722                         add_namespace(&mod->imported_namespaces, namespace);
1723                         namespace = get_next_modinfo(&info, "import_ns",
1724                                                      namespace);
1725                 }
1726         }
1727
1728         if (extra_warn && !get_modinfo(&info, "description"))
1729                 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1730         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1731                 symname = remove_dot(info.strtab + sym->st_name);
1732
1733                 handle_symbol(mod, &info, sym, symname);
1734                 handle_moddevtable(mod, &info, sym, symname);
1735         }
1736
1737         check_sec_ref(mod, &info);
1738
1739         if (!mod->is_vmlinux) {
1740                 version = get_modinfo(&info, "version");
1741                 if (version || all_versions)
1742                         get_src_version(mod->name, mod->srcversion,
1743                                         sizeof(mod->srcversion) - 1);
1744         }
1745
1746         parse_elf_finish(&info);
1747
1748         if (modversions) {
1749                 /*
1750                  * Our trick to get versioning for module struct etc. - it's
1751                  * never passed as an argument to an exported function, so
1752                  * the automatic versioning doesn't pick it up, but it's really
1753                  * important anyhow.
1754                  */
1755                 sym_add_unresolved("module_layout", mod, false);
1756
1757                 mod_set_crcs(mod);
1758         }
1759 }
1760
1761 static void read_symbols_from_files(const char *filename)
1762 {
1763         FILE *in = stdin;
1764         char fname[PATH_MAX];
1765
1766         in = fopen(filename, "r");
1767         if (!in)
1768                 fatal("Can't open filenames file %s: %m", filename);
1769
1770         while (fgets(fname, PATH_MAX, in) != NULL) {
1771                 if (strends(fname, "\n"))
1772                         fname[strlen(fname)-1] = '\0';
1773                 read_symbols(fname);
1774         }
1775
1776         fclose(in);
1777 }
1778
1779 #define SZ 500
1780
1781 /* We first write the generated file into memory using the
1782  * following helper, then compare to the file on disk and
1783  * only update the later if anything changed */
1784
1785 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1786                                                       const char *fmt, ...)
1787 {
1788         char tmp[SZ];
1789         int len;
1790         va_list ap;
1791
1792         va_start(ap, fmt);
1793         len = vsnprintf(tmp, SZ, fmt, ap);
1794         buf_write(buf, tmp, len);
1795         va_end(ap);
1796 }
1797
1798 void buf_write(struct buffer *buf, const char *s, int len)
1799 {
1800         if (buf->size - buf->pos < len) {
1801                 buf->size += len + SZ;
1802                 buf->p = NOFAIL(realloc(buf->p, buf->size));
1803         }
1804         strncpy(buf->p + buf->pos, s, len);
1805         buf->pos += len;
1806 }
1807
1808 static void check_exports(struct module *mod)
1809 {
1810         struct symbol *s, *exp;
1811
1812         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1813                 const char *basename;
1814                 exp = find_symbol(s->name);
1815                 if (!exp) {
1816                         if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1817                                 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1818                                             "\"%s\" [%s.ko] undefined!\n",
1819                                             s->name, mod->name);
1820                         continue;
1821                 }
1822                 if (exp->module == mod) {
1823                         error("\"%s\" [%s.ko] was exported without definition\n",
1824                               s->name, mod->name);
1825                         continue;
1826                 }
1827
1828                 exp->used = true;
1829                 s->module = exp->module;
1830                 s->crc_valid = exp->crc_valid;
1831                 s->crc = exp->crc;
1832
1833                 basename = strrchr(mod->name, '/');
1834                 if (basename)
1835                         basename++;
1836                 else
1837                         basename = mod->name;
1838
1839                 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1840                         modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1841                                     "module %s uses symbol %s from namespace %s, but does not import it.\n",
1842                                     basename, exp->name, exp->namespace);
1843                         add_namespace(&mod->missing_namespaces, exp->namespace);
1844                 }
1845
1846                 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1847                         error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1848                               basename, exp->name);
1849         }
1850 }
1851
1852 static void handle_white_list_exports(const char *white_list)
1853 {
1854         char *buf, *p, *name;
1855
1856         buf = read_text_file(white_list);
1857         p = buf;
1858
1859         while ((name = strsep(&p, "\n"))) {
1860                 struct symbol *sym = find_symbol(name);
1861
1862                 if (sym)
1863                         sym->used = true;
1864         }
1865
1866         free(buf);
1867 }
1868
1869 static void check_modname_len(struct module *mod)
1870 {
1871         const char *mod_name;
1872
1873         mod_name = strrchr(mod->name, '/');
1874         if (mod_name == NULL)
1875                 mod_name = mod->name;
1876         else
1877                 mod_name++;
1878         if (strlen(mod_name) >= MODULE_NAME_LEN)
1879                 error("module name is too long [%s.ko]\n", mod->name);
1880 }
1881
1882 /**
1883  * Header for the generated file
1884  **/
1885 static void add_header(struct buffer *b, struct module *mod)
1886 {
1887         buf_printf(b, "#include <linux/module.h>\n");
1888         /*
1889          * Include build-salt.h after module.h in order to
1890          * inherit the definitions.
1891          */
1892         buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1893         buf_printf(b, "#include <linux/build-salt.h>\n");
1894         buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1895         buf_printf(b, "#include <linux/export-internal.h>\n");
1896         buf_printf(b, "#include <linux/vermagic.h>\n");
1897         buf_printf(b, "#include <linux/compiler.h>\n");
1898         buf_printf(b, "\n");
1899         buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1900         buf_printf(b, "#include <asm/orc_header.h>\n");
1901         buf_printf(b, "ORC_HEADER;\n");
1902         buf_printf(b, "#endif\n");
1903         buf_printf(b, "\n");
1904         buf_printf(b, "BUILD_SALT;\n");
1905         buf_printf(b, "BUILD_LTO_INFO;\n");
1906         buf_printf(b, "\n");
1907         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1908         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1909         buf_printf(b, "\n");
1910         buf_printf(b, "__visible struct module __this_module\n");
1911         buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1912         buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1913         if (mod->has_init)
1914                 buf_printf(b, "\t.init = init_module,\n");
1915         if (mod->has_cleanup)
1916                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1917                               "\t.exit = cleanup_module,\n"
1918                               "#endif\n");
1919         buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1920         buf_printf(b, "};\n");
1921
1922         if (!external_module)
1923                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1924
1925         buf_printf(b,
1926                    "\n"
1927                    "#ifdef CONFIG_RETPOLINE\n"
1928                    "MODULE_INFO(retpoline, \"Y\");\n"
1929                    "#endif\n");
1930
1931         if (strstarts(mod->name, "drivers/staging"))
1932                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1933
1934         if (strstarts(mod->name, "tools/testing"))
1935                 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1936 }
1937
1938 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1939 {
1940         struct symbol *sym;
1941
1942         /* generate struct for exported symbols */
1943         buf_printf(buf, "\n");
1944         list_for_each_entry(sym, &mod->exported_symbols, list) {
1945                 if (trim_unused_exports && !sym->used)
1946                         continue;
1947
1948                 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1949                            sym->is_func ? "FUNC" : "DATA", sym->name,
1950                            sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1951         }
1952
1953         if (!modversions)
1954                 return;
1955
1956         /* record CRCs for exported symbols */
1957         buf_printf(buf, "\n");
1958         list_for_each_entry(sym, &mod->exported_symbols, list) {
1959                 if (trim_unused_exports && !sym->used)
1960                         continue;
1961
1962                 if (!sym->crc_valid)
1963                         warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1964                              "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1965                              sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1966                              sym->name);
1967
1968                 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1969                            sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1970         }
1971 }
1972
1973 /**
1974  * Record CRCs for unresolved symbols
1975  **/
1976 static void add_versions(struct buffer *b, struct module *mod)
1977 {
1978         struct symbol *s;
1979
1980         if (!modversions)
1981                 return;
1982
1983         buf_printf(b, "\n");
1984         buf_printf(b, "static const struct modversion_info ____versions[]\n");
1985         buf_printf(b, "__used __section(\"__versions\") = {\n");
1986
1987         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1988                 if (!s->module)
1989                         continue;
1990                 if (!s->crc_valid) {
1991                         warn("\"%s\" [%s.ko] has no CRC!\n",
1992                                 s->name, mod->name);
1993                         continue;
1994                 }
1995                 if (strlen(s->name) >= MODULE_NAME_LEN) {
1996                         error("too long symbol \"%s\" [%s.ko]\n",
1997                               s->name, mod->name);
1998                         break;
1999                 }
2000                 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
2001                            s->crc, s->name);
2002         }
2003
2004         buf_printf(b, "};\n");
2005 }
2006
2007 static void add_depends(struct buffer *b, struct module *mod)
2008 {
2009         struct symbol *s;
2010         int first = 1;
2011
2012         /* Clear ->seen flag of modules that own symbols needed by this. */
2013         list_for_each_entry(s, &mod->unresolved_symbols, list) {
2014                 if (s->module)
2015                         s->module->seen = s->module->is_vmlinux;
2016         }
2017
2018         buf_printf(b, "\n");
2019         buf_printf(b, "MODULE_INFO(depends, \"");
2020         list_for_each_entry(s, &mod->unresolved_symbols, list) {
2021                 const char *p;
2022                 if (!s->module)
2023                         continue;
2024
2025                 if (s->module->seen)
2026                         continue;
2027
2028                 s->module->seen = true;
2029                 p = strrchr(s->module->name, '/');
2030                 if (p)
2031                         p++;
2032                 else
2033                         p = s->module->name;
2034                 buf_printf(b, "%s%s", first ? "" : ",", p);
2035                 first = 0;
2036         }
2037         buf_printf(b, "\");\n");
2038 }
2039
2040 static void add_srcversion(struct buffer *b, struct module *mod)
2041 {
2042         if (mod->srcversion[0]) {
2043                 buf_printf(b, "\n");
2044                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2045                            mod->srcversion);
2046         }
2047 }
2048
2049 static void write_buf(struct buffer *b, const char *fname)
2050 {
2051         FILE *file;
2052
2053         if (error_occurred)
2054                 return;
2055
2056         file = fopen(fname, "w");
2057         if (!file) {
2058                 perror(fname);
2059                 exit(1);
2060         }
2061         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2062                 perror(fname);
2063                 exit(1);
2064         }
2065         if (fclose(file) != 0) {
2066                 perror(fname);
2067                 exit(1);
2068         }
2069 }
2070
2071 static void write_if_changed(struct buffer *b, const char *fname)
2072 {
2073         char *tmp;
2074         FILE *file;
2075         struct stat st;
2076
2077         file = fopen(fname, "r");
2078         if (!file)
2079                 goto write;
2080
2081         if (fstat(fileno(file), &st) < 0)
2082                 goto close_write;
2083
2084         if (st.st_size != b->pos)
2085                 goto close_write;
2086
2087         tmp = NOFAIL(malloc(b->pos));
2088         if (fread(tmp, 1, b->pos, file) != b->pos)
2089                 goto free_write;
2090
2091         if (memcmp(tmp, b->p, b->pos) != 0)
2092                 goto free_write;
2093
2094         free(tmp);
2095         fclose(file);
2096         return;
2097
2098  free_write:
2099         free(tmp);
2100  close_write:
2101         fclose(file);
2102  write:
2103         write_buf(b, fname);
2104 }
2105
2106 static void write_vmlinux_export_c_file(struct module *mod)
2107 {
2108         struct buffer buf = { };
2109
2110         buf_printf(&buf,
2111                    "#include <linux/export-internal.h>\n");
2112
2113         add_exported_symbols(&buf, mod);
2114         write_if_changed(&buf, ".vmlinux.export.c");
2115         free(buf.p);
2116 }
2117
2118 /* do sanity checks, and generate *.mod.c file */
2119 static void write_mod_c_file(struct module *mod)
2120 {
2121         struct buffer buf = { };
2122         char fname[PATH_MAX];
2123         int ret;
2124
2125         add_header(&buf, mod);
2126         add_exported_symbols(&buf, mod);
2127         add_versions(&buf, mod);
2128         add_depends(&buf, mod);
2129         add_moddevtable(&buf, mod);
2130         add_srcversion(&buf, mod);
2131
2132         ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2133         if (ret >= sizeof(fname)) {
2134                 error("%s: too long path was truncated\n", fname);
2135                 goto free;
2136         }
2137
2138         write_if_changed(&buf, fname);
2139
2140 free:
2141         free(buf.p);
2142 }
2143
2144 /* parse Module.symvers file. line format:
2145  * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2146  **/
2147 static void read_dump(const char *fname)
2148 {
2149         char *buf, *pos, *line;
2150
2151         buf = read_text_file(fname);
2152         if (!buf)
2153                 /* No symbol versions, silently ignore */
2154                 return;
2155
2156         pos = buf;
2157
2158         while ((line = get_line(&pos))) {
2159                 char *symname, *namespace, *modname, *d, *export;
2160                 unsigned int crc;
2161                 struct module *mod;
2162                 struct symbol *s;
2163                 bool gpl_only;
2164
2165                 if (!(symname = strchr(line, '\t')))
2166                         goto fail;
2167                 *symname++ = '\0';
2168                 if (!(modname = strchr(symname, '\t')))
2169                         goto fail;
2170                 *modname++ = '\0';
2171                 if (!(export = strchr(modname, '\t')))
2172                         goto fail;
2173                 *export++ = '\0';
2174                 if (!(namespace = strchr(export, '\t')))
2175                         goto fail;
2176                 *namespace++ = '\0';
2177
2178                 crc = strtoul(line, &d, 16);
2179                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2180                         goto fail;
2181
2182                 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2183                         gpl_only = true;
2184                 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2185                         gpl_only = false;
2186                 } else {
2187                         error("%s: unknown license %s. skip", symname, export);
2188                         continue;
2189                 }
2190
2191                 mod = find_module(modname);
2192                 if (!mod) {
2193                         mod = new_module(modname, strlen(modname));
2194                         mod->from_dump = true;
2195                 }
2196                 s = sym_add_exported(symname, mod, gpl_only, namespace);
2197                 sym_set_crc(s, crc);
2198         }
2199         free(buf);
2200         return;
2201 fail:
2202         free(buf);
2203         fatal("parse error in symbol dump file\n");
2204 }
2205
2206 static void write_dump(const char *fname)
2207 {
2208         struct buffer buf = { };
2209         struct module *mod;
2210         struct symbol *sym;
2211
2212         list_for_each_entry(mod, &modules, list) {
2213                 if (mod->from_dump)
2214                         continue;
2215                 list_for_each_entry(sym, &mod->exported_symbols, list) {
2216                         if (trim_unused_exports && !sym->used)
2217                                 continue;
2218
2219                         buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2220                                    sym->crc, sym->name, mod->name,
2221                                    sym->is_gpl_only ? "_GPL" : "",
2222                                    sym->namespace);
2223                 }
2224         }
2225         write_buf(&buf, fname);
2226         free(buf.p);
2227 }
2228
2229 static void write_namespace_deps_files(const char *fname)
2230 {
2231         struct module *mod;
2232         struct namespace_list *ns;
2233         struct buffer ns_deps_buf = {};
2234
2235         list_for_each_entry(mod, &modules, list) {
2236
2237                 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2238                         continue;
2239
2240                 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2241
2242                 list_for_each_entry(ns, &mod->missing_namespaces, list)
2243                         buf_printf(&ns_deps_buf, " %s", ns->namespace);
2244
2245                 buf_printf(&ns_deps_buf, "\n");
2246         }
2247
2248         write_if_changed(&ns_deps_buf, fname);
2249         free(ns_deps_buf.p);
2250 }
2251
2252 struct dump_list {
2253         struct list_head list;
2254         const char *file;
2255 };
2256
2257 int main(int argc, char **argv)
2258 {
2259         struct module *mod;
2260         char *missing_namespace_deps = NULL;
2261         char *unused_exports_white_list = NULL;
2262         char *dump_write = NULL, *files_source = NULL;
2263         int opt;
2264         LIST_HEAD(dump_lists);
2265         struct dump_list *dl, *dl2;
2266
2267         while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2268                 switch (opt) {
2269                 case 'e':
2270                         external_module = true;
2271                         break;
2272                 case 'i':
2273                         dl = NOFAIL(malloc(sizeof(*dl)));
2274                         dl->file = optarg;
2275                         list_add_tail(&dl->list, &dump_lists);
2276                         break;
2277                 case 'M':
2278                         module_enabled = true;
2279                         break;
2280                 case 'm':
2281                         modversions = true;
2282                         break;
2283                 case 'n':
2284                         ignore_missing_files = true;
2285                         break;
2286                 case 'o':
2287                         dump_write = optarg;
2288                         break;
2289                 case 'a':
2290                         all_versions = true;
2291                         break;
2292                 case 'T':
2293                         files_source = optarg;
2294                         break;
2295                 case 't':
2296                         trim_unused_exports = true;
2297                         break;
2298                 case 'u':
2299                         unused_exports_white_list = optarg;
2300                         break;
2301                 case 'W':
2302                         extra_warn = true;
2303                         break;
2304                 case 'w':
2305                         warn_unresolved = true;
2306                         break;
2307                 case 'E':
2308                         sec_mismatch_warn_only = false;
2309                         break;
2310                 case 'N':
2311                         allow_missing_ns_imports = true;
2312                         break;
2313                 case 'd':
2314                         missing_namespace_deps = optarg;
2315                         break;
2316                 default:
2317                         exit(1);
2318                 }
2319         }
2320
2321         list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2322                 read_dump(dl->file);
2323                 list_del(&dl->list);
2324                 free(dl);
2325         }
2326
2327         while (optind < argc)
2328                 read_symbols(argv[optind++]);
2329
2330         if (files_source)
2331                 read_symbols_from_files(files_source);
2332
2333         list_for_each_entry(mod, &modules, list) {
2334                 if (mod->from_dump || mod->is_vmlinux)
2335                         continue;
2336
2337                 check_modname_len(mod);
2338                 check_exports(mod);
2339         }
2340
2341         if (unused_exports_white_list)
2342                 handle_white_list_exports(unused_exports_white_list);
2343
2344         list_for_each_entry(mod, &modules, list) {
2345                 if (mod->from_dump)
2346                         continue;
2347
2348                 if (mod->is_vmlinux)
2349                         write_vmlinux_export_c_file(mod);
2350                 else
2351                         write_mod_c_file(mod);
2352         }
2353
2354         if (missing_namespace_deps)
2355                 write_namespace_deps_files(missing_namespace_deps);
2356
2357         if (dump_write)
2358                 write_dump(dump_write);
2359         if (sec_mismatch_count && !sec_mismatch_warn_only)
2360                 error("Section mismatches detected.\n"
2361                       "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2362
2363         if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2364                 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2365                      nr_unresolved - MAX_UNRESOLVED_REPORTS);
2366
2367         return error_occurred ? 1 : 0;
2368 }