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
  26 static bool module_enabled;
  27 /* Are we using CONFIG_MODVERSIONS? */
  28 static bool modversions;
  29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  30 static bool all_versions;
  31 /* If we are modposting external module set to 1 */
  32 static bool external_module;
  33 /* Only warn about unresolved symbols */
  34 static bool warn_unresolved;
  35
  36 static int sec_mismatch_count;
  37 static bool sec_mismatch_warn_only = true;
  38 /* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  39 static bool trim_unused_exports;
  40
  41 /* ignore missing files */
  42 static bool ignore_missing_files;
  43 /* If set to 1, only warn (instead of error) about missing ns imports */
  44 static bool allow_missing_ns_imports;
  45
  46 static bool error_occurred;
  47
  48 static bool extra_warn;
  49
  50 /*
  51  * Cut off the warnings when there are too many. This typically occurs when
  52  * vmlinux is missing. ('make modules' without building vmlinux.)
  53  */
  54 #define MAX_UNRESOLVED_REPORTS  10
  55 static unsigned int nr_unresolved;
  56
  57 /* In kernel, this size is defined in linux/module.h;
  58  * here we use Elf_Addr instead of long for covering cross-compile
  59  */
  60
  61 #define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  62
  63 void __attribute__((format(printf, 2, 3)))
  64 modpost_log(enum loglevel loglevel, const char *fmt, ...)
  65 {
  66         va_list arglist;
  67
  68         switch (loglevel) {
  69         case LOG_WARN:
  70                 fprintf(stderr, "WARNING: ");
  71                 break;
  72         case LOG_ERROR:
  73                 fprintf(stderr, "ERROR: ");
  74                 break;
  75         case LOG_FATAL:
  76                 fprintf(stderr, "FATAL: ");
  77                 break;
  78         default: /* invalid loglevel, ignore */
  79                 break;
  80         }
  81
  82         fprintf(stderr, "modpost: ");
  83
  84         va_start(arglist, fmt);
  85         vfprintf(stderr, fmt, arglist);
  86         va_end(arglist);
  87
  88         if (loglevel == LOG_FATAL)
  89                 exit(1);
  90         if (loglevel == LOG_ERROR)
  91                 error_occurred = true;
  92 }
  93
  94 static inline bool strends(const char *str, const char *postfix)
  95 {
  96         if (strlen(str) < strlen(postfix))
  97                 return false;
  98
  99         return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
 100 }
 101
 102 void *do_nofail(void *ptr, const char *expr)
 103 {
 104         if (!ptr)
 105                 fatal("Memory allocation failure: %s.\n", expr);
 106
 107         return ptr;
 108 }
 109
 110 char *read_text_file(const char *filename)
 111 {
 112         struct stat st;
 113         size_t nbytes;
 114         int fd;
 115         char *buf;
 116
 117         fd = open(filename, O_RDONLY);
 118         if (fd < 0) {
 119                 perror(filename);
 120                 exit(1);
 121         }
 122
 123         if (fstat(fd, &st) < 0) {
 124                 perror(filename);
 125                 exit(1);
 126         }
 127
 128         buf = NOFAIL(malloc(st.st_size + 1));
 129
 130         nbytes = st.st_size;
 131
 132         while (nbytes) {
 133                 ssize_t bytes_read;
 134
 135                 bytes_read = read(fd, buf, nbytes);
 136                 if (bytes_read < 0) {
 137                         perror(filename);
 138                         exit(1);
 139                 }
 140
 141                 nbytes -= bytes_read;
 142         }
 143         buf[st.st_size] = '\0';
 144
 145         close(fd);
 146
 147         return buf;
 148 }
 149
 150 char *get_line(char **stringp)
 151 {
 152         char *orig = *stringp, *next;
 153
 154         /* do not return the unwanted extra line at EOF */
 155         if (!orig || *orig == '\0')
 156                 return NULL;
 157
 158         /* don't use strsep here, it is not available everywhere */
 159         next = strchr(orig, '\n');
 160         if (next)
 161                 *next++ = '\0';
 162
 163         *stringp = next;
 164
 165         return orig;
 166 }
 167
 168 /* A list of all modules we processed */
 169 LIST_HEAD(modules);
 170
 171 static struct module *find_module(const char *modname)
 172 {
 173         struct module *mod;
 174
 175         list_for_each_entry(mod, &modules, list) {
 176                 if (strcmp(mod->name, modname) == 0)
 177                         return mod;
 178         }
 179         return NULL;
 180 }
 181
 182 static struct module *new_module(const char *name, size_t namelen)
 183 {
 184         struct module *mod;
 185
 186         mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
 187         memset(mod, 0, sizeof(*mod));
 188
 189         INIT_LIST_HEAD(&mod->exported_symbols);
 190         INIT_LIST_HEAD(&mod->unresolved_symbols);
 191         INIT_LIST_HEAD(&mod->missing_namespaces);
 192         INIT_LIST_HEAD(&mod->imported_namespaces);
 193
 194         memcpy(mod->name, name, namelen);
 195         mod->name[namelen] = '\0';
 196         mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 197
 198         /*
 199          * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 200          * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 201          * modpost will exit wiht error anyway.
 202          */
 203         mod->is_gpl_compatible = true;
 204
 205         list_add_tail(&mod->list, &modules);
 206
 207         return mod;
 208 }
 209
 210 /* A hash of all exported symbols,
 211  * struct symbol is also used for lists of unresolved symbols */
 212
 213 #define SYMBOL_HASH_SIZE 1024
 214
 215 struct symbol {
 216         struct symbol *next;
 217         struct list_head list;  /* link to module::exported_symbols or module::unresolved_symbols */
 218         struct module *module;
 219         char *namespace;
 220         unsigned int crc;
 221         bool crc_valid;
 222         bool weak;
 223         bool is_func;
 224         bool is_gpl_only;       /* exported by EXPORT_SYMBOL_GPL */
 225         bool used;              /* there exists a user of this symbol */
 226         char name[];
 227 };
 228
 229 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 230
 231 /* This is based on the hash algorithm from gdbm, via tdb */
 232 static inline unsigned int tdb_hash(const char *name)
 233 {
 234         unsigned value; /* Used to compute the hash value.  */
 235         unsigned   i;   /* Used to cycle through random values. */
 236
 237         /* Set the initial value from the key size. */
 238         for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 239                 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 240
 241         return (1103515243 * value + 12345);
 242 }
 243
 244 /**
 245  * Allocate a new symbols for use in the hash of exported symbols or
 246  * the list of unresolved symbols per module
 247  **/
 248 static struct symbol *alloc_symbol(const char *name)
 249 {
 250         struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 251
 252         memset(s, 0, sizeof(*s));
 253         strcpy(s->name, name);
 254
 255         return s;
 256 }
 257
 258 /* For the hash of exported symbols */
 259 static void hash_add_symbol(struct symbol *sym)
 260 {
 261         unsigned int hash;
 262
 263         hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
 264         sym->next = symbolhash[hash];
 265         symbolhash[hash] = sym;
 266 }
 267
 268 static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 269 {
 270         struct symbol *sym;
 271
 272         sym = alloc_symbol(name);
 273         sym->weak = weak;
 274
 275         list_add_tail(&sym->list, &mod->unresolved_symbols);
 276 }
 277
 278 static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 279 {
 280         struct symbol *s;
 281
 282         /* For our purposes, .foo matches foo.  PPC64 needs this. */
 283         if (name[0] == '.')
 284                 name++;
 285
 286         for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 287                 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 288                         return s;
 289         }
 290         return NULL;
 291 }
 292
 293 static struct symbol *find_symbol(const char *name)
 294 {
 295         return sym_find_with_module(name, NULL);
 296 }
 297
 298 struct namespace_list {
 299         struct list_head list;
 300         char namespace[];
 301 };
 302
 303 static bool contains_namespace(struct list_head *head, const char *namespace)
 304 {
 305         struct namespace_list *list;
 306
 307         /*
 308          * The default namespace is null string "", which is always implicitly
 309          * contained.
 310          */
 311         if (!namespace[0])
 312                 return true;
 313
 314         list_for_each_entry(list, head, list) {
 315                 if (!strcmp(list->namespace, namespace))
 316                         return true;
 317         }
 318
 319         return false;
 320 }
 321
 322 static void add_namespace(struct list_head *head, const char *namespace)
 323 {
 324         struct namespace_list *ns_entry;
 325
 326         if (!contains_namespace(head, namespace)) {
 327                 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 328                                          strlen(namespace) + 1));
 329                 strcpy(ns_entry->namespace, namespace);
 330                 list_add_tail(&ns_entry->list, head);
 331         }
 332 }
 333
 334 static void *sym_get_data_by_offset(const struct elf_info *info,
 335                                     unsigned int secindex, unsigned long offset)
 336 {
 337         Elf_Shdr *sechdr = &info->sechdrs[secindex];
 338
 339         return (void *)info->hdr + sechdr->sh_offset + offset;
 340 }
 341
 342 void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 343 {
 344         return sym_get_data_by_offset(info, get_secindex(info, sym),
 345                                       sym->st_value);
 346 }
 347
 348 static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 349 {
 350         return sym_get_data_by_offset(info, info->secindex_strings,
 351                                       sechdr->sh_name);
 352 }
 353
 354 static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 355 {
 356         /*
 357          * If sym->st_shndx is a special section index, there is no
 358          * corresponding section header.
 359          * Return "" if the index is out of range of info->sechdrs[] array.
 360          */
 361         if (secindex >= info->num_sections)
 362                 return "";
 363
 364         return sech_name(info, &info->sechdrs[secindex]);
 365 }
 366
 367 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 368
 369 static struct symbol *sym_add_exported(const char *name, struct module *mod,
 370                                        bool gpl_only, const char *namespace)
 371 {
 372         struct symbol *s = find_symbol(name);
 373
 374         if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 375                 error("%s: '%s' exported twice. Previous export was in %s%s\n",
 376                       mod->name, name, s->module->name,
 377                       s->module->is_vmlinux ? "" : ".ko");
 378         }
 379
 380         s = alloc_symbol(name);
 381         s->module = mod;
 382         s->is_gpl_only = gpl_only;
 383         s->namespace = NOFAIL(strdup(namespace));
 384         list_add_tail(&s->list, &mod->exported_symbols);
 385         hash_add_symbol(s);
 386
 387         return s;
 388 }
 389
 390 static void sym_set_crc(struct symbol *sym, unsigned int crc)
 391 {
 392         sym->crc = crc;
 393         sym->crc_valid = true;
 394 }
 395
 396 static void *grab_file(const char *filename, size_t *size)
 397 {
 398         struct stat st;
 399         void *map = MAP_FAILED;
 400         int fd;
 401
 402         fd = open(filename, O_RDONLY);
 403         if (fd < 0)
 404                 return NULL;
 405         if (fstat(fd, &st))
 406                 goto failed;
 407
 408         *size = st.st_size;
 409         map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 410
 411 failed:
 412         close(fd);
 413         if (map == MAP_FAILED)
 414                 return NULL;
 415         return map;
 416 }
 417
 418 static void release_file(void *file, size_t size)
 419 {
 420         munmap(file, size);
 421 }
 422
 423 static int parse_elf(struct elf_info *info, const char *filename)
 424 {
 425         unsigned int i;
 426         Elf_Ehdr *hdr;
 427         Elf_Shdr *sechdrs;
 428         Elf_Sym  *sym;
 429         const char *secstrings;
 430         unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 431
 432         hdr = grab_file(filename, &info->size);
 433         if (!hdr) {
 434                 if (ignore_missing_files) {
 435                         fprintf(stderr, "%s: %s (ignored)\n", filename,
 436                                 strerror(errno));
 437                         return 0;
 438                 }
 439                 perror(filename);
 440                 exit(1);
 441         }
 442         info->hdr = hdr;
 443         if (info->size < sizeof(*hdr)) {
 444                 /* file too small, assume this is an empty .o file */
 445                 return 0;
 446         }
 447         /* Is this a valid ELF file? */
 448         if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 449             (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 450             (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 451             (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 452                 /* Not an ELF file - silently ignore it */
 453                 return 0;
 454         }
 455         /* Fix endianness in ELF header */
 456         hdr->e_type      = TO_NATIVE(hdr->e_type);
 457         hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 458         hdr->e_version   = TO_NATIVE(hdr->e_version);
 459         hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 460         hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 461         hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 462         hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 463         hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 464         hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 465         hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 466         hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 467         hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 468         hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 469         sechdrs = (void *)hdr + hdr->e_shoff;
 470         info->sechdrs = sechdrs;
 471
 472         /* modpost only works for relocatable objects */
 473         if (hdr->e_type != ET_REL)
 474                 fatal("%s: not relocatable object.", filename);
 475
 476         /* Check if file offset is correct */
 477         if (hdr->e_shoff > info->size) {
 478                 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 479                       (unsigned long)hdr->e_shoff, filename, info->size);
 480                 return 0;
 481         }
 482
 483         if (hdr->e_shnum == SHN_UNDEF) {
 484                 /*
 485                  * There are more than 64k sections,
 486                  * read count from .sh_size.
 487                  */
 488                 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 489         }
 490         else {
 491                 info->num_sections = hdr->e_shnum;
 492         }
 493         if (hdr->e_shstrndx == SHN_XINDEX) {
 494                 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 495         }
 496         else {
 497                 info->secindex_strings = hdr->e_shstrndx;
 498         }
 499
 500         /* Fix endianness in section headers */
 501         for (i = 0; i < info->num_sections; i++) {
 502                 sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 503                 sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 504                 sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 505                 sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 506                 sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 507                 sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 508                 sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 509                 sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 510                 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 511                 sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 512         }
 513         /* Find symbol table. */
 514         secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 515         for (i = 1; i < info->num_sections; i++) {
 516                 const char *secname;
 517                 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 518
 519                 if (!nobits && sechdrs[i].sh_offset > info->size) {
 520                         fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 521                               filename, (unsigned long)sechdrs[i].sh_offset,
 522                               sizeof(*hdr));
 523                         return 0;
 524                 }
 525                 secname = secstrings + sechdrs[i].sh_name;
 526                 if (strcmp(secname, ".modinfo") == 0) {
 527                         if (nobits)
 528                                 fatal("%s has NOBITS .modinfo\n", filename);
 529                         info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 530                         info->modinfo_len = sechdrs[i].sh_size;
 531                 } else if (!strcmp(secname, ".export_symbol")) {
 532                         info->export_symbol_secndx = i;
 533                 }
 534
 535                 if (sechdrs[i].sh_type == SHT_SYMTAB) {
 536                         unsigned int sh_link_idx;
 537                         symtab_idx = i;
 538                         info->symtab_start = (void *)hdr +
 539                             sechdrs[i].sh_offset;
 540                         info->symtab_stop  = (void *)hdr +
 541                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 542                         sh_link_idx = sechdrs[i].sh_link;
 543                         info->strtab       = (void *)hdr +
 544                             sechdrs[sh_link_idx].sh_offset;
 545                 }
 546
 547                 /* 32bit section no. table? ("more than 64k sections") */
 548                 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 549                         symtab_shndx_idx = i;
 550                         info->symtab_shndx_start = (void *)hdr +
 551                             sechdrs[i].sh_offset;
 552                         info->symtab_shndx_stop  = (void *)hdr +
 553                             sechdrs[i].sh_offset + sechdrs[i].sh_size;
 554                 }
 555         }
 556         if (!info->symtab_start)
 557                 fatal("%s has no symtab?\n", filename);
 558
 559         /* Fix endianness in symbols */
 560         for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 561                 sym->st_shndx = TO_NATIVE(sym->st_shndx);
 562                 sym->st_name  = TO_NATIVE(sym->st_name);
 563                 sym->st_value = TO_NATIVE(sym->st_value);
 564                 sym->st_size  = TO_NATIVE(sym->st_size);
 565         }
 566
 567         if (symtab_shndx_idx != ~0U) {
 568                 Elf32_Word *p;
 569                 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 570                         fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 571                               filename, sechdrs[symtab_shndx_idx].sh_link,
 572                               symtab_idx);
 573                 /* Fix endianness */
 574                 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 575                      p++)
 576                         *p = TO_NATIVE(*p);
 577         }
 578
 579         symsearch_init(info);
 580
 581         return 1;
 582 }
 583
 584 static void parse_elf_finish(struct elf_info *info)
 585 {
 586         symsearch_finish(info);
 587         release_file(info->hdr, info->size);
 588 }
 589
 590 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 591 {
 592         /* ignore __this_module, it will be resolved shortly */
 593         if (strcmp(symname, "__this_module") == 0)
 594                 return 1;
 595         /* ignore global offset table */
 596         if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 597                 return 1;
 598         if (info->hdr->e_machine == EM_PPC)
 599                 /* Special register function linked on all modules during final link of .ko */
 600                 if (strstarts(symname, "_restgpr_") ||
 601                     strstarts(symname, "_savegpr_") ||
 602                     strstarts(symname, "_rest32gpr_") ||
 603                     strstarts(symname, "_save32gpr_") ||
 604                     strstarts(symname, "_restvr_") ||
 605                     strstarts(symname, "_savevr_"))
 606                         return 1;
 607         if (info->hdr->e_machine == EM_PPC64)
 608                 /* Special register function linked on all modules during final link of .ko */
 609                 if (strstarts(symname, "_restgpr0_") ||
 610                     strstarts(symname, "_savegpr0_") ||
 611                     strstarts(symname, "_restvr_") ||
 612                     strstarts(symname, "_savevr_") ||
 613                     strcmp(symname, ".TOC.") == 0)
 614                         return 1;
 615
 616         if (info->hdr->e_machine == EM_S390)
 617                 /* Expoline thunks are linked on all kernel modules during final link of .ko */
 618                 if (strstarts(symname, "__s390_indirect_jump_r"))
 619                         return 1;
 620         /* Do not ignore this symbol */
 621         return 0;
 622 }
 623
 624 static void handle_symbol(struct module *mod, struct elf_info *info,
 625                           const Elf_Sym *sym, const char *symname)
 626 {
 627         switch (sym->st_shndx) {
 628         case SHN_COMMON:
 629                 if (strstarts(symname, "__gnu_lto_")) {
 630                         /* Should warn here, but modpost runs before the linker */
 631                 } else
 632                         warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 633                 break;
 634         case SHN_UNDEF:
 635                 /* undefined symbol */
 636                 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 637                     ELF_ST_BIND(sym->st_info) != STB_WEAK)
 638                         break;
 639                 if (ignore_undef_symbol(info, symname))
 640                         break;
 641                 if (info->hdr->e_machine == EM_SPARC ||
 642                     info->hdr->e_machine == EM_SPARCV9) {
 643                         /* Ignore register directives. */
 644                         if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 645                                 break;
 646                         if (symname[0] == '.') {
 647                                 char *munged = NOFAIL(strdup(symname));
 648                                 munged[0] = '_';
 649                                 munged[1] = toupper(munged[1]);
 650                                 symname = munged;
 651                         }
 652                 }
 653
 654                 sym_add_unresolved(symname, mod,
 655                                    ELF_ST_BIND(sym->st_info) == STB_WEAK);
 656                 break;
 657         default:
 658                 if (strcmp(symname, "init_module") == 0)
 659                         mod->has_init = true;
 660                 if (strcmp(symname, "cleanup_module") == 0)
 661                         mod->has_cleanup = true;
 662                 break;
 663         }
 664 }
 665
 666 /**
 667  * Parse tag=value strings from .modinfo section
 668  **/
 669 static char *next_string(char *string, unsigned long *secsize)
 670 {
 671         /* Skip non-zero chars */
 672         while (string[0]) {
 673                 string++;
 674                 if ((*secsize)-- <= 1)
 675                         return NULL;
 676         }
 677
 678         /* Skip any zero padding. */
 679         while (!string[0]) {
 680                 string++;
 681                 if ((*secsize)-- <= 1)
 682                         return NULL;
 683         }
 684         return string;
 685 }
 686
 687 static char *get_next_modinfo(struct elf_info *info, const char *tag,
 688                               char *prev)
 689 {
 690         char *p;
 691         unsigned int taglen = strlen(tag);
 692         char *modinfo = info->modinfo;
 693         unsigned long size = info->modinfo_len;
 694
 695         if (prev) {
 696                 size -= prev - modinfo;
 697                 modinfo = next_string(prev, &size);
 698         }
 699
 700         for (p = modinfo; p; p = next_string(p, &size)) {
 701                 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 702                         return p + taglen + 1;
 703         }
 704         return NULL;
 705 }
 706
 707 static char *get_modinfo(struct elf_info *info, const char *tag)
 708
 709 {
 710         return get_next_modinfo(info, tag, NULL);
 711 }
 712
 713 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 714 {
 715         if (sym)
 716                 return elf->strtab + sym->st_name;
 717         else
 718                 return "(unknown)";
 719 }
 720
 721 /*
 722  * Check whether the 'string' argument matches one of the 'patterns',
 723  * an array of shell wildcard patterns (glob).
 724  *
 725  * Return true is there is a match.
 726  */
 727 static bool match(const char *string, const char *const patterns[])
 728 {
 729         const char *pattern;
 730
 731         while ((pattern = *patterns++)) {
 732                 if (!fnmatch(pattern, string, 0))
 733                         return true;
 734         }
 735
 736         return false;
 737 }
 738
 739 /* useful to pass patterns to match() directly */
 740 #define PATTERNS(...) \
 741         ({ \
 742                 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 743                 patterns; \
 744         })
 745
 746 /* sections that we do not want to do full section mismatch check on */
 747 static const char *const section_white_list[] =
 748 {
 749         ".comment*",
 750         ".debug*",
 751         ".zdebug*",             /* Compressed debug sections. */
 752         ".GCC.command.line",    /* record-gcc-switches */
 753         ".mdebug*",        /* alpha, score, mips etc. */
 754         ".pdr",            /* alpha, score, mips etc. */
 755         ".stab*",
 756         ".note*",
 757         ".got*",
 758         ".toc*",
 759         ".xt.prop",                              /* xtensa */
 760         ".xt.lit",         /* xtensa */
 761         ".arcextmap*",                  /* arc */
 762         ".gnu.linkonce.arcext*",        /* arc : modules */
 763         ".cmem*",                       /* EZchip */
 764         ".fmt_slot*",                   /* EZchip */
 765         ".gnu.lto*",
 766         ".discard.*",
 767         ".llvm.call-graph-profile",     /* call graph */
 768         NULL
 769 };
 770
 771 /*
 772  * This is used to find sections missing the SHF_ALLOC flag.
 773  * The cause of this is often a section specified in assembler
 774  * without "ax" / "aw".
 775  */
 776 static void check_section(const char *modname, struct elf_info *elf,
 777                           Elf_Shdr *sechdr)
 778 {
 779         const char *sec = sech_name(elf, sechdr);
 780
 781         if (sechdr->sh_type == SHT_PROGBITS &&
 782             !(sechdr->sh_flags & SHF_ALLOC) &&
 783             !match(sec, section_white_list)) {
 784                 warn("%s (%s): unexpected non-allocatable section.\n"
 785                      "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 786                      "Note that for example <linux/init.h> contains\n"
 787                      "section definitions for use in .S files.\n\n",
 788                      modname, sec);
 789         }
 790 }
 791
 792
 793
 794 #define ALL_INIT_DATA_SECTIONS \
 795         ".init.setup", ".init.rodata", ".meminit.rodata", \
 796         ".init.data", ".meminit.data"
 797
 798 #define ALL_PCI_INIT_SECTIONS   \
 799         ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 800         ".pci_fixup_enable", ".pci_fixup_resume", \
 801         ".pci_fixup_resume_early", ".pci_fixup_suspend"
 802
 803 #define ALL_XXXINIT_SECTIONS ".meminit.*"
 804
 805 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 806 #define ALL_EXIT_SECTIONS ".exit.*"
 807
 808 #define DATA_SECTIONS ".data", ".data.rel"
 809 #define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 810                 ".kprobes.text", ".cpuidle.text", ".noinstr.text"
 811 #define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 812                 ".fixup", ".entry.text", ".exception.text", \
 813                 ".coldtext", ".softirqentry.text"
 814
 815 #define INIT_SECTIONS      ".init.*"
 816
 817 #define ALL_TEXT_SECTIONS  ".init.text", ".meminit.text", ".exit.text", \
 818                 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 819
 820 enum mismatch {
 821         TEXTDATA_TO_ANY_INIT_EXIT,
 822         XXXINIT_TO_SOME_INIT,
 823         ANY_INIT_TO_ANY_EXIT,
 824         ANY_EXIT_TO_ANY_INIT,
 825         EXTABLE_TO_NON_TEXT,
 826 };
 827
 828 /**
 829  * Describe how to match sections on different criteria:
 830  *
 831  * @fromsec: Array of sections to be matched.
 832  *
 833  * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 834  * this array is forbidden (black-list).  Can be empty.
 835  *
 836  * @good_tosec: Relocations applied to a section in @fromsec must be
 837  * targeting sections in this array (white-list).  Can be empty.
 838  *
 839  * @mismatch: Type of mismatch.
 840  */
 841 struct sectioncheck {
 842         const char *fromsec[20];
 843         const char *bad_tosec[20];
 844         const char *good_tosec[20];
 845         enum mismatch mismatch;
 846 };
 847
 848 static const struct sectioncheck sectioncheck[] = {
 849 /* Do not reference init/exit code/data from
 850  * normal code and data
 851  */
 852 {
 853         .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 854         .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
 855         .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
 856 },
 857 /* Do not reference init code/data from meminit code/data */
 858 {
 859         .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 860         .bad_tosec = { INIT_SECTIONS, NULL },
 861         .mismatch = XXXINIT_TO_SOME_INIT,
 862 },
 863 /* Do not use exit code/data from init code */
 864 {
 865         .fromsec = { ALL_INIT_SECTIONS, NULL },
 866         .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 867         .mismatch = ANY_INIT_TO_ANY_EXIT,
 868 },
 869 /* Do not use init code/data from exit code */
 870 {
 871         .fromsec = { ALL_EXIT_SECTIONS, NULL },
 872         .bad_tosec = { ALL_INIT_SECTIONS, NULL },
 873         .mismatch = ANY_EXIT_TO_ANY_INIT,
 874 },
 875 {
 876         .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 877         .bad_tosec = { INIT_SECTIONS, NULL },
 878         .mismatch = ANY_INIT_TO_ANY_EXIT,
 879 },
 880 {
 881         .fromsec = { "__ex_table", NULL },
 882         /* If you're adding any new black-listed sections in here, consider
 883          * adding a special 'printer' for them in scripts/check_extable.
 884          */
 885         .bad_tosec = { ".altinstr_replacement", NULL },
 886         .good_tosec = {ALL_TEXT_SECTIONS , NULL},
 887         .mismatch = EXTABLE_TO_NON_TEXT,
 888 }
 889 };
 890
 891 static const struct sectioncheck *section_mismatch(
 892                 const char *fromsec, const char *tosec)
 893 {
 894         int i;
 895
 896         /*
 897          * The target section could be the SHT_NUL section when we're
 898          * handling relocations to un-resolved symbols, trying to match it
 899          * doesn't make much sense and causes build failures on parisc
 900          * architectures.
 901          */
 902         if (*tosec == '\0')
 903                 return NULL;
 904
 905         for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 906                 const struct sectioncheck *check = &sectioncheck[i];
 907
 908                 if (match(fromsec, check->fromsec)) {
 909                         if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 910                                 return check;
 911                         if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 912                                 return check;
 913                 }
 914         }
 915         return NULL;
 916 }
 917
 918 /**
 919  * Whitelist to allow certain references to pass with no warning.
 920  *
 921  * Pattern 1:
 922  *   If a module parameter is declared __initdata and permissions=0
 923  *   then this is legal despite the warning generated.
 924  *   We cannot see value of permissions here, so just ignore
 925  *   this pattern.
 926  *   The pattern is identified by:
 927  *   tosec   = .init.data
 928  *   fromsec = .data*
 929  *   atsym   =__param*
 930  *
 931  * Pattern 1a:
 932  *   module_param_call() ops can refer to __init set function if permissions=0
 933  *   The pattern is identified by:
 934  *   tosec   = .init.text
 935  *   fromsec = .data*
 936  *   atsym   = __param_ops_*
 937  *
 938  * Pattern 3:
 939  *   Whitelist all references from .head.text to any init section
 940  *
 941  * Pattern 4:
 942  *   Some symbols belong to init section but still it is ok to reference
 943  *   these from non-init sections as these symbols don't have any memory
 944  *   allocated for them and symbol address and value are same. So even
 945  *   if init section is freed, its ok to reference those symbols.
 946  *   For ex. symbols marking the init section boundaries.
 947  *   This pattern is identified by
 948  *   refsymname = __init_begin, _sinittext, _einittext
 949  *
 950  * Pattern 5:
 951  *   GCC may optimize static inlines when fed constant arg(s) resulting
 952  *   in functions like cpumask_empty() -- generating an associated symbol
 953  *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 954  *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 955  *   meaningless section warning.  May need to add isra symbols too...
 956  *   This pattern is identified by
 957  *   tosec   = init section
 958  *   fromsec = text section
 959  *   refsymname = *.constprop.*
 960  *
 961  **/
 962 static int secref_whitelist(const char *fromsec, const char *fromsym,
 963                             const char *tosec, const char *tosym)
 964 {
 965         /* Check for pattern 1 */
 966         if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 967             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 968             strstarts(fromsym, "__param"))
 969                 return 0;
 970
 971         /* Check for pattern 1a */
 972         if (strcmp(tosec, ".init.text") == 0 &&
 973             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 974             strstarts(fromsym, "__param_ops_"))
 975                 return 0;
 976
 977         /* symbols in data sections that may refer to any init/exit sections */
 978         if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 979             match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
 980             match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
 981                 return 0;
 982
 983         /*
 984          * symbols in data sections must not refer to .exit.*, but there are
 985          * quite a few offenders, so hide these unless for W=1 builds until
 986          * these are fixed.
 987          */
 988         if (!extra_warn &&
 989             match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 990             match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) &&
 991             match(fromsym, PATTERNS("*driver")))
 992                 return 0;
 993
 994         /* Check for pattern 3 */
 995         if (strstarts(fromsec, ".head.text") &&
 996             match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
 997                 return 0;
 998
 999         /* Check for pattern 4 */
1000         if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
1001                 return 0;
1002
1003         /* Check for pattern 5 */
1004         if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
1005             match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
1006             match(fromsym, PATTERNS("*.constprop.*")))
1007                 return 0;
1008
1009         return 1;
1010 }
1011
1012 static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1013                              unsigned int secndx)
1014 {
1015         return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1016 }
1017
1018 static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1019 {
1020         /* If the supplied symbol has a valid name, return it */
1021         if (is_valid_name(elf, sym))
1022                 return sym;
1023
1024         /*
1025          * Strive to find a better symbol name, but the resulting name may not
1026          * match the symbol referenced in the original code.
1027          */
1028         return symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1029                                       true, 20);
1030 }
1031
1032 static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1033 {
1034         if (secndx >= elf->num_sections)
1035                 return false;
1036
1037         return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1038 }
1039
1040 static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1041                                      const struct sectioncheck* const mismatch,
1042                                      Elf_Sym *tsym,
1043                                      unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1044                                      const char *tosec, Elf_Addr taddr)
1045 {
1046         Elf_Sym *from;
1047         const char *tosym;
1048         const char *fromsym;
1049
1050         from = find_fromsym(elf, faddr, fsecndx);
1051         fromsym = sym_name(elf, from);
1052
1053         tsym = find_tosym(elf, taddr, tsym);
1054         tosym = sym_name(elf, tsym);
1055
1056         /* check whitelist - we may ignore it */
1057         if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1058                 return;
1059
1060         sec_mismatch_count++;
1061
1062         warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1063              modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec);
1064
1065         if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1066                 if (match(tosec, mismatch->bad_tosec))
1067                         fatal("The relocation at %s+0x%lx references\n"
1068                               "section \"%s\" which is black-listed.\n"
1069                               "Something is seriously wrong and should be fixed.\n"
1070                               "You might get more information about where this is\n"
1071                               "coming from by using scripts/check_extable.sh %s\n",
1072                               fromsec, (long)faddr, tosec, modname);
1073                 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1074                         warn("The relocation at %s+0x%lx references\n"
1075                              "section \"%s\" which is not in the list of\n"
1076                              "authorized sections.  If you're adding a new section\n"
1077                              "and/or if this reference is valid, add \"%s\" to the\n"
1078                              "list of authorized sections to jump to on fault.\n"
1079                              "This can be achieved by adding \"%s\" to\n"
1080                              "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1081                              fromsec, (long)faddr, tosec, tosec, tosec);
1082                 else
1083                         error("%s+0x%lx references non-executable section '%s'\n",
1084                               fromsec, (long)faddr, tosec);
1085         }
1086 }
1087
1088 static void check_export_symbol(struct module *mod, struct elf_info *elf,
1089                                 Elf_Addr faddr, const char *secname,
1090                                 Elf_Sym *sym)
1091 {
1092         static const char *prefix = "__export_symbol_";
1093         const char *label_name, *name, *data;
1094         Elf_Sym *label;
1095         struct symbol *s;
1096         bool is_gpl;
1097
1098         label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1099         label_name = sym_name(elf, label);
1100
1101         if (!strstarts(label_name, prefix)) {
1102                 error("%s: .export_symbol section contains strange symbol '%s'\n",
1103                       mod->name, label_name);
1104                 return;
1105         }
1106
1107         if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1108             ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1109                 error("%s: local symbol '%s' was exported\n", mod->name,
1110                       label_name + strlen(prefix));
1111                 return;
1112         }
1113
1114         name = sym_name(elf, sym);
1115         if (strcmp(label_name + strlen(prefix), name)) {
1116                 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1117                       mod->name, name);
1118                 return;
1119         }
1120
1121         data = sym_get_data(elf, label);        /* license */
1122         if (!strcmp(data, "GPL")) {
1123                 is_gpl = true;
1124         } else if (!strcmp(data, "")) {
1125                 is_gpl = false;
1126         } else {
1127                 error("%s: unknown license '%s' was specified for '%s'\n",
1128                       mod->name, data, name);
1129                 return;
1130         }
1131
1132         data += strlen(data) + 1;       /* namespace */
1133         s = sym_add_exported(name, mod, is_gpl, data);
1134
1135         /*
1136          * We need to be aware whether we are exporting a function or
1137          * a data on some architectures.
1138          */
1139         s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1140
1141         /*
1142          * For parisc64, symbols prefixed $$ from the library have the symbol type
1143          * STT_LOPROC. They should be handled as functions too.
1144          */
1145         if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1146             elf->hdr->e_machine == EM_PARISC &&
1147             ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1148                 s->is_func = true;
1149
1150         if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1151                 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1152                      mod->name, name);
1153         else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1154                 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1155                      mod->name, name);
1156 }
1157
1158 static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1159                                    Elf_Sym *sym,
1160                                    unsigned int fsecndx, const char *fromsec,
1161                                    Elf_Addr faddr, Elf_Addr taddr)
1162 {
1163         const char *tosec = sec_name(elf, get_secindex(elf, sym));
1164         const struct sectioncheck *mismatch;
1165
1166         if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1167                 check_export_symbol(mod, elf, faddr, tosec, sym);
1168                 return;
1169         }
1170
1171         mismatch = section_mismatch(fromsec, tosec);
1172         if (!mismatch)
1173                 return;
1174
1175         default_mismatch_handler(mod->name, elf, mismatch, sym,
1176                                  fsecndx, fromsec, faddr,
1177                                  tosec, taddr);
1178 }
1179
1180 static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1181 {
1182         switch (r_type) {
1183         case R_386_32:
1184                 return TO_NATIVE(*location);
1185         case R_386_PC32:
1186                 return TO_NATIVE(*location) + 4;
1187         }
1188
1189         return (Elf_Addr)(-1);
1190 }
1191
1192 #ifndef R_ARM_CALL
1193 #define R_ARM_CALL      28
1194 #endif
1195 #ifndef R_ARM_JUMP24
1196 #define R_ARM_JUMP24    29
1197 #endif
1198
1199 #ifndef R_ARM_THM_CALL
1200 #define R_ARM_THM_CALL          10
1201 #endif
1202 #ifndef R_ARM_THM_JUMP24
1203 #define R_ARM_THM_JUMP24        30
1204 #endif
1205
1206 #ifndef R_ARM_MOVW_ABS_NC
1207 #define R_ARM_MOVW_ABS_NC       43
1208 #endif
1209
1210 #ifndef R_ARM_MOVT_ABS
1211 #define R_ARM_MOVT_ABS          44
1212 #endif
1213
1214 #ifndef R_ARM_THM_MOVW_ABS_NC
1215 #define R_ARM_THM_MOVW_ABS_NC   47
1216 #endif
1217
1218 #ifndef R_ARM_THM_MOVT_ABS
1219 #define R_ARM_THM_MOVT_ABS      48
1220 #endif
1221
1222 #ifndef R_ARM_THM_JUMP19
1223 #define R_ARM_THM_JUMP19        51
1224 #endif
1225
1226 static int32_t sign_extend32(int32_t value, int index)
1227 {
1228         uint8_t shift = 31 - index;
1229
1230         return (int32_t)(value << shift) >> shift;
1231 }
1232
1233 static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1234 {
1235         uint32_t inst, upper, lower, sign, j1, j2;
1236         int32_t offset;
1237
1238         switch (r_type) {
1239         case R_ARM_ABS32:
1240         case R_ARM_REL32:
1241                 inst = TO_NATIVE(*(uint32_t *)loc);
1242                 return inst + sym->st_value;
1243         case R_ARM_MOVW_ABS_NC:
1244         case R_ARM_MOVT_ABS:
1245                 inst = TO_NATIVE(*(uint32_t *)loc);
1246                 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1247                                        15);
1248                 return offset + sym->st_value;
1249         case R_ARM_PC24:
1250         case R_ARM_CALL:
1251         case R_ARM_JUMP24:
1252                 inst = TO_NATIVE(*(uint32_t *)loc);
1253                 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1254                 return offset + sym->st_value + 8;
1255         case R_ARM_THM_MOVW_ABS_NC:
1256         case R_ARM_THM_MOVT_ABS:
1257                 upper = TO_NATIVE(*(uint16_t *)loc);
1258                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1259                 offset = sign_extend32(((upper & 0x000f) << 12) |
1260                                        ((upper & 0x0400) << 1) |
1261                                        ((lower & 0x7000) >> 4) |
1262                                        (lower & 0x00ff),
1263                                        15);
1264                 return offset + sym->st_value;
1265         case R_ARM_THM_JUMP19:
1266                 /*
1267                  * Encoding T3:
1268                  * S     = upper[10]
1269                  * imm6  = upper[5:0]
1270                  * J1    = lower[13]
1271                  * J2    = lower[11]
1272                  * imm11 = lower[10:0]
1273                  * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1274                  */
1275                 upper = TO_NATIVE(*(uint16_t *)loc);
1276                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1277
1278                 sign = (upper >> 10) & 1;
1279                 j1 = (lower >> 13) & 1;
1280                 j2 = (lower >> 11) & 1;
1281                 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1282                                        ((upper & 0x03f) << 12) |
1283                                        ((lower & 0x07ff) << 1),
1284                                        20);
1285                 return offset + sym->st_value + 4;
1286         case R_ARM_THM_CALL:
1287         case R_ARM_THM_JUMP24:
1288                 /*
1289                  * Encoding T4:
1290                  * S     = upper[10]
1291                  * imm10 = upper[9:0]
1292                  * J1    = lower[13]
1293                  * J2    = lower[11]
1294                  * imm11 = lower[10:0]
1295                  * I1    = NOT(J1 XOR S)
1296                  * I2    = NOT(J2 XOR S)
1297                  * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1298                  */
1299                 upper = TO_NATIVE(*(uint16_t *)loc);
1300                 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1301
1302                 sign = (upper >> 10) & 1;
1303                 j1 = (lower >> 13) & 1;
1304                 j2 = (lower >> 11) & 1;
1305                 offset = sign_extend32((sign << 24) |
1306                                        ((~(j1 ^ sign) & 1) << 23) |
1307                                        ((~(j2 ^ sign) & 1) << 22) |
1308                                        ((upper & 0x03ff) << 12) |
1309                                        ((lower & 0x07ff) << 1),
1310                                        24);
1311                 return offset + sym->st_value + 4;
1312         }
1313
1314         return (Elf_Addr)(-1);
1315 }
1316
1317 static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1318 {
1319         uint32_t inst;
1320
1321         inst = TO_NATIVE(*location);
1322         switch (r_type) {
1323         case R_MIPS_LO16:
1324                 return inst & 0xffff;
1325         case R_MIPS_26:
1326                 return (inst & 0x03ffffff) << 2;
1327         case R_MIPS_32:
1328                 return inst;
1329         }
1330         return (Elf_Addr)(-1);
1331 }
1332
1333 #ifndef EM_RISCV
1334 #define EM_RISCV                243
1335 #endif
1336
1337 #ifndef R_RISCV_SUB32
1338 #define R_RISCV_SUB32           39
1339 #endif
1340
1341 #ifndef EM_LOONGARCH
1342 #define EM_LOONGARCH            258
1343 #endif
1344
1345 #ifndef R_LARCH_SUB32
1346 #define R_LARCH_SUB32           55
1347 #endif
1348
1349 static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1350                                  unsigned int *r_type, unsigned int *r_sym)
1351 {
1352         typedef struct {
1353                 Elf64_Word    r_sym;    /* Symbol index */
1354                 unsigned char r_ssym;   /* Special symbol for 2nd relocation */
1355                 unsigned char r_type3;  /* 3rd relocation type */
1356                 unsigned char r_type2;  /* 2nd relocation type */
1357                 unsigned char r_type;   /* 1st relocation type */
1358         } Elf64_Mips_R_Info;
1359
1360         bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1361
1362         if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1363                 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1364
1365                 *r_type = mips64_r_info->r_type;
1366                 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1367                 return;
1368         }
1369
1370         if (is_64bit)
1371                 r_info = TO_NATIVE((Elf64_Xword)r_info);
1372         else
1373                 r_info = TO_NATIVE((Elf32_Word)r_info);
1374
1375         *r_type = ELF_R_TYPE(r_info);
1376         *r_sym = ELF_R_SYM(r_info);
1377 }
1378
1379 static void section_rela(struct module *mod, struct elf_info *elf,
1380                          unsigned int fsecndx, const char *fromsec,
1381                          const Elf_Rela *start, const Elf_Rela *stop)
1382 {
1383         const Elf_Rela *rela;
1384
1385         for (rela = start; rela < stop; rela++) {
1386                 Elf_Sym *tsym;
1387                 Elf_Addr taddr, r_offset;
1388                 unsigned int r_type, r_sym;
1389
1390                 r_offset = TO_NATIVE(rela->r_offset);
1391                 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1392
1393                 tsym = elf->symtab_start + r_sym;
1394                 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1395
1396                 switch (elf->hdr->e_machine) {
1397                 case EM_RISCV:
1398                         if (!strcmp("__ex_table", fromsec) &&
1399                             r_type == R_RISCV_SUB32)
1400                                 continue;
1401                         break;
1402                 case EM_LOONGARCH:
1403                         if (!strcmp("__ex_table", fromsec) &&
1404                             r_type == R_LARCH_SUB32)
1405                                 continue;
1406                         break;
1407                 }
1408
1409                 check_section_mismatch(mod, elf, tsym,
1410                                        fsecndx, fromsec, r_offset, taddr);
1411         }
1412 }
1413
1414 static void section_rel(struct module *mod, struct elf_info *elf,
1415                         unsigned int fsecndx, const char *fromsec,
1416                         const Elf_Rel *start, const Elf_Rel *stop)
1417 {
1418         const Elf_Rel *rel;
1419
1420         for (rel = start; rel < stop; rel++) {
1421                 Elf_Sym *tsym;
1422                 Elf_Addr taddr = 0, r_offset;
1423                 unsigned int r_type, r_sym;
1424                 void *loc;
1425
1426                 r_offset = TO_NATIVE(rel->r_offset);
1427                 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1428
1429                 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1430                 tsym = elf->symtab_start + r_sym;
1431
1432                 switch (elf->hdr->e_machine) {
1433                 case EM_386:
1434                         taddr = addend_386_rel(loc, r_type);
1435                         break;
1436                 case EM_ARM:
1437                         taddr = addend_arm_rel(loc, tsym, r_type);
1438                         break;
1439                 case EM_MIPS:
1440                         taddr = addend_mips_rel(loc, r_type);
1441                         break;
1442                 default:
1443                         fatal("Please add code to calculate addend for this architecture\n");
1444                 }
1445
1446                 check_section_mismatch(mod, elf, tsym,
1447                                        fsecndx, fromsec, r_offset, taddr);
1448         }
1449 }
1450
1451 /**
1452  * A module includes a number of sections that are discarded
1453  * either when loaded or when used as built-in.
1454  * For loaded modules all functions marked __init and all data
1455  * marked __initdata will be discarded when the module has been initialized.
1456  * Likewise for modules used built-in the sections marked __exit
1457  * are discarded because __exit marked function are supposed to be called
1458  * only when a module is unloaded which never happens for built-in modules.
1459  * The check_sec_ref() function traverses all relocation records
1460  * to find all references to a section that reference a section that will
1461  * be discarded and warns about it.
1462  **/
1463 static void check_sec_ref(struct module *mod, struct elf_info *elf)
1464 {
1465         int i;
1466
1467         /* Walk through all sections */
1468         for (i = 0; i < elf->num_sections; i++) {
1469                 Elf_Shdr *sechdr = &elf->sechdrs[i];
1470
1471                 check_section(mod->name, elf, sechdr);
1472                 /* We want to process only relocation sections and not .init */
1473                 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1474                         /* section to which the relocation applies */
1475                         unsigned int secndx = sechdr->sh_info;
1476                         const char *secname = sec_name(elf, secndx);
1477                         const void *start, *stop;
1478
1479                         /* If the section is known good, skip it */
1480                         if (match(secname, section_white_list))
1481                                 continue;
1482
1483                         start = sym_get_data_by_offset(elf, i, 0);
1484                         stop = start + sechdr->sh_size;
1485
1486                         if (sechdr->sh_type == SHT_RELA)
1487                                 section_rela(mod, elf, secndx, secname,
1488                                              start, stop);
1489                         else
1490                                 section_rel(mod, elf, secndx, secname,
1491                                             start, stop);
1492                 }
1493         }
1494 }
1495
1496 static char *remove_dot(char *s)
1497 {
1498         size_t n = strcspn(s, ".");
1499
1500         if (n && s[n]) {
1501                 size_t m = strspn(s + n + 1, "0123456789");
1502                 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1503                         s[n] = 0;
1504         }
1505         return s;
1506 }
1507
1508 /*
1509  * The CRCs are recorded in .*.cmd files in the form of:
1510  * #SYMVER <name> <crc>
1511  */
1512 static void extract_crcs_for_object(const char *object, struct module *mod)
1513 {
1514         char cmd_file[PATH_MAX];
1515         char *buf, *p;
1516         const char *base;
1517         int dirlen, ret;
1518
1519         base = strrchr(object, '/');
1520         if (base) {
1521                 base++;
1522                 dirlen = base - object;
1523         } else {
1524                 dirlen = 0;
1525                 base = object;
1526         }
1527
1528         ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1529                        dirlen, object, base);
1530         if (ret >= sizeof(cmd_file)) {
1531                 error("%s: too long path was truncated\n", cmd_file);
1532                 return;
1533         }
1534
1535         buf = read_text_file(cmd_file);
1536         p = buf;
1537
1538         while ((p = strstr(p, "\n#SYMVER "))) {
1539                 char *name;
1540                 size_t namelen;
1541                 unsigned int crc;
1542                 struct symbol *sym;
1543
1544                 name = p + strlen("\n#SYMVER ");
1545
1546                 p = strchr(name, ' ');
1547                 if (!p)
1548                         break;
1549
1550                 namelen = p - name;
1551                 p++;
1552
1553                 if (!isdigit(*p))
1554                         continue;       /* skip this line */
1555
1556                 crc = strtoul(p, &p, 0);
1557                 if (*p != '\n')
1558                         continue;       /* skip this line */
1559
1560                 name[namelen] = '\0';
1561
1562                 /*
1563                  * sym_find_with_module() may return NULL here.
1564                  * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1565                  * Since commit e1327a127703, genksyms calculates CRCs of all
1566                  * symbols, including trimmed ones. Ignore orphan CRCs.
1567                  */
1568                 sym = sym_find_with_module(name, mod);
1569                 if (sym)
1570                         sym_set_crc(sym, crc);
1571         }
1572
1573         free(buf);
1574 }
1575
1576 /*
1577  * The symbol versions (CRC) are recorded in the .*.cmd files.
1578  * Parse them to retrieve CRCs for the current module.
1579  */
1580 static void mod_set_crcs(struct module *mod)
1581 {
1582         char objlist[PATH_MAX];
1583         char *buf, *p, *obj;
1584         int ret;
1585
1586         if (mod->is_vmlinux) {
1587                 strcpy(objlist, ".vmlinux.objs");
1588         } else {
1589                 /* objects for a module are listed in the *.mod file. */
1590                 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1591                 if (ret >= sizeof(objlist)) {
1592                         error("%s: too long path was truncated\n", objlist);
1593                         return;
1594                 }
1595         }
1596
1597         buf = read_text_file(objlist);
1598         p = buf;
1599
1600         while ((obj = strsep(&p, "\n")) && obj[0])
1601                 extract_crcs_for_object(obj, mod);
1602
1603         free(buf);
1604 }
1605
1606 static void read_symbols(const char *modname)
1607 {
1608         const char *symname;
1609         char *version;
1610         char *license;
1611         char *namespace;
1612         struct module *mod;
1613         struct elf_info info = { };
1614         Elf_Sym *sym;
1615
1616         if (!parse_elf(&info, modname))
1617                 return;
1618
1619         if (!strends(modname, ".o")) {
1620                 error("%s: filename must be suffixed with .o\n", modname);
1621                 return;
1622         }
1623
1624         /* strip trailing .o */
1625         mod = new_module(modname, strlen(modname) - strlen(".o"));
1626
1627         if (!mod->is_vmlinux) {
1628                 license = get_modinfo(&info, "license");
1629                 if (!license)
1630                         error("missing MODULE_LICENSE() in %s\n", modname);
1631                 while (license) {
1632                         if (!license_is_gpl_compatible(license)) {
1633                                 mod->is_gpl_compatible = false;
1634                                 break;
1635                         }
1636                         license = get_next_modinfo(&info, "license", license);
1637                 }
1638
1639                 namespace = get_modinfo(&info, "import_ns");
1640                 while (namespace) {
1641                         add_namespace(&mod->imported_namespaces, namespace);
1642                         namespace = get_next_modinfo(&info, "import_ns",
1643                                                      namespace);
1644                 }
1645         }
1646
1647         if (extra_warn && !get_modinfo(&info, "description"))
1648                 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1649         for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1650                 symname = remove_dot(info.strtab + sym->st_name);
1651
1652                 handle_symbol(mod, &info, sym, symname);
1653                 handle_moddevtable(mod, &info, sym, symname);
1654         }
1655
1656         check_sec_ref(mod, &info);
1657
1658         if (!mod->is_vmlinux) {
1659                 version = get_modinfo(&info, "version");
1660                 if (version || all_versions)
1661                         get_src_version(mod->name, mod->srcversion,
1662                                         sizeof(mod->srcversion) - 1);
1663         }
1664
1665         parse_elf_finish(&info);
1666
1667         if (modversions) {
1668                 /*
1669                  * Our trick to get versioning for module struct etc. - it's
1670                  * never passed as an argument to an exported function, so
1671                  * the automatic versioning doesn't pick it up, but it's really
1672                  * important anyhow.
1673                  */
1674                 sym_add_unresolved("module_layout", mod, false);
1675
1676                 mod_set_crcs(mod);
1677         }
1678 }
1679
1680 static void read_symbols_from_files(const char *filename)
1681 {
1682         FILE *in = stdin;
1683         char fname[PATH_MAX];
1684
1685         in = fopen(filename, "r");
1686         if (!in)
1687                 fatal("Can't open filenames file %s: %m", filename);
1688
1689         while (fgets(fname, PATH_MAX, in) != NULL) {
1690                 if (strends(fname, "\n"))
1691                         fname[strlen(fname)-1] = '\0';
1692                 read_symbols(fname);
1693         }
1694
1695         fclose(in);
1696 }
1697
1698 #define SZ 500
1699
1700 /* We first write the generated file into memory using the
1701  * following helper, then compare to the file on disk and
1702  * only update the later if anything changed */
1703
1704 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1705                                                       const char *fmt, ...)
1706 {
1707         char tmp[SZ];
1708         int len;
1709         va_list ap;
1710
1711         va_start(ap, fmt);
1712         len = vsnprintf(tmp, SZ, fmt, ap);
1713         buf_write(buf, tmp, len);
1714         va_end(ap);
1715 }
1716
1717 void buf_write(struct buffer *buf, const char *s, int len)
1718 {
1719         if (buf->size - buf->pos < len) {
1720                 buf->size += len + SZ;
1721                 buf->p = NOFAIL(realloc(buf->p, buf->size));
1722         }
1723         strncpy(buf->p + buf->pos, s, len);
1724         buf->pos += len;
1725 }
1726
1727 static void check_exports(struct module *mod)
1728 {
1729         struct symbol *s, *exp;
1730
1731         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1732                 const char *basename;
1733                 exp = find_symbol(s->name);
1734                 if (!exp) {
1735                         if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1736                                 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1737                                             "\"%s\" [%s.ko] undefined!\n",
1738                                             s->name, mod->name);
1739                         continue;
1740                 }
1741                 if (exp->module == mod) {
1742                         error("\"%s\" [%s.ko] was exported without definition\n",
1743                               s->name, mod->name);
1744                         continue;
1745                 }
1746
1747                 exp->used = true;
1748                 s->module = exp->module;
1749                 s->crc_valid = exp->crc_valid;
1750                 s->crc = exp->crc;
1751
1752                 basename = strrchr(mod->name, '/');
1753                 if (basename)
1754                         basename++;
1755                 else
1756                         basename = mod->name;
1757
1758                 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1759                         modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1760                                     "module %s uses symbol %s from namespace %s, but does not import it.\n",
1761                                     basename, exp->name, exp->namespace);
1762                         add_namespace(&mod->missing_namespaces, exp->namespace);
1763                 }
1764
1765                 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1766                         error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1767                               basename, exp->name);
1768         }
1769 }
1770
1771 static void handle_white_list_exports(const char *white_list)
1772 {
1773         char *buf, *p, *name;
1774
1775         buf = read_text_file(white_list);
1776         p = buf;
1777
1778         while ((name = strsep(&p, "\n"))) {
1779                 struct symbol *sym = find_symbol(name);
1780
1781                 if (sym)
1782                         sym->used = true;
1783         }
1784
1785         free(buf);
1786 }
1787
1788 static void check_modname_len(struct module *mod)
1789 {
1790         const char *mod_name;
1791
1792         mod_name = strrchr(mod->name, '/');
1793         if (mod_name == NULL)
1794                 mod_name = mod->name;
1795         else
1796                 mod_name++;
1797         if (strlen(mod_name) >= MODULE_NAME_LEN)
1798                 error("module name is too long [%s.ko]\n", mod->name);
1799 }
1800
1801 /**
1802  * Header for the generated file
1803  **/
1804 static void add_header(struct buffer *b, struct module *mod)
1805 {
1806         buf_printf(b, "#include <linux/module.h>\n");
1807         /*
1808          * Include build-salt.h after module.h in order to
1809          * inherit the definitions.
1810          */
1811         buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1812         buf_printf(b, "#include <linux/build-salt.h>\n");
1813         buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1814         buf_printf(b, "#include <linux/export-internal.h>\n");
1815         buf_printf(b, "#include <linux/vermagic.h>\n");
1816         buf_printf(b, "#include <linux/compiler.h>\n");
1817         buf_printf(b, "\n");
1818         buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1819         buf_printf(b, "#include <asm/orc_header.h>\n");
1820         buf_printf(b, "ORC_HEADER;\n");
1821         buf_printf(b, "#endif\n");
1822         buf_printf(b, "\n");
1823         buf_printf(b, "BUILD_SALT;\n");
1824         buf_printf(b, "BUILD_LTO_INFO;\n");
1825         buf_printf(b, "\n");
1826         buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1827         buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1828         buf_printf(b, "\n");
1829         buf_printf(b, "__visible struct module __this_module\n");
1830         buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1831         buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1832         if (mod->has_init)
1833                 buf_printf(b, "\t.init = init_module,\n");
1834         if (mod->has_cleanup)
1835                 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1836                               "\t.exit = cleanup_module,\n"
1837                               "#endif\n");
1838         buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1839         buf_printf(b, "};\n");
1840
1841         if (!external_module)
1842                 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1843
1844         buf_printf(b,
1845                    "\n"
1846                    "#ifdef CONFIG_RETPOLINE\n"
1847                    "MODULE_INFO(retpoline, \"Y\");\n"
1848                    "#endif\n");
1849
1850         if (strstarts(mod->name, "drivers/staging"))
1851                 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1852
1853         if (strstarts(mod->name, "tools/testing"))
1854                 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1855 }
1856
1857 static void add_exported_symbols(struct buffer *buf, struct module *mod)
1858 {
1859         struct symbol *sym;
1860
1861         /* generate struct for exported symbols */
1862         buf_printf(buf, "\n");
1863         list_for_each_entry(sym, &mod->exported_symbols, list) {
1864                 if (trim_unused_exports && !sym->used)
1865                         continue;
1866
1867                 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1868                            sym->is_func ? "FUNC" : "DATA", sym->name,
1869                            sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1870         }
1871
1872         if (!modversions)
1873                 return;
1874
1875         /* record CRCs for exported symbols */
1876         buf_printf(buf, "\n");
1877         list_for_each_entry(sym, &mod->exported_symbols, list) {
1878                 if (trim_unused_exports && !sym->used)
1879                         continue;
1880
1881                 if (!sym->crc_valid)
1882                         warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1883                              "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1884                              sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1885                              sym->name);
1886
1887                 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1888                            sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1889         }
1890 }
1891
1892 /**
1893  * Record CRCs for unresolved symbols
1894  **/
1895 static void add_versions(struct buffer *b, struct module *mod)
1896 {
1897         struct symbol *s;
1898
1899         if (!modversions)
1900                 return;
1901
1902         buf_printf(b, "\n");
1903         buf_printf(b, "static const struct modversion_info ____versions[]\n");
1904         buf_printf(b, "__used __section(\"__versions\") = {\n");
1905
1906         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1907                 if (!s->module)
1908                         continue;
1909                 if (!s->crc_valid) {
1910                         warn("\"%s\" [%s.ko] has no CRC!\n",
1911                                 s->name, mod->name);
1912                         continue;
1913                 }
1914                 if (strlen(s->name) >= MODULE_NAME_LEN) {
1915                         error("too long symbol \"%s\" [%s.ko]\n",
1916                               s->name, mod->name);
1917                         break;
1918                 }
1919                 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1920                            s->crc, s->name);
1921         }
1922
1923         buf_printf(b, "};\n");
1924 }
1925
1926 static void add_depends(struct buffer *b, struct module *mod)
1927 {
1928         struct symbol *s;
1929         int first = 1;
1930
1931         /* Clear ->seen flag of modules that own symbols needed by this. */
1932         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1933                 if (s->module)
1934                         s->module->seen = s->module->is_vmlinux;
1935         }
1936
1937         buf_printf(b, "\n");
1938         buf_printf(b, "MODULE_INFO(depends, \"");
1939         list_for_each_entry(s, &mod->unresolved_symbols, list) {
1940                 const char *p;
1941                 if (!s->module)
1942                         continue;
1943
1944                 if (s->module->seen)
1945                         continue;
1946
1947                 s->module->seen = true;
1948                 p = strrchr(s->module->name, '/');
1949                 if (p)
1950                         p++;
1951                 else
1952                         p = s->module->name;
1953                 buf_printf(b, "%s%s", first ? "" : ",", p);
1954                 first = 0;
1955         }
1956         buf_printf(b, "\");\n");
1957 }
1958
1959 static void add_srcversion(struct buffer *b, struct module *mod)
1960 {
1961         if (mod->srcversion[0]) {
1962                 buf_printf(b, "\n");
1963                 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1964                            mod->srcversion);
1965         }
1966 }
1967
1968 static void write_buf(struct buffer *b, const char *fname)
1969 {
1970         FILE *file;
1971
1972         if (error_occurred)
1973                 return;
1974
1975         file = fopen(fname, "w");
1976         if (!file) {
1977                 perror(fname);
1978                 exit(1);
1979         }
1980         if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1981                 perror(fname);
1982                 exit(1);
1983         }
1984         if (fclose(file) != 0) {
1985                 perror(fname);
1986                 exit(1);
1987         }
1988 }
1989
1990 static void write_if_changed(struct buffer *b, const char *fname)
1991 {
1992         char *tmp;
1993         FILE *file;
1994         struct stat st;
1995
1996         file = fopen(fname, "r");
1997         if (!file)
1998                 goto write;
1999
2000         if (fstat(fileno(file), &st) < 0)
2001                 goto close_write;
2002
2003         if (st.st_size != b->pos)
2004                 goto close_write;
2005
2006         tmp = NOFAIL(malloc(b->pos));
2007         if (fread(tmp, 1, b->pos, file) != b->pos)
2008                 goto free_write;
2009
2010         if (memcmp(tmp, b->p, b->pos) != 0)
2011                 goto free_write;
2012
2013         free(tmp);
2014         fclose(file);
2015         return;
2016
2017  free_write:
2018         free(tmp);
2019  close_write:
2020         fclose(file);
2021  write:
2022         write_buf(b, fname);
2023 }
2024
2025 static void write_vmlinux_export_c_file(struct module *mod)
2026 {
2027         struct buffer buf = { };
2028
2029         buf_printf(&buf,
2030                    "#include <linux/export-internal.h>\n");
2031
2032         add_exported_symbols(&buf, mod);
2033         write_if_changed(&buf, ".vmlinux.export.c");
2034         free(buf.p);
2035 }
2036
2037 /* do sanity checks, and generate *.mod.c file */
2038 static void write_mod_c_file(struct module *mod)
2039 {
2040         struct buffer buf = { };
2041         char fname[PATH_MAX];
2042         int ret;
2043
2044         add_header(&buf, mod);
2045         add_exported_symbols(&buf, mod);
2046         add_versions(&buf, mod);
2047         add_depends(&buf, mod);
2048         add_moddevtable(&buf, mod);
2049         add_srcversion(&buf, mod);
2050
2051         ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2052         if (ret >= sizeof(fname)) {
2053                 error("%s: too long path was truncated\n", fname);
2054                 goto free;
2055         }
2056
2057         write_if_changed(&buf, fname);
2058
2059 free:
2060         free(buf.p);
2061 }
2062
2063 /* parse Module.symvers file. line format:
2064  * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2065  **/
2066 static void read_dump(const char *fname)
2067 {
2068         char *buf, *pos, *line;
2069
2070         buf = read_text_file(fname);
2071         if (!buf)
2072                 /* No symbol versions, silently ignore */
2073                 return;
2074
2075         pos = buf;
2076
2077         while ((line = get_line(&pos))) {
2078                 char *symname, *namespace, *modname, *d, *export;
2079                 unsigned int crc;
2080                 struct module *mod;
2081                 struct symbol *s;
2082                 bool gpl_only;
2083
2084                 if (!(symname = strchr(line, '\t')))
2085                         goto fail;
2086                 *symname++ = '\0';
2087                 if (!(modname = strchr(symname, '\t')))
2088                         goto fail;
2089                 *modname++ = '\0';
2090                 if (!(export = strchr(modname, '\t')))
2091                         goto fail;
2092                 *export++ = '\0';
2093                 if (!(namespace = strchr(export, '\t')))
2094                         goto fail;
2095                 *namespace++ = '\0';
2096
2097                 crc = strtoul(line, &d, 16);
2098                 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2099                         goto fail;
2100
2101                 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2102                         gpl_only = true;
2103                 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2104                         gpl_only = false;
2105                 } else {
2106                         error("%s: unknown license %s. skip", symname, export);
2107                         continue;
2108                 }
2109
2110                 mod = find_module(modname);
2111                 if (!mod) {
2112                         mod = new_module(modname, strlen(modname));
2113                         mod->from_dump = true;
2114                 }
2115                 s = sym_add_exported(symname, mod, gpl_only, namespace);
2116                 sym_set_crc(s, crc);
2117         }
2118         free(buf);
2119         return;
2120 fail:
2121         free(buf);
2122         fatal("parse error in symbol dump file\n");
2123 }
2124
2125 static void write_dump(const char *fname)
2126 {
2127         struct buffer buf = { };
2128         struct module *mod;
2129         struct symbol *sym;
2130
2131         list_for_each_entry(mod, &modules, list) {
2132                 if (mod->from_dump)
2133                         continue;
2134                 list_for_each_entry(sym, &mod->exported_symbols, list) {
2135                         if (trim_unused_exports && !sym->used)
2136                                 continue;
2137
2138                         buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2139                                    sym->crc, sym->name, mod->name,
2140                                    sym->is_gpl_only ? "_GPL" : "",
2141                                    sym->namespace);
2142                 }
2143         }
2144         write_buf(&buf, fname);
2145         free(buf.p);
2146 }
2147
2148 static void write_namespace_deps_files(const char *fname)
2149 {
2150         struct module *mod;
2151         struct namespace_list *ns;
2152         struct buffer ns_deps_buf = {};
2153
2154         list_for_each_entry(mod, &modules, list) {
2155
2156                 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2157                         continue;
2158
2159                 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2160
2161                 list_for_each_entry(ns, &mod->missing_namespaces, list)
2162                         buf_printf(&ns_deps_buf, " %s", ns->namespace);
2163
2164                 buf_printf(&ns_deps_buf, "\n");
2165         }
2166
2167         write_if_changed(&ns_deps_buf, fname);
2168         free(ns_deps_buf.p);
2169 }
2170
2171 struct dump_list {
2172         struct list_head list;
2173         const char *file;
2174 };
2175
2176 int main(int argc, char **argv)
2177 {
2178         struct module *mod;
2179         char *missing_namespace_deps = NULL;
2180         char *unused_exports_white_list = NULL;
2181         char *dump_write = NULL, *files_source = NULL;
2182         int opt;
2183         LIST_HEAD(dump_lists);
2184         struct dump_list *dl, *dl2;
2185
2186         while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2187                 switch (opt) {
2188                 case 'e':
2189                         external_module = true;
2190                         break;
2191                 case 'i':
2192                         dl = NOFAIL(malloc(sizeof(*dl)));
2193                         dl->file = optarg;
2194                         list_add_tail(&dl->list, &dump_lists);
2195                         break;
2196                 case 'M':
2197                         module_enabled = true;
2198                         break;
2199                 case 'm':
2200                         modversions = true;
2201                         break;
2202                 case 'n':
2203                         ignore_missing_files = true;
2204                         break;
2205                 case 'o':
2206                         dump_write = optarg;
2207                         break;
2208                 case 'a':
2209                         all_versions = true;
2210                         break;
2211                 case 'T':
2212                         files_source = optarg;
2213                         break;
2214                 case 't':
2215                         trim_unused_exports = true;
2216                         break;
2217                 case 'u':
2218                         unused_exports_white_list = optarg;
2219                         break;
2220                 case 'W':
2221                         extra_warn = true;
2222                         break;
2223                 case 'w':
2224                         warn_unresolved = true;
2225                         break;
2226                 case 'E':
2227                         sec_mismatch_warn_only = false;
2228                         break;
2229                 case 'N':
2230                         allow_missing_ns_imports = true;
2231                         break;
2232                 case 'd':
2233                         missing_namespace_deps = optarg;
2234                         break;
2235                 default:
2236                         exit(1);
2237                 }
2238         }
2239
2240         list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2241                 read_dump(dl->file);
2242                 list_del(&dl->list);
2243                 free(dl);
2244         }
2245
2246         while (optind < argc)
2247                 read_symbols(argv[optind++]);
2248
2249         if (files_source)
2250                 read_symbols_from_files(files_source);
2251
2252         list_for_each_entry(mod, &modules, list) {
2253                 if (mod->from_dump || mod->is_vmlinux)
2254                         continue;
2255
2256                 check_modname_len(mod);
2257                 check_exports(mod);
2258         }
2259
2260         if (unused_exports_white_list)
2261                 handle_white_list_exports(unused_exports_white_list);
2262
2263         list_for_each_entry(mod, &modules, list) {
2264                 if (mod->from_dump)
2265                         continue;
2266
2267                 if (mod->is_vmlinux)
2268                         write_vmlinux_export_c_file(mod);
2269                 else
2270                         write_mod_c_file(mod);
2271         }
2272
2273         if (missing_namespace_deps)
2274                 write_namespace_deps_files(missing_namespace_deps);
2275
2276         if (dump_write)
2277                 write_dump(dump_write);
2278         if (sec_mismatch_count && !sec_mismatch_warn_only)
2279                 error("Section mismatches detected.\n"
2280                       "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2281
2282         if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2283                 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2284                      nr_unresolved - MAX_UNRESOLVED_REPORTS);
2285
2286         return error_occurred ? 1 : 0;
2287 }