linux/scripts/mod/modpost.c
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   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 <stdio.h>
  16#include <ctype.h>
  17#include "modpost.h"
  18#include "../../include/linux/license.h"
  19
  20/* Are we using CONFIG_MODVERSIONS? */
  21int modversions = 0;
  22/* Warn about undefined symbols? (do so if we have vmlinux) */
  23int have_vmlinux = 0;
  24/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  25static int all_versions = 0;
  26/* If we are modposting external module set to 1 */
  27static int external_module = 0;
  28/* Warn about section mismatch in vmlinux if set to 1 */
  29static int vmlinux_section_warnings = 1;
  30/* Only warn about unresolved symbols */
  31static int warn_unresolved = 0;
  32/* How a symbol is exported */
  33static int sec_mismatch_count = 0;
  34static int sec_mismatch_verbose = 1;
  35
  36enum export {
  37        export_plain,      export_unused,     export_gpl,
  38        export_unused_gpl, export_gpl_future, export_unknown
  39};
  40
  41#define PRINTF __attribute__ ((format (printf, 1, 2)))
  42
  43PRINTF void fatal(const char *fmt, ...)
  44{
  45        va_list arglist;
  46
  47        fprintf(stderr, "FATAL: ");
  48
  49        va_start(arglist, fmt);
  50        vfprintf(stderr, fmt, arglist);
  51        va_end(arglist);
  52
  53        exit(1);
  54}
  55
  56PRINTF void warn(const char *fmt, ...)
  57{
  58        va_list arglist;
  59
  60        fprintf(stderr, "WARNING: ");
  61
  62        va_start(arglist, fmt);
  63        vfprintf(stderr, fmt, arglist);
  64        va_end(arglist);
  65}
  66
  67PRINTF void merror(const char *fmt, ...)
  68{
  69        va_list arglist;
  70
  71        fprintf(stderr, "ERROR: ");
  72
  73        va_start(arglist, fmt);
  74        vfprintf(stderr, fmt, arglist);
  75        va_end(arglist);
  76}
  77
  78static int is_vmlinux(const char *modname)
  79{
  80        const char *myname;
  81
  82        myname = strrchr(modname, '/');
  83        if (myname)
  84                myname++;
  85        else
  86                myname = modname;
  87
  88        return (strcmp(myname, "vmlinux") == 0) ||
  89               (strcmp(myname, "vmlinux.o") == 0);
  90}
  91
  92void *do_nofail(void *ptr, const char *expr)
  93{
  94        if (!ptr)
  95                fatal("modpost: Memory allocation failure: %s.\n", expr);
  96
  97        return ptr;
  98}
  99
 100/* A list of all modules we processed */
 101static struct module *modules;
 102
 103static struct module *find_module(char *modname)
 104{
 105        struct module *mod;
 106
 107        for (mod = modules; mod; mod = mod->next)
 108                if (strcmp(mod->name, modname) == 0)
 109                        break;
 110        return mod;
 111}
 112
 113static struct module *new_module(char *modname)
 114{
 115        struct module *mod;
 116        char *p, *s;
 117
 118        mod = NOFAIL(malloc(sizeof(*mod)));
 119        memset(mod, 0, sizeof(*mod));
 120        p = NOFAIL(strdup(modname));
 121
 122        /* strip trailing .o */
 123        s = strrchr(p, '.');
 124        if (s != NULL)
 125                if (strcmp(s, ".o") == 0)
 126                        *s = '\0';
 127
 128        /* add to list */
 129        mod->name = p;
 130        mod->gpl_compatible = -1;
 131        mod->next = modules;
 132        modules = mod;
 133
 134        return mod;
 135}
 136
 137/* A hash of all exported symbols,
 138 * struct symbol is also used for lists of unresolved symbols */
 139
 140#define SYMBOL_HASH_SIZE 1024
 141
 142struct symbol {
 143        struct symbol *next;
 144        struct module *module;
 145        unsigned int crc;
 146        int crc_valid;
 147        unsigned int weak:1;
 148        unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
 149        unsigned int kernel:1;     /* 1 if symbol is from kernel
 150                                    *  (only for external modules) **/
 151        unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
 152        enum export  export;       /* Type of export */
 153        char name[0];
 154};
 155
 156static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 157
 158/* This is based on the hash agorithm from gdbm, via tdb */
 159static inline unsigned int tdb_hash(const char *name)
 160{
 161        unsigned value; /* Used to compute the hash value.  */
 162        unsigned   i;   /* Used to cycle through random values. */
 163
 164        /* Set the initial value from the key size. */
 165        for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 166                value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 167
 168        return (1103515243 * value + 12345);
 169}
 170
 171/**
 172 * Allocate a new symbols for use in the hash of exported symbols or
 173 * the list of unresolved symbols per module
 174 **/
 175static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 176                                   struct symbol *next)
 177{
 178        struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 179
 180        memset(s, 0, sizeof(*s));
 181        strcpy(s->name, name);
 182        s->weak = weak;
 183        s->next = next;
 184        return s;
 185}
 186
 187/* For the hash of exported symbols */
 188static struct symbol *new_symbol(const char *name, struct module *module,
 189                                 enum export export)
 190{
 191        unsigned int hash;
 192        struct symbol *new;
 193
 194        hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 195        new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 196        new->module = module;
 197        new->export = export;
 198        return new;
 199}
 200
 201static struct symbol *find_symbol(const char *name)
 202{
 203        struct symbol *s;
 204
 205        /* For our purposes, .foo matches foo.  PPC64 needs this. */
 206        if (name[0] == '.')
 207                name++;
 208
 209        for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 210                if (strcmp(s->name, name) == 0)
 211                        return s;
 212        }
 213        return NULL;
 214}
 215
 216static struct {
 217        const char *str;
 218        enum export export;
 219} export_list[] = {
 220        { .str = "EXPORT_SYMBOL",            .export = export_plain },
 221        { .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
 222        { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
 223        { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
 224        { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
 225        { .str = "(unknown)",                .export = export_unknown },
 226};
 227
 228
 229static const char *export_str(enum export ex)
 230{
 231        return export_list[ex].str;
 232}
 233
 234static enum export export_no(const char *s)
 235{
 236        int i;
 237
 238        if (!s)
 239                return export_unknown;
 240        for (i = 0; export_list[i].export != export_unknown; i++) {
 241                if (strcmp(export_list[i].str, s) == 0)
 242                        return export_list[i].export;
 243        }
 244        return export_unknown;
 245}
 246
 247static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
 248{
 249        if (sec == elf->export_sec)
 250                return export_plain;
 251        else if (sec == elf->export_unused_sec)
 252                return export_unused;
 253        else if (sec == elf->export_gpl_sec)
 254                return export_gpl;
 255        else if (sec == elf->export_unused_gpl_sec)
 256                return export_unused_gpl;
 257        else if (sec == elf->export_gpl_future_sec)
 258                return export_gpl_future;
 259        else
 260                return export_unknown;
 261}
 262
 263/**
 264 * Add an exported symbol - it may have already been added without a
 265 * CRC, in this case just update the CRC
 266 **/
 267static struct symbol *sym_add_exported(const char *name, struct module *mod,
 268                                       enum export export)
 269{
 270        struct symbol *s = find_symbol(name);
 271
 272        if (!s) {
 273                s = new_symbol(name, mod, export);
 274        } else {
 275                if (!s->preloaded) {
 276                        warn("%s: '%s' exported twice. Previous export "
 277                             "was in %s%s\n", mod->name, name,
 278                             s->module->name,
 279                             is_vmlinux(s->module->name) ?"":".ko");
 280                } else {
 281                        /* In case Modules.symvers was out of date */
 282                        s->module = mod;
 283                }
 284        }
 285        s->preloaded = 0;
 286        s->vmlinux   = is_vmlinux(mod->name);
 287        s->kernel    = 0;
 288        s->export    = export;
 289        return s;
 290}
 291
 292static void sym_update_crc(const char *name, struct module *mod,
 293                           unsigned int crc, enum export export)
 294{
 295        struct symbol *s = find_symbol(name);
 296
 297        if (!s)
 298                s = new_symbol(name, mod, export);
 299        s->crc = crc;
 300        s->crc_valid = 1;
 301}
 302
 303void *grab_file(const char *filename, unsigned long *size)
 304{
 305        struct stat st;
 306        void *map;
 307        int fd;
 308
 309        fd = open(filename, O_RDONLY);
 310        if (fd < 0 || fstat(fd, &st) != 0)
 311                return NULL;
 312
 313        *size = st.st_size;
 314        map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 315        close(fd);
 316
 317        if (map == MAP_FAILED)
 318                return NULL;
 319        return map;
 320}
 321
 322/**
 323  * Return a copy of the next line in a mmap'ed file.
 324  * spaces in the beginning of the line is trimmed away.
 325  * Return a pointer to a static buffer.
 326  **/
 327char *get_next_line(unsigned long *pos, void *file, unsigned long size)
 328{
 329        static char line[4096];
 330        int skip = 1;
 331        size_t len = 0;
 332        signed char *p = (signed char *)file + *pos;
 333        char *s = line;
 334
 335        for (; *pos < size ; (*pos)++) {
 336                if (skip && isspace(*p)) {
 337                        p++;
 338                        continue;
 339                }
 340                skip = 0;
 341                if (*p != '\n' && (*pos < size)) {
 342                        len++;
 343                        *s++ = *p++;
 344                        if (len > 4095)
 345                                break; /* Too long, stop */
 346                } else {
 347                        /* End of string */
 348                        *s = '\0';
 349                        return line;
 350                }
 351        }
 352        /* End of buffer */
 353        return NULL;
 354}
 355
 356void release_file(void *file, unsigned long size)
 357{
 358        munmap(file, size);
 359}
 360
 361static int parse_elf(struct elf_info *info, const char *filename)
 362{
 363        unsigned int i;
 364        Elf_Ehdr *hdr;
 365        Elf_Shdr *sechdrs;
 366        Elf_Sym  *sym;
 367
 368        hdr = grab_file(filename, &info->size);
 369        if (!hdr) {
 370                perror(filename);
 371                exit(1);
 372        }
 373        info->hdr = hdr;
 374        if (info->size < sizeof(*hdr)) {
 375                /* file too small, assume this is an empty .o file */
 376                return 0;
 377        }
 378        /* Is this a valid ELF file? */
 379        if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 380            (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 381            (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 382            (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 383                /* Not an ELF file - silently ignore it */
 384                return 0;
 385        }
 386        /* Fix endianness in ELF header */
 387        hdr->e_shoff    = TO_NATIVE(hdr->e_shoff);
 388        hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
 389        hdr->e_shnum    = TO_NATIVE(hdr->e_shnum);
 390        hdr->e_machine  = TO_NATIVE(hdr->e_machine);
 391        hdr->e_type     = TO_NATIVE(hdr->e_type);
 392        sechdrs = (void *)hdr + hdr->e_shoff;
 393        info->sechdrs = sechdrs;
 394
 395        /* Check if file offset is correct */
 396        if (hdr->e_shoff > info->size) {
 397                fatal("section header offset=%lu in file '%s' is bigger than "
 398                      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
 399                      filename, info->size);
 400                return 0;
 401        }
 402
 403        /* Fix endianness in section headers */
 404        for (i = 0; i < hdr->e_shnum; i++) {
 405                sechdrs[i].sh_type   = TO_NATIVE(sechdrs[i].sh_type);
 406                sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
 407                sechdrs[i].sh_size   = TO_NATIVE(sechdrs[i].sh_size);
 408                sechdrs[i].sh_link   = TO_NATIVE(sechdrs[i].sh_link);
 409                sechdrs[i].sh_name   = TO_NATIVE(sechdrs[i].sh_name);
 410                sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);
 411                sechdrs[i].sh_addr   = TO_NATIVE(sechdrs[i].sh_addr);
 412        }
 413        /* Find symbol table. */
 414        for (i = 1; i < hdr->e_shnum; i++) {
 415                const char *secstrings
 416                        = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 417                const char *secname;
 418
 419                if (sechdrs[i].sh_offset > info->size) {
 420                        fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
 421                              "sizeof(*hrd)=%zu\n", filename,
 422                              (unsigned long)sechdrs[i].sh_offset,
 423                              sizeof(*hdr));
 424                        return 0;
 425                }
 426                secname = secstrings + sechdrs[i].sh_name;
 427                if (strcmp(secname, ".modinfo") == 0) {
 428                        info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 429                        info->modinfo_len = sechdrs[i].sh_size;
 430                } else if (strcmp(secname, "__ksymtab") == 0)
 431                        info->export_sec = i;
 432                else if (strcmp(secname, "__ksymtab_unused") == 0)
 433                        info->export_unused_sec = i;
 434                else if (strcmp(secname, "__ksymtab_gpl") == 0)
 435                        info->export_gpl_sec = i;
 436                else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
 437                        info->export_unused_gpl_sec = i;
 438                else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 439                        info->export_gpl_future_sec = i;
 440                else if (strcmp(secname, "__markers_strings") == 0)
 441                        info->markers_strings_sec = i;
 442
 443                if (sechdrs[i].sh_type != SHT_SYMTAB)
 444                        continue;
 445
 446                info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
 447                info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
 448                                                 + sechdrs[i].sh_size;
 449                info->strtab       = (void *)hdr +
 450                                     sechdrs[sechdrs[i].sh_link].sh_offset;
 451        }
 452        if (!info->symtab_start)
 453                fatal("%s has no symtab?\n", filename);
 454
 455        /* Fix endianness in symbols */
 456        for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 457                sym->st_shndx = TO_NATIVE(sym->st_shndx);
 458                sym->st_name  = TO_NATIVE(sym->st_name);
 459                sym->st_value = TO_NATIVE(sym->st_value);
 460                sym->st_size  = TO_NATIVE(sym->st_size);
 461        }
 462        return 1;
 463}
 464
 465static void parse_elf_finish(struct elf_info *info)
 466{
 467        release_file(info->hdr, info->size);
 468}
 469
 470static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 471{
 472        /* ignore __this_module, it will be resolved shortly */
 473        if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 474                return 1;
 475        /* ignore global offset table */
 476        if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 477                return 1;
 478        if (info->hdr->e_machine == EM_PPC)
 479                /* Special register function linked on all modules during final link of .ko */
 480                if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
 481                    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
 482                    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
 483                    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
 484                        return 1;
 485        /* Do not ignore this symbol */
 486        return 0;
 487}
 488
 489#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
 490#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 491
 492static void handle_modversions(struct module *mod, struct elf_info *info,
 493                               Elf_Sym *sym, const char *symname)
 494{
 495        unsigned int crc;
 496        enum export export = export_from_sec(info, sym->st_shndx);
 497
 498        switch (sym->st_shndx) {
 499        case SHN_COMMON:
 500                warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 501                break;
 502        case SHN_ABS:
 503                /* CRC'd symbol */
 504                if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 505                        crc = (unsigned int) sym->st_value;
 506                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 507                                        export);
 508                }
 509                break;
 510        case SHN_UNDEF:
 511                /* undefined symbol */
 512                if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 513                    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 514                        break;
 515                if (ignore_undef_symbol(info, symname))
 516                        break;
 517/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 518#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 519/* add compatibility with older glibc */
 520#ifndef STT_SPARC_REGISTER
 521#define STT_SPARC_REGISTER STT_REGISTER
 522#endif
 523                if (info->hdr->e_machine == EM_SPARC ||
 524                    info->hdr->e_machine == EM_SPARCV9) {
 525                        /* Ignore register directives. */
 526                        if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 527                                break;
 528                        if (symname[0] == '.') {
 529                                char *munged = strdup(symname);
 530                                munged[0] = '_';
 531                                munged[1] = toupper(munged[1]);
 532                                symname = munged;
 533                        }
 534                }
 535#endif
 536
 537                if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 538                           strlen(MODULE_SYMBOL_PREFIX)) == 0) {
 539                        mod->unres =
 540                          alloc_symbol(symname +
 541                                       strlen(MODULE_SYMBOL_PREFIX),
 542                                       ELF_ST_BIND(sym->st_info) == STB_WEAK,
 543                                       mod->unres);
 544                }
 545                break;
 546        default:
 547                /* All exported symbols */
 548                if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 549                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 550                                        export);
 551                }
 552                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 553                        mod->has_init = 1;
 554                if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 555                        mod->has_cleanup = 1;
 556                break;
 557        }
 558}
 559
 560/**
 561 * Parse tag=value strings from .modinfo section
 562 **/
 563static char *next_string(char *string, unsigned long *secsize)
 564{
 565        /* Skip non-zero chars */
 566        while (string[0]) {
 567                string++;
 568                if ((*secsize)-- <= 1)
 569                        return NULL;
 570        }
 571
 572        /* Skip any zero padding. */
 573        while (!string[0]) {
 574                string++;
 575                if ((*secsize)-- <= 1)
 576                        return NULL;
 577        }
 578        return string;
 579}
 580
 581static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
 582                              const char *tag, char *info)
 583{
 584        char *p;
 585        unsigned int taglen = strlen(tag);
 586        unsigned long size = modinfo_len;
 587
 588        if (info) {
 589                size -= info - (char *)modinfo;
 590                modinfo = next_string(info, &size);
 591        }
 592
 593        for (p = modinfo; p; p = next_string(p, &size)) {
 594                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 595                        return p + taglen + 1;
 596        }
 597        return NULL;
 598}
 599
 600static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 601                         const char *tag)
 602
 603{
 604        return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
 605}
 606
 607/**
 608 * Test if string s ends in string sub
 609 * return 0 if match
 610 **/
 611static int strrcmp(const char *s, const char *sub)
 612{
 613        int slen, sublen;
 614
 615        if (!s || !sub)
 616                return 1;
 617
 618        slen = strlen(s);
 619        sublen = strlen(sub);
 620
 621        if ((slen == 0) || (sublen == 0))
 622                return 1;
 623
 624        if (sublen > slen)
 625                return 1;
 626
 627        return memcmp(s + slen - sublen, sub, sublen);
 628}
 629
 630static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 631{
 632        if (sym)
 633                return elf->strtab + sym->st_name;
 634        else
 635                return "(unknown)";
 636}
 637
 638static const char *sec_name(struct elf_info *elf, int shndx)
 639{
 640        Elf_Shdr *sechdrs = elf->sechdrs;
 641        return (void *)elf->hdr +
 642                elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
 643                sechdrs[shndx].sh_name;
 644}
 645
 646static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
 647{
 648        return (void *)elf->hdr +
 649                elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
 650                sechdr->sh_name;
 651}
 652
 653/* if sym is empty or point to a string
 654 * like ".[0-9]+" then return 1.
 655 * This is the optional prefix added by ld to some sections
 656 */
 657static int number_prefix(const char *sym)
 658{
 659        if (*sym++ == '\0')
 660                return 1;
 661        if (*sym != '.')
 662                return 0;
 663        do {
 664                char c = *sym++;
 665                if (c < '0' || c > '9')
 666                        return 0;
 667        } while (*sym);
 668        return 1;
 669}
 670
 671/* The pattern is an array of simple patterns.
 672 * "foo" will match an exact string equal to "foo"
 673 * "*foo" will match a string that ends with "foo"
 674 * "foo*" will match a string that begins with "foo"
 675 * "foo$" will match a string equal to "foo" or "foo.1"
 676 *   where the '1' can be any number including several digits.
 677 *   The $ syntax is for sections where ld append a dot number
 678 *   to make section name unique.
 679 */
 680int match(const char *sym, const char * const pat[])
 681{
 682        const char *p;
 683        while (*pat) {
 684                p = *pat++;
 685                const char *endp = p + strlen(p) - 1;
 686
 687                /* "*foo" */
 688                if (*p == '*') {
 689                        if (strrcmp(sym, p + 1) == 0)
 690                                return 1;
 691                }
 692                /* "foo*" */
 693                else if (*endp == '*') {
 694                        if (strncmp(sym, p, strlen(p) - 1) == 0)
 695                                return 1;
 696                }
 697                /* "foo$" */
 698                else if (*endp == '$') {
 699                        if (strncmp(sym, p, strlen(p) - 1) == 0) {
 700                                if (number_prefix(sym + strlen(p) - 1))
 701                                        return 1;
 702                        }
 703                }
 704                /* no wildcards */
 705                else {
 706                        if (strcmp(p, sym) == 0)
 707                                return 1;
 708                }
 709        }
 710        /* no match */
 711        return 0;
 712}
 713
 714/* sections that we do not want to do full section mismatch check on */
 715static const char *section_white_list[] =
 716        { ".debug*", ".stab*", ".note*", ".got*", ".toc*", NULL };
 717
 718/*
 719 * Is this section one we do not want to check?
 720 * This is often debug sections.
 721 * If we are going to check this section then
 722 * test if section name ends with a dot and a number.
 723 * This is used to find sections where the linker have
 724 * appended a dot-number to make the name unique.
 725 * The cause of this is often a section specified in assembler
 726 * without "ax" / "aw" and the same section used in .c
 727 * code where gcc add these.
 728 */
 729static int check_section(const char *modname, const char *sec)
 730{
 731        const char *e = sec + strlen(sec) - 1;
 732        if (match(sec, section_white_list))
 733                return 1;
 734
 735        if (*e && isdigit(*e)) {
 736                /* consume all digits */
 737                while (*e && e != sec && isdigit(*e))
 738                        e--;
 739                if (*e == '.' && !strstr(sec, ".linkonce")) {
 740                        warn("%s (%s): unexpected section name.\n"
 741                             "The (.[number]+) following section name are "
 742                             "ld generated and not expected.\n"
 743                             "Did you forget to use \"ax\"/\"aw\" "
 744                             "in a .S file?\n"
 745                             "Note that for example <linux/init.h> contains\n"
 746                             "section definitions for use in .S files.\n\n",
 747                             modname, sec);
 748                }
 749        }
 750        return 0;
 751}
 752
 753
 754
 755#define ALL_INIT_DATA_SECTIONS \
 756        ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
 757#define ALL_EXIT_DATA_SECTIONS \
 758        ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
 759
 760#define ALL_INIT_TEXT_SECTIONS \
 761        ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
 762#define ALL_EXIT_TEXT_SECTIONS \
 763        ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
 764
 765#define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS
 766#define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS
 767
 768#define DATA_SECTIONS ".data$", ".data.rel$"
 769#define TEXT_SECTIONS ".text$"
 770
 771#define INIT_SECTIONS      ".init.data$", ".init.text$"
 772#define DEV_INIT_SECTIONS  ".devinit.data$", ".devinit.text$"
 773#define CPU_INIT_SECTIONS  ".cpuinit.data$", ".cpuinit.text$"
 774#define MEM_INIT_SECTIONS  ".meminit.data$", ".meminit.text$"
 775
 776#define EXIT_SECTIONS      ".exit.data$", ".exit.text$"
 777#define DEV_EXIT_SECTIONS  ".devexit.data$", ".devexit.text$"
 778#define CPU_EXIT_SECTIONS  ".cpuexit.data$", ".cpuexit.text$"
 779#define MEM_EXIT_SECTIONS  ".memexit.data$", ".memexit.text$"
 780
 781/* init data sections */
 782static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 783
 784/* all init sections */
 785static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 786
 787/* All init and exit sections (code + data) */
 788static const char *init_exit_sections[] =
 789        {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 790
 791/* data section */
 792static const char *data_sections[] = { DATA_SECTIONS, NULL };
 793
 794/* sections that may refer to an init/exit section with no warning */
 795static const char *initref_sections[] =
 796{
 797        ".text.init.refok*",
 798        ".exit.text.refok*",
 799        ".data.init.refok*",
 800        NULL
 801};
 802
 803
 804/* symbols in .data that may refer to init/exit sections */
 805static const char *symbol_white_list[] =
 806{
 807        "*driver",
 808        "*_template", /* scsi uses *_template a lot */
 809        "*_timer",    /* arm uses ops structures named _timer a lot */
 810        "*_sht",      /* scsi also used *_sht to some extent */
 811        "*_ops",
 812        "*_probe",
 813        "*_probe_one",
 814        "*_console",
 815        NULL
 816};
 817
 818static const char *head_sections[] = { ".head.text*", NULL };
 819static const char *linker_symbols[] =
 820        { "__init_begin", "_sinittext", "_einittext", NULL };
 821
 822enum mismatch {
 823        NO_MISMATCH,
 824        TEXT_TO_INIT,
 825        DATA_TO_INIT,
 826        TEXT_TO_EXIT,
 827        DATA_TO_EXIT,
 828        XXXINIT_TO_INIT,
 829        XXXEXIT_TO_EXIT,
 830        INIT_TO_EXIT,
 831        EXIT_TO_INIT,
 832        EXPORT_TO_INIT_EXIT,
 833};
 834
 835struct sectioncheck {
 836        const char *fromsec[20];
 837        const char *tosec[20];
 838        enum mismatch mismatch;
 839};
 840
 841const struct sectioncheck sectioncheck[] = {
 842/* Do not reference init/exit code/data from
 843 * normal code and data
 844 */
 845{
 846        .fromsec = { TEXT_SECTIONS, NULL },
 847        .tosec   = { ALL_INIT_SECTIONS, NULL },
 848        .mismatch = TEXT_TO_INIT,
 849},
 850{
 851        .fromsec = { DATA_SECTIONS, NULL },
 852        .tosec   = { ALL_INIT_SECTIONS, NULL },
 853        .mismatch = DATA_TO_INIT,
 854},
 855{
 856        .fromsec = { TEXT_SECTIONS, NULL },
 857        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 858        .mismatch = TEXT_TO_EXIT,
 859},
 860{
 861        .fromsec = { DATA_SECTIONS, NULL },
 862        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 863        .mismatch = DATA_TO_EXIT,
 864},
 865/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
 866{
 867        .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
 868        .tosec   = { INIT_SECTIONS, NULL },
 869        .mismatch = XXXINIT_TO_INIT,
 870},
 871/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
 872{
 873        .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
 874        .tosec   = { EXIT_SECTIONS, NULL },
 875        .mismatch = XXXEXIT_TO_EXIT,
 876},
 877/* Do not use exit code/data from init code */
 878{
 879        .fromsec = { ALL_INIT_SECTIONS, NULL },
 880        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 881        .mismatch = INIT_TO_EXIT,
 882},
 883/* Do not use init code/data from exit code */
 884{
 885        .fromsec = { ALL_EXIT_SECTIONS, NULL },
 886        .tosec   = { ALL_INIT_SECTIONS, NULL },
 887        .mismatch = EXIT_TO_INIT,
 888},
 889/* Do not export init/exit functions or data */
 890{
 891        .fromsec = { "__ksymtab*", NULL },
 892        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
 893        .mismatch = EXPORT_TO_INIT_EXIT
 894}
 895};
 896
 897static int section_mismatch(const char *fromsec, const char *tosec)
 898{
 899        int i;
 900        int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
 901        const struct sectioncheck *check = &sectioncheck[0];
 902
 903        for (i = 0; i < elems; i++) {
 904                if (match(fromsec, check->fromsec) &&
 905                    match(tosec, check->tosec))
 906                        return check->mismatch;
 907                check++;
 908        }
 909        return NO_MISMATCH;
 910}
 911
 912/**
 913 * Whitelist to allow certain references to pass with no warning.
 914 *
 915 * Pattern 0:
 916 *   Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
 917 *   The pattern is identified by:
 918 *   fromsec = .text.init.refok* | .data.init.refok*
 919 *
 920 * Pattern 1:
 921 *   If a module parameter is declared __initdata and permissions=0
 922 *   then this is legal despite the warning generated.
 923 *   We cannot see value of permissions here, so just ignore
 924 *   this pattern.
 925 *   The pattern is identified by:
 926 *   tosec   = .init.data
 927 *   fromsec = .data*
 928 *   atsym   =__param*
 929 *
 930 * Pattern 2:
 931 *   Many drivers utilise a *driver container with references to
 932 *   add, remove, probe functions etc.
 933 *   These functions may often be marked __init and we do not want to
 934 *   warn here.
 935 *   the pattern is identified by:
 936 *   tosec   = init or exit section
 937 *   fromsec = data section
 938 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
 939 *           *probe_one, *_console, *_timer
 940 *
 941 * Pattern 3:
 942 *   Whitelist all refereces from .text.head to .init.data
 943 *   Whitelist all refereces from .text.head to .init.text
 944 *
 945 * Pattern 4:
 946 *   Some symbols belong to init section but still it is ok to reference
 947 *   these from non-init sections as these symbols don't have any memory
 948 *   allocated for them and symbol address and value are same. So even
 949 *   if init section is freed, its ok to reference those symbols.
 950 *   For ex. symbols marking the init section boundaries.
 951 *   This pattern is identified by
 952 *   refsymname = __init_begin, _sinittext, _einittext
 953 *
 954 **/
 955static int secref_whitelist(const char *fromsec, const char *fromsym,
 956                            const char *tosec, const char *tosym)
 957{
 958        /* Check for pattern 0 */
 959        if (match(fromsec, initref_sections))
 960                return 0;
 961
 962        /* Check for pattern 1 */
 963        if (match(tosec, init_data_sections) &&
 964            match(fromsec, data_sections) &&
 965            (strncmp(fromsym, "__param", strlen("__param")) == 0))
 966                return 0;
 967
 968        /* Check for pattern 2 */
 969        if (match(tosec, init_exit_sections) &&
 970            match(fromsec, data_sections) &&
 971            match(fromsym, symbol_white_list))
 972                return 0;
 973
 974        /* Check for pattern 3 */
 975        if (match(fromsec, head_sections) &&
 976            match(tosec, init_sections))
 977                return 0;
 978
 979        /* Check for pattern 4 */
 980        if (match(tosym, linker_symbols))
 981                return 0;
 982
 983        return 1;
 984}
 985
 986/**
 987 * Find symbol based on relocation record info.
 988 * In some cases the symbol supplied is a valid symbol so
 989 * return refsym. If st_name != 0 we assume this is a valid symbol.
 990 * In other cases the symbol needs to be looked up in the symbol table
 991 * based on section and address.
 992 *  **/
 993static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
 994                                Elf_Sym *relsym)
 995{
 996        Elf_Sym *sym;
 997        Elf_Sym *near = NULL;
 998        Elf64_Sword distance = 20;
 999        Elf64_Sword d;
1000
1001        if (relsym->st_name != 0)
1002                return relsym;
1003        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1004                if (sym->st_shndx != relsym->st_shndx)
1005                        continue;
1006                if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1007                        continue;
1008                if (sym->st_value == addr)
1009                        return sym;
1010                /* Find a symbol nearby - addr are maybe negative */
1011                d = sym->st_value - addr;
1012                if (d < 0)
1013                        d = addr - sym->st_value;
1014                if (d < distance) {
1015                        distance = d;
1016                        near = sym;
1017                }
1018        }
1019        /* We need a close match */
1020        if (distance < 20)
1021                return near;
1022        else
1023                return NULL;
1024}
1025
1026static inline int is_arm_mapping_symbol(const char *str)
1027{
1028        return str[0] == '$' && strchr("atd", str[1])
1029               && (str[2] == '\0' || str[2] == '.');
1030}
1031
1032/*
1033 * If there's no name there, ignore it; likewise, ignore it if it's
1034 * one of the magic symbols emitted used by current ARM tools.
1035 *
1036 * Otherwise if find_symbols_between() returns those symbols, they'll
1037 * fail the whitelist tests and cause lots of false alarms ... fixable
1038 * only by merging __exit and __init sections into __text, bloating
1039 * the kernel (which is especially evil on embedded platforms).
1040 */
1041static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1042{
1043        const char *name = elf->strtab + sym->st_name;
1044
1045        if (!name || !strlen(name))
1046                return 0;
1047        return !is_arm_mapping_symbol(name);
1048}
1049
1050/*
1051 * Find symbols before or equal addr and after addr - in the section sec.
1052 * If we find two symbols with equal offset prefer one with a valid name.
1053 * The ELF format may have a better way to detect what type of symbol
1054 * it is, but this works for now.
1055 **/
1056static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1057                                 const char *sec)
1058{
1059        Elf_Sym *sym;
1060        Elf_Sym *near = NULL;
1061        Elf_Addr distance = ~0;
1062
1063        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1064                const char *symsec;
1065
1066                if (sym->st_shndx >= SHN_LORESERVE)
1067                        continue;
1068                symsec = sec_name(elf, sym->st_shndx);
1069                if (strcmp(symsec, sec) != 0)
1070                        continue;
1071                if (!is_valid_name(elf, sym))
1072                        continue;
1073                if (sym->st_value <= addr) {
1074                        if ((addr - sym->st_value) < distance) {
1075                                distance = addr - sym->st_value;
1076                                near = sym;
1077                        } else if ((addr - sym->st_value) == distance) {
1078                                near = sym;
1079                        }
1080                }
1081        }
1082        return near;
1083}
1084
1085/*
1086 * Convert a section name to the function/data attribute
1087 * .init.text => __init
1088 * .cpuinit.data => __cpudata
1089 * .memexitconst => __memconst
1090 * etc.
1091*/
1092static char *sec2annotation(const char *s)
1093{
1094        if (match(s, init_exit_sections)) {
1095                char *p = malloc(20);
1096                char *r = p;
1097
1098                *p++ = '_';
1099                *p++ = '_';
1100                if (*s == '.')
1101                        s++;
1102                while (*s && *s != '.')
1103                        *p++ = *s++;
1104                *p = '\0';
1105                if (*s == '.')
1106                        s++;
1107                if (strstr(s, "rodata") != NULL)
1108                        strcat(p, "const ");
1109                else if (strstr(s, "data") != NULL)
1110                        strcat(p, "data ");
1111                else
1112                        strcat(p, " ");
1113                return r; /* we leak her but we do not care */
1114        } else {
1115                return "";
1116        }
1117}
1118
1119static int is_function(Elf_Sym *sym)
1120{
1121        if (sym)
1122                return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1123        else
1124                return -1;
1125}
1126
1127/*
1128 * Print a warning about a section mismatch.
1129 * Try to find symbols near it so user can find it.
1130 * Check whitelist before warning - it may be a false positive.
1131 */
1132static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
1133                                const char *fromsec,
1134                                unsigned long long fromaddr,
1135                                const char *fromsym,
1136                                int from_is_func,
1137                                const char *tosec, const char *tosym,
1138                                int to_is_func)
1139{
1140        const char *from, *from_p;
1141        const char *to, *to_p;
1142
1143        switch (from_is_func) {
1144        case 0: from = "variable"; from_p = "";   break;
1145        case 1: from = "function"; from_p = "()"; break;
1146        default: from = "(unknown reference)"; from_p = ""; break;
1147        }
1148        switch (to_is_func) {
1149        case 0: to = "variable"; to_p = "";   break;
1150        case 1: to = "function"; to_p = "()"; break;
1151        default: to = "(unknown reference)"; to_p = ""; break;
1152        }
1153
1154        sec_mismatch_count++;
1155        if (!sec_mismatch_verbose)
1156                return;
1157
1158        warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1159             "to the %s %s:%s%s\n",
1160             modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1161             tosym, to_p);
1162
1163        switch (mismatch) {
1164        case TEXT_TO_INIT:
1165                fprintf(stderr,
1166                "The function %s%s() references\n"
1167                "the %s %s%s%s.\n"
1168                "This is often because %s lacks a %s\n"
1169                "annotation or the annotation of %s is wrong.\n",
1170                sec2annotation(fromsec), fromsym,
1171                to, sec2annotation(tosec), tosym, to_p,
1172                fromsym, sec2annotation(tosec), tosym);
1173                break;
1174        case DATA_TO_INIT: {
1175                const char **s = symbol_white_list;
1176                fprintf(stderr,
1177                "The variable %s references\n"
1178                "the %s %s%s%s\n"
1179                "If the reference is valid then annotate the\n"
1180                "variable with __init* (see linux/init.h) "
1181                "or name the variable:\n",
1182                fromsym, to, sec2annotation(tosec), tosym, to_p);
1183                while (*s)
1184                        fprintf(stderr, "%s, ", *s++);
1185                fprintf(stderr, "\n");
1186                break;
1187        }
1188        case TEXT_TO_EXIT:
1189                fprintf(stderr,
1190                "The function %s() references a %s in an exit section.\n"
1191                "Often the %s %s%s has valid usage outside the exit section\n"
1192                "and the fix is to remove the %sannotation of %s.\n",
1193                fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1194                break;
1195        case DATA_TO_EXIT: {
1196                const char **s = symbol_white_list;
1197                fprintf(stderr,
1198                "The variable %s references\n"
1199                "the %s %s%s%s\n"
1200                "If the reference is valid then annotate the\n"
1201                "variable with __exit* (see linux/init.h) or "
1202                "name the variable:\n",
1203                fromsym, to, sec2annotation(tosec), tosym, to_p);
1204                while (*s)
1205                        fprintf(stderr, "%s, ", *s++);
1206                fprintf(stderr, "\n");
1207                break;
1208        }
1209        case XXXINIT_TO_INIT:
1210        case XXXEXIT_TO_EXIT:
1211                fprintf(stderr,
1212                "The %s %s%s%s references\n"
1213                "a %s %s%s%s.\n"
1214                "If %s is only used by %s then\n"
1215                "annotate %s with a matching annotation.\n",
1216                from, sec2annotation(fromsec), fromsym, from_p,
1217                to, sec2annotation(tosec), tosym, to_p,
1218                tosym, fromsym, tosym);
1219                break;
1220        case INIT_TO_EXIT:
1221                fprintf(stderr,
1222                "The %s %s%s%s references\n"
1223                "a %s %s%s%s.\n"
1224                "This is often seen when error handling "
1225                "in the init function\n"
1226                "uses functionality in the exit path.\n"
1227                "The fix is often to remove the %sannotation of\n"
1228                "%s%s so it may be used outside an exit section.\n",
1229                from, sec2annotation(fromsec), fromsym, from_p,
1230                to, sec2annotation(tosec), tosym, to_p,
1231                sec2annotation(tosec), tosym, to_p);
1232                break;
1233        case EXIT_TO_INIT:
1234                fprintf(stderr,
1235                "The %s %s%s%s references\n"
1236                "a %s %s%s%s.\n"
1237                "This is often seen when error handling "
1238                "in the exit function\n"
1239                "uses functionality in the init path.\n"
1240                "The fix is often to remove the %sannotation of\n"
1241                "%s%s so it may be used outside an init section.\n",
1242                from, sec2annotation(fromsec), fromsym, from_p,
1243                to, sec2annotation(tosec), tosym, to_p,
1244                sec2annotation(tosec), tosym, to_p);
1245                break;
1246        case EXPORT_TO_INIT_EXIT:
1247                fprintf(stderr,
1248                "The symbol %s is exported and annotated %s\n"
1249                "Fix this by removing the %sannotation of %s "
1250                "or drop the export.\n",
1251                tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1252        case NO_MISMATCH:
1253                /* To get warnings on missing members */
1254                break;
1255        }
1256        fprintf(stderr, "\n");
1257}
1258
1259static void check_section_mismatch(const char *modname, struct elf_info *elf,
1260                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1261{
1262        const char *tosec;
1263        enum mismatch mismatch;
1264
1265        tosec = sec_name(elf, sym->st_shndx);
1266        mismatch = section_mismatch(fromsec, tosec);
1267        if (mismatch != NO_MISMATCH) {
1268                Elf_Sym *to;
1269                Elf_Sym *from;
1270                const char *tosym;
1271                const char *fromsym;
1272
1273                from = find_elf_symbol2(elf, r->r_offset, fromsec);
1274                fromsym = sym_name(elf, from);
1275                to = find_elf_symbol(elf, r->r_addend, sym);
1276                tosym = sym_name(elf, to);
1277
1278                /* check whitelist - we may ignore it */
1279                if (secref_whitelist(fromsec, fromsym, tosec, tosym)) {
1280                        report_sec_mismatch(modname, mismatch,
1281                           fromsec, r->r_offset, fromsym,
1282                           is_function(from), tosec, tosym,
1283                           is_function(to));
1284                }
1285        }
1286}
1287
1288static unsigned int *reloc_location(struct elf_info *elf,
1289                                    Elf_Shdr *sechdr, Elf_Rela *r)
1290{
1291        Elf_Shdr *sechdrs = elf->sechdrs;
1292        int section = sechdr->sh_info;
1293
1294        return (void *)elf->hdr + sechdrs[section].sh_offset +
1295                (r->r_offset - sechdrs[section].sh_addr);
1296}
1297
1298static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1299{
1300        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1301        unsigned int *location = reloc_location(elf, sechdr, r);
1302
1303        switch (r_typ) {
1304        case R_386_32:
1305                r->r_addend = TO_NATIVE(*location);
1306                break;
1307        case R_386_PC32:
1308                r->r_addend = TO_NATIVE(*location) + 4;
1309                /* For CONFIG_RELOCATABLE=y */
1310                if (elf->hdr->e_type == ET_EXEC)
1311                        r->r_addend += r->r_offset;
1312                break;
1313        }
1314        return 0;
1315}
1316
1317static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1318{
1319        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1320
1321        switch (r_typ) {
1322        case R_ARM_ABS32:
1323                /* From ARM ABI: (S + A) | T */
1324                r->r_addend = (int)(long)
1325                              (elf->symtab_start + ELF_R_SYM(r->r_info));
1326                break;
1327        case R_ARM_PC24:
1328                /* From ARM ABI: ((S + A) | T) - P */
1329                r->r_addend = (int)(long)(elf->hdr +
1330                              sechdr->sh_offset +
1331                              (r->r_offset - sechdr->sh_addr));
1332                break;
1333        default:
1334                return 1;
1335        }
1336        return 0;
1337}
1338
1339static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1340{
1341        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1342        unsigned int *location = reloc_location(elf, sechdr, r);
1343        unsigned int inst;
1344
1345        if (r_typ == R_MIPS_HI16)
1346                return 1;       /* skip this */
1347        inst = TO_NATIVE(*location);
1348        switch (r_typ) {
1349        case R_MIPS_LO16:
1350                r->r_addend = inst & 0xffff;
1351                break;
1352        case R_MIPS_26:
1353                r->r_addend = (inst & 0x03ffffff) << 2;
1354                break;
1355        case R_MIPS_32:
1356                r->r_addend = inst;
1357                break;
1358        }
1359        return 0;
1360}
1361
1362static void section_rela(const char *modname, struct elf_info *elf,
1363                         Elf_Shdr *sechdr)
1364{
1365        Elf_Sym  *sym;
1366        Elf_Rela *rela;
1367        Elf_Rela r;
1368        unsigned int r_sym;
1369        const char *fromsec;
1370
1371        Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1372        Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1373
1374        fromsec = sech_name(elf, sechdr);
1375        fromsec += strlen(".rela");
1376        /* if from section (name) is know good then skip it */
1377        if (check_section(modname, fromsec))
1378                return;
1379
1380        for (rela = start; rela < stop; rela++) {
1381                r.r_offset = TO_NATIVE(rela->r_offset);
1382#if KERNEL_ELFCLASS == ELFCLASS64
1383                if (elf->hdr->e_machine == EM_MIPS) {
1384                        unsigned int r_typ;
1385                        r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1386                        r_sym = TO_NATIVE(r_sym);
1387                        r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1388                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1389                } else {
1390                        r.r_info = TO_NATIVE(rela->r_info);
1391                        r_sym = ELF_R_SYM(r.r_info);
1392                }
1393#else
1394                r.r_info = TO_NATIVE(rela->r_info);
1395                r_sym = ELF_R_SYM(r.r_info);
1396#endif
1397                r.r_addend = TO_NATIVE(rela->r_addend);
1398                sym = elf->symtab_start + r_sym;
1399                /* Skip special sections */
1400                if (sym->st_shndx >= SHN_LORESERVE)
1401                        continue;
1402                check_section_mismatch(modname, elf, &r, sym, fromsec);
1403        }
1404}
1405
1406static void section_rel(const char *modname, struct elf_info *elf,
1407                        Elf_Shdr *sechdr)
1408{
1409        Elf_Sym *sym;
1410        Elf_Rel *rel;
1411        Elf_Rela r;
1412        unsigned int r_sym;
1413        const char *fromsec;
1414
1415        Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1416        Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1417
1418        fromsec = sech_name(elf, sechdr);
1419        fromsec += strlen(".rel");
1420        /* if from section (name) is know good then skip it */
1421        if (check_section(modname, fromsec))
1422                return;
1423
1424        for (rel = start; rel < stop; rel++) {
1425                r.r_offset = TO_NATIVE(rel->r_offset);
1426#if KERNEL_ELFCLASS == ELFCLASS64
1427                if (elf->hdr->e_machine == EM_MIPS) {
1428                        unsigned int r_typ;
1429                        r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1430                        r_sym = TO_NATIVE(r_sym);
1431                        r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1432                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1433                } else {
1434                        r.r_info = TO_NATIVE(rel->r_info);
1435                        r_sym = ELF_R_SYM(r.r_info);
1436                }
1437#else
1438                r.r_info = TO_NATIVE(rel->r_info);
1439                r_sym = ELF_R_SYM(r.r_info);
1440#endif
1441                r.r_addend = 0;
1442                switch (elf->hdr->e_machine) {
1443                case EM_386:
1444                        if (addend_386_rel(elf, sechdr, &r))
1445                                continue;
1446                        break;
1447                case EM_ARM:
1448                        if (addend_arm_rel(elf, sechdr, &r))
1449                                continue;
1450                        break;
1451                case EM_MIPS:
1452                        if (addend_mips_rel(elf, sechdr, &r))
1453                                continue;
1454                        break;
1455                }
1456                sym = elf->symtab_start + r_sym;
1457                /* Skip special sections */
1458                if (sym->st_shndx >= SHN_LORESERVE)
1459                        continue;
1460                check_section_mismatch(modname, elf, &r, sym, fromsec);
1461        }
1462}
1463
1464/**
1465 * A module includes a number of sections that are discarded
1466 * either when loaded or when used as built-in.
1467 * For loaded modules all functions marked __init and all data
1468 * marked __initdata will be discarded when the module has been intialized.
1469 * Likewise for modules used built-in the sections marked __exit
1470 * are discarded because __exit marked function are supposed to be called
1471 * only when a module is unloaded which never happens for built-in modules.
1472 * The check_sec_ref() function traverses all relocation records
1473 * to find all references to a section that reference a section that will
1474 * be discarded and warns about it.
1475 **/
1476static void check_sec_ref(struct module *mod, const char *modname,
1477                          struct elf_info *elf)
1478{
1479        int i;
1480        Elf_Shdr *sechdrs = elf->sechdrs;
1481
1482        /* Walk through all sections */
1483        for (i = 0; i < elf->hdr->e_shnum; i++) {
1484                /* We want to process only relocation sections and not .init */
1485                if (sechdrs[i].sh_type == SHT_RELA)
1486                        section_rela(modname, elf, &elf->sechdrs[i]);
1487                else if (sechdrs[i].sh_type == SHT_REL)
1488                        section_rel(modname, elf, &elf->sechdrs[i]);
1489        }
1490}
1491
1492static void get_markers(struct elf_info *info, struct module *mod)
1493{
1494        const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec];
1495        const char *strings = (const char *) info->hdr + sh->sh_offset;
1496        const Elf_Sym *sym, *first_sym, *last_sym;
1497        size_t n;
1498
1499        if (!info->markers_strings_sec)
1500                return;
1501
1502        /*
1503         * First count the strings.  We look for all the symbols defined
1504         * in the __markers_strings section named __mstrtab_*.  For
1505         * these local names, the compiler puts a random .NNN suffix on,
1506         * so the names don't correspond exactly.
1507         */
1508        first_sym = last_sym = NULL;
1509        n = 0;
1510        for (sym = info->symtab_start; sym < info->symtab_stop; sym++)
1511                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
1512                    sym->st_shndx == info->markers_strings_sec &&
1513                    !strncmp(info->strtab + sym->st_name,
1514                             "__mstrtab_", sizeof "__mstrtab_" - 1)) {
1515                        if (first_sym == NULL)
1516                                first_sym = sym;
1517                        last_sym = sym;
1518                        ++n;
1519                }
1520
1521        if (n == 0)
1522                return;
1523
1524        /*
1525         * Now collect each name and format into a line for the output.
1526         * Lines look like:
1527         *      marker_name     vmlinux marker %s format %d
1528         * The format string after the second \t can use whitespace.
1529         */
1530        mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n));
1531        mod->nmarkers = n;
1532
1533        n = 0;
1534        for (sym = first_sym; sym <= last_sym; sym++)
1535                if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
1536                    sym->st_shndx == info->markers_strings_sec &&
1537                    !strncmp(info->strtab + sym->st_name,
1538                             "__mstrtab_", sizeof "__mstrtab_" - 1)) {
1539                        const char *name = strings + sym->st_value;
1540                        const char *fmt = strchr(name, '\0') + 1;
1541                        char *line = NULL;
1542                        asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
1543                        NOFAIL(line);
1544                        mod->markers[n++] = line;
1545                }
1546}
1547
1548static void read_symbols(char *modname)
1549{
1550        const char *symname;
1551        char *version;
1552        char *license;
1553        struct module *mod;
1554        struct elf_info info = { };
1555        Elf_Sym *sym;
1556
1557        if (!parse_elf(&info, modname))
1558                return;
1559
1560        mod = new_module(modname);
1561
1562        /* When there's no vmlinux, don't print warnings about
1563         * unresolved symbols (since there'll be too many ;) */
1564        if (is_vmlinux(modname)) {
1565                have_vmlinux = 1;
1566                mod->skip = 1;
1567        }
1568
1569        license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1570        if (info.modinfo && !license && !is_vmlinux(modname))
1571                warn("modpost: missing MODULE_LICENSE() in %s\n"
1572                     "see include/linux/module.h for "
1573                     "more information\n", modname);
1574        while (license) {
1575                if (license_is_gpl_compatible(license))
1576                        mod->gpl_compatible = 1;
1577                else {
1578                        mod->gpl_compatible = 0;
1579                        break;
1580                }
1581                license = get_next_modinfo(info.modinfo, info.modinfo_len,
1582                                           "license", license);
1583        }
1584
1585        for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1586                symname = info.strtab + sym->st_name;
1587
1588                handle_modversions(mod, &info, sym, symname);
1589                handle_moddevtable(mod, &info, sym, symname);
1590        }
1591        if (!is_vmlinux(modname) ||
1592             (is_vmlinux(modname) && vmlinux_section_warnings))
1593                check_sec_ref(mod, modname, &info);
1594
1595        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1596        if (version)
1597                maybe_frob_rcs_version(modname, version, info.modinfo,
1598                                       version - (char *)info.hdr);
1599        if (version || (all_versions && !is_vmlinux(modname)))
1600                get_src_version(modname, mod->srcversion,
1601                                sizeof(mod->srcversion)-1);
1602
1603        get_markers(&info, mod);
1604
1605        parse_elf_finish(&info);
1606
1607        /* Our trick to get versioning for struct_module - it's
1608         * never passed as an argument to an exported function, so
1609         * the automatic versioning doesn't pick it up, but it's really
1610         * important anyhow */
1611        if (modversions)
1612                mod->unres = alloc_symbol("struct_module", 0, mod->unres);
1613}
1614
1615#define SZ 500
1616
1617/* We first write the generated file into memory using the
1618 * following helper, then compare to the file on disk and
1619 * only update the later if anything changed */
1620
1621void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1622                                                      const char *fmt, ...)
1623{
1624        char tmp[SZ];
1625        int len;
1626        va_list ap;
1627
1628        va_start(ap, fmt);
1629        len = vsnprintf(tmp, SZ, fmt, ap);
1630        buf_write(buf, tmp, len);
1631        va_end(ap);
1632}
1633
1634void buf_write(struct buffer *buf, const char *s, int len)
1635{
1636        if (buf->size - buf->pos < len) {
1637                buf->size += len + SZ;
1638                buf->p = realloc(buf->p, buf->size);
1639        }
1640        strncpy(buf->p + buf->pos, s, len);
1641        buf->pos += len;
1642}
1643
1644static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1645{
1646        const char *e = is_vmlinux(m) ?"":".ko";
1647
1648        switch (exp) {
1649        case export_gpl:
1650                fatal("modpost: GPL-incompatible module %s%s "
1651                      "uses GPL-only symbol '%s'\n", m, e, s);
1652                break;
1653        case export_unused_gpl:
1654                fatal("modpost: GPL-incompatible module %s%s "
1655                      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1656                break;
1657        case export_gpl_future:
1658                warn("modpost: GPL-incompatible module %s%s "
1659                      "uses future GPL-only symbol '%s'\n", m, e, s);
1660                break;
1661        case export_plain:
1662        case export_unused:
1663        case export_unknown:
1664                /* ignore */
1665                break;
1666        }
1667}
1668
1669static void check_for_unused(enum export exp, const char *m, const char *s)
1670{
1671        const char *e = is_vmlinux(m) ?"":".ko";
1672
1673        switch (exp) {
1674        case export_unused:
1675        case export_unused_gpl:
1676                warn("modpost: module %s%s "
1677                      "uses symbol '%s' marked UNUSED\n", m, e, s);
1678                break;
1679        default:
1680                /* ignore */
1681                break;
1682        }
1683}
1684
1685static void check_exports(struct module *mod)
1686{
1687        struct symbol *s, *exp;
1688
1689        for (s = mod->unres; s; s = s->next) {
1690                const char *basename;
1691                exp = find_symbol(s->name);
1692                if (!exp || exp->module == mod)
1693                        continue;
1694                basename = strrchr(mod->name, '/');
1695                if (basename)
1696                        basename++;
1697                else
1698                        basename = mod->name;
1699                if (!mod->gpl_compatible)
1700                        check_for_gpl_usage(exp->export, basename, exp->name);
1701                check_for_unused(exp->export, basename, exp->name);
1702        }
1703}
1704
1705/**
1706 * Header for the generated file
1707 **/
1708static void add_header(struct buffer *b, struct module *mod)
1709{
1710        buf_printf(b, "#include <linux/module.h>\n");
1711        buf_printf(b, "#include <linux/vermagic.h>\n");
1712        buf_printf(b, "#include <linux/compiler.h>\n");
1713        buf_printf(b, "\n");
1714        buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1715        buf_printf(b, "\n");
1716        buf_printf(b, "struct module __this_module\n");
1717        buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1718        buf_printf(b, " .name = KBUILD_MODNAME,\n");
1719        if (mod->has_init)
1720                buf_printf(b, " .init = init_module,\n");
1721        if (mod->has_cleanup)
1722                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1723                              " .exit = cleanup_module,\n"
1724                              "#endif\n");
1725        buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1726        buf_printf(b, "};\n");
1727}
1728
1729void add_staging_flag(struct buffer *b, const char *name)
1730{
1731        static const char *staging_dir = "drivers/staging";
1732
1733        if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1734                buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1735}
1736
1737/**
1738 * Record CRCs for unresolved symbols
1739 **/
1740static int add_versions(struct buffer *b, struct module *mod)
1741{
1742        struct symbol *s, *exp;
1743        int err = 0;
1744
1745        for (s = mod->unres; s; s = s->next) {
1746                exp = find_symbol(s->name);
1747                if (!exp || exp->module == mod) {
1748                        if (have_vmlinux && !s->weak) {
1749                                if (warn_unresolved) {
1750                                        warn("\"%s\" [%s.ko] undefined!\n",
1751                                             s->name, mod->name);
1752                                } else {
1753                                        merror("\"%s\" [%s.ko] undefined!\n",
1754                                                  s->name, mod->name);
1755                                        err = 1;
1756                                }
1757                        }
1758                        continue;
1759                }
1760                s->module = exp->module;
1761                s->crc_valid = exp->crc_valid;
1762                s->crc = exp->crc;
1763        }
1764
1765        if (!modversions)
1766                return err;
1767
1768        buf_printf(b, "\n");
1769        buf_printf(b, "static const struct modversion_info ____versions[]\n");
1770        buf_printf(b, "__used\n");
1771        buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1772
1773        for (s = mod->unres; s; s = s->next) {
1774                if (!s->module)
1775                        continue;
1776                if (!s->crc_valid) {
1777                        warn("\"%s\" [%s.ko] has no CRC!\n",
1778                                s->name, mod->name);
1779                        continue;
1780                }
1781                buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1782        }
1783
1784        buf_printf(b, "};\n");
1785
1786        return err;
1787}
1788
1789static void add_depends(struct buffer *b, struct module *mod,
1790                        struct module *modules)
1791{
1792        struct symbol *s;
1793        struct module *m;
1794        int first = 1;
1795
1796        for (m = modules; m; m = m->next)
1797                m->seen = is_vmlinux(m->name);
1798
1799        buf_printf(b, "\n");
1800        buf_printf(b, "static const char __module_depends[]\n");
1801        buf_printf(b, "__used\n");
1802        buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1803        buf_printf(b, "\"depends=");
1804        for (s = mod->unres; s; s = s->next) {
1805                const char *p;
1806                if (!s->module)
1807                        continue;
1808
1809                if (s->module->seen)
1810                        continue;
1811
1812                s->module->seen = 1;
1813                p = strrchr(s->module->name, '/');
1814                if (p)
1815                        p++;
1816                else
1817                        p = s->module->name;
1818                buf_printf(b, "%s%s", first ? "" : ",", p);
1819                first = 0;
1820        }
1821        buf_printf(b, "\";\n");
1822}
1823
1824static void add_srcversion(struct buffer *b, struct module *mod)
1825{
1826        if (mod->srcversion[0]) {
1827                buf_printf(b, "\n");
1828                buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1829                           mod->srcversion);
1830        }
1831}
1832
1833static void write_if_changed(struct buffer *b, const char *fname)
1834{
1835        char *tmp;
1836        FILE *file;
1837        struct stat st;
1838
1839        file = fopen(fname, "r");
1840        if (!file)
1841                goto write;
1842
1843        if (fstat(fileno(file), &st) < 0)
1844                goto close_write;
1845
1846        if (st.st_size != b->pos)
1847                goto close_write;
1848
1849        tmp = NOFAIL(malloc(b->pos));
1850        if (fread(tmp, 1, b->pos, file) != b->pos)
1851                goto free_write;
1852
1853        if (memcmp(tmp, b->p, b->pos) != 0)
1854                goto free_write;
1855
1856        free(tmp);
1857        fclose(file);
1858        return;
1859
1860 free_write:
1861        free(tmp);
1862 close_write:
1863        fclose(file);
1864 write:
1865        file = fopen(fname, "w");
1866        if (!file) {
1867                perror(fname);
1868                exit(1);
1869        }
1870        if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1871                perror(fname);
1872                exit(1);
1873        }
1874        fclose(file);
1875}
1876
1877/* parse Module.symvers file. line format:
1878 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1879 **/
1880static void read_dump(const char *fname, unsigned int kernel)
1881{
1882        unsigned long size, pos = 0;
1883        void *file = grab_file(fname, &size);
1884        char *line;
1885
1886        if (!file)
1887                /* No symbol versions, silently ignore */
1888                return;
1889
1890        while ((line = get_next_line(&pos, file, size))) {
1891                char *symname, *modname, *d, *export, *end;
1892                unsigned int crc;
1893                struct module *mod;
1894                struct symbol *s;
1895
1896                if (!(symname = strchr(line, '\t')))
1897                        goto fail;
1898                *symname++ = '\0';
1899                if (!(modname = strchr(symname, '\t')))
1900                        goto fail;
1901                *modname++ = '\0';
1902                if ((export = strchr(modname, '\t')) != NULL)
1903                        *export++ = '\0';
1904                if (export && ((end = strchr(export, '\t')) != NULL))
1905                        *end = '\0';
1906                crc = strtoul(line, &d, 16);
1907                if (*symname == '\0' || *modname == '\0' || *d != '\0')
1908                        goto fail;
1909                mod = find_module(modname);
1910                if (!mod) {
1911                        if (is_vmlinux(modname))
1912                                have_vmlinux = 1;
1913                        mod = new_module(NOFAIL(strdup(modname)));
1914                        mod->skip = 1;
1915                }
1916                s = sym_add_exported(symname, mod, export_no(export));
1917                s->kernel    = kernel;
1918                s->preloaded = 1;
1919                sym_update_crc(symname, mod, crc, export_no(export));
1920        }
1921        return;
1922fail:
1923        fatal("parse error in symbol dump file\n");
1924}
1925
1926/* For normal builds always dump all symbols.
1927 * For external modules only dump symbols
1928 * that are not read from kernel Module.symvers.
1929 **/
1930static int dump_sym(struct symbol *sym)
1931{
1932        if (!external_module)
1933                return 1;
1934        if (sym->vmlinux || sym->kernel)
1935                return 0;
1936        return 1;
1937}
1938
1939static void write_dump(const char *fname)
1940{
1941        struct buffer buf = { };
1942        struct symbol *symbol;
1943        int n;
1944
1945        for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1946                symbol = symbolhash[n];
1947                while (symbol) {
1948                        if (dump_sym(symbol))
1949                                buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1950                                        symbol->crc, symbol->name,
1951                                        symbol->module->name,
1952                                        export_str(symbol->export));
1953                        symbol = symbol->next;
1954                }
1955        }
1956        write_if_changed(&buf, fname);
1957}
1958
1959static void add_marker(struct module *mod, const char *name, const char *fmt)
1960{
1961        char *line = NULL;
1962        asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
1963        NOFAIL(line);
1964
1965        mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) *
1966                                                     sizeof mod->markers[0])));
1967        mod->markers[mod->nmarkers++] = line;
1968}
1969
1970static void read_markers(const char *fname)
1971{
1972        unsigned long size, pos = 0;
1973        void *file = grab_file(fname, &size);
1974        char *line;
1975
1976        if (!file)              /* No old markers, silently ignore */
1977                return;
1978
1979        while ((line = get_next_line(&pos, file, size))) {
1980                char *marker, *modname, *fmt;
1981                struct module *mod;
1982
1983                marker = line;
1984                modname = strchr(marker, '\t');
1985                if (!modname)
1986                        goto fail;
1987                *modname++ = '\0';
1988                fmt = strchr(modname, '\t');
1989                if (!fmt)
1990                        goto fail;
1991                *fmt++ = '\0';
1992                if (*marker == '\0' || *modname == '\0')
1993                        goto fail;
1994
1995                mod = find_module(modname);
1996                if (!mod) {
1997                        mod = new_module(NOFAIL(strdup(modname)));
1998                        mod->skip = 1;
1999                }
2000                if (is_vmlinux(modname)) {
2001                        have_vmlinux = 1;
2002                        mod->skip = 0;
2003                }
2004
2005                if (!mod->skip)
2006                        add_marker(mod, marker, fmt);
2007        }
2008        return;
2009fail:
2010        fatal("parse error in markers list file\n");
2011}
2012
2013static int compare_strings(const void *a, const void *b)
2014{
2015        return strcmp(*(const char **) a, *(const char **) b);
2016}
2017
2018static void write_markers(const char *fname)
2019{
2020        struct buffer buf = { };
2021        struct module *mod;
2022        size_t i;
2023
2024        for (mod = modules; mod; mod = mod->next)
2025                if ((!external_module || !mod->skip) && mod->markers != NULL) {
2026                        /*
2027                         * Sort the strings so we can skip duplicates when
2028                         * we write them out.
2029                         */
2030                        qsort(mod->markers, mod->nmarkers,
2031                              sizeof mod->markers[0], &compare_strings);
2032                        for (i = 0; i < mod->nmarkers; ++i) {
2033                                char *line = mod->markers[i];
2034                                buf_write(&buf, line, strlen(line));
2035                                while (i + 1 < mod->nmarkers &&
2036                                       !strcmp(mod->markers[i],
2037                                               mod->markers[i + 1]))
2038                                        free(mod->markers[i++]);
2039                                free(mod->markers[i]);
2040                        }
2041                        free(mod->markers);
2042                        mod->markers = NULL;
2043                }
2044
2045        write_if_changed(&buf, fname);
2046}
2047
2048struct ext_sym_list {
2049        struct ext_sym_list *next;
2050        const char *file;
2051};
2052
2053int main(int argc, char **argv)
2054{
2055        struct module *mod;
2056        struct buffer buf = { };
2057        char *kernel_read = NULL, *module_read = NULL;
2058        char *dump_write = NULL;
2059        char *markers_read = NULL;
2060        char *markers_write = NULL;
2061        int opt;
2062        int err;
2063        struct ext_sym_list *extsym_iter;
2064        struct ext_sym_list *extsym_start = NULL;
2065
2066        while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2067                switch (opt) {
2068                case 'i':
2069                        kernel_read = optarg;
2070                        break;
2071                case 'I':
2072                        module_read = optarg;
2073                        external_module = 1;
2074                        break;
2075                case 'c':
2076                        cross_build = 1;
2077                        break;
2078                case 'e':
2079                        external_module = 1;
2080                        extsym_iter =
2081                           NOFAIL(malloc(sizeof(*extsym_iter)));
2082                        extsym_iter->next = extsym_start;
2083                        extsym_iter->file = optarg;
2084                        extsym_start = extsym_iter;
2085                        break;
2086                case 'm':
2087                        modversions = 1;
2088                        break;
2089                case 'o':
2090                        dump_write = optarg;
2091                        break;
2092                case 'a':
2093                        all_versions = 1;
2094                        break;
2095                case 's':
2096                        vmlinux_section_warnings = 0;
2097                        break;
2098                case 'S':
2099                        sec_mismatch_verbose = 0;
2100                        break;
2101                case 'w':
2102                        warn_unresolved = 1;
2103                        break;
2104                        case 'M':
2105                                markers_write = optarg;
2106                                break;
2107                        case 'K':
2108                                markers_read = optarg;
2109                                break;
2110                default:
2111                        exit(1);
2112                }
2113        }
2114
2115        if (kernel_read)
2116                read_dump(kernel_read, 1);
2117        if (module_read)
2118                read_dump(module_read, 0);
2119        while (extsym_start) {
2120                read_dump(extsym_start->file, 0);
2121                extsym_iter = extsym_start->next;
2122                free(extsym_start);
2123                extsym_start = extsym_iter;
2124        }
2125
2126        while (optind < argc)
2127                read_symbols(argv[optind++]);
2128
2129        for (mod = modules; mod; mod = mod->next) {
2130                if (mod->skip)
2131                        continue;
2132                check_exports(mod);
2133        }
2134
2135        err = 0;
2136
2137        for (mod = modules; mod; mod = mod->next) {
2138                char fname[strlen(mod->name) + 10];
2139
2140                if (mod->skip)
2141                        continue;
2142
2143                buf.pos = 0;
2144
2145                add_header(&buf, mod);
2146                add_staging_flag(&buf, mod->name);
2147                err |= add_versions(&buf, mod);
2148                add_depends(&buf, mod, modules);
2149                add_moddevtable(&buf, mod);
2150                add_srcversion(&buf, mod);
2151
2152                sprintf(fname, "%s.mod.c", mod->name);
2153                write_if_changed(&buf, fname);
2154        }
2155
2156        if (dump_write)
2157                write_dump(dump_write);
2158        if (sec_mismatch_count && !sec_mismatch_verbose)
2159                warn("modpost: Found %d section mismatch(es).\n"
2160                     "To see full details build your kernel with:\n"
2161                     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2162                     sec_mismatch_count);
2163
2164        if (markers_read)
2165                read_markers(markers_read);
2166
2167        if (markers_write)
2168                write_markers(markers_write);
2169
2170        return err;
2171}
2172