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 <string.h>
  18#include "modpost.h"
  19#include "../../include/generated/autoconf.h"
  20#include "../../include/linux/license.h"
  21
  22/* Some toolchains use a `_' prefix for all user symbols. */
  23#ifdef CONFIG_SYMBOL_PREFIX
  24#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
  25#else
  26#define MODULE_SYMBOL_PREFIX ""
  27#endif
  28
  29
  30/* Are we using CONFIG_MODVERSIONS? */
  31int modversions = 0;
  32/* Warn about undefined symbols? (do so if we have vmlinux) */
  33int have_vmlinux = 0;
  34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  35static int all_versions = 0;
  36/* If we are modposting external module set to 1 */
  37static int external_module = 0;
  38/* Warn about section mismatch in vmlinux if set to 1 */
  39static int vmlinux_section_warnings = 1;
  40/* Only warn about unresolved symbols */
  41static int warn_unresolved = 0;
  42/* How a symbol is exported */
  43static int sec_mismatch_count = 0;
  44static int sec_mismatch_verbose = 1;
  45
  46enum export {
  47        export_plain,      export_unused,     export_gpl,
  48        export_unused_gpl, export_gpl_future, export_unknown
  49};
  50
  51#define PRINTF __attribute__ ((format (printf, 1, 2)))
  52
  53PRINTF void fatal(const char *fmt, ...)
  54{
  55        va_list arglist;
  56
  57        fprintf(stderr, "FATAL: ");
  58
  59        va_start(arglist, fmt);
  60        vfprintf(stderr, fmt, arglist);
  61        va_end(arglist);
  62
  63        exit(1);
  64}
  65
  66PRINTF void warn(const char *fmt, ...)
  67{
  68        va_list arglist;
  69
  70        fprintf(stderr, "WARNING: ");
  71
  72        va_start(arglist, fmt);
  73        vfprintf(stderr, fmt, arglist);
  74        va_end(arglist);
  75}
  76
  77PRINTF void merror(const char *fmt, ...)
  78{
  79        va_list arglist;
  80
  81        fprintf(stderr, "ERROR: ");
  82
  83        va_start(arglist, fmt);
  84        vfprintf(stderr, fmt, arglist);
  85        va_end(arglist);
  86}
  87
  88static int is_vmlinux(const char *modname)
  89{
  90        const char *myname;
  91
  92        myname = strrchr(modname, '/');
  93        if (myname)
  94                myname++;
  95        else
  96                myname = modname;
  97
  98        return (strcmp(myname, "vmlinux") == 0) ||
  99               (strcmp(myname, "vmlinux.o") == 0);
 100}
 101
 102void *do_nofail(void *ptr, const char *expr)
 103{
 104        if (!ptr)
 105                fatal("modpost: Memory allocation failure: %s.\n", expr);
 106
 107        return ptr;
 108}
 109
 110/* A list of all modules we processed */
 111static struct module *modules;
 112
 113static struct module *find_module(char *modname)
 114{
 115        struct module *mod;
 116
 117        for (mod = modules; mod; mod = mod->next)
 118                if (strcmp(mod->name, modname) == 0)
 119                        break;
 120        return mod;
 121}
 122
 123static struct module *new_module(char *modname)
 124{
 125        struct module *mod;
 126        char *p, *s;
 127
 128        mod = NOFAIL(malloc(sizeof(*mod)));
 129        memset(mod, 0, sizeof(*mod));
 130        p = NOFAIL(strdup(modname));
 131
 132        /* strip trailing .o */
 133        s = strrchr(p, '.');
 134        if (s != NULL)
 135                if (strcmp(s, ".o") == 0)
 136                        *s = '\0';
 137
 138        /* add to list */
 139        mod->name = p;
 140        mod->gpl_compatible = -1;
 141        mod->next = modules;
 142        modules = mod;
 143
 144        return mod;
 145}
 146
 147/* A hash of all exported symbols,
 148 * struct symbol is also used for lists of unresolved symbols */
 149
 150#define SYMBOL_HASH_SIZE 1024
 151
 152struct symbol {
 153        struct symbol *next;
 154        struct module *module;
 155        unsigned int crc;
 156        int crc_valid;
 157        unsigned int weak:1;
 158        unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
 159        unsigned int kernel:1;     /* 1 if symbol is from kernel
 160                                    *  (only for external modules) **/
 161        unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
 162        enum export  export;       /* Type of export */
 163        char name[0];
 164};
 165
 166static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 167
 168/* This is based on the hash agorithm from gdbm, via tdb */
 169static inline unsigned int tdb_hash(const char *name)
 170{
 171        unsigned value; /* Used to compute the hash value.  */
 172        unsigned   i;   /* Used to cycle through random values. */
 173
 174        /* Set the initial value from the key size. */
 175        for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 176                value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 177
 178        return (1103515243 * value + 12345);
 179}
 180
 181/**
 182 * Allocate a new symbols for use in the hash of exported symbols or
 183 * the list of unresolved symbols per module
 184 **/
 185static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 186                                   struct symbol *next)
 187{
 188        struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 189
 190        memset(s, 0, sizeof(*s));
 191        strcpy(s->name, name);
 192        s->weak = weak;
 193        s->next = next;
 194        return s;
 195}
 196
 197/* For the hash of exported symbols */
 198static struct symbol *new_symbol(const char *name, struct module *module,
 199                                 enum export export)
 200{
 201        unsigned int hash;
 202        struct symbol *new;
 203
 204        hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 205        new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 206        new->module = module;
 207        new->export = export;
 208        return new;
 209}
 210
 211static struct symbol *find_symbol(const char *name)
 212{
 213        struct symbol *s;
 214
 215        /* For our purposes, .foo matches foo.  PPC64 needs this. */
 216        if (name[0] == '.')
 217                name++;
 218
 219        for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 220                if (strcmp(s->name, name) == 0)
 221                        return s;
 222        }
 223        return NULL;
 224}
 225
 226static struct {
 227        const char *str;
 228        enum export export;
 229} export_list[] = {
 230        { .str = "EXPORT_SYMBOL",            .export = export_plain },
 231        { .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
 232        { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
 233        { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
 234        { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
 235        { .str = "(unknown)",                .export = export_unknown },
 236};
 237
 238
 239static const char *export_str(enum export ex)
 240{
 241        return export_list[ex].str;
 242}
 243
 244static enum export export_no(const char *s)
 245{
 246        int i;
 247
 248        if (!s)
 249                return export_unknown;
 250        for (i = 0; export_list[i].export != export_unknown; i++) {
 251                if (strcmp(export_list[i].str, s) == 0)
 252                        return export_list[i].export;
 253        }
 254        return export_unknown;
 255}
 256
 257static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
 258{
 259        if (sec == elf->export_sec)
 260                return export_plain;
 261        else if (sec == elf->export_unused_sec)
 262                return export_unused;
 263        else if (sec == elf->export_gpl_sec)
 264                return export_gpl;
 265        else if (sec == elf->export_unused_gpl_sec)
 266                return export_unused_gpl;
 267        else if (sec == elf->export_gpl_future_sec)
 268                return export_gpl_future;
 269        else
 270                return export_unknown;
 271}
 272
 273/**
 274 * Add an exported symbol - it may have already been added without a
 275 * CRC, in this case just update the CRC
 276 **/
 277static struct symbol *sym_add_exported(const char *name, struct module *mod,
 278                                       enum export export)
 279{
 280        struct symbol *s = find_symbol(name);
 281
 282        if (!s) {
 283                s = new_symbol(name, mod, export);
 284        } else {
 285                if (!s->preloaded) {
 286                        warn("%s: '%s' exported twice. Previous export "
 287                             "was in %s%s\n", mod->name, name,
 288                             s->module->name,
 289                             is_vmlinux(s->module->name) ?"":".ko");
 290                } else {
 291                        /* In case Modules.symvers was out of date */
 292                        s->module = mod;
 293                }
 294        }
 295        s->preloaded = 0;
 296        s->vmlinux   = is_vmlinux(mod->name);
 297        s->kernel    = 0;
 298        s->export    = export;
 299        return s;
 300}
 301
 302static void sym_update_crc(const char *name, struct module *mod,
 303                           unsigned int crc, enum export export)
 304{
 305        struct symbol *s = find_symbol(name);
 306
 307        if (!s)
 308                s = new_symbol(name, mod, export);
 309        s->crc = crc;
 310        s->crc_valid = 1;
 311}
 312
 313void *grab_file(const char *filename, unsigned long *size)
 314{
 315        struct stat st;
 316        void *map;
 317        int fd;
 318
 319        fd = open(filename, O_RDONLY);
 320        if (fd < 0 || fstat(fd, &st) != 0)
 321                return NULL;
 322
 323        *size = st.st_size;
 324        map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 325        close(fd);
 326
 327        if (map == MAP_FAILED)
 328                return NULL;
 329        return map;
 330}
 331
 332/**
 333  * Return a copy of the next line in a mmap'ed file.
 334  * spaces in the beginning of the line is trimmed away.
 335  * Return a pointer to a static buffer.
 336  **/
 337char *get_next_line(unsigned long *pos, void *file, unsigned long size)
 338{
 339        static char line[4096];
 340        int skip = 1;
 341        size_t len = 0;
 342        signed char *p = (signed char *)file + *pos;
 343        char *s = line;
 344
 345        for (; *pos < size ; (*pos)++) {
 346                if (skip && isspace(*p)) {
 347                        p++;
 348                        continue;
 349                }
 350                skip = 0;
 351                if (*p != '\n' && (*pos < size)) {
 352                        len++;
 353                        *s++ = *p++;
 354                        if (len > 4095)
 355                                break; /* Too long, stop */
 356                } else {
 357                        /* End of string */
 358                        *s = '\0';
 359                        return line;
 360                }
 361        }
 362        /* End of buffer */
 363        return NULL;
 364}
 365
 366void release_file(void *file, unsigned long size)
 367{
 368        munmap(file, size);
 369}
 370
 371static int parse_elf(struct elf_info *info, const char *filename)
 372{
 373        unsigned int i;
 374        Elf_Ehdr *hdr;
 375        Elf_Shdr *sechdrs;
 376        Elf_Sym  *sym;
 377        const char *secstrings;
 378        unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 379
 380        hdr = grab_file(filename, &info->size);
 381        if (!hdr) {
 382                perror(filename);
 383                exit(1);
 384        }
 385        info->hdr = hdr;
 386        if (info->size < sizeof(*hdr)) {
 387                /* file too small, assume this is an empty .o file */
 388                return 0;
 389        }
 390        /* Is this a valid ELF file? */
 391        if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 392            (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 393            (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 394            (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 395                /* Not an ELF file - silently ignore it */
 396                return 0;
 397        }
 398        /* Fix endianness in ELF header */
 399        hdr->e_type      = TO_NATIVE(hdr->e_type);
 400        hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 401        hdr->e_version   = TO_NATIVE(hdr->e_version);
 402        hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 403        hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 404        hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 405        hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 406        hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 407        hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 408        hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 409        hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 410        hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 411        hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 412        sechdrs = (void *)hdr + hdr->e_shoff;
 413        info->sechdrs = sechdrs;
 414
 415        /* Check if file offset is correct */
 416        if (hdr->e_shoff > info->size) {
 417                fatal("section header offset=%lu in file '%s' is bigger than "
 418                      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
 419                      filename, info->size);
 420                return 0;
 421        }
 422
 423        if (hdr->e_shnum == SHN_UNDEF) {
 424                /*
 425                 * There are more than 64k sections,
 426                 * read count from .sh_size.
 427                 */
 428                info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 429        }
 430        else {
 431                info->num_sections = hdr->e_shnum;
 432        }
 433        if (hdr->e_shstrndx == SHN_XINDEX) {
 434                info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 435        }
 436        else {
 437                info->secindex_strings = hdr->e_shstrndx;
 438        }
 439
 440        /* Fix endianness in section headers */
 441        for (i = 0; i < info->num_sections; i++) {
 442                sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 443                sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 444                sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 445                sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 446                sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 447                sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 448                sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 449                sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 450                sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 451                sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 452        }
 453        /* Find symbol table. */
 454        secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 455        for (i = 1; i < info->num_sections; i++) {
 456                const char *secname;
 457                int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 458
 459                if (!nobits && sechdrs[i].sh_offset > info->size) {
 460                        fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
 461                              "sizeof(*hrd)=%zu\n", filename,
 462                              (unsigned long)sechdrs[i].sh_offset,
 463                              sizeof(*hdr));
 464                        return 0;
 465                }
 466                secname = secstrings + sechdrs[i].sh_name;
 467                if (strcmp(secname, ".modinfo") == 0) {
 468                        if (nobits)
 469                                fatal("%s has NOBITS .modinfo\n", filename);
 470                        info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 471                        info->modinfo_len = sechdrs[i].sh_size;
 472                } else if (strcmp(secname, "__ksymtab") == 0)
 473                        info->export_sec = i;
 474                else if (strcmp(secname, "__ksymtab_unused") == 0)
 475                        info->export_unused_sec = i;
 476                else if (strcmp(secname, "__ksymtab_gpl") == 0)
 477                        info->export_gpl_sec = i;
 478                else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
 479                        info->export_unused_gpl_sec = i;
 480                else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 481                        info->export_gpl_future_sec = i;
 482
 483                if (sechdrs[i].sh_type == SHT_SYMTAB) {
 484                        unsigned int sh_link_idx;
 485                        symtab_idx = i;
 486                        info->symtab_start = (void *)hdr +
 487                            sechdrs[i].sh_offset;
 488                        info->symtab_stop  = (void *)hdr +
 489                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 490                        sh_link_idx = sechdrs[i].sh_link;
 491                        info->strtab       = (void *)hdr +
 492                            sechdrs[sh_link_idx].sh_offset;
 493                }
 494
 495                /* 32bit section no. table? ("more than 64k sections") */
 496                if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 497                        symtab_shndx_idx = i;
 498                        info->symtab_shndx_start = (void *)hdr +
 499                            sechdrs[i].sh_offset;
 500                        info->symtab_shndx_stop  = (void *)hdr +
 501                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 502                }
 503        }
 504        if (!info->symtab_start)
 505                fatal("%s has no symtab?\n", filename);
 506
 507        /* Fix endianness in symbols */
 508        for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 509                sym->st_shndx = TO_NATIVE(sym->st_shndx);
 510                sym->st_name  = TO_NATIVE(sym->st_name);
 511                sym->st_value = TO_NATIVE(sym->st_value);
 512                sym->st_size  = TO_NATIVE(sym->st_size);
 513        }
 514
 515        if (symtab_shndx_idx != ~0U) {
 516                Elf32_Word *p;
 517                if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 518                        fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 519                              filename, sechdrs[symtab_shndx_idx].sh_link,
 520                              symtab_idx);
 521                /* Fix endianness */
 522                for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 523                     p++)
 524                        *p = TO_NATIVE(*p);
 525        }
 526
 527        return 1;
 528}
 529
 530static void parse_elf_finish(struct elf_info *info)
 531{
 532        release_file(info->hdr, info->size);
 533}
 534
 535static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 536{
 537        /* ignore __this_module, it will be resolved shortly */
 538        if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 539                return 1;
 540        /* ignore global offset table */
 541        if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 542                return 1;
 543        if (info->hdr->e_machine == EM_PPC)
 544                /* Special register function linked on all modules during final link of .ko */
 545                if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
 546                    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
 547                    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
 548                    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
 549                        return 1;
 550        if (info->hdr->e_machine == EM_PPC64)
 551                /* Special register function linked on all modules during final link of .ko */
 552                if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
 553                    strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
 554                        return 1;
 555        /* Do not ignore this symbol */
 556        return 0;
 557}
 558
 559#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
 560#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 561
 562static void handle_modversions(struct module *mod, struct elf_info *info,
 563                               Elf_Sym *sym, const char *symname)
 564{
 565        unsigned int crc;
 566        enum export export = export_from_sec(info, get_secindex(info, sym));
 567
 568        switch (sym->st_shndx) {
 569        case SHN_COMMON:
 570                warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 571                break;
 572        case SHN_ABS:
 573                /* CRC'd symbol */
 574                if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 575                        crc = (unsigned int) sym->st_value;
 576                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 577                                        export);
 578                }
 579                break;
 580        case SHN_UNDEF:
 581                /* undefined symbol */
 582                if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 583                    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 584                        break;
 585                if (ignore_undef_symbol(info, symname))
 586                        break;
 587/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 588#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 589/* add compatibility with older glibc */
 590#ifndef STT_SPARC_REGISTER
 591#define STT_SPARC_REGISTER STT_REGISTER
 592#endif
 593                if (info->hdr->e_machine == EM_SPARC ||
 594                    info->hdr->e_machine == EM_SPARCV9) {
 595                        /* Ignore register directives. */
 596                        if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 597                                break;
 598                        if (symname[0] == '.') {
 599                                char *munged = strdup(symname);
 600                                munged[0] = '_';
 601                                munged[1] = toupper(munged[1]);
 602                                symname = munged;
 603                        }
 604                }
 605#endif
 606
 607                if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 608                           strlen(MODULE_SYMBOL_PREFIX)) == 0) {
 609                        mod->unres =
 610                          alloc_symbol(symname +
 611                                       strlen(MODULE_SYMBOL_PREFIX),
 612                                       ELF_ST_BIND(sym->st_info) == STB_WEAK,
 613                                       mod->unres);
 614                }
 615                break;
 616        default:
 617                /* All exported symbols */
 618                if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 619                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 620                                        export);
 621                }
 622                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 623                        mod->has_init = 1;
 624                if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 625                        mod->has_cleanup = 1;
 626                break;
 627        }
 628}
 629
 630/**
 631 * Parse tag=value strings from .modinfo section
 632 **/
 633static char *next_string(char *string, unsigned long *secsize)
 634{
 635        /* Skip non-zero chars */
 636        while (string[0]) {
 637                string++;
 638                if ((*secsize)-- <= 1)
 639                        return NULL;
 640        }
 641
 642        /* Skip any zero padding. */
 643        while (!string[0]) {
 644                string++;
 645                if ((*secsize)-- <= 1)
 646                        return NULL;
 647        }
 648        return string;
 649}
 650
 651static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
 652                              const char *tag, char *info)
 653{
 654        char *p;
 655        unsigned int taglen = strlen(tag);
 656        unsigned long size = modinfo_len;
 657
 658        if (info) {
 659                size -= info - (char *)modinfo;
 660                modinfo = next_string(info, &size);
 661        }
 662
 663        for (p = modinfo; p; p = next_string(p, &size)) {
 664                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 665                        return p + taglen + 1;
 666        }
 667        return NULL;
 668}
 669
 670static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 671                         const char *tag)
 672
 673{
 674        return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
 675}
 676
 677/**
 678 * Test if string s ends in string sub
 679 * return 0 if match
 680 **/
 681static int strrcmp(const char *s, const char *sub)
 682{
 683        int slen, sublen;
 684
 685        if (!s || !sub)
 686                return 1;
 687
 688        slen = strlen(s);
 689        sublen = strlen(sub);
 690
 691        if ((slen == 0) || (sublen == 0))
 692                return 1;
 693
 694        if (sublen > slen)
 695                return 1;
 696
 697        return memcmp(s + slen - sublen, sub, sublen);
 698}
 699
 700static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 701{
 702        if (sym)
 703                return elf->strtab + sym->st_name;
 704        else
 705                return "(unknown)";
 706}
 707
 708static const char *sec_name(struct elf_info *elf, int secindex)
 709{
 710        Elf_Shdr *sechdrs = elf->sechdrs;
 711        return (void *)elf->hdr +
 712                elf->sechdrs[elf->secindex_strings].sh_offset +
 713                sechdrs[secindex].sh_name;
 714}
 715
 716static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
 717{
 718        return (void *)elf->hdr +
 719                elf->sechdrs[elf->secindex_strings].sh_offset +
 720                sechdr->sh_name;
 721}
 722
 723/* if sym is empty or point to a string
 724 * like ".[0-9]+" then return 1.
 725 * This is the optional prefix added by ld to some sections
 726 */
 727static int number_prefix(const char *sym)
 728{
 729        if (*sym++ == '\0')
 730                return 1;
 731        if (*sym != '.')
 732                return 0;
 733        do {
 734                char c = *sym++;
 735                if (c < '0' || c > '9')
 736                        return 0;
 737        } while (*sym);
 738        return 1;
 739}
 740
 741/* The pattern is an array of simple patterns.
 742 * "foo" will match an exact string equal to "foo"
 743 * "*foo" will match a string that ends with "foo"
 744 * "foo*" will match a string that begins with "foo"
 745 * "foo$" will match a string equal to "foo" or "foo.1"
 746 *   where the '1' can be any number including several digits.
 747 *   The $ syntax is for sections where ld append a dot number
 748 *   to make section name unique.
 749 */
 750static int match(const char *sym, const char * const pat[])
 751{
 752        const char *p;
 753        while (*pat) {
 754                p = *pat++;
 755                const char *endp = p + strlen(p) - 1;
 756
 757                /* "*foo" */
 758                if (*p == '*') {
 759                        if (strrcmp(sym, p + 1) == 0)
 760                                return 1;
 761                }
 762                /* "foo*" */
 763                else if (*endp == '*') {
 764                        if (strncmp(sym, p, strlen(p) - 1) == 0)
 765                                return 1;
 766                }
 767                /* "foo$" */
 768                else if (*endp == '$') {
 769                        if (strncmp(sym, p, strlen(p) - 1) == 0) {
 770                                if (number_prefix(sym + strlen(p) - 1))
 771                                        return 1;
 772                        }
 773                }
 774                /* no wildcards */
 775                else {
 776                        if (strcmp(p, sym) == 0)
 777                                return 1;
 778                }
 779        }
 780        /* no match */
 781        return 0;
 782}
 783
 784/* sections that we do not want to do full section mismatch check on */
 785static const char *section_white_list[] =
 786{
 787        ".comment*",
 788        ".debug*",
 789        ".zdebug*",             /* Compressed debug sections. */
 790        ".GCC-command-line",    /* mn10300 */
 791        ".mdebug*",        /* alpha, score, mips etc. */
 792        ".pdr",            /* alpha, score, mips etc. */
 793        ".stab*",
 794        ".note*",
 795        ".got*",
 796        ".toc*",
 797        NULL
 798};
 799
 800/*
 801 * This is used to find sections missing the SHF_ALLOC flag.
 802 * The cause of this is often a section specified in assembler
 803 * without "ax" / "aw".
 804 */
 805static void check_section(const char *modname, struct elf_info *elf,
 806                          Elf_Shdr *sechdr)
 807{
 808        const char *sec = sech_name(elf, sechdr);
 809
 810        if (sechdr->sh_type == SHT_PROGBITS &&
 811            !(sechdr->sh_flags & SHF_ALLOC) &&
 812            !match(sec, section_white_list)) {
 813                warn("%s (%s): unexpected non-allocatable section.\n"
 814                     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 815                     "Note that for example <linux/init.h> contains\n"
 816                     "section definitions for use in .S files.\n\n",
 817                     modname, sec);
 818        }
 819}
 820
 821
 822
 823#define ALL_INIT_DATA_SECTIONS \
 824        ".init.setup$", ".init.rodata$", \
 825        ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
 826        ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
 827#define ALL_EXIT_DATA_SECTIONS \
 828        ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
 829
 830#define ALL_INIT_TEXT_SECTIONS \
 831        ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
 832#define ALL_EXIT_TEXT_SECTIONS \
 833        ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
 834
 835#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
 836        MEM_INIT_SECTIONS
 837#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
 838        MEM_EXIT_SECTIONS
 839
 840#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 841#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 842
 843#define DATA_SECTIONS ".data$", ".data.rel$"
 844#define TEXT_SECTIONS ".text$"
 845
 846#define INIT_SECTIONS      ".init.*"
 847#define DEV_INIT_SECTIONS  ".devinit.*"
 848#define CPU_INIT_SECTIONS  ".cpuinit.*"
 849#define MEM_INIT_SECTIONS  ".meminit.*"
 850
 851#define EXIT_SECTIONS      ".exit.*"
 852#define DEV_EXIT_SECTIONS  ".devexit.*"
 853#define CPU_EXIT_SECTIONS  ".cpuexit.*"
 854#define MEM_EXIT_SECTIONS  ".memexit.*"
 855
 856/* init data sections */
 857static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 858
 859/* all init sections */
 860static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 861
 862/* All init and exit sections (code + data) */
 863static const char *init_exit_sections[] =
 864        {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 865
 866/* data section */
 867static const char *data_sections[] = { DATA_SECTIONS, NULL };
 868
 869
 870/* symbols in .data that may refer to init/exit sections */
 871#define DEFAULT_SYMBOL_WHITE_LIST                                       \
 872        "*driver",                                                      \
 873        "*_template", /* scsi uses *_template a lot */                  \
 874        "*_timer",    /* arm uses ops structures named _timer a lot */  \
 875        "*_sht",      /* scsi also used *_sht to some extent */         \
 876        "*_ops",                                                        \
 877        "*_probe",                                                      \
 878        "*_probe_one",                                                  \
 879        "*_console"
 880
 881static const char *head_sections[] = { ".head.text*", NULL };
 882static const char *linker_symbols[] =
 883        { "__init_begin", "_sinittext", "_einittext", NULL };
 884
 885enum mismatch {
 886        TEXT_TO_ANY_INIT,
 887        DATA_TO_ANY_INIT,
 888        TEXT_TO_ANY_EXIT,
 889        DATA_TO_ANY_EXIT,
 890        XXXINIT_TO_SOME_INIT,
 891        XXXEXIT_TO_SOME_EXIT,
 892        ANY_INIT_TO_ANY_EXIT,
 893        ANY_EXIT_TO_ANY_INIT,
 894        EXPORT_TO_INIT_EXIT,
 895};
 896
 897struct sectioncheck {
 898        const char *fromsec[20];
 899        const char *tosec[20];
 900        enum mismatch mismatch;
 901        const char *symbol_white_list[20];
 902};
 903
 904const struct sectioncheck sectioncheck[] = {
 905/* Do not reference init/exit code/data from
 906 * normal code and data
 907 */
 908{
 909        .fromsec = { TEXT_SECTIONS, NULL },
 910        .tosec   = { ALL_INIT_SECTIONS, NULL },
 911        .mismatch = TEXT_TO_ANY_INIT,
 912        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 913},
 914{
 915        .fromsec = { DATA_SECTIONS, NULL },
 916        .tosec   = { ALL_XXXINIT_SECTIONS, NULL },
 917        .mismatch = DATA_TO_ANY_INIT,
 918        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 919},
 920{
 921        .fromsec = { DATA_SECTIONS, NULL },
 922        .tosec   = { INIT_SECTIONS, NULL },
 923        .mismatch = DATA_TO_ANY_INIT,
 924        .symbol_white_list = {
 925                "*_template", "*_timer", "*_sht", "*_ops",
 926                "*_probe", "*_probe_one", "*_console", NULL
 927        },
 928},
 929{
 930        .fromsec = { TEXT_SECTIONS, NULL },
 931        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 932        .mismatch = TEXT_TO_ANY_EXIT,
 933        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 934},
 935{
 936        .fromsec = { DATA_SECTIONS, NULL },
 937        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 938        .mismatch = DATA_TO_ANY_EXIT,
 939        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 940},
 941/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
 942{
 943        .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 944        .tosec   = { INIT_SECTIONS, NULL },
 945        .mismatch = XXXINIT_TO_SOME_INIT,
 946        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 947},
 948/* Do not reference cpuinit code/data from meminit code/data */
 949{
 950        .fromsec = { MEM_INIT_SECTIONS, NULL },
 951        .tosec   = { CPU_INIT_SECTIONS, NULL },
 952        .mismatch = XXXINIT_TO_SOME_INIT,
 953        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 954},
 955/* Do not reference meminit code/data from cpuinit code/data */
 956{
 957        .fromsec = { CPU_INIT_SECTIONS, NULL },
 958        .tosec   = { MEM_INIT_SECTIONS, NULL },
 959        .mismatch = XXXINIT_TO_SOME_INIT,
 960        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 961},
 962/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
 963{
 964        .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
 965        .tosec   = { EXIT_SECTIONS, NULL },
 966        .mismatch = XXXEXIT_TO_SOME_EXIT,
 967        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 968},
 969/* Do not reference cpuexit code/data from memexit code/data */
 970{
 971        .fromsec = { MEM_EXIT_SECTIONS, NULL },
 972        .tosec   = { CPU_EXIT_SECTIONS, NULL },
 973        .mismatch = XXXEXIT_TO_SOME_EXIT,
 974        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 975},
 976/* Do not reference memexit code/data from cpuexit code/data */
 977{
 978        .fromsec = { CPU_EXIT_SECTIONS, NULL },
 979        .tosec   = { MEM_EXIT_SECTIONS, NULL },
 980        .mismatch = XXXEXIT_TO_SOME_EXIT,
 981        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 982},
 983/* Do not use exit code/data from init code */
 984{
 985        .fromsec = { ALL_INIT_SECTIONS, NULL },
 986        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 987        .mismatch = ANY_INIT_TO_ANY_EXIT,
 988        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 989},
 990/* Do not use init code/data from exit code */
 991{
 992        .fromsec = { ALL_EXIT_SECTIONS, NULL },
 993        .tosec   = { ALL_INIT_SECTIONS, NULL },
 994        .mismatch = ANY_EXIT_TO_ANY_INIT,
 995        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 996},
 997/* Do not export init/exit functions or data */
 998{
 999        .fromsec = { "__ksymtab*", NULL },
1000        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1001        .mismatch = EXPORT_TO_INIT_EXIT,
1002        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1003}
1004};
1005
1006static const struct sectioncheck *section_mismatch(
1007                const char *fromsec, const char *tosec)
1008{
1009        int i;
1010        int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1011        const struct sectioncheck *check = &sectioncheck[0];
1012
1013        for (i = 0; i < elems; i++) {
1014                if (match(fromsec, check->fromsec) &&
1015                    match(tosec, check->tosec))
1016                        return check;
1017                check++;
1018        }
1019        return NULL;
1020}
1021
1022/**
1023 * Whitelist to allow certain references to pass with no warning.
1024 *
1025 * Pattern 1:
1026 *   If a module parameter is declared __initdata and permissions=0
1027 *   then this is legal despite the warning generated.
1028 *   We cannot see value of permissions here, so just ignore
1029 *   this pattern.
1030 *   The pattern is identified by:
1031 *   tosec   = .init.data
1032 *   fromsec = .data*
1033 *   atsym   =__param*
1034 *
1035 * Pattern 1a:
1036 *   module_param_call() ops can refer to __init set function if permissions=0
1037 *   The pattern is identified by:
1038 *   tosec   = .init.text
1039 *   fromsec = .data*
1040 *   atsym   = __param_ops_*
1041 *
1042 * Pattern 2:
1043 *   Many drivers utilise a *driver container with references to
1044 *   add, remove, probe functions etc.
1045 *   These functions may often be marked __devinit and we do not want to
1046 *   warn here.
1047 *   the pattern is identified by:
1048 *   tosec   = init or exit section
1049 *   fromsec = data section
1050 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1051 *           *probe_one, *_console, *_timer
1052 *
1053 * Pattern 3:
1054 *   Whitelist all references from .head.text to any init section
1055 *
1056 * Pattern 4:
1057 *   Some symbols belong to init section but still it is ok to reference
1058 *   these from non-init sections as these symbols don't have any memory
1059 *   allocated for them and symbol address and value are same. So even
1060 *   if init section is freed, its ok to reference those symbols.
1061 *   For ex. symbols marking the init section boundaries.
1062 *   This pattern is identified by
1063 *   refsymname = __init_begin, _sinittext, _einittext
1064 *
1065 **/
1066static int secref_whitelist(const struct sectioncheck *mismatch,
1067                            const char *fromsec, const char *fromsym,
1068                            const char *tosec, const char *tosym)
1069{
1070        /* Check for pattern 1 */
1071        if (match(tosec, init_data_sections) &&
1072            match(fromsec, data_sections) &&
1073            (strncmp(fromsym, "__param", strlen("__param")) == 0))
1074                return 0;
1075
1076        /* Check for pattern 1a */
1077        if (strcmp(tosec, ".init.text") == 0 &&
1078            match(fromsec, data_sections) &&
1079            (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1080                return 0;
1081
1082        /* Check for pattern 2 */
1083        if (match(tosec, init_exit_sections) &&
1084            match(fromsec, data_sections) &&
1085            match(fromsym, mismatch->symbol_white_list))
1086                return 0;
1087
1088        /* Check for pattern 3 */
1089        if (match(fromsec, head_sections) &&
1090            match(tosec, init_sections))
1091                return 0;
1092
1093        /* Check for pattern 4 */
1094        if (match(tosym, linker_symbols))
1095                return 0;
1096
1097        return 1;
1098}
1099
1100/**
1101 * Find symbol based on relocation record info.
1102 * In some cases the symbol supplied is a valid symbol so
1103 * return refsym. If st_name != 0 we assume this is a valid symbol.
1104 * In other cases the symbol needs to be looked up in the symbol table
1105 * based on section and address.
1106 *  **/
1107static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1108                                Elf_Sym *relsym)
1109{
1110        Elf_Sym *sym;
1111        Elf_Sym *near = NULL;
1112        Elf64_Sword distance = 20;
1113        Elf64_Sword d;
1114        unsigned int relsym_secindex;
1115
1116        if (relsym->st_name != 0)
1117                return relsym;
1118
1119        relsym_secindex = get_secindex(elf, relsym);
1120        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1121                if (get_secindex(elf, sym) != relsym_secindex)
1122                        continue;
1123                if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1124                        continue;
1125                if (sym->st_value == addr)
1126                        return sym;
1127                /* Find a symbol nearby - addr are maybe negative */
1128                d = sym->st_value - addr;
1129                if (d < 0)
1130                        d = addr - sym->st_value;
1131                if (d < distance) {
1132                        distance = d;
1133                        near = sym;
1134                }
1135        }
1136        /* We need a close match */
1137        if (distance < 20)
1138                return near;
1139        else
1140                return NULL;
1141}
1142
1143static inline int is_arm_mapping_symbol(const char *str)
1144{
1145        return str[0] == '$' && strchr("atd", str[1])
1146               && (str[2] == '\0' || str[2] == '.');
1147}
1148
1149/*
1150 * If there's no name there, ignore it; likewise, ignore it if it's
1151 * one of the magic symbols emitted used by current ARM tools.
1152 *
1153 * Otherwise if find_symbols_between() returns those symbols, they'll
1154 * fail the whitelist tests and cause lots of false alarms ... fixable
1155 * only by merging __exit and __init sections into __text, bloating
1156 * the kernel (which is especially evil on embedded platforms).
1157 */
1158static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1159{
1160        const char *name = elf->strtab + sym->st_name;
1161
1162        if (!name || !strlen(name))
1163                return 0;
1164        return !is_arm_mapping_symbol(name);
1165}
1166
1167/*
1168 * Find symbols before or equal addr and after addr - in the section sec.
1169 * If we find two symbols with equal offset prefer one with a valid name.
1170 * The ELF format may have a better way to detect what type of symbol
1171 * it is, but this works for now.
1172 **/
1173static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1174                                 const char *sec)
1175{
1176        Elf_Sym *sym;
1177        Elf_Sym *near = NULL;
1178        Elf_Addr distance = ~0;
1179
1180        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1181                const char *symsec;
1182
1183                if (is_shndx_special(sym->st_shndx))
1184                        continue;
1185                symsec = sec_name(elf, get_secindex(elf, sym));
1186                if (strcmp(symsec, sec) != 0)
1187                        continue;
1188                if (!is_valid_name(elf, sym))
1189                        continue;
1190                if (sym->st_value <= addr) {
1191                        if ((addr - sym->st_value) < distance) {
1192                                distance = addr - sym->st_value;
1193                                near = sym;
1194                        } else if ((addr - sym->st_value) == distance) {
1195                                near = sym;
1196                        }
1197                }
1198        }
1199        return near;
1200}
1201
1202/*
1203 * Convert a section name to the function/data attribute
1204 * .init.text => __init
1205 * .cpuinit.data => __cpudata
1206 * .memexitconst => __memconst
1207 * etc.
1208 *
1209 * The memory of returned value has been allocated on a heap. The user of this
1210 * method should free it after usage.
1211*/
1212static char *sec2annotation(const char *s)
1213{
1214        if (match(s, init_exit_sections)) {
1215                char *p = malloc(20);
1216                char *r = p;
1217
1218                *p++ = '_';
1219                *p++ = '_';
1220                if (*s == '.')
1221                        s++;
1222                while (*s && *s != '.')
1223                        *p++ = *s++;
1224                *p = '\0';
1225                if (*s == '.')
1226                        s++;
1227                if (strstr(s, "rodata") != NULL)
1228                        strcat(p, "const ");
1229                else if (strstr(s, "data") != NULL)
1230                        strcat(p, "data ");
1231                else
1232                        strcat(p, " ");
1233                return r;
1234        } else {
1235                return strdup("");
1236        }
1237}
1238
1239static int is_function(Elf_Sym *sym)
1240{
1241        if (sym)
1242                return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1243        else
1244                return -1;
1245}
1246
1247static void print_section_list(const char * const list[20])
1248{
1249        const char *const *s = list;
1250
1251        while (*s) {
1252                fprintf(stderr, "%s", *s);
1253                s++;
1254                if (*s)
1255                        fprintf(stderr, ", ");
1256        }
1257        fprintf(stderr, "\n");
1258}
1259
1260/*
1261 * Print a warning about a section mismatch.
1262 * Try to find symbols near it so user can find it.
1263 * Check whitelist before warning - it may be a false positive.
1264 */
1265static void report_sec_mismatch(const char *modname,
1266                                const struct sectioncheck *mismatch,
1267                                const char *fromsec,
1268                                unsigned long long fromaddr,
1269                                const char *fromsym,
1270                                int from_is_func,
1271                                const char *tosec, const char *tosym,
1272                                int to_is_func)
1273{
1274        const char *from, *from_p;
1275        const char *to, *to_p;
1276        char *prl_from;
1277        char *prl_to;
1278
1279        switch (from_is_func) {
1280        case 0: from = "variable"; from_p = "";   break;
1281        case 1: from = "function"; from_p = "()"; break;
1282        default: from = "(unknown reference)"; from_p = ""; break;
1283        }
1284        switch (to_is_func) {
1285        case 0: to = "variable"; to_p = "";   break;
1286        case 1: to = "function"; to_p = "()"; break;
1287        default: to = "(unknown reference)"; to_p = ""; break;
1288        }
1289
1290        sec_mismatch_count++;
1291        if (!sec_mismatch_verbose)
1292                return;
1293
1294        warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1295             "to the %s %s:%s%s\n",
1296             modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1297             tosym, to_p);
1298
1299        switch (mismatch->mismatch) {
1300        case TEXT_TO_ANY_INIT:
1301                prl_from = sec2annotation(fromsec);
1302                prl_to = sec2annotation(tosec);
1303                fprintf(stderr,
1304                "The function %s%s() references\n"
1305                "the %s %s%s%s.\n"
1306                "This is often because %s lacks a %s\n"
1307                "annotation or the annotation of %s is wrong.\n",
1308                prl_from, fromsym,
1309                to, prl_to, tosym, to_p,
1310                fromsym, prl_to, tosym);
1311                free(prl_from);
1312                free(prl_to);
1313                break;
1314        case DATA_TO_ANY_INIT: {
1315                prl_to = sec2annotation(tosec);
1316                fprintf(stderr,
1317                "The variable %s references\n"
1318                "the %s %s%s%s\n"
1319                "If the reference is valid then annotate the\n"
1320                "variable with __init* or __refdata (see linux/init.h) "
1321                "or name the variable:\n",
1322                fromsym, to, prl_to, tosym, to_p);
1323                print_section_list(mismatch->symbol_white_list);
1324                free(prl_to);
1325                break;
1326        }
1327        case TEXT_TO_ANY_EXIT:
1328                prl_to = sec2annotation(tosec);
1329                fprintf(stderr,
1330                "The function %s() references a %s in an exit section.\n"
1331                "Often the %s %s%s has valid usage outside the exit section\n"
1332                "and the fix is to remove the %sannotation of %s.\n",
1333                fromsym, to, to, tosym, to_p, prl_to, tosym);
1334                free(prl_to);
1335                break;
1336        case DATA_TO_ANY_EXIT: {
1337                prl_to = sec2annotation(tosec);
1338                fprintf(stderr,
1339                "The variable %s references\n"
1340                "the %s %s%s%s\n"
1341                "If the reference is valid then annotate the\n"
1342                "variable with __exit* (see linux/init.h) or "
1343                "name the variable:\n",
1344                fromsym, to, prl_to, tosym, to_p);
1345                print_section_list(mismatch->symbol_white_list);
1346                free(prl_to);
1347                break;
1348        }
1349        case XXXINIT_TO_SOME_INIT:
1350        case XXXEXIT_TO_SOME_EXIT:
1351                prl_from = sec2annotation(fromsec);
1352                prl_to = sec2annotation(tosec);
1353                fprintf(stderr,
1354                "The %s %s%s%s references\n"
1355                "a %s %s%s%s.\n"
1356                "If %s is only used by %s then\n"
1357                "annotate %s with a matching annotation.\n",
1358                from, prl_from, fromsym, from_p,
1359                to, prl_to, tosym, to_p,
1360                tosym, fromsym, tosym);
1361                free(prl_from);
1362                free(prl_to);
1363                break;
1364        case ANY_INIT_TO_ANY_EXIT:
1365                prl_from = sec2annotation(fromsec);
1366                prl_to = sec2annotation(tosec);
1367                fprintf(stderr,
1368                "The %s %s%s%s references\n"
1369                "a %s %s%s%s.\n"
1370                "This is often seen when error handling "
1371                "in the init function\n"
1372                "uses functionality in the exit path.\n"
1373                "The fix is often to remove the %sannotation of\n"
1374                "%s%s so it may be used outside an exit section.\n",
1375                from, prl_from, fromsym, from_p,
1376                to, prl_to, tosym, to_p,
1377                prl_to, tosym, to_p);
1378                free(prl_from);
1379                free(prl_to);
1380                break;
1381        case ANY_EXIT_TO_ANY_INIT:
1382                prl_from = sec2annotation(fromsec);
1383                prl_to = sec2annotation(tosec);
1384                fprintf(stderr,
1385                "The %s %s%s%s references\n"
1386                "a %s %s%s%s.\n"
1387                "This is often seen when error handling "
1388                "in the exit function\n"
1389                "uses functionality in the init path.\n"
1390                "The fix is often to remove the %sannotation of\n"
1391                "%s%s so it may be used outside an init section.\n",
1392                from, prl_from, fromsym, from_p,
1393                to, prl_to, tosym, to_p,
1394                prl_to, tosym, to_p);
1395                free(prl_from);
1396                free(prl_to);
1397                break;
1398        case EXPORT_TO_INIT_EXIT:
1399                prl_to = sec2annotation(tosec);
1400                fprintf(stderr,
1401                "The symbol %s is exported and annotated %s\n"
1402                "Fix this by removing the %sannotation of %s "
1403                "or drop the export.\n",
1404                tosym, prl_to, prl_to, tosym);
1405                free(prl_to);
1406                break;
1407        }
1408        fprintf(stderr, "\n");
1409}
1410
1411static void check_section_mismatch(const char *modname, struct elf_info *elf,
1412                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1413{
1414        const char *tosec;
1415        const struct sectioncheck *mismatch;
1416
1417        tosec = sec_name(elf, get_secindex(elf, sym));
1418        mismatch = section_mismatch(fromsec, tosec);
1419        if (mismatch) {
1420                Elf_Sym *to;
1421                Elf_Sym *from;
1422                const char *tosym;
1423                const char *fromsym;
1424
1425                from = find_elf_symbol2(elf, r->r_offset, fromsec);
1426                fromsym = sym_name(elf, from);
1427                to = find_elf_symbol(elf, r->r_addend, sym);
1428                tosym = sym_name(elf, to);
1429
1430                /* check whitelist - we may ignore it */
1431                if (secref_whitelist(mismatch,
1432                                        fromsec, fromsym, tosec, tosym)) {
1433                        report_sec_mismatch(modname, mismatch,
1434                           fromsec, r->r_offset, fromsym,
1435                           is_function(from), tosec, tosym,
1436                           is_function(to));
1437                }
1438        }
1439}
1440
1441static unsigned int *reloc_location(struct elf_info *elf,
1442                                    Elf_Shdr *sechdr, Elf_Rela *r)
1443{
1444        Elf_Shdr *sechdrs = elf->sechdrs;
1445        int section = sechdr->sh_info;
1446
1447        return (void *)elf->hdr + sechdrs[section].sh_offset +
1448                r->r_offset;
1449}
1450
1451static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1452{
1453        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1454        unsigned int *location = reloc_location(elf, sechdr, r);
1455
1456        switch (r_typ) {
1457        case R_386_32:
1458                r->r_addend = TO_NATIVE(*location);
1459                break;
1460        case R_386_PC32:
1461                r->r_addend = TO_NATIVE(*location) + 4;
1462                /* For CONFIG_RELOCATABLE=y */
1463                if (elf->hdr->e_type == ET_EXEC)
1464                        r->r_addend += r->r_offset;
1465                break;
1466        }
1467        return 0;
1468}
1469
1470static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1471{
1472        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1473
1474        switch (r_typ) {
1475        case R_ARM_ABS32:
1476                /* From ARM ABI: (S + A) | T */
1477                r->r_addend = (int)(long)
1478                              (elf->symtab_start + ELF_R_SYM(r->r_info));
1479                break;
1480        case R_ARM_PC24:
1481                /* From ARM ABI: ((S + A) | T) - P */
1482                r->r_addend = (int)(long)(elf->hdr +
1483                              sechdr->sh_offset +
1484                              (r->r_offset - sechdr->sh_addr));
1485                break;
1486        default:
1487                return 1;
1488        }
1489        return 0;
1490}
1491
1492static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1493{
1494        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1495        unsigned int *location = reloc_location(elf, sechdr, r);
1496        unsigned int inst;
1497
1498        if (r_typ == R_MIPS_HI16)
1499                return 1;       /* skip this */
1500        inst = TO_NATIVE(*location);
1501        switch (r_typ) {
1502        case R_MIPS_LO16:
1503                r->r_addend = inst & 0xffff;
1504                break;
1505        case R_MIPS_26:
1506                r->r_addend = (inst & 0x03ffffff) << 2;
1507                break;
1508        case R_MIPS_32:
1509                r->r_addend = inst;
1510                break;
1511        }
1512        return 0;
1513}
1514
1515static void section_rela(const char *modname, struct elf_info *elf,
1516                         Elf_Shdr *sechdr)
1517{
1518        Elf_Sym  *sym;
1519        Elf_Rela *rela;
1520        Elf_Rela r;
1521        unsigned int r_sym;
1522        const char *fromsec;
1523
1524        Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1525        Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1526
1527        fromsec = sech_name(elf, sechdr);
1528        fromsec += strlen(".rela");
1529        /* if from section (name) is know good then skip it */
1530        if (match(fromsec, section_white_list))
1531                return;
1532
1533        for (rela = start; rela < stop; rela++) {
1534                r.r_offset = TO_NATIVE(rela->r_offset);
1535#if KERNEL_ELFCLASS == ELFCLASS64
1536                if (elf->hdr->e_machine == EM_MIPS) {
1537                        unsigned int r_typ;
1538                        r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1539                        r_sym = TO_NATIVE(r_sym);
1540                        r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1541                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1542                } else {
1543                        r.r_info = TO_NATIVE(rela->r_info);
1544                        r_sym = ELF_R_SYM(r.r_info);
1545                }
1546#else
1547                r.r_info = TO_NATIVE(rela->r_info);
1548                r_sym = ELF_R_SYM(r.r_info);
1549#endif
1550                r.r_addend = TO_NATIVE(rela->r_addend);
1551                sym = elf->symtab_start + r_sym;
1552                /* Skip special sections */
1553                if (is_shndx_special(sym->st_shndx))
1554                        continue;
1555                check_section_mismatch(modname, elf, &r, sym, fromsec);
1556        }
1557}
1558
1559static void section_rel(const char *modname, struct elf_info *elf,
1560                        Elf_Shdr *sechdr)
1561{
1562        Elf_Sym *sym;
1563        Elf_Rel *rel;
1564        Elf_Rela r;
1565        unsigned int r_sym;
1566        const char *fromsec;
1567
1568        Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1569        Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1570
1571        fromsec = sech_name(elf, sechdr);
1572        fromsec += strlen(".rel");
1573        /* if from section (name) is know good then skip it */
1574        if (match(fromsec, section_white_list))
1575                return;
1576
1577        for (rel = start; rel < stop; rel++) {
1578                r.r_offset = TO_NATIVE(rel->r_offset);
1579#if KERNEL_ELFCLASS == ELFCLASS64
1580                if (elf->hdr->e_machine == EM_MIPS) {
1581                        unsigned int r_typ;
1582                        r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1583                        r_sym = TO_NATIVE(r_sym);
1584                        r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1585                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1586                } else {
1587                        r.r_info = TO_NATIVE(rel->r_info);
1588                        r_sym = ELF_R_SYM(r.r_info);
1589                }
1590#else
1591                r.r_info = TO_NATIVE(rel->r_info);
1592                r_sym = ELF_R_SYM(r.r_info);
1593#endif
1594                r.r_addend = 0;
1595                switch (elf->hdr->e_machine) {
1596                case EM_386:
1597                        if (addend_386_rel(elf, sechdr, &r))
1598                                continue;
1599                        break;
1600                case EM_ARM:
1601                        if (addend_arm_rel(elf, sechdr, &r))
1602                                continue;
1603                        break;
1604                case EM_MIPS:
1605                        if (addend_mips_rel(elf, sechdr, &r))
1606                                continue;
1607                        break;
1608                }
1609                sym = elf->symtab_start + r_sym;
1610                /* Skip special sections */
1611                if (is_shndx_special(sym->st_shndx))
1612                        continue;
1613                check_section_mismatch(modname, elf, &r, sym, fromsec);
1614        }
1615}
1616
1617/**
1618 * A module includes a number of sections that are discarded
1619 * either when loaded or when used as built-in.
1620 * For loaded modules all functions marked __init and all data
1621 * marked __initdata will be discarded when the module has been initialized.
1622 * Likewise for modules used built-in the sections marked __exit
1623 * are discarded because __exit marked function are supposed to be called
1624 * only when a module is unloaded which never happens for built-in modules.
1625 * The check_sec_ref() function traverses all relocation records
1626 * to find all references to a section that reference a section that will
1627 * be discarded and warns about it.
1628 **/
1629static void check_sec_ref(struct module *mod, const char *modname,
1630                          struct elf_info *elf)
1631{
1632        int i;
1633        Elf_Shdr *sechdrs = elf->sechdrs;
1634
1635        /* Walk through all sections */
1636        for (i = 0; i < elf->num_sections; i++) {
1637                check_section(modname, elf, &elf->sechdrs[i]);
1638                /* We want to process only relocation sections and not .init */
1639                if (sechdrs[i].sh_type == SHT_RELA)
1640                        section_rela(modname, elf, &elf->sechdrs[i]);
1641                else if (sechdrs[i].sh_type == SHT_REL)
1642                        section_rel(modname, elf, &elf->sechdrs[i]);
1643        }
1644}
1645
1646static void read_symbols(char *modname)
1647{
1648        const char *symname;
1649        char *version;
1650        char *license;
1651        struct module *mod;
1652        struct elf_info info = { };
1653        Elf_Sym *sym;
1654
1655        if (!parse_elf(&info, modname))
1656                return;
1657
1658        mod = new_module(modname);
1659
1660        /* When there's no vmlinux, don't print warnings about
1661         * unresolved symbols (since there'll be too many ;) */
1662        if (is_vmlinux(modname)) {
1663                have_vmlinux = 1;
1664                mod->skip = 1;
1665        }
1666
1667        license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1668        if (info.modinfo && !license && !is_vmlinux(modname))
1669                warn("modpost: missing MODULE_LICENSE() in %s\n"
1670                     "see include/linux/module.h for "
1671                     "more information\n", modname);
1672        while (license) {
1673                if (license_is_gpl_compatible(license))
1674                        mod->gpl_compatible = 1;
1675                else {
1676                        mod->gpl_compatible = 0;
1677                        break;
1678                }
1679                license = get_next_modinfo(info.modinfo, info.modinfo_len,
1680                                           "license", license);
1681        }
1682
1683        for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1684                symname = info.strtab + sym->st_name;
1685
1686                handle_modversions(mod, &info, sym, symname);
1687                handle_moddevtable(mod, &info, sym, symname);
1688        }
1689        if (!is_vmlinux(modname) ||
1690             (is_vmlinux(modname) && vmlinux_section_warnings))
1691                check_sec_ref(mod, modname, &info);
1692
1693        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1694        if (version)
1695                maybe_frob_rcs_version(modname, version, info.modinfo,
1696                                       version - (char *)info.hdr);
1697        if (version || (all_versions && !is_vmlinux(modname)))
1698                get_src_version(modname, mod->srcversion,
1699                                sizeof(mod->srcversion)-1);
1700
1701        parse_elf_finish(&info);
1702
1703        /* Our trick to get versioning for module struct etc. - it's
1704         * never passed as an argument to an exported function, so
1705         * the automatic versioning doesn't pick it up, but it's really
1706         * important anyhow */
1707        if (modversions)
1708                mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1709}
1710
1711#define SZ 500
1712
1713/* We first write the generated file into memory using the
1714 * following helper, then compare to the file on disk and
1715 * only update the later if anything changed */
1716
1717void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1718                                                      const char *fmt, ...)
1719{
1720        char tmp[SZ];
1721        int len;
1722        va_list ap;
1723
1724        va_start(ap, fmt);
1725        len = vsnprintf(tmp, SZ, fmt, ap);
1726        buf_write(buf, tmp, len);
1727        va_end(ap);
1728}
1729
1730void buf_write(struct buffer *buf, const char *s, int len)
1731{
1732        if (buf->size - buf->pos < len) {
1733                buf->size += len + SZ;
1734                buf->p = realloc(buf->p, buf->size);
1735        }
1736        strncpy(buf->p + buf->pos, s, len);
1737        buf->pos += len;
1738}
1739
1740static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1741{
1742        const char *e = is_vmlinux(m) ?"":".ko";
1743
1744        switch (exp) {
1745        case export_gpl:
1746                fatal("modpost: GPL-incompatible module %s%s "
1747                      "uses GPL-only symbol '%s'\n", m, e, s);
1748                break;
1749        case export_unused_gpl:
1750                fatal("modpost: GPL-incompatible module %s%s "
1751                      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1752                break;
1753        case export_gpl_future:
1754                warn("modpost: GPL-incompatible module %s%s "
1755                      "uses future GPL-only symbol '%s'\n", m, e, s);
1756                break;
1757        case export_plain:
1758        case export_unused:
1759        case export_unknown:
1760                /* ignore */
1761                break;
1762        }
1763}
1764
1765static void check_for_unused(enum export exp, const char *m, const char *s)
1766{
1767        const char *e = is_vmlinux(m) ?"":".ko";
1768
1769        switch (exp) {
1770        case export_unused:
1771        case export_unused_gpl:
1772                warn("modpost: module %s%s "
1773                      "uses symbol '%s' marked UNUSED\n", m, e, s);
1774                break;
1775        default:
1776                /* ignore */
1777                break;
1778        }
1779}
1780
1781static void check_exports(struct module *mod)
1782{
1783        struct symbol *s, *exp;
1784
1785        for (s = mod->unres; s; s = s->next) {
1786                const char *basename;
1787                exp = find_symbol(s->name);
1788                if (!exp || exp->module == mod)
1789                        continue;
1790                basename = strrchr(mod->name, '/');
1791                if (basename)
1792                        basename++;
1793                else
1794                        basename = mod->name;
1795                if (!mod->gpl_compatible)
1796                        check_for_gpl_usage(exp->export, basename, exp->name);
1797                check_for_unused(exp->export, basename, exp->name);
1798        }
1799}
1800
1801/**
1802 * Header for the generated file
1803 **/
1804static void add_header(struct buffer *b, struct module *mod)
1805{
1806        buf_printf(b, "#include <linux/module.h>\n");
1807        buf_printf(b, "#include <linux/vermagic.h>\n");
1808        buf_printf(b, "#include <linux/compiler.h>\n");
1809        buf_printf(b, "\n");
1810        buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1811        buf_printf(b, "\n");
1812        buf_printf(b, "struct module __this_module\n");
1813        buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1814        buf_printf(b, " .name = KBUILD_MODNAME,\n");
1815        if (mod->has_init)
1816                buf_printf(b, " .init = init_module,\n");
1817        if (mod->has_cleanup)
1818                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1819                              " .exit = cleanup_module,\n"
1820                              "#endif\n");
1821        buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1822        buf_printf(b, "};\n");
1823}
1824
1825static void add_staging_flag(struct buffer *b, const char *name)
1826{
1827        static const char *staging_dir = "drivers/staging";
1828
1829        if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1830                buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1831}
1832
1833/**
1834 * Record CRCs for unresolved symbols
1835 **/
1836static int add_versions(struct buffer *b, struct module *mod)
1837{
1838        struct symbol *s, *exp;
1839        int err = 0;
1840
1841        for (s = mod->unres; s; s = s->next) {
1842                exp = find_symbol(s->name);
1843                if (!exp || exp->module == mod) {
1844                        if (have_vmlinux && !s->weak) {
1845                                if (warn_unresolved) {
1846                                        warn("\"%s\" [%s.ko] undefined!\n",
1847                                             s->name, mod->name);
1848                                } else {
1849                                        merror("\"%s\" [%s.ko] undefined!\n",
1850                                                  s->name, mod->name);
1851                                        err = 1;
1852                                }
1853                        }
1854                        continue;
1855                }
1856                s->module = exp->module;
1857                s->crc_valid = exp->crc_valid;
1858                s->crc = exp->crc;
1859        }
1860
1861        if (!modversions)
1862                return err;
1863
1864        buf_printf(b, "\n");
1865        buf_printf(b, "static const struct modversion_info ____versions[]\n");
1866        buf_printf(b, "__used\n");
1867        buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1868
1869        for (s = mod->unres; s; s = s->next) {
1870                if (!s->module)
1871                        continue;
1872                if (!s->crc_valid) {
1873                        warn("\"%s\" [%s.ko] has no CRC!\n",
1874                                s->name, mod->name);
1875                        continue;
1876                }
1877                buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1878        }
1879
1880        buf_printf(b, "};\n");
1881
1882        return err;
1883}
1884
1885static void add_depends(struct buffer *b, struct module *mod,
1886                        struct module *modules)
1887{
1888        struct symbol *s;
1889        struct module *m;
1890        int first = 1;
1891
1892        for (m = modules; m; m = m->next)
1893                m->seen = is_vmlinux(m->name);
1894
1895        buf_printf(b, "\n");
1896        buf_printf(b, "static const char __module_depends[]\n");
1897        buf_printf(b, "__used\n");
1898        buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1899        buf_printf(b, "\"depends=");
1900        for (s = mod->unres; s; s = s->next) {
1901                const char *p;
1902                if (!s->module)
1903                        continue;
1904
1905                if (s->module->seen)
1906                        continue;
1907
1908                s->module->seen = 1;
1909                p = strrchr(s->module->name, '/');
1910                if (p)
1911                        p++;
1912                else
1913                        p = s->module->name;
1914                buf_printf(b, "%s%s", first ? "" : ",", p);
1915                first = 0;
1916        }
1917        buf_printf(b, "\";\n");
1918}
1919
1920static void add_srcversion(struct buffer *b, struct module *mod)
1921{
1922        if (mod->srcversion[0]) {
1923                buf_printf(b, "\n");
1924                buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1925                           mod->srcversion);
1926        }
1927}
1928
1929static void write_if_changed(struct buffer *b, const char *fname)
1930{
1931        char *tmp;
1932        FILE *file;
1933        struct stat st;
1934
1935        file = fopen(fname, "r");
1936        if (!file)
1937                goto write;
1938
1939        if (fstat(fileno(file), &st) < 0)
1940                goto close_write;
1941
1942        if (st.st_size != b->pos)
1943                goto close_write;
1944
1945        tmp = NOFAIL(malloc(b->pos));
1946        if (fread(tmp, 1, b->pos, file) != b->pos)
1947                goto free_write;
1948
1949        if (memcmp(tmp, b->p, b->pos) != 0)
1950                goto free_write;
1951
1952        free(tmp);
1953        fclose(file);
1954        return;
1955
1956 free_write:
1957        free(tmp);
1958 close_write:
1959        fclose(file);
1960 write:
1961        file = fopen(fname, "w");
1962        if (!file) {
1963                perror(fname);
1964                exit(1);
1965        }
1966        if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1967                perror(fname);
1968                exit(1);
1969        }
1970        fclose(file);
1971}
1972
1973/* parse Module.symvers file. line format:
1974 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1975 **/
1976static void read_dump(const char *fname, unsigned int kernel)
1977{
1978        unsigned long size, pos = 0;
1979        void *file = grab_file(fname, &size);
1980        char *line;
1981
1982        if (!file)
1983                /* No symbol versions, silently ignore */
1984                return;
1985
1986        while ((line = get_next_line(&pos, file, size))) {
1987                char *symname, *modname, *d, *export, *end;
1988                unsigned int crc;
1989                struct module *mod;
1990                struct symbol *s;
1991
1992                if (!(symname = strchr(line, '\t')))
1993                        goto fail;
1994                *symname++ = '\0';
1995                if (!(modname = strchr(symname, '\t')))
1996                        goto fail;
1997                *modname++ = '\0';
1998                if ((export = strchr(modname, '\t')) != NULL)
1999                        *export++ = '\0';
2000                if (export && ((end = strchr(export, '\t')) != NULL))
2001                        *end = '\0';
2002                crc = strtoul(line, &d, 16);
2003                if (*symname == '\0' || *modname == '\0' || *d != '\0')
2004                        goto fail;
2005                mod = find_module(modname);
2006                if (!mod) {
2007                        if (is_vmlinux(modname))
2008                                have_vmlinux = 1;
2009                        mod = new_module(modname);
2010                        mod->skip = 1;
2011                }
2012                s = sym_add_exported(symname, mod, export_no(export));
2013                s->kernel    = kernel;
2014                s->preloaded = 1;
2015                sym_update_crc(symname, mod, crc, export_no(export));
2016        }
2017        return;
2018fail:
2019        fatal("parse error in symbol dump file\n");
2020}
2021
2022/* For normal builds always dump all symbols.
2023 * For external modules only dump symbols
2024 * that are not read from kernel Module.symvers.
2025 **/
2026static int dump_sym(struct symbol *sym)
2027{
2028        if (!external_module)
2029                return 1;
2030        if (sym->vmlinux || sym->kernel)
2031                return 0;
2032        return 1;
2033}
2034
2035static void write_dump(const char *fname)
2036{
2037        struct buffer buf = { };
2038        struct symbol *symbol;
2039        int n;
2040
2041        for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2042                symbol = symbolhash[n];
2043                while (symbol) {
2044                        if (dump_sym(symbol))
2045                                buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2046                                        symbol->crc, symbol->name,
2047                                        symbol->module->name,
2048                                        export_str(symbol->export));
2049                        symbol = symbol->next;
2050                }
2051        }
2052        write_if_changed(&buf, fname);
2053}
2054
2055struct ext_sym_list {
2056        struct ext_sym_list *next;
2057        const char *file;
2058};
2059
2060int main(int argc, char **argv)
2061{
2062        struct module *mod;
2063        struct buffer buf = { };
2064        char *kernel_read = NULL, *module_read = NULL;
2065        char *dump_write = NULL;
2066        int opt;
2067        int err;
2068        struct ext_sym_list *extsym_iter;
2069        struct ext_sym_list *extsym_start = NULL;
2070
2071        while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2072                switch (opt) {
2073                case 'i':
2074                        kernel_read = optarg;
2075                        break;
2076                case 'I':
2077                        module_read = optarg;
2078                        external_module = 1;
2079                        break;
2080                case 'c':
2081                        cross_build = 1;
2082                        break;
2083                case 'e':
2084                        external_module = 1;
2085                        extsym_iter =
2086                           NOFAIL(malloc(sizeof(*extsym_iter)));
2087                        extsym_iter->next = extsym_start;
2088                        extsym_iter->file = optarg;
2089                        extsym_start = extsym_iter;
2090                        break;
2091                case 'm':
2092                        modversions = 1;
2093                        break;
2094                case 'o':
2095                        dump_write = optarg;
2096                        break;
2097                case 'a':
2098                        all_versions = 1;
2099                        break;
2100                case 's':
2101                        vmlinux_section_warnings = 0;
2102                        break;
2103                case 'S':
2104                        sec_mismatch_verbose = 0;
2105                        break;
2106                case 'w':
2107                        warn_unresolved = 1;
2108                        break;
2109                default:
2110                        exit(1);
2111                }
2112        }
2113
2114        if (kernel_read)
2115                read_dump(kernel_read, 1);
2116        if (module_read)
2117                read_dump(module_read, 0);
2118        while (extsym_start) {
2119                read_dump(extsym_start->file, 0);
2120                extsym_iter = extsym_start->next;
2121                free(extsym_start);
2122                extsym_start = extsym_iter;
2123        }
2124
2125        while (optind < argc)
2126                read_symbols(argv[optind++]);
2127
2128        for (mod = modules; mod; mod = mod->next) {
2129                if (mod->skip)
2130                        continue;
2131                check_exports(mod);
2132        }
2133
2134        err = 0;
2135
2136        for (mod = modules; mod; mod = mod->next) {
2137                char fname[strlen(mod->name) + 10];
2138
2139                if (mod->skip)
2140                        continue;
2141
2142                buf.pos = 0;
2143
2144                add_header(&buf, mod);
2145                add_staging_flag(&buf, mod->name);
2146                err |= add_versions(&buf, mod);
2147                add_depends(&buf, mod, modules);
2148                add_moddevtable(&buf, mod);
2149                add_srcversion(&buf, mod);
2150
2151                sprintf(fname, "%s.mod.c", mod->name);
2152                write_if_changed(&buf, fname);
2153        }
2154
2155        if (dump_write)
2156                write_dump(dump_write);
2157        if (sec_mismatch_count && !sec_mismatch_verbose)
2158                warn("modpost: Found %d section mismatch(es).\n"
2159                     "To see full details build your kernel with:\n"
2160                     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2161                     sec_mismatch_count);
2162
2163        return err;
2164}
2165