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                        mod->is_dot_o = 1;
 138                }
 139
 140        /* add to list */
 141        mod->name = p;
 142        mod->gpl_compatible = -1;
 143        mod->next = modules;
 144        modules = mod;
 145
 146        return mod;
 147}
 148
 149/* A hash of all exported symbols,
 150 * struct symbol is also used for lists of unresolved symbols */
 151
 152#define SYMBOL_HASH_SIZE 1024
 153
 154struct symbol {
 155        struct symbol *next;
 156        struct module *module;
 157        unsigned int crc;
 158        int crc_valid;
 159        unsigned int weak:1;
 160        unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
 161        unsigned int kernel:1;     /* 1 if symbol is from kernel
 162                                    *  (only for external modules) **/
 163        unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
 164        enum export  export;       /* Type of export */
 165        char name[0];
 166};
 167
 168static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 169
 170/* This is based on the hash agorithm from gdbm, via tdb */
 171static inline unsigned int tdb_hash(const char *name)
 172{
 173        unsigned value; /* Used to compute the hash value.  */
 174        unsigned   i;   /* Used to cycle through random values. */
 175
 176        /* Set the initial value from the key size. */
 177        for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 178                value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 179
 180        return (1103515243 * value + 12345);
 181}
 182
 183/**
 184 * Allocate a new symbols for use in the hash of exported symbols or
 185 * the list of unresolved symbols per module
 186 **/
 187static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 188                                   struct symbol *next)
 189{
 190        struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 191
 192        memset(s, 0, sizeof(*s));
 193        strcpy(s->name, name);
 194        s->weak = weak;
 195        s->next = next;
 196        return s;
 197}
 198
 199/* For the hash of exported symbols */
 200static struct symbol *new_symbol(const char *name, struct module *module,
 201                                 enum export export)
 202{
 203        unsigned int hash;
 204        struct symbol *new;
 205
 206        hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 207        new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 208        new->module = module;
 209        new->export = export;
 210        return new;
 211}
 212
 213static struct symbol *find_symbol(const char *name)
 214{
 215        struct symbol *s;
 216
 217        /* For our purposes, .foo matches foo.  PPC64 needs this. */
 218        if (name[0] == '.')
 219                name++;
 220
 221        for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 222                if (strcmp(s->name, name) == 0)
 223                        return s;
 224        }
 225        return NULL;
 226}
 227
 228static struct {
 229        const char *str;
 230        enum export export;
 231} export_list[] = {
 232        { .str = "EXPORT_SYMBOL",            .export = export_plain },
 233        { .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
 234        { .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
 235        { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
 236        { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
 237        { .str = "(unknown)",                .export = export_unknown },
 238};
 239
 240
 241static const char *export_str(enum export ex)
 242{
 243        return export_list[ex].str;
 244}
 245
 246static enum export export_no(const char *s)
 247{
 248        int i;
 249
 250        if (!s)
 251                return export_unknown;
 252        for (i = 0; export_list[i].export != export_unknown; i++) {
 253                if (strcmp(export_list[i].str, s) == 0)
 254                        return export_list[i].export;
 255        }
 256        return export_unknown;
 257}
 258
 259static const char *sec_name(struct elf_info *elf, int secindex);
 260
 261#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 262
 263static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
 264{
 265        const char *secname = sec_name(elf, sec);
 266
 267        if (strstarts(secname, "___ksymtab+"))
 268                return export_plain;
 269        else if (strstarts(secname, "___ksymtab_unused+"))
 270                return export_unused;
 271        else if (strstarts(secname, "___ksymtab_gpl+"))
 272                return export_gpl;
 273        else if (strstarts(secname, "___ksymtab_unused_gpl+"))
 274                return export_unused_gpl;
 275        else if (strstarts(secname, "___ksymtab_gpl_future+"))
 276                return export_gpl_future;
 277        else
 278                return export_unknown;
 279}
 280
 281static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
 282{
 283        if (sec == elf->export_sec)
 284                return export_plain;
 285        else if (sec == elf->export_unused_sec)
 286                return export_unused;
 287        else if (sec == elf->export_gpl_sec)
 288                return export_gpl;
 289        else if (sec == elf->export_unused_gpl_sec)
 290                return export_unused_gpl;
 291        else if (sec == elf->export_gpl_future_sec)
 292                return export_gpl_future;
 293        else
 294                return export_unknown;
 295}
 296
 297/**
 298 * Add an exported symbol - it may have already been added without a
 299 * CRC, in this case just update the CRC
 300 **/
 301static struct symbol *sym_add_exported(const char *name, struct module *mod,
 302                                       enum export export)
 303{
 304        struct symbol *s = find_symbol(name);
 305
 306        if (!s) {
 307                s = new_symbol(name, mod, export);
 308        } else {
 309                if (!s->preloaded) {
 310                        warn("%s: '%s' exported twice. Previous export "
 311                             "was in %s%s\n", mod->name, name,
 312                             s->module->name,
 313                             is_vmlinux(s->module->name) ?"":".ko");
 314                } else {
 315                        /* In case Modules.symvers was out of date */
 316                        s->module = mod;
 317                }
 318        }
 319        s->preloaded = 0;
 320        s->vmlinux   = is_vmlinux(mod->name);
 321        s->kernel    = 0;
 322        s->export    = export;
 323        return s;
 324}
 325
 326static void sym_update_crc(const char *name, struct module *mod,
 327                           unsigned int crc, enum export export)
 328{
 329        struct symbol *s = find_symbol(name);
 330
 331        if (!s)
 332                s = new_symbol(name, mod, export);
 333        s->crc = crc;
 334        s->crc_valid = 1;
 335}
 336
 337void *grab_file(const char *filename, unsigned long *size)
 338{
 339        struct stat st;
 340        void *map;
 341        int fd;
 342
 343        fd = open(filename, O_RDONLY);
 344        if (fd < 0 || fstat(fd, &st) != 0)
 345                return NULL;
 346
 347        *size = st.st_size;
 348        map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 349        close(fd);
 350
 351        if (map == MAP_FAILED)
 352                return NULL;
 353        return map;
 354}
 355
 356/**
 357  * Return a copy of the next line in a mmap'ed file.
 358  * spaces in the beginning of the line is trimmed away.
 359  * Return a pointer to a static buffer.
 360  **/
 361char *get_next_line(unsigned long *pos, void *file, unsigned long size)
 362{
 363        static char line[4096];
 364        int skip = 1;
 365        size_t len = 0;
 366        signed char *p = (signed char *)file + *pos;
 367        char *s = line;
 368
 369        for (; *pos < size ; (*pos)++) {
 370                if (skip && isspace(*p)) {
 371                        p++;
 372                        continue;
 373                }
 374                skip = 0;
 375                if (*p != '\n' && (*pos < size)) {
 376                        len++;
 377                        *s++ = *p++;
 378                        if (len > 4095)
 379                                break; /* Too long, stop */
 380                } else {
 381                        /* End of string */
 382                        *s = '\0';
 383                        return line;
 384                }
 385        }
 386        /* End of buffer */
 387        return NULL;
 388}
 389
 390void release_file(void *file, unsigned long size)
 391{
 392        munmap(file, size);
 393}
 394
 395static int parse_elf(struct elf_info *info, const char *filename)
 396{
 397        unsigned int i;
 398        Elf_Ehdr *hdr;
 399        Elf_Shdr *sechdrs;
 400        Elf_Sym  *sym;
 401        const char *secstrings;
 402        unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 403
 404        hdr = grab_file(filename, &info->size);
 405        if (!hdr) {
 406                perror(filename);
 407                exit(1);
 408        }
 409        info->hdr = hdr;
 410        if (info->size < sizeof(*hdr)) {
 411                /* file too small, assume this is an empty .o file */
 412                return 0;
 413        }
 414        /* Is this a valid ELF file? */
 415        if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 416            (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 417            (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 418            (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 419                /* Not an ELF file - silently ignore it */
 420                return 0;
 421        }
 422        /* Fix endianness in ELF header */
 423        hdr->e_type      = TO_NATIVE(hdr->e_type);
 424        hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 425        hdr->e_version   = TO_NATIVE(hdr->e_version);
 426        hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 427        hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 428        hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 429        hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 430        hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 431        hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 432        hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 433        hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 434        hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 435        hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 436        sechdrs = (void *)hdr + hdr->e_shoff;
 437        info->sechdrs = sechdrs;
 438
 439        /* Check if file offset is correct */
 440        if (hdr->e_shoff > info->size) {
 441                fatal("section header offset=%lu in file '%s' is bigger than "
 442                      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
 443                      filename, info->size);
 444                return 0;
 445        }
 446
 447        if (hdr->e_shnum == SHN_UNDEF) {
 448                /*
 449                 * There are more than 64k sections,
 450                 * read count from .sh_size.
 451                 */
 452                info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 453        }
 454        else {
 455                info->num_sections = hdr->e_shnum;
 456        }
 457        if (hdr->e_shstrndx == SHN_XINDEX) {
 458                info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 459        }
 460        else {
 461                info->secindex_strings = hdr->e_shstrndx;
 462        }
 463
 464        /* Fix endianness in section headers */
 465        for (i = 0; i < info->num_sections; i++) {
 466                sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 467                sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 468                sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 469                sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 470                sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 471                sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 472                sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 473                sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 474                sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 475                sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 476        }
 477        /* Find symbol table. */
 478        secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 479        for (i = 1; i < info->num_sections; i++) {
 480                const char *secname;
 481                int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 482
 483                if (!nobits && sechdrs[i].sh_offset > info->size) {
 484                        fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
 485                              "sizeof(*hrd)=%zu\n", filename,
 486                              (unsigned long)sechdrs[i].sh_offset,
 487                              sizeof(*hdr));
 488                        return 0;
 489                }
 490                secname = secstrings + sechdrs[i].sh_name;
 491                if (strcmp(secname, ".modinfo") == 0) {
 492                        if (nobits)
 493                                fatal("%s has NOBITS .modinfo\n", filename);
 494                        info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 495                        info->modinfo_len = sechdrs[i].sh_size;
 496                } else if (strcmp(secname, "__ksymtab") == 0)
 497                        info->export_sec = i;
 498                else if (strcmp(secname, "__ksymtab_unused") == 0)
 499                        info->export_unused_sec = i;
 500                else if (strcmp(secname, "__ksymtab_gpl") == 0)
 501                        info->export_gpl_sec = i;
 502                else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
 503                        info->export_unused_gpl_sec = i;
 504                else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 505                        info->export_gpl_future_sec = i;
 506
 507                if (sechdrs[i].sh_type == SHT_SYMTAB) {
 508                        unsigned int sh_link_idx;
 509                        symtab_idx = i;
 510                        info->symtab_start = (void *)hdr +
 511                            sechdrs[i].sh_offset;
 512                        info->symtab_stop  = (void *)hdr +
 513                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 514                        sh_link_idx = sechdrs[i].sh_link;
 515                        info->strtab       = (void *)hdr +
 516                            sechdrs[sh_link_idx].sh_offset;
 517                }
 518
 519                /* 32bit section no. table? ("more than 64k sections") */
 520                if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 521                        symtab_shndx_idx = i;
 522                        info->symtab_shndx_start = (void *)hdr +
 523                            sechdrs[i].sh_offset;
 524                        info->symtab_shndx_stop  = (void *)hdr +
 525                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 526                }
 527        }
 528        if (!info->symtab_start)
 529                fatal("%s has no symtab?\n", filename);
 530
 531        /* Fix endianness in symbols */
 532        for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 533                sym->st_shndx = TO_NATIVE(sym->st_shndx);
 534                sym->st_name  = TO_NATIVE(sym->st_name);
 535                sym->st_value = TO_NATIVE(sym->st_value);
 536                sym->st_size  = TO_NATIVE(sym->st_size);
 537        }
 538
 539        if (symtab_shndx_idx != ~0U) {
 540                Elf32_Word *p;
 541                if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 542                        fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 543                              filename, sechdrs[symtab_shndx_idx].sh_link,
 544                              symtab_idx);
 545                /* Fix endianness */
 546                for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 547                     p++)
 548                        *p = TO_NATIVE(*p);
 549        }
 550
 551        return 1;
 552}
 553
 554static void parse_elf_finish(struct elf_info *info)
 555{
 556        release_file(info->hdr, info->size);
 557}
 558
 559static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 560{
 561        /* ignore __this_module, it will be resolved shortly */
 562        if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 563                return 1;
 564        /* ignore global offset table */
 565        if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 566                return 1;
 567        if (info->hdr->e_machine == EM_PPC)
 568                /* Special register function linked on all modules during final link of .ko */
 569                if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
 570                    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
 571                    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
 572                    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
 573                        return 1;
 574        if (info->hdr->e_machine == EM_PPC64)
 575                /* Special register function linked on all modules during final link of .ko */
 576                if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
 577                    strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
 578                        return 1;
 579        /* Do not ignore this symbol */
 580        return 0;
 581}
 582
 583#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
 584#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 585
 586static void handle_modversions(struct module *mod, struct elf_info *info,
 587                               Elf_Sym *sym, const char *symname)
 588{
 589        unsigned int crc;
 590        enum export export;
 591
 592        if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
 593            strncmp(symname, "__ksymtab", 9) == 0)
 594                export = export_from_secname(info, get_secindex(info, sym));
 595        else
 596                export = export_from_sec(info, get_secindex(info, sym));
 597
 598        switch (sym->st_shndx) {
 599        case SHN_COMMON:
 600                warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 601                break;
 602        case SHN_ABS:
 603                /* CRC'd symbol */
 604                if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 605                        crc = (unsigned int) sym->st_value;
 606                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 607                                        export);
 608                }
 609                break;
 610        case SHN_UNDEF:
 611                /* undefined symbol */
 612                if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 613                    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 614                        break;
 615                if (ignore_undef_symbol(info, symname))
 616                        break;
 617/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 618#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 619/* add compatibility with older glibc */
 620#ifndef STT_SPARC_REGISTER
 621#define STT_SPARC_REGISTER STT_REGISTER
 622#endif
 623                if (info->hdr->e_machine == EM_SPARC ||
 624                    info->hdr->e_machine == EM_SPARCV9) {
 625                        /* Ignore register directives. */
 626                        if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 627                                break;
 628                        if (symname[0] == '.') {
 629                                char *munged = strdup(symname);
 630                                munged[0] = '_';
 631                                munged[1] = toupper(munged[1]);
 632                                symname = munged;
 633                        }
 634                }
 635#endif
 636
 637                if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 638                           strlen(MODULE_SYMBOL_PREFIX)) == 0) {
 639                        mod->unres =
 640                          alloc_symbol(symname +
 641                                       strlen(MODULE_SYMBOL_PREFIX),
 642                                       ELF_ST_BIND(sym->st_info) == STB_WEAK,
 643                                       mod->unres);
 644                }
 645                break;
 646        default:
 647                /* All exported symbols */
 648                if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 649                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 650                                        export);
 651                }
 652                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 653                        mod->has_init = 1;
 654                if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 655                        mod->has_cleanup = 1;
 656                break;
 657        }
 658}
 659
 660/**
 661 * Parse tag=value strings from .modinfo section
 662 **/
 663static char *next_string(char *string, unsigned long *secsize)
 664{
 665        /* Skip non-zero chars */
 666        while (string[0]) {
 667                string++;
 668                if ((*secsize)-- <= 1)
 669                        return NULL;
 670        }
 671
 672        /* Skip any zero padding. */
 673        while (!string[0]) {
 674                string++;
 675                if ((*secsize)-- <= 1)
 676                        return NULL;
 677        }
 678        return string;
 679}
 680
 681static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
 682                              const char *tag, char *info)
 683{
 684        char *p;
 685        unsigned int taglen = strlen(tag);
 686        unsigned long size = modinfo_len;
 687
 688        if (info) {
 689                size -= info - (char *)modinfo;
 690                modinfo = next_string(info, &size);
 691        }
 692
 693        for (p = modinfo; p; p = next_string(p, &size)) {
 694                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 695                        return p + taglen + 1;
 696        }
 697        return NULL;
 698}
 699
 700static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 701                         const char *tag)
 702
 703{
 704        return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
 705}
 706
 707/**
 708 * Test if string s ends in string sub
 709 * return 0 if match
 710 **/
 711static int strrcmp(const char *s, const char *sub)
 712{
 713        int slen, sublen;
 714
 715        if (!s || !sub)
 716                return 1;
 717
 718        slen = strlen(s);
 719        sublen = strlen(sub);
 720
 721        if ((slen == 0) || (sublen == 0))
 722                return 1;
 723
 724        if (sublen > slen)
 725                return 1;
 726
 727        return memcmp(s + slen - sublen, sub, sublen);
 728}
 729
 730static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 731{
 732        if (sym)
 733                return elf->strtab + sym->st_name;
 734        else
 735                return "(unknown)";
 736}
 737
 738static const char *sec_name(struct elf_info *elf, int secindex)
 739{
 740        Elf_Shdr *sechdrs = elf->sechdrs;
 741        return (void *)elf->hdr +
 742                elf->sechdrs[elf->secindex_strings].sh_offset +
 743                sechdrs[secindex].sh_name;
 744}
 745
 746static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
 747{
 748        return (void *)elf->hdr +
 749                elf->sechdrs[elf->secindex_strings].sh_offset +
 750                sechdr->sh_name;
 751}
 752
 753/* if sym is empty or point to a string
 754 * like ".[0-9]+" then return 1.
 755 * This is the optional prefix added by ld to some sections
 756 */
 757static int number_prefix(const char *sym)
 758{
 759        if (*sym++ == '\0')
 760                return 1;
 761        if (*sym != '.')
 762                return 0;
 763        do {
 764                char c = *sym++;
 765                if (c < '0' || c > '9')
 766                        return 0;
 767        } while (*sym);
 768        return 1;
 769}
 770
 771/* The pattern is an array of simple patterns.
 772 * "foo" will match an exact string equal to "foo"
 773 * "*foo" will match a string that ends with "foo"
 774 * "foo*" will match a string that begins with "foo"
 775 * "foo$" will match a string equal to "foo" or "foo.1"
 776 *   where the '1' can be any number including several digits.
 777 *   The $ syntax is for sections where ld append a dot number
 778 *   to make section name unique.
 779 */
 780static int match(const char *sym, const char * const pat[])
 781{
 782        const char *p;
 783        while (*pat) {
 784                p = *pat++;
 785                const char *endp = p + strlen(p) - 1;
 786
 787                /* "*foo" */
 788                if (*p == '*') {
 789                        if (strrcmp(sym, p + 1) == 0)
 790                                return 1;
 791                }
 792                /* "foo*" */
 793                else if (*endp == '*') {
 794                        if (strncmp(sym, p, strlen(p) - 1) == 0)
 795                                return 1;
 796                }
 797                /* "foo$" */
 798                else if (*endp == '$') {
 799                        if (strncmp(sym, p, strlen(p) - 1) == 0) {
 800                                if (number_prefix(sym + strlen(p) - 1))
 801                                        return 1;
 802                        }
 803                }
 804                /* no wildcards */
 805                else {
 806                        if (strcmp(p, sym) == 0)
 807                                return 1;
 808                }
 809        }
 810        /* no match */
 811        return 0;
 812}
 813
 814/* sections that we do not want to do full section mismatch check on */
 815static const char *section_white_list[] =
 816{
 817        ".comment*",
 818        ".debug*",
 819        ".zdebug*",             /* Compressed debug sections. */
 820        ".GCC-command-line",    /* mn10300 */
 821        ".mdebug*",        /* alpha, score, mips etc. */
 822        ".pdr",            /* alpha, score, mips etc. */
 823        ".stab*",
 824        ".note*",
 825        ".got*",
 826        ".toc*",
 827        NULL
 828};
 829
 830/*
 831 * This is used to find sections missing the SHF_ALLOC flag.
 832 * The cause of this is often a section specified in assembler
 833 * without "ax" / "aw".
 834 */
 835static void check_section(const char *modname, struct elf_info *elf,
 836                          Elf_Shdr *sechdr)
 837{
 838        const char *sec = sech_name(elf, sechdr);
 839
 840        if (sechdr->sh_type == SHT_PROGBITS &&
 841            !(sechdr->sh_flags & SHF_ALLOC) &&
 842            !match(sec, section_white_list)) {
 843                warn("%s (%s): unexpected non-allocatable section.\n"
 844                     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 845                     "Note that for example <linux/init.h> contains\n"
 846                     "section definitions for use in .S files.\n\n",
 847                     modname, sec);
 848        }
 849}
 850
 851
 852
 853#define ALL_INIT_DATA_SECTIONS \
 854        ".init.setup$", ".init.rodata$", \
 855        ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \
 856        ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
 857#define ALL_EXIT_DATA_SECTIONS \
 858        ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
 859
 860#define ALL_INIT_TEXT_SECTIONS \
 861        ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
 862#define ALL_EXIT_TEXT_SECTIONS \
 863        ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
 864
 865#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
 866        MEM_INIT_SECTIONS
 867#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
 868        MEM_EXIT_SECTIONS
 869
 870#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 871#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 872
 873#define DATA_SECTIONS ".data$", ".data.rel$"
 874#define TEXT_SECTIONS ".text$"
 875
 876#define INIT_SECTIONS      ".init.*"
 877#define DEV_INIT_SECTIONS  ".devinit.*"
 878#define CPU_INIT_SECTIONS  ".cpuinit.*"
 879#define MEM_INIT_SECTIONS  ".meminit.*"
 880
 881#define EXIT_SECTIONS      ".exit.*"
 882#define DEV_EXIT_SECTIONS  ".devexit.*"
 883#define CPU_EXIT_SECTIONS  ".cpuexit.*"
 884#define MEM_EXIT_SECTIONS  ".memexit.*"
 885
 886/* init data sections */
 887static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 888
 889/* all init sections */
 890static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 891
 892/* All init and exit sections (code + data) */
 893static const char *init_exit_sections[] =
 894        {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 895
 896/* data section */
 897static const char *data_sections[] = { DATA_SECTIONS, NULL };
 898
 899
 900/* symbols in .data that may refer to init/exit sections */
 901#define DEFAULT_SYMBOL_WHITE_LIST                                       \
 902        "*driver",                                                      \
 903        "*_template", /* scsi uses *_template a lot */                  \
 904        "*_timer",    /* arm uses ops structures named _timer a lot */  \
 905        "*_sht",      /* scsi also used *_sht to some extent */         \
 906        "*_ops",                                                        \
 907        "*_probe",                                                      \
 908        "*_probe_one",                                                  \
 909        "*_console"
 910
 911static const char *head_sections[] = { ".head.text*", NULL };
 912static const char *linker_symbols[] =
 913        { "__init_begin", "_sinittext", "_einittext", NULL };
 914
 915enum mismatch {
 916        TEXT_TO_ANY_INIT,
 917        DATA_TO_ANY_INIT,
 918        TEXT_TO_ANY_EXIT,
 919        DATA_TO_ANY_EXIT,
 920        XXXINIT_TO_SOME_INIT,
 921        XXXEXIT_TO_SOME_EXIT,
 922        ANY_INIT_TO_ANY_EXIT,
 923        ANY_EXIT_TO_ANY_INIT,
 924        EXPORT_TO_INIT_EXIT,
 925};
 926
 927struct sectioncheck {
 928        const char *fromsec[20];
 929        const char *tosec[20];
 930        enum mismatch mismatch;
 931        const char *symbol_white_list[20];
 932};
 933
 934const struct sectioncheck sectioncheck[] = {
 935/* Do not reference init/exit code/data from
 936 * normal code and data
 937 */
 938{
 939        .fromsec = { TEXT_SECTIONS, NULL },
 940        .tosec   = { ALL_INIT_SECTIONS, NULL },
 941        .mismatch = TEXT_TO_ANY_INIT,
 942        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 943},
 944{
 945        .fromsec = { DATA_SECTIONS, NULL },
 946        .tosec   = { ALL_XXXINIT_SECTIONS, NULL },
 947        .mismatch = DATA_TO_ANY_INIT,
 948        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 949},
 950{
 951        .fromsec = { DATA_SECTIONS, NULL },
 952        .tosec   = { INIT_SECTIONS, NULL },
 953        .mismatch = DATA_TO_ANY_INIT,
 954        .symbol_white_list = {
 955                "*_template", "*_timer", "*_sht", "*_ops",
 956                "*_probe", "*_probe_one", "*_console", NULL
 957        },
 958},
 959{
 960        .fromsec = { TEXT_SECTIONS, NULL },
 961        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 962        .mismatch = TEXT_TO_ANY_EXIT,
 963        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 964},
 965{
 966        .fromsec = { DATA_SECTIONS, NULL },
 967        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 968        .mismatch = DATA_TO_ANY_EXIT,
 969        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 970},
 971/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
 972{
 973        .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 974        .tosec   = { INIT_SECTIONS, NULL },
 975        .mismatch = XXXINIT_TO_SOME_INIT,
 976        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 977},
 978/* Do not reference cpuinit code/data from meminit code/data */
 979{
 980        .fromsec = { MEM_INIT_SECTIONS, NULL },
 981        .tosec   = { CPU_INIT_SECTIONS, NULL },
 982        .mismatch = XXXINIT_TO_SOME_INIT,
 983        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 984},
 985/* Do not reference meminit code/data from cpuinit code/data */
 986{
 987        .fromsec = { CPU_INIT_SECTIONS, NULL },
 988        .tosec   = { MEM_INIT_SECTIONS, NULL },
 989        .mismatch = XXXINIT_TO_SOME_INIT,
 990        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 991},
 992/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
 993{
 994        .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
 995        .tosec   = { EXIT_SECTIONS, NULL },
 996        .mismatch = XXXEXIT_TO_SOME_EXIT,
 997        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 998},
 999/* Do not reference cpuexit code/data from memexit code/data */
1000{
1001        .fromsec = { MEM_EXIT_SECTIONS, NULL },
1002        .tosec   = { CPU_EXIT_SECTIONS, NULL },
1003        .mismatch = XXXEXIT_TO_SOME_EXIT,
1004        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1005},
1006/* Do not reference memexit code/data from cpuexit code/data */
1007{
1008        .fromsec = { CPU_EXIT_SECTIONS, NULL },
1009        .tosec   = { MEM_EXIT_SECTIONS, NULL },
1010        .mismatch = XXXEXIT_TO_SOME_EXIT,
1011        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1012},
1013/* Do not use exit code/data from init code */
1014{
1015        .fromsec = { ALL_INIT_SECTIONS, NULL },
1016        .tosec   = { ALL_EXIT_SECTIONS, NULL },
1017        .mismatch = ANY_INIT_TO_ANY_EXIT,
1018        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1019},
1020/* Do not use init code/data from exit code */
1021{
1022        .fromsec = { ALL_EXIT_SECTIONS, NULL },
1023        .tosec   = { ALL_INIT_SECTIONS, NULL },
1024        .mismatch = ANY_EXIT_TO_ANY_INIT,
1025        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1026},
1027/* Do not export init/exit functions or data */
1028{
1029        .fromsec = { "__ksymtab*", NULL },
1030        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1031        .mismatch = EXPORT_TO_INIT_EXIT,
1032        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1033}
1034};
1035
1036static const struct sectioncheck *section_mismatch(
1037                const char *fromsec, const char *tosec)
1038{
1039        int i;
1040        int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1041        const struct sectioncheck *check = &sectioncheck[0];
1042
1043        for (i = 0; i < elems; i++) {
1044                if (match(fromsec, check->fromsec) &&
1045                    match(tosec, check->tosec))
1046                        return check;
1047                check++;
1048        }
1049        return NULL;
1050}
1051
1052/**
1053 * Whitelist to allow certain references to pass with no warning.
1054 *
1055 * Pattern 1:
1056 *   If a module parameter is declared __initdata and permissions=0
1057 *   then this is legal despite the warning generated.
1058 *   We cannot see value of permissions here, so just ignore
1059 *   this pattern.
1060 *   The pattern is identified by:
1061 *   tosec   = .init.data
1062 *   fromsec = .data*
1063 *   atsym   =__param*
1064 *
1065 * Pattern 1a:
1066 *   module_param_call() ops can refer to __init set function if permissions=0
1067 *   The pattern is identified by:
1068 *   tosec   = .init.text
1069 *   fromsec = .data*
1070 *   atsym   = __param_ops_*
1071 *
1072 * Pattern 2:
1073 *   Many drivers utilise a *driver container with references to
1074 *   add, remove, probe functions etc.
1075 *   These functions may often be marked __devinit and we do not want to
1076 *   warn here.
1077 *   the pattern is identified by:
1078 *   tosec   = init or exit section
1079 *   fromsec = data section
1080 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1081 *           *probe_one, *_console, *_timer
1082 *
1083 * Pattern 3:
1084 *   Whitelist all references from .head.text to any init section
1085 *
1086 * Pattern 4:
1087 *   Some symbols belong to init section but still it is ok to reference
1088 *   these from non-init sections as these symbols don't have any memory
1089 *   allocated for them and symbol address and value are same. So even
1090 *   if init section is freed, its ok to reference those symbols.
1091 *   For ex. symbols marking the init section boundaries.
1092 *   This pattern is identified by
1093 *   refsymname = __init_begin, _sinittext, _einittext
1094 *
1095 **/
1096static int secref_whitelist(const struct sectioncheck *mismatch,
1097                            const char *fromsec, const char *fromsym,
1098                            const char *tosec, const char *tosym)
1099{
1100        /* Check for pattern 1 */
1101        if (match(tosec, init_data_sections) &&
1102            match(fromsec, data_sections) &&
1103            (strncmp(fromsym, "__param", strlen("__param")) == 0))
1104                return 0;
1105
1106        /* Check for pattern 1a */
1107        if (strcmp(tosec, ".init.text") == 0 &&
1108            match(fromsec, data_sections) &&
1109            (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1110                return 0;
1111
1112        /* Check for pattern 2 */
1113        if (match(tosec, init_exit_sections) &&
1114            match(fromsec, data_sections) &&
1115            match(fromsym, mismatch->symbol_white_list))
1116                return 0;
1117
1118        /* Check for pattern 3 */
1119        if (match(fromsec, head_sections) &&
1120            match(tosec, init_sections))
1121                return 0;
1122
1123        /* Check for pattern 4 */
1124        if (match(tosym, linker_symbols))
1125                return 0;
1126
1127        return 1;
1128}
1129
1130/**
1131 * Find symbol based on relocation record info.
1132 * In some cases the symbol supplied is a valid symbol so
1133 * return refsym. If st_name != 0 we assume this is a valid symbol.
1134 * In other cases the symbol needs to be looked up in the symbol table
1135 * based on section and address.
1136 *  **/
1137static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1138                                Elf_Sym *relsym)
1139{
1140        Elf_Sym *sym;
1141        Elf_Sym *near = NULL;
1142        Elf64_Sword distance = 20;
1143        Elf64_Sword d;
1144        unsigned int relsym_secindex;
1145
1146        if (relsym->st_name != 0)
1147                return relsym;
1148
1149        relsym_secindex = get_secindex(elf, relsym);
1150        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1151                if (get_secindex(elf, sym) != relsym_secindex)
1152                        continue;
1153                if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1154                        continue;
1155                if (sym->st_value == addr)
1156                        return sym;
1157                /* Find a symbol nearby - addr are maybe negative */
1158                d = sym->st_value - addr;
1159                if (d < 0)
1160                        d = addr - sym->st_value;
1161                if (d < distance) {
1162                        distance = d;
1163                        near = sym;
1164                }
1165        }
1166        /* We need a close match */
1167        if (distance < 20)
1168                return near;
1169        else
1170                return NULL;
1171}
1172
1173static inline int is_arm_mapping_symbol(const char *str)
1174{
1175        return str[0] == '$' && strchr("atd", str[1])
1176               && (str[2] == '\0' || str[2] == '.');
1177}
1178
1179/*
1180 * If there's no name there, ignore it; likewise, ignore it if it's
1181 * one of the magic symbols emitted used by current ARM tools.
1182 *
1183 * Otherwise if find_symbols_between() returns those symbols, they'll
1184 * fail the whitelist tests and cause lots of false alarms ... fixable
1185 * only by merging __exit and __init sections into __text, bloating
1186 * the kernel (which is especially evil on embedded platforms).
1187 */
1188static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1189{
1190        const char *name = elf->strtab + sym->st_name;
1191
1192        if (!name || !strlen(name))
1193                return 0;
1194        return !is_arm_mapping_symbol(name);
1195}
1196
1197/*
1198 * Find symbols before or equal addr and after addr - in the section sec.
1199 * If we find two symbols with equal offset prefer one with a valid name.
1200 * The ELF format may have a better way to detect what type of symbol
1201 * it is, but this works for now.
1202 **/
1203static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1204                                 const char *sec)
1205{
1206        Elf_Sym *sym;
1207        Elf_Sym *near = NULL;
1208        Elf_Addr distance = ~0;
1209
1210        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1211                const char *symsec;
1212
1213                if (is_shndx_special(sym->st_shndx))
1214                        continue;
1215                symsec = sec_name(elf, get_secindex(elf, sym));
1216                if (strcmp(symsec, sec) != 0)
1217                        continue;
1218                if (!is_valid_name(elf, sym))
1219                        continue;
1220                if (sym->st_value <= addr) {
1221                        if ((addr - sym->st_value) < distance) {
1222                                distance = addr - sym->st_value;
1223                                near = sym;
1224                        } else if ((addr - sym->st_value) == distance) {
1225                                near = sym;
1226                        }
1227                }
1228        }
1229        return near;
1230}
1231
1232/*
1233 * Convert a section name to the function/data attribute
1234 * .init.text => __init
1235 * .cpuinit.data => __cpudata
1236 * .memexitconst => __memconst
1237 * etc.
1238 *
1239 * The memory of returned value has been allocated on a heap. The user of this
1240 * method should free it after usage.
1241*/
1242static char *sec2annotation(const char *s)
1243{
1244        if (match(s, init_exit_sections)) {
1245                char *p = malloc(20);
1246                char *r = p;
1247
1248                *p++ = '_';
1249                *p++ = '_';
1250                if (*s == '.')
1251                        s++;
1252                while (*s && *s != '.')
1253                        *p++ = *s++;
1254                *p = '\0';
1255                if (*s == '.')
1256                        s++;
1257                if (strstr(s, "rodata") != NULL)
1258                        strcat(p, "const ");
1259                else if (strstr(s, "data") != NULL)
1260                        strcat(p, "data ");
1261                else
1262                        strcat(p, " ");
1263                return r;
1264        } else {
1265                return strdup("");
1266        }
1267}
1268
1269static int is_function(Elf_Sym *sym)
1270{
1271        if (sym)
1272                return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1273        else
1274                return -1;
1275}
1276
1277static void print_section_list(const char * const list[20])
1278{
1279        const char *const *s = list;
1280
1281        while (*s) {
1282                fprintf(stderr, "%s", *s);
1283                s++;
1284                if (*s)
1285                        fprintf(stderr, ", ");
1286        }
1287        fprintf(stderr, "\n");
1288}
1289
1290/*
1291 * Print a warning about a section mismatch.
1292 * Try to find symbols near it so user can find it.
1293 * Check whitelist before warning - it may be a false positive.
1294 */
1295static void report_sec_mismatch(const char *modname,
1296                                const struct sectioncheck *mismatch,
1297                                const char *fromsec,
1298                                unsigned long long fromaddr,
1299                                const char *fromsym,
1300                                int from_is_func,
1301                                const char *tosec, const char *tosym,
1302                                int to_is_func)
1303{
1304        const char *from, *from_p;
1305        const char *to, *to_p;
1306        char *prl_from;
1307        char *prl_to;
1308
1309        switch (from_is_func) {
1310        case 0: from = "variable"; from_p = "";   break;
1311        case 1: from = "function"; from_p = "()"; break;
1312        default: from = "(unknown reference)"; from_p = ""; break;
1313        }
1314        switch (to_is_func) {
1315        case 0: to = "variable"; to_p = "";   break;
1316        case 1: to = "function"; to_p = "()"; break;
1317        default: to = "(unknown reference)"; to_p = ""; break;
1318        }
1319
1320        sec_mismatch_count++;
1321        if (!sec_mismatch_verbose)
1322                return;
1323
1324        warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1325             "to the %s %s:%s%s\n",
1326             modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1327             tosym, to_p);
1328
1329        switch (mismatch->mismatch) {
1330        case TEXT_TO_ANY_INIT:
1331                prl_from = sec2annotation(fromsec);
1332                prl_to = sec2annotation(tosec);
1333                fprintf(stderr,
1334                "The function %s%s() references\n"
1335                "the %s %s%s%s.\n"
1336                "This is often because %s lacks a %s\n"
1337                "annotation or the annotation of %s is wrong.\n",
1338                prl_from, fromsym,
1339                to, prl_to, tosym, to_p,
1340                fromsym, prl_to, tosym);
1341                free(prl_from);
1342                free(prl_to);
1343                break;
1344        case DATA_TO_ANY_INIT: {
1345                prl_to = sec2annotation(tosec);
1346                fprintf(stderr,
1347                "The variable %s references\n"
1348                "the %s %s%s%s\n"
1349                "If the reference is valid then annotate the\n"
1350                "variable with __init* or __refdata (see linux/init.h) "
1351                "or name the variable:\n",
1352                fromsym, to, prl_to, tosym, to_p);
1353                print_section_list(mismatch->symbol_white_list);
1354                free(prl_to);
1355                break;
1356        }
1357        case TEXT_TO_ANY_EXIT:
1358                prl_to = sec2annotation(tosec);
1359                fprintf(stderr,
1360                "The function %s() references a %s in an exit section.\n"
1361                "Often the %s %s%s has valid usage outside the exit section\n"
1362                "and the fix is to remove the %sannotation of %s.\n",
1363                fromsym, to, to, tosym, to_p, prl_to, tosym);
1364                free(prl_to);
1365                break;
1366        case DATA_TO_ANY_EXIT: {
1367                prl_to = sec2annotation(tosec);
1368                fprintf(stderr,
1369                "The variable %s references\n"
1370                "the %s %s%s%s\n"
1371                "If the reference is valid then annotate the\n"
1372                "variable with __exit* (see linux/init.h) or "
1373                "name the variable:\n",
1374                fromsym, to, prl_to, tosym, to_p);
1375                print_section_list(mismatch->symbol_white_list);
1376                free(prl_to);
1377                break;
1378        }
1379        case XXXINIT_TO_SOME_INIT:
1380        case XXXEXIT_TO_SOME_EXIT:
1381                prl_from = sec2annotation(fromsec);
1382                prl_to = sec2annotation(tosec);
1383                fprintf(stderr,
1384                "The %s %s%s%s references\n"
1385                "a %s %s%s%s.\n"
1386                "If %s is only used by %s then\n"
1387                "annotate %s with a matching annotation.\n",
1388                from, prl_from, fromsym, from_p,
1389                to, prl_to, tosym, to_p,
1390                tosym, fromsym, tosym);
1391                free(prl_from);
1392                free(prl_to);
1393                break;
1394        case ANY_INIT_TO_ANY_EXIT:
1395                prl_from = sec2annotation(fromsec);
1396                prl_to = sec2annotation(tosec);
1397                fprintf(stderr,
1398                "The %s %s%s%s references\n"
1399                "a %s %s%s%s.\n"
1400                "This is often seen when error handling "
1401                "in the init function\n"
1402                "uses functionality in the exit path.\n"
1403                "The fix is often to remove the %sannotation of\n"
1404                "%s%s so it may be used outside an exit section.\n",
1405                from, prl_from, fromsym, from_p,
1406                to, prl_to, tosym, to_p,
1407                prl_to, tosym, to_p);
1408                free(prl_from);
1409                free(prl_to);
1410                break;
1411        case ANY_EXIT_TO_ANY_INIT:
1412                prl_from = sec2annotation(fromsec);
1413                prl_to = sec2annotation(tosec);
1414                fprintf(stderr,
1415                "The %s %s%s%s references\n"
1416                "a %s %s%s%s.\n"
1417                "This is often seen when error handling "
1418                "in the exit function\n"
1419                "uses functionality in the init path.\n"
1420                "The fix is often to remove the %sannotation of\n"
1421                "%s%s so it may be used outside an init section.\n",
1422                from, prl_from, fromsym, from_p,
1423                to, prl_to, tosym, to_p,
1424                prl_to, tosym, to_p);
1425                free(prl_from);
1426                free(prl_to);
1427                break;
1428        case EXPORT_TO_INIT_EXIT:
1429                prl_to = sec2annotation(tosec);
1430                fprintf(stderr,
1431                "The symbol %s is exported and annotated %s\n"
1432                "Fix this by removing the %sannotation of %s "
1433                "or drop the export.\n",
1434                tosym, prl_to, prl_to, tosym);
1435                free(prl_to);
1436                break;
1437        }
1438        fprintf(stderr, "\n");
1439}
1440
1441static void check_section_mismatch(const char *modname, struct elf_info *elf,
1442                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1443{
1444        const char *tosec;
1445        const struct sectioncheck *mismatch;
1446
1447        tosec = sec_name(elf, get_secindex(elf, sym));
1448        mismatch = section_mismatch(fromsec, tosec);
1449        if (mismatch) {
1450                Elf_Sym *to;
1451                Elf_Sym *from;
1452                const char *tosym;
1453                const char *fromsym;
1454
1455                from = find_elf_symbol2(elf, r->r_offset, fromsec);
1456                fromsym = sym_name(elf, from);
1457                to = find_elf_symbol(elf, r->r_addend, sym);
1458                tosym = sym_name(elf, to);
1459
1460                /* check whitelist - we may ignore it */
1461                if (secref_whitelist(mismatch,
1462                                        fromsec, fromsym, tosec, tosym)) {
1463                        report_sec_mismatch(modname, mismatch,
1464                           fromsec, r->r_offset, fromsym,
1465                           is_function(from), tosec, tosym,
1466                           is_function(to));
1467                }
1468        }
1469}
1470
1471static unsigned int *reloc_location(struct elf_info *elf,
1472                                    Elf_Shdr *sechdr, Elf_Rela *r)
1473{
1474        Elf_Shdr *sechdrs = elf->sechdrs;
1475        int section = sechdr->sh_info;
1476
1477        return (void *)elf->hdr + sechdrs[section].sh_offset +
1478                r->r_offset;
1479}
1480
1481static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1482{
1483        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1484        unsigned int *location = reloc_location(elf, sechdr, r);
1485
1486        switch (r_typ) {
1487        case R_386_32:
1488                r->r_addend = TO_NATIVE(*location);
1489                break;
1490        case R_386_PC32:
1491                r->r_addend = TO_NATIVE(*location) + 4;
1492                /* For CONFIG_RELOCATABLE=y */
1493                if (elf->hdr->e_type == ET_EXEC)
1494                        r->r_addend += r->r_offset;
1495                break;
1496        }
1497        return 0;
1498}
1499
1500#ifndef R_ARM_CALL
1501#define R_ARM_CALL      28
1502#endif
1503#ifndef R_ARM_JUMP24
1504#define R_ARM_JUMP24    29
1505#endif
1506
1507static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1508{
1509        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1510
1511        switch (r_typ) {
1512        case R_ARM_ABS32:
1513                /* From ARM ABI: (S + A) | T */
1514                r->r_addend = (int)(long)
1515                              (elf->symtab_start + ELF_R_SYM(r->r_info));
1516                break;
1517        case R_ARM_PC24:
1518        case R_ARM_CALL:
1519        case R_ARM_JUMP24:
1520                /* From ARM ABI: ((S + A) | T) - P */
1521                r->r_addend = (int)(long)(elf->hdr +
1522                              sechdr->sh_offset +
1523                              (r->r_offset - sechdr->sh_addr));
1524                break;
1525        default:
1526                return 1;
1527        }
1528        return 0;
1529}
1530
1531static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1532{
1533        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1534        unsigned int *location = reloc_location(elf, sechdr, r);
1535        unsigned int inst;
1536
1537        if (r_typ == R_MIPS_HI16)
1538                return 1;       /* skip this */
1539        inst = TO_NATIVE(*location);
1540        switch (r_typ) {
1541        case R_MIPS_LO16:
1542                r->r_addend = inst & 0xffff;
1543                break;
1544        case R_MIPS_26:
1545                r->r_addend = (inst & 0x03ffffff) << 2;
1546                break;
1547        case R_MIPS_32:
1548                r->r_addend = inst;
1549                break;
1550        }
1551        return 0;
1552}
1553
1554static void section_rela(const char *modname, struct elf_info *elf,
1555                         Elf_Shdr *sechdr)
1556{
1557        Elf_Sym  *sym;
1558        Elf_Rela *rela;
1559        Elf_Rela r;
1560        unsigned int r_sym;
1561        const char *fromsec;
1562
1563        Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1564        Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1565
1566        fromsec = sech_name(elf, sechdr);
1567        fromsec += strlen(".rela");
1568        /* if from section (name) is know good then skip it */
1569        if (match(fromsec, section_white_list))
1570                return;
1571
1572        for (rela = start; rela < stop; rela++) {
1573                r.r_offset = TO_NATIVE(rela->r_offset);
1574#if KERNEL_ELFCLASS == ELFCLASS64
1575                if (elf->hdr->e_machine == EM_MIPS) {
1576                        unsigned int r_typ;
1577                        r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1578                        r_sym = TO_NATIVE(r_sym);
1579                        r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1580                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1581                } else {
1582                        r.r_info = TO_NATIVE(rela->r_info);
1583                        r_sym = ELF_R_SYM(r.r_info);
1584                }
1585#else
1586                r.r_info = TO_NATIVE(rela->r_info);
1587                r_sym = ELF_R_SYM(r.r_info);
1588#endif
1589                r.r_addend = TO_NATIVE(rela->r_addend);
1590                sym = elf->symtab_start + r_sym;
1591                /* Skip special sections */
1592                if (is_shndx_special(sym->st_shndx))
1593                        continue;
1594                check_section_mismatch(modname, elf, &r, sym, fromsec);
1595        }
1596}
1597
1598static void section_rel(const char *modname, struct elf_info *elf,
1599                        Elf_Shdr *sechdr)
1600{
1601        Elf_Sym *sym;
1602        Elf_Rel *rel;
1603        Elf_Rela r;
1604        unsigned int r_sym;
1605        const char *fromsec;
1606
1607        Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1608        Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1609
1610        fromsec = sech_name(elf, sechdr);
1611        fromsec += strlen(".rel");
1612        /* if from section (name) is know good then skip it */
1613        if (match(fromsec, section_white_list))
1614                return;
1615
1616        for (rel = start; rel < stop; rel++) {
1617                r.r_offset = TO_NATIVE(rel->r_offset);
1618#if KERNEL_ELFCLASS == ELFCLASS64
1619                if (elf->hdr->e_machine == EM_MIPS) {
1620                        unsigned int r_typ;
1621                        r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1622                        r_sym = TO_NATIVE(r_sym);
1623                        r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1624                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1625                } else {
1626                        r.r_info = TO_NATIVE(rel->r_info);
1627                        r_sym = ELF_R_SYM(r.r_info);
1628                }
1629#else
1630                r.r_info = TO_NATIVE(rel->r_info);
1631                r_sym = ELF_R_SYM(r.r_info);
1632#endif
1633                r.r_addend = 0;
1634                switch (elf->hdr->e_machine) {
1635                case EM_386:
1636                        if (addend_386_rel(elf, sechdr, &r))
1637                                continue;
1638                        break;
1639                case EM_ARM:
1640                        if (addend_arm_rel(elf, sechdr, &r))
1641                                continue;
1642                        break;
1643                case EM_MIPS:
1644                        if (addend_mips_rel(elf, sechdr, &r))
1645                                continue;
1646                        break;
1647                }
1648                sym = elf->symtab_start + r_sym;
1649                /* Skip special sections */
1650                if (is_shndx_special(sym->st_shndx))
1651                        continue;
1652                check_section_mismatch(modname, elf, &r, sym, fromsec);
1653        }
1654}
1655
1656/**
1657 * A module includes a number of sections that are discarded
1658 * either when loaded or when used as built-in.
1659 * For loaded modules all functions marked __init and all data
1660 * marked __initdata will be discarded when the module has been initialized.
1661 * Likewise for modules used built-in the sections marked __exit
1662 * are discarded because __exit marked function are supposed to be called
1663 * only when a module is unloaded which never happens for built-in modules.
1664 * The check_sec_ref() function traverses all relocation records
1665 * to find all references to a section that reference a section that will
1666 * be discarded and warns about it.
1667 **/
1668static void check_sec_ref(struct module *mod, const char *modname,
1669                          struct elf_info *elf)
1670{
1671        int i;
1672        Elf_Shdr *sechdrs = elf->sechdrs;
1673
1674        /* Walk through all sections */
1675        for (i = 0; i < elf->num_sections; i++) {
1676                check_section(modname, elf, &elf->sechdrs[i]);
1677                /* We want to process only relocation sections and not .init */
1678                if (sechdrs[i].sh_type == SHT_RELA)
1679                        section_rela(modname, elf, &elf->sechdrs[i]);
1680                else if (sechdrs[i].sh_type == SHT_REL)
1681                        section_rel(modname, elf, &elf->sechdrs[i]);
1682        }
1683}
1684
1685static void read_symbols(char *modname)
1686{
1687        const char *symname;
1688        char *version;
1689        char *license;
1690        struct module *mod;
1691        struct elf_info info = { };
1692        Elf_Sym *sym;
1693
1694        if (!parse_elf(&info, modname))
1695                return;
1696
1697        mod = new_module(modname);
1698
1699        /* When there's no vmlinux, don't print warnings about
1700         * unresolved symbols (since there'll be too many ;) */
1701        if (is_vmlinux(modname)) {
1702                have_vmlinux = 1;
1703                mod->skip = 1;
1704        }
1705
1706        license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1707        if (info.modinfo && !license && !is_vmlinux(modname))
1708                warn("modpost: missing MODULE_LICENSE() in %s\n"
1709                     "see include/linux/module.h for "
1710                     "more information\n", modname);
1711        while (license) {
1712                if (license_is_gpl_compatible(license))
1713                        mod->gpl_compatible = 1;
1714                else {
1715                        mod->gpl_compatible = 0;
1716                        break;
1717                }
1718                license = get_next_modinfo(info.modinfo, info.modinfo_len,
1719                                           "license", license);
1720        }
1721
1722        for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1723                symname = info.strtab + sym->st_name;
1724
1725                handle_modversions(mod, &info, sym, symname);
1726                handle_moddevtable(mod, &info, sym, symname);
1727        }
1728        if (!is_vmlinux(modname) ||
1729             (is_vmlinux(modname) && vmlinux_section_warnings))
1730                check_sec_ref(mod, modname, &info);
1731
1732        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1733        if (version)
1734                maybe_frob_rcs_version(modname, version, info.modinfo,
1735                                       version - (char *)info.hdr);
1736        if (version || (all_versions && !is_vmlinux(modname)))
1737                get_src_version(modname, mod->srcversion,
1738                                sizeof(mod->srcversion)-1);
1739
1740        parse_elf_finish(&info);
1741
1742        /* Our trick to get versioning for module struct etc. - it's
1743         * never passed as an argument to an exported function, so
1744         * the automatic versioning doesn't pick it up, but it's really
1745         * important anyhow */
1746        if (modversions)
1747                mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1748}
1749
1750#define SZ 500
1751
1752/* We first write the generated file into memory using the
1753 * following helper, then compare to the file on disk and
1754 * only update the later if anything changed */
1755
1756void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1757                                                      const char *fmt, ...)
1758{
1759        char tmp[SZ];
1760        int len;
1761        va_list ap;
1762
1763        va_start(ap, fmt);
1764        len = vsnprintf(tmp, SZ, fmt, ap);
1765        buf_write(buf, tmp, len);
1766        va_end(ap);
1767}
1768
1769void buf_write(struct buffer *buf, const char *s, int len)
1770{
1771        if (buf->size - buf->pos < len) {
1772                buf->size += len + SZ;
1773                buf->p = realloc(buf->p, buf->size);
1774        }
1775        strncpy(buf->p + buf->pos, s, len);
1776        buf->pos += len;
1777}
1778
1779static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1780{
1781        const char *e = is_vmlinux(m) ?"":".ko";
1782
1783        switch (exp) {
1784        case export_gpl:
1785                fatal("modpost: GPL-incompatible module %s%s "
1786                      "uses GPL-only symbol '%s'\n", m, e, s);
1787                break;
1788        case export_unused_gpl:
1789                fatal("modpost: GPL-incompatible module %s%s "
1790                      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1791                break;
1792        case export_gpl_future:
1793                warn("modpost: GPL-incompatible module %s%s "
1794                      "uses future GPL-only symbol '%s'\n", m, e, s);
1795                break;
1796        case export_plain:
1797        case export_unused:
1798        case export_unknown:
1799                /* ignore */
1800                break;
1801        }
1802}
1803
1804static void check_for_unused(enum export exp, const char *m, const char *s)
1805{
1806        const char *e = is_vmlinux(m) ?"":".ko";
1807
1808        switch (exp) {
1809        case export_unused:
1810        case export_unused_gpl:
1811                warn("modpost: module %s%s "
1812                      "uses symbol '%s' marked UNUSED\n", m, e, s);
1813                break;
1814        default:
1815                /* ignore */
1816                break;
1817        }
1818}
1819
1820static void check_exports(struct module *mod)
1821{
1822        struct symbol *s, *exp;
1823
1824        for (s = mod->unres; s; s = s->next) {
1825                const char *basename;
1826                exp = find_symbol(s->name);
1827                if (!exp || exp->module == mod)
1828                        continue;
1829                basename = strrchr(mod->name, '/');
1830                if (basename)
1831                        basename++;
1832                else
1833                        basename = mod->name;
1834                if (!mod->gpl_compatible)
1835                        check_for_gpl_usage(exp->export, basename, exp->name);
1836                check_for_unused(exp->export, basename, exp->name);
1837        }
1838}
1839
1840/**
1841 * Header for the generated file
1842 **/
1843static void add_header(struct buffer *b, struct module *mod)
1844{
1845        buf_printf(b, "#include <linux/module.h>\n");
1846        buf_printf(b, "#include <linux/vermagic.h>\n");
1847        buf_printf(b, "#include <linux/compiler.h>\n");
1848        buf_printf(b, "\n");
1849        buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1850        buf_printf(b, "\n");
1851        buf_printf(b, "struct module __this_module\n");
1852        buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1853        buf_printf(b, " .name = KBUILD_MODNAME,\n");
1854        if (mod->has_init)
1855                buf_printf(b, " .init = init_module,\n");
1856        if (mod->has_cleanup)
1857                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1858                              " .exit = cleanup_module,\n"
1859                              "#endif\n");
1860        buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1861        buf_printf(b, "};\n");
1862}
1863
1864static void add_intree_flag(struct buffer *b, int is_intree)
1865{
1866        if (is_intree)
1867                buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1868}
1869
1870static void add_staging_flag(struct buffer *b, const char *name)
1871{
1872        static const char *staging_dir = "drivers/staging";
1873
1874        if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1875                buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1876}
1877
1878/**
1879 * Record CRCs for unresolved symbols
1880 **/
1881static int add_versions(struct buffer *b, struct module *mod)
1882{
1883        struct symbol *s, *exp;
1884        int err = 0;
1885
1886        for (s = mod->unres; s; s = s->next) {
1887                exp = find_symbol(s->name);
1888                if (!exp || exp->module == mod) {
1889                        if (have_vmlinux && !s->weak) {
1890                                if (warn_unresolved) {
1891                                        warn("\"%s\" [%s.ko] undefined!\n",
1892                                             s->name, mod->name);
1893                                } else {
1894                                        merror("\"%s\" [%s.ko] undefined!\n",
1895                                                  s->name, mod->name);
1896                                        err = 1;
1897                                }
1898                        }
1899                        continue;
1900                }
1901                s->module = exp->module;
1902                s->crc_valid = exp->crc_valid;
1903                s->crc = exp->crc;
1904        }
1905
1906        if (!modversions)
1907                return err;
1908
1909        buf_printf(b, "\n");
1910        buf_printf(b, "static const struct modversion_info ____versions[]\n");
1911        buf_printf(b, "__used\n");
1912        buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1913
1914        for (s = mod->unres; s; s = s->next) {
1915                if (!s->module)
1916                        continue;
1917                if (!s->crc_valid) {
1918                        warn("\"%s\" [%s.ko] has no CRC!\n",
1919                                s->name, mod->name);
1920                        continue;
1921                }
1922                buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1923        }
1924
1925        buf_printf(b, "};\n");
1926
1927        return err;
1928}
1929
1930static void add_depends(struct buffer *b, struct module *mod,
1931                        struct module *modules)
1932{
1933        struct symbol *s;
1934        struct module *m;
1935        int first = 1;
1936
1937        for (m = modules; m; m = m->next)
1938                m->seen = is_vmlinux(m->name);
1939
1940        buf_printf(b, "\n");
1941        buf_printf(b, "static const char __module_depends[]\n");
1942        buf_printf(b, "__used\n");
1943        buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1944        buf_printf(b, "\"depends=");
1945        for (s = mod->unres; s; s = s->next) {
1946                const char *p;
1947                if (!s->module)
1948                        continue;
1949
1950                if (s->module->seen)
1951                        continue;
1952
1953                s->module->seen = 1;
1954                p = strrchr(s->module->name, '/');
1955                if (p)
1956                        p++;
1957                else
1958                        p = s->module->name;
1959                buf_printf(b, "%s%s", first ? "" : ",", p);
1960                first = 0;
1961        }
1962        buf_printf(b, "\";\n");
1963}
1964
1965static void add_srcversion(struct buffer *b, struct module *mod)
1966{
1967        if (mod->srcversion[0]) {
1968                buf_printf(b, "\n");
1969                buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1970                           mod->srcversion);
1971        }
1972}
1973
1974static void write_if_changed(struct buffer *b, const char *fname)
1975{
1976        char *tmp;
1977        FILE *file;
1978        struct stat st;
1979
1980        file = fopen(fname, "r");
1981        if (!file)
1982                goto write;
1983
1984        if (fstat(fileno(file), &st) < 0)
1985                goto close_write;
1986
1987        if (st.st_size != b->pos)
1988                goto close_write;
1989
1990        tmp = NOFAIL(malloc(b->pos));
1991        if (fread(tmp, 1, b->pos, file) != b->pos)
1992                goto free_write;
1993
1994        if (memcmp(tmp, b->p, b->pos) != 0)
1995                goto free_write;
1996
1997        free(tmp);
1998        fclose(file);
1999        return;
2000
2001 free_write:
2002        free(tmp);
2003 close_write:
2004        fclose(file);
2005 write:
2006        file = fopen(fname, "w");
2007        if (!file) {
2008                perror(fname);
2009                exit(1);
2010        }
2011        if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2012                perror(fname);
2013                exit(1);
2014        }
2015        fclose(file);
2016}
2017
2018/* parse Module.symvers file. line format:
2019 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2020 **/
2021static void read_dump(const char *fname, unsigned int kernel)
2022{
2023        unsigned long size, pos = 0;
2024        void *file = grab_file(fname, &size);
2025        char *line;
2026
2027        if (!file)
2028                /* No symbol versions, silently ignore */
2029                return;
2030
2031        while ((line = get_next_line(&pos, file, size))) {
2032                char *symname, *modname, *d, *export, *end;
2033                unsigned int crc;
2034                struct module *mod;
2035                struct symbol *s;
2036
2037                if (!(symname = strchr(line, '\t')))
2038                        goto fail;
2039                *symname++ = '\0';
2040                if (!(modname = strchr(symname, '\t')))
2041                        goto fail;
2042                *modname++ = '\0';
2043                if ((export = strchr(modname, '\t')) != NULL)
2044                        *export++ = '\0';
2045                if (export && ((end = strchr(export, '\t')) != NULL))
2046                        *end = '\0';
2047                crc = strtoul(line, &d, 16);
2048                if (*symname == '\0' || *modname == '\0' || *d != '\0')
2049                        goto fail;
2050                mod = find_module(modname);
2051                if (!mod) {
2052                        if (is_vmlinux(modname))
2053                                have_vmlinux = 1;
2054                        mod = new_module(modname);
2055                        mod->skip = 1;
2056                }
2057                s = sym_add_exported(symname, mod, export_no(export));
2058                s->kernel    = kernel;
2059                s->preloaded = 1;
2060                sym_update_crc(symname, mod, crc, export_no(export));
2061        }
2062        return;
2063fail:
2064        fatal("parse error in symbol dump file\n");
2065}
2066
2067/* For normal builds always dump all symbols.
2068 * For external modules only dump symbols
2069 * that are not read from kernel Module.symvers.
2070 **/
2071static int dump_sym(struct symbol *sym)
2072{
2073        if (!external_module)
2074                return 1;
2075        if (sym->vmlinux || sym->kernel)
2076                return 0;
2077        return 1;
2078}
2079
2080static void write_dump(const char *fname)
2081{
2082        struct buffer buf = { };
2083        struct symbol *symbol;
2084        int n;
2085
2086        for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2087                symbol = symbolhash[n];
2088                while (symbol) {
2089                        if (dump_sym(symbol))
2090                                buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2091                                        symbol->crc, symbol->name,
2092                                        symbol->module->name,
2093                                        export_str(symbol->export));
2094                        symbol = symbol->next;
2095                }
2096        }
2097        write_if_changed(&buf, fname);
2098}
2099
2100struct ext_sym_list {
2101        struct ext_sym_list *next;
2102        const char *file;
2103};
2104
2105int main(int argc, char **argv)
2106{
2107        struct module *mod;
2108        struct buffer buf = { };
2109        char *kernel_read = NULL, *module_read = NULL;
2110        char *dump_write = NULL;
2111        int opt;
2112        int err;
2113        struct ext_sym_list *extsym_iter;
2114        struct ext_sym_list *extsym_start = NULL;
2115
2116        while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2117                switch (opt) {
2118                case 'i':
2119                        kernel_read = optarg;
2120                        break;
2121                case 'I':
2122                        module_read = optarg;
2123                        external_module = 1;
2124                        break;
2125                case 'c':
2126                        cross_build = 1;
2127                        break;
2128                case 'e':
2129                        external_module = 1;
2130                        extsym_iter =
2131                           NOFAIL(malloc(sizeof(*extsym_iter)));
2132                        extsym_iter->next = extsym_start;
2133                        extsym_iter->file = optarg;
2134                        extsym_start = extsym_iter;
2135                        break;
2136                case 'm':
2137                        modversions = 1;
2138                        break;
2139                case 'o':
2140                        dump_write = optarg;
2141                        break;
2142                case 'a':
2143                        all_versions = 1;
2144                        break;
2145                case 's':
2146                        vmlinux_section_warnings = 0;
2147                        break;
2148                case 'S':
2149                        sec_mismatch_verbose = 0;
2150                        break;
2151                case 'w':
2152                        warn_unresolved = 1;
2153                        break;
2154                default:
2155                        exit(1);
2156                }
2157        }
2158
2159        if (kernel_read)
2160                read_dump(kernel_read, 1);
2161        if (module_read)
2162                read_dump(module_read, 0);
2163        while (extsym_start) {
2164                read_dump(extsym_start->file, 0);
2165                extsym_iter = extsym_start->next;
2166                free(extsym_start);
2167                extsym_start = extsym_iter;
2168        }
2169
2170        while (optind < argc)
2171                read_symbols(argv[optind++]);
2172
2173        for (mod = modules; mod; mod = mod->next) {
2174                if (mod->skip)
2175                        continue;
2176                check_exports(mod);
2177        }
2178
2179        err = 0;
2180
2181        for (mod = modules; mod; mod = mod->next) {
2182                char fname[strlen(mod->name) + 10];
2183
2184                if (mod->skip)
2185                        continue;
2186
2187                buf.pos = 0;
2188
2189                add_header(&buf, mod);
2190                add_intree_flag(&buf, !external_module);
2191                add_staging_flag(&buf, mod->name);
2192                err |= add_versions(&buf, mod);
2193                add_depends(&buf, mod, modules);
2194                add_moddevtable(&buf, mod);
2195                add_srcversion(&buf, mod);
2196
2197                sprintf(fname, "%s.mod.c", mod->name);
2198                write_if_changed(&buf, fname);
2199        }
2200
2201        if (dump_write)
2202                write_dump(dump_write);
2203        if (sec_mismatch_count && !sec_mismatch_verbose)
2204                warn("modpost: Found %d section mismatch(es).\n"
2205                     "To see full details build your kernel with:\n"
2206                     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2207                     sec_mismatch_count);
2208
2209        return err;
2210}
2211