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 = MAP_FAILED;
 341        int fd;
 342
 343        fd = open(filename, O_RDONLY);
 344        if (fd < 0)
 345                return NULL;
 346        if (fstat(fd, &st))
 347                goto failed;
 348
 349        *size = st.st_size;
 350        map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 351
 352failed:
 353        close(fd);
 354        if (map == MAP_FAILED)
 355                return NULL;
 356        return map;
 357}
 358
 359/**
 360  * Return a copy of the next line in a mmap'ed file.
 361  * spaces in the beginning of the line is trimmed away.
 362  * Return a pointer to a static buffer.
 363  **/
 364char *get_next_line(unsigned long *pos, void *file, unsigned long size)
 365{
 366        static char line[4096];
 367        int skip = 1;
 368        size_t len = 0;
 369        signed char *p = (signed char *)file + *pos;
 370        char *s = line;
 371
 372        for (; *pos < size ; (*pos)++) {
 373                if (skip && isspace(*p)) {
 374                        p++;
 375                        continue;
 376                }
 377                skip = 0;
 378                if (*p != '\n' && (*pos < size)) {
 379                        len++;
 380                        *s++ = *p++;
 381                        if (len > 4095)
 382                                break; /* Too long, stop */
 383                } else {
 384                        /* End of string */
 385                        *s = '\0';
 386                        return line;
 387                }
 388        }
 389        /* End of buffer */
 390        return NULL;
 391}
 392
 393void release_file(void *file, unsigned long size)
 394{
 395        munmap(file, size);
 396}
 397
 398static int parse_elf(struct elf_info *info, const char *filename)
 399{
 400        unsigned int i;
 401        Elf_Ehdr *hdr;
 402        Elf_Shdr *sechdrs;
 403        Elf_Sym  *sym;
 404        const char *secstrings;
 405        unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 406
 407        hdr = grab_file(filename, &info->size);
 408        if (!hdr) {
 409                perror(filename);
 410                exit(1);
 411        }
 412        info->hdr = hdr;
 413        if (info->size < sizeof(*hdr)) {
 414                /* file too small, assume this is an empty .o file */
 415                return 0;
 416        }
 417        /* Is this a valid ELF file? */
 418        if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 419            (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 420            (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 421            (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 422                /* Not an ELF file - silently ignore it */
 423                return 0;
 424        }
 425        /* Fix endianness in ELF header */
 426        hdr->e_type      = TO_NATIVE(hdr->e_type);
 427        hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 428        hdr->e_version   = TO_NATIVE(hdr->e_version);
 429        hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 430        hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 431        hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 432        hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 433        hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 434        hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 435        hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 436        hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 437        hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 438        hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 439        sechdrs = (void *)hdr + hdr->e_shoff;
 440        info->sechdrs = sechdrs;
 441
 442        /* Check if file offset is correct */
 443        if (hdr->e_shoff > info->size) {
 444                fatal("section header offset=%lu in file '%s' is bigger than "
 445                      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
 446                      filename, info->size);
 447                return 0;
 448        }
 449
 450        if (hdr->e_shnum == SHN_UNDEF) {
 451                /*
 452                 * There are more than 64k sections,
 453                 * read count from .sh_size.
 454                 */
 455                info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 456        }
 457        else {
 458                info->num_sections = hdr->e_shnum;
 459        }
 460        if (hdr->e_shstrndx == SHN_XINDEX) {
 461                info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 462        }
 463        else {
 464                info->secindex_strings = hdr->e_shstrndx;
 465        }
 466
 467        /* Fix endianness in section headers */
 468        for (i = 0; i < info->num_sections; i++) {
 469                sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 470                sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 471                sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 472                sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 473                sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 474                sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 475                sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 476                sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 477                sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 478                sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 479        }
 480        /* Find symbol table. */
 481        secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 482        for (i = 1; i < info->num_sections; i++) {
 483                const char *secname;
 484                int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 485
 486                if (!nobits && sechdrs[i].sh_offset > info->size) {
 487                        fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
 488                              "sizeof(*hrd)=%zu\n", filename,
 489                              (unsigned long)sechdrs[i].sh_offset,
 490                              sizeof(*hdr));
 491                        return 0;
 492                }
 493                secname = secstrings + sechdrs[i].sh_name;
 494                if (strcmp(secname, ".modinfo") == 0) {
 495                        if (nobits)
 496                                fatal("%s has NOBITS .modinfo\n", filename);
 497                        info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 498                        info->modinfo_len = sechdrs[i].sh_size;
 499                } else if (strcmp(secname, "__ksymtab") == 0)
 500                        info->export_sec = i;
 501                else if (strcmp(secname, "__ksymtab_unused") == 0)
 502                        info->export_unused_sec = i;
 503                else if (strcmp(secname, "__ksymtab_gpl") == 0)
 504                        info->export_gpl_sec = i;
 505                else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
 506                        info->export_unused_gpl_sec = i;
 507                else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 508                        info->export_gpl_future_sec = i;
 509
 510                if (sechdrs[i].sh_type == SHT_SYMTAB) {
 511                        unsigned int sh_link_idx;
 512                        symtab_idx = i;
 513                        info->symtab_start = (void *)hdr +
 514                            sechdrs[i].sh_offset;
 515                        info->symtab_stop  = (void *)hdr +
 516                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 517                        sh_link_idx = sechdrs[i].sh_link;
 518                        info->strtab       = (void *)hdr +
 519                            sechdrs[sh_link_idx].sh_offset;
 520                }
 521
 522                /* 32bit section no. table? ("more than 64k sections") */
 523                if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 524                        symtab_shndx_idx = i;
 525                        info->symtab_shndx_start = (void *)hdr +
 526                            sechdrs[i].sh_offset;
 527                        info->symtab_shndx_stop  = (void *)hdr +
 528                            sechdrs[i].sh_offset + sechdrs[i].sh_size;
 529                }
 530        }
 531        if (!info->symtab_start)
 532                fatal("%s has no symtab?\n", filename);
 533
 534        /* Fix endianness in symbols */
 535        for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 536                sym->st_shndx = TO_NATIVE(sym->st_shndx);
 537                sym->st_name  = TO_NATIVE(sym->st_name);
 538                sym->st_value = TO_NATIVE(sym->st_value);
 539                sym->st_size  = TO_NATIVE(sym->st_size);
 540        }
 541
 542        if (symtab_shndx_idx != ~0U) {
 543                Elf32_Word *p;
 544                if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 545                        fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 546                              filename, sechdrs[symtab_shndx_idx].sh_link,
 547                              symtab_idx);
 548                /* Fix endianness */
 549                for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 550                     p++)
 551                        *p = TO_NATIVE(*p);
 552        }
 553
 554        return 1;
 555}
 556
 557static void parse_elf_finish(struct elf_info *info)
 558{
 559        release_file(info->hdr, info->size);
 560}
 561
 562static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 563{
 564        /* ignore __this_module, it will be resolved shortly */
 565        if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 566                return 1;
 567        /* ignore global offset table */
 568        if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 569                return 1;
 570        if (info->hdr->e_machine == EM_PPC)
 571                /* Special register function linked on all modules during final link of .ko */
 572                if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
 573                    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
 574                    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
 575                    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
 576                        return 1;
 577        if (info->hdr->e_machine == EM_PPC64)
 578                /* Special register function linked on all modules during final link of .ko */
 579                if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
 580                    strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
 581                        return 1;
 582        /* Do not ignore this symbol */
 583        return 0;
 584}
 585
 586#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
 587#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 588
 589static void handle_modversions(struct module *mod, struct elf_info *info,
 590                               Elf_Sym *sym, const char *symname)
 591{
 592        unsigned int crc;
 593        enum export export;
 594
 595        if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
 596            strncmp(symname, "__ksymtab", 9) == 0)
 597                export = export_from_secname(info, get_secindex(info, sym));
 598        else
 599                export = export_from_sec(info, get_secindex(info, sym));
 600
 601        switch (sym->st_shndx) {
 602        case SHN_COMMON:
 603                warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 604                break;
 605        case SHN_ABS:
 606                /* CRC'd symbol */
 607                if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 608                        crc = (unsigned int) sym->st_value;
 609                        sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 610                                        export);
 611                }
 612                break;
 613        case SHN_UNDEF:
 614                /* undefined symbol */
 615                if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 616                    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 617                        break;
 618                if (ignore_undef_symbol(info, symname))
 619                        break;
 620/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 621#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 622/* add compatibility with older glibc */
 623#ifndef STT_SPARC_REGISTER
 624#define STT_SPARC_REGISTER STT_REGISTER
 625#endif
 626                if (info->hdr->e_machine == EM_SPARC ||
 627                    info->hdr->e_machine == EM_SPARCV9) {
 628                        /* Ignore register directives. */
 629                        if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 630                                break;
 631                        if (symname[0] == '.') {
 632                                char *munged = strdup(symname);
 633                                munged[0] = '_';
 634                                munged[1] = toupper(munged[1]);
 635                                symname = munged;
 636                        }
 637                }
 638#endif
 639
 640                if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 641                           strlen(MODULE_SYMBOL_PREFIX)) == 0) {
 642                        mod->unres =
 643                          alloc_symbol(symname +
 644                                       strlen(MODULE_SYMBOL_PREFIX),
 645                                       ELF_ST_BIND(sym->st_info) == STB_WEAK,
 646                                       mod->unres);
 647                }
 648                break;
 649        default:
 650                /* All exported symbols */
 651                if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 652                        sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 653                                        export);
 654                }
 655                if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 656                        mod->has_init = 1;
 657                if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
 658                        mod->has_cleanup = 1;
 659                break;
 660        }
 661}
 662
 663/**
 664 * Parse tag=value strings from .modinfo section
 665 **/
 666static char *next_string(char *string, unsigned long *secsize)
 667{
 668        /* Skip non-zero chars */
 669        while (string[0]) {
 670                string++;
 671                if ((*secsize)-- <= 1)
 672                        return NULL;
 673        }
 674
 675        /* Skip any zero padding. */
 676        while (!string[0]) {
 677                string++;
 678                if ((*secsize)-- <= 1)
 679                        return NULL;
 680        }
 681        return string;
 682}
 683
 684static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
 685                              const char *tag, char *info)
 686{
 687        char *p;
 688        unsigned int taglen = strlen(tag);
 689        unsigned long size = modinfo_len;
 690
 691        if (info) {
 692                size -= info - (char *)modinfo;
 693                modinfo = next_string(info, &size);
 694        }
 695
 696        for (p = modinfo; p; p = next_string(p, &size)) {
 697                if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 698                        return p + taglen + 1;
 699        }
 700        return NULL;
 701}
 702
 703static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 704                         const char *tag)
 705
 706{
 707        return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
 708}
 709
 710/**
 711 * Test if string s ends in string sub
 712 * return 0 if match
 713 **/
 714static int strrcmp(const char *s, const char *sub)
 715{
 716        int slen, sublen;
 717
 718        if (!s || !sub)
 719                return 1;
 720
 721        slen = strlen(s);
 722        sublen = strlen(sub);
 723
 724        if ((slen == 0) || (sublen == 0))
 725                return 1;
 726
 727        if (sublen > slen)
 728                return 1;
 729
 730        return memcmp(s + slen - sublen, sub, sublen);
 731}
 732
 733static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 734{
 735        if (sym)
 736                return elf->strtab + sym->st_name;
 737        else
 738                return "(unknown)";
 739}
 740
 741static const char *sec_name(struct elf_info *elf, int secindex)
 742{
 743        Elf_Shdr *sechdrs = elf->sechdrs;
 744        return (void *)elf->hdr +
 745                elf->sechdrs[elf->secindex_strings].sh_offset +
 746                sechdrs[secindex].sh_name;
 747}
 748
 749static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
 750{
 751        return (void *)elf->hdr +
 752                elf->sechdrs[elf->secindex_strings].sh_offset +
 753                sechdr->sh_name;
 754}
 755
 756/* if sym is empty or point to a string
 757 * like ".[0-9]+" then return 1.
 758 * This is the optional prefix added by ld to some sections
 759 */
 760static int number_prefix(const char *sym)
 761{
 762        if (*sym++ == '\0')
 763                return 1;
 764        if (*sym != '.')
 765                return 0;
 766        do {
 767                char c = *sym++;
 768                if (c < '0' || c > '9')
 769                        return 0;
 770        } while (*sym);
 771        return 1;
 772}
 773
 774/* The pattern is an array of simple patterns.
 775 * "foo" will match an exact string equal to "foo"
 776 * "*foo" will match a string that ends with "foo"
 777 * "foo*" will match a string that begins with "foo"
 778 * "foo$" will match a string equal to "foo" or "foo.1"
 779 *   where the '1' can be any number including several digits.
 780 *   The $ syntax is for sections where ld append a dot number
 781 *   to make section name unique.
 782 */
 783static int match(const char *sym, const char * const pat[])
 784{
 785        const char *p;
 786        while (*pat) {
 787                p = *pat++;
 788                const char *endp = p + strlen(p) - 1;
 789
 790                /* "*foo" */
 791                if (*p == '*') {
 792                        if (strrcmp(sym, p + 1) == 0)
 793                                return 1;
 794                }
 795                /* "foo*" */
 796                else if (*endp == '*') {
 797                        if (strncmp(sym, p, strlen(p) - 1) == 0)
 798                                return 1;
 799                }
 800                /* "foo$" */
 801                else if (*endp == '$') {
 802                        if (strncmp(sym, p, strlen(p) - 1) == 0) {
 803                                if (number_prefix(sym + strlen(p) - 1))
 804                                        return 1;
 805                        }
 806                }
 807                /* no wildcards */
 808                else {
 809                        if (strcmp(p, sym) == 0)
 810                                return 1;
 811                }
 812        }
 813        /* no match */
 814        return 0;
 815}
 816
 817/* sections that we do not want to do full section mismatch check on */
 818static const char *section_white_list[] =
 819{
 820        ".comment*",
 821        ".debug*",
 822        ".zdebug*",             /* Compressed debug sections. */
 823        ".GCC-command-line",    /* mn10300 */
 824        ".GCC.command.line",    /* record-gcc-switches, non mn10300 */
 825        ".mdebug*",        /* alpha, score, mips etc. */
 826        ".pdr",            /* alpha, score, mips etc. */
 827        ".stab*",
 828        ".note*",
 829        ".got*",
 830        ".toc*",
 831        ".xt.prop",                              /* xtensa */
 832        ".xt.lit",         /* xtensa */
 833        NULL
 834};
 835
 836/*
 837 * This is used to find sections missing the SHF_ALLOC flag.
 838 * The cause of this is often a section specified in assembler
 839 * without "ax" / "aw".
 840 */
 841static void check_section(const char *modname, struct elf_info *elf,
 842                          Elf_Shdr *sechdr)
 843{
 844        const char *sec = sech_name(elf, sechdr);
 845
 846        if (sechdr->sh_type == SHT_PROGBITS &&
 847            !(sechdr->sh_flags & SHF_ALLOC) &&
 848            !match(sec, section_white_list)) {
 849                warn("%s (%s): unexpected non-allocatable section.\n"
 850                     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 851                     "Note that for example <linux/init.h> contains\n"
 852                     "section definitions for use in .S files.\n\n",
 853                     modname, sec);
 854        }
 855}
 856
 857
 858
 859#define ALL_INIT_DATA_SECTIONS \
 860        ".init.setup$", ".init.rodata$", \
 861        ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \
 862        ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
 863#define ALL_EXIT_DATA_SECTIONS \
 864        ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
 865
 866#define ALL_INIT_TEXT_SECTIONS \
 867        ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
 868#define ALL_EXIT_TEXT_SECTIONS \
 869        ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
 870
 871#define ALL_PCI_INIT_SECTIONS   \
 872        ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
 873        ".pci_fixup_enable$", ".pci_fixup_resume$", \
 874        ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
 875
 876#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
 877        MEM_INIT_SECTIONS
 878#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
 879        MEM_EXIT_SECTIONS
 880
 881#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 882#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 883
 884#define DATA_SECTIONS ".data$", ".data.rel$"
 885#define TEXT_SECTIONS ".text$"
 886
 887#define INIT_SECTIONS      ".init.*"
 888#define DEV_INIT_SECTIONS  ".devinit.*"
 889#define CPU_INIT_SECTIONS  ".cpuinit.*"
 890#define MEM_INIT_SECTIONS  ".meminit.*"
 891
 892#define EXIT_SECTIONS      ".exit.*"
 893#define DEV_EXIT_SECTIONS  ".devexit.*"
 894#define CPU_EXIT_SECTIONS  ".cpuexit.*"
 895#define MEM_EXIT_SECTIONS  ".memexit.*"
 896
 897/* init data sections */
 898static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 899
 900/* all init sections */
 901static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 902
 903/* All init and exit sections (code + data) */
 904static const char *init_exit_sections[] =
 905        {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 906
 907/* data section */
 908static const char *data_sections[] = { DATA_SECTIONS, NULL };
 909
 910
 911/* symbols in .data that may refer to init/exit sections */
 912#define DEFAULT_SYMBOL_WHITE_LIST                                       \
 913        "*driver",                                                      \
 914        "*_template", /* scsi uses *_template a lot */                  \
 915        "*_timer",    /* arm uses ops structures named _timer a lot */  \
 916        "*_sht",      /* scsi also used *_sht to some extent */         \
 917        "*_ops",                                                        \
 918        "*_probe",                                                      \
 919        "*_probe_one",                                                  \
 920        "*_console"
 921
 922static const char *head_sections[] = { ".head.text*", NULL };
 923static const char *linker_symbols[] =
 924        { "__init_begin", "_sinittext", "_einittext", NULL };
 925
 926enum mismatch {
 927        TEXT_TO_ANY_INIT,
 928        DATA_TO_ANY_INIT,
 929        TEXT_TO_ANY_EXIT,
 930        DATA_TO_ANY_EXIT,
 931        XXXINIT_TO_SOME_INIT,
 932        XXXEXIT_TO_SOME_EXIT,
 933        ANY_INIT_TO_ANY_EXIT,
 934        ANY_EXIT_TO_ANY_INIT,
 935        EXPORT_TO_INIT_EXIT,
 936};
 937
 938struct sectioncheck {
 939        const char *fromsec[20];
 940        const char *tosec[20];
 941        enum mismatch mismatch;
 942        const char *symbol_white_list[20];
 943};
 944
 945const struct sectioncheck sectioncheck[] = {
 946/* Do not reference init/exit code/data from
 947 * normal code and data
 948 */
 949{
 950        .fromsec = { TEXT_SECTIONS, NULL },
 951        .tosec   = { ALL_INIT_SECTIONS, NULL },
 952        .mismatch = TEXT_TO_ANY_INIT,
 953        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 954},
 955{
 956        .fromsec = { DATA_SECTIONS, NULL },
 957        .tosec   = { ALL_XXXINIT_SECTIONS, NULL },
 958        .mismatch = DATA_TO_ANY_INIT,
 959        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 960},
 961{
 962        .fromsec = { DATA_SECTIONS, NULL },
 963        .tosec   = { INIT_SECTIONS, NULL },
 964        .mismatch = DATA_TO_ANY_INIT,
 965        .symbol_white_list = {
 966                "*_template", "*_timer", "*_sht", "*_ops",
 967                "*_probe", "*_probe_one", "*_console", NULL
 968        },
 969},
 970{
 971        .fromsec = { TEXT_SECTIONS, NULL },
 972        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 973        .mismatch = TEXT_TO_ANY_EXIT,
 974        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 975},
 976{
 977        .fromsec = { DATA_SECTIONS, NULL },
 978        .tosec   = { ALL_EXIT_SECTIONS, NULL },
 979        .mismatch = DATA_TO_ANY_EXIT,
 980        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 981},
 982/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
 983{
 984        .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 985        .tosec   = { INIT_SECTIONS, NULL },
 986        .mismatch = XXXINIT_TO_SOME_INIT,
 987        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 988},
 989/* Do not reference cpuinit code/data from meminit code/data */
 990{
 991        .fromsec = { MEM_INIT_SECTIONS, NULL },
 992        .tosec   = { CPU_INIT_SECTIONS, NULL },
 993        .mismatch = XXXINIT_TO_SOME_INIT,
 994        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 995},
 996/* Do not reference meminit code/data from cpuinit code/data */
 997{
 998        .fromsec = { CPU_INIT_SECTIONS, NULL },
 999        .tosec   = { MEM_INIT_SECTIONS, NULL },
1000        .mismatch = XXXINIT_TO_SOME_INIT,
1001        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1002},
1003/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
1004{
1005        .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1006        .tosec   = { EXIT_SECTIONS, NULL },
1007        .mismatch = XXXEXIT_TO_SOME_EXIT,
1008        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1009},
1010/* Do not reference cpuexit code/data from memexit code/data */
1011{
1012        .fromsec = { MEM_EXIT_SECTIONS, NULL },
1013        .tosec   = { CPU_EXIT_SECTIONS, NULL },
1014        .mismatch = XXXEXIT_TO_SOME_EXIT,
1015        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1016},
1017/* Do not reference memexit code/data from cpuexit code/data */
1018{
1019        .fromsec = { CPU_EXIT_SECTIONS, NULL },
1020        .tosec   = { MEM_EXIT_SECTIONS, NULL },
1021        .mismatch = XXXEXIT_TO_SOME_EXIT,
1022        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1023},
1024/* Do not use exit code/data from init code */
1025{
1026        .fromsec = { ALL_INIT_SECTIONS, NULL },
1027        .tosec   = { ALL_EXIT_SECTIONS, NULL },
1028        .mismatch = ANY_INIT_TO_ANY_EXIT,
1029        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1030},
1031/* Do not use init code/data from exit code */
1032{
1033        .fromsec = { ALL_EXIT_SECTIONS, NULL },
1034        .tosec   = { ALL_INIT_SECTIONS, NULL },
1035        .mismatch = ANY_EXIT_TO_ANY_INIT,
1036        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1037},
1038{
1039        .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1040        .tosec   = { INIT_SECTIONS, NULL },
1041        .mismatch = ANY_INIT_TO_ANY_EXIT,
1042        .symbol_white_list = { NULL },
1043},
1044/* Do not export init/exit functions or data */
1045{
1046        .fromsec = { "__ksymtab*", NULL },
1047        .tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1048        .mismatch = EXPORT_TO_INIT_EXIT,
1049        .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1050}
1051};
1052
1053static const struct sectioncheck *section_mismatch(
1054                const char *fromsec, const char *tosec)
1055{
1056        int i;
1057        int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1058        const struct sectioncheck *check = &sectioncheck[0];
1059
1060        for (i = 0; i < elems; i++) {
1061                if (match(fromsec, check->fromsec) &&
1062                    match(tosec, check->tosec))
1063                        return check;
1064                check++;
1065        }
1066        return NULL;
1067}
1068
1069/**
1070 * Whitelist to allow certain references to pass with no warning.
1071 *
1072 * Pattern 1:
1073 *   If a module parameter is declared __initdata and permissions=0
1074 *   then this is legal despite the warning generated.
1075 *   We cannot see value of permissions here, so just ignore
1076 *   this pattern.
1077 *   The pattern is identified by:
1078 *   tosec   = .init.data
1079 *   fromsec = .data*
1080 *   atsym   =__param*
1081 *
1082 * Pattern 1a:
1083 *   module_param_call() ops can refer to __init set function if permissions=0
1084 *   The pattern is identified by:
1085 *   tosec   = .init.text
1086 *   fromsec = .data*
1087 *   atsym   = __param_ops_*
1088 *
1089 * Pattern 2:
1090 *   Many drivers utilise a *driver container with references to
1091 *   add, remove, probe functions etc.
1092 *   These functions may often be marked __devinit and we do not want to
1093 *   warn here.
1094 *   the pattern is identified by:
1095 *   tosec   = init or exit section
1096 *   fromsec = data section
1097 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1098 *           *probe_one, *_console, *_timer
1099 *
1100 * Pattern 3:
1101 *   Whitelist all references from .head.text to any init section
1102 *
1103 * Pattern 4:
1104 *   Some symbols belong to init section but still it is ok to reference
1105 *   these from non-init sections as these symbols don't have any memory
1106 *   allocated for them and symbol address and value are same. So even
1107 *   if init section is freed, its ok to reference those symbols.
1108 *   For ex. symbols marking the init section boundaries.
1109 *   This pattern is identified by
1110 *   refsymname = __init_begin, _sinittext, _einittext
1111 *
1112 **/
1113static int secref_whitelist(const struct sectioncheck *mismatch,
1114                            const char *fromsec, const char *fromsym,
1115                            const char *tosec, const char *tosym)
1116{
1117        /* Check for pattern 1 */
1118        if (match(tosec, init_data_sections) &&
1119            match(fromsec, data_sections) &&
1120            (strncmp(fromsym, "__param", strlen("__param")) == 0))
1121                return 0;
1122
1123        /* Check for pattern 1a */
1124        if (strcmp(tosec, ".init.text") == 0 &&
1125            match(fromsec, data_sections) &&
1126            (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1127                return 0;
1128
1129        /* Check for pattern 2 */
1130        if (match(tosec, init_exit_sections) &&
1131            match(fromsec, data_sections) &&
1132            match(fromsym, mismatch->symbol_white_list))
1133                return 0;
1134
1135        /* Check for pattern 3 */
1136        if (match(fromsec, head_sections) &&
1137            match(tosec, init_sections))
1138                return 0;
1139
1140        /* Check for pattern 4 */
1141        if (match(tosym, linker_symbols))
1142                return 0;
1143
1144        return 1;
1145}
1146
1147/**
1148 * Find symbol based on relocation record info.
1149 * In some cases the symbol supplied is a valid symbol so
1150 * return refsym. If st_name != 0 we assume this is a valid symbol.
1151 * In other cases the symbol needs to be looked up in the symbol table
1152 * based on section and address.
1153 *  **/
1154static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1155                                Elf_Sym *relsym)
1156{
1157        Elf_Sym *sym;
1158        Elf_Sym *near = NULL;
1159        Elf64_Sword distance = 20;
1160        Elf64_Sword d;
1161        unsigned int relsym_secindex;
1162
1163        if (relsym->st_name != 0)
1164                return relsym;
1165
1166        relsym_secindex = get_secindex(elf, relsym);
1167        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1168                if (get_secindex(elf, sym) != relsym_secindex)
1169                        continue;
1170                if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1171                        continue;
1172                if (sym->st_value == addr)
1173                        return sym;
1174                /* Find a symbol nearby - addr are maybe negative */
1175                d = sym->st_value - addr;
1176                if (d < 0)
1177                        d = addr - sym->st_value;
1178                if (d < distance) {
1179                        distance = d;
1180                        near = sym;
1181                }
1182        }
1183        /* We need a close match */
1184        if (distance < 20)
1185                return near;
1186        else
1187                return NULL;
1188}
1189
1190static inline int is_arm_mapping_symbol(const char *str)
1191{
1192        return str[0] == '$' && strchr("atd", str[1])
1193               && (str[2] == '\0' || str[2] == '.');
1194}
1195
1196/*
1197 * If there's no name there, ignore it; likewise, ignore it if it's
1198 * one of the magic symbols emitted used by current ARM tools.
1199 *
1200 * Otherwise if find_symbols_between() returns those symbols, they'll
1201 * fail the whitelist tests and cause lots of false alarms ... fixable
1202 * only by merging __exit and __init sections into __text, bloating
1203 * the kernel (which is especially evil on embedded platforms).
1204 */
1205static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1206{
1207        const char *name = elf->strtab + sym->st_name;
1208
1209        if (!name || !strlen(name))
1210                return 0;
1211        return !is_arm_mapping_symbol(name);
1212}
1213
1214/*
1215 * Find symbols before or equal addr and after addr - in the section sec.
1216 * If we find two symbols with equal offset prefer one with a valid name.
1217 * The ELF format may have a better way to detect what type of symbol
1218 * it is, but this works for now.
1219 **/
1220static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1221                                 const char *sec)
1222{
1223        Elf_Sym *sym;
1224        Elf_Sym *near = NULL;
1225        Elf_Addr distance = ~0;
1226
1227        for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1228                const char *symsec;
1229
1230                if (is_shndx_special(sym->st_shndx))
1231                        continue;
1232                symsec = sec_name(elf, get_secindex(elf, sym));
1233                if (strcmp(symsec, sec) != 0)
1234                        continue;
1235                if (!is_valid_name(elf, sym))
1236                        continue;
1237                if (sym->st_value <= addr) {
1238                        if ((addr - sym->st_value) < distance) {
1239                                distance = addr - sym->st_value;
1240                                near = sym;
1241                        } else if ((addr - sym->st_value) == distance) {
1242                                near = sym;
1243                        }
1244                }
1245        }
1246        return near;
1247}
1248
1249/*
1250 * Convert a section name to the function/data attribute
1251 * .init.text => __init
1252 * .cpuinit.data => __cpudata
1253 * .memexitconst => __memconst
1254 * etc.
1255 *
1256 * The memory of returned value has been allocated on a heap. The user of this
1257 * method should free it after usage.
1258*/
1259static char *sec2annotation(const char *s)
1260{
1261        if (match(s, init_exit_sections)) {
1262                char *p = malloc(20);
1263                char *r = p;
1264
1265                *p++ = '_';
1266                *p++ = '_';
1267                if (*s == '.')
1268                        s++;
1269                while (*s && *s != '.')
1270                        *p++ = *s++;
1271                *p = '\0';
1272                if (*s == '.')
1273                        s++;
1274                if (strstr(s, "rodata") != NULL)
1275                        strcat(p, "const ");
1276                else if (strstr(s, "data") != NULL)
1277                        strcat(p, "data ");
1278                else
1279                        strcat(p, " ");
1280                return r;
1281        } else {
1282                return strdup("");
1283        }
1284}
1285
1286static int is_function(Elf_Sym *sym)
1287{
1288        if (sym)
1289                return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1290        else
1291                return -1;
1292}
1293
1294static void print_section_list(const char * const list[20])
1295{
1296        const char *const *s = list;
1297
1298        while (*s) {
1299                fprintf(stderr, "%s", *s);
1300                s++;
1301                if (*s)
1302                        fprintf(stderr, ", ");
1303        }
1304        fprintf(stderr, "\n");
1305}
1306
1307/*
1308 * Print a warning about a section mismatch.
1309 * Try to find symbols near it so user can find it.
1310 * Check whitelist before warning - it may be a false positive.
1311 */
1312static void report_sec_mismatch(const char *modname,
1313                                const struct sectioncheck *mismatch,
1314                                const char *fromsec,
1315                                unsigned long long fromaddr,
1316                                const char *fromsym,
1317                                int from_is_func,
1318                                const char *tosec, const char *tosym,
1319                                int to_is_func)
1320{
1321        const char *from, *from_p;
1322        const char *to, *to_p;
1323        char *prl_from;
1324        char *prl_to;
1325
1326        switch (from_is_func) {
1327        case 0: from = "variable"; from_p = "";   break;
1328        case 1: from = "function"; from_p = "()"; break;
1329        default: from = "(unknown reference)"; from_p = ""; break;
1330        }
1331        switch (to_is_func) {
1332        case 0: to = "variable"; to_p = "";   break;
1333        case 1: to = "function"; to_p = "()"; break;
1334        default: to = "(unknown reference)"; to_p = ""; break;
1335        }
1336
1337        sec_mismatch_count++;
1338        if (!sec_mismatch_verbose)
1339                return;
1340
1341        warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1342             "to the %s %s:%s%s\n",
1343             modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1344             tosym, to_p);
1345
1346        switch (mismatch->mismatch) {
1347        case TEXT_TO_ANY_INIT:
1348                prl_from = sec2annotation(fromsec);
1349                prl_to = sec2annotation(tosec);
1350                fprintf(stderr,
1351                "The function %s%s() references\n"
1352                "the %s %s%s%s.\n"
1353                "This is often because %s lacks a %s\n"
1354                "annotation or the annotation of %s is wrong.\n",
1355                prl_from, fromsym,
1356                to, prl_to, tosym, to_p,
1357                fromsym, prl_to, tosym);
1358                free(prl_from);
1359                free(prl_to);
1360                break;
1361        case DATA_TO_ANY_INIT: {
1362                prl_to = sec2annotation(tosec);
1363                fprintf(stderr,
1364                "The variable %s references\n"
1365                "the %s %s%s%s\n"
1366                "If the reference is valid then annotate the\n"
1367                "variable with __init* or __refdata (see linux/init.h) "
1368                "or name the variable:\n",
1369                fromsym, to, prl_to, tosym, to_p);
1370                print_section_list(mismatch->symbol_white_list);
1371                free(prl_to);
1372                break;
1373        }
1374        case TEXT_TO_ANY_EXIT:
1375                prl_to = sec2annotation(tosec);
1376                fprintf(stderr,
1377                "The function %s() references a %s in an exit section.\n"
1378                "Often the %s %s%s has valid usage outside the exit section\n"
1379                "and the fix is to remove the %sannotation of %s.\n",
1380                fromsym, to, to, tosym, to_p, prl_to, tosym);
1381                free(prl_to);
1382                break;
1383        case DATA_TO_ANY_EXIT: {
1384                prl_to = sec2annotation(tosec);
1385                fprintf(stderr,
1386                "The variable %s references\n"
1387                "the %s %s%s%s\n"
1388                "If the reference is valid then annotate the\n"
1389                "variable with __exit* (see linux/init.h) or "
1390                "name the variable:\n",
1391                fromsym, to, prl_to, tosym, to_p);
1392                print_section_list(mismatch->symbol_white_list);
1393                free(prl_to);
1394                break;
1395        }
1396        case XXXINIT_TO_SOME_INIT:
1397        case XXXEXIT_TO_SOME_EXIT:
1398                prl_from = sec2annotation(fromsec);
1399                prl_to = sec2annotation(tosec);
1400                fprintf(stderr,
1401                "The %s %s%s%s references\n"
1402                "a %s %s%s%s.\n"
1403                "If %s is only used by %s then\n"
1404                "annotate %s with a matching annotation.\n",
1405                from, prl_from, fromsym, from_p,
1406                to, prl_to, tosym, to_p,
1407                tosym, fromsym, tosym);
1408                free(prl_from);
1409                free(prl_to);
1410                break;
1411        case ANY_INIT_TO_ANY_EXIT:
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 init function\n"
1419                "uses functionality in the exit path.\n"
1420                "The fix is often to remove the %sannotation of\n"
1421                "%s%s so it may be used outside an exit 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 ANY_EXIT_TO_ANY_INIT:
1429                prl_from = sec2annotation(fromsec);
1430                prl_to = sec2annotation(tosec);
1431                fprintf(stderr,
1432                "The %s %s%s%s references\n"
1433                "a %s %s%s%s.\n"
1434                "This is often seen when error handling "
1435                "in the exit function\n"
1436                "uses functionality in the init path.\n"
1437                "The fix is often to remove the %sannotation of\n"
1438                "%s%s so it may be used outside an init section.\n",
1439                from, prl_from, fromsym, from_p,
1440                to, prl_to, tosym, to_p,
1441                prl_to, tosym, to_p);
1442                free(prl_from);
1443                free(prl_to);
1444                break;
1445        case EXPORT_TO_INIT_EXIT:
1446                prl_to = sec2annotation(tosec);
1447                fprintf(stderr,
1448                "The symbol %s is exported and annotated %s\n"
1449                "Fix this by removing the %sannotation of %s "
1450                "or drop the export.\n",
1451                tosym, prl_to, prl_to, tosym);
1452                free(prl_to);
1453                break;
1454        }
1455        fprintf(stderr, "\n");
1456}
1457
1458static void check_section_mismatch(const char *modname, struct elf_info *elf,
1459                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1460{
1461        const char *tosec;
1462        const struct sectioncheck *mismatch;
1463
1464        tosec = sec_name(elf, get_secindex(elf, sym));
1465        mismatch = section_mismatch(fromsec, tosec);
1466        if (mismatch) {
1467                Elf_Sym *to;
1468                Elf_Sym *from;
1469                const char *tosym;
1470                const char *fromsym;
1471
1472                from = find_elf_symbol2(elf, r->r_offset, fromsec);
1473                fromsym = sym_name(elf, from);
1474                to = find_elf_symbol(elf, r->r_addend, sym);
1475                tosym = sym_name(elf, to);
1476
1477                /* check whitelist - we may ignore it */
1478                if (secref_whitelist(mismatch,
1479                                        fromsec, fromsym, tosec, tosym)) {
1480                        report_sec_mismatch(modname, mismatch,
1481                           fromsec, r->r_offset, fromsym,
1482                           is_function(from), tosec, tosym,
1483                           is_function(to));
1484                }
1485        }
1486}
1487
1488static unsigned int *reloc_location(struct elf_info *elf,
1489                                    Elf_Shdr *sechdr, Elf_Rela *r)
1490{
1491        Elf_Shdr *sechdrs = elf->sechdrs;
1492        int section = sechdr->sh_info;
1493
1494        return (void *)elf->hdr + sechdrs[section].sh_offset +
1495                r->r_offset;
1496}
1497
1498static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1499{
1500        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1501        unsigned int *location = reloc_location(elf, sechdr, r);
1502
1503        switch (r_typ) {
1504        case R_386_32:
1505                r->r_addend = TO_NATIVE(*location);
1506                break;
1507        case R_386_PC32:
1508                r->r_addend = TO_NATIVE(*location) + 4;
1509                /* For CONFIG_RELOCATABLE=y */
1510                if (elf->hdr->e_type == ET_EXEC)
1511                        r->r_addend += r->r_offset;
1512                break;
1513        }
1514        return 0;
1515}
1516
1517#ifndef R_ARM_CALL
1518#define R_ARM_CALL      28
1519#endif
1520#ifndef R_ARM_JUMP24
1521#define R_ARM_JUMP24    29
1522#endif
1523
1524static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1525{
1526        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1527
1528        switch (r_typ) {
1529        case R_ARM_ABS32:
1530                /* From ARM ABI: (S + A) | T */
1531                r->r_addend = (int)(long)
1532                              (elf->symtab_start + ELF_R_SYM(r->r_info));
1533                break;
1534        case R_ARM_PC24:
1535        case R_ARM_CALL:
1536        case R_ARM_JUMP24:
1537                /* From ARM ABI: ((S + A) | T) - P */
1538                r->r_addend = (int)(long)(elf->hdr +
1539                              sechdr->sh_offset +
1540                              (r->r_offset - sechdr->sh_addr));
1541                break;
1542        default:
1543                return 1;
1544        }
1545        return 0;
1546}
1547
1548static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1549{
1550        unsigned int r_typ = ELF_R_TYPE(r->r_info);
1551        unsigned int *location = reloc_location(elf, sechdr, r);
1552        unsigned int inst;
1553
1554        if (r_typ == R_MIPS_HI16)
1555                return 1;       /* skip this */
1556        inst = TO_NATIVE(*location);
1557        switch (r_typ) {
1558        case R_MIPS_LO16:
1559                r->r_addend = inst & 0xffff;
1560                break;
1561        case R_MIPS_26:
1562                r->r_addend = (inst & 0x03ffffff) << 2;
1563                break;
1564        case R_MIPS_32:
1565                r->r_addend = inst;
1566                break;
1567        }
1568        return 0;
1569}
1570
1571static void section_rela(const char *modname, struct elf_info *elf,
1572                         Elf_Shdr *sechdr)
1573{
1574        Elf_Sym  *sym;
1575        Elf_Rela *rela;
1576        Elf_Rela r;
1577        unsigned int r_sym;
1578        const char *fromsec;
1579
1580        Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1581        Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1582
1583        fromsec = sech_name(elf, sechdr);
1584        fromsec += strlen(".rela");
1585        /* if from section (name) is know good then skip it */
1586        if (match(fromsec, section_white_list))
1587                return;
1588
1589        for (rela = start; rela < stop; rela++) {
1590                r.r_offset = TO_NATIVE(rela->r_offset);
1591#if KERNEL_ELFCLASS == ELFCLASS64
1592                if (elf->hdr->e_machine == EM_MIPS) {
1593                        unsigned int r_typ;
1594                        r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1595                        r_sym = TO_NATIVE(r_sym);
1596                        r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1597                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1598                } else {
1599                        r.r_info = TO_NATIVE(rela->r_info);
1600                        r_sym = ELF_R_SYM(r.r_info);
1601                }
1602#else
1603                r.r_info = TO_NATIVE(rela->r_info);
1604                r_sym = ELF_R_SYM(r.r_info);
1605#endif
1606                r.r_addend = TO_NATIVE(rela->r_addend);
1607                sym = elf->symtab_start + r_sym;
1608                /* Skip special sections */
1609                if (is_shndx_special(sym->st_shndx))
1610                        continue;
1611                check_section_mismatch(modname, elf, &r, sym, fromsec);
1612        }
1613}
1614
1615static void section_rel(const char *modname, struct elf_info *elf,
1616                        Elf_Shdr *sechdr)
1617{
1618        Elf_Sym *sym;
1619        Elf_Rel *rel;
1620        Elf_Rela r;
1621        unsigned int r_sym;
1622        const char *fromsec;
1623
1624        Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1625        Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1626
1627        fromsec = sech_name(elf, sechdr);
1628        fromsec += strlen(".rel");
1629        /* if from section (name) is know good then skip it */
1630        if (match(fromsec, section_white_list))
1631                return;
1632
1633        for (rel = start; rel < stop; rel++) {
1634                r.r_offset = TO_NATIVE(rel->r_offset);
1635#if KERNEL_ELFCLASS == ELFCLASS64
1636                if (elf->hdr->e_machine == EM_MIPS) {
1637                        unsigned int r_typ;
1638                        r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1639                        r_sym = TO_NATIVE(r_sym);
1640                        r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1641                        r.r_info = ELF64_R_INFO(r_sym, r_typ);
1642                } else {
1643                        r.r_info = TO_NATIVE(rel->r_info);
1644                        r_sym = ELF_R_SYM(r.r_info);
1645                }
1646#else
1647                r.r_info = TO_NATIVE(rel->r_info);
1648                r_sym = ELF_R_SYM(r.r_info);
1649#endif
1650                r.r_addend = 0;
1651                switch (elf->hdr->e_machine) {
1652                case EM_386:
1653                        if (addend_386_rel(elf, sechdr, &r))
1654                                continue;
1655                        break;
1656                case EM_ARM:
1657                        if (addend_arm_rel(elf, sechdr, &r))
1658                                continue;
1659                        break;
1660                case EM_MIPS:
1661                        if (addend_mips_rel(elf, sechdr, &r))
1662                                continue;
1663                        break;
1664                }
1665                sym = elf->symtab_start + r_sym;
1666                /* Skip special sections */
1667                if (is_shndx_special(sym->st_shndx))
1668                        continue;
1669                check_section_mismatch(modname, elf, &r, sym, fromsec);
1670        }
1671}
1672
1673/**
1674 * A module includes a number of sections that are discarded
1675 * either when loaded or when used as built-in.
1676 * For loaded modules all functions marked __init and all data
1677 * marked __initdata will be discarded when the module has been initialized.
1678 * Likewise for modules used built-in the sections marked __exit
1679 * are discarded because __exit marked function are supposed to be called
1680 * only when a module is unloaded which never happens for built-in modules.
1681 * The check_sec_ref() function traverses all relocation records
1682 * to find all references to a section that reference a section that will
1683 * be discarded and warns about it.
1684 **/
1685static void check_sec_ref(struct module *mod, const char *modname,
1686                          struct elf_info *elf)
1687{
1688        int i;
1689        Elf_Shdr *sechdrs = elf->sechdrs;
1690
1691        /* Walk through all sections */
1692        for (i = 0; i < elf->num_sections; i++) {
1693                check_section(modname, elf, &elf->sechdrs[i]);
1694                /* We want to process only relocation sections and not .init */
1695                if (sechdrs[i].sh_type == SHT_RELA)
1696                        section_rela(modname, elf, &elf->sechdrs[i]);
1697                else if (sechdrs[i].sh_type == SHT_REL)
1698                        section_rel(modname, elf, &elf->sechdrs[i]);
1699        }
1700}
1701
1702static void read_symbols(char *modname)
1703{
1704        const char *symname;
1705        char *version;
1706        char *license;
1707        struct module *mod;
1708        struct elf_info info = { };
1709        Elf_Sym *sym;
1710
1711        if (!parse_elf(&info, modname))
1712                return;
1713
1714        mod = new_module(modname);
1715
1716        /* When there's no vmlinux, don't print warnings about
1717         * unresolved symbols (since there'll be too many ;) */
1718        if (is_vmlinux(modname)) {
1719                have_vmlinux = 1;
1720                mod->skip = 1;
1721        }
1722
1723        license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1724        if (info.modinfo && !license && !is_vmlinux(modname))
1725                warn("modpost: missing MODULE_LICENSE() in %s\n"
1726                     "see include/linux/module.h for "
1727                     "more information\n", modname);
1728        while (license) {
1729                if (license_is_gpl_compatible(license))
1730                        mod->gpl_compatible = 1;
1731                else {
1732                        mod->gpl_compatible = 0;
1733                        break;
1734                }
1735                license = get_next_modinfo(info.modinfo, info.modinfo_len,
1736                                           "license", license);
1737        }
1738
1739        for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1740                symname = info.strtab + sym->st_name;
1741
1742                handle_modversions(mod, &info, sym, symname);
1743                handle_moddevtable(mod, &info, sym, symname);
1744        }
1745        if (!is_vmlinux(modname) ||
1746             (is_vmlinux(modname) && vmlinux_section_warnings))
1747                check_sec_ref(mod, modname, &info);
1748
1749        version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1750        if (version)
1751                maybe_frob_rcs_version(modname, version, info.modinfo,
1752                                       version - (char *)info.hdr);
1753        if (version || (all_versions && !is_vmlinux(modname)))
1754                get_src_version(modname, mod->srcversion,
1755                                sizeof(mod->srcversion)-1);
1756
1757        parse_elf_finish(&info);
1758
1759        /* Our trick to get versioning for module struct etc. - it's
1760         * never passed as an argument to an exported function, so
1761         * the automatic versioning doesn't pick it up, but it's really
1762         * important anyhow */
1763        if (modversions)
1764                mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1765}
1766
1767#define SZ 500
1768
1769/* We first write the generated file into memory using the
1770 * following helper, then compare to the file on disk and
1771 * only update the later if anything changed */
1772
1773void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1774                                                      const char *fmt, ...)
1775{
1776        char tmp[SZ];
1777        int len;
1778        va_list ap;
1779
1780        va_start(ap, fmt);
1781        len = vsnprintf(tmp, SZ, fmt, ap);
1782        buf_write(buf, tmp, len);
1783        va_end(ap);
1784}
1785
1786void buf_write(struct buffer *buf, const char *s, int len)
1787{
1788        if (buf->size - buf->pos < len) {
1789                buf->size += len + SZ;
1790                buf->p = realloc(buf->p, buf->size);
1791        }
1792        strncpy(buf->p + buf->pos, s, len);
1793        buf->pos += len;
1794}
1795
1796static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1797{
1798        const char *e = is_vmlinux(m) ?"":".ko";
1799
1800        switch (exp) {
1801        case export_gpl:
1802                fatal("modpost: GPL-incompatible module %s%s "
1803                      "uses GPL-only symbol '%s'\n", m, e, s);
1804                break;
1805        case export_unused_gpl:
1806                fatal("modpost: GPL-incompatible module %s%s "
1807                      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1808                break;
1809        case export_gpl_future:
1810                warn("modpost: GPL-incompatible module %s%s "
1811                      "uses future GPL-only symbol '%s'\n", m, e, s);
1812                break;
1813        case export_plain:
1814        case export_unused:
1815        case export_unknown:
1816                /* ignore */
1817                break;
1818        }
1819}
1820
1821static void check_for_unused(enum export exp, const char *m, const char *s)
1822{
1823        const char *e = is_vmlinux(m) ?"":".ko";
1824
1825        switch (exp) {
1826        case export_unused:
1827        case export_unused_gpl:
1828                warn("modpost: module %s%s "
1829                      "uses symbol '%s' marked UNUSED\n", m, e, s);
1830                break;
1831        default:
1832                /* ignore */
1833                break;
1834        }
1835}
1836
1837static void check_exports(struct module *mod)
1838{
1839        struct symbol *s, *exp;
1840
1841        for (s = mod->unres; s; s = s->next) {
1842                const char *basename;
1843                exp = find_symbol(s->name);
1844                if (!exp || exp->module == mod)
1845                        continue;
1846                basename = strrchr(mod->name, '/');
1847                if (basename)
1848                        basename++;
1849                else
1850                        basename = mod->name;
1851                if (!mod->gpl_compatible)
1852                        check_for_gpl_usage(exp->export, basename, exp->name);
1853                check_for_unused(exp->export, basename, exp->name);
1854        }
1855}
1856
1857/**
1858 * Header for the generated file
1859 **/
1860static void add_header(struct buffer *b, struct module *mod)
1861{
1862        buf_printf(b, "#include <linux/module.h>\n");
1863        buf_printf(b, "#include <linux/vermagic.h>\n");
1864        buf_printf(b, "#include <linux/compiler.h>\n");
1865        buf_printf(b, "\n");
1866        buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1867        buf_printf(b, "\n");
1868        buf_printf(b, "struct module __this_module\n");
1869        buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1870        buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1871        if (mod->has_init)
1872                buf_printf(b, "\t.init = init_module,\n");
1873        if (mod->has_cleanup)
1874                buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1875                              "\t.exit = cleanup_module,\n"
1876                              "#endif\n");
1877        buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1878        buf_printf(b, "};\n");
1879}
1880
1881static void add_intree_flag(struct buffer *b, int is_intree)
1882{
1883        if (is_intree)
1884                buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1885}
1886
1887static void add_staging_flag(struct buffer *b, const char *name)
1888{
1889        static const char *staging_dir = "drivers/staging";
1890
1891        if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1892                buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1893}
1894
1895/**
1896 * Record CRCs for unresolved symbols
1897 **/
1898static int add_versions(struct buffer *b, struct module *mod)
1899{
1900        struct symbol *s, *exp;
1901        int err = 0;
1902
1903        for (s = mod->unres; s; s = s->next) {
1904                exp = find_symbol(s->name);
1905                if (!exp || exp->module == mod) {
1906                        if (have_vmlinux && !s->weak) {
1907                                if (warn_unresolved) {
1908                                        warn("\"%s\" [%s.ko] undefined!\n",
1909                                             s->name, mod->name);
1910                                } else {
1911                                        merror("\"%s\" [%s.ko] undefined!\n",
1912                                                  s->name, mod->name);
1913                                        err = 1;
1914                                }
1915                        }
1916                        continue;
1917                }
1918                s->module = exp->module;
1919                s->crc_valid = exp->crc_valid;
1920                s->crc = exp->crc;
1921        }
1922
1923        if (!modversions)
1924                return err;
1925
1926        buf_printf(b, "\n");
1927        buf_printf(b, "static const struct modversion_info ____versions[]\n");
1928        buf_printf(b, "__used\n");
1929        buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1930
1931        for (s = mod->unres; s; s = s->next) {
1932                if (!s->module)
1933                        continue;
1934                if (!s->crc_valid) {
1935                        warn("\"%s\" [%s.ko] has no CRC!\n",
1936                                s->name, mod->name);
1937                        continue;
1938                }
1939                buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1940        }
1941
1942        buf_printf(b, "};\n");
1943
1944        return err;
1945}
1946
1947static void add_depends(struct buffer *b, struct module *mod,
1948                        struct module *modules)
1949{
1950        struct symbol *s;
1951        struct module *m;
1952        int first = 1;
1953
1954        for (m = modules; m; m = m->next)
1955                m->seen = is_vmlinux(m->name);
1956
1957        buf_printf(b, "\n");
1958        buf_printf(b, "static const char __module_depends[]\n");
1959        buf_printf(b, "__used\n");
1960        buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1961        buf_printf(b, "\"depends=");
1962        for (s = mod->unres; s; s = s->next) {
1963                const char *p;
1964                if (!s->module)
1965                        continue;
1966
1967                if (s->module->seen)
1968                        continue;
1969
1970                s->module->seen = 1;
1971                p = strrchr(s->module->name, '/');
1972                if (p)
1973                        p++;
1974                else
1975                        p = s->module->name;
1976                buf_printf(b, "%s%s", first ? "" : ",", p);
1977                first = 0;
1978        }
1979        buf_printf(b, "\";\n");
1980}
1981
1982static void add_srcversion(struct buffer *b, struct module *mod)
1983{
1984        if (mod->srcversion[0]) {
1985                buf_printf(b, "\n");
1986                buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1987                           mod->srcversion);
1988        }
1989}
1990
1991static void write_if_changed(struct buffer *b, const char *fname)
1992{
1993        char *tmp;
1994        FILE *file;
1995        struct stat st;
1996
1997        file = fopen(fname, "r");
1998        if (!file)
1999                goto write;
2000
2001        if (fstat(fileno(file), &st) < 0)
2002                goto close_write;
2003
2004        if (st.st_size != b->pos)
2005                goto close_write;
2006
2007        tmp = NOFAIL(malloc(b->pos));
2008        if (fread(tmp, 1, b->pos, file) != b->pos)
2009                goto free_write;
2010
2011        if (memcmp(tmp, b->p, b->pos) != 0)
2012                goto free_write;
2013
2014        free(tmp);
2015        fclose(file);
2016        return;
2017
2018 free_write:
2019        free(tmp);
2020 close_write:
2021        fclose(file);
2022 write:
2023        file = fopen(fname, "w");
2024        if (!file) {
2025                perror(fname);
2026                exit(1);
2027        }
2028        if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2029                perror(fname);
2030                exit(1);
2031        }
2032        fclose(file);
2033}
2034
2035/* parse Module.symvers file. line format:
2036 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2037 **/
2038static void read_dump(const char *fname, unsigned int kernel)
2039{
2040        unsigned long size, pos = 0;
2041        void *file = grab_file(fname, &size);
2042        char *line;
2043
2044        if (!file)
2045                /* No symbol versions, silently ignore */
2046                return;
2047
2048        while ((line = get_next_line(&pos, file, size))) {
2049                char *symname, *modname, *d, *export, *end;
2050                unsigned int crc;
2051                struct module *mod;
2052                struct symbol *s;
2053
2054                if (!(symname = strchr(line, '\t')))
2055                        goto fail;
2056                *symname++ = '\0';
2057                if (!(modname = strchr(symname, '\t')))
2058                        goto fail;
2059                *modname++ = '\0';
2060                if ((export = strchr(modname, '\t')) != NULL)
2061                        *export++ = '\0';
2062                if (export && ((end = strchr(export, '\t')) != NULL))
2063                        *end = '\0';
2064                crc = strtoul(line, &d, 16);
2065                if (*symname == '\0' || *modname == '\0' || *d != '\0')
2066                        goto fail;
2067                mod = find_module(modname);
2068                if (!mod) {
2069                        if (is_vmlinux(modname))
2070                                have_vmlinux = 1;
2071                        mod = new_module(modname);
2072                        mod->skip = 1;
2073                }
2074                s = sym_add_exported(symname, mod, export_no(export));
2075                s->kernel    = kernel;
2076                s->preloaded = 1;
2077                sym_update_crc(symname, mod, crc, export_no(export));
2078        }
2079        return;
2080fail:
2081        fatal("parse error in symbol dump file\n");
2082}
2083
2084/* For normal builds always dump all symbols.
2085 * For external modules only dump symbols
2086 * that are not read from kernel Module.symvers.
2087 **/
2088static int dump_sym(struct symbol *sym)
2089{
2090        if (!external_module)
2091                return 1;
2092        if (sym->vmlinux || sym->kernel)
2093                return 0;
2094        return 1;
2095}
2096
2097static void write_dump(const char *fname)
2098{
2099        struct buffer buf = { };
2100        struct symbol *symbol;
2101        int n;
2102
2103        for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2104                symbol = symbolhash[n];
2105                while (symbol) {
2106                        if (dump_sym(symbol))
2107                                buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2108                                        symbol->crc, symbol->name,
2109                                        symbol->module->name,
2110                                        export_str(symbol->export));
2111                        symbol = symbol->next;
2112                }
2113        }
2114        write_if_changed(&buf, fname);
2115}
2116
2117struct ext_sym_list {
2118        struct ext_sym_list *next;
2119        const char *file;
2120};
2121
2122int main(int argc, char **argv)
2123{
2124        struct module *mod;
2125        struct buffer buf = { };
2126        char *kernel_read = NULL, *module_read = NULL;
2127        char *dump_write = NULL;
2128        int opt;
2129        int err;
2130        struct ext_sym_list *extsym_iter;
2131        struct ext_sym_list *extsym_start = NULL;
2132
2133        while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2134                switch (opt) {
2135                case 'i':
2136                        kernel_read = optarg;
2137                        break;
2138                case 'I':
2139                        module_read = optarg;
2140                        external_module = 1;
2141                        break;
2142                case 'c':
2143                        cross_build = 1;
2144                        break;
2145                case 'e':
2146                        external_module = 1;
2147                        extsym_iter =
2148                           NOFAIL(malloc(sizeof(*extsym_iter)));
2149                        extsym_iter->next = extsym_start;
2150                        extsym_iter->file = optarg;
2151                        extsym_start = extsym_iter;
2152                        break;
2153                case 'm':
2154                        modversions = 1;
2155                        break;
2156                case 'o':
2157                        dump_write = optarg;
2158                        break;
2159                case 'a':
2160                        all_versions = 1;
2161                        break;
2162                case 's':
2163                        vmlinux_section_warnings = 0;
2164                        break;
2165                case 'S':
2166                        sec_mismatch_verbose = 0;
2167                        break;
2168                case 'w':
2169                        warn_unresolved = 1;
2170                        break;
2171                default:
2172                        exit(1);
2173                }
2174        }
2175
2176        if (kernel_read)
2177                read_dump(kernel_read, 1);
2178        if (module_read)
2179                read_dump(module_read, 0);
2180        while (extsym_start) {
2181                read_dump(extsym_start->file, 0);
2182                extsym_iter = extsym_start->next;
2183                free(extsym_start);
2184                extsym_start = extsym_iter;
2185        }
2186
2187        while (optind < argc)
2188                read_symbols(argv[optind++]);
2189
2190        for (mod = modules; mod; mod = mod->next) {
2191                if (mod->skip)
2192                        continue;
2193                check_exports(mod);
2194        }
2195
2196        err = 0;
2197
2198        for (mod = modules; mod; mod = mod->next) {
2199                char fname[strlen(mod->name) + 10];
2200
2201                if (mod->skip)
2202                        continue;
2203
2204                buf.pos = 0;
2205
2206                add_header(&buf, mod);
2207                add_intree_flag(&buf, !external_module);
2208                add_staging_flag(&buf, mod->name);
2209                err |= add_versions(&buf, mod);
2210                add_depends(&buf, mod, modules);
2211                add_moddevtable(&buf, mod);
2212                add_srcversion(&buf, mod);
2213
2214                sprintf(fname, "%s.mod.c", mod->name);
2215                write_if_changed(&buf, fname);
2216        }
2217
2218        if (dump_write)
2219                write_dump(dump_write);
2220        if (sec_mismatch_count && !sec_mismatch_verbose)
2221                warn("modpost: Found %d section mismatch(es).\n"
2222                     "To see full details build your kernel with:\n"
2223                     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2224                     sec_mismatch_count);
2225
2226        return err;
2227}
2228
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