1/* Postprocess module symbol versions
   2 *
   3 * Copyright 2003       Kai Germaschewski
   4 * Copyright 2002-2004  Rusty Russell, IBM Corporation
   5 * Copyright 2006-2008  Sam Ravnborg
   6 * Based in part on module-init-tools/depmod.c,file2alias
   7 *
   8 * This software may be used and distributed according to the terms
   9 * of the GNU General Public License, incorporated herein by reference.
  10 *
  11 * Usage: modpost vmlinux module1.o module2.o ...
  12 */
  13
  14#define _GNU_SOURCE
  15#include <elf.h>
  16#include <fnmatch.h>
  17#include <stdio.h>
  18#include <ctype.h>
  19#include <string.h>
  20#include <limits.h>
  21#include <stdbool.h>
  22#include <errno.h>
  23
  24#include <hash.h>
  25#include <hashtable.h>
  26#include <list.h>
  27#include <xalloc.h>
  28#include "modpost.h"
  29#include "../../include/linux/license.h"
  30
  31static bool module_enabled;
  32/* Are we using CONFIG_MODVERSIONS? */
  33static bool modversions;
  34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  35static bool all_versions;
  36/* If we are modposting external module set to 1 */
  37static bool external_module;
  38/* Only warn about unresolved symbols */
  39static bool warn_unresolved;
  40
  41static int sec_mismatch_count;
  42static bool sec_mismatch_warn_only = true;
  43/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  44static bool trim_unused_exports;
  45
  46/* ignore missing files */
  47static bool ignore_missing_files;
  48/* If set to 1, only warn (instead of error) about missing ns imports */
  49static bool allow_missing_ns_imports;
  50
  51static bool error_occurred;
  52
  53static bool extra_warn;
  54
  55bool target_is_big_endian;
  56bool host_is_big_endian;
  57
  58/*
  59 * Cut off the warnings when there are too many. This typically occurs when
  60 * vmlinux is missing. ('make modules' without building vmlinux.)
  61 */
  62#define MAX_UNRESOLVED_REPORTS	10
  63static unsigned int nr_unresolved;
  64
 
 
 
 
 
 
  65/* In kernel, this size is defined in linux/module.h;
  66 * here we use Elf_Addr instead of long for covering cross-compile
  67 */
  68
  69#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  70
  71void modpost_log(bool is_error, const char *fmt, ...)
 
  72{
  73	va_list arglist;
  74
  75	if (is_error) {
  76		fprintf(stderr, "ERROR: ");
  77		error_occurred = true;
  78	} else {
  79		fprintf(stderr, "WARNING: ");
 
 
 
 
 
 
 
 
 
  80	}
  81
  82	fprintf(stderr, "modpost: ");
  83
  84	va_start(arglist, fmt);
  85	vfprintf(stderr, fmt, arglist);
  86	va_end(arglist);
 
 
 
 
 
  87}
  88
  89static inline bool strends(const char *str, const char *postfix)
  90{
  91	if (strlen(str) < strlen(postfix))
  92		return false;
  93
  94	return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
  95}
  96
  97char *read_text_file(const char *filename)
  98{
  99	struct stat st;
 100	size_t nbytes;
 101	int fd;
 102	char *buf;
 103
 104	fd = open(filename, O_RDONLY);
 105	if (fd < 0) {
 106		perror(filename);
 107		exit(1);
 108	}
 109
 110	if (fstat(fd, &st) < 0) {
 111		perror(filename);
 112		exit(1);
 113	}
 114
 115	buf = xmalloc(st.st_size + 1);
 116
 117	nbytes = st.st_size;
 118
 119	while (nbytes) {
 120		ssize_t bytes_read;
 121
 122		bytes_read = read(fd, buf, nbytes);
 123		if (bytes_read < 0) {
 124			perror(filename);
 125			exit(1);
 126		}
 127
 128		nbytes -= bytes_read;
 129	}
 130	buf[st.st_size] = '\0';
 131
 132	close(fd);
 133
 134	return buf;
 135}
 136
 137char *get_line(char **stringp)
 138{
 139	char *orig = *stringp, *next;
 140
 141	/* do not return the unwanted extra line at EOF */
 142	if (!orig || *orig == '\0')
 143		return NULL;
 144
 145	/* don't use strsep here, it is not available everywhere */
 146	next = strchr(orig, '\n');
 147	if (next)
 148		*next++ = '\0';
 149
 150	*stringp = next;
 151
 152	return orig;
 153}
 154
 155/* A list of all modules we processed */
 156LIST_HEAD(modules);
 157
 158static struct module *find_module(const char *filename, const char *modname)
 159{
 160	struct module *mod;
 161
 162	list_for_each_entry(mod, &modules, list) {
 163		if (!strcmp(mod->dump_file, filename) &&
 164		    !strcmp(mod->name, modname))
 165			return mod;
 166	}
 167	return NULL;
 168}
 169
 170static struct module *new_module(const char *name, size_t namelen)
 171{
 172	struct module *mod;
 173
 174	mod = xmalloc(sizeof(*mod) + namelen + 1);
 175	memset(mod, 0, sizeof(*mod));
 176
 177	INIT_LIST_HEAD(&mod->exported_symbols);
 178	INIT_LIST_HEAD(&mod->unresolved_symbols);
 179	INIT_LIST_HEAD(&mod->missing_namespaces);
 180	INIT_LIST_HEAD(&mod->imported_namespaces);
 181	INIT_LIST_HEAD(&mod->aliases);
 182
 183	memcpy(mod->name, name, namelen);
 184	mod->name[namelen] = '\0';
 185	mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 186
 187	/*
 188	 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 189	 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 190	 * modpost will exit wiht error anyway.
 191	 */
 192	mod->is_gpl_compatible = true;
 193
 194	list_add_tail(&mod->list, &modules);
 195
 196	return mod;
 197}
 198
 
 
 
 
 
 199struct symbol {
 200	struct hlist_node hnode;/* link to hash table */
 201	struct list_head list;	/* link to module::exported_symbols or module::unresolved_symbols */
 202	struct module *module;
 203	char *namespace;
 204	unsigned int crc;
 205	bool crc_valid;
 206	bool weak;
 207	bool is_func;
 208	bool is_gpl_only;	/* exported by EXPORT_SYMBOL_GPL */
 209	bool used;		/* there exists a user of this symbol */
 210	char name[];
 211};
 212
 213static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
 
 
 
 
 
 
 
 
 
 
 
 
 
 214
 215/**
 216 * Allocate a new symbols for use in the hash of exported symbols or
 217 * the list of unresolved symbols per module
 218 **/
 219static struct symbol *alloc_symbol(const char *name)
 
 220{
 221	struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1);
 222
 223	memset(s, 0, sizeof(*s));
 224	strcpy(s->name, name);
 225
 
 
 226	return s;
 227}
 228
 229/* For the hash of exported symbols */
 230static void hash_add_symbol(struct symbol *sym)
 
 231{
 232	hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name));
 233}
 234
 235static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 236{
 237	struct symbol *sym;
 238
 239	sym = alloc_symbol(name);
 240	sym->weak = weak;
 241
 242	list_add_tail(&sym->list, &mod->unresolved_symbols);
 243}
 244
 245static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 246{
 247	struct symbol *s;
 248
 249	/* For our purposes, .foo matches foo.  PPC64 needs this. */
 250	if (name[0] == '.')
 251		name++;
 252
 253	hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) {
 254		if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 255			return s;
 256	}
 257	return NULL;
 258}
 259
 260static struct symbol *find_symbol(const char *name)
 
 261{
 262	return sym_find_with_module(name, NULL);
 
 
 
 
 263}
 264
 265struct namespace_list {
 266	struct list_head list;
 267	char namespace[];
 268};
 269
 270static bool contains_namespace(struct list_head *head, const char *namespace)
 
 
 
 
 
 
 
 
 
 
 271{
 272	struct namespace_list *list;
 
 273
 274	/*
 275	 * The default namespace is null string "", which is always implicitly
 276	 * contained.
 277	 */
 278	if (!namespace[0])
 279		return true;
 
 
 280
 281	list_for_each_entry(list, head, list) {
 282		if (!strcmp(list->namespace, namespace))
 283			return true;
 284	}
 285
 286	return false;
 
 
 287}
 288
 289static void add_namespace(struct list_head *head, const char *namespace)
 290{
 291	struct namespace_list *ns_entry;
 292
 293	if (!contains_namespace(head, namespace)) {
 294		ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1);
 295		strcpy(ns_entry->namespace, namespace);
 296		list_add_tail(&ns_entry->list, head);
 
 297	}
 
 298}
 299
 300static void *sym_get_data_by_offset(const struct elf_info *info,
 301				    unsigned int secindex, unsigned long offset)
 302{
 303	Elf_Shdr *sechdr = &info->sechdrs[secindex];
 304
 
 
 
 305	return (void *)info->hdr + sechdr->sh_offset + offset;
 306}
 307
 308void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 309{
 310	return sym_get_data_by_offset(info, get_secindex(info, sym),
 311				      sym->st_value);
 312}
 313
 314static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 315{
 316	return sym_get_data_by_offset(info, info->secindex_strings,
 317				      sechdr->sh_name);
 318}
 319
 320static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 
 
 
 
 
 
 
 321{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 322	/*
 323	 * If sym->st_shndx is a special section index, there is no
 324	 * corresponding section header.
 325	 * Return "" if the index is out of range of info->sechdrs[] array.
 326	 */
 327	if (secindex >= info->num_sections)
 328		return "";
 
 
 
 329
 330	return sech_name(info, &info->sechdrs[secindex]);
 
 
 331}
 332
 
 
 
 
 333static struct symbol *sym_add_exported(const char *name, struct module *mod,
 334				       bool gpl_only, const char *namespace)
 335{
 336	struct symbol *s = find_symbol(name);
 337
 338	if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 339		error("%s: '%s' exported twice. Previous export was in %s%s\n",
 340		      mod->name, name, s->module->name,
 341		      s->module->is_vmlinux ? "" : ".ko");
 
 
 
 
 342	}
 343
 344	s = alloc_symbol(name);
 345	s->module = mod;
 346	s->is_gpl_only = gpl_only;
 347	s->namespace = xstrdup(namespace);
 348	list_add_tail(&s->list, &mod->exported_symbols);
 349	hash_add_symbol(s);
 350
 351	return s;
 352}
 353
 354static void sym_set_crc(struct symbol *sym, unsigned int crc)
 355{
 356	sym->crc = crc;
 357	sym->crc_valid = true;
 
 
 
 
 
 
 
 
 
 358}
 359
 360static void *grab_file(const char *filename, size_t *size)
 361{
 362	struct stat st;
 363	void *map = MAP_FAILED;
 364	int fd;
 365
 366	fd = open(filename, O_RDONLY);
 367	if (fd < 0)
 368		return NULL;
 369	if (fstat(fd, &st))
 370		goto failed;
 371
 372	*size = st.st_size;
 373	map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 374
 375failed:
 376	close(fd);
 377	if (map == MAP_FAILED)
 378		return NULL;
 379	return map;
 380}
 381
 382static void release_file(void *file, size_t size)
 383{
 384	munmap(file, size);
 385}
 386
 387static int parse_elf(struct elf_info *info, const char *filename)
 388{
 389	unsigned int i;
 390	Elf_Ehdr *hdr;
 391	Elf_Shdr *sechdrs;
 392	Elf_Sym  *sym;
 393	const char *secstrings;
 394	unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 395
 396	hdr = grab_file(filename, &info->size);
 397	if (!hdr) {
 398		if (ignore_missing_files) {
 399			fprintf(stderr, "%s: %s (ignored)\n", filename,
 400				strerror(errno));
 401			return 0;
 402		}
 403		perror(filename);
 404		exit(1);
 405	}
 406	info->hdr = hdr;
 407	if (info->size < sizeof(*hdr)) {
 408		/* file too small, assume this is an empty .o file */
 409		return 0;
 410	}
 411	/* Is this a valid ELF file? */
 412	if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 413	    (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 414	    (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 415	    (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 416		/* Not an ELF file - silently ignore it */
 417		return 0;
 418	}
 419
 420	switch (hdr->e_ident[EI_DATA]) {
 421	case ELFDATA2LSB:
 422		target_is_big_endian = false;
 423		break;
 424	case ELFDATA2MSB:
 425		target_is_big_endian = true;
 426		break;
 427	default:
 428		fatal("target endian is unknown\n");
 429	}
 430
 431	/* Fix endianness in ELF header */
 432	hdr->e_type      = TO_NATIVE(hdr->e_type);
 433	hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 434	hdr->e_version   = TO_NATIVE(hdr->e_version);
 435	hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 436	hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 437	hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 438	hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 439	hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 440	hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 441	hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 442	hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 443	hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 444	hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 445	sechdrs = (void *)hdr + hdr->e_shoff;
 446	info->sechdrs = sechdrs;
 447
 448	/* modpost only works for relocatable objects */
 449	if (hdr->e_type != ET_REL)
 450		fatal("%s: not relocatable object.", filename);
 451
 452	/* Check if file offset is correct */
 453	if (hdr->e_shoff > info->size)
 454		fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 455		      (unsigned long)hdr->e_shoff, filename, info->size);
 
 
 456
 457	if (hdr->e_shnum == SHN_UNDEF) {
 458		/*
 459		 * There are more than 64k sections,
 460		 * read count from .sh_size.
 461		 */
 462		info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 463	}
 464	else {
 465		info->num_sections = hdr->e_shnum;
 466	}
 467	if (hdr->e_shstrndx == SHN_XINDEX) {
 468		info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 469	}
 470	else {
 471		info->secindex_strings = hdr->e_shstrndx;
 472	}
 473
 474	/* Fix endianness in section headers */
 475	for (i = 0; i < info->num_sections; i++) {
 476		sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 477		sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 478		sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 479		sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 480		sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 481		sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 482		sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 483		sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 484		sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 485		sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 486	}
 487	/* Find symbol table. */
 488	secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 489	for (i = 1; i < info->num_sections; i++) {
 490		const char *secname;
 491		int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 492
 493		if (!nobits && sechdrs[i].sh_offset > info->size)
 494			fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 495			      filename, (unsigned long)sechdrs[i].sh_offset,
 
 496			      sizeof(*hdr));
 497
 
 498		secname = secstrings + sechdrs[i].sh_name;
 499		if (strcmp(secname, ".modinfo") == 0) {
 500			if (nobits)
 501				fatal("%s has NOBITS .modinfo\n", filename);
 502			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 503			info->modinfo_len = sechdrs[i].sh_size;
 504		} else if (!strcmp(secname, ".export_symbol")) {
 505			info->export_symbol_secndx = i;
 506		}
 
 507
 508		if (sechdrs[i].sh_type == SHT_SYMTAB) {
 509			unsigned int sh_link_idx;
 510			symtab_idx = i;
 511			info->symtab_start = (void *)hdr +
 512			    sechdrs[i].sh_offset;
 513			info->symtab_stop  = (void *)hdr +
 514			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 515			sh_link_idx = sechdrs[i].sh_link;
 516			info->strtab       = (void *)hdr +
 517			    sechdrs[sh_link_idx].sh_offset;
 518		}
 519
 520		/* 32bit section no. table? ("more than 64k sections") */
 521		if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 522			symtab_shndx_idx = i;
 523			info->symtab_shndx_start = (void *)hdr +
 524			    sechdrs[i].sh_offset;
 525			info->symtab_shndx_stop  = (void *)hdr +
 526			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 527		}
 528	}
 529	if (!info->symtab_start)
 530		fatal("%s has no symtab?\n", filename);
 531
 532	/* Fix endianness in symbols */
 533	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 534		sym->st_shndx = TO_NATIVE(sym->st_shndx);
 535		sym->st_name  = TO_NATIVE(sym->st_name);
 536		sym->st_value = TO_NATIVE(sym->st_value);
 537		sym->st_size  = TO_NATIVE(sym->st_size);
 538	}
 539
 540	if (symtab_shndx_idx != ~0U) {
 541		Elf32_Word *p;
 542		if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 543			fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 544			      filename, sechdrs[symtab_shndx_idx].sh_link,
 545			      symtab_idx);
 546		/* Fix endianness */
 547		for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 548		     p++)
 549			*p = TO_NATIVE(*p);
 550	}
 551
 552	symsearch_init(info);
 553
 554	return 1;
 555}
 556
 557static void parse_elf_finish(struct elf_info *info)
 558{
 559	symsearch_finish(info);
 560	release_file(info->hdr, info->size);
 561}
 562
 563static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 564{
 565	/* ignore __this_module, it will be resolved shortly */
 566	if (strcmp(symname, "__this_module") == 0)
 567		return 1;
 568	/* ignore global offset table */
 569	if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 570		return 1;
 571	if (info->hdr->e_machine == EM_PPC)
 572		/* Special register function linked on all modules during final link of .ko */
 573		if (strstarts(symname, "_restgpr_") ||
 574		    strstarts(symname, "_savegpr_") ||
 575		    strstarts(symname, "_rest32gpr_") ||
 576		    strstarts(symname, "_save32gpr_") ||
 577		    strstarts(symname, "_restvr_") ||
 578		    strstarts(symname, "_savevr_"))
 579			return 1;
 580	if (info->hdr->e_machine == EM_PPC64)
 581		/* Special register function linked on all modules during final link of .ko */
 582		if (strstarts(symname, "_restgpr0_") ||
 583		    strstarts(symname, "_savegpr0_") ||
 584		    strstarts(symname, "_restvr_") ||
 585		    strstarts(symname, "_savevr_") ||
 586		    strcmp(symname, ".TOC.") == 0)
 587			return 1;
 588	/* Do not ignore this symbol */
 589	return 0;
 590}
 591
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 592static void handle_symbol(struct module *mod, struct elf_info *info,
 593			  const Elf_Sym *sym, const char *symname)
 594{
 
 
 
 
 
 
 
 
 595	switch (sym->st_shndx) {
 596	case SHN_COMMON:
 597		if (strstarts(symname, "__gnu_lto_")) {
 598			/* Should warn here, but modpost runs before the linker */
 599		} else
 600			warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 601		break;
 602	case SHN_UNDEF:
 603		/* undefined symbol */
 604		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 605		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 606			break;
 607		if (ignore_undef_symbol(info, symname))
 608			break;
 609		if (info->hdr->e_machine == EM_SPARC ||
 610		    info->hdr->e_machine == EM_SPARCV9) {
 611			/* Ignore register directives. */
 612			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 613				break;
 614			if (symname[0] == '.') {
 615				char *munged = xstrdup(symname);
 616				munged[0] = '_';
 617				munged[1] = toupper(munged[1]);
 618				symname = munged;
 619			}
 620		}
 621
 622		sym_add_unresolved(symname, mod,
 623				   ELF_ST_BIND(sym->st_info) == STB_WEAK);
 
 624		break;
 625	default:
 
 
 
 
 
 626		if (strcmp(symname, "init_module") == 0)
 627			mod->has_init = true;
 628		if (strcmp(symname, "cleanup_module") == 0)
 629			mod->has_cleanup = true;
 630		break;
 631	}
 632}
 633
 634/**
 635 * Parse tag=value strings from .modinfo section
 636 **/
 637static char *next_string(char *string, unsigned long *secsize)
 638{
 639	/* Skip non-zero chars */
 640	while (string[0]) {
 641		string++;
 642		if ((*secsize)-- <= 1)
 643			return NULL;
 644	}
 645
 646	/* Skip any zero padding. */
 647	while (!string[0]) {
 648		string++;
 649		if ((*secsize)-- <= 1)
 650			return NULL;
 651	}
 652	return string;
 653}
 654
 655static char *get_next_modinfo(struct elf_info *info, const char *tag,
 656			      char *prev)
 657{
 658	char *p;
 659	unsigned int taglen = strlen(tag);
 660	char *modinfo = info->modinfo;
 661	unsigned long size = info->modinfo_len;
 662
 663	if (prev) {
 664		size -= prev - modinfo;
 665		modinfo = next_string(prev, &size);
 666	}
 667
 668	for (p = modinfo; p; p = next_string(p, &size)) {
 669		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 670			return p + taglen + 1;
 671	}
 672	return NULL;
 673}
 674
 675static char *get_modinfo(struct elf_info *info, const char *tag)
 676
 677{
 678	return get_next_modinfo(info, tag, NULL);
 679}
 680
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 681static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 682{
 683	return sym ? elf->strtab + sym->st_name : "";
 
 
 
 684}
 685
 686/*
 687 * Check whether the 'string' argument matches one of the 'patterns',
 688 * an array of shell wildcard patterns (glob).
 689 *
 690 * Return true is there is a match.
 691 */
 692static bool match(const char *string, const char *const patterns[])
 693{
 694	const char *pattern;
 695
 696	while ((pattern = *patterns++)) {
 697		if (!fnmatch(pattern, string, 0))
 698			return true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 699	}
 700
 701	return false;
 702}
 703
 704/* useful to pass patterns to match() directly */
 705#define PATTERNS(...) \
 706	({ \
 707		static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 708		patterns; \
 709	})
 710
 711/* sections that we do not want to do full section mismatch check on */
 712static const char *const section_white_list[] =
 713{
 714	".comment*",
 715	".debug*",
 
 716	".zdebug*",		/* Compressed debug sections. */
 717	".GCC.command.line",	/* record-gcc-switches */
 718	".mdebug*",        /* alpha, score, mips etc. */
 719	".pdr",            /* alpha, score, mips etc. */
 720	".stab*",
 721	".note*",
 722	".got*",
 723	".toc*",
 724	".xt.prop",				 /* xtensa */
 725	".xt.lit",         /* xtensa */
 726	".arcextmap*",			/* arc */
 727	".gnu.linkonce.arcext*",	/* arc : modules */
 728	".cmem*",			/* EZchip */
 729	".fmt_slot*",			/* EZchip */
 730	".gnu.lto*",
 731	".discard.*",
 732	".llvm.call-graph-profile",	/* call graph */
 733	NULL
 734};
 735
 736/*
 737 * This is used to find sections missing the SHF_ALLOC flag.
 738 * The cause of this is often a section specified in assembler
 739 * without "ax" / "aw".
 740 */
 741static void check_section(const char *modname, struct elf_info *elf,
 742			  Elf_Shdr *sechdr)
 743{
 744	const char *sec = sech_name(elf, sechdr);
 745
 746	if (sechdr->sh_type == SHT_PROGBITS &&
 747	    !(sechdr->sh_flags & SHF_ALLOC) &&
 748	    !match(sec, section_white_list)) {
 749		warn("%s (%s): unexpected non-allocatable section.\n"
 750		     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 751		     "Note that for example <linux/init.h> contains\n"
 752		     "section definitions for use in .S files.\n\n",
 753		     modname, sec);
 754	}
 755}
 756
 757
 758
 759#define ALL_INIT_DATA_SECTIONS \
 760	".init.setup", ".init.rodata", ".init.data"
 
 
 
 
 
 
 
 
 761
 762#define ALL_PCI_INIT_SECTIONS	\
 763	".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 764	".pci_fixup_enable", ".pci_fixup_resume", \
 765	".pci_fixup_resume_early", ".pci_fixup_suspend"
 766
 767#define ALL_INIT_SECTIONS ".init.*"
 768#define ALL_EXIT_SECTIONS ".exit.*"
 
 
 
 769
 770#define DATA_SECTIONS ".data", ".data.rel"
 771#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 772		".kprobes.text", ".cpuidle.text", ".noinstr.text", \
 773		".ltext", ".ltext.*"
 774#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 775		".fixup", ".entry.text", ".exception.text", \
 776		".coldtext", ".softirqentry.text", ".irqentry.text"
 
 
 
 
 
 
 777
 778#define ALL_TEXT_SECTIONS  ".init.text", ".exit.text", \
 779		TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 780
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 781enum mismatch {
 782	TEXTDATA_TO_ANY_INIT_EXIT,
 
 
 
 783	XXXINIT_TO_SOME_INIT,
 
 784	ANY_INIT_TO_ANY_EXIT,
 785	ANY_EXIT_TO_ANY_INIT,
 
 786	EXTABLE_TO_NON_TEXT,
 787};
 788
 789/**
 790 * Describe how to match sections on different criteria:
 791 *
 792 * @fromsec: Array of sections to be matched.
 793 *
 794 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 795 * this array is forbidden (black-list).  Can be empty.
 796 *
 797 * @good_tosec: Relocations applied to a section in @fromsec must be
 798 * targeting sections in this array (white-list).  Can be empty.
 799 *
 800 * @mismatch: Type of mismatch.
 
 
 
 
 
 
 
 801 */
 802struct sectioncheck {
 803	const char *fromsec[20];
 804	const char *bad_tosec[20];
 805	const char *good_tosec[20];
 806	enum mismatch mismatch;
 
 
 
 
 
 807};
 808
 
 
 
 
 
 809static const struct sectioncheck sectioncheck[] = {
 810/* Do not reference init/exit code/data from
 811 * normal code and data
 812 */
 813{
 814	.fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 815	.bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
 816	.mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 817},
 818/* Do not use exit code/data from init code */
 819{
 820	.fromsec = { ALL_INIT_SECTIONS, NULL },
 821	.bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 822	.mismatch = ANY_INIT_TO_ANY_EXIT,
 
 823},
 824/* Do not use init code/data from exit code */
 825{
 826	.fromsec = { ALL_EXIT_SECTIONS, NULL },
 827	.bad_tosec = { ALL_INIT_SECTIONS, NULL },
 828	.mismatch = ANY_EXIT_TO_ANY_INIT,
 
 829},
 830{
 831	.fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 832	.bad_tosec = { ALL_INIT_SECTIONS, NULL },
 833	.mismatch = ANY_INIT_TO_ANY_EXIT,
 
 
 
 
 
 
 
 
 834},
 835{
 836	.fromsec = { "__ex_table", NULL },
 837	/* If you're adding any new black-listed sections in here, consider
 838	 * adding a special 'printer' for them in scripts/check_extable.
 839	 */
 840	.bad_tosec = { ".altinstr_replacement", NULL },
 841	.good_tosec = {ALL_TEXT_SECTIONS , NULL},
 842	.mismatch = EXTABLE_TO_NON_TEXT,
 
 843}
 844};
 845
 846static const struct sectioncheck *section_mismatch(
 847		const char *fromsec, const char *tosec)
 848{
 849	int i;
 
 
 850
 851	/*
 852	 * The target section could be the SHT_NUL section when we're
 853	 * handling relocations to un-resolved symbols, trying to match it
 854	 * doesn't make much sense and causes build failures on parisc
 855	 * architectures.
 856	 */
 857	if (*tosec == '\0')
 858		return NULL;
 859
 860	for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 861		const struct sectioncheck *check = &sectioncheck[i];
 862
 863		if (match(fromsec, check->fromsec)) {
 864			if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 865				return check;
 866			if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 867				return check;
 868		}
 
 869	}
 870	return NULL;
 871}
 872
 873/**
 874 * Whitelist to allow certain references to pass with no warning.
 875 *
 876 * Pattern 1:
 877 *   If a module parameter is declared __initdata and permissions=0
 878 *   then this is legal despite the warning generated.
 879 *   We cannot see value of permissions here, so just ignore
 880 *   this pattern.
 881 *   The pattern is identified by:
 882 *   tosec   = .init.data
 883 *   fromsec = .data*
 884 *   atsym   =__param*
 885 *
 886 * Pattern 1a:
 887 *   module_param_call() ops can refer to __init set function if permissions=0
 888 *   The pattern is identified by:
 889 *   tosec   = .init.text
 890 *   fromsec = .data*
 891 *   atsym   = __param_ops_*
 892 *
 
 
 
 
 
 
 
 
 
 893 * Pattern 3:
 894 *   Whitelist all references from .head.text to any init section
 895 *
 896 * Pattern 4:
 897 *   Some symbols belong to init section but still it is ok to reference
 898 *   these from non-init sections as these symbols don't have any memory
 899 *   allocated for them and symbol address and value are same. So even
 900 *   if init section is freed, its ok to reference those symbols.
 901 *   For ex. symbols marking the init section boundaries.
 902 *   This pattern is identified by
 903 *   refsymname = __init_begin, _sinittext, _einittext
 904 *
 905 * Pattern 5:
 906 *   GCC may optimize static inlines when fed constant arg(s) resulting
 907 *   in functions like cpumask_empty() -- generating an associated symbol
 908 *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 909 *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 910 *   meaningless section warning.  May need to add isra symbols too...
 911 *   This pattern is identified by
 912 *   tosec   = init section
 913 *   fromsec = text section
 914 *   refsymname = *.constprop.*
 915 *
 
 
 
 
 
 
 
 
 916 **/
 917static int secref_whitelist(const char *fromsec, const char *fromsym,
 
 918			    const char *tosec, const char *tosym)
 919{
 920	/* Check for pattern 1 */
 921	if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 922	    match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 923	    strstarts(fromsym, "__param"))
 924		return 0;
 925
 926	/* Check for pattern 1a */
 927	if (strcmp(tosec, ".init.text") == 0 &&
 928	    match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 929	    strstarts(fromsym, "__param_ops_"))
 930		return 0;
 931
 932	/* symbols in data sections that may refer to any init/exit sections */
 933	if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 934	    match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
 935	    match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
 936		return 0;
 937
 938	/* Check for pattern 3 */
 939	if (strstarts(fromsec, ".head.text") &&
 940	    match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
 941		return 0;
 942
 943	/* Check for pattern 4 */
 944	if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
 945		return 0;
 946
 947	/* Check for pattern 5 */
 948	if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
 949	    match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
 950	    match(fromsym, PATTERNS("*.constprop.*")))
 
 
 
 
 951		return 0;
 952
 953	return 1;
 954}
 955
 956static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
 957			     unsigned int secndx)
 958{
 959	return symsearch_find_nearest(elf, addr, secndx, false, ~0);
 
 960}
 961
 962static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
 
 
 
 
 
 
 
 
 
 963{
 964	Elf_Sym *new_sym;
 965
 966	/* If the supplied symbol has a valid name, return it */
 967	if (is_valid_name(elf, sym))
 968		return sym;
 
 969
 970	/*
 971	 * Strive to find a better symbol name, but the resulting name may not
 972	 * match the symbol referenced in the original code.
 973	 */
 974	new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
 975					 true, 20);
 976	return new_sym ? new_sym : sym;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 977}
 978
 979static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
 
 
 
 
 
 
 
 980{
 981	if (secndx >= elf->num_sections)
 982		return false;
 
 983
 984	return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 985}
 986
 987static void default_mismatch_handler(const char *modname, struct elf_info *elf,
 988				     const struct sectioncheck* const mismatch,
 989				     Elf_Sym *tsym,
 990				     unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
 991				     const char *tosec, Elf_Addr taddr)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 992{
 993	Elf_Sym *from;
 994	const char *tosym;
 995	const char *fromsym;
 996	char taddr_str[16];
 
 997
 998	from = find_fromsym(elf, faddr, fsecndx);
 999	fromsym = sym_name(elf, from);
 
1000
1001	tsym = find_tosym(elf, taddr, tsym);
1002	tosym = sym_name(elf, tsym);
 
 
 
 
 
 
1003
1004	/* check whitelist - we may ignore it */
1005	if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1006		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1007
1008	sec_mismatch_count++;
1009
1010	if (!tosym[0])
1011		snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
1012
1013	/*
1014	 * The format for the reference source:      <symbol_name>+<offset> or <address>
1015	 * The format for the reference destination: <symbol_name>          or <address>
1016	 */
1017	warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
1018	     modname, fromsym, fromsym[0] ? "+" : "",
1019	     (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
1020	     fromsec, tosym[0] ? tosym : taddr_str, tosec);
1021
1022	if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1023		if (match(tosec, mismatch->bad_tosec))
1024			fatal("The relocation at %s+0x%lx references\n"
1025			      "section \"%s\" which is black-listed.\n"
1026			      "Something is seriously wrong and should be fixed.\n"
1027			      "You might get more information about where this is\n"
1028			      "coming from by using scripts/check_extable.sh %s\n",
1029			      fromsec, (long)faddr, tosec, modname);
1030		else if (is_executable_section(elf, get_secindex(elf, tsym)))
1031			warn("The relocation at %s+0x%lx references\n"
1032			     "section \"%s\" which is not in the list of\n"
1033			     "authorized sections.  If you're adding a new section\n"
1034			     "and/or if this reference is valid, add \"%s\" to the\n"
1035			     "list of authorized sections to jump to on fault.\n"
1036			     "This can be achieved by adding \"%s\" to\n"
1037			     "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1038			     fromsec, (long)faddr, tosec, tosec, tosec);
1039		else
1040			error("%s+0x%lx references non-executable section '%s'\n",
1041			      fromsec, (long)faddr, tosec);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1042	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1043}
1044
1045static void check_export_symbol(struct module *mod, struct elf_info *elf,
1046				Elf_Addr faddr, const char *secname,
1047				Elf_Sym *sym)
1048{
1049	static const char *prefix = "__export_symbol_";
1050	const char *label_name, *name, *data;
1051	Elf_Sym *label;
1052	struct symbol *s;
1053	bool is_gpl;
1054
1055	label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1056	label_name = sym_name(elf, label);
1057
1058	if (!strstarts(label_name, prefix)) {
1059		error("%s: .export_symbol section contains strange symbol '%s'\n",
1060		      mod->name, label_name);
1061		return;
1062	}
1063
1064	if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1065	    ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1066		error("%s: local symbol '%s' was exported\n", mod->name,
1067		      label_name + strlen(prefix));
1068		return;
1069	}
1070
1071	name = sym_name(elf, sym);
1072	if (strcmp(label_name + strlen(prefix), name)) {
1073		error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1074		      mod->name, name);
1075		return;
 
 
1076	}
 
1077
1078	data = sym_get_data(elf, label);	/* license */
1079	if (!strcmp(data, "GPL")) {
1080		is_gpl = true;
1081	} else if (!strcmp(data, "")) {
1082		is_gpl = false;
1083	} else {
1084		error("%s: unknown license '%s' was specified for '%s'\n",
1085		      mod->name, data, name);
1086		return;
1087	}
1088
1089	data += strlen(data) + 1;	/* namespace */
1090	s = sym_add_exported(name, mod, is_gpl, data);
1091
 
 
 
 
 
 
 
1092	/*
1093	 * We need to be aware whether we are exporting a function or
1094	 * a data on some architectures.
 
 
 
 
 
1095	 */
1096	s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
 
 
1097
 
 
1098	/*
1099	 * For parisc64, symbols prefixed $$ from the library have the symbol type
1100	 * STT_LOPROC. They should be handled as functions too.
 
1101	 */
1102	if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1103	    elf->hdr->e_machine == EM_PARISC &&
1104	    ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1105		s->is_func = true;
1106
1107	if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1108		warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1109		     mod->name, name);
1110	else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1111		warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1112		     mod->name, name);
1113}
1114
1115static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1116				   Elf_Sym *sym,
1117				   unsigned int fsecndx, const char *fromsec,
1118				   Elf_Addr faddr, Elf_Addr taddr)
1119{
1120	const char *tosec = sec_name(elf, get_secindex(elf, sym));
1121	const struct sectioncheck *mismatch;
1122
1123	if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1124		check_export_symbol(mod, elf, faddr, tosec, sym);
1125		return;
1126	}
1127
1128	mismatch = section_mismatch(fromsec, tosec);
1129	if (!mismatch)
1130		return;
1131
1132	default_mismatch_handler(mod->name, elf, mismatch, sym,
1133				 fsecndx, fromsec, faddr,
1134				 tosec, taddr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1135}
1136
1137static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
 
 
 
1138{
1139	switch (r_type) {
1140	case R_386_32:
1141		return get_unaligned_native(location);
1142	case R_386_PC32:
1143		return get_unaligned_native(location) + 4;
1144	}
1145
1146	return (Elf_Addr)(-1);
1147}
1148
1149static int32_t sign_extend32(int32_t value, int index)
1150{
1151	uint8_t shift = 31 - index;
1152
1153	return (int32_t)(value << shift) >> shift;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1154}
1155
1156static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
 
1157{
1158	uint32_t inst, upper, lower, sign, j1, j2;
1159	int32_t offset;
1160
1161	switch (r_type) {
1162	case R_ARM_ABS32:
1163	case R_ARM_REL32:
1164		inst = get_unaligned_native((uint32_t *)loc);
1165		return inst + sym->st_value;
1166	case R_ARM_MOVW_ABS_NC:
1167	case R_ARM_MOVT_ABS:
1168		inst = get_unaligned_native((uint32_t *)loc);
1169		offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1170				       15);
1171		return offset + sym->st_value;
1172	case R_ARM_PC24:
1173	case R_ARM_CALL:
1174	case R_ARM_JUMP24:
1175		inst = get_unaligned_native((uint32_t *)loc);
1176		offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1177		return offset + sym->st_value + 8;
1178	case R_ARM_THM_MOVW_ABS_NC:
1179	case R_ARM_THM_MOVT_ABS:
1180		upper = get_unaligned_native((uint16_t *)loc);
1181		lower = get_unaligned_native((uint16_t *)loc + 1);
1182		offset = sign_extend32(((upper & 0x000f) << 12) |
1183				       ((upper & 0x0400) << 1) |
1184				       ((lower & 0x7000) >> 4) |
1185				       (lower & 0x00ff),
1186				       15);
1187		return offset + sym->st_value;
1188	case R_ARM_THM_JUMP19:
1189		/*
1190		 * Encoding T3:
1191		 * S     = upper[10]
1192		 * imm6  = upper[5:0]
1193		 * J1    = lower[13]
1194		 * J2    = lower[11]
1195		 * imm11 = lower[10:0]
1196		 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1197		 */
1198		upper = get_unaligned_native((uint16_t *)loc);
1199		lower = get_unaligned_native((uint16_t *)loc + 1);
1200
1201		sign = (upper >> 10) & 1;
1202		j1 = (lower >> 13) & 1;
1203		j2 = (lower >> 11) & 1;
1204		offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1205				       ((upper & 0x03f) << 12) |
1206				       ((lower & 0x07ff) << 1),
1207				       20);
1208		return offset + sym->st_value + 4;
1209	case R_ARM_THM_PC22:
1210	case R_ARM_THM_JUMP24:
1211		/*
1212		 * Encoding T4:
1213		 * S     = upper[10]
1214		 * imm10 = upper[9:0]
1215		 * J1    = lower[13]
1216		 * J2    = lower[11]
1217		 * imm11 = lower[10:0]
1218		 * I1    = NOT(J1 XOR S)
1219		 * I2    = NOT(J2 XOR S)
1220		 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1221		 */
1222		upper = get_unaligned_native((uint16_t *)loc);
1223		lower = get_unaligned_native((uint16_t *)loc + 1);
1224
1225		sign = (upper >> 10) & 1;
1226		j1 = (lower >> 13) & 1;
1227		j2 = (lower >> 11) & 1;
1228		offset = sign_extend32((sign << 24) |
1229				       ((~(j1 ^ sign) & 1) << 23) |
1230				       ((~(j2 ^ sign) & 1) << 22) |
1231				       ((upper & 0x03ff) << 12) |
1232				       ((lower & 0x07ff) << 1),
1233				       24);
1234		return offset + sym->st_value + 4;
1235	}
 
1236
1237	return (Elf_Addr)(-1);
 
 
 
1238}
1239
1240static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1241{
1242	uint32_t inst;
 
1243
1244	inst = get_unaligned_native(location);
1245	switch (r_type) {
1246	case R_MIPS_LO16:
1247		return inst & 0xffff;
1248	case R_MIPS_26:
1249		return (inst & 0x03ffffff) << 2;
1250	case R_MIPS_32:
1251		return inst;
 
 
1252	}
1253	return (Elf_Addr)(-1);
1254}
1255
1256#ifndef EM_RISCV
1257#define EM_RISCV		243
1258#endif
1259
1260#ifndef R_RISCV_SUB32
1261#define R_RISCV_SUB32		39
1262#endif
1263
1264#ifndef EM_LOONGARCH
1265#define EM_LOONGARCH		258
1266#endif
1267
1268#ifndef R_LARCH_SUB32
1269#define R_LARCH_SUB32		55
1270#endif
1271
1272#ifndef R_LARCH_RELAX
1273#define R_LARCH_RELAX		100
1274#endif
1275
1276#ifndef R_LARCH_ALIGN
1277#define R_LARCH_ALIGN		102
1278#endif
1279
1280static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1281				 unsigned int *r_type, unsigned int *r_sym)
1282{
1283	typedef struct {
1284		Elf64_Word    r_sym;	/* Symbol index */
1285		unsigned char r_ssym;	/* Special symbol for 2nd relocation */
1286		unsigned char r_type3;	/* 3rd relocation type */
1287		unsigned char r_type2;	/* 2nd relocation type */
1288		unsigned char r_type;	/* 1st relocation type */
1289	} Elf64_Mips_R_Info;
1290
1291	bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1292
1293	if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1294		Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1295
1296		*r_type = mips64_r_info->r_type;
1297		*r_sym = TO_NATIVE(mips64_r_info->r_sym);
1298		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1299	}
 
 
1300
1301	if (is_64bit)
1302		r_info = TO_NATIVE((Elf64_Xword)r_info);
1303	else
1304		r_info = TO_NATIVE((Elf32_Word)r_info);
1305
1306	*r_type = ELF_R_TYPE(r_info);
1307	*r_sym = ELF_R_SYM(r_info);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1308}
1309
1310static void section_rela(struct module *mod, struct elf_info *elf,
1311			 unsigned int fsecndx, const char *fromsec,
1312			 const Elf_Rela *start, const Elf_Rela *stop)
1313{
1314	const Elf_Rela *rela;
 
 
 
 
 
 
 
 
 
 
 
 
 
1315
1316	for (rela = start; rela < stop; rela++) {
1317		Elf_Sym *tsym;
1318		Elf_Addr taddr, r_offset;
1319		unsigned int r_type, r_sym;
1320
1321		r_offset = TO_NATIVE(rela->r_offset);
1322		get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1323
1324		tsym = elf->symtab_start + r_sym;
1325		taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1326
1327		switch (elf->hdr->e_machine) {
1328		case EM_RISCV:
1329			if (!strcmp("__ex_table", fromsec) &&
1330			    r_type == R_RISCV_SUB32)
1331				continue;
1332			break;
1333		case EM_LOONGARCH:
1334			switch (r_type) {
1335			case R_LARCH_SUB32:
1336				if (!strcmp("__ex_table", fromsec))
1337					continue;
1338				break;
1339			case R_LARCH_RELAX:
1340			case R_LARCH_ALIGN:
1341				/* These relocs do not refer to symbols */
1342				continue;
1343			}
1344			break;
1345		}
1346
1347		check_section_mismatch(mod, elf, tsym,
1348				       fsecndx, fromsec, r_offset, taddr);
 
 
 
 
 
 
 
 
 
1349	}
1350}
1351
1352static void section_rel(struct module *mod, struct elf_info *elf,
1353			unsigned int fsecndx, const char *fromsec,
1354			const Elf_Rel *start, const Elf_Rel *stop)
1355{
1356	const Elf_Rel *rel;
 
 
 
 
 
 
 
 
 
 
 
 
 
1357
1358	for (rel = start; rel < stop; rel++) {
1359		Elf_Sym *tsym;
1360		Elf_Addr taddr, r_offset;
1361		unsigned int r_type, r_sym;
1362		void *loc;
1363
1364		r_offset = TO_NATIVE(rel->r_offset);
1365		get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1366
1367		loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1368		tsym = elf->symtab_start + r_sym;
1369
 
 
 
 
 
 
1370		switch (elf->hdr->e_machine) {
1371		case EM_386:
1372			taddr = addend_386_rel(loc, r_type);
 
1373			break;
1374		case EM_ARM:
1375			taddr = addend_arm_rel(loc, tsym, r_type);
 
1376			break;
1377		case EM_MIPS:
1378			taddr = addend_mips_rel(loc, r_type);
 
1379			break;
1380		default:
1381			fatal("Please add code to calculate addend for this architecture\n");
1382		}
1383
1384		check_section_mismatch(mod, elf, tsym,
1385				       fsecndx, fromsec, r_offset, taddr);
 
 
 
 
1386	}
1387}
1388
1389/**
1390 * A module includes a number of sections that are discarded
1391 * either when loaded or when used as built-in.
1392 * For loaded modules all functions marked __init and all data
1393 * marked __initdata will be discarded when the module has been initialized.
1394 * Likewise for modules used built-in the sections marked __exit
1395 * are discarded because __exit marked function are supposed to be called
1396 * only when a module is unloaded which never happens for built-in modules.
1397 * The check_sec_ref() function traverses all relocation records
1398 * to find all references to a section that reference a section that will
1399 * be discarded and warns about it.
1400 **/
1401static void check_sec_ref(struct module *mod, struct elf_info *elf)
 
1402{
1403	int i;
 
1404
1405	/* Walk through all sections */
1406	for (i = 0; i < elf->num_sections; i++) {
1407		Elf_Shdr *sechdr = &elf->sechdrs[i];
1408
1409		check_section(mod->name, elf, sechdr);
1410		/* We want to process only relocation sections and not .init */
1411		if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1412			/* section to which the relocation applies */
1413			unsigned int secndx = sechdr->sh_info;
1414			const char *secname = sec_name(elf, secndx);
1415			const void *start, *stop;
1416
1417			/* If the section is known good, skip it */
1418			if (match(secname, section_white_list))
1419				continue;
1420
1421			start = sym_get_data_by_offset(elf, i, 0);
1422			stop = start + sechdr->sh_size;
1423
1424			if (sechdr->sh_type == SHT_RELA)
1425				section_rela(mod, elf, secndx, secname,
1426					     start, stop);
1427			else
1428				section_rel(mod, elf, secndx, secname,
1429					    start, stop);
1430		}
1431	}
1432}
1433
1434static char *remove_dot(char *s)
1435{
1436	size_t n = strcspn(s, ".");
1437
1438	if (n && s[n]) {
1439		size_t m = strspn(s + n + 1, "0123456789");
1440		if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1441			s[n] = 0;
1442	}
1443	return s;
1444}
1445
1446/*
1447 * The CRCs are recorded in .*.cmd files in the form of:
1448 * #SYMVER <name> <crc>
1449 */
1450static void extract_crcs_for_object(const char *object, struct module *mod)
1451{
1452	char cmd_file[PATH_MAX];
1453	char *buf, *p;
1454	const char *base;
1455	int dirlen, ret;
1456
1457	base = strrchr(object, '/');
1458	if (base) {
1459		base++;
1460		dirlen = base - object;
1461	} else {
1462		dirlen = 0;
1463		base = object;
1464	}
1465
1466	ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1467		       dirlen, object, base);
1468	if (ret >= sizeof(cmd_file)) {
1469		error("%s: too long path was truncated\n", cmd_file);
1470		return;
1471	}
1472
1473	buf = read_text_file(cmd_file);
1474	p = buf;
1475
1476	while ((p = strstr(p, "\n#SYMVER "))) {
1477		char *name;
1478		size_t namelen;
1479		unsigned int crc;
1480		struct symbol *sym;
1481
1482		name = p + strlen("\n#SYMVER ");
1483
1484		p = strchr(name, ' ');
1485		if (!p)
1486			break;
1487
1488		namelen = p - name;
1489		p++;
1490
1491		if (!isdigit(*p))
1492			continue;	/* skip this line */
1493
1494		crc = strtoul(p, &p, 0);
1495		if (*p != '\n')
1496			continue;	/* skip this line */
1497
1498		name[namelen] = '\0';
1499
1500		/*
1501		 * sym_find_with_module() may return NULL here.
1502		 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1503		 * Since commit e1327a127703, genksyms calculates CRCs of all
1504		 * symbols, including trimmed ones. Ignore orphan CRCs.
1505		 */
1506		sym = sym_find_with_module(name, mod);
1507		if (sym)
1508			sym_set_crc(sym, crc);
1509	}
1510
1511	free(buf);
1512}
1513
1514/*
1515 * The symbol versions (CRC) are recorded in the .*.cmd files.
1516 * Parse them to retrieve CRCs for the current module.
1517 */
1518static void mod_set_crcs(struct module *mod)
1519{
1520	char objlist[PATH_MAX];
1521	char *buf, *p, *obj;
1522	int ret;
1523
1524	if (mod->is_vmlinux) {
1525		strcpy(objlist, ".vmlinux.objs");
1526	} else {
1527		/* objects for a module are listed in the *.mod file. */
1528		ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1529		if (ret >= sizeof(objlist)) {
1530			error("%s: too long path was truncated\n", objlist);
1531			return;
1532		}
1533	}
1534
1535	buf = read_text_file(objlist);
1536	p = buf;
1537
1538	while ((obj = strsep(&p, "\n")) && obj[0])
1539		extract_crcs_for_object(obj, mod);
1540
1541	free(buf);
1542}
1543
1544static void read_symbols(const char *modname)
1545{
1546	const char *symname;
1547	char *version;
1548	char *license;
1549	char *namespace;
1550	struct module *mod;
1551	struct elf_info info = { };
1552	Elf_Sym *sym;
1553
1554	if (!parse_elf(&info, modname))
1555		return;
1556
1557	if (!strends(modname, ".o")) {
1558		error("%s: filename must be suffixed with .o\n", modname);
1559		return;
1560	}
1561
1562	/* strip trailing .o */
1563	mod = new_module(modname, strlen(modname) - strlen(".o"));
 
 
 
 
 
 
 
1564
1565	if (!mod->is_vmlinux) {
1566		license = get_modinfo(&info, "license");
1567		if (!license)
1568			error("missing MODULE_LICENSE() in %s\n", modname);
1569		while (license) {
1570			if (!license_is_gpl_compatible(license)) {
1571				mod->is_gpl_compatible = false;
 
 
1572				break;
1573			}
1574			license = get_next_modinfo(&info, "license", license);
1575		}
1576
1577		namespace = get_modinfo(&info, "import_ns");
1578		while (namespace) {
1579			add_namespace(&mod->imported_namespaces, namespace);
1580			namespace = get_next_modinfo(&info, "import_ns",
1581						     namespace);
1582		}
1583
1584		if (extra_warn && !get_modinfo(&info, "description"))
1585			warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1586	}
1587
1588	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1589		symname = remove_dot(info.strtab + sym->st_name);
1590
1591		handle_symbol(mod, &info, sym, symname);
1592		handle_moddevtable(mod, &info, sym, symname);
1593	}
1594
1595	check_sec_ref(mod, &info);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1596
1597	if (!mod->is_vmlinux) {
1598		version = get_modinfo(&info, "version");
1599		if (version || all_versions)
1600			get_src_version(mod->name, mod->srcversion,
1601					sizeof(mod->srcversion) - 1);
1602	}
1603
1604	parse_elf_finish(&info);
1605
1606	if (modversions) {
1607		/*
1608		 * Our trick to get versioning for module struct etc. - it's
1609		 * never passed as an argument to an exported function, so
1610		 * the automatic versioning doesn't pick it up, but it's really
1611		 * important anyhow.
1612		 */
1613		sym_add_unresolved("module_layout", mod, false);
1614
1615		mod_set_crcs(mod);
1616	}
1617}
1618
1619static void read_symbols_from_files(const char *filename)
1620{
1621	FILE *in = stdin;
1622	char fname[PATH_MAX];
1623
1624	in = fopen(filename, "r");
1625	if (!in)
1626		fatal("Can't open filenames file %s: %m", filename);
 
 
1627
1628	while (fgets(fname, PATH_MAX, in) != NULL) {
1629		if (strends(fname, "\n"))
1630			fname[strlen(fname)-1] = '\0';
1631		read_symbols(fname);
1632	}
1633
1634	fclose(in);
 
1635}
1636
1637#define SZ 500
1638
1639/* We first write the generated file into memory using the
1640 * following helper, then compare to the file on disk and
1641 * only update the later if anything changed */
1642
1643void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1644						      const char *fmt, ...)
1645{
1646	char tmp[SZ];
1647	int len;
1648	va_list ap;
1649
1650	va_start(ap, fmt);
1651	len = vsnprintf(tmp, SZ, fmt, ap);
1652	buf_write(buf, tmp, len);
1653	va_end(ap);
1654}
1655
1656void buf_write(struct buffer *buf, const char *s, int len)
1657{
1658	if (buf->size - buf->pos < len) {
1659		buf->size += len + SZ;
1660		buf->p = xrealloc(buf->p, buf->size);
1661	}
1662	strncpy(buf->p + buf->pos, s, len);
1663	buf->pos += len;
1664}
1665
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1666static void check_exports(struct module *mod)
1667{
1668	struct symbol *s, *exp;
1669
1670	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1671		const char *basename;
1672		exp = find_symbol(s->name);
1673		if (!exp) {
1674			if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1675				modpost_log(!warn_unresolved,
1676					    "\"%s\" [%s.ko] undefined!\n",
1677					    s->name, mod->name);
1678			continue;
1679		}
1680		if (exp->module == mod) {
1681			error("\"%s\" [%s.ko] was exported without definition\n",
1682			      s->name, mod->name);
1683			continue;
1684		}
1685
1686		exp->used = true;
1687		s->module = exp->module;
1688		s->crc_valid = exp->crc_valid;
1689		s->crc = exp->crc;
1690
1691		basename = strrchr(mod->name, '/');
1692		if (basename)
1693			basename++;
1694		else
1695			basename = mod->name;
1696
1697		if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1698			modpost_log(!allow_missing_ns_imports,
 
1699				    "module %s uses symbol %s from namespace %s, but does not import it.\n",
1700				    basename, exp->name, exp->namespace);
1701			add_namespace(&mod->missing_namespaces, exp->namespace);
1702		}
1703
1704		if (!mod->is_gpl_compatible && exp->is_gpl_only)
1705			error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1706			      basename, exp->name);
1707	}
1708}
1709
1710static void handle_white_list_exports(const char *white_list)
1711{
1712	char *buf, *p, *name;
1713
1714	buf = read_text_file(white_list);
1715	p = buf;
1716
1717	while ((name = strsep(&p, "\n"))) {
1718		struct symbol *sym = find_symbol(name);
1719
1720		if (sym)
1721			sym->used = true;
1722	}
1723
1724	free(buf);
1725}
1726
1727static void check_modname_len(struct module *mod)
1728{
1729	const char *mod_name;
1730
1731	mod_name = strrchr(mod->name, '/');
1732	if (mod_name == NULL)
1733		mod_name = mod->name;
1734	else
1735		mod_name++;
1736	if (strlen(mod_name) >= MODULE_NAME_LEN)
1737		error("module name is too long [%s.ko]\n", mod->name);
1738}
1739
1740/**
1741 * Header for the generated file
1742 **/
1743static void add_header(struct buffer *b, struct module *mod)
1744{
1745	buf_printf(b, "#include <linux/module.h>\n");
1746	buf_printf(b, "#include <linux/export-internal.h>\n");
 
 
 
 
 
 
 
1747	buf_printf(b, "#include <linux/compiler.h>\n");
1748	buf_printf(b, "\n");
 
 
 
 
1749	buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1750	buf_printf(b, "\n");
1751	buf_printf(b, "__visible struct module __this_module\n");
1752	buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1753	buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1754	if (mod->has_init)
1755		buf_printf(b, "\t.init = init_module,\n");
1756	if (mod->has_cleanup)
1757		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1758			      "\t.exit = cleanup_module,\n"
1759			      "#endif\n");
1760	buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1761	buf_printf(b, "};\n");
 
1762
1763	if (!external_module)
 
 
1764		buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1765
1766	if (strstarts(mod->name, "drivers/staging"))
1767		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1768
1769	if (strstarts(mod->name, "tools/testing"))
1770		buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1771}
1772
1773static void add_exported_symbols(struct buffer *buf, struct module *mod)
 
1774{
1775	struct symbol *sym;
1776
1777	/* generate struct for exported symbols */
1778	buf_printf(buf, "\n");
1779	list_for_each_entry(sym, &mod->exported_symbols, list) {
1780		if (trim_unused_exports && !sym->used)
1781			continue;
1782
1783		buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1784			   sym->is_func ? "FUNC" : "DATA", sym->name,
1785			   sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1786	}
1787
1788	if (!modversions)
1789		return;
1790
1791	/* record CRCs for exported symbols */
1792	buf_printf(buf, "\n");
1793	list_for_each_entry(sym, &mod->exported_symbols, list) {
1794		if (trim_unused_exports && !sym->used)
1795			continue;
1796
1797		if (!sym->crc_valid)
1798			warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1799			     "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1800			     sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1801			     sym->name);
1802
1803		buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1804			   sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1805	}
 
1806}
1807
1808/**
1809 * Record CRCs for unresolved symbols
1810 **/
1811static void add_versions(struct buffer *b, struct module *mod)
1812{
1813	struct symbol *s;
 
 
 
 
 
 
 
 
 
1814
1815	if (!modversions)
1816		return;
1817
1818	buf_printf(b, "\n");
1819	buf_printf(b, "static const struct modversion_info ____versions[]\n");
1820	buf_printf(b, "__used __section(\"__versions\") = {\n");
1821
1822	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1823		if (!s->module)
1824			continue;
1825		if (!s->crc_valid) {
1826			warn("\"%s\" [%s.ko] has no CRC!\n",
1827				s->name, mod->name);
1828			continue;
1829		}
1830		if (strlen(s->name) >= MODULE_NAME_LEN) {
1831			error("too long symbol \"%s\" [%s.ko]\n",
1832			      s->name, mod->name);
1833			break;
1834		}
1835		buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1836			   s->crc, s->name);
1837	}
1838
1839	buf_printf(b, "};\n");
1840}
1841
1842static void add_depends(struct buffer *b, struct module *mod)
1843{
1844	struct symbol *s;
1845	int first = 1;
1846
1847	/* Clear ->seen flag of modules that own symbols needed by this. */
1848	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1849		if (s->module)
1850			s->module->seen = s->module->is_vmlinux;
1851	}
1852
1853	buf_printf(b, "\n");
1854	buf_printf(b, "MODULE_INFO(depends, \"");
1855	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1856		const char *p;
1857		if (!s->module)
1858			continue;
1859
1860		if (s->module->seen)
1861			continue;
1862
1863		s->module->seen = true;
1864		p = strrchr(s->module->name, '/');
1865		if (p)
1866			p++;
1867		else
1868			p = s->module->name;
1869		buf_printf(b, "%s%s", first ? "" : ",", p);
1870		first = 0;
1871	}
1872	buf_printf(b, "\");\n");
1873}
1874
1875static void add_srcversion(struct buffer *b, struct module *mod)
1876{
1877	if (mod->srcversion[0]) {
1878		buf_printf(b, "\n");
1879		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1880			   mod->srcversion);
1881	}
1882}
1883
1884static void write_buf(struct buffer *b, const char *fname)
1885{
1886	FILE *file;
1887
1888	if (error_occurred)
1889		return;
1890
1891	file = fopen(fname, "w");
1892	if (!file) {
1893		perror(fname);
1894		exit(1);
1895	}
1896	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1897		perror(fname);
1898		exit(1);
1899	}
1900	if (fclose(file) != 0) {
1901		perror(fname);
1902		exit(1);
1903	}
1904}
1905
1906static void write_if_changed(struct buffer *b, const char *fname)
1907{
1908	char *tmp;
1909	FILE *file;
1910	struct stat st;
1911
1912	file = fopen(fname, "r");
1913	if (!file)
1914		goto write;
1915
1916	if (fstat(fileno(file), &st) < 0)
1917		goto close_write;
1918
1919	if (st.st_size != b->pos)
1920		goto close_write;
1921
1922	tmp = xmalloc(b->pos);
1923	if (fread(tmp, 1, b->pos, file) != b->pos)
1924		goto free_write;
1925
1926	if (memcmp(tmp, b->p, b->pos) != 0)
1927		goto free_write;
1928
1929	free(tmp);
1930	fclose(file);
1931	return;
1932
1933 free_write:
1934	free(tmp);
1935 close_write:
1936	fclose(file);
1937 write:
1938	write_buf(b, fname);
1939}
1940
1941static void write_vmlinux_export_c_file(struct module *mod)
1942{
1943	struct buffer buf = { };
1944
1945	buf_printf(&buf,
1946		   "#include <linux/export-internal.h>\n");
1947
1948	add_exported_symbols(&buf, mod);
1949	write_if_changed(&buf, ".vmlinux.export.c");
1950	free(buf.p);
1951}
1952
1953/* do sanity checks, and generate *.mod.c file */
1954static void write_mod_c_file(struct module *mod)
1955{
1956	struct buffer buf = { };
1957	struct module_alias *alias, *next;
1958	char fname[PATH_MAX];
1959	int ret;
1960
1961	add_header(&buf, mod);
1962	add_exported_symbols(&buf, mod);
1963	add_versions(&buf, mod);
1964	add_depends(&buf, mod);
1965
1966	buf_printf(&buf, "\n");
1967	list_for_each_entry_safe(alias, next, &mod->aliases, node) {
1968		buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str);
1969		list_del(&alias->node);
1970		free(alias);
1971	}
1972
1973	add_srcversion(&buf, mod);
1974
1975	ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
1976	if (ret >= sizeof(fname)) {
1977		error("%s: too long path was truncated\n", fname);
1978		goto free;
1979	}
1980
1981	write_if_changed(&buf, fname);
1982
1983free:
1984	free(buf.p);
1985}
1986
1987/* parse Module.symvers file. line format:
1988 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
1989 **/
1990static void read_dump(const char *fname)
1991{
1992	char *buf, *pos, *line;
1993
1994	buf = read_text_file(fname);
1995	if (!buf)
1996		/* No symbol versions, silently ignore */
1997		return;
1998
1999	pos = buf;
2000
2001	while ((line = get_line(&pos))) {
2002		char *symname, *namespace, *modname, *d, *export;
2003		unsigned int crc;
2004		struct module *mod;
2005		struct symbol *s;
2006		bool gpl_only;
2007
2008		if (!(symname = strchr(line, '\t')))
2009			goto fail;
2010		*symname++ = '\0';
2011		if (!(modname = strchr(symname, '\t')))
2012			goto fail;
2013		*modname++ = '\0';
2014		if (!(export = strchr(modname, '\t')))
2015			goto fail;
2016		*export++ = '\0';
2017		if (!(namespace = strchr(export, '\t')))
2018			goto fail;
2019		*namespace++ = '\0';
2020
2021		crc = strtoul(line, &d, 16);
2022		if (*symname == '\0' || *modname == '\0' || *d != '\0')
2023			goto fail;
2024
2025		if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2026			gpl_only = true;
2027		} else if (!strcmp(export, "EXPORT_SYMBOL")) {
2028			gpl_only = false;
2029		} else {
2030			error("%s: unknown license %s. skip", symname, export);
2031			continue;
2032		}
2033
2034		mod = find_module(fname, modname);
2035		if (!mod) {
2036			mod = new_module(modname, strlen(modname));
2037			mod->dump_file = fname;
2038		}
2039		s = sym_add_exported(symname, mod, gpl_only, namespace);
2040		sym_set_crc(s, crc);
 
 
2041	}
2042	free(buf);
2043	return;
2044fail:
2045	free(buf);
2046	fatal("parse error in symbol dump file\n");
2047}
2048
2049static void write_dump(const char *fname)
2050{
2051	struct buffer buf = { };
2052	struct module *mod;
2053	struct symbol *sym;
2054
2055	list_for_each_entry(mod, &modules, list) {
2056		if (mod->dump_file)
2057			continue;
2058		list_for_each_entry(sym, &mod->exported_symbols, list) {
2059			if (trim_unused_exports && !sym->used)
2060				continue;
2061
2062			buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2063				   sym->crc, sym->name, mod->name,
2064				   sym->is_gpl_only ? "_GPL" : "",
2065				   sym->namespace);
 
 
2066		}
2067	}
2068	write_buf(&buf, fname);
2069	free(buf.p);
2070}
2071
2072static void write_namespace_deps_files(const char *fname)
2073{
2074	struct module *mod;
2075	struct namespace_list *ns;
2076	struct buffer ns_deps_buf = {};
2077
2078	list_for_each_entry(mod, &modules, list) {
2079
2080		if (mod->dump_file || list_empty(&mod->missing_namespaces))
2081			continue;
2082
2083		buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2084
2085		list_for_each_entry(ns, &mod->missing_namespaces, list)
2086			buf_printf(&ns_deps_buf, " %s", ns->namespace);
2087
2088		buf_printf(&ns_deps_buf, "\n");
2089	}
2090
2091	write_if_changed(&ns_deps_buf, fname);
2092	free(ns_deps_buf.p);
2093}
2094
2095struct dump_list {
2096	struct list_head list;
2097	const char *file;
2098};
2099
2100static void check_host_endian(void)
2101{
2102	static const union {
2103		short s;
2104		char c[2];
2105	} endian_test = { .c = {0x01, 0x02} };
2106
2107	switch (endian_test.s) {
2108	case 0x0102:
2109		host_is_big_endian = true;
2110		break;
2111	case 0x0201:
2112		host_is_big_endian = false;
2113		break;
2114	default:
2115		fatal("Unknown host endian\n");
2116	}
2117}
2118
2119int main(int argc, char **argv)
2120{
2121	struct module *mod;
 
2122	char *missing_namespace_deps = NULL;
2123	char *unused_exports_white_list = NULL;
2124	char *dump_write = NULL, *files_source = NULL;
2125	int opt;
2126	LIST_HEAD(dump_lists);
2127	struct dump_list *dl, *dl2;
 
2128
2129	while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2130		switch (opt) {
2131		case 'e':
2132			external_module = true;
2133			break;
2134		case 'i':
2135			dl = xmalloc(sizeof(*dl));
2136			dl->file = optarg;
2137			list_add_tail(&dl->list, &dump_lists);
2138			break;
2139		case 'M':
2140			module_enabled = true;
2141			break;
2142		case 'm':
2143			modversions = true;
2144			break;
2145		case 'n':
2146			ignore_missing_files = true;
2147			break;
2148		case 'o':
2149			dump_write = optarg;
2150			break;
2151		case 'a':
2152			all_versions = true;
2153			break;
2154		case 'T':
2155			files_source = optarg;
2156			break;
2157		case 't':
2158			trim_unused_exports = true;
2159			break;
2160		case 'u':
2161			unused_exports_white_list = optarg;
2162			break;
2163		case 'W':
2164			extra_warn = true;
2165			break;
2166		case 'w':
2167			warn_unresolved = true;
2168			break;
2169		case 'E':
2170			sec_mismatch_warn_only = false;
2171			break;
2172		case 'N':
2173			allow_missing_ns_imports = true;
2174			break;
2175		case 'd':
2176			missing_namespace_deps = optarg;
2177			break;
2178		default:
2179			exit(1);
2180		}
2181	}
2182
2183	check_host_endian();
 
2184
2185	list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2186		read_dump(dl->file);
2187		list_del(&dl->list);
2188		free(dl);
2189	}
2190
2191	while (optind < argc)
2192		read_symbols(argv[optind++]);
2193
2194	if (files_source)
2195		read_symbols_from_files(files_source);
2196
2197	list_for_each_entry(mod, &modules, list) {
2198		if (mod->dump_file || mod->is_vmlinux)
 
 
2199			continue;
2200
 
 
2201		check_modname_len(mod);
2202		check_exports(mod);
2203	}
2204
2205	if (unused_exports_white_list)
2206		handle_white_list_exports(unused_exports_white_list);
 
 
 
 
 
 
2207
2208	list_for_each_entry(mod, &modules, list) {
2209		if (mod->dump_file)
2210			continue;
2211
2212		if (mod->is_vmlinux)
2213			write_vmlinux_export_c_file(mod);
2214		else
2215			write_mod_c_file(mod);
2216	}
2217
2218	if (missing_namespace_deps)
2219		write_namespace_deps_files(missing_namespace_deps);
2220
2221	if (dump_write)
2222		write_dump(dump_write);
2223	if (sec_mismatch_count && !sec_mismatch_warn_only)
2224		error("Section mismatches detected.\n"
2225		      "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
 
 
 
 
 
 
 
 
 
 
2226
2227	if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2228		warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2229		     nr_unresolved - MAX_UNRESOLVED_REPORTS);
 
 
2230
2231	return error_occurred ? 1 : 0;
2232}