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#include "modpost.h"
  24#include "../../include/linux/license.h"
  25
  26static bool module_enabled;
  27/* Are we using CONFIG_MODVERSIONS? */
  28static bool modversions;
  29/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  30static bool all_versions;
  31/* If we are modposting external module set to 1 */
  32static bool external_module;
  33/* Only warn about unresolved symbols */
  34static bool warn_unresolved;
  35
  36static int sec_mismatch_count;
  37static bool sec_mismatch_warn_only = true;
  38/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
  39static bool trim_unused_exports;
  40
  41/* ignore missing files */
  42static bool ignore_missing_files;
  43/* If set to 1, only warn (instead of error) about missing ns imports */
  44static bool allow_missing_ns_imports;
  45
  46static bool error_occurred;
  47
  48static bool extra_warn;
  49
 
 
 
  50/*
  51 * Cut off the warnings when there are too many. This typically occurs when
  52 * vmlinux is missing. ('make modules' without building vmlinux.)
  53 */
  54#define MAX_UNRESOLVED_REPORTS	10
  55static unsigned int nr_unresolved;
  56
  57/* In kernel, this size is defined in linux/module.h;
  58 * here we use Elf_Addr instead of long for covering cross-compile
  59 */
  60
  61#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
  62
  63void modpost_log(enum loglevel loglevel, const char *fmt, ...)
  64{
  65	va_list arglist;
  66
  67	switch (loglevel) {
  68	case LOG_WARN:
  69		fprintf(stderr, "WARNING: ");
  70		break;
  71	case LOG_ERROR:
  72		fprintf(stderr, "ERROR: ");
  73		error_occurred = true;
  74		break;
  75	default: /* invalid loglevel, ignore */
  76		break;
  77	}
  78
  79	fprintf(stderr, "modpost: ");
  80
  81	va_start(arglist, fmt);
  82	vfprintf(stderr, fmt, arglist);
  83	va_end(arglist);
  84}
  85
  86static inline bool strends(const char *str, const char *postfix)
  87{
  88	if (strlen(str) < strlen(postfix))
  89		return false;
  90
  91	return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
  92}
  93
  94void *do_nofail(void *ptr, const char *expr)
  95{
  96	if (!ptr)
  97		fatal("Memory allocation failure: %s.\n", expr);
  98
  99	return ptr;
 100}
 101
 102char *read_text_file(const char *filename)
 103{
 104	struct stat st;
 105	size_t nbytes;
 106	int fd;
 107	char *buf;
 108
 109	fd = open(filename, O_RDONLY);
 110	if (fd < 0) {
 111		perror(filename);
 112		exit(1);
 113	}
 114
 115	if (fstat(fd, &st) < 0) {
 116		perror(filename);
 117		exit(1);
 118	}
 119
 120	buf = NOFAIL(malloc(st.st_size + 1));
 121
 122	nbytes = st.st_size;
 123
 124	while (nbytes) {
 125		ssize_t bytes_read;
 126
 127		bytes_read = read(fd, buf, nbytes);
 128		if (bytes_read < 0) {
 129			perror(filename);
 130			exit(1);
 131		}
 132
 133		nbytes -= bytes_read;
 134	}
 135	buf[st.st_size] = '\0';
 136
 137	close(fd);
 138
 139	return buf;
 140}
 141
 142char *get_line(char **stringp)
 143{
 144	char *orig = *stringp, *next;
 145
 146	/* do not return the unwanted extra line at EOF */
 147	if (!orig || *orig == '\0')
 148		return NULL;
 149
 150	/* don't use strsep here, it is not available everywhere */
 151	next = strchr(orig, '\n');
 152	if (next)
 153		*next++ = '\0';
 154
 155	*stringp = next;
 156
 157	return orig;
 158}
 159
 160/* A list of all modules we processed */
 161LIST_HEAD(modules);
 162
 163static struct module *find_module(const char *modname)
 164{
 165	struct module *mod;
 166
 167	list_for_each_entry(mod, &modules, list) {
 168		if (strcmp(mod->name, modname) == 0)
 
 169			return mod;
 170	}
 171	return NULL;
 172}
 173
 174static struct module *new_module(const char *name, size_t namelen)
 175{
 176	struct module *mod;
 177
 178	mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
 179	memset(mod, 0, sizeof(*mod));
 180
 181	INIT_LIST_HEAD(&mod->exported_symbols);
 182	INIT_LIST_HEAD(&mod->unresolved_symbols);
 183	INIT_LIST_HEAD(&mod->missing_namespaces);
 184	INIT_LIST_HEAD(&mod->imported_namespaces);
 
 185
 186	memcpy(mod->name, name, namelen);
 187	mod->name[namelen] = '\0';
 188	mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
 189
 190	/*
 191	 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
 192	 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
 193	 * modpost will exit wiht error anyway.
 194	 */
 195	mod->is_gpl_compatible = true;
 196
 197	list_add_tail(&mod->list, &modules);
 198
 199	return mod;
 200}
 201
 202/* A hash of all exported symbols,
 203 * struct symbol is also used for lists of unresolved symbols */
 204
 205#define SYMBOL_HASH_SIZE 1024
 206
 207struct symbol {
 208	struct symbol *next;
 209	struct list_head list;	/* link to module::exported_symbols or module::unresolved_symbols */
 210	struct module *module;
 211	char *namespace;
 212	unsigned int crc;
 213	bool crc_valid;
 214	bool weak;
 215	bool is_func;
 216	bool is_gpl_only;	/* exported by EXPORT_SYMBOL_GPL */
 217	bool used;		/* there exists a user of this symbol */
 218	char name[];
 219};
 220
 221static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 222
 223/* This is based on the hash algorithm from gdbm, via tdb */
 224static inline unsigned int tdb_hash(const char *name)
 225{
 226	unsigned value;	/* Used to compute the hash value.  */
 227	unsigned   i;	/* Used to cycle through random values. */
 228
 229	/* Set the initial value from the key size. */
 230	for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 231		value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 232
 233	return (1103515243 * value + 12345);
 234}
 235
 236/**
 237 * Allocate a new symbols for use in the hash of exported symbols or
 238 * the list of unresolved symbols per module
 239 **/
 240static struct symbol *alloc_symbol(const char *name)
 241{
 242	struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 243
 244	memset(s, 0, sizeof(*s));
 245	strcpy(s->name, name);
 246
 247	return s;
 248}
 249
 250/* For the hash of exported symbols */
 251static void hash_add_symbol(struct symbol *sym)
 252{
 253	unsigned int hash;
 254
 255	hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
 256	sym->next = symbolhash[hash];
 257	symbolhash[hash] = sym;
 258}
 259
 260static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
 261{
 262	struct symbol *sym;
 263
 264	sym = alloc_symbol(name);
 265	sym->weak = weak;
 266
 267	list_add_tail(&sym->list, &mod->unresolved_symbols);
 268}
 269
 270static struct symbol *sym_find_with_module(const char *name, struct module *mod)
 271{
 272	struct symbol *s;
 273
 274	/* For our purposes, .foo matches foo.  PPC64 needs this. */
 275	if (name[0] == '.')
 276		name++;
 277
 278	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 279		if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
 280			return s;
 281	}
 282	return NULL;
 283}
 284
 285static struct symbol *find_symbol(const char *name)
 286{
 287	return sym_find_with_module(name, NULL);
 288}
 289
 290struct namespace_list {
 291	struct list_head list;
 292	char namespace[];
 293};
 294
 295static bool contains_namespace(struct list_head *head, const char *namespace)
 296{
 297	struct namespace_list *list;
 298
 299	/*
 300	 * The default namespace is null string "", which is always implicitly
 301	 * contained.
 302	 */
 303	if (!namespace[0])
 304		return true;
 305
 306	list_for_each_entry(list, head, list) {
 307		if (!strcmp(list->namespace, namespace))
 308			return true;
 309	}
 310
 311	return false;
 312}
 313
 314static void add_namespace(struct list_head *head, const char *namespace)
 315{
 316	struct namespace_list *ns_entry;
 317
 318	if (!contains_namespace(head, namespace)) {
 319		ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
 320					 strlen(namespace) + 1));
 321		strcpy(ns_entry->namespace, namespace);
 322		list_add_tail(&ns_entry->list, head);
 323	}
 324}
 325
 326static void *sym_get_data_by_offset(const struct elf_info *info,
 327				    unsigned int secindex, unsigned long offset)
 328{
 329	Elf_Shdr *sechdr = &info->sechdrs[secindex];
 330
 331	return (void *)info->hdr + sechdr->sh_offset + offset;
 332}
 333
 334void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
 335{
 336	return sym_get_data_by_offset(info, get_secindex(info, sym),
 337				      sym->st_value);
 338}
 339
 340static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
 341{
 342	return sym_get_data_by_offset(info, info->secindex_strings,
 343				      sechdr->sh_name);
 344}
 345
 346static const char *sec_name(const struct elf_info *info, unsigned int secindex)
 347{
 348	/*
 349	 * If sym->st_shndx is a special section index, there is no
 350	 * corresponding section header.
 351	 * Return "" if the index is out of range of info->sechdrs[] array.
 352	 */
 353	if (secindex >= info->num_sections)
 354		return "";
 355
 356	return sech_name(info, &info->sechdrs[secindex]);
 357}
 358
 359#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 360
 361static struct symbol *sym_add_exported(const char *name, struct module *mod,
 362				       bool gpl_only, const char *namespace)
 363{
 364	struct symbol *s = find_symbol(name);
 365
 366	if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
 367		error("%s: '%s' exported twice. Previous export was in %s%s\n",
 368		      mod->name, name, s->module->name,
 369		      s->module->is_vmlinux ? "" : ".ko");
 370	}
 371
 372	s = alloc_symbol(name);
 373	s->module = mod;
 374	s->is_gpl_only = gpl_only;
 375	s->namespace = NOFAIL(strdup(namespace));
 376	list_add_tail(&s->list, &mod->exported_symbols);
 377	hash_add_symbol(s);
 378
 379	return s;
 380}
 381
 382static void sym_set_crc(struct symbol *sym, unsigned int crc)
 383{
 384	sym->crc = crc;
 385	sym->crc_valid = true;
 386}
 387
 388static void *grab_file(const char *filename, size_t *size)
 389{
 390	struct stat st;
 391	void *map = MAP_FAILED;
 392	int fd;
 393
 394	fd = open(filename, O_RDONLY);
 395	if (fd < 0)
 396		return NULL;
 397	if (fstat(fd, &st))
 398		goto failed;
 399
 400	*size = st.st_size;
 401	map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 402
 403failed:
 404	close(fd);
 405	if (map == MAP_FAILED)
 406		return NULL;
 407	return map;
 408}
 409
 410static void release_file(void *file, size_t size)
 411{
 412	munmap(file, size);
 413}
 414
 415static int parse_elf(struct elf_info *info, const char *filename)
 416{
 417	unsigned int i;
 418	Elf_Ehdr *hdr;
 419	Elf_Shdr *sechdrs;
 420	Elf_Sym  *sym;
 421	const char *secstrings;
 422	unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 423
 424	hdr = grab_file(filename, &info->size);
 425	if (!hdr) {
 426		if (ignore_missing_files) {
 427			fprintf(stderr, "%s: %s (ignored)\n", filename,
 428				strerror(errno));
 429			return 0;
 430		}
 431		perror(filename);
 432		exit(1);
 433	}
 434	info->hdr = hdr;
 435	if (info->size < sizeof(*hdr)) {
 436		/* file too small, assume this is an empty .o file */
 437		return 0;
 438	}
 439	/* Is this a valid ELF file? */
 440	if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 441	    (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 442	    (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 443	    (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 444		/* Not an ELF file - silently ignore it */
 445		return 0;
 446	}
 
 
 
 
 
 
 
 
 
 
 
 
 447	/* Fix endianness in ELF header */
 448	hdr->e_type      = TO_NATIVE(hdr->e_type);
 449	hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 450	hdr->e_version   = TO_NATIVE(hdr->e_version);
 451	hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 452	hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 453	hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 454	hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 455	hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 456	hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 457	hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 458	hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 459	hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 460	hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 461	sechdrs = (void *)hdr + hdr->e_shoff;
 462	info->sechdrs = sechdrs;
 463
 464	/* modpost only works for relocatable objects */
 465	if (hdr->e_type != ET_REL)
 466		fatal("%s: not relocatable object.", filename);
 467
 468	/* Check if file offset is correct */
 469	if (hdr->e_shoff > info->size)
 470		fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
 471		      (unsigned long)hdr->e_shoff, filename, info->size);
 472
 473	if (hdr->e_shnum == SHN_UNDEF) {
 474		/*
 475		 * There are more than 64k sections,
 476		 * read count from .sh_size.
 477		 */
 478		info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 479	}
 480	else {
 481		info->num_sections = hdr->e_shnum;
 482	}
 483	if (hdr->e_shstrndx == SHN_XINDEX) {
 484		info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 485	}
 486	else {
 487		info->secindex_strings = hdr->e_shstrndx;
 488	}
 489
 490	/* Fix endianness in section headers */
 491	for (i = 0; i < info->num_sections; i++) {
 492		sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 493		sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 494		sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 495		sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 496		sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 497		sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 498		sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 499		sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 500		sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 501		sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 502	}
 503	/* Find symbol table. */
 504	secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 505	for (i = 1; i < info->num_sections; i++) {
 506		const char *secname;
 507		int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 508
 509		if (!nobits && sechdrs[i].sh_offset > info->size)
 510			fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
 511			      filename, (unsigned long)sechdrs[i].sh_offset,
 512			      sizeof(*hdr));
 513
 514		secname = secstrings + sechdrs[i].sh_name;
 515		if (strcmp(secname, ".modinfo") == 0) {
 516			if (nobits)
 517				fatal("%s has NOBITS .modinfo\n", filename);
 518			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 519			info->modinfo_len = sechdrs[i].sh_size;
 520		} else if (!strcmp(secname, ".export_symbol")) {
 521			info->export_symbol_secndx = i;
 522		}
 523
 524		if (sechdrs[i].sh_type == SHT_SYMTAB) {
 525			unsigned int sh_link_idx;
 526			symtab_idx = i;
 527			info->symtab_start = (void *)hdr +
 528			    sechdrs[i].sh_offset;
 529			info->symtab_stop  = (void *)hdr +
 530			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 531			sh_link_idx = sechdrs[i].sh_link;
 532			info->strtab       = (void *)hdr +
 533			    sechdrs[sh_link_idx].sh_offset;
 534		}
 535
 536		/* 32bit section no. table? ("more than 64k sections") */
 537		if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 538			symtab_shndx_idx = i;
 539			info->symtab_shndx_start = (void *)hdr +
 540			    sechdrs[i].sh_offset;
 541			info->symtab_shndx_stop  = (void *)hdr +
 542			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 543		}
 544	}
 545	if (!info->symtab_start)
 546		fatal("%s has no symtab?\n", filename);
 547
 548	/* Fix endianness in symbols */
 549	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 550		sym->st_shndx = TO_NATIVE(sym->st_shndx);
 551		sym->st_name  = TO_NATIVE(sym->st_name);
 552		sym->st_value = TO_NATIVE(sym->st_value);
 553		sym->st_size  = TO_NATIVE(sym->st_size);
 554	}
 555
 556	if (symtab_shndx_idx != ~0U) {
 557		Elf32_Word *p;
 558		if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 559			fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 560			      filename, sechdrs[symtab_shndx_idx].sh_link,
 561			      symtab_idx);
 562		/* Fix endianness */
 563		for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 564		     p++)
 565			*p = TO_NATIVE(*p);
 566	}
 567
 568	symsearch_init(info);
 569
 570	return 1;
 571}
 572
 573static void parse_elf_finish(struct elf_info *info)
 574{
 575	symsearch_finish(info);
 576	release_file(info->hdr, info->size);
 577}
 578
 579static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 580{
 581	/* ignore __this_module, it will be resolved shortly */
 582	if (strcmp(symname, "__this_module") == 0)
 583		return 1;
 584	/* ignore global offset table */
 585	if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 586		return 1;
 587	if (info->hdr->e_machine == EM_PPC)
 588		/* Special register function linked on all modules during final link of .ko */
 589		if (strstarts(symname, "_restgpr_") ||
 590		    strstarts(symname, "_savegpr_") ||
 591		    strstarts(symname, "_rest32gpr_") ||
 592		    strstarts(symname, "_save32gpr_") ||
 593		    strstarts(symname, "_restvr_") ||
 594		    strstarts(symname, "_savevr_"))
 595			return 1;
 596	if (info->hdr->e_machine == EM_PPC64)
 597		/* Special register function linked on all modules during final link of .ko */
 598		if (strstarts(symname, "_restgpr0_") ||
 599		    strstarts(symname, "_savegpr0_") ||
 600		    strstarts(symname, "_restvr_") ||
 601		    strstarts(symname, "_savevr_") ||
 602		    strcmp(symname, ".TOC.") == 0)
 603			return 1;
 604
 605	if (info->hdr->e_machine == EM_S390)
 606		/* Expoline thunks are linked on all kernel modules during final link of .ko */
 607		if (strstarts(symname, "__s390_indirect_jump_r"))
 608			return 1;
 609	/* Do not ignore this symbol */
 610	return 0;
 611}
 612
 613static void handle_symbol(struct module *mod, struct elf_info *info,
 614			  const Elf_Sym *sym, const char *symname)
 615{
 616	switch (sym->st_shndx) {
 617	case SHN_COMMON:
 618		if (strstarts(symname, "__gnu_lto_")) {
 619			/* Should warn here, but modpost runs before the linker */
 620		} else
 621			warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 622		break;
 623	case SHN_UNDEF:
 624		/* undefined symbol */
 625		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 626		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 627			break;
 628		if (ignore_undef_symbol(info, symname))
 629			break;
 630		if (info->hdr->e_machine == EM_SPARC ||
 631		    info->hdr->e_machine == EM_SPARCV9) {
 632			/* Ignore register directives. */
 633			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 634				break;
 635			if (symname[0] == '.') {
 636				char *munged = NOFAIL(strdup(symname));
 637				munged[0] = '_';
 638				munged[1] = toupper(munged[1]);
 639				symname = munged;
 640			}
 641		}
 642
 643		sym_add_unresolved(symname, mod,
 644				   ELF_ST_BIND(sym->st_info) == STB_WEAK);
 645		break;
 646	default:
 647		if (strcmp(symname, "init_module") == 0)
 648			mod->has_init = true;
 649		if (strcmp(symname, "cleanup_module") == 0)
 650			mod->has_cleanup = true;
 651		break;
 652	}
 653}
 654
 655/**
 656 * Parse tag=value strings from .modinfo section
 657 **/
 658static char *next_string(char *string, unsigned long *secsize)
 659{
 660	/* Skip non-zero chars */
 661	while (string[0]) {
 662		string++;
 663		if ((*secsize)-- <= 1)
 664			return NULL;
 665	}
 666
 667	/* Skip any zero padding. */
 668	while (!string[0]) {
 669		string++;
 670		if ((*secsize)-- <= 1)
 671			return NULL;
 672	}
 673	return string;
 674}
 675
 676static char *get_next_modinfo(struct elf_info *info, const char *tag,
 677			      char *prev)
 678{
 679	char *p;
 680	unsigned int taglen = strlen(tag);
 681	char *modinfo = info->modinfo;
 682	unsigned long size = info->modinfo_len;
 683
 684	if (prev) {
 685		size -= prev - modinfo;
 686		modinfo = next_string(prev, &size);
 687	}
 688
 689	for (p = modinfo; p; p = next_string(p, &size)) {
 690		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 691			return p + taglen + 1;
 692	}
 693	return NULL;
 694}
 695
 696static char *get_modinfo(struct elf_info *info, const char *tag)
 697
 698{
 699	return get_next_modinfo(info, tag, NULL);
 700}
 701
 702static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 703{
 704	if (sym)
 705		return elf->strtab + sym->st_name;
 706	else
 707		return "(unknown)";
 708}
 709
 710/*
 711 * Check whether the 'string' argument matches one of the 'patterns',
 712 * an array of shell wildcard patterns (glob).
 713 *
 714 * Return true is there is a match.
 715 */
 716static bool match(const char *string, const char *const patterns[])
 717{
 718	const char *pattern;
 719
 720	while ((pattern = *patterns++)) {
 721		if (!fnmatch(pattern, string, 0))
 722			return true;
 723	}
 724
 725	return false;
 726}
 727
 728/* useful to pass patterns to match() directly */
 729#define PATTERNS(...) \
 730	({ \
 731		static const char *const patterns[] = {__VA_ARGS__, NULL}; \
 732		patterns; \
 733	})
 734
 735/* sections that we do not want to do full section mismatch check on */
 736static const char *const section_white_list[] =
 737{
 738	".comment*",
 739	".debug*",
 740	".zdebug*",		/* Compressed debug sections. */
 741	".GCC.command.line",	/* record-gcc-switches */
 742	".mdebug*",        /* alpha, score, mips etc. */
 743	".pdr",            /* alpha, score, mips etc. */
 744	".stab*",
 745	".note*",
 746	".got*",
 747	".toc*",
 748	".xt.prop",				 /* xtensa */
 749	".xt.lit",         /* xtensa */
 750	".arcextmap*",			/* arc */
 751	".gnu.linkonce.arcext*",	/* arc : modules */
 752	".cmem*",			/* EZchip */
 753	".fmt_slot*",			/* EZchip */
 754	".gnu.lto*",
 755	".discard.*",
 756	".llvm.call-graph-profile",	/* call graph */
 757	NULL
 758};
 759
 760/*
 761 * This is used to find sections missing the SHF_ALLOC flag.
 762 * The cause of this is often a section specified in assembler
 763 * without "ax" / "aw".
 764 */
 765static void check_section(const char *modname, struct elf_info *elf,
 766			  Elf_Shdr *sechdr)
 767{
 768	const char *sec = sech_name(elf, sechdr);
 769
 770	if (sechdr->sh_type == SHT_PROGBITS &&
 771	    !(sechdr->sh_flags & SHF_ALLOC) &&
 772	    !match(sec, section_white_list)) {
 773		warn("%s (%s): unexpected non-allocatable section.\n"
 774		     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 775		     "Note that for example <linux/init.h> contains\n"
 776		     "section definitions for use in .S files.\n\n",
 777		     modname, sec);
 778	}
 779}
 780
 781
 782
 783#define ALL_INIT_DATA_SECTIONS \
 784	".init.setup", ".init.rodata", ".meminit.rodata", \
 785	".init.data", ".meminit.data"
 786
 787#define ALL_PCI_INIT_SECTIONS	\
 788	".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
 789	".pci_fixup_enable", ".pci_fixup_resume", \
 790	".pci_fixup_resume_early", ".pci_fixup_suspend"
 791
 792#define ALL_XXXINIT_SECTIONS ".meminit.*"
 793
 794#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 795#define ALL_EXIT_SECTIONS ".exit.*"
 796
 797#define DATA_SECTIONS ".data", ".data.rel"
 798#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
 799		".kprobes.text", ".cpuidle.text", ".noinstr.text", \
 800		".ltext", ".ltext.*"
 801#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
 802		".fixup", ".entry.text", ".exception.text", \
 803		".coldtext", ".softirqentry.text"
 804
 805#define INIT_SECTIONS      ".init.*"
 806
 807#define ALL_TEXT_SECTIONS  ".init.text", ".meminit.text", ".exit.text", \
 808		TEXT_SECTIONS, OTHER_TEXT_SECTIONS
 809
 810enum mismatch {
 811	TEXTDATA_TO_ANY_INIT_EXIT,
 812	XXXINIT_TO_SOME_INIT,
 813	ANY_INIT_TO_ANY_EXIT,
 814	ANY_EXIT_TO_ANY_INIT,
 815	EXTABLE_TO_NON_TEXT,
 816};
 817
 818/**
 819 * Describe how to match sections on different criteria:
 820 *
 821 * @fromsec: Array of sections to be matched.
 822 *
 823 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
 824 * this array is forbidden (black-list).  Can be empty.
 825 *
 826 * @good_tosec: Relocations applied to a section in @fromsec must be
 827 * targeting sections in this array (white-list).  Can be empty.
 828 *
 829 * @mismatch: Type of mismatch.
 830 */
 831struct sectioncheck {
 832	const char *fromsec[20];
 833	const char *bad_tosec[20];
 834	const char *good_tosec[20];
 835	enum mismatch mismatch;
 836};
 837
 838static const struct sectioncheck sectioncheck[] = {
 839/* Do not reference init/exit code/data from
 840 * normal code and data
 841 */
 842{
 843	.fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
 844	.bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
 845	.mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
 846},
 847/* Do not reference init code/data from meminit code/data */
 848{
 849	.fromsec = { ALL_XXXINIT_SECTIONS, NULL },
 850	.bad_tosec = { INIT_SECTIONS, NULL },
 851	.mismatch = XXXINIT_TO_SOME_INIT,
 852},
 853/* Do not use exit code/data from init code */
 854{
 855	.fromsec = { ALL_INIT_SECTIONS, NULL },
 856	.bad_tosec = { ALL_EXIT_SECTIONS, NULL },
 857	.mismatch = ANY_INIT_TO_ANY_EXIT,
 858},
 859/* Do not use init code/data from exit code */
 860{
 861	.fromsec = { ALL_EXIT_SECTIONS, NULL },
 862	.bad_tosec = { ALL_INIT_SECTIONS, NULL },
 863	.mismatch = ANY_EXIT_TO_ANY_INIT,
 864},
 865{
 866	.fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
 867	.bad_tosec = { INIT_SECTIONS, NULL },
 868	.mismatch = ANY_INIT_TO_ANY_EXIT,
 869},
 870{
 871	.fromsec = { "__ex_table", NULL },
 872	/* If you're adding any new black-listed sections in here, consider
 873	 * adding a special 'printer' for them in scripts/check_extable.
 874	 */
 875	.bad_tosec = { ".altinstr_replacement", NULL },
 876	.good_tosec = {ALL_TEXT_SECTIONS , NULL},
 877	.mismatch = EXTABLE_TO_NON_TEXT,
 878}
 879};
 880
 881static const struct sectioncheck *section_mismatch(
 882		const char *fromsec, const char *tosec)
 883{
 884	int i;
 885
 886	/*
 887	 * The target section could be the SHT_NUL section when we're
 888	 * handling relocations to un-resolved symbols, trying to match it
 889	 * doesn't make much sense and causes build failures on parisc
 890	 * architectures.
 891	 */
 892	if (*tosec == '\0')
 893		return NULL;
 894
 895	for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
 896		const struct sectioncheck *check = &sectioncheck[i];
 897
 898		if (match(fromsec, check->fromsec)) {
 899			if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
 900				return check;
 901			if (check->good_tosec[0] && !match(tosec, check->good_tosec))
 902				return check;
 903		}
 904	}
 905	return NULL;
 906}
 907
 908/**
 909 * Whitelist to allow certain references to pass with no warning.
 910 *
 911 * Pattern 1:
 912 *   If a module parameter is declared __initdata and permissions=0
 913 *   then this is legal despite the warning generated.
 914 *   We cannot see value of permissions here, so just ignore
 915 *   this pattern.
 916 *   The pattern is identified by:
 917 *   tosec   = .init.data
 918 *   fromsec = .data*
 919 *   atsym   =__param*
 920 *
 921 * Pattern 1a:
 922 *   module_param_call() ops can refer to __init set function if permissions=0
 923 *   The pattern is identified by:
 924 *   tosec   = .init.text
 925 *   fromsec = .data*
 926 *   atsym   = __param_ops_*
 927 *
 928 * Pattern 3:
 929 *   Whitelist all references from .head.text to any init section
 930 *
 931 * Pattern 4:
 932 *   Some symbols belong to init section but still it is ok to reference
 933 *   these from non-init sections as these symbols don't have any memory
 934 *   allocated for them and symbol address and value are same. So even
 935 *   if init section is freed, its ok to reference those symbols.
 936 *   For ex. symbols marking the init section boundaries.
 937 *   This pattern is identified by
 938 *   refsymname = __init_begin, _sinittext, _einittext
 939 *
 940 * Pattern 5:
 941 *   GCC may optimize static inlines when fed constant arg(s) resulting
 942 *   in functions like cpumask_empty() -- generating an associated symbol
 943 *   cpumask_empty.constprop.3 that appears in the audit.  If the const that
 944 *   is passed in comes from __init, like say nmi_ipi_mask, we get a
 945 *   meaningless section warning.  May need to add isra symbols too...
 946 *   This pattern is identified by
 947 *   tosec   = init section
 948 *   fromsec = text section
 949 *   refsymname = *.constprop.*
 950 *
 951 **/
 952static int secref_whitelist(const char *fromsec, const char *fromsym,
 953			    const char *tosec, const char *tosym)
 954{
 955	/* Check for pattern 1 */
 956	if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
 957	    match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 958	    strstarts(fromsym, "__param"))
 959		return 0;
 960
 961	/* Check for pattern 1a */
 962	if (strcmp(tosec, ".init.text") == 0 &&
 963	    match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 964	    strstarts(fromsym, "__param_ops_"))
 965		return 0;
 966
 967	/* symbols in data sections that may refer to any init/exit sections */
 968	if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 969	    match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
 970	    match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
 971		return 0;
 972
 973	/*
 974	 * symbols in data sections must not refer to .exit.*, but there are
 975	 * quite a few offenders, so hide these unless for W=1 builds until
 976	 * these are fixed.
 977	 */
 978	if (!extra_warn &&
 979	    match(fromsec, PATTERNS(DATA_SECTIONS)) &&
 980	    match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) &&
 981	    match(fromsym, PATTERNS("*driver")))
 982		return 0;
 983
 984	/* Check for pattern 3 */
 985	if (strstarts(fromsec, ".head.text") &&
 986	    match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
 987		return 0;
 988
 989	/* Check for pattern 4 */
 990	if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
 991		return 0;
 992
 993	/* Check for pattern 5 */
 994	if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
 995	    match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
 996	    match(fromsym, PATTERNS("*.constprop.*")))
 997		return 0;
 998
 999	return 1;
1000}
1001
1002static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1003			     unsigned int secndx)
1004{
1005	return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1006}
1007
1008static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1009{
 
 
1010	/* If the supplied symbol has a valid name, return it */
1011	if (is_valid_name(elf, sym))
1012		return sym;
1013
1014	/*
1015	 * Strive to find a better symbol name, but the resulting name may not
1016	 * match the symbol referenced in the original code.
1017	 */
1018	return symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1019				      true, 20);
 
1020}
1021
1022static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1023{
1024	if (secndx >= elf->num_sections)
1025		return false;
1026
1027	return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1028}
1029
1030static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1031				     const struct sectioncheck* const mismatch,
1032				     Elf_Sym *tsym,
1033				     unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1034				     const char *tosec, Elf_Addr taddr)
1035{
1036	Elf_Sym *from;
1037	const char *tosym;
1038	const char *fromsym;
 
1039
1040	from = find_fromsym(elf, faddr, fsecndx);
1041	fromsym = sym_name(elf, from);
1042
1043	tsym = find_tosym(elf, taddr, tsym);
1044	tosym = sym_name(elf, tsym);
1045
1046	/* check whitelist - we may ignore it */
1047	if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1048		return;
1049
1050	sec_mismatch_count++;
1051
1052	warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1053	     modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec);
 
 
 
 
 
 
 
 
 
1054
1055	if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1056		if (match(tosec, mismatch->bad_tosec))
1057			fatal("The relocation at %s+0x%lx references\n"
1058			      "section \"%s\" which is black-listed.\n"
1059			      "Something is seriously wrong and should be fixed.\n"
1060			      "You might get more information about where this is\n"
1061			      "coming from by using scripts/check_extable.sh %s\n",
1062			      fromsec, (long)faddr, tosec, modname);
1063		else if (is_executable_section(elf, get_secindex(elf, tsym)))
1064			warn("The relocation at %s+0x%lx references\n"
1065			     "section \"%s\" which is not in the list of\n"
1066			     "authorized sections.  If you're adding a new section\n"
1067			     "and/or if this reference is valid, add \"%s\" to the\n"
1068			     "list of authorized sections to jump to on fault.\n"
1069			     "This can be achieved by adding \"%s\" to\n"
1070			     "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1071			     fromsec, (long)faddr, tosec, tosec, tosec);
1072		else
1073			error("%s+0x%lx references non-executable section '%s'\n",
1074			      fromsec, (long)faddr, tosec);
1075	}
1076}
1077
1078static void check_export_symbol(struct module *mod, struct elf_info *elf,
1079				Elf_Addr faddr, const char *secname,
1080				Elf_Sym *sym)
1081{
1082	static const char *prefix = "__export_symbol_";
1083	const char *label_name, *name, *data;
1084	Elf_Sym *label;
1085	struct symbol *s;
1086	bool is_gpl;
1087
1088	label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1089	label_name = sym_name(elf, label);
1090
1091	if (!strstarts(label_name, prefix)) {
1092		error("%s: .export_symbol section contains strange symbol '%s'\n",
1093		      mod->name, label_name);
1094		return;
1095	}
1096
1097	if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1098	    ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1099		error("%s: local symbol '%s' was exported\n", mod->name,
1100		      label_name + strlen(prefix));
1101		return;
1102	}
1103
1104	name = sym_name(elf, sym);
1105	if (strcmp(label_name + strlen(prefix), name)) {
1106		error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1107		      mod->name, name);
1108		return;
1109	}
1110
1111	data = sym_get_data(elf, label);	/* license */
1112	if (!strcmp(data, "GPL")) {
1113		is_gpl = true;
1114	} else if (!strcmp(data, "")) {
1115		is_gpl = false;
1116	} else {
1117		error("%s: unknown license '%s' was specified for '%s'\n",
1118		      mod->name, data, name);
1119		return;
1120	}
1121
1122	data += strlen(data) + 1;	/* namespace */
1123	s = sym_add_exported(name, mod, is_gpl, data);
1124
1125	/*
1126	 * We need to be aware whether we are exporting a function or
1127	 * a data on some architectures.
1128	 */
1129	s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1130
1131	/*
1132	 * For parisc64, symbols prefixed $$ from the library have the symbol type
1133	 * STT_LOPROC. They should be handled as functions too.
1134	 */
1135	if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1136	    elf->hdr->e_machine == EM_PARISC &&
1137	    ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1138		s->is_func = true;
1139
1140	if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1141		warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1142		     mod->name, name);
1143	else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1144		warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1145		     mod->name, name);
1146}
1147
1148static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1149				   Elf_Sym *sym,
1150				   unsigned int fsecndx, const char *fromsec,
1151				   Elf_Addr faddr, Elf_Addr taddr)
1152{
1153	const char *tosec = sec_name(elf, get_secindex(elf, sym));
1154	const struct sectioncheck *mismatch;
1155
1156	if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1157		check_export_symbol(mod, elf, faddr, tosec, sym);
1158		return;
1159	}
1160
1161	mismatch = section_mismatch(fromsec, tosec);
1162	if (!mismatch)
1163		return;
1164
1165	default_mismatch_handler(mod->name, elf, mismatch, sym,
1166				 fsecndx, fromsec, faddr,
1167				 tosec, taddr);
1168}
1169
1170static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1171{
1172	switch (r_type) {
1173	case R_386_32:
1174		return TO_NATIVE(*location);
1175	case R_386_PC32:
1176		return TO_NATIVE(*location) + 4;
1177	}
1178
1179	return (Elf_Addr)(-1);
1180}
1181
1182#ifndef R_ARM_CALL
1183#define R_ARM_CALL	28
1184#endif
1185#ifndef R_ARM_JUMP24
1186#define R_ARM_JUMP24	29
1187#endif
1188
1189#ifndef	R_ARM_THM_CALL
1190#define	R_ARM_THM_CALL		10
1191#endif
1192#ifndef	R_ARM_THM_JUMP24
1193#define	R_ARM_THM_JUMP24	30
1194#endif
1195
1196#ifndef R_ARM_MOVW_ABS_NC
1197#define R_ARM_MOVW_ABS_NC	43
1198#endif
1199
1200#ifndef R_ARM_MOVT_ABS
1201#define R_ARM_MOVT_ABS		44
1202#endif
1203
1204#ifndef R_ARM_THM_MOVW_ABS_NC
1205#define R_ARM_THM_MOVW_ABS_NC	47
1206#endif
1207
1208#ifndef R_ARM_THM_MOVT_ABS
1209#define R_ARM_THM_MOVT_ABS	48
1210#endif
1211
1212#ifndef	R_ARM_THM_JUMP19
1213#define	R_ARM_THM_JUMP19	51
1214#endif
1215
1216static int32_t sign_extend32(int32_t value, int index)
1217{
1218	uint8_t shift = 31 - index;
1219
1220	return (int32_t)(value << shift) >> shift;
1221}
1222
1223static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1224{
1225	uint32_t inst, upper, lower, sign, j1, j2;
1226	int32_t offset;
1227
1228	switch (r_type) {
1229	case R_ARM_ABS32:
1230	case R_ARM_REL32:
1231		inst = TO_NATIVE(*(uint32_t *)loc);
1232		return inst + sym->st_value;
1233	case R_ARM_MOVW_ABS_NC:
1234	case R_ARM_MOVT_ABS:
1235		inst = TO_NATIVE(*(uint32_t *)loc);
1236		offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1237				       15);
1238		return offset + sym->st_value;
1239	case R_ARM_PC24:
1240	case R_ARM_CALL:
1241	case R_ARM_JUMP24:
1242		inst = TO_NATIVE(*(uint32_t *)loc);
1243		offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1244		return offset + sym->st_value + 8;
1245	case R_ARM_THM_MOVW_ABS_NC:
1246	case R_ARM_THM_MOVT_ABS:
1247		upper = TO_NATIVE(*(uint16_t *)loc);
1248		lower = TO_NATIVE(*((uint16_t *)loc + 1));
1249		offset = sign_extend32(((upper & 0x000f) << 12) |
1250				       ((upper & 0x0400) << 1) |
1251				       ((lower & 0x7000) >> 4) |
1252				       (lower & 0x00ff),
1253				       15);
1254		return offset + sym->st_value;
1255	case R_ARM_THM_JUMP19:
1256		/*
1257		 * Encoding T3:
1258		 * S     = upper[10]
1259		 * imm6  = upper[5:0]
1260		 * J1    = lower[13]
1261		 * J2    = lower[11]
1262		 * imm11 = lower[10:0]
1263		 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1264		 */
1265		upper = TO_NATIVE(*(uint16_t *)loc);
1266		lower = TO_NATIVE(*((uint16_t *)loc + 1));
1267
1268		sign = (upper >> 10) & 1;
1269		j1 = (lower >> 13) & 1;
1270		j2 = (lower >> 11) & 1;
1271		offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1272				       ((upper & 0x03f) << 12) |
1273				       ((lower & 0x07ff) << 1),
1274				       20);
1275		return offset + sym->st_value + 4;
1276	case R_ARM_THM_CALL:
1277	case R_ARM_THM_JUMP24:
1278		/*
1279		 * Encoding T4:
1280		 * S     = upper[10]
1281		 * imm10 = upper[9:0]
1282		 * J1    = lower[13]
1283		 * J2    = lower[11]
1284		 * imm11 = lower[10:0]
1285		 * I1    = NOT(J1 XOR S)
1286		 * I2    = NOT(J2 XOR S)
1287		 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1288		 */
1289		upper = TO_NATIVE(*(uint16_t *)loc);
1290		lower = TO_NATIVE(*((uint16_t *)loc + 1));
1291
1292		sign = (upper >> 10) & 1;
1293		j1 = (lower >> 13) & 1;
1294		j2 = (lower >> 11) & 1;
1295		offset = sign_extend32((sign << 24) |
1296				       ((~(j1 ^ sign) & 1) << 23) |
1297				       ((~(j2 ^ sign) & 1) << 22) |
1298				       ((upper & 0x03ff) << 12) |
1299				       ((lower & 0x07ff) << 1),
1300				       24);
1301		return offset + sym->st_value + 4;
1302	}
1303
1304	return (Elf_Addr)(-1);
1305}
1306
1307static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1308{
1309	uint32_t inst;
1310
1311	inst = TO_NATIVE(*location);
1312	switch (r_type) {
1313	case R_MIPS_LO16:
1314		return inst & 0xffff;
1315	case R_MIPS_26:
1316		return (inst & 0x03ffffff) << 2;
1317	case R_MIPS_32:
1318		return inst;
1319	}
1320	return (Elf_Addr)(-1);
1321}
1322
1323#ifndef EM_RISCV
1324#define EM_RISCV		243
1325#endif
1326
1327#ifndef R_RISCV_SUB32
1328#define R_RISCV_SUB32		39
1329#endif
1330
1331#ifndef EM_LOONGARCH
1332#define EM_LOONGARCH		258
1333#endif
1334
1335#ifndef R_LARCH_SUB32
1336#define R_LARCH_SUB32		55
1337#endif
1338
1339#ifndef R_LARCH_RELAX
1340#define R_LARCH_RELAX		100
1341#endif
1342
1343#ifndef R_LARCH_ALIGN
1344#define R_LARCH_ALIGN		102
1345#endif
1346
1347static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1348				 unsigned int *r_type, unsigned int *r_sym)
1349{
1350	typedef struct {
1351		Elf64_Word    r_sym;	/* Symbol index */
1352		unsigned char r_ssym;	/* Special symbol for 2nd relocation */
1353		unsigned char r_type3;	/* 3rd relocation type */
1354		unsigned char r_type2;	/* 2nd relocation type */
1355		unsigned char r_type;	/* 1st relocation type */
1356	} Elf64_Mips_R_Info;
1357
1358	bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1359
1360	if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1361		Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1362
1363		*r_type = mips64_r_info->r_type;
1364		*r_sym = TO_NATIVE(mips64_r_info->r_sym);
1365		return;
1366	}
1367
1368	if (is_64bit)
1369		r_info = TO_NATIVE((Elf64_Xword)r_info);
1370	else
1371		r_info = TO_NATIVE((Elf32_Word)r_info);
1372
1373	*r_type = ELF_R_TYPE(r_info);
1374	*r_sym = ELF_R_SYM(r_info);
1375}
1376
1377static void section_rela(struct module *mod, struct elf_info *elf,
1378			 unsigned int fsecndx, const char *fromsec,
1379			 const Elf_Rela *start, const Elf_Rela *stop)
1380{
1381	const Elf_Rela *rela;
1382
1383	for (rela = start; rela < stop; rela++) {
1384		Elf_Sym *tsym;
1385		Elf_Addr taddr, r_offset;
1386		unsigned int r_type, r_sym;
1387
1388		r_offset = TO_NATIVE(rela->r_offset);
1389		get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1390
1391		tsym = elf->symtab_start + r_sym;
1392		taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1393
1394		switch (elf->hdr->e_machine) {
1395		case EM_RISCV:
1396			if (!strcmp("__ex_table", fromsec) &&
1397			    r_type == R_RISCV_SUB32)
1398				continue;
1399			break;
1400		case EM_LOONGARCH:
1401			switch (r_type) {
1402			case R_LARCH_SUB32:
1403				if (!strcmp("__ex_table", fromsec))
1404					continue;
1405				break;
1406			case R_LARCH_RELAX:
1407			case R_LARCH_ALIGN:
1408				/* These relocs do not refer to symbols */
1409				continue;
1410			}
1411			break;
1412		}
1413
1414		check_section_mismatch(mod, elf, tsym,
1415				       fsecndx, fromsec, r_offset, taddr);
1416	}
1417}
1418
1419static void section_rel(struct module *mod, struct elf_info *elf,
1420			unsigned int fsecndx, const char *fromsec,
1421			const Elf_Rel *start, const Elf_Rel *stop)
1422{
1423	const Elf_Rel *rel;
1424
1425	for (rel = start; rel < stop; rel++) {
1426		Elf_Sym *tsym;
1427		Elf_Addr taddr, r_offset;
1428		unsigned int r_type, r_sym;
1429		void *loc;
1430
1431		r_offset = TO_NATIVE(rel->r_offset);
1432		get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1433
1434		loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1435		tsym = elf->symtab_start + r_sym;
1436
1437		switch (elf->hdr->e_machine) {
1438		case EM_386:
1439			taddr = addend_386_rel(loc, r_type);
1440			break;
1441		case EM_ARM:
1442			taddr = addend_arm_rel(loc, tsym, r_type);
1443			break;
1444		case EM_MIPS:
1445			taddr = addend_mips_rel(loc, r_type);
1446			break;
1447		default:
1448			fatal("Please add code to calculate addend for this architecture\n");
1449		}
1450
1451		check_section_mismatch(mod, elf, tsym,
1452				       fsecndx, fromsec, r_offset, taddr);
1453	}
1454}
1455
1456/**
1457 * A module includes a number of sections that are discarded
1458 * either when loaded or when used as built-in.
1459 * For loaded modules all functions marked __init and all data
1460 * marked __initdata will be discarded when the module has been initialized.
1461 * Likewise for modules used built-in the sections marked __exit
1462 * are discarded because __exit marked function are supposed to be called
1463 * only when a module is unloaded which never happens for built-in modules.
1464 * The check_sec_ref() function traverses all relocation records
1465 * to find all references to a section that reference a section that will
1466 * be discarded and warns about it.
1467 **/
1468static void check_sec_ref(struct module *mod, struct elf_info *elf)
1469{
1470	int i;
1471
1472	/* Walk through all sections */
1473	for (i = 0; i < elf->num_sections; i++) {
1474		Elf_Shdr *sechdr = &elf->sechdrs[i];
1475
1476		check_section(mod->name, elf, sechdr);
1477		/* We want to process only relocation sections and not .init */
1478		if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1479			/* section to which the relocation applies */
1480			unsigned int secndx = sechdr->sh_info;
1481			const char *secname = sec_name(elf, secndx);
1482			const void *start, *stop;
1483
1484			/* If the section is known good, skip it */
1485			if (match(secname, section_white_list))
1486				continue;
1487
1488			start = sym_get_data_by_offset(elf, i, 0);
1489			stop = start + sechdr->sh_size;
1490
1491			if (sechdr->sh_type == SHT_RELA)
1492				section_rela(mod, elf, secndx, secname,
1493					     start, stop);
1494			else
1495				section_rel(mod, elf, secndx, secname,
1496					    start, stop);
1497		}
1498	}
1499}
1500
1501static char *remove_dot(char *s)
1502{
1503	size_t n = strcspn(s, ".");
1504
1505	if (n && s[n]) {
1506		size_t m = strspn(s + n + 1, "0123456789");
1507		if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1508			s[n] = 0;
1509	}
1510	return s;
1511}
1512
1513/*
1514 * The CRCs are recorded in .*.cmd files in the form of:
1515 * #SYMVER <name> <crc>
1516 */
1517static void extract_crcs_for_object(const char *object, struct module *mod)
1518{
1519	char cmd_file[PATH_MAX];
1520	char *buf, *p;
1521	const char *base;
1522	int dirlen, ret;
1523
1524	base = strrchr(object, '/');
1525	if (base) {
1526		base++;
1527		dirlen = base - object;
1528	} else {
1529		dirlen = 0;
1530		base = object;
1531	}
1532
1533	ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1534		       dirlen, object, base);
1535	if (ret >= sizeof(cmd_file)) {
1536		error("%s: too long path was truncated\n", cmd_file);
1537		return;
1538	}
1539
1540	buf = read_text_file(cmd_file);
1541	p = buf;
1542
1543	while ((p = strstr(p, "\n#SYMVER "))) {
1544		char *name;
1545		size_t namelen;
1546		unsigned int crc;
1547		struct symbol *sym;
1548
1549		name = p + strlen("\n#SYMVER ");
1550
1551		p = strchr(name, ' ');
1552		if (!p)
1553			break;
1554
1555		namelen = p - name;
1556		p++;
1557
1558		if (!isdigit(*p))
1559			continue;	/* skip this line */
1560
1561		crc = strtoul(p, &p, 0);
1562		if (*p != '\n')
1563			continue;	/* skip this line */
1564
1565		name[namelen] = '\0';
1566
1567		/*
1568		 * sym_find_with_module() may return NULL here.
1569		 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1570		 * Since commit e1327a127703, genksyms calculates CRCs of all
1571		 * symbols, including trimmed ones. Ignore orphan CRCs.
1572		 */
1573		sym = sym_find_with_module(name, mod);
1574		if (sym)
1575			sym_set_crc(sym, crc);
1576	}
1577
1578	free(buf);
1579}
1580
1581/*
1582 * The symbol versions (CRC) are recorded in the .*.cmd files.
1583 * Parse them to retrieve CRCs for the current module.
1584 */
1585static void mod_set_crcs(struct module *mod)
1586{
1587	char objlist[PATH_MAX];
1588	char *buf, *p, *obj;
1589	int ret;
1590
1591	if (mod->is_vmlinux) {
1592		strcpy(objlist, ".vmlinux.objs");
1593	} else {
1594		/* objects for a module are listed in the *.mod file. */
1595		ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1596		if (ret >= sizeof(objlist)) {
1597			error("%s: too long path was truncated\n", objlist);
1598			return;
1599		}
1600	}
1601
1602	buf = read_text_file(objlist);
1603	p = buf;
1604
1605	while ((obj = strsep(&p, "\n")) && obj[0])
1606		extract_crcs_for_object(obj, mod);
1607
1608	free(buf);
1609}
1610
1611static void read_symbols(const char *modname)
1612{
1613	const char *symname;
1614	char *version;
1615	char *license;
1616	char *namespace;
1617	struct module *mod;
1618	struct elf_info info = { };
1619	Elf_Sym *sym;
1620
1621	if (!parse_elf(&info, modname))
1622		return;
1623
1624	if (!strends(modname, ".o")) {
1625		error("%s: filename must be suffixed with .o\n", modname);
1626		return;
1627	}
1628
1629	/* strip trailing .o */
1630	mod = new_module(modname, strlen(modname) - strlen(".o"));
1631
1632	if (!mod->is_vmlinux) {
1633		license = get_modinfo(&info, "license");
1634		if (!license)
1635			error("missing MODULE_LICENSE() in %s\n", modname);
1636		while (license) {
1637			if (!license_is_gpl_compatible(license)) {
1638				mod->is_gpl_compatible = false;
1639				break;
1640			}
1641			license = get_next_modinfo(&info, "license", license);
1642		}
1643
1644		namespace = get_modinfo(&info, "import_ns");
1645		while (namespace) {
1646			add_namespace(&mod->imported_namespaces, namespace);
1647			namespace = get_next_modinfo(&info, "import_ns",
1648						     namespace);
1649		}
 
 
 
1650	}
1651
1652	if (extra_warn && !get_modinfo(&info, "description"))
1653		warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1654	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1655		symname = remove_dot(info.strtab + sym->st_name);
1656
1657		handle_symbol(mod, &info, sym, symname);
1658		handle_moddevtable(mod, &info, sym, symname);
1659	}
1660
1661	check_sec_ref(mod, &info);
1662
1663	if (!mod->is_vmlinux) {
1664		version = get_modinfo(&info, "version");
1665		if (version || all_versions)
1666			get_src_version(mod->name, mod->srcversion,
1667					sizeof(mod->srcversion) - 1);
1668	}
1669
1670	parse_elf_finish(&info);
1671
1672	if (modversions) {
1673		/*
1674		 * Our trick to get versioning for module struct etc. - it's
1675		 * never passed as an argument to an exported function, so
1676		 * the automatic versioning doesn't pick it up, but it's really
1677		 * important anyhow.
1678		 */
1679		sym_add_unresolved("module_layout", mod, false);
1680
1681		mod_set_crcs(mod);
1682	}
1683}
1684
1685static void read_symbols_from_files(const char *filename)
1686{
1687	FILE *in = stdin;
1688	char fname[PATH_MAX];
1689
1690	in = fopen(filename, "r");
1691	if (!in)
1692		fatal("Can't open filenames file %s: %m", filename);
1693
1694	while (fgets(fname, PATH_MAX, in) != NULL) {
1695		if (strends(fname, "\n"))
1696			fname[strlen(fname)-1] = '\0';
1697		read_symbols(fname);
1698	}
1699
1700	fclose(in);
1701}
1702
1703#define SZ 500
1704
1705/* We first write the generated file into memory using the
1706 * following helper, then compare to the file on disk and
1707 * only update the later if anything changed */
1708
1709void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1710						      const char *fmt, ...)
1711{
1712	char tmp[SZ];
1713	int len;
1714	va_list ap;
1715
1716	va_start(ap, fmt);
1717	len = vsnprintf(tmp, SZ, fmt, ap);
1718	buf_write(buf, tmp, len);
1719	va_end(ap);
1720}
1721
1722void buf_write(struct buffer *buf, const char *s, int len)
1723{
1724	if (buf->size - buf->pos < len) {
1725		buf->size += len + SZ;
1726		buf->p = NOFAIL(realloc(buf->p, buf->size));
1727	}
1728	strncpy(buf->p + buf->pos, s, len);
1729	buf->pos += len;
1730}
1731
1732static void check_exports(struct module *mod)
1733{
1734	struct symbol *s, *exp;
1735
1736	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1737		const char *basename;
1738		exp = find_symbol(s->name);
1739		if (!exp) {
1740			if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1741				modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1742					    "\"%s\" [%s.ko] undefined!\n",
1743					    s->name, mod->name);
1744			continue;
1745		}
1746		if (exp->module == mod) {
1747			error("\"%s\" [%s.ko] was exported without definition\n",
1748			      s->name, mod->name);
1749			continue;
1750		}
1751
1752		exp->used = true;
1753		s->module = exp->module;
1754		s->crc_valid = exp->crc_valid;
1755		s->crc = exp->crc;
1756
1757		basename = strrchr(mod->name, '/');
1758		if (basename)
1759			basename++;
1760		else
1761			basename = mod->name;
1762
1763		if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1764			modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1765				    "module %s uses symbol %s from namespace %s, but does not import it.\n",
1766				    basename, exp->name, exp->namespace);
1767			add_namespace(&mod->missing_namespaces, exp->namespace);
1768		}
1769
1770		if (!mod->is_gpl_compatible && exp->is_gpl_only)
1771			error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1772			      basename, exp->name);
1773	}
1774}
1775
1776static void handle_white_list_exports(const char *white_list)
1777{
1778	char *buf, *p, *name;
1779
1780	buf = read_text_file(white_list);
1781	p = buf;
1782
1783	while ((name = strsep(&p, "\n"))) {
1784		struct symbol *sym = find_symbol(name);
1785
1786		if (sym)
1787			sym->used = true;
1788	}
1789
1790	free(buf);
1791}
1792
1793static void check_modname_len(struct module *mod)
1794{
1795	const char *mod_name;
1796
1797	mod_name = strrchr(mod->name, '/');
1798	if (mod_name == NULL)
1799		mod_name = mod->name;
1800	else
1801		mod_name++;
1802	if (strlen(mod_name) >= MODULE_NAME_LEN)
1803		error("module name is too long [%s.ko]\n", mod->name);
1804}
1805
1806/**
1807 * Header for the generated file
1808 **/
1809static void add_header(struct buffer *b, struct module *mod)
1810{
1811	buf_printf(b, "#include <linux/module.h>\n");
1812	/*
1813	 * Include build-salt.h after module.h in order to
1814	 * inherit the definitions.
1815	 */
1816	buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1817	buf_printf(b, "#include <linux/build-salt.h>\n");
1818	buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1819	buf_printf(b, "#include <linux/export-internal.h>\n");
1820	buf_printf(b, "#include <linux/vermagic.h>\n");
1821	buf_printf(b, "#include <linux/compiler.h>\n");
1822	buf_printf(b, "\n");
1823	buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1824	buf_printf(b, "#include <asm/orc_header.h>\n");
1825	buf_printf(b, "ORC_HEADER;\n");
1826	buf_printf(b, "#endif\n");
1827	buf_printf(b, "\n");
1828	buf_printf(b, "BUILD_SALT;\n");
1829	buf_printf(b, "BUILD_LTO_INFO;\n");
1830	buf_printf(b, "\n");
1831	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1832	buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1833	buf_printf(b, "\n");
1834	buf_printf(b, "__visible struct module __this_module\n");
1835	buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1836	buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1837	if (mod->has_init)
1838		buf_printf(b, "\t.init = init_module,\n");
1839	if (mod->has_cleanup)
1840		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1841			      "\t.exit = cleanup_module,\n"
1842			      "#endif\n");
1843	buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1844	buf_printf(b, "};\n");
1845
1846	if (!external_module)
1847		buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1848
1849	buf_printf(b,
1850		   "\n"
1851		   "#ifdef CONFIG_RETPOLINE\n"
1852		   "MODULE_INFO(retpoline, \"Y\");\n"
1853		   "#endif\n");
1854
1855	if (strstarts(mod->name, "drivers/staging"))
1856		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1857
1858	if (strstarts(mod->name, "tools/testing"))
1859		buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1860}
1861
1862static void add_exported_symbols(struct buffer *buf, struct module *mod)
1863{
1864	struct symbol *sym;
1865
1866	/* generate struct for exported symbols */
1867	buf_printf(buf, "\n");
1868	list_for_each_entry(sym, &mod->exported_symbols, list) {
1869		if (trim_unused_exports && !sym->used)
1870			continue;
1871
1872		buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1873			   sym->is_func ? "FUNC" : "DATA", sym->name,
1874			   sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1875	}
1876
1877	if (!modversions)
1878		return;
1879
1880	/* record CRCs for exported symbols */
1881	buf_printf(buf, "\n");
1882	list_for_each_entry(sym, &mod->exported_symbols, list) {
1883		if (trim_unused_exports && !sym->used)
1884			continue;
1885
1886		if (!sym->crc_valid)
1887			warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1888			     "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1889			     sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1890			     sym->name);
1891
1892		buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1893			   sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1894	}
1895}
1896
1897/**
1898 * Record CRCs for unresolved symbols
1899 **/
1900static void add_versions(struct buffer *b, struct module *mod)
1901{
1902	struct symbol *s;
1903
1904	if (!modversions)
1905		return;
1906
1907	buf_printf(b, "\n");
1908	buf_printf(b, "static const struct modversion_info ____versions[]\n");
1909	buf_printf(b, "__used __section(\"__versions\") = {\n");
1910
1911	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1912		if (!s->module)
1913			continue;
1914		if (!s->crc_valid) {
1915			warn("\"%s\" [%s.ko] has no CRC!\n",
1916				s->name, mod->name);
1917			continue;
1918		}
1919		if (strlen(s->name) >= MODULE_NAME_LEN) {
1920			error("too long symbol \"%s\" [%s.ko]\n",
1921			      s->name, mod->name);
1922			break;
1923		}
1924		buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1925			   s->crc, s->name);
1926	}
1927
1928	buf_printf(b, "};\n");
1929}
1930
1931static void add_depends(struct buffer *b, struct module *mod)
1932{
1933	struct symbol *s;
1934	int first = 1;
1935
1936	/* Clear ->seen flag of modules that own symbols needed by this. */
1937	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1938		if (s->module)
1939			s->module->seen = s->module->is_vmlinux;
1940	}
1941
1942	buf_printf(b, "\n");
1943	buf_printf(b, "MODULE_INFO(depends, \"");
1944	list_for_each_entry(s, &mod->unresolved_symbols, list) {
1945		const char *p;
1946		if (!s->module)
1947			continue;
1948
1949		if (s->module->seen)
1950			continue;
1951
1952		s->module->seen = true;
1953		p = strrchr(s->module->name, '/');
1954		if (p)
1955			p++;
1956		else
1957			p = s->module->name;
1958		buf_printf(b, "%s%s", first ? "" : ",", p);
1959		first = 0;
1960	}
1961	buf_printf(b, "\");\n");
1962}
1963
1964static void add_srcversion(struct buffer *b, struct module *mod)
1965{
1966	if (mod->srcversion[0]) {
1967		buf_printf(b, "\n");
1968		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1969			   mod->srcversion);
1970	}
1971}
1972
1973static void write_buf(struct buffer *b, const char *fname)
1974{
1975	FILE *file;
1976
1977	if (error_occurred)
1978		return;
1979
1980	file = fopen(fname, "w");
1981	if (!file) {
1982		perror(fname);
1983		exit(1);
1984	}
1985	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1986		perror(fname);
1987		exit(1);
1988	}
1989	if (fclose(file) != 0) {
1990		perror(fname);
1991		exit(1);
1992	}
1993}
1994
1995static void write_if_changed(struct buffer *b, const char *fname)
1996{
1997	char *tmp;
1998	FILE *file;
1999	struct stat st;
2000
2001	file = fopen(fname, "r");
2002	if (!file)
2003		goto write;
2004
2005	if (fstat(fileno(file), &st) < 0)
2006		goto close_write;
2007
2008	if (st.st_size != b->pos)
2009		goto close_write;
2010
2011	tmp = NOFAIL(malloc(b->pos));
2012	if (fread(tmp, 1, b->pos, file) != b->pos)
2013		goto free_write;
2014
2015	if (memcmp(tmp, b->p, b->pos) != 0)
2016		goto free_write;
2017
2018	free(tmp);
2019	fclose(file);
2020	return;
2021
2022 free_write:
2023	free(tmp);
2024 close_write:
2025	fclose(file);
2026 write:
2027	write_buf(b, fname);
2028}
2029
2030static void write_vmlinux_export_c_file(struct module *mod)
2031{
2032	struct buffer buf = { };
2033
2034	buf_printf(&buf,
2035		   "#include <linux/export-internal.h>\n");
2036
2037	add_exported_symbols(&buf, mod);
2038	write_if_changed(&buf, ".vmlinux.export.c");
2039	free(buf.p);
2040}
2041
2042/* do sanity checks, and generate *.mod.c file */
2043static void write_mod_c_file(struct module *mod)
2044{
2045	struct buffer buf = { };
 
2046	char fname[PATH_MAX];
2047	int ret;
2048
2049	add_header(&buf, mod);
2050	add_exported_symbols(&buf, mod);
2051	add_versions(&buf, mod);
2052	add_depends(&buf, mod);
2053	add_moddevtable(&buf, mod);
 
 
 
 
 
 
 
2054	add_srcversion(&buf, mod);
2055
2056	ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2057	if (ret >= sizeof(fname)) {
2058		error("%s: too long path was truncated\n", fname);
2059		goto free;
2060	}
2061
2062	write_if_changed(&buf, fname);
2063
2064free:
2065	free(buf.p);
2066}
2067
2068/* parse Module.symvers file. line format:
2069 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2070 **/
2071static void read_dump(const char *fname)
2072{
2073	char *buf, *pos, *line;
2074
2075	buf = read_text_file(fname);
2076	if (!buf)
2077		/* No symbol versions, silently ignore */
2078		return;
2079
2080	pos = buf;
2081
2082	while ((line = get_line(&pos))) {
2083		char *symname, *namespace, *modname, *d, *export;
2084		unsigned int crc;
2085		struct module *mod;
2086		struct symbol *s;
2087		bool gpl_only;
2088
2089		if (!(symname = strchr(line, '\t')))
2090			goto fail;
2091		*symname++ = '\0';
2092		if (!(modname = strchr(symname, '\t')))
2093			goto fail;
2094		*modname++ = '\0';
2095		if (!(export = strchr(modname, '\t')))
2096			goto fail;
2097		*export++ = '\0';
2098		if (!(namespace = strchr(export, '\t')))
2099			goto fail;
2100		*namespace++ = '\0';
2101
2102		crc = strtoul(line, &d, 16);
2103		if (*symname == '\0' || *modname == '\0' || *d != '\0')
2104			goto fail;
2105
2106		if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2107			gpl_only = true;
2108		} else if (!strcmp(export, "EXPORT_SYMBOL")) {
2109			gpl_only = false;
2110		} else {
2111			error("%s: unknown license %s. skip", symname, export);
2112			continue;
2113		}
2114
2115		mod = find_module(modname);
2116		if (!mod) {
2117			mod = new_module(modname, strlen(modname));
2118			mod->from_dump = true;
2119		}
2120		s = sym_add_exported(symname, mod, gpl_only, namespace);
2121		sym_set_crc(s, crc);
2122	}
2123	free(buf);
2124	return;
2125fail:
2126	free(buf);
2127	fatal("parse error in symbol dump file\n");
2128}
2129
2130static void write_dump(const char *fname)
2131{
2132	struct buffer buf = { };
2133	struct module *mod;
2134	struct symbol *sym;
2135
2136	list_for_each_entry(mod, &modules, list) {
2137		if (mod->from_dump)
2138			continue;
2139		list_for_each_entry(sym, &mod->exported_symbols, list) {
2140			if (trim_unused_exports && !sym->used)
2141				continue;
2142
2143			buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2144				   sym->crc, sym->name, mod->name,
2145				   sym->is_gpl_only ? "_GPL" : "",
2146				   sym->namespace);
2147		}
2148	}
2149	write_buf(&buf, fname);
2150	free(buf.p);
2151}
2152
2153static void write_namespace_deps_files(const char *fname)
2154{
2155	struct module *mod;
2156	struct namespace_list *ns;
2157	struct buffer ns_deps_buf = {};
2158
2159	list_for_each_entry(mod, &modules, list) {
2160
2161		if (mod->from_dump || list_empty(&mod->missing_namespaces))
2162			continue;
2163
2164		buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2165
2166		list_for_each_entry(ns, &mod->missing_namespaces, list)
2167			buf_printf(&ns_deps_buf, " %s", ns->namespace);
2168
2169		buf_printf(&ns_deps_buf, "\n");
2170	}
2171
2172	write_if_changed(&ns_deps_buf, fname);
2173	free(ns_deps_buf.p);
2174}
2175
2176struct dump_list {
2177	struct list_head list;
2178	const char *file;
2179};
2180
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2181int main(int argc, char **argv)
2182{
2183	struct module *mod;
2184	char *missing_namespace_deps = NULL;
2185	char *unused_exports_white_list = NULL;
2186	char *dump_write = NULL, *files_source = NULL;
2187	int opt;
2188	LIST_HEAD(dump_lists);
2189	struct dump_list *dl, *dl2;
2190
2191	while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2192		switch (opt) {
2193		case 'e':
2194			external_module = true;
2195			break;
2196		case 'i':
2197			dl = NOFAIL(malloc(sizeof(*dl)));
2198			dl->file = optarg;
2199			list_add_tail(&dl->list, &dump_lists);
2200			break;
2201		case 'M':
2202			module_enabled = true;
2203			break;
2204		case 'm':
2205			modversions = true;
2206			break;
2207		case 'n':
2208			ignore_missing_files = true;
2209			break;
2210		case 'o':
2211			dump_write = optarg;
2212			break;
2213		case 'a':
2214			all_versions = true;
2215			break;
2216		case 'T':
2217			files_source = optarg;
2218			break;
2219		case 't':
2220			trim_unused_exports = true;
2221			break;
2222		case 'u':
2223			unused_exports_white_list = optarg;
2224			break;
2225		case 'W':
2226			extra_warn = true;
2227			break;
2228		case 'w':
2229			warn_unresolved = true;
2230			break;
2231		case 'E':
2232			sec_mismatch_warn_only = false;
2233			break;
2234		case 'N':
2235			allow_missing_ns_imports = true;
2236			break;
2237		case 'd':
2238			missing_namespace_deps = optarg;
2239			break;
2240		default:
2241			exit(1);
2242		}
2243	}
2244
 
 
2245	list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2246		read_dump(dl->file);
2247		list_del(&dl->list);
2248		free(dl);
2249	}
2250
2251	while (optind < argc)
2252		read_symbols(argv[optind++]);
2253
2254	if (files_source)
2255		read_symbols_from_files(files_source);
2256
2257	list_for_each_entry(mod, &modules, list) {
2258		if (mod->from_dump || mod->is_vmlinux)
2259			continue;
2260
2261		check_modname_len(mod);
2262		check_exports(mod);
2263	}
2264
2265	if (unused_exports_white_list)
2266		handle_white_list_exports(unused_exports_white_list);
2267
2268	list_for_each_entry(mod, &modules, list) {
2269		if (mod->from_dump)
2270			continue;
2271
2272		if (mod->is_vmlinux)
2273			write_vmlinux_export_c_file(mod);
2274		else
2275			write_mod_c_file(mod);
2276	}
2277
2278	if (missing_namespace_deps)
2279		write_namespace_deps_files(missing_namespace_deps);
2280
2281	if (dump_write)
2282		write_dump(dump_write);
2283	if (sec_mismatch_count && !sec_mismatch_warn_only)
2284		error("Section mismatches detected.\n"
2285		      "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2286
2287	if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2288		warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2289		     nr_unresolved - MAX_UNRESOLVED_REPORTS);
2290
2291	return error_occurred ? 1 : 0;
2292}