1/* Postprocess module symbol versions
   2 *
   3 * Copyright 2003       Kai Germaschewski
   4 * Copyright 2002-2004  Rusty Russell, IBM Corporation
   5 * Copyright 2006-2008  Sam Ravnborg
   6 * Based in part on module-init-tools/depmod.c,file2alias
   7 *
   8 * This software may be used and distributed according to the terms
   9 * of the GNU General Public License, incorporated herein by reference.
  10 *
  11 * Usage: modpost vmlinux module1.o module2.o ...
  12 */
  13
  14#define _GNU_SOURCE
  15#include <stdio.h>
  16#include <ctype.h>
  17#include <string.h>
  18#include <limits.h>
  19#include <stdbool.h>
  20#include <errno.h>
  21#include "modpost.h"
  22#include "../../include/generated/autoconf.h"
  23#include "../../include/linux/license.h"
  24#include "../../include/linux/export.h"
 
 
 
 
 
 
 
  25
  26/* Are we using CONFIG_MODVERSIONS? */
  27int modversions = 0;
  28/* Warn about undefined symbols? (do so if we have vmlinux) */
  29int have_vmlinux = 0;
  30/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
  31static int all_versions = 0;
  32/* If we are modposting external module set to 1 */
  33static int external_module = 0;
  34/* Warn about section mismatch in vmlinux if set to 1 */
  35static int vmlinux_section_warnings = 1;
  36/* Only warn about unresolved symbols */
  37static int warn_unresolved = 0;
  38/* How a symbol is exported */
  39static int sec_mismatch_count = 0;
  40static int sec_mismatch_verbose = 1;
  41/* ignore missing files */
  42static int ignore_missing_files;
  43
  44enum export {
  45	export_plain,      export_unused,     export_gpl,
  46	export_unused_gpl, export_gpl_future, export_unknown
  47};
  48
  49#define PRINTF __attribute__ ((format (printf, 1, 2)))
  50
  51PRINTF void fatal(const char *fmt, ...)
  52{
  53	va_list arglist;
  54
  55	fprintf(stderr, "FATAL: ");
  56
  57	va_start(arglist, fmt);
  58	vfprintf(stderr, fmt, arglist);
  59	va_end(arglist);
  60
  61	exit(1);
  62}
  63
  64PRINTF void warn(const char *fmt, ...)
  65{
  66	va_list arglist;
  67
  68	fprintf(stderr, "WARNING: ");
  69
  70	va_start(arglist, fmt);
  71	vfprintf(stderr, fmt, arglist);
  72	va_end(arglist);
  73}
  74
  75PRINTF void merror(const char *fmt, ...)
  76{
  77	va_list arglist;
  78
  79	fprintf(stderr, "ERROR: ");
  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
  94static int is_vmlinux(const char *modname)
  95{
  96	const char *myname;
  97
  98	myname = strrchr(modname, '/');
  99	if (myname)
 100		myname++;
 101	else
 102		myname = modname;
 103
 104	return (strcmp(myname, "vmlinux") == 0) ||
 105	       (strcmp(myname, "vmlinux.o") == 0);
 106}
 107
 108void *do_nofail(void *ptr, const char *expr)
 109{
 110	if (!ptr)
 111		fatal("modpost: Memory allocation failure: %s.\n", expr);
 112
 113	return ptr;
 114}
 115
 116/* A list of all modules we processed */
 117static struct module *modules;
 118
 119static struct module *find_module(char *modname)
 120{
 121	struct module *mod;
 122
 123	for (mod = modules; mod; mod = mod->next)
 124		if (strcmp(mod->name, modname) == 0)
 125			break;
 126	return mod;
 127}
 128
 129static struct module *new_module(const char *modname)
 130{
 131	struct module *mod;
 132	char *p;
 133
 134	mod = NOFAIL(malloc(sizeof(*mod)));
 135	memset(mod, 0, sizeof(*mod));
 136	p = NOFAIL(strdup(modname));
 137
 138	/* strip trailing .o */
 139	if (strends(p, ".o")) {
 140		p[strlen(p) - 2] = '\0';
 141		mod->is_dot_o = 1;
 142	}
 143
 144	/* add to list */
 145	mod->name = p;
 146	mod->gpl_compatible = -1;
 147	mod->next = modules;
 148	modules = mod;
 149
 150	return mod;
 151}
 152
 153/* A hash of all exported symbols,
 154 * struct symbol is also used for lists of unresolved symbols */
 155
 156#define SYMBOL_HASH_SIZE 1024
 157
 158struct symbol {
 159	struct symbol *next;
 160	struct module *module;
 161	unsigned int crc;
 162	int crc_valid;
 163	unsigned int weak:1;
 164	unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
 165	unsigned int kernel:1;     /* 1 if symbol is from kernel
 166				    *  (only for external modules) **/
 167	unsigned int preloaded:1;  /* 1 if symbol from Module.symvers, or crc */
 168	enum export  export;       /* Type of export */
 169	char name[0];
 170};
 171
 172static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
 173
 174/* This is based on the hash agorithm from gdbm, via tdb */
 175static inline unsigned int tdb_hash(const char *name)
 176{
 177	unsigned value;	/* Used to compute the hash value.  */
 178	unsigned   i;	/* Used to cycle through random values. */
 179
 180	/* Set the initial value from the key size. */
 181	for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
 182		value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
 183
 184	return (1103515243 * value + 12345);
 185}
 186
 187/**
 188 * Allocate a new symbols for use in the hash of exported symbols or
 189 * the list of unresolved symbols per module
 190 **/
 191static struct symbol *alloc_symbol(const char *name, unsigned int weak,
 192				   struct symbol *next)
 193{
 194	struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 195
 196	memset(s, 0, sizeof(*s));
 197	strcpy(s->name, name);
 198	s->weak = weak;
 199	s->next = next;
 200	return s;
 201}
 202
 203/* For the hash of exported symbols */
 204static struct symbol *new_symbol(const char *name, struct module *module,
 205				 enum export export)
 206{
 207	unsigned int hash;
 208	struct symbol *new;
 209
 210	hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 211	new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 212	new->module = module;
 213	new->export = export;
 214	return new;
 215}
 216
 217static struct symbol *find_symbol(const char *name)
 218{
 219	struct symbol *s;
 220
 221	/* For our purposes, .foo matches foo.  PPC64 needs this. */
 222	if (name[0] == '.')
 223		name++;
 224
 225	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
 226		if (strcmp(s->name, name) == 0)
 227			return s;
 228	}
 229	return NULL;
 230}
 231
 232static struct {
 233	const char *str;
 234	enum export export;
 235} export_list[] = {
 236	{ .str = "EXPORT_SYMBOL",            .export = export_plain },
 237	{ .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
 238	{ .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
 239	{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
 240	{ .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
 241	{ .str = "(unknown)",                .export = export_unknown },
 242};
 243
 244
 245static const char *export_str(enum export ex)
 246{
 247	return export_list[ex].str;
 248}
 249
 250static enum export export_no(const char *s)
 251{
 252	int i;
 253
 254	if (!s)
 255		return export_unknown;
 256	for (i = 0; export_list[i].export != export_unknown; i++) {
 257		if (strcmp(export_list[i].str, s) == 0)
 258			return export_list[i].export;
 259	}
 260	return export_unknown;
 261}
 262
 263static const char *sec_name(struct elf_info *elf, int secindex);
 264
 265#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
 266
 267static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
 268{
 269	const char *secname = sec_name(elf, sec);
 270
 271	if (strstarts(secname, "___ksymtab+"))
 272		return export_plain;
 273	else if (strstarts(secname, "___ksymtab_unused+"))
 274		return export_unused;
 275	else if (strstarts(secname, "___ksymtab_gpl+"))
 276		return export_gpl;
 277	else if (strstarts(secname, "___ksymtab_unused_gpl+"))
 278		return export_unused_gpl;
 279	else if (strstarts(secname, "___ksymtab_gpl_future+"))
 280		return export_gpl_future;
 281	else
 282		return export_unknown;
 283}
 284
 285static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
 286{
 287	if (sec == elf->export_sec)
 288		return export_plain;
 289	else if (sec == elf->export_unused_sec)
 290		return export_unused;
 291	else if (sec == elf->export_gpl_sec)
 292		return export_gpl;
 293	else if (sec == elf->export_unused_gpl_sec)
 294		return export_unused_gpl;
 295	else if (sec == elf->export_gpl_future_sec)
 296		return export_gpl_future;
 297	else
 298		return export_unknown;
 299}
 300
 301/**
 302 * Add an exported symbol - it may have already been added without a
 303 * CRC, in this case just update the CRC
 304 **/
 305static struct symbol *sym_add_exported(const char *name, struct module *mod,
 306				       enum export export)
 307{
 308	struct symbol *s = find_symbol(name);
 309
 310	if (!s) {
 311		s = new_symbol(name, mod, export);
 312	} else {
 313		if (!s->preloaded) {
 314			warn("%s: '%s' exported twice. Previous export "
 315			     "was in %s%s\n", mod->name, name,
 316			     s->module->name,
 317			     is_vmlinux(s->module->name) ?"":".ko");
 318		} else {
 319			/* In case Modules.symvers was out of date */
 320			s->module = mod;
 321		}
 322	}
 323	s->preloaded = 0;
 324	s->vmlinux   = is_vmlinux(mod->name);
 325	s->kernel    = 0;
 326	s->export    = export;
 327	return s;
 328}
 329
 330static void sym_update_crc(const char *name, struct module *mod,
 331			   unsigned int crc, enum export export)
 332{
 333	struct symbol *s = find_symbol(name);
 334
 335	if (!s) {
 336		s = new_symbol(name, mod, export);
 337		/* Don't complain when we find it later. */
 338		s->preloaded = 1;
 339	}
 340	s->crc = crc;
 341	s->crc_valid = 1;
 342}
 343
 344void *grab_file(const char *filename, unsigned long *size)
 345{
 346	struct stat st;
 347	void *map = MAP_FAILED;
 348	int fd;
 349
 350	fd = open(filename, O_RDONLY);
 351	if (fd < 0)
 352		return NULL;
 353	if (fstat(fd, &st))
 354		goto failed;
 355
 356	*size = st.st_size;
 357	map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
 358
 359failed:
 360	close(fd);
 
 361	if (map == MAP_FAILED)
 362		return NULL;
 363	return map;
 364}
 365
 366/**
 367  * Return a copy of the next line in a mmap'ed file.
 368  * spaces in the beginning of the line is trimmed away.
 369  * Return a pointer to a static buffer.
 370  **/
 371char *get_next_line(unsigned long *pos, void *file, unsigned long size)
 372{
 373	static char line[4096];
 374	int skip = 1;
 375	size_t len = 0;
 376	signed char *p = (signed char *)file + *pos;
 377	char *s = line;
 378
 379	for (; *pos < size ; (*pos)++) {
 380		if (skip && isspace(*p)) {
 381			p++;
 382			continue;
 383		}
 384		skip = 0;
 385		if (*p != '\n' && (*pos < size)) {
 386			len++;
 387			*s++ = *p++;
 388			if (len > 4095)
 389				break; /* Too long, stop */
 390		} else {
 391			/* End of string */
 392			*s = '\0';
 393			return line;
 394		}
 395	}
 396	/* End of buffer */
 397	return NULL;
 398}
 399
 400void release_file(void *file, unsigned long size)
 401{
 402	munmap(file, size);
 403}
 404
 405static int parse_elf(struct elf_info *info, const char *filename)
 406{
 407	unsigned int i;
 408	Elf_Ehdr *hdr;
 409	Elf_Shdr *sechdrs;
 410	Elf_Sym  *sym;
 411	const char *secstrings;
 412	unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
 413
 414	hdr = grab_file(filename, &info->size);
 415	if (!hdr) {
 416		if (ignore_missing_files) {
 417			fprintf(stderr, "%s: %s (ignored)\n", filename,
 418				strerror(errno));
 419			return 0;
 420		}
 421		perror(filename);
 422		exit(1);
 423	}
 424	info->hdr = hdr;
 425	if (info->size < sizeof(*hdr)) {
 426		/* file too small, assume this is an empty .o file */
 427		return 0;
 428	}
 429	/* Is this a valid ELF file? */
 430	if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
 431	    (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
 432	    (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
 433	    (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
 434		/* Not an ELF file - silently ignore it */
 435		return 0;
 436	}
 437	/* Fix endianness in ELF header */
 438	hdr->e_type      = TO_NATIVE(hdr->e_type);
 439	hdr->e_machine   = TO_NATIVE(hdr->e_machine);
 440	hdr->e_version   = TO_NATIVE(hdr->e_version);
 441	hdr->e_entry     = TO_NATIVE(hdr->e_entry);
 442	hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
 443	hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
 444	hdr->e_flags     = TO_NATIVE(hdr->e_flags);
 445	hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
 446	hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
 447	hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
 448	hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
 449	hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
 450	hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
 451	sechdrs = (void *)hdr + hdr->e_shoff;
 452	info->sechdrs = sechdrs;
 453
 454	/* Check if file offset is correct */
 455	if (hdr->e_shoff > info->size) {
 456		fatal("section header offset=%lu in file '%s' is bigger than "
 457		      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
 458		      filename, info->size);
 459		return 0;
 460	}
 461
 462	if (hdr->e_shnum == SHN_UNDEF) {
 463		/*
 464		 * There are more than 64k sections,
 465		 * read count from .sh_size.
 466		 */
 467		info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
 468	}
 469	else {
 470		info->num_sections = hdr->e_shnum;
 471	}
 472	if (hdr->e_shstrndx == SHN_XINDEX) {
 473		info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
 474	}
 475	else {
 476		info->secindex_strings = hdr->e_shstrndx;
 477	}
 478
 479	/* Fix endianness in section headers */
 480	for (i = 0; i < info->num_sections; i++) {
 481		sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
 482		sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
 483		sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
 484		sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
 485		sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
 486		sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
 487		sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
 488		sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
 489		sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
 490		sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
 491	}
 492	/* Find symbol table. */
 493	secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
 494	for (i = 1; i < info->num_sections; i++) {
 495		const char *secname;
 496		int nobits = sechdrs[i].sh_type == SHT_NOBITS;
 497
 498		if (!nobits && sechdrs[i].sh_offset > info->size) {
 499			fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
 500			      "sizeof(*hrd)=%zu\n", filename,
 501			      (unsigned long)sechdrs[i].sh_offset,
 502			      sizeof(*hdr));
 503			return 0;
 504		}
 505		secname = secstrings + sechdrs[i].sh_name;
 506		if (strcmp(secname, ".modinfo") == 0) {
 507			if (nobits)
 508				fatal("%s has NOBITS .modinfo\n", filename);
 509			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
 510			info->modinfo_len = sechdrs[i].sh_size;
 511		} else if (strcmp(secname, "__ksymtab") == 0)
 512			info->export_sec = i;
 513		else if (strcmp(secname, "__ksymtab_unused") == 0)
 514			info->export_unused_sec = i;
 515		else if (strcmp(secname, "__ksymtab_gpl") == 0)
 516			info->export_gpl_sec = i;
 517		else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
 518			info->export_unused_gpl_sec = i;
 519		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
 520			info->export_gpl_future_sec = i;
 521
 522		if (sechdrs[i].sh_type == SHT_SYMTAB) {
 523			unsigned int sh_link_idx;
 524			symtab_idx = i;
 525			info->symtab_start = (void *)hdr +
 526			    sechdrs[i].sh_offset;
 527			info->symtab_stop  = (void *)hdr +
 528			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 529			sh_link_idx = sechdrs[i].sh_link;
 530			info->strtab       = (void *)hdr +
 531			    sechdrs[sh_link_idx].sh_offset;
 532		}
 533
 534		/* 32bit section no. table? ("more than 64k sections") */
 535		if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
 536			symtab_shndx_idx = i;
 537			info->symtab_shndx_start = (void *)hdr +
 538			    sechdrs[i].sh_offset;
 539			info->symtab_shndx_stop  = (void *)hdr +
 540			    sechdrs[i].sh_offset + sechdrs[i].sh_size;
 541		}
 542	}
 543	if (!info->symtab_start)
 544		fatal("%s has no symtab?\n", filename);
 545
 546	/* Fix endianness in symbols */
 547	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
 548		sym->st_shndx = TO_NATIVE(sym->st_shndx);
 549		sym->st_name  = TO_NATIVE(sym->st_name);
 550		sym->st_value = TO_NATIVE(sym->st_value);
 551		sym->st_size  = TO_NATIVE(sym->st_size);
 552	}
 553
 554	if (symtab_shndx_idx != ~0U) {
 555		Elf32_Word *p;
 556		if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
 557			fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
 558			      filename, sechdrs[symtab_shndx_idx].sh_link,
 559			      symtab_idx);
 560		/* Fix endianness */
 561		for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
 562		     p++)
 563			*p = TO_NATIVE(*p);
 564	}
 565
 566	return 1;
 567}
 568
 569static void parse_elf_finish(struct elf_info *info)
 570{
 571	release_file(info->hdr, info->size);
 572}
 573
 574static int ignore_undef_symbol(struct elf_info *info, const char *symname)
 575{
 576	/* ignore __this_module, it will be resolved shortly */
 577	if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
 578		return 1;
 579	/* ignore global offset table */
 580	if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
 581		return 1;
 582	if (info->hdr->e_machine == EM_PPC)
 583		/* Special register function linked on all modules during final link of .ko */
 584		if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
 585		    strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
 586		    strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
 587		    strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
 588		    strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
 589		    strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
 590			return 1;
 591	if (info->hdr->e_machine == EM_PPC64)
 592		/* Special register function linked on all modules during final link of .ko */
 593		if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
 594		    strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
 595		    strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
 596		    strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
 597			return 1;
 598	/* Do not ignore this symbol */
 599	return 0;
 600}
 601
 602#define CRC_PFX     VMLINUX_SYMBOL_STR(__crc_)
 603#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
 604
 605static void handle_modversions(struct module *mod, struct elf_info *info,
 606			       Elf_Sym *sym, const char *symname)
 607{
 608	unsigned int crc;
 609	enum export export;
 610
 611	if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
 612	    strncmp(symname, "__ksymtab", 9) == 0)
 613		export = export_from_secname(info, get_secindex(info, sym));
 614	else
 615		export = export_from_sec(info, get_secindex(info, sym));
 616
 617	/* CRC'd symbol */
 618	if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 619		crc = (unsigned int) sym->st_value;
 620		sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
 621				export);
 622	}
 623
 624	switch (sym->st_shndx) {
 625	case SHN_COMMON:
 626		if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
 627			/* Should warn here, but modpost runs before the linker */
 628		} else
 629			warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 
 
 
 
 
 630		break;
 631	case SHN_UNDEF:
 632		/* undefined symbol */
 633		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
 634		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
 635			break;
 636		if (ignore_undef_symbol(info, symname))
 637			break;
 638/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
 639#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
 640/* add compatibility with older glibc */
 641#ifndef STT_SPARC_REGISTER
 642#define STT_SPARC_REGISTER STT_REGISTER
 643#endif
 644		if (info->hdr->e_machine == EM_SPARC ||
 645		    info->hdr->e_machine == EM_SPARCV9) {
 646			/* Ignore register directives. */
 647			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 648				break;
 649			if (symname[0] == '.') {
 650				char *munged = strdup(symname);
 651				munged[0] = '_';
 652				munged[1] = toupper(munged[1]);
 653				symname = munged;
 654			}
 655		}
 656#endif
 657
 658#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
 659		if (symname[0] != '_')
 660			break;
 661		else
 662			symname++;
 663#endif
 664		mod->unres = alloc_symbol(symname,
 665					  ELF_ST_BIND(sym->st_info) == STB_WEAK,
 666					  mod->unres);
 667		break;
 668	default:
 669		/* All exported symbols */
 670		if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
 671			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
 672					export);
 673		}
 674		if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
 675			mod->has_init = 1;
 676		if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
 677			mod->has_cleanup = 1;
 678		break;
 679	}
 680}
 681
 682/**
 683 * Parse tag=value strings from .modinfo section
 684 **/
 685static char *next_string(char *string, unsigned long *secsize)
 686{
 687	/* Skip non-zero chars */
 688	while (string[0]) {
 689		string++;
 690		if ((*secsize)-- <= 1)
 691			return NULL;
 692	}
 693
 694	/* Skip any zero padding. */
 695	while (!string[0]) {
 696		string++;
 697		if ((*secsize)-- <= 1)
 698			return NULL;
 699	}
 700	return string;
 701}
 702
 703static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
 704			      const char *tag, char *info)
 705{
 706	char *p;
 707	unsigned int taglen = strlen(tag);
 708	unsigned long size = modinfo_len;
 709
 710	if (info) {
 711		size -= info - (char *)modinfo;
 712		modinfo = next_string(info, &size);
 713	}
 714
 715	for (p = modinfo; p; p = next_string(p, &size)) {
 716		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 717			return p + taglen + 1;
 718	}
 719	return NULL;
 720}
 721
 722static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 723			 const char *tag)
 724
 725{
 726	return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
 727}
 728
 729/**
 730 * Test if string s ends in string sub
 731 * return 0 if match
 732 **/
 733static int strrcmp(const char *s, const char *sub)
 734{
 735	int slen, sublen;
 736
 737	if (!s || !sub)
 738		return 1;
 739
 740	slen = strlen(s);
 741	sublen = strlen(sub);
 742
 743	if ((slen == 0) || (sublen == 0))
 744		return 1;
 745
 746	if (sublen > slen)
 747		return 1;
 748
 749	return memcmp(s + slen - sublen, sub, sublen);
 750}
 751
 752static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
 753{
 754	if (sym)
 755		return elf->strtab + sym->st_name;
 756	else
 757		return "(unknown)";
 758}
 759
 760static const char *sec_name(struct elf_info *elf, int secindex)
 761{
 762	Elf_Shdr *sechdrs = elf->sechdrs;
 763	return (void *)elf->hdr +
 764		elf->sechdrs[elf->secindex_strings].sh_offset +
 765		sechdrs[secindex].sh_name;
 766}
 767
 768static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
 769{
 770	return (void *)elf->hdr +
 771		elf->sechdrs[elf->secindex_strings].sh_offset +
 772		sechdr->sh_name;
 773}
 774
 775/* if sym is empty or point to a string
 776 * like ".[0-9]+" then return 1.
 777 * This is the optional prefix added by ld to some sections
 778 */
 779static int number_prefix(const char *sym)
 780{
 781	if (*sym++ == '\0')
 782		return 1;
 783	if (*sym != '.')
 784		return 0;
 785	do {
 786		char c = *sym++;
 787		if (c < '0' || c > '9')
 788			return 0;
 789	} while (*sym);
 790	return 1;
 791}
 792
 793/* The pattern is an array of simple patterns.
 794 * "foo" will match an exact string equal to "foo"
 795 * "*foo" will match a string that ends with "foo"
 796 * "foo*" will match a string that begins with "foo"
 797 * "foo$" will match a string equal to "foo" or "foo.1"
 798 *   where the '1' can be any number including several digits.
 799 *   The $ syntax is for sections where ld append a dot number
 800 *   to make section name unique.
 801 */
 802static int match(const char *sym, const char * const pat[])
 803{
 804	const char *p;
 805	while (*pat) {
 806		p = *pat++;
 807		const char *endp = p + strlen(p) - 1;
 808
 809		/* "*foo" */
 810		if (*p == '*') {
 811			if (strrcmp(sym, p + 1) == 0)
 812				return 1;
 813		}
 814		/* "foo*" */
 815		else if (*endp == '*') {
 816			if (strncmp(sym, p, strlen(p) - 1) == 0)
 817				return 1;
 818		}
 819		/* "foo$" */
 820		else if (*endp == '$') {
 821			if (strncmp(sym, p, strlen(p) - 1) == 0) {
 822				if (number_prefix(sym + strlen(p) - 1))
 823					return 1;
 824			}
 825		}
 826		/* no wildcards */
 827		else {
 828			if (strcmp(p, sym) == 0)
 829				return 1;
 830		}
 831	}
 832	/* no match */
 833	return 0;
 834}
 835
 836/* sections that we do not want to do full section mismatch check on */
 837static const char *section_white_list[] =
 838{
 839	".comment*",
 840	".debug*",
 841	".cranges",		/* sh64 */
 842	".zdebug*",		/* Compressed debug sections. */
 843	".GCC-command-line",	/* mn10300 */
 844	".GCC.command.line",	/* record-gcc-switches, non mn10300 */
 845	".mdebug*",        /* alpha, score, mips etc. */
 846	".pdr",            /* alpha, score, mips etc. */
 847	".stab*",
 848	".note*",
 849	".got*",
 850	".toc*",
 851	".xt.prop",				 /* xtensa */
 852	".xt.lit",         /* xtensa */
 853	".arcextmap*",			/* arc */
 854	".gnu.linkonce.arcext*",	/* arc : modules */
 855	".gnu.lto*",
 856	NULL
 857};
 858
 859/*
 860 * This is used to find sections missing the SHF_ALLOC flag.
 861 * The cause of this is often a section specified in assembler
 862 * without "ax" / "aw".
 863 */
 864static void check_section(const char *modname, struct elf_info *elf,
 865                          Elf_Shdr *sechdr)
 866{
 867	const char *sec = sech_name(elf, sechdr);
 868
 869	if (sechdr->sh_type == SHT_PROGBITS &&
 870	    !(sechdr->sh_flags & SHF_ALLOC) &&
 871	    !match(sec, section_white_list)) {
 872		warn("%s (%s): unexpected non-allocatable section.\n"
 873		     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
 874		     "Note that for example <linux/init.h> contains\n"
 875		     "section definitions for use in .S files.\n\n",
 876		     modname, sec);
 877	}
 878}
 879
 880
 881
 882#define ALL_INIT_DATA_SECTIONS \
 883	".init.setup$", ".init.rodata$", ".meminit.rodata$", \
 884	".init.data$", ".meminit.data$"
 
 885#define ALL_EXIT_DATA_SECTIONS \
 886	".exit.data$", ".memexit.data$"
 887
 888#define ALL_INIT_TEXT_SECTIONS \
 889	".init.text$", ".meminit.text$"
 890#define ALL_EXIT_TEXT_SECTIONS \
 891	".exit.text$", ".memexit.text$"
 892
 893#define ALL_PCI_INIT_SECTIONS	\
 894	".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
 895	".pci_fixup_enable$", ".pci_fixup_resume$", \
 896	".pci_fixup_resume_early$", ".pci_fixup_suspend$"
 897
 898#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
 899#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
 900
 901#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
 902#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
 903
 904#define DATA_SECTIONS ".data$", ".data.rel$"
 905#define TEXT_SECTIONS ".text$", ".text.unlikely$"
 906
 907#define INIT_SECTIONS      ".init.*"
 
 
 908#define MEM_INIT_SECTIONS  ".meminit.*"
 909
 910#define EXIT_SECTIONS      ".exit.*"
 
 
 911#define MEM_EXIT_SECTIONS  ".memexit.*"
 912
 913/* init data sections */
 914static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
 915
 916/* all init sections */
 917static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
 918
 919/* All init and exit sections (code + data) */
 920static const char *init_exit_sections[] =
 921	{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
 922
 923/* data section */
 924static const char *data_sections[] = { DATA_SECTIONS, NULL };
 925
 926
 927/* symbols in .data that may refer to init/exit sections */
 928#define DEFAULT_SYMBOL_WHITE_LIST					\
 929	"*driver",							\
 930	"*_template", /* scsi uses *_template a lot */			\
 931	"*_timer",    /* arm uses ops structures named _timer a lot */	\
 932	"*_sht",      /* scsi also used *_sht to some extent */		\
 933	"*_ops",							\
 934	"*_probe",							\
 935	"*_probe_one",							\
 936	"*_console"
 937
 938static const char *head_sections[] = { ".head.text*", NULL };
 939static const char *linker_symbols[] =
 940	{ "__init_begin", "_sinittext", "_einittext", NULL };
 941
 942enum mismatch {
 943	TEXT_TO_ANY_INIT,
 944	DATA_TO_ANY_INIT,
 945	TEXT_TO_ANY_EXIT,
 946	DATA_TO_ANY_EXIT,
 947	XXXINIT_TO_SOME_INIT,
 948	XXXEXIT_TO_SOME_EXIT,
 949	ANY_INIT_TO_ANY_EXIT,
 950	ANY_EXIT_TO_ANY_INIT,
 951	EXPORT_TO_INIT_EXIT,
 952};
 953
 954struct sectioncheck {
 955	const char *fromsec[20];
 956	const char *tosec[20];
 957	enum mismatch mismatch;
 958	const char *symbol_white_list[20];
 959};
 960
 961const struct sectioncheck sectioncheck[] = {
 962/* Do not reference init/exit code/data from
 963 * normal code and data
 964 */
 965{
 966	.fromsec = { TEXT_SECTIONS, NULL },
 967	.tosec   = { ALL_INIT_SECTIONS, NULL },
 968	.mismatch = TEXT_TO_ANY_INIT,
 969	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 970},
 971{
 972	.fromsec = { DATA_SECTIONS, NULL },
 973	.tosec   = { ALL_XXXINIT_SECTIONS, NULL },
 974	.mismatch = DATA_TO_ANY_INIT,
 975	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 976},
 977{
 978	.fromsec = { DATA_SECTIONS, NULL },
 979	.tosec   = { INIT_SECTIONS, NULL },
 980	.mismatch = DATA_TO_ANY_INIT,
 981	.symbol_white_list = {
 982		"*_template", "*_timer", "*_sht", "*_ops",
 983		"*_probe", "*_probe_one", "*_console", NULL
 984	},
 985},
 986{
 987	.fromsec = { TEXT_SECTIONS, NULL },
 988	.tosec   = { ALL_EXIT_SECTIONS, NULL },
 989	.mismatch = TEXT_TO_ANY_EXIT,
 990	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 991},
 992{
 993	.fromsec = { DATA_SECTIONS, NULL },
 994	.tosec   = { ALL_EXIT_SECTIONS, NULL },
 995	.mismatch = DATA_TO_ANY_EXIT,
 996	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
 997},
 998/* Do not reference init code/data from meminit code/data */
 999{
1000	.fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1001	.tosec   = { INIT_SECTIONS, NULL },
1002	.mismatch = XXXINIT_TO_SOME_INIT,
1003	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1004},
1005/* Do not reference exit code/data from memexit code/data */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1006{
1007	.fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1008	.tosec   = { EXIT_SECTIONS, NULL },
1009	.mismatch = XXXEXIT_TO_SOME_EXIT,
1010	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1011},
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1012/* Do not use exit code/data from init code */
1013{
1014	.fromsec = { ALL_INIT_SECTIONS, NULL },
1015	.tosec   = { ALL_EXIT_SECTIONS, NULL },
1016	.mismatch = ANY_INIT_TO_ANY_EXIT,
1017	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1018},
1019/* Do not use init code/data from exit code */
1020{
1021	.fromsec = { ALL_EXIT_SECTIONS, NULL },
1022	.tosec   = { ALL_INIT_SECTIONS, NULL },
1023	.mismatch = ANY_EXIT_TO_ANY_INIT,
1024	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1025},
1026{
1027	.fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1028	.tosec   = { INIT_SECTIONS, NULL },
1029	.mismatch = ANY_INIT_TO_ANY_EXIT,
1030	.symbol_white_list = { NULL },
1031},
1032/* Do not export init/exit functions or data */
1033{
1034	.fromsec = { "__ksymtab*", NULL },
1035	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1036	.mismatch = EXPORT_TO_INIT_EXIT,
1037	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1038}
1039};
1040
1041static const struct sectioncheck *section_mismatch(
1042		const char *fromsec, const char *tosec)
1043{
1044	int i;
1045	int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1046	const struct sectioncheck *check = &sectioncheck[0];
1047
1048	for (i = 0; i < elems; i++) {
1049		if (match(fromsec, check->fromsec) &&
1050		    match(tosec, check->tosec))
1051			return check;
1052		check++;
1053	}
1054	return NULL;
1055}
1056
1057/**
1058 * Whitelist to allow certain references to pass with no warning.
1059 *
1060 * Pattern 1:
1061 *   If a module parameter is declared __initdata and permissions=0
1062 *   then this is legal despite the warning generated.
1063 *   We cannot see value of permissions here, so just ignore
1064 *   this pattern.
1065 *   The pattern is identified by:
1066 *   tosec   = .init.data
1067 *   fromsec = .data*
1068 *   atsym   =__param*
1069 *
1070 * Pattern 1a:
1071 *   module_param_call() ops can refer to __init set function if permissions=0
1072 *   The pattern is identified by:
1073 *   tosec   = .init.text
1074 *   fromsec = .data*
1075 *   atsym   = __param_ops_*
1076 *
1077 * Pattern 2:
1078 *   Many drivers utilise a *driver container with references to
1079 *   add, remove, probe functions etc.
 
 
1080 *   the pattern is identified by:
1081 *   tosec   = init or exit section
1082 *   fromsec = data section
1083 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
1084 *           *probe_one, *_console, *_timer
1085 *
1086 * Pattern 3:
1087 *   Whitelist all references from .head.text to any init section
1088 *
1089 * Pattern 4:
1090 *   Some symbols belong to init section but still it is ok to reference
1091 *   these from non-init sections as these symbols don't have any memory
1092 *   allocated for them and symbol address and value are same. So even
1093 *   if init section is freed, its ok to reference those symbols.
1094 *   For ex. symbols marking the init section boundaries.
1095 *   This pattern is identified by
1096 *   refsymname = __init_begin, _sinittext, _einittext
1097 *
1098 **/
1099static int secref_whitelist(const struct sectioncheck *mismatch,
1100			    const char *fromsec, const char *fromsym,
1101			    const char *tosec, const char *tosym)
1102{
1103	/* Check for pattern 1 */
1104	if (match(tosec, init_data_sections) &&
1105	    match(fromsec, data_sections) &&
1106	    (strncmp(fromsym, "__param", strlen("__param")) == 0))
1107		return 0;
1108
1109	/* Check for pattern 1a */
1110	if (strcmp(tosec, ".init.text") == 0 &&
1111	    match(fromsec, data_sections) &&
1112	    (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1113		return 0;
1114
1115	/* Check for pattern 2 */
1116	if (match(tosec, init_exit_sections) &&
1117	    match(fromsec, data_sections) &&
1118	    match(fromsym, mismatch->symbol_white_list))
1119		return 0;
1120
1121	/* Check for pattern 3 */
1122	if (match(fromsec, head_sections) &&
1123	    match(tosec, init_sections))
1124		return 0;
1125
1126	/* Check for pattern 4 */
1127	if (match(tosym, linker_symbols))
1128		return 0;
1129
1130	return 1;
1131}
1132
1133/**
1134 * Find symbol based on relocation record info.
1135 * In some cases the symbol supplied is a valid symbol so
1136 * return refsym. If st_name != 0 we assume this is a valid symbol.
1137 * In other cases the symbol needs to be looked up in the symbol table
1138 * based on section and address.
1139 *  **/
1140static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1141				Elf_Sym *relsym)
1142{
1143	Elf_Sym *sym;
1144	Elf_Sym *near = NULL;
1145	Elf64_Sword distance = 20;
1146	Elf64_Sword d;
1147	unsigned int relsym_secindex;
1148
1149	if (relsym->st_name != 0)
1150		return relsym;
1151
1152	relsym_secindex = get_secindex(elf, relsym);
1153	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1154		if (get_secindex(elf, sym) != relsym_secindex)
1155			continue;
1156		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1157			continue;
1158		if (sym->st_value == addr)
1159			return sym;
1160		/* Find a symbol nearby - addr are maybe negative */
1161		d = sym->st_value - addr;
1162		if (d < 0)
1163			d = addr - sym->st_value;
1164		if (d < distance) {
1165			distance = d;
1166			near = sym;
1167		}
1168	}
1169	/* We need a close match */
1170	if (distance < 20)
1171		return near;
1172	else
1173		return NULL;
1174}
1175
1176static inline int is_arm_mapping_symbol(const char *str)
1177{
1178	return str[0] == '$' && strchr("atd", str[1])
1179	       && (str[2] == '\0' || str[2] == '.');
1180}
1181
1182/*
1183 * If there's no name there, ignore it; likewise, ignore it if it's
1184 * one of the magic symbols emitted used by current ARM tools.
1185 *
1186 * Otherwise if find_symbols_between() returns those symbols, they'll
1187 * fail the whitelist tests and cause lots of false alarms ... fixable
1188 * only by merging __exit and __init sections into __text, bloating
1189 * the kernel (which is especially evil on embedded platforms).
1190 */
1191static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1192{
1193	const char *name = elf->strtab + sym->st_name;
1194
1195	if (!name || !strlen(name))
1196		return 0;
1197	return !is_arm_mapping_symbol(name);
1198}
1199
1200/*
1201 * Find symbols before or equal addr and after addr - in the section sec.
1202 * If we find two symbols with equal offset prefer one with a valid name.
1203 * The ELF format may have a better way to detect what type of symbol
1204 * it is, but this works for now.
1205 **/
1206static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1207				 const char *sec)
1208{
1209	Elf_Sym *sym;
1210	Elf_Sym *near = NULL;
1211	Elf_Addr distance = ~0;
1212
1213	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1214		const char *symsec;
1215
1216		if (is_shndx_special(sym->st_shndx))
1217			continue;
1218		symsec = sec_name(elf, get_secindex(elf, sym));
1219		if (strcmp(symsec, sec) != 0)
1220			continue;
1221		if (!is_valid_name(elf, sym))
1222			continue;
1223		if (sym->st_value <= addr) {
1224			if ((addr - sym->st_value) < distance) {
1225				distance = addr - sym->st_value;
1226				near = sym;
1227			} else if ((addr - sym->st_value) == distance) {
1228				near = sym;
1229			}
1230		}
1231	}
1232	return near;
1233}
1234
1235/*
1236 * Convert a section name to the function/data attribute
1237 * .init.text => __init
 
1238 * .memexitconst => __memconst
1239 * etc.
1240 *
1241 * The memory of returned value has been allocated on a heap. The user of this
1242 * method should free it after usage.
1243*/
1244static char *sec2annotation(const char *s)
1245{
1246	if (match(s, init_exit_sections)) {
1247		char *p = malloc(20);
1248		char *r = p;
1249
1250		*p++ = '_';
1251		*p++ = '_';
1252		if (*s == '.')
1253			s++;
1254		while (*s && *s != '.')
1255			*p++ = *s++;
1256		*p = '\0';
1257		if (*s == '.')
1258			s++;
1259		if (strstr(s, "rodata") != NULL)
1260			strcat(p, "const ");
1261		else if (strstr(s, "data") != NULL)
1262			strcat(p, "data ");
1263		else
1264			strcat(p, " ");
1265		return r;
1266	} else {
1267		return strdup("");
1268	}
1269}
1270
1271static int is_function(Elf_Sym *sym)
1272{
1273	if (sym)
1274		return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1275	else
1276		return -1;
1277}
1278
1279static void print_section_list(const char * const list[20])
1280{
1281	const char *const *s = list;
1282
1283	while (*s) {
1284		fprintf(stderr, "%s", *s);
1285		s++;
1286		if (*s)
1287			fprintf(stderr, ", ");
1288	}
1289	fprintf(stderr, "\n");
1290}
1291
1292/*
1293 * Print a warning about a section mismatch.
1294 * Try to find symbols near it so user can find it.
1295 * Check whitelist before warning - it may be a false positive.
1296 */
1297static void report_sec_mismatch(const char *modname,
1298				const struct sectioncheck *mismatch,
1299                                const char *fromsec,
1300                                unsigned long long fromaddr,
1301                                const char *fromsym,
1302                                int from_is_func,
1303                                const char *tosec, const char *tosym,
1304                                int to_is_func)
1305{
1306	const char *from, *from_p;
1307	const char *to, *to_p;
1308	char *prl_from;
1309	char *prl_to;
1310
1311	switch (from_is_func) {
1312	case 0: from = "variable"; from_p = "";   break;
1313	case 1: from = "function"; from_p = "()"; break;
1314	default: from = "(unknown reference)"; from_p = ""; break;
1315	}
1316	switch (to_is_func) {
1317	case 0: to = "variable"; to_p = "";   break;
1318	case 1: to = "function"; to_p = "()"; break;
1319	default: to = "(unknown reference)"; to_p = ""; break;
1320	}
1321
1322	sec_mismatch_count++;
1323	if (!sec_mismatch_verbose)
1324		return;
1325
1326	warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1327	     "to the %s %s:%s%s\n",
1328	     modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1329	     tosym, to_p);
1330
1331	switch (mismatch->mismatch) {
1332	case TEXT_TO_ANY_INIT:
1333		prl_from = sec2annotation(fromsec);
1334		prl_to = sec2annotation(tosec);
1335		fprintf(stderr,
1336		"The function %s%s() references\n"
1337		"the %s %s%s%s.\n"
1338		"This is often because %s lacks a %s\n"
1339		"annotation or the annotation of %s is wrong.\n",
1340		prl_from, fromsym,
1341		to, prl_to, tosym, to_p,
1342		fromsym, prl_to, tosym);
1343		free(prl_from);
1344		free(prl_to);
1345		break;
1346	case DATA_TO_ANY_INIT: {
1347		prl_to = sec2annotation(tosec);
1348		fprintf(stderr,
1349		"The variable %s references\n"
1350		"the %s %s%s%s\n"
1351		"If the reference is valid then annotate the\n"
1352		"variable with __init* or __refdata (see linux/init.h) "
1353		"or name the variable:\n",
1354		fromsym, to, prl_to, tosym, to_p);
1355		print_section_list(mismatch->symbol_white_list);
1356		free(prl_to);
1357		break;
1358	}
1359	case TEXT_TO_ANY_EXIT:
1360		prl_to = sec2annotation(tosec);
1361		fprintf(stderr,
1362		"The function %s() references a %s in an exit section.\n"
1363		"Often the %s %s%s has valid usage outside the exit section\n"
1364		"and the fix is to remove the %sannotation of %s.\n",
1365		fromsym, to, to, tosym, to_p, prl_to, tosym);
1366		free(prl_to);
1367		break;
1368	case DATA_TO_ANY_EXIT: {
1369		prl_to = sec2annotation(tosec);
1370		fprintf(stderr,
1371		"The variable %s references\n"
1372		"the %s %s%s%s\n"
1373		"If the reference is valid then annotate the\n"
1374		"variable with __exit* (see linux/init.h) or "
1375		"name the variable:\n",
1376		fromsym, to, prl_to, tosym, to_p);
1377		print_section_list(mismatch->symbol_white_list);
1378		free(prl_to);
1379		break;
1380	}
1381	case XXXINIT_TO_SOME_INIT:
1382	case XXXEXIT_TO_SOME_EXIT:
1383		prl_from = sec2annotation(fromsec);
1384		prl_to = sec2annotation(tosec);
1385		fprintf(stderr,
1386		"The %s %s%s%s references\n"
1387		"a %s %s%s%s.\n"
1388		"If %s is only used by %s then\n"
1389		"annotate %s with a matching annotation.\n",
1390		from, prl_from, fromsym, from_p,
1391		to, prl_to, tosym, to_p,
1392		tosym, fromsym, tosym);
1393		free(prl_from);
1394		free(prl_to);
1395		break;
1396	case ANY_INIT_TO_ANY_EXIT:
1397		prl_from = sec2annotation(fromsec);
1398		prl_to = sec2annotation(tosec);
1399		fprintf(stderr,
1400		"The %s %s%s%s references\n"
1401		"a %s %s%s%s.\n"
1402		"This is often seen when error handling "
1403		"in the init function\n"
1404		"uses functionality in the exit path.\n"
1405		"The fix is often to remove the %sannotation of\n"
1406		"%s%s so it may be used outside an exit section.\n",
1407		from, prl_from, fromsym, from_p,
1408		to, prl_to, tosym, to_p,
1409		prl_to, tosym, to_p);
1410		free(prl_from);
1411		free(prl_to);
1412		break;
1413	case ANY_EXIT_TO_ANY_INIT:
1414		prl_from = sec2annotation(fromsec);
1415		prl_to = sec2annotation(tosec);
1416		fprintf(stderr,
1417		"The %s %s%s%s references\n"
1418		"a %s %s%s%s.\n"
1419		"This is often seen when error handling "
1420		"in the exit function\n"
1421		"uses functionality in the init path.\n"
1422		"The fix is often to remove the %sannotation of\n"
1423		"%s%s so it may be used outside an init section.\n",
1424		from, prl_from, fromsym, from_p,
1425		to, prl_to, tosym, to_p,
1426		prl_to, tosym, to_p);
1427		free(prl_from);
1428		free(prl_to);
1429		break;
1430	case EXPORT_TO_INIT_EXIT:
1431		prl_to = sec2annotation(tosec);
1432		fprintf(stderr,
1433		"The symbol %s is exported and annotated %s\n"
1434		"Fix this by removing the %sannotation of %s "
1435		"or drop the export.\n",
1436		tosym, prl_to, prl_to, tosym);
1437		free(prl_to);
1438		break;
1439	}
1440	fprintf(stderr, "\n");
1441}
1442
1443static void check_section_mismatch(const char *modname, struct elf_info *elf,
1444                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1445{
1446	const char *tosec;
1447	const struct sectioncheck *mismatch;
1448
1449	tosec = sec_name(elf, get_secindex(elf, sym));
1450	mismatch = section_mismatch(fromsec, tosec);
1451	if (mismatch) {
1452		Elf_Sym *to;
1453		Elf_Sym *from;
1454		const char *tosym;
1455		const char *fromsym;
1456
1457		from = find_elf_symbol2(elf, r->r_offset, fromsec);
1458		fromsym = sym_name(elf, from);
1459		to = find_elf_symbol(elf, r->r_addend, sym);
1460		tosym = sym_name(elf, to);
1461
1462		if (!strncmp(fromsym, "reference___initcall",
1463				sizeof("reference___initcall")-1))
1464			return;
1465
1466		/* check whitelist - we may ignore it */
1467		if (secref_whitelist(mismatch,
1468					fromsec, fromsym, tosec, tosym)) {
1469			report_sec_mismatch(modname, mismatch,
1470			   fromsec, r->r_offset, fromsym,
1471			   is_function(from), tosec, tosym,
1472			   is_function(to));
1473		}
1474	}
1475}
1476
1477static unsigned int *reloc_location(struct elf_info *elf,
1478				    Elf_Shdr *sechdr, Elf_Rela *r)
1479{
1480	Elf_Shdr *sechdrs = elf->sechdrs;
1481	int section = sechdr->sh_info;
1482
1483	return (void *)elf->hdr + sechdrs[section].sh_offset +
1484		r->r_offset;
1485}
1486
1487static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1488{
1489	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1490	unsigned int *location = reloc_location(elf, sechdr, r);
1491
1492	switch (r_typ) {
1493	case R_386_32:
1494		r->r_addend = TO_NATIVE(*location);
1495		break;
1496	case R_386_PC32:
1497		r->r_addend = TO_NATIVE(*location) + 4;
1498		/* For CONFIG_RELOCATABLE=y */
1499		if (elf->hdr->e_type == ET_EXEC)
1500			r->r_addend += r->r_offset;
1501		break;
1502	}
1503	return 0;
1504}
1505
1506#ifndef R_ARM_CALL
1507#define R_ARM_CALL	28
1508#endif
1509#ifndef R_ARM_JUMP24
1510#define R_ARM_JUMP24	29
1511#endif
1512
1513#ifndef	R_ARM_THM_CALL
1514#define	R_ARM_THM_CALL		10
1515#endif
1516#ifndef	R_ARM_THM_JUMP24
1517#define	R_ARM_THM_JUMP24	30
1518#endif
1519#ifndef	R_ARM_THM_JUMP19
1520#define	R_ARM_THM_JUMP19	51
1521#endif
1522
1523static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1524{
1525	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1526
1527	switch (r_typ) {
1528	case R_ARM_ABS32:
1529		/* From ARM ABI: (S + A) | T */
1530		r->r_addend = (int)(long)
1531		              (elf->symtab_start + ELF_R_SYM(r->r_info));
1532		break;
1533	case R_ARM_PC24:
1534	case R_ARM_CALL:
1535	case R_ARM_JUMP24:
1536	case R_ARM_THM_CALL:
1537	case R_ARM_THM_JUMP24:
1538	case R_ARM_THM_JUMP19:
1539		/* From ARM ABI: ((S + A) | T) - P */
1540		r->r_addend = (int)(long)(elf->hdr +
1541		              sechdr->sh_offset +
1542		              (r->r_offset - sechdr->sh_addr));
1543		break;
1544	default:
1545		return 1;
1546	}
1547	return 0;
1548}
1549
1550static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1551{
1552	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1553	unsigned int *location = reloc_location(elf, sechdr, r);
1554	unsigned int inst;
1555
1556	if (r_typ == R_MIPS_HI16)
1557		return 1;	/* skip this */
1558	inst = TO_NATIVE(*location);
1559	switch (r_typ) {
1560	case R_MIPS_LO16:
1561		r->r_addend = inst & 0xffff;
1562		break;
1563	case R_MIPS_26:
1564		r->r_addend = (inst & 0x03ffffff) << 2;
1565		break;
1566	case R_MIPS_32:
1567		r->r_addend = inst;
1568		break;
1569	}
1570	return 0;
1571}
1572
1573static void section_rela(const char *modname, struct elf_info *elf,
1574                         Elf_Shdr *sechdr)
1575{
1576	Elf_Sym  *sym;
1577	Elf_Rela *rela;
1578	Elf_Rela r;
1579	unsigned int r_sym;
1580	const char *fromsec;
1581
1582	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1583	Elf_Rela *stop  = (void *)start + sechdr->sh_size;
1584
1585	fromsec = sech_name(elf, sechdr);
1586	fromsec += strlen(".rela");
1587	/* if from section (name) is know good then skip it */
1588	if (match(fromsec, section_white_list))
1589		return;
1590
1591	for (rela = start; rela < stop; rela++) {
1592		r.r_offset = TO_NATIVE(rela->r_offset);
1593#if KERNEL_ELFCLASS == ELFCLASS64
1594		if (elf->hdr->e_machine == EM_MIPS) {
1595			unsigned int r_typ;
1596			r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1597			r_sym = TO_NATIVE(r_sym);
1598			r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1599			r.r_info = ELF64_R_INFO(r_sym, r_typ);
1600		} else {
1601			r.r_info = TO_NATIVE(rela->r_info);
1602			r_sym = ELF_R_SYM(r.r_info);
1603		}
1604#else
1605		r.r_info = TO_NATIVE(rela->r_info);
1606		r_sym = ELF_R_SYM(r.r_info);
1607#endif
1608		r.r_addend = TO_NATIVE(rela->r_addend);
1609		sym = elf->symtab_start + r_sym;
1610		/* Skip special sections */
1611		if (is_shndx_special(sym->st_shndx))
1612			continue;
1613		check_section_mismatch(modname, elf, &r, sym, fromsec);
1614	}
1615}
1616
1617static void section_rel(const char *modname, struct elf_info *elf,
1618                        Elf_Shdr *sechdr)
1619{
1620	Elf_Sym *sym;
1621	Elf_Rel *rel;
1622	Elf_Rela r;
1623	unsigned int r_sym;
1624	const char *fromsec;
1625
1626	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1627	Elf_Rel *stop  = (void *)start + sechdr->sh_size;
1628
1629	fromsec = sech_name(elf, sechdr);
1630	fromsec += strlen(".rel");
1631	/* if from section (name) is know good then skip it */
1632	if (match(fromsec, section_white_list))
1633		return;
1634
1635	for (rel = start; rel < stop; rel++) {
1636		r.r_offset = TO_NATIVE(rel->r_offset);
1637#if KERNEL_ELFCLASS == ELFCLASS64
1638		if (elf->hdr->e_machine == EM_MIPS) {
1639			unsigned int r_typ;
1640			r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1641			r_sym = TO_NATIVE(r_sym);
1642			r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1643			r.r_info = ELF64_R_INFO(r_sym, r_typ);
1644		} else {
1645			r.r_info = TO_NATIVE(rel->r_info);
1646			r_sym = ELF_R_SYM(r.r_info);
1647		}
1648#else
1649		r.r_info = TO_NATIVE(rel->r_info);
1650		r_sym = ELF_R_SYM(r.r_info);
1651#endif
1652		r.r_addend = 0;
1653		switch (elf->hdr->e_machine) {
1654		case EM_386:
1655			if (addend_386_rel(elf, sechdr, &r))
1656				continue;
1657			break;
1658		case EM_ARM:
1659			if (addend_arm_rel(elf, sechdr, &r))
1660				continue;
1661			break;
1662		case EM_MIPS:
1663			if (addend_mips_rel(elf, sechdr, &r))
1664				continue;
1665			break;
1666		}
1667		sym = elf->symtab_start + r_sym;
1668		/* Skip special sections */
1669		if (is_shndx_special(sym->st_shndx))
1670			continue;
1671		check_section_mismatch(modname, elf, &r, sym, fromsec);
1672	}
1673}
1674
1675/**
1676 * A module includes a number of sections that are discarded
1677 * either when loaded or when used as built-in.
1678 * For loaded modules all functions marked __init and all data
1679 * marked __initdata will be discarded when the module has been initialized.
1680 * Likewise for modules used built-in the sections marked __exit
1681 * are discarded because __exit marked function are supposed to be called
1682 * only when a module is unloaded which never happens for built-in modules.
1683 * The check_sec_ref() function traverses all relocation records
1684 * to find all references to a section that reference a section that will
1685 * be discarded and warns about it.
1686 **/
1687static void check_sec_ref(struct module *mod, const char *modname,
1688                          struct elf_info *elf)
1689{
1690	int i;
1691	Elf_Shdr *sechdrs = elf->sechdrs;
1692
1693	/* Walk through all sections */
1694	for (i = 0; i < elf->num_sections; i++) {
1695		check_section(modname, elf, &elf->sechdrs[i]);
1696		/* We want to process only relocation sections and not .init */
1697		if (sechdrs[i].sh_type == SHT_RELA)
1698			section_rela(modname, elf, &elf->sechdrs[i]);
1699		else if (sechdrs[i].sh_type == SHT_REL)
1700			section_rel(modname, elf, &elf->sechdrs[i]);
1701	}
1702}
1703
1704static char *remove_dot(char *s)
1705{
1706	char *end;
1707	int n = strcspn(s, ".");
1708
1709	if (n > 0 && s[n] != 0) {
1710		strtoul(s + n + 1, &end, 10);
1711		if  (end > s + n + 1 && (*end == '.' || *end == 0))
1712			s[n] = 0;
1713	}
1714	return s;
1715}
1716
1717static void read_symbols(char *modname)
1718{
1719	const char *symname;
1720	char *version;
1721	char *license;
1722	struct module *mod;
1723	struct elf_info info = { };
1724	Elf_Sym *sym;
1725
1726	if (!parse_elf(&info, modname))
1727		return;
1728
1729	mod = new_module(modname);
1730
1731	/* When there's no vmlinux, don't print warnings about
1732	 * unresolved symbols (since there'll be too many ;) */
1733	if (is_vmlinux(modname)) {
1734		have_vmlinux = 1;
1735		mod->skip = 1;
1736	}
1737
1738	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1739	if (info.modinfo && !license && !is_vmlinux(modname))
1740		warn("modpost: missing MODULE_LICENSE() in %s\n"
1741		     "see include/linux/module.h for "
1742		     "more information\n", modname);
1743	while (license) {
1744		if (license_is_gpl_compatible(license))
1745			mod->gpl_compatible = 1;
1746		else {
1747			mod->gpl_compatible = 0;
1748			break;
1749		}
1750		license = get_next_modinfo(info.modinfo, info.modinfo_len,
1751					   "license", license);
1752	}
1753
1754	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1755		symname = remove_dot(info.strtab + sym->st_name);
1756
1757		handle_modversions(mod, &info, sym, symname);
1758		handle_moddevtable(mod, &info, sym, symname);
1759	}
1760	if (!is_vmlinux(modname) ||
1761	     (is_vmlinux(modname) && vmlinux_section_warnings))
1762		check_sec_ref(mod, modname, &info);
1763
1764	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1765	if (version)
1766		maybe_frob_rcs_version(modname, version, info.modinfo,
1767				       version - (char *)info.hdr);
1768	if (version || (all_versions && !is_vmlinux(modname)))
1769		get_src_version(modname, mod->srcversion,
1770				sizeof(mod->srcversion)-1);
1771
1772	parse_elf_finish(&info);
1773
1774	/* Our trick to get versioning for module struct etc. - it's
1775	 * never passed as an argument to an exported function, so
1776	 * the automatic versioning doesn't pick it up, but it's really
1777	 * important anyhow */
1778	if (modversions)
1779		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1780}
1781
1782static void read_symbols_from_files(const char *filename)
1783{
1784	FILE *in = stdin;
1785	char fname[PATH_MAX];
1786
1787	if (strcmp(filename, "-") != 0) {
1788		in = fopen(filename, "r");
1789		if (!in)
1790			fatal("Can't open filenames file %s: %m", filename);
1791	}
1792
1793	while (fgets(fname, PATH_MAX, in) != NULL) {
1794		if (strends(fname, "\n"))
1795			fname[strlen(fname)-1] = '\0';
1796		read_symbols(fname);
1797	}
1798
1799	if (in != stdin)
1800		fclose(in);
1801}
1802
1803#define SZ 500
1804
1805/* We first write the generated file into memory using the
1806 * following helper, then compare to the file on disk and
1807 * only update the later if anything changed */
1808
1809void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1810						      const char *fmt, ...)
1811{
1812	char tmp[SZ];
1813	int len;
1814	va_list ap;
1815
1816	va_start(ap, fmt);
1817	len = vsnprintf(tmp, SZ, fmt, ap);
1818	buf_write(buf, tmp, len);
1819	va_end(ap);
1820}
1821
1822void buf_write(struct buffer *buf, const char *s, int len)
1823{
1824	if (buf->size - buf->pos < len) {
1825		buf->size += len + SZ;
1826		buf->p = realloc(buf->p, buf->size);
1827	}
1828	strncpy(buf->p + buf->pos, s, len);
1829	buf->pos += len;
1830}
1831
1832static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1833{
1834	const char *e = is_vmlinux(m) ?"":".ko";
1835
1836	switch (exp) {
1837	case export_gpl:
1838		fatal("modpost: GPL-incompatible module %s%s "
1839		      "uses GPL-only symbol '%s'\n", m, e, s);
1840		break;
1841	case export_unused_gpl:
1842		fatal("modpost: GPL-incompatible module %s%s "
1843		      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1844		break;
1845	case export_gpl_future:
1846		warn("modpost: GPL-incompatible module %s%s "
1847		      "uses future GPL-only symbol '%s'\n", m, e, s);
1848		break;
1849	case export_plain:
1850	case export_unused:
1851	case export_unknown:
1852		/* ignore */
1853		break;
1854	}
1855}
1856
1857static void check_for_unused(enum export exp, const char *m, const char *s)
1858{
1859	const char *e = is_vmlinux(m) ?"":".ko";
1860
1861	switch (exp) {
1862	case export_unused:
1863	case export_unused_gpl:
1864		warn("modpost: module %s%s "
1865		      "uses symbol '%s' marked UNUSED\n", m, e, s);
1866		break;
1867	default:
1868		/* ignore */
1869		break;
1870	}
1871}
1872
1873static void check_exports(struct module *mod)
1874{
1875	struct symbol *s, *exp;
1876
1877	for (s = mod->unres; s; s = s->next) {
1878		const char *basename;
1879		exp = find_symbol(s->name);
1880		if (!exp || exp->module == mod)
1881			continue;
1882		basename = strrchr(mod->name, '/');
1883		if (basename)
1884			basename++;
1885		else
1886			basename = mod->name;
1887		if (!mod->gpl_compatible)
1888			check_for_gpl_usage(exp->export, basename, exp->name);
1889		check_for_unused(exp->export, basename, exp->name);
1890	}
1891}
1892
1893/**
1894 * Header for the generated file
1895 **/
1896static void add_header(struct buffer *b, struct module *mod)
1897{
1898	buf_printf(b, "#include <linux/module.h>\n");
1899	buf_printf(b, "#include <linux/vermagic.h>\n");
1900	buf_printf(b, "#include <linux/compiler.h>\n");
1901	buf_printf(b, "\n");
1902	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1903	buf_printf(b, "\n");
1904	buf_printf(b, "__visible struct module __this_module\n");
1905	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1906	buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1907	if (mod->has_init)
1908		buf_printf(b, "\t.init = init_module,\n");
1909	if (mod->has_cleanup)
1910		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1911			      "\t.exit = cleanup_module,\n"
1912			      "#endif\n");
1913	buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1914	buf_printf(b, "};\n");
1915}
1916
1917static void add_intree_flag(struct buffer *b, int is_intree)
1918{
1919	if (is_intree)
1920		buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1921}
1922
1923static void add_staging_flag(struct buffer *b, const char *name)
1924{
1925	static const char *staging_dir = "drivers/staging";
1926
1927	if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1928		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1929}
1930
1931/**
1932 * Record CRCs for unresolved symbols
1933 **/
1934static int add_versions(struct buffer *b, struct module *mod)
1935{
1936	struct symbol *s, *exp;
1937	int err = 0;
1938
1939	for (s = mod->unres; s; s = s->next) {
1940		exp = find_symbol(s->name);
1941		if (!exp || exp->module == mod) {
1942			if (have_vmlinux && !s->weak) {
1943				if (warn_unresolved) {
1944					warn("\"%s\" [%s.ko] undefined!\n",
1945					     s->name, mod->name);
1946				} else {
1947					merror("\"%s\" [%s.ko] undefined!\n",
1948					          s->name, mod->name);
1949					err = 1;
1950				}
1951			}
1952			continue;
1953		}
1954		s->module = exp->module;
1955		s->crc_valid = exp->crc_valid;
1956		s->crc = exp->crc;
1957	}
1958
1959	if (!modversions)
1960		return err;
1961
1962	buf_printf(b, "\n");
1963	buf_printf(b, "static const struct modversion_info ____versions[]\n");
1964	buf_printf(b, "__used\n");
1965	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1966
1967	for (s = mod->unres; s; s = s->next) {
1968		if (!s->module)
1969			continue;
1970		if (!s->crc_valid) {
1971			warn("\"%s\" [%s.ko] has no CRC!\n",
1972				s->name, mod->name);
1973			continue;
1974		}
1975		buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1976			   s->crc, s->name);
1977	}
1978
1979	buf_printf(b, "};\n");
1980
1981	return err;
1982}
1983
1984static void add_depends(struct buffer *b, struct module *mod,
1985			struct module *modules)
1986{
1987	struct symbol *s;
1988	struct module *m;
1989	int first = 1;
1990
1991	for (m = modules; m; m = m->next)
1992		m->seen = is_vmlinux(m->name);
1993
1994	buf_printf(b, "\n");
1995	buf_printf(b, "static const char __module_depends[]\n");
1996	buf_printf(b, "__used\n");
1997	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1998	buf_printf(b, "\"depends=");
1999	for (s = mod->unres; s; s = s->next) {
2000		const char *p;
2001		if (!s->module)
2002			continue;
2003
2004		if (s->module->seen)
2005			continue;
2006
2007		s->module->seen = 1;
2008		p = strrchr(s->module->name, '/');
2009		if (p)
2010			p++;
2011		else
2012			p = s->module->name;
2013		buf_printf(b, "%s%s", first ? "" : ",", p);
2014		first = 0;
2015	}
2016	buf_printf(b, "\";\n");
2017}
2018
2019static void add_srcversion(struct buffer *b, struct module *mod)
2020{
2021	if (mod->srcversion[0]) {
2022		buf_printf(b, "\n");
2023		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2024			   mod->srcversion);
2025	}
2026}
2027
2028static void write_if_changed(struct buffer *b, const char *fname)
2029{
2030	char *tmp;
2031	FILE *file;
2032	struct stat st;
2033
2034	file = fopen(fname, "r");
2035	if (!file)
2036		goto write;
2037
2038	if (fstat(fileno(file), &st) < 0)
2039		goto close_write;
2040
2041	if (st.st_size != b->pos)
2042		goto close_write;
2043
2044	tmp = NOFAIL(malloc(b->pos));
2045	if (fread(tmp, 1, b->pos, file) != b->pos)
2046		goto free_write;
2047
2048	if (memcmp(tmp, b->p, b->pos) != 0)
2049		goto free_write;
2050
2051	free(tmp);
2052	fclose(file);
2053	return;
2054
2055 free_write:
2056	free(tmp);
2057 close_write:
2058	fclose(file);
2059 write:
2060	file = fopen(fname, "w");
2061	if (!file) {
2062		perror(fname);
2063		exit(1);
2064	}
2065	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2066		perror(fname);
2067		exit(1);
2068	}
2069	fclose(file);
2070}
2071
2072/* parse Module.symvers file. line format:
2073 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2074 **/
2075static void read_dump(const char *fname, unsigned int kernel)
2076{
2077	unsigned long size, pos = 0;
2078	void *file = grab_file(fname, &size);
2079	char *line;
2080
2081	if (!file)
2082		/* No symbol versions, silently ignore */
2083		return;
2084
2085	while ((line = get_next_line(&pos, file, size))) {
2086		char *symname, *modname, *d, *export, *end;
2087		unsigned int crc;
2088		struct module *mod;
2089		struct symbol *s;
2090
2091		if (!(symname = strchr(line, '\t')))
2092			goto fail;
2093		*symname++ = '\0';
2094		if (!(modname = strchr(symname, '\t')))
2095			goto fail;
2096		*modname++ = '\0';
2097		if ((export = strchr(modname, '\t')) != NULL)
2098			*export++ = '\0';
2099		if (export && ((end = strchr(export, '\t')) != NULL))
2100			*end = '\0';
2101		crc = strtoul(line, &d, 16);
2102		if (*symname == '\0' || *modname == '\0' || *d != '\0')
2103			goto fail;
2104		mod = find_module(modname);
2105		if (!mod) {
2106			if (is_vmlinux(modname))
2107				have_vmlinux = 1;
2108			mod = new_module(modname);
2109			mod->skip = 1;
2110		}
2111		s = sym_add_exported(symname, mod, export_no(export));
2112		s->kernel    = kernel;
2113		s->preloaded = 1;
2114		sym_update_crc(symname, mod, crc, export_no(export));
2115	}
2116	return;
2117fail:
2118	fatal("parse error in symbol dump file\n");
2119}
2120
2121/* For normal builds always dump all symbols.
2122 * For external modules only dump symbols
2123 * that are not read from kernel Module.symvers.
2124 **/
2125static int dump_sym(struct symbol *sym)
2126{
2127	if (!external_module)
2128		return 1;
2129	if (sym->vmlinux || sym->kernel)
2130		return 0;
2131	return 1;
2132}
2133
2134static void write_dump(const char *fname)
2135{
2136	struct buffer buf = { };
2137	struct symbol *symbol;
2138	int n;
2139
2140	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2141		symbol = symbolhash[n];
2142		while (symbol) {
2143			if (dump_sym(symbol))
2144				buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2145					symbol->crc, symbol->name,
2146					symbol->module->name,
2147					export_str(symbol->export));
2148			symbol = symbol->next;
2149		}
2150	}
2151	write_if_changed(&buf, fname);
2152}
2153
2154struct ext_sym_list {
2155	struct ext_sym_list *next;
2156	const char *file;
2157};
2158
2159int main(int argc, char **argv)
2160{
2161	struct module *mod;
2162	struct buffer buf = { };
2163	char *kernel_read = NULL, *module_read = NULL;
2164	char *dump_write = NULL, *files_source = NULL;
2165	int opt;
2166	int err;
2167	struct ext_sym_list *extsym_iter;
2168	struct ext_sym_list *extsym_start = NULL;
2169
2170	while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:")) != -1) {
2171		switch (opt) {
2172		case 'i':
2173			kernel_read = optarg;
2174			break;
2175		case 'I':
2176			module_read = optarg;
2177			external_module = 1;
2178			break;
 
 
 
2179		case 'e':
2180			external_module = 1;
2181			extsym_iter =
2182			   NOFAIL(malloc(sizeof(*extsym_iter)));
2183			extsym_iter->next = extsym_start;
2184			extsym_iter->file = optarg;
2185			extsym_start = extsym_iter;
2186			break;
2187		case 'm':
2188			modversions = 1;
2189			break;
2190		case 'n':
2191			ignore_missing_files = 1;
2192			break;
2193		case 'o':
2194			dump_write = optarg;
2195			break;
2196		case 'a':
2197			all_versions = 1;
2198			break;
2199		case 's':
2200			vmlinux_section_warnings = 0;
2201			break;
2202		case 'S':
2203			sec_mismatch_verbose = 0;
2204			break;
2205		case 'T':
2206			files_source = optarg;
2207			break;
2208		case 'w':
2209			warn_unresolved = 1;
2210			break;
2211		default:
2212			exit(1);
2213		}
2214	}
2215
2216	if (kernel_read)
2217		read_dump(kernel_read, 1);
2218	if (module_read)
2219		read_dump(module_read, 0);
2220	while (extsym_start) {
2221		read_dump(extsym_start->file, 0);
2222		extsym_iter = extsym_start->next;
2223		free(extsym_start);
2224		extsym_start = extsym_iter;
2225	}
2226
2227	while (optind < argc)
2228		read_symbols(argv[optind++]);
2229
2230	if (files_source)
2231		read_symbols_from_files(files_source);
2232
2233	for (mod = modules; mod; mod = mod->next) {
2234		if (mod->skip)
2235			continue;
2236		check_exports(mod);
2237	}
2238
2239	err = 0;
2240
2241	for (mod = modules; mod; mod = mod->next) {
2242		char fname[strlen(mod->name) + 10];
2243
2244		if (mod->skip)
2245			continue;
2246
2247		buf.pos = 0;
2248
2249		add_header(&buf, mod);
2250		add_intree_flag(&buf, !external_module);
2251		add_staging_flag(&buf, mod->name);
2252		err |= add_versions(&buf, mod);
2253		add_depends(&buf, mod, modules);
2254		add_moddevtable(&buf, mod);
2255		add_srcversion(&buf, mod);
2256
2257		sprintf(fname, "%s.mod.c", mod->name);
2258		write_if_changed(&buf, fname);
2259	}
2260
2261	if (dump_write)
2262		write_dump(dump_write);
2263	if (sec_mismatch_count && !sec_mismatch_verbose)
2264		warn("modpost: Found %d section mismatch(es).\n"
2265		     "To see full details build your kernel with:\n"
2266		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2267		     sec_mismatch_count);
2268
2269	return err;
2270}