Loading...
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include "modpost.h"
19#include "../../include/generated/autoconf.h"
20#include "../../include/linux/license.h"
21
22/* Some toolchains use a `_' prefix for all user symbols. */
23#ifdef CONFIG_SYMBOL_PREFIX
24#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
25#else
26#define MODULE_SYMBOL_PREFIX ""
27#endif
28
29
30/* Are we using CONFIG_MODVERSIONS? */
31int modversions = 0;
32/* Warn about undefined symbols? (do so if we have vmlinux) */
33int have_vmlinux = 0;
34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35static int all_versions = 0;
36/* If we are modposting external module set to 1 */
37static int external_module = 0;
38/* Warn about section mismatch in vmlinux if set to 1 */
39static int vmlinux_section_warnings = 1;
40/* Only warn about unresolved symbols */
41static int warn_unresolved = 0;
42/* How a symbol is exported */
43static int sec_mismatch_count = 0;
44static int sec_mismatch_verbose = 1;
45
46enum export {
47 export_plain, export_unused, export_gpl,
48 export_unused_gpl, export_gpl_future, export_unknown
49};
50
51#define PRINTF __attribute__ ((format (printf, 1, 2)))
52
53PRINTF void fatal(const char *fmt, ...)
54{
55 va_list arglist;
56
57 fprintf(stderr, "FATAL: ");
58
59 va_start(arglist, fmt);
60 vfprintf(stderr, fmt, arglist);
61 va_end(arglist);
62
63 exit(1);
64}
65
66PRINTF void warn(const char *fmt, ...)
67{
68 va_list arglist;
69
70 fprintf(stderr, "WARNING: ");
71
72 va_start(arglist, fmt);
73 vfprintf(stderr, fmt, arglist);
74 va_end(arglist);
75}
76
77PRINTF void merror(const char *fmt, ...)
78{
79 va_list arglist;
80
81 fprintf(stderr, "ERROR: ");
82
83 va_start(arglist, fmt);
84 vfprintf(stderr, fmt, arglist);
85 va_end(arglist);
86}
87
88static int is_vmlinux(const char *modname)
89{
90 const char *myname;
91
92 myname = strrchr(modname, '/');
93 if (myname)
94 myname++;
95 else
96 myname = modname;
97
98 return (strcmp(myname, "vmlinux") == 0) ||
99 (strcmp(myname, "vmlinux.o") == 0);
100}
101
102void *do_nofail(void *ptr, const char *expr)
103{
104 if (!ptr)
105 fatal("modpost: Memory allocation failure: %s.\n", expr);
106
107 return ptr;
108}
109
110/* A list of all modules we processed */
111static struct module *modules;
112
113static struct module *find_module(char *modname)
114{
115 struct module *mod;
116
117 for (mod = modules; mod; mod = mod->next)
118 if (strcmp(mod->name, modname) == 0)
119 break;
120 return mod;
121}
122
123static struct module *new_module(char *modname)
124{
125 struct module *mod;
126 char *p, *s;
127
128 mod = NOFAIL(malloc(sizeof(*mod)));
129 memset(mod, 0, sizeof(*mod));
130 p = NOFAIL(strdup(modname));
131
132 /* strip trailing .o */
133 s = strrchr(p, '.');
134 if (s != NULL)
135 if (strcmp(s, ".o") == 0) {
136 *s = '\0';
137 mod->is_dot_o = 1;
138 }
139
140 /* add to list */
141 mod->name = p;
142 mod->gpl_compatible = -1;
143 mod->next = modules;
144 modules = mod;
145
146 return mod;
147}
148
149/* A hash of all exported symbols,
150 * struct symbol is also used for lists of unresolved symbols */
151
152#define SYMBOL_HASH_SIZE 1024
153
154struct symbol {
155 struct symbol *next;
156 struct module *module;
157 unsigned int crc;
158 int crc_valid;
159 unsigned int weak:1;
160 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
161 unsigned int kernel:1; /* 1 if symbol is from kernel
162 * (only for external modules) **/
163 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
164 enum export export; /* Type of export */
165 char name[0];
166};
167
168static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
169
170/* This is based on the hash agorithm from gdbm, via tdb */
171static inline unsigned int tdb_hash(const char *name)
172{
173 unsigned value; /* Used to compute the hash value. */
174 unsigned i; /* Used to cycle through random values. */
175
176 /* Set the initial value from the key size. */
177 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
178 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
179
180 return (1103515243 * value + 12345);
181}
182
183/**
184 * Allocate a new symbols for use in the hash of exported symbols or
185 * the list of unresolved symbols per module
186 **/
187static struct symbol *alloc_symbol(const char *name, unsigned int weak,
188 struct symbol *next)
189{
190 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
191
192 memset(s, 0, sizeof(*s));
193 strcpy(s->name, name);
194 s->weak = weak;
195 s->next = next;
196 return s;
197}
198
199/* For the hash of exported symbols */
200static struct symbol *new_symbol(const char *name, struct module *module,
201 enum export export)
202{
203 unsigned int hash;
204 struct symbol *new;
205
206 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
207 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
208 new->module = module;
209 new->export = export;
210 return new;
211}
212
213static struct symbol *find_symbol(const char *name)
214{
215 struct symbol *s;
216
217 /* For our purposes, .foo matches foo. PPC64 needs this. */
218 if (name[0] == '.')
219 name++;
220
221 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
222 if (strcmp(s->name, name) == 0)
223 return s;
224 }
225 return NULL;
226}
227
228static struct {
229 const char *str;
230 enum export export;
231} export_list[] = {
232 { .str = "EXPORT_SYMBOL", .export = export_plain },
233 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
234 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
235 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
236 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
237 { .str = "(unknown)", .export = export_unknown },
238};
239
240
241static const char *export_str(enum export ex)
242{
243 return export_list[ex].str;
244}
245
246static enum export export_no(const char *s)
247{
248 int i;
249
250 if (!s)
251 return export_unknown;
252 for (i = 0; export_list[i].export != export_unknown; i++) {
253 if (strcmp(export_list[i].str, s) == 0)
254 return export_list[i].export;
255 }
256 return export_unknown;
257}
258
259static const char *sec_name(struct elf_info *elf, int secindex);
260
261#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
262
263static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
264{
265 const char *secname = sec_name(elf, sec);
266
267 if (strstarts(secname, "___ksymtab+"))
268 return export_plain;
269 else if (strstarts(secname, "___ksymtab_unused+"))
270 return export_unused;
271 else if (strstarts(secname, "___ksymtab_gpl+"))
272 return export_gpl;
273 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
274 return export_unused_gpl;
275 else if (strstarts(secname, "___ksymtab_gpl_future+"))
276 return export_gpl_future;
277 else
278 return export_unknown;
279}
280
281static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
282{
283 if (sec == elf->export_sec)
284 return export_plain;
285 else if (sec == elf->export_unused_sec)
286 return export_unused;
287 else if (sec == elf->export_gpl_sec)
288 return export_gpl;
289 else if (sec == elf->export_unused_gpl_sec)
290 return export_unused_gpl;
291 else if (sec == elf->export_gpl_future_sec)
292 return export_gpl_future;
293 else
294 return export_unknown;
295}
296
297/**
298 * Add an exported symbol - it may have already been added without a
299 * CRC, in this case just update the CRC
300 **/
301static struct symbol *sym_add_exported(const char *name, struct module *mod,
302 enum export export)
303{
304 struct symbol *s = find_symbol(name);
305
306 if (!s) {
307 s = new_symbol(name, mod, export);
308 } else {
309 if (!s->preloaded) {
310 warn("%s: '%s' exported twice. Previous export "
311 "was in %s%s\n", mod->name, name,
312 s->module->name,
313 is_vmlinux(s->module->name) ?"":".ko");
314 } else {
315 /* In case Modules.symvers was out of date */
316 s->module = mod;
317 }
318 }
319 s->preloaded = 0;
320 s->vmlinux = is_vmlinux(mod->name);
321 s->kernel = 0;
322 s->export = export;
323 return s;
324}
325
326static void sym_update_crc(const char *name, struct module *mod,
327 unsigned int crc, enum export export)
328{
329 struct symbol *s = find_symbol(name);
330
331 if (!s)
332 s = new_symbol(name, mod, export);
333 s->crc = crc;
334 s->crc_valid = 1;
335}
336
337void *grab_file(const char *filename, unsigned long *size)
338{
339 struct stat st;
340 void *map = MAP_FAILED;
341 int fd;
342
343 fd = open(filename, O_RDONLY);
344 if (fd < 0)
345 return NULL;
346 if (fstat(fd, &st))
347 goto failed;
348
349 *size = st.st_size;
350 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
351
352failed:
353 close(fd);
354 if (map == MAP_FAILED)
355 return NULL;
356 return map;
357}
358
359/**
360 * Return a copy of the next line in a mmap'ed file.
361 * spaces in the beginning of the line is trimmed away.
362 * Return a pointer to a static buffer.
363 **/
364char *get_next_line(unsigned long *pos, void *file, unsigned long size)
365{
366 static char line[4096];
367 int skip = 1;
368 size_t len = 0;
369 signed char *p = (signed char *)file + *pos;
370 char *s = line;
371
372 for (; *pos < size ; (*pos)++) {
373 if (skip && isspace(*p)) {
374 p++;
375 continue;
376 }
377 skip = 0;
378 if (*p != '\n' && (*pos < size)) {
379 len++;
380 *s++ = *p++;
381 if (len > 4095)
382 break; /* Too long, stop */
383 } else {
384 /* End of string */
385 *s = '\0';
386 return line;
387 }
388 }
389 /* End of buffer */
390 return NULL;
391}
392
393void release_file(void *file, unsigned long size)
394{
395 munmap(file, size);
396}
397
398static int parse_elf(struct elf_info *info, const char *filename)
399{
400 unsigned int i;
401 Elf_Ehdr *hdr;
402 Elf_Shdr *sechdrs;
403 Elf_Sym *sym;
404 const char *secstrings;
405 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
406
407 hdr = grab_file(filename, &info->size);
408 if (!hdr) {
409 perror(filename);
410 exit(1);
411 }
412 info->hdr = hdr;
413 if (info->size < sizeof(*hdr)) {
414 /* file too small, assume this is an empty .o file */
415 return 0;
416 }
417 /* Is this a valid ELF file? */
418 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
419 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
420 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
421 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
422 /* Not an ELF file - silently ignore it */
423 return 0;
424 }
425 /* Fix endianness in ELF header */
426 hdr->e_type = TO_NATIVE(hdr->e_type);
427 hdr->e_machine = TO_NATIVE(hdr->e_machine);
428 hdr->e_version = TO_NATIVE(hdr->e_version);
429 hdr->e_entry = TO_NATIVE(hdr->e_entry);
430 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
431 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
432 hdr->e_flags = TO_NATIVE(hdr->e_flags);
433 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
434 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
435 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
436 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
437 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
438 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
439 sechdrs = (void *)hdr + hdr->e_shoff;
440 info->sechdrs = sechdrs;
441
442 /* Check if file offset is correct */
443 if (hdr->e_shoff > info->size) {
444 fatal("section header offset=%lu in file '%s' is bigger than "
445 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
446 filename, info->size);
447 return 0;
448 }
449
450 if (hdr->e_shnum == SHN_UNDEF) {
451 /*
452 * There are more than 64k sections,
453 * read count from .sh_size.
454 */
455 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
456 }
457 else {
458 info->num_sections = hdr->e_shnum;
459 }
460 if (hdr->e_shstrndx == SHN_XINDEX) {
461 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
462 }
463 else {
464 info->secindex_strings = hdr->e_shstrndx;
465 }
466
467 /* Fix endianness in section headers */
468 for (i = 0; i < info->num_sections; i++) {
469 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
470 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
471 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
472 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
473 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
474 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
475 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
476 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
477 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
478 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
479 }
480 /* Find symbol table. */
481 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
482 for (i = 1; i < info->num_sections; i++) {
483 const char *secname;
484 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
485
486 if (!nobits && sechdrs[i].sh_offset > info->size) {
487 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
488 "sizeof(*hrd)=%zu\n", filename,
489 (unsigned long)sechdrs[i].sh_offset,
490 sizeof(*hdr));
491 return 0;
492 }
493 secname = secstrings + sechdrs[i].sh_name;
494 if (strcmp(secname, ".modinfo") == 0) {
495 if (nobits)
496 fatal("%s has NOBITS .modinfo\n", filename);
497 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
498 info->modinfo_len = sechdrs[i].sh_size;
499 } else if (strcmp(secname, "__ksymtab") == 0)
500 info->export_sec = i;
501 else if (strcmp(secname, "__ksymtab_unused") == 0)
502 info->export_unused_sec = i;
503 else if (strcmp(secname, "__ksymtab_gpl") == 0)
504 info->export_gpl_sec = i;
505 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
506 info->export_unused_gpl_sec = i;
507 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
508 info->export_gpl_future_sec = i;
509
510 if (sechdrs[i].sh_type == SHT_SYMTAB) {
511 unsigned int sh_link_idx;
512 symtab_idx = i;
513 info->symtab_start = (void *)hdr +
514 sechdrs[i].sh_offset;
515 info->symtab_stop = (void *)hdr +
516 sechdrs[i].sh_offset + sechdrs[i].sh_size;
517 sh_link_idx = sechdrs[i].sh_link;
518 info->strtab = (void *)hdr +
519 sechdrs[sh_link_idx].sh_offset;
520 }
521
522 /* 32bit section no. table? ("more than 64k sections") */
523 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
524 symtab_shndx_idx = i;
525 info->symtab_shndx_start = (void *)hdr +
526 sechdrs[i].sh_offset;
527 info->symtab_shndx_stop = (void *)hdr +
528 sechdrs[i].sh_offset + sechdrs[i].sh_size;
529 }
530 }
531 if (!info->symtab_start)
532 fatal("%s has no symtab?\n", filename);
533
534 /* Fix endianness in symbols */
535 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
536 sym->st_shndx = TO_NATIVE(sym->st_shndx);
537 sym->st_name = TO_NATIVE(sym->st_name);
538 sym->st_value = TO_NATIVE(sym->st_value);
539 sym->st_size = TO_NATIVE(sym->st_size);
540 }
541
542 if (symtab_shndx_idx != ~0U) {
543 Elf32_Word *p;
544 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
545 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
546 filename, sechdrs[symtab_shndx_idx].sh_link,
547 symtab_idx);
548 /* Fix endianness */
549 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
550 p++)
551 *p = TO_NATIVE(*p);
552 }
553
554 return 1;
555}
556
557static void parse_elf_finish(struct elf_info *info)
558{
559 release_file(info->hdr, info->size);
560}
561
562static int ignore_undef_symbol(struct elf_info *info, const char *symname)
563{
564 /* ignore __this_module, it will be resolved shortly */
565 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
566 return 1;
567 /* ignore global offset table */
568 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
569 return 1;
570 if (info->hdr->e_machine == EM_PPC)
571 /* Special register function linked on all modules during final link of .ko */
572 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
573 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
574 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
575 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
576 return 1;
577 if (info->hdr->e_machine == EM_PPC64)
578 /* Special register function linked on all modules during final link of .ko */
579 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
580 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
581 return 1;
582 /* Do not ignore this symbol */
583 return 0;
584}
585
586#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
587#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
588
589static void handle_modversions(struct module *mod, struct elf_info *info,
590 Elf_Sym *sym, const char *symname)
591{
592 unsigned int crc;
593 enum export export;
594
595 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
596 strncmp(symname, "__ksymtab", 9) == 0)
597 export = export_from_secname(info, get_secindex(info, sym));
598 else
599 export = export_from_sec(info, get_secindex(info, sym));
600
601 switch (sym->st_shndx) {
602 case SHN_COMMON:
603 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
604 break;
605 case SHN_ABS:
606 /* CRC'd symbol */
607 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
608 crc = (unsigned int) sym->st_value;
609 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
610 export);
611 }
612 break;
613 case SHN_UNDEF:
614 /* undefined symbol */
615 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
616 ELF_ST_BIND(sym->st_info) != STB_WEAK)
617 break;
618 if (ignore_undef_symbol(info, symname))
619 break;
620/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
621#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
622/* add compatibility with older glibc */
623#ifndef STT_SPARC_REGISTER
624#define STT_SPARC_REGISTER STT_REGISTER
625#endif
626 if (info->hdr->e_machine == EM_SPARC ||
627 info->hdr->e_machine == EM_SPARCV9) {
628 /* Ignore register directives. */
629 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
630 break;
631 if (symname[0] == '.') {
632 char *munged = strdup(symname);
633 munged[0] = '_';
634 munged[1] = toupper(munged[1]);
635 symname = munged;
636 }
637 }
638#endif
639
640 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
641 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
642 mod->unres =
643 alloc_symbol(symname +
644 strlen(MODULE_SYMBOL_PREFIX),
645 ELF_ST_BIND(sym->st_info) == STB_WEAK,
646 mod->unres);
647 }
648 break;
649 default:
650 /* All exported symbols */
651 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
652 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
653 export);
654 }
655 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
656 mod->has_init = 1;
657 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
658 mod->has_cleanup = 1;
659 break;
660 }
661}
662
663/**
664 * Parse tag=value strings from .modinfo section
665 **/
666static char *next_string(char *string, unsigned long *secsize)
667{
668 /* Skip non-zero chars */
669 while (string[0]) {
670 string++;
671 if ((*secsize)-- <= 1)
672 return NULL;
673 }
674
675 /* Skip any zero padding. */
676 while (!string[0]) {
677 string++;
678 if ((*secsize)-- <= 1)
679 return NULL;
680 }
681 return string;
682}
683
684static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
685 const char *tag, char *info)
686{
687 char *p;
688 unsigned int taglen = strlen(tag);
689 unsigned long size = modinfo_len;
690
691 if (info) {
692 size -= info - (char *)modinfo;
693 modinfo = next_string(info, &size);
694 }
695
696 for (p = modinfo; p; p = next_string(p, &size)) {
697 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
698 return p + taglen + 1;
699 }
700 return NULL;
701}
702
703static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
704 const char *tag)
705
706{
707 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
708}
709
710/**
711 * Test if string s ends in string sub
712 * return 0 if match
713 **/
714static int strrcmp(const char *s, const char *sub)
715{
716 int slen, sublen;
717
718 if (!s || !sub)
719 return 1;
720
721 slen = strlen(s);
722 sublen = strlen(sub);
723
724 if ((slen == 0) || (sublen == 0))
725 return 1;
726
727 if (sublen > slen)
728 return 1;
729
730 return memcmp(s + slen - sublen, sub, sublen);
731}
732
733static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
734{
735 if (sym)
736 return elf->strtab + sym->st_name;
737 else
738 return "(unknown)";
739}
740
741static const char *sec_name(struct elf_info *elf, int secindex)
742{
743 Elf_Shdr *sechdrs = elf->sechdrs;
744 return (void *)elf->hdr +
745 elf->sechdrs[elf->secindex_strings].sh_offset +
746 sechdrs[secindex].sh_name;
747}
748
749static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
750{
751 return (void *)elf->hdr +
752 elf->sechdrs[elf->secindex_strings].sh_offset +
753 sechdr->sh_name;
754}
755
756/* if sym is empty or point to a string
757 * like ".[0-9]+" then return 1.
758 * This is the optional prefix added by ld to some sections
759 */
760static int number_prefix(const char *sym)
761{
762 if (*sym++ == '\0')
763 return 1;
764 if (*sym != '.')
765 return 0;
766 do {
767 char c = *sym++;
768 if (c < '0' || c > '9')
769 return 0;
770 } while (*sym);
771 return 1;
772}
773
774/* The pattern is an array of simple patterns.
775 * "foo" will match an exact string equal to "foo"
776 * "*foo" will match a string that ends with "foo"
777 * "foo*" will match a string that begins with "foo"
778 * "foo$" will match a string equal to "foo" or "foo.1"
779 * where the '1' can be any number including several digits.
780 * The $ syntax is for sections where ld append a dot number
781 * to make section name unique.
782 */
783static int match(const char *sym, const char * const pat[])
784{
785 const char *p;
786 while (*pat) {
787 p = *pat++;
788 const char *endp = p + strlen(p) - 1;
789
790 /* "*foo" */
791 if (*p == '*') {
792 if (strrcmp(sym, p + 1) == 0)
793 return 1;
794 }
795 /* "foo*" */
796 else if (*endp == '*') {
797 if (strncmp(sym, p, strlen(p) - 1) == 0)
798 return 1;
799 }
800 /* "foo$" */
801 else if (*endp == '$') {
802 if (strncmp(sym, p, strlen(p) - 1) == 0) {
803 if (number_prefix(sym + strlen(p) - 1))
804 return 1;
805 }
806 }
807 /* no wildcards */
808 else {
809 if (strcmp(p, sym) == 0)
810 return 1;
811 }
812 }
813 /* no match */
814 return 0;
815}
816
817/* sections that we do not want to do full section mismatch check on */
818static const char *section_white_list[] =
819{
820 ".comment*",
821 ".debug*",
822 ".zdebug*", /* Compressed debug sections. */
823 ".GCC-command-line", /* mn10300 */
824 ".mdebug*", /* alpha, score, mips etc. */
825 ".pdr", /* alpha, score, mips etc. */
826 ".stab*",
827 ".note*",
828 ".got*",
829 ".toc*",
830 NULL
831};
832
833/*
834 * This is used to find sections missing the SHF_ALLOC flag.
835 * The cause of this is often a section specified in assembler
836 * without "ax" / "aw".
837 */
838static void check_section(const char *modname, struct elf_info *elf,
839 Elf_Shdr *sechdr)
840{
841 const char *sec = sech_name(elf, sechdr);
842
843 if (sechdr->sh_type == SHT_PROGBITS &&
844 !(sechdr->sh_flags & SHF_ALLOC) &&
845 !match(sec, section_white_list)) {
846 warn("%s (%s): unexpected non-allocatable section.\n"
847 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
848 "Note that for example <linux/init.h> contains\n"
849 "section definitions for use in .S files.\n\n",
850 modname, sec);
851 }
852}
853
854
855
856#define ALL_INIT_DATA_SECTIONS \
857 ".init.setup$", ".init.rodata$", \
858 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$", \
859 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
860#define ALL_EXIT_DATA_SECTIONS \
861 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
862
863#define ALL_INIT_TEXT_SECTIONS \
864 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
865#define ALL_EXIT_TEXT_SECTIONS \
866 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
867
868#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
869 MEM_INIT_SECTIONS
870#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
871 MEM_EXIT_SECTIONS
872
873#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
874#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
875
876#define DATA_SECTIONS ".data$", ".data.rel$"
877#define TEXT_SECTIONS ".text$"
878
879#define INIT_SECTIONS ".init.*"
880#define DEV_INIT_SECTIONS ".devinit.*"
881#define CPU_INIT_SECTIONS ".cpuinit.*"
882#define MEM_INIT_SECTIONS ".meminit.*"
883
884#define EXIT_SECTIONS ".exit.*"
885#define DEV_EXIT_SECTIONS ".devexit.*"
886#define CPU_EXIT_SECTIONS ".cpuexit.*"
887#define MEM_EXIT_SECTIONS ".memexit.*"
888
889/* init data sections */
890static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
891
892/* all init sections */
893static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
894
895/* All init and exit sections (code + data) */
896static const char *init_exit_sections[] =
897 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
898
899/* data section */
900static const char *data_sections[] = { DATA_SECTIONS, NULL };
901
902
903/* symbols in .data that may refer to init/exit sections */
904#define DEFAULT_SYMBOL_WHITE_LIST \
905 "*driver", \
906 "*_template", /* scsi uses *_template a lot */ \
907 "*_timer", /* arm uses ops structures named _timer a lot */ \
908 "*_sht", /* scsi also used *_sht to some extent */ \
909 "*_ops", \
910 "*_probe", \
911 "*_probe_one", \
912 "*_console"
913
914static const char *head_sections[] = { ".head.text*", NULL };
915static const char *linker_symbols[] =
916 { "__init_begin", "_sinittext", "_einittext", NULL };
917
918enum mismatch {
919 TEXT_TO_ANY_INIT,
920 DATA_TO_ANY_INIT,
921 TEXT_TO_ANY_EXIT,
922 DATA_TO_ANY_EXIT,
923 XXXINIT_TO_SOME_INIT,
924 XXXEXIT_TO_SOME_EXIT,
925 ANY_INIT_TO_ANY_EXIT,
926 ANY_EXIT_TO_ANY_INIT,
927 EXPORT_TO_INIT_EXIT,
928};
929
930struct sectioncheck {
931 const char *fromsec[20];
932 const char *tosec[20];
933 enum mismatch mismatch;
934 const char *symbol_white_list[20];
935};
936
937const struct sectioncheck sectioncheck[] = {
938/* Do not reference init/exit code/data from
939 * normal code and data
940 */
941{
942 .fromsec = { TEXT_SECTIONS, NULL },
943 .tosec = { ALL_INIT_SECTIONS, NULL },
944 .mismatch = TEXT_TO_ANY_INIT,
945 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
946},
947{
948 .fromsec = { DATA_SECTIONS, NULL },
949 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
950 .mismatch = DATA_TO_ANY_INIT,
951 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
952},
953{
954 .fromsec = { DATA_SECTIONS, NULL },
955 .tosec = { INIT_SECTIONS, NULL },
956 .mismatch = DATA_TO_ANY_INIT,
957 .symbol_white_list = {
958 "*_template", "*_timer", "*_sht", "*_ops",
959 "*_probe", "*_probe_one", "*_console", NULL
960 },
961},
962{
963 .fromsec = { TEXT_SECTIONS, NULL },
964 .tosec = { ALL_EXIT_SECTIONS, NULL },
965 .mismatch = TEXT_TO_ANY_EXIT,
966 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
967},
968{
969 .fromsec = { DATA_SECTIONS, NULL },
970 .tosec = { ALL_EXIT_SECTIONS, NULL },
971 .mismatch = DATA_TO_ANY_EXIT,
972 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
973},
974/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
975{
976 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
977 .tosec = { INIT_SECTIONS, NULL },
978 .mismatch = XXXINIT_TO_SOME_INIT,
979 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
980},
981/* Do not reference cpuinit code/data from meminit code/data */
982{
983 .fromsec = { MEM_INIT_SECTIONS, NULL },
984 .tosec = { CPU_INIT_SECTIONS, NULL },
985 .mismatch = XXXINIT_TO_SOME_INIT,
986 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
987},
988/* Do not reference meminit code/data from cpuinit code/data */
989{
990 .fromsec = { CPU_INIT_SECTIONS, NULL },
991 .tosec = { MEM_INIT_SECTIONS, NULL },
992 .mismatch = XXXINIT_TO_SOME_INIT,
993 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
994},
995/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
996{
997 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
998 .tosec = { EXIT_SECTIONS, NULL },
999 .mismatch = XXXEXIT_TO_SOME_EXIT,
1000 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1001},
1002/* Do not reference cpuexit code/data from memexit code/data */
1003{
1004 .fromsec = { MEM_EXIT_SECTIONS, NULL },
1005 .tosec = { CPU_EXIT_SECTIONS, NULL },
1006 .mismatch = XXXEXIT_TO_SOME_EXIT,
1007 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1008},
1009/* Do not reference memexit code/data from cpuexit code/data */
1010{
1011 .fromsec = { CPU_EXIT_SECTIONS, NULL },
1012 .tosec = { MEM_EXIT_SECTIONS, NULL },
1013 .mismatch = XXXEXIT_TO_SOME_EXIT,
1014 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1015},
1016/* Do not use exit code/data from init code */
1017{
1018 .fromsec = { ALL_INIT_SECTIONS, NULL },
1019 .tosec = { ALL_EXIT_SECTIONS, NULL },
1020 .mismatch = ANY_INIT_TO_ANY_EXIT,
1021 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1022},
1023/* Do not use init code/data from exit code */
1024{
1025 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1026 .tosec = { ALL_INIT_SECTIONS, NULL },
1027 .mismatch = ANY_EXIT_TO_ANY_INIT,
1028 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1029},
1030/* Do not export init/exit functions or data */
1031{
1032 .fromsec = { "__ksymtab*", NULL },
1033 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1034 .mismatch = EXPORT_TO_INIT_EXIT,
1035 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1036}
1037};
1038
1039static const struct sectioncheck *section_mismatch(
1040 const char *fromsec, const char *tosec)
1041{
1042 int i;
1043 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1044 const struct sectioncheck *check = §ioncheck[0];
1045
1046 for (i = 0; i < elems; i++) {
1047 if (match(fromsec, check->fromsec) &&
1048 match(tosec, check->tosec))
1049 return check;
1050 check++;
1051 }
1052 return NULL;
1053}
1054
1055/**
1056 * Whitelist to allow certain references to pass with no warning.
1057 *
1058 * Pattern 1:
1059 * If a module parameter is declared __initdata and permissions=0
1060 * then this is legal despite the warning generated.
1061 * We cannot see value of permissions here, so just ignore
1062 * this pattern.
1063 * The pattern is identified by:
1064 * tosec = .init.data
1065 * fromsec = .data*
1066 * atsym =__param*
1067 *
1068 * Pattern 1a:
1069 * module_param_call() ops can refer to __init set function if permissions=0
1070 * The pattern is identified by:
1071 * tosec = .init.text
1072 * fromsec = .data*
1073 * atsym = __param_ops_*
1074 *
1075 * Pattern 2:
1076 * Many drivers utilise a *driver container with references to
1077 * add, remove, probe functions etc.
1078 * These functions may often be marked __devinit and we do not want to
1079 * warn here.
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 * .cpuinit.data => __cpudata
1239 * .memexitconst => __memconst
1240 * etc.
1241 *
1242 * The memory of returned value has been allocated on a heap. The user of this
1243 * method should free it after usage.
1244*/
1245static char *sec2annotation(const char *s)
1246{
1247 if (match(s, init_exit_sections)) {
1248 char *p = malloc(20);
1249 char *r = p;
1250
1251 *p++ = '_';
1252 *p++ = '_';
1253 if (*s == '.')
1254 s++;
1255 while (*s && *s != '.')
1256 *p++ = *s++;
1257 *p = '\0';
1258 if (*s == '.')
1259 s++;
1260 if (strstr(s, "rodata") != NULL)
1261 strcat(p, "const ");
1262 else if (strstr(s, "data") != NULL)
1263 strcat(p, "data ");
1264 else
1265 strcat(p, " ");
1266 return r;
1267 } else {
1268 return strdup("");
1269 }
1270}
1271
1272static int is_function(Elf_Sym *sym)
1273{
1274 if (sym)
1275 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1276 else
1277 return -1;
1278}
1279
1280static void print_section_list(const char * const list[20])
1281{
1282 const char *const *s = list;
1283
1284 while (*s) {
1285 fprintf(stderr, "%s", *s);
1286 s++;
1287 if (*s)
1288 fprintf(stderr, ", ");
1289 }
1290 fprintf(stderr, "\n");
1291}
1292
1293/*
1294 * Print a warning about a section mismatch.
1295 * Try to find symbols near it so user can find it.
1296 * Check whitelist before warning - it may be a false positive.
1297 */
1298static void report_sec_mismatch(const char *modname,
1299 const struct sectioncheck *mismatch,
1300 const char *fromsec,
1301 unsigned long long fromaddr,
1302 const char *fromsym,
1303 int from_is_func,
1304 const char *tosec, const char *tosym,
1305 int to_is_func)
1306{
1307 const char *from, *from_p;
1308 const char *to, *to_p;
1309 char *prl_from;
1310 char *prl_to;
1311
1312 switch (from_is_func) {
1313 case 0: from = "variable"; from_p = ""; break;
1314 case 1: from = "function"; from_p = "()"; break;
1315 default: from = "(unknown reference)"; from_p = ""; break;
1316 }
1317 switch (to_is_func) {
1318 case 0: to = "variable"; to_p = ""; break;
1319 case 1: to = "function"; to_p = "()"; break;
1320 default: to = "(unknown reference)"; to_p = ""; break;
1321 }
1322
1323 sec_mismatch_count++;
1324 if (!sec_mismatch_verbose)
1325 return;
1326
1327 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1328 "to the %s %s:%s%s\n",
1329 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1330 tosym, to_p);
1331
1332 switch (mismatch->mismatch) {
1333 case TEXT_TO_ANY_INIT:
1334 prl_from = sec2annotation(fromsec);
1335 prl_to = sec2annotation(tosec);
1336 fprintf(stderr,
1337 "The function %s%s() references\n"
1338 "the %s %s%s%s.\n"
1339 "This is often because %s lacks a %s\n"
1340 "annotation or the annotation of %s is wrong.\n",
1341 prl_from, fromsym,
1342 to, prl_to, tosym, to_p,
1343 fromsym, prl_to, tosym);
1344 free(prl_from);
1345 free(prl_to);
1346 break;
1347 case DATA_TO_ANY_INIT: {
1348 prl_to = sec2annotation(tosec);
1349 fprintf(stderr,
1350 "The variable %s references\n"
1351 "the %s %s%s%s\n"
1352 "If the reference is valid then annotate the\n"
1353 "variable with __init* or __refdata (see linux/init.h) "
1354 "or name the variable:\n",
1355 fromsym, to, prl_to, tosym, to_p);
1356 print_section_list(mismatch->symbol_white_list);
1357 free(prl_to);
1358 break;
1359 }
1360 case TEXT_TO_ANY_EXIT:
1361 prl_to = sec2annotation(tosec);
1362 fprintf(stderr,
1363 "The function %s() references a %s in an exit section.\n"
1364 "Often the %s %s%s has valid usage outside the exit section\n"
1365 "and the fix is to remove the %sannotation of %s.\n",
1366 fromsym, to, to, tosym, to_p, prl_to, tosym);
1367 free(prl_to);
1368 break;
1369 case DATA_TO_ANY_EXIT: {
1370 prl_to = sec2annotation(tosec);
1371 fprintf(stderr,
1372 "The variable %s references\n"
1373 "the %s %s%s%s\n"
1374 "If the reference is valid then annotate the\n"
1375 "variable with __exit* (see linux/init.h) or "
1376 "name the variable:\n",
1377 fromsym, to, prl_to, tosym, to_p);
1378 print_section_list(mismatch->symbol_white_list);
1379 free(prl_to);
1380 break;
1381 }
1382 case XXXINIT_TO_SOME_INIT:
1383 case XXXEXIT_TO_SOME_EXIT:
1384 prl_from = sec2annotation(fromsec);
1385 prl_to = sec2annotation(tosec);
1386 fprintf(stderr,
1387 "The %s %s%s%s references\n"
1388 "a %s %s%s%s.\n"
1389 "If %s is only used by %s then\n"
1390 "annotate %s with a matching annotation.\n",
1391 from, prl_from, fromsym, from_p,
1392 to, prl_to, tosym, to_p,
1393 tosym, fromsym, tosym);
1394 free(prl_from);
1395 free(prl_to);
1396 break;
1397 case ANY_INIT_TO_ANY_EXIT:
1398 prl_from = sec2annotation(fromsec);
1399 prl_to = sec2annotation(tosec);
1400 fprintf(stderr,
1401 "The %s %s%s%s references\n"
1402 "a %s %s%s%s.\n"
1403 "This is often seen when error handling "
1404 "in the init function\n"
1405 "uses functionality in the exit path.\n"
1406 "The fix is often to remove the %sannotation of\n"
1407 "%s%s so it may be used outside an exit section.\n",
1408 from, prl_from, fromsym, from_p,
1409 to, prl_to, tosym, to_p,
1410 prl_to, tosym, to_p);
1411 free(prl_from);
1412 free(prl_to);
1413 break;
1414 case ANY_EXIT_TO_ANY_INIT:
1415 prl_from = sec2annotation(fromsec);
1416 prl_to = sec2annotation(tosec);
1417 fprintf(stderr,
1418 "The %s %s%s%s references\n"
1419 "a %s %s%s%s.\n"
1420 "This is often seen when error handling "
1421 "in the exit function\n"
1422 "uses functionality in the init path.\n"
1423 "The fix is often to remove the %sannotation of\n"
1424 "%s%s so it may be used outside an init section.\n",
1425 from, prl_from, fromsym, from_p,
1426 to, prl_to, tosym, to_p,
1427 prl_to, tosym, to_p);
1428 free(prl_from);
1429 free(prl_to);
1430 break;
1431 case EXPORT_TO_INIT_EXIT:
1432 prl_to = sec2annotation(tosec);
1433 fprintf(stderr,
1434 "The symbol %s is exported and annotated %s\n"
1435 "Fix this by removing the %sannotation of %s "
1436 "or drop the export.\n",
1437 tosym, prl_to, prl_to, tosym);
1438 free(prl_to);
1439 break;
1440 }
1441 fprintf(stderr, "\n");
1442}
1443
1444static void check_section_mismatch(const char *modname, struct elf_info *elf,
1445 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1446{
1447 const char *tosec;
1448 const struct sectioncheck *mismatch;
1449
1450 tosec = sec_name(elf, get_secindex(elf, sym));
1451 mismatch = section_mismatch(fromsec, tosec);
1452 if (mismatch) {
1453 Elf_Sym *to;
1454 Elf_Sym *from;
1455 const char *tosym;
1456 const char *fromsym;
1457
1458 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1459 fromsym = sym_name(elf, from);
1460 to = find_elf_symbol(elf, r->r_addend, sym);
1461 tosym = sym_name(elf, to);
1462
1463 /* check whitelist - we may ignore it */
1464 if (secref_whitelist(mismatch,
1465 fromsec, fromsym, tosec, tosym)) {
1466 report_sec_mismatch(modname, mismatch,
1467 fromsec, r->r_offset, fromsym,
1468 is_function(from), tosec, tosym,
1469 is_function(to));
1470 }
1471 }
1472}
1473
1474static unsigned int *reloc_location(struct elf_info *elf,
1475 Elf_Shdr *sechdr, Elf_Rela *r)
1476{
1477 Elf_Shdr *sechdrs = elf->sechdrs;
1478 int section = sechdr->sh_info;
1479
1480 return (void *)elf->hdr + sechdrs[section].sh_offset +
1481 r->r_offset;
1482}
1483
1484static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1485{
1486 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1487 unsigned int *location = reloc_location(elf, sechdr, r);
1488
1489 switch (r_typ) {
1490 case R_386_32:
1491 r->r_addend = TO_NATIVE(*location);
1492 break;
1493 case R_386_PC32:
1494 r->r_addend = TO_NATIVE(*location) + 4;
1495 /* For CONFIG_RELOCATABLE=y */
1496 if (elf->hdr->e_type == ET_EXEC)
1497 r->r_addend += r->r_offset;
1498 break;
1499 }
1500 return 0;
1501}
1502
1503#ifndef R_ARM_CALL
1504#define R_ARM_CALL 28
1505#endif
1506#ifndef R_ARM_JUMP24
1507#define R_ARM_JUMP24 29
1508#endif
1509
1510static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1511{
1512 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1513
1514 switch (r_typ) {
1515 case R_ARM_ABS32:
1516 /* From ARM ABI: (S + A) | T */
1517 r->r_addend = (int)(long)
1518 (elf->symtab_start + ELF_R_SYM(r->r_info));
1519 break;
1520 case R_ARM_PC24:
1521 case R_ARM_CALL:
1522 case R_ARM_JUMP24:
1523 /* From ARM ABI: ((S + A) | T) - P */
1524 r->r_addend = (int)(long)(elf->hdr +
1525 sechdr->sh_offset +
1526 (r->r_offset - sechdr->sh_addr));
1527 break;
1528 default:
1529 return 1;
1530 }
1531 return 0;
1532}
1533
1534static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1535{
1536 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1537 unsigned int *location = reloc_location(elf, sechdr, r);
1538 unsigned int inst;
1539
1540 if (r_typ == R_MIPS_HI16)
1541 return 1; /* skip this */
1542 inst = TO_NATIVE(*location);
1543 switch (r_typ) {
1544 case R_MIPS_LO16:
1545 r->r_addend = inst & 0xffff;
1546 break;
1547 case R_MIPS_26:
1548 r->r_addend = (inst & 0x03ffffff) << 2;
1549 break;
1550 case R_MIPS_32:
1551 r->r_addend = inst;
1552 break;
1553 }
1554 return 0;
1555}
1556
1557static void section_rela(const char *modname, struct elf_info *elf,
1558 Elf_Shdr *sechdr)
1559{
1560 Elf_Sym *sym;
1561 Elf_Rela *rela;
1562 Elf_Rela r;
1563 unsigned int r_sym;
1564 const char *fromsec;
1565
1566 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1567 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1568
1569 fromsec = sech_name(elf, sechdr);
1570 fromsec += strlen(".rela");
1571 /* if from section (name) is know good then skip it */
1572 if (match(fromsec, section_white_list))
1573 return;
1574
1575 for (rela = start; rela < stop; rela++) {
1576 r.r_offset = TO_NATIVE(rela->r_offset);
1577#if KERNEL_ELFCLASS == ELFCLASS64
1578 if (elf->hdr->e_machine == EM_MIPS) {
1579 unsigned int r_typ;
1580 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1581 r_sym = TO_NATIVE(r_sym);
1582 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1583 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1584 } else {
1585 r.r_info = TO_NATIVE(rela->r_info);
1586 r_sym = ELF_R_SYM(r.r_info);
1587 }
1588#else
1589 r.r_info = TO_NATIVE(rela->r_info);
1590 r_sym = ELF_R_SYM(r.r_info);
1591#endif
1592 r.r_addend = TO_NATIVE(rela->r_addend);
1593 sym = elf->symtab_start + r_sym;
1594 /* Skip special sections */
1595 if (is_shndx_special(sym->st_shndx))
1596 continue;
1597 check_section_mismatch(modname, elf, &r, sym, fromsec);
1598 }
1599}
1600
1601static void section_rel(const char *modname, struct elf_info *elf,
1602 Elf_Shdr *sechdr)
1603{
1604 Elf_Sym *sym;
1605 Elf_Rel *rel;
1606 Elf_Rela r;
1607 unsigned int r_sym;
1608 const char *fromsec;
1609
1610 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1611 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1612
1613 fromsec = sech_name(elf, sechdr);
1614 fromsec += strlen(".rel");
1615 /* if from section (name) is know good then skip it */
1616 if (match(fromsec, section_white_list))
1617 return;
1618
1619 for (rel = start; rel < stop; rel++) {
1620 r.r_offset = TO_NATIVE(rel->r_offset);
1621#if KERNEL_ELFCLASS == ELFCLASS64
1622 if (elf->hdr->e_machine == EM_MIPS) {
1623 unsigned int r_typ;
1624 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1625 r_sym = TO_NATIVE(r_sym);
1626 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1627 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1628 } else {
1629 r.r_info = TO_NATIVE(rel->r_info);
1630 r_sym = ELF_R_SYM(r.r_info);
1631 }
1632#else
1633 r.r_info = TO_NATIVE(rel->r_info);
1634 r_sym = ELF_R_SYM(r.r_info);
1635#endif
1636 r.r_addend = 0;
1637 switch (elf->hdr->e_machine) {
1638 case EM_386:
1639 if (addend_386_rel(elf, sechdr, &r))
1640 continue;
1641 break;
1642 case EM_ARM:
1643 if (addend_arm_rel(elf, sechdr, &r))
1644 continue;
1645 break;
1646 case EM_MIPS:
1647 if (addend_mips_rel(elf, sechdr, &r))
1648 continue;
1649 break;
1650 }
1651 sym = elf->symtab_start + r_sym;
1652 /* Skip special sections */
1653 if (is_shndx_special(sym->st_shndx))
1654 continue;
1655 check_section_mismatch(modname, elf, &r, sym, fromsec);
1656 }
1657}
1658
1659/**
1660 * A module includes a number of sections that are discarded
1661 * either when loaded or when used as built-in.
1662 * For loaded modules all functions marked __init and all data
1663 * marked __initdata will be discarded when the module has been initialized.
1664 * Likewise for modules used built-in the sections marked __exit
1665 * are discarded because __exit marked function are supposed to be called
1666 * only when a module is unloaded which never happens for built-in modules.
1667 * The check_sec_ref() function traverses all relocation records
1668 * to find all references to a section that reference a section that will
1669 * be discarded and warns about it.
1670 **/
1671static void check_sec_ref(struct module *mod, const char *modname,
1672 struct elf_info *elf)
1673{
1674 int i;
1675 Elf_Shdr *sechdrs = elf->sechdrs;
1676
1677 /* Walk through all sections */
1678 for (i = 0; i < elf->num_sections; i++) {
1679 check_section(modname, elf, &elf->sechdrs[i]);
1680 /* We want to process only relocation sections and not .init */
1681 if (sechdrs[i].sh_type == SHT_RELA)
1682 section_rela(modname, elf, &elf->sechdrs[i]);
1683 else if (sechdrs[i].sh_type == SHT_REL)
1684 section_rel(modname, elf, &elf->sechdrs[i]);
1685 }
1686}
1687
1688static void read_symbols(char *modname)
1689{
1690 const char *symname;
1691 char *version;
1692 char *license;
1693 struct module *mod;
1694 struct elf_info info = { };
1695 Elf_Sym *sym;
1696
1697 if (!parse_elf(&info, modname))
1698 return;
1699
1700 mod = new_module(modname);
1701
1702 /* When there's no vmlinux, don't print warnings about
1703 * unresolved symbols (since there'll be too many ;) */
1704 if (is_vmlinux(modname)) {
1705 have_vmlinux = 1;
1706 mod->skip = 1;
1707 }
1708
1709 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1710 if (info.modinfo && !license && !is_vmlinux(modname))
1711 warn("modpost: missing MODULE_LICENSE() in %s\n"
1712 "see include/linux/module.h for "
1713 "more information\n", modname);
1714 while (license) {
1715 if (license_is_gpl_compatible(license))
1716 mod->gpl_compatible = 1;
1717 else {
1718 mod->gpl_compatible = 0;
1719 break;
1720 }
1721 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1722 "license", license);
1723 }
1724
1725 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1726 symname = info.strtab + sym->st_name;
1727
1728 handle_modversions(mod, &info, sym, symname);
1729 handle_moddevtable(mod, &info, sym, symname);
1730 }
1731 if (!is_vmlinux(modname) ||
1732 (is_vmlinux(modname) && vmlinux_section_warnings))
1733 check_sec_ref(mod, modname, &info);
1734
1735 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1736 if (version)
1737 maybe_frob_rcs_version(modname, version, info.modinfo,
1738 version - (char *)info.hdr);
1739 if (version || (all_versions && !is_vmlinux(modname)))
1740 get_src_version(modname, mod->srcversion,
1741 sizeof(mod->srcversion)-1);
1742
1743 parse_elf_finish(&info);
1744
1745 /* Our trick to get versioning for module struct etc. - it's
1746 * never passed as an argument to an exported function, so
1747 * the automatic versioning doesn't pick it up, but it's really
1748 * important anyhow */
1749 if (modversions)
1750 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1751}
1752
1753#define SZ 500
1754
1755/* We first write the generated file into memory using the
1756 * following helper, then compare to the file on disk and
1757 * only update the later if anything changed */
1758
1759void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1760 const char *fmt, ...)
1761{
1762 char tmp[SZ];
1763 int len;
1764 va_list ap;
1765
1766 va_start(ap, fmt);
1767 len = vsnprintf(tmp, SZ, fmt, ap);
1768 buf_write(buf, tmp, len);
1769 va_end(ap);
1770}
1771
1772void buf_write(struct buffer *buf, const char *s, int len)
1773{
1774 if (buf->size - buf->pos < len) {
1775 buf->size += len + SZ;
1776 buf->p = realloc(buf->p, buf->size);
1777 }
1778 strncpy(buf->p + buf->pos, s, len);
1779 buf->pos += len;
1780}
1781
1782static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1783{
1784 const char *e = is_vmlinux(m) ?"":".ko";
1785
1786 switch (exp) {
1787 case export_gpl:
1788 fatal("modpost: GPL-incompatible module %s%s "
1789 "uses GPL-only symbol '%s'\n", m, e, s);
1790 break;
1791 case export_unused_gpl:
1792 fatal("modpost: GPL-incompatible module %s%s "
1793 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1794 break;
1795 case export_gpl_future:
1796 warn("modpost: GPL-incompatible module %s%s "
1797 "uses future GPL-only symbol '%s'\n", m, e, s);
1798 break;
1799 case export_plain:
1800 case export_unused:
1801 case export_unknown:
1802 /* ignore */
1803 break;
1804 }
1805}
1806
1807static void check_for_unused(enum export exp, const char *m, const char *s)
1808{
1809 const char *e = is_vmlinux(m) ?"":".ko";
1810
1811 switch (exp) {
1812 case export_unused:
1813 case export_unused_gpl:
1814 warn("modpost: module %s%s "
1815 "uses symbol '%s' marked UNUSED\n", m, e, s);
1816 break;
1817 default:
1818 /* ignore */
1819 break;
1820 }
1821}
1822
1823static void check_exports(struct module *mod)
1824{
1825 struct symbol *s, *exp;
1826
1827 for (s = mod->unres; s; s = s->next) {
1828 const char *basename;
1829 exp = find_symbol(s->name);
1830 if (!exp || exp->module == mod)
1831 continue;
1832 basename = strrchr(mod->name, '/');
1833 if (basename)
1834 basename++;
1835 else
1836 basename = mod->name;
1837 if (!mod->gpl_compatible)
1838 check_for_gpl_usage(exp->export, basename, exp->name);
1839 check_for_unused(exp->export, basename, exp->name);
1840 }
1841}
1842
1843/**
1844 * Header for the generated file
1845 **/
1846static void add_header(struct buffer *b, struct module *mod)
1847{
1848 buf_printf(b, "#include <linux/module.h>\n");
1849 buf_printf(b, "#include <linux/vermagic.h>\n");
1850 buf_printf(b, "#include <linux/compiler.h>\n");
1851 buf_printf(b, "\n");
1852 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1853 buf_printf(b, "\n");
1854 buf_printf(b, "struct module __this_module\n");
1855 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1856 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1857 if (mod->has_init)
1858 buf_printf(b, "\t.init = init_module,\n");
1859 if (mod->has_cleanup)
1860 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1861 "\t.exit = cleanup_module,\n"
1862 "#endif\n");
1863 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1864 buf_printf(b, "};\n");
1865}
1866
1867static void add_intree_flag(struct buffer *b, int is_intree)
1868{
1869 if (is_intree)
1870 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1871}
1872
1873static void add_staging_flag(struct buffer *b, const char *name)
1874{
1875 static const char *staging_dir = "drivers/staging";
1876
1877 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1878 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1879}
1880
1881/**
1882 * Record CRCs for unresolved symbols
1883 **/
1884static int add_versions(struct buffer *b, struct module *mod)
1885{
1886 struct symbol *s, *exp;
1887 int err = 0;
1888
1889 for (s = mod->unres; s; s = s->next) {
1890 exp = find_symbol(s->name);
1891 if (!exp || exp->module == mod) {
1892 if (have_vmlinux && !s->weak) {
1893 if (warn_unresolved) {
1894 warn("\"%s\" [%s.ko] undefined!\n",
1895 s->name, mod->name);
1896 } else {
1897 merror("\"%s\" [%s.ko] undefined!\n",
1898 s->name, mod->name);
1899 err = 1;
1900 }
1901 }
1902 continue;
1903 }
1904 s->module = exp->module;
1905 s->crc_valid = exp->crc_valid;
1906 s->crc = exp->crc;
1907 }
1908
1909 if (!modversions)
1910 return err;
1911
1912 buf_printf(b, "\n");
1913 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1914 buf_printf(b, "__used\n");
1915 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1916
1917 for (s = mod->unres; s; s = s->next) {
1918 if (!s->module)
1919 continue;
1920 if (!s->crc_valid) {
1921 warn("\"%s\" [%s.ko] has no CRC!\n",
1922 s->name, mod->name);
1923 continue;
1924 }
1925 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1926 }
1927
1928 buf_printf(b, "};\n");
1929
1930 return err;
1931}
1932
1933static void add_depends(struct buffer *b, struct module *mod,
1934 struct module *modules)
1935{
1936 struct symbol *s;
1937 struct module *m;
1938 int first = 1;
1939
1940 for (m = modules; m; m = m->next)
1941 m->seen = is_vmlinux(m->name);
1942
1943 buf_printf(b, "\n");
1944 buf_printf(b, "static const char __module_depends[]\n");
1945 buf_printf(b, "__used\n");
1946 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1947 buf_printf(b, "\"depends=");
1948 for (s = mod->unres; s; s = s->next) {
1949 const char *p;
1950 if (!s->module)
1951 continue;
1952
1953 if (s->module->seen)
1954 continue;
1955
1956 s->module->seen = 1;
1957 p = strrchr(s->module->name, '/');
1958 if (p)
1959 p++;
1960 else
1961 p = s->module->name;
1962 buf_printf(b, "%s%s", first ? "" : ",", p);
1963 first = 0;
1964 }
1965 buf_printf(b, "\";\n");
1966}
1967
1968static void add_srcversion(struct buffer *b, struct module *mod)
1969{
1970 if (mod->srcversion[0]) {
1971 buf_printf(b, "\n");
1972 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1973 mod->srcversion);
1974 }
1975}
1976
1977static void write_if_changed(struct buffer *b, const char *fname)
1978{
1979 char *tmp;
1980 FILE *file;
1981 struct stat st;
1982
1983 file = fopen(fname, "r");
1984 if (!file)
1985 goto write;
1986
1987 if (fstat(fileno(file), &st) < 0)
1988 goto close_write;
1989
1990 if (st.st_size != b->pos)
1991 goto close_write;
1992
1993 tmp = NOFAIL(malloc(b->pos));
1994 if (fread(tmp, 1, b->pos, file) != b->pos)
1995 goto free_write;
1996
1997 if (memcmp(tmp, b->p, b->pos) != 0)
1998 goto free_write;
1999
2000 free(tmp);
2001 fclose(file);
2002 return;
2003
2004 free_write:
2005 free(tmp);
2006 close_write:
2007 fclose(file);
2008 write:
2009 file = fopen(fname, "w");
2010 if (!file) {
2011 perror(fname);
2012 exit(1);
2013 }
2014 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2015 perror(fname);
2016 exit(1);
2017 }
2018 fclose(file);
2019}
2020
2021/* parse Module.symvers file. line format:
2022 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2023 **/
2024static void read_dump(const char *fname, unsigned int kernel)
2025{
2026 unsigned long size, pos = 0;
2027 void *file = grab_file(fname, &size);
2028 char *line;
2029
2030 if (!file)
2031 /* No symbol versions, silently ignore */
2032 return;
2033
2034 while ((line = get_next_line(&pos, file, size))) {
2035 char *symname, *modname, *d, *export, *end;
2036 unsigned int crc;
2037 struct module *mod;
2038 struct symbol *s;
2039
2040 if (!(symname = strchr(line, '\t')))
2041 goto fail;
2042 *symname++ = '\0';
2043 if (!(modname = strchr(symname, '\t')))
2044 goto fail;
2045 *modname++ = '\0';
2046 if ((export = strchr(modname, '\t')) != NULL)
2047 *export++ = '\0';
2048 if (export && ((end = strchr(export, '\t')) != NULL))
2049 *end = '\0';
2050 crc = strtoul(line, &d, 16);
2051 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2052 goto fail;
2053 mod = find_module(modname);
2054 if (!mod) {
2055 if (is_vmlinux(modname))
2056 have_vmlinux = 1;
2057 mod = new_module(modname);
2058 mod->skip = 1;
2059 }
2060 s = sym_add_exported(symname, mod, export_no(export));
2061 s->kernel = kernel;
2062 s->preloaded = 1;
2063 sym_update_crc(symname, mod, crc, export_no(export));
2064 }
2065 return;
2066fail:
2067 fatal("parse error in symbol dump file\n");
2068}
2069
2070/* For normal builds always dump all symbols.
2071 * For external modules only dump symbols
2072 * that are not read from kernel Module.symvers.
2073 **/
2074static int dump_sym(struct symbol *sym)
2075{
2076 if (!external_module)
2077 return 1;
2078 if (sym->vmlinux || sym->kernel)
2079 return 0;
2080 return 1;
2081}
2082
2083static void write_dump(const char *fname)
2084{
2085 struct buffer buf = { };
2086 struct symbol *symbol;
2087 int n;
2088
2089 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2090 symbol = symbolhash[n];
2091 while (symbol) {
2092 if (dump_sym(symbol))
2093 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2094 symbol->crc, symbol->name,
2095 symbol->module->name,
2096 export_str(symbol->export));
2097 symbol = symbol->next;
2098 }
2099 }
2100 write_if_changed(&buf, fname);
2101}
2102
2103struct ext_sym_list {
2104 struct ext_sym_list *next;
2105 const char *file;
2106};
2107
2108int main(int argc, char **argv)
2109{
2110 struct module *mod;
2111 struct buffer buf = { };
2112 char *kernel_read = NULL, *module_read = NULL;
2113 char *dump_write = NULL;
2114 int opt;
2115 int err;
2116 struct ext_sym_list *extsym_iter;
2117 struct ext_sym_list *extsym_start = NULL;
2118
2119 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
2120 switch (opt) {
2121 case 'i':
2122 kernel_read = optarg;
2123 break;
2124 case 'I':
2125 module_read = optarg;
2126 external_module = 1;
2127 break;
2128 case 'c':
2129 cross_build = 1;
2130 break;
2131 case 'e':
2132 external_module = 1;
2133 extsym_iter =
2134 NOFAIL(malloc(sizeof(*extsym_iter)));
2135 extsym_iter->next = extsym_start;
2136 extsym_iter->file = optarg;
2137 extsym_start = extsym_iter;
2138 break;
2139 case 'm':
2140 modversions = 1;
2141 break;
2142 case 'o':
2143 dump_write = optarg;
2144 break;
2145 case 'a':
2146 all_versions = 1;
2147 break;
2148 case 's':
2149 vmlinux_section_warnings = 0;
2150 break;
2151 case 'S':
2152 sec_mismatch_verbose = 0;
2153 break;
2154 case 'w':
2155 warn_unresolved = 1;
2156 break;
2157 default:
2158 exit(1);
2159 }
2160 }
2161
2162 if (kernel_read)
2163 read_dump(kernel_read, 1);
2164 if (module_read)
2165 read_dump(module_read, 0);
2166 while (extsym_start) {
2167 read_dump(extsym_start->file, 0);
2168 extsym_iter = extsym_start->next;
2169 free(extsym_start);
2170 extsym_start = extsym_iter;
2171 }
2172
2173 while (optind < argc)
2174 read_symbols(argv[optind++]);
2175
2176 for (mod = modules; mod; mod = mod->next) {
2177 if (mod->skip)
2178 continue;
2179 check_exports(mod);
2180 }
2181
2182 err = 0;
2183
2184 for (mod = modules; mod; mod = mod->next) {
2185 char fname[strlen(mod->name) + 10];
2186
2187 if (mod->skip)
2188 continue;
2189
2190 buf.pos = 0;
2191
2192 add_header(&buf, mod);
2193 add_intree_flag(&buf, !external_module);
2194 add_staging_flag(&buf, mod->name);
2195 err |= add_versions(&buf, mod);
2196 add_depends(&buf, mod, modules);
2197 add_moddevtable(&buf, mod);
2198 add_srcversion(&buf, mod);
2199
2200 sprintf(fname, "%s.mod.c", mod->name);
2201 write_if_changed(&buf, fname);
2202 }
2203
2204 if (dump_write)
2205 write_dump(dump_write);
2206 if (sec_mismatch_count && !sec_mismatch_verbose)
2207 warn("modpost: Found %d section mismatch(es).\n"
2208 "To see full details build your kernel with:\n"
2209 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2210 sec_mismatch_count);
2211
2212 return err;
2213}
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <elf.h>
16#include <fnmatch.h>
17#include <stdio.h>
18#include <ctype.h>
19#include <string.h>
20#include <limits.h>
21#include <stdbool.h>
22#include <errno.h>
23
24#include <hash.h>
25#include <hashtable.h>
26#include <list.h>
27#include <xalloc.h>
28#include "modpost.h"
29#include "../../include/linux/license.h"
30
31static bool module_enabled;
32/* Are we using CONFIG_MODVERSIONS? */
33static bool modversions;
34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35static bool all_versions;
36/* If we are modposting external module set to 1 */
37static bool external_module;
38/* Only warn about unresolved symbols */
39static bool warn_unresolved;
40
41static int sec_mismatch_count;
42static bool sec_mismatch_warn_only = true;
43/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
44static bool trim_unused_exports;
45
46/* ignore missing files */
47static bool ignore_missing_files;
48/* If set to 1, only warn (instead of error) about missing ns imports */
49static bool allow_missing_ns_imports;
50
51static bool error_occurred;
52
53static bool extra_warn;
54
55bool target_is_big_endian;
56bool host_is_big_endian;
57
58/*
59 * Cut off the warnings when there are too many. This typically occurs when
60 * vmlinux is missing. ('make modules' without building vmlinux.)
61 */
62#define MAX_UNRESOLVED_REPORTS 10
63static unsigned int nr_unresolved;
64
65/* In kernel, this size is defined in linux/module.h;
66 * here we use Elf_Addr instead of long for covering cross-compile
67 */
68
69#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
70
71void modpost_log(bool is_error, const char *fmt, ...)
72{
73 va_list arglist;
74
75 if (is_error) {
76 fprintf(stderr, "ERROR: ");
77 error_occurred = true;
78 } else {
79 fprintf(stderr, "WARNING: ");
80 }
81
82 fprintf(stderr, "modpost: ");
83
84 va_start(arglist, fmt);
85 vfprintf(stderr, fmt, arglist);
86 va_end(arglist);
87}
88
89static inline bool strends(const char *str, const char *postfix)
90{
91 if (strlen(str) < strlen(postfix))
92 return false;
93
94 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
95}
96
97char *read_text_file(const char *filename)
98{
99 struct stat st;
100 size_t nbytes;
101 int fd;
102 char *buf;
103
104 fd = open(filename, O_RDONLY);
105 if (fd < 0) {
106 perror(filename);
107 exit(1);
108 }
109
110 if (fstat(fd, &st) < 0) {
111 perror(filename);
112 exit(1);
113 }
114
115 buf = xmalloc(st.st_size + 1);
116
117 nbytes = st.st_size;
118
119 while (nbytes) {
120 ssize_t bytes_read;
121
122 bytes_read = read(fd, buf, nbytes);
123 if (bytes_read < 0) {
124 perror(filename);
125 exit(1);
126 }
127
128 nbytes -= bytes_read;
129 }
130 buf[st.st_size] = '\0';
131
132 close(fd);
133
134 return buf;
135}
136
137char *get_line(char **stringp)
138{
139 char *orig = *stringp, *next;
140
141 /* do not return the unwanted extra line at EOF */
142 if (!orig || *orig == '\0')
143 return NULL;
144
145 /* don't use strsep here, it is not available everywhere */
146 next = strchr(orig, '\n');
147 if (next)
148 *next++ = '\0';
149
150 *stringp = next;
151
152 return orig;
153}
154
155/* A list of all modules we processed */
156LIST_HEAD(modules);
157
158static struct module *find_module(const char *filename, const char *modname)
159{
160 struct module *mod;
161
162 list_for_each_entry(mod, &modules, list) {
163 if (!strcmp(mod->dump_file, filename) &&
164 !strcmp(mod->name, modname))
165 return mod;
166 }
167 return NULL;
168}
169
170static struct module *new_module(const char *name, size_t namelen)
171{
172 struct module *mod;
173
174 mod = xmalloc(sizeof(*mod) + namelen + 1);
175 memset(mod, 0, sizeof(*mod));
176
177 INIT_LIST_HEAD(&mod->exported_symbols);
178 INIT_LIST_HEAD(&mod->unresolved_symbols);
179 INIT_LIST_HEAD(&mod->missing_namespaces);
180 INIT_LIST_HEAD(&mod->imported_namespaces);
181 INIT_LIST_HEAD(&mod->aliases);
182
183 memcpy(mod->name, name, namelen);
184 mod->name[namelen] = '\0';
185 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
186
187 /*
188 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
189 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
190 * modpost will exit wiht error anyway.
191 */
192 mod->is_gpl_compatible = true;
193
194 list_add_tail(&mod->list, &modules);
195
196 return mod;
197}
198
199struct symbol {
200 struct hlist_node hnode;/* link to hash table */
201 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
202 struct module *module;
203 char *namespace;
204 unsigned int crc;
205 bool crc_valid;
206 bool weak;
207 bool is_func;
208 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
209 bool used; /* there exists a user of this symbol */
210 char name[];
211};
212
213static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
214
215/**
216 * Allocate a new symbols for use in the hash of exported symbols or
217 * the list of unresolved symbols per module
218 **/
219static struct symbol *alloc_symbol(const char *name)
220{
221 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1);
222
223 memset(s, 0, sizeof(*s));
224 strcpy(s->name, name);
225
226 return s;
227}
228
229/* For the hash of exported symbols */
230static void hash_add_symbol(struct symbol *sym)
231{
232 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name));
233}
234
235static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
236{
237 struct symbol *sym;
238
239 sym = alloc_symbol(name);
240 sym->weak = weak;
241
242 list_add_tail(&sym->list, &mod->unresolved_symbols);
243}
244
245static struct symbol *sym_find_with_module(const char *name, struct module *mod)
246{
247 struct symbol *s;
248
249 /* For our purposes, .foo matches foo. PPC64 needs this. */
250 if (name[0] == '.')
251 name++;
252
253 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) {
254 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
255 return s;
256 }
257 return NULL;
258}
259
260static struct symbol *find_symbol(const char *name)
261{
262 return sym_find_with_module(name, NULL);
263}
264
265struct namespace_list {
266 struct list_head list;
267 char namespace[];
268};
269
270static bool contains_namespace(struct list_head *head, const char *namespace)
271{
272 struct namespace_list *list;
273
274 /*
275 * The default namespace is null string "", which is always implicitly
276 * contained.
277 */
278 if (!namespace[0])
279 return true;
280
281 list_for_each_entry(list, head, list) {
282 if (!strcmp(list->namespace, namespace))
283 return true;
284 }
285
286 return false;
287}
288
289static void add_namespace(struct list_head *head, const char *namespace)
290{
291 struct namespace_list *ns_entry;
292
293 if (!contains_namespace(head, namespace)) {
294 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1);
295 strcpy(ns_entry->namespace, namespace);
296 list_add_tail(&ns_entry->list, head);
297 }
298}
299
300static void *sym_get_data_by_offset(const struct elf_info *info,
301 unsigned int secindex, unsigned long offset)
302{
303 Elf_Shdr *sechdr = &info->sechdrs[secindex];
304
305 return (void *)info->hdr + sechdr->sh_offset + offset;
306}
307
308void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
309{
310 return sym_get_data_by_offset(info, get_secindex(info, sym),
311 sym->st_value);
312}
313
314static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
315{
316 return sym_get_data_by_offset(info, info->secindex_strings,
317 sechdr->sh_name);
318}
319
320static const char *sec_name(const struct elf_info *info, unsigned int secindex)
321{
322 /*
323 * If sym->st_shndx is a special section index, there is no
324 * corresponding section header.
325 * Return "" if the index is out of range of info->sechdrs[] array.
326 */
327 if (secindex >= info->num_sections)
328 return "";
329
330 return sech_name(info, &info->sechdrs[secindex]);
331}
332
333static struct symbol *sym_add_exported(const char *name, struct module *mod,
334 bool gpl_only, const char *namespace)
335{
336 struct symbol *s = find_symbol(name);
337
338 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
339 error("%s: '%s' exported twice. Previous export was in %s%s\n",
340 mod->name, name, s->module->name,
341 s->module->is_vmlinux ? "" : ".ko");
342 }
343
344 s = alloc_symbol(name);
345 s->module = mod;
346 s->is_gpl_only = gpl_only;
347 s->namespace = xstrdup(namespace);
348 list_add_tail(&s->list, &mod->exported_symbols);
349 hash_add_symbol(s);
350
351 return s;
352}
353
354static void sym_set_crc(struct symbol *sym, unsigned int crc)
355{
356 sym->crc = crc;
357 sym->crc_valid = true;
358}
359
360static void *grab_file(const char *filename, size_t *size)
361{
362 struct stat st;
363 void *map = MAP_FAILED;
364 int fd;
365
366 fd = open(filename, O_RDONLY);
367 if (fd < 0)
368 return NULL;
369 if (fstat(fd, &st))
370 goto failed;
371
372 *size = st.st_size;
373 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
374
375failed:
376 close(fd);
377 if (map == MAP_FAILED)
378 return NULL;
379 return map;
380}
381
382static void release_file(void *file, size_t size)
383{
384 munmap(file, size);
385}
386
387static int parse_elf(struct elf_info *info, const char *filename)
388{
389 unsigned int i;
390 Elf_Ehdr *hdr;
391 Elf_Shdr *sechdrs;
392 Elf_Sym *sym;
393 const char *secstrings;
394 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
395
396 hdr = grab_file(filename, &info->size);
397 if (!hdr) {
398 if (ignore_missing_files) {
399 fprintf(stderr, "%s: %s (ignored)\n", filename,
400 strerror(errno));
401 return 0;
402 }
403 perror(filename);
404 exit(1);
405 }
406 info->hdr = hdr;
407 if (info->size < sizeof(*hdr)) {
408 /* file too small, assume this is an empty .o file */
409 return 0;
410 }
411 /* Is this a valid ELF file? */
412 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
413 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
414 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
415 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
416 /* Not an ELF file - silently ignore it */
417 return 0;
418 }
419
420 switch (hdr->e_ident[EI_DATA]) {
421 case ELFDATA2LSB:
422 target_is_big_endian = false;
423 break;
424 case ELFDATA2MSB:
425 target_is_big_endian = true;
426 break;
427 default:
428 fatal("target endian is unknown\n");
429 }
430
431 /* Fix endianness in ELF header */
432 hdr->e_type = TO_NATIVE(hdr->e_type);
433 hdr->e_machine = TO_NATIVE(hdr->e_machine);
434 hdr->e_version = TO_NATIVE(hdr->e_version);
435 hdr->e_entry = TO_NATIVE(hdr->e_entry);
436 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
437 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
438 hdr->e_flags = TO_NATIVE(hdr->e_flags);
439 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
440 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
441 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
442 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
443 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
444 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
445 sechdrs = (void *)hdr + hdr->e_shoff;
446 info->sechdrs = sechdrs;
447
448 /* modpost only works for relocatable objects */
449 if (hdr->e_type != ET_REL)
450 fatal("%s: not relocatable object.", filename);
451
452 /* Check if file offset is correct */
453 if (hdr->e_shoff > info->size)
454 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
455 (unsigned long)hdr->e_shoff, filename, info->size);
456
457 if (hdr->e_shnum == SHN_UNDEF) {
458 /*
459 * There are more than 64k sections,
460 * read count from .sh_size.
461 */
462 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
463 }
464 else {
465 info->num_sections = hdr->e_shnum;
466 }
467 if (hdr->e_shstrndx == SHN_XINDEX) {
468 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
469 }
470 else {
471 info->secindex_strings = hdr->e_shstrndx;
472 }
473
474 /* Fix endianness in section headers */
475 for (i = 0; i < info->num_sections; i++) {
476 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
477 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
478 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
479 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
480 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
481 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
482 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
483 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
484 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
485 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
486 }
487 /* Find symbol table. */
488 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
489 for (i = 1; i < info->num_sections; i++) {
490 const char *secname;
491 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
492
493 if (!nobits && sechdrs[i].sh_offset > info->size)
494 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
495 filename, (unsigned long)sechdrs[i].sh_offset,
496 sizeof(*hdr));
497
498 secname = secstrings + sechdrs[i].sh_name;
499 if (strcmp(secname, ".modinfo") == 0) {
500 if (nobits)
501 fatal("%s has NOBITS .modinfo\n", filename);
502 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
503 info->modinfo_len = sechdrs[i].sh_size;
504 } else if (!strcmp(secname, ".export_symbol")) {
505 info->export_symbol_secndx = i;
506 }
507
508 if (sechdrs[i].sh_type == SHT_SYMTAB) {
509 unsigned int sh_link_idx;
510 symtab_idx = i;
511 info->symtab_start = (void *)hdr +
512 sechdrs[i].sh_offset;
513 info->symtab_stop = (void *)hdr +
514 sechdrs[i].sh_offset + sechdrs[i].sh_size;
515 sh_link_idx = sechdrs[i].sh_link;
516 info->strtab = (void *)hdr +
517 sechdrs[sh_link_idx].sh_offset;
518 }
519
520 /* 32bit section no. table? ("more than 64k sections") */
521 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
522 symtab_shndx_idx = i;
523 info->symtab_shndx_start = (void *)hdr +
524 sechdrs[i].sh_offset;
525 info->symtab_shndx_stop = (void *)hdr +
526 sechdrs[i].sh_offset + sechdrs[i].sh_size;
527 }
528 }
529 if (!info->symtab_start)
530 fatal("%s has no symtab?\n", filename);
531
532 /* Fix endianness in symbols */
533 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
534 sym->st_shndx = TO_NATIVE(sym->st_shndx);
535 sym->st_name = TO_NATIVE(sym->st_name);
536 sym->st_value = TO_NATIVE(sym->st_value);
537 sym->st_size = TO_NATIVE(sym->st_size);
538 }
539
540 if (symtab_shndx_idx != ~0U) {
541 Elf32_Word *p;
542 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
543 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
544 filename, sechdrs[symtab_shndx_idx].sh_link,
545 symtab_idx);
546 /* Fix endianness */
547 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
548 p++)
549 *p = TO_NATIVE(*p);
550 }
551
552 symsearch_init(info);
553
554 return 1;
555}
556
557static void parse_elf_finish(struct elf_info *info)
558{
559 symsearch_finish(info);
560 release_file(info->hdr, info->size);
561}
562
563static int ignore_undef_symbol(struct elf_info *info, const char *symname)
564{
565 /* ignore __this_module, it will be resolved shortly */
566 if (strcmp(symname, "__this_module") == 0)
567 return 1;
568 /* ignore global offset table */
569 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570 return 1;
571 if (info->hdr->e_machine == EM_PPC)
572 /* Special register function linked on all modules during final link of .ko */
573 if (strstarts(symname, "_restgpr_") ||
574 strstarts(symname, "_savegpr_") ||
575 strstarts(symname, "_rest32gpr_") ||
576 strstarts(symname, "_save32gpr_") ||
577 strstarts(symname, "_restvr_") ||
578 strstarts(symname, "_savevr_"))
579 return 1;
580 if (info->hdr->e_machine == EM_PPC64)
581 /* Special register function linked on all modules during final link of .ko */
582 if (strstarts(symname, "_restgpr0_") ||
583 strstarts(symname, "_savegpr0_") ||
584 strstarts(symname, "_restvr_") ||
585 strstarts(symname, "_savevr_") ||
586 strcmp(symname, ".TOC.") == 0)
587 return 1;
588 /* Do not ignore this symbol */
589 return 0;
590}
591
592static void handle_symbol(struct module *mod, struct elf_info *info,
593 const Elf_Sym *sym, const char *symname)
594{
595 switch (sym->st_shndx) {
596 case SHN_COMMON:
597 if (strstarts(symname, "__gnu_lto_")) {
598 /* Should warn here, but modpost runs before the linker */
599 } else
600 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
601 break;
602 case SHN_UNDEF:
603 /* undefined symbol */
604 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
605 ELF_ST_BIND(sym->st_info) != STB_WEAK)
606 break;
607 if (ignore_undef_symbol(info, symname))
608 break;
609 if (info->hdr->e_machine == EM_SPARC ||
610 info->hdr->e_machine == EM_SPARCV9) {
611 /* Ignore register directives. */
612 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
613 break;
614 if (symname[0] == '.') {
615 char *munged = xstrdup(symname);
616 munged[0] = '_';
617 munged[1] = toupper(munged[1]);
618 symname = munged;
619 }
620 }
621
622 sym_add_unresolved(symname, mod,
623 ELF_ST_BIND(sym->st_info) == STB_WEAK);
624 break;
625 default:
626 if (strcmp(symname, "init_module") == 0)
627 mod->has_init = true;
628 if (strcmp(symname, "cleanup_module") == 0)
629 mod->has_cleanup = true;
630 break;
631 }
632}
633
634/**
635 * Parse tag=value strings from .modinfo section
636 **/
637static char *next_string(char *string, unsigned long *secsize)
638{
639 /* Skip non-zero chars */
640 while (string[0]) {
641 string++;
642 if ((*secsize)-- <= 1)
643 return NULL;
644 }
645
646 /* Skip any zero padding. */
647 while (!string[0]) {
648 string++;
649 if ((*secsize)-- <= 1)
650 return NULL;
651 }
652 return string;
653}
654
655static char *get_next_modinfo(struct elf_info *info, const char *tag,
656 char *prev)
657{
658 char *p;
659 unsigned int taglen = strlen(tag);
660 char *modinfo = info->modinfo;
661 unsigned long size = info->modinfo_len;
662
663 if (prev) {
664 size -= prev - modinfo;
665 modinfo = next_string(prev, &size);
666 }
667
668 for (p = modinfo; p; p = next_string(p, &size)) {
669 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
670 return p + taglen + 1;
671 }
672 return NULL;
673}
674
675static char *get_modinfo(struct elf_info *info, const char *tag)
676
677{
678 return get_next_modinfo(info, tag, NULL);
679}
680
681static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
682{
683 return sym ? elf->strtab + sym->st_name : "";
684}
685
686/*
687 * Check whether the 'string' argument matches one of the 'patterns',
688 * an array of shell wildcard patterns (glob).
689 *
690 * Return true is there is a match.
691 */
692static bool match(const char *string, const char *const patterns[])
693{
694 const char *pattern;
695
696 while ((pattern = *patterns++)) {
697 if (!fnmatch(pattern, string, 0))
698 return true;
699 }
700
701 return false;
702}
703
704/* useful to pass patterns to match() directly */
705#define PATTERNS(...) \
706 ({ \
707 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
708 patterns; \
709 })
710
711/* sections that we do not want to do full section mismatch check on */
712static const char *const section_white_list[] =
713{
714 ".comment*",
715 ".debug*",
716 ".zdebug*", /* Compressed debug sections. */
717 ".GCC.command.line", /* record-gcc-switches */
718 ".mdebug*", /* alpha, score, mips etc. */
719 ".pdr", /* alpha, score, mips etc. */
720 ".stab*",
721 ".note*",
722 ".got*",
723 ".toc*",
724 ".xt.prop", /* xtensa */
725 ".xt.lit", /* xtensa */
726 ".arcextmap*", /* arc */
727 ".gnu.linkonce.arcext*", /* arc : modules */
728 ".cmem*", /* EZchip */
729 ".fmt_slot*", /* EZchip */
730 ".gnu.lto*",
731 ".discard.*",
732 ".llvm.call-graph-profile", /* call graph */
733 NULL
734};
735
736/*
737 * This is used to find sections missing the SHF_ALLOC flag.
738 * The cause of this is often a section specified in assembler
739 * without "ax" / "aw".
740 */
741static void check_section(const char *modname, struct elf_info *elf,
742 Elf_Shdr *sechdr)
743{
744 const char *sec = sech_name(elf, sechdr);
745
746 if (sechdr->sh_type == SHT_PROGBITS &&
747 !(sechdr->sh_flags & SHF_ALLOC) &&
748 !match(sec, section_white_list)) {
749 warn("%s (%s): unexpected non-allocatable section.\n"
750 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
751 "Note that for example <linux/init.h> contains\n"
752 "section definitions for use in .S files.\n\n",
753 modname, sec);
754 }
755}
756
757
758
759#define ALL_INIT_DATA_SECTIONS \
760 ".init.setup", ".init.rodata", ".init.data"
761
762#define ALL_PCI_INIT_SECTIONS \
763 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
764 ".pci_fixup_enable", ".pci_fixup_resume", \
765 ".pci_fixup_resume_early", ".pci_fixup_suspend"
766
767#define ALL_INIT_SECTIONS ".init.*"
768#define ALL_EXIT_SECTIONS ".exit.*"
769
770#define DATA_SECTIONS ".data", ".data.rel"
771#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
772 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
773 ".ltext", ".ltext.*"
774#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
775 ".fixup", ".entry.text", ".exception.text", \
776 ".coldtext", ".softirqentry.text", ".irqentry.text"
777
778#define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \
779 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
780
781enum mismatch {
782 TEXTDATA_TO_ANY_INIT_EXIT,
783 XXXINIT_TO_SOME_INIT,
784 ANY_INIT_TO_ANY_EXIT,
785 ANY_EXIT_TO_ANY_INIT,
786 EXTABLE_TO_NON_TEXT,
787};
788
789/**
790 * Describe how to match sections on different criteria:
791 *
792 * @fromsec: Array of sections to be matched.
793 *
794 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
795 * this array is forbidden (black-list). Can be empty.
796 *
797 * @good_tosec: Relocations applied to a section in @fromsec must be
798 * targeting sections in this array (white-list). Can be empty.
799 *
800 * @mismatch: Type of mismatch.
801 */
802struct sectioncheck {
803 const char *fromsec[20];
804 const char *bad_tosec[20];
805 const char *good_tosec[20];
806 enum mismatch mismatch;
807};
808
809static const struct sectioncheck sectioncheck[] = {
810/* Do not reference init/exit code/data from
811 * normal code and data
812 */
813{
814 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
815 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
816 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
817},
818/* Do not use exit code/data from init code */
819{
820 .fromsec = { ALL_INIT_SECTIONS, NULL },
821 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
822 .mismatch = ANY_INIT_TO_ANY_EXIT,
823},
824/* Do not use init code/data from exit code */
825{
826 .fromsec = { ALL_EXIT_SECTIONS, NULL },
827 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
828 .mismatch = ANY_EXIT_TO_ANY_INIT,
829},
830{
831 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
832 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
833 .mismatch = ANY_INIT_TO_ANY_EXIT,
834},
835{
836 .fromsec = { "__ex_table", NULL },
837 /* If you're adding any new black-listed sections in here, consider
838 * adding a special 'printer' for them in scripts/check_extable.
839 */
840 .bad_tosec = { ".altinstr_replacement", NULL },
841 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
842 .mismatch = EXTABLE_TO_NON_TEXT,
843}
844};
845
846static const struct sectioncheck *section_mismatch(
847 const char *fromsec, const char *tosec)
848{
849 int i;
850
851 /*
852 * The target section could be the SHT_NUL section when we're
853 * handling relocations to un-resolved symbols, trying to match it
854 * doesn't make much sense and causes build failures on parisc
855 * architectures.
856 */
857 if (*tosec == '\0')
858 return NULL;
859
860 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
861 const struct sectioncheck *check = §ioncheck[i];
862
863 if (match(fromsec, check->fromsec)) {
864 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
865 return check;
866 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
867 return check;
868 }
869 }
870 return NULL;
871}
872
873/**
874 * Whitelist to allow certain references to pass with no warning.
875 *
876 * Pattern 1:
877 * If a module parameter is declared __initdata and permissions=0
878 * then this is legal despite the warning generated.
879 * We cannot see value of permissions here, so just ignore
880 * this pattern.
881 * The pattern is identified by:
882 * tosec = .init.data
883 * fromsec = .data*
884 * atsym =__param*
885 *
886 * Pattern 1a:
887 * module_param_call() ops can refer to __init set function if permissions=0
888 * The pattern is identified by:
889 * tosec = .init.text
890 * fromsec = .data*
891 * atsym = __param_ops_*
892 *
893 * Pattern 3:
894 * Whitelist all references from .head.text to any init section
895 *
896 * Pattern 4:
897 * Some symbols belong to init section but still it is ok to reference
898 * these from non-init sections as these symbols don't have any memory
899 * allocated for them and symbol address and value are same. So even
900 * if init section is freed, its ok to reference those symbols.
901 * For ex. symbols marking the init section boundaries.
902 * This pattern is identified by
903 * refsymname = __init_begin, _sinittext, _einittext
904 *
905 * Pattern 5:
906 * GCC may optimize static inlines when fed constant arg(s) resulting
907 * in functions like cpumask_empty() -- generating an associated symbol
908 * cpumask_empty.constprop.3 that appears in the audit. If the const that
909 * is passed in comes from __init, like say nmi_ipi_mask, we get a
910 * meaningless section warning. May need to add isra symbols too...
911 * This pattern is identified by
912 * tosec = init section
913 * fromsec = text section
914 * refsymname = *.constprop.*
915 *
916 **/
917static int secref_whitelist(const char *fromsec, const char *fromsym,
918 const char *tosec, const char *tosym)
919{
920 /* Check for pattern 1 */
921 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
922 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
923 strstarts(fromsym, "__param"))
924 return 0;
925
926 /* Check for pattern 1a */
927 if (strcmp(tosec, ".init.text") == 0 &&
928 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
929 strstarts(fromsym, "__param_ops_"))
930 return 0;
931
932 /* symbols in data sections that may refer to any init/exit sections */
933 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
934 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
935 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
936 return 0;
937
938 /* Check for pattern 3 */
939 if (strstarts(fromsec, ".head.text") &&
940 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
941 return 0;
942
943 /* Check for pattern 4 */
944 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
945 return 0;
946
947 /* Check for pattern 5 */
948 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
949 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
950 match(fromsym, PATTERNS("*.constprop.*")))
951 return 0;
952
953 return 1;
954}
955
956static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
957 unsigned int secndx)
958{
959 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
960}
961
962static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
963{
964 Elf_Sym *new_sym;
965
966 /* If the supplied symbol has a valid name, return it */
967 if (is_valid_name(elf, sym))
968 return sym;
969
970 /*
971 * Strive to find a better symbol name, but the resulting name may not
972 * match the symbol referenced in the original code.
973 */
974 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
975 true, 20);
976 return new_sym ? new_sym : sym;
977}
978
979static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
980{
981 if (secndx >= elf->num_sections)
982 return false;
983
984 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
985}
986
987static void default_mismatch_handler(const char *modname, struct elf_info *elf,
988 const struct sectioncheck* const mismatch,
989 Elf_Sym *tsym,
990 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
991 const char *tosec, Elf_Addr taddr)
992{
993 Elf_Sym *from;
994 const char *tosym;
995 const char *fromsym;
996 char taddr_str[16];
997
998 from = find_fromsym(elf, faddr, fsecndx);
999 fromsym = sym_name(elf, from);
1000
1001 tsym = find_tosym(elf, taddr, tsym);
1002 tosym = sym_name(elf, tsym);
1003
1004 /* check whitelist - we may ignore it */
1005 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1006 return;
1007
1008 sec_mismatch_count++;
1009
1010 if (!tosym[0])
1011 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
1012
1013 /*
1014 * The format for the reference source: <symbol_name>+<offset> or <address>
1015 * The format for the reference destination: <symbol_name> or <address>
1016 */
1017 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
1018 modname, fromsym, fromsym[0] ? "+" : "",
1019 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
1020 fromsec, tosym[0] ? tosym : taddr_str, tosec);
1021
1022 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1023 if (match(tosec, mismatch->bad_tosec))
1024 fatal("The relocation at %s+0x%lx references\n"
1025 "section \"%s\" which is black-listed.\n"
1026 "Something is seriously wrong and should be fixed.\n"
1027 "You might get more information about where this is\n"
1028 "coming from by using scripts/check_extable.sh %s\n",
1029 fromsec, (long)faddr, tosec, modname);
1030 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1031 warn("The relocation at %s+0x%lx references\n"
1032 "section \"%s\" which is not in the list of\n"
1033 "authorized sections. If you're adding a new section\n"
1034 "and/or if this reference is valid, add \"%s\" to the\n"
1035 "list of authorized sections to jump to on fault.\n"
1036 "This can be achieved by adding \"%s\" to\n"
1037 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1038 fromsec, (long)faddr, tosec, tosec, tosec);
1039 else
1040 error("%s+0x%lx references non-executable section '%s'\n",
1041 fromsec, (long)faddr, tosec);
1042 }
1043}
1044
1045static void check_export_symbol(struct module *mod, struct elf_info *elf,
1046 Elf_Addr faddr, const char *secname,
1047 Elf_Sym *sym)
1048{
1049 static const char *prefix = "__export_symbol_";
1050 const char *label_name, *name, *data;
1051 Elf_Sym *label;
1052 struct symbol *s;
1053 bool is_gpl;
1054
1055 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1056 label_name = sym_name(elf, label);
1057
1058 if (!strstarts(label_name, prefix)) {
1059 error("%s: .export_symbol section contains strange symbol '%s'\n",
1060 mod->name, label_name);
1061 return;
1062 }
1063
1064 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1065 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1066 error("%s: local symbol '%s' was exported\n", mod->name,
1067 label_name + strlen(prefix));
1068 return;
1069 }
1070
1071 name = sym_name(elf, sym);
1072 if (strcmp(label_name + strlen(prefix), name)) {
1073 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1074 mod->name, name);
1075 return;
1076 }
1077
1078 data = sym_get_data(elf, label); /* license */
1079 if (!strcmp(data, "GPL")) {
1080 is_gpl = true;
1081 } else if (!strcmp(data, "")) {
1082 is_gpl = false;
1083 } else {
1084 error("%s: unknown license '%s' was specified for '%s'\n",
1085 mod->name, data, name);
1086 return;
1087 }
1088
1089 data += strlen(data) + 1; /* namespace */
1090 s = sym_add_exported(name, mod, is_gpl, data);
1091
1092 /*
1093 * We need to be aware whether we are exporting a function or
1094 * a data on some architectures.
1095 */
1096 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1097
1098 /*
1099 * For parisc64, symbols prefixed $$ from the library have the symbol type
1100 * STT_LOPROC. They should be handled as functions too.
1101 */
1102 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1103 elf->hdr->e_machine == EM_PARISC &&
1104 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1105 s->is_func = true;
1106
1107 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1108 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1109 mod->name, name);
1110 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1111 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1112 mod->name, name);
1113}
1114
1115static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1116 Elf_Sym *sym,
1117 unsigned int fsecndx, const char *fromsec,
1118 Elf_Addr faddr, Elf_Addr taddr)
1119{
1120 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1121 const struct sectioncheck *mismatch;
1122
1123 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1124 check_export_symbol(mod, elf, faddr, tosec, sym);
1125 return;
1126 }
1127
1128 mismatch = section_mismatch(fromsec, tosec);
1129 if (!mismatch)
1130 return;
1131
1132 default_mismatch_handler(mod->name, elf, mismatch, sym,
1133 fsecndx, fromsec, faddr,
1134 tosec, taddr);
1135}
1136
1137static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1138{
1139 switch (r_type) {
1140 case R_386_32:
1141 return get_unaligned_native(location);
1142 case R_386_PC32:
1143 return get_unaligned_native(location) + 4;
1144 }
1145
1146 return (Elf_Addr)(-1);
1147}
1148
1149static int32_t sign_extend32(int32_t value, int index)
1150{
1151 uint8_t shift = 31 - index;
1152
1153 return (int32_t)(value << shift) >> shift;
1154}
1155
1156static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1157{
1158 uint32_t inst, upper, lower, sign, j1, j2;
1159 int32_t offset;
1160
1161 switch (r_type) {
1162 case R_ARM_ABS32:
1163 case R_ARM_REL32:
1164 inst = get_unaligned_native((uint32_t *)loc);
1165 return inst + sym->st_value;
1166 case R_ARM_MOVW_ABS_NC:
1167 case R_ARM_MOVT_ABS:
1168 inst = get_unaligned_native((uint32_t *)loc);
1169 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1170 15);
1171 return offset + sym->st_value;
1172 case R_ARM_PC24:
1173 case R_ARM_CALL:
1174 case R_ARM_JUMP24:
1175 inst = get_unaligned_native((uint32_t *)loc);
1176 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1177 return offset + sym->st_value + 8;
1178 case R_ARM_THM_MOVW_ABS_NC:
1179 case R_ARM_THM_MOVT_ABS:
1180 upper = get_unaligned_native((uint16_t *)loc);
1181 lower = get_unaligned_native((uint16_t *)loc + 1);
1182 offset = sign_extend32(((upper & 0x000f) << 12) |
1183 ((upper & 0x0400) << 1) |
1184 ((lower & 0x7000) >> 4) |
1185 (lower & 0x00ff),
1186 15);
1187 return offset + sym->st_value;
1188 case R_ARM_THM_JUMP19:
1189 /*
1190 * Encoding T3:
1191 * S = upper[10]
1192 * imm6 = upper[5:0]
1193 * J1 = lower[13]
1194 * J2 = lower[11]
1195 * imm11 = lower[10:0]
1196 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1197 */
1198 upper = get_unaligned_native((uint16_t *)loc);
1199 lower = get_unaligned_native((uint16_t *)loc + 1);
1200
1201 sign = (upper >> 10) & 1;
1202 j1 = (lower >> 13) & 1;
1203 j2 = (lower >> 11) & 1;
1204 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1205 ((upper & 0x03f) << 12) |
1206 ((lower & 0x07ff) << 1),
1207 20);
1208 return offset + sym->st_value + 4;
1209 case R_ARM_THM_PC22:
1210 case R_ARM_THM_JUMP24:
1211 /*
1212 * Encoding T4:
1213 * S = upper[10]
1214 * imm10 = upper[9:0]
1215 * J1 = lower[13]
1216 * J2 = lower[11]
1217 * imm11 = lower[10:0]
1218 * I1 = NOT(J1 XOR S)
1219 * I2 = NOT(J2 XOR S)
1220 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1221 */
1222 upper = get_unaligned_native((uint16_t *)loc);
1223 lower = get_unaligned_native((uint16_t *)loc + 1);
1224
1225 sign = (upper >> 10) & 1;
1226 j1 = (lower >> 13) & 1;
1227 j2 = (lower >> 11) & 1;
1228 offset = sign_extend32((sign << 24) |
1229 ((~(j1 ^ sign) & 1) << 23) |
1230 ((~(j2 ^ sign) & 1) << 22) |
1231 ((upper & 0x03ff) << 12) |
1232 ((lower & 0x07ff) << 1),
1233 24);
1234 return offset + sym->st_value + 4;
1235 }
1236
1237 return (Elf_Addr)(-1);
1238}
1239
1240static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1241{
1242 uint32_t inst;
1243
1244 inst = get_unaligned_native(location);
1245 switch (r_type) {
1246 case R_MIPS_LO16:
1247 return inst & 0xffff;
1248 case R_MIPS_26:
1249 return (inst & 0x03ffffff) << 2;
1250 case R_MIPS_32:
1251 return inst;
1252 }
1253 return (Elf_Addr)(-1);
1254}
1255
1256#ifndef EM_RISCV
1257#define EM_RISCV 243
1258#endif
1259
1260#ifndef R_RISCV_SUB32
1261#define R_RISCV_SUB32 39
1262#endif
1263
1264#ifndef EM_LOONGARCH
1265#define EM_LOONGARCH 258
1266#endif
1267
1268#ifndef R_LARCH_SUB32
1269#define R_LARCH_SUB32 55
1270#endif
1271
1272#ifndef R_LARCH_RELAX
1273#define R_LARCH_RELAX 100
1274#endif
1275
1276#ifndef R_LARCH_ALIGN
1277#define R_LARCH_ALIGN 102
1278#endif
1279
1280static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1281 unsigned int *r_type, unsigned int *r_sym)
1282{
1283 typedef struct {
1284 Elf64_Word r_sym; /* Symbol index */
1285 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1286 unsigned char r_type3; /* 3rd relocation type */
1287 unsigned char r_type2; /* 2nd relocation type */
1288 unsigned char r_type; /* 1st relocation type */
1289 } Elf64_Mips_R_Info;
1290
1291 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1292
1293 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1294 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1295
1296 *r_type = mips64_r_info->r_type;
1297 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1298 return;
1299 }
1300
1301 if (is_64bit)
1302 r_info = TO_NATIVE((Elf64_Xword)r_info);
1303 else
1304 r_info = TO_NATIVE((Elf32_Word)r_info);
1305
1306 *r_type = ELF_R_TYPE(r_info);
1307 *r_sym = ELF_R_SYM(r_info);
1308}
1309
1310static void section_rela(struct module *mod, struct elf_info *elf,
1311 unsigned int fsecndx, const char *fromsec,
1312 const Elf_Rela *start, const Elf_Rela *stop)
1313{
1314 const Elf_Rela *rela;
1315
1316 for (rela = start; rela < stop; rela++) {
1317 Elf_Sym *tsym;
1318 Elf_Addr taddr, r_offset;
1319 unsigned int r_type, r_sym;
1320
1321 r_offset = TO_NATIVE(rela->r_offset);
1322 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1323
1324 tsym = elf->symtab_start + r_sym;
1325 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1326
1327 switch (elf->hdr->e_machine) {
1328 case EM_RISCV:
1329 if (!strcmp("__ex_table", fromsec) &&
1330 r_type == R_RISCV_SUB32)
1331 continue;
1332 break;
1333 case EM_LOONGARCH:
1334 switch (r_type) {
1335 case R_LARCH_SUB32:
1336 if (!strcmp("__ex_table", fromsec))
1337 continue;
1338 break;
1339 case R_LARCH_RELAX:
1340 case R_LARCH_ALIGN:
1341 /* These relocs do not refer to symbols */
1342 continue;
1343 }
1344 break;
1345 }
1346
1347 check_section_mismatch(mod, elf, tsym,
1348 fsecndx, fromsec, r_offset, taddr);
1349 }
1350}
1351
1352static void section_rel(struct module *mod, struct elf_info *elf,
1353 unsigned int fsecndx, const char *fromsec,
1354 const Elf_Rel *start, const Elf_Rel *stop)
1355{
1356 const Elf_Rel *rel;
1357
1358 for (rel = start; rel < stop; rel++) {
1359 Elf_Sym *tsym;
1360 Elf_Addr taddr, r_offset;
1361 unsigned int r_type, r_sym;
1362 void *loc;
1363
1364 r_offset = TO_NATIVE(rel->r_offset);
1365 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1366
1367 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1368 tsym = elf->symtab_start + r_sym;
1369
1370 switch (elf->hdr->e_machine) {
1371 case EM_386:
1372 taddr = addend_386_rel(loc, r_type);
1373 break;
1374 case EM_ARM:
1375 taddr = addend_arm_rel(loc, tsym, r_type);
1376 break;
1377 case EM_MIPS:
1378 taddr = addend_mips_rel(loc, r_type);
1379 break;
1380 default:
1381 fatal("Please add code to calculate addend for this architecture\n");
1382 }
1383
1384 check_section_mismatch(mod, elf, tsym,
1385 fsecndx, fromsec, r_offset, taddr);
1386 }
1387}
1388
1389/**
1390 * A module includes a number of sections that are discarded
1391 * either when loaded or when used as built-in.
1392 * For loaded modules all functions marked __init and all data
1393 * marked __initdata will be discarded when the module has been initialized.
1394 * Likewise for modules used built-in the sections marked __exit
1395 * are discarded because __exit marked function are supposed to be called
1396 * only when a module is unloaded which never happens for built-in modules.
1397 * The check_sec_ref() function traverses all relocation records
1398 * to find all references to a section that reference a section that will
1399 * be discarded and warns about it.
1400 **/
1401static void check_sec_ref(struct module *mod, struct elf_info *elf)
1402{
1403 int i;
1404
1405 /* Walk through all sections */
1406 for (i = 0; i < elf->num_sections; i++) {
1407 Elf_Shdr *sechdr = &elf->sechdrs[i];
1408
1409 check_section(mod->name, elf, sechdr);
1410 /* We want to process only relocation sections and not .init */
1411 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1412 /* section to which the relocation applies */
1413 unsigned int secndx = sechdr->sh_info;
1414 const char *secname = sec_name(elf, secndx);
1415 const void *start, *stop;
1416
1417 /* If the section is known good, skip it */
1418 if (match(secname, section_white_list))
1419 continue;
1420
1421 start = sym_get_data_by_offset(elf, i, 0);
1422 stop = start + sechdr->sh_size;
1423
1424 if (sechdr->sh_type == SHT_RELA)
1425 section_rela(mod, elf, secndx, secname,
1426 start, stop);
1427 else
1428 section_rel(mod, elf, secndx, secname,
1429 start, stop);
1430 }
1431 }
1432}
1433
1434static char *remove_dot(char *s)
1435{
1436 size_t n = strcspn(s, ".");
1437
1438 if (n && s[n]) {
1439 size_t m = strspn(s + n + 1, "0123456789");
1440 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1441 s[n] = 0;
1442 }
1443 return s;
1444}
1445
1446/*
1447 * The CRCs are recorded in .*.cmd files in the form of:
1448 * #SYMVER <name> <crc>
1449 */
1450static void extract_crcs_for_object(const char *object, struct module *mod)
1451{
1452 char cmd_file[PATH_MAX];
1453 char *buf, *p;
1454 const char *base;
1455 int dirlen, ret;
1456
1457 base = strrchr(object, '/');
1458 if (base) {
1459 base++;
1460 dirlen = base - object;
1461 } else {
1462 dirlen = 0;
1463 base = object;
1464 }
1465
1466 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1467 dirlen, object, base);
1468 if (ret >= sizeof(cmd_file)) {
1469 error("%s: too long path was truncated\n", cmd_file);
1470 return;
1471 }
1472
1473 buf = read_text_file(cmd_file);
1474 p = buf;
1475
1476 while ((p = strstr(p, "\n#SYMVER "))) {
1477 char *name;
1478 size_t namelen;
1479 unsigned int crc;
1480 struct symbol *sym;
1481
1482 name = p + strlen("\n#SYMVER ");
1483
1484 p = strchr(name, ' ');
1485 if (!p)
1486 break;
1487
1488 namelen = p - name;
1489 p++;
1490
1491 if (!isdigit(*p))
1492 continue; /* skip this line */
1493
1494 crc = strtoul(p, &p, 0);
1495 if (*p != '\n')
1496 continue; /* skip this line */
1497
1498 name[namelen] = '\0';
1499
1500 /*
1501 * sym_find_with_module() may return NULL here.
1502 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1503 * Since commit e1327a127703, genksyms calculates CRCs of all
1504 * symbols, including trimmed ones. Ignore orphan CRCs.
1505 */
1506 sym = sym_find_with_module(name, mod);
1507 if (sym)
1508 sym_set_crc(sym, crc);
1509 }
1510
1511 free(buf);
1512}
1513
1514/*
1515 * The symbol versions (CRC) are recorded in the .*.cmd files.
1516 * Parse them to retrieve CRCs for the current module.
1517 */
1518static void mod_set_crcs(struct module *mod)
1519{
1520 char objlist[PATH_MAX];
1521 char *buf, *p, *obj;
1522 int ret;
1523
1524 if (mod->is_vmlinux) {
1525 strcpy(objlist, ".vmlinux.objs");
1526 } else {
1527 /* objects for a module are listed in the *.mod file. */
1528 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1529 if (ret >= sizeof(objlist)) {
1530 error("%s: too long path was truncated\n", objlist);
1531 return;
1532 }
1533 }
1534
1535 buf = read_text_file(objlist);
1536 p = buf;
1537
1538 while ((obj = strsep(&p, "\n")) && obj[0])
1539 extract_crcs_for_object(obj, mod);
1540
1541 free(buf);
1542}
1543
1544static void read_symbols(const char *modname)
1545{
1546 const char *symname;
1547 char *version;
1548 char *license;
1549 char *namespace;
1550 struct module *mod;
1551 struct elf_info info = { };
1552 Elf_Sym *sym;
1553
1554 if (!parse_elf(&info, modname))
1555 return;
1556
1557 if (!strends(modname, ".o")) {
1558 error("%s: filename must be suffixed with .o\n", modname);
1559 return;
1560 }
1561
1562 /* strip trailing .o */
1563 mod = new_module(modname, strlen(modname) - strlen(".o"));
1564
1565 if (!mod->is_vmlinux) {
1566 license = get_modinfo(&info, "license");
1567 if (!license)
1568 error("missing MODULE_LICENSE() in %s\n", modname);
1569 while (license) {
1570 if (!license_is_gpl_compatible(license)) {
1571 mod->is_gpl_compatible = false;
1572 break;
1573 }
1574 license = get_next_modinfo(&info, "license", license);
1575 }
1576
1577 namespace = get_modinfo(&info, "import_ns");
1578 while (namespace) {
1579 add_namespace(&mod->imported_namespaces, namespace);
1580 namespace = get_next_modinfo(&info, "import_ns",
1581 namespace);
1582 }
1583
1584 if (extra_warn && !get_modinfo(&info, "description"))
1585 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1586 }
1587
1588 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1589 symname = remove_dot(info.strtab + sym->st_name);
1590
1591 handle_symbol(mod, &info, sym, symname);
1592 handle_moddevtable(mod, &info, sym, symname);
1593 }
1594
1595 check_sec_ref(mod, &info);
1596
1597 if (!mod->is_vmlinux) {
1598 version = get_modinfo(&info, "version");
1599 if (version || all_versions)
1600 get_src_version(mod->name, mod->srcversion,
1601 sizeof(mod->srcversion) - 1);
1602 }
1603
1604 parse_elf_finish(&info);
1605
1606 if (modversions) {
1607 /*
1608 * Our trick to get versioning for module struct etc. - it's
1609 * never passed as an argument to an exported function, so
1610 * the automatic versioning doesn't pick it up, but it's really
1611 * important anyhow.
1612 */
1613 sym_add_unresolved("module_layout", mod, false);
1614
1615 mod_set_crcs(mod);
1616 }
1617}
1618
1619static void read_symbols_from_files(const char *filename)
1620{
1621 FILE *in = stdin;
1622 char fname[PATH_MAX];
1623
1624 in = fopen(filename, "r");
1625 if (!in)
1626 fatal("Can't open filenames file %s: %m", filename);
1627
1628 while (fgets(fname, PATH_MAX, in) != NULL) {
1629 if (strends(fname, "\n"))
1630 fname[strlen(fname)-1] = '\0';
1631 read_symbols(fname);
1632 }
1633
1634 fclose(in);
1635}
1636
1637#define SZ 500
1638
1639/* We first write the generated file into memory using the
1640 * following helper, then compare to the file on disk and
1641 * only update the later if anything changed */
1642
1643void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1644 const char *fmt, ...)
1645{
1646 char tmp[SZ];
1647 int len;
1648 va_list ap;
1649
1650 va_start(ap, fmt);
1651 len = vsnprintf(tmp, SZ, fmt, ap);
1652 buf_write(buf, tmp, len);
1653 va_end(ap);
1654}
1655
1656void buf_write(struct buffer *buf, const char *s, int len)
1657{
1658 if (buf->size - buf->pos < len) {
1659 buf->size += len + SZ;
1660 buf->p = xrealloc(buf->p, buf->size);
1661 }
1662 strncpy(buf->p + buf->pos, s, len);
1663 buf->pos += len;
1664}
1665
1666static void check_exports(struct module *mod)
1667{
1668 struct symbol *s, *exp;
1669
1670 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1671 const char *basename;
1672 exp = find_symbol(s->name);
1673 if (!exp) {
1674 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1675 modpost_log(!warn_unresolved,
1676 "\"%s\" [%s.ko] undefined!\n",
1677 s->name, mod->name);
1678 continue;
1679 }
1680 if (exp->module == mod) {
1681 error("\"%s\" [%s.ko] was exported without definition\n",
1682 s->name, mod->name);
1683 continue;
1684 }
1685
1686 exp->used = true;
1687 s->module = exp->module;
1688 s->crc_valid = exp->crc_valid;
1689 s->crc = exp->crc;
1690
1691 basename = strrchr(mod->name, '/');
1692 if (basename)
1693 basename++;
1694 else
1695 basename = mod->name;
1696
1697 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1698 modpost_log(!allow_missing_ns_imports,
1699 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1700 basename, exp->name, exp->namespace);
1701 add_namespace(&mod->missing_namespaces, exp->namespace);
1702 }
1703
1704 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1705 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1706 basename, exp->name);
1707 }
1708}
1709
1710static void handle_white_list_exports(const char *white_list)
1711{
1712 char *buf, *p, *name;
1713
1714 buf = read_text_file(white_list);
1715 p = buf;
1716
1717 while ((name = strsep(&p, "\n"))) {
1718 struct symbol *sym = find_symbol(name);
1719
1720 if (sym)
1721 sym->used = true;
1722 }
1723
1724 free(buf);
1725}
1726
1727static void check_modname_len(struct module *mod)
1728{
1729 const char *mod_name;
1730
1731 mod_name = strrchr(mod->name, '/');
1732 if (mod_name == NULL)
1733 mod_name = mod->name;
1734 else
1735 mod_name++;
1736 if (strlen(mod_name) >= MODULE_NAME_LEN)
1737 error("module name is too long [%s.ko]\n", mod->name);
1738}
1739
1740/**
1741 * Header for the generated file
1742 **/
1743static void add_header(struct buffer *b, struct module *mod)
1744{
1745 buf_printf(b, "#include <linux/module.h>\n");
1746 buf_printf(b, "#include <linux/export-internal.h>\n");
1747 buf_printf(b, "#include <linux/compiler.h>\n");
1748 buf_printf(b, "\n");
1749 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1750 buf_printf(b, "\n");
1751 buf_printf(b, "__visible struct module __this_module\n");
1752 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1753 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1754 if (mod->has_init)
1755 buf_printf(b, "\t.init = init_module,\n");
1756 if (mod->has_cleanup)
1757 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1758 "\t.exit = cleanup_module,\n"
1759 "#endif\n");
1760 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1761 buf_printf(b, "};\n");
1762
1763 if (!external_module)
1764 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1765
1766 if (strstarts(mod->name, "drivers/staging"))
1767 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1768
1769 if (strstarts(mod->name, "tools/testing"))
1770 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1771}
1772
1773static void add_exported_symbols(struct buffer *buf, struct module *mod)
1774{
1775 struct symbol *sym;
1776
1777 /* generate struct for exported symbols */
1778 buf_printf(buf, "\n");
1779 list_for_each_entry(sym, &mod->exported_symbols, list) {
1780 if (trim_unused_exports && !sym->used)
1781 continue;
1782
1783 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1784 sym->is_func ? "FUNC" : "DATA", sym->name,
1785 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1786 }
1787
1788 if (!modversions)
1789 return;
1790
1791 /* record CRCs for exported symbols */
1792 buf_printf(buf, "\n");
1793 list_for_each_entry(sym, &mod->exported_symbols, list) {
1794 if (trim_unused_exports && !sym->used)
1795 continue;
1796
1797 if (!sym->crc_valid)
1798 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1799 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1800 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1801 sym->name);
1802
1803 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1804 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1805 }
1806}
1807
1808/**
1809 * Record CRCs for unresolved symbols
1810 **/
1811static void add_versions(struct buffer *b, struct module *mod)
1812{
1813 struct symbol *s;
1814
1815 if (!modversions)
1816 return;
1817
1818 buf_printf(b, "\n");
1819 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1820 buf_printf(b, "__used __section(\"__versions\") = {\n");
1821
1822 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1823 if (!s->module)
1824 continue;
1825 if (!s->crc_valid) {
1826 warn("\"%s\" [%s.ko] has no CRC!\n",
1827 s->name, mod->name);
1828 continue;
1829 }
1830 if (strlen(s->name) >= MODULE_NAME_LEN) {
1831 error("too long symbol \"%s\" [%s.ko]\n",
1832 s->name, mod->name);
1833 break;
1834 }
1835 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1836 s->crc, s->name);
1837 }
1838
1839 buf_printf(b, "};\n");
1840}
1841
1842static void add_depends(struct buffer *b, struct module *mod)
1843{
1844 struct symbol *s;
1845 int first = 1;
1846
1847 /* Clear ->seen flag of modules that own symbols needed by this. */
1848 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1849 if (s->module)
1850 s->module->seen = s->module->is_vmlinux;
1851 }
1852
1853 buf_printf(b, "\n");
1854 buf_printf(b, "MODULE_INFO(depends, \"");
1855 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1856 const char *p;
1857 if (!s->module)
1858 continue;
1859
1860 if (s->module->seen)
1861 continue;
1862
1863 s->module->seen = true;
1864 p = strrchr(s->module->name, '/');
1865 if (p)
1866 p++;
1867 else
1868 p = s->module->name;
1869 buf_printf(b, "%s%s", first ? "" : ",", p);
1870 first = 0;
1871 }
1872 buf_printf(b, "\");\n");
1873}
1874
1875static void add_srcversion(struct buffer *b, struct module *mod)
1876{
1877 if (mod->srcversion[0]) {
1878 buf_printf(b, "\n");
1879 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1880 mod->srcversion);
1881 }
1882}
1883
1884static void write_buf(struct buffer *b, const char *fname)
1885{
1886 FILE *file;
1887
1888 if (error_occurred)
1889 return;
1890
1891 file = fopen(fname, "w");
1892 if (!file) {
1893 perror(fname);
1894 exit(1);
1895 }
1896 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1897 perror(fname);
1898 exit(1);
1899 }
1900 if (fclose(file) != 0) {
1901 perror(fname);
1902 exit(1);
1903 }
1904}
1905
1906static void write_if_changed(struct buffer *b, const char *fname)
1907{
1908 char *tmp;
1909 FILE *file;
1910 struct stat st;
1911
1912 file = fopen(fname, "r");
1913 if (!file)
1914 goto write;
1915
1916 if (fstat(fileno(file), &st) < 0)
1917 goto close_write;
1918
1919 if (st.st_size != b->pos)
1920 goto close_write;
1921
1922 tmp = xmalloc(b->pos);
1923 if (fread(tmp, 1, b->pos, file) != b->pos)
1924 goto free_write;
1925
1926 if (memcmp(tmp, b->p, b->pos) != 0)
1927 goto free_write;
1928
1929 free(tmp);
1930 fclose(file);
1931 return;
1932
1933 free_write:
1934 free(tmp);
1935 close_write:
1936 fclose(file);
1937 write:
1938 write_buf(b, fname);
1939}
1940
1941static void write_vmlinux_export_c_file(struct module *mod)
1942{
1943 struct buffer buf = { };
1944
1945 buf_printf(&buf,
1946 "#include <linux/export-internal.h>\n");
1947
1948 add_exported_symbols(&buf, mod);
1949 write_if_changed(&buf, ".vmlinux.export.c");
1950 free(buf.p);
1951}
1952
1953/* do sanity checks, and generate *.mod.c file */
1954static void write_mod_c_file(struct module *mod)
1955{
1956 struct buffer buf = { };
1957 struct module_alias *alias, *next;
1958 char fname[PATH_MAX];
1959 int ret;
1960
1961 add_header(&buf, mod);
1962 add_exported_symbols(&buf, mod);
1963 add_versions(&buf, mod);
1964 add_depends(&buf, mod);
1965
1966 buf_printf(&buf, "\n");
1967 list_for_each_entry_safe(alias, next, &mod->aliases, node) {
1968 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str);
1969 list_del(&alias->node);
1970 free(alias);
1971 }
1972
1973 add_srcversion(&buf, mod);
1974
1975 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
1976 if (ret >= sizeof(fname)) {
1977 error("%s: too long path was truncated\n", fname);
1978 goto free;
1979 }
1980
1981 write_if_changed(&buf, fname);
1982
1983free:
1984 free(buf.p);
1985}
1986
1987/* parse Module.symvers file. line format:
1988 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
1989 **/
1990static void read_dump(const char *fname)
1991{
1992 char *buf, *pos, *line;
1993
1994 buf = read_text_file(fname);
1995 if (!buf)
1996 /* No symbol versions, silently ignore */
1997 return;
1998
1999 pos = buf;
2000
2001 while ((line = get_line(&pos))) {
2002 char *symname, *namespace, *modname, *d, *export;
2003 unsigned int crc;
2004 struct module *mod;
2005 struct symbol *s;
2006 bool gpl_only;
2007
2008 if (!(symname = strchr(line, '\t')))
2009 goto fail;
2010 *symname++ = '\0';
2011 if (!(modname = strchr(symname, '\t')))
2012 goto fail;
2013 *modname++ = '\0';
2014 if (!(export = strchr(modname, '\t')))
2015 goto fail;
2016 *export++ = '\0';
2017 if (!(namespace = strchr(export, '\t')))
2018 goto fail;
2019 *namespace++ = '\0';
2020
2021 crc = strtoul(line, &d, 16);
2022 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2023 goto fail;
2024
2025 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2026 gpl_only = true;
2027 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2028 gpl_only = false;
2029 } else {
2030 error("%s: unknown license %s. skip", symname, export);
2031 continue;
2032 }
2033
2034 mod = find_module(fname, modname);
2035 if (!mod) {
2036 mod = new_module(modname, strlen(modname));
2037 mod->dump_file = fname;
2038 }
2039 s = sym_add_exported(symname, mod, gpl_only, namespace);
2040 sym_set_crc(s, crc);
2041 }
2042 free(buf);
2043 return;
2044fail:
2045 free(buf);
2046 fatal("parse error in symbol dump file\n");
2047}
2048
2049static void write_dump(const char *fname)
2050{
2051 struct buffer buf = { };
2052 struct module *mod;
2053 struct symbol *sym;
2054
2055 list_for_each_entry(mod, &modules, list) {
2056 if (mod->dump_file)
2057 continue;
2058 list_for_each_entry(sym, &mod->exported_symbols, list) {
2059 if (trim_unused_exports && !sym->used)
2060 continue;
2061
2062 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2063 sym->crc, sym->name, mod->name,
2064 sym->is_gpl_only ? "_GPL" : "",
2065 sym->namespace);
2066 }
2067 }
2068 write_buf(&buf, fname);
2069 free(buf.p);
2070}
2071
2072static void write_namespace_deps_files(const char *fname)
2073{
2074 struct module *mod;
2075 struct namespace_list *ns;
2076 struct buffer ns_deps_buf = {};
2077
2078 list_for_each_entry(mod, &modules, list) {
2079
2080 if (mod->dump_file || list_empty(&mod->missing_namespaces))
2081 continue;
2082
2083 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2084
2085 list_for_each_entry(ns, &mod->missing_namespaces, list)
2086 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2087
2088 buf_printf(&ns_deps_buf, "\n");
2089 }
2090
2091 write_if_changed(&ns_deps_buf, fname);
2092 free(ns_deps_buf.p);
2093}
2094
2095struct dump_list {
2096 struct list_head list;
2097 const char *file;
2098};
2099
2100static void check_host_endian(void)
2101{
2102 static const union {
2103 short s;
2104 char c[2];
2105 } endian_test = { .c = {0x01, 0x02} };
2106
2107 switch (endian_test.s) {
2108 case 0x0102:
2109 host_is_big_endian = true;
2110 break;
2111 case 0x0201:
2112 host_is_big_endian = false;
2113 break;
2114 default:
2115 fatal("Unknown host endian\n");
2116 }
2117}
2118
2119int main(int argc, char **argv)
2120{
2121 struct module *mod;
2122 char *missing_namespace_deps = NULL;
2123 char *unused_exports_white_list = NULL;
2124 char *dump_write = NULL, *files_source = NULL;
2125 int opt;
2126 LIST_HEAD(dump_lists);
2127 struct dump_list *dl, *dl2;
2128
2129 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2130 switch (opt) {
2131 case 'e':
2132 external_module = true;
2133 break;
2134 case 'i':
2135 dl = xmalloc(sizeof(*dl));
2136 dl->file = optarg;
2137 list_add_tail(&dl->list, &dump_lists);
2138 break;
2139 case 'M':
2140 module_enabled = true;
2141 break;
2142 case 'm':
2143 modversions = true;
2144 break;
2145 case 'n':
2146 ignore_missing_files = true;
2147 break;
2148 case 'o':
2149 dump_write = optarg;
2150 break;
2151 case 'a':
2152 all_versions = true;
2153 break;
2154 case 'T':
2155 files_source = optarg;
2156 break;
2157 case 't':
2158 trim_unused_exports = true;
2159 break;
2160 case 'u':
2161 unused_exports_white_list = optarg;
2162 break;
2163 case 'W':
2164 extra_warn = true;
2165 break;
2166 case 'w':
2167 warn_unresolved = true;
2168 break;
2169 case 'E':
2170 sec_mismatch_warn_only = false;
2171 break;
2172 case 'N':
2173 allow_missing_ns_imports = true;
2174 break;
2175 case 'd':
2176 missing_namespace_deps = optarg;
2177 break;
2178 default:
2179 exit(1);
2180 }
2181 }
2182
2183 check_host_endian();
2184
2185 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2186 read_dump(dl->file);
2187 list_del(&dl->list);
2188 free(dl);
2189 }
2190
2191 while (optind < argc)
2192 read_symbols(argv[optind++]);
2193
2194 if (files_source)
2195 read_symbols_from_files(files_source);
2196
2197 list_for_each_entry(mod, &modules, list) {
2198 if (mod->dump_file || mod->is_vmlinux)
2199 continue;
2200
2201 check_modname_len(mod);
2202 check_exports(mod);
2203 }
2204
2205 if (unused_exports_white_list)
2206 handle_white_list_exports(unused_exports_white_list);
2207
2208 list_for_each_entry(mod, &modules, list) {
2209 if (mod->dump_file)
2210 continue;
2211
2212 if (mod->is_vmlinux)
2213 write_vmlinux_export_c_file(mod);
2214 else
2215 write_mod_c_file(mod);
2216 }
2217
2218 if (missing_namespace_deps)
2219 write_namespace_deps_files(missing_namespace_deps);
2220
2221 if (dump_write)
2222 write_dump(dump_write);
2223 if (sec_mismatch_count && !sec_mismatch_warn_only)
2224 error("Section mismatches detected.\n"
2225 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2226
2227 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2228 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2229 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2230
2231 return error_occurred ? 1 : 0;
2232}