projects/linux·blob v4.11-rc5 · refs

2520 lines · 66.0 KiB

1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include <limits.h>
19#include <stdbool.h>
20#include <errno.h>
21#include "modpost.h"
22#include "../../include/generated/autoconf.h"
23#include "../../include/linux/license.h"
24#include "../../include/linux/export.h"
25
26/* Are we using CONFIG_MODVERSIONS? */
27static int modversions = 0;
28/* Warn about undefined symbols? (do so if we have vmlinux) */
29static int have_vmlinux = 0;
30/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31static int all_versions = 0;
32/* If we are modposting external module set to 1 */
33static int external_module = 0;
34/* Warn about section mismatch in vmlinux if set to 1 */
35static int vmlinux_section_warnings = 1;
36/* Only warn about unresolved symbols */
37static int warn_unresolved = 0;
38/* How a symbol is exported */
39static int sec_mismatch_count = 0;
40static int sec_mismatch_verbose = 1;
41static int sec_mismatch_fatal = 0;
42/* ignore missing files */
43static int ignore_missing_files;
44
45enum export {
46 export_plain, export_unused, export_gpl,
47 export_unused_gpl, export_gpl_future, export_unknown
48};
49
50#define PRINTF __attribute__ ((format (printf, 1, 2)))
51
52PRINTF void fatal(const char *fmt, ...)
53{
54 va_list arglist;
55
56 fprintf(stderr, "FATAL: ");
57
58 va_start(arglist, fmt);
59 vfprintf(stderr, fmt, arglist);
60 va_end(arglist);
61
62 exit(1);
63}
64
65PRINTF void warn(const char *fmt, ...)
66{
67 va_list arglist;
68
69 fprintf(stderr, "WARNING: ");
70
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
73 va_end(arglist);
74}
75
76PRINTF void merror(const char *fmt, ...)
77{
78 va_list arglist;
79
80 fprintf(stderr, "ERROR: ");
81
82 va_start(arglist, fmt);
83 vfprintf(stderr, fmt, arglist);
84 va_end(arglist);
85}
86
87static inline bool strends(const char *str, const char *postfix)
88{
89 if (strlen(str) < strlen(postfix))
90 return false;
91
92 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
93}
94
95static int is_vmlinux(const char *modname)
96{
97 const char *myname;
98
99 myname = strrchr(modname, '/');
100 if (myname)
101 myname++;
102 else
103 myname = modname;
104
105 return (strcmp(myname, "vmlinux") == 0) ||
106 (strcmp(myname, "vmlinux.o") == 0);
107}
108
109void *do_nofail(void *ptr, const char *expr)
110{
111 if (!ptr)
112 fatal("modpost: Memory allocation failure: %s.\n", expr);
113
114 return ptr;
115}
116
117/* A list of all modules we processed */
118static struct module *modules;
119
120static struct module *find_module(char *modname)
121{
122 struct module *mod;
123
124 for (mod = modules; mod; mod = mod->next)
125 if (strcmp(mod->name, modname) == 0)
126 break;
127 return mod;
128}
129
130static struct module *new_module(const char *modname)
131{
132 struct module *mod;
133 char *p;
134
135 mod = NOFAIL(malloc(sizeof(*mod)));
136 memset(mod, 0, sizeof(*mod));
137 p = NOFAIL(strdup(modname));
138
139 /* strip trailing .o */
140 if (strends(p, ".o")) {
141 p[strlen(p) - 2] = '\0';
142 mod->is_dot_o = 1;
143 }
144
145 /* add to list */
146 mod->name = p;
147 mod->gpl_compatible = -1;
148 mod->next = modules;
149 modules = mod;
150
151 return mod;
152}
153
154/* A hash of all exported symbols,
155 * struct symbol is also used for lists of unresolved symbols */
156
157#define SYMBOL_HASH_SIZE 1024
158
159struct symbol {
160 struct symbol *next;
161 struct module *module;
162 unsigned int crc;
163 int crc_valid;
164 unsigned int weak:1;
165 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
166 unsigned int kernel:1; /* 1 if symbol is from kernel
167 * (only for external modules) **/
168 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
169 enum export export; /* Type of export */
170 char name[0];
171};
172
173static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
174
175/* This is based on the hash agorithm from gdbm, via tdb */
176static inline unsigned int tdb_hash(const char *name)
177{
178 unsigned value; /* Used to compute the hash value. */
179 unsigned i; /* Used to cycle through random values. */
180
181 /* Set the initial value from the key size. */
182 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
183 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
184
185 return (1103515243 * value + 12345);
186}
187
188/**
189 * Allocate a new symbols for use in the hash of exported symbols or
190 * the list of unresolved symbols per module
191 **/
192static struct symbol *alloc_symbol(const char *name, unsigned int weak,
193 struct symbol *next)
194{
195 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
196
197 memset(s, 0, sizeof(*s));
198 strcpy(s->name, name);
199 s->weak = weak;
200 s->next = next;
201 return s;
202}
203
204/* For the hash of exported symbols */
205static struct symbol *new_symbol(const char *name, struct module *module,
206 enum export export)
207{
208 unsigned int hash;
209 struct symbol *new;
210
211 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
212 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
213 new->module = module;
214 new->export = export;
215 return new;
216}
217
218static struct symbol *find_symbol(const char *name)
219{
220 struct symbol *s;
221
222 /* For our purposes, .foo matches foo. PPC64 needs this. */
223 if (name[0] == '.')
224 name++;
225
226 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
227 if (strcmp(s->name, name) == 0)
228 return s;
229 }
230 return NULL;
231}
232
233static const struct {
234 const char *str;
235 enum export export;
236} export_list[] = {
237 { .str = "EXPORT_SYMBOL", .export = export_plain },
238 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
239 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
240 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
241 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
242 { .str = "(unknown)", .export = export_unknown },
243};
244
245
246static const char *export_str(enum export ex)
247{
248 return export_list[ex].str;
249}
250
251static enum export export_no(const char *s)
252{
253 int i;
254
255 if (!s)
256 return export_unknown;
257 for (i = 0; export_list[i].export != export_unknown; i++) {
258 if (strcmp(export_list[i].str, s) == 0)
259 return export_list[i].export;
260 }
261 return export_unknown;
262}
263
264static const char *sec_name(struct elf_info *elf, int secindex);
265
266#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
267
268static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
269{
270 const char *secname = sec_name(elf, sec);
271
272 if (strstarts(secname, "___ksymtab+"))
273 return export_plain;
274 else if (strstarts(secname, "___ksymtab_unused+"))
275 return export_unused;
276 else if (strstarts(secname, "___ksymtab_gpl+"))
277 return export_gpl;
278 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
279 return export_unused_gpl;
280 else if (strstarts(secname, "___ksymtab_gpl_future+"))
281 return export_gpl_future;
282 else
283 return export_unknown;
284}
285
286static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
287{
288 if (sec == elf->export_sec)
289 return export_plain;
290 else if (sec == elf->export_unused_sec)
291 return export_unused;
292 else if (sec == elf->export_gpl_sec)
293 return export_gpl;
294 else if (sec == elf->export_unused_gpl_sec)
295 return export_unused_gpl;
296 else if (sec == elf->export_gpl_future_sec)
297 return export_gpl_future;
298 else
299 return export_unknown;
300}
301
302/**
303 * Add an exported symbol - it may have already been added without a
304 * CRC, in this case just update the CRC
305 **/
306static struct symbol *sym_add_exported(const char *name, struct module *mod,
307 enum export export)
308{
309 struct symbol *s = find_symbol(name);
310
311 if (!s) {
312 s = new_symbol(name, mod, export);
313 } else {
314 if (!s->preloaded) {
315 warn("%s: '%s' exported twice. Previous export "
316 "was in %s%s\n", mod->name, name,
317 s->module->name,
318 is_vmlinux(s->module->name) ?"":".ko");
319 } else {
320 /* In case Module.symvers was out of date */
321 s->module = mod;
322 }
323 }
324 s->preloaded = 0;
325 s->vmlinux = is_vmlinux(mod->name);
326 s->kernel = 0;
327 s->export = export;
328 return s;
329}
330
331static void sym_update_crc(const char *name, struct module *mod,
332 unsigned int crc, enum export export)
333{
334 struct symbol *s = find_symbol(name);
335
336 if (!s) {
337 s = new_symbol(name, mod, export);
338 /* Don't complain when we find it later. */
339 s->preloaded = 1;
340 }
341 s->crc = crc;
342 s->crc_valid = 1;
343}
344
345void *grab_file(const char *filename, unsigned long *size)
346{
347 struct stat st;
348 void *map = MAP_FAILED;
349 int fd;
350
351 fd = open(filename, O_RDONLY);
352 if (fd < 0)
353 return NULL;
354 if (fstat(fd, &st))
355 goto failed;
356
357 *size = st.st_size;
358 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
359
360failed:
361 close(fd);
362 if (map == MAP_FAILED)
363 return NULL;
364 return map;
365}
366
367/**
368 * Return a copy of the next line in a mmap'ed file.
369 * spaces in the beginning of the line is trimmed away.
370 * Return a pointer to a static buffer.
371 **/
372char *get_next_line(unsigned long *pos, void *file, unsigned long size)
373{
374 static char line[4096];
375 int skip = 1;
376 size_t len = 0;
377 signed char *p = (signed char *)file + *pos;
378 char *s = line;
379
380 for (; *pos < size ; (*pos)++) {
381 if (skip && isspace(*p)) {
382 p++;
383 continue;
384 }
385 skip = 0;
386 if (*p != '\n' && (*pos < size)) {
387 len++;
388 *s++ = *p++;
389 if (len > 4095)
390 break; /* Too long, stop */
391 } else {
392 /* End of string */
393 *s = '\0';
394 return line;
395 }
396 }
397 /* End of buffer */
398 return NULL;
399}
400
401void release_file(void *file, unsigned long size)
402{
403 munmap(file, size);
404}
405
406static int parse_elf(struct elf_info *info, const char *filename)
407{
408 unsigned int i;
409 Elf_Ehdr *hdr;
410 Elf_Shdr *sechdrs;
411 Elf_Sym *sym;
412 const char *secstrings;
413 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
414
415 hdr = grab_file(filename, &info->size);
416 if (!hdr) {
417 if (ignore_missing_files) {
418 fprintf(stderr, "%s: %s (ignored)\n", filename,
419 strerror(errno));
420 return 0;
421 }
422 perror(filename);
423 exit(1);
424 }
425 info->hdr = hdr;
426 if (info->size < sizeof(*hdr)) {
427 /* file too small, assume this is an empty .o file */
428 return 0;
429 }
430 /* Is this a valid ELF file? */
431 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
432 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
433 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
434 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
435 /* Not an ELF file - silently ignore it */
436 return 0;
437 }
438 /* Fix endianness in ELF header */
439 hdr->e_type = TO_NATIVE(hdr->e_type);
440 hdr->e_machine = TO_NATIVE(hdr->e_machine);
441 hdr->e_version = TO_NATIVE(hdr->e_version);
442 hdr->e_entry = TO_NATIVE(hdr->e_entry);
443 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
444 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
445 hdr->e_flags = TO_NATIVE(hdr->e_flags);
446 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
447 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
448 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
449 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
450 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
451 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
452 sechdrs = (void *)hdr + hdr->e_shoff;
453 info->sechdrs = sechdrs;
454
455 /* Check if file offset is correct */
456 if (hdr->e_shoff > info->size) {
457 fatal("section header offset=%lu in file '%s' is bigger than "
458 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
459 filename, info->size);
460 return 0;
461 }
462
463 if (hdr->e_shnum == SHN_UNDEF) {
464 /*
465 * There are more than 64k sections,
466 * read count from .sh_size.
467 */
468 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
469 }
470 else {
471 info->num_sections = hdr->e_shnum;
472 }
473 if (hdr->e_shstrndx == SHN_XINDEX) {
474 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
475 }
476 else {
477 info->secindex_strings = hdr->e_shstrndx;
478 }
479
480 /* Fix endianness in section headers */
481 for (i = 0; i < info->num_sections; i++) {
482 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
483 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
484 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
485 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
486 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
487 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
488 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
489 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
490 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
491 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
492 }
493 /* Find symbol table. */
494 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
495 for (i = 1; i < info->num_sections; i++) {
496 const char *secname;
497 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
498
499 if (!nobits && sechdrs[i].sh_offset > info->size) {
500 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
501 "sizeof(*hrd)=%zu\n", filename,
502 (unsigned long)sechdrs[i].sh_offset,
503 sizeof(*hdr));
504 return 0;
505 }
506 secname = secstrings + sechdrs[i].sh_name;
507 if (strcmp(secname, ".modinfo") == 0) {
508 if (nobits)
509 fatal("%s has NOBITS .modinfo\n", filename);
510 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
511 info->modinfo_len = sechdrs[i].sh_size;
512 } else if (strcmp(secname, "__ksymtab") == 0)
513 info->export_sec = i;
514 else if (strcmp(secname, "__ksymtab_unused") == 0)
515 info->export_unused_sec = i;
516 else if (strcmp(secname, "__ksymtab_gpl") == 0)
517 info->export_gpl_sec = i;
518 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
519 info->export_unused_gpl_sec = i;
520 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
521 info->export_gpl_future_sec = i;
522
523 if (sechdrs[i].sh_type == SHT_SYMTAB) {
524 unsigned int sh_link_idx;
525 symtab_idx = i;
526 info->symtab_start = (void *)hdr +
527 sechdrs[i].sh_offset;
528 info->symtab_stop = (void *)hdr +
529 sechdrs[i].sh_offset + sechdrs[i].sh_size;
530 sh_link_idx = sechdrs[i].sh_link;
531 info->strtab = (void *)hdr +
532 sechdrs[sh_link_idx].sh_offset;
533 }
534
535 /* 32bit section no. table? ("more than 64k sections") */
536 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
537 symtab_shndx_idx = i;
538 info->symtab_shndx_start = (void *)hdr +
539 sechdrs[i].sh_offset;
540 info->symtab_shndx_stop = (void *)hdr +
541 sechdrs[i].sh_offset + sechdrs[i].sh_size;
542 }
543 }
544 if (!info->symtab_start)
545 fatal("%s has no symtab?\n", filename);
546
547 /* Fix endianness in symbols */
548 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
549 sym->st_shndx = TO_NATIVE(sym->st_shndx);
550 sym->st_name = TO_NATIVE(sym->st_name);
551 sym->st_value = TO_NATIVE(sym->st_value);
552 sym->st_size = TO_NATIVE(sym->st_size);
553 }
554
555 if (symtab_shndx_idx != ~0U) {
556 Elf32_Word *p;
557 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
558 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
559 filename, sechdrs[symtab_shndx_idx].sh_link,
560 symtab_idx);
561 /* Fix endianness */
562 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
563 p++)
564 *p = TO_NATIVE(*p);
565 }
566
567 return 1;
568}
569
570static void parse_elf_finish(struct elf_info *info)
571{
572 release_file(info->hdr, info->size);
573}
574
575static int ignore_undef_symbol(struct elf_info *info, const char *symname)
576{
577 /* ignore __this_module, it will be resolved shortly */
578 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
579 return 1;
580 /* ignore global offset table */
581 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
582 return 1;
583 if (info->hdr->e_machine == EM_PPC)
584 /* Special register function linked on all modules during final link of .ko */
585 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
586 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
587 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
588 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
589 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
590 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
591 return 1;
592 if (info->hdr->e_machine == EM_PPC64)
593 /* Special register function linked on all modules during final link of .ko */
594 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
595 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
596 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
597 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0 ||
598 strcmp(symname, ".TOC.") == 0)
599 return 1;
600 /* Do not ignore this symbol */
601 return 0;
602}
603
604#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
605#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
606
607static void handle_modversions(struct module *mod, struct elf_info *info,
608 Elf_Sym *sym, const char *symname)
609{
610 unsigned int crc;
611 enum export export;
612 bool is_crc = false;
613
614 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
615 strncmp(symname, "__ksymtab", 9) == 0)
616 export = export_from_secname(info, get_secindex(info, sym));
617 else
618 export = export_from_sec(info, get_secindex(info, sym));
619
620 /* CRC'd symbol */
621 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
622 is_crc = true;
623 crc = (unsigned int) sym->st_value;
624 if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
625 unsigned int *crcp;
626
627 /* symbol points to the CRC in the ELF object */
628 crcp = (void *)info->hdr + sym->st_value +
629 info->sechdrs[sym->st_shndx].sh_offset -
630 (info->hdr->e_type != ET_REL ?
631 info->sechdrs[sym->st_shndx].sh_addr : 0);
632 crc = *crcp;
633 }
634 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
635 export);
636 }
637
638 switch (sym->st_shndx) {
639 case SHN_COMMON:
640 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
641 /* Should warn here, but modpost runs before the linker */
642 } else
643 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
644 break;
645 case SHN_UNDEF:
646 /* undefined symbol */
647 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
648 ELF_ST_BIND(sym->st_info) != STB_WEAK)
649 break;
650 if (ignore_undef_symbol(info, symname))
651 break;
652/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
653#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
654/* add compatibility with older glibc */
655#ifndef STT_SPARC_REGISTER
656#define STT_SPARC_REGISTER STT_REGISTER
657#endif
658 if (info->hdr->e_machine == EM_SPARC ||
659 info->hdr->e_machine == EM_SPARCV9) {
660 /* Ignore register directives. */
661 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
662 break;
663 if (symname[0] == '.') {
664 char *munged = strdup(symname);
665 munged[0] = '_';
666 munged[1] = toupper(munged[1]);
667 symname = munged;
668 }
669 }
670#endif
671
672#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
673 if (symname[0] != '_')
674 break;
675 else
676 symname++;
677#endif
678 if (is_crc) {
679 const char *e = is_vmlinux(mod->name) ?"":".ko";
680 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n", symname + strlen(CRC_PFX), mod->name, e);
681 }
682 mod->unres = alloc_symbol(symname,
683 ELF_ST_BIND(sym->st_info) == STB_WEAK,
684 mod->unres);
685 break;
686 default:
687 /* All exported symbols */
688 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
689 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
690 export);
691 }
692 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
693 mod->has_init = 1;
694 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
695 mod->has_cleanup = 1;
696 break;
697 }
698}
699
700/**
701 * Parse tag=value strings from .modinfo section
702 **/
703static char *next_string(char *string, unsigned long *secsize)
704{
705 /* Skip non-zero chars */
706 while (string[0]) {
707 string++;
708 if ((*secsize)-- <= 1)
709 return NULL;
710 }
711
712 /* Skip any zero padding. */
713 while (!string[0]) {
714 string++;
715 if ((*secsize)-- <= 1)
716 return NULL;
717 }
718 return string;
719}
720
721static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
722 const char *tag, char *info)
723{
724 char *p;
725 unsigned int taglen = strlen(tag);
726 unsigned long size = modinfo_len;
727
728 if (info) {
729 size -= info - (char *)modinfo;
730 modinfo = next_string(info, &size);
731 }
732
733 for (p = modinfo; p; p = next_string(p, &size)) {
734 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
735 return p + taglen + 1;
736 }
737 return NULL;
738}
739
740static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
741 const char *tag)
742
743{
744 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
745}
746
747/**
748 * Test if string s ends in string sub
749 * return 0 if match
750 **/
751static int strrcmp(const char *s, const char *sub)
752{
753 int slen, sublen;
754
755 if (!s || !sub)
756 return 1;
757
758 slen = strlen(s);
759 sublen = strlen(sub);
760
761 if ((slen == 0) || (sublen == 0))
762 return 1;
763
764 if (sublen > slen)
765 return 1;
766
767 return memcmp(s + slen - sublen, sub, sublen);
768}
769
770static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
771{
772 if (sym)
773 return elf->strtab + sym->st_name;
774 else
775 return "(unknown)";
776}
777
778static const char *sec_name(struct elf_info *elf, int secindex)
779{
780 Elf_Shdr *sechdrs = elf->sechdrs;
781 return (void *)elf->hdr +
782 elf->sechdrs[elf->secindex_strings].sh_offset +
783 sechdrs[secindex].sh_name;
784}
785
786static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
787{
788 return (void *)elf->hdr +
789 elf->sechdrs[elf->secindex_strings].sh_offset +
790 sechdr->sh_name;
791}
792
793/* The pattern is an array of simple patterns.
794 * "foo" will match an exact string equal to "foo"
795 * "*foo" will match a string that ends with "foo"
796 * "foo*" will match a string that begins with "foo"
797 * "*foo*" will match a string that contains "foo"
798 */
799static int match(const char *sym, const char * const pat[])
800{
801 const char *p;
802 while (*pat) {
803 p = *pat++;
804 const char *endp = p + strlen(p) - 1;
805
806 /* "*foo*" */
807 if (*p == '*' && *endp == '*') {
808 char *here, *bare = strndup(p + 1, strlen(p) - 2);
809
810 here = strstr(sym, bare);
811 free(bare);
812 if (here != NULL)
813 return 1;
814 }
815 /* "*foo" */
816 else if (*p == '*') {
817 if (strrcmp(sym, p + 1) == 0)
818 return 1;
819 }
820 /* "foo*" */
821 else if (*endp == '*') {
822 if (strncmp(sym, p, strlen(p) - 1) == 0)
823 return 1;
824 }
825 /* no wildcards */
826 else {
827 if (strcmp(p, sym) == 0)
828 return 1;
829 }
830 }
831 /* no match */
832 return 0;
833}
834
835/* sections that we do not want to do full section mismatch check on */
836static const char *const section_white_list[] =
837{
838 ".comment*",
839 ".debug*",
840 ".cranges", /* sh64 */
841 ".zdebug*", /* Compressed debug sections. */
842 ".GCC-command-line", /* mn10300 */
843 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
844 ".mdebug*", /* alpha, score, mips etc. */
845 ".pdr", /* alpha, score, mips etc. */
846 ".stab*",
847 ".note*",
848 ".got*",
849 ".toc*",
850 ".xt.prop", /* xtensa */
851 ".xt.lit", /* xtensa */
852 ".arcextmap*", /* arc */
853 ".gnu.linkonce.arcext*", /* arc : modules */
854 ".cmem*", /* EZchip */
855 ".fmt_slot*", /* EZchip */
856 ".gnu.lto*",
857 ".discard.*",
858 NULL
859};
860
861/*
862 * This is used to find sections missing the SHF_ALLOC flag.
863 * The cause of this is often a section specified in assembler
864 * without "ax" / "aw".
865 */
866static void check_section(const char *modname, struct elf_info *elf,
867 Elf_Shdr *sechdr)
868{
869 const char *sec = sech_name(elf, sechdr);
870
871 if (sechdr->sh_type == SHT_PROGBITS &&
872 !(sechdr->sh_flags & SHF_ALLOC) &&
873 !match(sec, section_white_list)) {
874 warn("%s (%s): unexpected non-allocatable section.\n"
875 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
876 "Note that for example <linux/init.h> contains\n"
877 "section definitions for use in .S files.\n\n",
878 modname, sec);
879 }
880}
881
882
883
884#define ALL_INIT_DATA_SECTIONS \
885 ".init.setup", ".init.rodata", ".meminit.rodata", \
886 ".init.data", ".meminit.data"
887#define ALL_EXIT_DATA_SECTIONS \
888 ".exit.data", ".memexit.data"
889
890#define ALL_INIT_TEXT_SECTIONS \
891 ".init.text", ".meminit.text"
892#define ALL_EXIT_TEXT_SECTIONS \
893 ".exit.text", ".memexit.text"
894
895#define ALL_PCI_INIT_SECTIONS \
896 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
897 ".pci_fixup_enable", ".pci_fixup_resume", \
898 ".pci_fixup_resume_early", ".pci_fixup_suspend"
899
900#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
901#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
902
903#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
904#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
905
906#define DATA_SECTIONS ".data", ".data.rel"
907#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
908 ".kprobes.text", ".cpuidle.text"
909#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
910 ".fixup", ".entry.text", ".exception.text", ".text.*", \
911 ".coldtext"
912
913#define INIT_SECTIONS ".init.*"
914#define MEM_INIT_SECTIONS ".meminit.*"
915
916#define EXIT_SECTIONS ".exit.*"
917#define MEM_EXIT_SECTIONS ".memexit.*"
918
919#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
920 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
921
922/* init data sections */
923static const char *const init_data_sections[] =
924 { ALL_INIT_DATA_SECTIONS, NULL };
925
926/* all init sections */
927static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
928
929/* All init and exit sections (code + data) */
930static const char *const init_exit_sections[] =
931 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
932
933/* all text sections */
934static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
935
936/* data section */
937static const char *const data_sections[] = { DATA_SECTIONS, NULL };
938
939
940/* symbols in .data that may refer to init/exit sections */
941#define DEFAULT_SYMBOL_WHITE_LIST \
942 "*driver", \
943 "*_template", /* scsi uses *_template a lot */ \
944 "*_timer", /* arm uses ops structures named _timer a lot */ \
945 "*_sht", /* scsi also used *_sht to some extent */ \
946 "*_ops", \
947 "*_probe", \
948 "*_probe_one", \
949 "*_console"
950
951static const char *const head_sections[] = { ".head.text*", NULL };
952static const char *const linker_symbols[] =
953 { "__init_begin", "_sinittext", "_einittext", NULL };
954static const char *const optim_symbols[] = { "*.constprop.*", NULL };
955
956enum mismatch {
957 TEXT_TO_ANY_INIT,
958 DATA_TO_ANY_INIT,
959 TEXT_TO_ANY_EXIT,
960 DATA_TO_ANY_EXIT,
961 XXXINIT_TO_SOME_INIT,
962 XXXEXIT_TO_SOME_EXIT,
963 ANY_INIT_TO_ANY_EXIT,
964 ANY_EXIT_TO_ANY_INIT,
965 EXPORT_TO_INIT_EXIT,
966 EXTABLE_TO_NON_TEXT,
967};
968
969/**
970 * Describe how to match sections on different criterias:
971 *
972 * @fromsec: Array of sections to be matched.
973 *
974 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
975 * this array is forbidden (black-list). Can be empty.
976 *
977 * @good_tosec: Relocations applied to a section in @fromsec must be
978 * targetting sections in this array (white-list). Can be empty.
979 *
980 * @mismatch: Type of mismatch.
981 *
982 * @symbol_white_list: Do not match a relocation to a symbol in this list
983 * even if it is targetting a section in @bad_to_sec.
984 *
985 * @handler: Specific handler to call when a match is found. If NULL,
986 * default_mismatch_handler() will be called.
987 *
988 */
989struct sectioncheck {
990 const char *fromsec[20];
991 const char *bad_tosec[20];
992 const char *good_tosec[20];
993 enum mismatch mismatch;
994 const char *symbol_white_list[20];
995 void (*handler)(const char *modname, struct elf_info *elf,
996 const struct sectioncheck* const mismatch,
997 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
998
999};
1000
1001static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1002 const struct sectioncheck* const mismatch,
1003 Elf_Rela *r, Elf_Sym *sym,
1004 const char *fromsec);
1005
1006static const struct sectioncheck sectioncheck[] = {
1007/* Do not reference init/exit code/data from
1008 * normal code and data
1009 */
1010{
1011 .fromsec = { TEXT_SECTIONS, NULL },
1012 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1013 .mismatch = TEXT_TO_ANY_INIT,
1014 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1015},
1016{
1017 .fromsec = { DATA_SECTIONS, NULL },
1018 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1019 .mismatch = DATA_TO_ANY_INIT,
1020 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1021},
1022{
1023 .fromsec = { DATA_SECTIONS, NULL },
1024 .bad_tosec = { INIT_SECTIONS, NULL },
1025 .mismatch = DATA_TO_ANY_INIT,
1026 .symbol_white_list = {
1027 "*_template", "*_timer", "*_sht", "*_ops",
1028 "*_probe", "*_probe_one", "*_console", NULL
1029 },
1030},
1031{
1032 .fromsec = { TEXT_SECTIONS, NULL },
1033 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1034 .mismatch = TEXT_TO_ANY_EXIT,
1035 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1036},
1037{
1038 .fromsec = { DATA_SECTIONS, NULL },
1039 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1040 .mismatch = DATA_TO_ANY_EXIT,
1041 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1042},
1043/* Do not reference init code/data from meminit code/data */
1044{
1045 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1046 .bad_tosec = { INIT_SECTIONS, NULL },
1047 .mismatch = XXXINIT_TO_SOME_INIT,
1048 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1049},
1050/* Do not reference exit code/data from memexit code/data */
1051{
1052 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1053 .bad_tosec = { EXIT_SECTIONS, NULL },
1054 .mismatch = XXXEXIT_TO_SOME_EXIT,
1055 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1056},
1057/* Do not use exit code/data from init code */
1058{
1059 .fromsec = { ALL_INIT_SECTIONS, NULL },
1060 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1061 .mismatch = ANY_INIT_TO_ANY_EXIT,
1062 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1063},
1064/* Do not use init code/data from exit code */
1065{
1066 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1067 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1068 .mismatch = ANY_EXIT_TO_ANY_INIT,
1069 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1070},
1071{
1072 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1073 .bad_tosec = { INIT_SECTIONS, NULL },
1074 .mismatch = ANY_INIT_TO_ANY_EXIT,
1075 .symbol_white_list = { NULL },
1076},
1077/* Do not export init/exit functions or data */
1078{
1079 .fromsec = { "__ksymtab*", NULL },
1080 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1081 .mismatch = EXPORT_TO_INIT_EXIT,
1082 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1083},
1084{
1085 .fromsec = { "__ex_table", NULL },
1086 /* If you're adding any new black-listed sections in here, consider
1087 * adding a special 'printer' for them in scripts/check_extable.
1088 */
1089 .bad_tosec = { ".altinstr_replacement", NULL },
1090 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1091 .mismatch = EXTABLE_TO_NON_TEXT,
1092 .handler = extable_mismatch_handler,
1093}
1094};
1095
1096static const struct sectioncheck *section_mismatch(
1097 const char *fromsec, const char *tosec)
1098{
1099 int i;
1100 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1101 const struct sectioncheck *check = &sectioncheck[0];
1102
1103 /*
1104 * The target section could be the SHT_NUL section when we're
1105 * handling relocations to un-resolved symbols, trying to match it
1106 * doesn't make much sense and causes build failures on parisc and
1107 * mn10300 architectures.
1108 */
1109 if (*tosec == '\0')
1110 return NULL;
1111
1112 for (i = 0; i < elems; i++) {
1113 if (match(fromsec, check->fromsec)) {
1114 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1115 return check;
1116 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1117 return check;
1118 }
1119 check++;
1120 }
1121 return NULL;
1122}
1123
1124/**
1125 * Whitelist to allow certain references to pass with no warning.
1126 *
1127 * Pattern 1:
1128 * If a module parameter is declared __initdata and permissions=0
1129 * then this is legal despite the warning generated.
1130 * We cannot see value of permissions here, so just ignore
1131 * this pattern.
1132 * The pattern is identified by:
1133 * tosec = .init.data
1134 * fromsec = .data*
1135 * atsym =__param*
1136 *
1137 * Pattern 1a:
1138 * module_param_call() ops can refer to __init set function if permissions=0
1139 * The pattern is identified by:
1140 * tosec = .init.text
1141 * fromsec = .data*
1142 * atsym = __param_ops_*
1143 *
1144 * Pattern 2:
1145 * Many drivers utilise a *driver container with references to
1146 * add, remove, probe functions etc.
1147 * the pattern is identified by:
1148 * tosec = init or exit section
1149 * fromsec = data section
1150 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1151 * *probe_one, *_console, *_timer
1152 *
1153 * Pattern 3:
1154 * Whitelist all references from .head.text to any init section
1155 *
1156 * Pattern 4:
1157 * Some symbols belong to init section but still it is ok to reference
1158 * these from non-init sections as these symbols don't have any memory
1159 * allocated for them and symbol address and value are same. So even
1160 * if init section is freed, its ok to reference those symbols.
1161 * For ex. symbols marking the init section boundaries.
1162 * This pattern is identified by
1163 * refsymname = __init_begin, _sinittext, _einittext
1164 *
1165 * Pattern 5:
1166 * GCC may optimize static inlines when fed constant arg(s) resulting
1167 * in functions like cpumask_empty() -- generating an associated symbol
1168 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1169 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1170 * meaningless section warning. May need to add isra symbols too...
1171 * This pattern is identified by
1172 * tosec = init section
1173 * fromsec = text section
1174 * refsymname = *.constprop.*
1175 *
1176 **/
1177static int secref_whitelist(const struct sectioncheck *mismatch,
1178 const char *fromsec, const char *fromsym,
1179 const char *tosec, const char *tosym)
1180{
1181 /* Check for pattern 1 */
1182 if (match(tosec, init_data_sections) &&
1183 match(fromsec, data_sections) &&
1184 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1185 return 0;
1186
1187 /* Check for pattern 1a */
1188 if (strcmp(tosec, ".init.text") == 0 &&
1189 match(fromsec, data_sections) &&
1190 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1191 return 0;
1192
1193 /* Check for pattern 2 */
1194 if (match(tosec, init_exit_sections) &&
1195 match(fromsec, data_sections) &&
1196 match(fromsym, mismatch->symbol_white_list))
1197 return 0;
1198
1199 /* Check for pattern 3 */
1200 if (match(fromsec, head_sections) &&
1201 match(tosec, init_sections))
1202 return 0;
1203
1204 /* Check for pattern 4 */
1205 if (match(tosym, linker_symbols))
1206 return 0;
1207
1208 /* Check for pattern 5 */
1209 if (match(fromsec, text_sections) &&
1210 match(tosec, init_sections) &&
1211 match(fromsym, optim_symbols))
1212 return 0;
1213
1214 return 1;
1215}
1216
1217/**
1218 * Find symbol based on relocation record info.
1219 * In some cases the symbol supplied is a valid symbol so
1220 * return refsym. If st_name != 0 we assume this is a valid symbol.
1221 * In other cases the symbol needs to be looked up in the symbol table
1222 * based on section and address.
1223 * **/
1224static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1225 Elf_Sym *relsym)
1226{
1227 Elf_Sym *sym;
1228 Elf_Sym *near = NULL;
1229 Elf64_Sword distance = 20;
1230 Elf64_Sword d;
1231 unsigned int relsym_secindex;
1232
1233 if (relsym->st_name != 0)
1234 return relsym;
1235
1236 relsym_secindex = get_secindex(elf, relsym);
1237 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1238 if (get_secindex(elf, sym) != relsym_secindex)
1239 continue;
1240 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1241 continue;
1242 if (sym->st_value == addr)
1243 return sym;
1244 /* Find a symbol nearby - addr are maybe negative */
1245 d = sym->st_value - addr;
1246 if (d < 0)
1247 d = addr - sym->st_value;
1248 if (d < distance) {
1249 distance = d;
1250 near = sym;
1251 }
1252 }
1253 /* We need a close match */
1254 if (distance < 20)
1255 return near;
1256 else
1257 return NULL;
1258}
1259
1260static inline int is_arm_mapping_symbol(const char *str)
1261{
1262 return str[0] == '$' && strchr("axtd", str[1])
1263 && (str[2] == '\0' || str[2] == '.');
1264}
1265
1266/*
1267 * If there's no name there, ignore it; likewise, ignore it if it's
1268 * one of the magic symbols emitted used by current ARM tools.
1269 *
1270 * Otherwise if find_symbols_between() returns those symbols, they'll
1271 * fail the whitelist tests and cause lots of false alarms ... fixable
1272 * only by merging __exit and __init sections into __text, bloating
1273 * the kernel (which is especially evil on embedded platforms).
1274 */
1275static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1276{
1277 const char *name = elf->strtab + sym->st_name;
1278
1279 if (!name || !strlen(name))
1280 return 0;
1281 return !is_arm_mapping_symbol(name);
1282}
1283
1284/*
1285 * Find symbols before or equal addr and after addr - in the section sec.
1286 * If we find two symbols with equal offset prefer one with a valid name.
1287 * The ELF format may have a better way to detect what type of symbol
1288 * it is, but this works for now.
1289 **/
1290static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1291 const char *sec)
1292{
1293 Elf_Sym *sym;
1294 Elf_Sym *near = NULL;
1295 Elf_Addr distance = ~0;
1296
1297 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1298 const char *symsec;
1299
1300 if (is_shndx_special(sym->st_shndx))
1301 continue;
1302 symsec = sec_name(elf, get_secindex(elf, sym));
1303 if (strcmp(symsec, sec) != 0)
1304 continue;
1305 if (!is_valid_name(elf, sym))
1306 continue;
1307 if (sym->st_value <= addr) {
1308 if ((addr - sym->st_value) < distance) {
1309 distance = addr - sym->st_value;
1310 near = sym;
1311 } else if ((addr - sym->st_value) == distance) {
1312 near = sym;
1313 }
1314 }
1315 }
1316 return near;
1317}
1318
1319/*
1320 * Convert a section name to the function/data attribute
1321 * .init.text => __init
1322 * .memexitconst => __memconst
1323 * etc.
1324 *
1325 * The memory of returned value has been allocated on a heap. The user of this
1326 * method should free it after usage.
1327*/
1328static char *sec2annotation(const char *s)
1329{
1330 if (match(s, init_exit_sections)) {
1331 char *p = malloc(20);
1332 char *r = p;
1333
1334 *p++ = '_';
1335 *p++ = '_';
1336 if (*s == '.')
1337 s++;
1338 while (*s && *s != '.')
1339 *p++ = *s++;
1340 *p = '\0';
1341 if (*s == '.')
1342 s++;
1343 if (strstr(s, "rodata") != NULL)
1344 strcat(p, "const ");
1345 else if (strstr(s, "data") != NULL)
1346 strcat(p, "data ");
1347 else
1348 strcat(p, " ");
1349 return r;
1350 } else {
1351 return strdup("");
1352 }
1353}
1354
1355static int is_function(Elf_Sym *sym)
1356{
1357 if (sym)
1358 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1359 else
1360 return -1;
1361}
1362
1363static void print_section_list(const char * const list[20])
1364{
1365 const char *const *s = list;
1366
1367 while (*s) {
1368 fprintf(stderr, "%s", *s);
1369 s++;
1370 if (*s)
1371 fprintf(stderr, ", ");
1372 }
1373 fprintf(stderr, "\n");
1374}
1375
1376static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1377{
1378 switch (is_func) {
1379 case 0: *name = "variable"; *name_p = ""; break;
1380 case 1: *name = "function"; *name_p = "()"; break;
1381 default: *name = "(unknown reference)"; *name_p = ""; break;
1382 }
1383}
1384
1385/*
1386 * Print a warning about a section mismatch.
1387 * Try to find symbols near it so user can find it.
1388 * Check whitelist before warning - it may be a false positive.
1389 */
1390static void report_sec_mismatch(const char *modname,
1391 const struct sectioncheck *mismatch,
1392 const char *fromsec,
1393 unsigned long long fromaddr,
1394 const char *fromsym,
1395 int from_is_func,
1396 const char *tosec, const char *tosym,
1397 int to_is_func)
1398{
1399 const char *from, *from_p;
1400 const char *to, *to_p;
1401 char *prl_from;
1402 char *prl_to;
1403
1404 sec_mismatch_count++;
1405 if (!sec_mismatch_verbose)
1406 return;
1407
1408 get_pretty_name(from_is_func, &from, &from_p);
1409 get_pretty_name(to_is_func, &to, &to_p);
1410
1411 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1412 "to the %s %s:%s%s\n",
1413 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1414 tosym, to_p);
1415
1416 switch (mismatch->mismatch) {
1417 case TEXT_TO_ANY_INIT:
1418 prl_from = sec2annotation(fromsec);
1419 prl_to = sec2annotation(tosec);
1420 fprintf(stderr,
1421 "The function %s%s() references\n"
1422 "the %s %s%s%s.\n"
1423 "This is often because %s lacks a %s\n"
1424 "annotation or the annotation of %s is wrong.\n",
1425 prl_from, fromsym,
1426 to, prl_to, tosym, to_p,
1427 fromsym, prl_to, tosym);
1428 free(prl_from);
1429 free(prl_to);
1430 break;
1431 case DATA_TO_ANY_INIT: {
1432 prl_to = sec2annotation(tosec);
1433 fprintf(stderr,
1434 "The variable %s references\n"
1435 "the %s %s%s%s\n"
1436 "If the reference is valid then annotate the\n"
1437 "variable with __init* or __refdata (see linux/init.h) "
1438 "or name the variable:\n",
1439 fromsym, to, prl_to, tosym, to_p);
1440 print_section_list(mismatch->symbol_white_list);
1441 free(prl_to);
1442 break;
1443 }
1444 case TEXT_TO_ANY_EXIT:
1445 prl_to = sec2annotation(tosec);
1446 fprintf(stderr,
1447 "The function %s() references a %s in an exit section.\n"
1448 "Often the %s %s%s has valid usage outside the exit section\n"
1449 "and the fix is to remove the %sannotation of %s.\n",
1450 fromsym, to, to, tosym, to_p, prl_to, tosym);
1451 free(prl_to);
1452 break;
1453 case DATA_TO_ANY_EXIT: {
1454 prl_to = sec2annotation(tosec);
1455 fprintf(stderr,
1456 "The variable %s references\n"
1457 "the %s %s%s%s\n"
1458 "If the reference is valid then annotate the\n"
1459 "variable with __exit* (see linux/init.h) or "
1460 "name the variable:\n",
1461 fromsym, to, prl_to, tosym, to_p);
1462 print_section_list(mismatch->symbol_white_list);
1463 free(prl_to);
1464 break;
1465 }
1466 case XXXINIT_TO_SOME_INIT:
1467 case XXXEXIT_TO_SOME_EXIT:
1468 prl_from = sec2annotation(fromsec);
1469 prl_to = sec2annotation(tosec);
1470 fprintf(stderr,
1471 "The %s %s%s%s references\n"
1472 "a %s %s%s%s.\n"
1473 "If %s is only used by %s then\n"
1474 "annotate %s with a matching annotation.\n",
1475 from, prl_from, fromsym, from_p,
1476 to, prl_to, tosym, to_p,
1477 tosym, fromsym, tosym);
1478 free(prl_from);
1479 free(prl_to);
1480 break;
1481 case ANY_INIT_TO_ANY_EXIT:
1482 prl_from = sec2annotation(fromsec);
1483 prl_to = sec2annotation(tosec);
1484 fprintf(stderr,
1485 "The %s %s%s%s references\n"
1486 "a %s %s%s%s.\n"
1487 "This is often seen when error handling "
1488 "in the init function\n"
1489 "uses functionality in the exit path.\n"
1490 "The fix is often to remove the %sannotation of\n"
1491 "%s%s so it may be used outside an exit section.\n",
1492 from, prl_from, fromsym, from_p,
1493 to, prl_to, tosym, to_p,
1494 prl_to, tosym, to_p);
1495 free(prl_from);
1496 free(prl_to);
1497 break;
1498 case ANY_EXIT_TO_ANY_INIT:
1499 prl_from = sec2annotation(fromsec);
1500 prl_to = sec2annotation(tosec);
1501 fprintf(stderr,
1502 "The %s %s%s%s references\n"
1503 "a %s %s%s%s.\n"
1504 "This is often seen when error handling "
1505 "in the exit function\n"
1506 "uses functionality in the init path.\n"
1507 "The fix is often to remove the %sannotation of\n"
1508 "%s%s so it may be used outside an init section.\n",
1509 from, prl_from, fromsym, from_p,
1510 to, prl_to, tosym, to_p,
1511 prl_to, tosym, to_p);
1512 free(prl_from);
1513 free(prl_to);
1514 break;
1515 case EXPORT_TO_INIT_EXIT:
1516 prl_to = sec2annotation(tosec);
1517 fprintf(stderr,
1518 "The symbol %s is exported and annotated %s\n"
1519 "Fix this by removing the %sannotation of %s "
1520 "or drop the export.\n",
1521 tosym, prl_to, prl_to, tosym);
1522 free(prl_to);
1523 break;
1524 case EXTABLE_TO_NON_TEXT:
1525 fatal("There's a special handler for this mismatch type, "
1526 "we should never get here.");
1527 break;
1528 }
1529 fprintf(stderr, "\n");
1530}
1531
1532static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1533 const struct sectioncheck* const mismatch,
1534 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1535{
1536 const char *tosec;
1537 Elf_Sym *to;
1538 Elf_Sym *from;
1539 const char *tosym;
1540 const char *fromsym;
1541
1542 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1543 fromsym = sym_name(elf, from);
1544
1545 if (!strncmp(fromsym, "reference___initcall",
1546 sizeof("reference___initcall")-1))
1547 return;
1548
1549 tosec = sec_name(elf, get_secindex(elf, sym));
1550 to = find_elf_symbol(elf, r->r_addend, sym);
1551 tosym = sym_name(elf, to);
1552
1553 /* check whitelist - we may ignore it */
1554 if (secref_whitelist(mismatch,
1555 fromsec, fromsym, tosec, tosym)) {
1556 report_sec_mismatch(modname, mismatch,
1557 fromsec, r->r_offset, fromsym,
1558 is_function(from), tosec, tosym,
1559 is_function(to));
1560 }
1561}
1562
1563static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1564{
1565 if (section_index > elf->num_sections)
1566 fatal("section_index is outside elf->num_sections!\n");
1567
1568 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1569}
1570
1571/*
1572 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1573 * to know the sizeof(struct exception_table_entry) for the target architecture.
1574 */
1575static unsigned int extable_entry_size = 0;
1576static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1577{
1578 /*
1579 * If we're currently checking the second relocation within __ex_table,
1580 * that relocation offset tells us the offsetof(struct
1581 * exception_table_entry, fixup) which is equal to sizeof(struct
1582 * exception_table_entry) divided by two. We use that to our advantage
1583 * since there's no portable way to get that size as every architecture
1584 * seems to go with different sized types. Not pretty but better than
1585 * hard-coding the size for every architecture..
1586 */
1587 if (!extable_entry_size)
1588 extable_entry_size = r->r_offset * 2;
1589}
1590
1591static inline bool is_extable_fault_address(Elf_Rela *r)
1592{
1593 /*
1594 * extable_entry_size is only discovered after we've handled the
1595 * _second_ relocation in __ex_table, so only abort when we're not
1596 * handling the first reloc and extable_entry_size is zero.
1597 */
1598 if (r->r_offset && extable_entry_size == 0)
1599 fatal("extable_entry size hasn't been discovered!\n");
1600
1601 return ((r->r_offset == 0) ||
1602 (r->r_offset % extable_entry_size == 0));
1603}
1604
1605#define is_second_extable_reloc(Start, Cur, Sec) \
1606 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1607
1608static void report_extable_warnings(const char* modname, struct elf_info* elf,
1609 const struct sectioncheck* const mismatch,
1610 Elf_Rela* r, Elf_Sym* sym,
1611 const char* fromsec, const char* tosec)
1612{
1613 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1614 const char* fromsym_name = sym_name(elf, fromsym);
1615 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1616 const char* tosym_name = sym_name(elf, tosym);
1617 const char* from_pretty_name;
1618 const char* from_pretty_name_p;
1619 const char* to_pretty_name;
1620 const char* to_pretty_name_p;
1621
1622 get_pretty_name(is_function(fromsym),
1623 &from_pretty_name, &from_pretty_name_p);
1624 get_pretty_name(is_function(tosym),
1625 &to_pretty_name, &to_pretty_name_p);
1626
1627 warn("%s(%s+0x%lx): Section mismatch in reference"
1628 " from the %s %s%s to the %s %s:%s%s\n",
1629 modname, fromsec, (long)r->r_offset, from_pretty_name,
1630 fromsym_name, from_pretty_name_p,
1631 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1632
1633 if (!match(tosec, mismatch->bad_tosec) &&
1634 is_executable_section(elf, get_secindex(elf, sym)))
1635 fprintf(stderr,
1636 "The relocation at %s+0x%lx references\n"
1637 "section \"%s\" which is not in the list of\n"
1638 "authorized sections. If you're adding a new section\n"
1639 "and/or if this reference is valid, add \"%s\" to the\n"
1640 "list of authorized sections to jump to on fault.\n"
1641 "This can be achieved by adding \"%s\" to \n"
1642 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1643 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1644}
1645
1646static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1647 const struct sectioncheck* const mismatch,
1648 Elf_Rela* r, Elf_Sym* sym,
1649 const char *fromsec)
1650{
1651 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1652
1653 sec_mismatch_count++;
1654
1655 if (sec_mismatch_verbose)
1656 report_extable_warnings(modname, elf, mismatch, r, sym,
1657 fromsec, tosec);
1658
1659 if (match(tosec, mismatch->bad_tosec))
1660 fatal("The relocation at %s+0x%lx references\n"
1661 "section \"%s\" which is black-listed.\n"
1662 "Something is seriously wrong and should be fixed.\n"
1663 "You might get more information about where this is\n"
1664 "coming from by using scripts/check_extable.sh %s\n",
1665 fromsec, (long)r->r_offset, tosec, modname);
1666 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1667 if (is_extable_fault_address(r))
1668 fatal("The relocation at %s+0x%lx references\n"
1669 "section \"%s\" which is not executable, IOW\n"
1670 "it is not possible for the kernel to fault\n"
1671 "at that address. Something is seriously wrong\n"
1672 "and should be fixed.\n",
1673 fromsec, (long)r->r_offset, tosec);
1674 else
1675 fatal("The relocation at %s+0x%lx references\n"
1676 "section \"%s\" which is not executable, IOW\n"
1677 "the kernel will fault if it ever tries to\n"
1678 "jump to it. Something is seriously wrong\n"
1679 "and should be fixed.\n",
1680 fromsec, (long)r->r_offset, tosec);
1681 }
1682}
1683
1684static void check_section_mismatch(const char *modname, struct elf_info *elf,
1685 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1686{
1687 const char *tosec = sec_name(elf, get_secindex(elf, sym));;
1688 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1689
1690 if (mismatch) {
1691 if (mismatch->handler)
1692 mismatch->handler(modname, elf, mismatch,
1693 r, sym, fromsec);
1694 else
1695 default_mismatch_handler(modname, elf, mismatch,
1696 r, sym, fromsec);
1697 }
1698}
1699
1700static unsigned int *reloc_location(struct elf_info *elf,
1701 Elf_Shdr *sechdr, Elf_Rela *r)
1702{
1703 Elf_Shdr *sechdrs = elf->sechdrs;
1704 int section = sechdr->sh_info;
1705
1706 return (void *)elf->hdr + sechdrs[section].sh_offset +
1707 r->r_offset;
1708}
1709
1710static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1711{
1712 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1713 unsigned int *location = reloc_location(elf, sechdr, r);
1714
1715 switch (r_typ) {
1716 case R_386_32:
1717 r->r_addend = TO_NATIVE(*location);
1718 break;
1719 case R_386_PC32:
1720 r->r_addend = TO_NATIVE(*location) + 4;
1721 /* For CONFIG_RELOCATABLE=y */
1722 if (elf->hdr->e_type == ET_EXEC)
1723 r->r_addend += r->r_offset;
1724 break;
1725 }
1726 return 0;
1727}
1728
1729#ifndef R_ARM_CALL
1730#define R_ARM_CALL 28
1731#endif
1732#ifndef R_ARM_JUMP24
1733#define R_ARM_JUMP24 29
1734#endif
1735
1736#ifndef R_ARM_THM_CALL
1737#define R_ARM_THM_CALL 10
1738#endif
1739#ifndef R_ARM_THM_JUMP24
1740#define R_ARM_THM_JUMP24 30
1741#endif
1742#ifndef R_ARM_THM_JUMP19
1743#define R_ARM_THM_JUMP19 51
1744#endif
1745
1746static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1747{
1748 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1749
1750 switch (r_typ) {
1751 case R_ARM_ABS32:
1752 /* From ARM ABI: (S + A) | T */
1753 r->r_addend = (int)(long)
1754 (elf->symtab_start + ELF_R_SYM(r->r_info));
1755 break;
1756 case R_ARM_PC24:
1757 case R_ARM_CALL:
1758 case R_ARM_JUMP24:
1759 case R_ARM_THM_CALL:
1760 case R_ARM_THM_JUMP24:
1761 case R_ARM_THM_JUMP19:
1762 /* From ARM ABI: ((S + A) | T) - P */
1763 r->r_addend = (int)(long)(elf->hdr +
1764 sechdr->sh_offset +
1765 (r->r_offset - sechdr->sh_addr));
1766 break;
1767 default:
1768 return 1;
1769 }
1770 return 0;
1771}
1772
1773static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1774{
1775 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1776 unsigned int *location = reloc_location(elf, sechdr, r);
1777 unsigned int inst;
1778
1779 if (r_typ == R_MIPS_HI16)
1780 return 1; /* skip this */
1781 inst = TO_NATIVE(*location);
1782 switch (r_typ) {
1783 case R_MIPS_LO16:
1784 r->r_addend = inst & 0xffff;
1785 break;
1786 case R_MIPS_26:
1787 r->r_addend = (inst & 0x03ffffff) << 2;
1788 break;
1789 case R_MIPS_32:
1790 r->r_addend = inst;
1791 break;
1792 }
1793 return 0;
1794}
1795
1796static void section_rela(const char *modname, struct elf_info *elf,
1797 Elf_Shdr *sechdr)
1798{
1799 Elf_Sym *sym;
1800 Elf_Rela *rela;
1801 Elf_Rela r;
1802 unsigned int r_sym;
1803 const char *fromsec;
1804
1805 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1806 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1807
1808 fromsec = sech_name(elf, sechdr);
1809 fromsec += strlen(".rela");
1810 /* if from section (name) is know good then skip it */
1811 if (match(fromsec, section_white_list))
1812 return;
1813
1814 for (rela = start; rela < stop; rela++) {
1815 r.r_offset = TO_NATIVE(rela->r_offset);
1816#if KERNEL_ELFCLASS == ELFCLASS64
1817 if (elf->hdr->e_machine == EM_MIPS) {
1818 unsigned int r_typ;
1819 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1820 r_sym = TO_NATIVE(r_sym);
1821 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1822 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1823 } else {
1824 r.r_info = TO_NATIVE(rela->r_info);
1825 r_sym = ELF_R_SYM(r.r_info);
1826 }
1827#else
1828 r.r_info = TO_NATIVE(rela->r_info);
1829 r_sym = ELF_R_SYM(r.r_info);
1830#endif
1831 r.r_addend = TO_NATIVE(rela->r_addend);
1832 sym = elf->symtab_start + r_sym;
1833 /* Skip special sections */
1834 if (is_shndx_special(sym->st_shndx))
1835 continue;
1836 if (is_second_extable_reloc(start, rela, fromsec))
1837 find_extable_entry_size(fromsec, &r);
1838 check_section_mismatch(modname, elf, &r, sym, fromsec);
1839 }
1840}
1841
1842static void section_rel(const char *modname, struct elf_info *elf,
1843 Elf_Shdr *sechdr)
1844{
1845 Elf_Sym *sym;
1846 Elf_Rel *rel;
1847 Elf_Rela r;
1848 unsigned int r_sym;
1849 const char *fromsec;
1850
1851 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1852 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1853
1854 fromsec = sech_name(elf, sechdr);
1855 fromsec += strlen(".rel");
1856 /* if from section (name) is know good then skip it */
1857 if (match(fromsec, section_white_list))
1858 return;
1859
1860 for (rel = start; rel < stop; rel++) {
1861 r.r_offset = TO_NATIVE(rel->r_offset);
1862#if KERNEL_ELFCLASS == ELFCLASS64
1863 if (elf->hdr->e_machine == EM_MIPS) {
1864 unsigned int r_typ;
1865 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1866 r_sym = TO_NATIVE(r_sym);
1867 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1868 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1869 } else {
1870 r.r_info = TO_NATIVE(rel->r_info);
1871 r_sym = ELF_R_SYM(r.r_info);
1872 }
1873#else
1874 r.r_info = TO_NATIVE(rel->r_info);
1875 r_sym = ELF_R_SYM(r.r_info);
1876#endif
1877 r.r_addend = 0;
1878 switch (elf->hdr->e_machine) {
1879 case EM_386:
1880 if (addend_386_rel(elf, sechdr, &r))
1881 continue;
1882 break;
1883 case EM_ARM:
1884 if (addend_arm_rel(elf, sechdr, &r))
1885 continue;
1886 break;
1887 case EM_MIPS:
1888 if (addend_mips_rel(elf, sechdr, &r))
1889 continue;
1890 break;
1891 }
1892 sym = elf->symtab_start + r_sym;
1893 /* Skip special sections */
1894 if (is_shndx_special(sym->st_shndx))
1895 continue;
1896 if (is_second_extable_reloc(start, rel, fromsec))
1897 find_extable_entry_size(fromsec, &r);
1898 check_section_mismatch(modname, elf, &r, sym, fromsec);
1899 }
1900}
1901
1902/**
1903 * A module includes a number of sections that are discarded
1904 * either when loaded or when used as built-in.
1905 * For loaded modules all functions marked __init and all data
1906 * marked __initdata will be discarded when the module has been initialized.
1907 * Likewise for modules used built-in the sections marked __exit
1908 * are discarded because __exit marked function are supposed to be called
1909 * only when a module is unloaded which never happens for built-in modules.
1910 * The check_sec_ref() function traverses all relocation records
1911 * to find all references to a section that reference a section that will
1912 * be discarded and warns about it.
1913 **/
1914static void check_sec_ref(struct module *mod, const char *modname,
1915 struct elf_info *elf)
1916{
1917 int i;
1918 Elf_Shdr *sechdrs = elf->sechdrs;
1919
1920 /* Walk through all sections */
1921 for (i = 0; i < elf->num_sections; i++) {
1922 check_section(modname, elf, &elf->sechdrs[i]);
1923 /* We want to process only relocation sections and not .init */
1924 if (sechdrs[i].sh_type == SHT_RELA)
1925 section_rela(modname, elf, &elf->sechdrs[i]);
1926 else if (sechdrs[i].sh_type == SHT_REL)
1927 section_rel(modname, elf, &elf->sechdrs[i]);
1928 }
1929}
1930
1931static char *remove_dot(char *s)
1932{
1933 size_t n = strcspn(s, ".");
1934
1935 if (n && s[n]) {
1936 size_t m = strspn(s + n + 1, "0123456789");
1937 if (m && (s[n + m] == '.' || s[n + m] == 0))
1938 s[n] = 0;
1939 }
1940 return s;
1941}
1942
1943static void read_symbols(char *modname)
1944{
1945 const char *symname;
1946 char *version;
1947 char *license;
1948 struct module *mod;
1949 struct elf_info info = { };
1950 Elf_Sym *sym;
1951
1952 if (!parse_elf(&info, modname))
1953 return;
1954
1955 mod = new_module(modname);
1956
1957 /* When there's no vmlinux, don't print warnings about
1958 * unresolved symbols (since there'll be too many ;) */
1959 if (is_vmlinux(modname)) {
1960 have_vmlinux = 1;
1961 mod->skip = 1;
1962 }
1963
1964 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1965 if (info.modinfo && !license && !is_vmlinux(modname))
1966 warn("modpost: missing MODULE_LICENSE() in %s\n"
1967 "see include/linux/module.h for "
1968 "more information\n", modname);
1969 while (license) {
1970 if (license_is_gpl_compatible(license))
1971 mod->gpl_compatible = 1;
1972 else {
1973 mod->gpl_compatible = 0;
1974 break;
1975 }
1976 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1977 "license", license);
1978 }
1979
1980 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1981 symname = remove_dot(info.strtab + sym->st_name);
1982
1983 handle_modversions(mod, &info, sym, symname);
1984 handle_moddevtable(mod, &info, sym, symname);
1985 }
1986 if (!is_vmlinux(modname) ||
1987 (is_vmlinux(modname) && vmlinux_section_warnings))
1988 check_sec_ref(mod, modname, &info);
1989
1990 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1991 if (version)
1992 maybe_frob_rcs_version(modname, version, info.modinfo,
1993 version - (char *)info.hdr);
1994 if (version || (all_versions && !is_vmlinux(modname)))
1995 get_src_version(modname, mod->srcversion,
1996 sizeof(mod->srcversion)-1);
1997
1998 parse_elf_finish(&info);
1999
2000 /* Our trick to get versioning for module struct etc. - it's
2001 * never passed as an argument to an exported function, so
2002 * the automatic versioning doesn't pick it up, but it's really
2003 * important anyhow */
2004 if (modversions)
2005 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2006}
2007
2008static void read_symbols_from_files(const char *filename)
2009{
2010 FILE *in = stdin;
2011 char fname[PATH_MAX];
2012
2013 if (strcmp(filename, "-") != 0) {
2014 in = fopen(filename, "r");
2015 if (!in)
2016 fatal("Can't open filenames file %s: %m", filename);
2017 }
2018
2019 while (fgets(fname, PATH_MAX, in) != NULL) {
2020 if (strends(fname, "\n"))
2021 fname[strlen(fname)-1] = '\0';
2022 read_symbols(fname);
2023 }
2024
2025 if (in != stdin)
2026 fclose(in);
2027}
2028
2029#define SZ 500
2030
2031/* We first write the generated file into memory using the
2032 * following helper, then compare to the file on disk and
2033 * only update the later if anything changed */
2034
2035void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2036 const char *fmt, ...)
2037{
2038 char tmp[SZ];
2039 int len;
2040 va_list ap;
2041
2042 va_start(ap, fmt);
2043 len = vsnprintf(tmp, SZ, fmt, ap);
2044 buf_write(buf, tmp, len);
2045 va_end(ap);
2046}
2047
2048void buf_write(struct buffer *buf, const char *s, int len)
2049{
2050 if (buf->size - buf->pos < len) {
2051 buf->size += len + SZ;
2052 buf->p = realloc(buf->p, buf->size);
2053 }
2054 strncpy(buf->p + buf->pos, s, len);
2055 buf->pos += len;
2056}
2057
2058static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2059{
2060 const char *e = is_vmlinux(m) ?"":".ko";
2061
2062 switch (exp) {
2063 case export_gpl:
2064 fatal("modpost: GPL-incompatible module %s%s "
2065 "uses GPL-only symbol '%s'\n", m, e, s);
2066 break;
2067 case export_unused_gpl:
2068 fatal("modpost: GPL-incompatible module %s%s "
2069 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2070 break;
2071 case export_gpl_future:
2072 warn("modpost: GPL-incompatible module %s%s "
2073 "uses future GPL-only symbol '%s'\n", m, e, s);
2074 break;
2075 case export_plain:
2076 case export_unused:
2077 case export_unknown:
2078 /* ignore */
2079 break;
2080 }
2081}
2082
2083static void check_for_unused(enum export exp, const char *m, const char *s)
2084{
2085 const char *e = is_vmlinux(m) ?"":".ko";
2086
2087 switch (exp) {
2088 case export_unused:
2089 case export_unused_gpl:
2090 warn("modpost: module %s%s "
2091 "uses symbol '%s' marked UNUSED\n", m, e, s);
2092 break;
2093 default:
2094 /* ignore */
2095 break;
2096 }
2097}
2098
2099static void check_exports(struct module *mod)
2100{
2101 struct symbol *s, *exp;
2102
2103 for (s = mod->unres; s; s = s->next) {
2104 const char *basename;
2105 exp = find_symbol(s->name);
2106 if (!exp || exp->module == mod)
2107 continue;
2108 basename = strrchr(mod->name, '/');
2109 if (basename)
2110 basename++;
2111 else
2112 basename = mod->name;
2113 if (!mod->gpl_compatible)
2114 check_for_gpl_usage(exp->export, basename, exp->name);
2115 check_for_unused(exp->export, basename, exp->name);
2116 }
2117}
2118
2119/**
2120 * Header for the generated file
2121 **/
2122static void add_header(struct buffer *b, struct module *mod)
2123{
2124 buf_printf(b, "#include <linux/module.h>\n");
2125 buf_printf(b, "#include <linux/vermagic.h>\n");
2126 buf_printf(b, "#include <linux/compiler.h>\n");
2127 buf_printf(b, "\n");
2128 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2129 buf_printf(b, "\n");
2130 buf_printf(b, "__visible struct module __this_module\n");
2131 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
2132 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2133 if (mod->has_init)
2134 buf_printf(b, "\t.init = init_module,\n");
2135 if (mod->has_cleanup)
2136 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2137 "\t.exit = cleanup_module,\n"
2138 "#endif\n");
2139 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2140 buf_printf(b, "};\n");
2141}
2142
2143static void add_intree_flag(struct buffer *b, int is_intree)
2144{
2145 if (is_intree)
2146 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2147}
2148
2149static void add_staging_flag(struct buffer *b, const char *name)
2150{
2151 static const char *staging_dir = "drivers/staging";
2152
2153 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
2154 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2155}
2156
2157/* In kernel, this size is defined in linux/module.h;
2158 * here we use Elf_Addr instead of long for covering cross-compile
2159 */
2160#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
2161
2162/**
2163 * Record CRCs for unresolved symbols
2164 **/
2165static int add_versions(struct buffer *b, struct module *mod)
2166{
2167 struct symbol *s, *exp;
2168 int err = 0;
2169
2170 for (s = mod->unres; s; s = s->next) {
2171 exp = find_symbol(s->name);
2172 if (!exp || exp->module == mod) {
2173 if (have_vmlinux && !s->weak) {
2174 if (warn_unresolved) {
2175 warn("\"%s\" [%s.ko] undefined!\n",
2176 s->name, mod->name);
2177 } else {
2178 merror("\"%s\" [%s.ko] undefined!\n",
2179 s->name, mod->name);
2180 err = 1;
2181 }
2182 }
2183 continue;
2184 }
2185 s->module = exp->module;
2186 s->crc_valid = exp->crc_valid;
2187 s->crc = exp->crc;
2188 }
2189
2190 if (!modversions)
2191 return err;
2192
2193 buf_printf(b, "\n");
2194 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2195 buf_printf(b, "__used\n");
2196 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
2197
2198 for (s = mod->unres; s; s = s->next) {
2199 if (!s->module)
2200 continue;
2201 if (!s->crc_valid) {
2202 warn("\"%s\" [%s.ko] has no CRC!\n",
2203 s->name, mod->name);
2204 continue;
2205 }
2206 if (strlen(s->name) >= MODULE_NAME_LEN) {
2207 merror("too long symbol \"%s\" [%s.ko]\n",
2208 s->name, mod->name);
2209 err = 1;
2210 break;
2211 }
2212 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
2213 s->crc, s->name);
2214 }
2215
2216 buf_printf(b, "};\n");
2217
2218 return err;
2219}
2220
2221static void add_depends(struct buffer *b, struct module *mod,
2222 struct module *modules)
2223{
2224 struct symbol *s;
2225 struct module *m;
2226 int first = 1;
2227
2228 for (m = modules; m; m = m->next)
2229 m->seen = is_vmlinux(m->name);
2230
2231 buf_printf(b, "\n");
2232 buf_printf(b, "static const char __module_depends[]\n");
2233 buf_printf(b, "__used\n");
2234 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
2235 buf_printf(b, "\"depends=");
2236 for (s = mod->unres; s; s = s->next) {
2237 const char *p;
2238 if (!s->module)
2239 continue;
2240
2241 if (s->module->seen)
2242 continue;
2243
2244 s->module->seen = 1;
2245 p = strrchr(s->module->name, '/');
2246 if (p)
2247 p++;
2248 else
2249 p = s->module->name;
2250 buf_printf(b, "%s%s", first ? "" : ",", p);
2251 first = 0;
2252 }
2253 buf_printf(b, "\";\n");
2254}
2255
2256static void add_srcversion(struct buffer *b, struct module *mod)
2257{
2258 if (mod->srcversion[0]) {
2259 buf_printf(b, "\n");
2260 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2261 mod->srcversion);
2262 }
2263}
2264
2265static void write_if_changed(struct buffer *b, const char *fname)
2266{
2267 char *tmp;
2268 FILE *file;
2269 struct stat st;
2270
2271 file = fopen(fname, "r");
2272 if (!file)
2273 goto write;
2274
2275 if (fstat(fileno(file), &st) < 0)
2276 goto close_write;
2277
2278 if (st.st_size != b->pos)
2279 goto close_write;
2280
2281 tmp = NOFAIL(malloc(b->pos));
2282 if (fread(tmp, 1, b->pos, file) != b->pos)
2283 goto free_write;
2284
2285 if (memcmp(tmp, b->p, b->pos) != 0)
2286 goto free_write;
2287
2288 free(tmp);
2289 fclose(file);
2290 return;
2291
2292 free_write:
2293 free(tmp);
2294 close_write:
2295 fclose(file);
2296 write:
2297 file = fopen(fname, "w");
2298 if (!file) {
2299 perror(fname);
2300 exit(1);
2301 }
2302 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2303 perror(fname);
2304 exit(1);
2305 }
2306 fclose(file);
2307}
2308
2309/* parse Module.symvers file. line format:
2310 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2311 **/
2312static void read_dump(const char *fname, unsigned int kernel)
2313{
2314 unsigned long size, pos = 0;
2315 void *file = grab_file(fname, &size);
2316 char *line;
2317
2318 if (!file)
2319 /* No symbol versions, silently ignore */
2320 return;
2321
2322 while ((line = get_next_line(&pos, file, size))) {
2323 char *symname, *modname, *d, *export, *end;
2324 unsigned int crc;
2325 struct module *mod;
2326 struct symbol *s;
2327
2328 if (!(symname = strchr(line, '\t')))
2329 goto fail;
2330 *symname++ = '\0';
2331 if (!(modname = strchr(symname, '\t')))
2332 goto fail;
2333 *modname++ = '\0';
2334 if ((export = strchr(modname, '\t')) != NULL)
2335 *export++ = '\0';
2336 if (export && ((end = strchr(export, '\t')) != NULL))
2337 *end = '\0';
2338 crc = strtoul(line, &d, 16);
2339 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2340 goto fail;
2341 mod = find_module(modname);
2342 if (!mod) {
2343 if (is_vmlinux(modname))
2344 have_vmlinux = 1;
2345 mod = new_module(modname);
2346 mod->skip = 1;
2347 }
2348 s = sym_add_exported(symname, mod, export_no(export));
2349 s->kernel = kernel;
2350 s->preloaded = 1;
2351 sym_update_crc(symname, mod, crc, export_no(export));
2352 }
2353 release_file(file, size);
2354 return;
2355fail:
2356 release_file(file, size);
2357 fatal("parse error in symbol dump file\n");
2358}
2359
2360/* For normal builds always dump all symbols.
2361 * For external modules only dump symbols
2362 * that are not read from kernel Module.symvers.
2363 **/
2364static int dump_sym(struct symbol *sym)
2365{
2366 if (!external_module)
2367 return 1;
2368 if (sym->vmlinux || sym->kernel)
2369 return 0;
2370 return 1;
2371}
2372
2373static void write_dump(const char *fname)
2374{
2375 struct buffer buf = { };
2376 struct symbol *symbol;
2377 int n;
2378
2379 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2380 symbol = symbolhash[n];
2381 while (symbol) {
2382 if (dump_sym(symbol))
2383 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2384 symbol->crc, symbol->name,
2385 symbol->module->name,
2386 export_str(symbol->export));
2387 symbol = symbol->next;
2388 }
2389 }
2390 write_if_changed(&buf, fname);
2391 free(buf.p);
2392}
2393
2394struct ext_sym_list {
2395 struct ext_sym_list *next;
2396 const char *file;
2397};
2398
2399int main(int argc, char **argv)
2400{
2401 struct module *mod;
2402 struct buffer buf = { };
2403 char *kernel_read = NULL, *module_read = NULL;
2404 char *dump_write = NULL, *files_source = NULL;
2405 int opt;
2406 int err;
2407 struct ext_sym_list *extsym_iter;
2408 struct ext_sym_list *extsym_start = NULL;
2409
2410 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:E")) != -1) {
2411 switch (opt) {
2412 case 'i':
2413 kernel_read = optarg;
2414 break;
2415 case 'I':
2416 module_read = optarg;
2417 external_module = 1;
2418 break;
2419 case 'e':
2420 external_module = 1;
2421 extsym_iter =
2422 NOFAIL(malloc(sizeof(*extsym_iter)));
2423 extsym_iter->next = extsym_start;
2424 extsym_iter->file = optarg;
2425 extsym_start = extsym_iter;
2426 break;
2427 case 'm':
2428 modversions = 1;
2429 break;
2430 case 'n':
2431 ignore_missing_files = 1;
2432 break;
2433 case 'o':
2434 dump_write = optarg;
2435 break;
2436 case 'a':
2437 all_versions = 1;
2438 break;
2439 case 's':
2440 vmlinux_section_warnings = 0;
2441 break;
2442 case 'S':
2443 sec_mismatch_verbose = 0;
2444 break;
2445 case 'T':
2446 files_source = optarg;
2447 break;
2448 case 'w':
2449 warn_unresolved = 1;
2450 break;
2451 case 'E':
2452 sec_mismatch_fatal = 1;
2453 break;
2454 default:
2455 exit(1);
2456 }
2457 }
2458
2459 if (kernel_read)
2460 read_dump(kernel_read, 1);
2461 if (module_read)
2462 read_dump(module_read, 0);
2463 while (extsym_start) {
2464 read_dump(extsym_start->file, 0);
2465 extsym_iter = extsym_start->next;
2466 free(extsym_start);
2467 extsym_start = extsym_iter;
2468 }
2469
2470 while (optind < argc)
2471 read_symbols(argv[optind++]);
2472
2473 if (files_source)
2474 read_symbols_from_files(files_source);
2475
2476 for (mod = modules; mod; mod = mod->next) {
2477 if (mod->skip)
2478 continue;
2479 check_exports(mod);
2480 }
2481
2482 err = 0;
2483
2484 for (mod = modules; mod; mod = mod->next) {
2485 char fname[PATH_MAX];
2486
2487 if (mod->skip)
2488 continue;
2489
2490 buf.pos = 0;
2491
2492 add_header(&buf, mod);
2493 add_intree_flag(&buf, !external_module);
2494 add_staging_flag(&buf, mod->name);
2495 err |= add_versions(&buf, mod);
2496 add_depends(&buf, mod, modules);
2497 add_moddevtable(&buf, mod);
2498 add_srcversion(&buf, mod);
2499
2500 sprintf(fname, "%s.mod.c", mod->name);
2501 write_if_changed(&buf, fname);
2502 }
2503 if (dump_write)
2504 write_dump(dump_write);
2505 if (sec_mismatch_count) {
2506 if (!sec_mismatch_verbose) {
2507 warn("modpost: Found %d section mismatch(es).\n"
2508 "To see full details build your kernel with:\n"
2509 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2510 sec_mismatch_count);
2511 }
2512 if (sec_mismatch_fatal) {
2513 fatal("modpost: Section mismatches detected.\n"
2514 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2515 }
2516 }
2517 free(buf.p);
2518
2519 return err;
2520}