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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/linux/license.h"
23
24/* Are we using CONFIG_MODVERSIONS? */
25static int modversions = 0;
26/* Warn about undefined symbols? (do so if we have vmlinux) */
27static int have_vmlinux = 0;
28/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
29static int all_versions = 0;
30/* If we are modposting external module set to 1 */
31static int external_module = 0;
32/* Warn about section mismatch in vmlinux if set to 1 */
33static int vmlinux_section_warnings = 1;
34/* Only warn about unresolved symbols */
35static int warn_unresolved = 0;
36/* How a symbol is exported */
37static int sec_mismatch_count = 0;
38static int sec_mismatch_fatal = 0;
39/* ignore missing files */
40static int ignore_missing_files;
41/* write namespace dependencies */
42static int write_namespace_deps;
43
44enum export {
45 export_plain, export_unused, export_gpl,
46 export_unused_gpl, export_gpl_future, export_unknown
47};
48
49/* In kernel, this size is defined in linux/module.h;
50 * here we use Elf_Addr instead of long for covering cross-compile
51 */
52
53#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
54
55#define PRINTF __attribute__ ((format (printf, 1, 2)))
56
57PRINTF void fatal(const char *fmt, ...)
58{
59 va_list arglist;
60
61 fprintf(stderr, "FATAL: ");
62
63 va_start(arglist, fmt);
64 vfprintf(stderr, fmt, arglist);
65 va_end(arglist);
66
67 exit(1);
68}
69
70PRINTF void warn(const char *fmt, ...)
71{
72 va_list arglist;
73
74 fprintf(stderr, "WARNING: ");
75
76 va_start(arglist, fmt);
77 vfprintf(stderr, fmt, arglist);
78 va_end(arglist);
79}
80
81PRINTF void merror(const char *fmt, ...)
82{
83 va_list arglist;
84
85 fprintf(stderr, "ERROR: ");
86
87 va_start(arglist, fmt);
88 vfprintf(stderr, fmt, arglist);
89 va_end(arglist);
90}
91
92static inline bool strends(const char *str, const char *postfix)
93{
94 if (strlen(str) < strlen(postfix))
95 return false;
96
97 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
98}
99
100static int is_vmlinux(const char *modname)
101{
102 const char *myname;
103
104 myname = strrchr(modname, '/');
105 if (myname)
106 myname++;
107 else
108 myname = modname;
109
110 return (strcmp(myname, "vmlinux") == 0) ||
111 (strcmp(myname, "vmlinux.o") == 0);
112}
113
114void *do_nofail(void *ptr, const char *expr)
115{
116 if (!ptr)
117 fatal("modpost: Memory allocation failure: %s.\n", expr);
118
119 return ptr;
120}
121
122/* A list of all modules we processed */
123static struct module *modules;
124
125static struct module *find_module(const char *modname)
126{
127 struct module *mod;
128
129 for (mod = modules; mod; mod = mod->next)
130 if (strcmp(mod->name, modname) == 0)
131 break;
132 return mod;
133}
134
135static struct module *new_module(const char *modname)
136{
137 struct module *mod;
138 char *p;
139
140 mod = NOFAIL(malloc(sizeof(*mod)));
141 memset(mod, 0, sizeof(*mod));
142 p = NOFAIL(strdup(modname));
143
144 /* strip trailing .o */
145 if (strends(p, ".o")) {
146 p[strlen(p) - 2] = '\0';
147 mod->is_dot_o = 1;
148 }
149
150 /* add to list */
151 mod->name = p;
152 mod->gpl_compatible = -1;
153 mod->next = modules;
154 modules = mod;
155
156 return mod;
157}
158
159/* A hash of all exported symbols,
160 * struct symbol is also used for lists of unresolved symbols */
161
162#define SYMBOL_HASH_SIZE 1024
163
164struct symbol {
165 struct symbol *next;
166 struct module *module;
167 unsigned int crc;
168 int crc_valid;
169 char *namespace;
170 unsigned int weak:1;
171 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
172 unsigned int kernel:1; /* 1 if symbol is from kernel
173 * (only for external modules) **/
174 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
175 unsigned int is_static:1; /* 1 if symbol is not global */
176 enum export export; /* Type of export */
177 char name[0];
178};
179
180static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
181
182/* This is based on the hash agorithm from gdbm, via tdb */
183static inline unsigned int tdb_hash(const char *name)
184{
185 unsigned value; /* Used to compute the hash value. */
186 unsigned i; /* Used to cycle through random values. */
187
188 /* Set the initial value from the key size. */
189 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
190 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
191
192 return (1103515243 * value + 12345);
193}
194
195/**
196 * Allocate a new symbols for use in the hash of exported symbols or
197 * the list of unresolved symbols per module
198 **/
199static struct symbol *alloc_symbol(const char *name, unsigned int weak,
200 struct symbol *next)
201{
202 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
203
204 memset(s, 0, sizeof(*s));
205 strcpy(s->name, name);
206 s->weak = weak;
207 s->next = next;
208 s->is_static = 1;
209 return s;
210}
211
212/* For the hash of exported symbols */
213static struct symbol *new_symbol(const char *name, struct module *module,
214 enum export export)
215{
216 unsigned int hash;
217 struct symbol *new;
218
219 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
220 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
221 new->module = module;
222 new->export = export;
223 return new;
224}
225
226static struct symbol *find_symbol(const char *name)
227{
228 struct symbol *s;
229
230 /* For our purposes, .foo matches foo. PPC64 needs this. */
231 if (name[0] == '.')
232 name++;
233
234 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
235 if (strcmp(s->name, name) == 0)
236 return s;
237 }
238 return NULL;
239}
240
241static bool contains_namespace(struct namespace_list *list,
242 const char *namespace)
243{
244 struct namespace_list *ns_entry;
245
246 for (ns_entry = list; ns_entry != NULL; ns_entry = ns_entry->next)
247 if (strcmp(ns_entry->namespace, namespace) == 0)
248 return true;
249
250 return false;
251}
252
253static void add_namespace(struct namespace_list **list, const char *namespace)
254{
255 struct namespace_list *ns_entry;
256
257 if (!contains_namespace(*list, namespace)) {
258 ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) +
259 strlen(namespace) + 1));
260 strcpy(ns_entry->namespace, namespace);
261 ns_entry->next = *list;
262 *list = ns_entry;
263 }
264}
265
266static bool module_imports_namespace(struct module *module,
267 const char *namespace)
268{
269 return contains_namespace(module->imported_namespaces, namespace);
270}
271
272static const struct {
273 const char *str;
274 enum export export;
275} export_list[] = {
276 { .str = "EXPORT_SYMBOL", .export = export_plain },
277 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
278 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
279 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
280 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
281 { .str = "(unknown)", .export = export_unknown },
282};
283
284
285static const char *export_str(enum export ex)
286{
287 return export_list[ex].str;
288}
289
290static enum export export_no(const char *s)
291{
292 int i;
293
294 if (!s)
295 return export_unknown;
296 for (i = 0; export_list[i].export != export_unknown; i++) {
297 if (strcmp(export_list[i].str, s) == 0)
298 return export_list[i].export;
299 }
300 return export_unknown;
301}
302
303static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
304{
305 return (void *)elf->hdr +
306 elf->sechdrs[elf->secindex_strings].sh_offset +
307 sechdr->sh_name;
308}
309
310static const char *sec_name(struct elf_info *elf, int secindex)
311{
312 return sech_name(elf, &elf->sechdrs[secindex]);
313}
314
315#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
316
317static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
318{
319 const char *secname = sec_name(elf, sec);
320
321 if (strstarts(secname, "___ksymtab+"))
322 return export_plain;
323 else if (strstarts(secname, "___ksymtab_unused+"))
324 return export_unused;
325 else if (strstarts(secname, "___ksymtab_gpl+"))
326 return export_gpl;
327 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
328 return export_unused_gpl;
329 else if (strstarts(secname, "___ksymtab_gpl_future+"))
330 return export_gpl_future;
331 else
332 return export_unknown;
333}
334
335static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
336{
337 if (sec == elf->export_sec)
338 return export_plain;
339 else if (sec == elf->export_unused_sec)
340 return export_unused;
341 else if (sec == elf->export_gpl_sec)
342 return export_gpl;
343 else if (sec == elf->export_unused_gpl_sec)
344 return export_unused_gpl;
345 else if (sec == elf->export_gpl_future_sec)
346 return export_gpl_future;
347 else
348 return export_unknown;
349}
350
351static const char *namespace_from_kstrtabns(struct elf_info *info,
352 Elf_Sym *kstrtabns)
353{
354 char *value = info->ksymtab_strings + kstrtabns->st_value;
355 return value[0] ? value : NULL;
356}
357
358static void sym_update_namespace(const char *symname, const char *namespace)
359{
360 struct symbol *s = find_symbol(symname);
361
362 /*
363 * That symbol should have been created earlier and thus this is
364 * actually an assertion.
365 */
366 if (!s) {
367 merror("Could not update namespace(%s) for symbol %s\n",
368 namespace, symname);
369 return;
370 }
371
372 free(s->namespace);
373 s->namespace =
374 namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
375}
376
377/**
378 * Add an exported symbol - it may have already been added without a
379 * CRC, in this case just update the CRC
380 **/
381static struct symbol *sym_add_exported(const char *name, struct module *mod,
382 enum export export)
383{
384 struct symbol *s = find_symbol(name);
385
386 if (!s) {
387 s = new_symbol(name, mod, export);
388 } else {
389 if (!s->preloaded) {
390 warn("%s: '%s' exported twice. Previous export was in %s%s\n",
391 mod->name, name, s->module->name,
392 is_vmlinux(s->module->name) ? "" : ".ko");
393 } else {
394 /* In case Module.symvers was out of date */
395 s->module = mod;
396 }
397 }
398 s->preloaded = 0;
399 s->vmlinux = is_vmlinux(mod->name);
400 s->kernel = 0;
401 s->export = export;
402 return s;
403}
404
405static void sym_update_crc(const char *name, struct module *mod,
406 unsigned int crc, enum export export)
407{
408 struct symbol *s = find_symbol(name);
409
410 if (!s) {
411 s = new_symbol(name, mod, export);
412 /* Don't complain when we find it later. */
413 s->preloaded = 1;
414 }
415 s->crc = crc;
416 s->crc_valid = 1;
417}
418
419void *grab_file(const char *filename, unsigned long *size)
420{
421 struct stat st;
422 void *map = MAP_FAILED;
423 int fd;
424
425 fd = open(filename, O_RDONLY);
426 if (fd < 0)
427 return NULL;
428 if (fstat(fd, &st))
429 goto failed;
430
431 *size = st.st_size;
432 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
433
434failed:
435 close(fd);
436 if (map == MAP_FAILED)
437 return NULL;
438 return map;
439}
440
441/**
442 * Return a copy of the next line in a mmap'ed file.
443 * spaces in the beginning of the line is trimmed away.
444 * Return a pointer to a static buffer.
445 **/
446char *get_next_line(unsigned long *pos, void *file, unsigned long size)
447{
448 static char line[4096];
449 int skip = 1;
450 size_t len = 0;
451 signed char *p = (signed char *)file + *pos;
452 char *s = line;
453
454 for (; *pos < size ; (*pos)++) {
455 if (skip && isspace(*p)) {
456 p++;
457 continue;
458 }
459 skip = 0;
460 if (*p != '\n' && (*pos < size)) {
461 len++;
462 *s++ = *p++;
463 if (len > 4095)
464 break; /* Too long, stop */
465 } else {
466 /* End of string */
467 *s = '\0';
468 return line;
469 }
470 }
471 /* End of buffer */
472 return NULL;
473}
474
475void release_file(void *file, unsigned long size)
476{
477 munmap(file, size);
478}
479
480static int parse_elf(struct elf_info *info, const char *filename)
481{
482 unsigned int i;
483 Elf_Ehdr *hdr;
484 Elf_Shdr *sechdrs;
485 Elf_Sym *sym;
486 const char *secstrings;
487 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
488
489 hdr = grab_file(filename, &info->size);
490 if (!hdr) {
491 if (ignore_missing_files) {
492 fprintf(stderr, "%s: %s (ignored)\n", filename,
493 strerror(errno));
494 return 0;
495 }
496 perror(filename);
497 exit(1);
498 }
499 info->hdr = hdr;
500 if (info->size < sizeof(*hdr)) {
501 /* file too small, assume this is an empty .o file */
502 return 0;
503 }
504 /* Is this a valid ELF file? */
505 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
506 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
507 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
508 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
509 /* Not an ELF file - silently ignore it */
510 return 0;
511 }
512 /* Fix endianness in ELF header */
513 hdr->e_type = TO_NATIVE(hdr->e_type);
514 hdr->e_machine = TO_NATIVE(hdr->e_machine);
515 hdr->e_version = TO_NATIVE(hdr->e_version);
516 hdr->e_entry = TO_NATIVE(hdr->e_entry);
517 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
518 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
519 hdr->e_flags = TO_NATIVE(hdr->e_flags);
520 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
521 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
522 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
523 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
524 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
525 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
526 sechdrs = (void *)hdr + hdr->e_shoff;
527 info->sechdrs = sechdrs;
528
529 /* Check if file offset is correct */
530 if (hdr->e_shoff > info->size) {
531 fatal("section header offset=%lu in file '%s' is bigger than "
532 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
533 filename, info->size);
534 return 0;
535 }
536
537 if (hdr->e_shnum == SHN_UNDEF) {
538 /*
539 * There are more than 64k sections,
540 * read count from .sh_size.
541 */
542 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
543 }
544 else {
545 info->num_sections = hdr->e_shnum;
546 }
547 if (hdr->e_shstrndx == SHN_XINDEX) {
548 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
549 }
550 else {
551 info->secindex_strings = hdr->e_shstrndx;
552 }
553
554 /* Fix endianness in section headers */
555 for (i = 0; i < info->num_sections; i++) {
556 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
557 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
558 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
559 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
560 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
561 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
562 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
563 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
564 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
565 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
566 }
567 /* Find symbol table. */
568 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
569 for (i = 1; i < info->num_sections; i++) {
570 const char *secname;
571 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
572
573 if (!nobits && sechdrs[i].sh_offset > info->size) {
574 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
575 "sizeof(*hrd)=%zu\n", filename,
576 (unsigned long)sechdrs[i].sh_offset,
577 sizeof(*hdr));
578 return 0;
579 }
580 secname = secstrings + sechdrs[i].sh_name;
581 if (strcmp(secname, ".modinfo") == 0) {
582 if (nobits)
583 fatal("%s has NOBITS .modinfo\n", filename);
584 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
585 info->modinfo_len = sechdrs[i].sh_size;
586 } else if (strcmp(secname, "__ksymtab") == 0)
587 info->export_sec = i;
588 else if (strcmp(secname, "__ksymtab_unused") == 0)
589 info->export_unused_sec = i;
590 else if (strcmp(secname, "__ksymtab_gpl") == 0)
591 info->export_gpl_sec = i;
592 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
593 info->export_unused_gpl_sec = i;
594 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
595 info->export_gpl_future_sec = i;
596 else if (strcmp(secname, "__ksymtab_strings") == 0)
597 info->ksymtab_strings = (void *)hdr +
598 sechdrs[i].sh_offset -
599 sechdrs[i].sh_addr;
600
601 if (sechdrs[i].sh_type == SHT_SYMTAB) {
602 unsigned int sh_link_idx;
603 symtab_idx = i;
604 info->symtab_start = (void *)hdr +
605 sechdrs[i].sh_offset;
606 info->symtab_stop = (void *)hdr +
607 sechdrs[i].sh_offset + sechdrs[i].sh_size;
608 sh_link_idx = sechdrs[i].sh_link;
609 info->strtab = (void *)hdr +
610 sechdrs[sh_link_idx].sh_offset;
611 }
612
613 /* 32bit section no. table? ("more than 64k sections") */
614 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
615 symtab_shndx_idx = i;
616 info->symtab_shndx_start = (void *)hdr +
617 sechdrs[i].sh_offset;
618 info->symtab_shndx_stop = (void *)hdr +
619 sechdrs[i].sh_offset + sechdrs[i].sh_size;
620 }
621 }
622 if (!info->symtab_start)
623 fatal("%s has no symtab?\n", filename);
624
625 /* Fix endianness in symbols */
626 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
627 sym->st_shndx = TO_NATIVE(sym->st_shndx);
628 sym->st_name = TO_NATIVE(sym->st_name);
629 sym->st_value = TO_NATIVE(sym->st_value);
630 sym->st_size = TO_NATIVE(sym->st_size);
631 }
632
633 if (symtab_shndx_idx != ~0U) {
634 Elf32_Word *p;
635 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
636 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
637 filename, sechdrs[symtab_shndx_idx].sh_link,
638 symtab_idx);
639 /* Fix endianness */
640 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
641 p++)
642 *p = TO_NATIVE(*p);
643 }
644
645 return 1;
646}
647
648static void parse_elf_finish(struct elf_info *info)
649{
650 release_file(info->hdr, info->size);
651}
652
653static int ignore_undef_symbol(struct elf_info *info, const char *symname)
654{
655 /* ignore __this_module, it will be resolved shortly */
656 if (strcmp(symname, "__this_module") == 0)
657 return 1;
658 /* ignore global offset table */
659 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
660 return 1;
661 if (info->hdr->e_machine == EM_PPC)
662 /* Special register function linked on all modules during final link of .ko */
663 if (strstarts(symname, "_restgpr_") ||
664 strstarts(symname, "_savegpr_") ||
665 strstarts(symname, "_rest32gpr_") ||
666 strstarts(symname, "_save32gpr_") ||
667 strstarts(symname, "_restvr_") ||
668 strstarts(symname, "_savevr_"))
669 return 1;
670 if (info->hdr->e_machine == EM_PPC64)
671 /* Special register function linked on all modules during final link of .ko */
672 if (strstarts(symname, "_restgpr0_") ||
673 strstarts(symname, "_savegpr0_") ||
674 strstarts(symname, "_restvr_") ||
675 strstarts(symname, "_savevr_") ||
676 strcmp(symname, ".TOC.") == 0)
677 return 1;
678 /* Do not ignore this symbol */
679 return 0;
680}
681
682static void handle_modversions(struct module *mod, struct elf_info *info,
683 Elf_Sym *sym, const char *symname)
684{
685 unsigned int crc;
686 enum export export;
687 bool is_crc = false;
688 const char *name;
689
690 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
691 strstarts(symname, "__ksymtab"))
692 export = export_from_secname(info, get_secindex(info, sym));
693 else
694 export = export_from_sec(info, get_secindex(info, sym));
695
696 /* CRC'd symbol */
697 if (strstarts(symname, "__crc_")) {
698 is_crc = true;
699 crc = (unsigned int) sym->st_value;
700 if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
701 unsigned int *crcp;
702
703 /* symbol points to the CRC in the ELF object */
704 crcp = (void *)info->hdr + sym->st_value +
705 info->sechdrs[sym->st_shndx].sh_offset -
706 (info->hdr->e_type != ET_REL ?
707 info->sechdrs[sym->st_shndx].sh_addr : 0);
708 crc = TO_NATIVE(*crcp);
709 }
710 sym_update_crc(symname + strlen("__crc_"), mod, crc,
711 export);
712 }
713
714 switch (sym->st_shndx) {
715 case SHN_COMMON:
716 if (strstarts(symname, "__gnu_lto_")) {
717 /* Should warn here, but modpost runs before the linker */
718 } else
719 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
720 break;
721 case SHN_UNDEF:
722 /* undefined symbol */
723 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
724 ELF_ST_BIND(sym->st_info) != STB_WEAK)
725 break;
726 if (ignore_undef_symbol(info, symname))
727 break;
728/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
729#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
730/* add compatibility with older glibc */
731#ifndef STT_SPARC_REGISTER
732#define STT_SPARC_REGISTER STT_REGISTER
733#endif
734 if (info->hdr->e_machine == EM_SPARC ||
735 info->hdr->e_machine == EM_SPARCV9) {
736 /* Ignore register directives. */
737 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
738 break;
739 if (symname[0] == '.') {
740 char *munged = NOFAIL(strdup(symname));
741 munged[0] = '_';
742 munged[1] = toupper(munged[1]);
743 symname = munged;
744 }
745 }
746#endif
747
748 if (is_crc) {
749 const char *e = is_vmlinux(mod->name) ?"":".ko";
750 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
751 symname + strlen("__crc_"), mod->name, e);
752 }
753 mod->unres = alloc_symbol(symname,
754 ELF_ST_BIND(sym->st_info) == STB_WEAK,
755 mod->unres);
756 break;
757 default:
758 /* All exported symbols */
759 if (strstarts(symname, "__ksymtab_")) {
760 name = symname + strlen("__ksymtab_");
761 sym_add_exported(name, mod, export);
762 }
763 if (strcmp(symname, "init_module") == 0)
764 mod->has_init = 1;
765 if (strcmp(symname, "cleanup_module") == 0)
766 mod->has_cleanup = 1;
767 break;
768 }
769}
770
771/**
772 * Parse tag=value strings from .modinfo section
773 **/
774static char *next_string(char *string, unsigned long *secsize)
775{
776 /* Skip non-zero chars */
777 while (string[0]) {
778 string++;
779 if ((*secsize)-- <= 1)
780 return NULL;
781 }
782
783 /* Skip any zero padding. */
784 while (!string[0]) {
785 string++;
786 if ((*secsize)-- <= 1)
787 return NULL;
788 }
789 return string;
790}
791
792static char *get_next_modinfo(struct elf_info *info, const char *tag,
793 char *prev)
794{
795 char *p;
796 unsigned int taglen = strlen(tag);
797 char *modinfo = info->modinfo;
798 unsigned long size = info->modinfo_len;
799
800 if (prev) {
801 size -= prev - modinfo;
802 modinfo = next_string(prev, &size);
803 }
804
805 for (p = modinfo; p; p = next_string(p, &size)) {
806 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
807 return p + taglen + 1;
808 }
809 return NULL;
810}
811
812static char *get_modinfo(struct elf_info *info, const char *tag)
813
814{
815 return get_next_modinfo(info, tag, NULL);
816}
817
818/**
819 * Test if string s ends in string sub
820 * return 0 if match
821 **/
822static int strrcmp(const char *s, const char *sub)
823{
824 int slen, sublen;
825
826 if (!s || !sub)
827 return 1;
828
829 slen = strlen(s);
830 sublen = strlen(sub);
831
832 if ((slen == 0) || (sublen == 0))
833 return 1;
834
835 if (sublen > slen)
836 return 1;
837
838 return memcmp(s + slen - sublen, sub, sublen);
839}
840
841static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
842{
843 if (sym)
844 return elf->strtab + sym->st_name;
845 else
846 return "(unknown)";
847}
848
849/* The pattern is an array of simple patterns.
850 * "foo" will match an exact string equal to "foo"
851 * "*foo" will match a string that ends with "foo"
852 * "foo*" will match a string that begins with "foo"
853 * "*foo*" will match a string that contains "foo"
854 */
855static int match(const char *sym, const char * const pat[])
856{
857 const char *p;
858 while (*pat) {
859 p = *pat++;
860 const char *endp = p + strlen(p) - 1;
861
862 /* "*foo*" */
863 if (*p == '*' && *endp == '*') {
864 char *bare = NOFAIL(strndup(p + 1, strlen(p) - 2));
865 char *here = strstr(sym, bare);
866
867 free(bare);
868 if (here != NULL)
869 return 1;
870 }
871 /* "*foo" */
872 else if (*p == '*') {
873 if (strrcmp(sym, p + 1) == 0)
874 return 1;
875 }
876 /* "foo*" */
877 else if (*endp == '*') {
878 if (strncmp(sym, p, strlen(p) - 1) == 0)
879 return 1;
880 }
881 /* no wildcards */
882 else {
883 if (strcmp(p, sym) == 0)
884 return 1;
885 }
886 }
887 /* no match */
888 return 0;
889}
890
891/* sections that we do not want to do full section mismatch check on */
892static const char *const section_white_list[] =
893{
894 ".comment*",
895 ".debug*",
896 ".cranges", /* sh64 */
897 ".zdebug*", /* Compressed debug sections. */
898 ".GCC.command.line", /* record-gcc-switches */
899 ".mdebug*", /* alpha, score, mips etc. */
900 ".pdr", /* alpha, score, mips etc. */
901 ".stab*",
902 ".note*",
903 ".got*",
904 ".toc*",
905 ".xt.prop", /* xtensa */
906 ".xt.lit", /* xtensa */
907 ".arcextmap*", /* arc */
908 ".gnu.linkonce.arcext*", /* arc : modules */
909 ".cmem*", /* EZchip */
910 ".fmt_slot*", /* EZchip */
911 ".gnu.lto*",
912 ".discard.*",
913 NULL
914};
915
916/*
917 * This is used to find sections missing the SHF_ALLOC flag.
918 * The cause of this is often a section specified in assembler
919 * without "ax" / "aw".
920 */
921static void check_section(const char *modname, struct elf_info *elf,
922 Elf_Shdr *sechdr)
923{
924 const char *sec = sech_name(elf, sechdr);
925
926 if (sechdr->sh_type == SHT_PROGBITS &&
927 !(sechdr->sh_flags & SHF_ALLOC) &&
928 !match(sec, section_white_list)) {
929 warn("%s (%s): unexpected non-allocatable section.\n"
930 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
931 "Note that for example <linux/init.h> contains\n"
932 "section definitions for use in .S files.\n\n",
933 modname, sec);
934 }
935}
936
937
938
939#define ALL_INIT_DATA_SECTIONS \
940 ".init.setup", ".init.rodata", ".meminit.rodata", \
941 ".init.data", ".meminit.data"
942#define ALL_EXIT_DATA_SECTIONS \
943 ".exit.data", ".memexit.data"
944
945#define ALL_INIT_TEXT_SECTIONS \
946 ".init.text", ".meminit.text"
947#define ALL_EXIT_TEXT_SECTIONS \
948 ".exit.text", ".memexit.text"
949
950#define ALL_PCI_INIT_SECTIONS \
951 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
952 ".pci_fixup_enable", ".pci_fixup_resume", \
953 ".pci_fixup_resume_early", ".pci_fixup_suspend"
954
955#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
956#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
957
958#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
959#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
960
961#define DATA_SECTIONS ".data", ".data.rel"
962#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
963 ".kprobes.text", ".cpuidle.text"
964#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
965 ".fixup", ".entry.text", ".exception.text", ".text.*", \
966 ".coldtext"
967
968#define INIT_SECTIONS ".init.*"
969#define MEM_INIT_SECTIONS ".meminit.*"
970
971#define EXIT_SECTIONS ".exit.*"
972#define MEM_EXIT_SECTIONS ".memexit.*"
973
974#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
975 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
976
977/* init data sections */
978static const char *const init_data_sections[] =
979 { ALL_INIT_DATA_SECTIONS, NULL };
980
981/* all init sections */
982static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
983
984/* All init and exit sections (code + data) */
985static const char *const init_exit_sections[] =
986 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
987
988/* all text sections */
989static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
990
991/* data section */
992static const char *const data_sections[] = { DATA_SECTIONS, NULL };
993
994
995/* symbols in .data that may refer to init/exit sections */
996#define DEFAULT_SYMBOL_WHITE_LIST \
997 "*driver", \
998 "*_template", /* scsi uses *_template a lot */ \
999 "*_timer", /* arm uses ops structures named _timer a lot */ \
1000 "*_sht", /* scsi also used *_sht to some extent */ \
1001 "*_ops", \
1002 "*_probe", \
1003 "*_probe_one", \
1004 "*_console"
1005
1006static const char *const head_sections[] = { ".head.text*", NULL };
1007static const char *const linker_symbols[] =
1008 { "__init_begin", "_sinittext", "_einittext", NULL };
1009static const char *const optim_symbols[] = { "*.constprop.*", NULL };
1010
1011enum mismatch {
1012 TEXT_TO_ANY_INIT,
1013 DATA_TO_ANY_INIT,
1014 TEXT_TO_ANY_EXIT,
1015 DATA_TO_ANY_EXIT,
1016 XXXINIT_TO_SOME_INIT,
1017 XXXEXIT_TO_SOME_EXIT,
1018 ANY_INIT_TO_ANY_EXIT,
1019 ANY_EXIT_TO_ANY_INIT,
1020 EXPORT_TO_INIT_EXIT,
1021 EXTABLE_TO_NON_TEXT,
1022};
1023
1024/**
1025 * Describe how to match sections on different criterias:
1026 *
1027 * @fromsec: Array of sections to be matched.
1028 *
1029 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
1030 * this array is forbidden (black-list). Can be empty.
1031 *
1032 * @good_tosec: Relocations applied to a section in @fromsec must be
1033 * targetting sections in this array (white-list). Can be empty.
1034 *
1035 * @mismatch: Type of mismatch.
1036 *
1037 * @symbol_white_list: Do not match a relocation to a symbol in this list
1038 * even if it is targetting a section in @bad_to_sec.
1039 *
1040 * @handler: Specific handler to call when a match is found. If NULL,
1041 * default_mismatch_handler() will be called.
1042 *
1043 */
1044struct sectioncheck {
1045 const char *fromsec[20];
1046 const char *bad_tosec[20];
1047 const char *good_tosec[20];
1048 enum mismatch mismatch;
1049 const char *symbol_white_list[20];
1050 void (*handler)(const char *modname, struct elf_info *elf,
1051 const struct sectioncheck* const mismatch,
1052 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
1053
1054};
1055
1056static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1057 const struct sectioncheck* const mismatch,
1058 Elf_Rela *r, Elf_Sym *sym,
1059 const char *fromsec);
1060
1061static const struct sectioncheck sectioncheck[] = {
1062/* Do not reference init/exit code/data from
1063 * normal code and data
1064 */
1065{
1066 .fromsec = { TEXT_SECTIONS, NULL },
1067 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1068 .mismatch = TEXT_TO_ANY_INIT,
1069 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1070},
1071{
1072 .fromsec = { DATA_SECTIONS, NULL },
1073 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1074 .mismatch = DATA_TO_ANY_INIT,
1075 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1076},
1077{
1078 .fromsec = { DATA_SECTIONS, NULL },
1079 .bad_tosec = { INIT_SECTIONS, NULL },
1080 .mismatch = DATA_TO_ANY_INIT,
1081 .symbol_white_list = {
1082 "*_template", "*_timer", "*_sht", "*_ops",
1083 "*_probe", "*_probe_one", "*_console", NULL
1084 },
1085},
1086{
1087 .fromsec = { TEXT_SECTIONS, NULL },
1088 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1089 .mismatch = TEXT_TO_ANY_EXIT,
1090 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1091},
1092{
1093 .fromsec = { DATA_SECTIONS, NULL },
1094 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1095 .mismatch = DATA_TO_ANY_EXIT,
1096 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1097},
1098/* Do not reference init code/data from meminit code/data */
1099{
1100 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1101 .bad_tosec = { INIT_SECTIONS, NULL },
1102 .mismatch = XXXINIT_TO_SOME_INIT,
1103 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1104},
1105/* Do not reference exit code/data from memexit code/data */
1106{
1107 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1108 .bad_tosec = { EXIT_SECTIONS, NULL },
1109 .mismatch = XXXEXIT_TO_SOME_EXIT,
1110 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1111},
1112/* Do not use exit code/data from init code */
1113{
1114 .fromsec = { ALL_INIT_SECTIONS, NULL },
1115 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1116 .mismatch = ANY_INIT_TO_ANY_EXIT,
1117 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1118},
1119/* Do not use init code/data from exit code */
1120{
1121 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1122 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1123 .mismatch = ANY_EXIT_TO_ANY_INIT,
1124 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1125},
1126{
1127 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1128 .bad_tosec = { INIT_SECTIONS, NULL },
1129 .mismatch = ANY_INIT_TO_ANY_EXIT,
1130 .symbol_white_list = { NULL },
1131},
1132/* Do not export init/exit functions or data */
1133{
1134 .fromsec = { "__ksymtab*", NULL },
1135 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1136 .mismatch = EXPORT_TO_INIT_EXIT,
1137 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1138},
1139{
1140 .fromsec = { "__ex_table", NULL },
1141 /* If you're adding any new black-listed sections in here, consider
1142 * adding a special 'printer' for them in scripts/check_extable.
1143 */
1144 .bad_tosec = { ".altinstr_replacement", NULL },
1145 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1146 .mismatch = EXTABLE_TO_NON_TEXT,
1147 .handler = extable_mismatch_handler,
1148}
1149};
1150
1151static const struct sectioncheck *section_mismatch(
1152 const char *fromsec, const char *tosec)
1153{
1154 int i;
1155 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1156 const struct sectioncheck *check = §ioncheck[0];
1157
1158 /*
1159 * The target section could be the SHT_NUL section when we're
1160 * handling relocations to un-resolved symbols, trying to match it
1161 * doesn't make much sense and causes build failures on parisc
1162 * architectures.
1163 */
1164 if (*tosec == '\0')
1165 return NULL;
1166
1167 for (i = 0; i < elems; i++) {
1168 if (match(fromsec, check->fromsec)) {
1169 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1170 return check;
1171 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1172 return check;
1173 }
1174 check++;
1175 }
1176 return NULL;
1177}
1178
1179/**
1180 * Whitelist to allow certain references to pass with no warning.
1181 *
1182 * Pattern 1:
1183 * If a module parameter is declared __initdata and permissions=0
1184 * then this is legal despite the warning generated.
1185 * We cannot see value of permissions here, so just ignore
1186 * this pattern.
1187 * The pattern is identified by:
1188 * tosec = .init.data
1189 * fromsec = .data*
1190 * atsym =__param*
1191 *
1192 * Pattern 1a:
1193 * module_param_call() ops can refer to __init set function if permissions=0
1194 * The pattern is identified by:
1195 * tosec = .init.text
1196 * fromsec = .data*
1197 * atsym = __param_ops_*
1198 *
1199 * Pattern 2:
1200 * Many drivers utilise a *driver container with references to
1201 * add, remove, probe functions etc.
1202 * the pattern is identified by:
1203 * tosec = init or exit section
1204 * fromsec = data section
1205 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1206 * *probe_one, *_console, *_timer
1207 *
1208 * Pattern 3:
1209 * Whitelist all references from .head.text to any init section
1210 *
1211 * Pattern 4:
1212 * Some symbols belong to init section but still it is ok to reference
1213 * these from non-init sections as these symbols don't have any memory
1214 * allocated for them and symbol address and value are same. So even
1215 * if init section is freed, its ok to reference those symbols.
1216 * For ex. symbols marking the init section boundaries.
1217 * This pattern is identified by
1218 * refsymname = __init_begin, _sinittext, _einittext
1219 *
1220 * Pattern 5:
1221 * GCC may optimize static inlines when fed constant arg(s) resulting
1222 * in functions like cpumask_empty() -- generating an associated symbol
1223 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1224 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1225 * meaningless section warning. May need to add isra symbols too...
1226 * This pattern is identified by
1227 * tosec = init section
1228 * fromsec = text section
1229 * refsymname = *.constprop.*
1230 *
1231 * Pattern 6:
1232 * Hide section mismatch warnings for ELF local symbols. The goal
1233 * is to eliminate false positive modpost warnings caused by
1234 * compiler-generated ELF local symbol names such as ".LANCHOR1".
1235 * Autogenerated symbol names bypass modpost's "Pattern 2"
1236 * whitelisting, which relies on pattern-matching against symbol
1237 * names to work. (One situation where gcc can autogenerate ELF
1238 * local symbols is when "-fsection-anchors" is used.)
1239 **/
1240static int secref_whitelist(const struct sectioncheck *mismatch,
1241 const char *fromsec, const char *fromsym,
1242 const char *tosec, const char *tosym)
1243{
1244 /* Check for pattern 1 */
1245 if (match(tosec, init_data_sections) &&
1246 match(fromsec, data_sections) &&
1247 strstarts(fromsym, "__param"))
1248 return 0;
1249
1250 /* Check for pattern 1a */
1251 if (strcmp(tosec, ".init.text") == 0 &&
1252 match(fromsec, data_sections) &&
1253 strstarts(fromsym, "__param_ops_"))
1254 return 0;
1255
1256 /* Check for pattern 2 */
1257 if (match(tosec, init_exit_sections) &&
1258 match(fromsec, data_sections) &&
1259 match(fromsym, mismatch->symbol_white_list))
1260 return 0;
1261
1262 /* Check for pattern 3 */
1263 if (match(fromsec, head_sections) &&
1264 match(tosec, init_sections))
1265 return 0;
1266
1267 /* Check for pattern 4 */
1268 if (match(tosym, linker_symbols))
1269 return 0;
1270
1271 /* Check for pattern 5 */
1272 if (match(fromsec, text_sections) &&
1273 match(tosec, init_sections) &&
1274 match(fromsym, optim_symbols))
1275 return 0;
1276
1277 /* Check for pattern 6 */
1278 if (strstarts(fromsym, ".L"))
1279 return 0;
1280
1281 return 1;
1282}
1283
1284static inline int is_arm_mapping_symbol(const char *str)
1285{
1286 return str[0] == '$' && strchr("axtd", str[1])
1287 && (str[2] == '\0' || str[2] == '.');
1288}
1289
1290/*
1291 * If there's no name there, ignore it; likewise, ignore it if it's
1292 * one of the magic symbols emitted used by current ARM tools.
1293 *
1294 * Otherwise if find_symbols_between() returns those symbols, they'll
1295 * fail the whitelist tests and cause lots of false alarms ... fixable
1296 * only by merging __exit and __init sections into __text, bloating
1297 * the kernel (which is especially evil on embedded platforms).
1298 */
1299static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1300{
1301 const char *name = elf->strtab + sym->st_name;
1302
1303 if (!name || !strlen(name))
1304 return 0;
1305 return !is_arm_mapping_symbol(name);
1306}
1307
1308/**
1309 * Find symbol based on relocation record info.
1310 * In some cases the symbol supplied is a valid symbol so
1311 * return refsym. If st_name != 0 we assume this is a valid symbol.
1312 * In other cases the symbol needs to be looked up in the symbol table
1313 * based on section and address.
1314 * **/
1315static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1316 Elf_Sym *relsym)
1317{
1318 Elf_Sym *sym;
1319 Elf_Sym *near = NULL;
1320 Elf64_Sword distance = 20;
1321 Elf64_Sword d;
1322 unsigned int relsym_secindex;
1323
1324 if (relsym->st_name != 0)
1325 return relsym;
1326
1327 relsym_secindex = get_secindex(elf, relsym);
1328 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1329 if (get_secindex(elf, sym) != relsym_secindex)
1330 continue;
1331 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1332 continue;
1333 if (!is_valid_name(elf, sym))
1334 continue;
1335 if (sym->st_value == addr)
1336 return sym;
1337 /* Find a symbol nearby - addr are maybe negative */
1338 d = sym->st_value - addr;
1339 if (d < 0)
1340 d = addr - sym->st_value;
1341 if (d < distance) {
1342 distance = d;
1343 near = sym;
1344 }
1345 }
1346 /* We need a close match */
1347 if (distance < 20)
1348 return near;
1349 else
1350 return NULL;
1351}
1352
1353/*
1354 * Find symbols before or equal addr and after addr - in the section sec.
1355 * If we find two symbols with equal offset prefer one with a valid name.
1356 * The ELF format may have a better way to detect what type of symbol
1357 * it is, but this works for now.
1358 **/
1359static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1360 const char *sec)
1361{
1362 Elf_Sym *sym;
1363 Elf_Sym *near = NULL;
1364 Elf_Addr distance = ~0;
1365
1366 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1367 const char *symsec;
1368
1369 if (is_shndx_special(sym->st_shndx))
1370 continue;
1371 symsec = sec_name(elf, get_secindex(elf, sym));
1372 if (strcmp(symsec, sec) != 0)
1373 continue;
1374 if (!is_valid_name(elf, sym))
1375 continue;
1376 if (sym->st_value <= addr) {
1377 if ((addr - sym->st_value) < distance) {
1378 distance = addr - sym->st_value;
1379 near = sym;
1380 } else if ((addr - sym->st_value) == distance) {
1381 near = sym;
1382 }
1383 }
1384 }
1385 return near;
1386}
1387
1388/*
1389 * Convert a section name to the function/data attribute
1390 * .init.text => __init
1391 * .memexitconst => __memconst
1392 * etc.
1393 *
1394 * The memory of returned value has been allocated on a heap. The user of this
1395 * method should free it after usage.
1396*/
1397static char *sec2annotation(const char *s)
1398{
1399 if (match(s, init_exit_sections)) {
1400 char *p = NOFAIL(malloc(20));
1401 char *r = p;
1402
1403 *p++ = '_';
1404 *p++ = '_';
1405 if (*s == '.')
1406 s++;
1407 while (*s && *s != '.')
1408 *p++ = *s++;
1409 *p = '\0';
1410 if (*s == '.')
1411 s++;
1412 if (strstr(s, "rodata") != NULL)
1413 strcat(p, "const ");
1414 else if (strstr(s, "data") != NULL)
1415 strcat(p, "data ");
1416 else
1417 strcat(p, " ");
1418 return r;
1419 } else {
1420 return NOFAIL(strdup(""));
1421 }
1422}
1423
1424static int is_function(Elf_Sym *sym)
1425{
1426 if (sym)
1427 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1428 else
1429 return -1;
1430}
1431
1432static void print_section_list(const char * const list[20])
1433{
1434 const char *const *s = list;
1435
1436 while (*s) {
1437 fprintf(stderr, "%s", *s);
1438 s++;
1439 if (*s)
1440 fprintf(stderr, ", ");
1441 }
1442 fprintf(stderr, "\n");
1443}
1444
1445static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1446{
1447 switch (is_func) {
1448 case 0: *name = "variable"; *name_p = ""; break;
1449 case 1: *name = "function"; *name_p = "()"; break;
1450 default: *name = "(unknown reference)"; *name_p = ""; break;
1451 }
1452}
1453
1454/*
1455 * Print a warning about a section mismatch.
1456 * Try to find symbols near it so user can find it.
1457 * Check whitelist before warning - it may be a false positive.
1458 */
1459static void report_sec_mismatch(const char *modname,
1460 const struct sectioncheck *mismatch,
1461 const char *fromsec,
1462 unsigned long long fromaddr,
1463 const char *fromsym,
1464 int from_is_func,
1465 const char *tosec, const char *tosym,
1466 int to_is_func)
1467{
1468 const char *from, *from_p;
1469 const char *to, *to_p;
1470 char *prl_from;
1471 char *prl_to;
1472
1473 sec_mismatch_count++;
1474
1475 get_pretty_name(from_is_func, &from, &from_p);
1476 get_pretty_name(to_is_func, &to, &to_p);
1477
1478 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1479 "to the %s %s:%s%s\n",
1480 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1481 tosym, to_p);
1482
1483 switch (mismatch->mismatch) {
1484 case TEXT_TO_ANY_INIT:
1485 prl_from = sec2annotation(fromsec);
1486 prl_to = sec2annotation(tosec);
1487 fprintf(stderr,
1488 "The function %s%s() references\n"
1489 "the %s %s%s%s.\n"
1490 "This is often because %s lacks a %s\n"
1491 "annotation or the annotation of %s is wrong.\n",
1492 prl_from, fromsym,
1493 to, prl_to, tosym, to_p,
1494 fromsym, prl_to, tosym);
1495 free(prl_from);
1496 free(prl_to);
1497 break;
1498 case DATA_TO_ANY_INIT: {
1499 prl_to = sec2annotation(tosec);
1500 fprintf(stderr,
1501 "The variable %s references\n"
1502 "the %s %s%s%s\n"
1503 "If the reference is valid then annotate the\n"
1504 "variable with __init* or __refdata (see linux/init.h) "
1505 "or name the variable:\n",
1506 fromsym, to, prl_to, tosym, to_p);
1507 print_section_list(mismatch->symbol_white_list);
1508 free(prl_to);
1509 break;
1510 }
1511 case TEXT_TO_ANY_EXIT:
1512 prl_to = sec2annotation(tosec);
1513 fprintf(stderr,
1514 "The function %s() references a %s in an exit section.\n"
1515 "Often the %s %s%s has valid usage outside the exit section\n"
1516 "and the fix is to remove the %sannotation of %s.\n",
1517 fromsym, to, to, tosym, to_p, prl_to, tosym);
1518 free(prl_to);
1519 break;
1520 case DATA_TO_ANY_EXIT: {
1521 prl_to = sec2annotation(tosec);
1522 fprintf(stderr,
1523 "The variable %s references\n"
1524 "the %s %s%s%s\n"
1525 "If the reference is valid then annotate the\n"
1526 "variable with __exit* (see linux/init.h) or "
1527 "name the variable:\n",
1528 fromsym, to, prl_to, tosym, to_p);
1529 print_section_list(mismatch->symbol_white_list);
1530 free(prl_to);
1531 break;
1532 }
1533 case XXXINIT_TO_SOME_INIT:
1534 case XXXEXIT_TO_SOME_EXIT:
1535 prl_from = sec2annotation(fromsec);
1536 prl_to = sec2annotation(tosec);
1537 fprintf(stderr,
1538 "The %s %s%s%s references\n"
1539 "a %s %s%s%s.\n"
1540 "If %s is only used by %s then\n"
1541 "annotate %s with a matching annotation.\n",
1542 from, prl_from, fromsym, from_p,
1543 to, prl_to, tosym, to_p,
1544 tosym, fromsym, tosym);
1545 free(prl_from);
1546 free(prl_to);
1547 break;
1548 case ANY_INIT_TO_ANY_EXIT:
1549 prl_from = sec2annotation(fromsec);
1550 prl_to = sec2annotation(tosec);
1551 fprintf(stderr,
1552 "The %s %s%s%s references\n"
1553 "a %s %s%s%s.\n"
1554 "This is often seen when error handling "
1555 "in the init function\n"
1556 "uses functionality in the exit path.\n"
1557 "The fix is often to remove the %sannotation of\n"
1558 "%s%s so it may be used outside an exit section.\n",
1559 from, prl_from, fromsym, from_p,
1560 to, prl_to, tosym, to_p,
1561 prl_to, tosym, to_p);
1562 free(prl_from);
1563 free(prl_to);
1564 break;
1565 case ANY_EXIT_TO_ANY_INIT:
1566 prl_from = sec2annotation(fromsec);
1567 prl_to = sec2annotation(tosec);
1568 fprintf(stderr,
1569 "The %s %s%s%s references\n"
1570 "a %s %s%s%s.\n"
1571 "This is often seen when error handling "
1572 "in the exit function\n"
1573 "uses functionality in the init path.\n"
1574 "The fix is often to remove the %sannotation of\n"
1575 "%s%s so it may be used outside an init section.\n",
1576 from, prl_from, fromsym, from_p,
1577 to, prl_to, tosym, to_p,
1578 prl_to, tosym, to_p);
1579 free(prl_from);
1580 free(prl_to);
1581 break;
1582 case EXPORT_TO_INIT_EXIT:
1583 prl_to = sec2annotation(tosec);
1584 fprintf(stderr,
1585 "The symbol %s is exported and annotated %s\n"
1586 "Fix this by removing the %sannotation of %s "
1587 "or drop the export.\n",
1588 tosym, prl_to, prl_to, tosym);
1589 free(prl_to);
1590 break;
1591 case EXTABLE_TO_NON_TEXT:
1592 fatal("There's a special handler for this mismatch type, "
1593 "we should never get here.");
1594 break;
1595 }
1596 fprintf(stderr, "\n");
1597}
1598
1599static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1600 const struct sectioncheck* const mismatch,
1601 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1602{
1603 const char *tosec;
1604 Elf_Sym *to;
1605 Elf_Sym *from;
1606 const char *tosym;
1607 const char *fromsym;
1608
1609 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1610 fromsym = sym_name(elf, from);
1611
1612 if (strstarts(fromsym, "reference___initcall"))
1613 return;
1614
1615 tosec = sec_name(elf, get_secindex(elf, sym));
1616 to = find_elf_symbol(elf, r->r_addend, sym);
1617 tosym = sym_name(elf, to);
1618
1619 /* check whitelist - we may ignore it */
1620 if (secref_whitelist(mismatch,
1621 fromsec, fromsym, tosec, tosym)) {
1622 report_sec_mismatch(modname, mismatch,
1623 fromsec, r->r_offset, fromsym,
1624 is_function(from), tosec, tosym,
1625 is_function(to));
1626 }
1627}
1628
1629static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1630{
1631 if (section_index > elf->num_sections)
1632 fatal("section_index is outside elf->num_sections!\n");
1633
1634 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1635}
1636
1637/*
1638 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1639 * to know the sizeof(struct exception_table_entry) for the target architecture.
1640 */
1641static unsigned int extable_entry_size = 0;
1642static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1643{
1644 /*
1645 * If we're currently checking the second relocation within __ex_table,
1646 * that relocation offset tells us the offsetof(struct
1647 * exception_table_entry, fixup) which is equal to sizeof(struct
1648 * exception_table_entry) divided by two. We use that to our advantage
1649 * since there's no portable way to get that size as every architecture
1650 * seems to go with different sized types. Not pretty but better than
1651 * hard-coding the size for every architecture..
1652 */
1653 if (!extable_entry_size)
1654 extable_entry_size = r->r_offset * 2;
1655}
1656
1657static inline bool is_extable_fault_address(Elf_Rela *r)
1658{
1659 /*
1660 * extable_entry_size is only discovered after we've handled the
1661 * _second_ relocation in __ex_table, so only abort when we're not
1662 * handling the first reloc and extable_entry_size is zero.
1663 */
1664 if (r->r_offset && extable_entry_size == 0)
1665 fatal("extable_entry size hasn't been discovered!\n");
1666
1667 return ((r->r_offset == 0) ||
1668 (r->r_offset % extable_entry_size == 0));
1669}
1670
1671#define is_second_extable_reloc(Start, Cur, Sec) \
1672 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1673
1674static void report_extable_warnings(const char* modname, struct elf_info* elf,
1675 const struct sectioncheck* const mismatch,
1676 Elf_Rela* r, Elf_Sym* sym,
1677 const char* fromsec, const char* tosec)
1678{
1679 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1680 const char* fromsym_name = sym_name(elf, fromsym);
1681 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1682 const char* tosym_name = sym_name(elf, tosym);
1683 const char* from_pretty_name;
1684 const char* from_pretty_name_p;
1685 const char* to_pretty_name;
1686 const char* to_pretty_name_p;
1687
1688 get_pretty_name(is_function(fromsym),
1689 &from_pretty_name, &from_pretty_name_p);
1690 get_pretty_name(is_function(tosym),
1691 &to_pretty_name, &to_pretty_name_p);
1692
1693 warn("%s(%s+0x%lx): Section mismatch in reference"
1694 " from the %s %s%s to the %s %s:%s%s\n",
1695 modname, fromsec, (long)r->r_offset, from_pretty_name,
1696 fromsym_name, from_pretty_name_p,
1697 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1698
1699 if (!match(tosec, mismatch->bad_tosec) &&
1700 is_executable_section(elf, get_secindex(elf, sym)))
1701 fprintf(stderr,
1702 "The relocation at %s+0x%lx references\n"
1703 "section \"%s\" which is not in the list of\n"
1704 "authorized sections. If you're adding a new section\n"
1705 "and/or if this reference is valid, add \"%s\" to the\n"
1706 "list of authorized sections to jump to on fault.\n"
1707 "This can be achieved by adding \"%s\" to \n"
1708 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1709 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1710}
1711
1712static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1713 const struct sectioncheck* const mismatch,
1714 Elf_Rela* r, Elf_Sym* sym,
1715 const char *fromsec)
1716{
1717 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1718
1719 sec_mismatch_count++;
1720
1721 report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec);
1722
1723 if (match(tosec, mismatch->bad_tosec))
1724 fatal("The relocation at %s+0x%lx references\n"
1725 "section \"%s\" which is black-listed.\n"
1726 "Something is seriously wrong and should be fixed.\n"
1727 "You might get more information about where this is\n"
1728 "coming from by using scripts/check_extable.sh %s\n",
1729 fromsec, (long)r->r_offset, tosec, modname);
1730 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1731 if (is_extable_fault_address(r))
1732 fatal("The relocation at %s+0x%lx references\n"
1733 "section \"%s\" which is not executable, IOW\n"
1734 "it is not possible for the kernel to fault\n"
1735 "at that address. Something is seriously wrong\n"
1736 "and should be fixed.\n",
1737 fromsec, (long)r->r_offset, tosec);
1738 else
1739 fatal("The relocation at %s+0x%lx references\n"
1740 "section \"%s\" which is not executable, IOW\n"
1741 "the kernel will fault if it ever tries to\n"
1742 "jump to it. Something is seriously wrong\n"
1743 "and should be fixed.\n",
1744 fromsec, (long)r->r_offset, tosec);
1745 }
1746}
1747
1748static void check_section_mismatch(const char *modname, struct elf_info *elf,
1749 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1750{
1751 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1752 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1753
1754 if (mismatch) {
1755 if (mismatch->handler)
1756 mismatch->handler(modname, elf, mismatch,
1757 r, sym, fromsec);
1758 else
1759 default_mismatch_handler(modname, elf, mismatch,
1760 r, sym, fromsec);
1761 }
1762}
1763
1764static unsigned int *reloc_location(struct elf_info *elf,
1765 Elf_Shdr *sechdr, Elf_Rela *r)
1766{
1767 Elf_Shdr *sechdrs = elf->sechdrs;
1768 int section = sechdr->sh_info;
1769
1770 return (void *)elf->hdr + sechdrs[section].sh_offset +
1771 r->r_offset;
1772}
1773
1774static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1775{
1776 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1777 unsigned int *location = reloc_location(elf, sechdr, r);
1778
1779 switch (r_typ) {
1780 case R_386_32:
1781 r->r_addend = TO_NATIVE(*location);
1782 break;
1783 case R_386_PC32:
1784 r->r_addend = TO_NATIVE(*location) + 4;
1785 /* For CONFIG_RELOCATABLE=y */
1786 if (elf->hdr->e_type == ET_EXEC)
1787 r->r_addend += r->r_offset;
1788 break;
1789 }
1790 return 0;
1791}
1792
1793#ifndef R_ARM_CALL
1794#define R_ARM_CALL 28
1795#endif
1796#ifndef R_ARM_JUMP24
1797#define R_ARM_JUMP24 29
1798#endif
1799
1800#ifndef R_ARM_THM_CALL
1801#define R_ARM_THM_CALL 10
1802#endif
1803#ifndef R_ARM_THM_JUMP24
1804#define R_ARM_THM_JUMP24 30
1805#endif
1806#ifndef R_ARM_THM_JUMP19
1807#define R_ARM_THM_JUMP19 51
1808#endif
1809
1810static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1811{
1812 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1813
1814 switch (r_typ) {
1815 case R_ARM_ABS32:
1816 /* From ARM ABI: (S + A) | T */
1817 r->r_addend = (int)(long)
1818 (elf->symtab_start + ELF_R_SYM(r->r_info));
1819 break;
1820 case R_ARM_PC24:
1821 case R_ARM_CALL:
1822 case R_ARM_JUMP24:
1823 case R_ARM_THM_CALL:
1824 case R_ARM_THM_JUMP24:
1825 case R_ARM_THM_JUMP19:
1826 /* From ARM ABI: ((S + A) | T) - P */
1827 r->r_addend = (int)(long)(elf->hdr +
1828 sechdr->sh_offset +
1829 (r->r_offset - sechdr->sh_addr));
1830 break;
1831 default:
1832 return 1;
1833 }
1834 return 0;
1835}
1836
1837static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1838{
1839 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1840 unsigned int *location = reloc_location(elf, sechdr, r);
1841 unsigned int inst;
1842
1843 if (r_typ == R_MIPS_HI16)
1844 return 1; /* skip this */
1845 inst = TO_NATIVE(*location);
1846 switch (r_typ) {
1847 case R_MIPS_LO16:
1848 r->r_addend = inst & 0xffff;
1849 break;
1850 case R_MIPS_26:
1851 r->r_addend = (inst & 0x03ffffff) << 2;
1852 break;
1853 case R_MIPS_32:
1854 r->r_addend = inst;
1855 break;
1856 }
1857 return 0;
1858}
1859
1860static void section_rela(const char *modname, struct elf_info *elf,
1861 Elf_Shdr *sechdr)
1862{
1863 Elf_Sym *sym;
1864 Elf_Rela *rela;
1865 Elf_Rela r;
1866 unsigned int r_sym;
1867 const char *fromsec;
1868
1869 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1870 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1871
1872 fromsec = sech_name(elf, sechdr);
1873 fromsec += strlen(".rela");
1874 /* if from section (name) is know good then skip it */
1875 if (match(fromsec, section_white_list))
1876 return;
1877
1878 for (rela = start; rela < stop; rela++) {
1879 r.r_offset = TO_NATIVE(rela->r_offset);
1880#if KERNEL_ELFCLASS == ELFCLASS64
1881 if (elf->hdr->e_machine == EM_MIPS) {
1882 unsigned int r_typ;
1883 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1884 r_sym = TO_NATIVE(r_sym);
1885 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1886 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1887 } else {
1888 r.r_info = TO_NATIVE(rela->r_info);
1889 r_sym = ELF_R_SYM(r.r_info);
1890 }
1891#else
1892 r.r_info = TO_NATIVE(rela->r_info);
1893 r_sym = ELF_R_SYM(r.r_info);
1894#endif
1895 r.r_addend = TO_NATIVE(rela->r_addend);
1896 sym = elf->symtab_start + r_sym;
1897 /* Skip special sections */
1898 if (is_shndx_special(sym->st_shndx))
1899 continue;
1900 if (is_second_extable_reloc(start, rela, fromsec))
1901 find_extable_entry_size(fromsec, &r);
1902 check_section_mismatch(modname, elf, &r, sym, fromsec);
1903 }
1904}
1905
1906static void section_rel(const char *modname, struct elf_info *elf,
1907 Elf_Shdr *sechdr)
1908{
1909 Elf_Sym *sym;
1910 Elf_Rel *rel;
1911 Elf_Rela r;
1912 unsigned int r_sym;
1913 const char *fromsec;
1914
1915 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1916 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1917
1918 fromsec = sech_name(elf, sechdr);
1919 fromsec += strlen(".rel");
1920 /* if from section (name) is know good then skip it */
1921 if (match(fromsec, section_white_list))
1922 return;
1923
1924 for (rel = start; rel < stop; rel++) {
1925 r.r_offset = TO_NATIVE(rel->r_offset);
1926#if KERNEL_ELFCLASS == ELFCLASS64
1927 if (elf->hdr->e_machine == EM_MIPS) {
1928 unsigned int r_typ;
1929 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1930 r_sym = TO_NATIVE(r_sym);
1931 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1932 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1933 } else {
1934 r.r_info = TO_NATIVE(rel->r_info);
1935 r_sym = ELF_R_SYM(r.r_info);
1936 }
1937#else
1938 r.r_info = TO_NATIVE(rel->r_info);
1939 r_sym = ELF_R_SYM(r.r_info);
1940#endif
1941 r.r_addend = 0;
1942 switch (elf->hdr->e_machine) {
1943 case EM_386:
1944 if (addend_386_rel(elf, sechdr, &r))
1945 continue;
1946 break;
1947 case EM_ARM:
1948 if (addend_arm_rel(elf, sechdr, &r))
1949 continue;
1950 break;
1951 case EM_MIPS:
1952 if (addend_mips_rel(elf, sechdr, &r))
1953 continue;
1954 break;
1955 }
1956 sym = elf->symtab_start + r_sym;
1957 /* Skip special sections */
1958 if (is_shndx_special(sym->st_shndx))
1959 continue;
1960 if (is_second_extable_reloc(start, rel, fromsec))
1961 find_extable_entry_size(fromsec, &r);
1962 check_section_mismatch(modname, elf, &r, sym, fromsec);
1963 }
1964}
1965
1966/**
1967 * A module includes a number of sections that are discarded
1968 * either when loaded or when used as built-in.
1969 * For loaded modules all functions marked __init and all data
1970 * marked __initdata will be discarded when the module has been initialized.
1971 * Likewise for modules used built-in the sections marked __exit
1972 * are discarded because __exit marked function are supposed to be called
1973 * only when a module is unloaded which never happens for built-in modules.
1974 * The check_sec_ref() function traverses all relocation records
1975 * to find all references to a section that reference a section that will
1976 * be discarded and warns about it.
1977 **/
1978static void check_sec_ref(struct module *mod, const char *modname,
1979 struct elf_info *elf)
1980{
1981 int i;
1982 Elf_Shdr *sechdrs = elf->sechdrs;
1983
1984 /* Walk through all sections */
1985 for (i = 0; i < elf->num_sections; i++) {
1986 check_section(modname, elf, &elf->sechdrs[i]);
1987 /* We want to process only relocation sections and not .init */
1988 if (sechdrs[i].sh_type == SHT_RELA)
1989 section_rela(modname, elf, &elf->sechdrs[i]);
1990 else if (sechdrs[i].sh_type == SHT_REL)
1991 section_rel(modname, elf, &elf->sechdrs[i]);
1992 }
1993}
1994
1995static char *remove_dot(char *s)
1996{
1997 size_t n = strcspn(s, ".");
1998
1999 if (n && s[n]) {
2000 size_t m = strspn(s + n + 1, "0123456789");
2001 if (m && (s[n + m] == '.' || s[n + m] == 0))
2002 s[n] = 0;
2003 }
2004 return s;
2005}
2006
2007static void read_symbols(const char *modname)
2008{
2009 const char *symname;
2010 char *version;
2011 char *license;
2012 char *namespace;
2013 struct module *mod;
2014 struct elf_info info = { };
2015 Elf_Sym *sym;
2016
2017 if (!parse_elf(&info, modname))
2018 return;
2019
2020 mod = new_module(modname);
2021
2022 /* When there's no vmlinux, don't print warnings about
2023 * unresolved symbols (since there'll be too many ;) */
2024 if (is_vmlinux(modname)) {
2025 have_vmlinux = 1;
2026 mod->skip = 1;
2027 }
2028
2029 license = get_modinfo(&info, "license");
2030 if (!license && !is_vmlinux(modname))
2031 warn("modpost: missing MODULE_LICENSE() in %s\n"
2032 "see include/linux/module.h for "
2033 "more information\n", modname);
2034 while (license) {
2035 if (license_is_gpl_compatible(license))
2036 mod->gpl_compatible = 1;
2037 else {
2038 mod->gpl_compatible = 0;
2039 break;
2040 }
2041 license = get_next_modinfo(&info, "license", license);
2042 }
2043
2044 namespace = get_modinfo(&info, "import_ns");
2045 while (namespace) {
2046 add_namespace(&mod->imported_namespaces, namespace);
2047 namespace = get_next_modinfo(&info, "import_ns", namespace);
2048 }
2049
2050 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2051 symname = remove_dot(info.strtab + sym->st_name);
2052
2053 handle_modversions(mod, &info, sym, symname);
2054 handle_moddevtable(mod, &info, sym, symname);
2055 }
2056
2057 /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
2058 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2059 symname = remove_dot(info.strtab + sym->st_name);
2060
2061 if (strstarts(symname, "__kstrtabns_"))
2062 sym_update_namespace(symname + strlen("__kstrtabns_"),
2063 namespace_from_kstrtabns(&info,
2064 sym));
2065 }
2066
2067 // check for static EXPORT_SYMBOL_* functions && global vars
2068 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2069 unsigned char bind = ELF_ST_BIND(sym->st_info);
2070
2071 if (bind == STB_GLOBAL || bind == STB_WEAK) {
2072 struct symbol *s =
2073 find_symbol(remove_dot(info.strtab +
2074 sym->st_name));
2075
2076 if (s)
2077 s->is_static = 0;
2078 }
2079 }
2080
2081 if (!is_vmlinux(modname) || vmlinux_section_warnings)
2082 check_sec_ref(mod, modname, &info);
2083
2084 version = get_modinfo(&info, "version");
2085 if (version)
2086 maybe_frob_rcs_version(modname, version, info.modinfo,
2087 version - (char *)info.hdr);
2088 if (version || (all_versions && !is_vmlinux(modname)))
2089 get_src_version(modname, mod->srcversion,
2090 sizeof(mod->srcversion)-1);
2091
2092 parse_elf_finish(&info);
2093
2094 /* Our trick to get versioning for module struct etc. - it's
2095 * never passed as an argument to an exported function, so
2096 * the automatic versioning doesn't pick it up, but it's really
2097 * important anyhow */
2098 if (modversions)
2099 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2100}
2101
2102static void read_symbols_from_files(const char *filename)
2103{
2104 FILE *in = stdin;
2105 char fname[PATH_MAX];
2106
2107 if (strcmp(filename, "-") != 0) {
2108 in = fopen(filename, "r");
2109 if (!in)
2110 fatal("Can't open filenames file %s: %m", filename);
2111 }
2112
2113 while (fgets(fname, PATH_MAX, in) != NULL) {
2114 if (strends(fname, "\n"))
2115 fname[strlen(fname)-1] = '\0';
2116 read_symbols(fname);
2117 }
2118
2119 if (in != stdin)
2120 fclose(in);
2121}
2122
2123#define SZ 500
2124
2125/* We first write the generated file into memory using the
2126 * following helper, then compare to the file on disk and
2127 * only update the later if anything changed */
2128
2129void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2130 const char *fmt, ...)
2131{
2132 char tmp[SZ];
2133 int len;
2134 va_list ap;
2135
2136 va_start(ap, fmt);
2137 len = vsnprintf(tmp, SZ, fmt, ap);
2138 buf_write(buf, tmp, len);
2139 va_end(ap);
2140}
2141
2142void buf_write(struct buffer *buf, const char *s, int len)
2143{
2144 if (buf->size - buf->pos < len) {
2145 buf->size += len + SZ;
2146 buf->p = NOFAIL(realloc(buf->p, buf->size));
2147 }
2148 strncpy(buf->p + buf->pos, s, len);
2149 buf->pos += len;
2150}
2151
2152static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2153{
2154 const char *e = is_vmlinux(m) ?"":".ko";
2155
2156 switch (exp) {
2157 case export_gpl:
2158 fatal("modpost: GPL-incompatible module %s%s "
2159 "uses GPL-only symbol '%s'\n", m, e, s);
2160 break;
2161 case export_unused_gpl:
2162 fatal("modpost: GPL-incompatible module %s%s "
2163 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2164 break;
2165 case export_gpl_future:
2166 warn("modpost: GPL-incompatible module %s%s "
2167 "uses future GPL-only symbol '%s'\n", m, e, s);
2168 break;
2169 case export_plain:
2170 case export_unused:
2171 case export_unknown:
2172 /* ignore */
2173 break;
2174 }
2175}
2176
2177static void check_for_unused(enum export exp, const char *m, const char *s)
2178{
2179 const char *e = is_vmlinux(m) ?"":".ko";
2180
2181 switch (exp) {
2182 case export_unused:
2183 case export_unused_gpl:
2184 warn("modpost: module %s%s "
2185 "uses symbol '%s' marked UNUSED\n", m, e, s);
2186 break;
2187 default:
2188 /* ignore */
2189 break;
2190 }
2191}
2192
2193static int check_exports(struct module *mod)
2194{
2195 struct symbol *s, *exp;
2196 int err = 0;
2197
2198 for (s = mod->unres; s; s = s->next) {
2199 const char *basename;
2200 exp = find_symbol(s->name);
2201 if (!exp || exp->module == mod) {
2202 if (have_vmlinux && !s->weak) {
2203 if (warn_unresolved) {
2204 warn("\"%s\" [%s.ko] undefined!\n",
2205 s->name, mod->name);
2206 } else {
2207 merror("\"%s\" [%s.ko] undefined!\n",
2208 s->name, mod->name);
2209 err = 1;
2210 }
2211 }
2212 continue;
2213 }
2214 basename = strrchr(mod->name, '/');
2215 if (basename)
2216 basename++;
2217 else
2218 basename = mod->name;
2219
2220 if (exp->namespace) {
2221 add_namespace(&mod->required_namespaces,
2222 exp->namespace);
2223
2224 if (!write_namespace_deps &&
2225 !module_imports_namespace(mod, exp->namespace)) {
2226 warn("module %s uses symbol %s from namespace %s, but does not import it.\n",
2227 basename, exp->name, exp->namespace);
2228 }
2229 }
2230
2231 if (!mod->gpl_compatible)
2232 check_for_gpl_usage(exp->export, basename, exp->name);
2233 check_for_unused(exp->export, basename, exp->name);
2234 }
2235
2236 return err;
2237}
2238
2239static int check_modname_len(struct module *mod)
2240{
2241 const char *mod_name;
2242
2243 mod_name = strrchr(mod->name, '/');
2244 if (mod_name == NULL)
2245 mod_name = mod->name;
2246 else
2247 mod_name++;
2248 if (strlen(mod_name) >= MODULE_NAME_LEN) {
2249 merror("module name is too long [%s.ko]\n", mod->name);
2250 return 1;
2251 }
2252
2253 return 0;
2254}
2255
2256/**
2257 * Header for the generated file
2258 **/
2259static void add_header(struct buffer *b, struct module *mod)
2260{
2261 buf_printf(b, "#include <linux/build-salt.h>\n");
2262 buf_printf(b, "#include <linux/module.h>\n");
2263 buf_printf(b, "#include <linux/vermagic.h>\n");
2264 buf_printf(b, "#include <linux/compiler.h>\n");
2265 buf_printf(b, "\n");
2266 buf_printf(b, "BUILD_SALT;\n");
2267 buf_printf(b, "\n");
2268 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2269 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
2270 buf_printf(b, "\n");
2271 buf_printf(b, "__visible struct module __this_module\n");
2272 buf_printf(b, "__section(.gnu.linkonce.this_module) = {\n");
2273 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2274 if (mod->has_init)
2275 buf_printf(b, "\t.init = init_module,\n");
2276 if (mod->has_cleanup)
2277 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2278 "\t.exit = cleanup_module,\n"
2279 "#endif\n");
2280 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2281 buf_printf(b, "};\n");
2282}
2283
2284static void add_intree_flag(struct buffer *b, int is_intree)
2285{
2286 if (is_intree)
2287 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2288}
2289
2290/* Cannot check for assembler */
2291static void add_retpoline(struct buffer *b)
2292{
2293 buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
2294 buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
2295 buf_printf(b, "#endif\n");
2296}
2297
2298static void add_staging_flag(struct buffer *b, const char *name)
2299{
2300 if (strstarts(name, "drivers/staging"))
2301 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2302}
2303
2304/**
2305 * Record CRCs for unresolved symbols
2306 **/
2307static int add_versions(struct buffer *b, struct module *mod)
2308{
2309 struct symbol *s, *exp;
2310 int err = 0;
2311
2312 for (s = mod->unres; s; s = s->next) {
2313 exp = find_symbol(s->name);
2314 if (!exp || exp->module == mod)
2315 continue;
2316 s->module = exp->module;
2317 s->crc_valid = exp->crc_valid;
2318 s->crc = exp->crc;
2319 }
2320
2321 if (!modversions)
2322 return err;
2323
2324 buf_printf(b, "\n");
2325 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2326 buf_printf(b, "__used __section(__versions) = {\n");
2327
2328 for (s = mod->unres; s; s = s->next) {
2329 if (!s->module)
2330 continue;
2331 if (!s->crc_valid) {
2332 warn("\"%s\" [%s.ko] has no CRC!\n",
2333 s->name, mod->name);
2334 continue;
2335 }
2336 if (strlen(s->name) >= MODULE_NAME_LEN) {
2337 merror("too long symbol \"%s\" [%s.ko]\n",
2338 s->name, mod->name);
2339 err = 1;
2340 break;
2341 }
2342 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
2343 s->crc, s->name);
2344 }
2345
2346 buf_printf(b, "};\n");
2347
2348 return err;
2349}
2350
2351static void add_depends(struct buffer *b, struct module *mod)
2352{
2353 struct symbol *s;
2354 int first = 1;
2355
2356 /* Clear ->seen flag of modules that own symbols needed by this. */
2357 for (s = mod->unres; s; s = s->next)
2358 if (s->module)
2359 s->module->seen = is_vmlinux(s->module->name);
2360
2361 buf_printf(b, "\n");
2362 buf_printf(b, "MODULE_INFO(depends, \"");
2363 for (s = mod->unres; s; s = s->next) {
2364 const char *p;
2365 if (!s->module)
2366 continue;
2367
2368 if (s->module->seen)
2369 continue;
2370
2371 s->module->seen = 1;
2372 p = strrchr(s->module->name, '/');
2373 if (p)
2374 p++;
2375 else
2376 p = s->module->name;
2377 buf_printf(b, "%s%s", first ? "" : ",", p);
2378 first = 0;
2379 }
2380 buf_printf(b, "\");\n");
2381}
2382
2383static void add_srcversion(struct buffer *b, struct module *mod)
2384{
2385 if (mod->srcversion[0]) {
2386 buf_printf(b, "\n");
2387 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2388 mod->srcversion);
2389 }
2390}
2391
2392static void write_if_changed(struct buffer *b, const char *fname)
2393{
2394 char *tmp;
2395 FILE *file;
2396 struct stat st;
2397
2398 file = fopen(fname, "r");
2399 if (!file)
2400 goto write;
2401
2402 if (fstat(fileno(file), &st) < 0)
2403 goto close_write;
2404
2405 if (st.st_size != b->pos)
2406 goto close_write;
2407
2408 tmp = NOFAIL(malloc(b->pos));
2409 if (fread(tmp, 1, b->pos, file) != b->pos)
2410 goto free_write;
2411
2412 if (memcmp(tmp, b->p, b->pos) != 0)
2413 goto free_write;
2414
2415 free(tmp);
2416 fclose(file);
2417 return;
2418
2419 free_write:
2420 free(tmp);
2421 close_write:
2422 fclose(file);
2423 write:
2424 file = fopen(fname, "w");
2425 if (!file) {
2426 perror(fname);
2427 exit(1);
2428 }
2429 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2430 perror(fname);
2431 exit(1);
2432 }
2433 fclose(file);
2434}
2435
2436/* parse Module.symvers file. line format:
2437 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2438 **/
2439static void read_dump(const char *fname, unsigned int kernel)
2440{
2441 unsigned long size, pos = 0;
2442 void *file = grab_file(fname, &size);
2443 char *line;
2444
2445 if (!file)
2446 /* No symbol versions, silently ignore */
2447 return;
2448
2449 while ((line = get_next_line(&pos, file, size))) {
2450 char *symname, *namespace, *modname, *d, *export, *end;
2451 unsigned int crc;
2452 struct module *mod;
2453 struct symbol *s;
2454
2455 if (!(symname = strchr(line, '\t')))
2456 goto fail;
2457 *symname++ = '\0';
2458 if (!(namespace = strchr(symname, '\t')))
2459 goto fail;
2460 *namespace++ = '\0';
2461 if (!(modname = strchr(namespace, '\t')))
2462 goto fail;
2463 *modname++ = '\0';
2464 if ((export = strchr(modname, '\t')) != NULL)
2465 *export++ = '\0';
2466 if (export && ((end = strchr(export, '\t')) != NULL))
2467 *end = '\0';
2468 crc = strtoul(line, &d, 16);
2469 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2470 goto fail;
2471 mod = find_module(modname);
2472 if (!mod) {
2473 if (is_vmlinux(modname))
2474 have_vmlinux = 1;
2475 mod = new_module(modname);
2476 mod->skip = 1;
2477 }
2478 s = sym_add_exported(symname, mod, export_no(export));
2479 s->kernel = kernel;
2480 s->preloaded = 1;
2481 s->is_static = 0;
2482 sym_update_crc(symname, mod, crc, export_no(export));
2483 sym_update_namespace(symname, namespace);
2484 }
2485 release_file(file, size);
2486 return;
2487fail:
2488 release_file(file, size);
2489 fatal("parse error in symbol dump file\n");
2490}
2491
2492/* For normal builds always dump all symbols.
2493 * For external modules only dump symbols
2494 * that are not read from kernel Module.symvers.
2495 **/
2496static int dump_sym(struct symbol *sym)
2497{
2498 if (!external_module)
2499 return 1;
2500 if (sym->vmlinux || sym->kernel)
2501 return 0;
2502 return 1;
2503}
2504
2505static void write_dump(const char *fname)
2506{
2507 struct buffer buf = { };
2508 struct symbol *symbol;
2509 const char *namespace;
2510 int n;
2511
2512 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2513 symbol = symbolhash[n];
2514 while (symbol) {
2515 if (dump_sym(symbol)) {
2516 namespace = symbol->namespace;
2517 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n",
2518 symbol->crc, symbol->name,
2519 namespace ? namespace : "",
2520 symbol->module->name,
2521 export_str(symbol->export));
2522 }
2523 symbol = symbol->next;
2524 }
2525 }
2526 write_if_changed(&buf, fname);
2527 free(buf.p);
2528}
2529
2530static void write_namespace_deps_files(void)
2531{
2532 struct module *mod;
2533 struct namespace_list *ns;
2534 struct buffer ns_deps_buf = {};
2535
2536 for (mod = modules; mod; mod = mod->next) {
2537 char fname[PATH_MAX];
2538
2539 if (mod->skip)
2540 continue;
2541
2542 ns_deps_buf.pos = 0;
2543
2544 for (ns = mod->required_namespaces; ns; ns = ns->next)
2545 buf_printf(&ns_deps_buf, "%s\n", ns->namespace);
2546
2547 if (ns_deps_buf.pos == 0)
2548 continue;
2549
2550 sprintf(fname, "%s.ns_deps", mod->name);
2551 write_if_changed(&ns_deps_buf, fname);
2552 }
2553}
2554
2555struct ext_sym_list {
2556 struct ext_sym_list *next;
2557 const char *file;
2558};
2559
2560int main(int argc, char **argv)
2561{
2562 struct module *mod;
2563 struct buffer buf = { };
2564 char *kernel_read = NULL, *module_read = NULL;
2565 char *dump_write = NULL, *files_source = NULL;
2566 int opt;
2567 int err;
2568 int n;
2569 struct ext_sym_list *extsym_iter;
2570 struct ext_sym_list *extsym_start = NULL;
2571
2572 while ((opt = getopt(argc, argv, "i:I:e:mnsT:o:awEd")) != -1) {
2573 switch (opt) {
2574 case 'i':
2575 kernel_read = optarg;
2576 break;
2577 case 'I':
2578 module_read = optarg;
2579 external_module = 1;
2580 break;
2581 case 'e':
2582 external_module = 1;
2583 extsym_iter =
2584 NOFAIL(malloc(sizeof(*extsym_iter)));
2585 extsym_iter->next = extsym_start;
2586 extsym_iter->file = optarg;
2587 extsym_start = extsym_iter;
2588 break;
2589 case 'm':
2590 modversions = 1;
2591 break;
2592 case 'n':
2593 ignore_missing_files = 1;
2594 break;
2595 case 'o':
2596 dump_write = optarg;
2597 break;
2598 case 'a':
2599 all_versions = 1;
2600 break;
2601 case 's':
2602 vmlinux_section_warnings = 0;
2603 break;
2604 case 'T':
2605 files_source = optarg;
2606 break;
2607 case 'w':
2608 warn_unresolved = 1;
2609 break;
2610 case 'E':
2611 sec_mismatch_fatal = 1;
2612 break;
2613 case 'd':
2614 write_namespace_deps = 1;
2615 break;
2616 default:
2617 exit(1);
2618 }
2619 }
2620
2621 if (kernel_read)
2622 read_dump(kernel_read, 1);
2623 if (module_read)
2624 read_dump(module_read, 0);
2625 while (extsym_start) {
2626 read_dump(extsym_start->file, 0);
2627 extsym_iter = extsym_start->next;
2628 free(extsym_start);
2629 extsym_start = extsym_iter;
2630 }
2631
2632 while (optind < argc)
2633 read_symbols(argv[optind++]);
2634
2635 if (files_source)
2636 read_symbols_from_files(files_source);
2637
2638 err = 0;
2639
2640 for (mod = modules; mod; mod = mod->next) {
2641 char fname[PATH_MAX];
2642
2643 if (mod->skip)
2644 continue;
2645
2646 buf.pos = 0;
2647
2648 err |= check_modname_len(mod);
2649 err |= check_exports(mod);
2650 if (write_namespace_deps)
2651 continue;
2652
2653 add_header(&buf, mod);
2654 add_intree_flag(&buf, !external_module);
2655 add_retpoline(&buf);
2656 add_staging_flag(&buf, mod->name);
2657 err |= add_versions(&buf, mod);
2658 add_depends(&buf, mod);
2659 add_moddevtable(&buf, mod);
2660 add_srcversion(&buf, mod);
2661
2662 sprintf(fname, "%s.mod.c", mod->name);
2663 write_if_changed(&buf, fname);
2664 }
2665
2666 if (write_namespace_deps) {
2667 write_namespace_deps_files();
2668 return 0;
2669 }
2670
2671 if (dump_write)
2672 write_dump(dump_write);
2673 if (sec_mismatch_count && sec_mismatch_fatal)
2674 fatal("modpost: Section mismatches detected.\n"
2675 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2676 for (n = 0; n < SYMBOL_HASH_SIZE; n++) {
2677 struct symbol *s;
2678
2679 for (s = symbolhash[n]; s; s = s->next) {
2680 /*
2681 * Do not check "vmlinux". This avoids the same warnings
2682 * shown twice, and false-positives for ARCH=um.
2683 */
2684 if (is_vmlinux(s->module->name) && !s->module->is_dot_o)
2685 continue;
2686
2687 if (s->is_static)
2688 warn("\"%s\" [%s] is a static %s\n",
2689 s->name, s->module->name,
2690 export_str(s->export));
2691 }
2692 }
2693
2694 free(buf.p);
2695
2696 return err;
2697}
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include <limits.h>
19#include <stdbool.h>
20#include <errno.h>
21#include "modpost.h"
22#include "../../include/generated/autoconf.h"
23#include "../../include/linux/license.h"
24#include "../../include/linux/export.h"
25
26/* Are we using CONFIG_MODVERSIONS? */
27int modversions = 0;
28/* Warn about undefined symbols? (do so if we have vmlinux) */
29int have_vmlinux = 0;
30/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31static int all_versions = 0;
32/* If we are modposting external module set to 1 */
33static int external_module = 0;
34/* Warn about section mismatch in vmlinux if set to 1 */
35static int vmlinux_section_warnings = 1;
36/* Only warn about unresolved symbols */
37static int warn_unresolved = 0;
38/* How a symbol is exported */
39static int sec_mismatch_count = 0;
40static int sec_mismatch_verbose = 1;
41/* ignore missing files */
42static int ignore_missing_files;
43
44enum export {
45 export_plain, export_unused, export_gpl,
46 export_unused_gpl, export_gpl_future, export_unknown
47};
48
49#define PRINTF __attribute__ ((format (printf, 1, 2)))
50
51PRINTF void fatal(const char *fmt, ...)
52{
53 va_list arglist;
54
55 fprintf(stderr, "FATAL: ");
56
57 va_start(arglist, fmt);
58 vfprintf(stderr, fmt, arglist);
59 va_end(arglist);
60
61 exit(1);
62}
63
64PRINTF void warn(const char *fmt, ...)
65{
66 va_list arglist;
67
68 fprintf(stderr, "WARNING: ");
69
70 va_start(arglist, fmt);
71 vfprintf(stderr, fmt, arglist);
72 va_end(arglist);
73}
74
75PRINTF void merror(const char *fmt, ...)
76{
77 va_list arglist;
78
79 fprintf(stderr, "ERROR: ");
80
81 va_start(arglist, fmt);
82 vfprintf(stderr, fmt, arglist);
83 va_end(arglist);
84}
85
86static inline bool strends(const char *str, const char *postfix)
87{
88 if (strlen(str) < strlen(postfix))
89 return false;
90
91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
92}
93
94static int is_vmlinux(const char *modname)
95{
96 const char *myname;
97
98 myname = strrchr(modname, '/');
99 if (myname)
100 myname++;
101 else
102 myname = modname;
103
104 return (strcmp(myname, "vmlinux") == 0) ||
105 (strcmp(myname, "vmlinux.o") == 0);
106}
107
108void *do_nofail(void *ptr, const char *expr)
109{
110 if (!ptr)
111 fatal("modpost: Memory allocation failure: %s.\n", expr);
112
113 return ptr;
114}
115
116/* A list of all modules we processed */
117static struct module *modules;
118
119static struct module *find_module(char *modname)
120{
121 struct module *mod;
122
123 for (mod = modules; mod; mod = mod->next)
124 if (strcmp(mod->name, modname) == 0)
125 break;
126 return mod;
127}
128
129static struct module *new_module(const char *modname)
130{
131 struct module *mod;
132 char *p;
133
134 mod = NOFAIL(malloc(sizeof(*mod)));
135 memset(mod, 0, sizeof(*mod));
136 p = NOFAIL(strdup(modname));
137
138 /* strip trailing .o */
139 if (strends(p, ".o")) {
140 p[strlen(p) - 2] = '\0';
141 mod->is_dot_o = 1;
142 }
143
144 /* add to list */
145 mod->name = p;
146 mod->gpl_compatible = -1;
147 mod->next = modules;
148 modules = mod;
149
150 return mod;
151}
152
153/* A hash of all exported symbols,
154 * struct symbol is also used for lists of unresolved symbols */
155
156#define SYMBOL_HASH_SIZE 1024
157
158struct symbol {
159 struct symbol *next;
160 struct module *module;
161 unsigned int crc;
162 int crc_valid;
163 unsigned int weak:1;
164 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
165 unsigned int kernel:1; /* 1 if symbol is from kernel
166 * (only for external modules) **/
167 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
168 enum export export; /* Type of export */
169 char name[0];
170};
171
172static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
173
174/* This is based on the hash agorithm from gdbm, via tdb */
175static inline unsigned int tdb_hash(const char *name)
176{
177 unsigned value; /* Used to compute the hash value. */
178 unsigned i; /* Used to cycle through random values. */
179
180 /* Set the initial value from the key size. */
181 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
182 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
183
184 return (1103515243 * value + 12345);
185}
186
187/**
188 * Allocate a new symbols for use in the hash of exported symbols or
189 * the list of unresolved symbols per module
190 **/
191static struct symbol *alloc_symbol(const char *name, unsigned int weak,
192 struct symbol *next)
193{
194 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
195
196 memset(s, 0, sizeof(*s));
197 strcpy(s->name, name);
198 s->weak = weak;
199 s->next = next;
200 return s;
201}
202
203/* For the hash of exported symbols */
204static struct symbol *new_symbol(const char *name, struct module *module,
205 enum export export)
206{
207 unsigned int hash;
208 struct symbol *new;
209
210 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
211 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
212 new->module = module;
213 new->export = export;
214 return new;
215}
216
217static struct symbol *find_symbol(const char *name)
218{
219 struct symbol *s;
220
221 /* For our purposes, .foo matches foo. PPC64 needs this. */
222 if (name[0] == '.')
223 name++;
224
225 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
226 if (strcmp(s->name, name) == 0)
227 return s;
228 }
229 return NULL;
230}
231
232static struct {
233 const char *str;
234 enum export export;
235} export_list[] = {
236 { .str = "EXPORT_SYMBOL", .export = export_plain },
237 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
238 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
239 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
240 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
241 { .str = "(unknown)", .export = export_unknown },
242};
243
244
245static const char *export_str(enum export ex)
246{
247 return export_list[ex].str;
248}
249
250static enum export export_no(const char *s)
251{
252 int i;
253
254 if (!s)
255 return export_unknown;
256 for (i = 0; export_list[i].export != export_unknown; i++) {
257 if (strcmp(export_list[i].str, s) == 0)
258 return export_list[i].export;
259 }
260 return export_unknown;
261}
262
263static const char *sec_name(struct elf_info *elf, int secindex);
264
265#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
266
267static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
268{
269 const char *secname = sec_name(elf, sec);
270
271 if (strstarts(secname, "___ksymtab+"))
272 return export_plain;
273 else if (strstarts(secname, "___ksymtab_unused+"))
274 return export_unused;
275 else if (strstarts(secname, "___ksymtab_gpl+"))
276 return export_gpl;
277 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
278 return export_unused_gpl;
279 else if (strstarts(secname, "___ksymtab_gpl_future+"))
280 return export_gpl_future;
281 else
282 return export_unknown;
283}
284
285static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
286{
287 if (sec == elf->export_sec)
288 return export_plain;
289 else if (sec == elf->export_unused_sec)
290 return export_unused;
291 else if (sec == elf->export_gpl_sec)
292 return export_gpl;
293 else if (sec == elf->export_unused_gpl_sec)
294 return export_unused_gpl;
295 else if (sec == elf->export_gpl_future_sec)
296 return export_gpl_future;
297 else
298 return export_unknown;
299}
300
301/**
302 * Add an exported symbol - it may have already been added without a
303 * CRC, in this case just update the CRC
304 **/
305static struct symbol *sym_add_exported(const char *name, struct module *mod,
306 enum export export)
307{
308 struct symbol *s = find_symbol(name);
309
310 if (!s) {
311 s = new_symbol(name, mod, export);
312 } else {
313 if (!s->preloaded) {
314 warn("%s: '%s' exported twice. Previous export "
315 "was in %s%s\n", mod->name, name,
316 s->module->name,
317 is_vmlinux(s->module->name) ?"":".ko");
318 } else {
319 /* In case Modules.symvers was out of date */
320 s->module = mod;
321 }
322 }
323 s->preloaded = 0;
324 s->vmlinux = is_vmlinux(mod->name);
325 s->kernel = 0;
326 s->export = export;
327 return s;
328}
329
330static void sym_update_crc(const char *name, struct module *mod,
331 unsigned int crc, enum export export)
332{
333 struct symbol *s = find_symbol(name);
334
335 if (!s) {
336 s = new_symbol(name, mod, export);
337 /* Don't complain when we find it later. */
338 s->preloaded = 1;
339 }
340 s->crc = crc;
341 s->crc_valid = 1;
342}
343
344void *grab_file(const char *filename, unsigned long *size)
345{
346 struct stat st;
347 void *map = MAP_FAILED;
348 int fd;
349
350 fd = open(filename, O_RDONLY);
351 if (fd < 0)
352 return NULL;
353 if (fstat(fd, &st))
354 goto failed;
355
356 *size = st.st_size;
357 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
358
359failed:
360 close(fd);
361 if (map == MAP_FAILED)
362 return NULL;
363 return map;
364}
365
366/**
367 * Return a copy of the next line in a mmap'ed file.
368 * spaces in the beginning of the line is trimmed away.
369 * Return a pointer to a static buffer.
370 **/
371char *get_next_line(unsigned long *pos, void *file, unsigned long size)
372{
373 static char line[4096];
374 int skip = 1;
375 size_t len = 0;
376 signed char *p = (signed char *)file + *pos;
377 char *s = line;
378
379 for (; *pos < size ; (*pos)++) {
380 if (skip && isspace(*p)) {
381 p++;
382 continue;
383 }
384 skip = 0;
385 if (*p != '\n' && (*pos < size)) {
386 len++;
387 *s++ = *p++;
388 if (len > 4095)
389 break; /* Too long, stop */
390 } else {
391 /* End of string */
392 *s = '\0';
393 return line;
394 }
395 }
396 /* End of buffer */
397 return NULL;
398}
399
400void release_file(void *file, unsigned long size)
401{
402 munmap(file, size);
403}
404
405static int parse_elf(struct elf_info *info, const char *filename)
406{
407 unsigned int i;
408 Elf_Ehdr *hdr;
409 Elf_Shdr *sechdrs;
410 Elf_Sym *sym;
411 const char *secstrings;
412 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
413
414 hdr = grab_file(filename, &info->size);
415 if (!hdr) {
416 if (ignore_missing_files) {
417 fprintf(stderr, "%s: %s (ignored)\n", filename,
418 strerror(errno));
419 return 0;
420 }
421 perror(filename);
422 exit(1);
423 }
424 info->hdr = hdr;
425 if (info->size < sizeof(*hdr)) {
426 /* file too small, assume this is an empty .o file */
427 return 0;
428 }
429 /* Is this a valid ELF file? */
430 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
431 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
432 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
433 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
434 /* Not an ELF file - silently ignore it */
435 return 0;
436 }
437 /* Fix endianness in ELF header */
438 hdr->e_type = TO_NATIVE(hdr->e_type);
439 hdr->e_machine = TO_NATIVE(hdr->e_machine);
440 hdr->e_version = TO_NATIVE(hdr->e_version);
441 hdr->e_entry = TO_NATIVE(hdr->e_entry);
442 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
443 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
444 hdr->e_flags = TO_NATIVE(hdr->e_flags);
445 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
446 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
447 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
448 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
449 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
450 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
451 sechdrs = (void *)hdr + hdr->e_shoff;
452 info->sechdrs = sechdrs;
453
454 /* Check if file offset is correct */
455 if (hdr->e_shoff > info->size) {
456 fatal("section header offset=%lu in file '%s' is bigger than "
457 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
458 filename, info->size);
459 return 0;
460 }
461
462 if (hdr->e_shnum == SHN_UNDEF) {
463 /*
464 * There are more than 64k sections,
465 * read count from .sh_size.
466 */
467 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
468 }
469 else {
470 info->num_sections = hdr->e_shnum;
471 }
472 if (hdr->e_shstrndx == SHN_XINDEX) {
473 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
474 }
475 else {
476 info->secindex_strings = hdr->e_shstrndx;
477 }
478
479 /* Fix endianness in section headers */
480 for (i = 0; i < info->num_sections; i++) {
481 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
482 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
483 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
484 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
485 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
486 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
487 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
488 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
489 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
490 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
491 }
492 /* Find symbol table. */
493 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
494 for (i = 1; i < info->num_sections; i++) {
495 const char *secname;
496 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
497
498 if (!nobits && sechdrs[i].sh_offset > info->size) {
499 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
500 "sizeof(*hrd)=%zu\n", filename,
501 (unsigned long)sechdrs[i].sh_offset,
502 sizeof(*hdr));
503 return 0;
504 }
505 secname = secstrings + sechdrs[i].sh_name;
506 if (strcmp(secname, ".modinfo") == 0) {
507 if (nobits)
508 fatal("%s has NOBITS .modinfo\n", filename);
509 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
510 info->modinfo_len = sechdrs[i].sh_size;
511 } else if (strcmp(secname, "__ksymtab") == 0)
512 info->export_sec = i;
513 else if (strcmp(secname, "__ksymtab_unused") == 0)
514 info->export_unused_sec = i;
515 else if (strcmp(secname, "__ksymtab_gpl") == 0)
516 info->export_gpl_sec = i;
517 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
518 info->export_unused_gpl_sec = i;
519 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
520 info->export_gpl_future_sec = i;
521
522 if (sechdrs[i].sh_type == SHT_SYMTAB) {
523 unsigned int sh_link_idx;
524 symtab_idx = i;
525 info->symtab_start = (void *)hdr +
526 sechdrs[i].sh_offset;
527 info->symtab_stop = (void *)hdr +
528 sechdrs[i].sh_offset + sechdrs[i].sh_size;
529 sh_link_idx = sechdrs[i].sh_link;
530 info->strtab = (void *)hdr +
531 sechdrs[sh_link_idx].sh_offset;
532 }
533
534 /* 32bit section no. table? ("more than 64k sections") */
535 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
536 symtab_shndx_idx = i;
537 info->symtab_shndx_start = (void *)hdr +
538 sechdrs[i].sh_offset;
539 info->symtab_shndx_stop = (void *)hdr +
540 sechdrs[i].sh_offset + sechdrs[i].sh_size;
541 }
542 }
543 if (!info->symtab_start)
544 fatal("%s has no symtab?\n", filename);
545
546 /* Fix endianness in symbols */
547 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
548 sym->st_shndx = TO_NATIVE(sym->st_shndx);
549 sym->st_name = TO_NATIVE(sym->st_name);
550 sym->st_value = TO_NATIVE(sym->st_value);
551 sym->st_size = TO_NATIVE(sym->st_size);
552 }
553
554 if (symtab_shndx_idx != ~0U) {
555 Elf32_Word *p;
556 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
557 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
558 filename, sechdrs[symtab_shndx_idx].sh_link,
559 symtab_idx);
560 /* Fix endianness */
561 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
562 p++)
563 *p = TO_NATIVE(*p);
564 }
565
566 return 1;
567}
568
569static void parse_elf_finish(struct elf_info *info)
570{
571 release_file(info->hdr, info->size);
572}
573
574static int ignore_undef_symbol(struct elf_info *info, const char *symname)
575{
576 /* ignore __this_module, it will be resolved shortly */
577 if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)
578 return 1;
579 /* ignore global offset table */
580 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
581 return 1;
582 if (info->hdr->e_machine == EM_PPC)
583 /* Special register function linked on all modules during final link of .ko */
584 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
585 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
586 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
587 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0 ||
588 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
589 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
590 return 1;
591 if (info->hdr->e_machine == EM_PPC64)
592 /* Special register function linked on all modules during final link of .ko */
593 if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
594 strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
595 strncmp(symname, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
596 strncmp(symname, "_savevr_", sizeof("_savevr_") - 1) == 0)
597 return 1;
598 /* Do not ignore this symbol */
599 return 0;
600}
601
602#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
603#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
604
605static void handle_modversions(struct module *mod, struct elf_info *info,
606 Elf_Sym *sym, const char *symname)
607{
608 unsigned int crc;
609 enum export export;
610
611 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
612 strncmp(symname, "__ksymtab", 9) == 0)
613 export = export_from_secname(info, get_secindex(info, sym));
614 else
615 export = export_from_sec(info, get_secindex(info, sym));
616
617 /* CRC'd symbol */
618 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
619 crc = (unsigned int) sym->st_value;
620 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
621 export);
622 }
623
624 switch (sym->st_shndx) {
625 case SHN_COMMON:
626 if (!strncmp(symname, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
627 /* Should warn here, but modpost runs before the linker */
628 } else
629 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
630 break;
631 case SHN_UNDEF:
632 /* undefined symbol */
633 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
634 ELF_ST_BIND(sym->st_info) != STB_WEAK)
635 break;
636 if (ignore_undef_symbol(info, symname))
637 break;
638/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
639#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
640/* add compatibility with older glibc */
641#ifndef STT_SPARC_REGISTER
642#define STT_SPARC_REGISTER STT_REGISTER
643#endif
644 if (info->hdr->e_machine == EM_SPARC ||
645 info->hdr->e_machine == EM_SPARCV9) {
646 /* Ignore register directives. */
647 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
648 break;
649 if (symname[0] == '.') {
650 char *munged = strdup(symname);
651 munged[0] = '_';
652 munged[1] = toupper(munged[1]);
653 symname = munged;
654 }
655 }
656#endif
657
658#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
659 if (symname[0] != '_')
660 break;
661 else
662 symname++;
663#endif
664 mod->unres = alloc_symbol(symname,
665 ELF_ST_BIND(sym->st_info) == STB_WEAK,
666 mod->unres);
667 break;
668 default:
669 /* All exported symbols */
670 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
671 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
672 export);
673 }
674 if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)
675 mod->has_init = 1;
676 if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)
677 mod->has_cleanup = 1;
678 break;
679 }
680}
681
682/**
683 * Parse tag=value strings from .modinfo section
684 **/
685static char *next_string(char *string, unsigned long *secsize)
686{
687 /* Skip non-zero chars */
688 while (string[0]) {
689 string++;
690 if ((*secsize)-- <= 1)
691 return NULL;
692 }
693
694 /* Skip any zero padding. */
695 while (!string[0]) {
696 string++;
697 if ((*secsize)-- <= 1)
698 return NULL;
699 }
700 return string;
701}
702
703static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
704 const char *tag, char *info)
705{
706 char *p;
707 unsigned int taglen = strlen(tag);
708 unsigned long size = modinfo_len;
709
710 if (info) {
711 size -= info - (char *)modinfo;
712 modinfo = next_string(info, &size);
713 }
714
715 for (p = modinfo; p; p = next_string(p, &size)) {
716 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
717 return p + taglen + 1;
718 }
719 return NULL;
720}
721
722static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
723 const char *tag)
724
725{
726 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
727}
728
729/**
730 * Test if string s ends in string sub
731 * return 0 if match
732 **/
733static int strrcmp(const char *s, const char *sub)
734{
735 int slen, sublen;
736
737 if (!s || !sub)
738 return 1;
739
740 slen = strlen(s);
741 sublen = strlen(sub);
742
743 if ((slen == 0) || (sublen == 0))
744 return 1;
745
746 if (sublen > slen)
747 return 1;
748
749 return memcmp(s + slen - sublen, sub, sublen);
750}
751
752static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
753{
754 if (sym)
755 return elf->strtab + sym->st_name;
756 else
757 return "(unknown)";
758}
759
760static const char *sec_name(struct elf_info *elf, int secindex)
761{
762 Elf_Shdr *sechdrs = elf->sechdrs;
763 return (void *)elf->hdr +
764 elf->sechdrs[elf->secindex_strings].sh_offset +
765 sechdrs[secindex].sh_name;
766}
767
768static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
769{
770 return (void *)elf->hdr +
771 elf->sechdrs[elf->secindex_strings].sh_offset +
772 sechdr->sh_name;
773}
774
775/* if sym is empty or point to a string
776 * like ".[0-9]+" then return 1.
777 * This is the optional prefix added by ld to some sections
778 */
779static int number_prefix(const char *sym)
780{
781 if (*sym++ == '\0')
782 return 1;
783 if (*sym != '.')
784 return 0;
785 do {
786 char c = *sym++;
787 if (c < '0' || c > '9')
788 return 0;
789 } while (*sym);
790 return 1;
791}
792
793/* The pattern is an array of simple patterns.
794 * "foo" will match an exact string equal to "foo"
795 * "*foo" will match a string that ends with "foo"
796 * "foo*" will match a string that begins with "foo"
797 * "foo$" will match a string equal to "foo" or "foo.1"
798 * where the '1' can be any number including several digits.
799 * The $ syntax is for sections where ld append a dot number
800 * to make section name unique.
801 */
802static int match(const char *sym, const char * const pat[])
803{
804 const char *p;
805 while (*pat) {
806 p = *pat++;
807 const char *endp = p + strlen(p) - 1;
808
809 /* "*foo" */
810 if (*p == '*') {
811 if (strrcmp(sym, p + 1) == 0)
812 return 1;
813 }
814 /* "foo*" */
815 else if (*endp == '*') {
816 if (strncmp(sym, p, strlen(p) - 1) == 0)
817 return 1;
818 }
819 /* "foo$" */
820 else if (*endp == '$') {
821 if (strncmp(sym, p, strlen(p) - 1) == 0) {
822 if (number_prefix(sym + strlen(p) - 1))
823 return 1;
824 }
825 }
826 /* no wildcards */
827 else {
828 if (strcmp(p, sym) == 0)
829 return 1;
830 }
831 }
832 /* no match */
833 return 0;
834}
835
836/* sections that we do not want to do full section mismatch check on */
837static const char *section_white_list[] =
838{
839 ".comment*",
840 ".debug*",
841 ".cranges", /* sh64 */
842 ".zdebug*", /* Compressed debug sections. */
843 ".GCC-command-line", /* mn10300 */
844 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
845 ".mdebug*", /* alpha, score, mips etc. */
846 ".pdr", /* alpha, score, mips etc. */
847 ".stab*",
848 ".note*",
849 ".got*",
850 ".toc*",
851 ".xt.prop", /* xtensa */
852 ".xt.lit", /* xtensa */
853 ".arcextmap*", /* arc */
854 ".gnu.linkonce.arcext*", /* arc : modules */
855 ".gnu.lto*",
856 NULL
857};
858
859/*
860 * This is used to find sections missing the SHF_ALLOC flag.
861 * The cause of this is often a section specified in assembler
862 * without "ax" / "aw".
863 */
864static void check_section(const char *modname, struct elf_info *elf,
865 Elf_Shdr *sechdr)
866{
867 const char *sec = sech_name(elf, sechdr);
868
869 if (sechdr->sh_type == SHT_PROGBITS &&
870 !(sechdr->sh_flags & SHF_ALLOC) &&
871 !match(sec, section_white_list)) {
872 warn("%s (%s): unexpected non-allocatable section.\n"
873 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
874 "Note that for example <linux/init.h> contains\n"
875 "section definitions for use in .S files.\n\n",
876 modname, sec);
877 }
878}
879
880
881
882#define ALL_INIT_DATA_SECTIONS \
883 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
884 ".init.data$", ".meminit.data$"
885#define ALL_EXIT_DATA_SECTIONS \
886 ".exit.data$", ".memexit.data$"
887
888#define ALL_INIT_TEXT_SECTIONS \
889 ".init.text$", ".meminit.text$"
890#define ALL_EXIT_TEXT_SECTIONS \
891 ".exit.text$", ".memexit.text$"
892
893#define ALL_PCI_INIT_SECTIONS \
894 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
895 ".pci_fixup_enable$", ".pci_fixup_resume$", \
896 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
897
898#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
899#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
900
901#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
902#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
903
904#define DATA_SECTIONS ".data$", ".data.rel$"
905#define TEXT_SECTIONS ".text$", ".text.unlikely$"
906
907#define INIT_SECTIONS ".init.*"
908#define MEM_INIT_SECTIONS ".meminit.*"
909
910#define EXIT_SECTIONS ".exit.*"
911#define MEM_EXIT_SECTIONS ".memexit.*"
912
913/* init data sections */
914static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
915
916/* all init sections */
917static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
918
919/* All init and exit sections (code + data) */
920static const char *init_exit_sections[] =
921 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
922
923/* data section */
924static const char *data_sections[] = { DATA_SECTIONS, NULL };
925
926
927/* symbols in .data that may refer to init/exit sections */
928#define DEFAULT_SYMBOL_WHITE_LIST \
929 "*driver", \
930 "*_template", /* scsi uses *_template a lot */ \
931 "*_timer", /* arm uses ops structures named _timer a lot */ \
932 "*_sht", /* scsi also used *_sht to some extent */ \
933 "*_ops", \
934 "*_probe", \
935 "*_probe_one", \
936 "*_console"
937
938static const char *head_sections[] = { ".head.text*", NULL };
939static const char *linker_symbols[] =
940 { "__init_begin", "_sinittext", "_einittext", NULL };
941
942enum mismatch {
943 TEXT_TO_ANY_INIT,
944 DATA_TO_ANY_INIT,
945 TEXT_TO_ANY_EXIT,
946 DATA_TO_ANY_EXIT,
947 XXXINIT_TO_SOME_INIT,
948 XXXEXIT_TO_SOME_EXIT,
949 ANY_INIT_TO_ANY_EXIT,
950 ANY_EXIT_TO_ANY_INIT,
951 EXPORT_TO_INIT_EXIT,
952};
953
954struct sectioncheck {
955 const char *fromsec[20];
956 const char *tosec[20];
957 enum mismatch mismatch;
958 const char *symbol_white_list[20];
959};
960
961const struct sectioncheck sectioncheck[] = {
962/* Do not reference init/exit code/data from
963 * normal code and data
964 */
965{
966 .fromsec = { TEXT_SECTIONS, NULL },
967 .tosec = { ALL_INIT_SECTIONS, NULL },
968 .mismatch = TEXT_TO_ANY_INIT,
969 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
970},
971{
972 .fromsec = { DATA_SECTIONS, NULL },
973 .tosec = { ALL_XXXINIT_SECTIONS, NULL },
974 .mismatch = DATA_TO_ANY_INIT,
975 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
976},
977{
978 .fromsec = { DATA_SECTIONS, NULL },
979 .tosec = { INIT_SECTIONS, NULL },
980 .mismatch = DATA_TO_ANY_INIT,
981 .symbol_white_list = {
982 "*_template", "*_timer", "*_sht", "*_ops",
983 "*_probe", "*_probe_one", "*_console", NULL
984 },
985},
986{
987 .fromsec = { TEXT_SECTIONS, NULL },
988 .tosec = { ALL_EXIT_SECTIONS, NULL },
989 .mismatch = TEXT_TO_ANY_EXIT,
990 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
991},
992{
993 .fromsec = { DATA_SECTIONS, NULL },
994 .tosec = { ALL_EXIT_SECTIONS, NULL },
995 .mismatch = DATA_TO_ANY_EXIT,
996 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
997},
998/* Do not reference init code/data from meminit code/data */
999{
1000 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1001 .tosec = { INIT_SECTIONS, NULL },
1002 .mismatch = XXXINIT_TO_SOME_INIT,
1003 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1004},
1005/* Do not reference exit code/data from memexit code/data */
1006{
1007 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1008 .tosec = { EXIT_SECTIONS, NULL },
1009 .mismatch = XXXEXIT_TO_SOME_EXIT,
1010 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1011},
1012/* Do not use exit code/data from init code */
1013{
1014 .fromsec = { ALL_INIT_SECTIONS, NULL },
1015 .tosec = { ALL_EXIT_SECTIONS, NULL },
1016 .mismatch = ANY_INIT_TO_ANY_EXIT,
1017 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1018},
1019/* Do not use init code/data from exit code */
1020{
1021 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1022 .tosec = { ALL_INIT_SECTIONS, NULL },
1023 .mismatch = ANY_EXIT_TO_ANY_INIT,
1024 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1025},
1026{
1027 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1028 .tosec = { INIT_SECTIONS, NULL },
1029 .mismatch = ANY_INIT_TO_ANY_EXIT,
1030 .symbol_white_list = { NULL },
1031},
1032/* Do not export init/exit functions or data */
1033{
1034 .fromsec = { "__ksymtab*", NULL },
1035 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1036 .mismatch = EXPORT_TO_INIT_EXIT,
1037 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1038}
1039};
1040
1041static const struct sectioncheck *section_mismatch(
1042 const char *fromsec, const char *tosec)
1043{
1044 int i;
1045 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1046 const struct sectioncheck *check = §ioncheck[0];
1047
1048 for (i = 0; i < elems; i++) {
1049 if (match(fromsec, check->fromsec) &&
1050 match(tosec, check->tosec))
1051 return check;
1052 check++;
1053 }
1054 return NULL;
1055}
1056
1057/**
1058 * Whitelist to allow certain references to pass with no warning.
1059 *
1060 * Pattern 1:
1061 * If a module parameter is declared __initdata and permissions=0
1062 * then this is legal despite the warning generated.
1063 * We cannot see value of permissions here, so just ignore
1064 * this pattern.
1065 * The pattern is identified by:
1066 * tosec = .init.data
1067 * fromsec = .data*
1068 * atsym =__param*
1069 *
1070 * Pattern 1a:
1071 * module_param_call() ops can refer to __init set function if permissions=0
1072 * The pattern is identified by:
1073 * tosec = .init.text
1074 * fromsec = .data*
1075 * atsym = __param_ops_*
1076 *
1077 * Pattern 2:
1078 * Many drivers utilise a *driver container with references to
1079 * add, remove, probe functions etc.
1080 * the pattern is identified by:
1081 * tosec = init or exit section
1082 * fromsec = data section
1083 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1084 * *probe_one, *_console, *_timer
1085 *
1086 * Pattern 3:
1087 * Whitelist all references from .head.text to any init section
1088 *
1089 * Pattern 4:
1090 * Some symbols belong to init section but still it is ok to reference
1091 * these from non-init sections as these symbols don't have any memory
1092 * allocated for them and symbol address and value are same. So even
1093 * if init section is freed, its ok to reference those symbols.
1094 * For ex. symbols marking the init section boundaries.
1095 * This pattern is identified by
1096 * refsymname = __init_begin, _sinittext, _einittext
1097 *
1098 **/
1099static int secref_whitelist(const struct sectioncheck *mismatch,
1100 const char *fromsec, const char *fromsym,
1101 const char *tosec, const char *tosym)
1102{
1103 /* Check for pattern 1 */
1104 if (match(tosec, init_data_sections) &&
1105 match(fromsec, data_sections) &&
1106 (strncmp(fromsym, "__param", strlen("__param")) == 0))
1107 return 0;
1108
1109 /* Check for pattern 1a */
1110 if (strcmp(tosec, ".init.text") == 0 &&
1111 match(fromsec, data_sections) &&
1112 (strncmp(fromsym, "__param_ops_", strlen("__param_ops_")) == 0))
1113 return 0;
1114
1115 /* Check for pattern 2 */
1116 if (match(tosec, init_exit_sections) &&
1117 match(fromsec, data_sections) &&
1118 match(fromsym, mismatch->symbol_white_list))
1119 return 0;
1120
1121 /* Check for pattern 3 */
1122 if (match(fromsec, head_sections) &&
1123 match(tosec, init_sections))
1124 return 0;
1125
1126 /* Check for pattern 4 */
1127 if (match(tosym, linker_symbols))
1128 return 0;
1129
1130 return 1;
1131}
1132
1133/**
1134 * Find symbol based on relocation record info.
1135 * In some cases the symbol supplied is a valid symbol so
1136 * return refsym. If st_name != 0 we assume this is a valid symbol.
1137 * In other cases the symbol needs to be looked up in the symbol table
1138 * based on section and address.
1139 * **/
1140static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1141 Elf_Sym *relsym)
1142{
1143 Elf_Sym *sym;
1144 Elf_Sym *near = NULL;
1145 Elf64_Sword distance = 20;
1146 Elf64_Sword d;
1147 unsigned int relsym_secindex;
1148
1149 if (relsym->st_name != 0)
1150 return relsym;
1151
1152 relsym_secindex = get_secindex(elf, relsym);
1153 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1154 if (get_secindex(elf, sym) != relsym_secindex)
1155 continue;
1156 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1157 continue;
1158 if (sym->st_value == addr)
1159 return sym;
1160 /* Find a symbol nearby - addr are maybe negative */
1161 d = sym->st_value - addr;
1162 if (d < 0)
1163 d = addr - sym->st_value;
1164 if (d < distance) {
1165 distance = d;
1166 near = sym;
1167 }
1168 }
1169 /* We need a close match */
1170 if (distance < 20)
1171 return near;
1172 else
1173 return NULL;
1174}
1175
1176static inline int is_arm_mapping_symbol(const char *str)
1177{
1178 return str[0] == '$' && strchr("atd", str[1])
1179 && (str[2] == '\0' || str[2] == '.');
1180}
1181
1182/*
1183 * If there's no name there, ignore it; likewise, ignore it if it's
1184 * one of the magic symbols emitted used by current ARM tools.
1185 *
1186 * Otherwise if find_symbols_between() returns those symbols, they'll
1187 * fail the whitelist tests and cause lots of false alarms ... fixable
1188 * only by merging __exit and __init sections into __text, bloating
1189 * the kernel (which is especially evil on embedded platforms).
1190 */
1191static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1192{
1193 const char *name = elf->strtab + sym->st_name;
1194
1195 if (!name || !strlen(name))
1196 return 0;
1197 return !is_arm_mapping_symbol(name);
1198}
1199
1200/*
1201 * Find symbols before or equal addr and after addr - in the section sec.
1202 * If we find two symbols with equal offset prefer one with a valid name.
1203 * The ELF format may have a better way to detect what type of symbol
1204 * it is, but this works for now.
1205 **/
1206static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1207 const char *sec)
1208{
1209 Elf_Sym *sym;
1210 Elf_Sym *near = NULL;
1211 Elf_Addr distance = ~0;
1212
1213 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1214 const char *symsec;
1215
1216 if (is_shndx_special(sym->st_shndx))
1217 continue;
1218 symsec = sec_name(elf, get_secindex(elf, sym));
1219 if (strcmp(symsec, sec) != 0)
1220 continue;
1221 if (!is_valid_name(elf, sym))
1222 continue;
1223 if (sym->st_value <= addr) {
1224 if ((addr - sym->st_value) < distance) {
1225 distance = addr - sym->st_value;
1226 near = sym;
1227 } else if ((addr - sym->st_value) == distance) {
1228 near = sym;
1229 }
1230 }
1231 }
1232 return near;
1233}
1234
1235/*
1236 * Convert a section name to the function/data attribute
1237 * .init.text => __init
1238 * .memexitconst => __memconst
1239 * etc.
1240 *
1241 * The memory of returned value has been allocated on a heap. The user of this
1242 * method should free it after usage.
1243*/
1244static char *sec2annotation(const char *s)
1245{
1246 if (match(s, init_exit_sections)) {
1247 char *p = malloc(20);
1248 char *r = p;
1249
1250 *p++ = '_';
1251 *p++ = '_';
1252 if (*s == '.')
1253 s++;
1254 while (*s && *s != '.')
1255 *p++ = *s++;
1256 *p = '\0';
1257 if (*s == '.')
1258 s++;
1259 if (strstr(s, "rodata") != NULL)
1260 strcat(p, "const ");
1261 else if (strstr(s, "data") != NULL)
1262 strcat(p, "data ");
1263 else
1264 strcat(p, " ");
1265 return r;
1266 } else {
1267 return strdup("");
1268 }
1269}
1270
1271static int is_function(Elf_Sym *sym)
1272{
1273 if (sym)
1274 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1275 else
1276 return -1;
1277}
1278
1279static void print_section_list(const char * const list[20])
1280{
1281 const char *const *s = list;
1282
1283 while (*s) {
1284 fprintf(stderr, "%s", *s);
1285 s++;
1286 if (*s)
1287 fprintf(stderr, ", ");
1288 }
1289 fprintf(stderr, "\n");
1290}
1291
1292/*
1293 * Print a warning about a section mismatch.
1294 * Try to find symbols near it so user can find it.
1295 * Check whitelist before warning - it may be a false positive.
1296 */
1297static void report_sec_mismatch(const char *modname,
1298 const struct sectioncheck *mismatch,
1299 const char *fromsec,
1300 unsigned long long fromaddr,
1301 const char *fromsym,
1302 int from_is_func,
1303 const char *tosec, const char *tosym,
1304 int to_is_func)
1305{
1306 const char *from, *from_p;
1307 const char *to, *to_p;
1308 char *prl_from;
1309 char *prl_to;
1310
1311 switch (from_is_func) {
1312 case 0: from = "variable"; from_p = ""; break;
1313 case 1: from = "function"; from_p = "()"; break;
1314 default: from = "(unknown reference)"; from_p = ""; break;
1315 }
1316 switch (to_is_func) {
1317 case 0: to = "variable"; to_p = ""; break;
1318 case 1: to = "function"; to_p = "()"; break;
1319 default: to = "(unknown reference)"; to_p = ""; break;
1320 }
1321
1322 sec_mismatch_count++;
1323 if (!sec_mismatch_verbose)
1324 return;
1325
1326 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1327 "to the %s %s:%s%s\n",
1328 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1329 tosym, to_p);
1330
1331 switch (mismatch->mismatch) {
1332 case TEXT_TO_ANY_INIT:
1333 prl_from = sec2annotation(fromsec);
1334 prl_to = sec2annotation(tosec);
1335 fprintf(stderr,
1336 "The function %s%s() references\n"
1337 "the %s %s%s%s.\n"
1338 "This is often because %s lacks a %s\n"
1339 "annotation or the annotation of %s is wrong.\n",
1340 prl_from, fromsym,
1341 to, prl_to, tosym, to_p,
1342 fromsym, prl_to, tosym);
1343 free(prl_from);
1344 free(prl_to);
1345 break;
1346 case DATA_TO_ANY_INIT: {
1347 prl_to = sec2annotation(tosec);
1348 fprintf(stderr,
1349 "The variable %s references\n"
1350 "the %s %s%s%s\n"
1351 "If the reference is valid then annotate the\n"
1352 "variable with __init* or __refdata (see linux/init.h) "
1353 "or name the variable:\n",
1354 fromsym, to, prl_to, tosym, to_p);
1355 print_section_list(mismatch->symbol_white_list);
1356 free(prl_to);
1357 break;
1358 }
1359 case TEXT_TO_ANY_EXIT:
1360 prl_to = sec2annotation(tosec);
1361 fprintf(stderr,
1362 "The function %s() references a %s in an exit section.\n"
1363 "Often the %s %s%s has valid usage outside the exit section\n"
1364 "and the fix is to remove the %sannotation of %s.\n",
1365 fromsym, to, to, tosym, to_p, prl_to, tosym);
1366 free(prl_to);
1367 break;
1368 case DATA_TO_ANY_EXIT: {
1369 prl_to = sec2annotation(tosec);
1370 fprintf(stderr,
1371 "The variable %s references\n"
1372 "the %s %s%s%s\n"
1373 "If the reference is valid then annotate the\n"
1374 "variable with __exit* (see linux/init.h) or "
1375 "name the variable:\n",
1376 fromsym, to, prl_to, tosym, to_p);
1377 print_section_list(mismatch->symbol_white_list);
1378 free(prl_to);
1379 break;
1380 }
1381 case XXXINIT_TO_SOME_INIT:
1382 case XXXEXIT_TO_SOME_EXIT:
1383 prl_from = sec2annotation(fromsec);
1384 prl_to = sec2annotation(tosec);
1385 fprintf(stderr,
1386 "The %s %s%s%s references\n"
1387 "a %s %s%s%s.\n"
1388 "If %s is only used by %s then\n"
1389 "annotate %s with a matching annotation.\n",
1390 from, prl_from, fromsym, from_p,
1391 to, prl_to, tosym, to_p,
1392 tosym, fromsym, tosym);
1393 free(prl_from);
1394 free(prl_to);
1395 break;
1396 case ANY_INIT_TO_ANY_EXIT:
1397 prl_from = sec2annotation(fromsec);
1398 prl_to = sec2annotation(tosec);
1399 fprintf(stderr,
1400 "The %s %s%s%s references\n"
1401 "a %s %s%s%s.\n"
1402 "This is often seen when error handling "
1403 "in the init function\n"
1404 "uses functionality in the exit path.\n"
1405 "The fix is often to remove the %sannotation of\n"
1406 "%s%s so it may be used outside an exit section.\n",
1407 from, prl_from, fromsym, from_p,
1408 to, prl_to, tosym, to_p,
1409 prl_to, tosym, to_p);
1410 free(prl_from);
1411 free(prl_to);
1412 break;
1413 case ANY_EXIT_TO_ANY_INIT:
1414 prl_from = sec2annotation(fromsec);
1415 prl_to = sec2annotation(tosec);
1416 fprintf(stderr,
1417 "The %s %s%s%s references\n"
1418 "a %s %s%s%s.\n"
1419 "This is often seen when error handling "
1420 "in the exit function\n"
1421 "uses functionality in the init path.\n"
1422 "The fix is often to remove the %sannotation of\n"
1423 "%s%s so it may be used outside an init section.\n",
1424 from, prl_from, fromsym, from_p,
1425 to, prl_to, tosym, to_p,
1426 prl_to, tosym, to_p);
1427 free(prl_from);
1428 free(prl_to);
1429 break;
1430 case EXPORT_TO_INIT_EXIT:
1431 prl_to = sec2annotation(tosec);
1432 fprintf(stderr,
1433 "The symbol %s is exported and annotated %s\n"
1434 "Fix this by removing the %sannotation of %s "
1435 "or drop the export.\n",
1436 tosym, prl_to, prl_to, tosym);
1437 free(prl_to);
1438 break;
1439 }
1440 fprintf(stderr, "\n");
1441}
1442
1443static void check_section_mismatch(const char *modname, struct elf_info *elf,
1444 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1445{
1446 const char *tosec;
1447 const struct sectioncheck *mismatch;
1448
1449 tosec = sec_name(elf, get_secindex(elf, sym));
1450 mismatch = section_mismatch(fromsec, tosec);
1451 if (mismatch) {
1452 Elf_Sym *to;
1453 Elf_Sym *from;
1454 const char *tosym;
1455 const char *fromsym;
1456
1457 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1458 fromsym = sym_name(elf, from);
1459 to = find_elf_symbol(elf, r->r_addend, sym);
1460 tosym = sym_name(elf, to);
1461
1462 if (!strncmp(fromsym, "reference___initcall",
1463 sizeof("reference___initcall")-1))
1464 return;
1465
1466 /* check whitelist - we may ignore it */
1467 if (secref_whitelist(mismatch,
1468 fromsec, fromsym, tosec, tosym)) {
1469 report_sec_mismatch(modname, mismatch,
1470 fromsec, r->r_offset, fromsym,
1471 is_function(from), tosec, tosym,
1472 is_function(to));
1473 }
1474 }
1475}
1476
1477static unsigned int *reloc_location(struct elf_info *elf,
1478 Elf_Shdr *sechdr, Elf_Rela *r)
1479{
1480 Elf_Shdr *sechdrs = elf->sechdrs;
1481 int section = sechdr->sh_info;
1482
1483 return (void *)elf->hdr + sechdrs[section].sh_offset +
1484 r->r_offset;
1485}
1486
1487static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1488{
1489 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1490 unsigned int *location = reloc_location(elf, sechdr, r);
1491
1492 switch (r_typ) {
1493 case R_386_32:
1494 r->r_addend = TO_NATIVE(*location);
1495 break;
1496 case R_386_PC32:
1497 r->r_addend = TO_NATIVE(*location) + 4;
1498 /* For CONFIG_RELOCATABLE=y */
1499 if (elf->hdr->e_type == ET_EXEC)
1500 r->r_addend += r->r_offset;
1501 break;
1502 }
1503 return 0;
1504}
1505
1506#ifndef R_ARM_CALL
1507#define R_ARM_CALL 28
1508#endif
1509#ifndef R_ARM_JUMP24
1510#define R_ARM_JUMP24 29
1511#endif
1512
1513#ifndef R_ARM_THM_CALL
1514#define R_ARM_THM_CALL 10
1515#endif
1516#ifndef R_ARM_THM_JUMP24
1517#define R_ARM_THM_JUMP24 30
1518#endif
1519#ifndef R_ARM_THM_JUMP19
1520#define R_ARM_THM_JUMP19 51
1521#endif
1522
1523static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1524{
1525 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1526
1527 switch (r_typ) {
1528 case R_ARM_ABS32:
1529 /* From ARM ABI: (S + A) | T */
1530 r->r_addend = (int)(long)
1531 (elf->symtab_start + ELF_R_SYM(r->r_info));
1532 break;
1533 case R_ARM_PC24:
1534 case R_ARM_CALL:
1535 case R_ARM_JUMP24:
1536 case R_ARM_THM_CALL:
1537 case R_ARM_THM_JUMP24:
1538 case R_ARM_THM_JUMP19:
1539 /* From ARM ABI: ((S + A) | T) - P */
1540 r->r_addend = (int)(long)(elf->hdr +
1541 sechdr->sh_offset +
1542 (r->r_offset - sechdr->sh_addr));
1543 break;
1544 default:
1545 return 1;
1546 }
1547 return 0;
1548}
1549
1550static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1551{
1552 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1553 unsigned int *location = reloc_location(elf, sechdr, r);
1554 unsigned int inst;
1555
1556 if (r_typ == R_MIPS_HI16)
1557 return 1; /* skip this */
1558 inst = TO_NATIVE(*location);
1559 switch (r_typ) {
1560 case R_MIPS_LO16:
1561 r->r_addend = inst & 0xffff;
1562 break;
1563 case R_MIPS_26:
1564 r->r_addend = (inst & 0x03ffffff) << 2;
1565 break;
1566 case R_MIPS_32:
1567 r->r_addend = inst;
1568 break;
1569 }
1570 return 0;
1571}
1572
1573static void section_rela(const char *modname, struct elf_info *elf,
1574 Elf_Shdr *sechdr)
1575{
1576 Elf_Sym *sym;
1577 Elf_Rela *rela;
1578 Elf_Rela r;
1579 unsigned int r_sym;
1580 const char *fromsec;
1581
1582 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1583 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1584
1585 fromsec = sech_name(elf, sechdr);
1586 fromsec += strlen(".rela");
1587 /* if from section (name) is know good then skip it */
1588 if (match(fromsec, section_white_list))
1589 return;
1590
1591 for (rela = start; rela < stop; rela++) {
1592 r.r_offset = TO_NATIVE(rela->r_offset);
1593#if KERNEL_ELFCLASS == ELFCLASS64
1594 if (elf->hdr->e_machine == EM_MIPS) {
1595 unsigned int r_typ;
1596 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1597 r_sym = TO_NATIVE(r_sym);
1598 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1599 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1600 } else {
1601 r.r_info = TO_NATIVE(rela->r_info);
1602 r_sym = ELF_R_SYM(r.r_info);
1603 }
1604#else
1605 r.r_info = TO_NATIVE(rela->r_info);
1606 r_sym = ELF_R_SYM(r.r_info);
1607#endif
1608 r.r_addend = TO_NATIVE(rela->r_addend);
1609 sym = elf->symtab_start + r_sym;
1610 /* Skip special sections */
1611 if (is_shndx_special(sym->st_shndx))
1612 continue;
1613 check_section_mismatch(modname, elf, &r, sym, fromsec);
1614 }
1615}
1616
1617static void section_rel(const char *modname, struct elf_info *elf,
1618 Elf_Shdr *sechdr)
1619{
1620 Elf_Sym *sym;
1621 Elf_Rel *rel;
1622 Elf_Rela r;
1623 unsigned int r_sym;
1624 const char *fromsec;
1625
1626 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1627 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1628
1629 fromsec = sech_name(elf, sechdr);
1630 fromsec += strlen(".rel");
1631 /* if from section (name) is know good then skip it */
1632 if (match(fromsec, section_white_list))
1633 return;
1634
1635 for (rel = start; rel < stop; rel++) {
1636 r.r_offset = TO_NATIVE(rel->r_offset);
1637#if KERNEL_ELFCLASS == ELFCLASS64
1638 if (elf->hdr->e_machine == EM_MIPS) {
1639 unsigned int r_typ;
1640 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1641 r_sym = TO_NATIVE(r_sym);
1642 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1643 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1644 } else {
1645 r.r_info = TO_NATIVE(rel->r_info);
1646 r_sym = ELF_R_SYM(r.r_info);
1647 }
1648#else
1649 r.r_info = TO_NATIVE(rel->r_info);
1650 r_sym = ELF_R_SYM(r.r_info);
1651#endif
1652 r.r_addend = 0;
1653 switch (elf->hdr->e_machine) {
1654 case EM_386:
1655 if (addend_386_rel(elf, sechdr, &r))
1656 continue;
1657 break;
1658 case EM_ARM:
1659 if (addend_arm_rel(elf, sechdr, &r))
1660 continue;
1661 break;
1662 case EM_MIPS:
1663 if (addend_mips_rel(elf, sechdr, &r))
1664 continue;
1665 break;
1666 }
1667 sym = elf->symtab_start + r_sym;
1668 /* Skip special sections */
1669 if (is_shndx_special(sym->st_shndx))
1670 continue;
1671 check_section_mismatch(modname, elf, &r, sym, fromsec);
1672 }
1673}
1674
1675/**
1676 * A module includes a number of sections that are discarded
1677 * either when loaded or when used as built-in.
1678 * For loaded modules all functions marked __init and all data
1679 * marked __initdata will be discarded when the module has been initialized.
1680 * Likewise for modules used built-in the sections marked __exit
1681 * are discarded because __exit marked function are supposed to be called
1682 * only when a module is unloaded which never happens for built-in modules.
1683 * The check_sec_ref() function traverses all relocation records
1684 * to find all references to a section that reference a section that will
1685 * be discarded and warns about it.
1686 **/
1687static void check_sec_ref(struct module *mod, const char *modname,
1688 struct elf_info *elf)
1689{
1690 int i;
1691 Elf_Shdr *sechdrs = elf->sechdrs;
1692
1693 /* Walk through all sections */
1694 for (i = 0; i < elf->num_sections; i++) {
1695 check_section(modname, elf, &elf->sechdrs[i]);
1696 /* We want to process only relocation sections and not .init */
1697 if (sechdrs[i].sh_type == SHT_RELA)
1698 section_rela(modname, elf, &elf->sechdrs[i]);
1699 else if (sechdrs[i].sh_type == SHT_REL)
1700 section_rel(modname, elf, &elf->sechdrs[i]);
1701 }
1702}
1703
1704static char *remove_dot(char *s)
1705{
1706 char *end;
1707 int n = strcspn(s, ".");
1708
1709 if (n > 0 && s[n] != 0) {
1710 strtoul(s + n + 1, &end, 10);
1711 if (end > s + n + 1 && (*end == '.' || *end == 0))
1712 s[n] = 0;
1713 }
1714 return s;
1715}
1716
1717static void read_symbols(char *modname)
1718{
1719 const char *symname;
1720 char *version;
1721 char *license;
1722 struct module *mod;
1723 struct elf_info info = { };
1724 Elf_Sym *sym;
1725
1726 if (!parse_elf(&info, modname))
1727 return;
1728
1729 mod = new_module(modname);
1730
1731 /* When there's no vmlinux, don't print warnings about
1732 * unresolved symbols (since there'll be too many ;) */
1733 if (is_vmlinux(modname)) {
1734 have_vmlinux = 1;
1735 mod->skip = 1;
1736 }
1737
1738 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1739 if (info.modinfo && !license && !is_vmlinux(modname))
1740 warn("modpost: missing MODULE_LICENSE() in %s\n"
1741 "see include/linux/module.h for "
1742 "more information\n", modname);
1743 while (license) {
1744 if (license_is_gpl_compatible(license))
1745 mod->gpl_compatible = 1;
1746 else {
1747 mod->gpl_compatible = 0;
1748 break;
1749 }
1750 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1751 "license", license);
1752 }
1753
1754 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1755 symname = remove_dot(info.strtab + sym->st_name);
1756
1757 handle_modversions(mod, &info, sym, symname);
1758 handle_moddevtable(mod, &info, sym, symname);
1759 }
1760 if (!is_vmlinux(modname) ||
1761 (is_vmlinux(modname) && vmlinux_section_warnings))
1762 check_sec_ref(mod, modname, &info);
1763
1764 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1765 if (version)
1766 maybe_frob_rcs_version(modname, version, info.modinfo,
1767 version - (char *)info.hdr);
1768 if (version || (all_versions && !is_vmlinux(modname)))
1769 get_src_version(modname, mod->srcversion,
1770 sizeof(mod->srcversion)-1);
1771
1772 parse_elf_finish(&info);
1773
1774 /* Our trick to get versioning for module struct etc. - it's
1775 * never passed as an argument to an exported function, so
1776 * the automatic versioning doesn't pick it up, but it's really
1777 * important anyhow */
1778 if (modversions)
1779 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1780}
1781
1782static void read_symbols_from_files(const char *filename)
1783{
1784 FILE *in = stdin;
1785 char fname[PATH_MAX];
1786
1787 if (strcmp(filename, "-") != 0) {
1788 in = fopen(filename, "r");
1789 if (!in)
1790 fatal("Can't open filenames file %s: %m", filename);
1791 }
1792
1793 while (fgets(fname, PATH_MAX, in) != NULL) {
1794 if (strends(fname, "\n"))
1795 fname[strlen(fname)-1] = '\0';
1796 read_symbols(fname);
1797 }
1798
1799 if (in != stdin)
1800 fclose(in);
1801}
1802
1803#define SZ 500
1804
1805/* We first write the generated file into memory using the
1806 * following helper, then compare to the file on disk and
1807 * only update the later if anything changed */
1808
1809void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1810 const char *fmt, ...)
1811{
1812 char tmp[SZ];
1813 int len;
1814 va_list ap;
1815
1816 va_start(ap, fmt);
1817 len = vsnprintf(tmp, SZ, fmt, ap);
1818 buf_write(buf, tmp, len);
1819 va_end(ap);
1820}
1821
1822void buf_write(struct buffer *buf, const char *s, int len)
1823{
1824 if (buf->size - buf->pos < len) {
1825 buf->size += len + SZ;
1826 buf->p = realloc(buf->p, buf->size);
1827 }
1828 strncpy(buf->p + buf->pos, s, len);
1829 buf->pos += len;
1830}
1831
1832static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1833{
1834 const char *e = is_vmlinux(m) ?"":".ko";
1835
1836 switch (exp) {
1837 case export_gpl:
1838 fatal("modpost: GPL-incompatible module %s%s "
1839 "uses GPL-only symbol '%s'\n", m, e, s);
1840 break;
1841 case export_unused_gpl:
1842 fatal("modpost: GPL-incompatible module %s%s "
1843 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1844 break;
1845 case export_gpl_future:
1846 warn("modpost: GPL-incompatible module %s%s "
1847 "uses future GPL-only symbol '%s'\n", m, e, s);
1848 break;
1849 case export_plain:
1850 case export_unused:
1851 case export_unknown:
1852 /* ignore */
1853 break;
1854 }
1855}
1856
1857static void check_for_unused(enum export exp, const char *m, const char *s)
1858{
1859 const char *e = is_vmlinux(m) ?"":".ko";
1860
1861 switch (exp) {
1862 case export_unused:
1863 case export_unused_gpl:
1864 warn("modpost: module %s%s "
1865 "uses symbol '%s' marked UNUSED\n", m, e, s);
1866 break;
1867 default:
1868 /* ignore */
1869 break;
1870 }
1871}
1872
1873static void check_exports(struct module *mod)
1874{
1875 struct symbol *s, *exp;
1876
1877 for (s = mod->unres; s; s = s->next) {
1878 const char *basename;
1879 exp = find_symbol(s->name);
1880 if (!exp || exp->module == mod)
1881 continue;
1882 basename = strrchr(mod->name, '/');
1883 if (basename)
1884 basename++;
1885 else
1886 basename = mod->name;
1887 if (!mod->gpl_compatible)
1888 check_for_gpl_usage(exp->export, basename, exp->name);
1889 check_for_unused(exp->export, basename, exp->name);
1890 }
1891}
1892
1893/**
1894 * Header for the generated file
1895 **/
1896static void add_header(struct buffer *b, struct module *mod)
1897{
1898 buf_printf(b, "#include <linux/module.h>\n");
1899 buf_printf(b, "#include <linux/vermagic.h>\n");
1900 buf_printf(b, "#include <linux/compiler.h>\n");
1901 buf_printf(b, "\n");
1902 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1903 buf_printf(b, "\n");
1904 buf_printf(b, "__visible struct module __this_module\n");
1905 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1906 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1907 if (mod->has_init)
1908 buf_printf(b, "\t.init = init_module,\n");
1909 if (mod->has_cleanup)
1910 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1911 "\t.exit = cleanup_module,\n"
1912 "#endif\n");
1913 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1914 buf_printf(b, "};\n");
1915}
1916
1917static void add_intree_flag(struct buffer *b, int is_intree)
1918{
1919 if (is_intree)
1920 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1921}
1922
1923static void add_staging_flag(struct buffer *b, const char *name)
1924{
1925 static const char *staging_dir = "drivers/staging";
1926
1927 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1928 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1929}
1930
1931/**
1932 * Record CRCs for unresolved symbols
1933 **/
1934static int add_versions(struct buffer *b, struct module *mod)
1935{
1936 struct symbol *s, *exp;
1937 int err = 0;
1938
1939 for (s = mod->unres; s; s = s->next) {
1940 exp = find_symbol(s->name);
1941 if (!exp || exp->module == mod) {
1942 if (have_vmlinux && !s->weak) {
1943 if (warn_unresolved) {
1944 warn("\"%s\" [%s.ko] undefined!\n",
1945 s->name, mod->name);
1946 } else {
1947 merror("\"%s\" [%s.ko] undefined!\n",
1948 s->name, mod->name);
1949 err = 1;
1950 }
1951 }
1952 continue;
1953 }
1954 s->module = exp->module;
1955 s->crc_valid = exp->crc_valid;
1956 s->crc = exp->crc;
1957 }
1958
1959 if (!modversions)
1960 return err;
1961
1962 buf_printf(b, "\n");
1963 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1964 buf_printf(b, "__used\n");
1965 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1966
1967 for (s = mod->unres; s; s = s->next) {
1968 if (!s->module)
1969 continue;
1970 if (!s->crc_valid) {
1971 warn("\"%s\" [%s.ko] has no CRC!\n",
1972 s->name, mod->name);
1973 continue;
1974 }
1975 buf_printf(b, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1976 s->crc, s->name);
1977 }
1978
1979 buf_printf(b, "};\n");
1980
1981 return err;
1982}
1983
1984static void add_depends(struct buffer *b, struct module *mod,
1985 struct module *modules)
1986{
1987 struct symbol *s;
1988 struct module *m;
1989 int first = 1;
1990
1991 for (m = modules; m; m = m->next)
1992 m->seen = is_vmlinux(m->name);
1993
1994 buf_printf(b, "\n");
1995 buf_printf(b, "static const char __module_depends[]\n");
1996 buf_printf(b, "__used\n");
1997 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1998 buf_printf(b, "\"depends=");
1999 for (s = mod->unres; s; s = s->next) {
2000 const char *p;
2001 if (!s->module)
2002 continue;
2003
2004 if (s->module->seen)
2005 continue;
2006
2007 s->module->seen = 1;
2008 p = strrchr(s->module->name, '/');
2009 if (p)
2010 p++;
2011 else
2012 p = s->module->name;
2013 buf_printf(b, "%s%s", first ? "" : ",", p);
2014 first = 0;
2015 }
2016 buf_printf(b, "\";\n");
2017}
2018
2019static void add_srcversion(struct buffer *b, struct module *mod)
2020{
2021 if (mod->srcversion[0]) {
2022 buf_printf(b, "\n");
2023 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2024 mod->srcversion);
2025 }
2026}
2027
2028static void write_if_changed(struct buffer *b, const char *fname)
2029{
2030 char *tmp;
2031 FILE *file;
2032 struct stat st;
2033
2034 file = fopen(fname, "r");
2035 if (!file)
2036 goto write;
2037
2038 if (fstat(fileno(file), &st) < 0)
2039 goto close_write;
2040
2041 if (st.st_size != b->pos)
2042 goto close_write;
2043
2044 tmp = NOFAIL(malloc(b->pos));
2045 if (fread(tmp, 1, b->pos, file) != b->pos)
2046 goto free_write;
2047
2048 if (memcmp(tmp, b->p, b->pos) != 0)
2049 goto free_write;
2050
2051 free(tmp);
2052 fclose(file);
2053 return;
2054
2055 free_write:
2056 free(tmp);
2057 close_write:
2058 fclose(file);
2059 write:
2060 file = fopen(fname, "w");
2061 if (!file) {
2062 perror(fname);
2063 exit(1);
2064 }
2065 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2066 perror(fname);
2067 exit(1);
2068 }
2069 fclose(file);
2070}
2071
2072/* parse Module.symvers file. line format:
2073 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2074 **/
2075static void read_dump(const char *fname, unsigned int kernel)
2076{
2077 unsigned long size, pos = 0;
2078 void *file = grab_file(fname, &size);
2079 char *line;
2080
2081 if (!file)
2082 /* No symbol versions, silently ignore */
2083 return;
2084
2085 while ((line = get_next_line(&pos, file, size))) {
2086 char *symname, *modname, *d, *export, *end;
2087 unsigned int crc;
2088 struct module *mod;
2089 struct symbol *s;
2090
2091 if (!(symname = strchr(line, '\t')))
2092 goto fail;
2093 *symname++ = '\0';
2094 if (!(modname = strchr(symname, '\t')))
2095 goto fail;
2096 *modname++ = '\0';
2097 if ((export = strchr(modname, '\t')) != NULL)
2098 *export++ = '\0';
2099 if (export && ((end = strchr(export, '\t')) != NULL))
2100 *end = '\0';
2101 crc = strtoul(line, &d, 16);
2102 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2103 goto fail;
2104 mod = find_module(modname);
2105 if (!mod) {
2106 if (is_vmlinux(modname))
2107 have_vmlinux = 1;
2108 mod = new_module(modname);
2109 mod->skip = 1;
2110 }
2111 s = sym_add_exported(symname, mod, export_no(export));
2112 s->kernel = kernel;
2113 s->preloaded = 1;
2114 sym_update_crc(symname, mod, crc, export_no(export));
2115 }
2116 return;
2117fail:
2118 fatal("parse error in symbol dump file\n");
2119}
2120
2121/* For normal builds always dump all symbols.
2122 * For external modules only dump symbols
2123 * that are not read from kernel Module.symvers.
2124 **/
2125static int dump_sym(struct symbol *sym)
2126{
2127 if (!external_module)
2128 return 1;
2129 if (sym->vmlinux || sym->kernel)
2130 return 0;
2131 return 1;
2132}
2133
2134static void write_dump(const char *fname)
2135{
2136 struct buffer buf = { };
2137 struct symbol *symbol;
2138 int n;
2139
2140 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2141 symbol = symbolhash[n];
2142 while (symbol) {
2143 if (dump_sym(symbol))
2144 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
2145 symbol->crc, symbol->name,
2146 symbol->module->name,
2147 export_str(symbol->export));
2148 symbol = symbol->next;
2149 }
2150 }
2151 write_if_changed(&buf, fname);
2152}
2153
2154struct ext_sym_list {
2155 struct ext_sym_list *next;
2156 const char *file;
2157};
2158
2159int main(int argc, char **argv)
2160{
2161 struct module *mod;
2162 struct buffer buf = { };
2163 char *kernel_read = NULL, *module_read = NULL;
2164 char *dump_write = NULL, *files_source = NULL;
2165 int opt;
2166 int err;
2167 struct ext_sym_list *extsym_iter;
2168 struct ext_sym_list *extsym_start = NULL;
2169
2170 while ((opt = getopt(argc, argv, "i:I:e:mnsST:o:awM:K:")) != -1) {
2171 switch (opt) {
2172 case 'i':
2173 kernel_read = optarg;
2174 break;
2175 case 'I':
2176 module_read = optarg;
2177 external_module = 1;
2178 break;
2179 case 'e':
2180 external_module = 1;
2181 extsym_iter =
2182 NOFAIL(malloc(sizeof(*extsym_iter)));
2183 extsym_iter->next = extsym_start;
2184 extsym_iter->file = optarg;
2185 extsym_start = extsym_iter;
2186 break;
2187 case 'm':
2188 modversions = 1;
2189 break;
2190 case 'n':
2191 ignore_missing_files = 1;
2192 break;
2193 case 'o':
2194 dump_write = optarg;
2195 break;
2196 case 'a':
2197 all_versions = 1;
2198 break;
2199 case 's':
2200 vmlinux_section_warnings = 0;
2201 break;
2202 case 'S':
2203 sec_mismatch_verbose = 0;
2204 break;
2205 case 'T':
2206 files_source = optarg;
2207 break;
2208 case 'w':
2209 warn_unresolved = 1;
2210 break;
2211 default:
2212 exit(1);
2213 }
2214 }
2215
2216 if (kernel_read)
2217 read_dump(kernel_read, 1);
2218 if (module_read)
2219 read_dump(module_read, 0);
2220 while (extsym_start) {
2221 read_dump(extsym_start->file, 0);
2222 extsym_iter = extsym_start->next;
2223 free(extsym_start);
2224 extsym_start = extsym_iter;
2225 }
2226
2227 while (optind < argc)
2228 read_symbols(argv[optind++]);
2229
2230 if (files_source)
2231 read_symbols_from_files(files_source);
2232
2233 for (mod = modules; mod; mod = mod->next) {
2234 if (mod->skip)
2235 continue;
2236 check_exports(mod);
2237 }
2238
2239 err = 0;
2240
2241 for (mod = modules; mod; mod = mod->next) {
2242 char fname[strlen(mod->name) + 10];
2243
2244 if (mod->skip)
2245 continue;
2246
2247 buf.pos = 0;
2248
2249 add_header(&buf, mod);
2250 add_intree_flag(&buf, !external_module);
2251 add_staging_flag(&buf, mod->name);
2252 err |= add_versions(&buf, mod);
2253 add_depends(&buf, mod, modules);
2254 add_moddevtable(&buf, mod);
2255 add_srcversion(&buf, mod);
2256
2257 sprintf(fname, "%s.mod.c", mod->name);
2258 write_if_changed(&buf, fname);
2259 }
2260
2261 if (dump_write)
2262 write_dump(dump_write);
2263 if (sec_mismatch_count && !sec_mismatch_verbose)
2264 warn("modpost: Found %d section mismatch(es).\n"
2265 "To see full details build your kernel with:\n"
2266 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2267 sec_mismatch_count);
2268
2269 return err;
2270}