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