projects/linux·blob uaccess-cleanups · refs

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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 <fnmatch.h>
17#include <stdio.h>
18#include <ctype.h>
19#include <string.h>
20#include <limits.h>
21#include <stdbool.h>
22#include <errno.h>
23
24#include <hash.h>
25#include <hashtable.h>
26#include <list.h>
27#include <xalloc.h>
28#include "modpost.h"
29#include "../../include/linux/license.h"
30
31#define MODULE_NS_PREFIX "module:"
32
33static bool module_enabled;
34/* Are we using CONFIG_MODVERSIONS? */
35static bool modversions;
36/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
37static bool all_versions;
38/* Is CONFIG_BASIC_MODVERSIONS set? */
39static bool basic_modversions;
40/* Is CONFIG_EXTENDED_MODVERSIONS set? */
41static bool extended_modversions;
42/* If we are modposting external module set to 1 */
43static bool external_module;
44/* Only warn about unresolved symbols */
45static bool warn_unresolved;
46
47static int sec_mismatch_count;
48static bool sec_mismatch_warn_only = true;
49/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
50static bool trim_unused_exports;
51
52/* ignore missing files */
53static bool ignore_missing_files;
54/* If set to 1, only warn (instead of error) about missing ns imports */
55static bool allow_missing_ns_imports;
56
57static bool error_occurred;
58
59static bool extra_warn __attribute__((unused));
60
61bool target_is_big_endian;
62bool host_is_big_endian;
63
64/*
65 * Cut off the warnings when there are too many. This typically occurs when
66 * vmlinux is missing. ('make modules' without building vmlinux.)
67 */
68#define MAX_UNRESOLVED_REPORTS 10
69static unsigned int nr_unresolved;
70
71/* In kernel, this size is defined in linux/module.h;
72 * here we use Elf_Addr instead of long for covering cross-compile
73 */
74
75#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
76
77void modpost_log(bool is_error, struct module *mod, const char *fmt, ...)
78{
79 va_list arglist;
80
81 if (is_error) {
82 fprintf(stderr, "ERROR: ");
83 error_occurred = true;
84 } else {
85 fprintf(stderr, "WARNING: ");
86 }
87
88 fprintf(stderr, "modpost: ");
89
90 if (mod)
91 fprintf(stderr, "%s%s: ", mod->name, mod->is_vmlinux ? "" : ".ko");
92
93 va_start(arglist, fmt);
94 vfprintf(stderr, fmt, arglist);
95 va_end(arglist);
96}
97
98#define mod_warn(mod, fmt, args...) modpost_log(false, mod, fmt, ##args)
99#define mod_error(mod, fmt, args...) modpost_log(true, mod, fmt, ##args)
100
101static inline bool strends(const char *str, const char *postfix)
102{
103 if (strlen(str) < strlen(postfix))
104 return false;
105
106 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
107}
108
109/**
110 * get_basename - return the last part of a pathname.
111 *
112 * @path: path to extract the filename from.
113 */
114const char *get_basename(const char *path)
115{
116 const char *tail = strrchr(path, '/');
117
118 return tail ? tail + 1 : path;
119}
120
121char *read_text_file(const char *filename)
122{
123 struct stat st;
124 size_t nbytes;
125 int fd;
126 char *buf;
127
128 fd = open(filename, O_RDONLY);
129 if (fd < 0) {
130 perror(filename);
131 exit(1);
132 }
133
134 if (fstat(fd, &st) < 0) {
135 perror(filename);
136 exit(1);
137 }
138
139 buf = xmalloc(st.st_size + 1);
140
141 nbytes = st.st_size;
142
143 while (nbytes) {
144 ssize_t bytes_read;
145
146 bytes_read = read(fd, buf, nbytes);
147 if (bytes_read < 0) {
148 perror(filename);
149 exit(1);
150 }
151
152 nbytes -= bytes_read;
153 }
154 buf[st.st_size] = '\0';
155
156 close(fd);
157
158 return buf;
159}
160
161char *get_line(char **stringp)
162{
163 char *orig = *stringp, *next;
164
165 /* do not return the unwanted extra line at EOF */
166 if (!orig || *orig == '\0')
167 return NULL;
168
169 /* don't use strsep here, it is not available everywhere */
170 next = strchr(orig, '\n');
171 if (next)
172 *next++ = '\0';
173
174 *stringp = next;
175
176 return orig;
177}
178
179/* A list of all modules we processed */
180LIST_HEAD(modules);
181
182static struct module *find_module(const char *filename, const char *modname)
183{
184 struct module *mod;
185
186 list_for_each_entry(mod, &modules, list) {
187 if (!strcmp(mod->dump_file, filename) &&
188 !strcmp(mod->name, modname))
189 return mod;
190 }
191 return NULL;
192}
193
194static struct module *new_module(const char *name, size_t namelen)
195{
196 struct module *mod;
197
198 mod = xmalloc(sizeof(*mod) + namelen + 1);
199 memset(mod, 0, sizeof(*mod));
200
201 INIT_LIST_HEAD(&mod->exported_symbols);
202 INIT_LIST_HEAD(&mod->unresolved_symbols);
203 INIT_LIST_HEAD(&mod->missing_namespaces);
204 INIT_LIST_HEAD(&mod->imported_namespaces);
205 INIT_LIST_HEAD(&mod->aliases);
206
207 memcpy(mod->name, name, namelen);
208 mod->name[namelen] = '\0';
209 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
210
211 /*
212 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
213 * is missing, do not check the use for EXPORT_SYMBOL_GPL() because
214 * modpost will exit with an error anyway.
215 */
216 mod->is_gpl_compatible = true;
217
218 list_add_tail(&mod->list, &modules);
219
220 return mod;
221}
222
223struct symbol {
224 struct hlist_node hnode;/* link to hash table */
225 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
226 struct module *module;
227 char *namespace;
228 unsigned int crc;
229 bool crc_valid;
230 bool weak;
231 bool is_func;
232 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
233 bool used; /* there exists a user of this symbol */
234 char name[];
235};
236
237static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
238
239/**
240 * Allocate a new symbols for use in the hash of exported symbols or
241 * the list of unresolved symbols per module
242 **/
243static struct symbol *alloc_symbol(const char *name)
244{
245 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1);
246
247 memset(s, 0, sizeof(*s));
248 strcpy(s->name, name);
249
250 return s;
251}
252
253static uint8_t get_symbol_flags(const struct symbol *sym)
254{
255 return sym->is_gpl_only ? KSYM_FLAG_GPL_ONLY : 0;
256}
257
258/* For the hash of exported symbols */
259static void hash_add_symbol(struct symbol *sym)
260{
261 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name));
262}
263
264static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
265{
266 struct symbol *sym;
267
268 sym = alloc_symbol(name);
269 sym->weak = weak;
270
271 list_add_tail(&sym->list, &mod->unresolved_symbols);
272}
273
274static struct symbol *sym_find_with_module(const char *name, struct module *mod)
275{
276 struct symbol *s;
277
278 /* For our purposes, .foo matches foo. PPC64 needs this. */
279 if (name[0] == '.')
280 name++;
281
282 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) {
283 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
284 return s;
285 }
286 return NULL;
287}
288
289static struct symbol *find_symbol(const char *name)
290{
291 return sym_find_with_module(name, NULL);
292}
293
294struct namespace_list {
295 struct list_head list;
296 char namespace[];
297};
298
299static bool contains_namespace(struct list_head *head, const char *namespace)
300{
301 struct namespace_list *list;
302
303 /*
304 * The default namespace is null string "", which is always implicitly
305 * contained.
306 */
307 if (!namespace[0])
308 return true;
309
310 list_for_each_entry(list, head, list) {
311 if (!strcmp(list->namespace, namespace))
312 return true;
313 }
314
315 return false;
316}
317
318static void add_namespace(struct list_head *head, const char *namespace)
319{
320 struct namespace_list *ns_entry;
321
322 if (!contains_namespace(head, namespace)) {
323 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1);
324 strcpy(ns_entry->namespace, namespace);
325 list_add_tail(&ns_entry->list, head);
326 }
327}
328
329static void *sym_get_data_by_offset(const struct elf_info *info,
330 unsigned int secindex, unsigned long offset)
331{
332 Elf_Shdr *sechdr = &info->sechdrs[secindex];
333
334 return (void *)info->hdr + sechdr->sh_offset + offset;
335}
336
337void *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, unsigned int secindex)
350{
351 /*
352 * If sym->st_shndx is a special section index, there is no
353 * corresponding section header.
354 * Return "" if the index is out of range of info->sechdrs[] array.
355 */
356 if (secindex >= info->num_sections)
357 return "";
358
359 return sech_name(info, &info->sechdrs[secindex]);
360}
361
362static struct symbol *sym_add_exported(const char *name, struct module *mod,
363 bool gpl_only, const char *namespace)
364{
365 struct symbol *s = find_symbol(name);
366
367 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
368 mod_error(mod, "symbol '%s' exported twice. Previous export was in %s%s\n",
369 name, s->module->name, s->module->is_vmlinux ? "" : ".ko");
370 }
371
372 s = alloc_symbol(name);
373 s->module = mod;
374 s->is_gpl_only = gpl_only;
375 s->namespace = xstrdup(namespace);
376 list_add_tail(&s->list, &mod->exported_symbols);
377 hash_add_symbol(s);
378
379 return s;
380}
381
382static void sym_set_crc(struct symbol *sym, unsigned int crc)
383{
384 sym->crc = crc;
385 sym->crc_valid = true;
386}
387
388static void *grab_file(const char *filename, size_t *size)
389{
390 struct stat st;
391 void *map = MAP_FAILED;
392 int fd;
393
394 fd = open(filename, O_RDONLY);
395 if (fd < 0)
396 return NULL;
397 if (fstat(fd, &st))
398 goto failed;
399
400 *size = st.st_size;
401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
402
403failed:
404 close(fd);
405 if (map == MAP_FAILED)
406 return NULL;
407 return map;
408}
409
410static void release_file(void *file, size_t size)
411{
412 munmap(file, size);
413}
414
415static int parse_elf(struct elf_info *info, const char *filename)
416{
417 unsigned int i;
418 Elf_Ehdr *hdr;
419 Elf_Shdr *sechdrs;
420 Elf_Sym *sym;
421 const char *secstrings;
422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
423
424 hdr = grab_file(filename, &info->size);
425 if (!hdr) {
426 if (ignore_missing_files) {
427 fprintf(stderr, "%s: %s (ignored)\n", filename,
428 strerror(errno));
429 return 0;
430 }
431 perror(filename);
432 exit(1);
433 }
434 info->hdr = hdr;
435 if (info->size < sizeof(*hdr)) {
436 /* file too small, assume this is an empty .o file */
437 return 0;
438 }
439 /* Is this a valid ELF file? */
440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
441 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
442 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
444 /* Not an ELF file - silently ignore it */
445 return 0;
446 }
447
448 switch (hdr->e_ident[EI_DATA]) {
449 case ELFDATA2LSB:
450 target_is_big_endian = false;
451 break;
452 case ELFDATA2MSB:
453 target_is_big_endian = true;
454 break;
455 default:
456 fatal("target endian is unknown\n");
457 }
458
459 /* Fix endianness in ELF header */
460 hdr->e_type = TO_NATIVE(hdr->e_type);
461 hdr->e_machine = TO_NATIVE(hdr->e_machine);
462 hdr->e_version = TO_NATIVE(hdr->e_version);
463 hdr->e_entry = TO_NATIVE(hdr->e_entry);
464 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
465 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
466 hdr->e_flags = TO_NATIVE(hdr->e_flags);
467 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
468 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
469 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
470 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
471 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
472 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
473 sechdrs = (void *)hdr + hdr->e_shoff;
474 info->sechdrs = sechdrs;
475
476 /* modpost only works for relocatable objects */
477 if (hdr->e_type != ET_REL)
478 fatal("%s: not relocatable object.", filename);
479
480 /* Check if file offset is correct */
481 if (hdr->e_shoff > info->size)
482 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
483 (unsigned long)hdr->e_shoff, filename, info->size);
484
485 if (hdr->e_shnum == SHN_UNDEF) {
486 /*
487 * There are more than 64k sections,
488 * read count from .sh_size.
489 */
490 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
491 }
492 else {
493 info->num_sections = hdr->e_shnum;
494 }
495 if (hdr->e_shstrndx == SHN_XINDEX) {
496 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
497 }
498 else {
499 info->secindex_strings = hdr->e_shstrndx;
500 }
501
502 /* Fix endianness in section headers */
503 for (i = 0; i < info->num_sections; i++) {
504 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
505 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
506 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
507 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
508 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
509 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
510 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
511 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
512 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
513 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
514 }
515 /* Find symbol table. */
516 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
517 for (i = 1; i < info->num_sections; i++) {
518 const char *secname;
519 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
520
521 if (!nobits && sechdrs[i].sh_offset > info->size)
522 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
523 filename, (unsigned long)sechdrs[i].sh_offset,
524 sizeof(*hdr));
525
526 secname = secstrings + sechdrs[i].sh_name;
527 if (strcmp(secname, ".modinfo") == 0) {
528 if (nobits)
529 fatal("%s has NOBITS .modinfo\n", filename);
530 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
531 info->modinfo_len = sechdrs[i].sh_size;
532 } else if (!strcmp(secname, ".export_symbol")) {
533 info->export_symbol_secndx = i;
534 } else if (!strcmp(secname, ".no_trim_symbol")) {
535 info->no_trim_symbol = (void *)hdr + sechdrs[i].sh_offset;
536 info->no_trim_symbol_len = sechdrs[i].sh_size;
537 }
538
539 if (sechdrs[i].sh_type == SHT_SYMTAB) {
540 unsigned int sh_link_idx;
541 symtab_idx = i;
542 info->symtab_start = (void *)hdr +
543 sechdrs[i].sh_offset;
544 info->symtab_stop = (void *)hdr +
545 sechdrs[i].sh_offset + sechdrs[i].sh_size;
546 sh_link_idx = sechdrs[i].sh_link;
547 info->strtab = (void *)hdr +
548 sechdrs[sh_link_idx].sh_offset;
549 }
550
551 /* 32bit section no. table? ("more than 64k sections") */
552 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
553 symtab_shndx_idx = i;
554 info->symtab_shndx_start = (void *)hdr +
555 sechdrs[i].sh_offset;
556 info->symtab_shndx_stop = (void *)hdr +
557 sechdrs[i].sh_offset + sechdrs[i].sh_size;
558 }
559 }
560 if (!info->symtab_start)
561 fatal("%s has no symtab?\n", filename);
562
563 /* Fix endianness in symbols */
564 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
565 sym->st_shndx = TO_NATIVE(sym->st_shndx);
566 sym->st_name = TO_NATIVE(sym->st_name);
567 sym->st_value = TO_NATIVE(sym->st_value);
568 sym->st_size = TO_NATIVE(sym->st_size);
569 }
570
571 if (symtab_shndx_idx != ~0U) {
572 Elf32_Word *p;
573 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
574 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
575 filename, sechdrs[symtab_shndx_idx].sh_link,
576 symtab_idx);
577 /* Fix endianness */
578 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
579 p++)
580 *p = TO_NATIVE(*p);
581 }
582
583 symsearch_init(info);
584
585 return 1;
586}
587
588static void parse_elf_finish(struct elf_info *info)
589{
590 symsearch_finish(info);
591 release_file(info->hdr, info->size);
592}
593
594static int ignore_undef_symbol(struct elf_info *info, const char *symname)
595{
596 /* ignore __this_module, it will be resolved shortly */
597 if (strcmp(symname, "__this_module") == 0)
598 return 1;
599 /* ignore global offset table */
600 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
601 return 1;
602 if (info->hdr->e_machine == EM_PPC)
603 /* Special register function linked on all modules during final link of .ko */
604 if (strstarts(symname, "_restgpr_") ||
605 strstarts(symname, "_savegpr_") ||
606 strstarts(symname, "_rest32gpr_") ||
607 strstarts(symname, "_save32gpr_") ||
608 strstarts(symname, "_restvr_") ||
609 strstarts(symname, "_savevr_"))
610 return 1;
611 if (info->hdr->e_machine == EM_PPC64)
612 /* Special register function linked on all modules during final link of .ko */
613 if (strstarts(symname, "_restgpr0_") ||
614 strstarts(symname, "_savegpr0_") ||
615 strstarts(symname, "_restgpr1_") ||
616 strstarts(symname, "_savegpr1_") ||
617 strstarts(symname, "_restfpr_") ||
618 strstarts(symname, "_savefpr_") ||
619 strstarts(symname, "_restvr_") ||
620 strstarts(symname, "_savevr_") ||
621 strcmp(symname, ".TOC.") == 0)
622 return 1;
623
624 /* ignore linker-created section bounds variables */
625 if (strstarts(symname, "__start_") || strstarts(symname, "__stop_"))
626 return 1;
627
628 /* Do not ignore this symbol */
629 return 0;
630}
631
632static void handle_symbol(struct module *mod, struct elf_info *info,
633 const Elf_Sym *sym, const char *symname)
634{
635 switch (sym->st_shndx) {
636 case SHN_COMMON:
637 if (strstarts(symname, "__gnu_lto_")) {
638 /* Should warn here, but modpost runs before the linker */
639 } else
640 mod_warn(mod, "'%s' is COMMON symbol\n", symname);
641 break;
642 case SHN_UNDEF:
643 /* undefined symbol */
644 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
645 ELF_ST_BIND(sym->st_info) != STB_WEAK)
646 break;
647 if (ignore_undef_symbol(info, symname))
648 break;
649 if (info->hdr->e_machine == EM_SPARC ||
650 info->hdr->e_machine == EM_SPARCV9) {
651 /* Ignore register directives. */
652 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
653 break;
654 if (symname[0] == '.') {
655 char *munged = xstrdup(symname);
656 munged[0] = '_';
657 munged[1] = toupper(munged[1]);
658 symname = munged;
659 }
660 }
661
662 sym_add_unresolved(symname, mod,
663 ELF_ST_BIND(sym->st_info) == STB_WEAK);
664 break;
665 default:
666 if (strcmp(symname, "init_module") == 0)
667 mod->has_init = true;
668 if (strcmp(symname, "cleanup_module") == 0)
669 mod->has_cleanup = true;
670 break;
671 }
672}
673
674/**
675 * Parse tag=value strings from .modinfo section
676 **/
677static char *next_string(char *string, unsigned long *secsize)
678{
679 /* Skip non-zero chars */
680 while (string[0]) {
681 string++;
682 if ((*secsize)-- <= 1)
683 return NULL;
684 }
685
686 /* Skip any zero padding. */
687 while (!string[0]) {
688 string++;
689 if ((*secsize)-- <= 1)
690 return NULL;
691 }
692 return string;
693}
694
695static char *get_next_modinfo(struct elf_info *info, const char *tag,
696 char *prev)
697{
698 char *p;
699 unsigned int taglen = strlen(tag);
700 char *modinfo = info->modinfo;
701 unsigned long size = info->modinfo_len;
702
703 if (prev) {
704 size -= prev - modinfo;
705 modinfo = next_string(prev, &size);
706 }
707
708 for (p = modinfo; p; p = next_string(p, &size)) {
709 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
710 return p + taglen + 1;
711 }
712 return NULL;
713}
714
715static char *get_modinfo(struct elf_info *info, const char *tag)
716
717{
718 return get_next_modinfo(info, tag, NULL);
719}
720
721static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
722{
723 return sym ? elf->strtab + sym->st_name : "";
724}
725
726/*
727 * Check whether the 'string' argument matches one of the 'patterns',
728 * an array of shell wildcard patterns (glob).
729 *
730 * Return true is there is a match.
731 */
732static bool match(const char *string, const char *const patterns[])
733{
734 const char *pattern;
735
736 while ((pattern = *patterns++)) {
737 if (!fnmatch(pattern, string, 0))
738 return true;
739 }
740
741 return false;
742}
743
744/* useful to pass patterns to match() directly */
745#define PATTERNS(...) \
746 ({ \
747 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
748 patterns; \
749 })
750
751/* sections that we do not want to do full section mismatch check on */
752static const char *const section_white_list[] =
753{
754 ".comment*",
755 ".debug*",
756 ".zdebug*", /* Compressed debug sections. */
757 ".GCC.command.line", /* record-gcc-switches */
758 ".mdebug*", /* alpha, score, mips etc. */
759 ".pdr", /* alpha, score, mips etc. */
760 ".stab*",
761 ".note*",
762 ".got*",
763 ".toc*",
764 ".xt.prop", /* xtensa */
765 ".xt.lit", /* xtensa */
766 ".arcextmap*", /* arc */
767 ".gnu.linkonce.arcext*", /* arc : modules */
768 ".cmem*", /* EZchip */
769 ".fmt_slot*", /* EZchip */
770 ".gnu.lto*",
771 ".discard.*",
772 ".llvm.call-graph-profile", /* call graph */
773 "__llvm_covfun",
774 "__llvm_covmap",
775 ".klp.symid", /* objtool --klp-symids */
776 NULL
777};
778
779/*
780 * This is used to find sections missing the SHF_ALLOC flag.
781 * The cause of this is often a section specified in assembler
782 * without "ax" / "aw".
783 */
784static void check_section(struct module *mod, struct elf_info *elf,
785 Elf_Shdr *sechdr)
786{
787 const char *sec = sech_name(elf, sechdr);
788
789 if (sechdr->sh_type == SHT_PROGBITS &&
790 !(sechdr->sh_flags & SHF_ALLOC) &&
791 !match(sec, section_white_list)) {
792 mod_warn(mod, "unexpected non-allocatable section '%s'.\n"
793 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
794 "Note that for example <linux/init.h> contains\n"
795 "section definitions for use in .S files.\n\n",
796 sec);
797 }
798}
799
800
801
802#define ALL_INIT_DATA_SECTIONS \
803 ".init.setup", ".init.rodata", ".init.data"
804
805#define ALL_PCI_INIT_SECTIONS \
806 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
807 ".pci_fixup_enable", ".pci_fixup_resume", \
808 ".pci_fixup_resume_early", ".pci_fixup_suspend"
809
810#define ALL_INIT_SECTIONS ".init.*"
811#define ALL_EXIT_SECTIONS ".exit.*"
812
813#define DATA_SECTIONS ".data", ".data.rel"
814#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
815 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
816 ".ltext", ".ltext.*"
817#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
818 ".fixup", ".entry.text", ".exception.text", \
819 ".coldtext", ".softirqentry.text", ".irqentry.text"
820
821#define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \
822 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
823
824enum mismatch {
825 TEXTDATA_TO_ANY_INIT_EXIT,
826 XXXINIT_TO_SOME_INIT,
827 ANY_INIT_TO_ANY_EXIT,
828 ANY_EXIT_TO_ANY_INIT,
829 EXTABLE_TO_NON_TEXT,
830};
831
832/**
833 * Describe how to match sections on different criteria:
834 *
835 * @fromsec: Array of sections to be matched.
836 *
837 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
838 * this array is forbidden (black-list). Can be empty.
839 *
840 * @good_tosec: Relocations applied to a section in @fromsec must be
841 * targeting sections in this array (white-list). Can be empty.
842 *
843 * @mismatch: Type of mismatch.
844 */
845struct sectioncheck {
846 const char *fromsec[20];
847 const char *bad_tosec[20];
848 const char *good_tosec[20];
849 enum mismatch mismatch;
850};
851
852static const struct sectioncheck sectioncheck[] = {
853/* Do not reference init/exit code/data from
854 * normal code and data
855 */
856{
857 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
858 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
859 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
860},
861/* Do not use exit code/data from init code */
862{
863 .fromsec = { ALL_INIT_SECTIONS, NULL },
864 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
865 .mismatch = ANY_INIT_TO_ANY_EXIT,
866},
867/* Do not use init code/data from exit code */
868{
869 .fromsec = { ALL_EXIT_SECTIONS, NULL },
870 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
871 .mismatch = ANY_EXIT_TO_ANY_INIT,
872},
873{
874 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
875 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
876 .mismatch = ANY_INIT_TO_ANY_EXIT,
877},
878{
879 .fromsec = { "__ex_table", NULL },
880 /* If you're adding any new black-listed sections in here, consider
881 * adding a special 'printer' for them in scripts/check_extable.
882 */
883 .bad_tosec = { ".altinstr_replacement", NULL },
884 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
885 .mismatch = EXTABLE_TO_NON_TEXT,
886}
887};
888
889static const struct sectioncheck *section_mismatch(
890 const char *fromsec, const char *tosec)
891{
892 int i;
893
894 /*
895 * The target section could be the SHT_NUL section when we're
896 * handling relocations to un-resolved symbols, trying to match it
897 * doesn't make much sense and causes build failures on parisc
898 * architectures.
899 */
900 if (*tosec == '\0')
901 return NULL;
902
903 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
904 const struct sectioncheck *check = &sectioncheck[i];
905
906 if (match(fromsec, check->fromsec)) {
907 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
908 return check;
909 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
910 return check;
911 }
912 }
913 return NULL;
914}
915
916/**
917 * Whitelist to allow certain references to pass with no warning.
918 *
919 * Pattern 1:
920 * If a module parameter is declared __initdata and permissions=0
921 * then this is legal despite the warning generated.
922 * We cannot see value of permissions here, so just ignore
923 * this pattern.
924 * The pattern is identified by:
925 * tosec = .init.data
926 * fromsec = .data*
927 * atsym =__param*
928 *
929 * Pattern 1a:
930 * module_param_call() ops can refer to __init set function if permissions=0
931 * The pattern is identified by:
932 * tosec = .init.text
933 * fromsec = .data*
934 * atsym = __param_ops_*
935 *
936 * Pattern 3:
937 * Whitelist all references from .head.text to any init section
938 *
939 * Pattern 4:
940 * Some symbols belong to init section but still it is ok to reference
941 * these from non-init sections as these symbols don't have any memory
942 * allocated for them and symbol address and value are same. So even
943 * if init section is freed, its ok to reference those symbols.
944 * For ex. symbols marking the init section boundaries.
945 * This pattern is identified by
946 * refsymname = __init_begin, _sinittext, _einittext
947 *
948 * Pattern 5:
949 * GCC may optimize static inlines when fed constant arg(s) resulting
950 * in functions like cpumask_empty() -- generating an associated symbol
951 * cpumask_empty.constprop.3 that appears in the audit. If the const that
952 * is passed in comes from __init, like say nmi_ipi_mask, we get a
953 * meaningless section warning. May need to add isra symbols too...
954 * This pattern is identified by
955 * tosec = init section
956 * fromsec = text section
957 * refsymname = *.constprop.*
958 *
959 **/
960static int secref_whitelist(const char *fromsec, const char *fromsym,
961 const char *tosec, const char *tosym)
962{
963 /* Check for pattern 1 */
964 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
965 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
966 strstarts(fromsym, "__param"))
967 return 0;
968
969 /* Check for pattern 1a */
970 if (strcmp(tosec, ".init.text") == 0 &&
971 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
972 strstarts(fromsym, "__param_ops_"))
973 return 0;
974
975 /* symbols in data sections that may refer to any init/exit sections */
976 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
977 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
978 match(fromsym, PATTERNS("*_ops", "*_ops.llvm.*", "*_console")))
979 return 0;
980
981 /* Check for pattern 3 */
982 if (strstarts(fromsec, ".head.text") &&
983 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
984 return 0;
985
986 /* Check for pattern 4 */
987 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
988 return 0;
989
990 /* Check for pattern 5 */
991 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
992 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
993 match(fromsym, PATTERNS("*.constprop.*")))
994 return 0;
995
996 return 1;
997}
998
999static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1000 unsigned int secndx)
1001{
1002 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1003}
1004
1005static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1006{
1007 Elf_Sym *new_sym;
1008
1009 /* If the supplied symbol has a valid name, return it */
1010 if (is_valid_name(elf, sym))
1011 return sym;
1012
1013 /*
1014 * Strive to find a better symbol name, but the resulting name may not
1015 * match the symbol referenced in the original code.
1016 */
1017 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1018 true, 20);
1019 return new_sym ? new_sym : sym;
1020}
1021
1022static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1023{
1024 if (secndx >= elf->num_sections)
1025 return false;
1026
1027 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1028}
1029
1030static void default_mismatch_handler(struct module *mod, struct elf_info *elf,
1031 const struct sectioncheck* const mismatch,
1032 Elf_Sym *tsym,
1033 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1034 const char *tosec, Elf_Addr taddr)
1035{
1036 Elf_Sym *from;
1037 const char *tosym;
1038 const char *fromsym;
1039 char taddr_str[16];
1040
1041 from = find_fromsym(elf, faddr, fsecndx);
1042 fromsym = sym_name(elf, from);
1043
1044 tsym = find_tosym(elf, taddr, tsym);
1045 tosym = sym_name(elf, tsym);
1046
1047 /* check whitelist - we may ignore it */
1048 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1049 return;
1050
1051 sec_mismatch_count++;
1052
1053 if (!tosym[0])
1054 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
1055
1056 /*
1057 * The format for the reference source: <symbol_name>+<offset> or <address>
1058 * The format for the reference destination: <symbol_name> or <address>
1059 */
1060 mod_warn(mod, "section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
1061 fromsym, fromsym[0] ? "+" : "",
1062 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
1063 fromsec, tosym[0] ? tosym : taddr_str, tosec);
1064
1065 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1066 if (match(tosec, mismatch->bad_tosec))
1067 fatal("The relocation at %s+0x%lx references\n"
1068 "section \"%s\" which is black-listed.\n"
1069 "Something is seriously wrong and should be fixed.\n"
1070 "You might get more information about where this is\n"
1071 "coming from by using scripts/check_extable.sh %s\n",
1072 fromsec, (long)faddr, tosec, mod->name);
1073 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1074 warn("The relocation at %s+0x%lx references\n"
1075 "section \"%s\" which is not in the list of\n"
1076 "authorized sections. If you're adding a new section\n"
1077 "and/or if this reference is valid, add \"%s\" to the\n"
1078 "list of authorized sections to jump to on fault.\n"
1079 "This can be achieved by adding \"%s\" to\n"
1080 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1081 fromsec, (long)faddr, tosec, tosec, tosec);
1082 else
1083 error("%s+0x%lx references non-executable section '%s'\n",
1084 fromsec, (long)faddr, tosec);
1085 }
1086}
1087
1088static void check_export_symbol(struct module *mod, struct elf_info *elf,
1089 Elf_Addr faddr, const char *secname,
1090 Elf_Sym *sym)
1091{
1092 static const char *prefix = "__export_symbol_";
1093 const char *label_name, *name, *data;
1094 Elf_Sym *label;
1095 struct symbol *s;
1096 bool is_gpl;
1097
1098 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1099 label_name = sym_name(elf, label);
1100
1101 if (!strstarts(label_name, prefix)) {
1102 mod_error(mod, ".export_symbol section contains strange symbol '%s'\n",
1103 label_name);
1104 return;
1105 }
1106
1107 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1108 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1109 mod_error(mod, "local symbol '%s' was exported\n",
1110 label_name + strlen(prefix));
1111 return;
1112 }
1113
1114 name = sym_name(elf, sym);
1115 if (strcmp(label_name + strlen(prefix), name)) {
1116 mod_error(mod, ".export_symbol section references '%s', but it does not seem to be an export symbol\n",
1117 name);
1118 return;
1119 }
1120
1121 data = sym_get_data(elf, label); /* license */
1122 if (!strcmp(data, "GPL")) {
1123 is_gpl = true;
1124 } else if (!strcmp(data, "")) {
1125 is_gpl = false;
1126 } else {
1127 mod_error(mod, "unknown license '%s' was specified for '%s'\n",
1128 data, name);
1129 return;
1130 }
1131
1132 data += strlen(data) + 1; /* namespace */
1133 s = sym_add_exported(name, mod, is_gpl, data);
1134
1135 /*
1136 * We need to be aware whether we are exporting a function or
1137 * a data on some architectures.
1138 */
1139 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1140
1141 /*
1142 * For parisc64, symbols prefixed $$ from the library have the symbol type
1143 * STT_LOPROC. They should be handled as functions too.
1144 */
1145 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1146 elf->hdr->e_machine == EM_PARISC &&
1147 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1148 s->is_func = true;
1149
1150 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1151 mod_warn(mod, "EXPORT_SYMBOL used for init symbol '%s'. Remove __init or EXPORT_SYMBOL.\n",
1152 name);
1153 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1154 mod_warn(mod, "EXPORT_SYMBOL used for exit symbol '%s'. Remove __exit or EXPORT_SYMBOL.\n",
1155 name);
1156}
1157
1158static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1159 Elf_Sym *sym,
1160 unsigned int fsecndx, const char *fromsec,
1161 Elf_Addr faddr, Elf_Addr taddr)
1162{
1163 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1164 const struct sectioncheck *mismatch;
1165
1166 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1167 check_export_symbol(mod, elf, faddr, tosec, sym);
1168 return;
1169 }
1170
1171 mismatch = section_mismatch(fromsec, tosec);
1172 if (!mismatch)
1173 return;
1174
1175 default_mismatch_handler(mod, elf, mismatch, sym,
1176 fsecndx, fromsec, faddr,
1177 tosec, taddr);
1178}
1179
1180static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1181{
1182 switch (r_type) {
1183 case R_386_32:
1184 return get_unaligned_native(location);
1185 case R_386_PC32:
1186 return get_unaligned_native(location) + 4;
1187 }
1188
1189 return (Elf_Addr)(-1);
1190}
1191
1192static int32_t sign_extend32(int32_t value, int index)
1193{
1194 uint8_t shift = 31 - index;
1195
1196 return (int32_t)(value << shift) >> shift;
1197}
1198
1199static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1200{
1201 uint32_t inst, upper, lower, sign, j1, j2;
1202 int32_t offset;
1203
1204 switch (r_type) {
1205 case R_ARM_ABS32:
1206 case R_ARM_REL32:
1207 inst = get_unaligned_native((uint32_t *)loc);
1208 return inst + sym->st_value;
1209 case R_ARM_MOVW_ABS_NC:
1210 case R_ARM_MOVT_ABS:
1211 inst = get_unaligned_native((uint32_t *)loc);
1212 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1213 15);
1214 return offset + sym->st_value;
1215 case R_ARM_PC24:
1216 case R_ARM_CALL:
1217 case R_ARM_JUMP24:
1218 inst = get_unaligned_native((uint32_t *)loc);
1219 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1220 return offset + sym->st_value + 8;
1221 case R_ARM_THM_MOVW_ABS_NC:
1222 case R_ARM_THM_MOVT_ABS:
1223 upper = get_unaligned_native((uint16_t *)loc);
1224 lower = get_unaligned_native((uint16_t *)loc + 1);
1225 offset = sign_extend32(((upper & 0x000f) << 12) |
1226 ((upper & 0x0400) << 1) |
1227 ((lower & 0x7000) >> 4) |
1228 (lower & 0x00ff),
1229 15);
1230 return offset + sym->st_value;
1231 case R_ARM_THM_JUMP19:
1232 /*
1233 * Encoding T3:
1234 * S = upper[10]
1235 * imm6 = upper[5:0]
1236 * J1 = lower[13]
1237 * J2 = lower[11]
1238 * imm11 = lower[10:0]
1239 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1240 */
1241 upper = get_unaligned_native((uint16_t *)loc);
1242 lower = get_unaligned_native((uint16_t *)loc + 1);
1243
1244 sign = (upper >> 10) & 1;
1245 j1 = (lower >> 13) & 1;
1246 j2 = (lower >> 11) & 1;
1247 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1248 ((upper & 0x03f) << 12) |
1249 ((lower & 0x07ff) << 1),
1250 20);
1251 return offset + sym->st_value + 4;
1252 case R_ARM_THM_PC22:
1253 case R_ARM_THM_JUMP24:
1254 /*
1255 * Encoding T4:
1256 * S = upper[10]
1257 * imm10 = upper[9:0]
1258 * J1 = lower[13]
1259 * J2 = lower[11]
1260 * imm11 = lower[10:0]
1261 * I1 = NOT(J1 XOR S)
1262 * I2 = NOT(J2 XOR S)
1263 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1264 */
1265 upper = get_unaligned_native((uint16_t *)loc);
1266 lower = get_unaligned_native((uint16_t *)loc + 1);
1267
1268 sign = (upper >> 10) & 1;
1269 j1 = (lower >> 13) & 1;
1270 j2 = (lower >> 11) & 1;
1271 offset = sign_extend32((sign << 24) |
1272 ((~(j1 ^ sign) & 1) << 23) |
1273 ((~(j2 ^ sign) & 1) << 22) |
1274 ((upper & 0x03ff) << 12) |
1275 ((lower & 0x07ff) << 1),
1276 24);
1277 return offset + sym->st_value + 4;
1278 }
1279
1280 return (Elf_Addr)(-1);
1281}
1282
1283static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1284{
1285 uint32_t inst;
1286
1287 inst = get_unaligned_native(location);
1288 switch (r_type) {
1289 case R_MIPS_LO16:
1290 return inst & 0xffff;
1291 case R_MIPS_26:
1292 return (inst & 0x03ffffff) << 2;
1293 case R_MIPS_32:
1294 return inst;
1295 }
1296 return (Elf_Addr)(-1);
1297}
1298
1299#ifndef EM_RISCV
1300#define EM_RISCV 243
1301#endif
1302
1303#ifndef R_RISCV_SUB32
1304#define R_RISCV_SUB32 39
1305#endif
1306
1307#ifndef EM_LOONGARCH
1308#define EM_LOONGARCH 258
1309#endif
1310
1311#ifndef R_LARCH_SUB32
1312#define R_LARCH_SUB32 55
1313#endif
1314
1315#ifndef R_LARCH_RELAX
1316#define R_LARCH_RELAX 100
1317#endif
1318
1319#ifndef R_LARCH_ALIGN
1320#define R_LARCH_ALIGN 102
1321#endif
1322
1323static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1324 unsigned int *r_type, unsigned int *r_sym)
1325{
1326 typedef struct {
1327 Elf64_Word r_sym; /* Symbol index */
1328 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1329 unsigned char r_type3; /* 3rd relocation type */
1330 unsigned char r_type2; /* 2nd relocation type */
1331 unsigned char r_type; /* 1st relocation type */
1332 } Elf64_Mips_R_Info;
1333
1334 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1335
1336 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1337 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1338
1339 *r_type = mips64_r_info->r_type;
1340 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1341 return;
1342 }
1343
1344 if (is_64bit)
1345 r_info = TO_NATIVE((Elf64_Xword)r_info);
1346 else
1347 r_info = TO_NATIVE((Elf32_Word)r_info);
1348
1349 *r_type = ELF_R_TYPE(r_info);
1350 *r_sym = ELF_R_SYM(r_info);
1351}
1352
1353static void section_rela(struct module *mod, struct elf_info *elf,
1354 unsigned int fsecndx, const char *fromsec,
1355 const Elf_Rela *start, const Elf_Rela *stop)
1356{
1357 const Elf_Rela *rela;
1358
1359 for (rela = start; rela < stop; rela++) {
1360 Elf_Sym *tsym;
1361 Elf_Addr taddr, r_offset;
1362 unsigned int r_type, r_sym;
1363
1364 r_offset = TO_NATIVE(rela->r_offset);
1365 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1366
1367 tsym = elf->symtab_start + r_sym;
1368 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1369
1370 switch (elf->hdr->e_machine) {
1371 case EM_RISCV:
1372 if (!strcmp("__ex_table", fromsec) &&
1373 r_type == R_RISCV_SUB32)
1374 continue;
1375 break;
1376 case EM_LOONGARCH:
1377 switch (r_type) {
1378 case R_LARCH_SUB32:
1379 if (!strcmp("__ex_table", fromsec))
1380 continue;
1381 break;
1382 case R_LARCH_RELAX:
1383 case R_LARCH_ALIGN:
1384 /* These relocs do not refer to symbols */
1385 continue;
1386 }
1387 break;
1388 }
1389
1390 check_section_mismatch(mod, elf, tsym,
1391 fsecndx, fromsec, r_offset, taddr);
1392 }
1393}
1394
1395static void section_rel(struct module *mod, struct elf_info *elf,
1396 unsigned int fsecndx, const char *fromsec,
1397 const Elf_Rel *start, const Elf_Rel *stop)
1398{
1399 const Elf_Rel *rel;
1400
1401 for (rel = start; rel < stop; rel++) {
1402 Elf_Sym *tsym;
1403 Elf_Addr taddr, r_offset;
1404 unsigned int r_type, r_sym;
1405 void *loc;
1406
1407 r_offset = TO_NATIVE(rel->r_offset);
1408 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1409
1410 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1411 tsym = elf->symtab_start + r_sym;
1412
1413 switch (elf->hdr->e_machine) {
1414 case EM_386:
1415 taddr = addend_386_rel(loc, r_type);
1416 break;
1417 case EM_ARM:
1418 taddr = addend_arm_rel(loc, tsym, r_type);
1419 break;
1420 case EM_MIPS:
1421 taddr = addend_mips_rel(loc, r_type);
1422 break;
1423 default:
1424 fatal("Please add code to calculate addend for this architecture\n");
1425 }
1426
1427 check_section_mismatch(mod, elf, tsym,
1428 fsecndx, fromsec, r_offset, taddr);
1429 }
1430}
1431
1432/**
1433 * A module includes a number of sections that are discarded
1434 * either when loaded or when used as built-in.
1435 * For loaded modules all functions marked __init and all data
1436 * marked __initdata will be discarded when the module has been initialized.
1437 * Likewise for modules used built-in the sections marked __exit
1438 * are discarded because __exit marked function are supposed to be called
1439 * only when a module is unloaded which never happens for built-in modules.
1440 * The check_sec_ref() function traverses all relocation records
1441 * to find all references to a section that reference a section that will
1442 * be discarded and warns about it.
1443 **/
1444static void check_sec_ref(struct module *mod, struct elf_info *elf)
1445{
1446 int i;
1447
1448 /* Walk through all sections */
1449 for (i = 0; i < elf->num_sections; i++) {
1450 Elf_Shdr *sechdr = &elf->sechdrs[i];
1451
1452 check_section(mod, elf, sechdr);
1453 /* We want to process only relocation sections and not .init */
1454 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1455 /* section to which the relocation applies */
1456 unsigned int secndx = sechdr->sh_info;
1457 const char *secname = sec_name(elf, secndx);
1458 const void *start, *stop;
1459
1460 /* If the section is known good, skip it */
1461 if (match(secname, section_white_list))
1462 continue;
1463
1464 start = sym_get_data_by_offset(elf, i, 0);
1465 stop = start + sechdr->sh_size;
1466
1467 if (sechdr->sh_type == SHT_RELA)
1468 section_rela(mod, elf, secndx, secname,
1469 start, stop);
1470 else
1471 section_rel(mod, elf, secndx, secname,
1472 start, stop);
1473 }
1474 }
1475}
1476
1477static char *remove_dot(char *s)
1478{
1479 size_t n = strcspn(s, ".");
1480
1481 if (n && s[n]) {
1482 size_t m = strspn(s + n + 1, "0123456789");
1483 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1484 s[n] = 0;
1485 }
1486 return s;
1487}
1488
1489/*
1490 * The CRCs are recorded in .*.cmd files in the form of:
1491 * #SYMVER <name> <crc>
1492 */
1493static void extract_crcs_for_object(const char *object, struct module *mod)
1494{
1495 char cmd_file[PATH_MAX];
1496 char *buf, *p;
1497 const char *base;
1498 int dirlen, baselen_without_suffix, ret;
1499
1500 base = get_basename(object);
1501 dirlen = base - object;
1502
1503 baselen_without_suffix = strlen(object) - dirlen - strlen(".o");
1504
1505 /*
1506 * When CONFIG_LTO_CLANG_THIN_DIST=y, the ELF is *.thinlto-native.o
1507 * but the symbol CRCs are recorded in *.o.cmd file.
1508 */
1509 if (strends(object, ".thinlto-native.o"))
1510 baselen_without_suffix -= strlen(".thinlto-native");
1511
1512 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%.*s.o.cmd",
1513 dirlen, object, baselen_without_suffix, base);
1514 if (ret >= sizeof(cmd_file)) {
1515 error("%s: too long path was truncated\n", cmd_file);
1516 return;
1517 }
1518
1519 buf = read_text_file(cmd_file);
1520 p = buf;
1521
1522 while ((p = strstr(p, "\n#SYMVER "))) {
1523 char *name;
1524 size_t namelen;
1525 unsigned int crc;
1526 struct symbol *sym;
1527
1528 name = p + strlen("\n#SYMVER ");
1529
1530 p = strchr(name, ' ');
1531 if (!p)
1532 break;
1533
1534 namelen = p - name;
1535 p++;
1536
1537 if (!isdigit(*p))
1538 continue; /* skip this line */
1539
1540 crc = strtoul(p, &p, 0);
1541 if (*p != '\n')
1542 continue; /* skip this line */
1543
1544 name[namelen] = '\0';
1545
1546 /*
1547 * sym_find_with_module() may return NULL here.
1548 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1549 * Since commit e1327a127703, genksyms calculates CRCs of all
1550 * symbols, including trimmed ones. Ignore orphan CRCs.
1551 */
1552 sym = sym_find_with_module(name, mod);
1553 if (sym)
1554 sym_set_crc(sym, crc);
1555 }
1556
1557 free(buf);
1558}
1559
1560/*
1561 * The symbol versions (CRC) are recorded in the .*.cmd files.
1562 * Parse them to retrieve CRCs for the current module.
1563 */
1564static void mod_set_crcs(struct module *mod)
1565{
1566 char objlist[PATH_MAX];
1567 char *buf, *p, *obj;
1568 int ret;
1569
1570 if (mod->is_vmlinux) {
1571 strcpy(objlist, ".vmlinux.objs");
1572 } else {
1573 /* objects for a module are listed in the *.mod file. */
1574 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1575 if (ret >= sizeof(objlist)) {
1576 error("%s: too long path was truncated\n", objlist);
1577 return;
1578 }
1579 }
1580
1581 buf = read_text_file(objlist);
1582 p = buf;
1583
1584 while ((obj = strsep(&p, "\n")) && obj[0])
1585 extract_crcs_for_object(obj, mod);
1586
1587 free(buf);
1588}
1589
1590static void read_symbols(const char *modname)
1591{
1592 const char *symname;
1593 char *version;
1594 char *license;
1595 char *namespace;
1596 struct module *mod;
1597 struct elf_info info = { };
1598 Elf_Sym *sym;
1599
1600 if (!strends(modname, ".o")) {
1601 error("%s: filename must be suffixed with .o\n", modname);
1602 return;
1603 }
1604
1605 if (!parse_elf(&info, modname))
1606 return;
1607
1608 /* strip trailing .o */
1609 mod = new_module(modname, strlen(modname) - strlen(".o"));
1610
1611 /* save .no_trim_symbol section for later use */
1612 if (info.no_trim_symbol_len) {
1613 mod->no_trim_symbol = xmalloc(info.no_trim_symbol_len);
1614 memcpy(mod->no_trim_symbol, info.no_trim_symbol,
1615 info.no_trim_symbol_len);
1616 mod->no_trim_symbol_len = info.no_trim_symbol_len;
1617 }
1618
1619 if (!mod->is_vmlinux) {
1620 license = get_modinfo(&info, "license");
1621 if (!license)
1622 mod_error(mod, "missing MODULE_LICENSE()\n");
1623 while (license) {
1624 if (!license_is_gpl_compatible(license)) {
1625 mod->is_gpl_compatible = false;
1626 break;
1627 }
1628 license = get_next_modinfo(&info, "license", license);
1629 }
1630
1631 for (namespace = get_modinfo(&info, "import_ns");
1632 namespace;
1633 namespace = get_next_modinfo(&info, "import_ns", namespace)) {
1634 if (strstarts(namespace, MODULE_NS_PREFIX))
1635 mod_error(mod, "explicitly importing namespace '%s' is not allowed.\n",
1636 namespace);
1637
1638 add_namespace(&mod->imported_namespaces, namespace);
1639 }
1640
1641 if (!get_modinfo(&info, "description"))
1642 mod_warn(mod, "missing MODULE_DESCRIPTION()\n");
1643 }
1644
1645 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1646 symname = remove_dot(info.strtab + sym->st_name);
1647
1648 handle_symbol(mod, &info, sym, symname);
1649 handle_moddevtable(mod, &info, sym, symname);
1650 }
1651
1652 check_sec_ref(mod, &info);
1653
1654 if (!mod->is_vmlinux) {
1655 version = get_modinfo(&info, "version");
1656 if (version || all_versions)
1657 get_src_version(mod->name, mod->srcversion,
1658 sizeof(mod->srcversion) - 1);
1659 }
1660
1661 parse_elf_finish(&info);
1662
1663 if (modversions) {
1664 /*
1665 * Our trick to get versioning for module struct etc. - it's
1666 * never passed as an argument to an exported function, so
1667 * the automatic versioning doesn't pick it up, but it's really
1668 * important anyhow.
1669 */
1670 sym_add_unresolved("module_layout", mod, false);
1671
1672 mod_set_crcs(mod);
1673 }
1674}
1675
1676static void read_symbols_from_files(const char *filename)
1677{
1678 FILE *in = stdin;
1679 char fname[PATH_MAX];
1680
1681 in = fopen(filename, "r");
1682 if (!in)
1683 fatal("Can't open filenames file %s: %m", filename);
1684
1685 while (fgets(fname, PATH_MAX, in) != NULL) {
1686 if (strends(fname, "\n"))
1687 fname[strlen(fname)-1] = '\0';
1688 read_symbols(fname);
1689 }
1690
1691 fclose(in);
1692}
1693
1694#define SZ 500
1695
1696/* We first write the generated file into memory using the
1697 * following helper, then compare to the file on disk and
1698 * only update the later if anything changed */
1699
1700void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1701 const char *fmt, ...)
1702{
1703 char tmp[SZ];
1704 int len;
1705 va_list ap;
1706
1707 va_start(ap, fmt);
1708 len = vsnprintf(tmp, SZ, fmt, ap);
1709 va_end(ap);
1710
1711 if (len < 0) {
1712 perror("vsnprintf failed");
1713 exit(1);
1714 }
1715 if (len >= SZ)
1716 fatal("buf_printf output truncated for string %s: %d bytes needed, %d available\n",
1717 tmp, len + 1, SZ);
1718
1719 buf_write(buf, tmp, len);
1720}
1721
1722void buf_write(struct buffer *buf, const char *s, int len)
1723{
1724 if (buf->size - buf->pos < len) {
1725 buf->size += len + SZ;
1726 buf->p = xrealloc(buf->p, buf->size);
1727 }
1728 strncpy(buf->p + buf->pos, s, len);
1729 buf->pos += len;
1730}
1731
1732/**
1733 * verify_module_namespace() - does @modname have access to this symbol's @namespace
1734 * @namespace: export symbol namespace
1735 * @modname: module name
1736 *
1737 * If @namespace is prefixed with "module:" to indicate it is a module namespace
1738 * then test if @modname matches any of the comma separated patterns.
1739 *
1740 * The patterns only support tail-glob.
1741 */
1742static bool verify_module_namespace(const char *namespace, const char *modname)
1743{
1744 size_t len, modlen = strlen(modname);
1745 const char *prefix = "module:";
1746 const char *sep;
1747 bool glob;
1748
1749 if (!strstarts(namespace, prefix))
1750 return false;
1751
1752 for (namespace += strlen(prefix); *namespace; namespace = sep) {
1753 sep = strchrnul(namespace, ',');
1754 len = sep - namespace;
1755
1756 glob = false;
1757 if (sep[-1] == '*') {
1758 len--;
1759 glob = true;
1760 }
1761
1762 if (*sep)
1763 sep++;
1764
1765 if (strncmp(namespace, modname, len) == 0 && (glob || len == modlen))
1766 return true;
1767 }
1768
1769 return false;
1770}
1771
1772static void check_exports(struct module *mod)
1773{
1774 struct symbol *s, *exp;
1775
1776 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1777 const char *basename;
1778 exp = find_symbol(s->name);
1779 if (!exp) {
1780 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1781 modpost_log(!warn_unresolved, mod,
1782 "symbol '%s' undefined!\n",
1783 s->name);
1784 continue;
1785 }
1786 if (exp->module == mod) {
1787 mod_error(mod, "symbol '%s' was exported without definition\n", s->name);
1788 continue;
1789 }
1790
1791 exp->used = true;
1792 s->module = exp->module;
1793 s->crc_valid = exp->crc_valid;
1794 s->crc = exp->crc;
1795
1796 basename = get_basename(mod->name);
1797
1798 if (!verify_module_namespace(exp->namespace, basename) &&
1799 !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1800 modpost_log(!allow_missing_ns_imports, mod,
1801 "module uses symbol '%s' from namespace '%s', but does not import it.\n",
1802 exp->name, exp->namespace);
1803 add_namespace(&mod->missing_namespaces, exp->namespace);
1804 }
1805
1806 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1807 mod_error(mod, "GPL-incompatible module uses GPL-only symbol '%s'\n",
1808 exp->name);
1809 }
1810}
1811
1812static void handle_white_list_exports(const char *white_list)
1813{
1814 char *buf, *p, *name;
1815
1816 buf = read_text_file(white_list);
1817 p = buf;
1818
1819 while ((name = strsep(&p, "\n"))) {
1820 struct symbol *sym = find_symbol(name);
1821
1822 if (sym)
1823 sym->used = true;
1824 }
1825
1826 free(buf);
1827}
1828
1829/*
1830 * Keep symbols recorded in the .no_trim_symbol section. This is necessary to
1831 * prevent CONFIG_TRIM_UNUSED_KSYMS from dropping EXPORT_SYMBOL because
1832 * symbol_get() relies on the symbol being present in the ksymtab for lookups.
1833 */
1834static void keep_no_trim_symbols(struct module *mod)
1835{
1836 unsigned long size = mod->no_trim_symbol_len;
1837
1838 for (char *s = mod->no_trim_symbol; s; s = next_string(s , &size)) {
1839 struct symbol *sym;
1840
1841 /*
1842 * If find_symbol() returns NULL, this symbol is not provided
1843 * by any module, and symbol_get() will fail.
1844 */
1845 sym = find_symbol(s);
1846 if (sym)
1847 sym->used = true;
1848 }
1849}
1850
1851static void check_modname_len(struct module *mod)
1852{
1853 const char *mod_name;
1854
1855 mod_name = get_basename(mod->name);
1856
1857 if (strlen(mod_name) >= MODULE_NAME_LEN)
1858 mod_error(mod, "module name is too long\n");
1859}
1860
1861/**
1862 * Header for the generated file
1863 **/
1864static void add_header(struct buffer *b, struct module *mod)
1865{
1866 buf_printf(b, "#include <linux/module.h>\n");
1867 buf_printf(b, "#include <linux/export-internal.h>\n");
1868 buf_printf(b, "#include <linux/compiler.h>\n");
1869 buf_printf(b, "\n");
1870 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1871 buf_printf(b, "\n");
1872 buf_printf(b, "__visible struct module __this_module\n");
1873 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1874 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1875 if (mod->has_init)
1876 buf_printf(b, "\t.init = init_module,\n");
1877 if (mod->has_cleanup)
1878 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1879 "\t.exit = cleanup_module,\n"
1880 "#endif\n");
1881 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1882 buf_printf(b, "};\n");
1883
1884 if (!external_module)
1885 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1886
1887 if (strstarts(mod->name, "drivers/staging"))
1888 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1889
1890 if (strstarts(mod->name, "tools/testing"))
1891 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1892}
1893
1894static void add_exported_symbols(struct buffer *buf, struct module *mod)
1895{
1896 struct symbol *sym;
1897
1898 /* generate struct for exported symbols */
1899 buf_printf(buf, "\n");
1900 list_for_each_entry(sym, &mod->exported_symbols, list) {
1901 if (trim_unused_exports && !sym->used)
1902 continue;
1903
1904 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\");\n",
1905 sym->is_func ? "FUNC" : "DATA", sym->name,
1906 sym->namespace);
1907
1908 buf_printf(buf, "SYMBOL_FLAGS(%s, 0x%02x);\n",
1909 sym->name, get_symbol_flags(sym));
1910 }
1911
1912 if (!modversions)
1913 return;
1914
1915 /* record CRCs for exported symbols */
1916 buf_printf(buf, "\n");
1917 list_for_each_entry(sym, &mod->exported_symbols, list) {
1918 if (trim_unused_exports && !sym->used)
1919 continue;
1920
1921 if (!sym->crc_valid)
1922 mod_warn(mod, "EXPORT symbol '%s' version generation failed, symbol will not be versioned.\n"
1923 "Is '%s' prototyped in <asm/asm-prototypes.h>?\n",
1924 sym->name, sym->name);
1925
1926 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x);\n",
1927 sym->name, sym->crc);
1928 }
1929}
1930
1931/**
1932 * Record CRCs for unresolved symbols, supporting long names
1933 */
1934static void add_extended_versions(struct buffer *b, struct module *mod)
1935{
1936 struct symbol *s;
1937
1938 if (!extended_modversions)
1939 return;
1940
1941 buf_printf(b, "\n");
1942 buf_printf(b, "static const u32 ____version_ext_crcs[]\n");
1943 buf_printf(b, "__used __section(\"__version_ext_crcs\") = {\n");
1944 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1945 if (!s->module)
1946 continue;
1947 if (!s->crc_valid) {
1948 mod_warn(mod, "symbol '%s' has no CRC!\n", s->name);
1949 continue;
1950 }
1951 buf_printf(b, "\t0x%08x,\n", s->crc);
1952 }
1953 buf_printf(b, "};\n");
1954
1955 buf_printf(b, "static const char ____version_ext_names[]\n");
1956 buf_printf(b, "__used __section(\"__version_ext_names\") =\n");
1957 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1958 if (!s->module)
1959 continue;
1960 if (!s->crc_valid)
1961 /*
1962 * We already warned on this when producing the crc
1963 * table.
1964 * We need to skip its name too, as the indexes in
1965 * both tables need to align.
1966 */
1967 continue;
1968 buf_printf(b, "\t\"%s\\0\"\n", s->name);
1969 }
1970 buf_printf(b, ";\n");
1971}
1972
1973/**
1974 * Record CRCs for unresolved symbols
1975 **/
1976static void add_versions(struct buffer *b, struct module *mod)
1977{
1978 struct symbol *s;
1979
1980 if (!basic_modversions)
1981 return;
1982
1983 buf_printf(b, "\n");
1984 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1985 buf_printf(b, "__used __section(\"__versions\") = {\n");
1986
1987 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1988 if (!s->module)
1989 continue;
1990 if (!s->crc_valid) {
1991 mod_warn(mod, "symbol '%s' has no CRC!\n", s->name);
1992 continue;
1993 }
1994 if (strlen(s->name) >= MODULE_NAME_LEN) {
1995 if (extended_modversions) {
1996 /* this symbol will only be in the extended info */
1997 continue;
1998 } else {
1999 mod_error(mod, "too long symbol '%s'\n", s->name);
2000 break;
2001 }
2002 }
2003 buf_printf(b, "\t{ 0x%08x, \"%s\" },\n",
2004 s->crc, s->name);
2005 }
2006
2007 buf_printf(b, "};\n");
2008}
2009
2010static void add_depends(struct buffer *b, struct module *mod)
2011{
2012 struct symbol *s;
2013 int first = 1;
2014
2015 /* Clear ->seen flag of modules that own symbols needed by this. */
2016 list_for_each_entry(s, &mod->unresolved_symbols, list) {
2017 if (s->module)
2018 s->module->seen = s->module->is_vmlinux;
2019 }
2020
2021 buf_printf(b, "\n");
2022 buf_printf(b, "MODULE_INFO(depends, \"");
2023 list_for_each_entry(s, &mod->unresolved_symbols, list) {
2024 const char *p;
2025 if (!s->module)
2026 continue;
2027
2028 if (s->module->seen)
2029 continue;
2030
2031 s->module->seen = true;
2032 p = get_basename(s->module->name);
2033 buf_printf(b, "%s%s", first ? "" : ",", p);
2034 first = 0;
2035 }
2036 buf_printf(b, "\");\n");
2037}
2038
2039static void add_srcversion(struct buffer *b, struct module *mod)
2040{
2041 if (mod->srcversion[0]) {
2042 buf_printf(b, "\n");
2043 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2044 mod->srcversion);
2045 }
2046}
2047
2048static void write_buf(struct buffer *b, const char *fname)
2049{
2050 FILE *file;
2051
2052 if (error_occurred)
2053 return;
2054
2055 file = fopen(fname, "w");
2056 if (!file) {
2057 perror(fname);
2058 exit(1);
2059 }
2060 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2061 perror(fname);
2062 exit(1);
2063 }
2064 if (fclose(file) != 0) {
2065 perror(fname);
2066 exit(1);
2067 }
2068}
2069
2070static void write_if_changed(struct buffer *b, const char *fname)
2071{
2072 char *tmp;
2073 FILE *file;
2074 struct stat st;
2075
2076 file = fopen(fname, "r");
2077 if (!file)
2078 goto write;
2079
2080 if (fstat(fileno(file), &st) < 0)
2081 goto close_write;
2082
2083 if (st.st_size != b->pos)
2084 goto close_write;
2085
2086 tmp = xmalloc(b->pos);
2087 if (fread(tmp, 1, b->pos, file) != b->pos)
2088 goto free_write;
2089
2090 if (memcmp(tmp, b->p, b->pos) != 0)
2091 goto free_write;
2092
2093 free(tmp);
2094 fclose(file);
2095 return;
2096
2097 free_write:
2098 free(tmp);
2099 close_write:
2100 fclose(file);
2101 write:
2102 write_buf(b, fname);
2103}
2104
2105static void write_vmlinux_export_c_file(struct module *mod)
2106{
2107 struct buffer buf = { };
2108 struct module_alias *alias, *next;
2109
2110 buf_printf(&buf,
2111 "#include <linux/export-internal.h>\n");
2112
2113 add_exported_symbols(&buf, mod);
2114
2115 buf_printf(&buf,
2116 "#include <linux/module.h>\n"
2117 "#undef __MODULE_INFO_PREFIX\n"
2118 "#define __MODULE_INFO_PREFIX\n");
2119
2120 list_for_each_entry_safe(alias, next, &mod->aliases, node) {
2121 buf_printf(&buf, "MODULE_INFO(%s.alias, \"%s\");\n",
2122 alias->builtin_modname, alias->str);
2123 list_del(&alias->node);
2124 free(alias->builtin_modname);
2125 free(alias);
2126 }
2127
2128 write_if_changed(&buf, ".vmlinux.export.c");
2129 free(buf.p);
2130}
2131
2132/* do sanity checks, and generate *.mod.c file */
2133static void write_mod_c_file(struct module *mod)
2134{
2135 struct buffer buf = { };
2136 struct module_alias *alias, *next;
2137 char fname[PATH_MAX];
2138 int ret;
2139
2140 add_header(&buf, mod);
2141 add_exported_symbols(&buf, mod);
2142 add_versions(&buf, mod);
2143 add_extended_versions(&buf, mod);
2144 add_depends(&buf, mod);
2145
2146 buf_printf(&buf, "\n");
2147 list_for_each_entry_safe(alias, next, &mod->aliases, node) {
2148 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str);
2149 list_del(&alias->node);
2150 free(alias);
2151 }
2152
2153 add_srcversion(&buf, mod);
2154
2155 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2156 if (ret >= sizeof(fname)) {
2157 error("%s: too long path was truncated\n", fname);
2158 goto free;
2159 }
2160
2161 write_if_changed(&buf, fname);
2162
2163free:
2164 free(buf.p);
2165}
2166
2167/* parse Module.symvers file. line format:
2168 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2169 **/
2170static void read_dump(const char *fname)
2171{
2172 char *buf, *pos, *line;
2173
2174 buf = read_text_file(fname);
2175 if (!buf)
2176 /* No symbol versions, silently ignore */
2177 return;
2178
2179 pos = buf;
2180
2181 while ((line = get_line(&pos))) {
2182 char *symname, *namespace, *modname, *d, *export;
2183 unsigned int crc;
2184 struct module *mod;
2185 struct symbol *s;
2186 bool gpl_only;
2187
2188 if (!(symname = strchr(line, '\t')))
2189 goto fail;
2190 *symname++ = '\0';
2191 if (!(modname = strchr(symname, '\t')))
2192 goto fail;
2193 *modname++ = '\0';
2194 if (!(export = strchr(modname, '\t')))
2195 goto fail;
2196 *export++ = '\0';
2197 if (!(namespace = strchr(export, '\t')))
2198 goto fail;
2199 *namespace++ = '\0';
2200
2201 crc = strtoul(line, &d, 16);
2202 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2203 goto fail;
2204
2205 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2206 gpl_only = true;
2207 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2208 gpl_only = false;
2209 } else {
2210 error("%s: unknown license %s. skip", symname, export);
2211 continue;
2212 }
2213
2214 mod = find_module(fname, modname);
2215 if (!mod) {
2216 mod = new_module(modname, strlen(modname));
2217 mod->dump_file = fname;
2218 }
2219 s = sym_add_exported(symname, mod, gpl_only, namespace);
2220 sym_set_crc(s, crc);
2221 }
2222 free(buf);
2223 return;
2224fail:
2225 free(buf);
2226 fatal("parse error in symbol dump file\n");
2227}
2228
2229static void write_dump(const char *fname)
2230{
2231 struct buffer buf = { };
2232 struct module *mod;
2233 struct symbol *sym;
2234
2235 list_for_each_entry(mod, &modules, list) {
2236 if (mod->dump_file)
2237 continue;
2238 list_for_each_entry(sym, &mod->exported_symbols, list) {
2239 if (trim_unused_exports && !sym->used)
2240 continue;
2241
2242 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2243 sym->crc, sym->name, mod->name,
2244 sym->is_gpl_only ? "_GPL" : "",
2245 sym->namespace);
2246 }
2247 }
2248 write_buf(&buf, fname);
2249 free(buf.p);
2250}
2251
2252static void write_namespace_deps_files(const char *fname)
2253{
2254 struct module *mod;
2255 struct namespace_list *ns;
2256 struct buffer ns_deps_buf = {};
2257
2258 list_for_each_entry(mod, &modules, list) {
2259
2260 if (mod->dump_file || list_empty(&mod->missing_namespaces))
2261 continue;
2262
2263 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2264
2265 list_for_each_entry(ns, &mod->missing_namespaces, list)
2266 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2267
2268 buf_printf(&ns_deps_buf, "\n");
2269 }
2270
2271 write_if_changed(&ns_deps_buf, fname);
2272 free(ns_deps_buf.p);
2273}
2274
2275struct dump_list {
2276 struct list_head list;
2277 const char *file;
2278};
2279
2280static void check_host_endian(void)
2281{
2282 static const union {
2283 short s;
2284 char c[2];
2285 } endian_test = { .c = {0x01, 0x02} };
2286
2287 switch (endian_test.s) {
2288 case 0x0102:
2289 host_is_big_endian = true;
2290 break;
2291 case 0x0201:
2292 host_is_big_endian = false;
2293 break;
2294 default:
2295 fatal("Unknown host endian\n");
2296 }
2297}
2298
2299int main(int argc, char **argv)
2300{
2301 struct module *mod;
2302 char *missing_namespace_deps = NULL;
2303 char *unused_exports_white_list = NULL;
2304 char *dump_write = NULL, *files_source = NULL;
2305 int opt;
2306 LIST_HEAD(dump_lists);
2307 struct dump_list *dl, *dl2;
2308
2309 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:xb")) != -1) {
2310 switch (opt) {
2311 case 'e':
2312 external_module = true;
2313 break;
2314 case 'i':
2315 dl = xmalloc(sizeof(*dl));
2316 dl->file = optarg;
2317 list_add_tail(&dl->list, &dump_lists);
2318 break;
2319 case 'M':
2320 module_enabled = true;
2321 break;
2322 case 'm':
2323 modversions = true;
2324 break;
2325 case 'n':
2326 ignore_missing_files = true;
2327 break;
2328 case 'o':
2329 dump_write = optarg;
2330 break;
2331 case 'a':
2332 all_versions = true;
2333 break;
2334 case 'T':
2335 files_source = optarg;
2336 break;
2337 case 't':
2338 trim_unused_exports = true;
2339 break;
2340 case 'u':
2341 unused_exports_white_list = optarg;
2342 break;
2343 case 'W':
2344 extra_warn = true;
2345 break;
2346 case 'w':
2347 warn_unresolved = true;
2348 break;
2349 case 'E':
2350 sec_mismatch_warn_only = false;
2351 break;
2352 case 'N':
2353 allow_missing_ns_imports = true;
2354 break;
2355 case 'd':
2356 missing_namespace_deps = optarg;
2357 break;
2358 case 'b':
2359 basic_modversions = true;
2360 break;
2361 case 'x':
2362 extended_modversions = true;
2363 break;
2364 default:
2365 exit(1);
2366 }
2367 }
2368
2369 check_host_endian();
2370
2371 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2372 read_dump(dl->file);
2373 list_del(&dl->list);
2374 free(dl);
2375 }
2376
2377 while (optind < argc)
2378 read_symbols(argv[optind++]);
2379
2380 if (files_source)
2381 read_symbols_from_files(files_source);
2382
2383 list_for_each_entry(mod, &modules, list) {
2384 keep_no_trim_symbols(mod);
2385
2386 if (mod->dump_file || mod->is_vmlinux)
2387 continue;
2388
2389 check_modname_len(mod);
2390 check_exports(mod);
2391 }
2392
2393 if (unused_exports_white_list)
2394 handle_white_list_exports(unused_exports_white_list);
2395
2396 list_for_each_entry(mod, &modules, list) {
2397 if (mod->dump_file)
2398 continue;
2399
2400 if (mod->is_vmlinux)
2401 write_vmlinux_export_c_file(mod);
2402 else
2403 write_mod_c_file(mod);
2404 }
2405
2406 if (missing_namespace_deps)
2407 write_namespace_deps_files(missing_namespace_deps);
2408
2409 if (dump_write)
2410 write_dump(dump_write);
2411 if (sec_mismatch_count && !sec_mismatch_warn_only)
2412 error("Section mismatches detected.\n"
2413 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2414
2415 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2416 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2417 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2418
2419 return error_occurred ? 1 : 0;
2420}