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1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <stdio.h>
16#include <ctype.h>
17#include <string.h>
18#include <limits.h>
19#include <stdbool.h>
20#include <errno.h>
21#include "modpost.h"
22#include "../../include/linux/license.h"
23
24/* Are we using CONFIG_MODVERSIONS? */
25static int modversions = 0;
26/* Warn about undefined symbols? (do so if we have vmlinux) */
27static int have_vmlinux = 0;
28/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
29static int all_versions = 0;
30/* If we are modposting external module set to 1 */
31static int external_module = 0;
32/* Warn about section mismatch in vmlinux if set to 1 */
33static int vmlinux_section_warnings = 1;
34/* Only warn about unresolved symbols */
35static int warn_unresolved = 0;
36/* How a symbol is exported */
37static int sec_mismatch_count = 0;
38static int sec_mismatch_fatal = 0;
39/* ignore missing files */
40static int ignore_missing_files;
41/* write namespace dependencies */
42static int write_namespace_deps;
43
44enum export {
45 export_plain, export_unused, export_gpl,
46 export_unused_gpl, export_gpl_future, export_unknown
47};
48
49/* In kernel, this size is defined in linux/module.h;
50 * here we use Elf_Addr instead of long for covering cross-compile
51 */
52
53#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
54
55#define PRINTF __attribute__ ((format (printf, 1, 2)))
56
57PRINTF void fatal(const char *fmt, ...)
58{
59 va_list arglist;
60
61 fprintf(stderr, "FATAL: ");
62
63 va_start(arglist, fmt);
64 vfprintf(stderr, fmt, arglist);
65 va_end(arglist);
66
67 exit(1);
68}
69
70PRINTF void warn(const char *fmt, ...)
71{
72 va_list arglist;
73
74 fprintf(stderr, "WARNING: ");
75
76 va_start(arglist, fmt);
77 vfprintf(stderr, fmt, arglist);
78 va_end(arglist);
79}
80
81PRINTF void merror(const char *fmt, ...)
82{
83 va_list arglist;
84
85 fprintf(stderr, "ERROR: ");
86
87 va_start(arglist, fmt);
88 vfprintf(stderr, fmt, arglist);
89 va_end(arglist);
90}
91
92static inline bool strends(const char *str, const char *postfix)
93{
94 if (strlen(str) < strlen(postfix))
95 return false;
96
97 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
98}
99
100static int is_vmlinux(const char *modname)
101{
102 const char *myname;
103
104 myname = strrchr(modname, '/');
105 if (myname)
106 myname++;
107 else
108 myname = modname;
109
110 return (strcmp(myname, "vmlinux") == 0) ||
111 (strcmp(myname, "vmlinux.o") == 0);
112}
113
114void *do_nofail(void *ptr, const char *expr)
115{
116 if (!ptr)
117 fatal("modpost: Memory allocation failure: %s.\n", expr);
118
119 return ptr;
120}
121
122/* A list of all modules we processed */
123static struct module *modules;
124
125static struct module *find_module(const char *modname)
126{
127 struct module *mod;
128
129 for (mod = modules; mod; mod = mod->next)
130 if (strcmp(mod->name, modname) == 0)
131 break;
132 return mod;
133}
134
135static struct module *new_module(const char *modname)
136{
137 struct module *mod;
138 char *p;
139
140 mod = NOFAIL(malloc(sizeof(*mod)));
141 memset(mod, 0, sizeof(*mod));
142 p = NOFAIL(strdup(modname));
143
144 /* strip trailing .o */
145 if (strends(p, ".o")) {
146 p[strlen(p) - 2] = '\0';
147 mod->is_dot_o = 1;
148 }
149
150 /* add to list */
151 mod->name = p;
152 mod->gpl_compatible = -1;
153 mod->next = modules;
154 modules = mod;
155
156 return mod;
157}
158
159/* A hash of all exported symbols,
160 * struct symbol is also used for lists of unresolved symbols */
161
162#define SYMBOL_HASH_SIZE 1024
163
164struct symbol {
165 struct symbol *next;
166 struct module *module;
167 unsigned int crc;
168 int crc_valid;
169 char *namespace;
170 unsigned int weak:1;
171 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
172 unsigned int kernel:1; /* 1 if symbol is from kernel
173 * (only for external modules) **/
174 unsigned int preloaded:1; /* 1 if symbol from Module.symvers, or crc */
175 unsigned int is_static:1; /* 1 if symbol is not global */
176 enum export export; /* Type of export */
177 char name[0];
178};
179
180static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
181
182/* This is based on the hash agorithm from gdbm, via tdb */
183static inline unsigned int tdb_hash(const char *name)
184{
185 unsigned value; /* Used to compute the hash value. */
186 unsigned i; /* Used to cycle through random values. */
187
188 /* Set the initial value from the key size. */
189 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
190 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
191
192 return (1103515243 * value + 12345);
193}
194
195/**
196 * Allocate a new symbols for use in the hash of exported symbols or
197 * the list of unresolved symbols per module
198 **/
199static struct symbol *alloc_symbol(const char *name, unsigned int weak,
200 struct symbol *next)
201{
202 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
203
204 memset(s, 0, sizeof(*s));
205 strcpy(s->name, name);
206 s->weak = weak;
207 s->next = next;
208 s->is_static = 1;
209 return s;
210}
211
212/* For the hash of exported symbols */
213static struct symbol *new_symbol(const char *name, struct module *module,
214 enum export export)
215{
216 unsigned int hash;
217 struct symbol *new;
218
219 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
220 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
221 new->module = module;
222 new->export = export;
223 return new;
224}
225
226static struct symbol *find_symbol(const char *name)
227{
228 struct symbol *s;
229
230 /* For our purposes, .foo matches foo. PPC64 needs this. */
231 if (name[0] == '.')
232 name++;
233
234 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
235 if (strcmp(s->name, name) == 0)
236 return s;
237 }
238 return NULL;
239}
240
241static bool contains_namespace(struct namespace_list *list,
242 const char *namespace)
243{
244 struct namespace_list *ns_entry;
245
246 for (ns_entry = list; ns_entry != NULL; ns_entry = ns_entry->next)
247 if (strcmp(ns_entry->namespace, namespace) == 0)
248 return true;
249
250 return false;
251}
252
253static void add_namespace(struct namespace_list **list, const char *namespace)
254{
255 struct namespace_list *ns_entry;
256
257 if (!contains_namespace(*list, namespace)) {
258 ns_entry = NOFAIL(malloc(sizeof(struct namespace_list) +
259 strlen(namespace) + 1));
260 strcpy(ns_entry->namespace, namespace);
261 ns_entry->next = *list;
262 *list = ns_entry;
263 }
264}
265
266static bool module_imports_namespace(struct module *module,
267 const char *namespace)
268{
269 return contains_namespace(module->imported_namespaces, namespace);
270}
271
272static const struct {
273 const char *str;
274 enum export export;
275} export_list[] = {
276 { .str = "EXPORT_SYMBOL", .export = export_plain },
277 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
278 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
279 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
280 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
281 { .str = "(unknown)", .export = export_unknown },
282};
283
284
285static const char *export_str(enum export ex)
286{
287 return export_list[ex].str;
288}
289
290static enum export export_no(const char *s)
291{
292 int i;
293
294 if (!s)
295 return export_unknown;
296 for (i = 0; export_list[i].export != export_unknown; i++) {
297 if (strcmp(export_list[i].str, s) == 0)
298 return export_list[i].export;
299 }
300 return export_unknown;
301}
302
303static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
304{
305 return (void *)elf->hdr +
306 elf->sechdrs[elf->secindex_strings].sh_offset +
307 sechdr->sh_name;
308}
309
310static const char *sec_name(struct elf_info *elf, int secindex)
311{
312 return sech_name(elf, &elf->sechdrs[secindex]);
313}
314
315#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
316
317static enum export export_from_secname(struct elf_info *elf, unsigned int sec)
318{
319 const char *secname = sec_name(elf, sec);
320
321 if (strstarts(secname, "___ksymtab+"))
322 return export_plain;
323 else if (strstarts(secname, "___ksymtab_unused+"))
324 return export_unused;
325 else if (strstarts(secname, "___ksymtab_gpl+"))
326 return export_gpl;
327 else if (strstarts(secname, "___ksymtab_unused_gpl+"))
328 return export_unused_gpl;
329 else if (strstarts(secname, "___ksymtab_gpl_future+"))
330 return export_gpl_future;
331 else
332 return export_unknown;
333}
334
335static enum export export_from_sec(struct elf_info *elf, unsigned int sec)
336{
337 if (sec == elf->export_sec)
338 return export_plain;
339 else if (sec == elf->export_unused_sec)
340 return export_unused;
341 else if (sec == elf->export_gpl_sec)
342 return export_gpl;
343 else if (sec == elf->export_unused_gpl_sec)
344 return export_unused_gpl;
345 else if (sec == elf->export_gpl_future_sec)
346 return export_gpl_future;
347 else
348 return export_unknown;
349}
350
351static const char *namespace_from_kstrtabns(struct elf_info *info,
352 Elf_Sym *kstrtabns)
353{
354 char *value = info->ksymtab_strings + kstrtabns->st_value;
355 return value[0] ? value : NULL;
356}
357
358static void sym_update_namespace(const char *symname, const char *namespace)
359{
360 struct symbol *s = find_symbol(symname);
361
362 /*
363 * That symbol should have been created earlier and thus this is
364 * actually an assertion.
365 */
366 if (!s) {
367 merror("Could not update namespace(%s) for symbol %s\n",
368 namespace, symname);
369 return;
370 }
371
372 free(s->namespace);
373 s->namespace =
374 namespace && namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
375}
376
377/**
378 * Add an exported symbol - it may have already been added without a
379 * CRC, in this case just update the CRC
380 **/
381static struct symbol *sym_add_exported(const char *name, struct module *mod,
382 enum export export)
383{
384 struct symbol *s = find_symbol(name);
385
386 if (!s) {
387 s = new_symbol(name, mod, export);
388 } else {
389 if (!s->preloaded) {
390 warn("%s: '%s' exported twice. Previous export was in %s%s\n",
391 mod->name, name, s->module->name,
392 is_vmlinux(s->module->name) ? "" : ".ko");
393 } else {
394 /* In case Module.symvers was out of date */
395 s->module = mod;
396 }
397 }
398 s->preloaded = 0;
399 s->vmlinux = is_vmlinux(mod->name);
400 s->kernel = 0;
401 s->export = export;
402 return s;
403}
404
405static void sym_update_crc(const char *name, struct module *mod,
406 unsigned int crc, enum export export)
407{
408 struct symbol *s = find_symbol(name);
409
410 if (!s) {
411 s = new_symbol(name, mod, export);
412 /* Don't complain when we find it later. */
413 s->preloaded = 1;
414 }
415 s->crc = crc;
416 s->crc_valid = 1;
417}
418
419void *grab_file(const char *filename, unsigned long *size)
420{
421 struct stat st;
422 void *map = MAP_FAILED;
423 int fd;
424
425 fd = open(filename, O_RDONLY);
426 if (fd < 0)
427 return NULL;
428 if (fstat(fd, &st))
429 goto failed;
430
431 *size = st.st_size;
432 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
433
434failed:
435 close(fd);
436 if (map == MAP_FAILED)
437 return NULL;
438 return map;
439}
440
441/**
442 * Return a copy of the next line in a mmap'ed file.
443 * spaces in the beginning of the line is trimmed away.
444 * Return a pointer to a static buffer.
445 **/
446char *get_next_line(unsigned long *pos, void *file, unsigned long size)
447{
448 static char line[4096];
449 int skip = 1;
450 size_t len = 0;
451 signed char *p = (signed char *)file + *pos;
452 char *s = line;
453
454 for (; *pos < size ; (*pos)++) {
455 if (skip && isspace(*p)) {
456 p++;
457 continue;
458 }
459 skip = 0;
460 if (*p != '\n' && (*pos < size)) {
461 len++;
462 *s++ = *p++;
463 if (len > 4095)
464 break; /* Too long, stop */
465 } else {
466 /* End of string */
467 *s = '\0';
468 return line;
469 }
470 }
471 /* End of buffer */
472 return NULL;
473}
474
475void release_file(void *file, unsigned long size)
476{
477 munmap(file, size);
478}
479
480static int parse_elf(struct elf_info *info, const char *filename)
481{
482 unsigned int i;
483 Elf_Ehdr *hdr;
484 Elf_Shdr *sechdrs;
485 Elf_Sym *sym;
486 const char *secstrings;
487 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
488
489 hdr = grab_file(filename, &info->size);
490 if (!hdr) {
491 if (ignore_missing_files) {
492 fprintf(stderr, "%s: %s (ignored)\n", filename,
493 strerror(errno));
494 return 0;
495 }
496 perror(filename);
497 exit(1);
498 }
499 info->hdr = hdr;
500 if (info->size < sizeof(*hdr)) {
501 /* file too small, assume this is an empty .o file */
502 return 0;
503 }
504 /* Is this a valid ELF file? */
505 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
506 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
507 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
508 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
509 /* Not an ELF file - silently ignore it */
510 return 0;
511 }
512 /* Fix endianness in ELF header */
513 hdr->e_type = TO_NATIVE(hdr->e_type);
514 hdr->e_machine = TO_NATIVE(hdr->e_machine);
515 hdr->e_version = TO_NATIVE(hdr->e_version);
516 hdr->e_entry = TO_NATIVE(hdr->e_entry);
517 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
518 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
519 hdr->e_flags = TO_NATIVE(hdr->e_flags);
520 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
521 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
522 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
523 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
524 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
525 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
526 sechdrs = (void *)hdr + hdr->e_shoff;
527 info->sechdrs = sechdrs;
528
529 /* Check if file offset is correct */
530 if (hdr->e_shoff > info->size) {
531 fatal("section header offset=%lu in file '%s' is bigger than "
532 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
533 filename, info->size);
534 return 0;
535 }
536
537 if (hdr->e_shnum == SHN_UNDEF) {
538 /*
539 * There are more than 64k sections,
540 * read count from .sh_size.
541 */
542 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
543 }
544 else {
545 info->num_sections = hdr->e_shnum;
546 }
547 if (hdr->e_shstrndx == SHN_XINDEX) {
548 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
549 }
550 else {
551 info->secindex_strings = hdr->e_shstrndx;
552 }
553
554 /* Fix endianness in section headers */
555 for (i = 0; i < info->num_sections; i++) {
556 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
557 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
558 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
559 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
560 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
561 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
562 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
563 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
564 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
565 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
566 }
567 /* Find symbol table. */
568 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
569 for (i = 1; i < info->num_sections; i++) {
570 const char *secname;
571 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
572
573 if (!nobits && sechdrs[i].sh_offset > info->size) {
574 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
575 "sizeof(*hrd)=%zu\n", filename,
576 (unsigned long)sechdrs[i].sh_offset,
577 sizeof(*hdr));
578 return 0;
579 }
580 secname = secstrings + sechdrs[i].sh_name;
581 if (strcmp(secname, ".modinfo") == 0) {
582 if (nobits)
583 fatal("%s has NOBITS .modinfo\n", filename);
584 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
585 info->modinfo_len = sechdrs[i].sh_size;
586 } else if (strcmp(secname, "__ksymtab") == 0)
587 info->export_sec = i;
588 else if (strcmp(secname, "__ksymtab_unused") == 0)
589 info->export_unused_sec = i;
590 else if (strcmp(secname, "__ksymtab_gpl") == 0)
591 info->export_gpl_sec = i;
592 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
593 info->export_unused_gpl_sec = i;
594 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
595 info->export_gpl_future_sec = i;
596 else if (strcmp(secname, "__ksymtab_strings") == 0)
597 info->ksymtab_strings = (void *)hdr +
598 sechdrs[i].sh_offset -
599 sechdrs[i].sh_addr;
600
601 if (sechdrs[i].sh_type == SHT_SYMTAB) {
602 unsigned int sh_link_idx;
603 symtab_idx = i;
604 info->symtab_start = (void *)hdr +
605 sechdrs[i].sh_offset;
606 info->symtab_stop = (void *)hdr +
607 sechdrs[i].sh_offset + sechdrs[i].sh_size;
608 sh_link_idx = sechdrs[i].sh_link;
609 info->strtab = (void *)hdr +
610 sechdrs[sh_link_idx].sh_offset;
611 }
612
613 /* 32bit section no. table? ("more than 64k sections") */
614 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
615 symtab_shndx_idx = i;
616 info->symtab_shndx_start = (void *)hdr +
617 sechdrs[i].sh_offset;
618 info->symtab_shndx_stop = (void *)hdr +
619 sechdrs[i].sh_offset + sechdrs[i].sh_size;
620 }
621 }
622 if (!info->symtab_start)
623 fatal("%s has no symtab?\n", filename);
624
625 /* Fix endianness in symbols */
626 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
627 sym->st_shndx = TO_NATIVE(sym->st_shndx);
628 sym->st_name = TO_NATIVE(sym->st_name);
629 sym->st_value = TO_NATIVE(sym->st_value);
630 sym->st_size = TO_NATIVE(sym->st_size);
631 }
632
633 if (symtab_shndx_idx != ~0U) {
634 Elf32_Word *p;
635 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
636 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
637 filename, sechdrs[symtab_shndx_idx].sh_link,
638 symtab_idx);
639 /* Fix endianness */
640 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
641 p++)
642 *p = TO_NATIVE(*p);
643 }
644
645 return 1;
646}
647
648static void parse_elf_finish(struct elf_info *info)
649{
650 release_file(info->hdr, info->size);
651}
652
653static int ignore_undef_symbol(struct elf_info *info, const char *symname)
654{
655 /* ignore __this_module, it will be resolved shortly */
656 if (strcmp(symname, "__this_module") == 0)
657 return 1;
658 /* ignore global offset table */
659 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
660 return 1;
661 if (info->hdr->e_machine == EM_PPC)
662 /* Special register function linked on all modules during final link of .ko */
663 if (strstarts(symname, "_restgpr_") ||
664 strstarts(symname, "_savegpr_") ||
665 strstarts(symname, "_rest32gpr_") ||
666 strstarts(symname, "_save32gpr_") ||
667 strstarts(symname, "_restvr_") ||
668 strstarts(symname, "_savevr_"))
669 return 1;
670 if (info->hdr->e_machine == EM_PPC64)
671 /* Special register function linked on all modules during final link of .ko */
672 if (strstarts(symname, "_restgpr0_") ||
673 strstarts(symname, "_savegpr0_") ||
674 strstarts(symname, "_restvr_") ||
675 strstarts(symname, "_savevr_") ||
676 strcmp(symname, ".TOC.") == 0)
677 return 1;
678 /* Do not ignore this symbol */
679 return 0;
680}
681
682static void handle_modversions(struct module *mod, struct elf_info *info,
683 Elf_Sym *sym, const char *symname)
684{
685 unsigned int crc;
686 enum export export;
687 bool is_crc = false;
688 const char *name;
689
690 if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&
691 strstarts(symname, "__ksymtab"))
692 export = export_from_secname(info, get_secindex(info, sym));
693 else
694 export = export_from_sec(info, get_secindex(info, sym));
695
696 /* CRC'd symbol */
697 if (strstarts(symname, "__crc_")) {
698 is_crc = true;
699 crc = (unsigned int) sym->st_value;
700 if (sym->st_shndx != SHN_UNDEF && sym->st_shndx != SHN_ABS) {
701 unsigned int *crcp;
702
703 /* symbol points to the CRC in the ELF object */
704 crcp = (void *)info->hdr + sym->st_value +
705 info->sechdrs[sym->st_shndx].sh_offset -
706 (info->hdr->e_type != ET_REL ?
707 info->sechdrs[sym->st_shndx].sh_addr : 0);
708 crc = TO_NATIVE(*crcp);
709 }
710 sym_update_crc(symname + strlen("__crc_"), mod, crc,
711 export);
712 }
713
714 switch (sym->st_shndx) {
715 case SHN_COMMON:
716 if (strstarts(symname, "__gnu_lto_")) {
717 /* Should warn here, but modpost runs before the linker */
718 } else
719 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
720 break;
721 case SHN_UNDEF:
722 /* undefined symbol */
723 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
724 ELF_ST_BIND(sym->st_info) != STB_WEAK)
725 break;
726 if (ignore_undef_symbol(info, symname))
727 break;
728/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
729#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
730/* add compatibility with older glibc */
731#ifndef STT_SPARC_REGISTER
732#define STT_SPARC_REGISTER STT_REGISTER
733#endif
734 if (info->hdr->e_machine == EM_SPARC ||
735 info->hdr->e_machine == EM_SPARCV9) {
736 /* Ignore register directives. */
737 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
738 break;
739 if (symname[0] == '.') {
740 char *munged = NOFAIL(strdup(symname));
741 munged[0] = '_';
742 munged[1] = toupper(munged[1]);
743 symname = munged;
744 }
745 }
746#endif
747
748 if (is_crc) {
749 const char *e = is_vmlinux(mod->name) ?"":".ko";
750 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n",
751 symname + strlen("__crc_"), mod->name, e);
752 }
753 mod->unres = alloc_symbol(symname,
754 ELF_ST_BIND(sym->st_info) == STB_WEAK,
755 mod->unres);
756 break;
757 default:
758 /* All exported symbols */
759 if (strstarts(symname, "__ksymtab_")) {
760 name = symname + strlen("__ksymtab_");
761 sym_add_exported(name, mod, export);
762 }
763 if (strcmp(symname, "init_module") == 0)
764 mod->has_init = 1;
765 if (strcmp(symname, "cleanup_module") == 0)
766 mod->has_cleanup = 1;
767 break;
768 }
769}
770
771/**
772 * Parse tag=value strings from .modinfo section
773 **/
774static char *next_string(char *string, unsigned long *secsize)
775{
776 /* Skip non-zero chars */
777 while (string[0]) {
778 string++;
779 if ((*secsize)-- <= 1)
780 return NULL;
781 }
782
783 /* Skip any zero padding. */
784 while (!string[0]) {
785 string++;
786 if ((*secsize)-- <= 1)
787 return NULL;
788 }
789 return string;
790}
791
792static char *get_next_modinfo(struct elf_info *info, const char *tag,
793 char *prev)
794{
795 char *p;
796 unsigned int taglen = strlen(tag);
797 char *modinfo = info->modinfo;
798 unsigned long size = info->modinfo_len;
799
800 if (prev) {
801 size -= prev - modinfo;
802 modinfo = next_string(prev, &size);
803 }
804
805 for (p = modinfo; p; p = next_string(p, &size)) {
806 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
807 return p + taglen + 1;
808 }
809 return NULL;
810}
811
812static char *get_modinfo(struct elf_info *info, const char *tag)
813
814{
815 return get_next_modinfo(info, tag, NULL);
816}
817
818/**
819 * Test if string s ends in string sub
820 * return 0 if match
821 **/
822static int strrcmp(const char *s, const char *sub)
823{
824 int slen, sublen;
825
826 if (!s || !sub)
827 return 1;
828
829 slen = strlen(s);
830 sublen = strlen(sub);
831
832 if ((slen == 0) || (sublen == 0))
833 return 1;
834
835 if (sublen > slen)
836 return 1;
837
838 return memcmp(s + slen - sublen, sub, sublen);
839}
840
841static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
842{
843 if (sym)
844 return elf->strtab + sym->st_name;
845 else
846 return "(unknown)";
847}
848
849/* The pattern is an array of simple patterns.
850 * "foo" will match an exact string equal to "foo"
851 * "*foo" will match a string that ends with "foo"
852 * "foo*" will match a string that begins with "foo"
853 * "*foo*" will match a string that contains "foo"
854 */
855static int match(const char *sym, const char * const pat[])
856{
857 const char *p;
858 while (*pat) {
859 p = *pat++;
860 const char *endp = p + strlen(p) - 1;
861
862 /* "*foo*" */
863 if (*p == '*' && *endp == '*') {
864 char *bare = NOFAIL(strndup(p + 1, strlen(p) - 2));
865 char *here = strstr(sym, bare);
866
867 free(bare);
868 if (here != NULL)
869 return 1;
870 }
871 /* "*foo" */
872 else if (*p == '*') {
873 if (strrcmp(sym, p + 1) == 0)
874 return 1;
875 }
876 /* "foo*" */
877 else if (*endp == '*') {
878 if (strncmp(sym, p, strlen(p) - 1) == 0)
879 return 1;
880 }
881 /* no wildcards */
882 else {
883 if (strcmp(p, sym) == 0)
884 return 1;
885 }
886 }
887 /* no match */
888 return 0;
889}
890
891/* sections that we do not want to do full section mismatch check on */
892static const char *const section_white_list[] =
893{
894 ".comment*",
895 ".debug*",
896 ".cranges", /* sh64 */
897 ".zdebug*", /* Compressed debug sections. */
898 ".GCC.command.line", /* record-gcc-switches */
899 ".mdebug*", /* alpha, score, mips etc. */
900 ".pdr", /* alpha, score, mips etc. */
901 ".stab*",
902 ".note*",
903 ".got*",
904 ".toc*",
905 ".xt.prop", /* xtensa */
906 ".xt.lit", /* xtensa */
907 ".arcextmap*", /* arc */
908 ".gnu.linkonce.arcext*", /* arc : modules */
909 ".cmem*", /* EZchip */
910 ".fmt_slot*", /* EZchip */
911 ".gnu.lto*",
912 ".discard.*",
913 NULL
914};
915
916/*
917 * This is used to find sections missing the SHF_ALLOC flag.
918 * The cause of this is often a section specified in assembler
919 * without "ax" / "aw".
920 */
921static void check_section(const char *modname, struct elf_info *elf,
922 Elf_Shdr *sechdr)
923{
924 const char *sec = sech_name(elf, sechdr);
925
926 if (sechdr->sh_type == SHT_PROGBITS &&
927 !(sechdr->sh_flags & SHF_ALLOC) &&
928 !match(sec, section_white_list)) {
929 warn("%s (%s): unexpected non-allocatable section.\n"
930 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
931 "Note that for example <linux/init.h> contains\n"
932 "section definitions for use in .S files.\n\n",
933 modname, sec);
934 }
935}
936
937
938
939#define ALL_INIT_DATA_SECTIONS \
940 ".init.setup", ".init.rodata", ".meminit.rodata", \
941 ".init.data", ".meminit.data"
942#define ALL_EXIT_DATA_SECTIONS \
943 ".exit.data", ".memexit.data"
944
945#define ALL_INIT_TEXT_SECTIONS \
946 ".init.text", ".meminit.text"
947#define ALL_EXIT_TEXT_SECTIONS \
948 ".exit.text", ".memexit.text"
949
950#define ALL_PCI_INIT_SECTIONS \
951 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
952 ".pci_fixup_enable", ".pci_fixup_resume", \
953 ".pci_fixup_resume_early", ".pci_fixup_suspend"
954
955#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
956#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
957
958#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
959#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
960
961#define DATA_SECTIONS ".data", ".data.rel"
962#define TEXT_SECTIONS ".text", ".text.unlikely", ".sched.text", \
963 ".kprobes.text", ".cpuidle.text"
964#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
965 ".fixup", ".entry.text", ".exception.text", ".text.*", \
966 ".coldtext"
967
968#define INIT_SECTIONS ".init.*"
969#define MEM_INIT_SECTIONS ".meminit.*"
970
971#define EXIT_SECTIONS ".exit.*"
972#define MEM_EXIT_SECTIONS ".memexit.*"
973
974#define ALL_TEXT_SECTIONS ALL_INIT_TEXT_SECTIONS, ALL_EXIT_TEXT_SECTIONS, \
975 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
976
977/* init data sections */
978static const char *const init_data_sections[] =
979 { ALL_INIT_DATA_SECTIONS, NULL };
980
981/* all init sections */
982static const char *const init_sections[] = { ALL_INIT_SECTIONS, NULL };
983
984/* All init and exit sections (code + data) */
985static const char *const init_exit_sections[] =
986 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
987
988/* all text sections */
989static const char *const text_sections[] = { ALL_TEXT_SECTIONS, NULL };
990
991/* data section */
992static const char *const data_sections[] = { DATA_SECTIONS, NULL };
993
994
995/* symbols in .data that may refer to init/exit sections */
996#define DEFAULT_SYMBOL_WHITE_LIST \
997 "*driver", \
998 "*_template", /* scsi uses *_template a lot */ \
999 "*_timer", /* arm uses ops structures named _timer a lot */ \
1000 "*_sht", /* scsi also used *_sht to some extent */ \
1001 "*_ops", \
1002 "*_probe", \
1003 "*_probe_one", \
1004 "*_console"
1005
1006static const char *const head_sections[] = { ".head.text*", NULL };
1007static const char *const linker_symbols[] =
1008 { "__init_begin", "_sinittext", "_einittext", NULL };
1009static const char *const optim_symbols[] = { "*.constprop.*", NULL };
1010
1011enum mismatch {
1012 TEXT_TO_ANY_INIT,
1013 DATA_TO_ANY_INIT,
1014 TEXT_TO_ANY_EXIT,
1015 DATA_TO_ANY_EXIT,
1016 XXXINIT_TO_SOME_INIT,
1017 XXXEXIT_TO_SOME_EXIT,
1018 ANY_INIT_TO_ANY_EXIT,
1019 ANY_EXIT_TO_ANY_INIT,
1020 EXPORT_TO_INIT_EXIT,
1021 EXTABLE_TO_NON_TEXT,
1022};
1023
1024/**
1025 * Describe how to match sections on different criterias:
1026 *
1027 * @fromsec: Array of sections to be matched.
1028 *
1029 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
1030 * this array is forbidden (black-list). Can be empty.
1031 *
1032 * @good_tosec: Relocations applied to a section in @fromsec must be
1033 * targetting sections in this array (white-list). Can be empty.
1034 *
1035 * @mismatch: Type of mismatch.
1036 *
1037 * @symbol_white_list: Do not match a relocation to a symbol in this list
1038 * even if it is targetting a section in @bad_to_sec.
1039 *
1040 * @handler: Specific handler to call when a match is found. If NULL,
1041 * default_mismatch_handler() will be called.
1042 *
1043 */
1044struct sectioncheck {
1045 const char *fromsec[20];
1046 const char *bad_tosec[20];
1047 const char *good_tosec[20];
1048 enum mismatch mismatch;
1049 const char *symbol_white_list[20];
1050 void (*handler)(const char *modname, struct elf_info *elf,
1051 const struct sectioncheck* const mismatch,
1052 Elf_Rela *r, Elf_Sym *sym, const char *fromsec);
1053
1054};
1055
1056static void extable_mismatch_handler(const char *modname, struct elf_info *elf,
1057 const struct sectioncheck* const mismatch,
1058 Elf_Rela *r, Elf_Sym *sym,
1059 const char *fromsec);
1060
1061static const struct sectioncheck sectioncheck[] = {
1062/* Do not reference init/exit code/data from
1063 * normal code and data
1064 */
1065{
1066 .fromsec = { TEXT_SECTIONS, NULL },
1067 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1068 .mismatch = TEXT_TO_ANY_INIT,
1069 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1070},
1071{
1072 .fromsec = { DATA_SECTIONS, NULL },
1073 .bad_tosec = { ALL_XXXINIT_SECTIONS, NULL },
1074 .mismatch = DATA_TO_ANY_INIT,
1075 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1076},
1077{
1078 .fromsec = { DATA_SECTIONS, NULL },
1079 .bad_tosec = { INIT_SECTIONS, NULL },
1080 .mismatch = DATA_TO_ANY_INIT,
1081 .symbol_white_list = {
1082 "*_template", "*_timer", "*_sht", "*_ops",
1083 "*_probe", "*_probe_one", "*_console", NULL
1084 },
1085},
1086{
1087 .fromsec = { TEXT_SECTIONS, NULL },
1088 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1089 .mismatch = TEXT_TO_ANY_EXIT,
1090 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1091},
1092{
1093 .fromsec = { DATA_SECTIONS, NULL },
1094 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1095 .mismatch = DATA_TO_ANY_EXIT,
1096 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1097},
1098/* Do not reference init code/data from meminit code/data */
1099{
1100 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
1101 .bad_tosec = { INIT_SECTIONS, NULL },
1102 .mismatch = XXXINIT_TO_SOME_INIT,
1103 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1104},
1105/* Do not reference exit code/data from memexit code/data */
1106{
1107 .fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
1108 .bad_tosec = { EXIT_SECTIONS, NULL },
1109 .mismatch = XXXEXIT_TO_SOME_EXIT,
1110 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1111},
1112/* Do not use exit code/data from init code */
1113{
1114 .fromsec = { ALL_INIT_SECTIONS, NULL },
1115 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
1116 .mismatch = ANY_INIT_TO_ANY_EXIT,
1117 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1118},
1119/* Do not use init code/data from exit code */
1120{
1121 .fromsec = { ALL_EXIT_SECTIONS, NULL },
1122 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
1123 .mismatch = ANY_EXIT_TO_ANY_INIT,
1124 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1125},
1126{
1127 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
1128 .bad_tosec = { INIT_SECTIONS, NULL },
1129 .mismatch = ANY_INIT_TO_ANY_EXIT,
1130 .symbol_white_list = { NULL },
1131},
1132/* Do not export init/exit functions or data */
1133{
1134 .fromsec = { "__ksymtab*", NULL },
1135 .bad_tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
1136 .mismatch = EXPORT_TO_INIT_EXIT,
1137 .symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
1138},
1139{
1140 .fromsec = { "__ex_table", NULL },
1141 /* If you're adding any new black-listed sections in here, consider
1142 * adding a special 'printer' for them in scripts/check_extable.
1143 */
1144 .bad_tosec = { ".altinstr_replacement", NULL },
1145 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
1146 .mismatch = EXTABLE_TO_NON_TEXT,
1147 .handler = extable_mismatch_handler,
1148}
1149};
1150
1151static const struct sectioncheck *section_mismatch(
1152 const char *fromsec, const char *tosec)
1153{
1154 int i;
1155 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
1156 const struct sectioncheck *check = §ioncheck[0];
1157
1158 /*
1159 * The target section could be the SHT_NUL section when we're
1160 * handling relocations to un-resolved symbols, trying to match it
1161 * doesn't make much sense and causes build failures on parisc
1162 * architectures.
1163 */
1164 if (*tosec == '\0')
1165 return NULL;
1166
1167 for (i = 0; i < elems; i++) {
1168 if (match(fromsec, check->fromsec)) {
1169 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
1170 return check;
1171 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
1172 return check;
1173 }
1174 check++;
1175 }
1176 return NULL;
1177}
1178
1179/**
1180 * Whitelist to allow certain references to pass with no warning.
1181 *
1182 * Pattern 1:
1183 * If a module parameter is declared __initdata and permissions=0
1184 * then this is legal despite the warning generated.
1185 * We cannot see value of permissions here, so just ignore
1186 * this pattern.
1187 * The pattern is identified by:
1188 * tosec = .init.data
1189 * fromsec = .data*
1190 * atsym =__param*
1191 *
1192 * Pattern 1a:
1193 * module_param_call() ops can refer to __init set function if permissions=0
1194 * The pattern is identified by:
1195 * tosec = .init.text
1196 * fromsec = .data*
1197 * atsym = __param_ops_*
1198 *
1199 * Pattern 2:
1200 * Many drivers utilise a *driver container with references to
1201 * add, remove, probe functions etc.
1202 * the pattern is identified by:
1203 * tosec = init or exit section
1204 * fromsec = data section
1205 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1206 * *probe_one, *_console, *_timer
1207 *
1208 * Pattern 3:
1209 * Whitelist all references from .head.text to any init section
1210 *
1211 * Pattern 4:
1212 * Some symbols belong to init section but still it is ok to reference
1213 * these from non-init sections as these symbols don't have any memory
1214 * allocated for them and symbol address and value are same. So even
1215 * if init section is freed, its ok to reference those symbols.
1216 * For ex. symbols marking the init section boundaries.
1217 * This pattern is identified by
1218 * refsymname = __init_begin, _sinittext, _einittext
1219 *
1220 * Pattern 5:
1221 * GCC may optimize static inlines when fed constant arg(s) resulting
1222 * in functions like cpumask_empty() -- generating an associated symbol
1223 * cpumask_empty.constprop.3 that appears in the audit. If the const that
1224 * is passed in comes from __init, like say nmi_ipi_mask, we get a
1225 * meaningless section warning. May need to add isra symbols too...
1226 * This pattern is identified by
1227 * tosec = init section
1228 * fromsec = text section
1229 * refsymname = *.constprop.*
1230 *
1231 * Pattern 6:
1232 * Hide section mismatch warnings for ELF local symbols. The goal
1233 * is to eliminate false positive modpost warnings caused by
1234 * compiler-generated ELF local symbol names such as ".LANCHOR1".
1235 * Autogenerated symbol names bypass modpost's "Pattern 2"
1236 * whitelisting, which relies on pattern-matching against symbol
1237 * names to work. (One situation where gcc can autogenerate ELF
1238 * local symbols is when "-fsection-anchors" is used.)
1239 **/
1240static int secref_whitelist(const struct sectioncheck *mismatch,
1241 const char *fromsec, const char *fromsym,
1242 const char *tosec, const char *tosym)
1243{
1244 /* Check for pattern 1 */
1245 if (match(tosec, init_data_sections) &&
1246 match(fromsec, data_sections) &&
1247 strstarts(fromsym, "__param"))
1248 return 0;
1249
1250 /* Check for pattern 1a */
1251 if (strcmp(tosec, ".init.text") == 0 &&
1252 match(fromsec, data_sections) &&
1253 strstarts(fromsym, "__param_ops_"))
1254 return 0;
1255
1256 /* Check for pattern 2 */
1257 if (match(tosec, init_exit_sections) &&
1258 match(fromsec, data_sections) &&
1259 match(fromsym, mismatch->symbol_white_list))
1260 return 0;
1261
1262 /* Check for pattern 3 */
1263 if (match(fromsec, head_sections) &&
1264 match(tosec, init_sections))
1265 return 0;
1266
1267 /* Check for pattern 4 */
1268 if (match(tosym, linker_symbols))
1269 return 0;
1270
1271 /* Check for pattern 5 */
1272 if (match(fromsec, text_sections) &&
1273 match(tosec, init_sections) &&
1274 match(fromsym, optim_symbols))
1275 return 0;
1276
1277 /* Check for pattern 6 */
1278 if (strstarts(fromsym, ".L"))
1279 return 0;
1280
1281 return 1;
1282}
1283
1284static inline int is_arm_mapping_symbol(const char *str)
1285{
1286 return str[0] == '$' && strchr("axtd", str[1])
1287 && (str[2] == '\0' || str[2] == '.');
1288}
1289
1290/*
1291 * If there's no name there, ignore it; likewise, ignore it if it's
1292 * one of the magic symbols emitted used by current ARM tools.
1293 *
1294 * Otherwise if find_symbols_between() returns those symbols, they'll
1295 * fail the whitelist tests and cause lots of false alarms ... fixable
1296 * only by merging __exit and __init sections into __text, bloating
1297 * the kernel (which is especially evil on embedded platforms).
1298 */
1299static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1300{
1301 const char *name = elf->strtab + sym->st_name;
1302
1303 if (!name || !strlen(name))
1304 return 0;
1305 return !is_arm_mapping_symbol(name);
1306}
1307
1308/**
1309 * Find symbol based on relocation record info.
1310 * In some cases the symbol supplied is a valid symbol so
1311 * return refsym. If st_name != 0 we assume this is a valid symbol.
1312 * In other cases the symbol needs to be looked up in the symbol table
1313 * based on section and address.
1314 * **/
1315static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1316 Elf_Sym *relsym)
1317{
1318 Elf_Sym *sym;
1319 Elf_Sym *near = NULL;
1320 Elf64_Sword distance = 20;
1321 Elf64_Sword d;
1322 unsigned int relsym_secindex;
1323
1324 if (relsym->st_name != 0)
1325 return relsym;
1326
1327 relsym_secindex = get_secindex(elf, relsym);
1328 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1329 if (get_secindex(elf, sym) != relsym_secindex)
1330 continue;
1331 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1332 continue;
1333 if (!is_valid_name(elf, sym))
1334 continue;
1335 if (sym->st_value == addr)
1336 return sym;
1337 /* Find a symbol nearby - addr are maybe negative */
1338 d = sym->st_value - addr;
1339 if (d < 0)
1340 d = addr - sym->st_value;
1341 if (d < distance) {
1342 distance = d;
1343 near = sym;
1344 }
1345 }
1346 /* We need a close match */
1347 if (distance < 20)
1348 return near;
1349 else
1350 return NULL;
1351}
1352
1353/*
1354 * Find symbols before or equal addr and after addr - in the section sec.
1355 * If we find two symbols with equal offset prefer one with a valid name.
1356 * The ELF format may have a better way to detect what type of symbol
1357 * it is, but this works for now.
1358 **/
1359static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1360 const char *sec)
1361{
1362 Elf_Sym *sym;
1363 Elf_Sym *near = NULL;
1364 Elf_Addr distance = ~0;
1365
1366 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1367 const char *symsec;
1368
1369 if (is_shndx_special(sym->st_shndx))
1370 continue;
1371 symsec = sec_name(elf, get_secindex(elf, sym));
1372 if (strcmp(symsec, sec) != 0)
1373 continue;
1374 if (!is_valid_name(elf, sym))
1375 continue;
1376 if (sym->st_value <= addr) {
1377 if ((addr - sym->st_value) < distance) {
1378 distance = addr - sym->st_value;
1379 near = sym;
1380 } else if ((addr - sym->st_value) == distance) {
1381 near = sym;
1382 }
1383 }
1384 }
1385 return near;
1386}
1387
1388/*
1389 * Convert a section name to the function/data attribute
1390 * .init.text => __init
1391 * .memexitconst => __memconst
1392 * etc.
1393 *
1394 * The memory of returned value has been allocated on a heap. The user of this
1395 * method should free it after usage.
1396*/
1397static char *sec2annotation(const char *s)
1398{
1399 if (match(s, init_exit_sections)) {
1400 char *p = NOFAIL(malloc(20));
1401 char *r = p;
1402
1403 *p++ = '_';
1404 *p++ = '_';
1405 if (*s == '.')
1406 s++;
1407 while (*s && *s != '.')
1408 *p++ = *s++;
1409 *p = '\0';
1410 if (*s == '.')
1411 s++;
1412 if (strstr(s, "rodata") != NULL)
1413 strcat(p, "const ");
1414 else if (strstr(s, "data") != NULL)
1415 strcat(p, "data ");
1416 else
1417 strcat(p, " ");
1418 return r;
1419 } else {
1420 return NOFAIL(strdup(""));
1421 }
1422}
1423
1424static int is_function(Elf_Sym *sym)
1425{
1426 if (sym)
1427 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1428 else
1429 return -1;
1430}
1431
1432static void print_section_list(const char * const list[20])
1433{
1434 const char *const *s = list;
1435
1436 while (*s) {
1437 fprintf(stderr, "%s", *s);
1438 s++;
1439 if (*s)
1440 fprintf(stderr, ", ");
1441 }
1442 fprintf(stderr, "\n");
1443}
1444
1445static inline void get_pretty_name(int is_func, const char** name, const char** name_p)
1446{
1447 switch (is_func) {
1448 case 0: *name = "variable"; *name_p = ""; break;
1449 case 1: *name = "function"; *name_p = "()"; break;
1450 default: *name = "(unknown reference)"; *name_p = ""; break;
1451 }
1452}
1453
1454/*
1455 * Print a warning about a section mismatch.
1456 * Try to find symbols near it so user can find it.
1457 * Check whitelist before warning - it may be a false positive.
1458 */
1459static void report_sec_mismatch(const char *modname,
1460 const struct sectioncheck *mismatch,
1461 const char *fromsec,
1462 unsigned long long fromaddr,
1463 const char *fromsym,
1464 int from_is_func,
1465 const char *tosec, const char *tosym,
1466 int to_is_func)
1467{
1468 const char *from, *from_p;
1469 const char *to, *to_p;
1470 char *prl_from;
1471 char *prl_to;
1472
1473 sec_mismatch_count++;
1474
1475 get_pretty_name(from_is_func, &from, &from_p);
1476 get_pretty_name(to_is_func, &to, &to_p);
1477
1478 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1479 "to the %s %s:%s%s\n",
1480 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1481 tosym, to_p);
1482
1483 switch (mismatch->mismatch) {
1484 case TEXT_TO_ANY_INIT:
1485 prl_from = sec2annotation(fromsec);
1486 prl_to = sec2annotation(tosec);
1487 fprintf(stderr,
1488 "The function %s%s() references\n"
1489 "the %s %s%s%s.\n"
1490 "This is often because %s lacks a %s\n"
1491 "annotation or the annotation of %s is wrong.\n",
1492 prl_from, fromsym,
1493 to, prl_to, tosym, to_p,
1494 fromsym, prl_to, tosym);
1495 free(prl_from);
1496 free(prl_to);
1497 break;
1498 case DATA_TO_ANY_INIT: {
1499 prl_to = sec2annotation(tosec);
1500 fprintf(stderr,
1501 "The variable %s references\n"
1502 "the %s %s%s%s\n"
1503 "If the reference is valid then annotate the\n"
1504 "variable with __init* or __refdata (see linux/init.h) "
1505 "or name the variable:\n",
1506 fromsym, to, prl_to, tosym, to_p);
1507 print_section_list(mismatch->symbol_white_list);
1508 free(prl_to);
1509 break;
1510 }
1511 case TEXT_TO_ANY_EXIT:
1512 prl_to = sec2annotation(tosec);
1513 fprintf(stderr,
1514 "The function %s() references a %s in an exit section.\n"
1515 "Often the %s %s%s has valid usage outside the exit section\n"
1516 "and the fix is to remove the %sannotation of %s.\n",
1517 fromsym, to, to, tosym, to_p, prl_to, tosym);
1518 free(prl_to);
1519 break;
1520 case DATA_TO_ANY_EXIT: {
1521 prl_to = sec2annotation(tosec);
1522 fprintf(stderr,
1523 "The variable %s references\n"
1524 "the %s %s%s%s\n"
1525 "If the reference is valid then annotate the\n"
1526 "variable with __exit* (see linux/init.h) or "
1527 "name the variable:\n",
1528 fromsym, to, prl_to, tosym, to_p);
1529 print_section_list(mismatch->symbol_white_list);
1530 free(prl_to);
1531 break;
1532 }
1533 case XXXINIT_TO_SOME_INIT:
1534 case XXXEXIT_TO_SOME_EXIT:
1535 prl_from = sec2annotation(fromsec);
1536 prl_to = sec2annotation(tosec);
1537 fprintf(stderr,
1538 "The %s %s%s%s references\n"
1539 "a %s %s%s%s.\n"
1540 "If %s is only used by %s then\n"
1541 "annotate %s with a matching annotation.\n",
1542 from, prl_from, fromsym, from_p,
1543 to, prl_to, tosym, to_p,
1544 tosym, fromsym, tosym);
1545 free(prl_from);
1546 free(prl_to);
1547 break;
1548 case ANY_INIT_TO_ANY_EXIT:
1549 prl_from = sec2annotation(fromsec);
1550 prl_to = sec2annotation(tosec);
1551 fprintf(stderr,
1552 "The %s %s%s%s references\n"
1553 "a %s %s%s%s.\n"
1554 "This is often seen when error handling "
1555 "in the init function\n"
1556 "uses functionality in the exit path.\n"
1557 "The fix is often to remove the %sannotation of\n"
1558 "%s%s so it may be used outside an exit section.\n",
1559 from, prl_from, fromsym, from_p,
1560 to, prl_to, tosym, to_p,
1561 prl_to, tosym, to_p);
1562 free(prl_from);
1563 free(prl_to);
1564 break;
1565 case ANY_EXIT_TO_ANY_INIT:
1566 prl_from = sec2annotation(fromsec);
1567 prl_to = sec2annotation(tosec);
1568 fprintf(stderr,
1569 "The %s %s%s%s references\n"
1570 "a %s %s%s%s.\n"
1571 "This is often seen when error handling "
1572 "in the exit function\n"
1573 "uses functionality in the init path.\n"
1574 "The fix is often to remove the %sannotation of\n"
1575 "%s%s so it may be used outside an init section.\n",
1576 from, prl_from, fromsym, from_p,
1577 to, prl_to, tosym, to_p,
1578 prl_to, tosym, to_p);
1579 free(prl_from);
1580 free(prl_to);
1581 break;
1582 case EXPORT_TO_INIT_EXIT:
1583 prl_to = sec2annotation(tosec);
1584 fprintf(stderr,
1585 "The symbol %s is exported and annotated %s\n"
1586 "Fix this by removing the %sannotation of %s "
1587 "or drop the export.\n",
1588 tosym, prl_to, prl_to, tosym);
1589 free(prl_to);
1590 break;
1591 case EXTABLE_TO_NON_TEXT:
1592 fatal("There's a special handler for this mismatch type, "
1593 "we should never get here.");
1594 break;
1595 }
1596 fprintf(stderr, "\n");
1597}
1598
1599static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1600 const struct sectioncheck* const mismatch,
1601 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1602{
1603 const char *tosec;
1604 Elf_Sym *to;
1605 Elf_Sym *from;
1606 const char *tosym;
1607 const char *fromsym;
1608
1609 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1610 fromsym = sym_name(elf, from);
1611
1612 if (strstarts(fromsym, "reference___initcall"))
1613 return;
1614
1615 tosec = sec_name(elf, get_secindex(elf, sym));
1616 to = find_elf_symbol(elf, r->r_addend, sym);
1617 tosym = sym_name(elf, to);
1618
1619 /* check whitelist - we may ignore it */
1620 if (secref_whitelist(mismatch,
1621 fromsec, fromsym, tosec, tosym)) {
1622 report_sec_mismatch(modname, mismatch,
1623 fromsec, r->r_offset, fromsym,
1624 is_function(from), tosec, tosym,
1625 is_function(to));
1626 }
1627}
1628
1629static int is_executable_section(struct elf_info* elf, unsigned int section_index)
1630{
1631 if (section_index > elf->num_sections)
1632 fatal("section_index is outside elf->num_sections!\n");
1633
1634 return ((elf->sechdrs[section_index].sh_flags & SHF_EXECINSTR) == SHF_EXECINSTR);
1635}
1636
1637/*
1638 * We rely on a gross hack in section_rel[a]() calling find_extable_entry_size()
1639 * to know the sizeof(struct exception_table_entry) for the target architecture.
1640 */
1641static unsigned int extable_entry_size = 0;
1642static void find_extable_entry_size(const char* const sec, const Elf_Rela* r)
1643{
1644 /*
1645 * If we're currently checking the second relocation within __ex_table,
1646 * that relocation offset tells us the offsetof(struct
1647 * exception_table_entry, fixup) which is equal to sizeof(struct
1648 * exception_table_entry) divided by two. We use that to our advantage
1649 * since there's no portable way to get that size as every architecture
1650 * seems to go with different sized types. Not pretty but better than
1651 * hard-coding the size for every architecture..
1652 */
1653 if (!extable_entry_size)
1654 extable_entry_size = r->r_offset * 2;
1655}
1656
1657static inline bool is_extable_fault_address(Elf_Rela *r)
1658{
1659 /*
1660 * extable_entry_size is only discovered after we've handled the
1661 * _second_ relocation in __ex_table, so only abort when we're not
1662 * handling the first reloc and extable_entry_size is zero.
1663 */
1664 if (r->r_offset && extable_entry_size == 0)
1665 fatal("extable_entry size hasn't been discovered!\n");
1666
1667 return ((r->r_offset == 0) ||
1668 (r->r_offset % extable_entry_size == 0));
1669}
1670
1671#define is_second_extable_reloc(Start, Cur, Sec) \
1672 (((Cur) == (Start) + 1) && (strcmp("__ex_table", (Sec)) == 0))
1673
1674static void report_extable_warnings(const char* modname, struct elf_info* elf,
1675 const struct sectioncheck* const mismatch,
1676 Elf_Rela* r, Elf_Sym* sym,
1677 const char* fromsec, const char* tosec)
1678{
1679 Elf_Sym* fromsym = find_elf_symbol2(elf, r->r_offset, fromsec);
1680 const char* fromsym_name = sym_name(elf, fromsym);
1681 Elf_Sym* tosym = find_elf_symbol(elf, r->r_addend, sym);
1682 const char* tosym_name = sym_name(elf, tosym);
1683 const char* from_pretty_name;
1684 const char* from_pretty_name_p;
1685 const char* to_pretty_name;
1686 const char* to_pretty_name_p;
1687
1688 get_pretty_name(is_function(fromsym),
1689 &from_pretty_name, &from_pretty_name_p);
1690 get_pretty_name(is_function(tosym),
1691 &to_pretty_name, &to_pretty_name_p);
1692
1693 warn("%s(%s+0x%lx): Section mismatch in reference"
1694 " from the %s %s%s to the %s %s:%s%s\n",
1695 modname, fromsec, (long)r->r_offset, from_pretty_name,
1696 fromsym_name, from_pretty_name_p,
1697 to_pretty_name, tosec, tosym_name, to_pretty_name_p);
1698
1699 if (!match(tosec, mismatch->bad_tosec) &&
1700 is_executable_section(elf, get_secindex(elf, sym)))
1701 fprintf(stderr,
1702 "The relocation at %s+0x%lx references\n"
1703 "section \"%s\" which is not in the list of\n"
1704 "authorized sections. If you're adding a new section\n"
1705 "and/or if this reference is valid, add \"%s\" to the\n"
1706 "list of authorized sections to jump to on fault.\n"
1707 "This can be achieved by adding \"%s\" to \n"
1708 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1709 fromsec, (long)r->r_offset, tosec, tosec, tosec);
1710}
1711
1712static void extable_mismatch_handler(const char* modname, struct elf_info *elf,
1713 const struct sectioncheck* const mismatch,
1714 Elf_Rela* r, Elf_Sym* sym,
1715 const char *fromsec)
1716{
1717 const char* tosec = sec_name(elf, get_secindex(elf, sym));
1718
1719 sec_mismatch_count++;
1720
1721 report_extable_warnings(modname, elf, mismatch, r, sym, fromsec, tosec);
1722
1723 if (match(tosec, mismatch->bad_tosec))
1724 fatal("The relocation at %s+0x%lx references\n"
1725 "section \"%s\" which is black-listed.\n"
1726 "Something is seriously wrong and should be fixed.\n"
1727 "You might get more information about where this is\n"
1728 "coming from by using scripts/check_extable.sh %s\n",
1729 fromsec, (long)r->r_offset, tosec, modname);
1730 else if (!is_executable_section(elf, get_secindex(elf, sym))) {
1731 if (is_extable_fault_address(r))
1732 fatal("The relocation at %s+0x%lx references\n"
1733 "section \"%s\" which is not executable, IOW\n"
1734 "it is not possible for the kernel to fault\n"
1735 "at that address. Something is seriously wrong\n"
1736 "and should be fixed.\n",
1737 fromsec, (long)r->r_offset, tosec);
1738 else
1739 fatal("The relocation at %s+0x%lx references\n"
1740 "section \"%s\" which is not executable, IOW\n"
1741 "the kernel will fault if it ever tries to\n"
1742 "jump to it. Something is seriously wrong\n"
1743 "and should be fixed.\n",
1744 fromsec, (long)r->r_offset, tosec);
1745 }
1746}
1747
1748static void check_section_mismatch(const char *modname, struct elf_info *elf,
1749 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1750{
1751 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1752 const struct sectioncheck *mismatch = section_mismatch(fromsec, tosec);
1753
1754 if (mismatch) {
1755 if (mismatch->handler)
1756 mismatch->handler(modname, elf, mismatch,
1757 r, sym, fromsec);
1758 else
1759 default_mismatch_handler(modname, elf, mismatch,
1760 r, sym, fromsec);
1761 }
1762}
1763
1764static unsigned int *reloc_location(struct elf_info *elf,
1765 Elf_Shdr *sechdr, Elf_Rela *r)
1766{
1767 Elf_Shdr *sechdrs = elf->sechdrs;
1768 int section = sechdr->sh_info;
1769
1770 return (void *)elf->hdr + sechdrs[section].sh_offset +
1771 r->r_offset;
1772}
1773
1774static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1775{
1776 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1777 unsigned int *location = reloc_location(elf, sechdr, r);
1778
1779 switch (r_typ) {
1780 case R_386_32:
1781 r->r_addend = TO_NATIVE(*location);
1782 break;
1783 case R_386_PC32:
1784 r->r_addend = TO_NATIVE(*location) + 4;
1785 /* For CONFIG_RELOCATABLE=y */
1786 if (elf->hdr->e_type == ET_EXEC)
1787 r->r_addend += r->r_offset;
1788 break;
1789 }
1790 return 0;
1791}
1792
1793#ifndef R_ARM_CALL
1794#define R_ARM_CALL 28
1795#endif
1796#ifndef R_ARM_JUMP24
1797#define R_ARM_JUMP24 29
1798#endif
1799
1800#ifndef R_ARM_THM_CALL
1801#define R_ARM_THM_CALL 10
1802#endif
1803#ifndef R_ARM_THM_JUMP24
1804#define R_ARM_THM_JUMP24 30
1805#endif
1806#ifndef R_ARM_THM_JUMP19
1807#define R_ARM_THM_JUMP19 51
1808#endif
1809
1810static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1811{
1812 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1813
1814 switch (r_typ) {
1815 case R_ARM_ABS32:
1816 /* From ARM ABI: (S + A) | T */
1817 r->r_addend = (int)(long)
1818 (elf->symtab_start + ELF_R_SYM(r->r_info));
1819 break;
1820 case R_ARM_PC24:
1821 case R_ARM_CALL:
1822 case R_ARM_JUMP24:
1823 case R_ARM_THM_CALL:
1824 case R_ARM_THM_JUMP24:
1825 case R_ARM_THM_JUMP19:
1826 /* From ARM ABI: ((S + A) | T) - P */
1827 r->r_addend = (int)(long)(elf->hdr +
1828 sechdr->sh_offset +
1829 (r->r_offset - sechdr->sh_addr));
1830 break;
1831 default:
1832 return 1;
1833 }
1834 return 0;
1835}
1836
1837static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1838{
1839 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1840 unsigned int *location = reloc_location(elf, sechdr, r);
1841 unsigned int inst;
1842
1843 if (r_typ == R_MIPS_HI16)
1844 return 1; /* skip this */
1845 inst = TO_NATIVE(*location);
1846 switch (r_typ) {
1847 case R_MIPS_LO16:
1848 r->r_addend = inst & 0xffff;
1849 break;
1850 case R_MIPS_26:
1851 r->r_addend = (inst & 0x03ffffff) << 2;
1852 break;
1853 case R_MIPS_32:
1854 r->r_addend = inst;
1855 break;
1856 }
1857 return 0;
1858}
1859
1860static void section_rela(const char *modname, struct elf_info *elf,
1861 Elf_Shdr *sechdr)
1862{
1863 Elf_Sym *sym;
1864 Elf_Rela *rela;
1865 Elf_Rela r;
1866 unsigned int r_sym;
1867 const char *fromsec;
1868
1869 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1870 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1871
1872 fromsec = sech_name(elf, sechdr);
1873 fromsec += strlen(".rela");
1874 /* if from section (name) is know good then skip it */
1875 if (match(fromsec, section_white_list))
1876 return;
1877
1878 for (rela = start; rela < stop; rela++) {
1879 r.r_offset = TO_NATIVE(rela->r_offset);
1880#if KERNEL_ELFCLASS == ELFCLASS64
1881 if (elf->hdr->e_machine == EM_MIPS) {
1882 unsigned int r_typ;
1883 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1884 r_sym = TO_NATIVE(r_sym);
1885 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1886 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1887 } else {
1888 r.r_info = TO_NATIVE(rela->r_info);
1889 r_sym = ELF_R_SYM(r.r_info);
1890 }
1891#else
1892 r.r_info = TO_NATIVE(rela->r_info);
1893 r_sym = ELF_R_SYM(r.r_info);
1894#endif
1895 r.r_addend = TO_NATIVE(rela->r_addend);
1896 sym = elf->symtab_start + r_sym;
1897 /* Skip special sections */
1898 if (is_shndx_special(sym->st_shndx))
1899 continue;
1900 if (is_second_extable_reloc(start, rela, fromsec))
1901 find_extable_entry_size(fromsec, &r);
1902 check_section_mismatch(modname, elf, &r, sym, fromsec);
1903 }
1904}
1905
1906static void section_rel(const char *modname, struct elf_info *elf,
1907 Elf_Shdr *sechdr)
1908{
1909 Elf_Sym *sym;
1910 Elf_Rel *rel;
1911 Elf_Rela r;
1912 unsigned int r_sym;
1913 const char *fromsec;
1914
1915 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1916 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1917
1918 fromsec = sech_name(elf, sechdr);
1919 fromsec += strlen(".rel");
1920 /* if from section (name) is know good then skip it */
1921 if (match(fromsec, section_white_list))
1922 return;
1923
1924 for (rel = start; rel < stop; rel++) {
1925 r.r_offset = TO_NATIVE(rel->r_offset);
1926#if KERNEL_ELFCLASS == ELFCLASS64
1927 if (elf->hdr->e_machine == EM_MIPS) {
1928 unsigned int r_typ;
1929 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1930 r_sym = TO_NATIVE(r_sym);
1931 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1932 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1933 } else {
1934 r.r_info = TO_NATIVE(rel->r_info);
1935 r_sym = ELF_R_SYM(r.r_info);
1936 }
1937#else
1938 r.r_info = TO_NATIVE(rel->r_info);
1939 r_sym = ELF_R_SYM(r.r_info);
1940#endif
1941 r.r_addend = 0;
1942 switch (elf->hdr->e_machine) {
1943 case EM_386:
1944 if (addend_386_rel(elf, sechdr, &r))
1945 continue;
1946 break;
1947 case EM_ARM:
1948 if (addend_arm_rel(elf, sechdr, &r))
1949 continue;
1950 break;
1951 case EM_MIPS:
1952 if (addend_mips_rel(elf, sechdr, &r))
1953 continue;
1954 break;
1955 }
1956 sym = elf->symtab_start + r_sym;
1957 /* Skip special sections */
1958 if (is_shndx_special(sym->st_shndx))
1959 continue;
1960 if (is_second_extable_reloc(start, rel, fromsec))
1961 find_extable_entry_size(fromsec, &r);
1962 check_section_mismatch(modname, elf, &r, sym, fromsec);
1963 }
1964}
1965
1966/**
1967 * A module includes a number of sections that are discarded
1968 * either when loaded or when used as built-in.
1969 * For loaded modules all functions marked __init and all data
1970 * marked __initdata will be discarded when the module has been initialized.
1971 * Likewise for modules used built-in the sections marked __exit
1972 * are discarded because __exit marked function are supposed to be called
1973 * only when a module is unloaded which never happens for built-in modules.
1974 * The check_sec_ref() function traverses all relocation records
1975 * to find all references to a section that reference a section that will
1976 * be discarded and warns about it.
1977 **/
1978static void check_sec_ref(struct module *mod, const char *modname,
1979 struct elf_info *elf)
1980{
1981 int i;
1982 Elf_Shdr *sechdrs = elf->sechdrs;
1983
1984 /* Walk through all sections */
1985 for (i = 0; i < elf->num_sections; i++) {
1986 check_section(modname, elf, &elf->sechdrs[i]);
1987 /* We want to process only relocation sections and not .init */
1988 if (sechdrs[i].sh_type == SHT_RELA)
1989 section_rela(modname, elf, &elf->sechdrs[i]);
1990 else if (sechdrs[i].sh_type == SHT_REL)
1991 section_rel(modname, elf, &elf->sechdrs[i]);
1992 }
1993}
1994
1995static char *remove_dot(char *s)
1996{
1997 size_t n = strcspn(s, ".");
1998
1999 if (n && s[n]) {
2000 size_t m = strspn(s + n + 1, "0123456789");
2001 if (m && (s[n + m] == '.' || s[n + m] == 0))
2002 s[n] = 0;
2003 }
2004 return s;
2005}
2006
2007static void read_symbols(const char *modname)
2008{
2009 const char *symname;
2010 char *version;
2011 char *license;
2012 char *namespace;
2013 struct module *mod;
2014 struct elf_info info = { };
2015 Elf_Sym *sym;
2016
2017 if (!parse_elf(&info, modname))
2018 return;
2019
2020 mod = new_module(modname);
2021
2022 /* When there's no vmlinux, don't print warnings about
2023 * unresolved symbols (since there'll be too many ;) */
2024 if (is_vmlinux(modname)) {
2025 have_vmlinux = 1;
2026 mod->skip = 1;
2027 }
2028
2029 license = get_modinfo(&info, "license");
2030 if (!license && !is_vmlinux(modname))
2031 warn("modpost: missing MODULE_LICENSE() in %s\n"
2032 "see include/linux/module.h for "
2033 "more information\n", modname);
2034 while (license) {
2035 if (license_is_gpl_compatible(license))
2036 mod->gpl_compatible = 1;
2037 else {
2038 mod->gpl_compatible = 0;
2039 break;
2040 }
2041 license = get_next_modinfo(&info, "license", license);
2042 }
2043
2044 namespace = get_modinfo(&info, "import_ns");
2045 while (namespace) {
2046 add_namespace(&mod->imported_namespaces, namespace);
2047 namespace = get_next_modinfo(&info, "import_ns", namespace);
2048 }
2049
2050 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2051 symname = remove_dot(info.strtab + sym->st_name);
2052
2053 handle_modversions(mod, &info, sym, symname);
2054 handle_moddevtable(mod, &info, sym, symname);
2055 }
2056
2057 /* Apply symbol namespaces from __kstrtabns_<symbol> entries. */
2058 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2059 symname = remove_dot(info.strtab + sym->st_name);
2060
2061 if (strstarts(symname, "__kstrtabns_"))
2062 sym_update_namespace(symname + strlen("__kstrtabns_"),
2063 namespace_from_kstrtabns(&info,
2064 sym));
2065 }
2066
2067 // check for static EXPORT_SYMBOL_* functions && global vars
2068 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
2069 unsigned char bind = ELF_ST_BIND(sym->st_info);
2070
2071 if (bind == STB_GLOBAL || bind == STB_WEAK) {
2072 struct symbol *s =
2073 find_symbol(remove_dot(info.strtab +
2074 sym->st_name));
2075
2076 if (s)
2077 s->is_static = 0;
2078 }
2079 }
2080
2081 if (!is_vmlinux(modname) || vmlinux_section_warnings)
2082 check_sec_ref(mod, modname, &info);
2083
2084 version = get_modinfo(&info, "version");
2085 if (version)
2086 maybe_frob_rcs_version(modname, version, info.modinfo,
2087 version - (char *)info.hdr);
2088 if (version || (all_versions && !is_vmlinux(modname)))
2089 get_src_version(modname, mod->srcversion,
2090 sizeof(mod->srcversion)-1);
2091
2092 parse_elf_finish(&info);
2093
2094 /* Our trick to get versioning for module struct etc. - it's
2095 * never passed as an argument to an exported function, so
2096 * the automatic versioning doesn't pick it up, but it's really
2097 * important anyhow */
2098 if (modversions)
2099 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
2100}
2101
2102static void read_symbols_from_files(const char *filename)
2103{
2104 FILE *in = stdin;
2105 char fname[PATH_MAX];
2106
2107 if (strcmp(filename, "-") != 0) {
2108 in = fopen(filename, "r");
2109 if (!in)
2110 fatal("Can't open filenames file %s: %m", filename);
2111 }
2112
2113 while (fgets(fname, PATH_MAX, in) != NULL) {
2114 if (strends(fname, "\n"))
2115 fname[strlen(fname)-1] = '\0';
2116 read_symbols(fname);
2117 }
2118
2119 if (in != stdin)
2120 fclose(in);
2121}
2122
2123#define SZ 500
2124
2125/* We first write the generated file into memory using the
2126 * following helper, then compare to the file on disk and
2127 * only update the later if anything changed */
2128
2129void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
2130 const char *fmt, ...)
2131{
2132 char tmp[SZ];
2133 int len;
2134 va_list ap;
2135
2136 va_start(ap, fmt);
2137 len = vsnprintf(tmp, SZ, fmt, ap);
2138 buf_write(buf, tmp, len);
2139 va_end(ap);
2140}
2141
2142void buf_write(struct buffer *buf, const char *s, int len)
2143{
2144 if (buf->size - buf->pos < len) {
2145 buf->size += len + SZ;
2146 buf->p = NOFAIL(realloc(buf->p, buf->size));
2147 }
2148 strncpy(buf->p + buf->pos, s, len);
2149 buf->pos += len;
2150}
2151
2152static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
2153{
2154 const char *e = is_vmlinux(m) ?"":".ko";
2155
2156 switch (exp) {
2157 case export_gpl:
2158 fatal("modpost: GPL-incompatible module %s%s "
2159 "uses GPL-only symbol '%s'\n", m, e, s);
2160 break;
2161 case export_unused_gpl:
2162 fatal("modpost: GPL-incompatible module %s%s "
2163 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
2164 break;
2165 case export_gpl_future:
2166 warn("modpost: GPL-incompatible module %s%s "
2167 "uses future GPL-only symbol '%s'\n", m, e, s);
2168 break;
2169 case export_plain:
2170 case export_unused:
2171 case export_unknown:
2172 /* ignore */
2173 break;
2174 }
2175}
2176
2177static void check_for_unused(enum export exp, const char *m, const char *s)
2178{
2179 const char *e = is_vmlinux(m) ?"":".ko";
2180
2181 switch (exp) {
2182 case export_unused:
2183 case export_unused_gpl:
2184 warn("modpost: module %s%s "
2185 "uses symbol '%s' marked UNUSED\n", m, e, s);
2186 break;
2187 default:
2188 /* ignore */
2189 break;
2190 }
2191}
2192
2193static int check_exports(struct module *mod)
2194{
2195 struct symbol *s, *exp;
2196 int err = 0;
2197
2198 for (s = mod->unres; s; s = s->next) {
2199 const char *basename;
2200 exp = find_symbol(s->name);
2201 if (!exp || exp->module == mod) {
2202 if (have_vmlinux && !s->weak) {
2203 if (warn_unresolved) {
2204 warn("\"%s\" [%s.ko] undefined!\n",
2205 s->name, mod->name);
2206 } else {
2207 merror("\"%s\" [%s.ko] undefined!\n",
2208 s->name, mod->name);
2209 err = 1;
2210 }
2211 }
2212 continue;
2213 }
2214 basename = strrchr(mod->name, '/');
2215 if (basename)
2216 basename++;
2217 else
2218 basename = mod->name;
2219
2220 if (exp->namespace) {
2221 add_namespace(&mod->required_namespaces,
2222 exp->namespace);
2223
2224 if (!write_namespace_deps &&
2225 !module_imports_namespace(mod, exp->namespace)) {
2226 warn("module %s uses symbol %s from namespace %s, but does not import it.\n",
2227 basename, exp->name, exp->namespace);
2228 }
2229 }
2230
2231 if (!mod->gpl_compatible)
2232 check_for_gpl_usage(exp->export, basename, exp->name);
2233 check_for_unused(exp->export, basename, exp->name);
2234 }
2235
2236 return err;
2237}
2238
2239static int check_modname_len(struct module *mod)
2240{
2241 const char *mod_name;
2242
2243 mod_name = strrchr(mod->name, '/');
2244 if (mod_name == NULL)
2245 mod_name = mod->name;
2246 else
2247 mod_name++;
2248 if (strlen(mod_name) >= MODULE_NAME_LEN) {
2249 merror("module name is too long [%s.ko]\n", mod->name);
2250 return 1;
2251 }
2252
2253 return 0;
2254}
2255
2256/**
2257 * Header for the generated file
2258 **/
2259static void add_header(struct buffer *b, struct module *mod)
2260{
2261 buf_printf(b, "#include <linux/build-salt.h>\n");
2262 buf_printf(b, "#include <linux/module.h>\n");
2263 buf_printf(b, "#include <linux/vermagic.h>\n");
2264 buf_printf(b, "#include <linux/compiler.h>\n");
2265 buf_printf(b, "\n");
2266 buf_printf(b, "BUILD_SALT;\n");
2267 buf_printf(b, "\n");
2268 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
2269 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
2270 buf_printf(b, "\n");
2271 buf_printf(b, "__visible struct module __this_module\n");
2272 buf_printf(b, "__section(.gnu.linkonce.this_module) = {\n");
2273 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
2274 if (mod->has_init)
2275 buf_printf(b, "\t.init = init_module,\n");
2276 if (mod->has_cleanup)
2277 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
2278 "\t.exit = cleanup_module,\n"
2279 "#endif\n");
2280 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
2281 buf_printf(b, "};\n");
2282}
2283
2284static void add_intree_flag(struct buffer *b, int is_intree)
2285{
2286 if (is_intree)
2287 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
2288}
2289
2290/* Cannot check for assembler */
2291static void add_retpoline(struct buffer *b)
2292{
2293 buf_printf(b, "\n#ifdef CONFIG_RETPOLINE\n");
2294 buf_printf(b, "MODULE_INFO(retpoline, \"Y\");\n");
2295 buf_printf(b, "#endif\n");
2296}
2297
2298static void add_staging_flag(struct buffer *b, const char *name)
2299{
2300 if (strstarts(name, "drivers/staging"))
2301 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
2302}
2303
2304/**
2305 * Record CRCs for unresolved symbols
2306 **/
2307static int add_versions(struct buffer *b, struct module *mod)
2308{
2309 struct symbol *s, *exp;
2310 int err = 0;
2311
2312 for (s = mod->unres; s; s = s->next) {
2313 exp = find_symbol(s->name);
2314 if (!exp || exp->module == mod)
2315 continue;
2316 s->module = exp->module;
2317 s->crc_valid = exp->crc_valid;
2318 s->crc = exp->crc;
2319 }
2320
2321 if (!modversions)
2322 return err;
2323
2324 buf_printf(b, "\n");
2325 buf_printf(b, "static const struct modversion_info ____versions[]\n");
2326 buf_printf(b, "__used __section(__versions) = {\n");
2327
2328 for (s = mod->unres; s; s = s->next) {
2329 if (!s->module)
2330 continue;
2331 if (!s->crc_valid) {
2332 warn("\"%s\" [%s.ko] has no CRC!\n",
2333 s->name, mod->name);
2334 continue;
2335 }
2336 if (strlen(s->name) >= MODULE_NAME_LEN) {
2337 merror("too long symbol \"%s\" [%s.ko]\n",
2338 s->name, mod->name);
2339 err = 1;
2340 break;
2341 }
2342 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
2343 s->crc, s->name);
2344 }
2345
2346 buf_printf(b, "};\n");
2347
2348 return err;
2349}
2350
2351static void add_depends(struct buffer *b, struct module *mod)
2352{
2353 struct symbol *s;
2354 int first = 1;
2355
2356 /* Clear ->seen flag of modules that own symbols needed by this. */
2357 for (s = mod->unres; s; s = s->next)
2358 if (s->module)
2359 s->module->seen = is_vmlinux(s->module->name);
2360
2361 buf_printf(b, "\n");
2362 buf_printf(b, "MODULE_INFO(depends, \"");
2363 for (s = mod->unres; s; s = s->next) {
2364 const char *p;
2365 if (!s->module)
2366 continue;
2367
2368 if (s->module->seen)
2369 continue;
2370
2371 s->module->seen = 1;
2372 p = strrchr(s->module->name, '/');
2373 if (p)
2374 p++;
2375 else
2376 p = s->module->name;
2377 buf_printf(b, "%s%s", first ? "" : ",", p);
2378 first = 0;
2379 }
2380 buf_printf(b, "\");\n");
2381}
2382
2383static void add_srcversion(struct buffer *b, struct module *mod)
2384{
2385 if (mod->srcversion[0]) {
2386 buf_printf(b, "\n");
2387 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
2388 mod->srcversion);
2389 }
2390}
2391
2392static void write_if_changed(struct buffer *b, const char *fname)
2393{
2394 char *tmp;
2395 FILE *file;
2396 struct stat st;
2397
2398 file = fopen(fname, "r");
2399 if (!file)
2400 goto write;
2401
2402 if (fstat(fileno(file), &st) < 0)
2403 goto close_write;
2404
2405 if (st.st_size != b->pos)
2406 goto close_write;
2407
2408 tmp = NOFAIL(malloc(b->pos));
2409 if (fread(tmp, 1, b->pos, file) != b->pos)
2410 goto free_write;
2411
2412 if (memcmp(tmp, b->p, b->pos) != 0)
2413 goto free_write;
2414
2415 free(tmp);
2416 fclose(file);
2417 return;
2418
2419 free_write:
2420 free(tmp);
2421 close_write:
2422 fclose(file);
2423 write:
2424 file = fopen(fname, "w");
2425 if (!file) {
2426 perror(fname);
2427 exit(1);
2428 }
2429 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
2430 perror(fname);
2431 exit(1);
2432 }
2433 fclose(file);
2434}
2435
2436/* parse Module.symvers file. line format:
2437 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2438 **/
2439static void read_dump(const char *fname, unsigned int kernel)
2440{
2441 unsigned long size, pos = 0;
2442 void *file = grab_file(fname, &size);
2443 char *line;
2444
2445 if (!file)
2446 /* No symbol versions, silently ignore */
2447 return;
2448
2449 while ((line = get_next_line(&pos, file, size))) {
2450 char *symname, *namespace, *modname, *d, *export, *end;
2451 unsigned int crc;
2452 struct module *mod;
2453 struct symbol *s;
2454
2455 if (!(symname = strchr(line, '\t')))
2456 goto fail;
2457 *symname++ = '\0';
2458 if (!(namespace = strchr(symname, '\t')))
2459 goto fail;
2460 *namespace++ = '\0';
2461 if (!(modname = strchr(namespace, '\t')))
2462 goto fail;
2463 *modname++ = '\0';
2464 if ((export = strchr(modname, '\t')) != NULL)
2465 *export++ = '\0';
2466 if (export && ((end = strchr(export, '\t')) != NULL))
2467 *end = '\0';
2468 crc = strtoul(line, &d, 16);
2469 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2470 goto fail;
2471 mod = find_module(modname);
2472 if (!mod) {
2473 if (is_vmlinux(modname))
2474 have_vmlinux = 1;
2475 mod = new_module(modname);
2476 mod->skip = 1;
2477 }
2478 s = sym_add_exported(symname, mod, export_no(export));
2479 s->kernel = kernel;
2480 s->preloaded = 1;
2481 s->is_static = 0;
2482 sym_update_crc(symname, mod, crc, export_no(export));
2483 sym_update_namespace(symname, namespace);
2484 }
2485 release_file(file, size);
2486 return;
2487fail:
2488 release_file(file, size);
2489 fatal("parse error in symbol dump file\n");
2490}
2491
2492/* For normal builds always dump all symbols.
2493 * For external modules only dump symbols
2494 * that are not read from kernel Module.symvers.
2495 **/
2496static int dump_sym(struct symbol *sym)
2497{
2498 if (!external_module)
2499 return 1;
2500 if (sym->vmlinux || sym->kernel)
2501 return 0;
2502 return 1;
2503}
2504
2505static void write_dump(const char *fname)
2506{
2507 struct buffer buf = { };
2508 struct symbol *symbol;
2509 const char *namespace;
2510 int n;
2511
2512 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
2513 symbol = symbolhash[n];
2514 while (symbol) {
2515 if (dump_sym(symbol)) {
2516 namespace = symbol->namespace;
2517 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\t%s\n",
2518 symbol->crc, symbol->name,
2519 namespace ? namespace : "",
2520 symbol->module->name,
2521 export_str(symbol->export));
2522 }
2523 symbol = symbol->next;
2524 }
2525 }
2526 write_if_changed(&buf, fname);
2527 free(buf.p);
2528}
2529
2530static void write_namespace_deps_files(void)
2531{
2532 struct module *mod;
2533 struct namespace_list *ns;
2534 struct buffer ns_deps_buf = {};
2535
2536 for (mod = modules; mod; mod = mod->next) {
2537 char fname[PATH_MAX];
2538
2539 if (mod->skip)
2540 continue;
2541
2542 ns_deps_buf.pos = 0;
2543
2544 for (ns = mod->required_namespaces; ns; ns = ns->next)
2545 buf_printf(&ns_deps_buf, "%s\n", ns->namespace);
2546
2547 if (ns_deps_buf.pos == 0)
2548 continue;
2549
2550 sprintf(fname, "%s.ns_deps", mod->name);
2551 write_if_changed(&ns_deps_buf, fname);
2552 }
2553}
2554
2555struct ext_sym_list {
2556 struct ext_sym_list *next;
2557 const char *file;
2558};
2559
2560int main(int argc, char **argv)
2561{
2562 struct module *mod;
2563 struct buffer buf = { };
2564 char *kernel_read = NULL, *module_read = NULL;
2565 char *dump_write = NULL, *files_source = NULL;
2566 int opt;
2567 int err;
2568 int n;
2569 struct ext_sym_list *extsym_iter;
2570 struct ext_sym_list *extsym_start = NULL;
2571
2572 while ((opt = getopt(argc, argv, "i:I:e:mnsT:o:awEd")) != -1) {
2573 switch (opt) {
2574 case 'i':
2575 kernel_read = optarg;
2576 break;
2577 case 'I':
2578 module_read = optarg;
2579 external_module = 1;
2580 break;
2581 case 'e':
2582 external_module = 1;
2583 extsym_iter =
2584 NOFAIL(malloc(sizeof(*extsym_iter)));
2585 extsym_iter->next = extsym_start;
2586 extsym_iter->file = optarg;
2587 extsym_start = extsym_iter;
2588 break;
2589 case 'm':
2590 modversions = 1;
2591 break;
2592 case 'n':
2593 ignore_missing_files = 1;
2594 break;
2595 case 'o':
2596 dump_write = optarg;
2597 break;
2598 case 'a':
2599 all_versions = 1;
2600 break;
2601 case 's':
2602 vmlinux_section_warnings = 0;
2603 break;
2604 case 'T':
2605 files_source = optarg;
2606 break;
2607 case 'w':
2608 warn_unresolved = 1;
2609 break;
2610 case 'E':
2611 sec_mismatch_fatal = 1;
2612 break;
2613 case 'd':
2614 write_namespace_deps = 1;
2615 break;
2616 default:
2617 exit(1);
2618 }
2619 }
2620
2621 if (kernel_read)
2622 read_dump(kernel_read, 1);
2623 if (module_read)
2624 read_dump(module_read, 0);
2625 while (extsym_start) {
2626 read_dump(extsym_start->file, 0);
2627 extsym_iter = extsym_start->next;
2628 free(extsym_start);
2629 extsym_start = extsym_iter;
2630 }
2631
2632 while (optind < argc)
2633 read_symbols(argv[optind++]);
2634
2635 if (files_source)
2636 read_symbols_from_files(files_source);
2637
2638 err = 0;
2639
2640 for (mod = modules; mod; mod = mod->next) {
2641 char fname[PATH_MAX];
2642
2643 if (mod->skip)
2644 continue;
2645
2646 buf.pos = 0;
2647
2648 err |= check_modname_len(mod);
2649 err |= check_exports(mod);
2650 if (write_namespace_deps)
2651 continue;
2652
2653 add_header(&buf, mod);
2654 add_intree_flag(&buf, !external_module);
2655 add_retpoline(&buf);
2656 add_staging_flag(&buf, mod->name);
2657 err |= add_versions(&buf, mod);
2658 add_depends(&buf, mod);
2659 add_moddevtable(&buf, mod);
2660 add_srcversion(&buf, mod);
2661
2662 sprintf(fname, "%s.mod.c", mod->name);
2663 write_if_changed(&buf, fname);
2664 }
2665
2666 if (write_namespace_deps) {
2667 write_namespace_deps_files();
2668 return 0;
2669 }
2670
2671 if (dump_write)
2672 write_dump(dump_write);
2673 if (sec_mismatch_count && sec_mismatch_fatal)
2674 fatal("modpost: Section mismatches detected.\n"
2675 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2676 for (n = 0; n < SYMBOL_HASH_SIZE; n++) {
2677 struct symbol *s;
2678
2679 for (s = symbolhash[n]; s; s = s->next) {
2680 /*
2681 * Do not check "vmlinux". This avoids the same warnings
2682 * shown twice, and false-positives for ARCH=um.
2683 */
2684 if (is_vmlinux(s->module->name) && !s->module->is_dot_o)
2685 continue;
2686
2687 if (s->is_static)
2688 warn("\"%s\" [%s] is a static %s\n",
2689 s->name, s->module->name,
2690 export_str(s->export));
2691 }
2692 }
2693
2694 free(buf.p);
2695
2696 return err;
2697}
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14#define _GNU_SOURCE
15#include <elf.h>
16#include <fnmatch.h>
17#include <stdio.h>
18#include <ctype.h>
19#include <string.h>
20#include <limits.h>
21#include <stdbool.h>
22#include <errno.h>
23
24#include <hash.h>
25#include <hashtable.h>
26#include <list.h>
27#include <xalloc.h>
28#include "modpost.h"
29#include "../../include/linux/license.h"
30
31static bool module_enabled;
32/* Are we using CONFIG_MODVERSIONS? */
33static bool modversions;
34/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35static bool all_versions;
36/* If we are modposting external module set to 1 */
37static bool external_module;
38/* Only warn about unresolved symbols */
39static bool warn_unresolved;
40
41static int sec_mismatch_count;
42static bool sec_mismatch_warn_only = true;
43/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
44static bool trim_unused_exports;
45
46/* ignore missing files */
47static bool ignore_missing_files;
48/* If set to 1, only warn (instead of error) about missing ns imports */
49static bool allow_missing_ns_imports;
50
51static bool error_occurred;
52
53static bool extra_warn;
54
55bool target_is_big_endian;
56bool host_is_big_endian;
57
58/*
59 * Cut off the warnings when there are too many. This typically occurs when
60 * vmlinux is missing. ('make modules' without building vmlinux.)
61 */
62#define MAX_UNRESOLVED_REPORTS 10
63static unsigned int nr_unresolved;
64
65/* In kernel, this size is defined in linux/module.h;
66 * here we use Elf_Addr instead of long for covering cross-compile
67 */
68
69#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
70
71void modpost_log(bool is_error, const char *fmt, ...)
72{
73 va_list arglist;
74
75 if (is_error) {
76 fprintf(stderr, "ERROR: ");
77 error_occurred = true;
78 } else {
79 fprintf(stderr, "WARNING: ");
80 }
81
82 fprintf(stderr, "modpost: ");
83
84 va_start(arglist, fmt);
85 vfprintf(stderr, fmt, arglist);
86 va_end(arglist);
87}
88
89static inline bool strends(const char *str, const char *postfix)
90{
91 if (strlen(str) < strlen(postfix))
92 return false;
93
94 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
95}
96
97char *read_text_file(const char *filename)
98{
99 struct stat st;
100 size_t nbytes;
101 int fd;
102 char *buf;
103
104 fd = open(filename, O_RDONLY);
105 if (fd < 0) {
106 perror(filename);
107 exit(1);
108 }
109
110 if (fstat(fd, &st) < 0) {
111 perror(filename);
112 exit(1);
113 }
114
115 buf = xmalloc(st.st_size + 1);
116
117 nbytes = st.st_size;
118
119 while (nbytes) {
120 ssize_t bytes_read;
121
122 bytes_read = read(fd, buf, nbytes);
123 if (bytes_read < 0) {
124 perror(filename);
125 exit(1);
126 }
127
128 nbytes -= bytes_read;
129 }
130 buf[st.st_size] = '\0';
131
132 close(fd);
133
134 return buf;
135}
136
137char *get_line(char **stringp)
138{
139 char *orig = *stringp, *next;
140
141 /* do not return the unwanted extra line at EOF */
142 if (!orig || *orig == '\0')
143 return NULL;
144
145 /* don't use strsep here, it is not available everywhere */
146 next = strchr(orig, '\n');
147 if (next)
148 *next++ = '\0';
149
150 *stringp = next;
151
152 return orig;
153}
154
155/* A list of all modules we processed */
156LIST_HEAD(modules);
157
158static struct module *find_module(const char *filename, const char *modname)
159{
160 struct module *mod;
161
162 list_for_each_entry(mod, &modules, list) {
163 if (!strcmp(mod->dump_file, filename) &&
164 !strcmp(mod->name, modname))
165 return mod;
166 }
167 return NULL;
168}
169
170static struct module *new_module(const char *name, size_t namelen)
171{
172 struct module *mod;
173
174 mod = xmalloc(sizeof(*mod) + namelen + 1);
175 memset(mod, 0, sizeof(*mod));
176
177 INIT_LIST_HEAD(&mod->exported_symbols);
178 INIT_LIST_HEAD(&mod->unresolved_symbols);
179 INIT_LIST_HEAD(&mod->missing_namespaces);
180 INIT_LIST_HEAD(&mod->imported_namespaces);
181 INIT_LIST_HEAD(&mod->aliases);
182
183 memcpy(mod->name, name, namelen);
184 mod->name[namelen] = '\0';
185 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
186
187 /*
188 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
189 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
190 * modpost will exit wiht error anyway.
191 */
192 mod->is_gpl_compatible = true;
193
194 list_add_tail(&mod->list, &modules);
195
196 return mod;
197}
198
199struct symbol {
200 struct hlist_node hnode;/* link to hash table */
201 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
202 struct module *module;
203 char *namespace;
204 unsigned int crc;
205 bool crc_valid;
206 bool weak;
207 bool is_func;
208 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
209 bool used; /* there exists a user of this symbol */
210 char name[];
211};
212
213static HASHTABLE_DEFINE(symbol_hashtable, 1U << 10);
214
215/**
216 * Allocate a new symbols for use in the hash of exported symbols or
217 * the list of unresolved symbols per module
218 **/
219static struct symbol *alloc_symbol(const char *name)
220{
221 struct symbol *s = xmalloc(sizeof(*s) + strlen(name) + 1);
222
223 memset(s, 0, sizeof(*s));
224 strcpy(s->name, name);
225
226 return s;
227}
228
229/* For the hash of exported symbols */
230static void hash_add_symbol(struct symbol *sym)
231{
232 hash_add(symbol_hashtable, &sym->hnode, hash_str(sym->name));
233}
234
235static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
236{
237 struct symbol *sym;
238
239 sym = alloc_symbol(name);
240 sym->weak = weak;
241
242 list_add_tail(&sym->list, &mod->unresolved_symbols);
243}
244
245static struct symbol *sym_find_with_module(const char *name, struct module *mod)
246{
247 struct symbol *s;
248
249 /* For our purposes, .foo matches foo. PPC64 needs this. */
250 if (name[0] == '.')
251 name++;
252
253 hash_for_each_possible(symbol_hashtable, s, hnode, hash_str(name)) {
254 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
255 return s;
256 }
257 return NULL;
258}
259
260static struct symbol *find_symbol(const char *name)
261{
262 return sym_find_with_module(name, NULL);
263}
264
265struct namespace_list {
266 struct list_head list;
267 char namespace[];
268};
269
270static bool contains_namespace(struct list_head *head, const char *namespace)
271{
272 struct namespace_list *list;
273
274 /*
275 * The default namespace is null string "", which is always implicitly
276 * contained.
277 */
278 if (!namespace[0])
279 return true;
280
281 list_for_each_entry(list, head, list) {
282 if (!strcmp(list->namespace, namespace))
283 return true;
284 }
285
286 return false;
287}
288
289static void add_namespace(struct list_head *head, const char *namespace)
290{
291 struct namespace_list *ns_entry;
292
293 if (!contains_namespace(head, namespace)) {
294 ns_entry = xmalloc(sizeof(*ns_entry) + strlen(namespace) + 1);
295 strcpy(ns_entry->namespace, namespace);
296 list_add_tail(&ns_entry->list, head);
297 }
298}
299
300static void *sym_get_data_by_offset(const struct elf_info *info,
301 unsigned int secindex, unsigned long offset)
302{
303 Elf_Shdr *sechdr = &info->sechdrs[secindex];
304
305 return (void *)info->hdr + sechdr->sh_offset + offset;
306}
307
308void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
309{
310 return sym_get_data_by_offset(info, get_secindex(info, sym),
311 sym->st_value);
312}
313
314static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
315{
316 return sym_get_data_by_offset(info, info->secindex_strings,
317 sechdr->sh_name);
318}
319
320static const char *sec_name(const struct elf_info *info, unsigned int secindex)
321{
322 /*
323 * If sym->st_shndx is a special section index, there is no
324 * corresponding section header.
325 * Return "" if the index is out of range of info->sechdrs[] array.
326 */
327 if (secindex >= info->num_sections)
328 return "";
329
330 return sech_name(info, &info->sechdrs[secindex]);
331}
332
333static struct symbol *sym_add_exported(const char *name, struct module *mod,
334 bool gpl_only, const char *namespace)
335{
336 struct symbol *s = find_symbol(name);
337
338 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
339 error("%s: '%s' exported twice. Previous export was in %s%s\n",
340 mod->name, name, s->module->name,
341 s->module->is_vmlinux ? "" : ".ko");
342 }
343
344 s = alloc_symbol(name);
345 s->module = mod;
346 s->is_gpl_only = gpl_only;
347 s->namespace = xstrdup(namespace);
348 list_add_tail(&s->list, &mod->exported_symbols);
349 hash_add_symbol(s);
350
351 return s;
352}
353
354static void sym_set_crc(struct symbol *sym, unsigned int crc)
355{
356 sym->crc = crc;
357 sym->crc_valid = true;
358}
359
360static void *grab_file(const char *filename, size_t *size)
361{
362 struct stat st;
363 void *map = MAP_FAILED;
364 int fd;
365
366 fd = open(filename, O_RDONLY);
367 if (fd < 0)
368 return NULL;
369 if (fstat(fd, &st))
370 goto failed;
371
372 *size = st.st_size;
373 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
374
375failed:
376 close(fd);
377 if (map == MAP_FAILED)
378 return NULL;
379 return map;
380}
381
382static void release_file(void *file, size_t size)
383{
384 munmap(file, size);
385}
386
387static int parse_elf(struct elf_info *info, const char *filename)
388{
389 unsigned int i;
390 Elf_Ehdr *hdr;
391 Elf_Shdr *sechdrs;
392 Elf_Sym *sym;
393 const char *secstrings;
394 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
395
396 hdr = grab_file(filename, &info->size);
397 if (!hdr) {
398 if (ignore_missing_files) {
399 fprintf(stderr, "%s: %s (ignored)\n", filename,
400 strerror(errno));
401 return 0;
402 }
403 perror(filename);
404 exit(1);
405 }
406 info->hdr = hdr;
407 if (info->size < sizeof(*hdr)) {
408 /* file too small, assume this is an empty .o file */
409 return 0;
410 }
411 /* Is this a valid ELF file? */
412 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
413 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
414 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
415 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
416 /* Not an ELF file - silently ignore it */
417 return 0;
418 }
419
420 switch (hdr->e_ident[EI_DATA]) {
421 case ELFDATA2LSB:
422 target_is_big_endian = false;
423 break;
424 case ELFDATA2MSB:
425 target_is_big_endian = true;
426 break;
427 default:
428 fatal("target endian is unknown\n");
429 }
430
431 /* Fix endianness in ELF header */
432 hdr->e_type = TO_NATIVE(hdr->e_type);
433 hdr->e_machine = TO_NATIVE(hdr->e_machine);
434 hdr->e_version = TO_NATIVE(hdr->e_version);
435 hdr->e_entry = TO_NATIVE(hdr->e_entry);
436 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
437 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
438 hdr->e_flags = TO_NATIVE(hdr->e_flags);
439 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
440 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
441 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
442 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
443 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
444 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
445 sechdrs = (void *)hdr + hdr->e_shoff;
446 info->sechdrs = sechdrs;
447
448 /* modpost only works for relocatable objects */
449 if (hdr->e_type != ET_REL)
450 fatal("%s: not relocatable object.", filename);
451
452 /* Check if file offset is correct */
453 if (hdr->e_shoff > info->size)
454 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
455 (unsigned long)hdr->e_shoff, filename, info->size);
456
457 if (hdr->e_shnum == SHN_UNDEF) {
458 /*
459 * There are more than 64k sections,
460 * read count from .sh_size.
461 */
462 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
463 }
464 else {
465 info->num_sections = hdr->e_shnum;
466 }
467 if (hdr->e_shstrndx == SHN_XINDEX) {
468 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
469 }
470 else {
471 info->secindex_strings = hdr->e_shstrndx;
472 }
473
474 /* Fix endianness in section headers */
475 for (i = 0; i < info->num_sections; i++) {
476 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
477 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
478 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
479 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
480 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
481 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
482 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
483 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
484 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
485 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
486 }
487 /* Find symbol table. */
488 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
489 for (i = 1; i < info->num_sections; i++) {
490 const char *secname;
491 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
492
493 if (!nobits && sechdrs[i].sh_offset > info->size)
494 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
495 filename, (unsigned long)sechdrs[i].sh_offset,
496 sizeof(*hdr));
497
498 secname = secstrings + sechdrs[i].sh_name;
499 if (strcmp(secname, ".modinfo") == 0) {
500 if (nobits)
501 fatal("%s has NOBITS .modinfo\n", filename);
502 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
503 info->modinfo_len = sechdrs[i].sh_size;
504 } else if (!strcmp(secname, ".export_symbol")) {
505 info->export_symbol_secndx = i;
506 }
507
508 if (sechdrs[i].sh_type == SHT_SYMTAB) {
509 unsigned int sh_link_idx;
510 symtab_idx = i;
511 info->symtab_start = (void *)hdr +
512 sechdrs[i].sh_offset;
513 info->symtab_stop = (void *)hdr +
514 sechdrs[i].sh_offset + sechdrs[i].sh_size;
515 sh_link_idx = sechdrs[i].sh_link;
516 info->strtab = (void *)hdr +
517 sechdrs[sh_link_idx].sh_offset;
518 }
519
520 /* 32bit section no. table? ("more than 64k sections") */
521 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
522 symtab_shndx_idx = i;
523 info->symtab_shndx_start = (void *)hdr +
524 sechdrs[i].sh_offset;
525 info->symtab_shndx_stop = (void *)hdr +
526 sechdrs[i].sh_offset + sechdrs[i].sh_size;
527 }
528 }
529 if (!info->symtab_start)
530 fatal("%s has no symtab?\n", filename);
531
532 /* Fix endianness in symbols */
533 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
534 sym->st_shndx = TO_NATIVE(sym->st_shndx);
535 sym->st_name = TO_NATIVE(sym->st_name);
536 sym->st_value = TO_NATIVE(sym->st_value);
537 sym->st_size = TO_NATIVE(sym->st_size);
538 }
539
540 if (symtab_shndx_idx != ~0U) {
541 Elf32_Word *p;
542 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
543 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
544 filename, sechdrs[symtab_shndx_idx].sh_link,
545 symtab_idx);
546 /* Fix endianness */
547 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
548 p++)
549 *p = TO_NATIVE(*p);
550 }
551
552 symsearch_init(info);
553
554 return 1;
555}
556
557static void parse_elf_finish(struct elf_info *info)
558{
559 symsearch_finish(info);
560 release_file(info->hdr, info->size);
561}
562
563static int ignore_undef_symbol(struct elf_info *info, const char *symname)
564{
565 /* ignore __this_module, it will be resolved shortly */
566 if (strcmp(symname, "__this_module") == 0)
567 return 1;
568 /* ignore global offset table */
569 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
570 return 1;
571 if (info->hdr->e_machine == EM_PPC)
572 /* Special register function linked on all modules during final link of .ko */
573 if (strstarts(symname, "_restgpr_") ||
574 strstarts(symname, "_savegpr_") ||
575 strstarts(symname, "_rest32gpr_") ||
576 strstarts(symname, "_save32gpr_") ||
577 strstarts(symname, "_restvr_") ||
578 strstarts(symname, "_savevr_"))
579 return 1;
580 if (info->hdr->e_machine == EM_PPC64)
581 /* Special register function linked on all modules during final link of .ko */
582 if (strstarts(symname, "_restgpr0_") ||
583 strstarts(symname, "_savegpr0_") ||
584 strstarts(symname, "_restvr_") ||
585 strstarts(symname, "_savevr_") ||
586 strcmp(symname, ".TOC.") == 0)
587 return 1;
588 /* Do not ignore this symbol */
589 return 0;
590}
591
592static void handle_symbol(struct module *mod, struct elf_info *info,
593 const Elf_Sym *sym, const char *symname)
594{
595 switch (sym->st_shndx) {
596 case SHN_COMMON:
597 if (strstarts(symname, "__gnu_lto_")) {
598 /* Should warn here, but modpost runs before the linker */
599 } else
600 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
601 break;
602 case SHN_UNDEF:
603 /* undefined symbol */
604 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
605 ELF_ST_BIND(sym->st_info) != STB_WEAK)
606 break;
607 if (ignore_undef_symbol(info, symname))
608 break;
609 if (info->hdr->e_machine == EM_SPARC ||
610 info->hdr->e_machine == EM_SPARCV9) {
611 /* Ignore register directives. */
612 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
613 break;
614 if (symname[0] == '.') {
615 char *munged = xstrdup(symname);
616 munged[0] = '_';
617 munged[1] = toupper(munged[1]);
618 symname = munged;
619 }
620 }
621
622 sym_add_unresolved(symname, mod,
623 ELF_ST_BIND(sym->st_info) == STB_WEAK);
624 break;
625 default:
626 if (strcmp(symname, "init_module") == 0)
627 mod->has_init = true;
628 if (strcmp(symname, "cleanup_module") == 0)
629 mod->has_cleanup = true;
630 break;
631 }
632}
633
634/**
635 * Parse tag=value strings from .modinfo section
636 **/
637static char *next_string(char *string, unsigned long *secsize)
638{
639 /* Skip non-zero chars */
640 while (string[0]) {
641 string++;
642 if ((*secsize)-- <= 1)
643 return NULL;
644 }
645
646 /* Skip any zero padding. */
647 while (!string[0]) {
648 string++;
649 if ((*secsize)-- <= 1)
650 return NULL;
651 }
652 return string;
653}
654
655static char *get_next_modinfo(struct elf_info *info, const char *tag,
656 char *prev)
657{
658 char *p;
659 unsigned int taglen = strlen(tag);
660 char *modinfo = info->modinfo;
661 unsigned long size = info->modinfo_len;
662
663 if (prev) {
664 size -= prev - modinfo;
665 modinfo = next_string(prev, &size);
666 }
667
668 for (p = modinfo; p; p = next_string(p, &size)) {
669 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
670 return p + taglen + 1;
671 }
672 return NULL;
673}
674
675static char *get_modinfo(struct elf_info *info, const char *tag)
676
677{
678 return get_next_modinfo(info, tag, NULL);
679}
680
681static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
682{
683 return sym ? elf->strtab + sym->st_name : "";
684}
685
686/*
687 * Check whether the 'string' argument matches one of the 'patterns',
688 * an array of shell wildcard patterns (glob).
689 *
690 * Return true is there is a match.
691 */
692static bool match(const char *string, const char *const patterns[])
693{
694 const char *pattern;
695
696 while ((pattern = *patterns++)) {
697 if (!fnmatch(pattern, string, 0))
698 return true;
699 }
700
701 return false;
702}
703
704/* useful to pass patterns to match() directly */
705#define PATTERNS(...) \
706 ({ \
707 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
708 patterns; \
709 })
710
711/* sections that we do not want to do full section mismatch check on */
712static const char *const section_white_list[] =
713{
714 ".comment*",
715 ".debug*",
716 ".zdebug*", /* Compressed debug sections. */
717 ".GCC.command.line", /* record-gcc-switches */
718 ".mdebug*", /* alpha, score, mips etc. */
719 ".pdr", /* alpha, score, mips etc. */
720 ".stab*",
721 ".note*",
722 ".got*",
723 ".toc*",
724 ".xt.prop", /* xtensa */
725 ".xt.lit", /* xtensa */
726 ".arcextmap*", /* arc */
727 ".gnu.linkonce.arcext*", /* arc : modules */
728 ".cmem*", /* EZchip */
729 ".fmt_slot*", /* EZchip */
730 ".gnu.lto*",
731 ".discard.*",
732 ".llvm.call-graph-profile", /* call graph */
733 NULL
734};
735
736/*
737 * This is used to find sections missing the SHF_ALLOC flag.
738 * The cause of this is often a section specified in assembler
739 * without "ax" / "aw".
740 */
741static void check_section(const char *modname, struct elf_info *elf,
742 Elf_Shdr *sechdr)
743{
744 const char *sec = sech_name(elf, sechdr);
745
746 if (sechdr->sh_type == SHT_PROGBITS &&
747 !(sechdr->sh_flags & SHF_ALLOC) &&
748 !match(sec, section_white_list)) {
749 warn("%s (%s): unexpected non-allocatable section.\n"
750 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
751 "Note that for example <linux/init.h> contains\n"
752 "section definitions for use in .S files.\n\n",
753 modname, sec);
754 }
755}
756
757
758
759#define ALL_INIT_DATA_SECTIONS \
760 ".init.setup", ".init.rodata", ".init.data"
761
762#define ALL_PCI_INIT_SECTIONS \
763 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
764 ".pci_fixup_enable", ".pci_fixup_resume", \
765 ".pci_fixup_resume_early", ".pci_fixup_suspend"
766
767#define ALL_INIT_SECTIONS ".init.*"
768#define ALL_EXIT_SECTIONS ".exit.*"
769
770#define DATA_SECTIONS ".data", ".data.rel"
771#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
772 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
773 ".ltext", ".ltext.*"
774#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
775 ".fixup", ".entry.text", ".exception.text", \
776 ".coldtext", ".softirqentry.text", ".irqentry.text"
777
778#define ALL_TEXT_SECTIONS ".init.text", ".exit.text", \
779 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
780
781enum mismatch {
782 TEXTDATA_TO_ANY_INIT_EXIT,
783 XXXINIT_TO_SOME_INIT,
784 ANY_INIT_TO_ANY_EXIT,
785 ANY_EXIT_TO_ANY_INIT,
786 EXTABLE_TO_NON_TEXT,
787};
788
789/**
790 * Describe how to match sections on different criteria:
791 *
792 * @fromsec: Array of sections to be matched.
793 *
794 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
795 * this array is forbidden (black-list). Can be empty.
796 *
797 * @good_tosec: Relocations applied to a section in @fromsec must be
798 * targeting sections in this array (white-list). Can be empty.
799 *
800 * @mismatch: Type of mismatch.
801 */
802struct sectioncheck {
803 const char *fromsec[20];
804 const char *bad_tosec[20];
805 const char *good_tosec[20];
806 enum mismatch mismatch;
807};
808
809static const struct sectioncheck sectioncheck[] = {
810/* Do not reference init/exit code/data from
811 * normal code and data
812 */
813{
814 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
815 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
816 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
817},
818/* Do not use exit code/data from init code */
819{
820 .fromsec = { ALL_INIT_SECTIONS, NULL },
821 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
822 .mismatch = ANY_INIT_TO_ANY_EXIT,
823},
824/* Do not use init code/data from exit code */
825{
826 .fromsec = { ALL_EXIT_SECTIONS, NULL },
827 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
828 .mismatch = ANY_EXIT_TO_ANY_INIT,
829},
830{
831 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
832 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
833 .mismatch = ANY_INIT_TO_ANY_EXIT,
834},
835{
836 .fromsec = { "__ex_table", NULL },
837 /* If you're adding any new black-listed sections in here, consider
838 * adding a special 'printer' for them in scripts/check_extable.
839 */
840 .bad_tosec = { ".altinstr_replacement", NULL },
841 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
842 .mismatch = EXTABLE_TO_NON_TEXT,
843}
844};
845
846static const struct sectioncheck *section_mismatch(
847 const char *fromsec, const char *tosec)
848{
849 int i;
850
851 /*
852 * The target section could be the SHT_NUL section when we're
853 * handling relocations to un-resolved symbols, trying to match it
854 * doesn't make much sense and causes build failures on parisc
855 * architectures.
856 */
857 if (*tosec == '\0')
858 return NULL;
859
860 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
861 const struct sectioncheck *check = §ioncheck[i];
862
863 if (match(fromsec, check->fromsec)) {
864 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
865 return check;
866 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
867 return check;
868 }
869 }
870 return NULL;
871}
872
873/**
874 * Whitelist to allow certain references to pass with no warning.
875 *
876 * Pattern 1:
877 * If a module parameter is declared __initdata and permissions=0
878 * then this is legal despite the warning generated.
879 * We cannot see value of permissions here, so just ignore
880 * this pattern.
881 * The pattern is identified by:
882 * tosec = .init.data
883 * fromsec = .data*
884 * atsym =__param*
885 *
886 * Pattern 1a:
887 * module_param_call() ops can refer to __init set function if permissions=0
888 * The pattern is identified by:
889 * tosec = .init.text
890 * fromsec = .data*
891 * atsym = __param_ops_*
892 *
893 * Pattern 3:
894 * Whitelist all references from .head.text to any init section
895 *
896 * Pattern 4:
897 * Some symbols belong to init section but still it is ok to reference
898 * these from non-init sections as these symbols don't have any memory
899 * allocated for them and symbol address and value are same. So even
900 * if init section is freed, its ok to reference those symbols.
901 * For ex. symbols marking the init section boundaries.
902 * This pattern is identified by
903 * refsymname = __init_begin, _sinittext, _einittext
904 *
905 * Pattern 5:
906 * GCC may optimize static inlines when fed constant arg(s) resulting
907 * in functions like cpumask_empty() -- generating an associated symbol
908 * cpumask_empty.constprop.3 that appears in the audit. If the const that
909 * is passed in comes from __init, like say nmi_ipi_mask, we get a
910 * meaningless section warning. May need to add isra symbols too...
911 * This pattern is identified by
912 * tosec = init section
913 * fromsec = text section
914 * refsymname = *.constprop.*
915 *
916 **/
917static int secref_whitelist(const char *fromsec, const char *fromsym,
918 const char *tosec, const char *tosym)
919{
920 /* Check for pattern 1 */
921 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
922 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
923 strstarts(fromsym, "__param"))
924 return 0;
925
926 /* Check for pattern 1a */
927 if (strcmp(tosec, ".init.text") == 0 &&
928 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
929 strstarts(fromsym, "__param_ops_"))
930 return 0;
931
932 /* symbols in data sections that may refer to any init/exit sections */
933 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
934 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
935 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
936 return 0;
937
938 /* Check for pattern 3 */
939 if (strstarts(fromsec, ".head.text") &&
940 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
941 return 0;
942
943 /* Check for pattern 4 */
944 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
945 return 0;
946
947 /* Check for pattern 5 */
948 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
949 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
950 match(fromsym, PATTERNS("*.constprop.*")))
951 return 0;
952
953 return 1;
954}
955
956static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
957 unsigned int secndx)
958{
959 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
960}
961
962static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
963{
964 Elf_Sym *new_sym;
965
966 /* If the supplied symbol has a valid name, return it */
967 if (is_valid_name(elf, sym))
968 return sym;
969
970 /*
971 * Strive to find a better symbol name, but the resulting name may not
972 * match the symbol referenced in the original code.
973 */
974 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
975 true, 20);
976 return new_sym ? new_sym : sym;
977}
978
979static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
980{
981 if (secndx >= elf->num_sections)
982 return false;
983
984 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
985}
986
987static void default_mismatch_handler(const char *modname, struct elf_info *elf,
988 const struct sectioncheck* const mismatch,
989 Elf_Sym *tsym,
990 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
991 const char *tosec, Elf_Addr taddr)
992{
993 Elf_Sym *from;
994 const char *tosym;
995 const char *fromsym;
996 char taddr_str[16];
997
998 from = find_fromsym(elf, faddr, fsecndx);
999 fromsym = sym_name(elf, from);
1000
1001 tsym = find_tosym(elf, taddr, tsym);
1002 tosym = sym_name(elf, tsym);
1003
1004 /* check whitelist - we may ignore it */
1005 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1006 return;
1007
1008 sec_mismatch_count++;
1009
1010 if (!tosym[0])
1011 snprintf(taddr_str, sizeof(taddr_str), "0x%x", (unsigned int)taddr);
1012
1013 /*
1014 * The format for the reference source: <symbol_name>+<offset> or <address>
1015 * The format for the reference destination: <symbol_name> or <address>
1016 */
1017 warn("%s: section mismatch in reference: %s%s0x%x (section: %s) -> %s (section: %s)\n",
1018 modname, fromsym, fromsym[0] ? "+" : "",
1019 (unsigned int)(faddr - (fromsym[0] ? from->st_value : 0)),
1020 fromsec, tosym[0] ? tosym : taddr_str, tosec);
1021
1022 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1023 if (match(tosec, mismatch->bad_tosec))
1024 fatal("The relocation at %s+0x%lx references\n"
1025 "section \"%s\" which is black-listed.\n"
1026 "Something is seriously wrong and should be fixed.\n"
1027 "You might get more information about where this is\n"
1028 "coming from by using scripts/check_extable.sh %s\n",
1029 fromsec, (long)faddr, tosec, modname);
1030 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1031 warn("The relocation at %s+0x%lx references\n"
1032 "section \"%s\" which is not in the list of\n"
1033 "authorized sections. If you're adding a new section\n"
1034 "and/or if this reference is valid, add \"%s\" to the\n"
1035 "list of authorized sections to jump to on fault.\n"
1036 "This can be achieved by adding \"%s\" to\n"
1037 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1038 fromsec, (long)faddr, tosec, tosec, tosec);
1039 else
1040 error("%s+0x%lx references non-executable section '%s'\n",
1041 fromsec, (long)faddr, tosec);
1042 }
1043}
1044
1045static void check_export_symbol(struct module *mod, struct elf_info *elf,
1046 Elf_Addr faddr, const char *secname,
1047 Elf_Sym *sym)
1048{
1049 static const char *prefix = "__export_symbol_";
1050 const char *label_name, *name, *data;
1051 Elf_Sym *label;
1052 struct symbol *s;
1053 bool is_gpl;
1054
1055 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1056 label_name = sym_name(elf, label);
1057
1058 if (!strstarts(label_name, prefix)) {
1059 error("%s: .export_symbol section contains strange symbol '%s'\n",
1060 mod->name, label_name);
1061 return;
1062 }
1063
1064 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1065 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1066 error("%s: local symbol '%s' was exported\n", mod->name,
1067 label_name + strlen(prefix));
1068 return;
1069 }
1070
1071 name = sym_name(elf, sym);
1072 if (strcmp(label_name + strlen(prefix), name)) {
1073 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1074 mod->name, name);
1075 return;
1076 }
1077
1078 data = sym_get_data(elf, label); /* license */
1079 if (!strcmp(data, "GPL")) {
1080 is_gpl = true;
1081 } else if (!strcmp(data, "")) {
1082 is_gpl = false;
1083 } else {
1084 error("%s: unknown license '%s' was specified for '%s'\n",
1085 mod->name, data, name);
1086 return;
1087 }
1088
1089 data += strlen(data) + 1; /* namespace */
1090 s = sym_add_exported(name, mod, is_gpl, data);
1091
1092 /*
1093 * We need to be aware whether we are exporting a function or
1094 * a data on some architectures.
1095 */
1096 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1097
1098 /*
1099 * For parisc64, symbols prefixed $$ from the library have the symbol type
1100 * STT_LOPROC. They should be handled as functions too.
1101 */
1102 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1103 elf->hdr->e_machine == EM_PARISC &&
1104 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1105 s->is_func = true;
1106
1107 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1108 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1109 mod->name, name);
1110 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1111 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1112 mod->name, name);
1113}
1114
1115static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1116 Elf_Sym *sym,
1117 unsigned int fsecndx, const char *fromsec,
1118 Elf_Addr faddr, Elf_Addr taddr)
1119{
1120 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1121 const struct sectioncheck *mismatch;
1122
1123 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1124 check_export_symbol(mod, elf, faddr, tosec, sym);
1125 return;
1126 }
1127
1128 mismatch = section_mismatch(fromsec, tosec);
1129 if (!mismatch)
1130 return;
1131
1132 default_mismatch_handler(mod->name, elf, mismatch, sym,
1133 fsecndx, fromsec, faddr,
1134 tosec, taddr);
1135}
1136
1137static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1138{
1139 switch (r_type) {
1140 case R_386_32:
1141 return get_unaligned_native(location);
1142 case R_386_PC32:
1143 return get_unaligned_native(location) + 4;
1144 }
1145
1146 return (Elf_Addr)(-1);
1147}
1148
1149static int32_t sign_extend32(int32_t value, int index)
1150{
1151 uint8_t shift = 31 - index;
1152
1153 return (int32_t)(value << shift) >> shift;
1154}
1155
1156static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1157{
1158 uint32_t inst, upper, lower, sign, j1, j2;
1159 int32_t offset;
1160
1161 switch (r_type) {
1162 case R_ARM_ABS32:
1163 case R_ARM_REL32:
1164 inst = get_unaligned_native((uint32_t *)loc);
1165 return inst + sym->st_value;
1166 case R_ARM_MOVW_ABS_NC:
1167 case R_ARM_MOVT_ABS:
1168 inst = get_unaligned_native((uint32_t *)loc);
1169 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1170 15);
1171 return offset + sym->st_value;
1172 case R_ARM_PC24:
1173 case R_ARM_CALL:
1174 case R_ARM_JUMP24:
1175 inst = get_unaligned_native((uint32_t *)loc);
1176 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1177 return offset + sym->st_value + 8;
1178 case R_ARM_THM_MOVW_ABS_NC:
1179 case R_ARM_THM_MOVT_ABS:
1180 upper = get_unaligned_native((uint16_t *)loc);
1181 lower = get_unaligned_native((uint16_t *)loc + 1);
1182 offset = sign_extend32(((upper & 0x000f) << 12) |
1183 ((upper & 0x0400) << 1) |
1184 ((lower & 0x7000) >> 4) |
1185 (lower & 0x00ff),
1186 15);
1187 return offset + sym->st_value;
1188 case R_ARM_THM_JUMP19:
1189 /*
1190 * Encoding T3:
1191 * S = upper[10]
1192 * imm6 = upper[5:0]
1193 * J1 = lower[13]
1194 * J2 = lower[11]
1195 * imm11 = lower[10:0]
1196 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1197 */
1198 upper = get_unaligned_native((uint16_t *)loc);
1199 lower = get_unaligned_native((uint16_t *)loc + 1);
1200
1201 sign = (upper >> 10) & 1;
1202 j1 = (lower >> 13) & 1;
1203 j2 = (lower >> 11) & 1;
1204 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1205 ((upper & 0x03f) << 12) |
1206 ((lower & 0x07ff) << 1),
1207 20);
1208 return offset + sym->st_value + 4;
1209 case R_ARM_THM_PC22:
1210 case R_ARM_THM_JUMP24:
1211 /*
1212 * Encoding T4:
1213 * S = upper[10]
1214 * imm10 = upper[9:0]
1215 * J1 = lower[13]
1216 * J2 = lower[11]
1217 * imm11 = lower[10:0]
1218 * I1 = NOT(J1 XOR S)
1219 * I2 = NOT(J2 XOR S)
1220 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1221 */
1222 upper = get_unaligned_native((uint16_t *)loc);
1223 lower = get_unaligned_native((uint16_t *)loc + 1);
1224
1225 sign = (upper >> 10) & 1;
1226 j1 = (lower >> 13) & 1;
1227 j2 = (lower >> 11) & 1;
1228 offset = sign_extend32((sign << 24) |
1229 ((~(j1 ^ sign) & 1) << 23) |
1230 ((~(j2 ^ sign) & 1) << 22) |
1231 ((upper & 0x03ff) << 12) |
1232 ((lower & 0x07ff) << 1),
1233 24);
1234 return offset + sym->st_value + 4;
1235 }
1236
1237 return (Elf_Addr)(-1);
1238}
1239
1240static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1241{
1242 uint32_t inst;
1243
1244 inst = get_unaligned_native(location);
1245 switch (r_type) {
1246 case R_MIPS_LO16:
1247 return inst & 0xffff;
1248 case R_MIPS_26:
1249 return (inst & 0x03ffffff) << 2;
1250 case R_MIPS_32:
1251 return inst;
1252 }
1253 return (Elf_Addr)(-1);
1254}
1255
1256#ifndef EM_RISCV
1257#define EM_RISCV 243
1258#endif
1259
1260#ifndef R_RISCV_SUB32
1261#define R_RISCV_SUB32 39
1262#endif
1263
1264#ifndef EM_LOONGARCH
1265#define EM_LOONGARCH 258
1266#endif
1267
1268#ifndef R_LARCH_SUB32
1269#define R_LARCH_SUB32 55
1270#endif
1271
1272#ifndef R_LARCH_RELAX
1273#define R_LARCH_RELAX 100
1274#endif
1275
1276#ifndef R_LARCH_ALIGN
1277#define R_LARCH_ALIGN 102
1278#endif
1279
1280static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1281 unsigned int *r_type, unsigned int *r_sym)
1282{
1283 typedef struct {
1284 Elf64_Word r_sym; /* Symbol index */
1285 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1286 unsigned char r_type3; /* 3rd relocation type */
1287 unsigned char r_type2; /* 2nd relocation type */
1288 unsigned char r_type; /* 1st relocation type */
1289 } Elf64_Mips_R_Info;
1290
1291 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1292
1293 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1294 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1295
1296 *r_type = mips64_r_info->r_type;
1297 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1298 return;
1299 }
1300
1301 if (is_64bit)
1302 r_info = TO_NATIVE((Elf64_Xword)r_info);
1303 else
1304 r_info = TO_NATIVE((Elf32_Word)r_info);
1305
1306 *r_type = ELF_R_TYPE(r_info);
1307 *r_sym = ELF_R_SYM(r_info);
1308}
1309
1310static void section_rela(struct module *mod, struct elf_info *elf,
1311 unsigned int fsecndx, const char *fromsec,
1312 const Elf_Rela *start, const Elf_Rela *stop)
1313{
1314 const Elf_Rela *rela;
1315
1316 for (rela = start; rela < stop; rela++) {
1317 Elf_Sym *tsym;
1318 Elf_Addr taddr, r_offset;
1319 unsigned int r_type, r_sym;
1320
1321 r_offset = TO_NATIVE(rela->r_offset);
1322 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1323
1324 tsym = elf->symtab_start + r_sym;
1325 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1326
1327 switch (elf->hdr->e_machine) {
1328 case EM_RISCV:
1329 if (!strcmp("__ex_table", fromsec) &&
1330 r_type == R_RISCV_SUB32)
1331 continue;
1332 break;
1333 case EM_LOONGARCH:
1334 switch (r_type) {
1335 case R_LARCH_SUB32:
1336 if (!strcmp("__ex_table", fromsec))
1337 continue;
1338 break;
1339 case R_LARCH_RELAX:
1340 case R_LARCH_ALIGN:
1341 /* These relocs do not refer to symbols */
1342 continue;
1343 }
1344 break;
1345 }
1346
1347 check_section_mismatch(mod, elf, tsym,
1348 fsecndx, fromsec, r_offset, taddr);
1349 }
1350}
1351
1352static void section_rel(struct module *mod, struct elf_info *elf,
1353 unsigned int fsecndx, const char *fromsec,
1354 const Elf_Rel *start, const Elf_Rel *stop)
1355{
1356 const Elf_Rel *rel;
1357
1358 for (rel = start; rel < stop; rel++) {
1359 Elf_Sym *tsym;
1360 Elf_Addr taddr, r_offset;
1361 unsigned int r_type, r_sym;
1362 void *loc;
1363
1364 r_offset = TO_NATIVE(rel->r_offset);
1365 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1366
1367 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1368 tsym = elf->symtab_start + r_sym;
1369
1370 switch (elf->hdr->e_machine) {
1371 case EM_386:
1372 taddr = addend_386_rel(loc, r_type);
1373 break;
1374 case EM_ARM:
1375 taddr = addend_arm_rel(loc, tsym, r_type);
1376 break;
1377 case EM_MIPS:
1378 taddr = addend_mips_rel(loc, r_type);
1379 break;
1380 default:
1381 fatal("Please add code to calculate addend for this architecture\n");
1382 }
1383
1384 check_section_mismatch(mod, elf, tsym,
1385 fsecndx, fromsec, r_offset, taddr);
1386 }
1387}
1388
1389/**
1390 * A module includes a number of sections that are discarded
1391 * either when loaded or when used as built-in.
1392 * For loaded modules all functions marked __init and all data
1393 * marked __initdata will be discarded when the module has been initialized.
1394 * Likewise for modules used built-in the sections marked __exit
1395 * are discarded because __exit marked function are supposed to be called
1396 * only when a module is unloaded which never happens for built-in modules.
1397 * The check_sec_ref() function traverses all relocation records
1398 * to find all references to a section that reference a section that will
1399 * be discarded and warns about it.
1400 **/
1401static void check_sec_ref(struct module *mod, struct elf_info *elf)
1402{
1403 int i;
1404
1405 /* Walk through all sections */
1406 for (i = 0; i < elf->num_sections; i++) {
1407 Elf_Shdr *sechdr = &elf->sechdrs[i];
1408
1409 check_section(mod->name, elf, sechdr);
1410 /* We want to process only relocation sections and not .init */
1411 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1412 /* section to which the relocation applies */
1413 unsigned int secndx = sechdr->sh_info;
1414 const char *secname = sec_name(elf, secndx);
1415 const void *start, *stop;
1416
1417 /* If the section is known good, skip it */
1418 if (match(secname, section_white_list))
1419 continue;
1420
1421 start = sym_get_data_by_offset(elf, i, 0);
1422 stop = start + sechdr->sh_size;
1423
1424 if (sechdr->sh_type == SHT_RELA)
1425 section_rela(mod, elf, secndx, secname,
1426 start, stop);
1427 else
1428 section_rel(mod, elf, secndx, secname,
1429 start, stop);
1430 }
1431 }
1432}
1433
1434static char *remove_dot(char *s)
1435{
1436 size_t n = strcspn(s, ".");
1437
1438 if (n && s[n]) {
1439 size_t m = strspn(s + n + 1, "0123456789");
1440 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1441 s[n] = 0;
1442 }
1443 return s;
1444}
1445
1446/*
1447 * The CRCs are recorded in .*.cmd files in the form of:
1448 * #SYMVER <name> <crc>
1449 */
1450static void extract_crcs_for_object(const char *object, struct module *mod)
1451{
1452 char cmd_file[PATH_MAX];
1453 char *buf, *p;
1454 const char *base;
1455 int dirlen, ret;
1456
1457 base = strrchr(object, '/');
1458 if (base) {
1459 base++;
1460 dirlen = base - object;
1461 } else {
1462 dirlen = 0;
1463 base = object;
1464 }
1465
1466 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1467 dirlen, object, base);
1468 if (ret >= sizeof(cmd_file)) {
1469 error("%s: too long path was truncated\n", cmd_file);
1470 return;
1471 }
1472
1473 buf = read_text_file(cmd_file);
1474 p = buf;
1475
1476 while ((p = strstr(p, "\n#SYMVER "))) {
1477 char *name;
1478 size_t namelen;
1479 unsigned int crc;
1480 struct symbol *sym;
1481
1482 name = p + strlen("\n#SYMVER ");
1483
1484 p = strchr(name, ' ');
1485 if (!p)
1486 break;
1487
1488 namelen = p - name;
1489 p++;
1490
1491 if (!isdigit(*p))
1492 continue; /* skip this line */
1493
1494 crc = strtoul(p, &p, 0);
1495 if (*p != '\n')
1496 continue; /* skip this line */
1497
1498 name[namelen] = '\0';
1499
1500 /*
1501 * sym_find_with_module() may return NULL here.
1502 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1503 * Since commit e1327a127703, genksyms calculates CRCs of all
1504 * symbols, including trimmed ones. Ignore orphan CRCs.
1505 */
1506 sym = sym_find_with_module(name, mod);
1507 if (sym)
1508 sym_set_crc(sym, crc);
1509 }
1510
1511 free(buf);
1512}
1513
1514/*
1515 * The symbol versions (CRC) are recorded in the .*.cmd files.
1516 * Parse them to retrieve CRCs for the current module.
1517 */
1518static void mod_set_crcs(struct module *mod)
1519{
1520 char objlist[PATH_MAX];
1521 char *buf, *p, *obj;
1522 int ret;
1523
1524 if (mod->is_vmlinux) {
1525 strcpy(objlist, ".vmlinux.objs");
1526 } else {
1527 /* objects for a module are listed in the *.mod file. */
1528 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1529 if (ret >= sizeof(objlist)) {
1530 error("%s: too long path was truncated\n", objlist);
1531 return;
1532 }
1533 }
1534
1535 buf = read_text_file(objlist);
1536 p = buf;
1537
1538 while ((obj = strsep(&p, "\n")) && obj[0])
1539 extract_crcs_for_object(obj, mod);
1540
1541 free(buf);
1542}
1543
1544static void read_symbols(const char *modname)
1545{
1546 const char *symname;
1547 char *version;
1548 char *license;
1549 char *namespace;
1550 struct module *mod;
1551 struct elf_info info = { };
1552 Elf_Sym *sym;
1553
1554 if (!parse_elf(&info, modname))
1555 return;
1556
1557 if (!strends(modname, ".o")) {
1558 error("%s: filename must be suffixed with .o\n", modname);
1559 return;
1560 }
1561
1562 /* strip trailing .o */
1563 mod = new_module(modname, strlen(modname) - strlen(".o"));
1564
1565 if (!mod->is_vmlinux) {
1566 license = get_modinfo(&info, "license");
1567 if (!license)
1568 error("missing MODULE_LICENSE() in %s\n", modname);
1569 while (license) {
1570 if (!license_is_gpl_compatible(license)) {
1571 mod->is_gpl_compatible = false;
1572 break;
1573 }
1574 license = get_next_modinfo(&info, "license", license);
1575 }
1576
1577 namespace = get_modinfo(&info, "import_ns");
1578 while (namespace) {
1579 add_namespace(&mod->imported_namespaces, namespace);
1580 namespace = get_next_modinfo(&info, "import_ns",
1581 namespace);
1582 }
1583
1584 if (extra_warn && !get_modinfo(&info, "description"))
1585 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1586 }
1587
1588 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1589 symname = remove_dot(info.strtab + sym->st_name);
1590
1591 handle_symbol(mod, &info, sym, symname);
1592 handle_moddevtable(mod, &info, sym, symname);
1593 }
1594
1595 check_sec_ref(mod, &info);
1596
1597 if (!mod->is_vmlinux) {
1598 version = get_modinfo(&info, "version");
1599 if (version || all_versions)
1600 get_src_version(mod->name, mod->srcversion,
1601 sizeof(mod->srcversion) - 1);
1602 }
1603
1604 parse_elf_finish(&info);
1605
1606 if (modversions) {
1607 /*
1608 * Our trick to get versioning for module struct etc. - it's
1609 * never passed as an argument to an exported function, so
1610 * the automatic versioning doesn't pick it up, but it's really
1611 * important anyhow.
1612 */
1613 sym_add_unresolved("module_layout", mod, false);
1614
1615 mod_set_crcs(mod);
1616 }
1617}
1618
1619static void read_symbols_from_files(const char *filename)
1620{
1621 FILE *in = stdin;
1622 char fname[PATH_MAX];
1623
1624 in = fopen(filename, "r");
1625 if (!in)
1626 fatal("Can't open filenames file %s: %m", filename);
1627
1628 while (fgets(fname, PATH_MAX, in) != NULL) {
1629 if (strends(fname, "\n"))
1630 fname[strlen(fname)-1] = '\0';
1631 read_symbols(fname);
1632 }
1633
1634 fclose(in);
1635}
1636
1637#define SZ 500
1638
1639/* We first write the generated file into memory using the
1640 * following helper, then compare to the file on disk and
1641 * only update the later if anything changed */
1642
1643void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1644 const char *fmt, ...)
1645{
1646 char tmp[SZ];
1647 int len;
1648 va_list ap;
1649
1650 va_start(ap, fmt);
1651 len = vsnprintf(tmp, SZ, fmt, ap);
1652 buf_write(buf, tmp, len);
1653 va_end(ap);
1654}
1655
1656void buf_write(struct buffer *buf, const char *s, int len)
1657{
1658 if (buf->size - buf->pos < len) {
1659 buf->size += len + SZ;
1660 buf->p = xrealloc(buf->p, buf->size);
1661 }
1662 strncpy(buf->p + buf->pos, s, len);
1663 buf->pos += len;
1664}
1665
1666static void check_exports(struct module *mod)
1667{
1668 struct symbol *s, *exp;
1669
1670 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1671 const char *basename;
1672 exp = find_symbol(s->name);
1673 if (!exp) {
1674 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1675 modpost_log(!warn_unresolved,
1676 "\"%s\" [%s.ko] undefined!\n",
1677 s->name, mod->name);
1678 continue;
1679 }
1680 if (exp->module == mod) {
1681 error("\"%s\" [%s.ko] was exported without definition\n",
1682 s->name, mod->name);
1683 continue;
1684 }
1685
1686 exp->used = true;
1687 s->module = exp->module;
1688 s->crc_valid = exp->crc_valid;
1689 s->crc = exp->crc;
1690
1691 basename = strrchr(mod->name, '/');
1692 if (basename)
1693 basename++;
1694 else
1695 basename = mod->name;
1696
1697 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1698 modpost_log(!allow_missing_ns_imports,
1699 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1700 basename, exp->name, exp->namespace);
1701 add_namespace(&mod->missing_namespaces, exp->namespace);
1702 }
1703
1704 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1705 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1706 basename, exp->name);
1707 }
1708}
1709
1710static void handle_white_list_exports(const char *white_list)
1711{
1712 char *buf, *p, *name;
1713
1714 buf = read_text_file(white_list);
1715 p = buf;
1716
1717 while ((name = strsep(&p, "\n"))) {
1718 struct symbol *sym = find_symbol(name);
1719
1720 if (sym)
1721 sym->used = true;
1722 }
1723
1724 free(buf);
1725}
1726
1727static void check_modname_len(struct module *mod)
1728{
1729 const char *mod_name;
1730
1731 mod_name = strrchr(mod->name, '/');
1732 if (mod_name == NULL)
1733 mod_name = mod->name;
1734 else
1735 mod_name++;
1736 if (strlen(mod_name) >= MODULE_NAME_LEN)
1737 error("module name is too long [%s.ko]\n", mod->name);
1738}
1739
1740/**
1741 * Header for the generated file
1742 **/
1743static void add_header(struct buffer *b, struct module *mod)
1744{
1745 buf_printf(b, "#include <linux/module.h>\n");
1746 buf_printf(b, "#include <linux/export-internal.h>\n");
1747 buf_printf(b, "#include <linux/compiler.h>\n");
1748 buf_printf(b, "\n");
1749 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1750 buf_printf(b, "\n");
1751 buf_printf(b, "__visible struct module __this_module\n");
1752 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1753 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1754 if (mod->has_init)
1755 buf_printf(b, "\t.init = init_module,\n");
1756 if (mod->has_cleanup)
1757 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1758 "\t.exit = cleanup_module,\n"
1759 "#endif\n");
1760 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1761 buf_printf(b, "};\n");
1762
1763 if (!external_module)
1764 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1765
1766 if (strstarts(mod->name, "drivers/staging"))
1767 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1768
1769 if (strstarts(mod->name, "tools/testing"))
1770 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1771}
1772
1773static void add_exported_symbols(struct buffer *buf, struct module *mod)
1774{
1775 struct symbol *sym;
1776
1777 /* generate struct for exported symbols */
1778 buf_printf(buf, "\n");
1779 list_for_each_entry(sym, &mod->exported_symbols, list) {
1780 if (trim_unused_exports && !sym->used)
1781 continue;
1782
1783 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1784 sym->is_func ? "FUNC" : "DATA", sym->name,
1785 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1786 }
1787
1788 if (!modversions)
1789 return;
1790
1791 /* record CRCs for exported symbols */
1792 buf_printf(buf, "\n");
1793 list_for_each_entry(sym, &mod->exported_symbols, list) {
1794 if (trim_unused_exports && !sym->used)
1795 continue;
1796
1797 if (!sym->crc_valid)
1798 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1799 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1800 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1801 sym->name);
1802
1803 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1804 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1805 }
1806}
1807
1808/**
1809 * Record CRCs for unresolved symbols
1810 **/
1811static void add_versions(struct buffer *b, struct module *mod)
1812{
1813 struct symbol *s;
1814
1815 if (!modversions)
1816 return;
1817
1818 buf_printf(b, "\n");
1819 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1820 buf_printf(b, "__used __section(\"__versions\") = {\n");
1821
1822 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1823 if (!s->module)
1824 continue;
1825 if (!s->crc_valid) {
1826 warn("\"%s\" [%s.ko] has no CRC!\n",
1827 s->name, mod->name);
1828 continue;
1829 }
1830 if (strlen(s->name) >= MODULE_NAME_LEN) {
1831 error("too long symbol \"%s\" [%s.ko]\n",
1832 s->name, mod->name);
1833 break;
1834 }
1835 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1836 s->crc, s->name);
1837 }
1838
1839 buf_printf(b, "};\n");
1840}
1841
1842static void add_depends(struct buffer *b, struct module *mod)
1843{
1844 struct symbol *s;
1845 int first = 1;
1846
1847 /* Clear ->seen flag of modules that own symbols needed by this. */
1848 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1849 if (s->module)
1850 s->module->seen = s->module->is_vmlinux;
1851 }
1852
1853 buf_printf(b, "\n");
1854 buf_printf(b, "MODULE_INFO(depends, \"");
1855 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1856 const char *p;
1857 if (!s->module)
1858 continue;
1859
1860 if (s->module->seen)
1861 continue;
1862
1863 s->module->seen = true;
1864 p = strrchr(s->module->name, '/');
1865 if (p)
1866 p++;
1867 else
1868 p = s->module->name;
1869 buf_printf(b, "%s%s", first ? "" : ",", p);
1870 first = 0;
1871 }
1872 buf_printf(b, "\");\n");
1873}
1874
1875static void add_srcversion(struct buffer *b, struct module *mod)
1876{
1877 if (mod->srcversion[0]) {
1878 buf_printf(b, "\n");
1879 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1880 mod->srcversion);
1881 }
1882}
1883
1884static void write_buf(struct buffer *b, const char *fname)
1885{
1886 FILE *file;
1887
1888 if (error_occurred)
1889 return;
1890
1891 file = fopen(fname, "w");
1892 if (!file) {
1893 perror(fname);
1894 exit(1);
1895 }
1896 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1897 perror(fname);
1898 exit(1);
1899 }
1900 if (fclose(file) != 0) {
1901 perror(fname);
1902 exit(1);
1903 }
1904}
1905
1906static void write_if_changed(struct buffer *b, const char *fname)
1907{
1908 char *tmp;
1909 FILE *file;
1910 struct stat st;
1911
1912 file = fopen(fname, "r");
1913 if (!file)
1914 goto write;
1915
1916 if (fstat(fileno(file), &st) < 0)
1917 goto close_write;
1918
1919 if (st.st_size != b->pos)
1920 goto close_write;
1921
1922 tmp = xmalloc(b->pos);
1923 if (fread(tmp, 1, b->pos, file) != b->pos)
1924 goto free_write;
1925
1926 if (memcmp(tmp, b->p, b->pos) != 0)
1927 goto free_write;
1928
1929 free(tmp);
1930 fclose(file);
1931 return;
1932
1933 free_write:
1934 free(tmp);
1935 close_write:
1936 fclose(file);
1937 write:
1938 write_buf(b, fname);
1939}
1940
1941static void write_vmlinux_export_c_file(struct module *mod)
1942{
1943 struct buffer buf = { };
1944
1945 buf_printf(&buf,
1946 "#include <linux/export-internal.h>\n");
1947
1948 add_exported_symbols(&buf, mod);
1949 write_if_changed(&buf, ".vmlinux.export.c");
1950 free(buf.p);
1951}
1952
1953/* do sanity checks, and generate *.mod.c file */
1954static void write_mod_c_file(struct module *mod)
1955{
1956 struct buffer buf = { };
1957 struct module_alias *alias, *next;
1958 char fname[PATH_MAX];
1959 int ret;
1960
1961 add_header(&buf, mod);
1962 add_exported_symbols(&buf, mod);
1963 add_versions(&buf, mod);
1964 add_depends(&buf, mod);
1965
1966 buf_printf(&buf, "\n");
1967 list_for_each_entry_safe(alias, next, &mod->aliases, node) {
1968 buf_printf(&buf, "MODULE_ALIAS(\"%s\");\n", alias->str);
1969 list_del(&alias->node);
1970 free(alias);
1971 }
1972
1973 add_srcversion(&buf, mod);
1974
1975 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
1976 if (ret >= sizeof(fname)) {
1977 error("%s: too long path was truncated\n", fname);
1978 goto free;
1979 }
1980
1981 write_if_changed(&buf, fname);
1982
1983free:
1984 free(buf.p);
1985}
1986
1987/* parse Module.symvers file. line format:
1988 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
1989 **/
1990static void read_dump(const char *fname)
1991{
1992 char *buf, *pos, *line;
1993
1994 buf = read_text_file(fname);
1995 if (!buf)
1996 /* No symbol versions, silently ignore */
1997 return;
1998
1999 pos = buf;
2000
2001 while ((line = get_line(&pos))) {
2002 char *symname, *namespace, *modname, *d, *export;
2003 unsigned int crc;
2004 struct module *mod;
2005 struct symbol *s;
2006 bool gpl_only;
2007
2008 if (!(symname = strchr(line, '\t')))
2009 goto fail;
2010 *symname++ = '\0';
2011 if (!(modname = strchr(symname, '\t')))
2012 goto fail;
2013 *modname++ = '\0';
2014 if (!(export = strchr(modname, '\t')))
2015 goto fail;
2016 *export++ = '\0';
2017 if (!(namespace = strchr(export, '\t')))
2018 goto fail;
2019 *namespace++ = '\0';
2020
2021 crc = strtoul(line, &d, 16);
2022 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2023 goto fail;
2024
2025 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2026 gpl_only = true;
2027 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2028 gpl_only = false;
2029 } else {
2030 error("%s: unknown license %s. skip", symname, export);
2031 continue;
2032 }
2033
2034 mod = find_module(fname, modname);
2035 if (!mod) {
2036 mod = new_module(modname, strlen(modname));
2037 mod->dump_file = fname;
2038 }
2039 s = sym_add_exported(symname, mod, gpl_only, namespace);
2040 sym_set_crc(s, crc);
2041 }
2042 free(buf);
2043 return;
2044fail:
2045 free(buf);
2046 fatal("parse error in symbol dump file\n");
2047}
2048
2049static void write_dump(const char *fname)
2050{
2051 struct buffer buf = { };
2052 struct module *mod;
2053 struct symbol *sym;
2054
2055 list_for_each_entry(mod, &modules, list) {
2056 if (mod->dump_file)
2057 continue;
2058 list_for_each_entry(sym, &mod->exported_symbols, list) {
2059 if (trim_unused_exports && !sym->used)
2060 continue;
2061
2062 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2063 sym->crc, sym->name, mod->name,
2064 sym->is_gpl_only ? "_GPL" : "",
2065 sym->namespace);
2066 }
2067 }
2068 write_buf(&buf, fname);
2069 free(buf.p);
2070}
2071
2072static void write_namespace_deps_files(const char *fname)
2073{
2074 struct module *mod;
2075 struct namespace_list *ns;
2076 struct buffer ns_deps_buf = {};
2077
2078 list_for_each_entry(mod, &modules, list) {
2079
2080 if (mod->dump_file || list_empty(&mod->missing_namespaces))
2081 continue;
2082
2083 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2084
2085 list_for_each_entry(ns, &mod->missing_namespaces, list)
2086 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2087
2088 buf_printf(&ns_deps_buf, "\n");
2089 }
2090
2091 write_if_changed(&ns_deps_buf, fname);
2092 free(ns_deps_buf.p);
2093}
2094
2095struct dump_list {
2096 struct list_head list;
2097 const char *file;
2098};
2099
2100static void check_host_endian(void)
2101{
2102 static const union {
2103 short s;
2104 char c[2];
2105 } endian_test = { .c = {0x01, 0x02} };
2106
2107 switch (endian_test.s) {
2108 case 0x0102:
2109 host_is_big_endian = true;
2110 break;
2111 case 0x0201:
2112 host_is_big_endian = false;
2113 break;
2114 default:
2115 fatal("Unknown host endian\n");
2116 }
2117}
2118
2119int main(int argc, char **argv)
2120{
2121 struct module *mod;
2122 char *missing_namespace_deps = NULL;
2123 char *unused_exports_white_list = NULL;
2124 char *dump_write = NULL, *files_source = NULL;
2125 int opt;
2126 LIST_HEAD(dump_lists);
2127 struct dump_list *dl, *dl2;
2128
2129 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2130 switch (opt) {
2131 case 'e':
2132 external_module = true;
2133 break;
2134 case 'i':
2135 dl = xmalloc(sizeof(*dl));
2136 dl->file = optarg;
2137 list_add_tail(&dl->list, &dump_lists);
2138 break;
2139 case 'M':
2140 module_enabled = true;
2141 break;
2142 case 'm':
2143 modversions = true;
2144 break;
2145 case 'n':
2146 ignore_missing_files = true;
2147 break;
2148 case 'o':
2149 dump_write = optarg;
2150 break;
2151 case 'a':
2152 all_versions = true;
2153 break;
2154 case 'T':
2155 files_source = optarg;
2156 break;
2157 case 't':
2158 trim_unused_exports = true;
2159 break;
2160 case 'u':
2161 unused_exports_white_list = optarg;
2162 break;
2163 case 'W':
2164 extra_warn = true;
2165 break;
2166 case 'w':
2167 warn_unresolved = true;
2168 break;
2169 case 'E':
2170 sec_mismatch_warn_only = false;
2171 break;
2172 case 'N':
2173 allow_missing_ns_imports = true;
2174 break;
2175 case 'd':
2176 missing_namespace_deps = optarg;
2177 break;
2178 default:
2179 exit(1);
2180 }
2181 }
2182
2183 check_host_endian();
2184
2185 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2186 read_dump(dl->file);
2187 list_del(&dl->list);
2188 free(dl);
2189 }
2190
2191 while (optind < argc)
2192 read_symbols(argv[optind++]);
2193
2194 if (files_source)
2195 read_symbols_from_files(files_source);
2196
2197 list_for_each_entry(mod, &modules, list) {
2198 if (mod->dump_file || mod->is_vmlinux)
2199 continue;
2200
2201 check_modname_len(mod);
2202 check_exports(mod);
2203 }
2204
2205 if (unused_exports_white_list)
2206 handle_white_list_exports(unused_exports_white_list);
2207
2208 list_for_each_entry(mod, &modules, list) {
2209 if (mod->dump_file)
2210 continue;
2211
2212 if (mod->is_vmlinux)
2213 write_vmlinux_export_c_file(mod);
2214 else
2215 write_mod_c_file(mod);
2216 }
2217
2218 if (missing_namespace_deps)
2219 write_namespace_deps_files(missing_namespace_deps);
2220
2221 if (dump_write)
2222 write_dump(dump_write);
2223 if (sec_mismatch_count && !sec_mismatch_warn_only)
2224 error("Section mismatches detected.\n"
2225 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2226
2227 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2228 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2229 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2230
2231 return error_occurred ? 1 : 0;
2232}