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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#include "modpost.h"
24#include "../../include/linux/license.h"
25
26static bool module_enabled;
27/* Are we using CONFIG_MODVERSIONS? */
28static bool modversions;
29/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30static bool all_versions;
31/* If we are modposting external module set to 1 */
32static bool external_module;
33/* Only warn about unresolved symbols */
34static bool warn_unresolved;
35
36static int sec_mismatch_count;
37static bool sec_mismatch_warn_only = true;
38/* Trim EXPORT_SYMBOLs that are unused by in-tree modules */
39static bool trim_unused_exports;
40
41/* ignore missing files */
42static bool ignore_missing_files;
43/* If set to 1, only warn (instead of error) about missing ns imports */
44static bool allow_missing_ns_imports;
45
46static bool error_occurred;
47
48static bool extra_warn;
49
50/*
51 * Cut off the warnings when there are too many. This typically occurs when
52 * vmlinux is missing. ('make modules' without building vmlinux.)
53 */
54#define MAX_UNRESOLVED_REPORTS 10
55static unsigned int nr_unresolved;
56
57/* In kernel, this size is defined in linux/module.h;
58 * here we use Elf_Addr instead of long for covering cross-compile
59 */
60
61#define MODULE_NAME_LEN (64 - sizeof(Elf_Addr))
62
63void modpost_log(enum loglevel loglevel, const char *fmt, ...)
64{
65 va_list arglist;
66
67 switch (loglevel) {
68 case LOG_WARN:
69 fprintf(stderr, "WARNING: ");
70 break;
71 case LOG_ERROR:
72 fprintf(stderr, "ERROR: ");
73 error_occurred = true;
74 break;
75 default: /* invalid loglevel, ignore */
76 break;
77 }
78
79 fprintf(stderr, "modpost: ");
80
81 va_start(arglist, fmt);
82 vfprintf(stderr, fmt, arglist);
83 va_end(arglist);
84}
85
86static inline bool strends(const char *str, const char *postfix)
87{
88 if (strlen(str) < strlen(postfix))
89 return false;
90
91 return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;
92}
93
94void *do_nofail(void *ptr, const char *expr)
95{
96 if (!ptr)
97 fatal("Memory allocation failure: %s.\n", expr);
98
99 return ptr;
100}
101
102char *read_text_file(const char *filename)
103{
104 struct stat st;
105 size_t nbytes;
106 int fd;
107 char *buf;
108
109 fd = open(filename, O_RDONLY);
110 if (fd < 0) {
111 perror(filename);
112 exit(1);
113 }
114
115 if (fstat(fd, &st) < 0) {
116 perror(filename);
117 exit(1);
118 }
119
120 buf = NOFAIL(malloc(st.st_size + 1));
121
122 nbytes = st.st_size;
123
124 while (nbytes) {
125 ssize_t bytes_read;
126
127 bytes_read = read(fd, buf, nbytes);
128 if (bytes_read < 0) {
129 perror(filename);
130 exit(1);
131 }
132
133 nbytes -= bytes_read;
134 }
135 buf[st.st_size] = '\0';
136
137 close(fd);
138
139 return buf;
140}
141
142char *get_line(char **stringp)
143{
144 char *orig = *stringp, *next;
145
146 /* do not return the unwanted extra line at EOF */
147 if (!orig || *orig == '\0')
148 return NULL;
149
150 /* don't use strsep here, it is not available everywhere */
151 next = strchr(orig, '\n');
152 if (next)
153 *next++ = '\0';
154
155 *stringp = next;
156
157 return orig;
158}
159
160/* A list of all modules we processed */
161LIST_HEAD(modules);
162
163static struct module *find_module(const char *modname)
164{
165 struct module *mod;
166
167 list_for_each_entry(mod, &modules, list) {
168 if (strcmp(mod->name, modname) == 0)
169 return mod;
170 }
171 return NULL;
172}
173
174static struct module *new_module(const char *name, size_t namelen)
175{
176 struct module *mod;
177
178 mod = NOFAIL(malloc(sizeof(*mod) + namelen + 1));
179 memset(mod, 0, sizeof(*mod));
180
181 INIT_LIST_HEAD(&mod->exported_symbols);
182 INIT_LIST_HEAD(&mod->unresolved_symbols);
183 INIT_LIST_HEAD(&mod->missing_namespaces);
184 INIT_LIST_HEAD(&mod->imported_namespaces);
185
186 memcpy(mod->name, name, namelen);
187 mod->name[namelen] = '\0';
188 mod->is_vmlinux = (strcmp(mod->name, "vmlinux") == 0);
189
190 /*
191 * Set mod->is_gpl_compatible to true by default. If MODULE_LICENSE()
192 * is missing, do not check the use for EXPORT_SYMBOL_GPL() becasue
193 * modpost will exit wiht error anyway.
194 */
195 mod->is_gpl_compatible = true;
196
197 list_add_tail(&mod->list, &modules);
198
199 return mod;
200}
201
202/* A hash of all exported symbols,
203 * struct symbol is also used for lists of unresolved symbols */
204
205#define SYMBOL_HASH_SIZE 1024
206
207struct symbol {
208 struct symbol *next;
209 struct list_head list; /* link to module::exported_symbols or module::unresolved_symbols */
210 struct module *module;
211 char *namespace;
212 unsigned int crc;
213 bool crc_valid;
214 bool weak;
215 bool is_func;
216 bool is_gpl_only; /* exported by EXPORT_SYMBOL_GPL */
217 bool used; /* there exists a user of this symbol */
218 char name[];
219};
220
221static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
222
223/* This is based on the hash algorithm from gdbm, via tdb */
224static inline unsigned int tdb_hash(const char *name)
225{
226 unsigned value; /* Used to compute the hash value. */
227 unsigned i; /* Used to cycle through random values. */
228
229 /* Set the initial value from the key size. */
230 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
231 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
232
233 return (1103515243 * value + 12345);
234}
235
236/**
237 * Allocate a new symbols for use in the hash of exported symbols or
238 * the list of unresolved symbols per module
239 **/
240static struct symbol *alloc_symbol(const char *name)
241{
242 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
243
244 memset(s, 0, sizeof(*s));
245 strcpy(s->name, name);
246
247 return s;
248}
249
250/* For the hash of exported symbols */
251static void hash_add_symbol(struct symbol *sym)
252{
253 unsigned int hash;
254
255 hash = tdb_hash(sym->name) % SYMBOL_HASH_SIZE;
256 sym->next = symbolhash[hash];
257 symbolhash[hash] = sym;
258}
259
260static void sym_add_unresolved(const char *name, struct module *mod, bool weak)
261{
262 struct symbol *sym;
263
264 sym = alloc_symbol(name);
265 sym->weak = weak;
266
267 list_add_tail(&sym->list, &mod->unresolved_symbols);
268}
269
270static struct symbol *sym_find_with_module(const char *name, struct module *mod)
271{
272 struct symbol *s;
273
274 /* For our purposes, .foo matches foo. PPC64 needs this. */
275 if (name[0] == '.')
276 name++;
277
278 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
279 if (strcmp(s->name, name) == 0 && (!mod || s->module == mod))
280 return s;
281 }
282 return NULL;
283}
284
285static struct symbol *find_symbol(const char *name)
286{
287 return sym_find_with_module(name, NULL);
288}
289
290struct namespace_list {
291 struct list_head list;
292 char namespace[];
293};
294
295static bool contains_namespace(struct list_head *head, const char *namespace)
296{
297 struct namespace_list *list;
298
299 /*
300 * The default namespace is null string "", which is always implicitly
301 * contained.
302 */
303 if (!namespace[0])
304 return true;
305
306 list_for_each_entry(list, head, list) {
307 if (!strcmp(list->namespace, namespace))
308 return true;
309 }
310
311 return false;
312}
313
314static void add_namespace(struct list_head *head, const char *namespace)
315{
316 struct namespace_list *ns_entry;
317
318 if (!contains_namespace(head, namespace)) {
319 ns_entry = NOFAIL(malloc(sizeof(*ns_entry) +
320 strlen(namespace) + 1));
321 strcpy(ns_entry->namespace, namespace);
322 list_add_tail(&ns_entry->list, head);
323 }
324}
325
326static void *sym_get_data_by_offset(const struct elf_info *info,
327 unsigned int secindex, unsigned long offset)
328{
329 Elf_Shdr *sechdr = &info->sechdrs[secindex];
330
331 return (void *)info->hdr + sechdr->sh_offset + offset;
332}
333
334void *sym_get_data(const struct elf_info *info, const Elf_Sym *sym)
335{
336 return sym_get_data_by_offset(info, get_secindex(info, sym),
337 sym->st_value);
338}
339
340static const char *sech_name(const struct elf_info *info, Elf_Shdr *sechdr)
341{
342 return sym_get_data_by_offset(info, info->secindex_strings,
343 sechdr->sh_name);
344}
345
346static const char *sec_name(const struct elf_info *info, unsigned int secindex)
347{
348 /*
349 * If sym->st_shndx is a special section index, there is no
350 * corresponding section header.
351 * Return "" if the index is out of range of info->sechdrs[] array.
352 */
353 if (secindex >= info->num_sections)
354 return "";
355
356 return sech_name(info, &info->sechdrs[secindex]);
357}
358
359#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
360
361static struct symbol *sym_add_exported(const char *name, struct module *mod,
362 bool gpl_only, const char *namespace)
363{
364 struct symbol *s = find_symbol(name);
365
366 if (s && (!external_module || s->module->is_vmlinux || s->module == mod)) {
367 error("%s: '%s' exported twice. Previous export was in %s%s\n",
368 mod->name, name, s->module->name,
369 s->module->is_vmlinux ? "" : ".ko");
370 }
371
372 s = alloc_symbol(name);
373 s->module = mod;
374 s->is_gpl_only = gpl_only;
375 s->namespace = NOFAIL(strdup(namespace));
376 list_add_tail(&s->list, &mod->exported_symbols);
377 hash_add_symbol(s);
378
379 return s;
380}
381
382static void sym_set_crc(struct symbol *sym, unsigned int crc)
383{
384 sym->crc = crc;
385 sym->crc_valid = true;
386}
387
388static void *grab_file(const char *filename, size_t *size)
389{
390 struct stat st;
391 void *map = MAP_FAILED;
392 int fd;
393
394 fd = open(filename, O_RDONLY);
395 if (fd < 0)
396 return NULL;
397 if (fstat(fd, &st))
398 goto failed;
399
400 *size = st.st_size;
401 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
402
403failed:
404 close(fd);
405 if (map == MAP_FAILED)
406 return NULL;
407 return map;
408}
409
410static void release_file(void *file, size_t size)
411{
412 munmap(file, size);
413}
414
415static int parse_elf(struct elf_info *info, const char *filename)
416{
417 unsigned int i;
418 Elf_Ehdr *hdr;
419 Elf_Shdr *sechdrs;
420 Elf_Sym *sym;
421 const char *secstrings;
422 unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;
423
424 hdr = grab_file(filename, &info->size);
425 if (!hdr) {
426 if (ignore_missing_files) {
427 fprintf(stderr, "%s: %s (ignored)\n", filename,
428 strerror(errno));
429 return 0;
430 }
431 perror(filename);
432 exit(1);
433 }
434 info->hdr = hdr;
435 if (info->size < sizeof(*hdr)) {
436 /* file too small, assume this is an empty .o file */
437 return 0;
438 }
439 /* Is this a valid ELF file? */
440 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
441 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
442 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
443 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
444 /* Not an ELF file - silently ignore it */
445 return 0;
446 }
447 /* Fix endianness in ELF header */
448 hdr->e_type = TO_NATIVE(hdr->e_type);
449 hdr->e_machine = TO_NATIVE(hdr->e_machine);
450 hdr->e_version = TO_NATIVE(hdr->e_version);
451 hdr->e_entry = TO_NATIVE(hdr->e_entry);
452 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
453 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
454 hdr->e_flags = TO_NATIVE(hdr->e_flags);
455 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
456 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
457 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
458 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
459 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
460 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
461 sechdrs = (void *)hdr + hdr->e_shoff;
462 info->sechdrs = sechdrs;
463
464 /* modpost only works for relocatable objects */
465 if (hdr->e_type != ET_REL)
466 fatal("%s: not relocatable object.", filename);
467
468 /* Check if file offset is correct */
469 if (hdr->e_shoff > info->size)
470 fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
471 (unsigned long)hdr->e_shoff, filename, info->size);
472
473 if (hdr->e_shnum == SHN_UNDEF) {
474 /*
475 * There are more than 64k sections,
476 * read count from .sh_size.
477 */
478 info->num_sections = TO_NATIVE(sechdrs[0].sh_size);
479 }
480 else {
481 info->num_sections = hdr->e_shnum;
482 }
483 if (hdr->e_shstrndx == SHN_XINDEX) {
484 info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);
485 }
486 else {
487 info->secindex_strings = hdr->e_shstrndx;
488 }
489
490 /* Fix endianness in section headers */
491 for (i = 0; i < info->num_sections; i++) {
492 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
493 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
494 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
495 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
496 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
497 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
498 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
499 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
500 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
501 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
502 }
503 /* Find symbol table. */
504 secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;
505 for (i = 1; i < info->num_sections; i++) {
506 const char *secname;
507 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
508
509 if (!nobits && sechdrs[i].sh_offset > info->size)
510 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n",
511 filename, (unsigned long)sechdrs[i].sh_offset,
512 sizeof(*hdr));
513
514 secname = secstrings + sechdrs[i].sh_name;
515 if (strcmp(secname, ".modinfo") == 0) {
516 if (nobits)
517 fatal("%s has NOBITS .modinfo\n", filename);
518 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
519 info->modinfo_len = sechdrs[i].sh_size;
520 } else if (!strcmp(secname, ".export_symbol")) {
521 info->export_symbol_secndx = i;
522 }
523
524 if (sechdrs[i].sh_type == SHT_SYMTAB) {
525 unsigned int sh_link_idx;
526 symtab_idx = i;
527 info->symtab_start = (void *)hdr +
528 sechdrs[i].sh_offset;
529 info->symtab_stop = (void *)hdr +
530 sechdrs[i].sh_offset + sechdrs[i].sh_size;
531 sh_link_idx = sechdrs[i].sh_link;
532 info->strtab = (void *)hdr +
533 sechdrs[sh_link_idx].sh_offset;
534 }
535
536 /* 32bit section no. table? ("more than 64k sections") */
537 if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {
538 symtab_shndx_idx = i;
539 info->symtab_shndx_start = (void *)hdr +
540 sechdrs[i].sh_offset;
541 info->symtab_shndx_stop = (void *)hdr +
542 sechdrs[i].sh_offset + sechdrs[i].sh_size;
543 }
544 }
545 if (!info->symtab_start)
546 fatal("%s has no symtab?\n", filename);
547
548 /* Fix endianness in symbols */
549 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
550 sym->st_shndx = TO_NATIVE(sym->st_shndx);
551 sym->st_name = TO_NATIVE(sym->st_name);
552 sym->st_value = TO_NATIVE(sym->st_value);
553 sym->st_size = TO_NATIVE(sym->st_size);
554 }
555
556 if (symtab_shndx_idx != ~0U) {
557 Elf32_Word *p;
558 if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)
559 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
560 filename, sechdrs[symtab_shndx_idx].sh_link,
561 symtab_idx);
562 /* Fix endianness */
563 for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;
564 p++)
565 *p = TO_NATIVE(*p);
566 }
567
568 symsearch_init(info);
569
570 return 1;
571}
572
573static void parse_elf_finish(struct elf_info *info)
574{
575 symsearch_finish(info);
576 release_file(info->hdr, info->size);
577}
578
579static int ignore_undef_symbol(struct elf_info *info, const char *symname)
580{
581 /* ignore __this_module, it will be resolved shortly */
582 if (strcmp(symname, "__this_module") == 0)
583 return 1;
584 /* ignore global offset table */
585 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
586 return 1;
587 if (info->hdr->e_machine == EM_PPC)
588 /* Special register function linked on all modules during final link of .ko */
589 if (strstarts(symname, "_restgpr_") ||
590 strstarts(symname, "_savegpr_") ||
591 strstarts(symname, "_rest32gpr_") ||
592 strstarts(symname, "_save32gpr_") ||
593 strstarts(symname, "_restvr_") ||
594 strstarts(symname, "_savevr_"))
595 return 1;
596 if (info->hdr->e_machine == EM_PPC64)
597 /* Special register function linked on all modules during final link of .ko */
598 if (strstarts(symname, "_restgpr0_") ||
599 strstarts(symname, "_savegpr0_") ||
600 strstarts(symname, "_restvr_") ||
601 strstarts(symname, "_savevr_") ||
602 strcmp(symname, ".TOC.") == 0)
603 return 1;
604
605 if (info->hdr->e_machine == EM_S390)
606 /* Expoline thunks are linked on all kernel modules during final link of .ko */
607 if (strstarts(symname, "__s390_indirect_jump_r"))
608 return 1;
609 /* Do not ignore this symbol */
610 return 0;
611}
612
613static void handle_symbol(struct module *mod, struct elf_info *info,
614 const Elf_Sym *sym, const char *symname)
615{
616 switch (sym->st_shndx) {
617 case SHN_COMMON:
618 if (strstarts(symname, "__gnu_lto_")) {
619 /* Should warn here, but modpost runs before the linker */
620 } else
621 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
622 break;
623 case SHN_UNDEF:
624 /* undefined symbol */
625 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
626 ELF_ST_BIND(sym->st_info) != STB_WEAK)
627 break;
628 if (ignore_undef_symbol(info, symname))
629 break;
630 if (info->hdr->e_machine == EM_SPARC ||
631 info->hdr->e_machine == EM_SPARCV9) {
632 /* Ignore register directives. */
633 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
634 break;
635 if (symname[0] == '.') {
636 char *munged = NOFAIL(strdup(symname));
637 munged[0] = '_';
638 munged[1] = toupper(munged[1]);
639 symname = munged;
640 }
641 }
642
643 sym_add_unresolved(symname, mod,
644 ELF_ST_BIND(sym->st_info) == STB_WEAK);
645 break;
646 default:
647 if (strcmp(symname, "init_module") == 0)
648 mod->has_init = true;
649 if (strcmp(symname, "cleanup_module") == 0)
650 mod->has_cleanup = true;
651 break;
652 }
653}
654
655/**
656 * Parse tag=value strings from .modinfo section
657 **/
658static char *next_string(char *string, unsigned long *secsize)
659{
660 /* Skip non-zero chars */
661 while (string[0]) {
662 string++;
663 if ((*secsize)-- <= 1)
664 return NULL;
665 }
666
667 /* Skip any zero padding. */
668 while (!string[0]) {
669 string++;
670 if ((*secsize)-- <= 1)
671 return NULL;
672 }
673 return string;
674}
675
676static char *get_next_modinfo(struct elf_info *info, const char *tag,
677 char *prev)
678{
679 char *p;
680 unsigned int taglen = strlen(tag);
681 char *modinfo = info->modinfo;
682 unsigned long size = info->modinfo_len;
683
684 if (prev) {
685 size -= prev - modinfo;
686 modinfo = next_string(prev, &size);
687 }
688
689 for (p = modinfo; p; p = next_string(p, &size)) {
690 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
691 return p + taglen + 1;
692 }
693 return NULL;
694}
695
696static char *get_modinfo(struct elf_info *info, const char *tag)
697
698{
699 return get_next_modinfo(info, tag, NULL);
700}
701
702static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
703{
704 if (sym)
705 return elf->strtab + sym->st_name;
706 else
707 return "(unknown)";
708}
709
710/*
711 * Check whether the 'string' argument matches one of the 'patterns',
712 * an array of shell wildcard patterns (glob).
713 *
714 * Return true is there is a match.
715 */
716static bool match(const char *string, const char *const patterns[])
717{
718 const char *pattern;
719
720 while ((pattern = *patterns++)) {
721 if (!fnmatch(pattern, string, 0))
722 return true;
723 }
724
725 return false;
726}
727
728/* useful to pass patterns to match() directly */
729#define PATTERNS(...) \
730 ({ \
731 static const char *const patterns[] = {__VA_ARGS__, NULL}; \
732 patterns; \
733 })
734
735/* sections that we do not want to do full section mismatch check on */
736static const char *const section_white_list[] =
737{
738 ".comment*",
739 ".debug*",
740 ".zdebug*", /* Compressed debug sections. */
741 ".GCC.command.line", /* record-gcc-switches */
742 ".mdebug*", /* alpha, score, mips etc. */
743 ".pdr", /* alpha, score, mips etc. */
744 ".stab*",
745 ".note*",
746 ".got*",
747 ".toc*",
748 ".xt.prop", /* xtensa */
749 ".xt.lit", /* xtensa */
750 ".arcextmap*", /* arc */
751 ".gnu.linkonce.arcext*", /* arc : modules */
752 ".cmem*", /* EZchip */
753 ".fmt_slot*", /* EZchip */
754 ".gnu.lto*",
755 ".discard.*",
756 ".llvm.call-graph-profile", /* call graph */
757 NULL
758};
759
760/*
761 * This is used to find sections missing the SHF_ALLOC flag.
762 * The cause of this is often a section specified in assembler
763 * without "ax" / "aw".
764 */
765static void check_section(const char *modname, struct elf_info *elf,
766 Elf_Shdr *sechdr)
767{
768 const char *sec = sech_name(elf, sechdr);
769
770 if (sechdr->sh_type == SHT_PROGBITS &&
771 !(sechdr->sh_flags & SHF_ALLOC) &&
772 !match(sec, section_white_list)) {
773 warn("%s (%s): unexpected non-allocatable section.\n"
774 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
775 "Note that for example <linux/init.h> contains\n"
776 "section definitions for use in .S files.\n\n",
777 modname, sec);
778 }
779}
780
781
782
783#define ALL_INIT_DATA_SECTIONS \
784 ".init.setup", ".init.rodata", ".meminit.rodata", \
785 ".init.data", ".meminit.data"
786
787#define ALL_PCI_INIT_SECTIONS \
788 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
789 ".pci_fixup_enable", ".pci_fixup_resume", \
790 ".pci_fixup_resume_early", ".pci_fixup_suspend"
791
792#define ALL_XXXINIT_SECTIONS ".meminit.*"
793
794#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
795#define ALL_EXIT_SECTIONS ".exit.*"
796
797#define DATA_SECTIONS ".data", ".data.rel"
798#define TEXT_SECTIONS ".text", ".text.*", ".sched.text", \
799 ".kprobes.text", ".cpuidle.text", ".noinstr.text", \
800 ".ltext", ".ltext.*"
801#define OTHER_TEXT_SECTIONS ".ref.text", ".head.text", ".spinlock.text", \
802 ".fixup", ".entry.text", ".exception.text", \
803 ".coldtext", ".softirqentry.text"
804
805#define INIT_SECTIONS ".init.*"
806
807#define ALL_TEXT_SECTIONS ".init.text", ".meminit.text", ".exit.text", \
808 TEXT_SECTIONS, OTHER_TEXT_SECTIONS
809
810enum mismatch {
811 TEXTDATA_TO_ANY_INIT_EXIT,
812 XXXINIT_TO_SOME_INIT,
813 ANY_INIT_TO_ANY_EXIT,
814 ANY_EXIT_TO_ANY_INIT,
815 EXTABLE_TO_NON_TEXT,
816};
817
818/**
819 * Describe how to match sections on different criteria:
820 *
821 * @fromsec: Array of sections to be matched.
822 *
823 * @bad_tosec: Relocations applied to a section in @fromsec to a section in
824 * this array is forbidden (black-list). Can be empty.
825 *
826 * @good_tosec: Relocations applied to a section in @fromsec must be
827 * targeting sections in this array (white-list). Can be empty.
828 *
829 * @mismatch: Type of mismatch.
830 */
831struct sectioncheck {
832 const char *fromsec[20];
833 const char *bad_tosec[20];
834 const char *good_tosec[20];
835 enum mismatch mismatch;
836};
837
838static const struct sectioncheck sectioncheck[] = {
839/* Do not reference init/exit code/data from
840 * normal code and data
841 */
842{
843 .fromsec = { TEXT_SECTIONS, DATA_SECTIONS, NULL },
844 .bad_tosec = { ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL },
845 .mismatch = TEXTDATA_TO_ANY_INIT_EXIT,
846},
847/* Do not reference init code/data from meminit code/data */
848{
849 .fromsec = { ALL_XXXINIT_SECTIONS, NULL },
850 .bad_tosec = { INIT_SECTIONS, NULL },
851 .mismatch = XXXINIT_TO_SOME_INIT,
852},
853/* Do not use exit code/data from init code */
854{
855 .fromsec = { ALL_INIT_SECTIONS, NULL },
856 .bad_tosec = { ALL_EXIT_SECTIONS, NULL },
857 .mismatch = ANY_INIT_TO_ANY_EXIT,
858},
859/* Do not use init code/data from exit code */
860{
861 .fromsec = { ALL_EXIT_SECTIONS, NULL },
862 .bad_tosec = { ALL_INIT_SECTIONS, NULL },
863 .mismatch = ANY_EXIT_TO_ANY_INIT,
864},
865{
866 .fromsec = { ALL_PCI_INIT_SECTIONS, NULL },
867 .bad_tosec = { INIT_SECTIONS, NULL },
868 .mismatch = ANY_INIT_TO_ANY_EXIT,
869},
870{
871 .fromsec = { "__ex_table", NULL },
872 /* If you're adding any new black-listed sections in here, consider
873 * adding a special 'printer' for them in scripts/check_extable.
874 */
875 .bad_tosec = { ".altinstr_replacement", NULL },
876 .good_tosec = {ALL_TEXT_SECTIONS , NULL},
877 .mismatch = EXTABLE_TO_NON_TEXT,
878}
879};
880
881static const struct sectioncheck *section_mismatch(
882 const char *fromsec, const char *tosec)
883{
884 int i;
885
886 /*
887 * The target section could be the SHT_NUL section when we're
888 * handling relocations to un-resolved symbols, trying to match it
889 * doesn't make much sense and causes build failures on parisc
890 * architectures.
891 */
892 if (*tosec == '\0')
893 return NULL;
894
895 for (i = 0; i < ARRAY_SIZE(sectioncheck); i++) {
896 const struct sectioncheck *check = §ioncheck[i];
897
898 if (match(fromsec, check->fromsec)) {
899 if (check->bad_tosec[0] && match(tosec, check->bad_tosec))
900 return check;
901 if (check->good_tosec[0] && !match(tosec, check->good_tosec))
902 return check;
903 }
904 }
905 return NULL;
906}
907
908/**
909 * Whitelist to allow certain references to pass with no warning.
910 *
911 * Pattern 1:
912 * If a module parameter is declared __initdata and permissions=0
913 * then this is legal despite the warning generated.
914 * We cannot see value of permissions here, so just ignore
915 * this pattern.
916 * The pattern is identified by:
917 * tosec = .init.data
918 * fromsec = .data*
919 * atsym =__param*
920 *
921 * Pattern 1a:
922 * module_param_call() ops can refer to __init set function if permissions=0
923 * The pattern is identified by:
924 * tosec = .init.text
925 * fromsec = .data*
926 * atsym = __param_ops_*
927 *
928 * Pattern 3:
929 * Whitelist all references from .head.text to any init section
930 *
931 * Pattern 4:
932 * Some symbols belong to init section but still it is ok to reference
933 * these from non-init sections as these symbols don't have any memory
934 * allocated for them and symbol address and value are same. So even
935 * if init section is freed, its ok to reference those symbols.
936 * For ex. symbols marking the init section boundaries.
937 * This pattern is identified by
938 * refsymname = __init_begin, _sinittext, _einittext
939 *
940 * Pattern 5:
941 * GCC may optimize static inlines when fed constant arg(s) resulting
942 * in functions like cpumask_empty() -- generating an associated symbol
943 * cpumask_empty.constprop.3 that appears in the audit. If the const that
944 * is passed in comes from __init, like say nmi_ipi_mask, we get a
945 * meaningless section warning. May need to add isra symbols too...
946 * This pattern is identified by
947 * tosec = init section
948 * fromsec = text section
949 * refsymname = *.constprop.*
950 *
951 **/
952static int secref_whitelist(const char *fromsec, const char *fromsym,
953 const char *tosec, const char *tosym)
954{
955 /* Check for pattern 1 */
956 if (match(tosec, PATTERNS(ALL_INIT_DATA_SECTIONS)) &&
957 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
958 strstarts(fromsym, "__param"))
959 return 0;
960
961 /* Check for pattern 1a */
962 if (strcmp(tosec, ".init.text") == 0 &&
963 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
964 strstarts(fromsym, "__param_ops_"))
965 return 0;
966
967 /* symbols in data sections that may refer to any init/exit sections */
968 if (match(fromsec, PATTERNS(DATA_SECTIONS)) &&
969 match(tosec, PATTERNS(ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS)) &&
970 match(fromsym, PATTERNS("*_ops", "*_probe", "*_console")))
971 return 0;
972
973 /*
974 * symbols in data sections must not refer to .exit.*, but there are
975 * quite a few offenders, so hide these unless for W=1 builds until
976 * these are fixed.
977 */
978 if (!extra_warn &&
979 match(fromsec, PATTERNS(DATA_SECTIONS)) &&
980 match(tosec, PATTERNS(ALL_EXIT_SECTIONS)) &&
981 match(fromsym, PATTERNS("*driver")))
982 return 0;
983
984 /* Check for pattern 3 */
985 if (strstarts(fromsec, ".head.text") &&
986 match(tosec, PATTERNS(ALL_INIT_SECTIONS)))
987 return 0;
988
989 /* Check for pattern 4 */
990 if (match(tosym, PATTERNS("__init_begin", "_sinittext", "_einittext")))
991 return 0;
992
993 /* Check for pattern 5 */
994 if (match(fromsec, PATTERNS(ALL_TEXT_SECTIONS)) &&
995 match(tosec, PATTERNS(ALL_INIT_SECTIONS)) &&
996 match(fromsym, PATTERNS("*.constprop.*")))
997 return 0;
998
999 return 1;
1000}
1001
1002static Elf_Sym *find_fromsym(struct elf_info *elf, Elf_Addr addr,
1003 unsigned int secndx)
1004{
1005 return symsearch_find_nearest(elf, addr, secndx, false, ~0);
1006}
1007
1008static Elf_Sym *find_tosym(struct elf_info *elf, Elf_Addr addr, Elf_Sym *sym)
1009{
1010 Elf_Sym *new_sym;
1011
1012 /* If the supplied symbol has a valid name, return it */
1013 if (is_valid_name(elf, sym))
1014 return sym;
1015
1016 /*
1017 * Strive to find a better symbol name, but the resulting name may not
1018 * match the symbol referenced in the original code.
1019 */
1020 new_sym = symsearch_find_nearest(elf, addr, get_secindex(elf, sym),
1021 true, 20);
1022 return new_sym ? new_sym : sym;
1023}
1024
1025static bool is_executable_section(struct elf_info *elf, unsigned int secndx)
1026{
1027 if (secndx >= elf->num_sections)
1028 return false;
1029
1030 return (elf->sechdrs[secndx].sh_flags & SHF_EXECINSTR) != 0;
1031}
1032
1033static void default_mismatch_handler(const char *modname, struct elf_info *elf,
1034 const struct sectioncheck* const mismatch,
1035 Elf_Sym *tsym,
1036 unsigned int fsecndx, const char *fromsec, Elf_Addr faddr,
1037 const char *tosec, Elf_Addr taddr)
1038{
1039 Elf_Sym *from;
1040 const char *tosym;
1041 const char *fromsym;
1042
1043 from = find_fromsym(elf, faddr, fsecndx);
1044 fromsym = sym_name(elf, from);
1045
1046 tsym = find_tosym(elf, taddr, tsym);
1047 tosym = sym_name(elf, tsym);
1048
1049 /* check whitelist - we may ignore it */
1050 if (!secref_whitelist(fromsec, fromsym, tosec, tosym))
1051 return;
1052
1053 sec_mismatch_count++;
1054
1055 warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n",
1056 modname, fromsym,
1057 (unsigned int)(faddr - (from ? from->st_value : 0)),
1058 fromsec, tosym, tosec);
1059
1060 if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) {
1061 if (match(tosec, mismatch->bad_tosec))
1062 fatal("The relocation at %s+0x%lx references\n"
1063 "section \"%s\" which is black-listed.\n"
1064 "Something is seriously wrong and should be fixed.\n"
1065 "You might get more information about where this is\n"
1066 "coming from by using scripts/check_extable.sh %s\n",
1067 fromsec, (long)faddr, tosec, modname);
1068 else if (is_executable_section(elf, get_secindex(elf, tsym)))
1069 warn("The relocation at %s+0x%lx references\n"
1070 "section \"%s\" which is not in the list of\n"
1071 "authorized sections. If you're adding a new section\n"
1072 "and/or if this reference is valid, add \"%s\" to the\n"
1073 "list of authorized sections to jump to on fault.\n"
1074 "This can be achieved by adding \"%s\" to\n"
1075 "OTHER_TEXT_SECTIONS in scripts/mod/modpost.c.\n",
1076 fromsec, (long)faddr, tosec, tosec, tosec);
1077 else
1078 error("%s+0x%lx references non-executable section '%s'\n",
1079 fromsec, (long)faddr, tosec);
1080 }
1081}
1082
1083static void check_export_symbol(struct module *mod, struct elf_info *elf,
1084 Elf_Addr faddr, const char *secname,
1085 Elf_Sym *sym)
1086{
1087 static const char *prefix = "__export_symbol_";
1088 const char *label_name, *name, *data;
1089 Elf_Sym *label;
1090 struct symbol *s;
1091 bool is_gpl;
1092
1093 label = find_fromsym(elf, faddr, elf->export_symbol_secndx);
1094 label_name = sym_name(elf, label);
1095
1096 if (!strstarts(label_name, prefix)) {
1097 error("%s: .export_symbol section contains strange symbol '%s'\n",
1098 mod->name, label_name);
1099 return;
1100 }
1101
1102 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
1103 ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1104 error("%s: local symbol '%s' was exported\n", mod->name,
1105 label_name + strlen(prefix));
1106 return;
1107 }
1108
1109 name = sym_name(elf, sym);
1110 if (strcmp(label_name + strlen(prefix), name)) {
1111 error("%s: .export_symbol section references '%s', but it does not seem to be an export symbol\n",
1112 mod->name, name);
1113 return;
1114 }
1115
1116 data = sym_get_data(elf, label); /* license */
1117 if (!strcmp(data, "GPL")) {
1118 is_gpl = true;
1119 } else if (!strcmp(data, "")) {
1120 is_gpl = false;
1121 } else {
1122 error("%s: unknown license '%s' was specified for '%s'\n",
1123 mod->name, data, name);
1124 return;
1125 }
1126
1127 data += strlen(data) + 1; /* namespace */
1128 s = sym_add_exported(name, mod, is_gpl, data);
1129
1130 /*
1131 * We need to be aware whether we are exporting a function or
1132 * a data on some architectures.
1133 */
1134 s->is_func = (ELF_ST_TYPE(sym->st_info) == STT_FUNC);
1135
1136 /*
1137 * For parisc64, symbols prefixed $$ from the library have the symbol type
1138 * STT_LOPROC. They should be handled as functions too.
1139 */
1140 if (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64 &&
1141 elf->hdr->e_machine == EM_PARISC &&
1142 ELF_ST_TYPE(sym->st_info) == STT_LOPROC)
1143 s->is_func = true;
1144
1145 if (match(secname, PATTERNS(ALL_INIT_SECTIONS)))
1146 warn("%s: %s: EXPORT_SYMBOL used for init symbol. Remove __init or EXPORT_SYMBOL.\n",
1147 mod->name, name);
1148 else if (match(secname, PATTERNS(ALL_EXIT_SECTIONS)))
1149 warn("%s: %s: EXPORT_SYMBOL used for exit symbol. Remove __exit or EXPORT_SYMBOL.\n",
1150 mod->name, name);
1151}
1152
1153static void check_section_mismatch(struct module *mod, struct elf_info *elf,
1154 Elf_Sym *sym,
1155 unsigned int fsecndx, const char *fromsec,
1156 Elf_Addr faddr, Elf_Addr taddr)
1157{
1158 const char *tosec = sec_name(elf, get_secindex(elf, sym));
1159 const struct sectioncheck *mismatch;
1160
1161 if (module_enabled && elf->export_symbol_secndx == fsecndx) {
1162 check_export_symbol(mod, elf, faddr, tosec, sym);
1163 return;
1164 }
1165
1166 mismatch = section_mismatch(fromsec, tosec);
1167 if (!mismatch)
1168 return;
1169
1170 default_mismatch_handler(mod->name, elf, mismatch, sym,
1171 fsecndx, fromsec, faddr,
1172 tosec, taddr);
1173}
1174
1175static Elf_Addr addend_386_rel(uint32_t *location, unsigned int r_type)
1176{
1177 switch (r_type) {
1178 case R_386_32:
1179 return TO_NATIVE(*location);
1180 case R_386_PC32:
1181 return TO_NATIVE(*location) + 4;
1182 }
1183
1184 return (Elf_Addr)(-1);
1185}
1186
1187#ifndef R_ARM_CALL
1188#define R_ARM_CALL 28
1189#endif
1190#ifndef R_ARM_JUMP24
1191#define R_ARM_JUMP24 29
1192#endif
1193
1194#ifndef R_ARM_THM_CALL
1195#define R_ARM_THM_CALL 10
1196#endif
1197#ifndef R_ARM_THM_JUMP24
1198#define R_ARM_THM_JUMP24 30
1199#endif
1200
1201#ifndef R_ARM_MOVW_ABS_NC
1202#define R_ARM_MOVW_ABS_NC 43
1203#endif
1204
1205#ifndef R_ARM_MOVT_ABS
1206#define R_ARM_MOVT_ABS 44
1207#endif
1208
1209#ifndef R_ARM_THM_MOVW_ABS_NC
1210#define R_ARM_THM_MOVW_ABS_NC 47
1211#endif
1212
1213#ifndef R_ARM_THM_MOVT_ABS
1214#define R_ARM_THM_MOVT_ABS 48
1215#endif
1216
1217#ifndef R_ARM_THM_JUMP19
1218#define R_ARM_THM_JUMP19 51
1219#endif
1220
1221static int32_t sign_extend32(int32_t value, int index)
1222{
1223 uint8_t shift = 31 - index;
1224
1225 return (int32_t)(value << shift) >> shift;
1226}
1227
1228static Elf_Addr addend_arm_rel(void *loc, Elf_Sym *sym, unsigned int r_type)
1229{
1230 uint32_t inst, upper, lower, sign, j1, j2;
1231 int32_t offset;
1232
1233 switch (r_type) {
1234 case R_ARM_ABS32:
1235 case R_ARM_REL32:
1236 inst = TO_NATIVE(*(uint32_t *)loc);
1237 return inst + sym->st_value;
1238 case R_ARM_MOVW_ABS_NC:
1239 case R_ARM_MOVT_ABS:
1240 inst = TO_NATIVE(*(uint32_t *)loc);
1241 offset = sign_extend32(((inst & 0xf0000) >> 4) | (inst & 0xfff),
1242 15);
1243 return offset + sym->st_value;
1244 case R_ARM_PC24:
1245 case R_ARM_CALL:
1246 case R_ARM_JUMP24:
1247 inst = TO_NATIVE(*(uint32_t *)loc);
1248 offset = sign_extend32((inst & 0x00ffffff) << 2, 25);
1249 return offset + sym->st_value + 8;
1250 case R_ARM_THM_MOVW_ABS_NC:
1251 case R_ARM_THM_MOVT_ABS:
1252 upper = TO_NATIVE(*(uint16_t *)loc);
1253 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1254 offset = sign_extend32(((upper & 0x000f) << 12) |
1255 ((upper & 0x0400) << 1) |
1256 ((lower & 0x7000) >> 4) |
1257 (lower & 0x00ff),
1258 15);
1259 return offset + sym->st_value;
1260 case R_ARM_THM_JUMP19:
1261 /*
1262 * Encoding T3:
1263 * S = upper[10]
1264 * imm6 = upper[5:0]
1265 * J1 = lower[13]
1266 * J2 = lower[11]
1267 * imm11 = lower[10:0]
1268 * imm32 = SignExtend(S:J2:J1:imm6:imm11:'0')
1269 */
1270 upper = TO_NATIVE(*(uint16_t *)loc);
1271 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1272
1273 sign = (upper >> 10) & 1;
1274 j1 = (lower >> 13) & 1;
1275 j2 = (lower >> 11) & 1;
1276 offset = sign_extend32((sign << 20) | (j2 << 19) | (j1 << 18) |
1277 ((upper & 0x03f) << 12) |
1278 ((lower & 0x07ff) << 1),
1279 20);
1280 return offset + sym->st_value + 4;
1281 case R_ARM_THM_CALL:
1282 case R_ARM_THM_JUMP24:
1283 /*
1284 * Encoding T4:
1285 * S = upper[10]
1286 * imm10 = upper[9:0]
1287 * J1 = lower[13]
1288 * J2 = lower[11]
1289 * imm11 = lower[10:0]
1290 * I1 = NOT(J1 XOR S)
1291 * I2 = NOT(J2 XOR S)
1292 * imm32 = SignExtend(S:I1:I2:imm10:imm11:'0')
1293 */
1294 upper = TO_NATIVE(*(uint16_t *)loc);
1295 lower = TO_NATIVE(*((uint16_t *)loc + 1));
1296
1297 sign = (upper >> 10) & 1;
1298 j1 = (lower >> 13) & 1;
1299 j2 = (lower >> 11) & 1;
1300 offset = sign_extend32((sign << 24) |
1301 ((~(j1 ^ sign) & 1) << 23) |
1302 ((~(j2 ^ sign) & 1) << 22) |
1303 ((upper & 0x03ff) << 12) |
1304 ((lower & 0x07ff) << 1),
1305 24);
1306 return offset + sym->st_value + 4;
1307 }
1308
1309 return (Elf_Addr)(-1);
1310}
1311
1312static Elf_Addr addend_mips_rel(uint32_t *location, unsigned int r_type)
1313{
1314 uint32_t inst;
1315
1316 inst = TO_NATIVE(*location);
1317 switch (r_type) {
1318 case R_MIPS_LO16:
1319 return inst & 0xffff;
1320 case R_MIPS_26:
1321 return (inst & 0x03ffffff) << 2;
1322 case R_MIPS_32:
1323 return inst;
1324 }
1325 return (Elf_Addr)(-1);
1326}
1327
1328#ifndef EM_RISCV
1329#define EM_RISCV 243
1330#endif
1331
1332#ifndef R_RISCV_SUB32
1333#define R_RISCV_SUB32 39
1334#endif
1335
1336#ifndef EM_LOONGARCH
1337#define EM_LOONGARCH 258
1338#endif
1339
1340#ifndef R_LARCH_SUB32
1341#define R_LARCH_SUB32 55
1342#endif
1343
1344#ifndef R_LARCH_RELAX
1345#define R_LARCH_RELAX 100
1346#endif
1347
1348#ifndef R_LARCH_ALIGN
1349#define R_LARCH_ALIGN 102
1350#endif
1351
1352static void get_rel_type_and_sym(struct elf_info *elf, uint64_t r_info,
1353 unsigned int *r_type, unsigned int *r_sym)
1354{
1355 typedef struct {
1356 Elf64_Word r_sym; /* Symbol index */
1357 unsigned char r_ssym; /* Special symbol for 2nd relocation */
1358 unsigned char r_type3; /* 3rd relocation type */
1359 unsigned char r_type2; /* 2nd relocation type */
1360 unsigned char r_type; /* 1st relocation type */
1361 } Elf64_Mips_R_Info;
1362
1363 bool is_64bit = (elf->hdr->e_ident[EI_CLASS] == ELFCLASS64);
1364
1365 if (elf->hdr->e_machine == EM_MIPS && is_64bit) {
1366 Elf64_Mips_R_Info *mips64_r_info = (void *)&r_info;
1367
1368 *r_type = mips64_r_info->r_type;
1369 *r_sym = TO_NATIVE(mips64_r_info->r_sym);
1370 return;
1371 }
1372
1373 if (is_64bit)
1374 r_info = TO_NATIVE((Elf64_Xword)r_info);
1375 else
1376 r_info = TO_NATIVE((Elf32_Word)r_info);
1377
1378 *r_type = ELF_R_TYPE(r_info);
1379 *r_sym = ELF_R_SYM(r_info);
1380}
1381
1382static void section_rela(struct module *mod, struct elf_info *elf,
1383 unsigned int fsecndx, const char *fromsec,
1384 const Elf_Rela *start, const Elf_Rela *stop)
1385{
1386 const Elf_Rela *rela;
1387
1388 for (rela = start; rela < stop; rela++) {
1389 Elf_Sym *tsym;
1390 Elf_Addr taddr, r_offset;
1391 unsigned int r_type, r_sym;
1392
1393 r_offset = TO_NATIVE(rela->r_offset);
1394 get_rel_type_and_sym(elf, rela->r_info, &r_type, &r_sym);
1395
1396 tsym = elf->symtab_start + r_sym;
1397 taddr = tsym->st_value + TO_NATIVE(rela->r_addend);
1398
1399 switch (elf->hdr->e_machine) {
1400 case EM_RISCV:
1401 if (!strcmp("__ex_table", fromsec) &&
1402 r_type == R_RISCV_SUB32)
1403 continue;
1404 break;
1405 case EM_LOONGARCH:
1406 switch (r_type) {
1407 case R_LARCH_SUB32:
1408 if (!strcmp("__ex_table", fromsec))
1409 continue;
1410 break;
1411 case R_LARCH_RELAX:
1412 case R_LARCH_ALIGN:
1413 /* These relocs do not refer to symbols */
1414 continue;
1415 }
1416 break;
1417 }
1418
1419 check_section_mismatch(mod, elf, tsym,
1420 fsecndx, fromsec, r_offset, taddr);
1421 }
1422}
1423
1424static void section_rel(struct module *mod, struct elf_info *elf,
1425 unsigned int fsecndx, const char *fromsec,
1426 const Elf_Rel *start, const Elf_Rel *stop)
1427{
1428 const Elf_Rel *rel;
1429
1430 for (rel = start; rel < stop; rel++) {
1431 Elf_Sym *tsym;
1432 Elf_Addr taddr, r_offset;
1433 unsigned int r_type, r_sym;
1434 void *loc;
1435
1436 r_offset = TO_NATIVE(rel->r_offset);
1437 get_rel_type_and_sym(elf, rel->r_info, &r_type, &r_sym);
1438
1439 loc = sym_get_data_by_offset(elf, fsecndx, r_offset);
1440 tsym = elf->symtab_start + r_sym;
1441
1442 switch (elf->hdr->e_machine) {
1443 case EM_386:
1444 taddr = addend_386_rel(loc, r_type);
1445 break;
1446 case EM_ARM:
1447 taddr = addend_arm_rel(loc, tsym, r_type);
1448 break;
1449 case EM_MIPS:
1450 taddr = addend_mips_rel(loc, r_type);
1451 break;
1452 default:
1453 fatal("Please add code to calculate addend for this architecture\n");
1454 }
1455
1456 check_section_mismatch(mod, elf, tsym,
1457 fsecndx, fromsec, r_offset, taddr);
1458 }
1459}
1460
1461/**
1462 * A module includes a number of sections that are discarded
1463 * either when loaded or when used as built-in.
1464 * For loaded modules all functions marked __init and all data
1465 * marked __initdata will be discarded when the module has been initialized.
1466 * Likewise for modules used built-in the sections marked __exit
1467 * are discarded because __exit marked function are supposed to be called
1468 * only when a module is unloaded which never happens for built-in modules.
1469 * The check_sec_ref() function traverses all relocation records
1470 * to find all references to a section that reference a section that will
1471 * be discarded and warns about it.
1472 **/
1473static void check_sec_ref(struct module *mod, struct elf_info *elf)
1474{
1475 int i;
1476
1477 /* Walk through all sections */
1478 for (i = 0; i < elf->num_sections; i++) {
1479 Elf_Shdr *sechdr = &elf->sechdrs[i];
1480
1481 check_section(mod->name, elf, sechdr);
1482 /* We want to process only relocation sections and not .init */
1483 if (sechdr->sh_type == SHT_REL || sechdr->sh_type == SHT_RELA) {
1484 /* section to which the relocation applies */
1485 unsigned int secndx = sechdr->sh_info;
1486 const char *secname = sec_name(elf, secndx);
1487 const void *start, *stop;
1488
1489 /* If the section is known good, skip it */
1490 if (match(secname, section_white_list))
1491 continue;
1492
1493 start = sym_get_data_by_offset(elf, i, 0);
1494 stop = start + sechdr->sh_size;
1495
1496 if (sechdr->sh_type == SHT_RELA)
1497 section_rela(mod, elf, secndx, secname,
1498 start, stop);
1499 else
1500 section_rel(mod, elf, secndx, secname,
1501 start, stop);
1502 }
1503 }
1504}
1505
1506static char *remove_dot(char *s)
1507{
1508 size_t n = strcspn(s, ".");
1509
1510 if (n && s[n]) {
1511 size_t m = strspn(s + n + 1, "0123456789");
1512 if (m && (s[n + m + 1] == '.' || s[n + m + 1] == 0))
1513 s[n] = 0;
1514 }
1515 return s;
1516}
1517
1518/*
1519 * The CRCs are recorded in .*.cmd files in the form of:
1520 * #SYMVER <name> <crc>
1521 */
1522static void extract_crcs_for_object(const char *object, struct module *mod)
1523{
1524 char cmd_file[PATH_MAX];
1525 char *buf, *p;
1526 const char *base;
1527 int dirlen, ret;
1528
1529 base = strrchr(object, '/');
1530 if (base) {
1531 base++;
1532 dirlen = base - object;
1533 } else {
1534 dirlen = 0;
1535 base = object;
1536 }
1537
1538 ret = snprintf(cmd_file, sizeof(cmd_file), "%.*s.%s.cmd",
1539 dirlen, object, base);
1540 if (ret >= sizeof(cmd_file)) {
1541 error("%s: too long path was truncated\n", cmd_file);
1542 return;
1543 }
1544
1545 buf = read_text_file(cmd_file);
1546 p = buf;
1547
1548 while ((p = strstr(p, "\n#SYMVER "))) {
1549 char *name;
1550 size_t namelen;
1551 unsigned int crc;
1552 struct symbol *sym;
1553
1554 name = p + strlen("\n#SYMVER ");
1555
1556 p = strchr(name, ' ');
1557 if (!p)
1558 break;
1559
1560 namelen = p - name;
1561 p++;
1562
1563 if (!isdigit(*p))
1564 continue; /* skip this line */
1565
1566 crc = strtoul(p, &p, 0);
1567 if (*p != '\n')
1568 continue; /* skip this line */
1569
1570 name[namelen] = '\0';
1571
1572 /*
1573 * sym_find_with_module() may return NULL here.
1574 * It typically occurs when CONFIG_TRIM_UNUSED_KSYMS=y.
1575 * Since commit e1327a127703, genksyms calculates CRCs of all
1576 * symbols, including trimmed ones. Ignore orphan CRCs.
1577 */
1578 sym = sym_find_with_module(name, mod);
1579 if (sym)
1580 sym_set_crc(sym, crc);
1581 }
1582
1583 free(buf);
1584}
1585
1586/*
1587 * The symbol versions (CRC) are recorded in the .*.cmd files.
1588 * Parse them to retrieve CRCs for the current module.
1589 */
1590static void mod_set_crcs(struct module *mod)
1591{
1592 char objlist[PATH_MAX];
1593 char *buf, *p, *obj;
1594 int ret;
1595
1596 if (mod->is_vmlinux) {
1597 strcpy(objlist, ".vmlinux.objs");
1598 } else {
1599 /* objects for a module are listed in the *.mod file. */
1600 ret = snprintf(objlist, sizeof(objlist), "%s.mod", mod->name);
1601 if (ret >= sizeof(objlist)) {
1602 error("%s: too long path was truncated\n", objlist);
1603 return;
1604 }
1605 }
1606
1607 buf = read_text_file(objlist);
1608 p = buf;
1609
1610 while ((obj = strsep(&p, "\n")) && obj[0])
1611 extract_crcs_for_object(obj, mod);
1612
1613 free(buf);
1614}
1615
1616static void read_symbols(const char *modname)
1617{
1618 const char *symname;
1619 char *version;
1620 char *license;
1621 char *namespace;
1622 struct module *mod;
1623 struct elf_info info = { };
1624 Elf_Sym *sym;
1625
1626 if (!parse_elf(&info, modname))
1627 return;
1628
1629 if (!strends(modname, ".o")) {
1630 error("%s: filename must be suffixed with .o\n", modname);
1631 return;
1632 }
1633
1634 /* strip trailing .o */
1635 mod = new_module(modname, strlen(modname) - strlen(".o"));
1636
1637 if (!mod->is_vmlinux) {
1638 license = get_modinfo(&info, "license");
1639 if (!license)
1640 error("missing MODULE_LICENSE() in %s\n", modname);
1641 while (license) {
1642 if (!license_is_gpl_compatible(license)) {
1643 mod->is_gpl_compatible = false;
1644 break;
1645 }
1646 license = get_next_modinfo(&info, "license", license);
1647 }
1648
1649 namespace = get_modinfo(&info, "import_ns");
1650 while (namespace) {
1651 add_namespace(&mod->imported_namespaces, namespace);
1652 namespace = get_next_modinfo(&info, "import_ns",
1653 namespace);
1654 }
1655 }
1656
1657 if (extra_warn && !get_modinfo(&info, "description"))
1658 warn("missing MODULE_DESCRIPTION() in %s\n", modname);
1659 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1660 symname = remove_dot(info.strtab + sym->st_name);
1661
1662 handle_symbol(mod, &info, sym, symname);
1663 handle_moddevtable(mod, &info, sym, symname);
1664 }
1665
1666 check_sec_ref(mod, &info);
1667
1668 if (!mod->is_vmlinux) {
1669 version = get_modinfo(&info, "version");
1670 if (version || all_versions)
1671 get_src_version(mod->name, mod->srcversion,
1672 sizeof(mod->srcversion) - 1);
1673 }
1674
1675 parse_elf_finish(&info);
1676
1677 if (modversions) {
1678 /*
1679 * Our trick to get versioning for module struct etc. - it's
1680 * never passed as an argument to an exported function, so
1681 * the automatic versioning doesn't pick it up, but it's really
1682 * important anyhow.
1683 */
1684 sym_add_unresolved("module_layout", mod, false);
1685
1686 mod_set_crcs(mod);
1687 }
1688}
1689
1690static void read_symbols_from_files(const char *filename)
1691{
1692 FILE *in = stdin;
1693 char fname[PATH_MAX];
1694
1695 in = fopen(filename, "r");
1696 if (!in)
1697 fatal("Can't open filenames file %s: %m", filename);
1698
1699 while (fgets(fname, PATH_MAX, in) != NULL) {
1700 if (strends(fname, "\n"))
1701 fname[strlen(fname)-1] = '\0';
1702 read_symbols(fname);
1703 }
1704
1705 fclose(in);
1706}
1707
1708#define SZ 500
1709
1710/* We first write the generated file into memory using the
1711 * following helper, then compare to the file on disk and
1712 * only update the later if anything changed */
1713
1714void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1715 const char *fmt, ...)
1716{
1717 char tmp[SZ];
1718 int len;
1719 va_list ap;
1720
1721 va_start(ap, fmt);
1722 len = vsnprintf(tmp, SZ, fmt, ap);
1723 buf_write(buf, tmp, len);
1724 va_end(ap);
1725}
1726
1727void buf_write(struct buffer *buf, const char *s, int len)
1728{
1729 if (buf->size - buf->pos < len) {
1730 buf->size += len + SZ;
1731 buf->p = NOFAIL(realloc(buf->p, buf->size));
1732 }
1733 strncpy(buf->p + buf->pos, s, len);
1734 buf->pos += len;
1735}
1736
1737static void check_exports(struct module *mod)
1738{
1739 struct symbol *s, *exp;
1740
1741 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1742 const char *basename;
1743 exp = find_symbol(s->name);
1744 if (!exp) {
1745 if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
1746 modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
1747 "\"%s\" [%s.ko] undefined!\n",
1748 s->name, mod->name);
1749 continue;
1750 }
1751 if (exp->module == mod) {
1752 error("\"%s\" [%s.ko] was exported without definition\n",
1753 s->name, mod->name);
1754 continue;
1755 }
1756
1757 exp->used = true;
1758 s->module = exp->module;
1759 s->crc_valid = exp->crc_valid;
1760 s->crc = exp->crc;
1761
1762 basename = strrchr(mod->name, '/');
1763 if (basename)
1764 basename++;
1765 else
1766 basename = mod->name;
1767
1768 if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
1769 modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
1770 "module %s uses symbol %s from namespace %s, but does not import it.\n",
1771 basename, exp->name, exp->namespace);
1772 add_namespace(&mod->missing_namespaces, exp->namespace);
1773 }
1774
1775 if (!mod->is_gpl_compatible && exp->is_gpl_only)
1776 error("GPL-incompatible module %s.ko uses GPL-only symbol '%s'\n",
1777 basename, exp->name);
1778 }
1779}
1780
1781static void handle_white_list_exports(const char *white_list)
1782{
1783 char *buf, *p, *name;
1784
1785 buf = read_text_file(white_list);
1786 p = buf;
1787
1788 while ((name = strsep(&p, "\n"))) {
1789 struct symbol *sym = find_symbol(name);
1790
1791 if (sym)
1792 sym->used = true;
1793 }
1794
1795 free(buf);
1796}
1797
1798static void check_modname_len(struct module *mod)
1799{
1800 const char *mod_name;
1801
1802 mod_name = strrchr(mod->name, '/');
1803 if (mod_name == NULL)
1804 mod_name = mod->name;
1805 else
1806 mod_name++;
1807 if (strlen(mod_name) >= MODULE_NAME_LEN)
1808 error("module name is too long [%s.ko]\n", mod->name);
1809}
1810
1811/**
1812 * Header for the generated file
1813 **/
1814static void add_header(struct buffer *b, struct module *mod)
1815{
1816 buf_printf(b, "#include <linux/module.h>\n");
1817 /*
1818 * Include build-salt.h after module.h in order to
1819 * inherit the definitions.
1820 */
1821 buf_printf(b, "#define INCLUDE_VERMAGIC\n");
1822 buf_printf(b, "#include <linux/build-salt.h>\n");
1823 buf_printf(b, "#include <linux/elfnote-lto.h>\n");
1824 buf_printf(b, "#include <linux/export-internal.h>\n");
1825 buf_printf(b, "#include <linux/vermagic.h>\n");
1826 buf_printf(b, "#include <linux/compiler.h>\n");
1827 buf_printf(b, "\n");
1828 buf_printf(b, "#ifdef CONFIG_UNWINDER_ORC\n");
1829 buf_printf(b, "#include <asm/orc_header.h>\n");
1830 buf_printf(b, "ORC_HEADER;\n");
1831 buf_printf(b, "#endif\n");
1832 buf_printf(b, "\n");
1833 buf_printf(b, "BUILD_SALT;\n");
1834 buf_printf(b, "BUILD_LTO_INFO;\n");
1835 buf_printf(b, "\n");
1836 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1837 buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
1838 buf_printf(b, "\n");
1839 buf_printf(b, "__visible struct module __this_module\n");
1840 buf_printf(b, "__section(\".gnu.linkonce.this_module\") = {\n");
1841 buf_printf(b, "\t.name = KBUILD_MODNAME,\n");
1842 if (mod->has_init)
1843 buf_printf(b, "\t.init = init_module,\n");
1844 if (mod->has_cleanup)
1845 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1846 "\t.exit = cleanup_module,\n"
1847 "#endif\n");
1848 buf_printf(b, "\t.arch = MODULE_ARCH_INIT,\n");
1849 buf_printf(b, "};\n");
1850
1851 if (!external_module)
1852 buf_printf(b, "\nMODULE_INFO(intree, \"Y\");\n");
1853
1854 buf_printf(b,
1855 "\n"
1856 "#ifdef CONFIG_MITIGATION_RETPOLINE\n"
1857 "MODULE_INFO(retpoline, \"Y\");\n"
1858 "#endif\n");
1859
1860 if (strstarts(mod->name, "drivers/staging"))
1861 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1862
1863 if (strstarts(mod->name, "tools/testing"))
1864 buf_printf(b, "\nMODULE_INFO(test, \"Y\");\n");
1865}
1866
1867static void add_exported_symbols(struct buffer *buf, struct module *mod)
1868{
1869 struct symbol *sym;
1870
1871 /* generate struct for exported symbols */
1872 buf_printf(buf, "\n");
1873 list_for_each_entry(sym, &mod->exported_symbols, list) {
1874 if (trim_unused_exports && !sym->used)
1875 continue;
1876
1877 buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
1878 sym->is_func ? "FUNC" : "DATA", sym->name,
1879 sym->is_gpl_only ? "_gpl" : "", sym->namespace);
1880 }
1881
1882 if (!modversions)
1883 return;
1884
1885 /* record CRCs for exported symbols */
1886 buf_printf(buf, "\n");
1887 list_for_each_entry(sym, &mod->exported_symbols, list) {
1888 if (trim_unused_exports && !sym->used)
1889 continue;
1890
1891 if (!sym->crc_valid)
1892 warn("EXPORT symbol \"%s\" [%s%s] version generation failed, symbol will not be versioned.\n"
1893 "Is \"%s\" prototyped in <asm/asm-prototypes.h>?\n",
1894 sym->name, mod->name, mod->is_vmlinux ? "" : ".ko",
1895 sym->name);
1896
1897 buf_printf(buf, "SYMBOL_CRC(%s, 0x%08x, \"%s\");\n",
1898 sym->name, sym->crc, sym->is_gpl_only ? "_gpl" : "");
1899 }
1900}
1901
1902/**
1903 * Record CRCs for unresolved symbols
1904 **/
1905static void add_versions(struct buffer *b, struct module *mod)
1906{
1907 struct symbol *s;
1908
1909 if (!modversions)
1910 return;
1911
1912 buf_printf(b, "\n");
1913 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1914 buf_printf(b, "__used __section(\"__versions\") = {\n");
1915
1916 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1917 if (!s->module)
1918 continue;
1919 if (!s->crc_valid) {
1920 warn("\"%s\" [%s.ko] has no CRC!\n",
1921 s->name, mod->name);
1922 continue;
1923 }
1924 if (strlen(s->name) >= MODULE_NAME_LEN) {
1925 error("too long symbol \"%s\" [%s.ko]\n",
1926 s->name, mod->name);
1927 break;
1928 }
1929 buf_printf(b, "\t{ %#8x, \"%s\" },\n",
1930 s->crc, s->name);
1931 }
1932
1933 buf_printf(b, "};\n");
1934}
1935
1936static void add_depends(struct buffer *b, struct module *mod)
1937{
1938 struct symbol *s;
1939 int first = 1;
1940
1941 /* Clear ->seen flag of modules that own symbols needed by this. */
1942 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1943 if (s->module)
1944 s->module->seen = s->module->is_vmlinux;
1945 }
1946
1947 buf_printf(b, "\n");
1948 buf_printf(b, "MODULE_INFO(depends, \"");
1949 list_for_each_entry(s, &mod->unresolved_symbols, list) {
1950 const char *p;
1951 if (!s->module)
1952 continue;
1953
1954 if (s->module->seen)
1955 continue;
1956
1957 s->module->seen = true;
1958 p = strrchr(s->module->name, '/');
1959 if (p)
1960 p++;
1961 else
1962 p = s->module->name;
1963 buf_printf(b, "%s%s", first ? "" : ",", p);
1964 first = 0;
1965 }
1966 buf_printf(b, "\");\n");
1967}
1968
1969static void add_srcversion(struct buffer *b, struct module *mod)
1970{
1971 if (mod->srcversion[0]) {
1972 buf_printf(b, "\n");
1973 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1974 mod->srcversion);
1975 }
1976}
1977
1978static void write_buf(struct buffer *b, const char *fname)
1979{
1980 FILE *file;
1981
1982 if (error_occurred)
1983 return;
1984
1985 file = fopen(fname, "w");
1986 if (!file) {
1987 perror(fname);
1988 exit(1);
1989 }
1990 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1991 perror(fname);
1992 exit(1);
1993 }
1994 if (fclose(file) != 0) {
1995 perror(fname);
1996 exit(1);
1997 }
1998}
1999
2000static void write_if_changed(struct buffer *b, const char *fname)
2001{
2002 char *tmp;
2003 FILE *file;
2004 struct stat st;
2005
2006 file = fopen(fname, "r");
2007 if (!file)
2008 goto write;
2009
2010 if (fstat(fileno(file), &st) < 0)
2011 goto close_write;
2012
2013 if (st.st_size != b->pos)
2014 goto close_write;
2015
2016 tmp = NOFAIL(malloc(b->pos));
2017 if (fread(tmp, 1, b->pos, file) != b->pos)
2018 goto free_write;
2019
2020 if (memcmp(tmp, b->p, b->pos) != 0)
2021 goto free_write;
2022
2023 free(tmp);
2024 fclose(file);
2025 return;
2026
2027 free_write:
2028 free(tmp);
2029 close_write:
2030 fclose(file);
2031 write:
2032 write_buf(b, fname);
2033}
2034
2035static void write_vmlinux_export_c_file(struct module *mod)
2036{
2037 struct buffer buf = { };
2038
2039 buf_printf(&buf,
2040 "#include <linux/export-internal.h>\n");
2041
2042 add_exported_symbols(&buf, mod);
2043 write_if_changed(&buf, ".vmlinux.export.c");
2044 free(buf.p);
2045}
2046
2047/* do sanity checks, and generate *.mod.c file */
2048static void write_mod_c_file(struct module *mod)
2049{
2050 struct buffer buf = { };
2051 char fname[PATH_MAX];
2052 int ret;
2053
2054 add_header(&buf, mod);
2055 add_exported_symbols(&buf, mod);
2056 add_versions(&buf, mod);
2057 add_depends(&buf, mod);
2058 add_moddevtable(&buf, mod);
2059 add_srcversion(&buf, mod);
2060
2061 ret = snprintf(fname, sizeof(fname), "%s.mod.c", mod->name);
2062 if (ret >= sizeof(fname)) {
2063 error("%s: too long path was truncated\n", fname);
2064 goto free;
2065 }
2066
2067 write_if_changed(&buf, fname);
2068
2069free:
2070 free(buf.p);
2071}
2072
2073/* parse Module.symvers file. line format:
2074 * 0x12345678<tab>symbol<tab>module<tab>export<tab>namespace
2075 **/
2076static void read_dump(const char *fname)
2077{
2078 char *buf, *pos, *line;
2079
2080 buf = read_text_file(fname);
2081 if (!buf)
2082 /* No symbol versions, silently ignore */
2083 return;
2084
2085 pos = buf;
2086
2087 while ((line = get_line(&pos))) {
2088 char *symname, *namespace, *modname, *d, *export;
2089 unsigned int crc;
2090 struct module *mod;
2091 struct symbol *s;
2092 bool gpl_only;
2093
2094 if (!(symname = strchr(line, '\t')))
2095 goto fail;
2096 *symname++ = '\0';
2097 if (!(modname = strchr(symname, '\t')))
2098 goto fail;
2099 *modname++ = '\0';
2100 if (!(export = strchr(modname, '\t')))
2101 goto fail;
2102 *export++ = '\0';
2103 if (!(namespace = strchr(export, '\t')))
2104 goto fail;
2105 *namespace++ = '\0';
2106
2107 crc = strtoul(line, &d, 16);
2108 if (*symname == '\0' || *modname == '\0' || *d != '\0')
2109 goto fail;
2110
2111 if (!strcmp(export, "EXPORT_SYMBOL_GPL")) {
2112 gpl_only = true;
2113 } else if (!strcmp(export, "EXPORT_SYMBOL")) {
2114 gpl_only = false;
2115 } else {
2116 error("%s: unknown license %s. skip", symname, export);
2117 continue;
2118 }
2119
2120 mod = find_module(modname);
2121 if (!mod) {
2122 mod = new_module(modname, strlen(modname));
2123 mod->from_dump = true;
2124 }
2125 s = sym_add_exported(symname, mod, gpl_only, namespace);
2126 sym_set_crc(s, crc);
2127 }
2128 free(buf);
2129 return;
2130fail:
2131 free(buf);
2132 fatal("parse error in symbol dump file\n");
2133}
2134
2135static void write_dump(const char *fname)
2136{
2137 struct buffer buf = { };
2138 struct module *mod;
2139 struct symbol *sym;
2140
2141 list_for_each_entry(mod, &modules, list) {
2142 if (mod->from_dump)
2143 continue;
2144 list_for_each_entry(sym, &mod->exported_symbols, list) {
2145 if (trim_unused_exports && !sym->used)
2146 continue;
2147
2148 buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
2149 sym->crc, sym->name, mod->name,
2150 sym->is_gpl_only ? "_GPL" : "",
2151 sym->namespace);
2152 }
2153 }
2154 write_buf(&buf, fname);
2155 free(buf.p);
2156}
2157
2158static void write_namespace_deps_files(const char *fname)
2159{
2160 struct module *mod;
2161 struct namespace_list *ns;
2162 struct buffer ns_deps_buf = {};
2163
2164 list_for_each_entry(mod, &modules, list) {
2165
2166 if (mod->from_dump || list_empty(&mod->missing_namespaces))
2167 continue;
2168
2169 buf_printf(&ns_deps_buf, "%s.ko:", mod->name);
2170
2171 list_for_each_entry(ns, &mod->missing_namespaces, list)
2172 buf_printf(&ns_deps_buf, " %s", ns->namespace);
2173
2174 buf_printf(&ns_deps_buf, "\n");
2175 }
2176
2177 write_if_changed(&ns_deps_buf, fname);
2178 free(ns_deps_buf.p);
2179}
2180
2181struct dump_list {
2182 struct list_head list;
2183 const char *file;
2184};
2185
2186int main(int argc, char **argv)
2187{
2188 struct module *mod;
2189 char *missing_namespace_deps = NULL;
2190 char *unused_exports_white_list = NULL;
2191 char *dump_write = NULL, *files_source = NULL;
2192 int opt;
2193 LIST_HEAD(dump_lists);
2194 struct dump_list *dl, *dl2;
2195
2196 while ((opt = getopt(argc, argv, "ei:MmnT:to:au:WwENd:")) != -1) {
2197 switch (opt) {
2198 case 'e':
2199 external_module = true;
2200 break;
2201 case 'i':
2202 dl = NOFAIL(malloc(sizeof(*dl)));
2203 dl->file = optarg;
2204 list_add_tail(&dl->list, &dump_lists);
2205 break;
2206 case 'M':
2207 module_enabled = true;
2208 break;
2209 case 'm':
2210 modversions = true;
2211 break;
2212 case 'n':
2213 ignore_missing_files = true;
2214 break;
2215 case 'o':
2216 dump_write = optarg;
2217 break;
2218 case 'a':
2219 all_versions = true;
2220 break;
2221 case 'T':
2222 files_source = optarg;
2223 break;
2224 case 't':
2225 trim_unused_exports = true;
2226 break;
2227 case 'u':
2228 unused_exports_white_list = optarg;
2229 break;
2230 case 'W':
2231 extra_warn = true;
2232 break;
2233 case 'w':
2234 warn_unresolved = true;
2235 break;
2236 case 'E':
2237 sec_mismatch_warn_only = false;
2238 break;
2239 case 'N':
2240 allow_missing_ns_imports = true;
2241 break;
2242 case 'd':
2243 missing_namespace_deps = optarg;
2244 break;
2245 default:
2246 exit(1);
2247 }
2248 }
2249
2250 list_for_each_entry_safe(dl, dl2, &dump_lists, list) {
2251 read_dump(dl->file);
2252 list_del(&dl->list);
2253 free(dl);
2254 }
2255
2256 while (optind < argc)
2257 read_symbols(argv[optind++]);
2258
2259 if (files_source)
2260 read_symbols_from_files(files_source);
2261
2262 list_for_each_entry(mod, &modules, list) {
2263 if (mod->from_dump || mod->is_vmlinux)
2264 continue;
2265
2266 check_modname_len(mod);
2267 check_exports(mod);
2268 }
2269
2270 if (unused_exports_white_list)
2271 handle_white_list_exports(unused_exports_white_list);
2272
2273 list_for_each_entry(mod, &modules, list) {
2274 if (mod->from_dump)
2275 continue;
2276
2277 if (mod->is_vmlinux)
2278 write_vmlinux_export_c_file(mod);
2279 else
2280 write_mod_c_file(mod);
2281 }
2282
2283 if (missing_namespace_deps)
2284 write_namespace_deps_files(missing_namespace_deps);
2285
2286 if (dump_write)
2287 write_dump(dump_write);
2288 if (sec_mismatch_count && !sec_mismatch_warn_only)
2289 error("Section mismatches detected.\n"
2290 "Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
2291
2292 if (nr_unresolved > MAX_UNRESOLVED_REPORTS)
2293 warn("suppressed %u unresolved symbol warnings because there were too many)\n",
2294 nr_unresolved - MAX_UNRESOLVED_REPORTS);
2295
2296 return error_occurred ? 1 : 0;
2297}