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