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