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kbuild: Fix modpost segfault
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / scripts / mod / modpost.c
blob17c95a384285755bc0ded3efcd2714cb75ad4dff
1 /* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
7 *
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
10 *
11 * Usage: modpost vmlinux module1.o module2.o ...
12 */
13
14 #define _GNU_SOURCE
15 #include <stdio.h>
16 #include <ctype.h>
17 #include "modpost.h"
18 #include "../../include/generated/autoconf.h"
19 #include "../../include/linux/license.h"
20
21 /* Some toolchains use a `_' prefix for all user symbols. */
22 #ifdef CONFIG_SYMBOL_PREFIX
23 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
24 #else
25 #define MODULE_SYMBOL_PREFIX ""
26 #endif
27
28
29 /* Are we using CONFIG_MODVERSIONS? */
30 int modversions = 0;
31 /* Warn about undefined symbols? (do so if we have vmlinux) */
32 int have_vmlinux = 0;
33 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
34 static int all_versions = 0;
35 /* If we are modposting external module set to 1 */
36 static int external_module = 0;
37 /* Warn about section mismatch in vmlinux if set to 1 */
38 static int vmlinux_section_warnings = 1;
39 /* Only warn about unresolved symbols */
40 static int warn_unresolved = 0;
41 /* How a symbol is exported */
42 static int sec_mismatch_count = 0;
43 static int sec_mismatch_verbose = 1;
44
45 enum export {
46 export_plain, export_unused, export_gpl,
47 export_unused_gpl, export_gpl_future, export_unknown
48 };
49
50 #define PRINTF __attribute__ ((format (printf, 1, 2)))
51
52 PRINTF void fatal(const char *fmt, ...)
53 {
54 va_list arglist;
55
56 fprintf(stderr, "FATAL: ");
57
58 va_start(arglist, fmt);
59 vfprintf(stderr, fmt, arglist);
60 va_end(arglist);
61
62 exit(1);
63 }
64
65 PRINTF void warn(const char *fmt, ...)
66 {
67 va_list arglist;
68
69 fprintf(stderr, "WARNING: ");
70
71 va_start(arglist, fmt);
72 vfprintf(stderr, fmt, arglist);
73 va_end(arglist);
74 }
75
76 PRINTF void merror(const char *fmt, ...)
77 {
78 va_list arglist;
79
80 fprintf(stderr, "ERROR: ");
81
82 va_start(arglist, fmt);
83 vfprintf(stderr, fmt, arglist);
84 va_end(arglist);
85 }
86
87 static int is_vmlinux(const char *modname)
88 {
89 const char *myname;
90
91 myname = strrchr(modname, '/');
92 if (myname)
93 myname++;
94 else
95 myname = modname;
96
97 return (strcmp(myname, "vmlinux") == 0) ||
98 (strcmp(myname, "vmlinux.o") == 0);
99 }
100
101 void *do_nofail(void *ptr, const char *expr)
102 {
103 if (!ptr)
104 fatal("modpost: Memory allocation failure: %s.\n", expr);
105
106 return ptr;
107 }
108
109 /* A list of all modules we processed */
110 static struct module *modules;
111
112 static struct module *find_module(char *modname)
113 {
114 struct module *mod;
115
116 for (mod = modules; mod; mod = mod->next)
117 if (strcmp(mod->name, modname) == 0)
118 break;
119 return mod;
120 }
121
122 static struct module *new_module(char *modname)
123 {
124 struct module *mod;
125 char *p, *s;
126
127 mod = NOFAIL(malloc(sizeof(*mod)));
128 memset(mod, 0, sizeof(*mod));
129 p = NOFAIL(strdup(modname));
130
131 /* strip trailing .o */
132 s = strrchr(p, '.');
133 if (s != NULL)
134 if (strcmp(s, ".o") == 0)
135 *s = '\0';
136
137 /* add to list */
138 mod->name = p;
139 mod->gpl_compatible = -1;
140 mod->next = modules;
141 modules = mod;
142
143 return mod;
144 }
145
146 /* A hash of all exported symbols,
147 * struct symbol is also used for lists of unresolved symbols */
148
149 #define SYMBOL_HASH_SIZE 1024
150
151 struct symbol {
152 struct symbol *next;
153 struct module *module;
154 unsigned int crc;
155 int crc_valid;
156 unsigned int weak:1;
157 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
158 unsigned int kernel:1; /* 1 if symbol is from kernel
159 * (only for external modules) **/
160 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
161 enum export export; /* Type of export */
162 char name[0];
163 };
164
165 static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
166
167 /* This is based on the hash agorithm from gdbm, via tdb */
168 static inline unsigned int tdb_hash(const char *name)
169 {
170 unsigned value; /* Used to compute the hash value. */
171 unsigned i; /* Used to cycle through random values. */
172
173 /* Set the initial value from the key size. */
174 for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
175 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
176
177 return (1103515243 * value + 12345);
178 }
179
180 /**
181 * Allocate a new symbols for use in the hash of exported symbols or
182 * the list of unresolved symbols per module
183 **/
184 static struct symbol *alloc_symbol(const char *name, unsigned int weak,
185 struct symbol *next)
186 {
187 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
188
189 memset(s, 0, sizeof(*s));
190 strcpy(s->name, name);
191 s->weak = weak;
192 s->next = next;
193 return s;
194 }
195
196 /* For the hash of exported symbols */
197 static struct symbol *new_symbol(const char *name, struct module *module,
198 enum export export)
199 {
200 unsigned int hash;
201 struct symbol *new;
202
203 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
204 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
205 new->module = module;
206 new->export = export;
207 return new;
208 }
209
210 static struct symbol *find_symbol(const char *name)
211 {
212 struct symbol *s;
213
214 /* For our purposes, .foo matches foo. PPC64 needs this. */
215 if (name[0] == '.')
216 name++;
217
218 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
219 if (strcmp(s->name, name) == 0)
220 return s;
221 }
222 return NULL;
223 }
224
225 static struct {
226 const char *str;
227 enum export export;
228 } export_list[] = {
229 { .str = "EXPORT_SYMBOL", .export = export_plain },
230 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
231 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
232 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
233 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
234 { .str = "(unknown)", .export = export_unknown },
235 };
236
237
238 static const char *export_str(enum export ex)
239 {
240 return export_list[ex].str;
241 }
242
243 static enum export export_no(const char *s)
244 {
245 int i;
246
247 if (!s)
248 return export_unknown;
249 for (i = 0; export_list[i].export != export_unknown; i++) {
250 if (strcmp(export_list[i].str, s) == 0)
251 return export_list[i].export;
252 }
253 return export_unknown;
254 }
255
256 static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
257 {
258 if (sec == elf->export_sec)
259 return export_plain;
260 else if (sec == elf->export_unused_sec)
261 return export_unused;
262 else if (sec == elf->export_gpl_sec)
263 return export_gpl;
264 else if (sec == elf->export_unused_gpl_sec)
265 return export_unused_gpl;
266 else if (sec == elf->export_gpl_future_sec)
267 return export_gpl_future;
268 else
269 return export_unknown;
270 }
271
272 /**
273 * Add an exported symbol - it may have already been added without a
274 * CRC, in this case just update the CRC
275 **/
276 static struct symbol *sym_add_exported(const char *name, struct module *mod,
277 enum export export)
278 {
279 struct symbol *s = find_symbol(name);
280
281 if (!s) {
282 s = new_symbol(name, mod, export);
283 } else {
284 if (!s->preloaded) {
285 warn("%s: '%s' exported twice. Previous export "
286 "was in %s%s\n", mod->name, name,
287 s->module->name,
288 is_vmlinux(s->module->name) ?"":".ko");
289 } else {
290 /* In case Modules.symvers was out of date */
291 s->module = mod;
292 }
293 }
294 s->preloaded = 0;
295 s->vmlinux = is_vmlinux(mod->name);
296 s->kernel = 0;
297 s->export = export;
298 return s;
299 }
300
301 static void sym_update_crc(const char *name, struct module *mod,
302 unsigned int crc, enum export export)
303 {
304 struct symbol *s = find_symbol(name);
305
306 if (!s)
307 s = new_symbol(name, mod, export);
308 s->crc = crc;
309 s->crc_valid = 1;
310 }
311
312 void *grab_file(const char *filename, unsigned long *size)
313 {
314 struct stat st;
315 void *map;
316 int fd;
317
318 fd = open(filename, O_RDONLY);
319 if (fd < 0 || fstat(fd, &st) != 0)
320 return NULL;
321
322 *size = st.st_size;
323 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
324 close(fd);
325
326 if (map == MAP_FAILED)
327 return NULL;
328 return map;
329 }
330
331 /**
332 * Return a copy of the next line in a mmap'ed file.
333 * spaces in the beginning of the line is trimmed away.
334 * Return a pointer to a static buffer.
335 **/
336 char *get_next_line(unsigned long *pos, void *file, unsigned long size)
337 {
338 static char line[4096];
339 int skip = 1;
340 size_t len = 0;
341 signed char *p = (signed char *)file + *pos;
342 char *s = line;
343
344 for (; *pos < size ; (*pos)++) {
345 if (skip && isspace(*p)) {
346 p++;
347 continue;
348 }
349 skip = 0;
350 if (*p != '\n' && (*pos < size)) {
351 len++;
352 *s++ = *p++;
353 if (len > 4095)
354 break; /* Too long, stop */
355 } else {
356 /* End of string */
357 *s = '\0';
358 return line;
359 }
360 }
361 /* End of buffer */
362 return NULL;
363 }
364
365 void release_file(void *file, unsigned long size)
366 {
367 munmap(file, size);
368 }
369
370 static int parse_elf(struct elf_info *info, const char *filename)
371 {
372 unsigned int i;
373 Elf_Ehdr *hdr;
374 Elf_Shdr *sechdrs;
375 Elf_Sym *sym;
376
377 hdr = grab_file(filename, &info->size);
378 if (!hdr) {
379 perror(filename);
380 exit(1);
381 }
382 info->hdr = hdr;
383 if (info->size < sizeof(*hdr)) {
384 /* file too small, assume this is an empty .o file */
385 return 0;
386 }
387 /* Is this a valid ELF file? */
388 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
389 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
390 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
391 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
392 /* Not an ELF file - silently ignore it */
393 return 0;
394 }
395 /* Fix endianness in ELF header */
396 hdr->e_type = TO_NATIVE(hdr->e_type);
397 hdr->e_machine = TO_NATIVE(hdr->e_machine);
398 hdr->e_version = TO_NATIVE(hdr->e_version);
399 hdr->e_entry = TO_NATIVE(hdr->e_entry);
400 hdr->e_phoff = TO_NATIVE(hdr->e_phoff);
401 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
402 hdr->e_flags = TO_NATIVE(hdr->e_flags);
403 hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);
404 hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
405 hdr->e_phnum = TO_NATIVE(hdr->e_phnum);
406 hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
407 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
408 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
409 sechdrs = (void *)hdr + hdr->e_shoff;
410 info->sechdrs = sechdrs;
411
412 /* Check if file offset is correct */
413 if (hdr->e_shoff > info->size) {
414 fatal("section header offset=%lu in file '%s' is bigger than "
415 "filesize=%lu\n", (unsigned long)hdr->e_shoff,
416 filename, info->size);
417 return 0;
418 }
419
420 /* Fix endianness in section headers */
421 for (i = 0; i < hdr->e_shnum; i++) {
422 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
423 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
424 sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);
425 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
426 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
427 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
428 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
429 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
430 sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
431 sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);
432 }
433 /* Find symbol table. */
434 for (i = 1; i < hdr->e_shnum; i++) {
435 const char *secstrings
436 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
437 const char *secname;
438 int nobits = sechdrs[i].sh_type == SHT_NOBITS;
439
440 if (!nobits && sechdrs[i].sh_offset > info->size) {
441 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
442 "sizeof(*hrd)=%zu\n", filename,
443 (unsigned long)sechdrs[i].sh_offset,
444 sizeof(*hdr));
445 return 0;
446 }
447 secname = secstrings + sechdrs[i].sh_name;
448 if (strcmp(secname, ".modinfo") == 0) {
449 if (nobits)
450 fatal("%s has NOBITS .modinfo\n", filename);
451 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
452 info->modinfo_len = sechdrs[i].sh_size;
453 } else if (strcmp(secname, "__ksymtab") == 0)
454 info->export_sec = i;
455 else if (strcmp(secname, "__ksymtab_unused") == 0)
456 info->export_unused_sec = i;
457 else if (strcmp(secname, "__ksymtab_gpl") == 0)
458 info->export_gpl_sec = i;
459 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
460 info->export_unused_gpl_sec = i;
461 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
462 info->export_gpl_future_sec = i;
463
464 if (sechdrs[i].sh_type != SHT_SYMTAB)
465 continue;
466
467 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
468 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
469 + sechdrs[i].sh_size;
470 info->strtab = (void *)hdr +
471 sechdrs[sechdrs[i].sh_link].sh_offset;
472 }
473 if (!info->symtab_start)
474 fatal("%s has no symtab?\n", filename);
475
476 /* Fix endianness in symbols */
477 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
478 sym->st_shndx = TO_NATIVE(sym->st_shndx);
479 sym->st_name = TO_NATIVE(sym->st_name);
480 sym->st_value = TO_NATIVE(sym->st_value);
481 sym->st_size = TO_NATIVE(sym->st_size);
482 }
483 return 1;
484 }
485
486 static void parse_elf_finish(struct elf_info *info)
487 {
488 release_file(info->hdr, info->size);
489 }
490
491 static int ignore_undef_symbol(struct elf_info *info, const char *symname)
492 {
493 /* ignore __this_module, it will be resolved shortly */
494 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
495 return 1;
496 /* ignore global offset table */
497 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
498 return 1;
499 if (info->hdr->e_machine == EM_PPC)
500 /* Special register function linked on all modules during final link of .ko */
501 if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
502 strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
503 strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
504 strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
505 return 1;
506 /* Do not ignore this symbol */
507 return 0;
508 }
509
510 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
511 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
512
513 static void handle_modversions(struct module *mod, struct elf_info *info,
514 Elf_Sym *sym, const char *symname)
515 {
516 unsigned int crc;
517 enum export export = export_from_sec(info, sym->st_shndx);
518
519 switch (sym->st_shndx) {
520 case SHN_COMMON:
521 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
522 break;
523 case SHN_ABS:
524 /* CRC'd symbol */
525 if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
526 crc = (unsigned int) sym->st_value;
527 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
528 export);
529 }
530 break;
531 case SHN_UNDEF:
532 /* undefined symbol */
533 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
534 ELF_ST_BIND(sym->st_info) != STB_WEAK)
535 break;
536 if (ignore_undef_symbol(info, symname))
537 break;
538 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
539 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
540 /* add compatibility with older glibc */
541 #ifndef STT_SPARC_REGISTER
542 #define STT_SPARC_REGISTER STT_REGISTER
543 #endif
544 if (info->hdr->e_machine == EM_SPARC ||
545 info->hdr->e_machine == EM_SPARCV9) {
546 /* Ignore register directives. */
547 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
548 break;
549 if (symname[0] == '.') {
550 char *munged = strdup(symname);
551 munged[0] = '_';
552 munged[1] = toupper(munged[1]);
553 symname = munged;
554 }
555 }
556 #endif
557
558 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
559 strlen(MODULE_SYMBOL_PREFIX)) == 0) {
560 mod->unres =
561 alloc_symbol(symname +
562 strlen(MODULE_SYMBOL_PREFIX),
563 ELF_ST_BIND(sym->st_info) == STB_WEAK,
564 mod->unres);
565 }
566 break;
567 default:
568 /* All exported symbols */
569 if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
570 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
571 export);
572 }
573 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
574 mod->has_init = 1;
575 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
576 mod->has_cleanup = 1;
577 break;
578 }
579 }
580
581 /**
582 * Parse tag=value strings from .modinfo section
583 **/
584 static char *next_string(char *string, unsigned long *secsize)
585 {
586 /* Skip non-zero chars */
587 while (string[0]) {
588 string++;
589 if ((*secsize)-- <= 1)
590 return NULL;
591 }
592
593 /* Skip any zero padding. */
594 while (!string[0]) {
595 string++;
596 if ((*secsize)-- <= 1)
597 return NULL;
598 }
599 return string;
600 }
601
602 static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
603 const char *tag, char *info)
604 {
605 char *p;
606 unsigned int taglen = strlen(tag);
607 unsigned long size = modinfo_len;
608
609 if (info) {
610 size -= info - (char *)modinfo;
611 modinfo = next_string(info, &size);
612 }
613
614 for (p = modinfo; p; p = next_string(p, &size)) {
615 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
616 return p + taglen + 1;
617 }
618 return NULL;
619 }
620
621 static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
622 const char *tag)
623
624 {
625 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
626 }
627
628 /**
629 * Test if string s ends in string sub
630 * return 0 if match
631 **/
632 static int strrcmp(const char *s, const char *sub)
633 {
634 int slen, sublen;
635
636 if (!s || !sub)
637 return 1;
638
639 slen = strlen(s);
640 sublen = strlen(sub);
641
642 if ((slen == 0) || (sublen == 0))
643 return 1;
644
645 if (sublen > slen)
646 return 1;
647
648 return memcmp(s + slen - sublen, sub, sublen);
649 }
650
651 static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
652 {
653 if (sym)
654 return elf->strtab + sym->st_name;
655 else
656 return "(unknown)";
657 }
658
659 static const char *sec_name(struct elf_info *elf, int shndx)
660 {
661 Elf_Shdr *sechdrs = elf->sechdrs;
662 return (void *)elf->hdr +
663 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
664 sechdrs[shndx].sh_name;
665 }
666
667 static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
668 {
669 return (void *)elf->hdr +
670 elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
671 sechdr->sh_name;
672 }
673
674 /* if sym is empty or point to a string
675 * like ".[0-9]+" then return 1.
676 * This is the optional prefix added by ld to some sections
677 */
678 static int number_prefix(const char *sym)
679 {
680 if (*sym++ == '\0')
681 return 1;
682 if (*sym != '.')
683 return 0;
684 do {
685 char c = *sym++;
686 if (c < '0' || c > '9')
687 return 0;
688 } while (*sym);
689 return 1;
690 }
691
692 /* The pattern is an array of simple patterns.
693 * "foo" will match an exact string equal to "foo"
694 * "*foo" will match a string that ends with "foo"
695 * "foo*" will match a string that begins with "foo"
696 * "foo$" will match a string equal to "foo" or "foo.1"
697 * where the '1' can be any number including several digits.
698 * The $ syntax is for sections where ld append a dot number
699 * to make section name unique.
700 */
701 static int match(const char *sym, const char * const pat[])
702 {
703 const char *p;
704 while (*pat) {
705 p = *pat++;
706 const char *endp = p + strlen(p) - 1;
707
708 /* "*foo" */
709 if (*p == '*') {
710 if (strrcmp(sym, p + 1) == 0)
711 return 1;
712 }
713 /* "foo*" */
714 else if (*endp == '*') {
715 if (strncmp(sym, p, strlen(p) - 1) == 0)
716 return 1;
717 }
718 /* "foo$" */
719 else if (*endp == '$') {
720 if (strncmp(sym, p, strlen(p) - 1) == 0) {
721 if (number_prefix(sym + strlen(p) - 1))
722 return 1;
723 }
724 }
725 /* no wildcards */
726 else {
727 if (strcmp(p, sym) == 0)
728 return 1;
729 }
730 }
731 /* no match */
732 return 0;
733 }
734
735 /* sections that we do not want to do full section mismatch check on */
736 static const char *section_white_list[] =
737 {
738 ".comment*",
739 ".debug*",
740 ".mdebug*", /* alpha, score, mips etc. */
741 ".pdr", /* alpha, score, mips etc. */
742 ".stab*",
743 ".note*",
744 ".got*",
745 ".toc*",
746 NULL
747 };
748
749 /*
750 * This is used to find sections missing the SHF_ALLOC flag.
751 * The cause of this is often a section specified in assembler
752 * without "ax" / "aw".
753 */
754 static void check_section(const char *modname, struct elf_info *elf,
755 Elf_Shdr *sechdr)
756 {
757 const char *sec = sech_name(elf, sechdr);
758
759 if (sechdr->sh_type == SHT_PROGBITS &&
760 !(sechdr->sh_flags & SHF_ALLOC) &&
761 !match(sec, section_white_list)) {
762 warn("%s (%s): unexpected non-allocatable section.\n"
763 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
764 "Note that for example <linux/init.h> contains\n"
765 "section definitions for use in .S files.\n\n",
766 modname, sec);
767 }
768 }
769
770
771
772 #define ALL_INIT_DATA_SECTIONS \
773 ".init.setup$", ".init.rodata$", \
774 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
775 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
776 #define ALL_EXIT_DATA_SECTIONS \
777 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
778
779 #define ALL_INIT_TEXT_SECTIONS \
780 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
781 #define ALL_EXIT_TEXT_SECTIONS \
782 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
783
784 #define ALL_INIT_SECTIONS INIT_SECTIONS, DEV_INIT_SECTIONS, \
785 CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
786 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, DEV_EXIT_SECTIONS, \
787 CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
788
789 #define DATA_SECTIONS ".data$", ".data.rel$"
790 #define TEXT_SECTIONS ".text$"
791
792 #define INIT_SECTIONS ".init.*"
793 #define DEV_INIT_SECTIONS ".devinit.*"
794 #define CPU_INIT_SECTIONS ".cpuinit.*"
795 #define MEM_INIT_SECTIONS ".meminit.*"
796
797 #define EXIT_SECTIONS ".exit.*"
798 #define DEV_EXIT_SECTIONS ".devexit.*"
799 #define CPU_EXIT_SECTIONS ".cpuexit.*"
800 #define MEM_EXIT_SECTIONS ".memexit.*"
801
802 /* init data sections */
803 static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
804
805 /* all init sections */
806 static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
807
808 /* All init and exit sections (code + data) */
809 static const char *init_exit_sections[] =
810 {ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
811
812 /* data section */
813 static const char *data_sections[] = { DATA_SECTIONS, NULL };
814
815
816 /* symbols in .data that may refer to init/exit sections */
817 static const char *symbol_white_list[] =
818 {
819 "*driver",
820 "*_template", /* scsi uses *_template a lot */
821 "*_timer", /* arm uses ops structures named _timer a lot */
822 "*_sht", /* scsi also used *_sht to some extent */
823 "*_ops",
824 "*_probe",
825 "*_probe_one",
826 "*_console",
827 NULL
828 };
829
830 static const char *head_sections[] = { ".head.text*", NULL };
831 static const char *linker_symbols[] =
832 { "__init_begin", "_sinittext", "_einittext", NULL };
833
834 enum mismatch {
835 NO_MISMATCH,
836 TEXT_TO_INIT,
837 DATA_TO_INIT,
838 TEXT_TO_EXIT,
839 DATA_TO_EXIT,
840 XXXINIT_TO_INIT,
841 XXXEXIT_TO_EXIT,
842 INIT_TO_EXIT,
843 EXIT_TO_INIT,
844 EXPORT_TO_INIT_EXIT,
845 };
846
847 struct sectioncheck {
848 const char *fromsec[20];
849 const char *tosec[20];
850 enum mismatch mismatch;
851 };
852
853 const struct sectioncheck sectioncheck[] = {
854 /* Do not reference init/exit code/data from
855 * normal code and data
856 */
857 {
858 .fromsec = { TEXT_SECTIONS, NULL },
859 .tosec = { ALL_INIT_SECTIONS, NULL },
860 .mismatch = TEXT_TO_INIT,
861 },
862 {
863 .fromsec = { DATA_SECTIONS, NULL },
864 .tosec = { ALL_INIT_SECTIONS, NULL },
865 .mismatch = DATA_TO_INIT,
866 },
867 {
868 .fromsec = { TEXT_SECTIONS, NULL },
869 .tosec = { ALL_EXIT_SECTIONS, NULL },
870 .mismatch = TEXT_TO_EXIT,
871 },
872 {
873 .fromsec = { DATA_SECTIONS, NULL },
874 .tosec = { ALL_EXIT_SECTIONS, NULL },
875 .mismatch = DATA_TO_EXIT,
876 },
877 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
878 {
879 .fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
880 .tosec = { INIT_SECTIONS, NULL },
881 .mismatch = XXXINIT_TO_INIT,
882 },
883 /* Do not reference cpuinit code/data from meminit code/data */
884 {
885 .fromsec = { MEM_INIT_SECTIONS, NULL },
886 .tosec = { CPU_INIT_SECTIONS, NULL },
887 .mismatch = XXXINIT_TO_INIT,
888 },
889 /* Do not reference meminit code/data from cpuinit code/data */
890 {
891 .fromsec = { CPU_INIT_SECTIONS, NULL },
892 .tosec = { MEM_INIT_SECTIONS, NULL },
893 .mismatch = XXXINIT_TO_INIT,
894 },
895 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
896 {
897 .fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
898 .tosec = { EXIT_SECTIONS, NULL },
899 .mismatch = XXXEXIT_TO_EXIT,
900 },
901 /* Do not reference cpuexit code/data from memexit code/data */
902 {
903 .fromsec = { MEM_EXIT_SECTIONS, NULL },
904 .tosec = { CPU_EXIT_SECTIONS, NULL },
905 .mismatch = XXXEXIT_TO_EXIT,
906 },
907 /* Do not reference memexit code/data from cpuexit code/data */
908 {
909 .fromsec = { CPU_EXIT_SECTIONS, NULL },
910 .tosec = { MEM_EXIT_SECTIONS, NULL },
911 .mismatch = XXXEXIT_TO_EXIT,
912 },
913 /* Do not use exit code/data from init code */
914 {
915 .fromsec = { ALL_INIT_SECTIONS, NULL },
916 .tosec = { ALL_EXIT_SECTIONS, NULL },
917 .mismatch = INIT_TO_EXIT,
918 },
919 /* Do not use init code/data from exit code */
920 {
921 .fromsec = { ALL_EXIT_SECTIONS, NULL },
922 .tosec = { ALL_INIT_SECTIONS, NULL },
923 .mismatch = EXIT_TO_INIT,
924 },
925 /* Do not export init/exit functions or data */
926 {
927 .fromsec = { "__ksymtab*", NULL },
928 .tosec = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
929 .mismatch = EXPORT_TO_INIT_EXIT
930 }
931 };
932
933 static int section_mismatch(const char *fromsec, const char *tosec)
934 {
935 int i;
936 int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
937 const struct sectioncheck *check = &sectioncheck[0];
938
939 for (i = 0; i < elems; i++) {
940 if (match(fromsec, check->fromsec) &&
941 match(tosec, check->tosec))
942 return check->mismatch;
943 check++;
944 }
945 return NO_MISMATCH;
946 }
947
948 /**
949 * Whitelist to allow certain references to pass with no warning.
950 *
951 * Pattern 1:
952 * If a module parameter is declared __initdata and permissions=0
953 * then this is legal despite the warning generated.
954 * We cannot see value of permissions here, so just ignore
955 * this pattern.
956 * The pattern is identified by:
957 * tosec = .init.data
958 * fromsec = .data*
959 * atsym =__param*
960 *
961 * Pattern 2:
962 * Many drivers utilise a *driver container with references to
963 * add, remove, probe functions etc.
964 * These functions may often be marked __init and we do not want to
965 * warn here.
966 * the pattern is identified by:
967 * tosec = init or exit section
968 * fromsec = data section
969 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
970 * *probe_one, *_console, *_timer
971 *
972 * Pattern 3:
973 * Whitelist all references from .head.text to any init section
974 *
975 * Pattern 4:
976 * Some symbols belong to init section but still it is ok to reference
977 * these from non-init sections as these symbols don't have any memory
978 * allocated for them and symbol address and value are same. So even
979 * if init section is freed, its ok to reference those symbols.
980 * For ex. symbols marking the init section boundaries.
981 * This pattern is identified by
982 * refsymname = __init_begin, _sinittext, _einittext
983 *
984 **/
985 static int secref_whitelist(const char *fromsec, const char *fromsym,
986 const char *tosec, const char *tosym)
987 {
988 /* Check for pattern 1 */
989 if (match(tosec, init_data_sections) &&
990 match(fromsec, data_sections) &&
991 (strncmp(fromsym, "__param", strlen("__param")) == 0))
992 return 0;
993
994 /* Check for pattern 2 */
995 if (match(tosec, init_exit_sections) &&
996 match(fromsec, data_sections) &&
997 match(fromsym, symbol_white_list))
998 return 0;
999
1000 /* Check for pattern 3 */
1001 if (match(fromsec, head_sections) &&
1002 match(tosec, init_sections))
1003 return 0;
1004
1005 /* Check for pattern 4 */
1006 if (match(tosym, linker_symbols))
1007 return 0;
1008
1009 return 1;
1010 }
1011
1012 /**
1013 * Find symbol based on relocation record info.
1014 * In some cases the symbol supplied is a valid symbol so
1015 * return refsym. If st_name != 0 we assume this is a valid symbol.
1016 * In other cases the symbol needs to be looked up in the symbol table
1017 * based on section and address.
1018 * **/
1019 static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1020 Elf_Sym *relsym)
1021 {
1022 Elf_Sym *sym;
1023 Elf_Sym *near = NULL;
1024 Elf64_Sword distance = 20;
1025 Elf64_Sword d;
1026
1027 if (relsym->st_name != 0)
1028 return relsym;
1029 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1030 if (sym->st_shndx != relsym->st_shndx)
1031 continue;
1032 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
1033 continue;
1034 if (sym->st_value == addr)
1035 return sym;
1036 /* Find a symbol nearby - addr are maybe negative */
1037 d = sym->st_value - addr;
1038 if (d < 0)
1039 d = addr - sym->st_value;
1040 if (d < distance) {
1041 distance = d;
1042 near = sym;
1043 }
1044 }
1045 /* We need a close match */
1046 if (distance < 20)
1047 return near;
1048 else
1049 return NULL;
1050 }
1051
1052 static inline int is_arm_mapping_symbol(const char *str)
1053 {
1054 return str[0] == '$' && strchr("atd", str[1])
1055 && (str[2] == '\0' || str[2] == '.');
1056 }
1057
1058 /*
1059 * If there's no name there, ignore it; likewise, ignore it if it's
1060 * one of the magic symbols emitted used by current ARM tools.
1061 *
1062 * Otherwise if find_symbols_between() returns those symbols, they'll
1063 * fail the whitelist tests and cause lots of false alarms ... fixable
1064 * only by merging __exit and __init sections into __text, bloating
1065 * the kernel (which is especially evil on embedded platforms).
1066 */
1067 static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
1068 {
1069 const char *name = elf->strtab + sym->st_name;
1070
1071 if (!name || !strlen(name))
1072 return 0;
1073 return !is_arm_mapping_symbol(name);
1074 }
1075
1076 /*
1077 * Find symbols before or equal addr and after addr - in the section sec.
1078 * If we find two symbols with equal offset prefer one with a valid name.
1079 * The ELF format may have a better way to detect what type of symbol
1080 * it is, but this works for now.
1081 **/
1082 static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
1083 const char *sec)
1084 {
1085 Elf_Sym *sym;
1086 Elf_Sym *near = NULL;
1087 Elf_Addr distance = ~0;
1088
1089 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
1090 const char *symsec;
1091
1092 if (sym->st_shndx >= SHN_LORESERVE)
1093 continue;
1094 symsec = sec_name(elf, sym->st_shndx);
1095 if (strcmp(symsec, sec) != 0)
1096 continue;
1097 if (!is_valid_name(elf, sym))
1098 continue;
1099 if (sym->st_value <= addr) {
1100 if ((addr - sym->st_value) < distance) {
1101 distance = addr - sym->st_value;
1102 near = sym;
1103 } else if ((addr - sym->st_value) == distance) {
1104 near = sym;
1105 }
1106 }
1107 }
1108 return near;
1109 }
1110
1111 /*
1112 * Convert a section name to the function/data attribute
1113 * .init.text => __init
1114 * .cpuinit.data => __cpudata
1115 * .memexitconst => __memconst
1116 * etc.
1117 */
1118 static char *sec2annotation(const char *s)
1119 {
1120 if (match(s, init_exit_sections)) {
1121 char *p = malloc(20);
1122 char *r = p;
1123
1124 *p++ = '_';
1125 *p++ = '_';
1126 if (*s == '.')
1127 s++;
1128 while (*s && *s != '.')
1129 *p++ = *s++;
1130 *p = '\0';
1131 if (*s == '.')
1132 s++;
1133 if (strstr(s, "rodata") != NULL)
1134 strcat(p, "const ");
1135 else if (strstr(s, "data") != NULL)
1136 strcat(p, "data ");
1137 else
1138 strcat(p, " ");
1139 return r; /* we leak her but we do not care */
1140 } else {
1141 return "";
1142 }
1143 }
1144
1145 static int is_function(Elf_Sym *sym)
1146 {
1147 if (sym)
1148 return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
1149 else
1150 return -1;
1151 }
1152
1153 /*
1154 * Print a warning about a section mismatch.
1155 * Try to find symbols near it so user can find it.
1156 * Check whitelist before warning - it may be a false positive.
1157 */
1158 static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
1159 const char *fromsec,
1160 unsigned long long fromaddr,
1161 const char *fromsym,
1162 int from_is_func,
1163 const char *tosec, const char *tosym,
1164 int to_is_func)
1165 {
1166 const char *from, *from_p;
1167 const char *to, *to_p;
1168
1169 switch (from_is_func) {
1170 case 0: from = "variable"; from_p = ""; break;
1171 case 1: from = "function"; from_p = "()"; break;
1172 default: from = "(unknown reference)"; from_p = ""; break;
1173 }
1174 switch (to_is_func) {
1175 case 0: to = "variable"; to_p = ""; break;
1176 case 1: to = "function"; to_p = "()"; break;
1177 default: to = "(unknown reference)"; to_p = ""; break;
1178 }
1179
1180 sec_mismatch_count++;
1181 if (!sec_mismatch_verbose)
1182 return;
1183
1184 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1185 "to the %s %s:%s%s\n",
1186 modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
1187 tosym, to_p);
1188
1189 switch (mismatch) {
1190 case TEXT_TO_INIT:
1191 fprintf(stderr,
1192 "The function %s%s() references\n"
1193 "the %s %s%s%s.\n"
1194 "This is often because %s lacks a %s\n"
1195 "annotation or the annotation of %s is wrong.\n",
1196 sec2annotation(fromsec), fromsym,
1197 to, sec2annotation(tosec), tosym, to_p,
1198 fromsym, sec2annotation(tosec), tosym);
1199 break;
1200 case DATA_TO_INIT: {
1201 const char **s = symbol_white_list;
1202 fprintf(stderr,
1203 "The variable %s references\n"
1204 "the %s %s%s%s\n"
1205 "If the reference is valid then annotate the\n"
1206 "variable with __init* or __refdata (see linux/init.h) "
1207 "or name the variable:\n",
1208 fromsym, to, sec2annotation(tosec), tosym, to_p);
1209 while (*s)
1210 fprintf(stderr, "%s, ", *s++);
1211 fprintf(stderr, "\n");
1212 break;
1213 }
1214 case TEXT_TO_EXIT:
1215 fprintf(stderr,
1216 "The function %s() references a %s in an exit section.\n"
1217 "Often the %s %s%s has valid usage outside the exit section\n"
1218 "and the fix is to remove the %sannotation of %s.\n",
1219 fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
1220 break;
1221 case DATA_TO_EXIT: {
1222 const char **s = symbol_white_list;
1223 fprintf(stderr,
1224 "The variable %s references\n"
1225 "the %s %s%s%s\n"
1226 "If the reference is valid then annotate the\n"
1227 "variable with __exit* (see linux/init.h) or "
1228 "name the variable:\n",
1229 fromsym, to, sec2annotation(tosec), tosym, to_p);
1230 while (*s)
1231 fprintf(stderr, "%s, ", *s++);
1232 fprintf(stderr, "\n");
1233 break;
1234 }
1235 case XXXINIT_TO_INIT:
1236 case XXXEXIT_TO_EXIT:
1237 fprintf(stderr,
1238 "The %s %s%s%s references\n"
1239 "a %s %s%s%s.\n"
1240 "If %s is only used by %s then\n"
1241 "annotate %s with a matching annotation.\n",
1242 from, sec2annotation(fromsec), fromsym, from_p,
1243 to, sec2annotation(tosec), tosym, to_p,
1244 tosym, fromsym, tosym);
1245 break;
1246 case INIT_TO_EXIT:
1247 fprintf(stderr,
1248 "The %s %s%s%s references\n"
1249 "a %s %s%s%s.\n"
1250 "This is often seen when error handling "
1251 "in the init function\n"
1252 "uses functionality in the exit path.\n"
1253 "The fix is often to remove the %sannotation of\n"
1254 "%s%s so it may be used outside an exit section.\n",
1255 from, sec2annotation(fromsec), fromsym, from_p,
1256 to, sec2annotation(tosec), tosym, to_p,
1257 sec2annotation(tosec), tosym, to_p);
1258 break;
1259 case EXIT_TO_INIT:
1260 fprintf(stderr,
1261 "The %s %s%s%s references\n"
1262 "a %s %s%s%s.\n"
1263 "This is often seen when error handling "
1264 "in the exit function\n"
1265 "uses functionality in the init path.\n"
1266 "The fix is often to remove the %sannotation of\n"
1267 "%s%s so it may be used outside an init section.\n",
1268 from, sec2annotation(fromsec), fromsym, from_p,
1269 to, sec2annotation(tosec), tosym, to_p,
1270 sec2annotation(tosec), tosym, to_p);
1271 break;
1272 case EXPORT_TO_INIT_EXIT:
1273 fprintf(stderr,
1274 "The symbol %s is exported and annotated %s\n"
1275 "Fix this by removing the %sannotation of %s "
1276 "or drop the export.\n",
1277 tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
1278 case NO_MISMATCH:
1279 /* To get warnings on missing members */
1280 break;
1281 }
1282 fprintf(stderr, "\n");
1283 }
1284
1285 static void check_section_mismatch(const char *modname, struct elf_info *elf,
1286 Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
1287 {
1288 const char *tosec;
1289 enum mismatch mismatch;
1290
1291 tosec = sec_name(elf, sym->st_shndx);
1292 mismatch = section_mismatch(fromsec, tosec);
1293 if (mismatch != NO_MISMATCH) {
1294 Elf_Sym *to;
1295 Elf_Sym *from;
1296 const char *tosym;
1297 const char *fromsym;
1298
1299 from = find_elf_symbol2(elf, r->r_offset, fromsec);
1300 fromsym = sym_name(elf, from);
1301 to = find_elf_symbol(elf, r->r_addend, sym);
1302 tosym = sym_name(elf, to);
1303
1304 /* check whitelist - we may ignore it */
1305 if (secref_whitelist(fromsec, fromsym, tosec, tosym)) {
1306 report_sec_mismatch(modname, mismatch,
1307 fromsec, r->r_offset, fromsym,
1308 is_function(from), tosec, tosym,
1309 is_function(to));
1310 }
1311 }
1312 }
1313
1314 static unsigned int *reloc_location(struct elf_info *elf,
1315 Elf_Shdr *sechdr, Elf_Rela *r)
1316 {
1317 Elf_Shdr *sechdrs = elf->sechdrs;
1318 int section = sechdr->sh_info;
1319
1320 return (void *)elf->hdr + sechdrs[section].sh_offset +
1321 r->r_offset - sechdrs[section].sh_addr;
1322 }
1323
1324 static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1325 {
1326 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1327 unsigned int *location = reloc_location(elf, sechdr, r);
1328
1329 switch (r_typ) {
1330 case R_386_32:
1331 r->r_addend = TO_NATIVE(*location);
1332 break;
1333 case R_386_PC32:
1334 r->r_addend = TO_NATIVE(*location) + 4;
1335 /* For CONFIG_RELOCATABLE=y */
1336 if (elf->hdr->e_type == ET_EXEC)
1337 r->r_addend += r->r_offset;
1338 break;
1339 }
1340 return 0;
1341 }
1342
1343 static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1344 {
1345 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1346
1347 switch (r_typ) {
1348 case R_ARM_ABS32:
1349 /* From ARM ABI: (S + A) | T */
1350 r->r_addend = (int)(long)
1351 (elf->symtab_start + ELF_R_SYM(r->r_info));
1352 break;
1353 case R_ARM_PC24:
1354 /* From ARM ABI: ((S + A) | T) - P */
1355 r->r_addend = (int)(long)(elf->hdr +
1356 sechdr->sh_offset +
1357 (r->r_offset - sechdr->sh_addr));
1358 break;
1359 default:
1360 return 1;
1361 }
1362 return 0;
1363 }
1364
1365 static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1366 {
1367 unsigned int r_typ = ELF_R_TYPE(r->r_info);
1368 unsigned int *location = reloc_location(elf, sechdr, r);
1369 unsigned int inst;
1370
1371 if (r_typ == R_MIPS_HI16)
1372 return 1; /* skip this */
1373 inst = TO_NATIVE(*location);
1374 switch (r_typ) {
1375 case R_MIPS_LO16:
1376 r->r_addend = inst & 0xffff;
1377 break;
1378 case R_MIPS_26:
1379 r->r_addend = (inst & 0x03ffffff) << 2;
1380 break;
1381 case R_MIPS_32:
1382 r->r_addend = inst;
1383 break;
1384 }
1385 return 0;
1386 }
1387
1388 static void section_rela(const char *modname, struct elf_info *elf,
1389 Elf_Shdr *sechdr)
1390 {
1391 Elf_Sym *sym;
1392 Elf_Rela *rela;
1393 Elf_Rela r;
1394 unsigned int r_sym;
1395 const char *fromsec;
1396
1397 Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1398 Elf_Rela *stop = (void *)start + sechdr->sh_size;
1399
1400 fromsec = sech_name(elf, sechdr);
1401 fromsec += strlen(".rela");
1402 /* if from section (name) is know good then skip it */
1403 if (match(fromsec, section_white_list))
1404 return;
1405
1406 for (rela = start; rela < stop; rela++) {
1407 r.r_offset = TO_NATIVE(rela->r_offset);
1408 #if KERNEL_ELFCLASS == ELFCLASS64
1409 if (elf->hdr->e_machine == EM_MIPS) {
1410 unsigned int r_typ;
1411 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1412 r_sym = TO_NATIVE(r_sym);
1413 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1414 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1415 } else {
1416 r.r_info = TO_NATIVE(rela->r_info);
1417 r_sym = ELF_R_SYM(r.r_info);
1418 }
1419 #else
1420 r.r_info = TO_NATIVE(rela->r_info);
1421 r_sym = ELF_R_SYM(r.r_info);
1422 #endif
1423 r.r_addend = TO_NATIVE(rela->r_addend);
1424 sym = elf->symtab_start + r_sym;
1425 /* Skip special sections */
1426 if (sym->st_shndx >= SHN_LORESERVE)
1427 continue;
1428 check_section_mismatch(modname, elf, &r, sym, fromsec);
1429 }
1430 }
1431
1432 static void section_rel(const char *modname, struct elf_info *elf,
1433 Elf_Shdr *sechdr)
1434 {
1435 Elf_Sym *sym;
1436 Elf_Rel *rel;
1437 Elf_Rela r;
1438 unsigned int r_sym;
1439 const char *fromsec;
1440
1441 Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1442 Elf_Rel *stop = (void *)start + sechdr->sh_size;
1443
1444 fromsec = sech_name(elf, sechdr);
1445 fromsec += strlen(".rel");
1446 /* if from section (name) is know good then skip it */
1447 if (match(fromsec, section_white_list))
1448 return;
1449
1450 for (rel = start; rel < stop; rel++) {
1451 r.r_offset = TO_NATIVE(rel->r_offset);
1452 #if KERNEL_ELFCLASS == ELFCLASS64
1453 if (elf->hdr->e_machine == EM_MIPS) {
1454 unsigned int r_typ;
1455 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1456 r_sym = TO_NATIVE(r_sym);
1457 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1458 r.r_info = ELF64_R_INFO(r_sym, r_typ);
1459 } else {
1460 r.r_info = TO_NATIVE(rel->r_info);
1461 r_sym = ELF_R_SYM(r.r_info);
1462 }
1463 #else
1464 r.r_info = TO_NATIVE(rel->r_info);
1465 r_sym = ELF_R_SYM(r.r_info);
1466 #endif
1467 r.r_addend = 0;
1468 switch (elf->hdr->e_machine) {
1469 case EM_386:
1470 if (addend_386_rel(elf, sechdr, &r))
1471 continue;
1472 break;
1473 case EM_ARM:
1474 if (addend_arm_rel(elf, sechdr, &r))
1475 continue;
1476 break;
1477 case EM_MIPS:
1478 if (addend_mips_rel(elf, sechdr, &r))
1479 continue;
1480 break;
1481 }
1482 sym = elf->symtab_start + r_sym;
1483 /* Skip special sections */
1484 if (sym->st_shndx >= SHN_LORESERVE)
1485 continue;
1486 check_section_mismatch(modname, elf, &r, sym, fromsec);
1487 }
1488 }
1489
1490 /**
1491 * A module includes a number of sections that are discarded
1492 * either when loaded or when used as built-in.
1493 * For loaded modules all functions marked __init and all data
1494 * marked __initdata will be discarded when the module has been intialized.
1495 * Likewise for modules used built-in the sections marked __exit
1496 * are discarded because __exit marked function are supposed to be called
1497 * only when a module is unloaded which never happens for built-in modules.
1498 * The check_sec_ref() function traverses all relocation records
1499 * to find all references to a section that reference a section that will
1500 * be discarded and warns about it.
1501 **/
1502 static void check_sec_ref(struct module *mod, const char *modname,
1503 struct elf_info *elf)
1504 {
1505 int i;
1506 Elf_Shdr *sechdrs = elf->sechdrs;
1507
1508 /* Walk through all sections */
1509 for (i = 0; i < elf->hdr->e_shnum; i++) {
1510 check_section(modname, elf, &elf->sechdrs[i]);
1511 /* We want to process only relocation sections and not .init */
1512 if (sechdrs[i].sh_type == SHT_RELA)
1513 section_rela(modname, elf, &elf->sechdrs[i]);
1514 else if (sechdrs[i].sh_type == SHT_REL)
1515 section_rel(modname, elf, &elf->sechdrs[i]);
1516 }
1517 }
1518
1519 static void read_symbols(char *modname)
1520 {
1521 const char *symname;
1522 char *version;
1523 char *license;
1524 struct module *mod;
1525 struct elf_info info = { };
1526 Elf_Sym *sym;
1527
1528 if (!parse_elf(&info, modname))
1529 return;
1530
1531 mod = new_module(modname);
1532
1533 /* When there's no vmlinux, don't print warnings about
1534 * unresolved symbols (since there'll be too many ;) */
1535 if (is_vmlinux(modname)) {
1536 have_vmlinux = 1;
1537 mod->skip = 1;
1538 }
1539
1540 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1541 if (info.modinfo && !license && !is_vmlinux(modname))
1542 warn("modpost: missing MODULE_LICENSE() in %s\n"
1543 "see include/linux/module.h for "
1544 "more information\n", modname);
1545 while (license) {
1546 if (license_is_gpl_compatible(license))
1547 mod->gpl_compatible = 1;
1548 else {
1549 mod->gpl_compatible = 0;
1550 break;
1551 }
1552 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1553 "license", license);
1554 }
1555
1556 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1557 symname = info.strtab + sym->st_name;
1558
1559 handle_modversions(mod, &info, sym, symname);
1560 handle_moddevtable(mod, &info, sym, symname);
1561 }
1562 if (!is_vmlinux(modname) ||
1563 (is_vmlinux(modname) && vmlinux_section_warnings))
1564 check_sec_ref(mod, modname, &info);
1565
1566 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1567 if (version)
1568 maybe_frob_rcs_version(modname, version, info.modinfo,
1569 version - (char *)info.hdr);
1570 if (version || (all_versions && !is_vmlinux(modname)))
1571 get_src_version(modname, mod->srcversion,
1572 sizeof(mod->srcversion)-1);
1573
1574 parse_elf_finish(&info);
1575
1576 /* Our trick to get versioning for module struct etc. - it's
1577 * never passed as an argument to an exported function, so
1578 * the automatic versioning doesn't pick it up, but it's really
1579 * important anyhow */
1580 if (modversions)
1581 mod->unres = alloc_symbol("module_layout", 0, mod->unres);
1582 }
1583
1584 #define SZ 500
1585
1586 /* We first write the generated file into memory using the
1587 * following helper, then compare to the file on disk and
1588 * only update the later if anything changed */
1589
1590 void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1591 const char *fmt, ...)
1592 {
1593 char tmp[SZ];
1594 int len;
1595 va_list ap;
1596
1597 va_start(ap, fmt);
1598 len = vsnprintf(tmp, SZ, fmt, ap);
1599 buf_write(buf, tmp, len);
1600 va_end(ap);
1601 }
1602
1603 void buf_write(struct buffer *buf, const char *s, int len)
1604 {
1605 if (buf->size - buf->pos < len) {
1606 buf->size += len + SZ;
1607 buf->p = realloc(buf->p, buf->size);
1608 }
1609 strncpy(buf->p + buf->pos, s, len);
1610 buf->pos += len;
1611 }
1612
1613 static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1614 {
1615 const char *e = is_vmlinux(m) ?"":".ko";
1616
1617 switch (exp) {
1618 case export_gpl:
1619 fatal("modpost: GPL-incompatible module %s%s "
1620 "uses GPL-only symbol '%s'\n", m, e, s);
1621 break;
1622 case export_unused_gpl:
1623 fatal("modpost: GPL-incompatible module %s%s "
1624 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1625 break;
1626 case export_gpl_future:
1627 warn("modpost: GPL-incompatible module %s%s "
1628 "uses future GPL-only symbol '%s'\n", m, e, s);
1629 break;
1630 case export_plain:
1631 case export_unused:
1632 case export_unknown:
1633 /* ignore */
1634 break;
1635 }
1636 }
1637
1638 static void check_for_unused(enum export exp, const char *m, const char *s)
1639 {
1640 const char *e = is_vmlinux(m) ?"":".ko";
1641
1642 switch (exp) {
1643 case export_unused:
1644 case export_unused_gpl:
1645 warn("modpost: module %s%s "
1646 "uses symbol '%s' marked UNUSED\n", m, e, s);
1647 break;
1648 default:
1649 /* ignore */
1650 break;
1651 }
1652 }
1653
1654 static void check_exports(struct module *mod)
1655 {
1656 struct symbol *s, *exp;
1657
1658 for (s = mod->unres; s; s = s->next) {
1659 const char *basename;
1660 exp = find_symbol(s->name);
1661 if (!exp || exp->module == mod)
1662 continue;
1663 basename = strrchr(mod->name, '/');
1664 if (basename)
1665 basename++;
1666 else
1667 basename = mod->name;
1668 if (!mod->gpl_compatible)
1669 check_for_gpl_usage(exp->export, basename, exp->name);
1670 check_for_unused(exp->export, basename, exp->name);
1671 }
1672 }
1673
1674 /**
1675 * Header for the generated file
1676 **/
1677 static void add_header(struct buffer *b, struct module *mod)
1678 {
1679 buf_printf(b, "#include <linux/module.h>\n");
1680 buf_printf(b, "#include <linux/vermagic.h>\n");
1681 buf_printf(b, "#include <linux/compiler.h>\n");
1682 buf_printf(b, "\n");
1683 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1684 buf_printf(b, "\n");
1685 buf_printf(b, "struct module __this_module\n");
1686 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1687 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1688 if (mod->has_init)
1689 buf_printf(b, " .init = init_module,\n");
1690 if (mod->has_cleanup)
1691 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1692 " .exit = cleanup_module,\n"
1693 "#endif\n");
1694 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1695 buf_printf(b, "};\n");
1696 }
1697
1698 static void add_staging_flag(struct buffer *b, const char *name)
1699 {
1700 static const char *staging_dir = "drivers/staging";
1701
1702 if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
1703 buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
1704 }
1705
1706 /**
1707 * Record CRCs for unresolved symbols
1708 **/
1709 static int add_versions(struct buffer *b, struct module *mod)
1710 {
1711 struct symbol *s, *exp;
1712 int err = 0;
1713
1714 for (s = mod->unres; s; s = s->next) {
1715 exp = find_symbol(s->name);
1716 if (!exp || exp->module == mod) {
1717 if (have_vmlinux && !s->weak) {
1718 if (warn_unresolved) {
1719 warn("\"%s\" [%s.ko] undefined!\n",
1720 s->name, mod->name);
1721 } else {
1722 merror("\"%s\" [%s.ko] undefined!\n",
1723 s->name, mod->name);
1724 err = 1;
1725 }
1726 }
1727 continue;
1728 }
1729 s->module = exp->module;
1730 s->crc_valid = exp->crc_valid;
1731 s->crc = exp->crc;
1732 }
1733
1734 if (!modversions)
1735 return err;
1736
1737 buf_printf(b, "\n");
1738 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1739 buf_printf(b, "__used\n");
1740 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1741
1742 for (s = mod->unres; s; s = s->next) {
1743 if (!s->module)
1744 continue;
1745 if (!s->crc_valid) {
1746 warn("\"%s\" [%s.ko] has no CRC!\n",
1747 s->name, mod->name);
1748 continue;
1749 }
1750 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1751 }
1752
1753 buf_printf(b, "};\n");
1754
1755 return err;
1756 }
1757
1758 static void add_depends(struct buffer *b, struct module *mod,
1759 struct module *modules)
1760 {
1761 struct symbol *s;
1762 struct module *m;
1763 int first = 1;
1764
1765 for (m = modules; m; m = m->next)
1766 m->seen = is_vmlinux(m->name);
1767
1768 buf_printf(b, "\n");
1769 buf_printf(b, "static const char __module_depends[]\n");
1770 buf_printf(b, "__used\n");
1771 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1772 buf_printf(b, "\"depends=");
1773 for (s = mod->unres; s; s = s->next) {
1774 const char *p;
1775 if (!s->module)
1776 continue;
1777
1778 if (s->module->seen)
1779 continue;
1780
1781 s->module->seen = 1;
1782 p = strrchr(s->module->name, '/');
1783 if (p)
1784 p++;
1785 else
1786 p = s->module->name;
1787 buf_printf(b, "%s%s", first ? "" : ",", p);
1788 first = 0;
1789 }
1790 buf_printf(b, "\";\n");
1791 }
1792
1793 static void add_srcversion(struct buffer *b, struct module *mod)
1794 {
1795 if (mod->srcversion[0]) {
1796 buf_printf(b, "\n");
1797 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1798 mod->srcversion);
1799 }
1800 }
1801
1802 static void write_if_changed(struct buffer *b, const char *fname)
1803 {
1804 char *tmp;
1805 FILE *file;
1806 struct stat st;
1807
1808 file = fopen(fname, "r");
1809 if (!file)
1810 goto write;
1811
1812 if (fstat(fileno(file), &st) < 0)
1813 goto close_write;
1814
1815 if (st.st_size != b->pos)
1816 goto close_write;
1817
1818 tmp = NOFAIL(malloc(b->pos));
1819 if (fread(tmp, 1, b->pos, file) != b->pos)
1820 goto free_write;
1821
1822 if (memcmp(tmp, b->p, b->pos) != 0)
1823 goto free_write;
1824
1825 free(tmp);
1826 fclose(file);
1827 return;
1828
1829 free_write:
1830 free(tmp);
1831 close_write:
1832 fclose(file);
1833 write:
1834 file = fopen(fname, "w");
1835 if (!file) {
1836 perror(fname);
1837 exit(1);
1838 }
1839 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1840 perror(fname);
1841 exit(1);
1842 }
1843 fclose(file);
1844 }
1845
1846 /* parse Module.symvers file. line format:
1847 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1848 **/
1849 static void read_dump(const char *fname, unsigned int kernel)
1850 {
1851 unsigned long size, pos = 0;
1852 void *file = grab_file(fname, &size);
1853 char *line;
1854
1855 if (!file)
1856 /* No symbol versions, silently ignore */
1857 return;
1858
1859 while ((line = get_next_line(&pos, file, size))) {
1860 char *symname, *modname, *d, *export, *end;
1861 unsigned int crc;
1862 struct module *mod;
1863 struct symbol *s;
1864
1865 if (!(symname = strchr(line, '\t')))
1866 goto fail;
1867 *symname++ = '\0';
1868 if (!(modname = strchr(symname, '\t')))
1869 goto fail;
1870 *modname++ = '\0';
1871 if ((export = strchr(modname, '\t')) != NULL)
1872 *export++ = '\0';
1873 if (export && ((end = strchr(export, '\t')) != NULL))
1874 *end = '\0';
1875 crc = strtoul(line, &d, 16);
1876 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1877 goto fail;
1878 mod = find_module(modname);
1879 if (!mod) {
1880 if (is_vmlinux(modname))
1881 have_vmlinux = 1;
1882 mod = new_module(modname);
1883 mod->skip = 1;
1884 }
1885 s = sym_add_exported(symname, mod, export_no(export));
1886 s->kernel = kernel;
1887 s->preloaded = 1;
1888 sym_update_crc(symname, mod, crc, export_no(export));
1889 }
1890 return;
1891 fail:
1892 fatal("parse error in symbol dump file\n");
1893 }
1894
1895 /* For normal builds always dump all symbols.
1896 * For external modules only dump symbols
1897 * that are not read from kernel Module.symvers.
1898 **/
1899 static int dump_sym(struct symbol *sym)
1900 {
1901 if (!external_module)
1902 return 1;
1903 if (sym->vmlinux || sym->kernel)
1904 return 0;
1905 return 1;
1906 }
1907
1908 static void write_dump(const char *fname)
1909 {
1910 struct buffer buf = { };
1911 struct symbol *symbol;
1912 int n;
1913
1914 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1915 symbol = symbolhash[n];
1916 while (symbol) {
1917 if (dump_sym(symbol))
1918 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1919 symbol->crc, symbol->name,
1920 symbol->module->name,
1921 export_str(symbol->export));
1922 symbol = symbol->next;
1923 }
1924 }
1925 write_if_changed(&buf, fname);
1926 }
1927
1928 struct ext_sym_list {
1929 struct ext_sym_list *next;
1930 const char *file;
1931 };
1932
1933 int main(int argc, char **argv)
1934 {
1935 struct module *mod;
1936 struct buffer buf = { };
1937 char *kernel_read = NULL, *module_read = NULL;
1938 char *dump_write = NULL;
1939 int opt;
1940 int err;
1941 struct ext_sym_list *extsym_iter;
1942 struct ext_sym_list *extsym_start = NULL;
1943
1944 while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
1945 switch (opt) {
1946 case 'i':
1947 kernel_read = optarg;
1948 break;
1949 case 'I':
1950 module_read = optarg;
1951 external_module = 1;
1952 break;
1953 case 'c':
1954 cross_build = 1;
1955 break;
1956 case 'e':
1957 external_module = 1;
1958 extsym_iter =
1959 NOFAIL(malloc(sizeof(*extsym_iter)));
1960 extsym_iter->next = extsym_start;
1961 extsym_iter->file = optarg;
1962 extsym_start = extsym_iter;
1963 break;
1964 case 'm':
1965 modversions = 1;
1966 break;
1967 case 'o':
1968 dump_write = optarg;
1969 break;
1970 case 'a':
1971 all_versions = 1;
1972 break;
1973 case 's':
1974 vmlinux_section_warnings = 0;
1975 break;
1976 case 'S':
1977 sec_mismatch_verbose = 0;
1978 break;
1979 case 'w':
1980 warn_unresolved = 1;
1981 break;
1982 default:
1983 exit(1);
1984 }
1985 }
1986
1987 if (kernel_read)
1988 read_dump(kernel_read, 1);
1989 if (module_read)
1990 read_dump(module_read, 0);
1991 while (extsym_start) {
1992 read_dump(extsym_start->file, 0);
1993 extsym_iter = extsym_start->next;
1994 free(extsym_start);
1995 extsym_start = extsym_iter;
1996 }
1997
1998 while (optind < argc)
1999 read_symbols(argv[optind++]);
2000
2001 for (mod = modules; mod; mod = mod->next) {
2002 if (mod->skip)
2003 continue;
2004 check_exports(mod);
2005 }
2006
2007 err = 0;
2008
2009 for (mod = modules; mod; mod = mod->next) {
2010 char fname[strlen(mod->name) + 10];
2011
2012 if (mod->skip)
2013 continue;
2014
2015 buf.pos = 0;
2016
2017 add_header(&buf, mod);
2018 add_staging_flag(&buf, mod->name);
2019 err |= add_versions(&buf, mod);
2020 add_depends(&buf, mod, modules);
2021 add_moddevtable(&buf, mod);
2022 add_srcversion(&buf, mod);
2023
2024 sprintf(fname, "%s.mod.c", mod->name);
2025 write_if_changed(&buf, fname);
2026 }
2027
2028 if (dump_write)
2029 write_dump(dump_write);
2030 if (sec_mismatch_count && !sec_mismatch_verbose)
2031 warn("modpost: Found %d section mismatch(es).\n"
2032 "To see full details build your kernel with:\n"
2033 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2034 sec_mismatch_count);
2035
2036 return err;
2037 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree