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CommitLineData
1da177e4
LT
1/* Postprocess module symbol versions
2 *
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
382168f4 5 * Copyright 2006 Sam Ravnborg
1da177e4
LT
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#include <ctype.h>
15#include "modpost.h"
b817f6fe 16#include "../../include/linux/license.h"
1da177e4
LT
17
18/* Are we using CONFIG_MODVERSIONS? */
19int modversions = 0;
20/* Warn about undefined symbols? (do so if we have vmlinux) */
21int have_vmlinux = 0;
22/* Is CONFIG_MODULE_SRCVERSION_ALL set? */
23static int all_versions = 0;
040fcc81
SR
24/* If we are modposting external module set to 1 */
25static int external_module = 0;
8d8d8289
SR
26/* Warn about section mismatch in vmlinux if set to 1 */
27static int vmlinux_section_warnings = 1;
c53ddacd
KK
28/* Only warn about unresolved symbols */
29static int warn_unresolved = 0;
bd5cbced 30/* How a symbol is exported */
c96fca21
SR
31enum export {
32 export_plain, export_unused, export_gpl,
33 export_unused_gpl, export_gpl_future, export_unknown
34};
1da177e4 35
5c3ead8c 36void fatal(const char *fmt, ...)
1da177e4
LT
37{
38 va_list arglist;
39
40 fprintf(stderr, "FATAL: ");
41
42 va_start(arglist, fmt);
43 vfprintf(stderr, fmt, arglist);
44 va_end(arglist);
45
46 exit(1);
47}
48
5c3ead8c 49void warn(const char *fmt, ...)
1da177e4
LT
50{
51 va_list arglist;
52
53 fprintf(stderr, "WARNING: ");
54
55 va_start(arglist, fmt);
56 vfprintf(stderr, fmt, arglist);
57 va_end(arglist);
58}
59
2a116659
MW
60void merror(const char *fmt, ...)
61{
62 va_list arglist;
63
64 fprintf(stderr, "ERROR: ");
65
66 va_start(arglist, fmt);
67 vfprintf(stderr, fmt, arglist);
68 va_end(arglist);
69}
70
040fcc81
SR
71static int is_vmlinux(const char *modname)
72{
73 const char *myname;
74
75 if ((myname = strrchr(modname, '/')))
76 myname++;
77 else
78 myname = modname;
79
741f98fe
SR
80 return (strcmp(myname, "vmlinux") == 0) ||
81 (strcmp(myname, "vmlinux.o") == 0);
040fcc81
SR
82}
83
1da177e4
LT
84void *do_nofail(void *ptr, const char *expr)
85{
86 if (!ptr) {
87 fatal("modpost: Memory allocation failure: %s.\n", expr);
88 }
89 return ptr;
90}
91
92/* A list of all modules we processed */
93
94static struct module *modules;
95
5c3ead8c 96static struct module *find_module(char *modname)
1da177e4
LT
97{
98 struct module *mod;
99
100 for (mod = modules; mod; mod = mod->next)
101 if (strcmp(mod->name, modname) == 0)
102 break;
103 return mod;
104}
105
5c3ead8c 106static struct module *new_module(char *modname)
1da177e4
LT
107{
108 struct module *mod;
109 char *p, *s;
62070fa4 110
1da177e4
LT
111 mod = NOFAIL(malloc(sizeof(*mod)));
112 memset(mod, 0, sizeof(*mod));
113 p = NOFAIL(strdup(modname));
114
115 /* strip trailing .o */
116 if ((s = strrchr(p, '.')) != NULL)
117 if (strcmp(s, ".o") == 0)
118 *s = '\0';
119
120 /* add to list */
121 mod->name = p;
b817f6fe 122 mod->gpl_compatible = -1;
1da177e4
LT
123 mod->next = modules;
124 modules = mod;
125
126 return mod;
127}
128
129/* A hash of all exported symbols,
130 * struct symbol is also used for lists of unresolved symbols */
131
132#define SYMBOL_HASH_SIZE 1024
133
134struct symbol {
135 struct symbol *next;
136 struct module *module;
137 unsigned int crc;
138 int crc_valid;
139 unsigned int weak:1;
040fcc81
SR
140 unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */
141 unsigned int kernel:1; /* 1 if symbol is from kernel
142 * (only for external modules) **/
8e70c458 143 unsigned int preloaded:1; /* 1 if symbol from Module.symvers */
bd5cbced 144 enum export export; /* Type of export */
1da177e4
LT
145 char name[0];
146};
147
148static struct symbol *symbolhash[SYMBOL_HASH_SIZE];
149
150/* This is based on the hash agorithm from gdbm, via tdb */
151static inline unsigned int tdb_hash(const char *name)
152{
153 unsigned value; /* Used to compute the hash value. */
154 unsigned i; /* Used to cycle through random values. */
155
156 /* Set the initial value from the key size. */
157 for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++)
158 value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));
159
160 return (1103515243 * value + 12345);
161}
162
5c3ead8c
SR
163/**
164 * Allocate a new symbols for use in the hash of exported symbols or
165 * the list of unresolved symbols per module
166 **/
167static struct symbol *alloc_symbol(const char *name, unsigned int weak,
168 struct symbol *next)
1da177e4
LT
169{
170 struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
171
172 memset(s, 0, sizeof(*s));
173 strcpy(s->name, name);
174 s->weak = weak;
175 s->next = next;
176 return s;
177}
178
179/* For the hash of exported symbols */
bd5cbced
RP
180static struct symbol *new_symbol(const char *name, struct module *module,
181 enum export export)
1da177e4
LT
182{
183 unsigned int hash;
184 struct symbol *new;
185
186 hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
187 new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
188 new->module = module;
bd5cbced 189 new->export = export;
040fcc81 190 return new;
1da177e4
LT
191}
192
5c3ead8c 193static struct symbol *find_symbol(const char *name)
1da177e4
LT
194{
195 struct symbol *s;
196
197 /* For our purposes, .foo matches foo. PPC64 needs this. */
198 if (name[0] == '.')
199 name++;
200
201 for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) {
202 if (strcmp(s->name, name) == 0)
203 return s;
204 }
205 return NULL;
206}
207
bd5cbced
RP
208static struct {
209 const char *str;
210 enum export export;
211} export_list[] = {
212 { .str = "EXPORT_SYMBOL", .export = export_plain },
c96fca21 213 { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
bd5cbced 214 { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
c96fca21 215 { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
bd5cbced
RP
216 { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
217 { .str = "(unknown)", .export = export_unknown },
218};
219
220
221static const char *export_str(enum export ex)
222{
223 return export_list[ex].str;
224}
225
226static enum export export_no(const char * s)
227{
228 int i;
534b89a9
SR
229 if (!s)
230 return export_unknown;
bd5cbced
RP
231 for (i = 0; export_list[i].export != export_unknown; i++) {
232 if (strcmp(export_list[i].str, s) == 0)
233 return export_list[i].export;
234 }
235 return export_unknown;
236}
237
238static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
239{
240 if (sec == elf->export_sec)
241 return export_plain;
c96fca21
SR
242 else if (sec == elf->export_unused_sec)
243 return export_unused;
bd5cbced
RP
244 else if (sec == elf->export_gpl_sec)
245 return export_gpl;
c96fca21
SR
246 else if (sec == elf->export_unused_gpl_sec)
247 return export_unused_gpl;
bd5cbced
RP
248 else if (sec == elf->export_gpl_future_sec)
249 return export_gpl_future;
250 else
251 return export_unknown;
252}
253
5c3ead8c
SR
254/**
255 * Add an exported symbol - it may have already been added without a
256 * CRC, in this case just update the CRC
257 **/
bd5cbced
RP
258static struct symbol *sym_add_exported(const char *name, struct module *mod,
259 enum export export)
1da177e4
LT
260{
261 struct symbol *s = find_symbol(name);
262
263 if (!s) {
bd5cbced 264 s = new_symbol(name, mod, export);
8e70c458
SR
265 } else {
266 if (!s->preloaded) {
7b75b13c 267 warn("%s: '%s' exported twice. Previous export "
8e70c458
SR
268 "was in %s%s\n", mod->name, name,
269 s->module->name,
270 is_vmlinux(s->module->name) ?"":".ko");
271 }
1da177e4 272 }
8e70c458 273 s->preloaded = 0;
040fcc81
SR
274 s->vmlinux = is_vmlinux(mod->name);
275 s->kernel = 0;
bd5cbced 276 s->export = export;
040fcc81
SR
277 return s;
278}
279
280static void sym_update_crc(const char *name, struct module *mod,
bd5cbced 281 unsigned int crc, enum export export)
040fcc81
SR
282{
283 struct symbol *s = find_symbol(name);
284
285 if (!s)
bd5cbced 286 s = new_symbol(name, mod, export);
040fcc81
SR
287 s->crc = crc;
288 s->crc_valid = 1;
1da177e4
LT
289}
290
5c3ead8c 291void *grab_file(const char *filename, unsigned long *size)
1da177e4
LT
292{
293 struct stat st;
294 void *map;
295 int fd;
296
297 fd = open(filename, O_RDONLY);
298 if (fd < 0 || fstat(fd, &st) != 0)
299 return NULL;
300
301 *size = st.st_size;
302 map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
303 close(fd);
304
305 if (map == MAP_FAILED)
306 return NULL;
307 return map;
308}
309
5c3ead8c
SR
310/**
311 * Return a copy of the next line in a mmap'ed file.
312 * spaces in the beginning of the line is trimmed away.
313 * Return a pointer to a static buffer.
314 **/
315char* get_next_line(unsigned long *pos, void *file, unsigned long size)
1da177e4
LT
316{
317 static char line[4096];
318 int skip = 1;
319 size_t len = 0;
320 signed char *p = (signed char *)file + *pos;
321 char *s = line;
322
323 for (; *pos < size ; (*pos)++)
324 {
325 if (skip && isspace(*p)) {
326 p++;
327 continue;
328 }
329 skip = 0;
330 if (*p != '\n' && (*pos < size)) {
331 len++;
332 *s++ = *p++;
333 if (len > 4095)
334 break; /* Too long, stop */
335 } else {
336 /* End of string */
337 *s = '\0';
338 return line;
339 }
340 }
341 /* End of buffer */
342 return NULL;
343}
344
5c3ead8c 345void release_file(void *file, unsigned long size)
1da177e4
LT
346{
347 munmap(file, size);
348}
349
85bd2fdd 350static int parse_elf(struct elf_info *info, const char *filename)
1da177e4
LT
351{
352 unsigned int i;
85bd2fdd 353 Elf_Ehdr *hdr;
1da177e4
LT
354 Elf_Shdr *sechdrs;
355 Elf_Sym *sym;
356
357 hdr = grab_file(filename, &info->size);
358 if (!hdr) {
359 perror(filename);
6803dc0e 360 exit(1);
1da177e4
LT
361 }
362 info->hdr = hdr;
85bd2fdd
SR
363 if (info->size < sizeof(*hdr)) {
364 /* file too small, assume this is an empty .o file */
365 return 0;
366 }
367 /* Is this a valid ELF file? */
368 if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||
369 (hdr->e_ident[EI_MAG1] != ELFMAG1) ||
370 (hdr->e_ident[EI_MAG2] != ELFMAG2) ||
371 (hdr->e_ident[EI_MAG3] != ELFMAG3)) {
372 /* Not an ELF file - silently ignore it */
373 return 0;
374 }
1da177e4
LT
375 /* Fix endianness in ELF header */
376 hdr->e_shoff = TO_NATIVE(hdr->e_shoff);
377 hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
378 hdr->e_shnum = TO_NATIVE(hdr->e_shnum);
379 hdr->e_machine = TO_NATIVE(hdr->e_machine);
ae4ac123 380 hdr->e_type = TO_NATIVE(hdr->e_type);
1da177e4
LT
381 sechdrs = (void *)hdr + hdr->e_shoff;
382 info->sechdrs = sechdrs;
383
384 /* Fix endianness in section headers */
385 for (i = 0; i < hdr->e_shnum; i++) {
386 sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);
387 sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);
388 sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);
389 sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);
390 sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);
ae4ac123
AN
391 sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);
392 sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);
1da177e4
LT
393 }
394 /* Find symbol table. */
395 for (i = 1; i < hdr->e_shnum; i++) {
396 const char *secstrings
397 = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
bd5cbced 398 const char *secname;
1da177e4 399
85bd2fdd
SR
400 if (sechdrs[i].sh_offset > info->size) {
401 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr));
402 return 0;
403 }
bd5cbced
RP
404 secname = secstrings + sechdrs[i].sh_name;
405 if (strcmp(secname, ".modinfo") == 0) {
1da177e4
LT
406 info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
407 info->modinfo_len = sechdrs[i].sh_size;
bd5cbced
RP
408 } else if (strcmp(secname, "__ksymtab") == 0)
409 info->export_sec = i;
c96fca21
SR
410 else if (strcmp(secname, "__ksymtab_unused") == 0)
411 info->export_unused_sec = i;
bd5cbced
RP
412 else if (strcmp(secname, "__ksymtab_gpl") == 0)
413 info->export_gpl_sec = i;
c96fca21
SR
414 else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
415 info->export_unused_gpl_sec = i;
bd5cbced
RP
416 else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
417 info->export_gpl_future_sec = i;
418
1da177e4
LT
419 if (sechdrs[i].sh_type != SHT_SYMTAB)
420 continue;
421
422 info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
62070fa4 423 info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset
1da177e4 424 + sechdrs[i].sh_size;
62070fa4 425 info->strtab = (void *)hdr +
1da177e4
LT
426 sechdrs[sechdrs[i].sh_link].sh_offset;
427 }
428 if (!info->symtab_start) {
cb80514d 429 fatal("%s has no symtab?\n", filename);
1da177e4
LT
430 }
431 /* Fix endianness in symbols */
432 for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
433 sym->st_shndx = TO_NATIVE(sym->st_shndx);
434 sym->st_name = TO_NATIVE(sym->st_name);
435 sym->st_value = TO_NATIVE(sym->st_value);
436 sym->st_size = TO_NATIVE(sym->st_size);
437 }
85bd2fdd 438 return 1;
1da177e4
LT
439}
440
5c3ead8c 441static void parse_elf_finish(struct elf_info *info)
1da177e4
LT
442{
443 release_file(info->hdr, info->size);
444}
445
f7b05e64
LY
446#define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
447#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
1da177e4 448
5c3ead8c
SR
449static void handle_modversions(struct module *mod, struct elf_info *info,
450 Elf_Sym *sym, const char *symname)
1da177e4
LT
451{
452 unsigned int crc;
bd5cbced 453 enum export export = export_from_sec(info, sym->st_shndx);
1da177e4
LT
454
455 switch (sym->st_shndx) {
456 case SHN_COMMON:
cb80514d 457 warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
1da177e4
LT
458 break;
459 case SHN_ABS:
460 /* CRC'd symbol */
461 if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
462 crc = (unsigned int) sym->st_value;
bd5cbced
RP
463 sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
464 export);
1da177e4
LT
465 }
466 break;
467 case SHN_UNDEF:
468 /* undefined symbol */
469 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
470 ELF_ST_BIND(sym->st_info) != STB_WEAK)
471 break;
472 /* ignore global offset table */
473 if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
474 break;
475 /* ignore __this_module, it will be resolved shortly */
476 if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
477 break;
8d529014
BC
478/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
479#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
480/* add compatibility with older glibc */
481#ifndef STT_SPARC_REGISTER
482#define STT_SPARC_REGISTER STT_REGISTER
483#endif
1da177e4
LT
484 if (info->hdr->e_machine == EM_SPARC ||
485 info->hdr->e_machine == EM_SPARCV9) {
486 /* Ignore register directives. */
8d529014 487 if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
1da177e4 488 break;
62070fa4
SR
489 if (symname[0] == '.') {
490 char *munged = strdup(symname);
491 munged[0] = '_';
492 munged[1] = toupper(munged[1]);
493 symname = munged;
494 }
1da177e4
LT
495 }
496#endif
62070fa4 497
1da177e4
LT
498 if (memcmp(symname, MODULE_SYMBOL_PREFIX,
499 strlen(MODULE_SYMBOL_PREFIX)) == 0)
500 mod->unres = alloc_symbol(symname +
501 strlen(MODULE_SYMBOL_PREFIX),
502 ELF_ST_BIND(sym->st_info) == STB_WEAK,
503 mod->unres);
504 break;
505 default:
506 /* All exported symbols */
507 if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
bd5cbced
RP
508 sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
509 export);
1da177e4
LT
510 }
511 if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
512 mod->has_init = 1;
513 if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
514 mod->has_cleanup = 1;
515 break;
516 }
517}
518
5c3ead8c
SR
519/**
520 * Parse tag=value strings from .modinfo section
521 **/
1da177e4
LT
522static char *next_string(char *string, unsigned long *secsize)
523{
524 /* Skip non-zero chars */
525 while (string[0]) {
526 string++;
527 if ((*secsize)-- <= 1)
528 return NULL;
529 }
530
531 /* Skip any zero padding. */
532 while (!string[0]) {
533 string++;
534 if ((*secsize)-- <= 1)
535 return NULL;
536 }
537 return string;
538}
539
b817f6fe
SR
540static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
541 const char *tag, char *info)
1da177e4
LT
542{
543 char *p;
544 unsigned int taglen = strlen(tag);
545 unsigned long size = modinfo_len;
546
b817f6fe
SR
547 if (info) {
548 size -= info - (char *)modinfo;
549 modinfo = next_string(info, &size);
550 }
551
1da177e4
LT
552 for (p = modinfo; p; p = next_string(p, &size)) {
553 if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
554 return p + taglen + 1;
555 }
556 return NULL;
557}
558
b817f6fe
SR
559static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
560 const char *tag)
561
562{
563 return get_next_modinfo(modinfo, modinfo_len, tag, NULL);
564}
565
4c8fbca5
SR
566/**
567 * Test if string s ends in string sub
568 * return 0 if match
569 **/
570static int strrcmp(const char *s, const char *sub)
571{
572 int slen, sublen;
62070fa4 573
4c8fbca5
SR
574 if (!s || !sub)
575 return 1;
62070fa4 576
4c8fbca5
SR
577 slen = strlen(s);
578 sublen = strlen(sub);
62070fa4 579
4c8fbca5
SR
580 if ((slen == 0) || (sublen == 0))
581 return 1;
582
583 if (sublen > slen)
584 return 1;
585
586 return memcmp(s + slen - sublen, sub, sublen);
587}
588
2f5ee619
SR
589/*
590 * Functions used only during module init is marked __init and is stored in
591 * a .init.text section. Likewise data is marked __initdata and stored in
592 * a .init.data section.
593 * If this section is one of these sections return 1
594 * See include/linux/init.h for the details
595 */
596static int init_section(const char *name)
597{
598 if (strcmp(name, ".init") == 0)
599 return 1;
600 if (strncmp(name, ".init.", strlen(".init.")) == 0)
601 return 1;
602 return 0;
603}
604
605/*
606 * Functions used only during module exit is marked __exit and is stored in
607 * a .exit.text section. Likewise data is marked __exitdata and stored in
608 * a .exit.data section.
609 * If this section is one of these sections return 1
610 * See include/linux/init.h for the details
611 **/
612static int exit_section(const char *name)
613{
614 if (strcmp(name, ".exit.text") == 0)
615 return 1;
616 if (strcmp(name, ".exit.data") == 0)
617 return 1;
618 return 0;
619
620}
621
622/*
623 * Data sections are named like this:
624 * .data | .data.rel | .data.rel.*
625 * Return 1 if the specified section is a data section
626 */
627static int data_section(const char *name)
628{
629 if ((strcmp(name, ".data") == 0) ||
630 (strcmp(name, ".data.rel") == 0) ||
631 (strncmp(name, ".data.rel.", strlen(".data.rel.")) == 0))
632 return 1;
633 else
634 return 0;
635}
636
4c8fbca5
SR
637/**
638 * Whitelist to allow certain references to pass with no warning.
0e0d314e
SR
639 *
640 * Pattern 0:
641 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
642 * The pattern is identified by:
cb7e51d8 643 * fromsec = .text.init.refok* | .data.init.refok*
0e0d314e 644 *
4c8fbca5
SR
645 * Pattern 1:
646 * If a module parameter is declared __initdata and permissions=0
647 * then this is legal despite the warning generated.
648 * We cannot see value of permissions here, so just ignore
649 * this pattern.
650 * The pattern is identified by:
651 * tosec = .init.data
9209aed0 652 * fromsec = .data*
4c8fbca5 653 * atsym =__param*
62070fa4 654 *
4c8fbca5 655 * Pattern 2:
72ee59b5 656 * Many drivers utilise a *driver container with references to
4c8fbca5
SR
657 * add, remove, probe functions etc.
658 * These functions may often be marked __init and we do not want to
659 * warn here.
660 * the pattern is identified by:
83cda2bb
SR
661 * tosec = init or exit section
662 * fromsec = data section
1e29a706 663 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer
ee6a8545
VG
664 *
665 * Pattern 3:
9bf8cb9b
SR
666 * Whitelist all refereces from .text.head to .init.data
667 * Whitelist all refereces from .text.head to .init.text
668 *
1d8af559 669 * Pattern 4:
ee6a8545
VG
670 * Some symbols belong to init section but still it is ok to reference
671 * these from non-init sections as these symbols don't have any memory
672 * allocated for them and symbol address and value are same. So even
673 * if init section is freed, its ok to reference those symbols.
674 * For ex. symbols marking the init section boundaries.
675 * This pattern is identified by
676 * refsymname = __init_begin, _sinittext, _einittext
9bf8cb9b 677 *
cb7e51d8
SR
678 * Pattern 5:
679 * Xtensa uses literal sections for constants that are accessed PC-relative.
680 * Literal sections may safely reference their text sections.
681 * (Note that the name for the literal section omits any trailing '.text')
682 * tosec = <section>[.text]
683 * fromsec = <section>.literal
4c8fbca5 684 **/
9e157a5a 685static int secref_whitelist(const char *modname, const char *tosec,
ee6a8545
VG
686 const char *fromsec, const char *atsym,
687 const char *refsymname)
4c8fbca5 688{
cb7e51d8 689 int len;
4c8fbca5
SR
690 const char **s;
691 const char *pat2sym[] = {
72ee59b5 692 "driver",
5ecdd0f6 693 "_template", /* scsi uses *_template a lot */
1e29a706 694 "_timer", /* arm uses ops structures named _timer a lot */
5ecdd0f6 695 "_sht", /* scsi also used *_sht to some extent */
4c8fbca5
SR
696 "_ops",
697 "_probe",
698 "_probe_one",
118c0ace 699 "_console",
4c8fbca5
SR
700 NULL
701 };
62070fa4 702
ee6a8545
VG
703 const char *pat3refsym[] = {
704 "__init_begin",
705 "_sinittext",
706 "_einittext",
707 NULL
708 };
709
0e0d314e 710 /* Check for pattern 0 */
cb7e51d8 711 if ((strncmp(fromsec, ".text.init.refok", strlen(".text.init.refok")) == 0) ||
4665079c 712 (strncmp(fromsec, ".exit.text.refok", strlen(".exit.text.refok")) == 0) ||
cb7e51d8 713 (strncmp(fromsec, ".data.init.refok", strlen(".data.init.refok")) == 0))
0e0d314e
SR
714 return 1;
715
4c8fbca5 716 /* Check for pattern 1 */
83cda2bb
SR
717 if ((strcmp(tosec, ".init.data") == 0) &&
718 (strncmp(fromsec, ".data", strlen(".data")) == 0) &&
719 (strncmp(atsym, "__param", strlen("__param")) == 0))
720 return 1;
4c8fbca5
SR
721
722 /* Check for pattern 2 */
83cda2bb
SR
723 if ((init_section(tosec) || exit_section(tosec)) && data_section(fromsec))
724 for (s = pat2sym; *s; s++)
725 if (strrcmp(atsym, *s) == 0)
726 return 1;
4c8fbca5 727
9bf8cb9b 728 /* Check for pattern 3 */
9bf8cb9b
SR
729 if ((strcmp(fromsec, ".text.head") == 0) &&
730 ((strcmp(tosec, ".init.data") == 0) ||
731 (strcmp(tosec, ".init.text") == 0)))
732 return 1;
733
1d8af559 734 /* Check for pattern 4 */
9bf8cb9b
SR
735 for (s = pat3refsym; *s; s++)
736 if (strcmp(refsymname, *s) == 0)
737 return 1;
738
cb7e51d8
SR
739 /* Check for pattern 5 */
740 if (strrcmp(tosec, ".text") == 0)
741 len = strlen(tosec) - strlen(".text");
742 else
743 len = strlen(tosec);
744 if ((strncmp(tosec, fromsec, len) == 0) && (strlen(fromsec) > len) &&
745 (strcmp(fromsec + len, ".literal") == 0))
746 return 1;
747
93659af1 748 return 0;
4c8fbca5
SR
749}
750
93684d3b
SR
751/**
752 * Find symbol based on relocation record info.
753 * In some cases the symbol supplied is a valid symbol so
754 * return refsym. If st_name != 0 we assume this is a valid symbol.
755 * In other cases the symbol needs to be looked up in the symbol table
756 * based on section and address.
757 * **/
758static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
759 Elf_Sym *relsym)
760{
761 Elf_Sym *sym;
762
763 if (relsym->st_name != 0)
764 return relsym;
765 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
766 if (sym->st_shndx != relsym->st_shndx)
767 continue;
ae4ac123
AN
768 if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
769 continue;
93684d3b
SR
770 if (sym->st_value == addr)
771 return sym;
772 }
773 return NULL;
774}
775
da68d61f
DB
776static inline int is_arm_mapping_symbol(const char *str)
777{
778 return str[0] == '$' && strchr("atd", str[1])
779 && (str[2] == '\0' || str[2] == '.');
780}
781
782/*
783 * If there's no name there, ignore it; likewise, ignore it if it's
784 * one of the magic symbols emitted used by current ARM tools.
785 *
786 * Otherwise if find_symbols_between() returns those symbols, they'll
787 * fail the whitelist tests and cause lots of false alarms ... fixable
788 * only by merging __exit and __init sections into __text, bloating
789 * the kernel (which is especially evil on embedded platforms).
790 */
791static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
792{
793 const char *name = elf->strtab + sym->st_name;
794
795 if (!name || !strlen(name))
796 return 0;
797 return !is_arm_mapping_symbol(name);
798}
799
b39927cf 800/*
43c74d17
SR
801 * Find symbols before or equal addr and after addr - in the section sec.
802 * If we find two symbols with equal offset prefer one with a valid name.
803 * The ELF format may have a better way to detect what type of symbol
804 * it is, but this works for now.
b39927cf
SR
805 **/
806static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
807 const char *sec,
808 Elf_Sym **before, Elf_Sym **after)
809{
810 Elf_Sym *sym;
811 Elf_Ehdr *hdr = elf->hdr;
812 Elf_Addr beforediff = ~0;
813 Elf_Addr afterdiff = ~0;
814 const char *secstrings = (void *)hdr +
815 elf->sechdrs[hdr->e_shstrndx].sh_offset;
62070fa4 816
b39927cf
SR
817 *before = NULL;
818 *after = NULL;
819
820 for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
821 const char *symsec;
822
823 if (sym->st_shndx >= SHN_LORESERVE)
824 continue;
825 symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
826 if (strcmp(symsec, sec) != 0)
827 continue;
da68d61f
DB
828 if (!is_valid_name(elf, sym))
829 continue;
b39927cf
SR
830 if (sym->st_value <= addr) {
831 if ((addr - sym->st_value) < beforediff) {
832 beforediff = addr - sym->st_value;
833 *before = sym;
834 }
43c74d17 835 else if ((addr - sym->st_value) == beforediff) {
da68d61f 836 *before = sym;
43c74d17 837 }
b39927cf
SR
838 }
839 else
840 {
841 if ((sym->st_value - addr) < afterdiff) {
842 afterdiff = sym->st_value - addr;
843 *after = sym;
844 }
43c74d17 845 else if ((sym->st_value - addr) == afterdiff) {
da68d61f 846 *after = sym;
43c74d17 847 }
b39927cf
SR
848 }
849 }
850}
851
852/**
853 * Print a warning about a section mismatch.
854 * Try to find symbols near it so user can find it.
4c8fbca5 855 * Check whitelist before warning - it may be a false positive.
b39927cf
SR
856 **/
857static void warn_sec_mismatch(const char *modname, const char *fromsec,
858 struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
859{
93684d3b
SR
860 const char *refsymname = "";
861 Elf_Sym *before, *after;
862 Elf_Sym *refsym;
b39927cf
SR
863 Elf_Ehdr *hdr = elf->hdr;
864 Elf_Shdr *sechdrs = elf->sechdrs;
865 const char *secstrings = (void *)hdr +
866 sechdrs[hdr->e_shstrndx].sh_offset;
867 const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
62070fa4 868
b39927cf
SR
869 find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
870
93684d3b
SR
871 refsym = find_elf_symbol(elf, r.r_addend, sym);
872 if (refsym && strlen(elf->strtab + refsym->st_name))
873 refsymname = elf->strtab + refsym->st_name;
4c8fbca5
SR
874
875 /* check whitelist - we may ignore it */
cb7e51d8
SR
876 if (secref_whitelist(modname, secname, fromsec,
877 before ? elf->strtab + before->st_name : "",
878 refsymname))
4c8fbca5 879 return;
62070fa4 880
b39927cf 881 if (before && after) {
25601209
RK
882 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
883 "(between '%s' and '%s')\n",
884 modname, fromsec, (unsigned long long)r.r_offset,
885 secname, refsymname,
b39927cf 886 elf->strtab + before->st_name,
b39927cf
SR
887 elf->strtab + after->st_name);
888 } else if (before) {
25601209
RK
889 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
890 "(after '%s')\n",
891 modname, fromsec, (unsigned long long)r.r_offset,
892 secname, refsymname,
893 elf->strtab + before->st_name);
b39927cf 894 } else if (after) {
25601209 895 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
93684d3b 896 "before '%s' (at offset -0x%llx)\n",
25601209
RK
897 modname, fromsec, (unsigned long long)r.r_offset,
898 secname, refsymname,
899 elf->strtab + after->st_name);
b39927cf 900 } else {
25601209
RK
901 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
902 modname, fromsec, (unsigned long long)r.r_offset,
903 secname, refsymname);
b39927cf
SR
904 }
905}
906
ae4ac123
AN
907static unsigned int *reloc_location(struct elf_info *elf,
908 int rsection, Elf_Rela *r)
909{
910 Elf_Shdr *sechdrs = elf->sechdrs;
911 int section = sechdrs[rsection].sh_info;
912
913 return (void *)elf->hdr + sechdrs[section].sh_offset +
914 (r->r_offset - sechdrs[section].sh_addr);
915}
916
917static int addend_386_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
918{
919 unsigned int r_typ = ELF_R_TYPE(r->r_info);
920 unsigned int *location = reloc_location(elf, rsection, r);
921
922 switch (r_typ) {
923 case R_386_32:
924 r->r_addend = TO_NATIVE(*location);
925 break;
926 case R_386_PC32:
927 r->r_addend = TO_NATIVE(*location) + 4;
928 /* For CONFIG_RELOCATABLE=y */
929 if (elf->hdr->e_type == ET_EXEC)
930 r->r_addend += r->r_offset;
931 break;
932 }
933 return 0;
934}
935
56a974fa
SR
936static int addend_arm_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
937{
938 unsigned int r_typ = ELF_R_TYPE(r->r_info);
939
940 switch (r_typ) {
941 case R_ARM_ABS32:
942 /* From ARM ABI: (S + A) | T */
943 r->r_addend = (int)(long)(elf->symtab_start + ELF_R_SYM(r->r_info));
944 break;
945 case R_ARM_PC24:
946 /* From ARM ABI: ((S + A) | T) - P */
947 r->r_addend = (int)(long)(elf->hdr + elf->sechdrs[rsection].sh_offset +
948 (r->r_offset - elf->sechdrs[rsection].sh_addr));
949 break;
950 default:
951 return 1;
952 }
953 return 0;
954}
955
ae4ac123
AN
956static int addend_mips_rel(struct elf_info *elf, int rsection, Elf_Rela *r)
957{
958 unsigned int r_typ = ELF_R_TYPE(r->r_info);
959 unsigned int *location = reloc_location(elf, rsection, r);
960 unsigned int inst;
961
962 if (r_typ == R_MIPS_HI16)
963 return 1; /* skip this */
964 inst = TO_NATIVE(*location);
965 switch (r_typ) {
966 case R_MIPS_LO16:
967 r->r_addend = inst & 0xffff;
968 break;
969 case R_MIPS_26:
970 r->r_addend = (inst & 0x03ffffff) << 2;
971 break;
972 case R_MIPS_32:
973 r->r_addend = inst;
974 break;
975 }
976 return 0;
977}
978
b39927cf
SR
979/**
980 * A module includes a number of sections that are discarded
981 * either when loaded or when used as built-in.
982 * For loaded modules all functions marked __init and all data
983 * marked __initdata will be discarded when the module has been intialized.
984 * Likewise for modules used built-in the sections marked __exit
985 * are discarded because __exit marked function are supposed to be called
986 * only when a moduel is unloaded which never happes for built-in modules.
987 * The check_sec_ref() function traverses all relocation records
988 * to find all references to a section that reference a section that will
989 * be discarded and warns about it.
990 **/
991static void check_sec_ref(struct module *mod, const char *modname,
992 struct elf_info *elf,
993 int section(const char*),
994 int section_ref_ok(const char *))
995{
996 int i;
997 Elf_Sym *sym;
998 Elf_Ehdr *hdr = elf->hdr;
999 Elf_Shdr *sechdrs = elf->sechdrs;
1000 const char *secstrings = (void *)hdr +
1001 sechdrs[hdr->e_shstrndx].sh_offset;
62070fa4 1002
b39927cf
SR
1003 /* Walk through all sections */
1004 for (i = 0; i < hdr->e_shnum; i++) {
2c1a51f3
AN
1005 const char *name = secstrings + sechdrs[i].sh_name;
1006 const char *secname;
1007 Elf_Rela r;
eae07ac6 1008 unsigned int r_sym;
b39927cf 1009 /* We want to process only relocation sections and not .init */
2c1a51f3
AN
1010 if (sechdrs[i].sh_type == SHT_RELA) {
1011 Elf_Rela *rela;
1012 Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
1013 Elf_Rela *stop = (void*)start + sechdrs[i].sh_size;
1014 name += strlen(".rela");
1015 if (section_ref_ok(name))
1016 continue;
b39927cf 1017
2c1a51f3
AN
1018 for (rela = start; rela < stop; rela++) {
1019 r.r_offset = TO_NATIVE(rela->r_offset);
eae07ac6
AN
1020#if KERNEL_ELFCLASS == ELFCLASS64
1021 if (hdr->e_machine == EM_MIPS) {
ae4ac123 1022 unsigned int r_typ;
eae07ac6
AN
1023 r_sym = ELF64_MIPS_R_SYM(rela->r_info);
1024 r_sym = TO_NATIVE(r_sym);
ae4ac123
AN
1025 r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
1026 r.r_info = ELF64_R_INFO(r_sym, r_typ);
eae07ac6
AN
1027 } else {
1028 r.r_info = TO_NATIVE(rela->r_info);
1029 r_sym = ELF_R_SYM(r.r_info);
1030 }
1031#else
1032 r.r_info = TO_NATIVE(rela->r_info);
1033 r_sym = ELF_R_SYM(r.r_info);
1034#endif
2c1a51f3 1035 r.r_addend = TO_NATIVE(rela->r_addend);
eae07ac6 1036 sym = elf->symtab_start + r_sym;
2c1a51f3
AN
1037 /* Skip special sections */
1038 if (sym->st_shndx >= SHN_LORESERVE)
1039 continue;
1040
1041 secname = secstrings +
1042 sechdrs[sym->st_shndx].sh_name;
1043 if (section(secname))
1044 warn_sec_mismatch(modname, name,
1045 elf, sym, r);
1046 }
1047 } else if (sechdrs[i].sh_type == SHT_REL) {
1048 Elf_Rel *rel;
1049 Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset;
1050 Elf_Rel *stop = (void*)start + sechdrs[i].sh_size;
1051 name += strlen(".rel");
1052 if (section_ref_ok(name))
b39927cf
SR
1053 continue;
1054
2c1a51f3
AN
1055 for (rel = start; rel < stop; rel++) {
1056 r.r_offset = TO_NATIVE(rel->r_offset);
eae07ac6
AN
1057#if KERNEL_ELFCLASS == ELFCLASS64
1058 if (hdr->e_machine == EM_MIPS) {
ae4ac123 1059 unsigned int r_typ;
eae07ac6
AN
1060 r_sym = ELF64_MIPS_R_SYM(rel->r_info);
1061 r_sym = TO_NATIVE(r_sym);
ae4ac123
AN
1062 r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
1063 r.r_info = ELF64_R_INFO(r_sym, r_typ);
eae07ac6
AN
1064 } else {
1065 r.r_info = TO_NATIVE(rel->r_info);
1066 r_sym = ELF_R_SYM(r.r_info);
1067 }
1068#else
1069 r.r_info = TO_NATIVE(rel->r_info);
1070 r_sym = ELF_R_SYM(r.r_info);
1071#endif
2c1a51f3 1072 r.r_addend = 0;
ae4ac123
AN
1073 switch (hdr->e_machine) {
1074 case EM_386:
1075 if (addend_386_rel(elf, i, &r))
1076 continue;
1077 break;
56a974fa
SR
1078 case EM_ARM:
1079 if(addend_arm_rel(elf, i, &r))
1080 continue;
1081 break;
ae4ac123
AN
1082 case EM_MIPS:
1083 if (addend_mips_rel(elf, i, &r))
1084 continue;
1085 break;
1086 }
eae07ac6 1087 sym = elf->symtab_start + r_sym;
2c1a51f3
AN
1088 /* Skip special sections */
1089 if (sym->st_shndx >= SHN_LORESERVE)
1090 continue;
1091
1092 secname = secstrings +
1093 sechdrs[sym->st_shndx].sh_name;
1094 if (section(secname))
1095 warn_sec_mismatch(modname, name,
1096 elf, sym, r);
1097 }
b39927cf
SR
1098 }
1099 }
1100}
1101
1087247b
SR
1102/*
1103 * Identify sections from which references to either a
1104 * .init or a .exit section is OK.
1105 *
1106 * [OPD] Keith Ownes <kaos@sgi.com> commented:
1107 * For our future {in}sanity, add a comment that this is the ppc .opd
1108 * section, not the ia64 .opd section.
1109 * ia64 .opd should not point to discarded sections.
1110 * [.rodata] like for .init.text we ignore .rodata references -same reason
1d8af559 1111 */
1087247b
SR
1112static int initexit_section_ref_ok(const char *name)
1113{
1114 const char **s;
1115 /* Absolute section names */
1116 const char *namelist1[] = {
1117 "__bug_table", /* used by powerpc for BUG() */
1118 "__ex_table",
1119 ".altinstructions",
1120 ".cranges", /* used by sh64 */
1121 ".fixup",
1d8af559
SR
1122 ".machvec", /* ia64 + powerpc uses these */
1123 ".machine.desc",
1087247b 1124 ".opd", /* See comment [OPD] */
ad0b1427 1125 "__dbe_table",
1087247b
SR
1126 ".parainstructions",
1127 ".pdr",
1128 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
1129 ".smp_locks",
1130 ".stab",
3a5df1d4 1131 ".m68k_fixup",
cb7e51d8
SR
1132 ".xt.prop", /* xtensa informational section */
1133 ".xt.lit", /* xtensa informational section */
1087247b
SR
1134 NULL
1135 };
1136 /* Start of section names */
1137 const char *namelist2[] = {
1138 ".debug",
1139 ".eh_frame",
1140 ".note", /* ignore ELF notes - may contain anything */
1141 ".got", /* powerpc - global offset table */
1142 ".toc", /* powerpc - table of contents */
1143 NULL
1144 };
1145 /* part of section name */
1146 const char *namelist3 [] = {
1147 ".unwind", /* Sample: IA_64.unwind.exit.text */
1148 NULL
1149 };
1150
1151 for (s = namelist1; *s; s++)
1152 if (strcmp(*s, name) == 0)
1153 return 1;
1154 for (s = namelist2; *s; s++)
1155 if (strncmp(*s, name, strlen(*s)) == 0)
1156 return 1;
1157 for (s = namelist3; *s; s++)
1158 if (strstr(name, *s) != NULL)
1159 return 1;
1160 return 0;
1161}
1162
b39927cf 1163
1087247b 1164/*
b39927cf 1165 * Identify sections from which references to a .init section is OK.
62070fa4 1166 *
b39927cf
SR
1167 * Unfortunately references to read only data that referenced .init
1168 * sections had to be excluded. Almost all of these are false
1169 * positives, they are created by gcc. The downside of excluding rodata
1170 * is that there really are some user references from rodata to
1171 * init code, e.g. drivers/video/vgacon.c:
62070fa4 1172 *
b39927cf
SR
1173 * const struct consw vga_con = {
1174 * con_startup: vgacon_startup,
1175 *
1176 * where vgacon_startup is __init. If you want to wade through the false
1177 * positives, take out the check for rodata.
1087247b 1178 */
b39927cf
SR
1179static int init_section_ref_ok(const char *name)
1180{
1181 const char **s;
1182 /* Absolute section names */
1183 const char *namelist1[] = {
eec73e88 1184 "__dbe_table", /* MIPS generate these */
21c4ff80
BH
1185 "__ftr_fixup", /* powerpc cpu feature fixup */
1186 "__fw_ftr_fixup", /* powerpc firmware feature fixup */
1087247b
SR
1187 "__param",
1188 ".data.rel.ro", /* used by parisc64 */
1189 ".init",
1190 ".text.lock",
b39927cf
SR
1191 NULL
1192 };
1193 /* Start of section names */
1194 const char *namelist2[] = {
1195 ".init.",
1087247b 1196 ".pci_fixup",
742433b0 1197 ".rodata",
6e10133f
SR
1198 NULL
1199 };
1200
1087247b
SR
1201 if (initexit_section_ref_ok(name))
1202 return 1;
1203
b39927cf
SR
1204 for (s = namelist1; *s; s++)
1205 if (strcmp(*s, name) == 0)
1206 return 1;
62070fa4 1207 for (s = namelist2; *s; s++)
b39927cf
SR
1208 if (strncmp(*s, name, strlen(*s)) == 0)
1209 return 1;
1087247b
SR
1210
1211 /* If section name ends with ".init" we allow references
1212 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc
1213 */
468d9494
AV
1214 if (strrcmp(name, ".init") == 0)
1215 return 1;
b39927cf
SR
1216 return 0;
1217}
1218
b39927cf
SR
1219/*
1220 * Identify sections from which references to a .exit section is OK.
1087247b 1221 */
b39927cf
SR
1222static int exit_section_ref_ok(const char *name)
1223{
1224 const char **s;
1225 /* Absolute section names */
1226 const char *namelist1[] = {
b39927cf 1227 ".exit.data",
1087247b
SR
1228 ".exit.text",
1229 ".exitcall.exit",
5ecdd0f6 1230 ".rodata",
6e10133f
SR
1231 NULL
1232 };
62070fa4 1233
1087247b
SR
1234 if (initexit_section_ref_ok(name))
1235 return 1;
1236
b39927cf
SR
1237 for (s = namelist1; *s; s++)
1238 if (strcmp(*s, name) == 0)
1239 return 1;
b39927cf
SR
1240 return 0;
1241}
1242
5c3ead8c 1243static void read_symbols(char *modname)
1da177e4
LT
1244{
1245 const char *symname;
1246 char *version;
b817f6fe 1247 char *license;
1da177e4
LT
1248 struct module *mod;
1249 struct elf_info info = { };
1250 Elf_Sym *sym;
1251
85bd2fdd
SR
1252 if (!parse_elf(&info, modname))
1253 return;
1da177e4
LT
1254
1255 mod = new_module(modname);
1256
1257 /* When there's no vmlinux, don't print warnings about
1258 * unresolved symbols (since there'll be too many ;) */
1259 if (is_vmlinux(modname)) {
1da177e4 1260 have_vmlinux = 1;
1da177e4
LT
1261 mod->skip = 1;
1262 }
1263
b817f6fe
SR
1264 license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1265 while (license) {
1266 if (license_is_gpl_compatible(license))
1267 mod->gpl_compatible = 1;
1268 else {
1269 mod->gpl_compatible = 0;
1270 break;
1271 }
1272 license = get_next_modinfo(info.modinfo, info.modinfo_len,
1273 "license", license);
1274 }
1275
1da177e4
LT
1276 for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
1277 symname = info.strtab + sym->st_name;
1278
1279 handle_modversions(mod, &info, sym, symname);
1280 handle_moddevtable(mod, &info, sym, symname);
1281 }
8d8d8289
SR
1282 if (is_vmlinux(modname) && vmlinux_section_warnings) {
1283 check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
1284 check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
1285 }
1da177e4
LT
1286
1287 version = get_modinfo(info.modinfo, info.modinfo_len, "version");
1288 if (version)
1289 maybe_frob_rcs_version(modname, version, info.modinfo,
1290 version - (char *)info.hdr);
1291 if (version || (all_versions && !is_vmlinux(modname)))
1292 get_src_version(modname, mod->srcversion,
1293 sizeof(mod->srcversion)-1);
1294
1295 parse_elf_finish(&info);
1296
1297 /* Our trick to get versioning for struct_module - it's
1298 * never passed as an argument to an exported function, so
1299 * the automatic versioning doesn't pick it up, but it's really
1300 * important anyhow */
1301 if (modversions)
1302 mod->unres = alloc_symbol("struct_module", 0, mod->unres);
1303}
1304
1305#define SZ 500
1306
1307/* We first write the generated file into memory using the
1308 * following helper, then compare to the file on disk and
1309 * only update the later if anything changed */
1310
5c3ead8c
SR
1311void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
1312 const char *fmt, ...)
1da177e4
LT
1313{
1314 char tmp[SZ];
1315 int len;
1316 va_list ap;
62070fa4 1317
1da177e4
LT
1318 va_start(ap, fmt);
1319 len = vsnprintf(tmp, SZ, fmt, ap);
7670f023 1320 buf_write(buf, tmp, len);
1da177e4
LT
1321 va_end(ap);
1322}
1323
5c3ead8c 1324void buf_write(struct buffer *buf, const char *s, int len)
1da177e4
LT
1325{
1326 if (buf->size - buf->pos < len) {
7670f023 1327 buf->size += len + SZ;
1da177e4
LT
1328 buf->p = realloc(buf->p, buf->size);
1329 }
1330 strncpy(buf->p + buf->pos, s, len);
1331 buf->pos += len;
1332}
1333
c96fca21
SR
1334static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
1335{
1336 const char *e = is_vmlinux(m) ?"":".ko";
1337
1338 switch (exp) {
1339 case export_gpl:
1340 fatal("modpost: GPL-incompatible module %s%s "
1341 "uses GPL-only symbol '%s'\n", m, e, s);
1342 break;
1343 case export_unused_gpl:
1344 fatal("modpost: GPL-incompatible module %s%s "
1345 "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
1346 break;
1347 case export_gpl_future:
1348 warn("modpost: GPL-incompatible module %s%s "
1349 "uses future GPL-only symbol '%s'\n", m, e, s);
1350 break;
1351 case export_plain:
1352 case export_unused:
1353 case export_unknown:
1354 /* ignore */
1355 break;
1356 }
1357}
1358
1359static void check_for_unused(enum export exp, const char* m, const char* s)
1360{
1361 const char *e = is_vmlinux(m) ?"":".ko";
1362
1363 switch (exp) {
1364 case export_unused:
1365 case export_unused_gpl:
1366 warn("modpost: module %s%s "
1367 "uses symbol '%s' marked UNUSED\n", m, e, s);
1368 break;
1369 default:
1370 /* ignore */
1371 break;
1372 }
1373}
1374
1375static void check_exports(struct module *mod)
b817f6fe
SR
1376{
1377 struct symbol *s, *exp;
1378
1379 for (s = mod->unres; s; s = s->next) {
6449bd62 1380 const char *basename;
b817f6fe
SR
1381 exp = find_symbol(s->name);
1382 if (!exp || exp->module == mod)
1383 continue;
6449bd62 1384 basename = strrchr(mod->name, '/');
b817f6fe
SR
1385 if (basename)
1386 basename++;
c96fca21
SR
1387 else
1388 basename = mod->name;
1389 if (!mod->gpl_compatible)
1390 check_for_gpl_usage(exp->export, basename, exp->name);
1391 check_for_unused(exp->export, basename, exp->name);
b817f6fe
SR
1392 }
1393}
1394
5c3ead8c
SR
1395/**
1396 * Header for the generated file
1397 **/
1398static void add_header(struct buffer *b, struct module *mod)
1da177e4
LT
1399{
1400 buf_printf(b, "#include <linux/module.h>\n");
1401 buf_printf(b, "#include <linux/vermagic.h>\n");
1402 buf_printf(b, "#include <linux/compiler.h>\n");
1403 buf_printf(b, "\n");
1404 buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1405 buf_printf(b, "\n");
1da177e4
LT
1406 buf_printf(b, "struct module __this_module\n");
1407 buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
f83b5e32 1408 buf_printf(b, " .name = KBUILD_MODNAME,\n");
1da177e4
LT
1409 if (mod->has_init)
1410 buf_printf(b, " .init = init_module,\n");
1411 if (mod->has_cleanup)
1412 buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
1413 " .exit = cleanup_module,\n"
1414 "#endif\n");
e61a1c1c 1415 buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
1da177e4
LT
1416 buf_printf(b, "};\n");
1417}
1418
5c3ead8c
SR
1419/**
1420 * Record CRCs for unresolved symbols
1421 **/
c53ddacd 1422static int add_versions(struct buffer *b, struct module *mod)
1da177e4
LT
1423{
1424 struct symbol *s, *exp;
c53ddacd 1425 int err = 0;
1da177e4
LT
1426
1427 for (s = mod->unres; s; s = s->next) {
1428 exp = find_symbol(s->name);
1429 if (!exp || exp->module == mod) {
c53ddacd 1430 if (have_vmlinux && !s->weak) {
2a116659
MW
1431 if (warn_unresolved) {
1432 warn("\"%s\" [%s.ko] undefined!\n",
1433 s->name, mod->name);
1434 } else {
1435 merror("\"%s\" [%s.ko] undefined!\n",
1436 s->name, mod->name);
1437 err = 1;
1438 }
c53ddacd 1439 }
1da177e4
LT
1440 continue;
1441 }
1442 s->module = exp->module;
1443 s->crc_valid = exp->crc_valid;
1444 s->crc = exp->crc;
1445 }
1446
1447 if (!modversions)
c53ddacd 1448 return err;
1da177e4
LT
1449
1450 buf_printf(b, "\n");
1451 buf_printf(b, "static const struct modversion_info ____versions[]\n");
1452 buf_printf(b, "__attribute_used__\n");
1453 buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");
1454
1455 for (s = mod->unres; s; s = s->next) {
1456 if (!s->module) {
1457 continue;
1458 }
1459 if (!s->crc_valid) {
cb80514d 1460 warn("\"%s\" [%s.ko] has no CRC!\n",
1da177e4
LT
1461 s->name, mod->name);
1462 continue;
1463 }
1464 buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
1465 }
1466
1467 buf_printf(b, "};\n");
c53ddacd
KK
1468
1469 return err;
1da177e4
LT
1470}
1471
5c3ead8c
SR
1472static void add_depends(struct buffer *b, struct module *mod,
1473 struct module *modules)
1da177e4
LT
1474{
1475 struct symbol *s;
1476 struct module *m;
1477 int first = 1;
1478
1479 for (m = modules; m; m = m->next) {
1480 m->seen = is_vmlinux(m->name);
1481 }
1482
1483 buf_printf(b, "\n");
1484 buf_printf(b, "static const char __module_depends[]\n");
1485 buf_printf(b, "__attribute_used__\n");
1486 buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
1487 buf_printf(b, "\"depends=");
1488 for (s = mod->unres; s; s = s->next) {
a61b2dfd 1489 const char *p;
1da177e4
LT
1490 if (!s->module)
1491 continue;
1492
1493 if (s->module->seen)
1494 continue;
1495
1496 s->module->seen = 1;
a61b2dfd
SR
1497 if ((p = strrchr(s->module->name, '/')) != NULL)
1498 p++;
1499 else
1500 p = s->module->name;
1501 buf_printf(b, "%s%s", first ? "" : ",", p);
1da177e4
LT
1502 first = 0;
1503 }
1504 buf_printf(b, "\";\n");
1505}
1506
5c3ead8c 1507static void add_srcversion(struct buffer *b, struct module *mod)
1da177e4
LT
1508{
1509 if (mod->srcversion[0]) {
1510 buf_printf(b, "\n");
1511 buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
1512 mod->srcversion);
1513 }
1514}
1515
5c3ead8c 1516static void write_if_changed(struct buffer *b, const char *fname)
1da177e4
LT
1517{
1518 char *tmp;
1519 FILE *file;
1520 struct stat st;
1521
1522 file = fopen(fname, "r");
1523 if (!file)
1524 goto write;
1525
1526 if (fstat(fileno(file), &st) < 0)
1527 goto close_write;
1528
1529 if (st.st_size != b->pos)
1530 goto close_write;
1531
1532 tmp = NOFAIL(malloc(b->pos));
1533 if (fread(tmp, 1, b->pos, file) != b->pos)
1534 goto free_write;
1535
1536 if (memcmp(tmp, b->p, b->pos) != 0)
1537 goto free_write;
1538
1539 free(tmp);
1540 fclose(file);
1541 return;
1542
1543 free_write:
1544 free(tmp);
1545 close_write:
1546 fclose(file);
1547 write:
1548 file = fopen(fname, "w");
1549 if (!file) {
1550 perror(fname);
1551 exit(1);
1552 }
1553 if (fwrite(b->p, 1, b->pos, file) != b->pos) {
1554 perror(fname);
1555 exit(1);
1556 }
1557 fclose(file);
1558}
1559
bd5cbced 1560/* parse Module.symvers file. line format:
534b89a9 1561 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
bd5cbced 1562 **/
040fcc81 1563static void read_dump(const char *fname, unsigned int kernel)
1da177e4
LT
1564{
1565 unsigned long size, pos = 0;
1566 void *file = grab_file(fname, &size);
1567 char *line;
1568
1569 if (!file)
1570 /* No symbol versions, silently ignore */
1571 return;
1572
1573 while ((line = get_next_line(&pos, file, size))) {
534b89a9 1574 char *symname, *modname, *d, *export, *end;
1da177e4
LT
1575 unsigned int crc;
1576 struct module *mod;
040fcc81 1577 struct symbol *s;
1da177e4
LT
1578
1579 if (!(symname = strchr(line, '\t')))
1580 goto fail;
1581 *symname++ = '\0';
1582 if (!(modname = strchr(symname, '\t')))
1583 goto fail;
1584 *modname++ = '\0';
9ac545b0 1585 if ((export = strchr(modname, '\t')) != NULL)
bd5cbced 1586 *export++ = '\0';
534b89a9
SR
1587 if (export && ((end = strchr(export, '\t')) != NULL))
1588 *end = '\0';
1da177e4
LT
1589 crc = strtoul(line, &d, 16);
1590 if (*symname == '\0' || *modname == '\0' || *d != '\0')
1591 goto fail;
1592
1593 if (!(mod = find_module(modname))) {
1594 if (is_vmlinux(modname)) {
1595 have_vmlinux = 1;
1596 }
1597 mod = new_module(NOFAIL(strdup(modname)));
1598 mod->skip = 1;
1599 }
bd5cbced 1600 s = sym_add_exported(symname, mod, export_no(export));
8e70c458
SR
1601 s->kernel = kernel;
1602 s->preloaded = 1;
bd5cbced 1603 sym_update_crc(symname, mod, crc, export_no(export));
1da177e4
LT
1604 }
1605 return;
1606fail:
1607 fatal("parse error in symbol dump file\n");
1608}
1609
040fcc81
SR
1610/* For normal builds always dump all symbols.
1611 * For external modules only dump symbols
1612 * that are not read from kernel Module.symvers.
1613 **/
1614static int dump_sym(struct symbol *sym)
1615{
1616 if (!external_module)
1617 return 1;
1618 if (sym->vmlinux || sym->kernel)
1619 return 0;
1620 return 1;
1621}
62070fa4 1622
5c3ead8c 1623static void write_dump(const char *fname)
1da177e4
LT
1624{
1625 struct buffer buf = { };
1626 struct symbol *symbol;
1627 int n;
1628
1629 for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
1630 symbol = symbolhash[n];
1631 while (symbol) {
040fcc81 1632 if (dump_sym(symbol))
bd5cbced 1633 buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
62070fa4 1634 symbol->crc, symbol->name,
bd5cbced
RP
1635 symbol->module->name,
1636 export_str(symbol->export));
1da177e4
LT
1637 symbol = symbol->next;
1638 }
1639 }
1640 write_if_changed(&buf, fname);
1641}
1642
5c3ead8c 1643int main(int argc, char **argv)
1da177e4
LT
1644{
1645 struct module *mod;
1646 struct buffer buf = { };
1647 char fname[SZ];
040fcc81
SR
1648 char *kernel_read = NULL, *module_read = NULL;
1649 char *dump_write = NULL;
1da177e4 1650 int opt;
c53ddacd 1651 int err;
1da177e4 1652
8d8d8289 1653 while ((opt = getopt(argc, argv, "i:I:mso:aw")) != -1) {
1da177e4
LT
1654 switch(opt) {
1655 case 'i':
040fcc81
SR
1656 kernel_read = optarg;
1657 break;
1658 case 'I':
1659 module_read = optarg;
1660 external_module = 1;
1da177e4
LT
1661 break;
1662 case 'm':
1663 modversions = 1;
1664 break;
1665 case 'o':
1666 dump_write = optarg;
1667 break;
1668 case 'a':
1669 all_versions = 1;
1670 break;
8d8d8289
SR
1671 case 's':
1672 vmlinux_section_warnings = 0;
1673 break;
c53ddacd
KK
1674 case 'w':
1675 warn_unresolved = 1;
1676 break;
1da177e4
LT
1677 default:
1678 exit(1);
1679 }
1680 }
1681
040fcc81
SR
1682 if (kernel_read)
1683 read_dump(kernel_read, 1);
1684 if (module_read)
1685 read_dump(module_read, 0);
1da177e4
LT
1686
1687 while (optind < argc) {
1688 read_symbols(argv[optind++]);
1689 }
1690
b817f6fe
SR
1691 for (mod = modules; mod; mod = mod->next) {
1692 if (mod->skip)
1693 continue;
c96fca21 1694 check_exports(mod);
b817f6fe
SR
1695 }
1696
c53ddacd
KK
1697 err = 0;
1698
1da177e4
LT
1699 for (mod = modules; mod; mod = mod->next) {
1700 if (mod->skip)
1701 continue;
1702
1703 buf.pos = 0;
1704
1705 add_header(&buf, mod);
c53ddacd 1706 err |= add_versions(&buf, mod);
1da177e4
LT
1707 add_depends(&buf, mod, modules);
1708 add_moddevtable(&buf, mod);
1709 add_srcversion(&buf, mod);
1710
1711 sprintf(fname, "%s.mod.c", mod->name);
1712 write_if_changed(&buf, fname);
1713 }
1714
1715 if (dump_write)
1716 write_dump(dump_write);
1717
c53ddacd 1718 return err;
1da177e4 1719}