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1da177e4 LT |
1 | /* Postprocess module symbol versions |
2 | * | |
3 | * Copyright 2003 Kai Germaschewski | |
4 | * Copyright 2002-2004 Rusty Russell, IBM Corporation | |
5 | * | |
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" | |
16 | ||
17 | /* Are we using CONFIG_MODVERSIONS? */ | |
18 | int modversions = 0; | |
19 | /* Warn about undefined symbols? (do so if we have vmlinux) */ | |
20 | int have_vmlinux = 0; | |
21 | /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ | |
22 | static int all_versions = 0; | |
040fcc81 SR |
23 | /* If we are modposting external module set to 1 */ |
24 | static int external_module = 0; | |
1da177e4 | 25 | |
5c3ead8c | 26 | void fatal(const char *fmt, ...) |
1da177e4 LT |
27 | { |
28 | va_list arglist; | |
29 | ||
30 | fprintf(stderr, "FATAL: "); | |
31 | ||
32 | va_start(arglist, fmt); | |
33 | vfprintf(stderr, fmt, arglist); | |
34 | va_end(arglist); | |
35 | ||
36 | exit(1); | |
37 | } | |
38 | ||
5c3ead8c | 39 | void warn(const char *fmt, ...) |
1da177e4 LT |
40 | { |
41 | va_list arglist; | |
42 | ||
43 | fprintf(stderr, "WARNING: "); | |
44 | ||
45 | va_start(arglist, fmt); | |
46 | vfprintf(stderr, fmt, arglist); | |
47 | va_end(arglist); | |
48 | } | |
49 | ||
040fcc81 SR |
50 | static int is_vmlinux(const char *modname) |
51 | { | |
52 | const char *myname; | |
53 | ||
54 | if ((myname = strrchr(modname, '/'))) | |
55 | myname++; | |
56 | else | |
57 | myname = modname; | |
58 | ||
59 | return strcmp(myname, "vmlinux") == 0; | |
60 | } | |
61 | ||
1da177e4 LT |
62 | void *do_nofail(void *ptr, const char *expr) |
63 | { | |
64 | if (!ptr) { | |
65 | fatal("modpost: Memory allocation failure: %s.\n", expr); | |
66 | } | |
67 | return ptr; | |
68 | } | |
69 | ||
70 | /* A list of all modules we processed */ | |
71 | ||
72 | static struct module *modules; | |
73 | ||
5c3ead8c | 74 | static struct module *find_module(char *modname) |
1da177e4 LT |
75 | { |
76 | struct module *mod; | |
77 | ||
78 | for (mod = modules; mod; mod = mod->next) | |
79 | if (strcmp(mod->name, modname) == 0) | |
80 | break; | |
81 | return mod; | |
82 | } | |
83 | ||
5c3ead8c | 84 | static struct module *new_module(char *modname) |
1da177e4 LT |
85 | { |
86 | struct module *mod; | |
87 | char *p, *s; | |
88 | ||
89 | mod = NOFAIL(malloc(sizeof(*mod))); | |
90 | memset(mod, 0, sizeof(*mod)); | |
91 | p = NOFAIL(strdup(modname)); | |
92 | ||
93 | /* strip trailing .o */ | |
94 | if ((s = strrchr(p, '.')) != NULL) | |
95 | if (strcmp(s, ".o") == 0) | |
96 | *s = '\0'; | |
97 | ||
98 | /* add to list */ | |
99 | mod->name = p; | |
100 | mod->next = modules; | |
101 | modules = mod; | |
102 | ||
103 | return mod; | |
104 | } | |
105 | ||
106 | /* A hash of all exported symbols, | |
107 | * struct symbol is also used for lists of unresolved symbols */ | |
108 | ||
109 | #define SYMBOL_HASH_SIZE 1024 | |
110 | ||
111 | struct symbol { | |
112 | struct symbol *next; | |
113 | struct module *module; | |
114 | unsigned int crc; | |
115 | int crc_valid; | |
116 | unsigned int weak:1; | |
040fcc81 SR |
117 | unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ |
118 | unsigned int kernel:1; /* 1 if symbol is from kernel | |
119 | * (only for external modules) **/ | |
8e70c458 | 120 | unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ |
1da177e4 LT |
121 | char name[0]; |
122 | }; | |
123 | ||
124 | static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; | |
125 | ||
126 | /* This is based on the hash agorithm from gdbm, via tdb */ | |
127 | static inline unsigned int tdb_hash(const char *name) | |
128 | { | |
129 | unsigned value; /* Used to compute the hash value. */ | |
130 | unsigned i; /* Used to cycle through random values. */ | |
131 | ||
132 | /* Set the initial value from the key size. */ | |
133 | for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) | |
134 | value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); | |
135 | ||
136 | return (1103515243 * value + 12345); | |
137 | } | |
138 | ||
5c3ead8c SR |
139 | /** |
140 | * Allocate a new symbols for use in the hash of exported symbols or | |
141 | * the list of unresolved symbols per module | |
142 | **/ | |
143 | static struct symbol *alloc_symbol(const char *name, unsigned int weak, | |
144 | struct symbol *next) | |
1da177e4 LT |
145 | { |
146 | struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); | |
147 | ||
148 | memset(s, 0, sizeof(*s)); | |
149 | strcpy(s->name, name); | |
150 | s->weak = weak; | |
151 | s->next = next; | |
152 | return s; | |
153 | } | |
154 | ||
155 | /* For the hash of exported symbols */ | |
040fcc81 | 156 | static struct symbol *new_symbol(const char *name, struct module *module) |
1da177e4 LT |
157 | { |
158 | unsigned int hash; | |
159 | struct symbol *new; | |
160 | ||
161 | hash = tdb_hash(name) % SYMBOL_HASH_SIZE; | |
162 | new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); | |
163 | new->module = module; | |
040fcc81 | 164 | return new; |
1da177e4 LT |
165 | } |
166 | ||
5c3ead8c | 167 | static struct symbol *find_symbol(const char *name) |
1da177e4 LT |
168 | { |
169 | struct symbol *s; | |
170 | ||
171 | /* For our purposes, .foo matches foo. PPC64 needs this. */ | |
172 | if (name[0] == '.') | |
173 | name++; | |
174 | ||
175 | for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { | |
176 | if (strcmp(s->name, name) == 0) | |
177 | return s; | |
178 | } | |
179 | return NULL; | |
180 | } | |
181 | ||
5c3ead8c SR |
182 | /** |
183 | * Add an exported symbol - it may have already been added without a | |
184 | * CRC, in this case just update the CRC | |
185 | **/ | |
040fcc81 | 186 | static struct symbol *sym_add_exported(const char *name, struct module *mod) |
1da177e4 LT |
187 | { |
188 | struct symbol *s = find_symbol(name); | |
189 | ||
8e70c458 | 190 | if (!s) { |
040fcc81 | 191 | s = new_symbol(name, mod); |
8e70c458 SR |
192 | } else { |
193 | if (!s->preloaded) { | |
194 | warn("%s: duplicate symbol '%s' previous definition " | |
195 | "was in %s%s\n", mod->name, name, | |
196 | s->module->name, | |
197 | is_vmlinux(s->module->name) ?"":".ko"); | |
198 | } | |
199 | } | |
200 | s->preloaded = 0; | |
040fcc81 SR |
201 | s->vmlinux = is_vmlinux(mod->name); |
202 | s->kernel = 0; | |
203 | return s; | |
204 | } | |
205 | ||
206 | static void sym_update_crc(const char *name, struct module *mod, | |
207 | unsigned int crc) | |
208 | { | |
209 | struct symbol *s = find_symbol(name); | |
210 | ||
211 | if (!s) | |
212 | s = new_symbol(name, mod); | |
213 | s->crc = crc; | |
214 | s->crc_valid = 1; | |
1da177e4 LT |
215 | } |
216 | ||
5c3ead8c | 217 | void *grab_file(const char *filename, unsigned long *size) |
1da177e4 LT |
218 | { |
219 | struct stat st; | |
220 | void *map; | |
221 | int fd; | |
222 | ||
223 | fd = open(filename, O_RDONLY); | |
224 | if (fd < 0 || fstat(fd, &st) != 0) | |
225 | return NULL; | |
226 | ||
227 | *size = st.st_size; | |
228 | map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); | |
229 | close(fd); | |
230 | ||
231 | if (map == MAP_FAILED) | |
232 | return NULL; | |
233 | return map; | |
234 | } | |
235 | ||
5c3ead8c SR |
236 | /** |
237 | * Return a copy of the next line in a mmap'ed file. | |
238 | * spaces in the beginning of the line is trimmed away. | |
239 | * Return a pointer to a static buffer. | |
240 | **/ | |
241 | char* get_next_line(unsigned long *pos, void *file, unsigned long size) | |
1da177e4 LT |
242 | { |
243 | static char line[4096]; | |
244 | int skip = 1; | |
245 | size_t len = 0; | |
246 | signed char *p = (signed char *)file + *pos; | |
247 | char *s = line; | |
248 | ||
249 | for (; *pos < size ; (*pos)++) | |
250 | { | |
251 | if (skip && isspace(*p)) { | |
252 | p++; | |
253 | continue; | |
254 | } | |
255 | skip = 0; | |
256 | if (*p != '\n' && (*pos < size)) { | |
257 | len++; | |
258 | *s++ = *p++; | |
259 | if (len > 4095) | |
260 | break; /* Too long, stop */ | |
261 | } else { | |
262 | /* End of string */ | |
263 | *s = '\0'; | |
264 | return line; | |
265 | } | |
266 | } | |
267 | /* End of buffer */ | |
268 | return NULL; | |
269 | } | |
270 | ||
5c3ead8c | 271 | void release_file(void *file, unsigned long size) |
1da177e4 LT |
272 | { |
273 | munmap(file, size); | |
274 | } | |
275 | ||
5c3ead8c | 276 | static void parse_elf(struct elf_info *info, const char *filename) |
1da177e4 LT |
277 | { |
278 | unsigned int i; | |
279 | Elf_Ehdr *hdr = info->hdr; | |
280 | Elf_Shdr *sechdrs; | |
281 | Elf_Sym *sym; | |
282 | ||
283 | hdr = grab_file(filename, &info->size); | |
284 | if (!hdr) { | |
285 | perror(filename); | |
286 | abort(); | |
287 | } | |
288 | info->hdr = hdr; | |
289 | if (info->size < sizeof(*hdr)) | |
290 | goto truncated; | |
291 | ||
292 | /* Fix endianness in ELF header */ | |
293 | hdr->e_shoff = TO_NATIVE(hdr->e_shoff); | |
294 | hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); | |
295 | hdr->e_shnum = TO_NATIVE(hdr->e_shnum); | |
296 | hdr->e_machine = TO_NATIVE(hdr->e_machine); | |
297 | sechdrs = (void *)hdr + hdr->e_shoff; | |
298 | info->sechdrs = sechdrs; | |
299 | ||
300 | /* Fix endianness in section headers */ | |
301 | for (i = 0; i < hdr->e_shnum; i++) { | |
302 | sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); | |
303 | sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); | |
304 | sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); | |
305 | sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); | |
306 | sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); | |
307 | } | |
308 | /* Find symbol table. */ | |
309 | for (i = 1; i < hdr->e_shnum; i++) { | |
310 | const char *secstrings | |
311 | = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
312 | ||
313 | if (sechdrs[i].sh_offset > info->size) | |
314 | goto truncated; | |
315 | if (strcmp(secstrings+sechdrs[i].sh_name, ".modinfo") == 0) { | |
316 | info->modinfo = (void *)hdr + sechdrs[i].sh_offset; | |
317 | info->modinfo_len = sechdrs[i].sh_size; | |
318 | } | |
319 | if (sechdrs[i].sh_type != SHT_SYMTAB) | |
320 | continue; | |
321 | ||
322 | info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; | |
323 | info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset | |
324 | + sechdrs[i].sh_size; | |
325 | info->strtab = (void *)hdr + | |
326 | sechdrs[sechdrs[i].sh_link].sh_offset; | |
327 | } | |
328 | if (!info->symtab_start) { | |
cb80514d | 329 | fatal("%s has no symtab?\n", filename); |
1da177e4 LT |
330 | } |
331 | /* Fix endianness in symbols */ | |
332 | for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { | |
333 | sym->st_shndx = TO_NATIVE(sym->st_shndx); | |
334 | sym->st_name = TO_NATIVE(sym->st_name); | |
335 | sym->st_value = TO_NATIVE(sym->st_value); | |
336 | sym->st_size = TO_NATIVE(sym->st_size); | |
337 | } | |
338 | return; | |
339 | ||
340 | truncated: | |
cb80514d | 341 | fatal("%s is truncated.\n", filename); |
1da177e4 LT |
342 | } |
343 | ||
5c3ead8c | 344 | static void parse_elf_finish(struct elf_info *info) |
1da177e4 LT |
345 | { |
346 | release_file(info->hdr, info->size); | |
347 | } | |
348 | ||
9572b28f LY |
349 | #define CRC_PFX "__crc_" |
350 | #define KSYMTAB_PFX "__ksymtab_" | |
1da177e4 | 351 | |
5c3ead8c SR |
352 | static void handle_modversions(struct module *mod, struct elf_info *info, |
353 | Elf_Sym *sym, const char *symname) | |
1da177e4 LT |
354 | { |
355 | unsigned int crc; | |
356 | ||
357 | switch (sym->st_shndx) { | |
358 | case SHN_COMMON: | |
cb80514d | 359 | warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); |
1da177e4 LT |
360 | break; |
361 | case SHN_ABS: | |
362 | /* CRC'd symbol */ | |
363 | if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { | |
364 | crc = (unsigned int) sym->st_value; | |
040fcc81 | 365 | sym_update_crc(symname + strlen(CRC_PFX), mod, crc); |
1da177e4 LT |
366 | } |
367 | break; | |
368 | case SHN_UNDEF: | |
369 | /* undefined symbol */ | |
370 | if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && | |
371 | ELF_ST_BIND(sym->st_info) != STB_WEAK) | |
372 | break; | |
373 | /* ignore global offset table */ | |
374 | if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) | |
375 | break; | |
376 | /* ignore __this_module, it will be resolved shortly */ | |
377 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) | |
378 | break; | |
8d529014 BC |
379 | /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ |
380 | #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) | |
381 | /* add compatibility with older glibc */ | |
382 | #ifndef STT_SPARC_REGISTER | |
383 | #define STT_SPARC_REGISTER STT_REGISTER | |
384 | #endif | |
1da177e4 LT |
385 | if (info->hdr->e_machine == EM_SPARC || |
386 | info->hdr->e_machine == EM_SPARCV9) { | |
387 | /* Ignore register directives. */ | |
8d529014 | 388 | if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) |
1da177e4 | 389 | break; |
7caaeabb AV |
390 | if (symname[0] == '.') { |
391 | char *munged = strdup(symname); | |
392 | munged[0] = '_'; | |
393 | munged[1] = toupper(munged[1]); | |
394 | symname = munged; | |
395 | } | |
1da177e4 LT |
396 | } |
397 | #endif | |
398 | ||
399 | if (memcmp(symname, MODULE_SYMBOL_PREFIX, | |
400 | strlen(MODULE_SYMBOL_PREFIX)) == 0) | |
401 | mod->unres = alloc_symbol(symname + | |
402 | strlen(MODULE_SYMBOL_PREFIX), | |
403 | ELF_ST_BIND(sym->st_info) == STB_WEAK, | |
404 | mod->unres); | |
405 | break; | |
406 | default: | |
407 | /* All exported symbols */ | |
408 | if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { | |
040fcc81 | 409 | sym_add_exported(symname + strlen(KSYMTAB_PFX), mod); |
1da177e4 LT |
410 | } |
411 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) | |
412 | mod->has_init = 1; | |
413 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) | |
414 | mod->has_cleanup = 1; | |
415 | break; | |
416 | } | |
417 | } | |
418 | ||
5c3ead8c SR |
419 | /** |
420 | * Parse tag=value strings from .modinfo section | |
421 | **/ | |
1da177e4 LT |
422 | static char *next_string(char *string, unsigned long *secsize) |
423 | { | |
424 | /* Skip non-zero chars */ | |
425 | while (string[0]) { | |
426 | string++; | |
427 | if ((*secsize)-- <= 1) | |
428 | return NULL; | |
429 | } | |
430 | ||
431 | /* Skip any zero padding. */ | |
432 | while (!string[0]) { | |
433 | string++; | |
434 | if ((*secsize)-- <= 1) | |
435 | return NULL; | |
436 | } | |
437 | return string; | |
438 | } | |
439 | ||
440 | static char *get_modinfo(void *modinfo, unsigned long modinfo_len, | |
441 | const char *tag) | |
442 | { | |
443 | char *p; | |
444 | unsigned int taglen = strlen(tag); | |
445 | unsigned long size = modinfo_len; | |
446 | ||
447 | for (p = modinfo; p; p = next_string(p, &size)) { | |
448 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') | |
449 | return p + taglen + 1; | |
450 | } | |
451 | return NULL; | |
452 | } | |
453 | ||
b39927cf SR |
454 | /* |
455 | * Find symbols before or equal addr and after addr - in the section sec | |
456 | **/ | |
457 | static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, | |
458 | const char *sec, | |
459 | Elf_Sym **before, Elf_Sym **after) | |
460 | { | |
461 | Elf_Sym *sym; | |
462 | Elf_Ehdr *hdr = elf->hdr; | |
463 | Elf_Addr beforediff = ~0; | |
464 | Elf_Addr afterdiff = ~0; | |
465 | const char *secstrings = (void *)hdr + | |
466 | elf->sechdrs[hdr->e_shstrndx].sh_offset; | |
467 | ||
468 | *before = NULL; | |
469 | *after = NULL; | |
470 | ||
471 | for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { | |
472 | const char *symsec; | |
473 | ||
474 | if (sym->st_shndx >= SHN_LORESERVE) | |
475 | continue; | |
476 | symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; | |
477 | if (strcmp(symsec, sec) != 0) | |
478 | continue; | |
479 | if (sym->st_value <= addr) { | |
480 | if ((addr - sym->st_value) < beforediff) { | |
481 | beforediff = addr - sym->st_value; | |
482 | *before = sym; | |
483 | } | |
484 | } | |
485 | else | |
486 | { | |
487 | if ((sym->st_value - addr) < afterdiff) { | |
488 | afterdiff = sym->st_value - addr; | |
489 | *after = sym; | |
490 | } | |
491 | } | |
492 | } | |
493 | } | |
494 | ||
495 | /** | |
496 | * Print a warning about a section mismatch. | |
497 | * Try to find symbols near it so user can find it. | |
498 | **/ | |
499 | static void warn_sec_mismatch(const char *modname, const char *fromsec, | |
500 | struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) | |
501 | { | |
502 | Elf_Sym *before; | |
503 | Elf_Sym *after; | |
504 | Elf_Ehdr *hdr = elf->hdr; | |
505 | Elf_Shdr *sechdrs = elf->sechdrs; | |
506 | const char *secstrings = (void *)hdr + | |
507 | sechdrs[hdr->e_shstrndx].sh_offset; | |
508 | const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; | |
509 | ||
510 | find_symbols_between(elf, r.r_offset, fromsec, &before, &after); | |
511 | ||
512 | if (before && after) { | |
513 | warn("%s - Section mismatch: reference to %s from %s " | |
514 | "between '%s' (at offset 0x%lx) and '%s'\n", | |
515 | modname, secname, fromsec, | |
516 | elf->strtab + before->st_name, | |
517 | (long)(r.r_offset - before->st_value), | |
518 | elf->strtab + after->st_name); | |
519 | } else if (before) { | |
520 | warn("%s - Section mismatch: reference to %s from %s " | |
521 | "after '%s' (at offset 0x%lx)\n", | |
522 | modname, secname, fromsec, | |
523 | elf->strtab + before->st_name, | |
524 | (long)(r.r_offset - before->st_value)); | |
525 | } else if (after) { | |
526 | warn("%s - Section mismatch: reference to %s from %s " | |
527 | "before '%s' (at offset -0x%lx)\n", | |
528 | modname, secname, fromsec, | |
529 | elf->strtab + before->st_name, | |
530 | (long)(before->st_value - r.r_offset)); | |
531 | } else { | |
532 | warn("%s - Section mismatch: reference to %s from %s " | |
533 | "(offset 0x%lx)\n", | |
534 | modname, secname, fromsec, (long)r.r_offset); | |
535 | } | |
536 | } | |
537 | ||
538 | /** | |
539 | * A module includes a number of sections that are discarded | |
540 | * either when loaded or when used as built-in. | |
541 | * For loaded modules all functions marked __init and all data | |
542 | * marked __initdata will be discarded when the module has been intialized. | |
543 | * Likewise for modules used built-in the sections marked __exit | |
544 | * are discarded because __exit marked function are supposed to be called | |
545 | * only when a moduel is unloaded which never happes for built-in modules. | |
546 | * The check_sec_ref() function traverses all relocation records | |
547 | * to find all references to a section that reference a section that will | |
548 | * be discarded and warns about it. | |
549 | **/ | |
550 | static void check_sec_ref(struct module *mod, const char *modname, | |
551 | struct elf_info *elf, | |
552 | int section(const char*), | |
553 | int section_ref_ok(const char *)) | |
554 | { | |
555 | int i; | |
556 | Elf_Sym *sym; | |
557 | Elf_Ehdr *hdr = elf->hdr; | |
558 | Elf_Shdr *sechdrs = elf->sechdrs; | |
559 | const char *secstrings = (void *)hdr + | |
560 | sechdrs[hdr->e_shstrndx].sh_offset; | |
561 | ||
562 | /* Walk through all sections */ | |
563 | for (i = 0; i < hdr->e_shnum; i++) { | |
564 | const char *name = secstrings + sechdrs[i].sh_name + | |
565 | strlen(".rela"); | |
566 | /* We want to process only relocation sections and not .init */ | |
567 | if (section_ref_ok(name) || (sechdrs[i].sh_type != SHT_RELA)) | |
568 | continue; | |
569 | Elf_Rela *rela; | |
570 | Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; | |
571 | Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; | |
572 | ||
573 | for (rela = start; rela < stop; rela++) { | |
574 | Elf_Rela r; | |
575 | const char *secname; | |
576 | r.r_offset = TO_NATIVE(rela->r_offset); | |
577 | r.r_info = TO_NATIVE(rela->r_info); | |
578 | sym = elf->symtab_start + ELF_R_SYM(r.r_info); | |
b39927cf SR |
579 | /* Skip special sections */ |
580 | if (sym->st_shndx >= SHN_LORESERVE) | |
581 | continue; | |
582 | ||
8ea80ca4 | 583 | secname = secstrings + sechdrs[sym->st_shndx].sh_name; |
b39927cf SR |
584 | if (section(secname)) |
585 | warn_sec_mismatch(modname, name, elf, sym, r); | |
586 | } | |
587 | } | |
588 | } | |
589 | ||
590 | /** | |
591 | * Functions used only during module init is marked __init and is stored in | |
592 | * a .init.text section. Likewise data is marked __initdata and stored in | |
593 | * a .init.data section. | |
594 | * If this section is one of these sections return 1 | |
595 | * See include/linux/init.h for the details | |
596 | **/ | |
597 | static int init_section(const char *name) | |
598 | { | |
599 | if (strcmp(name, ".init") == 0) | |
600 | return 1; | |
601 | if (strncmp(name, ".init.", strlen(".init.")) == 0) | |
602 | return 1; | |
603 | return 0; | |
604 | } | |
605 | ||
606 | /** | |
607 | * Identify sections from which references to a .init section is OK. | |
608 | * | |
609 | * Unfortunately references to read only data that referenced .init | |
610 | * sections had to be excluded. Almost all of these are false | |
611 | * positives, they are created by gcc. The downside of excluding rodata | |
612 | * is that there really are some user references from rodata to | |
613 | * init code, e.g. drivers/video/vgacon.c: | |
614 | * | |
615 | * const struct consw vga_con = { | |
616 | * con_startup: vgacon_startup, | |
617 | * | |
618 | * where vgacon_startup is __init. If you want to wade through the false | |
619 | * positives, take out the check for rodata. | |
620 | **/ | |
621 | static int init_section_ref_ok(const char *name) | |
622 | { | |
623 | const char **s; | |
624 | /* Absolute section names */ | |
625 | const char *namelist1[] = { | |
626 | ".init", | |
627 | ".stab", | |
628 | ".rodata", | |
629 | ".text.lock", | |
630 | ".pci_fixup_header", | |
631 | ".pci_fixup_final", | |
632 | ".pdr", | |
633 | "__param", | |
634 | NULL | |
635 | }; | |
636 | /* Start of section names */ | |
637 | const char *namelist2[] = { | |
638 | ".init.", | |
639 | ".altinstructions", | |
640 | ".eh_frame", | |
641 | ".debug", | |
642 | NULL | |
643 | }; | |
644 | ||
645 | for (s = namelist1; *s; s++) | |
646 | if (strcmp(*s, name) == 0) | |
647 | return 1; | |
648 | for (s = namelist2; *s; s++) | |
649 | if (strncmp(*s, name, strlen(*s)) == 0) | |
650 | return 1; | |
651 | return 0; | |
652 | } | |
653 | ||
654 | /* | |
655 | * Functions used only during module exit is marked __exit and is stored in | |
656 | * a .exit.text section. Likewise data is marked __exitdata and stored in | |
657 | * a .exit.data section. | |
658 | * If this section is one of these sections return 1 | |
659 | * See include/linux/init.h for the details | |
660 | **/ | |
661 | static int exit_section(const char *name) | |
662 | { | |
663 | if (strcmp(name, ".exit.text") == 0) | |
664 | return 1; | |
665 | if (strcmp(name, ".exit.data") == 0) | |
666 | return 1; | |
667 | return 0; | |
668 | ||
669 | } | |
670 | ||
671 | /* | |
672 | * Identify sections from which references to a .exit section is OK. | |
673 | * | |
674 | * [OPD] Keith Ownes <kaos@sgi.com> commented: | |
675 | * For our future {in}sanity, add a comment that this is the ppc .opd | |
676 | * section, not the ia64 .opd section. | |
677 | * ia64 .opd should not point to discarded sections. | |
678 | **/ | |
679 | static int exit_section_ref_ok(const char *name) | |
680 | { | |
681 | const char **s; | |
682 | /* Absolute section names */ | |
683 | const char *namelist1[] = { | |
684 | ".exit.text", | |
685 | ".exit.data", | |
686 | ".init.text", | |
687 | ".opd", /* See comment [OPD] */ | |
688 | ".altinstructions", | |
689 | ".pdr", | |
690 | ".exitcall.exit", | |
691 | ".eh_frame", | |
692 | ".stab", | |
693 | NULL | |
694 | }; | |
695 | /* Start of section names */ | |
696 | const char *namelist2[] = { | |
697 | ".debug", | |
698 | NULL | |
699 | }; | |
700 | ||
701 | for (s = namelist1; *s; s++) | |
702 | if (strcmp(*s, name) == 0) | |
703 | return 1; | |
704 | for (s = namelist2; *s; s++) | |
705 | if (strncmp(*s, name, strlen(*s)) == 0) | |
706 | return 1; | |
707 | return 0; | |
708 | } | |
709 | ||
5c3ead8c | 710 | static void read_symbols(char *modname) |
1da177e4 LT |
711 | { |
712 | const char *symname; | |
713 | char *version; | |
714 | struct module *mod; | |
715 | struct elf_info info = { }; | |
716 | Elf_Sym *sym; | |
717 | ||
718 | parse_elf(&info, modname); | |
719 | ||
720 | mod = new_module(modname); | |
721 | ||
722 | /* When there's no vmlinux, don't print warnings about | |
723 | * unresolved symbols (since there'll be too many ;) */ | |
724 | if (is_vmlinux(modname)) { | |
1da177e4 | 725 | have_vmlinux = 1; |
1da177e4 LT |
726 | mod->skip = 1; |
727 | } | |
728 | ||
729 | for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { | |
730 | symname = info.strtab + sym->st_name; | |
731 | ||
732 | handle_modversions(mod, &info, sym, symname); | |
733 | handle_moddevtable(mod, &info, sym, symname); | |
734 | } | |
b39927cf SR |
735 | check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); |
736 | check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); | |
1da177e4 LT |
737 | |
738 | version = get_modinfo(info.modinfo, info.modinfo_len, "version"); | |
739 | if (version) | |
740 | maybe_frob_rcs_version(modname, version, info.modinfo, | |
741 | version - (char *)info.hdr); | |
742 | if (version || (all_versions && !is_vmlinux(modname))) | |
743 | get_src_version(modname, mod->srcversion, | |
744 | sizeof(mod->srcversion)-1); | |
745 | ||
746 | parse_elf_finish(&info); | |
747 | ||
748 | /* Our trick to get versioning for struct_module - it's | |
749 | * never passed as an argument to an exported function, so | |
750 | * the automatic versioning doesn't pick it up, but it's really | |
751 | * important anyhow */ | |
752 | if (modversions) | |
753 | mod->unres = alloc_symbol("struct_module", 0, mod->unres); | |
754 | } | |
755 | ||
756 | #define SZ 500 | |
757 | ||
758 | /* We first write the generated file into memory using the | |
759 | * following helper, then compare to the file on disk and | |
760 | * only update the later if anything changed */ | |
761 | ||
5c3ead8c SR |
762 | void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, |
763 | const char *fmt, ...) | |
1da177e4 LT |
764 | { |
765 | char tmp[SZ]; | |
766 | int len; | |
767 | va_list ap; | |
768 | ||
769 | va_start(ap, fmt); | |
770 | len = vsnprintf(tmp, SZ, fmt, ap); | |
771 | if (buf->size - buf->pos < len + 1) { | |
772 | buf->size += 128; | |
773 | buf->p = realloc(buf->p, buf->size); | |
774 | } | |
775 | strncpy(buf->p + buf->pos, tmp, len + 1); | |
776 | buf->pos += len; | |
777 | va_end(ap); | |
778 | } | |
779 | ||
5c3ead8c | 780 | void buf_write(struct buffer *buf, const char *s, int len) |
1da177e4 LT |
781 | { |
782 | if (buf->size - buf->pos < len) { | |
783 | buf->size += len; | |
784 | buf->p = realloc(buf->p, buf->size); | |
785 | } | |
786 | strncpy(buf->p + buf->pos, s, len); | |
787 | buf->pos += len; | |
788 | } | |
789 | ||
5c3ead8c SR |
790 | /** |
791 | * Header for the generated file | |
792 | **/ | |
793 | static void add_header(struct buffer *b, struct module *mod) | |
1da177e4 LT |
794 | { |
795 | buf_printf(b, "#include <linux/module.h>\n"); | |
796 | buf_printf(b, "#include <linux/vermagic.h>\n"); | |
797 | buf_printf(b, "#include <linux/compiler.h>\n"); | |
798 | buf_printf(b, "\n"); | |
799 | buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); | |
800 | buf_printf(b, "\n"); | |
1da177e4 LT |
801 | buf_printf(b, "struct module __this_module\n"); |
802 | buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); | |
f83b5e32 | 803 | buf_printf(b, " .name = KBUILD_MODNAME,\n"); |
1da177e4 LT |
804 | if (mod->has_init) |
805 | buf_printf(b, " .init = init_module,\n"); | |
806 | if (mod->has_cleanup) | |
807 | buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" | |
808 | " .exit = cleanup_module,\n" | |
809 | "#endif\n"); | |
810 | buf_printf(b, "};\n"); | |
811 | } | |
812 | ||
5c3ead8c SR |
813 | /** |
814 | * Record CRCs for unresolved symbols | |
815 | **/ | |
816 | static void add_versions(struct buffer *b, struct module *mod) | |
1da177e4 LT |
817 | { |
818 | struct symbol *s, *exp; | |
819 | ||
820 | for (s = mod->unres; s; s = s->next) { | |
821 | exp = find_symbol(s->name); | |
822 | if (!exp || exp->module == mod) { | |
823 | if (have_vmlinux && !s->weak) | |
cb80514d SR |
824 | warn("\"%s\" [%s.ko] undefined!\n", |
825 | s->name, mod->name); | |
1da177e4 LT |
826 | continue; |
827 | } | |
828 | s->module = exp->module; | |
829 | s->crc_valid = exp->crc_valid; | |
830 | s->crc = exp->crc; | |
831 | } | |
832 | ||
833 | if (!modversions) | |
834 | return; | |
835 | ||
836 | buf_printf(b, "\n"); | |
837 | buf_printf(b, "static const struct modversion_info ____versions[]\n"); | |
838 | buf_printf(b, "__attribute_used__\n"); | |
839 | buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); | |
840 | ||
841 | for (s = mod->unres; s; s = s->next) { | |
842 | if (!s->module) { | |
843 | continue; | |
844 | } | |
845 | if (!s->crc_valid) { | |
cb80514d | 846 | warn("\"%s\" [%s.ko] has no CRC!\n", |
1da177e4 LT |
847 | s->name, mod->name); |
848 | continue; | |
849 | } | |
850 | buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); | |
851 | } | |
852 | ||
853 | buf_printf(b, "};\n"); | |
854 | } | |
855 | ||
5c3ead8c SR |
856 | static void add_depends(struct buffer *b, struct module *mod, |
857 | struct module *modules) | |
1da177e4 LT |
858 | { |
859 | struct symbol *s; | |
860 | struct module *m; | |
861 | int first = 1; | |
862 | ||
863 | for (m = modules; m; m = m->next) { | |
864 | m->seen = is_vmlinux(m->name); | |
865 | } | |
866 | ||
867 | buf_printf(b, "\n"); | |
868 | buf_printf(b, "static const char __module_depends[]\n"); | |
869 | buf_printf(b, "__attribute_used__\n"); | |
870 | buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); | |
871 | buf_printf(b, "\"depends="); | |
872 | for (s = mod->unres; s; s = s->next) { | |
873 | if (!s->module) | |
874 | continue; | |
875 | ||
876 | if (s->module->seen) | |
877 | continue; | |
878 | ||
879 | s->module->seen = 1; | |
880 | buf_printf(b, "%s%s", first ? "" : ",", | |
881 | strrchr(s->module->name, '/') + 1); | |
882 | first = 0; | |
883 | } | |
884 | buf_printf(b, "\";\n"); | |
885 | } | |
886 | ||
5c3ead8c | 887 | static void add_srcversion(struct buffer *b, struct module *mod) |
1da177e4 LT |
888 | { |
889 | if (mod->srcversion[0]) { | |
890 | buf_printf(b, "\n"); | |
891 | buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", | |
892 | mod->srcversion); | |
893 | } | |
894 | } | |
895 | ||
5c3ead8c | 896 | static void write_if_changed(struct buffer *b, const char *fname) |
1da177e4 LT |
897 | { |
898 | char *tmp; | |
899 | FILE *file; | |
900 | struct stat st; | |
901 | ||
902 | file = fopen(fname, "r"); | |
903 | if (!file) | |
904 | goto write; | |
905 | ||
906 | if (fstat(fileno(file), &st) < 0) | |
907 | goto close_write; | |
908 | ||
909 | if (st.st_size != b->pos) | |
910 | goto close_write; | |
911 | ||
912 | tmp = NOFAIL(malloc(b->pos)); | |
913 | if (fread(tmp, 1, b->pos, file) != b->pos) | |
914 | goto free_write; | |
915 | ||
916 | if (memcmp(tmp, b->p, b->pos) != 0) | |
917 | goto free_write; | |
918 | ||
919 | free(tmp); | |
920 | fclose(file); | |
921 | return; | |
922 | ||
923 | free_write: | |
924 | free(tmp); | |
925 | close_write: | |
926 | fclose(file); | |
927 | write: | |
928 | file = fopen(fname, "w"); | |
929 | if (!file) { | |
930 | perror(fname); | |
931 | exit(1); | |
932 | } | |
933 | if (fwrite(b->p, 1, b->pos, file) != b->pos) { | |
934 | perror(fname); | |
935 | exit(1); | |
936 | } | |
937 | fclose(file); | |
938 | } | |
939 | ||
040fcc81 | 940 | static void read_dump(const char *fname, unsigned int kernel) |
1da177e4 LT |
941 | { |
942 | unsigned long size, pos = 0; | |
943 | void *file = grab_file(fname, &size); | |
944 | char *line; | |
945 | ||
946 | if (!file) | |
947 | /* No symbol versions, silently ignore */ | |
948 | return; | |
949 | ||
950 | while ((line = get_next_line(&pos, file, size))) { | |
951 | char *symname, *modname, *d; | |
952 | unsigned int crc; | |
953 | struct module *mod; | |
040fcc81 | 954 | struct symbol *s; |
1da177e4 LT |
955 | |
956 | if (!(symname = strchr(line, '\t'))) | |
957 | goto fail; | |
958 | *symname++ = '\0'; | |
959 | if (!(modname = strchr(symname, '\t'))) | |
960 | goto fail; | |
961 | *modname++ = '\0'; | |
962 | if (strchr(modname, '\t')) | |
963 | goto fail; | |
964 | crc = strtoul(line, &d, 16); | |
965 | if (*symname == '\0' || *modname == '\0' || *d != '\0') | |
966 | goto fail; | |
967 | ||
968 | if (!(mod = find_module(modname))) { | |
969 | if (is_vmlinux(modname)) { | |
970 | have_vmlinux = 1; | |
971 | } | |
972 | mod = new_module(NOFAIL(strdup(modname))); | |
973 | mod->skip = 1; | |
974 | } | |
040fcc81 | 975 | s = sym_add_exported(symname, mod); |
8e70c458 SR |
976 | s->kernel = kernel; |
977 | s->preloaded = 1; | |
040fcc81 | 978 | sym_update_crc(symname, mod, crc); |
1da177e4 LT |
979 | } |
980 | return; | |
981 | fail: | |
982 | fatal("parse error in symbol dump file\n"); | |
983 | } | |
984 | ||
040fcc81 SR |
985 | /* For normal builds always dump all symbols. |
986 | * For external modules only dump symbols | |
987 | * that are not read from kernel Module.symvers. | |
988 | **/ | |
989 | static int dump_sym(struct symbol *sym) | |
990 | { | |
991 | if (!external_module) | |
992 | return 1; | |
993 | if (sym->vmlinux || sym->kernel) | |
994 | return 0; | |
995 | return 1; | |
996 | } | |
997 | ||
5c3ead8c | 998 | static void write_dump(const char *fname) |
1da177e4 LT |
999 | { |
1000 | struct buffer buf = { }; | |
1001 | struct symbol *symbol; | |
1002 | int n; | |
1003 | ||
1004 | for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { | |
1005 | symbol = symbolhash[n]; | |
1006 | while (symbol) { | |
040fcc81 SR |
1007 | if (dump_sym(symbol)) |
1008 | buf_printf(&buf, "0x%08x\t%s\t%s\n", | |
1009 | symbol->crc, symbol->name, | |
1010 | symbol->module->name); | |
1da177e4 LT |
1011 | symbol = symbol->next; |
1012 | } | |
1013 | } | |
1014 | write_if_changed(&buf, fname); | |
1015 | } | |
1016 | ||
5c3ead8c | 1017 | int main(int argc, char **argv) |
1da177e4 LT |
1018 | { |
1019 | struct module *mod; | |
1020 | struct buffer buf = { }; | |
1021 | char fname[SZ]; | |
040fcc81 SR |
1022 | char *kernel_read = NULL, *module_read = NULL; |
1023 | char *dump_write = NULL; | |
1da177e4 LT |
1024 | int opt; |
1025 | ||
040fcc81 | 1026 | while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) { |
1da177e4 LT |
1027 | switch(opt) { |
1028 | case 'i': | |
040fcc81 SR |
1029 | kernel_read = optarg; |
1030 | break; | |
1031 | case 'I': | |
1032 | module_read = optarg; | |
1033 | external_module = 1; | |
1da177e4 LT |
1034 | break; |
1035 | case 'm': | |
1036 | modversions = 1; | |
1037 | break; | |
1038 | case 'o': | |
1039 | dump_write = optarg; | |
1040 | break; | |
1041 | case 'a': | |
1042 | all_versions = 1; | |
1043 | break; | |
1044 | default: | |
1045 | exit(1); | |
1046 | } | |
1047 | } | |
1048 | ||
040fcc81 SR |
1049 | if (kernel_read) |
1050 | read_dump(kernel_read, 1); | |
1051 | if (module_read) | |
1052 | read_dump(module_read, 0); | |
1da177e4 LT |
1053 | |
1054 | while (optind < argc) { | |
1055 | read_symbols(argv[optind++]); | |
1056 | } | |
1057 | ||
1058 | for (mod = modules; mod; mod = mod->next) { | |
1059 | if (mod->skip) | |
1060 | continue; | |
1061 | ||
1062 | buf.pos = 0; | |
1063 | ||
1064 | add_header(&buf, mod); | |
1065 | add_versions(&buf, mod); | |
1066 | add_depends(&buf, mod, modules); | |
1067 | add_moddevtable(&buf, mod); | |
1068 | add_srcversion(&buf, mod); | |
1069 | ||
1070 | sprintf(fname, "%s.mod.c", mod->name); | |
1071 | write_if_changed(&buf, fname); | |
1072 | } | |
1073 | ||
1074 | if (dump_write) | |
1075 | write_dump(dump_write); | |
1076 | ||
1077 | return 0; | |
1078 | } |