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Commit | Line | Data |
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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 | |
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? */ | |
19 | int modversions = 0; | |
20 | /* Warn about undefined symbols? (do so if we have vmlinux) */ | |
21 | int have_vmlinux = 0; | |
22 | /* Is CONFIG_MODULE_SRCVERSION_ALL set? */ | |
23 | static int all_versions = 0; | |
040fcc81 SR |
24 | /* If we are modposting external module set to 1 */ |
25 | static int external_module = 0; | |
c53ddacd KK |
26 | /* Only warn about unresolved symbols */ |
27 | static int warn_unresolved = 0; | |
bd5cbced | 28 | /* How a symbol is exported */ |
c96fca21 SR |
29 | enum export { |
30 | export_plain, export_unused, export_gpl, | |
31 | export_unused_gpl, export_gpl_future, export_unknown | |
32 | }; | |
1da177e4 | 33 | |
5c3ead8c | 34 | void fatal(const char *fmt, ...) |
1da177e4 LT |
35 | { |
36 | va_list arglist; | |
37 | ||
38 | fprintf(stderr, "FATAL: "); | |
39 | ||
40 | va_start(arglist, fmt); | |
41 | vfprintf(stderr, fmt, arglist); | |
42 | va_end(arglist); | |
43 | ||
44 | exit(1); | |
45 | } | |
46 | ||
5c3ead8c | 47 | void warn(const char *fmt, ...) |
1da177e4 LT |
48 | { |
49 | va_list arglist; | |
50 | ||
51 | fprintf(stderr, "WARNING: "); | |
52 | ||
53 | va_start(arglist, fmt); | |
54 | vfprintf(stderr, fmt, arglist); | |
55 | va_end(arglist); | |
56 | } | |
57 | ||
040fcc81 SR |
58 | static int is_vmlinux(const char *modname) |
59 | { | |
60 | const char *myname; | |
61 | ||
62 | if ((myname = strrchr(modname, '/'))) | |
63 | myname++; | |
64 | else | |
65 | myname = modname; | |
66 | ||
67 | return strcmp(myname, "vmlinux") == 0; | |
68 | } | |
69 | ||
1da177e4 LT |
70 | void *do_nofail(void *ptr, const char *expr) |
71 | { | |
72 | if (!ptr) { | |
73 | fatal("modpost: Memory allocation failure: %s.\n", expr); | |
74 | } | |
75 | return ptr; | |
76 | } | |
77 | ||
78 | /* A list of all modules we processed */ | |
79 | ||
80 | static struct module *modules; | |
81 | ||
5c3ead8c | 82 | static struct module *find_module(char *modname) |
1da177e4 LT |
83 | { |
84 | struct module *mod; | |
85 | ||
86 | for (mod = modules; mod; mod = mod->next) | |
87 | if (strcmp(mod->name, modname) == 0) | |
88 | break; | |
89 | return mod; | |
90 | } | |
91 | ||
5c3ead8c | 92 | static struct module *new_module(char *modname) |
1da177e4 LT |
93 | { |
94 | struct module *mod; | |
95 | char *p, *s; | |
62070fa4 | 96 | |
1da177e4 LT |
97 | mod = NOFAIL(malloc(sizeof(*mod))); |
98 | memset(mod, 0, sizeof(*mod)); | |
99 | p = NOFAIL(strdup(modname)); | |
100 | ||
101 | /* strip trailing .o */ | |
102 | if ((s = strrchr(p, '.')) != NULL) | |
103 | if (strcmp(s, ".o") == 0) | |
104 | *s = '\0'; | |
105 | ||
106 | /* add to list */ | |
107 | mod->name = p; | |
b817f6fe | 108 | mod->gpl_compatible = -1; |
1da177e4 LT |
109 | mod->next = modules; |
110 | modules = mod; | |
111 | ||
112 | return mod; | |
113 | } | |
114 | ||
115 | /* A hash of all exported symbols, | |
116 | * struct symbol is also used for lists of unresolved symbols */ | |
117 | ||
118 | #define SYMBOL_HASH_SIZE 1024 | |
119 | ||
120 | struct symbol { | |
121 | struct symbol *next; | |
122 | struct module *module; | |
123 | unsigned int crc; | |
124 | int crc_valid; | |
125 | unsigned int weak:1; | |
040fcc81 SR |
126 | unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */ |
127 | unsigned int kernel:1; /* 1 if symbol is from kernel | |
128 | * (only for external modules) **/ | |
8e70c458 | 129 | unsigned int preloaded:1; /* 1 if symbol from Module.symvers */ |
bd5cbced | 130 | enum export export; /* Type of export */ |
1da177e4 LT |
131 | char name[0]; |
132 | }; | |
133 | ||
134 | static struct symbol *symbolhash[SYMBOL_HASH_SIZE]; | |
135 | ||
136 | /* This is based on the hash agorithm from gdbm, via tdb */ | |
137 | static inline unsigned int tdb_hash(const char *name) | |
138 | { | |
139 | unsigned value; /* Used to compute the hash value. */ | |
140 | unsigned i; /* Used to cycle through random values. */ | |
141 | ||
142 | /* Set the initial value from the key size. */ | |
143 | for (value = 0x238F13AF * strlen(name), i=0; name[i]; i++) | |
144 | value = (value + (((unsigned char *)name)[i] << (i*5 % 24))); | |
145 | ||
146 | return (1103515243 * value + 12345); | |
147 | } | |
148 | ||
5c3ead8c SR |
149 | /** |
150 | * Allocate a new symbols for use in the hash of exported symbols or | |
151 | * the list of unresolved symbols per module | |
152 | **/ | |
153 | static struct symbol *alloc_symbol(const char *name, unsigned int weak, | |
154 | struct symbol *next) | |
1da177e4 LT |
155 | { |
156 | struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1)); | |
157 | ||
158 | memset(s, 0, sizeof(*s)); | |
159 | strcpy(s->name, name); | |
160 | s->weak = weak; | |
161 | s->next = next; | |
162 | return s; | |
163 | } | |
164 | ||
165 | /* For the hash of exported symbols */ | |
bd5cbced RP |
166 | static struct symbol *new_symbol(const char *name, struct module *module, |
167 | enum export export) | |
1da177e4 LT |
168 | { |
169 | unsigned int hash; | |
170 | struct symbol *new; | |
171 | ||
172 | hash = tdb_hash(name) % SYMBOL_HASH_SIZE; | |
173 | new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]); | |
174 | new->module = module; | |
bd5cbced | 175 | new->export = export; |
040fcc81 | 176 | return new; |
1da177e4 LT |
177 | } |
178 | ||
5c3ead8c | 179 | static struct symbol *find_symbol(const char *name) |
1da177e4 LT |
180 | { |
181 | struct symbol *s; | |
182 | ||
183 | /* For our purposes, .foo matches foo. PPC64 needs this. */ | |
184 | if (name[0] == '.') | |
185 | name++; | |
186 | ||
187 | for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s=s->next) { | |
188 | if (strcmp(s->name, name) == 0) | |
189 | return s; | |
190 | } | |
191 | return NULL; | |
192 | } | |
193 | ||
bd5cbced RP |
194 | static struct { |
195 | const char *str; | |
196 | enum export export; | |
197 | } export_list[] = { | |
198 | { .str = "EXPORT_SYMBOL", .export = export_plain }, | |
c96fca21 | 199 | { .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused }, |
bd5cbced | 200 | { .str = "EXPORT_SYMBOL_GPL", .export = export_gpl }, |
c96fca21 | 201 | { .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl }, |
bd5cbced RP |
202 | { .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future }, |
203 | { .str = "(unknown)", .export = export_unknown }, | |
204 | }; | |
205 | ||
206 | ||
207 | static const char *export_str(enum export ex) | |
208 | { | |
209 | return export_list[ex].str; | |
210 | } | |
211 | ||
212 | static enum export export_no(const char * s) | |
213 | { | |
214 | int i; | |
534b89a9 SR |
215 | if (!s) |
216 | return export_unknown; | |
bd5cbced RP |
217 | for (i = 0; export_list[i].export != export_unknown; i++) { |
218 | if (strcmp(export_list[i].str, s) == 0) | |
219 | return export_list[i].export; | |
220 | } | |
221 | return export_unknown; | |
222 | } | |
223 | ||
224 | static enum export export_from_sec(struct elf_info *elf, Elf_Section sec) | |
225 | { | |
226 | if (sec == elf->export_sec) | |
227 | return export_plain; | |
c96fca21 SR |
228 | else if (sec == elf->export_unused_sec) |
229 | return export_unused; | |
bd5cbced RP |
230 | else if (sec == elf->export_gpl_sec) |
231 | return export_gpl; | |
c96fca21 SR |
232 | else if (sec == elf->export_unused_gpl_sec) |
233 | return export_unused_gpl; | |
bd5cbced RP |
234 | else if (sec == elf->export_gpl_future_sec) |
235 | return export_gpl_future; | |
236 | else | |
237 | return export_unknown; | |
238 | } | |
239 | ||
5c3ead8c SR |
240 | /** |
241 | * Add an exported symbol - it may have already been added without a | |
242 | * CRC, in this case just update the CRC | |
243 | **/ | |
bd5cbced RP |
244 | static struct symbol *sym_add_exported(const char *name, struct module *mod, |
245 | enum export export) | |
1da177e4 LT |
246 | { |
247 | struct symbol *s = find_symbol(name); | |
248 | ||
249 | if (!s) { | |
bd5cbced | 250 | s = new_symbol(name, mod, export); |
8e70c458 SR |
251 | } else { |
252 | if (!s->preloaded) { | |
7b75b13c | 253 | warn("%s: '%s' exported twice. Previous export " |
8e70c458 SR |
254 | "was in %s%s\n", mod->name, name, |
255 | s->module->name, | |
256 | is_vmlinux(s->module->name) ?"":".ko"); | |
257 | } | |
1da177e4 | 258 | } |
8e70c458 | 259 | s->preloaded = 0; |
040fcc81 SR |
260 | s->vmlinux = is_vmlinux(mod->name); |
261 | s->kernel = 0; | |
bd5cbced | 262 | s->export = export; |
040fcc81 SR |
263 | return s; |
264 | } | |
265 | ||
266 | static void sym_update_crc(const char *name, struct module *mod, | |
bd5cbced | 267 | unsigned int crc, enum export export) |
040fcc81 SR |
268 | { |
269 | struct symbol *s = find_symbol(name); | |
270 | ||
271 | if (!s) | |
bd5cbced | 272 | s = new_symbol(name, mod, export); |
040fcc81 SR |
273 | s->crc = crc; |
274 | s->crc_valid = 1; | |
1da177e4 LT |
275 | } |
276 | ||
5c3ead8c | 277 | void *grab_file(const char *filename, unsigned long *size) |
1da177e4 LT |
278 | { |
279 | struct stat st; | |
280 | void *map; | |
281 | int fd; | |
282 | ||
283 | fd = open(filename, O_RDONLY); | |
284 | if (fd < 0 || fstat(fd, &st) != 0) | |
285 | return NULL; | |
286 | ||
287 | *size = st.st_size; | |
288 | map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0); | |
289 | close(fd); | |
290 | ||
291 | if (map == MAP_FAILED) | |
292 | return NULL; | |
293 | return map; | |
294 | } | |
295 | ||
5c3ead8c SR |
296 | /** |
297 | * Return a copy of the next line in a mmap'ed file. | |
298 | * spaces in the beginning of the line is trimmed away. | |
299 | * Return a pointer to a static buffer. | |
300 | **/ | |
301 | char* get_next_line(unsigned long *pos, void *file, unsigned long size) | |
1da177e4 LT |
302 | { |
303 | static char line[4096]; | |
304 | int skip = 1; | |
305 | size_t len = 0; | |
306 | signed char *p = (signed char *)file + *pos; | |
307 | char *s = line; | |
308 | ||
309 | for (; *pos < size ; (*pos)++) | |
310 | { | |
311 | if (skip && isspace(*p)) { | |
312 | p++; | |
313 | continue; | |
314 | } | |
315 | skip = 0; | |
316 | if (*p != '\n' && (*pos < size)) { | |
317 | len++; | |
318 | *s++ = *p++; | |
319 | if (len > 4095) | |
320 | break; /* Too long, stop */ | |
321 | } else { | |
322 | /* End of string */ | |
323 | *s = '\0'; | |
324 | return line; | |
325 | } | |
326 | } | |
327 | /* End of buffer */ | |
328 | return NULL; | |
329 | } | |
330 | ||
5c3ead8c | 331 | void release_file(void *file, unsigned long size) |
1da177e4 LT |
332 | { |
333 | munmap(file, size); | |
334 | } | |
335 | ||
85bd2fdd | 336 | static int parse_elf(struct elf_info *info, const char *filename) |
1da177e4 LT |
337 | { |
338 | unsigned int i; | |
85bd2fdd | 339 | Elf_Ehdr *hdr; |
1da177e4 LT |
340 | Elf_Shdr *sechdrs; |
341 | Elf_Sym *sym; | |
342 | ||
343 | hdr = grab_file(filename, &info->size); | |
344 | if (!hdr) { | |
345 | perror(filename); | |
6803dc0e | 346 | exit(1); |
1da177e4 LT |
347 | } |
348 | info->hdr = hdr; | |
85bd2fdd SR |
349 | if (info->size < sizeof(*hdr)) { |
350 | /* file too small, assume this is an empty .o file */ | |
351 | return 0; | |
352 | } | |
353 | /* Is this a valid ELF file? */ | |
354 | if ((hdr->e_ident[EI_MAG0] != ELFMAG0) || | |
355 | (hdr->e_ident[EI_MAG1] != ELFMAG1) || | |
356 | (hdr->e_ident[EI_MAG2] != ELFMAG2) || | |
357 | (hdr->e_ident[EI_MAG3] != ELFMAG3)) { | |
358 | /* Not an ELF file - silently ignore it */ | |
359 | return 0; | |
360 | } | |
1da177e4 LT |
361 | /* Fix endianness in ELF header */ |
362 | hdr->e_shoff = TO_NATIVE(hdr->e_shoff); | |
363 | hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx); | |
364 | hdr->e_shnum = TO_NATIVE(hdr->e_shnum); | |
365 | hdr->e_machine = TO_NATIVE(hdr->e_machine); | |
366 | sechdrs = (void *)hdr + hdr->e_shoff; | |
367 | info->sechdrs = sechdrs; | |
368 | ||
369 | /* Fix endianness in section headers */ | |
370 | for (i = 0; i < hdr->e_shnum; i++) { | |
371 | sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type); | |
372 | sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset); | |
373 | sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size); | |
374 | sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link); | |
375 | sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name); | |
376 | } | |
377 | /* Find symbol table. */ | |
378 | for (i = 1; i < hdr->e_shnum; i++) { | |
379 | const char *secstrings | |
380 | = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; | |
bd5cbced | 381 | const char *secname; |
1da177e4 | 382 | |
85bd2fdd SR |
383 | if (sechdrs[i].sh_offset > info->size) { |
384 | fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename, (unsigned int)sechdrs[i].sh_offset, sizeof(*hdr)); | |
385 | return 0; | |
386 | } | |
bd5cbced RP |
387 | secname = secstrings + sechdrs[i].sh_name; |
388 | if (strcmp(secname, ".modinfo") == 0) { | |
1da177e4 LT |
389 | info->modinfo = (void *)hdr + sechdrs[i].sh_offset; |
390 | info->modinfo_len = sechdrs[i].sh_size; | |
bd5cbced RP |
391 | } else if (strcmp(secname, "__ksymtab") == 0) |
392 | info->export_sec = i; | |
c96fca21 SR |
393 | else if (strcmp(secname, "__ksymtab_unused") == 0) |
394 | info->export_unused_sec = i; | |
bd5cbced RP |
395 | else if (strcmp(secname, "__ksymtab_gpl") == 0) |
396 | info->export_gpl_sec = i; | |
c96fca21 SR |
397 | else if (strcmp(secname, "__ksymtab_unused_gpl") == 0) |
398 | info->export_unused_gpl_sec = i; | |
bd5cbced RP |
399 | else if (strcmp(secname, "__ksymtab_gpl_future") == 0) |
400 | info->export_gpl_future_sec = i; | |
401 | ||
1da177e4 LT |
402 | if (sechdrs[i].sh_type != SHT_SYMTAB) |
403 | continue; | |
404 | ||
405 | info->symtab_start = (void *)hdr + sechdrs[i].sh_offset; | |
62070fa4 | 406 | info->symtab_stop = (void *)hdr + sechdrs[i].sh_offset |
1da177e4 | 407 | + sechdrs[i].sh_size; |
62070fa4 | 408 | info->strtab = (void *)hdr + |
1da177e4 LT |
409 | sechdrs[sechdrs[i].sh_link].sh_offset; |
410 | } | |
411 | if (!info->symtab_start) { | |
cb80514d | 412 | fatal("%s has no symtab?\n", filename); |
1da177e4 LT |
413 | } |
414 | /* Fix endianness in symbols */ | |
415 | for (sym = info->symtab_start; sym < info->symtab_stop; sym++) { | |
416 | sym->st_shndx = TO_NATIVE(sym->st_shndx); | |
417 | sym->st_name = TO_NATIVE(sym->st_name); | |
418 | sym->st_value = TO_NATIVE(sym->st_value); | |
419 | sym->st_size = TO_NATIVE(sym->st_size); | |
420 | } | |
85bd2fdd | 421 | return 1; |
1da177e4 LT |
422 | } |
423 | ||
5c3ead8c | 424 | static void parse_elf_finish(struct elf_info *info) |
1da177e4 LT |
425 | { |
426 | release_file(info->hdr, info->size); | |
427 | } | |
428 | ||
f7b05e64 LY |
429 | #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_" |
430 | #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_" | |
1da177e4 | 431 | |
5c3ead8c SR |
432 | static void handle_modversions(struct module *mod, struct elf_info *info, |
433 | Elf_Sym *sym, const char *symname) | |
1da177e4 LT |
434 | { |
435 | unsigned int crc; | |
bd5cbced | 436 | enum export export = export_from_sec(info, sym->st_shndx); |
1da177e4 LT |
437 | |
438 | switch (sym->st_shndx) { | |
439 | case SHN_COMMON: | |
cb80514d | 440 | warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name); |
1da177e4 LT |
441 | break; |
442 | case SHN_ABS: | |
443 | /* CRC'd symbol */ | |
444 | if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) { | |
445 | crc = (unsigned int) sym->st_value; | |
bd5cbced RP |
446 | sym_update_crc(symname + strlen(CRC_PFX), mod, crc, |
447 | export); | |
1da177e4 LT |
448 | } |
449 | break; | |
450 | case SHN_UNDEF: | |
451 | /* undefined symbol */ | |
452 | if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL && | |
453 | ELF_ST_BIND(sym->st_info) != STB_WEAK) | |
454 | break; | |
455 | /* ignore global offset table */ | |
456 | if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0) | |
457 | break; | |
458 | /* ignore __this_module, it will be resolved shortly */ | |
459 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0) | |
460 | break; | |
8d529014 BC |
461 | /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */ |
462 | #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER) | |
463 | /* add compatibility with older glibc */ | |
464 | #ifndef STT_SPARC_REGISTER | |
465 | #define STT_SPARC_REGISTER STT_REGISTER | |
466 | #endif | |
1da177e4 LT |
467 | if (info->hdr->e_machine == EM_SPARC || |
468 | info->hdr->e_machine == EM_SPARCV9) { | |
469 | /* Ignore register directives. */ | |
8d529014 | 470 | if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER) |
1da177e4 | 471 | break; |
62070fa4 SR |
472 | if (symname[0] == '.') { |
473 | char *munged = strdup(symname); | |
474 | munged[0] = '_'; | |
475 | munged[1] = toupper(munged[1]); | |
476 | symname = munged; | |
477 | } | |
1da177e4 LT |
478 | } |
479 | #endif | |
62070fa4 | 480 | |
1da177e4 LT |
481 | if (memcmp(symname, MODULE_SYMBOL_PREFIX, |
482 | strlen(MODULE_SYMBOL_PREFIX)) == 0) | |
483 | mod->unres = alloc_symbol(symname + | |
484 | strlen(MODULE_SYMBOL_PREFIX), | |
485 | ELF_ST_BIND(sym->st_info) == STB_WEAK, | |
486 | mod->unres); | |
487 | break; | |
488 | default: | |
489 | /* All exported symbols */ | |
490 | if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) { | |
bd5cbced RP |
491 | sym_add_exported(symname + strlen(KSYMTAB_PFX), mod, |
492 | export); | |
1da177e4 LT |
493 | } |
494 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0) | |
495 | mod->has_init = 1; | |
496 | if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0) | |
497 | mod->has_cleanup = 1; | |
498 | break; | |
499 | } | |
500 | } | |
501 | ||
5c3ead8c SR |
502 | /** |
503 | * Parse tag=value strings from .modinfo section | |
504 | **/ | |
1da177e4 LT |
505 | static char *next_string(char *string, unsigned long *secsize) |
506 | { | |
507 | /* Skip non-zero chars */ | |
508 | while (string[0]) { | |
509 | string++; | |
510 | if ((*secsize)-- <= 1) | |
511 | return NULL; | |
512 | } | |
513 | ||
514 | /* Skip any zero padding. */ | |
515 | while (!string[0]) { | |
516 | string++; | |
517 | if ((*secsize)-- <= 1) | |
518 | return NULL; | |
519 | } | |
520 | return string; | |
521 | } | |
522 | ||
b817f6fe SR |
523 | static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len, |
524 | const char *tag, char *info) | |
1da177e4 LT |
525 | { |
526 | char *p; | |
527 | unsigned int taglen = strlen(tag); | |
528 | unsigned long size = modinfo_len; | |
529 | ||
b817f6fe SR |
530 | if (info) { |
531 | size -= info - (char *)modinfo; | |
532 | modinfo = next_string(info, &size); | |
533 | } | |
534 | ||
1da177e4 LT |
535 | for (p = modinfo; p; p = next_string(p, &size)) { |
536 | if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=') | |
537 | return p + taglen + 1; | |
538 | } | |
539 | return NULL; | |
540 | } | |
541 | ||
b817f6fe SR |
542 | static char *get_modinfo(void *modinfo, unsigned long modinfo_len, |
543 | const char *tag) | |
544 | ||
545 | { | |
546 | return get_next_modinfo(modinfo, modinfo_len, tag, NULL); | |
547 | } | |
548 | ||
4c8fbca5 SR |
549 | /** |
550 | * Test if string s ends in string sub | |
551 | * return 0 if match | |
552 | **/ | |
553 | static int strrcmp(const char *s, const char *sub) | |
554 | { | |
555 | int slen, sublen; | |
62070fa4 | 556 | |
4c8fbca5 SR |
557 | if (!s || !sub) |
558 | return 1; | |
62070fa4 | 559 | |
4c8fbca5 SR |
560 | slen = strlen(s); |
561 | sublen = strlen(sub); | |
62070fa4 | 562 | |
4c8fbca5 SR |
563 | if ((slen == 0) || (sublen == 0)) |
564 | return 1; | |
565 | ||
566 | if (sublen > slen) | |
567 | return 1; | |
568 | ||
569 | return memcmp(s + slen - sublen, sub, sublen); | |
570 | } | |
571 | ||
572 | /** | |
573 | * Whitelist to allow certain references to pass with no warning. | |
574 | * Pattern 1: | |
575 | * If a module parameter is declared __initdata and permissions=0 | |
576 | * then this is legal despite the warning generated. | |
577 | * We cannot see value of permissions here, so just ignore | |
578 | * this pattern. | |
579 | * The pattern is identified by: | |
580 | * tosec = .init.data | |
9209aed0 | 581 | * fromsec = .data* |
4c8fbca5 | 582 | * atsym =__param* |
62070fa4 | 583 | * |
4c8fbca5 | 584 | * Pattern 2: |
72ee59b5 | 585 | * Many drivers utilise a *driver container with references to |
4c8fbca5 SR |
586 | * add, remove, probe functions etc. |
587 | * These functions may often be marked __init and we do not want to | |
588 | * warn here. | |
589 | * the pattern is identified by: | |
5ecdd0f6 | 590 | * tosec = .init.text | .exit.text | .init.data |
4c8fbca5 | 591 | * fromsec = .data |
72ee59b5 | 592 | * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one |
ee6a8545 VG |
593 | * |
594 | * Pattern 3: | |
595 | * Some symbols belong to init section but still it is ok to reference | |
596 | * these from non-init sections as these symbols don't have any memory | |
597 | * allocated for them and symbol address and value are same. So even | |
598 | * if init section is freed, its ok to reference those symbols. | |
599 | * For ex. symbols marking the init section boundaries. | |
600 | * This pattern is identified by | |
601 | * refsymname = __init_begin, _sinittext, _einittext | |
4c8fbca5 | 602 | **/ |
9e157a5a | 603 | static int secref_whitelist(const char *modname, const char *tosec, |
ee6a8545 VG |
604 | const char *fromsec, const char *atsym, |
605 | const char *refsymname) | |
4c8fbca5 SR |
606 | { |
607 | int f1 = 1, f2 = 1; | |
608 | const char **s; | |
609 | const char *pat2sym[] = { | |
72ee59b5 | 610 | "driver", |
5ecdd0f6 SR |
611 | "_template", /* scsi uses *_template a lot */ |
612 | "_sht", /* scsi also used *_sht to some extent */ | |
4c8fbca5 SR |
613 | "_ops", |
614 | "_probe", | |
615 | "_probe_one", | |
118c0ace | 616 | "_console", |
4c8fbca5 SR |
617 | NULL |
618 | }; | |
62070fa4 | 619 | |
ee6a8545 VG |
620 | const char *pat3refsym[] = { |
621 | "__init_begin", | |
622 | "_sinittext", | |
623 | "_einittext", | |
624 | NULL | |
625 | }; | |
626 | ||
4c8fbca5 SR |
627 | /* Check for pattern 1 */ |
628 | if (strcmp(tosec, ".init.data") != 0) | |
629 | f1 = 0; | |
9209aed0 | 630 | if (strncmp(fromsec, ".data", strlen(".data")) != 0) |
4c8fbca5 SR |
631 | f1 = 0; |
632 | if (strncmp(atsym, "__param", strlen("__param")) != 0) | |
633 | f1 = 0; | |
634 | ||
635 | if (f1) | |
636 | return f1; | |
637 | ||
638 | /* Check for pattern 2 */ | |
62070fa4 | 639 | if ((strcmp(tosec, ".init.text") != 0) && |
5ecdd0f6 SR |
640 | (strcmp(tosec, ".exit.text") != 0) && |
641 | (strcmp(tosec, ".init.data") != 0)) | |
4c8fbca5 SR |
642 | f2 = 0; |
643 | if (strcmp(fromsec, ".data") != 0) | |
644 | f2 = 0; | |
645 | ||
646 | for (s = pat2sym; *s; s++) | |
647 | if (strrcmp(atsym, *s) == 0) | |
648 | f1 = 1; | |
9e157a5a MD |
649 | if (f1 && f2) |
650 | return 1; | |
4c8fbca5 | 651 | |
f8657e1b VG |
652 | /* Whitelist all references from .pci_fixup section if vmlinux |
653 | * Whitelist all refereces from .text.head to .init.data if vmlinux | |
654 | * Whitelist all refereces from .text.head to .init.text if vmlinux | |
655 | */ | |
9e157a5a MD |
656 | if (is_vmlinux(modname)) { |
657 | if ((strcmp(fromsec, ".pci_fixup") == 0) && | |
658 | (strcmp(tosec, ".init.text") == 0)) | |
659 | return 1; | |
ee6a8545 | 660 | |
f8657e1b VG |
661 | if ((strcmp(fromsec, ".text.head") == 0) && |
662 | ((strcmp(tosec, ".init.data") == 0) || | |
663 | (strcmp(tosec, ".init.text") == 0))) | |
664 | return 1; | |
665 | ||
ee6a8545 VG |
666 | /* Check for pattern 3 */ |
667 | for (s = pat3refsym; *s; s++) | |
668 | if (strcmp(refsymname, *s) == 0) | |
669 | return 1; | |
9e157a5a | 670 | } |
93659af1 | 671 | return 0; |
4c8fbca5 SR |
672 | } |
673 | ||
93684d3b SR |
674 | /** |
675 | * Find symbol based on relocation record info. | |
676 | * In some cases the symbol supplied is a valid symbol so | |
677 | * return refsym. If st_name != 0 we assume this is a valid symbol. | |
678 | * In other cases the symbol needs to be looked up in the symbol table | |
679 | * based on section and address. | |
680 | * **/ | |
681 | static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr, | |
682 | Elf_Sym *relsym) | |
683 | { | |
684 | Elf_Sym *sym; | |
685 | ||
686 | if (relsym->st_name != 0) | |
687 | return relsym; | |
688 | for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { | |
689 | if (sym->st_shndx != relsym->st_shndx) | |
690 | continue; | |
691 | if (sym->st_value == addr) | |
692 | return sym; | |
693 | } | |
694 | return NULL; | |
695 | } | |
696 | ||
da68d61f DB |
697 | static inline int is_arm_mapping_symbol(const char *str) |
698 | { | |
699 | return str[0] == '$' && strchr("atd", str[1]) | |
700 | && (str[2] == '\0' || str[2] == '.'); | |
701 | } | |
702 | ||
703 | /* | |
704 | * If there's no name there, ignore it; likewise, ignore it if it's | |
705 | * one of the magic symbols emitted used by current ARM tools. | |
706 | * | |
707 | * Otherwise if find_symbols_between() returns those symbols, they'll | |
708 | * fail the whitelist tests and cause lots of false alarms ... fixable | |
709 | * only by merging __exit and __init sections into __text, bloating | |
710 | * the kernel (which is especially evil on embedded platforms). | |
711 | */ | |
712 | static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym) | |
713 | { | |
714 | const char *name = elf->strtab + sym->st_name; | |
715 | ||
716 | if (!name || !strlen(name)) | |
717 | return 0; | |
718 | return !is_arm_mapping_symbol(name); | |
719 | } | |
720 | ||
b39927cf | 721 | /* |
43c74d17 SR |
722 | * Find symbols before or equal addr and after addr - in the section sec. |
723 | * If we find two symbols with equal offset prefer one with a valid name. | |
724 | * The ELF format may have a better way to detect what type of symbol | |
725 | * it is, but this works for now. | |
b39927cf SR |
726 | **/ |
727 | static void find_symbols_between(struct elf_info *elf, Elf_Addr addr, | |
728 | const char *sec, | |
729 | Elf_Sym **before, Elf_Sym **after) | |
730 | { | |
731 | Elf_Sym *sym; | |
732 | Elf_Ehdr *hdr = elf->hdr; | |
733 | Elf_Addr beforediff = ~0; | |
734 | Elf_Addr afterdiff = ~0; | |
735 | const char *secstrings = (void *)hdr + | |
736 | elf->sechdrs[hdr->e_shstrndx].sh_offset; | |
62070fa4 | 737 | |
b39927cf SR |
738 | *before = NULL; |
739 | *after = NULL; | |
740 | ||
741 | for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) { | |
742 | const char *symsec; | |
743 | ||
744 | if (sym->st_shndx >= SHN_LORESERVE) | |
745 | continue; | |
746 | symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name; | |
747 | if (strcmp(symsec, sec) != 0) | |
748 | continue; | |
da68d61f DB |
749 | if (!is_valid_name(elf, sym)) |
750 | continue; | |
b39927cf SR |
751 | if (sym->st_value <= addr) { |
752 | if ((addr - sym->st_value) < beforediff) { | |
753 | beforediff = addr - sym->st_value; | |
754 | *before = sym; | |
755 | } | |
43c74d17 | 756 | else if ((addr - sym->st_value) == beforediff) { |
da68d61f | 757 | *before = sym; |
43c74d17 | 758 | } |
b39927cf SR |
759 | } |
760 | else | |
761 | { | |
762 | if ((sym->st_value - addr) < afterdiff) { | |
763 | afterdiff = sym->st_value - addr; | |
764 | *after = sym; | |
765 | } | |
43c74d17 | 766 | else if ((sym->st_value - addr) == afterdiff) { |
da68d61f | 767 | *after = sym; |
43c74d17 | 768 | } |
b39927cf SR |
769 | } |
770 | } | |
771 | } | |
772 | ||
773 | /** | |
774 | * Print a warning about a section mismatch. | |
775 | * Try to find symbols near it so user can find it. | |
4c8fbca5 | 776 | * Check whitelist before warning - it may be a false positive. |
b39927cf SR |
777 | **/ |
778 | static void warn_sec_mismatch(const char *modname, const char *fromsec, | |
779 | struct elf_info *elf, Elf_Sym *sym, Elf_Rela r) | |
780 | { | |
93684d3b SR |
781 | const char *refsymname = ""; |
782 | Elf_Sym *before, *after; | |
783 | Elf_Sym *refsym; | |
b39927cf SR |
784 | Elf_Ehdr *hdr = elf->hdr; |
785 | Elf_Shdr *sechdrs = elf->sechdrs; | |
786 | const char *secstrings = (void *)hdr + | |
787 | sechdrs[hdr->e_shstrndx].sh_offset; | |
788 | const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name; | |
62070fa4 | 789 | |
b39927cf SR |
790 | find_symbols_between(elf, r.r_offset, fromsec, &before, &after); |
791 | ||
93684d3b SR |
792 | refsym = find_elf_symbol(elf, r.r_addend, sym); |
793 | if (refsym && strlen(elf->strtab + refsym->st_name)) | |
794 | refsymname = elf->strtab + refsym->st_name; | |
4c8fbca5 SR |
795 | |
796 | /* check whitelist - we may ignore it */ | |
62070fa4 | 797 | if (before && |
9e157a5a | 798 | secref_whitelist(modname, secname, fromsec, |
ee6a8545 | 799 | elf->strtab + before->st_name, refsymname)) |
4c8fbca5 | 800 | return; |
62070fa4 | 801 | |
b39927cf | 802 | if (before && after) { |
93684d3b SR |
803 | warn("%s - Section mismatch: reference to %s:%s from %s " |
804 | "between '%s' (at offset 0x%llx) and '%s'\n", | |
805 | modname, secname, refsymname, fromsec, | |
b39927cf | 806 | elf->strtab + before->st_name, |
93684d3b | 807 | (long long)r.r_offset, |
b39927cf SR |
808 | elf->strtab + after->st_name); |
809 | } else if (before) { | |
93684d3b SR |
810 | warn("%s - Section mismatch: reference to %s:%s from %s " |
811 | "after '%s' (at offset 0x%llx)\n", | |
62070fa4 | 812 | modname, secname, refsymname, fromsec, |
b39927cf | 813 | elf->strtab + before->st_name, |
93684d3b | 814 | (long long)r.r_offset); |
b39927cf | 815 | } else if (after) { |
93684d3b SR |
816 | warn("%s - Section mismatch: reference to %s:%s from %s " |
817 | "before '%s' (at offset -0x%llx)\n", | |
62070fa4 | 818 | modname, secname, refsymname, fromsec, |
eaaae38c | 819 | elf->strtab + after->st_name, |
93684d3b | 820 | (long long)r.r_offset); |
b39927cf | 821 | } else { |
93684d3b SR |
822 | warn("%s - Section mismatch: reference to %s:%s from %s " |
823 | "(offset 0x%llx)\n", | |
824 | modname, secname, fromsec, refsymname, | |
825 | (long long)r.r_offset); | |
b39927cf SR |
826 | } |
827 | } | |
828 | ||
829 | /** | |
830 | * A module includes a number of sections that are discarded | |
831 | * either when loaded or when used as built-in. | |
832 | * For loaded modules all functions marked __init and all data | |
833 | * marked __initdata will be discarded when the module has been intialized. | |
834 | * Likewise for modules used built-in the sections marked __exit | |
835 | * are discarded because __exit marked function are supposed to be called | |
836 | * only when a moduel is unloaded which never happes for built-in modules. | |
837 | * The check_sec_ref() function traverses all relocation records | |
838 | * to find all references to a section that reference a section that will | |
839 | * be discarded and warns about it. | |
840 | **/ | |
841 | static void check_sec_ref(struct module *mod, const char *modname, | |
842 | struct elf_info *elf, | |
843 | int section(const char*), | |
844 | int section_ref_ok(const char *)) | |
845 | { | |
846 | int i; | |
847 | Elf_Sym *sym; | |
848 | Elf_Ehdr *hdr = elf->hdr; | |
849 | Elf_Shdr *sechdrs = elf->sechdrs; | |
850 | const char *secstrings = (void *)hdr + | |
851 | sechdrs[hdr->e_shstrndx].sh_offset; | |
62070fa4 | 852 | |
b39927cf SR |
853 | /* Walk through all sections */ |
854 | for (i = 0; i < hdr->e_shnum; i++) { | |
2c1a51f3 AN |
855 | const char *name = secstrings + sechdrs[i].sh_name; |
856 | const char *secname; | |
857 | Elf_Rela r; | |
eae07ac6 | 858 | unsigned int r_sym; |
b39927cf | 859 | /* We want to process only relocation sections and not .init */ |
2c1a51f3 AN |
860 | if (sechdrs[i].sh_type == SHT_RELA) { |
861 | Elf_Rela *rela; | |
862 | Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset; | |
863 | Elf_Rela *stop = (void*)start + sechdrs[i].sh_size; | |
864 | name += strlen(".rela"); | |
865 | if (section_ref_ok(name)) | |
866 | continue; | |
b39927cf | 867 | |
2c1a51f3 AN |
868 | for (rela = start; rela < stop; rela++) { |
869 | r.r_offset = TO_NATIVE(rela->r_offset); | |
eae07ac6 AN |
870 | #if KERNEL_ELFCLASS == ELFCLASS64 |
871 | if (hdr->e_machine == EM_MIPS) { | |
872 | r_sym = ELF64_MIPS_R_SYM(rela->r_info); | |
873 | r_sym = TO_NATIVE(r_sym); | |
874 | } else { | |
875 | r.r_info = TO_NATIVE(rela->r_info); | |
876 | r_sym = ELF_R_SYM(r.r_info); | |
877 | } | |
878 | #else | |
879 | r.r_info = TO_NATIVE(rela->r_info); | |
880 | r_sym = ELF_R_SYM(r.r_info); | |
881 | #endif | |
2c1a51f3 | 882 | r.r_addend = TO_NATIVE(rela->r_addend); |
eae07ac6 | 883 | sym = elf->symtab_start + r_sym; |
2c1a51f3 AN |
884 | /* Skip special sections */ |
885 | if (sym->st_shndx >= SHN_LORESERVE) | |
886 | continue; | |
887 | ||
888 | secname = secstrings + | |
889 | sechdrs[sym->st_shndx].sh_name; | |
890 | if (section(secname)) | |
891 | warn_sec_mismatch(modname, name, | |
892 | elf, sym, r); | |
893 | } | |
894 | } else if (sechdrs[i].sh_type == SHT_REL) { | |
895 | Elf_Rel *rel; | |
896 | Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset; | |
897 | Elf_Rel *stop = (void*)start + sechdrs[i].sh_size; | |
898 | name += strlen(".rel"); | |
899 | if (section_ref_ok(name)) | |
b39927cf SR |
900 | continue; |
901 | ||
2c1a51f3 AN |
902 | for (rel = start; rel < stop; rel++) { |
903 | r.r_offset = TO_NATIVE(rel->r_offset); | |
eae07ac6 AN |
904 | #if KERNEL_ELFCLASS == ELFCLASS64 |
905 | if (hdr->e_machine == EM_MIPS) { | |
906 | r_sym = ELF64_MIPS_R_SYM(rel->r_info); | |
907 | r_sym = TO_NATIVE(r_sym); | |
908 | } else { | |
909 | r.r_info = TO_NATIVE(rel->r_info); | |
910 | r_sym = ELF_R_SYM(r.r_info); | |
911 | } | |
912 | #else | |
913 | r.r_info = TO_NATIVE(rel->r_info); | |
914 | r_sym = ELF_R_SYM(r.r_info); | |
915 | #endif | |
2c1a51f3 | 916 | r.r_addend = 0; |
eae07ac6 | 917 | sym = elf->symtab_start + r_sym; |
2c1a51f3 AN |
918 | /* Skip special sections */ |
919 | if (sym->st_shndx >= SHN_LORESERVE) | |
920 | continue; | |
921 | ||
922 | secname = secstrings + | |
923 | sechdrs[sym->st_shndx].sh_name; | |
924 | if (section(secname)) | |
925 | warn_sec_mismatch(modname, name, | |
926 | elf, sym, r); | |
927 | } | |
b39927cf SR |
928 | } |
929 | } | |
930 | } | |
931 | ||
932 | /** | |
933 | * Functions used only during module init is marked __init and is stored in | |
934 | * a .init.text section. Likewise data is marked __initdata and stored in | |
935 | * a .init.data section. | |
936 | * If this section is one of these sections return 1 | |
937 | * See include/linux/init.h for the details | |
938 | **/ | |
939 | static int init_section(const char *name) | |
940 | { | |
941 | if (strcmp(name, ".init") == 0) | |
942 | return 1; | |
943 | if (strncmp(name, ".init.", strlen(".init.")) == 0) | |
944 | return 1; | |
945 | return 0; | |
946 | } | |
947 | ||
948 | /** | |
949 | * Identify sections from which references to a .init section is OK. | |
62070fa4 | 950 | * |
b39927cf SR |
951 | * Unfortunately references to read only data that referenced .init |
952 | * sections had to be excluded. Almost all of these are false | |
953 | * positives, they are created by gcc. The downside of excluding rodata | |
954 | * is that there really are some user references from rodata to | |
955 | * init code, e.g. drivers/video/vgacon.c: | |
62070fa4 | 956 | * |
b39927cf SR |
957 | * const struct consw vga_con = { |
958 | * con_startup: vgacon_startup, | |
959 | * | |
960 | * where vgacon_startup is __init. If you want to wade through the false | |
961 | * positives, take out the check for rodata. | |
962 | **/ | |
963 | static int init_section_ref_ok(const char *name) | |
964 | { | |
965 | const char **s; | |
966 | /* Absolute section names */ | |
967 | const char *namelist1[] = { | |
968 | ".init", | |
9209aed0 SR |
969 | ".opd", /* see comment [OPD] at exit_section_ref_ok() */ |
970 | ".toc1", /* used by ppc64 */ | |
b39927cf | 971 | ".stab", |
742433b0 | 972 | ".data.rel.ro", /* used by parisc64 */ |
139ec7c4 | 973 | ".parainstructions", |
b39927cf | 974 | ".text.lock", |
9209aed0 | 975 | "__bug_table", /* used by powerpc for BUG() */ |
b39927cf SR |
976 | ".pci_fixup_header", |
977 | ".pci_fixup_final", | |
978 | ".pdr", | |
979 | "__param", | |
468d9494 AV |
980 | "__ex_table", |
981 | ".fixup", | |
35899c57 | 982 | ".smp_locks", |
909252d2 | 983 | ".plt", /* seen on ARCH=um build on x86_64. Harmless */ |
21c4ff80 BH |
984 | "__ftr_fixup", /* powerpc cpu feature fixup */ |
985 | "__fw_ftr_fixup", /* powerpc firmware feature fixup */ | |
b39927cf SR |
986 | NULL |
987 | }; | |
988 | /* Start of section names */ | |
989 | const char *namelist2[] = { | |
990 | ".init.", | |
991 | ".altinstructions", | |
992 | ".eh_frame", | |
993 | ".debug", | |
139ec7c4 | 994 | ".parainstructions", |
742433b0 | 995 | ".rodata", |
b39927cf SR |
996 | NULL |
997 | }; | |
6e10133f SR |
998 | /* part of section name */ |
999 | const char *namelist3 [] = { | |
1000 | ".unwind", /* sample: IA_64.unwind.init.text */ | |
1001 | NULL | |
1002 | }; | |
1003 | ||
b39927cf SR |
1004 | for (s = namelist1; *s; s++) |
1005 | if (strcmp(*s, name) == 0) | |
1006 | return 1; | |
62070fa4 | 1007 | for (s = namelist2; *s; s++) |
b39927cf SR |
1008 | if (strncmp(*s, name, strlen(*s)) == 0) |
1009 | return 1; | |
62070fa4 | 1010 | for (s = namelist3; *s; s++) |
e835a39c | 1011 | if (strstr(name, *s) != NULL) |
6e10133f | 1012 | return 1; |
468d9494 AV |
1013 | if (strrcmp(name, ".init") == 0) |
1014 | return 1; | |
b39927cf SR |
1015 | return 0; |
1016 | } | |
1017 | ||
1018 | /* | |
1019 | * Functions used only during module exit is marked __exit and is stored in | |
1020 | * a .exit.text section. Likewise data is marked __exitdata and stored in | |
1021 | * a .exit.data section. | |
1022 | * If this section is one of these sections return 1 | |
1023 | * See include/linux/init.h for the details | |
1024 | **/ | |
1025 | static int exit_section(const char *name) | |
1026 | { | |
1027 | if (strcmp(name, ".exit.text") == 0) | |
1028 | return 1; | |
1029 | if (strcmp(name, ".exit.data") == 0) | |
1030 | return 1; | |
1031 | return 0; | |
62070fa4 | 1032 | |
b39927cf SR |
1033 | } |
1034 | ||
1035 | /* | |
1036 | * Identify sections from which references to a .exit section is OK. | |
62070fa4 | 1037 | * |
b39927cf SR |
1038 | * [OPD] Keith Ownes <kaos@sgi.com> commented: |
1039 | * For our future {in}sanity, add a comment that this is the ppc .opd | |
1040 | * section, not the ia64 .opd section. | |
1041 | * ia64 .opd should not point to discarded sections. | |
5ecdd0f6 | 1042 | * [.rodata] like for .init.text we ignore .rodata references -same reason |
b39927cf SR |
1043 | **/ |
1044 | static int exit_section_ref_ok(const char *name) | |
1045 | { | |
1046 | const char **s; | |
1047 | /* Absolute section names */ | |
1048 | const char *namelist1[] = { | |
1049 | ".exit.text", | |
1050 | ".exit.data", | |
1051 | ".init.text", | |
5ecdd0f6 | 1052 | ".rodata", |
b39927cf | 1053 | ".opd", /* See comment [OPD] */ |
9209aed0 | 1054 | ".toc1", /* used by ppc64 */ |
b39927cf SR |
1055 | ".altinstructions", |
1056 | ".pdr", | |
9209aed0 | 1057 | "__bug_table", /* used by powerpc for BUG() */ |
b39927cf SR |
1058 | ".exitcall.exit", |
1059 | ".eh_frame", | |
acd19499 | 1060 | ".parainstructions", |
b39927cf | 1061 | ".stab", |
468d9494 AV |
1062 | "__ex_table", |
1063 | ".fixup", | |
35899c57 | 1064 | ".smp_locks", |
909252d2 | 1065 | ".plt", /* seen on ARCH=um build on x86_64. Harmless */ |
b39927cf SR |
1066 | NULL |
1067 | }; | |
1068 | /* Start of section names */ | |
1069 | const char *namelist2[] = { | |
1070 | ".debug", | |
1071 | NULL | |
1072 | }; | |
6e10133f SR |
1073 | /* part of section name */ |
1074 | const char *namelist3 [] = { | |
1075 | ".unwind", /* Sample: IA_64.unwind.exit.text */ | |
1076 | NULL | |
1077 | }; | |
62070fa4 | 1078 | |
b39927cf SR |
1079 | for (s = namelist1; *s; s++) |
1080 | if (strcmp(*s, name) == 0) | |
1081 | return 1; | |
62070fa4 | 1082 | for (s = namelist2; *s; s++) |
b39927cf SR |
1083 | if (strncmp(*s, name, strlen(*s)) == 0) |
1084 | return 1; | |
62070fa4 | 1085 | for (s = namelist3; *s; s++) |
e835a39c | 1086 | if (strstr(name, *s) != NULL) |
6e10133f | 1087 | return 1; |
b39927cf SR |
1088 | return 0; |
1089 | } | |
1090 | ||
5c3ead8c | 1091 | static void read_symbols(char *modname) |
1da177e4 LT |
1092 | { |
1093 | const char *symname; | |
1094 | char *version; | |
b817f6fe | 1095 | char *license; |
1da177e4 LT |
1096 | struct module *mod; |
1097 | struct elf_info info = { }; | |
1098 | Elf_Sym *sym; | |
1099 | ||
85bd2fdd SR |
1100 | if (!parse_elf(&info, modname)) |
1101 | return; | |
1da177e4 LT |
1102 | |
1103 | mod = new_module(modname); | |
1104 | ||
1105 | /* When there's no vmlinux, don't print warnings about | |
1106 | * unresolved symbols (since there'll be too many ;) */ | |
1107 | if (is_vmlinux(modname)) { | |
1da177e4 | 1108 | have_vmlinux = 1; |
1da177e4 LT |
1109 | mod->skip = 1; |
1110 | } | |
1111 | ||
b817f6fe SR |
1112 | license = get_modinfo(info.modinfo, info.modinfo_len, "license"); |
1113 | while (license) { | |
1114 | if (license_is_gpl_compatible(license)) | |
1115 | mod->gpl_compatible = 1; | |
1116 | else { | |
1117 | mod->gpl_compatible = 0; | |
1118 | break; | |
1119 | } | |
1120 | license = get_next_modinfo(info.modinfo, info.modinfo_len, | |
1121 | "license", license); | |
1122 | } | |
1123 | ||
1da177e4 LT |
1124 | for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { |
1125 | symname = info.strtab + sym->st_name; | |
1126 | ||
1127 | handle_modversions(mod, &info, sym, symname); | |
1128 | handle_moddevtable(mod, &info, sym, symname); | |
1129 | } | |
b39927cf SR |
1130 | check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok); |
1131 | check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok); | |
1da177e4 LT |
1132 | |
1133 | version = get_modinfo(info.modinfo, info.modinfo_len, "version"); | |
1134 | if (version) | |
1135 | maybe_frob_rcs_version(modname, version, info.modinfo, | |
1136 | version - (char *)info.hdr); | |
1137 | if (version || (all_versions && !is_vmlinux(modname))) | |
1138 | get_src_version(modname, mod->srcversion, | |
1139 | sizeof(mod->srcversion)-1); | |
1140 | ||
1141 | parse_elf_finish(&info); | |
1142 | ||
1143 | /* Our trick to get versioning for struct_module - it's | |
1144 | * never passed as an argument to an exported function, so | |
1145 | * the automatic versioning doesn't pick it up, but it's really | |
1146 | * important anyhow */ | |
1147 | if (modversions) | |
1148 | mod->unres = alloc_symbol("struct_module", 0, mod->unres); | |
1149 | } | |
1150 | ||
1151 | #define SZ 500 | |
1152 | ||
1153 | /* We first write the generated file into memory using the | |
1154 | * following helper, then compare to the file on disk and | |
1155 | * only update the later if anything changed */ | |
1156 | ||
5c3ead8c SR |
1157 | void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf, |
1158 | const char *fmt, ...) | |
1da177e4 LT |
1159 | { |
1160 | char tmp[SZ]; | |
1161 | int len; | |
1162 | va_list ap; | |
62070fa4 | 1163 | |
1da177e4 LT |
1164 | va_start(ap, fmt); |
1165 | len = vsnprintf(tmp, SZ, fmt, ap); | |
7670f023 | 1166 | buf_write(buf, tmp, len); |
1da177e4 LT |
1167 | va_end(ap); |
1168 | } | |
1169 | ||
5c3ead8c | 1170 | void buf_write(struct buffer *buf, const char *s, int len) |
1da177e4 LT |
1171 | { |
1172 | if (buf->size - buf->pos < len) { | |
7670f023 | 1173 | buf->size += len + SZ; |
1da177e4 LT |
1174 | buf->p = realloc(buf->p, buf->size); |
1175 | } | |
1176 | strncpy(buf->p + buf->pos, s, len); | |
1177 | buf->pos += len; | |
1178 | } | |
1179 | ||
c96fca21 SR |
1180 | static void check_for_gpl_usage(enum export exp, const char *m, const char *s) |
1181 | { | |
1182 | const char *e = is_vmlinux(m) ?"":".ko"; | |
1183 | ||
1184 | switch (exp) { | |
1185 | case export_gpl: | |
1186 | fatal("modpost: GPL-incompatible module %s%s " | |
1187 | "uses GPL-only symbol '%s'\n", m, e, s); | |
1188 | break; | |
1189 | case export_unused_gpl: | |
1190 | fatal("modpost: GPL-incompatible module %s%s " | |
1191 | "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s); | |
1192 | break; | |
1193 | case export_gpl_future: | |
1194 | warn("modpost: GPL-incompatible module %s%s " | |
1195 | "uses future GPL-only symbol '%s'\n", m, e, s); | |
1196 | break; | |
1197 | case export_plain: | |
1198 | case export_unused: | |
1199 | case export_unknown: | |
1200 | /* ignore */ | |
1201 | break; | |
1202 | } | |
1203 | } | |
1204 | ||
1205 | static void check_for_unused(enum export exp, const char* m, const char* s) | |
1206 | { | |
1207 | const char *e = is_vmlinux(m) ?"":".ko"; | |
1208 | ||
1209 | switch (exp) { | |
1210 | case export_unused: | |
1211 | case export_unused_gpl: | |
1212 | warn("modpost: module %s%s " | |
1213 | "uses symbol '%s' marked UNUSED\n", m, e, s); | |
1214 | break; | |
1215 | default: | |
1216 | /* ignore */ | |
1217 | break; | |
1218 | } | |
1219 | } | |
1220 | ||
1221 | static void check_exports(struct module *mod) | |
b817f6fe SR |
1222 | { |
1223 | struct symbol *s, *exp; | |
1224 | ||
1225 | for (s = mod->unres; s; s = s->next) { | |
6449bd62 | 1226 | const char *basename; |
b817f6fe SR |
1227 | exp = find_symbol(s->name); |
1228 | if (!exp || exp->module == mod) | |
1229 | continue; | |
6449bd62 | 1230 | basename = strrchr(mod->name, '/'); |
b817f6fe SR |
1231 | if (basename) |
1232 | basename++; | |
c96fca21 SR |
1233 | else |
1234 | basename = mod->name; | |
1235 | if (!mod->gpl_compatible) | |
1236 | check_for_gpl_usage(exp->export, basename, exp->name); | |
1237 | check_for_unused(exp->export, basename, exp->name); | |
b817f6fe SR |
1238 | } |
1239 | } | |
1240 | ||
5c3ead8c SR |
1241 | /** |
1242 | * Header for the generated file | |
1243 | **/ | |
1244 | static void add_header(struct buffer *b, struct module *mod) | |
1da177e4 LT |
1245 | { |
1246 | buf_printf(b, "#include <linux/module.h>\n"); | |
1247 | buf_printf(b, "#include <linux/vermagic.h>\n"); | |
1248 | buf_printf(b, "#include <linux/compiler.h>\n"); | |
1249 | buf_printf(b, "\n"); | |
1250 | buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n"); | |
1251 | buf_printf(b, "\n"); | |
1da177e4 LT |
1252 | buf_printf(b, "struct module __this_module\n"); |
1253 | buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n"); | |
f83b5e32 | 1254 | buf_printf(b, " .name = KBUILD_MODNAME,\n"); |
1da177e4 LT |
1255 | if (mod->has_init) |
1256 | buf_printf(b, " .init = init_module,\n"); | |
1257 | if (mod->has_cleanup) | |
1258 | buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n" | |
1259 | " .exit = cleanup_module,\n" | |
1260 | "#endif\n"); | |
1261 | buf_printf(b, "};\n"); | |
1262 | } | |
1263 | ||
5c3ead8c SR |
1264 | /** |
1265 | * Record CRCs for unresolved symbols | |
1266 | **/ | |
c53ddacd | 1267 | static int add_versions(struct buffer *b, struct module *mod) |
1da177e4 LT |
1268 | { |
1269 | struct symbol *s, *exp; | |
c53ddacd | 1270 | int err = 0; |
1da177e4 LT |
1271 | |
1272 | for (s = mod->unres; s; s = s->next) { | |
1273 | exp = find_symbol(s->name); | |
1274 | if (!exp || exp->module == mod) { | |
c53ddacd | 1275 | if (have_vmlinux && !s->weak) { |
cb80514d SR |
1276 | warn("\"%s\" [%s.ko] undefined!\n", |
1277 | s->name, mod->name); | |
c53ddacd KK |
1278 | err = warn_unresolved ? 0 : 1; |
1279 | } | |
1da177e4 LT |
1280 | continue; |
1281 | } | |
1282 | s->module = exp->module; | |
1283 | s->crc_valid = exp->crc_valid; | |
1284 | s->crc = exp->crc; | |
1285 | } | |
1286 | ||
1287 | if (!modversions) | |
c53ddacd | 1288 | return err; |
1da177e4 LT |
1289 | |
1290 | buf_printf(b, "\n"); | |
1291 | buf_printf(b, "static const struct modversion_info ____versions[]\n"); | |
1292 | buf_printf(b, "__attribute_used__\n"); | |
1293 | buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n"); | |
1294 | ||
1295 | for (s = mod->unres; s; s = s->next) { | |
1296 | if (!s->module) { | |
1297 | continue; | |
1298 | } | |
1299 | if (!s->crc_valid) { | |
cb80514d | 1300 | warn("\"%s\" [%s.ko] has no CRC!\n", |
1da177e4 LT |
1301 | s->name, mod->name); |
1302 | continue; | |
1303 | } | |
1304 | buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name); | |
1305 | } | |
1306 | ||
1307 | buf_printf(b, "};\n"); | |
c53ddacd KK |
1308 | |
1309 | return err; | |
1da177e4 LT |
1310 | } |
1311 | ||
5c3ead8c SR |
1312 | static void add_depends(struct buffer *b, struct module *mod, |
1313 | struct module *modules) | |
1da177e4 LT |
1314 | { |
1315 | struct symbol *s; | |
1316 | struct module *m; | |
1317 | int first = 1; | |
1318 | ||
1319 | for (m = modules; m; m = m->next) { | |
1320 | m->seen = is_vmlinux(m->name); | |
1321 | } | |
1322 | ||
1323 | buf_printf(b, "\n"); | |
1324 | buf_printf(b, "static const char __module_depends[]\n"); | |
1325 | buf_printf(b, "__attribute_used__\n"); | |
1326 | buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n"); | |
1327 | buf_printf(b, "\"depends="); | |
1328 | for (s = mod->unres; s; s = s->next) { | |
1329 | if (!s->module) | |
1330 | continue; | |
1331 | ||
1332 | if (s->module->seen) | |
1333 | continue; | |
1334 | ||
1335 | s->module->seen = 1; | |
1336 | buf_printf(b, "%s%s", first ? "" : ",", | |
1337 | strrchr(s->module->name, '/') + 1); | |
1338 | first = 0; | |
1339 | } | |
1340 | buf_printf(b, "\";\n"); | |
1341 | } | |
1342 | ||
5c3ead8c | 1343 | static void add_srcversion(struct buffer *b, struct module *mod) |
1da177e4 LT |
1344 | { |
1345 | if (mod->srcversion[0]) { | |
1346 | buf_printf(b, "\n"); | |
1347 | buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n", | |
1348 | mod->srcversion); | |
1349 | } | |
1350 | } | |
1351 | ||
5c3ead8c | 1352 | static void write_if_changed(struct buffer *b, const char *fname) |
1da177e4 LT |
1353 | { |
1354 | char *tmp; | |
1355 | FILE *file; | |
1356 | struct stat st; | |
1357 | ||
1358 | file = fopen(fname, "r"); | |
1359 | if (!file) | |
1360 | goto write; | |
1361 | ||
1362 | if (fstat(fileno(file), &st) < 0) | |
1363 | goto close_write; | |
1364 | ||
1365 | if (st.st_size != b->pos) | |
1366 | goto close_write; | |
1367 | ||
1368 | tmp = NOFAIL(malloc(b->pos)); | |
1369 | if (fread(tmp, 1, b->pos, file) != b->pos) | |
1370 | goto free_write; | |
1371 | ||
1372 | if (memcmp(tmp, b->p, b->pos) != 0) | |
1373 | goto free_write; | |
1374 | ||
1375 | free(tmp); | |
1376 | fclose(file); | |
1377 | return; | |
1378 | ||
1379 | free_write: | |
1380 | free(tmp); | |
1381 | close_write: | |
1382 | fclose(file); | |
1383 | write: | |
1384 | file = fopen(fname, "w"); | |
1385 | if (!file) { | |
1386 | perror(fname); | |
1387 | exit(1); | |
1388 | } | |
1389 | if (fwrite(b->p, 1, b->pos, file) != b->pos) { | |
1390 | perror(fname); | |
1391 | exit(1); | |
1392 | } | |
1393 | fclose(file); | |
1394 | } | |
1395 | ||
bd5cbced | 1396 | /* parse Module.symvers file. line format: |
534b89a9 | 1397 | * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something] |
bd5cbced | 1398 | **/ |
040fcc81 | 1399 | static void read_dump(const char *fname, unsigned int kernel) |
1da177e4 LT |
1400 | { |
1401 | unsigned long size, pos = 0; | |
1402 | void *file = grab_file(fname, &size); | |
1403 | char *line; | |
1404 | ||
1405 | if (!file) | |
1406 | /* No symbol versions, silently ignore */ | |
1407 | return; | |
1408 | ||
1409 | while ((line = get_next_line(&pos, file, size))) { | |
534b89a9 | 1410 | char *symname, *modname, *d, *export, *end; |
1da177e4 LT |
1411 | unsigned int crc; |
1412 | struct module *mod; | |
040fcc81 | 1413 | struct symbol *s; |
1da177e4 LT |
1414 | |
1415 | if (!(symname = strchr(line, '\t'))) | |
1416 | goto fail; | |
1417 | *symname++ = '\0'; | |
1418 | if (!(modname = strchr(symname, '\t'))) | |
1419 | goto fail; | |
1420 | *modname++ = '\0'; | |
9ac545b0 | 1421 | if ((export = strchr(modname, '\t')) != NULL) |
bd5cbced | 1422 | *export++ = '\0'; |
534b89a9 SR |
1423 | if (export && ((end = strchr(export, '\t')) != NULL)) |
1424 | *end = '\0'; | |
1da177e4 LT |
1425 | crc = strtoul(line, &d, 16); |
1426 | if (*symname == '\0' || *modname == '\0' || *d != '\0') | |
1427 | goto fail; | |
1428 | ||
1429 | if (!(mod = find_module(modname))) { | |
1430 | if (is_vmlinux(modname)) { | |
1431 | have_vmlinux = 1; | |
1432 | } | |
1433 | mod = new_module(NOFAIL(strdup(modname))); | |
1434 | mod->skip = 1; | |
1435 | } | |
bd5cbced | 1436 | s = sym_add_exported(symname, mod, export_no(export)); |
8e70c458 SR |
1437 | s->kernel = kernel; |
1438 | s->preloaded = 1; | |
bd5cbced | 1439 | sym_update_crc(symname, mod, crc, export_no(export)); |
1da177e4 LT |
1440 | } |
1441 | return; | |
1442 | fail: | |
1443 | fatal("parse error in symbol dump file\n"); | |
1444 | } | |
1445 | ||
040fcc81 SR |
1446 | /* For normal builds always dump all symbols. |
1447 | * For external modules only dump symbols | |
1448 | * that are not read from kernel Module.symvers. | |
1449 | **/ | |
1450 | static int dump_sym(struct symbol *sym) | |
1451 | { | |
1452 | if (!external_module) | |
1453 | return 1; | |
1454 | if (sym->vmlinux || sym->kernel) | |
1455 | return 0; | |
1456 | return 1; | |
1457 | } | |
62070fa4 | 1458 | |
5c3ead8c | 1459 | static void write_dump(const char *fname) |
1da177e4 LT |
1460 | { |
1461 | struct buffer buf = { }; | |
1462 | struct symbol *symbol; | |
1463 | int n; | |
1464 | ||
1465 | for (n = 0; n < SYMBOL_HASH_SIZE ; n++) { | |
1466 | symbol = symbolhash[n]; | |
1467 | while (symbol) { | |
040fcc81 | 1468 | if (dump_sym(symbol)) |
bd5cbced | 1469 | buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n", |
62070fa4 | 1470 | symbol->crc, symbol->name, |
bd5cbced RP |
1471 | symbol->module->name, |
1472 | export_str(symbol->export)); | |
1da177e4 LT |
1473 | symbol = symbol->next; |
1474 | } | |
1475 | } | |
1476 | write_if_changed(&buf, fname); | |
1477 | } | |
1478 | ||
5c3ead8c | 1479 | int main(int argc, char **argv) |
1da177e4 LT |
1480 | { |
1481 | struct module *mod; | |
1482 | struct buffer buf = { }; | |
1483 | char fname[SZ]; | |
040fcc81 SR |
1484 | char *kernel_read = NULL, *module_read = NULL; |
1485 | char *dump_write = NULL; | |
1da177e4 | 1486 | int opt; |
c53ddacd | 1487 | int err; |
1da177e4 | 1488 | |
c53ddacd | 1489 | while ((opt = getopt(argc, argv, "i:I:mo:aw")) != -1) { |
1da177e4 LT |
1490 | switch(opt) { |
1491 | case 'i': | |
040fcc81 SR |
1492 | kernel_read = optarg; |
1493 | break; | |
1494 | case 'I': | |
1495 | module_read = optarg; | |
1496 | external_module = 1; | |
1da177e4 LT |
1497 | break; |
1498 | case 'm': | |
1499 | modversions = 1; | |
1500 | break; | |
1501 | case 'o': | |
1502 | dump_write = optarg; | |
1503 | break; | |
1504 | case 'a': | |
1505 | all_versions = 1; | |
1506 | break; | |
c53ddacd KK |
1507 | case 'w': |
1508 | warn_unresolved = 1; | |
1509 | break; | |
1da177e4 LT |
1510 | default: |
1511 | exit(1); | |
1512 | } | |
1513 | } | |
1514 | ||
040fcc81 SR |
1515 | if (kernel_read) |
1516 | read_dump(kernel_read, 1); | |
1517 | if (module_read) | |
1518 | read_dump(module_read, 0); | |
1da177e4 LT |
1519 | |
1520 | while (optind < argc) { | |
1521 | read_symbols(argv[optind++]); | |
1522 | } | |
1523 | ||
b817f6fe SR |
1524 | for (mod = modules; mod; mod = mod->next) { |
1525 | if (mod->skip) | |
1526 | continue; | |
c96fca21 | 1527 | check_exports(mod); |
b817f6fe SR |
1528 | } |
1529 | ||
c53ddacd KK |
1530 | err = 0; |
1531 | ||
1da177e4 LT |
1532 | for (mod = modules; mod; mod = mod->next) { |
1533 | if (mod->skip) | |
1534 | continue; | |
1535 | ||
1536 | buf.pos = 0; | |
1537 | ||
1538 | add_header(&buf, mod); | |
c53ddacd | 1539 | err |= add_versions(&buf, mod); |
1da177e4 LT |
1540 | add_depends(&buf, mod, modules); |
1541 | add_moddevtable(&buf, mod); | |
1542 | add_srcversion(&buf, mod); | |
1543 | ||
1544 | sprintf(fname, "%s.mod.c", mod->name); | |
1545 | write_if_changed(&buf, fname); | |
1546 | } | |
1547 | ||
1548 | if (dump_write) | |
1549 | write_dump(dump_write); | |
1550 | ||
c53ddacd | 1551 | return err; |
1da177e4 | 1552 | } |