1 /*
2 * This file is taken from the Linux kernel and is distributed under GPL v2.
3 */
4 #include <stdio.h>
5 #include <stdarg.h>
6 #include <stdlib.h>
7 #include <stdint.h>
8 #include <string.h>
9 #include <errno.h>
10 #include <unistd.h>
11 #include <elf.h>
12 #include <byteswap.h>
13 #define USE_BSD
14 #include <endian.h>
15 #include <regex.h>
16 #include <tools/le_byteshift.h>
17
18 static void die(char *fmt, ...);
19
20 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
21 static Elf32_Ehdr ehdr;
22 static unsigned long reloc_count, reloc_idx;
23 static unsigned long *relocs;
24 static unsigned long reloc16_count, reloc16_idx;
25 static unsigned long *relocs16;
26
27 struct section {
28 Elf32_Shdr shdr;
29 struct section *link;
30 Elf32_Sym *symtab;
31 Elf32_Rel *reltab;
32 char *strtab;
33 };
34 static struct section *secs;
35
36 enum symtype {
37 S_ABS,
38 S_REL,
39 S_SEG,
40 S_LIN,
41 S_NSYMTYPES
42 };
43
44 static const char * const sym_regex_kernel[S_NSYMTYPES] = {
45 /*
46 * Following symbols have been audited. Don't warn user about
47 * absolute relocations present w.r.t these symbols.
48 */
49 [S_ABS] =
50 "^(__.*_len|__.*_dwords)$",
51
52 /*
53 * These symbols are known to be relative, even if the linker marks them
54 * as absolute (typically defined outside any section in the linker script.)
55 */
56 [S_REL] =
57 "^(__.*_start|__.*_end|_end|_[se](text|data))$",
58 };
59
60
61 static const char * const sym_regex_realmode[S_NSYMTYPES] = {
62 /*
63 * These are 16-bit segment symbols when compiling 16-bit code.
64 */
65 [S_SEG] =
66 "^real_mode_seg$",
67
68 /*
69 * These are offsets belonging to segments, as opposed to linear addresses,
70 * when compiling 16-bit code.
71 */
72 [S_LIN] =
73 "^pa_",
74 };
75
76 static const char * const *sym_regex;
77
78 static regex_t sym_regex_c[S_NSYMTYPES];
is_reloc(enum symtype type,const char * sym_name)79 static int is_reloc(enum symtype type, const char *sym_name)
80 {
81 return sym_regex[type] &&
82 !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
83 }
84
regex_init(int use_real_mode)85 static void regex_init(int use_real_mode)
86 {
87 char errbuf[128];
88 int err;
89 int i;
90
91 if (use_real_mode)
92 sym_regex = sym_regex_realmode;
93 else
94 sym_regex = sym_regex_kernel;
95
96 for (i = 0; i < S_NSYMTYPES; i++) {
97 if (!sym_regex[i])
98 continue;
99
100 err = regcomp(&sym_regex_c[i], sym_regex[i],
101 REG_EXTENDED|REG_NOSUB);
102
103 if (err) {
104 regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
105 die("%s", errbuf);
106 }
107 }
108 }
109
die(char * fmt,...)110 static void die(char *fmt, ...)
111 {
112 va_list ap;
113 va_start(ap, fmt);
114 vfprintf(stderr, fmt, ap);
115 va_end(ap);
116 exit(1);
117 }
118
sym_type(unsigned type)119 static const char *sym_type(unsigned type)
120 {
121 static const char *type_name[] = {
122 #define SYM_TYPE(X) [X] = #X
123 SYM_TYPE(STT_NOTYPE),
124 SYM_TYPE(STT_OBJECT),
125 SYM_TYPE(STT_FUNC),
126 SYM_TYPE(STT_SECTION),
127 SYM_TYPE(STT_FILE),
128 SYM_TYPE(STT_COMMON),
129 SYM_TYPE(STT_TLS),
130 #undef SYM_TYPE
131 };
132 const char *name = "unknown sym type name";
133 if (type < ARRAY_SIZE(type_name)) {
134 name = type_name[type];
135 }
136 return name;
137 }
138
sym_bind(unsigned bind)139 static const char *sym_bind(unsigned bind)
140 {
141 static const char *bind_name[] = {
142 #define SYM_BIND(X) [X] = #X
143 SYM_BIND(STB_LOCAL),
144 SYM_BIND(STB_GLOBAL),
145 SYM_BIND(STB_WEAK),
146 #undef SYM_BIND
147 };
148 const char *name = "unknown sym bind name";
149 if (bind < ARRAY_SIZE(bind_name)) {
150 name = bind_name[bind];
151 }
152 return name;
153 }
154
sym_visibility(unsigned visibility)155 static const char *sym_visibility(unsigned visibility)
156 {
157 static const char *visibility_name[] = {
158 #define SYM_VISIBILITY(X) [X] = #X
159 SYM_VISIBILITY(STV_DEFAULT),
160 SYM_VISIBILITY(STV_INTERNAL),
161 SYM_VISIBILITY(STV_HIDDEN),
162 SYM_VISIBILITY(STV_PROTECTED),
163 #undef SYM_VISIBILITY
164 };
165 const char *name = "unknown sym visibility name";
166 if (visibility < ARRAY_SIZE(visibility_name)) {
167 name = visibility_name[visibility];
168 }
169 return name;
170 }
171
rel_type(unsigned type)172 static const char *rel_type(unsigned type)
173 {
174 static const char *type_name[] = {
175 #define REL_TYPE(X) [X] = #X
176 REL_TYPE(R_386_NONE),
177 REL_TYPE(R_386_32),
178 REL_TYPE(R_386_PC32),
179 REL_TYPE(R_386_GOT32),
180 REL_TYPE(R_386_PLT32),
181 REL_TYPE(R_386_COPY),
182 REL_TYPE(R_386_GLOB_DAT),
183 REL_TYPE(R_386_JMP_SLOT),
184 REL_TYPE(R_386_RELATIVE),
185 REL_TYPE(R_386_GOTOFF),
186 REL_TYPE(R_386_GOTPC),
187 REL_TYPE(R_386_8),
188 REL_TYPE(R_386_PC8),
189 REL_TYPE(R_386_16),
190 REL_TYPE(R_386_PC16),
191 #undef REL_TYPE
192 };
193 const char *name = "unknown type rel type name";
194 if (type < ARRAY_SIZE(type_name) && type_name[type]) {
195 name = type_name[type];
196 }
197 return name;
198 }
199
sec_name(unsigned shndx)200 static const char *sec_name(unsigned shndx)
201 {
202 const char *sec_strtab;
203 const char *name;
204 sec_strtab = secs[ehdr.e_shstrndx].strtab;
205 name = "<noname>";
206 if (shndx < ehdr.e_shnum) {
207 name = sec_strtab + secs[shndx].shdr.sh_name;
208 }
209 else if (shndx == SHN_ABS) {
210 name = "ABSOLUTE";
211 }
212 else if (shndx == SHN_COMMON) {
213 name = "COMMON";
214 }
215 return name;
216 }
217
sym_name(const char * sym_strtab,Elf32_Sym * sym)218 static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
219 {
220 const char *name;
221 name = "<noname>";
222 if (sym->st_name) {
223 name = sym_strtab + sym->st_name;
224 }
225 else {
226 name = sec_name(sym->st_shndx);
227 }
228 return name;
229 }
230
231
232
233 #if BYTE_ORDER == LITTLE_ENDIAN
234 #define le16_to_cpu(val) (val)
235 #define le32_to_cpu(val) (val)
236 #endif
237 #if BYTE_ORDER == BIG_ENDIAN
238 #define le16_to_cpu(val) bswap_16(val)
239 #define le32_to_cpu(val) bswap_32(val)
240 #endif
241
elf16_to_cpu(uint16_t val)242 static uint16_t elf16_to_cpu(uint16_t val)
243 {
244 return le16_to_cpu(val);
245 }
246
elf32_to_cpu(uint32_t val)247 static uint32_t elf32_to_cpu(uint32_t val)
248 {
249 return le32_to_cpu(val);
250 }
251
read_ehdr(FILE * fp)252 static void read_ehdr(FILE *fp)
253 {
254 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
255 die("Cannot read ELF header: %s\n",
256 strerror(errno));
257 }
258 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
259 die("No ELF magic\n");
260 }
261 if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
262 die("Not a 32 bit executable\n");
263 }
264 if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
265 die("Not a LSB ELF executable\n");
266 }
267 if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
268 die("Unknown ELF version\n");
269 }
270 /* Convert the fields to native endian */
271 ehdr.e_type = elf16_to_cpu(ehdr.e_type);
272 ehdr.e_machine = elf16_to_cpu(ehdr.e_machine);
273 ehdr.e_version = elf32_to_cpu(ehdr.e_version);
274 ehdr.e_entry = elf32_to_cpu(ehdr.e_entry);
275 ehdr.e_phoff = elf32_to_cpu(ehdr.e_phoff);
276 ehdr.e_shoff = elf32_to_cpu(ehdr.e_shoff);
277 ehdr.e_flags = elf32_to_cpu(ehdr.e_flags);
278 ehdr.e_ehsize = elf16_to_cpu(ehdr.e_ehsize);
279 ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
280 ehdr.e_phnum = elf16_to_cpu(ehdr.e_phnum);
281 ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
282 ehdr.e_shnum = elf16_to_cpu(ehdr.e_shnum);
283 ehdr.e_shstrndx = elf16_to_cpu(ehdr.e_shstrndx);
284
285 if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
286 die("Unsupported ELF header type\n");
287 }
288 if (ehdr.e_machine != EM_386) {
289 die("Not for x86\n");
290 }
291 if (ehdr.e_version != EV_CURRENT) {
292 die("Unknown ELF version\n");
293 }
294 if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
295 die("Bad Elf header size\n");
296 }
297 if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
298 die("Bad program header entry\n");
299 }
300 if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
301 die("Bad section header entry\n");
302 }
303 if (ehdr.e_shstrndx >= ehdr.e_shnum) {
304 die("String table index out of bounds\n");
305 }
306 }
307
read_shdrs(FILE * fp)308 static void read_shdrs(FILE *fp)
309 {
310 int i;
311 Elf32_Shdr shdr;
312
313 secs = calloc(ehdr.e_shnum, sizeof(struct section));
314 if (!secs) {
315 die("Unable to allocate %d section headers\n",
316 ehdr.e_shnum);
317 }
318 if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
319 die("Seek to %d failed: %s\n",
320 ehdr.e_shoff, strerror(errno));
321 }
322 for (i = 0; i < ehdr.e_shnum; i++) {
323 struct section *sec = &secs[i];
324 if (fread(&shdr, sizeof shdr, 1, fp) != 1)
325 die("Cannot read ELF section headers %d/%d: %s\n",
326 i, ehdr.e_shnum, strerror(errno));
327 sec->shdr.sh_name = elf32_to_cpu(shdr.sh_name);
328 sec->shdr.sh_type = elf32_to_cpu(shdr.sh_type);
329 sec->shdr.sh_flags = elf32_to_cpu(shdr.sh_flags);
330 sec->shdr.sh_addr = elf32_to_cpu(shdr.sh_addr);
331 sec->shdr.sh_offset = elf32_to_cpu(shdr.sh_offset);
332 sec->shdr.sh_size = elf32_to_cpu(shdr.sh_size);
333 sec->shdr.sh_link = elf32_to_cpu(shdr.sh_link);
334 sec->shdr.sh_info = elf32_to_cpu(shdr.sh_info);
335 sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
336 sec->shdr.sh_entsize = elf32_to_cpu(shdr.sh_entsize);
337 if (sec->shdr.sh_link < ehdr.e_shnum)
338 sec->link = &secs[sec->shdr.sh_link];
339 }
340
341 }
342
read_strtabs(FILE * fp)343 static void read_strtabs(FILE *fp)
344 {
345 int i;
346 for (i = 0; i < ehdr.e_shnum; i++) {
347 struct section *sec = &secs[i];
348 if (sec->shdr.sh_type != SHT_STRTAB) {
349 continue;
350 }
351 sec->strtab = malloc(sec->shdr.sh_size);
352 if (!sec->strtab) {
353 die("malloc of %d bytes for strtab failed\n",
354 sec->shdr.sh_size);
355 }
356 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
357 die("Seek to %d failed: %s\n",
358 sec->shdr.sh_offset, strerror(errno));
359 }
360 if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
361 != sec->shdr.sh_size) {
362 die("Cannot read symbol table: %s\n",
363 strerror(errno));
364 }
365 }
366 }
367
read_symtabs(FILE * fp)368 static void read_symtabs(FILE *fp)
369 {
370 int i,j;
371 for (i = 0; i < ehdr.e_shnum; i++) {
372 struct section *sec = &secs[i];
373 if (sec->shdr.sh_type != SHT_SYMTAB) {
374 continue;
375 }
376 sec->symtab = malloc(sec->shdr.sh_size);
377 if (!sec->symtab) {
378 die("malloc of %d bytes for symtab failed\n",
379 sec->shdr.sh_size);
380 }
381 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
382 die("Seek to %d failed: %s\n",
383 sec->shdr.sh_offset, strerror(errno));
384 }
385 if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
386 != sec->shdr.sh_size) {
387 die("Cannot read symbol table: %s\n",
388 strerror(errno));
389 }
390 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
391 Elf32_Sym *sym = &sec->symtab[j];
392 sym->st_name = elf32_to_cpu(sym->st_name);
393 sym->st_value = elf32_to_cpu(sym->st_value);
394 sym->st_size = elf32_to_cpu(sym->st_size);
395 sym->st_shndx = elf16_to_cpu(sym->st_shndx);
396 }
397 }
398 }
399
400
read_relocs(FILE * fp)401 static void read_relocs(FILE *fp)
402 {
403 int i,j;
404 for (i = 0; i < ehdr.e_shnum; i++) {
405 struct section *sec = &secs[i];
406 if (sec->shdr.sh_type != SHT_REL) {
407 continue;
408 }
409 sec->reltab = malloc(sec->shdr.sh_size);
410 if (!sec->reltab) {
411 die("malloc of %d bytes for relocs failed\n",
412 sec->shdr.sh_size);
413 }
414 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
415 die("Seek to %d failed: %s\n",
416 sec->shdr.sh_offset, strerror(errno));
417 }
418 if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
419 != sec->shdr.sh_size) {
420 die("Cannot read symbol table: %s\n",
421 strerror(errno));
422 }
423 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
424 Elf32_Rel *rel = &sec->reltab[j];
425 rel->r_offset = elf32_to_cpu(rel->r_offset);
426 rel->r_info = elf32_to_cpu(rel->r_info);
427 }
428 }
429 }
430
431
print_absolute_symbols(void)432 static void print_absolute_symbols(void)
433 {
434 int i;
435 printf("Absolute symbols\n");
436 printf(" Num: Value Size Type Bind Visibility Name\n");
437 for (i = 0; i < ehdr.e_shnum; i++) {
438 struct section *sec = &secs[i];
439 char *sym_strtab;
440 int j;
441
442 if (sec->shdr.sh_type != SHT_SYMTAB) {
443 continue;
444 }
445 sym_strtab = sec->link->strtab;
446 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
447 Elf32_Sym *sym;
448 const char *name;
449 sym = &sec->symtab[j];
450 name = sym_name(sym_strtab, sym);
451 if (sym->st_shndx != SHN_ABS) {
452 continue;
453 }
454 printf("%5d %08x %5d %10s %10s %12s %s\n",
455 j, sym->st_value, sym->st_size,
456 sym_type(ELF32_ST_TYPE(sym->st_info)),
457 sym_bind(ELF32_ST_BIND(sym->st_info)),
458 sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
459 name);
460 }
461 }
462 printf("\n");
463 }
464
print_absolute_relocs(void)465 static void print_absolute_relocs(void)
466 {
467 int i, printed = 0;
468
469 for (i = 0; i < ehdr.e_shnum; i++) {
470 struct section *sec = &secs[i];
471 struct section *sec_applies, *sec_symtab;
472 char *sym_strtab;
473 Elf32_Sym *sh_symtab;
474 int j;
475 if (sec->shdr.sh_type != SHT_REL) {
476 continue;
477 }
478 sec_symtab = sec->link;
479 sec_applies = &secs[sec->shdr.sh_info];
480 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
481 continue;
482 }
483 sh_symtab = sec_symtab->symtab;
484 sym_strtab = sec_symtab->link->strtab;
485 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
486 Elf32_Rel *rel;
487 Elf32_Sym *sym;
488 const char *name;
489 rel = &sec->reltab[j];
490 sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
491 name = sym_name(sym_strtab, sym);
492 if (sym->st_shndx != SHN_ABS) {
493 continue;
494 }
495
496 /* Absolute symbols are not relocated if bzImage is
497 * loaded at a non-compiled address. Display a warning
498 * to user at compile time about the absolute
499 * relocations present.
500 *
501 * User need to audit the code to make sure
502 * some symbols which should have been section
503 * relative have not become absolute because of some
504 * linker optimization or wrong programming usage.
505 *
506 * Before warning check if this absolute symbol
507 * relocation is harmless.
508 */
509 if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
510 continue;
511
512 if (!printed) {
513 printf("WARNING: Absolute relocations"
514 " present\n");
515 printf("Offset Info Type Sym.Value "
516 "Sym.Name\n");
517 printed = 1;
518 }
519
520 printf("%08x %08x %10s %08x %s\n",
521 rel->r_offset,
522 rel->r_info,
523 rel_type(ELF32_R_TYPE(rel->r_info)),
524 sym->st_value,
525 name);
526 }
527 }
528
529 if (printed)
530 printf("\n");
531 }
532
walk_relocs(void (* visit)(Elf32_Rel * rel,Elf32_Sym * sym),int use_real_mode)533 static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
534 int use_real_mode)
535 {
536 int i;
537 /* Walk through the relocations */
538 for (i = 0; i < ehdr.e_shnum; i++) {
539 char *sym_strtab;
540 Elf32_Sym *sh_symtab;
541 struct section *sec_applies, *sec_symtab;
542 int j;
543 struct section *sec = &secs[i];
544
545 if (sec->shdr.sh_type != SHT_REL) {
546 continue;
547 }
548 sec_symtab = sec->link;
549 sec_applies = &secs[sec->shdr.sh_info];
550 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
551 continue;
552 }
553 sh_symtab = sec_symtab->symtab;
554 sym_strtab = sec_symtab->link->strtab;
555 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
556 Elf32_Rel *rel;
557 Elf32_Sym *sym;
558 unsigned r_type;
559 const char *symname;
560 int shn_abs;
561
562 rel = &sec->reltab[j];
563 sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
564 r_type = ELF32_R_TYPE(rel->r_info);
565
566 shn_abs = sym->st_shndx == SHN_ABS;
567
568 switch (r_type) {
569 case R_386_NONE:
570 case R_386_PC32:
571 case R_386_PC16:
572 case R_386_PC8:
573 case R_386_GOTPC:
574 case R_386_GOTOFF:
575 case R_386_GOT32:
576 case R_386_PLT32:
577 /*
578 * NONE can be ignored and and PC relative
579 * relocations don't need to be adjusted.
580 */
581 break;
582
583 case R_386_16:
584 symname = sym_name(sym_strtab, sym);
585 if (!use_real_mode)
586 goto bad;
587 if (shn_abs) {
588 if (is_reloc(S_ABS, symname))
589 break;
590 else if (!is_reloc(S_SEG, symname))
591 goto bad;
592 } else {
593 if (is_reloc(S_LIN, symname))
594 goto bad;
595 else
596 break;
597 }
598 visit(rel, sym);
599 break;
600
601 case R_386_32:
602 symname = sym_name(sym_strtab, sym);
603 if (shn_abs) {
604 if (is_reloc(S_ABS, symname))
605 break;
606 else if (!is_reloc(S_REL, symname))
607 goto bad;
608 } else {
609 if (use_real_mode &&
610 !is_reloc(S_LIN, symname))
611 break;
612 }
613 visit(rel, sym);
614 break;
615 default:
616 die("Unsupported relocation type: %s (%d)\n",
617 rel_type(r_type), r_type);
618 break;
619 bad:
620 symname = sym_name(sym_strtab, sym);
621 die("Invalid %s %s relocation: %s\n",
622 shn_abs ? "absolute" : "relative",
623 rel_type(r_type), symname);
624 }
625 }
626 }
627 }
628
count_reloc(Elf32_Rel * rel,Elf32_Sym * sym)629 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
630 {
631 (void)sym;
632
633 if (ELF32_R_TYPE(rel->r_info) == R_386_16)
634 reloc16_count++;
635 else
636 reloc_count++;
637 }
638
collect_reloc(Elf32_Rel * rel,Elf32_Sym * sym)639 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
640 {
641 (void)sym;
642
643 /* Remember the address that needs to be adjusted. */
644 if (ELF32_R_TYPE(rel->r_info) == R_386_16)
645 relocs16[reloc16_idx++] = rel->r_offset;
646 else
647 relocs[reloc_idx++] = rel->r_offset;
648 }
649
cmp_relocs(const void * va,const void * vb)650 static int cmp_relocs(const void *va, const void *vb)
651 {
652 const unsigned long *a, *b;
653 a = va; b = vb;
654 return (*a == *b)? 0 : (*a > *b)? 1 : -1;
655 }
656
write32(unsigned int v,FILE * f)657 static int write32(unsigned int v, FILE *f)
658 {
659 unsigned char buf[4];
660
661 put_unaligned_le32(v, buf);
662 return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
663 }
664
emit_relocs(int as_text,int use_real_mode)665 static void emit_relocs(int as_text, int use_real_mode)
666 {
667 int i;
668 /* Count how many relocations I have and allocate space for them. */
669 reloc_count = 0;
670 walk_relocs(count_reloc, use_real_mode);
671 relocs = malloc(reloc_count * sizeof(relocs[0]));
672 if (!relocs) {
673 die("malloc of %d entries for relocs failed\n",
674 reloc_count);
675 }
676
677 relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
678 if (!relocs16) {
679 die("malloc of %d entries for relocs16 failed\n",
680 reloc16_count);
681 }
682 /* Collect up the relocations */
683 reloc_idx = 0;
684 walk_relocs(collect_reloc, use_real_mode);
685
686 if (reloc16_count && !use_real_mode)
687 die("Segment relocations found but --realmode not specified\n");
688
689 /* Order the relocations for more efficient processing */
690 qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
691 qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs);
692
693 /* Print the relocations */
694 if (as_text) {
695 /* Print the relocations in a form suitable that
696 * gas will like.
697 */
698 printf(".section \".data.reloc\",\"a\"\n");
699 printf(".balign 4\n");
700 if (use_real_mode) {
701 printf("\t.long %lu\n", reloc16_count);
702 for (i = 0; i < reloc16_count; i++)
703 printf("\t.long 0x%08lx\n", relocs16[i]);
704 printf("\t.long %lu\n", reloc_count);
705 for (i = 0; i < reloc_count; i++) {
706 printf("\t.long 0x%08lx\n", relocs[i]);
707 }
708 } else {
709 for (i = 0; i < reloc_count; i++) {
710 printf("\t.long 0x%08lx\n", relocs[i]);
711 }
712 /* Print a stop */
713 printf("\t.long 0x%08lx\n", (unsigned long)0);
714 }
715
716 printf("\n");
717 }
718 else {
719 if (use_real_mode) {
720 write32(reloc16_count, stdout);
721 for (i = 0; i < reloc16_count; i++)
722 write32(relocs16[i], stdout);
723 write32(reloc_count, stdout);
724
725 /* Now print each relocation */
726 for (i = 0; i < reloc_count; i++)
727 write32(relocs[i], stdout);
728 } else {
729 /* Now print each relocation */
730 for (i = 0; i < reloc_count; i++) {
731 write32(relocs[i], stdout);
732 }
733
734 /* Print a stop */
735 write32(0, stdout);
736 }
737 }
738 }
739
usage(void)740 static void usage(void)
741 {
742 die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
743 }
744
main(int argc,char ** argv)745 int main(int argc, char **argv)
746 {
747 int show_absolute_syms, show_absolute_relocs;
748 int as_text, use_real_mode;
749 const char *fname;
750 FILE *fp;
751 int i;
752
753 show_absolute_syms = 0;
754 show_absolute_relocs = 0;
755 as_text = 0;
756 use_real_mode = 0;
757 fname = NULL;
758 for (i = 1; i < argc; i++) {
759 char *arg = argv[i];
760 if (*arg == '-') {
761 if (strcmp(arg, "--abs-syms") == 0) {
762 show_absolute_syms = 1;
763 continue;
764 }
765 if (strcmp(arg, "--abs-relocs") == 0) {
766 show_absolute_relocs = 1;
767 continue;
768 }
769 if (strcmp(arg, "--text") == 0) {
770 as_text = 1;
771 continue;
772 }
773 if (strcmp(arg, "--realmode") == 0) {
774 use_real_mode = 1;
775 continue;
776 }
777 }
778 else if (!fname) {
779 fname = arg;
780 continue;
781 }
782 usage();
783 }
784 if (!fname) {
785 usage();
786 }
787 regex_init(use_real_mode);
788 fp = fopen(fname, "r");
789 if (!fp) {
790 die("Cannot open %s: %s\n",
791 fname, strerror(errno));
792 }
793 read_ehdr(fp);
794 read_shdrs(fp);
795 read_strtabs(fp);
796 read_symtabs(fp);
797 read_relocs(fp);
798 if (show_absolute_syms) {
799 print_absolute_symbols();
800 return 0;
801 }
802 if (show_absolute_relocs) {
803 print_absolute_relocs();
804 return 0;
805 }
806 emit_relocs(as_text, use_real_mode);
807 return 0;
808 }
809