Linux 3.4-rc7
[linux-2.6.git] / arch / x86 / tools / relocs.c
1 #include <stdio.h>
2 #include <stdarg.h>
3 #include <stdlib.h>
4 #include <stdint.h>
5 #include <string.h>
6 #include <errno.h>
7 #include <unistd.h>
8 #include <elf.h>
9 #include <byteswap.h>
10 #define USE_BSD
11 #include <endian.h>
12 #include <regex.h>
13 #include <tools/le_byteshift.h>
14
15 static void die(char *fmt, ...);
16
17 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
18 static Elf32_Ehdr ehdr;
19 static unsigned long reloc_count, reloc_idx;
20 static unsigned long *relocs;
21 static unsigned long reloc16_count, reloc16_idx;
22 static unsigned long *relocs16;
23
24 struct section {
25         Elf32_Shdr     shdr;
26         struct section *link;
27         Elf32_Sym      *symtab;
28         Elf32_Rel      *reltab;
29         char           *strtab;
30 };
31 static struct section *secs;
32
33 enum symtype {
34         S_ABS,
35         S_REL,
36         S_SEG,
37         S_LIN,
38         S_NSYMTYPES
39 };
40
41 static const char * const sym_regex_kernel[S_NSYMTYPES] = {
42 /*
43  * Following symbols have been audited. There values are constant and do
44  * not change if bzImage is loaded at a different physical address than
45  * the address for which it has been compiled. Don't warn user about
46  * absolute relocations present w.r.t these symbols.
47  */
48         [S_ABS] =
49         "^(xen_irq_disable_direct_reloc$|"
50         "xen_save_fl_direct_reloc$|"
51         "VDSO|"
52         "__crc_)",
53
54 /*
55  * These symbols are known to be relative, even if the linker marks them
56  * as absolute (typically defined outside any section in the linker script.)
57  */
58         [S_REL] =
59         "^_end$",
60 };
61
62
63 static const char * const sym_regex_realmode[S_NSYMTYPES] = {
64 /*
65  * These are 16-bit segment symbols when compiling 16-bit code.
66  */
67         [S_SEG] =
68         "^real_mode_seg$",
69
70 /*
71  * These are offsets belonging to segments, as opposed to linear addresses,
72  * when compiling 16-bit code.
73  */
74         [S_LIN] =
75         "^pa_",
76 };
77
78 static const char * const *sym_regex;
79
80 static regex_t sym_regex_c[S_NSYMTYPES];
81 static int is_reloc(enum symtype type, const char *sym_name)
82 {
83         return sym_regex[type] &&
84                 !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
85 }
86
87 static void regex_init(int use_real_mode)
88 {
89         char errbuf[128];
90         int err;
91         int i;
92
93         if (use_real_mode)
94                 sym_regex = sym_regex_realmode;
95         else
96                 sym_regex = sym_regex_kernel;
97
98         for (i = 0; i < S_NSYMTYPES; i++) {
99                 if (!sym_regex[i])
100                         continue;
101
102                 err = regcomp(&sym_regex_c[i], sym_regex[i],
103                               REG_EXTENDED|REG_NOSUB);
104
105                 if (err) {
106                         regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
107                         die("%s", errbuf);
108                 }
109         }
110 }
111
112 static void die(char *fmt, ...)
113 {
114         va_list ap;
115         va_start(ap, fmt);
116         vfprintf(stderr, fmt, ap);
117         va_end(ap);
118         exit(1);
119 }
120
121 static const char *sym_type(unsigned type)
122 {
123         static const char *type_name[] = {
124 #define SYM_TYPE(X) [X] = #X
125                 SYM_TYPE(STT_NOTYPE),
126                 SYM_TYPE(STT_OBJECT),
127                 SYM_TYPE(STT_FUNC),
128                 SYM_TYPE(STT_SECTION),
129                 SYM_TYPE(STT_FILE),
130                 SYM_TYPE(STT_COMMON),
131                 SYM_TYPE(STT_TLS),
132 #undef SYM_TYPE
133         };
134         const char *name = "unknown sym type name";
135         if (type < ARRAY_SIZE(type_name)) {
136                 name = type_name[type];
137         }
138         return name;
139 }
140
141 static const char *sym_bind(unsigned bind)
142 {
143         static const char *bind_name[] = {
144 #define SYM_BIND(X) [X] = #X
145                 SYM_BIND(STB_LOCAL),
146                 SYM_BIND(STB_GLOBAL),
147                 SYM_BIND(STB_WEAK),
148 #undef SYM_BIND
149         };
150         const char *name = "unknown sym bind name";
151         if (bind < ARRAY_SIZE(bind_name)) {
152                 name = bind_name[bind];
153         }
154         return name;
155 }
156
157 static const char *sym_visibility(unsigned visibility)
158 {
159         static const char *visibility_name[] = {
160 #define SYM_VISIBILITY(X) [X] = #X
161                 SYM_VISIBILITY(STV_DEFAULT),
162                 SYM_VISIBILITY(STV_INTERNAL),
163                 SYM_VISIBILITY(STV_HIDDEN),
164                 SYM_VISIBILITY(STV_PROTECTED),
165 #undef SYM_VISIBILITY
166         };
167         const char *name = "unknown sym visibility name";
168         if (visibility < ARRAY_SIZE(visibility_name)) {
169                 name = visibility_name[visibility];
170         }
171         return name;
172 }
173
174 static const char *rel_type(unsigned type)
175 {
176         static const char *type_name[] = {
177 #define REL_TYPE(X) [X] = #X
178                 REL_TYPE(R_386_NONE),
179                 REL_TYPE(R_386_32),
180                 REL_TYPE(R_386_PC32),
181                 REL_TYPE(R_386_GOT32),
182                 REL_TYPE(R_386_PLT32),
183                 REL_TYPE(R_386_COPY),
184                 REL_TYPE(R_386_GLOB_DAT),
185                 REL_TYPE(R_386_JMP_SLOT),
186                 REL_TYPE(R_386_RELATIVE),
187                 REL_TYPE(R_386_GOTOFF),
188                 REL_TYPE(R_386_GOTPC),
189                 REL_TYPE(R_386_8),
190                 REL_TYPE(R_386_PC8),
191                 REL_TYPE(R_386_16),
192                 REL_TYPE(R_386_PC16),
193 #undef REL_TYPE
194         };
195         const char *name = "unknown type rel type name";
196         if (type < ARRAY_SIZE(type_name) && type_name[type]) {
197                 name = type_name[type];
198         }
199         return name;
200 }
201
202 static const char *sec_name(unsigned shndx)
203 {
204         const char *sec_strtab;
205         const char *name;
206         sec_strtab = secs[ehdr.e_shstrndx].strtab;
207         name = "<noname>";
208         if (shndx < ehdr.e_shnum) {
209                 name = sec_strtab + secs[shndx].shdr.sh_name;
210         }
211         else if (shndx == SHN_ABS) {
212                 name = "ABSOLUTE";
213         }
214         else if (shndx == SHN_COMMON) {
215                 name = "COMMON";
216         }
217         return name;
218 }
219
220 static const char *sym_name(const char *sym_strtab, Elf32_Sym *sym)
221 {
222         const char *name;
223         name = "<noname>";
224         if (sym->st_name) {
225                 name = sym_strtab + sym->st_name;
226         }
227         else {
228                 name = sec_name(sym->st_shndx);
229         }
230         return name;
231 }
232
233
234
235 #if BYTE_ORDER == LITTLE_ENDIAN
236 #define le16_to_cpu(val) (val)
237 #define le32_to_cpu(val) (val)
238 #endif
239 #if BYTE_ORDER == BIG_ENDIAN
240 #define le16_to_cpu(val) bswap_16(val)
241 #define le32_to_cpu(val) bswap_32(val)
242 #endif
243
244 static uint16_t elf16_to_cpu(uint16_t val)
245 {
246         return le16_to_cpu(val);
247 }
248
249 static uint32_t elf32_to_cpu(uint32_t val)
250 {
251         return le32_to_cpu(val);
252 }
253
254 static void read_ehdr(FILE *fp)
255 {
256         if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
257                 die("Cannot read ELF header: %s\n",
258                         strerror(errno));
259         }
260         if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
261                 die("No ELF magic\n");
262         }
263         if (ehdr.e_ident[EI_CLASS] != ELFCLASS32) {
264                 die("Not a 32 bit executable\n");
265         }
266         if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
267                 die("Not a LSB ELF executable\n");
268         }
269         if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
270                 die("Unknown ELF version\n");
271         }
272         /* Convert the fields to native endian */
273         ehdr.e_type      = elf16_to_cpu(ehdr.e_type);
274         ehdr.e_machine   = elf16_to_cpu(ehdr.e_machine);
275         ehdr.e_version   = elf32_to_cpu(ehdr.e_version);
276         ehdr.e_entry     = elf32_to_cpu(ehdr.e_entry);
277         ehdr.e_phoff     = elf32_to_cpu(ehdr.e_phoff);
278         ehdr.e_shoff     = elf32_to_cpu(ehdr.e_shoff);
279         ehdr.e_flags     = elf32_to_cpu(ehdr.e_flags);
280         ehdr.e_ehsize    = elf16_to_cpu(ehdr.e_ehsize);
281         ehdr.e_phentsize = elf16_to_cpu(ehdr.e_phentsize);
282         ehdr.e_phnum     = elf16_to_cpu(ehdr.e_phnum);
283         ehdr.e_shentsize = elf16_to_cpu(ehdr.e_shentsize);
284         ehdr.e_shnum     = elf16_to_cpu(ehdr.e_shnum);
285         ehdr.e_shstrndx  = elf16_to_cpu(ehdr.e_shstrndx);
286
287         if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
288                 die("Unsupported ELF header type\n");
289         }
290         if (ehdr.e_machine != EM_386) {
291                 die("Not for x86\n");
292         }
293         if (ehdr.e_version != EV_CURRENT) {
294                 die("Unknown ELF version\n");
295         }
296         if (ehdr.e_ehsize != sizeof(Elf32_Ehdr)) {
297                 die("Bad Elf header size\n");
298         }
299         if (ehdr.e_phentsize != sizeof(Elf32_Phdr)) {
300                 die("Bad program header entry\n");
301         }
302         if (ehdr.e_shentsize != sizeof(Elf32_Shdr)) {
303                 die("Bad section header entry\n");
304         }
305         if (ehdr.e_shstrndx >= ehdr.e_shnum) {
306                 die("String table index out of bounds\n");
307         }
308 }
309
310 static void read_shdrs(FILE *fp)
311 {
312         int i;
313         Elf32_Shdr shdr;
314
315         secs = calloc(ehdr.e_shnum, sizeof(struct section));
316         if (!secs) {
317                 die("Unable to allocate %d section headers\n",
318                     ehdr.e_shnum);
319         }
320         if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
321                 die("Seek to %d failed: %s\n",
322                         ehdr.e_shoff, strerror(errno));
323         }
324         for (i = 0; i < ehdr.e_shnum; i++) {
325                 struct section *sec = &secs[i];
326                 if (fread(&shdr, sizeof shdr, 1, fp) != 1)
327                         die("Cannot read ELF section headers %d/%d: %s\n",
328                             i, ehdr.e_shnum, strerror(errno));
329                 sec->shdr.sh_name      = elf32_to_cpu(shdr.sh_name);
330                 sec->shdr.sh_type      = elf32_to_cpu(shdr.sh_type);
331                 sec->shdr.sh_flags     = elf32_to_cpu(shdr.sh_flags);
332                 sec->shdr.sh_addr      = elf32_to_cpu(shdr.sh_addr);
333                 sec->shdr.sh_offset    = elf32_to_cpu(shdr.sh_offset);
334                 sec->shdr.sh_size      = elf32_to_cpu(shdr.sh_size);
335                 sec->shdr.sh_link      = elf32_to_cpu(shdr.sh_link);
336                 sec->shdr.sh_info      = elf32_to_cpu(shdr.sh_info);
337                 sec->shdr.sh_addralign = elf32_to_cpu(shdr.sh_addralign);
338                 sec->shdr.sh_entsize   = elf32_to_cpu(shdr.sh_entsize);
339                 if (sec->shdr.sh_link < ehdr.e_shnum)
340                         sec->link = &secs[sec->shdr.sh_link];
341         }
342
343 }
344
345 static void read_strtabs(FILE *fp)
346 {
347         int i;
348         for (i = 0; i < ehdr.e_shnum; i++) {
349                 struct section *sec = &secs[i];
350                 if (sec->shdr.sh_type != SHT_STRTAB) {
351                         continue;
352                 }
353                 sec->strtab = malloc(sec->shdr.sh_size);
354                 if (!sec->strtab) {
355                         die("malloc of %d bytes for strtab failed\n",
356                                 sec->shdr.sh_size);
357                 }
358                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
359                         die("Seek to %d failed: %s\n",
360                                 sec->shdr.sh_offset, strerror(errno));
361                 }
362                 if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
363                     != sec->shdr.sh_size) {
364                         die("Cannot read symbol table: %s\n",
365                                 strerror(errno));
366                 }
367         }
368 }
369
370 static void read_symtabs(FILE *fp)
371 {
372         int i,j;
373         for (i = 0; i < ehdr.e_shnum; i++) {
374                 struct section *sec = &secs[i];
375                 if (sec->shdr.sh_type != SHT_SYMTAB) {
376                         continue;
377                 }
378                 sec->symtab = malloc(sec->shdr.sh_size);
379                 if (!sec->symtab) {
380                         die("malloc of %d bytes for symtab failed\n",
381                                 sec->shdr.sh_size);
382                 }
383                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
384                         die("Seek to %d failed: %s\n",
385                                 sec->shdr.sh_offset, strerror(errno));
386                 }
387                 if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
388                     != sec->shdr.sh_size) {
389                         die("Cannot read symbol table: %s\n",
390                                 strerror(errno));
391                 }
392                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
393                         Elf32_Sym *sym = &sec->symtab[j];
394                         sym->st_name  = elf32_to_cpu(sym->st_name);
395                         sym->st_value = elf32_to_cpu(sym->st_value);
396                         sym->st_size  = elf32_to_cpu(sym->st_size);
397                         sym->st_shndx = elf16_to_cpu(sym->st_shndx);
398                 }
399         }
400 }
401
402
403 static void read_relocs(FILE *fp)
404 {
405         int i,j;
406         for (i = 0; i < ehdr.e_shnum; i++) {
407                 struct section *sec = &secs[i];
408                 if (sec->shdr.sh_type != SHT_REL) {
409                         continue;
410                 }
411                 sec->reltab = malloc(sec->shdr.sh_size);
412                 if (!sec->reltab) {
413                         die("malloc of %d bytes for relocs failed\n",
414                                 sec->shdr.sh_size);
415                 }
416                 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
417                         die("Seek to %d failed: %s\n",
418                                 sec->shdr.sh_offset, strerror(errno));
419                 }
420                 if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
421                     != sec->shdr.sh_size) {
422                         die("Cannot read symbol table: %s\n",
423                                 strerror(errno));
424                 }
425                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
426                         Elf32_Rel *rel = &sec->reltab[j];
427                         rel->r_offset = elf32_to_cpu(rel->r_offset);
428                         rel->r_info   = elf32_to_cpu(rel->r_info);
429                 }
430         }
431 }
432
433
434 static void print_absolute_symbols(void)
435 {
436         int i;
437         printf("Absolute symbols\n");
438         printf(" Num:    Value Size  Type       Bind        Visibility  Name\n");
439         for (i = 0; i < ehdr.e_shnum; i++) {
440                 struct section *sec = &secs[i];
441                 char *sym_strtab;
442                 int j;
443
444                 if (sec->shdr.sh_type != SHT_SYMTAB) {
445                         continue;
446                 }
447                 sym_strtab = sec->link->strtab;
448                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Sym); j++) {
449                         Elf32_Sym *sym;
450                         const char *name;
451                         sym = &sec->symtab[j];
452                         name = sym_name(sym_strtab, sym);
453                         if (sym->st_shndx != SHN_ABS) {
454                                 continue;
455                         }
456                         printf("%5d %08x %5d %10s %10s %12s %s\n",
457                                 j, sym->st_value, sym->st_size,
458                                 sym_type(ELF32_ST_TYPE(sym->st_info)),
459                                 sym_bind(ELF32_ST_BIND(sym->st_info)),
460                                 sym_visibility(ELF32_ST_VISIBILITY(sym->st_other)),
461                                 name);
462                 }
463         }
464         printf("\n");
465 }
466
467 static void print_absolute_relocs(void)
468 {
469         int i, printed = 0;
470
471         for (i = 0; i < ehdr.e_shnum; i++) {
472                 struct section *sec = &secs[i];
473                 struct section *sec_applies, *sec_symtab;
474                 char *sym_strtab;
475                 Elf32_Sym *sh_symtab;
476                 int j;
477                 if (sec->shdr.sh_type != SHT_REL) {
478                         continue;
479                 }
480                 sec_symtab  = sec->link;
481                 sec_applies = &secs[sec->shdr.sh_info];
482                 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
483                         continue;
484                 }
485                 sh_symtab  = sec_symtab->symtab;
486                 sym_strtab = sec_symtab->link->strtab;
487                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
488                         Elf32_Rel *rel;
489                         Elf32_Sym *sym;
490                         const char *name;
491                         rel = &sec->reltab[j];
492                         sym = &sh_symtab[ELF32_R_SYM(rel->r_info)];
493                         name = sym_name(sym_strtab, sym);
494                         if (sym->st_shndx != SHN_ABS) {
495                                 continue;
496                         }
497
498                         /* Absolute symbols are not relocated if bzImage is
499                          * loaded at a non-compiled address. Display a warning
500                          * to user at compile time about the absolute
501                          * relocations present.
502                          *
503                          * User need to audit the code to make sure
504                          * some symbols which should have been section
505                          * relative have not become absolute because of some
506                          * linker optimization or wrong programming usage.
507                          *
508                          * Before warning check if this absolute symbol
509                          * relocation is harmless.
510                          */
511                         if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
512                                 continue;
513
514                         if (!printed) {
515                                 printf("WARNING: Absolute relocations"
516                                         " present\n");
517                                 printf("Offset     Info     Type     Sym.Value "
518                                         "Sym.Name\n");
519                                 printed = 1;
520                         }
521
522                         printf("%08x %08x %10s %08x  %s\n",
523                                 rel->r_offset,
524                                 rel->r_info,
525                                 rel_type(ELF32_R_TYPE(rel->r_info)),
526                                 sym->st_value,
527                                 name);
528                 }
529         }
530
531         if (printed)
532                 printf("\n");
533 }
534
535 static void walk_relocs(void (*visit)(Elf32_Rel *rel, Elf32_Sym *sym),
536                         int use_real_mode)
537 {
538         int i;
539         /* Walk through the relocations */
540         for (i = 0; i < ehdr.e_shnum; i++) {
541                 char *sym_strtab;
542                 Elf32_Sym *sh_symtab;
543                 struct section *sec_applies, *sec_symtab;
544                 int j;
545                 struct section *sec = &secs[i];
546
547                 if (sec->shdr.sh_type != SHT_REL) {
548                         continue;
549                 }
550                 sec_symtab  = sec->link;
551                 sec_applies = &secs[sec->shdr.sh_info];
552                 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
553                         continue;
554                 }
555                 sh_symtab = sec_symtab->symtab;
556                 sym_strtab = sec_symtab->link->strtab;
557                 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf32_Rel); j++) {
558                         Elf32_Rel *rel;
559                         Elf32_Sym *sym;
560                         unsigned r_type;
561                         const char *symname;
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                         switch (r_type) {
567                         case R_386_NONE:
568                         case R_386_PC32:
569                         case R_386_PC16:
570                         case R_386_PC8:
571                                 /*
572                                  * NONE can be ignored and and PC relative
573                                  * relocations don't need to be adjusted.
574                                  */
575                                 break;
576
577                         case R_386_16:
578                                 symname = sym_name(sym_strtab, sym);
579                                 if (!use_real_mode)
580                                         goto bad;
581                                 if (sym->st_shndx == SHN_ABS) {
582                                         if (is_reloc(S_ABS, symname))
583                                                 break;
584                                         else if (!is_reloc(S_SEG, symname))
585                                                 goto bad;
586                                 } else {
587                                         if (is_reloc(S_LIN, symname))
588                                                 goto bad;
589                                         else
590                                                 break;
591                                 }
592                                 visit(rel, sym);
593                                 break;
594
595                         case R_386_32:
596                                 symname = sym_name(sym_strtab, sym);
597                                 if (sym->st_shndx == SHN_ABS) {
598                                         if (is_reloc(S_ABS, symname))
599                                                 break;
600                                         else if (!is_reloc(S_REL, symname))
601                                                 goto bad;
602                                 } else {
603                                         if (use_real_mode &&
604                                             !is_reloc(S_LIN, symname))
605                                                 break;
606                                 }
607                                 visit(rel, sym);
608                                 break;
609                         default:
610                                 die("Unsupported relocation type: %s (%d)\n",
611                                     rel_type(r_type), r_type);
612                                 break;
613                         bad:
614                                 symname = sym_name(sym_strtab, sym);
615                                 die("Invalid %s relocation: %s\n",
616                                     rel_type(r_type), symname);
617                         }
618                 }
619         }
620 }
621
622 static void count_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
623 {
624         if (ELF32_R_TYPE(rel->r_info) == R_386_16)
625                 reloc16_count++;
626         else
627                 reloc_count++;
628 }
629
630 static void collect_reloc(Elf32_Rel *rel, Elf32_Sym *sym)
631 {
632         /* Remember the address that needs to be adjusted. */
633         if (ELF32_R_TYPE(rel->r_info) == R_386_16)
634                 relocs16[reloc16_idx++] = rel->r_offset;
635         else
636                 relocs[reloc_idx++] = rel->r_offset;
637 }
638
639 static int cmp_relocs(const void *va, const void *vb)
640 {
641         const unsigned long *a, *b;
642         a = va; b = vb;
643         return (*a == *b)? 0 : (*a > *b)? 1 : -1;
644 }
645
646 static int write32(unsigned int v, FILE *f)
647 {
648         unsigned char buf[4];
649
650         put_unaligned_le32(v, buf);
651         return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
652 }
653
654 static void emit_relocs(int as_text, int use_real_mode)
655 {
656         int i;
657         /* Count how many relocations I have and allocate space for them. */
658         reloc_count = 0;
659         walk_relocs(count_reloc, use_real_mode);
660         relocs = malloc(reloc_count * sizeof(relocs[0]));
661         if (!relocs) {
662                 die("malloc of %d entries for relocs failed\n",
663                         reloc_count);
664         }
665
666         relocs16 = malloc(reloc16_count * sizeof(relocs[0]));
667         if (!relocs16) {
668                 die("malloc of %d entries for relocs16 failed\n",
669                         reloc16_count);
670         }
671         /* Collect up the relocations */
672         reloc_idx = 0;
673         walk_relocs(collect_reloc, use_real_mode);
674
675         if (reloc16_count && !use_real_mode)
676                 die("Segment relocations found but --realmode not specified\n");
677
678         /* Order the relocations for more efficient processing */
679         qsort(relocs, reloc_count, sizeof(relocs[0]), cmp_relocs);
680         qsort(relocs16, reloc16_count, sizeof(relocs16[0]), cmp_relocs);
681
682         /* Print the relocations */
683         if (as_text) {
684                 /* Print the relocations in a form suitable that
685                  * gas will like.
686                  */
687                 printf(".section \".data.reloc\",\"a\"\n");
688                 printf(".balign 4\n");
689                 if (use_real_mode) {
690                         printf("\t.long %lu\n", reloc16_count);
691                         for (i = 0; i < reloc16_count; i++)
692                                 printf("\t.long 0x%08lx\n", relocs16[i]);
693                         printf("\t.long %lu\n", reloc_count);
694                         for (i = 0; i < reloc_count; i++) {
695                                 printf("\t.long 0x%08lx\n", relocs[i]);
696                         }
697                 } else {
698                         /* Print a stop */
699                         printf("\t.long 0x%08lx\n", (unsigned long)0);
700                         for (i = 0; i < reloc_count; i++) {
701                                 printf("\t.long 0x%08lx\n", relocs[i]);
702                         }
703                 }
704
705                 printf("\n");
706         }
707         else {
708                 if (use_real_mode) {
709                         write32(reloc16_count, stdout);
710                         for (i = 0; i < reloc16_count; i++)
711                                 write32(relocs16[i], stdout);
712                         write32(reloc_count, stdout);
713
714                         /* Now print each relocation */
715                         for (i = 0; i < reloc_count; i++)
716                                 write32(relocs[i], stdout);
717                 } else {
718                         /* Print a stop */
719                         write32(0, stdout);
720
721                         /* Now print each relocation */
722                         for (i = 0; i < reloc_count; i++) {
723                                 write32(relocs[i], stdout);
724                         }
725                 }
726         }
727 }
728
729 static void usage(void)
730 {
731         die("relocs [--abs-syms|--abs-relocs|--text|--realmode] vmlinux\n");
732 }
733
734 int main(int argc, char **argv)
735 {
736         int show_absolute_syms, show_absolute_relocs;
737         int as_text, use_real_mode;
738         const char *fname;
739         FILE *fp;
740         int i;
741
742         show_absolute_syms = 0;
743         show_absolute_relocs = 0;
744         as_text = 0;
745         use_real_mode = 0;
746         fname = NULL;
747         for (i = 1; i < argc; i++) {
748                 char *arg = argv[i];
749                 if (*arg == '-') {
750                         if (strcmp(arg, "--abs-syms") == 0) {
751                                 show_absolute_syms = 1;
752                                 continue;
753                         }
754                         if (strcmp(arg, "--abs-relocs") == 0) {
755                                 show_absolute_relocs = 1;
756                                 continue;
757                         }
758                         if (strcmp(arg, "--text") == 0) {
759                                 as_text = 1;
760                                 continue;
761                         }
762                         if (strcmp(arg, "--realmode") == 0) {
763                                 use_real_mode = 1;
764                                 continue;
765                         }
766                 }
767                 else if (!fname) {
768                         fname = arg;
769                         continue;
770                 }
771                 usage();
772         }
773         if (!fname) {
774                 usage();
775         }
776         regex_init(use_real_mode);
777         fp = fopen(fname, "r");
778         if (!fp) {
779                 die("Cannot open %s: %s\n",
780                         fname, strerror(errno));
781         }
782         read_ehdr(fp);
783         read_shdrs(fp);
784         read_strtabs(fp);
785         read_symtabs(fp);
786         read_relocs(fp);
787         if (show_absolute_syms) {
788                 print_absolute_symbols();
789                 return 0;
790         }
791         if (show_absolute_relocs) {
792                 print_absolute_relocs();
793                 return 0;
794         }
795         emit_relocs(as_text, use_real_mode);
796         return 0;
797 }