Annotation of src/usr.bin/nm/elf.c, Revision 1.30
1.30 ! semarie 1: /* $OpenBSD: elf.c,v 1.29 2015/06/23 13:43:08 semarie Exp $ */
1.1 mickey 2:
3: /*
4: * Copyright (c) 2003 Michael Shalayeff
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19: * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
20: * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21: * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22: * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24: * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25: * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
26: * THE POSSIBILITY OF SUCH DAMAGE.
27: */
28:
1.10 mickey 29: #include <sys/mman.h>
30: #include <unistd.h>
31: #include <a.out.h>
32: #include <elf_abi.h>
33: #include <errno.h>
34: #include <err.h>
1.26 millert 35: #include <stdint.h>
1.10 mickey 36: #include <stdio.h>
37: #include <stdlib.h>
38: #include <string.h>
39: #include <ctype.h>
40: #include "elfuncs.h"
41: #include "util.h"
42:
43: #if ELFSIZE == 32
1.1 mickey 44: #define swap_addr swap32
45: #define swap_off swap32
46: #define swap_sword swap32
47: #define swap_word swap32
48: #define swap_sxword swap32
49: #define swap_xword swap32
50: #define swap_half swap16
51: #define swap_quarter swap16
1.10 mickey 52: #define elf_fix_header elf32_fix_header
53: #define elf_load_shdrs elf32_load_shdrs
1.13 grange 54: #define elf_load_phdrs elf32_load_phdrs
1.10 mickey 55: #define elf_fix_shdrs elf32_fix_shdrs
56: #define elf_fix_phdrs elf32_fix_phdrs
57: #define elf_fix_sym elf32_fix_sym
58: #define elf_size elf32_size
1.14 kettenis 59: #define elf_symloadx elf32_symloadx
1.10 mickey 60: #define elf_symload elf32_symload
61: #define elf2nlist elf32_2nlist
62: #define elf_shn2type elf32_shn2type
63: #elif ELFSIZE == 64
1.1 mickey 64: #define swap_addr swap64
65: #define swap_off swap64
66: #ifdef __alpha__
67: #define swap_sword swap64
68: #define swap_word swap64
69: #else
70: #define swap_sword swap32
71: #define swap_word swap32
72: #endif
73: #define swap_sxword swap64
74: #define swap_xword swap64
75: #define swap_half swap64
76: #define swap_quarter swap16
1.10 mickey 77: #define elf_fix_header elf64_fix_header
78: #define elf_load_shdrs elf64_load_shdrs
1.13 grange 79: #define elf_load_phdrs elf64_load_phdrs
1.10 mickey 80: #define elf_fix_shdrs elf64_fix_shdrs
81: #define elf_fix_phdrs elf64_fix_phdrs
82: #define elf_fix_sym elf64_fix_sym
83: #define elf_size elf64_size
1.14 kettenis 84: #define elf_symloadx elf64_symloadx
1.10 mickey 85: #define elf_symload elf64_symload
86: #define elf2nlist elf64_2nlist
87: #define elf_shn2type elf64_shn2type
1.1 mickey 88: #else
89: #error "Unsupported ELF class"
90: #endif
91:
1.9 mickey 92: #define ELF_SDATA ".sdata"
1.20 uwe 93: #define ELF_TDATA ".tdata"
1.3 mickey 94: #define ELF_SBSS ".sbss"
1.20 uwe 95: #define ELF_TBSS ".tbss"
1.6 mickey 96: #define ELF_PLT ".plt"
1.3 mickey 97:
1.11 mickey 98: #ifndef SHN_MIPS_ACOMMON
99: #define SHN_MIPS_ACOMMON SHN_LOPROC + 0
100: #endif
101: #ifndef SHN_MIPS_TEXT
102: #define SHN_MIPS_TEXT SHN_LOPROC + 1
103: #endif
104: #ifndef SHN_MIPS_DATA
105: #define SHN_MIPS_DATA SHN_LOPROC + 2
106: #endif
107: #ifndef SHN_MIPS_SUNDEFINED
108: #define SHN_MIPS_SUNDEFINED SHN_LOPROC + 4
109: #endif
110: #ifndef SHN_MIPS_SCOMMON
111: #define SHN_MIPS_SCOMMON SHN_LOPROC + 3
112: #endif
113:
114: #ifndef STT_PARISC_MILLI
115: #define STT_PARISC_MILLI STT_LOPROC + 0
116: #endif
117:
1.22 deraadt 118: int elf_shn2type(Elf_Ehdr *, u_int, const char *);
119: int elf2nlist(Elf_Sym *, Elf_Ehdr *, Elf_Shdr *, char *, struct nlist *);
120:
1.1 mickey 121: int
122: elf_fix_header(Elf_Ehdr *eh)
123: {
124: /* nothing to do */
125: if (eh->e_ident[EI_DATA] == ELF_TARG_DATA)
126: return (0);
127:
128: eh->e_type = swap16(eh->e_type);
129: eh->e_machine = swap16(eh->e_machine);
130: eh->e_version = swap32(eh->e_version);
131: eh->e_entry = swap_addr(eh->e_entry);
132: eh->e_phoff = swap_off(eh->e_phoff);
133: eh->e_shoff = swap_off(eh->e_shoff);
134: eh->e_flags = swap32(eh->e_flags);
135: eh->e_ehsize = swap16(eh->e_ehsize);
136: eh->e_phentsize = swap16(eh->e_phentsize);
137: eh->e_phnum = swap16(eh->e_phnum);
138: eh->e_shentsize = swap16(eh->e_shentsize);
139: eh->e_shnum = swap16(eh->e_shnum);
140: eh->e_shstrndx = swap16(eh->e_shstrndx);
141:
142: return (1);
143: }
144:
1.10 mickey 145: Elf_Shdr *
146: elf_load_shdrs(const char *name, FILE *fp, off_t foff, Elf_Ehdr *head)
147: {
148: Elf_Shdr *shdr;
149:
150: elf_fix_header(head);
1.29 semarie 151:
152: if (head->e_shnum == 0) {
153: warnx("%s: no section header table", name);
154: return (NULL);
155: }
156:
157: if (head->e_shstrndx >= head->e_shnum) {
158: warnx("%s: inconsistent section header table", name);
159: return (NULL);
160: }
1.10 mickey 161:
1.18 deraadt 162: if ((shdr = calloc(head->e_shentsize, head->e_shnum)) == NULL) {
1.10 mickey 163: warn("%s: malloc shdr", name);
164: return (NULL);
165: }
166:
167: if (fseeko(fp, foff + head->e_shoff, SEEK_SET)) {
168: warn("%s: fseeko", name);
169: free(shdr);
170: return (NULL);
171: }
172:
173: if (fread(shdr, head->e_shentsize, head->e_shnum, fp) != head->e_shnum) {
174: warnx("%s: premature EOF", name);
175: free(shdr);
176: return (NULL);
177: }
178:
179: elf_fix_shdrs(head, shdr);
180: return (shdr);
1.13 grange 181: }
182:
183: Elf_Phdr *
184: elf_load_phdrs(const char *name, FILE *fp, off_t foff, Elf_Ehdr *head)
185: {
186: Elf_Phdr *phdr;
187:
1.18 deraadt 188: if ((phdr = calloc(head->e_phentsize, head->e_phnum)) == NULL) {
1.13 grange 189: warn("%s: malloc phdr", name);
190: return (NULL);
191: }
192:
193: if (fseeko(fp, foff + head->e_phoff, SEEK_SET)) {
194: warn("%s: fseeko", name);
195: free(phdr);
196: return (NULL);
197: }
198:
199: if (fread(phdr, head->e_phentsize, head->e_phnum, fp) != head->e_phnum) {
200: warnx("%s: premature EOF", name);
201: free(phdr);
202: return (NULL);
203: }
204:
205: elf_fix_phdrs(head, phdr);
206: return (phdr);
1.10 mickey 207: }
208:
1.1 mickey 209: int
210: elf_fix_shdrs(Elf_Ehdr *eh, Elf_Shdr *shdr)
211: {
212: int i;
213:
214: /* nothing to do */
215: if (eh->e_ident[EI_DATA] == ELF_TARG_DATA)
216: return (0);
217:
218: for (i = eh->e_shnum; i--; shdr++) {
219: shdr->sh_name = swap32(shdr->sh_name);
220: shdr->sh_type = swap32(shdr->sh_type);
221: shdr->sh_flags = swap_xword(shdr->sh_flags);
222: shdr->sh_addr = swap_addr(shdr->sh_addr);
223: shdr->sh_offset = swap_off(shdr->sh_offset);
224: shdr->sh_size = swap_xword(shdr->sh_size);
225: shdr->sh_link = swap32(shdr->sh_link);
226: shdr->sh_info = swap32(shdr->sh_info);
227: shdr->sh_addralign = swap_xword(shdr->sh_addralign);
228: shdr->sh_entsize = swap_xword(shdr->sh_entsize);
229: }
230:
231: return (1);
232: }
233:
234: int
235: elf_fix_phdrs(Elf_Ehdr *eh, Elf_Phdr *phdr)
236: {
237: int i;
238:
239: /* nothing to do */
240: if (eh->e_ident[EI_DATA] == ELF_TARG_DATA)
241: return (0);
242:
243: for (i = eh->e_phnum; i--; phdr++) {
244: phdr->p_type = swap32(phdr->p_type);
245: phdr->p_flags = swap32(phdr->p_flags);
246: phdr->p_offset = swap_off(phdr->p_offset);
247: phdr->p_vaddr = swap_addr(phdr->p_vaddr);
248: phdr->p_paddr = swap_addr(phdr->p_paddr);
249: phdr->p_filesz = swap_xword(phdr->p_filesz);
250: phdr->p_memsz = swap_xword(phdr->p_memsz);
251: phdr->p_align = swap_xword(phdr->p_align);
252: }
253:
254: return (1);
255: }
256:
257: int
258: elf_fix_sym(Elf_Ehdr *eh, Elf_Sym *sym)
259: {
260: /* nothing to do */
261: if (eh->e_ident[EI_DATA] == ELF_TARG_DATA)
262: return (0);
263:
264: sym->st_name = swap32(sym->st_name);
265: sym->st_shndx = swap16(sym->st_shndx);
266: sym->st_value = swap_addr(sym->st_value);
267: sym->st_size = swap_xword(sym->st_size);
268:
269: return (1);
270: }
271:
1.9 mickey 272: int
1.11 mickey 273: elf_shn2type(Elf_Ehdr *eh, u_int shn, const char *sn)
1.9 mickey 274: {
275: switch (shn) {
276: case SHN_MIPS_SUNDEFINED:
1.11 mickey 277: if (eh->e_machine == EM_MIPS)
278: return (N_UNDF | N_EXT);
279: break;
280:
1.9 mickey 281: case SHN_UNDEF:
282: return (N_UNDF | N_EXT);
1.11 mickey 283:
1.9 mickey 284: case SHN_ABS:
285: return (N_ABS);
1.11 mickey 286:
1.9 mickey 287: case SHN_MIPS_ACOMMON:
1.11 mickey 288: if (eh->e_machine == EM_MIPS)
289: return (N_COMM);
290: break;
291:
1.9 mickey 292: case SHN_MIPS_SCOMMON:
1.11 mickey 293: if (eh->e_machine == EM_MIPS)
294: return (N_COMM);
295: break;
296:
1.9 mickey 297: case SHN_COMMON:
298: return (N_COMM);
1.11 mickey 299:
1.9 mickey 300: case SHN_MIPS_TEXT:
1.11 mickey 301: if (eh->e_machine == EM_MIPS)
302: return (N_TEXT);
303: break;
304:
1.9 mickey 305: case SHN_MIPS_DATA:
1.11 mickey 306: if (eh->e_machine == EM_MIPS)
307: return (N_DATA);
308: break;
309:
1.9 mickey 310: default:
1.20 uwe 311: /* TODO: beyond 8 a table-driven binsearch should be used */
1.9 mickey 312: if (sn == NULL)
313: return (-1);
314: else if (!strcmp(sn, ELF_TEXT))
315: return (N_TEXT);
316: else if (!strcmp(sn, ELF_RODATA))
317: return (N_SIZE);
318: else if (!strcmp(sn, ELF_DATA))
319: return (N_DATA);
320: else if (!strcmp(sn, ELF_SDATA))
321: return (N_DATA);
1.20 uwe 322: else if (!strcmp(sn, ELF_TDATA))
323: return (N_DATA);
1.9 mickey 324: else if (!strcmp(sn, ELF_BSS))
325: return (N_BSS);
326: else if (!strcmp(sn, ELF_SBSS))
327: return (N_BSS);
1.20 uwe 328: else if (!strcmp(sn, ELF_TBSS))
329: return (N_BSS);
1.9 mickey 330: else if (!strncmp(sn, ELF_GOT, sizeof(ELF_GOT) - 1))
331: return (N_DATA);
332: else if (!strncmp(sn, ELF_PLT, sizeof(ELF_PLT) - 1))
333: return (N_DATA);
334: }
1.11 mickey 335:
336: return (-1);
1.9 mickey 337: }
338:
1.1 mickey 339: /*
340: * Devise nlist's type from Elf_Sym.
341: * XXX this task is done as well in libc and kvm_mkdb.
342: */
343: int
344: elf2nlist(Elf_Sym *sym, Elf_Ehdr *eh, Elf_Shdr *shdr, char *shstr, struct nlist *np)
345: {
1.9 mickey 346: u_char stt;
1.1 mickey 347: const char *sn;
1.9 mickey 348: int type;
1.1 mickey 349:
350: if (sym->st_shndx < eh->e_shnum)
351: sn = shstr + shdr[sym->st_shndx].sh_name;
352: else
1.9 mickey 353: sn = NULL;
1.6 mickey 354: #if 0
355: {
356: extern char *stab;
1.21 miod 357: printf("%d:%s %d %d %s\n", sym->st_shndx, sn? sn : "",
358: ELF_ST_TYPE(sym->st_info), ELF_ST_BIND(sym->st_info),
359: stab + sym->st_name);
1.6 mickey 360: }
361: #endif
1.9 mickey 362:
363: switch (stt = ELF_ST_TYPE(sym->st_info)) {
1.1 mickey 364: case STT_NOTYPE:
1.9 mickey 365: case STT_OBJECT:
1.20 uwe 366: case STT_TLS:
1.11 mickey 367: type = elf_shn2type(eh, sym->st_shndx, sn);
1.9 mickey 368: if (type < 0) {
369: if (sn == NULL)
370: np->n_other = '?';
371: else
372: np->n_type = stt == STT_NOTYPE? N_COMM : N_DATA;
373: } else {
374: /* a hack for .rodata check (; */
375: if (type == N_SIZE) {
1.1 mickey 376: np->n_type = N_DATA;
1.8 mickey 377: np->n_other = 'r';
1.9 mickey 378: } else
379: np->n_type = type;
1.8 mickey 380: }
1.21 miod 381: if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
382: np->n_other = 'W';
1.8 mickey 383: break;
384:
1.1 mickey 385: case STT_FUNC:
1.11 mickey 386: type = elf_shn2type(eh, sym->st_shndx, NULL);
1.9 mickey 387: np->n_type = type < 0? N_TEXT : type;
1.1 mickey 388: if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
389: np->n_other = 'W';
1.14 kettenis 390: } else if (sn != NULL && *sn != 0 &&
1.9 mickey 391: strcmp(sn, ELF_INIT) &&
1.6 mickey 392: strcmp(sn, ELF_TEXT) &&
393: strcmp(sn, ELF_FINI)) /* XXX GNU compat */
1.1 mickey 394: np->n_other = '?';
395: break;
396:
1.8 mickey 397: case STT_SECTION:
1.11 mickey 398: type = elf_shn2type(eh, sym->st_shndx, NULL);
1.9 mickey 399: if (type < 0)
1.8 mickey 400: np->n_other = '?';
1.9 mickey 401: else
402: np->n_type = type;
1.1 mickey 403: break;
404:
405: case STT_FILE:
406: np->n_type = N_FN | N_EXT;
407: break;
408:
409: case STT_PARISC_MILLI:
1.11 mickey 410: if (eh->e_machine == EM_PARISC)
411: np->n_type = N_TEXT;
412: else
413: np->n_other = '?';
1.1 mickey 414: break;
1.11 mickey 415:
1.1 mickey 416: default:
417: np->n_other = '?';
418: break;
419: }
420: if (np->n_type != N_UNDF && ELF_ST_BIND(sym->st_info) != STB_LOCAL) {
421: np->n_type |= N_EXT;
422: if (np->n_other)
1.23 deraadt 423: np->n_other = toupper((unsigned char)np->n_other);
1.10 mickey 424: }
425:
426: return (0);
427: }
428:
429: int
430: elf_size(Elf_Ehdr *head, Elf_Shdr *shdr,
431: u_long *ptext, u_long *pdata, u_long *pbss)
432: {
433: int i;
434:
435: *ptext = *pdata = *pbss = 0;
436:
437: for (i = 0; i < head->e_shnum; i++) {
438: if (!(shdr[i].sh_flags & SHF_ALLOC))
439: ;
440: else if (shdr[i].sh_flags & SHF_EXECINSTR ||
441: !(shdr[i].sh_flags & SHF_WRITE))
442: *ptext += shdr[i].sh_size;
443: else if (shdr[i].sh_type == SHT_NOBITS)
444: *pbss += shdr[i].sh_size;
445: else
446: *pdata += shdr[i].sh_size;
447: }
448:
449: return (0);
450: }
451:
452: int
1.14 kettenis 453: elf_symloadx(const char *name, FILE *fp, off_t foff, Elf_Ehdr *eh,
1.30 ! semarie 454: Elf_Shdr *shdr, char *shstr, long shstrsize, struct nlist **pnames,
1.14 kettenis 455: struct nlist ***psnames, size_t *pstabsize, int *pnrawnames,
456: const char *strtab, const char *symtab)
1.10 mickey 457: {
1.14 kettenis 458: long symsize;
1.10 mickey 459: struct nlist *np;
460: Elf_Sym sbuf;
461: int i;
462:
463: for (i = 0; i < eh->e_shnum; i++) {
1.30 ! semarie 464: if (shdr[i].sh_name >= shstrsize) {
! 465: warnx("%s: corrupt file", name);
! 466: return (1);
! 467: }
1.14 kettenis 468: if (!strcmp(shstr + shdr[i].sh_name, strtab)) {
1.10 mickey 469: *pstabsize = shdr[i].sh_size;
1.26 millert 470: if (*pstabsize > SIZE_MAX) {
1.10 mickey 471: warnx("%s: corrupt file", name);
472: return (1);
473: }
474:
475: MMAP(stab, *pstabsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
476: fileno(fp), foff + shdr[i].sh_offset);
1.16 ray 477: if (stab == MAP_FAILED)
1.10 mickey 478: return (1);
479: }
480: }
481: for (i = 0; i < eh->e_shnum; i++) {
1.14 kettenis 482: if (!strcmp(shstr + shdr[i].sh_name, symtab)) {
1.10 mickey 483: symsize = shdr[i].sh_size;
484: if (fseeko(fp, foff + shdr[i].sh_offset, SEEK_SET)) {
485: warn("%s: fseeko", name);
486: if (stab)
487: MUNMAP(stab, *pstabsize);
488: return (1);
489: }
490:
491: *pnrawnames = symsize / sizeof(sbuf);
492: if ((*pnames = calloc(*pnrawnames, sizeof(*np))) == NULL) {
493: warn("%s: malloc names", name);
494: if (stab)
495: MUNMAP(stab, *pstabsize);
496: return (1);
497: }
1.18 deraadt 498: if ((*psnames = calloc(*pnrawnames, sizeof(np))) == NULL) {
1.10 mickey 499: warn("%s: malloc snames", name);
500: if (stab)
501: MUNMAP(stab, *pstabsize);
502: free(*pnames);
503: return (1);
504: }
505:
506: for (np = *pnames; symsize > 0; symsize -= sizeof(sbuf)) {
507: if (fread(&sbuf, 1, sizeof(sbuf),
508: fp) != sizeof(sbuf)) {
509: warn("%s: read symbol", name);
510: if (stab)
511: MUNMAP(stab, *pstabsize);
512: free(*pnames);
513: free(*psnames);
514: return (1);
515: }
516:
517: elf_fix_sym(eh, &sbuf);
518:
1.15 mickey 519: if (!sbuf.st_name ||
520: sbuf.st_name > *pstabsize)
1.10 mickey 521: continue;
522:
523: elf2nlist(&sbuf, eh, shdr, shstr, np);
524: np->n_value = sbuf.st_value;
525: np->n_un.n_strx = sbuf.st_name;
526: np++;
527: }
528: *pnrawnames = np - *pnames;
529: }
1.14 kettenis 530: }
1.22 deraadt 531: return (0);
1.14 kettenis 532: }
533:
534: int
535: elf_symload(const char *name, FILE *fp, off_t foff, Elf_Ehdr *eh,
536: Elf_Shdr *shdr, struct nlist **pnames, struct nlist ***psnames,
537: size_t *pstabsize, int *pnrawnames)
538: {
539: long shstrsize;
540: char *shstr;
541:
542: shstrsize = shdr[eh->e_shstrndx].sh_size;
1.17 miod 543: if (shstrsize == 0) {
544: warnx("%s: no name list", name);
545: return (1);
546: }
547:
1.14 kettenis 548: if ((shstr = malloc(shstrsize)) == NULL) {
549: warn("%s: malloc shsrt", name);
550: return (1);
551: }
552:
553: if (fseeko(fp, foff + shdr[eh->e_shstrndx].sh_offset, SEEK_SET)) {
554: warn("%s: fseeko", name);
555: free(shstr);
556: return (1);
557: }
558:
559: if (fread(shstr, 1, shstrsize, fp) != shstrsize) {
560: warnx("%s: premature EOF", name);
561: free(shstr);
562: return(1);
563: }
564:
565: stab = NULL;
1.25 miod 566: *pnames = NULL; *psnames = NULL; *pnrawnames = 0;
1.28 guenther 567: if (!dynamic_only) {
1.30 ! semarie 568: elf_symloadx(name, fp, foff, eh, shdr, shstr, shstrsize, pnames,
1.28 guenther 569: psnames, pstabsize, pnrawnames, ELF_STRTAB, ELF_SYMTAB);
570: }
1.14 kettenis 571: if (stab == NULL) {
1.30 ! semarie 572: elf_symloadx(name, fp, foff, eh, shdr, shstr, shstrsize, pnames,
1.14 kettenis 573: psnames, pstabsize, pnrawnames, ELF_DYNSTR, ELF_DYNSYM);
1.10 mickey 574: }
575:
576: free(shstr);
577: if (stab == NULL) {
578: warnx("%s: no name list", name);
579: if (*pnames)
580: free(*pnames);
581: if (*psnames)
582: free(*psnames);
583: return (1);
1.1 mickey 584: }
585:
586: return (0);
587: }
![[BACK]](/icons/back.gif){kind=icon}
Return to elf.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / nm