2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)nlist.c 8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
35 #include <sys/param.h>
39 #include <arpa/inet.h>
47 #if !defined(__NO_A_OUT_SUPPORT)
48 #define _NLIST_DO_AOUT
53 #include "local-elf.h"
56 #define SIZE_T_MAX 0xffffffffU
59 static int __aout_fdnlist(int, struct nlist *);
61 #define N_SYMSIZE(a) ((a).a_syms)
65 static int __elf_fdnlist(int, struct nlist *);
68 /* FIXME: This function is used by libkvm0, so we need to export it.
69 It is not declared in the include files though. */
70 int __fdnlist(int, struct nlist *);
79 fd = open(name, O_RDONLY, 0);
82 n = __fdnlist(fd, list);
87 static struct nlist_handlers {
88 int (*fn)(int fd, struct nlist *list);
106 for (i = 0; i < sizeof(nlist_fn) / sizeof(nlist_fn[0]); i++) {
107 n = (nlist_fn[i].fn)(fd, list);
114 #define ISLAST(p) (p->n_un.n_name == 0 || p->n_un.n_name[0] == 0)
116 #ifdef _NLIST_DO_AOUT
118 __aout_fdnlist(fd, list)
122 struct nlist *p, *symtab;
123 caddr_t strtab, a_out_mmap;
124 off_t stroff, symoff;
130 /* check that file is at least as large as struct exec! */
131 if ((fstat(fd, &st) < 0) || (st.st_size < sizeof(struct exec)))
134 /* Check for files too large to mmap. */
135 if (st.st_size > SIZE_T_MAX) {
141 * Map the whole a.out file into our address space.
142 * We then find the string table within this area.
143 * We do not just mmap the string table, as it probably
144 * does not start at a page boundary - we save ourselves a
145 * lot of nastiness by mmapping the whole file.
147 * This gives us an easy way to randomly access all the strings,
148 * without making the memory allocation permanent as with
149 * malloc/free (i.e., munmap will return it to the system).
151 a_out_mmap = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_PRIVATE, fd, (off_t)0);
152 if (a_out_mmap == MAP_FAILED)
155 exec = (struct exec *)a_out_mmap;
156 if (N_BADMAG(*exec)) {
157 munmap(a_out_mmap, (size_t)st.st_size);
161 symoff = N_SYMOFF(*exec);
162 symsize = N_SYMSIZE(*exec);
163 stroff = symoff + symsize;
165 /* find the string table in our mmapped area */
166 strtab = a_out_mmap + stroff;
167 symtab = (struct nlist *)(a_out_mmap + symoff);
170 * clean out any left-over information for all valid entries.
171 * Type and value defined to be 0 if not found; historical
172 * versions cleared other and desc as well. Also figure out
173 * the largest string length so don't read any more of the
174 * string table than we have to.
176 * XXX clearing anything other than n_type and n_value violates
177 * the semantics given in the man page.
180 for (p = list; !ISLAST(p); ++p) {
188 while (symsize > 0) {
191 symsize-= sizeof(struct nlist);
192 soff = symtab->n_un.n_strx;
195 if (soff != 0 && (symtab->n_type & N_STAB) == 0)
196 for (p = list; !ISLAST(p); p++)
197 if (!strcmp(&strtab[soff], p->n_un.n_name)) {
198 p->n_value = symtab->n_value;
199 p->n_type = symtab->n_type;
200 p->n_desc = symtab->n_desc;
201 p->n_other = symtab->n_other;
207 munmap(a_out_mmap, (size_t)st.st_size);
213 static void elf_sym_to_nlist(struct nlist *, Elf_Sym *, Elf_Shdr *, int);
216 * __elf_is_okay__ - Determine if ehdr really
217 * is ELF and valid for the target platform.
219 * WARNING: This is NOT an ELF ABI function and
220 * as such its use should be restricted.
223 __elf_is_okay__(ehdr)
228 * We need to check magic, class size, endianess,
229 * and version before we look at the rest of the
230 * Elf_Ehdr structure. These few elements are
231 * represented in a machine independent fashion.
234 ehdr->e_ident[EI_CLASS] == ELF_TARG_CLASS &&
235 ehdr->e_ident[EI_DATA] == ELF_TARG_DATA &&
236 ehdr->e_ident[EI_VERSION] == ELF_TARG_VER) {
238 /* Now check the machine dependent header */
239 if (ehdr->e_machine == ELF_TARG_MACH &&
240 ehdr->e_version == ELF_TARG_VER)
247 __elf_fdnlist(fd, list)
252 Elf_Off symoff = 0, symstroff = 0;
253 Elf_Word symsize = 0, symstrsize = 0;
261 Elf_Shdr *shdr = NULL;
266 /* Make sure obj is OK */
267 if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
268 read(fd, &ehdr, sizeof(Elf_Ehdr)) != sizeof(Elf_Ehdr) ||
269 !__elf_is_okay__(&ehdr) ||
273 /* calculate section header table size */
274 shdr_size = ehdr.e_shentsize * ehdr.e_shnum;
276 /* Make sure it's not too big to mmap */
277 if (shdr_size > SIZE_T_MAX) {
282 /* mmap section header table */
283 base = mmap(NULL, (size_t)shdr_size, PROT_READ, 0, fd,
284 (off_t)ehdr.e_shoff);
285 if (base == MAP_FAILED)
287 shdr = (Elf_Shdr *)base;
290 * Find the symbol table entry and it's corresponding
291 * string table entry. Version 1.1 of the ABI states
292 * that there is only one symbol table but that this
293 * could change in the future.
295 for (i = 0; i < ehdr.e_shnum; i++) {
296 if (shdr[i].sh_type == SHT_SYMTAB) {
297 symoff = shdr[i].sh_offset;
298 symsize = shdr[i].sh_size;
299 symstroff = shdr[shdr[i].sh_link].sh_offset;
300 symstrsize = shdr[shdr[i].sh_link].sh_size;
305 /* Check for files too large to mmap. */
306 if (symstrsize > SIZE_T_MAX) {
311 * Map string table into our address space. This gives us
312 * an easy way to randomly access all the strings, without
313 * making the memory allocation permanent as with malloc/free
314 * (i.e., munmap will return it to the system).
316 base = mmap(NULL, (size_t)symstrsize, PROT_READ, 0, fd,
318 if (base == MAP_FAILED)
320 strtab = (char *)base;
323 * clean out any left-over information for all valid entries.
324 * Type and value defined to be 0 if not found; historical
325 * versions cleared other and desc as well. Also figure out
326 * the largest string length so don't read any more of the
327 * string table than we have to.
329 * XXX clearing anything other than n_type and n_value violates
330 * the semantics given in the man page.
333 for (p = list; !ISLAST(p); ++p) {
341 /* Don't process any further if object is stripped. */
345 if (lseek(fd, (off_t) symoff, SEEK_SET) == -1) {
350 while (symsize > 0 && nent > 0) {
351 cc = MIN(symsize, sizeof(sbuf));
352 if (read(fd, sbuf, cc) != cc)
355 for (s = sbuf; cc > 0 && nent > 0; ++s, cc -= sizeof(*s)) {
359 name = strtab + s->st_name;
362 for (p = list; !ISLAST(p); p++) {
363 if ((p->n_un.n_name[0] == '_' &&
364 strcmp(name, p->n_un.n_name+1) == 0)
365 || strcmp(name, p->n_un.n_name) == 0) {
366 elf_sym_to_nlist(p, s, shdr,
377 munmap(strtab, symstrsize);
379 munmap(shdr, shdr_size);
385 * Convert an Elf_Sym into an nlist structure. This fills in only the
386 * n_value and n_type members.
389 elf_sym_to_nlist(nl, s, shdr, shnum)
395 nl->n_value = s->st_value;
397 switch (s->st_shndx) {
403 nl->n_type = ELF_ST_TYPE(s->st_info) == STT_FILE ?
407 if (s->st_shndx >= shnum)
410 Elf_Shdr *sh = shdr + s->st_shndx;
412 nl->n_type = sh->sh_type == SHT_PROGBITS ?
413 (sh->sh_flags & SHF_WRITE ? N_DATA : N_TEXT) :
414 (sh->sh_type == SHT_NOBITS ? N_BSS : N_UNDF);
419 if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
420 ELF_ST_BIND(s->st_info) == STB_WEAK)
423 #endif /* _NLIST_DO_ELF */