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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)nlist.c 8.1 (Berkeley) 6/4/93";
36 #endif /* LIBC_SCCS and not lint */
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include "namespace.h"
41 #include <sys/param.h>
45 #include <arpa/inet.h>
52 #include "un-namespace.h"
54 #define _NLIST_DO_AOUT
58 #include <machine/elf.h>
59 #include <elf-hints.h>
62 int __fdnlist(int, struct nlist *);
63 int __aout_fdnlist(int, struct nlist *);
64 int __elf_fdnlist(int, struct nlist *);
73 fd = _open(name, O_RDONLY, 0);
76 n = __fdnlist(fd, list);
81 static struct nlist_handlers {
82 int (*fn)(int fd, struct nlist *list);
99 for (i = 0; i < sizeof(nlist_fn) / sizeof(nlist_fn[0]); i++) {
100 n = (nlist_fn[i].fn)(fd, list);
107 #define ISLAST(p) (p->n_un.n_name == 0 || p->n_un.n_name[0] == 0)
109 #ifdef _NLIST_DO_AOUT
111 __aout_fdnlist(fd, list)
115 struct nlist *p, *symtab;
116 caddr_t strtab, a_out_mmap;
117 off_t stroff, symoff;
123 /* check that file is at least as large as struct exec! */
124 if ((_fstat(fd, &st) < 0) || (st.st_size < sizeof(struct exec)))
127 /* Check for files too large to mmap. */
128 if (st.st_size > SIZE_T_MAX) {
134 * Map the whole a.out file into our address space.
135 * We then find the string table withing this area.
136 * We do not just mmap the string table, as it probably
137 * does not start at a page boundary - we save ourselves a
138 * lot of nastiness by mmapping the whole file.
140 * This gives us an easy way to randomly access all the strings,
141 * without making the memory allocation permanent as with
142 * malloc/free (i.e., munmap will return it to the system).
144 a_out_mmap = mmap(NULL, (size_t)st.st_size, PROT_READ, MAP_PRIVATE, fd, (off_t)0);
145 if (a_out_mmap == MAP_FAILED)
148 exec = (struct exec *)a_out_mmap;
149 if (N_BADMAG(*exec)) {
150 munmap(a_out_mmap, (size_t)st.st_size);
154 symoff = N_SYMOFF(*exec);
155 symsize = exec->a_syms;
156 stroff = symoff + symsize;
158 /* find the string table in our mmapped area */
159 strtab = a_out_mmap + stroff;
160 symtab = (struct nlist *)(a_out_mmap + symoff);
163 * clean out any left-over information for all valid entries.
164 * Type and value defined to be 0 if not found; historical
165 * versions cleared other and desc as well. Also figure out
166 * the largest string length so don't read any more of the
167 * string table than we have to.
169 * XXX clearing anything other than n_type and n_value violates
170 * the semantics given in the man page.
173 for (p = list; !ISLAST(p); ++p) {
181 while (symsize > 0) {
184 symsize-= sizeof(struct nlist);
185 soff = symtab->n_un.n_strx;
188 if (soff != 0 && (symtab->n_type & N_STAB) == 0)
189 for (p = list; !ISLAST(p); p++)
190 if (!strcmp(&strtab[soff], p->n_un.n_name)) {
191 p->n_value = symtab->n_value;
192 p->n_type = symtab->n_type;
193 p->n_desc = symtab->n_desc;
194 p->n_other = symtab->n_other;
200 munmap(a_out_mmap, (size_t)st.st_size);
206 static void elf_sym_to_nlist(struct nlist *, Elf_Sym *, Elf_Shdr *, int);
209 * __elf_is_okay__ - Determine if ehdr really
210 * is ELF and valid for the target platform.
212 * WARNING: This is NOT an ELF ABI function and
213 * as such its use should be restricted.
216 __elf_is_okay__(ehdr)
221 * We need to check magic, class size, endianess,
222 * and version before we look at the rest of the
223 * Elf_Ehdr structure. These few elements are
224 * represented in a machine independant fashion.
227 ehdr->e_ident[EI_CLASS] == ELF_TARG_CLASS &&
228 ehdr->e_ident[EI_DATA] == ELF_TARG_DATA &&
229 ehdr->e_ident[EI_VERSION] == ELF_TARG_VER) {
231 /* Now check the machine dependant header */
232 if (ehdr->e_machine == ELF_TARG_MACH &&
233 ehdr->e_version == ELF_TARG_VER)
240 __elf_fdnlist(fd, list)
245 Elf_Off symoff = 0, symstroff = 0;
246 Elf_Size symsize = 0, symstrsize = 0;
254 Elf_Shdr *shdr = NULL;
259 /* Make sure obj is OK */
260 if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
261 _read(fd, &ehdr, sizeof(Elf_Ehdr)) != sizeof(Elf_Ehdr) ||
262 !__elf_is_okay__(&ehdr) ||
266 /* calculate section header table size */
267 shdr_size = ehdr.e_shentsize * ehdr.e_shnum;
269 /* Make sure it's not too big to mmap */
270 if (shdr_size > SIZE_T_MAX) {
275 /* mmap section header table */
276 base = mmap(NULL, (size_t)shdr_size, PROT_READ, 0, fd,
277 (off_t)ehdr.e_shoff);
278 if (base == MAP_FAILED)
280 shdr = (Elf_Shdr *)base;
283 * Find the symbol table entry and it's corresponding
284 * string table entry. Version 1.1 of the ABI states
285 * that there is only one symbol table but that this
286 * could change in the future.
288 for (i = 0; i < ehdr.e_shnum; i++) {
289 if (shdr[i].sh_type == SHT_SYMTAB) {
290 symoff = shdr[i].sh_offset;
291 symsize = shdr[i].sh_size;
292 symstroff = shdr[shdr[i].sh_link].sh_offset;
293 symstrsize = shdr[shdr[i].sh_link].sh_size;
298 /* Check for files too large to mmap. */
299 if (symstrsize > SIZE_T_MAX) {
304 * Map string table into our address space. This gives us
305 * an easy way to randomly access all the strings, without
306 * making the memory allocation permanent as with malloc/free
307 * (i.e., munmap will return it to the system).
309 base = mmap(NULL, (size_t)symstrsize, PROT_READ, 0, fd,
311 if (base == MAP_FAILED)
313 strtab = (char *)base;
316 * clean out any left-over information for all valid entries.
317 * Type and value defined to be 0 if not found; historical
318 * versions cleared other and desc as well. Also figure out
319 * the largest string length so don't read any more of the
320 * string table than we have to.
322 * XXX clearing anything other than n_type and n_value violates
323 * the semantics given in the man page.
326 for (p = list; !ISLAST(p); ++p) {
334 /* Don't process any further if object is stripped. */
338 if (lseek(fd, (off_t) symoff, SEEK_SET) == -1) {
343 while (symsize > 0 && nent > 0) {
344 cc = MIN(symsize, sizeof(sbuf));
345 if (_read(fd, sbuf, cc) != cc)
348 for (s = sbuf; cc > 0 && nent > 0; ++s, cc -= sizeof(*s)) {
352 name = strtab + s->st_name;
355 for (p = list; !ISLAST(p); p++) {
356 if ((p->n_un.n_name[0] == '_' &&
357 strcmp(name, p->n_un.n_name+1) == 0)
358 || strcmp(name, p->n_un.n_name) == 0) {
359 elf_sym_to_nlist(p, s, shdr,
370 munmap(strtab, symstrsize);
372 munmap(shdr, shdr_size);
378 * Convert an Elf_Sym into an nlist structure. This fills in only the
379 * n_value and n_type members.
382 elf_sym_to_nlist(nl, s, shdr, shnum)
388 nl->n_value = s->st_value;
390 switch (s->st_shndx) {
396 nl->n_type = ELF_ST_TYPE(s->st_info) == STT_FILE ?
400 if (s->st_shndx >= shnum)
403 Elf_Shdr *sh = shdr + s->st_shndx;
405 nl->n_type = sh->sh_type == SHT_PROGBITS ?
406 (sh->sh_flags & SHF_WRITE ? N_DATA : N_TEXT) :
407 (sh->sh_type == SHT_NOBITS ? N_BSS : N_UNDF);
412 if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
413 ELF_ST_BIND(s->st_info) == STB_WEAK)
416 #endif /* _NLIST_DO_ELF */