2 * Copyright (c) 2000, Boris Popov
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 Boris Popov.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #include <sys/param.h>
36 #include <sys/linker.h>
43 #include <machine/elf.h>
53 struct elf_file *ef_efile;
58 void* ef_fpage; /* First block of the file */
59 int ef_fplen; /* length of first block */
60 Elf_Dyn* ef_dyn; /* Symbol table etc. */
61 Elf_Hashelt ef_nbuckets;
62 Elf_Hashelt ef_nchains;
63 Elf_Hashelt* ef_buckets;
64 Elf_Hashelt* ef_chains;
65 Elf_Hashelt* ef_hashtab;
72 Elf_Phdr * ef_segs[2];
74 Elf_Rel * ef_rel; /* relocation table */
75 int ef_relsz; /* number of entries */
76 Elf_Rela * ef_rela; /* relocation table */
77 int ef_relasz; /* number of entries */
80 static void ef_print_phdr(Elf_Phdr *);
81 static u_long ef_get_offset(elf_file_t, Elf_Off);
82 static int ef_parse_dynamic(elf_file_t);
84 static int ef_get_type(elf_file_t ef);
85 static int ef_close(elf_file_t ef);
86 static int ef_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest);
87 static int ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr);
88 static int ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest);
89 static int ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len,
91 static int ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
93 static int ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
95 static Elf_Addr ef_symaddr(elf_file_t ef, Elf_Size symidx);
96 static int ef_lookup_set(elf_file_t ef, const char *name, long *startp,
97 long *stopp, long *countp);
98 static int ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym);
100 static struct elf_file_ops ef_file_ops = {
108 ef_seg_read_entry_rel,
115 ef_print_phdr(Elf_Phdr *phdr)
118 if ((phdr->p_flags & PF_W) == 0) {
119 printf("text=0x%lx ", (long)phdr->p_filesz);
121 printf("data=0x%lx", (long)phdr->p_filesz);
122 if (phdr->p_filesz < phdr->p_memsz)
123 printf("+0x%lx", (long)(phdr->p_memsz - phdr->p_filesz));
129 ef_get_offset(elf_file_t ef, Elf_Off off)
134 for (i = 0; i < ef->ef_nsegs; i++) {
136 if (off >= ph->p_vaddr && off < ph->p_vaddr + ph->p_memsz) {
137 return ph->p_offset + (off - ph->p_vaddr);
144 ef_get_type(elf_file_t ef)
147 return (ef->ef_type);
151 * next three functions copied from link_elf.c
154 elf_hash(const char *name)
156 const unsigned char *p = (const unsigned char *) name;
162 if ((g = h & 0xf0000000) != 0)
170 ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
172 unsigned long symnum;
177 /* First, search hashed global symbols */
178 hash = elf_hash(name);
179 symnum = ef->ef_buckets[hash % ef->ef_nbuckets];
181 while (symnum != STN_UNDEF) {
182 if (symnum >= ef->ef_nchains) {
183 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
188 symp = ef->ef_symtab + symnum;
189 if (symp->st_name == 0) {
190 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
195 strp = ef->ef_strtab + symp->st_name;
197 if (strcmp(name, strp) == 0) {
198 if (symp->st_shndx != SHN_UNDEF ||
199 (symp->st_value != 0 &&
200 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
207 symnum = ef->ef_chains[symnum];
214 ef_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp,
221 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
222 setsym = malloc(len);
226 /* get address of first entry */
227 snprintf(setsym, len, "%s%s", "__start_set_", name);
228 error = ef_lookup_symbol(ef, setsym, &sym);
231 *startp = sym->st_value;
233 /* get address of last entry */
234 snprintf(setsym, len, "%s%s", "__stop_set_", name);
235 error = ef_lookup_symbol(ef, setsym, &sym);
238 *stopp = sym->st_value;
240 /* and the number of entries */
241 *countp = (*stopp - *startp) / sizeof(void *);
249 ef_symaddr(elf_file_t ef, Elf_Size symidx)
253 if (symidx >= ef->ef_nchains)
255 sym = ef->ef_symtab + symidx;
257 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL &&
258 sym->st_shndx != SHN_UNDEF && sym->st_value != 0)
259 return (sym->st_value);
264 ef_parse_dynamic(elf_file_t ef)
267 Elf_Hashelt hashhdr[2];
268 /* int plttype = DT_REL;*/
277 rel_off = rela_off = 0;
278 rel_sz = rela_sz = 0;
279 rel_entry = rela_entry = 0;
280 for (dp = ef->ef_dyn; dp->d_tag != DT_NULL; dp++) {
283 error = ef_read(ef, ef_get_offset(ef, dp->d_un.d_ptr),
284 sizeof(hashhdr), hashhdr);
286 warnx("can't read hash header (%lx)",
287 ef_get_offset(ef, dp->d_un.d_ptr));
290 ef->ef_nbuckets = hashhdr[0];
291 ef->ef_nchains = hashhdr[1];
292 error = ef_read_entry(ef, -1,
293 (hashhdr[0] + hashhdr[1]) * sizeof(Elf_Hashelt),
294 (void**)&ef->ef_hashtab);
296 warnx("can't read hash table");
299 ef->ef_buckets = ef->ef_hashtab;
300 ef->ef_chains = ef->ef_buckets + ef->ef_nbuckets;
303 ef->ef_stroff = dp->d_un.d_ptr;
306 ef->ef_strsz = dp->d_un.d_val;
309 ef->ef_symoff = dp->d_un.d_ptr;
312 if (dp->d_un.d_val != sizeof(Elf_Sym))
317 warnx("second DT_REL entry ignored");
318 rel_off = dp->d_un.d_ptr;
322 warnx("second DT_RELSZ entry ignored");
323 rel_sz = dp->d_un.d_val;
327 warnx("second DT_RELENT entry ignored");
328 rel_entry = dp->d_un.d_val;
332 warnx("second DT_RELA entry ignored");
333 rela_off = dp->d_un.d_ptr;
337 warnx("second DT_RELASZ entry ignored");
338 rela_sz = dp->d_un.d_val;
342 warnx("second DT_RELAENT entry ignored");
343 rela_entry = dp->d_un.d_val;
347 if (ef->ef_symoff == 0) {
348 warnx("%s: no .dynsym section found\n", ef->ef_name);
351 if (ef->ef_stroff == 0) {
352 warnx("%s: no .dynstr section found\n", ef->ef_name);
355 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_symoff),
356 ef->ef_nchains * sizeof(Elf_Sym),
357 (void**)&ef->ef_symtab) != 0) {
359 warnx("%s: can't load .dynsym section (0x%lx)",
360 ef->ef_name, (long)ef->ef_symoff);
363 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_stroff), ef->ef_strsz,
364 (void**)&ef->ef_strtab) != 0) {
365 warnx("can't load .dynstr section");
369 if (rel_entry == 0) {
370 warnx("%s: no DT_RELENT for DT_REL", ef->ef_name);
373 if (rel_entry != sizeof(Elf_Rel)) {
374 warnx("%s: inconsistent DT_RELENT value",
378 if (rel_sz % rel_entry != 0) {
379 warnx("%s: inconsistent values for DT_RELSZ and "
380 "DT_RELENT", ef->ef_name);
383 if (ef_read_entry(ef, ef_get_offset(ef, rel_off), rel_sz,
384 (void **)&ef->ef_rel) != 0) {
385 warnx("%s: cannot load DT_REL section", ef->ef_name);
388 ef->ef_relsz = rel_sz / rel_entry;
390 warnx("%s: %d REL entries", ef->ef_name,
394 if (rela_entry == 0) {
395 warnx("%s: no DT_RELAENT for DT_RELA", ef->ef_name);
398 if (rela_entry != sizeof(Elf_Rela)) {
399 warnx("%s: inconsistent DT_RELAENT value",
403 if (rela_sz % rela_entry != 0) {
404 warnx("%s: inconsistent values for DT_RELASZ and "
405 "DT_RELAENT", ef->ef_name);
408 if (ef_read_entry(ef, ef_get_offset(ef, rela_off), rela_sz,
409 (void **)&ef->ef_rela) != 0) {
410 warnx("%s: cannot load DT_RELA section", ef->ef_name);
413 ef->ef_relasz = rela_sz / rela_entry;
415 warnx("%s: %d RELA entries", ef->ef_name,
422 ef_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
426 if (offset != (Elf_Off)-1) {
427 if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
431 r = read(ef->ef_fd, dest, len);
432 if (r != -1 && (size_t)r == len)
439 ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
446 error = ef_read(ef, offset, len, *ptr);
453 ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
455 u_long ofs = ef_get_offset(ef, offset);
459 warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
460 ef->ef_name, (long)offset, ofs);
463 return ef_read(ef, ofs, len, dest);
467 ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
469 u_long ofs = ef_get_offset(ef, offset);
476 warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
477 ef->ef_name, (long)offset, ofs);
480 if ((error = ef_read(ef, ofs, len, dest)) != 0)
483 for (r = ef->ef_rel; r < &ef->ef_rel[ef->ef_relsz]; r++) {
484 error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, 0, offset, len,
489 for (a = ef->ef_rela; a < &ef->ef_rela[ef->ef_relasz]; a++) {
490 error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA, 0, offset, len,
499 ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
506 error = ef_seg_read(ef, offset, len, *ptr);
513 ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
520 error = ef_seg_read_rel(ef, offset, len, *ptr);
527 ef_open(const char *filename, struct elf_file *efile, int verbose)
535 Elf_Phdr *phdr, *phdyn, *phphdr, *phlimit;
537 if (filename == NULL)
539 if ((fd = open(filename, O_RDONLY)) == -1)
542 ef = malloc(sizeof(*ef));
549 efile->ef_ops = &ef_file_ops;
551 bzero(ef, sizeof(*ef));
552 ef->ef_verbose = verbose;
554 ef->ef_name = strdup(filename);
555 ef->ef_efile = efile;
556 hdr = (Elf_Ehdr *)&ef->ef_hdr;
558 res = read(fd, hdr, sizeof(*hdr));
560 if (res != sizeof(*hdr))
564 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
565 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
566 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
567 hdr->e_version != EV_CURRENT ||
568 hdr->e_machine != ELF_TARG_MACH ||
569 hdr->e_phentsize != sizeof(Elf_Phdr))
571 phlen = hdr->e_phnum * sizeof(Elf_Phdr);
572 if (ef_read_entry(ef, hdr->e_phoff, phlen,
573 (void**)&ef->ef_ph) != 0)
576 phlimit = phdr + hdr->e_phnum;
580 while (phdr < phlimit) {
583 switch (phdr->p_type) {
586 warnx("%s: too many sections",
590 ef->ef_segs[nsegs++] = phdr;
603 ef->ef_nsegs = nsegs;
605 warnx("file isn't dynamically-linked");
608 if (ef_read_entry(ef, phdyn->p_offset,
609 phdyn->p_filesz, (void**)&ef->ef_dyn) != 0) {
610 printf("ef_read_entry failed\n");
613 error = ef_parse_dynamic(ef);
616 if (hdr->e_type == ET_DYN) {
617 ef->ef_type = EFT_KLD;
618 /* pad = (u_int)dest & PAGE_MASK;
620 dest += PAGE_SIZE - pad;*/
622 } else if (hdr->e_type == ET_EXEC) {
623 /* dest = hdr->e_entry;
626 ef->ef_type = EFT_KERNEL;
637 ef_close(elf_file_t ef)
641 free(ef->ef_fpage);*/
644 ef->ef_efile->ef_ops = NULL;
645 ef->ef_efile->ef_ef = NULL;