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>
52 struct elf_file *ef_efile;
57 void* ef_fpage; /* First block of the file */
58 int ef_fplen; /* length of first block */
59 Elf_Dyn* ef_dyn; /* Symbol table etc. */
60 Elf_Hashelt ef_nbuckets;
61 Elf_Hashelt ef_nchains;
62 Elf_Hashelt* ef_buckets;
63 Elf_Hashelt* ef_chains;
64 Elf_Hashelt* ef_hashtab;
71 Elf_Phdr * ef_segs[2];
73 Elf_Rel * ef_rel; /* relocation table */
74 int ef_relsz; /* number of entries */
75 Elf_Rela * ef_rela; /* relocation table */
76 int ef_relasz; /* number of entries */
79 static void ef_print_phdr(Elf_Phdr *);
80 static u_long ef_get_offset(elf_file_t, Elf_Off);
81 static int ef_parse_dynamic(elf_file_t);
83 static int ef_get_type(elf_file_t ef);
84 static int ef_close(elf_file_t ef);
85 static int ef_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest);
86 static int ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr);
87 static int ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest);
88 static int ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len,
90 static int ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
92 static int ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
94 static Elf_Addr ef_symaddr(elf_file_t ef, Elf_Size symidx);
95 static int ef_lookup_set(elf_file_t ef, const char *name, long *startp,
96 long *stopp, long *countp);
97 static int ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym);
99 static struct elf_file_ops ef_file_ops = {
107 ef_seg_read_entry_rel,
114 ef_print_phdr(Elf_Phdr *phdr)
117 if ((phdr->p_flags & PF_W) == 0) {
118 printf("text=0x%lx ", (long)phdr->p_filesz);
120 printf("data=0x%lx", (long)phdr->p_filesz);
121 if (phdr->p_filesz < phdr->p_memsz)
122 printf("+0x%lx", (long)(phdr->p_memsz - phdr->p_filesz));
128 ef_get_offset(elf_file_t ef, Elf_Off off)
133 for (i = 0; i < ef->ef_nsegs; i++) {
135 if (off >= ph->p_vaddr && off < ph->p_vaddr + ph->p_memsz) {
136 return ph->p_offset + (off - ph->p_vaddr);
143 ef_get_type(elf_file_t ef)
146 return (ef->ef_type);
150 * next three functions copied from link_elf.c
153 elf_hash(const char *name)
155 const unsigned char *p = (const unsigned char *) name;
161 if ((g = h & 0xf0000000) != 0)
169 ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
171 unsigned long symnum;
176 /* First, search hashed global symbols */
177 hash = elf_hash(name);
178 symnum = ef->ef_buckets[hash % ef->ef_nbuckets];
180 while (symnum != STN_UNDEF) {
181 if (symnum >= ef->ef_nchains) {
182 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
187 symp = ef->ef_symtab + symnum;
188 if (symp->st_name == 0) {
189 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
194 strp = ef->ef_strtab + symp->st_name;
196 if (strcmp(name, strp) == 0) {
197 if (symp->st_shndx != SHN_UNDEF ||
198 (symp->st_value != 0 &&
199 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
206 symnum = ef->ef_chains[symnum];
213 ef_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp,
220 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
221 setsym = malloc(len);
225 /* get address of first entry */
226 snprintf(setsym, len, "%s%s", "__start_set_", name);
227 error = ef_lookup_symbol(ef, setsym, &sym);
230 *startp = sym->st_value;
232 /* get address of last entry */
233 snprintf(setsym, len, "%s%s", "__stop_set_", name);
234 error = ef_lookup_symbol(ef, setsym, &sym);
237 *stopp = sym->st_value;
239 /* and the number of entries */
240 *countp = (*stopp - *startp) / sizeof(void *);
248 ef_symaddr(elf_file_t ef, Elf_Size symidx)
252 if (symidx >= ef->ef_nchains)
254 sym = ef->ef_symtab + symidx;
256 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL &&
257 sym->st_shndx != SHN_UNDEF && sym->st_value != 0)
258 return (sym->st_value);
263 ef_parse_dynamic(elf_file_t ef)
266 Elf_Hashelt hashhdr[2];
267 /* int plttype = DT_REL;*/
276 rel_off = rela_off = 0;
277 rel_sz = rela_sz = 0;
278 rel_entry = rela_entry = 0;
279 for (dp = ef->ef_dyn; dp->d_tag != DT_NULL; dp++) {
282 error = ef_read(ef, ef_get_offset(ef, dp->d_un.d_ptr),
283 sizeof(hashhdr), hashhdr);
285 warnx("can't read hash header (%lx)",
286 ef_get_offset(ef, dp->d_un.d_ptr));
289 ef->ef_nbuckets = hashhdr[0];
290 ef->ef_nchains = hashhdr[1];
291 error = ef_read_entry(ef, -1,
292 (hashhdr[0] + hashhdr[1]) * sizeof(Elf_Hashelt),
293 (void**)&ef->ef_hashtab);
295 warnx("can't read hash table");
298 ef->ef_buckets = ef->ef_hashtab;
299 ef->ef_chains = ef->ef_buckets + ef->ef_nbuckets;
302 ef->ef_stroff = dp->d_un.d_ptr;
305 ef->ef_strsz = dp->d_un.d_val;
308 ef->ef_symoff = dp->d_un.d_ptr;
311 if (dp->d_un.d_val != sizeof(Elf_Sym))
316 warnx("second DT_REL entry ignored");
317 rel_off = dp->d_un.d_ptr;
321 warnx("second DT_RELSZ entry ignored");
322 rel_sz = dp->d_un.d_val;
326 warnx("second DT_RELENT entry ignored");
327 rel_entry = dp->d_un.d_val;
331 warnx("second DT_RELA entry ignored");
332 rela_off = dp->d_un.d_ptr;
336 warnx("second DT_RELASZ entry ignored");
337 rela_sz = dp->d_un.d_val;
341 warnx("second DT_RELAENT entry ignored");
342 rela_entry = dp->d_un.d_val;
346 if (ef->ef_symoff == 0) {
347 warnx("%s: no .dynsym section found\n", ef->ef_name);
350 if (ef->ef_stroff == 0) {
351 warnx("%s: no .dynstr section found\n", ef->ef_name);
354 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_symoff),
355 ef->ef_nchains * sizeof(Elf_Sym),
356 (void**)&ef->ef_symtab) != 0) {
358 warnx("%s: can't load .dynsym section (0x%lx)",
359 ef->ef_name, (long)ef->ef_symoff);
362 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_stroff), ef->ef_strsz,
363 (void**)&ef->ef_strtab) != 0) {
364 warnx("can't load .dynstr section");
368 if (rel_entry == 0) {
369 warnx("%s: no DT_RELENT for DT_REL", ef->ef_name);
372 if (rel_entry != sizeof(Elf_Rel)) {
373 warnx("%s: inconsistent DT_RELENT value",
377 if (rel_sz % rel_entry != 0) {
378 warnx("%s: inconsistent values for DT_RELSZ and "
379 "DT_RELENT", ef->ef_name);
382 if (ef_read_entry(ef, ef_get_offset(ef, rel_off), rel_sz,
383 (void **)&ef->ef_rel) != 0) {
384 warnx("%s: cannot load DT_REL section", ef->ef_name);
387 ef->ef_relsz = rel_sz / rel_entry;
389 warnx("%s: %d REL entries", ef->ef_name,
393 if (rela_entry == 0) {
394 warnx("%s: no DT_RELAENT for DT_RELA", ef->ef_name);
397 if (rela_entry != sizeof(Elf_Rela)) {
398 warnx("%s: inconsistent DT_RELAENT value",
402 if (rela_sz % rela_entry != 0) {
403 warnx("%s: inconsistent values for DT_RELASZ and "
404 "DT_RELAENT", ef->ef_name);
407 if (ef_read_entry(ef, ef_get_offset(ef, rela_off), rela_sz,
408 (void **)&ef->ef_rela) != 0) {
409 warnx("%s: cannot load DT_RELA section", ef->ef_name);
412 ef->ef_relasz = rela_sz / rela_entry;
414 warnx("%s: %d RELA entries", ef->ef_name,
421 ef_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
425 if (offset != (Elf_Off)-1) {
426 if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
430 r = read(ef->ef_fd, dest, len);
431 if (r != -1 && (size_t)r == len)
438 ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
445 error = ef_read(ef, offset, len, *ptr);
452 ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
454 u_long ofs = ef_get_offset(ef, offset);
458 warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
459 ef->ef_name, (long)offset, ofs);
462 return ef_read(ef, ofs, len, dest);
466 ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
468 u_long ofs = ef_get_offset(ef, offset);
475 warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
476 ef->ef_name, (long)offset, ofs);
479 if ((error = ef_read(ef, ofs, len, dest)) != 0)
482 for (r = ef->ef_rel; r < &ef->ef_rel[ef->ef_relsz]; r++) {
483 error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, 0, offset, len,
488 for (a = ef->ef_rela; a < &ef->ef_rela[ef->ef_relasz]; a++) {
489 error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA, 0, offset, len,
498 ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
505 error = ef_seg_read(ef, offset, len, *ptr);
512 ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
519 error = ef_seg_read_rel(ef, offset, len, *ptr);
526 ef_open(const char *filename, struct elf_file *efile, int verbose)
534 Elf_Phdr *phdr, *phdyn, *phlimit;
536 if (filename == NULL)
538 if ((fd = open(filename, O_RDONLY)) == -1)
541 ef = malloc(sizeof(*ef));
548 efile->ef_ops = &ef_file_ops;
550 bzero(ef, sizeof(*ef));
551 ef->ef_verbose = verbose;
553 ef->ef_name = strdup(filename);
554 ef->ef_efile = efile;
555 hdr = (Elf_Ehdr *)&ef->ef_hdr;
557 res = read(fd, hdr, sizeof(*hdr));
559 if (res != sizeof(*hdr))
563 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
564 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
565 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
566 hdr->e_version != EV_CURRENT ||
567 hdr->e_machine != ELF_TARG_MACH ||
568 hdr->e_phentsize != sizeof(Elf_Phdr))
570 phlen = hdr->e_phnum * sizeof(Elf_Phdr);
571 if (ef_read_entry(ef, hdr->e_phoff, phlen,
572 (void**)&ef->ef_ph) != 0)
575 phlimit = phdr + hdr->e_phnum;
578 while (phdr < phlimit) {
581 switch (phdr->p_type) {
584 warnx("%s: too many sections",
588 ef->ef_segs[nsegs++] = phdr;
600 ef->ef_nsegs = nsegs;
602 warnx("file isn't dynamically-linked");
605 if (ef_read_entry(ef, phdyn->p_offset,
606 phdyn->p_filesz, (void**)&ef->ef_dyn) != 0) {
607 printf("ef_read_entry failed\n");
610 error = ef_parse_dynamic(ef);
613 if (hdr->e_type == ET_DYN) {
614 ef->ef_type = EFT_KLD;
615 /* pad = (u_int)dest & PAGE_MASK;
617 dest += PAGE_SIZE - pad;*/
619 } else if (hdr->e_type == ET_EXEC) {
620 /* dest = hdr->e_entry;
623 ef->ef_type = EFT_KERNEL;
634 ef_close(elf_file_t ef)
638 free(ef->ef_fpage);*/
641 ef->ef_efile->ef_ops = NULL;
642 ef->ef_efile->ef_ef = NULL;