2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 2000, Boris Popov
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Boris Popov.
18 * 4. Neither the name of the author nor the names of any co-contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #include <sys/param.h>
38 #include <sys/linker.h>
45 #include <machine/elf.h>
55 struct elf_file *ef_efile;
60 void* ef_fpage; /* First block of the file */
61 int ef_fplen; /* length of first block */
62 Elf_Dyn* ef_dyn; /* Symbol table etc. */
63 Elf_Hashelt ef_nbuckets;
64 Elf_Hashelt ef_nchains;
65 Elf_Hashelt* ef_buckets;
66 Elf_Hashelt* ef_chains;
67 Elf_Hashelt* ef_hashtab;
74 Elf_Phdr * ef_segs[MAXSEGS];
76 Elf_Rel * ef_rel; /* relocation table */
77 int ef_relsz; /* number of entries */
78 Elf_Rela * ef_rela; /* relocation table */
79 int ef_relasz; /* number of entries */
82 static void ef_print_phdr(Elf_Phdr *);
83 static u_long ef_get_offset(elf_file_t, Elf_Off);
84 static int ef_parse_dynamic(elf_file_t);
86 static int ef_get_type(elf_file_t ef);
87 static int ef_close(elf_file_t ef);
88 static int ef_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest);
89 static int ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr);
90 static int ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest);
91 static int ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len,
93 static int ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
95 static int ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
97 static Elf_Addr ef_symaddr(elf_file_t ef, Elf_Size symidx);
98 static int ef_lookup_set(elf_file_t ef, const char *name, long *startp,
99 long *stopp, long *countp);
100 static int ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym);
102 static struct elf_file_ops ef_file_ops = {
110 ef_seg_read_entry_rel,
117 ef_print_phdr(Elf_Phdr *phdr)
120 if ((phdr->p_flags & PF_W) == 0) {
121 printf("text=0x%lx ", (long)phdr->p_filesz);
123 printf("data=0x%lx", (long)phdr->p_filesz);
124 if (phdr->p_filesz < phdr->p_memsz)
125 printf("+0x%lx", (long)(phdr->p_memsz - phdr->p_filesz));
131 ef_get_offset(elf_file_t ef, Elf_Off off)
136 for (i = 0; i < ef->ef_nsegs; i++) {
138 if (off >= ph->p_vaddr && off < ph->p_vaddr + ph->p_memsz) {
139 return ph->p_offset + (off - ph->p_vaddr);
146 ef_get_type(elf_file_t ef)
149 return (ef->ef_type);
153 * next three functions copied from link_elf.c
156 elf_hash(const char *name)
158 const unsigned char *p = (const unsigned char *) name;
164 if ((g = h & 0xf0000000) != 0)
172 ef_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
174 unsigned long symnum;
179 /* First, search hashed global symbols */
180 hash = elf_hash(name);
181 symnum = ef->ef_buckets[hash % ef->ef_nbuckets];
183 while (symnum != STN_UNDEF) {
184 if (symnum >= ef->ef_nchains) {
185 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
190 symp = ef->ef_symtab + symnum;
191 if (symp->st_name == 0) {
192 warnx("ef_lookup_symbol: file %s have corrupted symbol table\n",
197 strp = ef->ef_strtab + symp->st_name;
199 if (strcmp(name, strp) == 0) {
200 if (symp->st_shndx != SHN_UNDEF ||
201 (symp->st_value != 0 &&
202 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
209 symnum = ef->ef_chains[symnum];
216 ef_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp,
223 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
224 setsym = malloc(len);
228 /* get address of first entry */
229 snprintf(setsym, len, "%s%s", "__start_set_", name);
230 error = ef_lookup_symbol(ef, setsym, &sym);
233 *startp = sym->st_value;
235 /* get address of last entry */
236 snprintf(setsym, len, "%s%s", "__stop_set_", name);
237 error = ef_lookup_symbol(ef, setsym, &sym);
240 *stopp = sym->st_value;
242 /* and the number of entries */
243 *countp = (*stopp - *startp) / sizeof(void *);
251 ef_symaddr(elf_file_t ef, Elf_Size symidx)
255 if (symidx >= ef->ef_nchains)
257 sym = ef->ef_symtab + symidx;
259 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL &&
260 sym->st_shndx != SHN_UNDEF && sym->st_value != 0)
261 return (sym->st_value);
266 ef_parse_dynamic(elf_file_t ef)
269 Elf_Hashelt hashhdr[2];
270 /* int plttype = DT_REL;*/
279 rel_off = rela_off = 0;
280 rel_sz = rela_sz = 0;
281 rel_entry = rela_entry = 0;
282 for (dp = ef->ef_dyn; dp->d_tag != DT_NULL; dp++) {
285 error = ef_read(ef, ef_get_offset(ef, dp->d_un.d_ptr),
286 sizeof(hashhdr), hashhdr);
288 warnx("can't read hash header (%lx)",
289 ef_get_offset(ef, dp->d_un.d_ptr));
292 ef->ef_nbuckets = hashhdr[0];
293 ef->ef_nchains = hashhdr[1];
294 error = ef_read_entry(ef, -1,
295 (hashhdr[0] + hashhdr[1]) * sizeof(Elf_Hashelt),
296 (void**)&ef->ef_hashtab);
298 warnx("can't read hash table");
301 ef->ef_buckets = ef->ef_hashtab;
302 ef->ef_chains = ef->ef_buckets + ef->ef_nbuckets;
305 ef->ef_stroff = dp->d_un.d_ptr;
308 ef->ef_strsz = dp->d_un.d_val;
311 ef->ef_symoff = dp->d_un.d_ptr;
314 if (dp->d_un.d_val != sizeof(Elf_Sym))
319 warnx("second DT_REL entry ignored");
320 rel_off = dp->d_un.d_ptr;
324 warnx("second DT_RELSZ entry ignored");
325 rel_sz = dp->d_un.d_val;
329 warnx("second DT_RELENT entry ignored");
330 rel_entry = dp->d_un.d_val;
334 warnx("second DT_RELA entry ignored");
335 rela_off = dp->d_un.d_ptr;
339 warnx("second DT_RELASZ entry ignored");
340 rela_sz = dp->d_un.d_val;
344 warnx("second DT_RELAENT entry ignored");
345 rela_entry = dp->d_un.d_val;
349 if (ef->ef_symoff == 0) {
350 warnx("%s: no .dynsym section found\n", ef->ef_name);
353 if (ef->ef_stroff == 0) {
354 warnx("%s: no .dynstr section found\n", ef->ef_name);
357 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_symoff),
358 ef->ef_nchains * sizeof(Elf_Sym),
359 (void**)&ef->ef_symtab) != 0) {
361 warnx("%s: can't load .dynsym section (0x%lx)",
362 ef->ef_name, (long)ef->ef_symoff);
365 if (ef_read_entry(ef, ef_get_offset(ef, ef->ef_stroff), ef->ef_strsz,
366 (void**)&ef->ef_strtab) != 0) {
367 warnx("can't load .dynstr section");
371 if (rel_entry == 0) {
372 warnx("%s: no DT_RELENT for DT_REL", ef->ef_name);
375 if (rel_entry != sizeof(Elf_Rel)) {
376 warnx("%s: inconsistent DT_RELENT value",
380 if (rel_sz % rel_entry != 0) {
381 warnx("%s: inconsistent values for DT_RELSZ and "
382 "DT_RELENT", ef->ef_name);
385 if (ef_read_entry(ef, ef_get_offset(ef, rel_off), rel_sz,
386 (void **)&ef->ef_rel) != 0) {
387 warnx("%s: cannot load DT_REL section", ef->ef_name);
390 ef->ef_relsz = rel_sz / rel_entry;
392 warnx("%s: %d REL entries", ef->ef_name,
396 if (rela_entry == 0) {
397 warnx("%s: no DT_RELAENT for DT_RELA", ef->ef_name);
400 if (rela_entry != sizeof(Elf_Rela)) {
401 warnx("%s: inconsistent DT_RELAENT value",
405 if (rela_sz % rela_entry != 0) {
406 warnx("%s: inconsistent values for DT_RELASZ and "
407 "DT_RELAENT", ef->ef_name);
410 if (ef_read_entry(ef, ef_get_offset(ef, rela_off), rela_sz,
411 (void **)&ef->ef_rela) != 0) {
412 warnx("%s: cannot load DT_RELA section", ef->ef_name);
415 ef->ef_relasz = rela_sz / rela_entry;
417 warnx("%s: %d RELA entries", ef->ef_name,
424 ef_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
428 if (offset != (Elf_Off)-1) {
429 if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
433 r = read(ef->ef_fd, dest, len);
434 if (r != -1 && (size_t)r == len)
441 ef_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
448 error = ef_read(ef, offset, len, *ptr);
455 ef_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
457 u_long ofs = ef_get_offset(ef, offset);
461 warnx("ef_seg_read(%s): zero offset (%lx:%ld)",
462 ef->ef_name, (long)offset, ofs);
465 return ef_read(ef, ofs, len, dest);
469 ef_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void*dest)
471 u_long ofs = ef_get_offset(ef, offset);
478 warnx("ef_seg_read_rel(%s): zero offset (%lx:%ld)",
479 ef->ef_name, (long)offset, ofs);
482 if ((error = ef_read(ef, ofs, len, dest)) != 0)
485 for (r = ef->ef_rel; r < &ef->ef_rel[ef->ef_relsz]; r++) {
486 error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, 0, offset, len,
491 for (a = ef->ef_rela; a < &ef->ef_rela[ef->ef_relasz]; a++) {
492 error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA, 0, offset, len,
501 ef_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
508 error = ef_seg_read(ef, offset, len, *ptr);
515 ef_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len, void**ptr)
522 error = ef_seg_read_rel(ef, offset, len, *ptr);
529 ef_open(const char *filename, struct elf_file *efile, int verbose)
537 Elf_Phdr *phdr, *phdyn, *phlimit;
539 if (filename == NULL)
541 if ((fd = open(filename, O_RDONLY)) == -1)
544 ef = malloc(sizeof(*ef));
551 efile->ef_ops = &ef_file_ops;
553 bzero(ef, sizeof(*ef));
554 ef->ef_verbose = verbose;
556 ef->ef_name = strdup(filename);
557 ef->ef_efile = efile;
558 hdr = (Elf_Ehdr *)&ef->ef_hdr;
560 res = read(fd, hdr, sizeof(*hdr));
562 if (res != sizeof(*hdr))
566 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
567 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
568 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
569 hdr->e_version != EV_CURRENT ||
570 hdr->e_machine != ELF_TARG_MACH ||
571 hdr->e_phentsize != sizeof(Elf_Phdr))
573 phlen = hdr->e_phnum * sizeof(Elf_Phdr);
574 if (ef_read_entry(ef, hdr->e_phoff, phlen,
575 (void**)&ef->ef_ph) != 0)
578 phlimit = phdr + hdr->e_phnum;
581 while (phdr < phlimit) {
584 switch (phdr->p_type) {
587 ef->ef_segs[nsegs] = phdr;
601 warnx("Skipping %s: not dynamically-linked",
604 } else if (nsegs > MAXSEGS) {
605 warnx("%s: too many segments", filename);
608 ef->ef_nsegs = nsegs;
609 if (ef_read_entry(ef, phdyn->p_offset,
610 phdyn->p_filesz, (void**)&ef->ef_dyn) != 0) {
611 printf("ef_read_entry failed\n");
614 error = ef_parse_dynamic(ef);
617 if (hdr->e_type == ET_DYN) {
618 ef->ef_type = EFT_KLD;
619 /* pad = (u_int)dest & PAGE_MASK;
621 dest += PAGE_SIZE - pad;*/
623 } else if (hdr->e_type == ET_EXEC) {
624 /* dest = hdr->e_entry;
627 ef->ef_type = EFT_KERNEL;
638 ef_close(elf_file_t ef)
642 free(ef->ef_fpage);*/
645 ef->ef_efile->ef_ops = NULL;
646 ef->ef_efile->ef_ef = NULL;