2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 2000, Boris Popov
5 * Copyright (c) 1998-2000 Doug Rabson
6 * Copyright (c) 2004 Peter Wemm
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by Boris Popov.
20 * 4. Neither the name of the author nor the names of any co-contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 #include <sys/param.h>
40 #include <sys/linker.h>
47 #include <machine/elf.h>
58 int sec; /* Original section */
78 struct elf_file *ef_efile;
93 Elf_Sym *ddbsymtab; /* The symbol table we are using */
94 long ddbsymcnt; /* Number of symbols */
95 caddr_t ddbstrtab; /* String table */
96 long ddbstrcnt; /* number of bytes in string table */
98 caddr_t shstrtab; /* Section name string table */
99 long shstrcnt; /* number of bytes in string table */
104 static int ef_obj_get_type(elf_file_t ef);
105 static int ef_obj_close(elf_file_t ef);
106 static int ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest);
107 static int ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
109 static int ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len,
111 static int ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len,
113 static int ef_obj_seg_read_string(elf_file_t ef, Elf_Off offset, size_t len,
115 static int ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
117 static int ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
119 static Elf_Addr ef_obj_symaddr(elf_file_t ef, Elf_Size symidx);
120 static int ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp,
121 long *stopp, long *countp);
122 static int ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym);
124 static struct elf_file_ops ef_obj_file_ops = {
131 ef_obj_seg_read_string,
132 ef_obj_seg_read_entry,
133 ef_obj_seg_read_entry_rel,
140 ef_obj_get_type(elf_file_t __unused ef)
147 ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
153 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
154 strp = ef->ddbstrtab + symp->st_name;
155 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
164 ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp,
169 for (i = 0; i < ef->nprogtab; i++) {
170 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
171 strcmp(ef->progtab[i].name + 4, name) == 0) {
172 *startp = (char *)ef->progtab[i].addr - ef->address;
173 *stopp = (char *)ef->progtab[i].addr +
174 ef->progtab[i].size - ef->address;
175 *countp = (*stopp - *startp) / sizeof(void *);
183 ef_obj_symaddr(elf_file_t ef, Elf_Size symidx)
187 if (symidx >= (size_t) ef->ddbsymcnt)
189 sym = ef->ddbsymtab + symidx;
191 if (sym->st_shndx != SHN_UNDEF)
192 return (sym->st_value - (Elf_Addr)ef->address);
197 ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
201 if (offset != (Elf_Off)-1) {
202 if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
206 r = read(ef->ef_fd, dest, len);
207 if (r != -1 && (size_t)r == len)
214 ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr)
221 error = ef_obj_read(ef, offset, len, *ptr);
228 ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
231 if (offset + len > ef->size) {
233 warnx("ef_obj_seg_read(%s): bad offset/len (%lx:%ld)",
234 ef->ef_name, (long)offset, (long)len);
237 bcopy(ef->address + offset, dest, len);
242 ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
247 Elf_Off secbase, dataoff;
250 if (offset + len > ef->size) {
252 warnx("ef_obj_seg_read_rel(%s): bad offset/len (%lx:%ld)",
253 ef->ef_name, (long)offset, (long)len);
256 bcopy(ef->address + offset, dest, len);
258 /* Find out which section contains the data. */
259 memaddr = ef->address + offset;
261 secbase = dataoff = 0;
262 for (i = 0; i < ef->nprogtab; i++) {
263 if (ef->progtab[i].addr == NULL)
265 if (memaddr < (char *)ef->progtab[i].addr || memaddr + len >
266 (char *)ef->progtab[i].addr + ef->progtab[i].size)
268 sec = ef->progtab[i].sec;
269 /* We relocate to address 0. */
270 secbase = (char *)ef->progtab[i].addr - ef->address;
271 dataoff = memaddr - ef->address;
278 /* Now do the relocations. */
279 for (i = 0; i < ef->nrel; i++) {
280 if (ef->reltab[i].sec != sec)
282 for (r = ef->reltab[i].rel;
283 r < &ef->reltab[i].rel[ef->reltab[i].nrel]; r++) {
284 error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, secbase,
290 for (i = 0; i < ef->nrela; i++) {
291 if (ef->relatab[i].sec != sec)
293 for (a = ef->relatab[i].rela;
294 a < &ef->relatab[i].rela[ef->relatab[i].nrela]; a++) {
295 error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA,
296 secbase, dataoff, len, dest);
305 ef_obj_seg_read_string(elf_file_t ef, Elf_Off offset, size_t len, char *dest)
308 if (offset >= ef->size) {
310 warnx("ef_obj_seg_read_string(%s): bad offset (%lx)",
311 ef->ef_name, (long)offset);
315 if (ef->size - offset < len)
316 len = ef->size - offset;
318 if (strnlen(ef->address + offset, len) == len)
321 memcpy(dest, ef->address + offset, len);
326 ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr)
333 error = ef_obj_seg_read(ef, offset, len, *ptr);
340 ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
348 error = ef_obj_seg_read_rel(ef, offset, len, *ptr);
355 ef_obj_open(const char *filename, struct elf_file *efile, int verbose)
363 size_t mapsize, alignmask, max_addralign;
364 int error, fd, pb, ra, res, rl;
365 int i, j, nbytes, nsym, shstrindex, symstrindex, symtabindex;
367 if (filename == NULL)
369 if ((fd = open(filename, O_RDONLY)) == -1)
372 ef = calloc(1, sizeof(*ef));
379 efile->ef_ops = &ef_obj_file_ops;
381 ef->ef_verbose = verbose;
383 ef->ef_name = strdup(filename);
384 ef->ef_efile = efile;
385 hdr = (Elf_Ehdr *)&ef->ef_hdr;
387 res = read(fd, hdr, sizeof(*hdr));
389 if (res != sizeof(*hdr))
393 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
394 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
395 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
396 hdr->e_version != EV_CURRENT || hdr->e_machine != ELF_TARG_MACH ||
397 hdr->e_type != ET_REL)
400 nbytes = hdr->e_shnum * hdr->e_shentsize;
401 if (nbytes == 0 || hdr->e_shoff == 0 ||
402 hdr->e_shentsize != sizeof(Elf_Shdr))
405 if (ef_obj_read_entry(ef, hdr->e_shoff, nbytes, &vtmp) != 0) {
406 printf("ef_read_entry failed\n");
409 ef->e_shdr = shdr = vtmp;
411 /* Scan the section header for information and table sizing. */
415 for (i = 0; i < hdr->e_shnum; i++) {
416 switch (shdr[i].sh_type) {
424 symstrindex = shdr[i].sh_link;
437 if (ef->nprogtab == 0) {
438 warnx("%s: file has no contents", filename);
442 warnx("%s: file has no valid symbol table", filename);
445 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
446 shdr[symstrindex].sh_type != SHT_STRTAB) {
447 warnx("%s: file has invalid symbol strings", filename);
451 /* Allocate space for tracking the load chunks */
452 if (ef->nprogtab != 0)
453 ef->progtab = calloc(ef->nprogtab, sizeof(*ef->progtab));
455 ef->reltab = calloc(ef->nrel, sizeof(*ef->reltab));
457 ef->relatab = calloc(ef->nrela, sizeof(*ef->relatab));
458 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
459 (ef->nrel != 0 && ef->reltab == NULL) ||
460 (ef->nrela != 0 && ef->relatab == NULL)) {
461 printf("malloc failed\n");
466 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
467 if (ef_obj_read_entry(ef, shdr[symtabindex].sh_offset,
468 shdr[symtabindex].sh_size, (void**)&ef->ddbsymtab) != 0) {
469 printf("ef_read_entry failed\n");
473 ef->ddbstrcnt = shdr[symstrindex].sh_size;
474 if (ef_obj_read_entry(ef, shdr[symstrindex].sh_offset,
475 shdr[symstrindex].sh_size, (void**)&ef->ddbstrtab) != 0) {
476 printf("ef_read_entry failed\n");
480 /* Do we have a string table for the section names? */
482 if (hdr->e_shstrndx != 0 &&
483 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
484 shstrindex = hdr->e_shstrndx;
485 ef->shstrcnt = shdr[shstrindex].sh_size;
486 if (ef_obj_read_entry(ef, shdr[shstrindex].sh_offset,
487 shdr[shstrindex].sh_size, (void**)&ef->shstrtab) != 0) {
488 printf("ef_read_entry failed\n");
493 /* Size up code/data(progbits) and bss(nobits). */
497 for (i = 0; i < hdr->e_shnum; i++) {
498 switch (shdr[i].sh_type) {
501 alignmask = shdr[i].sh_addralign - 1;
502 if (shdr[i].sh_addralign > max_addralign)
503 max_addralign = shdr[i].sh_addralign;
504 mapsize += alignmask;
505 mapsize &= ~alignmask;
506 mapsize += shdr[i].sh_size;
511 /* We know how much space we need for the text/data/bss/etc. */
513 if (posix_memalign((void **)&ef->address, max_addralign, mapsize)) {
514 printf("posix_memalign failed\n");
517 mapbase = ef->address;
520 * Now load code/data(progbits), zero bss(nobits), allocate
521 * space for and load relocs
527 for (i = 0; i < hdr->e_shnum; i++) {
528 switch (shdr[i].sh_type) {
531 alignmask = shdr[i].sh_addralign - 1;
532 mapbase += alignmask;
533 mapbase = (char *)((uintptr_t)mapbase & ~alignmask);
534 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
535 if (shdr[i].sh_type == SHT_PROGBITS) {
536 ef->progtab[pb].name = "<<PROGBITS>>";
537 if (ef_obj_read(ef, shdr[i].sh_offset,
539 ef->progtab[pb].addr) != 0) {
540 printf("failed to read progbits\n");
544 ef->progtab[pb].name = "<<NOBITS>>";
545 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
547 ef->progtab[pb].size = shdr[i].sh_size;
548 ef->progtab[pb].sec = i;
549 if (ef->shstrtab && shdr[i].sh_name != 0)
550 ef->progtab[pb].name =
551 ef->shstrtab + shdr[i].sh_name;
553 /* Update all symbol values with the offset. */
554 for (j = 0; j < ef->ddbsymcnt; j++) {
555 es = &ef->ddbsymtab[j];
556 if (es->st_shndx != i)
558 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
560 mapbase += shdr[i].sh_size;
564 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
565 ef->reltab[rl].sec = shdr[i].sh_info;
566 if (ef_obj_read_entry(ef, shdr[i].sh_offset,
567 shdr[i].sh_size, (void**)&ef->reltab[rl].rel) !=
569 printf("ef_read_entry failed\n");
575 ef->relatab[ra].nrela =
576 shdr[i].sh_size / sizeof(Elf_Rela);
577 ef->relatab[ra].sec = shdr[i].sh_info;
578 if (ef_obj_read_entry(ef, shdr[i].sh_offset,
579 shdr[i].sh_size, (void**)&ef->relatab[ra].rela) !=
581 printf("ef_read_entry failed\n");
596 ef_obj_close(elf_file_t ef)
603 if (ef->e_shdr != NULL)
607 if (ef->nprogtab != 0)
610 for (i = 0; i < ef->nrel; i++)
611 if (ef->reltab[i].rel != NULL)
612 free(ef->reltab[i].rel);
615 if (ef->nrela != 0) {
616 for (i = 0; i < ef->nrela; i++)
617 if (ef->relatab[i].rela != NULL)
618 free(ef->relatab[i].rela);
621 if (ef->ddbsymtab != NULL)
623 if (ef->ddbstrtab != NULL)
625 if (ef->shstrtab != NULL)
627 ef->ef_efile->ef_ops = NULL;
628 ef->ef_efile->ef_ef = NULL;