2 * Copyright (c) 2000, Boris Popov
3 * Copyright (c) 1998-2000 Doug Rabson
4 * Copyright (c) 2004 Peter Wemm
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>
56 int sec; /* Original section */
76 struct elf_file *ef_efile;
91 Elf_Sym *ddbsymtab; /* The symbol table we are using */
92 long ddbsymcnt; /* Number of symbols */
93 caddr_t ddbstrtab; /* String table */
94 long ddbstrcnt; /* number of bytes in string table */
96 caddr_t shstrtab; /* Section name string table */
97 long shstrcnt; /* number of bytes in string table */
102 static int ef_obj_get_type(elf_file_t ef);
103 static int ef_obj_close(elf_file_t ef);
104 static int ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void* dest);
105 static int ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
107 static int ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len,
109 static int ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len,
111 static int ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len,
113 static int ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
115 static Elf_Addr ef_obj_symaddr(elf_file_t ef, Elf_Size symidx);
116 static int ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp,
117 long *stopp, long *countp);
118 static int ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym);
120 static struct elf_file_ops ef_obj_file_ops = {
127 ef_obj_seg_read_entry,
128 ef_obj_seg_read_entry_rel,
135 ef_obj_get_type(elf_file_t __unused ef)
142 ef_obj_lookup_symbol(elf_file_t ef, const char* name, Elf_Sym** sym)
148 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
149 strp = ef->ddbstrtab + symp->st_name;
150 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
159 ef_obj_lookup_set(elf_file_t ef, const char *name, long *startp, long *stopp,
164 for (i = 0; i < ef->nprogtab; i++) {
165 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
166 strcmp(ef->progtab[i].name + 4, name) == 0) {
167 *startp = (char *)ef->progtab[i].addr - ef->address;
168 *stopp = (char *)ef->progtab[i].addr +
169 ef->progtab[i].size - ef->address;
170 *countp = (*stopp - *startp) / sizeof(void *);
178 ef_obj_symaddr(elf_file_t ef, Elf_Size symidx)
182 if (symidx >= (size_t) ef->ddbsymcnt)
184 sym = ef->ddbsymtab + symidx;
186 if (sym->st_shndx != SHN_UNDEF)
187 return (sym->st_value - (Elf_Addr)ef->address);
192 ef_obj_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
196 if (offset != (Elf_Off)-1) {
197 if (lseek(ef->ef_fd, offset, SEEK_SET) == -1)
201 r = read(ef->ef_fd, dest, len);
202 if (r != -1 && (size_t)r == len)
209 ef_obj_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr)
216 error = ef_obj_read(ef, offset, len, *ptr);
223 ef_obj_seg_read(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
226 if (offset + len > ef->size) {
228 warnx("ef_seg_read_rel(%s): bad offset/len (%lx:%ld)",
229 ef->ef_name, (long)offset, (long)len);
232 bcopy(ef->address + offset, dest, len);
237 ef_obj_seg_read_rel(elf_file_t ef, Elf_Off offset, size_t len, void *dest)
242 Elf_Off secbase, dataoff;
245 if (offset + len > ef->size) {
247 warnx("ef_seg_read_rel(%s): bad offset/len (%lx:%ld)",
248 ef->ef_name, (long)offset, (long)len);
251 bcopy(ef->address + offset, dest, len);
253 /* Find out which section contains the data. */
254 memaddr = ef->address + offset;
256 secbase = dataoff = 0;
257 for (i = 0; i < ef->nprogtab; i++) {
258 if (ef->progtab[i].addr == NULL)
260 if (memaddr < (char *)ef->progtab[i].addr || memaddr + len >
261 (char *)ef->progtab[i].addr + ef->progtab[i].size)
263 sec = ef->progtab[i].sec;
264 /* We relocate to address 0. */
265 secbase = (char *)ef->progtab[i].addr - ef->address;
266 dataoff = memaddr - ef->address;
273 /* Now do the relocations. */
274 for (i = 0; i < ef->nrel; i++) {
275 if (ef->reltab[i].sec != sec)
277 for (r = ef->reltab[i].rel;
278 r < &ef->reltab[i].rel[ef->reltab[i].nrel]; r++) {
279 error = ef_reloc(ef->ef_efile, r, EF_RELOC_REL, secbase,
285 for (i = 0; i < ef->nrela; i++) {
286 if (ef->relatab[i].sec != sec)
288 for (a = ef->relatab[i].rela;
289 a < &ef->relatab[i].rela[ef->relatab[i].nrela]; a++) {
290 error = ef_reloc(ef->ef_efile, a, EF_RELOC_RELA,
291 secbase, dataoff, len, dest);
300 ef_obj_seg_read_entry(elf_file_t ef, Elf_Off offset, size_t len, void **ptr)
307 error = ef_obj_seg_read(ef, offset, len, *ptr);
314 ef_obj_seg_read_entry_rel(elf_file_t ef, Elf_Off offset, size_t len,
322 error = ef_obj_seg_read_rel(ef, offset, len, *ptr);
329 ef_obj_open(const char *filename, struct elf_file *efile, int verbose)
337 size_t mapsize, alignmask, max_addralign;
338 int error, fd, pb, ra, res, rl;
339 int i, j, nbytes, nsym, shstrindex, symstrindex, symtabindex;
341 if (filename == NULL)
343 if ((fd = open(filename, O_RDONLY)) == -1)
346 ef = calloc(1, sizeof(*ef));
353 efile->ef_ops = &ef_obj_file_ops;
355 ef->ef_verbose = verbose;
357 ef->ef_name = strdup(filename);
358 ef->ef_efile = efile;
359 hdr = (Elf_Ehdr *)&ef->ef_hdr;
361 res = read(fd, hdr, sizeof(*hdr));
363 if (res != sizeof(*hdr))
367 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
368 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
369 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
370 hdr->e_version != EV_CURRENT || hdr->e_machine != ELF_TARG_MACH ||
371 hdr->e_type != ET_REL)
374 nbytes = hdr->e_shnum * hdr->e_shentsize;
375 if (nbytes == 0 || hdr->e_shoff == 0 ||
376 hdr->e_shentsize != sizeof(Elf_Shdr))
379 if (ef_obj_read_entry(ef, hdr->e_shoff, nbytes, &vtmp) != 0) {
380 printf("ef_read_entry failed\n");
383 ef->e_shdr = shdr = vtmp;
385 /* Scan the section header for information and table sizing. */
389 for (i = 0; i < hdr->e_shnum; i++) {
390 switch (shdr[i].sh_type) {
398 symstrindex = shdr[i].sh_link;
411 if (ef->nprogtab == 0) {
412 warnx("%s: file has no contents", filename);
416 warnx("%s: file has no valid symbol table", filename);
419 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
420 shdr[symstrindex].sh_type != SHT_STRTAB) {
421 warnx("%s: file has invalid symbol strings", filename);
425 /* Allocate space for tracking the load chunks */
426 if (ef->nprogtab != 0)
427 ef->progtab = calloc(ef->nprogtab, sizeof(*ef->progtab));
429 ef->reltab = calloc(ef->nrel, sizeof(*ef->reltab));
431 ef->relatab = calloc(ef->nrela, sizeof(*ef->relatab));
432 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
433 (ef->nrel != 0 && ef->reltab == NULL) ||
434 (ef->nrela != 0 && ef->relatab == NULL)) {
435 printf("malloc failed\n");
440 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
441 if (ef_obj_read_entry(ef, shdr[symtabindex].sh_offset,
442 shdr[symtabindex].sh_size, (void**)&ef->ddbsymtab) != 0) {
443 printf("ef_read_entry failed\n");
447 ef->ddbstrcnt = shdr[symstrindex].sh_size;
448 if (ef_obj_read_entry(ef, shdr[symstrindex].sh_offset,
449 shdr[symstrindex].sh_size, (void**)&ef->ddbstrtab) != 0) {
450 printf("ef_read_entry failed\n");
454 /* Do we have a string table for the section names? */
456 if (hdr->e_shstrndx != 0 &&
457 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
458 shstrindex = hdr->e_shstrndx;
459 ef->shstrcnt = shdr[shstrindex].sh_size;
460 if (ef_obj_read_entry(ef, shdr[shstrindex].sh_offset,
461 shdr[shstrindex].sh_size, (void**)&ef->shstrtab) != 0) {
462 printf("ef_read_entry failed\n");
467 /* Size up code/data(progbits) and bss(nobits). */
471 for (i = 0; i < hdr->e_shnum; i++) {
472 switch (shdr[i].sh_type) {
475 alignmask = shdr[i].sh_addralign - 1;
476 if (shdr[i].sh_addralign > max_addralign)
477 max_addralign = shdr[i].sh_addralign;
478 mapsize += alignmask;
479 mapsize &= ~alignmask;
480 mapsize += shdr[i].sh_size;
485 /* We know how much space we need for the text/data/bss/etc. */
487 if (posix_memalign((void **)&ef->address, max_addralign, mapsize)) {
488 printf("posix_memalign failed\n");
491 mapbase = ef->address;
494 * Now load code/data(progbits), zero bss(nobits), allocate
495 * space for and load relocs
501 for (i = 0; i < hdr->e_shnum; i++) {
502 switch (shdr[i].sh_type) {
505 alignmask = shdr[i].sh_addralign - 1;
506 mapbase += alignmask;
507 mapbase = (char *)((uintptr_t)mapbase & ~alignmask);
508 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
509 if (shdr[i].sh_type == SHT_PROGBITS) {
510 ef->progtab[pb].name = "<<PROGBITS>>";
511 if (ef_obj_read(ef, shdr[i].sh_offset,
513 ef->progtab[pb].addr) != 0) {
514 printf("failed to read progbits\n");
518 ef->progtab[pb].name = "<<NOBITS>>";
519 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
521 ef->progtab[pb].size = shdr[i].sh_size;
522 ef->progtab[pb].sec = i;
523 if (ef->shstrtab && shdr[i].sh_name != 0)
524 ef->progtab[pb].name =
525 ef->shstrtab + shdr[i].sh_name;
527 /* Update all symbol values with the offset. */
528 for (j = 0; j < ef->ddbsymcnt; j++) {
529 es = &ef->ddbsymtab[j];
530 if (es->st_shndx != i)
532 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
534 mapbase += shdr[i].sh_size;
538 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
539 ef->reltab[rl].sec = shdr[i].sh_info;
540 if (ef_obj_read_entry(ef, shdr[i].sh_offset,
541 shdr[i].sh_size, (void**)&ef->reltab[rl].rel) !=
543 printf("ef_read_entry failed\n");
549 ef->relatab[ra].nrela =
550 shdr[i].sh_size / sizeof(Elf_Rela);
551 ef->relatab[ra].sec = shdr[i].sh_info;
552 if (ef_obj_read_entry(ef, shdr[i].sh_offset,
553 shdr[i].sh_size, (void**)&ef->relatab[ra].rela) !=
555 printf("ef_read_entry failed\n");
570 ef_obj_close(elf_file_t ef)
577 if (ef->e_shdr != NULL)
581 if (ef->nprogtab != 0)
584 for (i = 0; i < ef->nrel; i++)
585 if (ef->reltab[i].rel != NULL)
586 free(ef->reltab[i].rel);
589 if (ef->nrela != 0) {
590 for (i = 0; i < ef->nrela; i++)
591 if (ef->relatab[i].rela != NULL)
592 free(ef->relatab[i].rela);
595 if (ef->ddbsymtab != NULL)
597 if (ef->ddbstrtab != NULL)
599 if (ef->shstrtab != NULL)
601 ef->ef_efile->ef_ops = NULL;
602 ef->ef_efile->ef_ef = NULL;