2 * Copyright (c) 1997 Christopher G. Demetriou. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed by Christopher G. Demetriou
15 * for the NetBSD Project.
16 * 4. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * $NetBSD: exec_elf32.c,v 1.4 1997/08/12 06:07:24 mikel Exp $
31 * $FreeBSD: src/usr.sbin/crunch/crunchide/exec_elf32.c,v 1.1.6.2 2002/07/25 09:33:17 ru Exp $
32 * $DragonFly: src/usr.sbin/crunch/crunchide/exec_elf32.c,v 1.2 2003/06/17 04:29:53 dillon Exp $
35 #include <sys/cdefs.h>
41 #include <sys/types.h>
52 #if (defined(NLIST_ELF32) && (ELFSIZE == 32)) || \
53 (defined(NLIST_ELF64) && (ELFSIZE == 64))
55 #define __ELF_WORD_SIZE ELFSIZE
57 #include <sys/elf32.h>
59 #include <sys/elf64.h>
61 #include <sys/elf_generic.h>
63 #define CONCAT(x,y) __CONCAT(x,y)
64 #define ELFNAME(x) CONCAT(elf,CONCAT(ELFSIZE,CONCAT(_,x)))
65 #define ELFNAME2(x,y) CONCAT(x,CONCAT(_elf,CONCAT(ELFSIZE,CONCAT(_,y))))
66 #define ELFNAMEEND(x) CONCAT(x,CONCAT(_elf,ELFSIZE))
67 #define ELFDEFNNAME(x) CONCAT(ELF,CONCAT(ELFSIZE,CONCAT(_,x)))
70 struct listelem *next;
77 xreadatoff(int fd, void *buf, off_t off, size_t size, const char *fn)
81 if (lseek(fd, off, SEEK_SET) != off) {
85 if ((rv = read(fd, buf, size)) != size) {
86 fprintf(stderr, "%s: read error: %s\n", fn,
87 rv == -1 ? strerror(errno) : "short read");
94 xwriteatoff(int fd, void *buf, off_t off, size_t size, const char *fn)
98 if (lseek(fd, off, SEEK_SET) != off) {
102 if ((rv = write(fd, buf, size)) != size) {
103 fprintf(stderr, "%s: write error: %s\n", fn,
104 rv == -1 ? strerror(errno) : "short write");
111 xmalloc(size_t size, const char *fn, const char *use)
117 fprintf(stderr, "%s: out of memory (allocating for %s)\n",
123 ELFNAMEEND(check)(int fd, const char *fn)
129 * Check the header to maek sure it's an ELF file (of the
132 if (fstat(fd, &sb) == -1)
134 if (sb.st_size < sizeof eh)
136 if (read(fd, &eh, sizeof eh) != sizeof eh)
142 switch (eh.e_machine) {
144 case EM_ALPHA: break;
145 /* ELFDEFNNAME(MACHDEP_ID_CASES) */
155 ELFNAMEEND(hide)(int fd, const char *fn)
158 Elf_Shdr *shdrp = NULL, *symtabshdr, *strtabshdr;
159 Elf_Sym *symtabp = NULL;
160 char *strtabp = NULL;
161 Elf_Word *symfwmap = NULL, *symrvmap = NULL, nsyms, nlocalsyms, ewi;
162 struct listelem *relalist = NULL, *rellist = NULL, *tmpl;
167 if (xreadatoff(fd, &ehdr, 0, sizeof ehdr, fn) != sizeof ehdr)
170 shdrsize = ehdr.e_shnum * ehdr.e_shentsize;
171 if ((shdrp = xmalloc(shdrsize, fn, "section header table")) == NULL)
173 if (xreadatoff(fd, shdrp, ehdr.e_shoff, shdrsize, fn) != shdrsize)
176 symtabshdr = strtabshdr = NULL;
178 for (i = 0; i < ehdr.e_shnum; i++) {
179 switch (shdrp[i].sh_type) {
181 if (symtabshdr != NULL)
183 symtabshdr = &shdrp[i];
184 strtabshdr = &shdrp[shdrp[i].sh_link];
187 tmpl = xmalloc(sizeof *tmpl, fn, "rela list element");
191 tmpl->file = shdrp[i].sh_offset;
192 tmpl->size = shdrp[i].sh_size;
193 tmpl->next = relalist;
197 tmpl = xmalloc(sizeof *tmpl, fn, "rel list element");
201 tmpl->file = shdrp[i].sh_offset;
202 tmpl->size = shdrp[i].sh_size;
203 tmpl->next = rellist;
208 if (symtabshdr == NULL)
210 if (strtabshdr == NULL)
213 fprintf(stderr, "%s: weird executable (unsupported)\n", fn);
218 * load up everything we need
222 if ((symtabp = xmalloc(symtabshdr->sh_size, fn, "symbol table"))
225 if (xreadatoff(fd, symtabp, symtabshdr->sh_offset, symtabshdr->sh_size,
226 fn) != symtabshdr->sh_size)
230 if ((strtabp = xmalloc(strtabshdr->sh_size, fn, "string table"))
233 if (xreadatoff(fd, strtabp, strtabshdr->sh_offset, strtabshdr->sh_size,
234 fn) != strtabshdr->sh_size)
237 /* any rela tables */
238 for (tmpl = relalist; tmpl != NULL; tmpl = tmpl->next) {
239 if ((tmpl->mem = xmalloc(tmpl->size, fn, "rela table"))
242 if (xreadatoff(fd, tmpl->mem, tmpl->file, tmpl->size, fn) !=
248 for (tmpl = rellist; tmpl != NULL; tmpl = tmpl->next) {
249 if ((tmpl->mem = xmalloc(tmpl->size, fn, "rel table"))
252 if (xreadatoff(fd, tmpl->mem, tmpl->file, tmpl->size, fn) !=
257 /* Prepare data structures for symbol movement. */
258 nsyms = symtabshdr->sh_size / symtabshdr->sh_entsize;
259 nlocalsyms = symtabshdr->sh_info;
260 if ((symfwmap = xmalloc(nsyms * sizeof (Elf_Word), fn,
261 "symbol forward mapping table")) == NULL)
263 if ((symrvmap = xmalloc(nsyms * sizeof (Elf_Word), fn,
264 "symbol reverse mapping table")) == NULL)
267 /* init location -> symbol # table */
268 for (ewi = 0; ewi < nsyms; ewi++)
271 /* move symbols, making them local */
272 for (ewi = nlocalsyms; ewi < nsyms; ewi++) {
273 Elf_Sym *sp, symswap;
278 /* if it's on our keep list, don't move it */
279 if (in_keep_list(strtabp + sp->st_name))
282 /* if it's an undefined symbol, keep it */
283 if (sp->st_shndx == SHN_UNDEF)
286 /* adjust the symbol so that it's local */
288 ELF_ST_INFO(STB_LOCAL, sp->st_info);
289 /* (STB_LOCAL << 4) | ELF_SYM_TYPE(sp->st_info); *//* XXX */
292 * move the symbol to its new location
295 /* note that symbols in those locations have been swapped */
296 mapswap = symrvmap[ewi];
297 symrvmap[ewi] = symrvmap[nlocalsyms];
298 symrvmap[nlocalsyms] = mapswap;
300 /* and swap the symbols */
302 *sp = symtabp[nlocalsyms];
303 symtabp[nlocalsyms] = symswap;
305 nlocalsyms++; /* note new local sym */
307 symtabshdr->sh_info = nlocalsyms;
309 /* set up symbol # -> location mapping table */
310 for (ewi = 0; ewi < nsyms; ewi++)
311 symfwmap[symrvmap[ewi]] = ewi;
313 /* any rela tables */
314 for (tmpl = relalist; tmpl != NULL; tmpl = tmpl->next) {
315 Elf_Rela *relap = tmpl->mem;
317 for (ewi = 0; ewi < tmpl->size / sizeof(*relap); ewi++) {
319 #if (ELFSIZE == 32) /* XXX */
320 symfwmap[ELF_R_SYM(relap[ewi].r_info)] << 8 |
321 ELF_R_TYPE(relap[ewi].r_info);
322 #elif (ELFSIZE == 64) /* XXX */
323 symfwmap[ELF_R_SYM(relap[ewi].r_info)] << 32 |
324 ELF_R_TYPE(relap[ewi].r_info);
330 for (tmpl = rellist; tmpl != NULL; tmpl = tmpl->next) {
331 Elf_Rel *relp = tmpl->mem;
333 for (ewi = 0; ewi < tmpl->size / sizeof *relp; ewi++) {
335 #if (ELFSIZE == 32) /* XXX */
336 symfwmap[ELF_R_SYM(relp[ewi].r_info)] << 8 |
337 ELF_R_TYPE(relp[ewi].r_info);
338 #elif (ELFSIZE == 64) /* XXX */
339 symfwmap[ELF_R_SYM(relp[ewi].r_info)] << 32 |
340 ELF_R_TYPE(relp[ewi].r_info);
346 * write new tables to the file
348 if (xwriteatoff(fd, shdrp, ehdr.e_shoff, shdrsize, fn) != shdrsize)
350 if (xwriteatoff(fd, symtabp, symtabshdr->sh_offset,
351 symtabshdr->sh_size, fn) != symtabshdr->sh_size)
353 for (tmpl = relalist; tmpl != NULL; tmpl = tmpl->next) {
354 if (xwriteatoff(fd, tmpl->mem, tmpl->file, tmpl->size, fn) !=
358 for (tmpl = rellist; tmpl != NULL; tmpl = tmpl->next) {
359 if (xwriteatoff(fd, tmpl->mem, tmpl->file, tmpl->size, fn) !=
371 if (symfwmap != NULL)
373 if (symrvmap != NULL)
375 while ((tmpl = relalist) != NULL) {
376 relalist = tmpl->next;
377 if (tmpl->mem != NULL)
381 while ((tmpl = rellist) != NULL) {
382 rellist = tmpl->next;
383 if (tmpl->mem != NULL)
394 #endif /* include this size of ELF */