1 /*-
2 * Copyright (c) 1998-2000 Doug Rabson
3 * Copyright (c) 2004 Peter Wemm
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD: releng/6.0/sys/kern/link_elf_obj.c 151023 2005-10-06 19:01:42Z delphij $");
30
31 #include "opt_ddb.h"
32 #include "opt_mac.h"
33
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/mac.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
41 #include <sys/proc.h>
42 #include <sys/namei.h>
43 #include <sys/fcntl.h>
44 #include <sys/vnode.h>
45 #include <sys/linker.h>
46
47 #include <machine/elf.h>
48
49 #include <vm/vm.h>
50 #include <vm/vm_param.h>
51 #include <vm/vm_object.h>
52 #include <vm/vm_kern.h>
53 #include <vm/vm_extern.h>
54 #include <vm/pmap.h>
55 #include <vm/vm_map.h>
56
57 #include <sys/link_elf.h>
58
59 #include "linker_if.h"
60
61 typedef struct {
62 void *addr;
63 Elf_Off size;
64 int flags;
65 int sec; /* Original section */
66 char *name;
67 } Elf_progent;
68
69 typedef struct {
70 Elf_Rel *rel;
71 int nrel;
72 int sec;
73 } Elf_relent;
74
75 typedef struct {
76 Elf_Rela *rela;
77 int nrela;
78 int sec;
79 } Elf_relaent;
80
81
82 typedef struct elf_file {
83 struct linker_file lf; /* Common fields */
84
85 int preloaded;
86 caddr_t address; /* Relocation address */
87 vm_object_t object; /* VM object to hold file pages */
88 Elf_Shdr *e_shdr;
89
90 Elf_progent *progtab;
91 int nprogtab;
92
93 Elf_relaent *relatab;
94 int nrela;
95
96 Elf_relent *reltab;
97 int nrel;
98
99 Elf_Sym *ddbsymtab; /* The symbol table we are using */
100 long ddbsymcnt; /* Number of symbols */
101 caddr_t ddbstrtab; /* String table */
102 long ddbstrcnt; /* number of bytes in string table */
103
104 caddr_t shstrtab; /* Section name string table */
105 long shstrcnt; /* number of bytes in string table */
106
107 } *elf_file_t;
108
109 static int link_elf_link_preload(linker_class_t cls,
110 const char *, linker_file_t *);
111 static int link_elf_link_preload_finish(linker_file_t);
112 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *);
113 static int link_elf_lookup_symbol(linker_file_t, const char *,
114 c_linker_sym_t *);
115 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
116 linker_symval_t *);
117 static int link_elf_search_symbol(linker_file_t, caddr_t value,
118 c_linker_sym_t *sym, long *diffp);
119
120 static void link_elf_unload_file(linker_file_t);
121 static int link_elf_lookup_set(linker_file_t, const char *,
122 void ***, void ***, int *);
123 static int link_elf_each_function_name(linker_file_t,
124 int (*)(const char *, void *), void *);
125 static void link_elf_reloc_local(linker_file_t);
126
127 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Word symidx, int deps);
128
129 static kobj_method_t link_elf_methods[] = {
130 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
131 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
132 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
133 KOBJMETHOD(linker_unload, link_elf_unload_file),
134 KOBJMETHOD(linker_load_file, link_elf_load_file),
135 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
136 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
137 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
138 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
139 { 0, 0 }
140 };
141
142 static struct linker_class link_elf_class = {
143 #if ELF_TARG_CLASS == ELFCLASS32
144 "elf32_obj",
145 #else
146 "elf64_obj",
147 #endif
148 link_elf_methods, sizeof(struct elf_file)
149 };
150
151 static int relocate_file(elf_file_t ef);
152
153 static void
154 link_elf_error(const char *s)
155 {
156 printf("kldload: %s\n", s);
157 }
158
159 static void
160 link_elf_init(void *arg)
161 {
162
163 linker_add_class(&link_elf_class);
164 }
165
166 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
167
168 static int
169 link_elf_link_preload(linker_class_t cls, const char *filename,
170 linker_file_t *result)
171 {
172 Elf_Ehdr *hdr;
173 Elf_Shdr *shdr;
174 Elf_Sym *es;
175 void *modptr, *baseptr, *sizeptr;
176 char *type;
177 elf_file_t ef;
178 linker_file_t lf;
179 Elf_Addr off;
180 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
181
182 /* Look to see if we have the file preloaded */
183 modptr = preload_search_by_name(filename);
184 if (modptr == NULL)
185 return ENOENT;
186
187 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
188 baseptr = preload_search_info(modptr, MODINFO_ADDR);
189 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
190 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
191 MODINFOMD_ELFHDR);
192 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
193 MODINFOMD_SHDR);
194 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
195 " obj module") != 0 &&
196 strcmp(type, "elf obj module") != 0)) {
197 return (EFTYPE);
198 }
199 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
200 shdr == NULL)
201 return (EINVAL);
202
203 lf = linker_make_file(filename, &link_elf_class);
204 if (lf == NULL)
205 return (ENOMEM);
206
207 ef = (elf_file_t)lf;
208 ef->preloaded = 1;
209 ef->address = *(caddr_t *)baseptr;
210 lf->address = *(caddr_t *)baseptr;
211 lf->size = *(size_t *)sizeptr;
212
213 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
214 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
215 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
216 hdr->e_version != EV_CURRENT ||
217 hdr->e_type != ET_REL ||
218 hdr->e_machine != ELF_TARG_MACH) {
219 error = EFTYPE;
220 goto out;
221 }
222 ef->e_shdr = shdr;
223
224 /* Scan the section header for information and table sizing. */
225 symtabindex = -1;
226 symstrindex = -1;
227 for (i = 0; i < hdr->e_shnum; i++) {
228 switch (shdr[i].sh_type) {
229 case SHT_PROGBITS:
230 case SHT_NOBITS:
231 ef->nprogtab++;
232 break;
233 case SHT_SYMTAB:
234 symtabindex = i;
235 symstrindex = shdr[i].sh_link;
236 break;
237 case SHT_REL:
238 ef->nrel++;
239 break;
240 case SHT_RELA:
241 ef->nrela++;
242 break;
243 }
244 }
245
246 shstrindex = hdr->e_shstrndx;
247 if (ef->nprogtab == 0 || symstrindex < 0 ||
248 symstrindex >= hdr->e_shnum ||
249 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
250 shstrindex >= hdr->e_shnum ||
251 shdr[shstrindex].sh_type != SHT_STRTAB) {
252 printf("%s: bad/missing section headers\n", filename);
253 error = ENOEXEC;
254 goto out;
255 }
256
257 /* Allocate space for tracking the load chunks */
258 if (ef->nprogtab != 0)
259 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
260 M_LINKER, M_WAITOK | M_ZERO);
261 if (ef->nrel != 0)
262 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER,
263 M_WAITOK | M_ZERO);
264 if (ef->nrela != 0)
265 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER,
266 M_WAITOK | M_ZERO);
267 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
268 (ef->nrel != 0 && ef->reltab == NULL) ||
269 (ef->nrela != 0 && ef->relatab == NULL)) {
270 error = ENOMEM;
271 goto out;
272 }
273
274 /* XXX, relocate the sh_addr fields saved by the loader. */
275 off = 0;
276 for (i = 0; i < hdr->e_shnum; i++) {
277 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
278 off = shdr[i].sh_addr;
279 }
280 for (i = 0; i < hdr->e_shnum; i++) {
281 if (shdr[i].sh_addr != 0)
282 shdr[i].sh_addr = shdr[i].sh_addr - off +
283 (Elf_Addr)ef->address;
284 }
285
286 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
287 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
288 ef->ddbstrcnt = shdr[symstrindex].sh_size;
289 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
290 ef->shstrcnt = shdr[shstrindex].sh_size;
291 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
292
293 /* Now fill out progtab and the relocation tables. */
294 pb = 0;
295 rl = 0;
296 ra = 0;
297 for (i = 0; i < hdr->e_shnum; i++) {
298 switch (shdr[i].sh_type) {
299 case SHT_PROGBITS:
300 case SHT_NOBITS:
301 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
302 if (shdr[i].sh_type == SHT_PROGBITS)
303 ef->progtab[pb].name = "<<PROGBITS>>";
304 else
305 ef->progtab[pb].name = "<<NOBITS>>";
306 ef->progtab[pb].size = shdr[i].sh_size;
307 ef->progtab[pb].sec = i;
308 if (ef->shstrtab && shdr[i].sh_name != 0)
309 ef->progtab[pb].name =
310 ef->shstrtab + shdr[i].sh_name;
311
312 /* Update all symbol values with the offset. */
313 for (j = 0; j < ef->ddbsymcnt; j++) {
314 es = &ef->ddbsymtab[j];
315 if (es->st_shndx != i)
316 continue;
317 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
318 }
319 pb++;
320 break;
321 case SHT_REL:
322 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
323 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
324 ef->reltab[rl].sec = shdr[i].sh_info;
325 rl++;
326 break;
327 case SHT_RELA:
328 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
329 ef->relatab[ra].nrela =
330 shdr[i].sh_size / sizeof(Elf_Rela);
331 ef->relatab[ra].sec = shdr[i].sh_info;
332 ra++;
333 break;
334 }
335 }
336 if (pb != ef->nprogtab)
337 panic("lost progbits");
338 if (rl != ef->nrel)
339 panic("lost rel");
340 if (ra != ef->nrela)
341 panic("lost rela");
342
343 /* Local intra-module relocations */
344 link_elf_reloc_local(lf);
345
346 *result = lf;
347 return (0);
348
349 out:
350 /* preload not done this way */
351 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
352 return (error);
353 }
354
355 static int
356 link_elf_link_preload_finish(linker_file_t lf)
357 {
358 elf_file_t ef;
359 int error;
360
361 ef = (elf_file_t)lf;
362 error = relocate_file(ef);
363 if (error)
364 return error;
365
366 /* Notify MD code that a module is being loaded. */
367 error = elf_cpu_load_file(lf);
368 if (error)
369 return (error);
370
371 return (0);
372 }
373
374 static int
375 link_elf_load_file(linker_class_t cls, const char *filename,
376 linker_file_t *result)
377 {
378 struct nameidata nd;
379 struct thread *td = curthread; /* XXX */
380 Elf_Ehdr *hdr;
381 Elf_Shdr *shdr;
382 Elf_Sym *es;
383 int nbytes, i, j;
384 vm_offset_t mapbase;
385 size_t mapsize;
386 int error = 0;
387 int resid, flags;
388 elf_file_t ef;
389 linker_file_t lf;
390 int symtabindex;
391 int symstrindex;
392 int shstrindex;
393 int nsym;
394 int pb, rl, ra;
395 int alignmask;
396
397 GIANT_REQUIRED;
398
399 shdr = NULL;
400 lf = NULL;
401 mapsize = 0;
402 hdr = NULL;
403
404 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
405 flags = FREAD;
406 error = vn_open(&nd, &flags, 0, -1);
407 if (error)
408 return error;
409 NDFREE(&nd, NDF_ONLY_PNBUF);
410 #ifdef MAC
411 error = mac_check_kld_load(td->td_ucred, nd.ni_vp);
412 if (error) {
413 goto out;
414 }
415 #endif
416
417 /* Read the elf header from the file. */
418 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
419 if (hdr == NULL) {
420 error = ENOMEM;
421 goto out;
422 }
423 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
424 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
425 &resid, td);
426 if (error)
427 goto out;
428 if (resid != 0){
429 error = ENOEXEC;
430 goto out;
431 }
432
433 if (!IS_ELF(*hdr)) {
434 error = ENOEXEC;
435 goto out;
436 }
437
438 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
439 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
440 link_elf_error("Unsupported file layout");
441 error = ENOEXEC;
442 goto out;
443 }
444 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
445 || hdr->e_version != EV_CURRENT) {
446 link_elf_error("Unsupported file version");
447 error = ENOEXEC;
448 goto out;
449 }
450 if (hdr->e_type != ET_REL) {
451 link_elf_error("Unsupported file type");
452 error = ENOEXEC;
453 goto out;
454 }
455 if (hdr->e_machine != ELF_TARG_MACH) {
456 link_elf_error("Unsupported machine");
457 error = ENOEXEC;
458 goto out;
459 }
460
461 lf = linker_make_file(filename, &link_elf_class);
462 if (!lf) {
463 error = ENOMEM;
464 goto out;
465 }
466 ef = (elf_file_t) lf;
467 ef->nprogtab = 0;
468 ef->e_shdr = 0;
469 ef->nrel = 0;
470 ef->nrela = 0;
471
472 /* Allocate and read in the section header */
473 nbytes = hdr->e_shnum * hdr->e_shentsize;
474 if (nbytes == 0 || hdr->e_shoff == 0 ||
475 hdr->e_shentsize != sizeof(Elf_Shdr)) {
476 error = ENOEXEC;
477 goto out;
478 }
479 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
480 if (shdr == NULL) {
481 error = ENOMEM;
482 goto out;
483 }
484 ef->e_shdr = shdr;
485 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
486 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
487 if (error)
488 goto out;
489 if (resid) {
490 error = ENOEXEC;
491 goto out;
492 }
493
494 /* Scan the section header for information and table sizing. */
495 nsym = 0;
496 symtabindex = -1;
497 symstrindex = -1;
498 for (i = 0; i < hdr->e_shnum; i++) {
499 switch (shdr[i].sh_type) {
500 case SHT_PROGBITS:
501 case SHT_NOBITS:
502 ef->nprogtab++;
503 break;
504 case SHT_SYMTAB:
505 nsym++;
506 symtabindex = i;
507 symstrindex = shdr[i].sh_link;
508 break;
509 case SHT_REL:
510 ef->nrel++;
511 break;
512 case SHT_RELA:
513 ef->nrela++;
514 break;
515 case SHT_STRTAB:
516 break;
517 }
518 }
519 if (ef->nprogtab == 0) {
520 link_elf_error("file has no contents");
521 error = ENOEXEC;
522 goto out;
523 }
524 if (nsym != 1) {
525 /* Only allow one symbol table for now */
526 link_elf_error("file has no valid symbol table");
527 error = ENOEXEC;
528 goto out;
529 }
530 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
531 shdr[symstrindex].sh_type != SHT_STRTAB) {
532 link_elf_error("file has invalid symbol strings");
533 error = ENOEXEC;
534 goto out;
535 }
536
537 /* Allocate space for tracking the load chunks */
538 if (ef->nprogtab != 0)
539 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
540 M_LINKER, M_WAITOK | M_ZERO);
541 if (ef->nrel != 0)
542 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER,
543 M_WAITOK | M_ZERO);
544 if (ef->nrela != 0)
545 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER,
546 M_WAITOK | M_ZERO);
547 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
548 (ef->nrel != 0 && ef->reltab == NULL) ||
549 (ef->nrela != 0 && ef->relatab == NULL)) {
550 error = ENOMEM;
551 goto out;
552 }
553
554 if (symtabindex == -1)
555 panic("lost symbol table index");
556 /* Allocate space for and load the symbol table */
557 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
558 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
559 if (ef->ddbsymtab == NULL) {
560 error = ENOMEM;
561 goto out;
562 }
563 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
564 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
565 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
566 &resid, td);
567 if (error)
568 goto out;
569 if (resid != 0){
570 error = EINVAL;
571 goto out;
572 }
573
574 if (symstrindex == -1)
575 panic("lost symbol string index");
576 /* Allocate space for and load the symbol strings */
577 ef->ddbstrcnt = shdr[symstrindex].sh_size;
578 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
579 if (ef->ddbstrtab == NULL) {
580 error = ENOMEM;
581 goto out;
582 }
583 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
584 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
585 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
586 &resid, td);
587 if (error)
588 goto out;
589 if (resid != 0){
590 error = EINVAL;
591 goto out;
592 }
593
594 /* Do we have a string table for the section names? */
595 shstrindex = -1;
596 if (hdr->e_shstrndx != 0 &&
597 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
598 shstrindex = hdr->e_shstrndx;
599 ef->shstrcnt = shdr[shstrindex].sh_size;
600 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
601 M_WAITOK);
602 if (ef->shstrtab == NULL) {
603 error = ENOMEM;
604 goto out;
605 }
606 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
607 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
608 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
609 &resid, td);
610 if (error)
611 goto out;
612 if (resid != 0){
613 error = EINVAL;
614 goto out;
615 }
616 }
617
618 /* Size up code/data(progbits) and bss(nobits). */
619 alignmask = 0;
620 for (i = 0; i < hdr->e_shnum; i++) {
621 switch (shdr[i].sh_type) {
622 case SHT_PROGBITS:
623 case SHT_NOBITS:
624 alignmask = shdr[i].sh_addralign - 1;
625 mapsize += alignmask;
626 mapsize &= ~alignmask;
627 mapsize += shdr[i].sh_size;
628 break;
629 }
630 }
631
632 /*
633 * We know how much space we need for the text/data/bss/etc.
634 * This stuff needs to be in a single chunk so that profiling etc
635 * can get the bounds and gdb can associate offsets with modules
636 */
637 ef->object = vm_object_allocate(OBJT_DEFAULT,
638 round_page(mapsize) >> PAGE_SHIFT);
639 if (ef->object == NULL) {
640 error = ENOMEM;
641 goto out;
642 }
643 ef->address = (caddr_t) vm_map_min(kernel_map);
644 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
645 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
646 if (error) {
647 vm_object_deallocate(ef->object);
648 ef->object = 0;
649 goto out;
650 }
651
652 /* Wire the pages */
653 error = vm_map_wire(kernel_map, mapbase,
654 mapbase + round_page(mapsize),
655 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
656 if (error != KERN_SUCCESS) {
657 error = ENOMEM;
658 goto out;
659 }
660
661 /* Inform the kld system about the situation */
662 lf->address = ef->address = (caddr_t)mapbase;
663 lf->size = mapsize;
664
665 /*
666 * Now load code/data(progbits), zero bss(nobits), allocate space for
667 * and load relocs
668 */
669 pb = 0;
670 rl = 0;
671 ra = 0;
672 alignmask = 0;
673 for (i = 0; i < hdr->e_shnum; i++) {
674 switch (shdr[i].sh_type) {
675 case SHT_PROGBITS:
676 case SHT_NOBITS:
677 alignmask = shdr[i].sh_addralign - 1;
678 mapbase += alignmask;
679 mapbase &= ~alignmask;
680 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
681 if (shdr[i].sh_type == SHT_PROGBITS) {
682 ef->progtab[pb].name = "<<PROGBITS>>";
683 error = vn_rdwr(UIO_READ, nd.ni_vp,
684 ef->progtab[pb].addr,
685 shdr[i].sh_size, shdr[i].sh_offset,
686 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
687 NOCRED, &resid, td);
688 if (error)
689 goto out;
690 if (resid != 0){
691 error = EINVAL;
692 goto out;
693 }
694 } else {
695 ef->progtab[pb].name = "<<NOBITS>>";
696 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
697 }
698 ef->progtab[pb].size = shdr[i].sh_size;
699 ef->progtab[pb].sec = i;
700 if (ef->shstrtab && shdr[i].sh_name != 0)
701 ef->progtab[pb].name =
702 ef->shstrtab + shdr[i].sh_name;
703
704 /* Update all symbol values with the offset. */
705 for (j = 0; j < ef->ddbsymcnt; j++) {
706 es = &ef->ddbsymtab[j];
707 if (es->st_shndx != i)
708 continue;
709 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
710 }
711 mapbase += shdr[i].sh_size;
712 pb++;
713 break;
714 case SHT_REL:
715 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
716 M_WAITOK);
717 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
718 ef->reltab[rl].sec = shdr[i].sh_info;
719 error = vn_rdwr(UIO_READ, nd.ni_vp,
720 (void *)ef->reltab[rl].rel,
721 shdr[i].sh_size, shdr[i].sh_offset,
722 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
723 &resid, td);
724 if (error)
725 goto out;
726 if (resid != 0){
727 error = EINVAL;
728 goto out;
729 }
730 rl++;
731 break;
732 case SHT_RELA:
733 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
734 M_WAITOK);
735 ef->relatab[ra].nrela =
736 shdr[i].sh_size / sizeof(Elf_Rela);
737 ef->relatab[ra].sec = shdr[i].sh_info;
738 error = vn_rdwr(UIO_READ, nd.ni_vp,
739 (void *)ef->relatab[ra].rela,
740 shdr[i].sh_size, shdr[i].sh_offset,
741 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
742 &resid, td);
743 if (error)
744 goto out;
745 if (resid != 0){
746 error = EINVAL;
747 goto out;
748 }
749 ra++;
750 break;
751 }
752 }
753 if (pb != ef->nprogtab)
754 panic("lost progbits");
755 if (rl != ef->nrel)
756 panic("lost rel");
757 if (ra != ef->nrela)
758 panic("lost rela");
759 if (mapbase != (vm_offset_t)ef->address + mapsize)
760 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
761 mapbase, ef->address, mapsize,
762 (vm_offset_t)ef->address + mapsize);
763
764 /* Local intra-module relocations */
765 link_elf_reloc_local(lf);
766
767 /* Pull in dependencies */
768 error = linker_load_dependencies(lf);
769 if (error)
770 goto out;
771
772 /* External relocations */
773 error = relocate_file(ef);
774 if (error)
775 goto out;
776
777 /* Notify MD code that a module is being loaded. */
778 error = elf_cpu_load_file(lf);
779 if (error)
780 goto out;
781
782 *result = lf;
783
784 out:
785 if (error && lf)
786 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
787 if (hdr)
788 free(hdr, M_LINKER);
789 VOP_UNLOCK(nd.ni_vp, 0, td);
790 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
791
792 return error;
793 }
794
795 static void
796 link_elf_unload_file(linker_file_t file)
797 {
798 elf_file_t ef = (elf_file_t) file;
799 int i;
800
801 /* Notify MD code that a module is being unloaded. */
802 elf_cpu_unload_file(file);
803
804 if (ef->preloaded) {
805 if (ef->reltab)
806 free(ef->reltab, M_LINKER);
807 if (ef->relatab)
808 free(ef->relatab, M_LINKER);
809 if (ef->progtab)
810 free(ef->progtab, M_LINKER);
811 if (file->filename != NULL)
812 preload_delete_name(file->filename);
813 /* XXX reclaim module memory? */
814 return;
815 }
816
817 for (i = 0; i < ef->nrel; i++)
818 if (ef->reltab[i].rel)
819 free(ef->reltab[i].rel, M_LINKER);
820 for (i = 0; i < ef->nrela; i++)
821 if (ef->relatab[i].rela)
822 free(ef->relatab[i].rela, M_LINKER);
823 if (ef->reltab)
824 free(ef->reltab, M_LINKER);
825 if (ef->relatab)
826 free(ef->relatab, M_LINKER);
827 if (ef->progtab)
828 free(ef->progtab, M_LINKER);
829
830 if (ef->object) {
831 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
832 (vm_offset_t) ef->address +
833 (ef->object->size << PAGE_SHIFT));
834 }
835 if (ef->e_shdr)
836 free(ef->e_shdr, M_LINKER);
837 if (ef->ddbsymtab)
838 free(ef->ddbsymtab, M_LINKER);
839 if (ef->ddbstrtab)
840 free(ef->ddbstrtab, M_LINKER);
841 if (ef->shstrtab)
842 free(ef->shstrtab, M_LINKER);
843 }
844
845 static const char *
846 symbol_name(elf_file_t ef, Elf_Word r_info)
847 {
848 const Elf_Sym *ref;
849
850 if (ELF_R_SYM(r_info)) {
851 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
852 return ef->ddbstrtab + ref->st_name;
853 } else
854 return NULL;
855 }
856
857 static Elf_Addr
858 findbase(elf_file_t ef, int sec)
859 {
860 int i;
861 Elf_Addr base = 0;
862
863 for (i = 0; i < ef->nprogtab; i++) {
864 if (sec == ef->progtab[i].sec) {
865 base = (Elf_Addr)ef->progtab[i].addr;
866 break;
867 }
868 }
869 return base;
870 }
871
872 static int
873 relocate_file(elf_file_t ef)
874 {
875 const Elf_Rel *rellim;
876 const Elf_Rel *rel;
877 const Elf_Rela *relalim;
878 const Elf_Rela *rela;
879 const char *symname;
880 const Elf_Sym *sym;
881 int i;
882 Elf_Word symidx;
883 Elf_Addr base;
884
885
886 /* Perform relocations without addend if there are any: */
887 for (i = 0; i < ef->nrel; i++) {
888 rel = ef->reltab[i].rel;
889 if (rel == NULL)
890 panic("lost a reltab!");
891 rellim = rel + ef->reltab[i].nrel;
892 base = findbase(ef, ef->reltab[i].sec);
893 if (base == 0)
894 panic("lost base for reltab");
895 for ( ; rel < rellim; rel++) {
896 symidx = ELF_R_SYM(rel->r_info);
897 if (symidx >= ef->ddbsymcnt)
898 continue;
899 sym = ef->ddbsymtab + symidx;
900 /* Local relocs are already done */
901 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
902 continue;
903 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
904 elf_obj_lookup)) {
905 symname = symbol_name(ef, rel->r_info);
906 printf("link_elf_obj: symbol %s undefined\n",
907 symname);
908 return ENOENT;
909 }
910 }
911 }
912
913 /* Perform relocations with addend if there are any: */
914 for (i = 0; i < ef->nrela; i++) {
915 rela = ef->relatab[i].rela;
916 if (rela == NULL)
917 panic("lost a relatab!");
918 relalim = rela + ef->relatab[i].nrela;
919 base = findbase(ef, ef->relatab[i].sec);
920 if (base == 0)
921 panic("lost base for relatab");
922 for ( ; rela < relalim; rela++) {
923 symidx = ELF_R_SYM(rela->r_info);
924 if (symidx >= ef->ddbsymcnt)
925 continue;
926 sym = ef->ddbsymtab + symidx;
927 /* Local relocs are already done */
928 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
929 continue;
930 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
931 elf_obj_lookup)) {
932 symname = symbol_name(ef, rela->r_info);
933 printf("link_elf_obj: symbol %s undefined\n",
934 symname);
935 return ENOENT;
936 }
937 }
938 }
939
940 return 0;
941 }
942
943 static int
944 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
945 {
946 elf_file_t ef = (elf_file_t) lf;
947 const Elf_Sym *symp;
948 const char *strp;
949 int i;
950
951 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
952 strp = ef->ddbstrtab + symp->st_name;
953 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
954 *sym = (c_linker_sym_t) symp;
955 return 0;
956 }
957 }
958 return ENOENT;
959 }
960
961 static int
962 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
963 linker_symval_t *symval)
964 {
965 elf_file_t ef = (elf_file_t) lf;
966 const Elf_Sym *es = (const Elf_Sym*) sym;
967
968 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
969 symval->name = ef->ddbstrtab + es->st_name;
970 symval->value = (caddr_t)es->st_value;
971 symval->size = es->st_size;
972 return 0;
973 }
974 return ENOENT;
975 }
976
977 static int
978 link_elf_search_symbol(linker_file_t lf, caddr_t value,
979 c_linker_sym_t *sym, long *diffp)
980 {
981 elf_file_t ef = (elf_file_t) lf;
982 u_long off = (uintptr_t) (void *) value;
983 u_long diff = off;
984 u_long st_value;
985 const Elf_Sym *es;
986 const Elf_Sym *best = 0;
987 int i;
988
989 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
990 if (es->st_name == 0)
991 continue;
992 st_value = es->st_value;
993 if (off >= st_value) {
994 if (off - st_value < diff) {
995 diff = off - st_value;
996 best = es;
997 if (diff == 0)
998 break;
999 } else if (off - st_value == diff) {
1000 best = es;
1001 }
1002 }
1003 }
1004 if (best == 0)
1005 *diffp = off;
1006 else
1007 *diffp = diff;
1008 *sym = (c_linker_sym_t) best;
1009
1010 return 0;
1011 }
1012
1013 /*
1014 * Look up a linker set on an ELF system.
1015 */
1016 static int
1017 link_elf_lookup_set(linker_file_t lf, const char *name,
1018 void ***startp, void ***stopp, int *countp)
1019 {
1020 elf_file_t ef = (elf_file_t)lf;
1021 void **start, **stop;
1022 int i, count;
1023
1024 /* Relative to section number */
1025 for (i = 0; i < ef->nprogtab; i++) {
1026 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1027 strcmp(ef->progtab[i].name + 4, name) == 0) {
1028 start = (void **)ef->progtab[i].addr;
1029 stop = (void **)((char *)ef->progtab[i].addr +
1030 ef->progtab[i].size);
1031 count = stop - start;
1032 if (startp)
1033 *startp = start;
1034 if (stopp)
1035 *stopp = stop;
1036 if (countp)
1037 *countp = count;
1038 return (0);
1039 }
1040 }
1041 return (ESRCH);
1042 }
1043
1044 static int
1045 link_elf_each_function_name(linker_file_t file,
1046 int (*callback)(const char *, void *), void *opaque)
1047 {
1048 elf_file_t ef = (elf_file_t)file;
1049 const Elf_Sym *symp;
1050 int i, error;
1051
1052 /* Exhaustive search */
1053 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1054 if (symp->st_value != 0 &&
1055 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1056 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1057 if (error)
1058 return (error);
1059 }
1060 }
1061 return (0);
1062 }
1063
1064 /*
1065 * Symbol lookup function that can be used when the symbol index is known (ie
1066 * in relocations). It uses the symbol index instead of doing a fully fledged
1067 * hash table based lookup when such is valid. For example for local symbols.
1068 * This is not only more efficient, it's also more correct. It's not always
1069 * the case that the symbol can be found through the hash table.
1070 */
1071 static Elf_Addr
1072 elf_obj_lookup(linker_file_t lf, Elf_Word symidx, int deps)
1073 {
1074 elf_file_t ef = (elf_file_t)lf;
1075 const Elf_Sym *sym;
1076 const char *symbol;
1077 Elf_Addr ret;
1078
1079 /* Don't even try to lookup the symbol if the index is bogus. */
1080 if (symidx >= ef->ddbsymcnt)
1081 return (0);
1082
1083 sym = ef->ddbsymtab + symidx;
1084
1085 /* Quick answer if there is a definition included. */
1086 if (sym->st_shndx != SHN_UNDEF)
1087 return (sym->st_value);
1088
1089 /* If we get here, then it is undefined and needs a lookup. */
1090 switch (ELF_ST_BIND(sym->st_info)) {
1091 case STB_LOCAL:
1092 /* Local, but undefined? huh? */
1093 return (0);
1094
1095 case STB_GLOBAL:
1096 /* Relative to Data or Function name */
1097 symbol = ef->ddbstrtab + sym->st_name;
1098
1099 /* Force a lookup failure if the symbol name is bogus. */
1100 if (*symbol == 0)
1101 return (0);
1102 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1103 return ret;
1104
1105 case STB_WEAK:
1106 printf("link_elf_obj: Weak symbols not supported\n");
1107 return (0);
1108
1109 default:
1110 return (0);
1111 }
1112 }
1113
1114 static void
1115 link_elf_reloc_local(linker_file_t lf)
1116 {
1117 elf_file_t ef = (elf_file_t)lf;
1118 const Elf_Rel *rellim;
1119 const Elf_Rel *rel;
1120 const Elf_Rela *relalim;
1121 const Elf_Rela *rela;
1122 const Elf_Sym *sym;
1123 Elf_Addr base;
1124 int i;
1125 Elf_Word symidx;
1126
1127 /* Perform relocations without addend if there are any: */
1128 for (i = 0; i < ef->nrel; i++) {
1129 rel = ef->reltab[i].rel;
1130 if (rel == NULL)
1131 panic("lost a reltab!");
1132 rellim = rel + ef->reltab[i].nrel;
1133 base = findbase(ef, ef->reltab[i].sec);
1134 if (base == 0)
1135 panic("lost base for reltab");
1136 for ( ; rel < rellim; rel++) {
1137 symidx = ELF_R_SYM(rel->r_info);
1138 if (symidx >= ef->ddbsymcnt)
1139 continue;
1140 sym = ef->ddbsymtab + symidx;
1141 /* Only do local relocs */
1142 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1143 continue;
1144 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1145 elf_obj_lookup);
1146 }
1147 }
1148
1149 /* Perform relocations with addend if there are any: */
1150 for (i = 0; i < ef->nrela; i++) {
1151 rela = ef->relatab[i].rela;
1152 if (rela == NULL)
1153 panic("lost a relatab!");
1154 relalim = rela + ef->relatab[i].nrela;
1155 base = findbase(ef, ef->relatab[i].sec);
1156 if (base == 0)
1157 panic("lost base for relatab");
1158 for ( ; rela < relalim; rela++) {
1159 symidx = ELF_R_SYM(rela->r_info);
1160 if (symidx >= ef->ddbsymcnt)
1161 continue;
1162 sym = ef->ddbsymtab + symidx;
1163 /* Only do local relocs */
1164 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1165 continue;
1166 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1167 elf_obj_lookup);
1168 }
1169 }
1170 }
Cache object: 3bc9d24cc1e3069949bd1ca9caf0d50f
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