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/5.3/sys/kern/link_elf_obj.c 136588 2004-10-16 08:43:07Z cvs2svn $");
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 vm_object_reference(ef->object);
644 ef->address = (caddr_t) vm_map_min(kernel_map);
645 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
646 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
647 if (error) {
648 vm_object_deallocate(ef->object);
649 ef->object = 0;
650 goto out;
651 }
652
653 /* Wire the pages */
654 vm_map_wire(kernel_map, mapbase,
655 mapbase + round_page(mapsize),
656 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
657
658 /* Inform the kld system about the situation */
659 lf->address = ef->address = (caddr_t)mapbase;
660 lf->size = mapsize;
661
662 /*
663 * Now load code/data(progbits), zero bss(nobits), allocate space for
664 * and load relocs
665 */
666 pb = 0;
667 rl = 0;
668 ra = 0;
669 alignmask = 0;
670 for (i = 0; i < hdr->e_shnum; i++) {
671 switch (shdr[i].sh_type) {
672 case SHT_PROGBITS:
673 case SHT_NOBITS:
674 alignmask = shdr[i].sh_addralign - 1;
675 mapbase += alignmask;
676 mapbase &= ~alignmask;
677 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
678 if (shdr[i].sh_type == SHT_PROGBITS) {
679 ef->progtab[pb].name = "<<PROGBITS>>";
680 error = vn_rdwr(UIO_READ, nd.ni_vp,
681 ef->progtab[pb].addr,
682 shdr[i].sh_size, shdr[i].sh_offset,
683 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
684 NOCRED, &resid, td);
685 if (error)
686 goto out;
687 if (resid != 0){
688 error = EINVAL;
689 goto out;
690 }
691 } else {
692 ef->progtab[pb].name = "<<NOBITS>>";
693 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
694 }
695 ef->progtab[pb].size = shdr[i].sh_size;
696 ef->progtab[pb].sec = i;
697 if (ef->shstrtab && shdr[i].sh_name != 0)
698 ef->progtab[pb].name =
699 ef->shstrtab + shdr[i].sh_name;
700
701 /* Update all symbol values with the offset. */
702 for (j = 0; j < ef->ddbsymcnt; j++) {
703 es = &ef->ddbsymtab[j];
704 if (es->st_shndx != i)
705 continue;
706 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
707 }
708 mapbase += shdr[i].sh_size;
709 pb++;
710 break;
711 case SHT_REL:
712 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
713 M_WAITOK);
714 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
715 ef->reltab[rl].sec = shdr[i].sh_info;
716 error = vn_rdwr(UIO_READ, nd.ni_vp,
717 (void *)ef->reltab[rl].rel,
718 shdr[i].sh_size, shdr[i].sh_offset,
719 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
720 &resid, td);
721 if (error)
722 goto out;
723 if (resid != 0){
724 error = EINVAL;
725 goto out;
726 }
727 rl++;
728 break;
729 case SHT_RELA:
730 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
731 M_WAITOK);
732 ef->relatab[ra].nrela =
733 shdr[i].sh_size / sizeof(Elf_Rela);
734 ef->relatab[ra].sec = shdr[i].sh_info;
735 error = vn_rdwr(UIO_READ, nd.ni_vp,
736 (void *)ef->relatab[ra].rela,
737 shdr[i].sh_size, shdr[i].sh_offset,
738 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
739 &resid, td);
740 if (error)
741 goto out;
742 if (resid != 0){
743 error = EINVAL;
744 goto out;
745 }
746 ra++;
747 break;
748 }
749 }
750 if (pb != ef->nprogtab)
751 panic("lost progbits");
752 if (rl != ef->nrel)
753 panic("lost rel");
754 if (ra != ef->nrela)
755 panic("lost rela");
756 if (mapbase != (vm_offset_t)ef->address + mapsize)
757 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
758 mapbase, ef->address, mapsize,
759 (vm_offset_t)ef->address + mapsize);
760
761 /* Local intra-module relocations */
762 link_elf_reloc_local(lf);
763
764 /* Pull in dependencies */
765 error = linker_load_dependencies(lf);
766 if (error)
767 goto out;
768
769 /* External relocations */
770 error = relocate_file(ef);
771 if (error)
772 goto out;
773
774 /* Notify MD code that a module is being loaded. */
775 error = elf_cpu_load_file(lf);
776 if (error)
777 goto out;
778
779 *result = lf;
780
781 out:
782 if (error && lf)
783 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
784 if (hdr)
785 free(hdr, M_LINKER);
786 VOP_UNLOCK(nd.ni_vp, 0, td);
787 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
788
789 return error;
790 }
791
792 static void
793 link_elf_unload_file(linker_file_t file)
794 {
795 elf_file_t ef = (elf_file_t) file;
796 int i;
797
798 /* Notify MD code that a module is being unloaded. */
799 elf_cpu_unload_file(file);
800
801 if (ef->preloaded) {
802 if (ef->reltab)
803 free(ef->reltab, M_LINKER);
804 if (ef->relatab)
805 free(ef->relatab, M_LINKER);
806 if (ef->progtab)
807 free(ef->progtab, M_LINKER);
808 if (file->filename != NULL)
809 preload_delete_name(file->filename);
810 /* XXX reclaim module memory? */
811 return;
812 }
813
814 for (i = 0; i < ef->nrel; i++)
815 if (ef->reltab[i].rel)
816 free(ef->reltab[i].rel, M_LINKER);
817 for (i = 0; i < ef->nrela; i++)
818 if (ef->relatab[i].rela)
819 free(ef->relatab[i].rela, M_LINKER);
820 if (ef->reltab)
821 free(ef->reltab, M_LINKER);
822 if (ef->relatab)
823 free(ef->relatab, M_LINKER);
824 if (ef->progtab)
825 free(ef->progtab, M_LINKER);
826
827 if (ef->object) {
828 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
829 (vm_offset_t) ef->address +
830 (ef->object->size << PAGE_SHIFT));
831 vm_object_deallocate(ef->object);
832 }
833 if (ef->e_shdr)
834 free(ef->e_shdr, M_LINKER);
835 if (ef->ddbsymtab)
836 free(ef->ddbsymtab, M_LINKER);
837 if (ef->ddbstrtab)
838 free(ef->ddbstrtab, M_LINKER);
839 if (ef->shstrtab)
840 free(ef->shstrtab, M_LINKER);
841 }
842
843 static const char *
844 symbol_name(elf_file_t ef, Elf_Word r_info)
845 {
846 const Elf_Sym *ref;
847
848 if (ELF_R_SYM(r_info)) {
849 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
850 return ef->ddbstrtab + ref->st_name;
851 } else
852 return NULL;
853 }
854
855 static Elf_Addr
856 findbase(elf_file_t ef, int sec)
857 {
858 int i;
859 Elf_Addr base = 0;
860
861 for (i = 0; i < ef->nprogtab; i++) {
862 if (sec == ef->progtab[i].sec) {
863 base = (Elf_Addr)ef->progtab[i].addr;
864 break;
865 }
866 }
867 return base;
868 }
869
870 static int
871 relocate_file(elf_file_t ef)
872 {
873 const Elf_Rel *rellim;
874 const Elf_Rel *rel;
875 const Elf_Rela *relalim;
876 const Elf_Rela *rela;
877 const char *symname;
878 const Elf_Sym *sym;
879 int i;
880 Elf_Word symidx;
881 Elf_Addr base;
882
883
884 /* Perform relocations without addend if there are any: */
885 for (i = 0; i < ef->nrel; i++) {
886 rel = ef->reltab[i].rel;
887 if (rel == NULL)
888 panic("lost a reltab!");
889 rellim = rel + ef->reltab[i].nrel;
890 base = findbase(ef, ef->reltab[i].sec);
891 if (base == 0)
892 panic("lost base for reltab");
893 for ( ; rel < rellim; rel++) {
894 symidx = ELF_R_SYM(rel->r_info);
895 if (symidx >= ef->ddbsymcnt)
896 continue;
897 sym = ef->ddbsymtab + symidx;
898 /* Local relocs are already done */
899 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
900 continue;
901 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
902 elf_obj_lookup)) {
903 symname = symbol_name(ef, rel->r_info);
904 printf("link_elf_obj: symbol %s undefined\n",
905 symname);
906 return ENOENT;
907 }
908 }
909 }
910
911 /* Perform relocations with addend if there are any: */
912 for (i = 0; i < ef->nrela; i++) {
913 rela = ef->relatab[i].rela;
914 if (rela == NULL)
915 panic("lost a relatab!");
916 relalim = rela + ef->relatab[i].nrela;
917 base = findbase(ef, ef->relatab[i].sec);
918 if (base == 0)
919 panic("lost base for relatab");
920 for ( ; rela < relalim; rela++) {
921 symidx = ELF_R_SYM(rela->r_info);
922 if (symidx >= ef->ddbsymcnt)
923 continue;
924 sym = ef->ddbsymtab + symidx;
925 /* Local relocs are already done */
926 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
927 continue;
928 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
929 elf_obj_lookup)) {
930 symname = symbol_name(ef, rela->r_info);
931 printf("link_elf_obj: symbol %s undefined\n",
932 symname);
933 return ENOENT;
934 }
935 }
936 }
937
938 return 0;
939 }
940
941 static int
942 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
943 {
944 elf_file_t ef = (elf_file_t) lf;
945 const Elf_Sym *symp;
946 const char *strp;
947 int i;
948
949 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
950 strp = ef->ddbstrtab + symp->st_name;
951 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
952 *sym = (c_linker_sym_t) symp;
953 return 0;
954 }
955 }
956 return ENOENT;
957 }
958
959 static int
960 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
961 linker_symval_t *symval)
962 {
963 elf_file_t ef = (elf_file_t) lf;
964 const Elf_Sym *es = (const Elf_Sym*) sym;
965
966 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
967 symval->name = ef->ddbstrtab + es->st_name;
968 symval->value = (caddr_t)es->st_value;
969 symval->size = es->st_size;
970 return 0;
971 }
972 return ENOENT;
973 }
974
975 static int
976 link_elf_search_symbol(linker_file_t lf, caddr_t value,
977 c_linker_sym_t *sym, long *diffp)
978 {
979 elf_file_t ef = (elf_file_t) lf;
980 u_long off = (uintptr_t) (void *) value;
981 u_long diff = off;
982 u_long st_value;
983 const Elf_Sym *es;
984 const Elf_Sym *best = 0;
985 int i;
986
987 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
988 if (es->st_name == 0)
989 continue;
990 st_value = es->st_value;
991 if (off >= st_value) {
992 if (off - st_value < diff) {
993 diff = off - st_value;
994 best = es;
995 if (diff == 0)
996 break;
997 } else if (off - st_value == diff) {
998 best = es;
999 }
1000 }
1001 }
1002 if (best == 0)
1003 *diffp = off;
1004 else
1005 *diffp = diff;
1006 *sym = (c_linker_sym_t) best;
1007
1008 return 0;
1009 }
1010
1011 /*
1012 * Look up a linker set on an ELF system.
1013 */
1014 static int
1015 link_elf_lookup_set(linker_file_t lf, const char *name,
1016 void ***startp, void ***stopp, int *countp)
1017 {
1018 elf_file_t ef = (elf_file_t)lf;
1019 void **start, **stop;
1020 int i, count;
1021
1022 /* Relative to section number */
1023 for (i = 0; i < ef->nprogtab; i++) {
1024 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1025 strcmp(ef->progtab[i].name + 4, name) == 0) {
1026 start = (void **)ef->progtab[i].addr;
1027 stop = (void **)((char *)ef->progtab[i].addr +
1028 ef->progtab[i].size);
1029 count = stop - start;
1030 if (startp)
1031 *startp = start;
1032 if (stopp)
1033 *stopp = stop;
1034 if (countp)
1035 *countp = count;
1036 return (0);
1037 }
1038 }
1039 return (ESRCH);
1040 }
1041
1042 static int
1043 link_elf_each_function_name(linker_file_t file,
1044 int (*callback)(const char *, void *), void *opaque)
1045 {
1046 elf_file_t ef = (elf_file_t)file;
1047 const Elf_Sym *symp;
1048 int i, error;
1049
1050 /* Exhaustive search */
1051 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1052 if (symp->st_value != 0 &&
1053 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1054 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1055 if (error)
1056 return (error);
1057 }
1058 }
1059 return (0);
1060 }
1061
1062 /*
1063 * Symbol lookup function that can be used when the symbol index is known (ie
1064 * in relocations). It uses the symbol index instead of doing a fully fledged
1065 * hash table based lookup when such is valid. For example for local symbols.
1066 * This is not only more efficient, it's also more correct. It's not always
1067 * the case that the symbol can be found through the hash table.
1068 */
1069 static Elf_Addr
1070 elf_obj_lookup(linker_file_t lf, Elf_Word symidx, int deps)
1071 {
1072 elf_file_t ef = (elf_file_t)lf;
1073 const Elf_Sym *sym;
1074 const char *symbol;
1075 Elf_Addr ret;
1076
1077 /* Don't even try to lookup the symbol if the index is bogus. */
1078 if (symidx >= ef->ddbsymcnt)
1079 return (0);
1080
1081 sym = ef->ddbsymtab + symidx;
1082
1083 /* Quick answer if there is a definition included. */
1084 if (sym->st_shndx != SHN_UNDEF)
1085 return (sym->st_value);
1086
1087 /* If we get here, then it is undefined and needs a lookup. */
1088 switch (ELF_ST_BIND(sym->st_info)) {
1089 case STB_LOCAL:
1090 /* Local, but undefined? huh? */
1091 return (0);
1092
1093 case STB_GLOBAL:
1094 /* Relative to Data or Function name */
1095 symbol = ef->ddbstrtab + sym->st_name;
1096
1097 /* Force a lookup failure if the symbol name is bogus. */
1098 if (*symbol == 0)
1099 return (0);
1100 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1101 return ret;
1102
1103 case STB_WEAK:
1104 printf("link_elf_obj: Weak symbols not supported\n");
1105 return (0);
1106
1107 default:
1108 return (0);
1109 }
1110 }
1111
1112 static void
1113 link_elf_reloc_local(linker_file_t lf)
1114 {
1115 elf_file_t ef = (elf_file_t)lf;
1116 const Elf_Rel *rellim;
1117 const Elf_Rel *rel;
1118 const Elf_Rela *relalim;
1119 const Elf_Rela *rela;
1120 const Elf_Sym *sym;
1121 Elf_Addr base;
1122 int i;
1123 Elf_Word symidx;
1124
1125 /* Perform relocations without addend if there are any: */
1126 for (i = 0; i < ef->nrel; i++) {
1127 rel = ef->reltab[i].rel;
1128 if (rel == NULL)
1129 panic("lost a reltab!");
1130 rellim = rel + ef->reltab[i].nrel;
1131 base = findbase(ef, ef->reltab[i].sec);
1132 if (base == 0)
1133 panic("lost base for reltab");
1134 for ( ; rel < rellim; rel++) {
1135 symidx = ELF_R_SYM(rel->r_info);
1136 if (symidx >= ef->ddbsymcnt)
1137 continue;
1138 sym = ef->ddbsymtab + symidx;
1139 /* Only do local relocs */
1140 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1141 continue;
1142 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1143 elf_obj_lookup);
1144 }
1145 }
1146
1147 /* Perform relocations with addend if there are any: */
1148 for (i = 0; i < ef->nrela; i++) {
1149 rela = ef->relatab[i].rela;
1150 if (rela == NULL)
1151 panic("lost a relatab!");
1152 relalim = rela + ef->relatab[i].nrela;
1153 base = findbase(ef, ef->relatab[i].sec);
1154 if (base == 0)
1155 panic("lost base for relatab");
1156 for ( ; rela < relalim; rela++) {
1157 symidx = ELF_R_SYM(rela->r_info);
1158 if (symidx >= ef->ddbsymcnt)
1159 continue;
1160 sym = ef->ddbsymtab + symidx;
1161 /* Only do local relocs */
1162 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1163 continue;
1164 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1165 elf_obj_lookup);
1166 }
1167 }
1168 }
Cache object: aa46b51cd5b8c95b95c8460c454a98e4
|