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("$FreeBSD$");
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/malloc.h>
39 #include <sys/mutex.h>
40 #include <sys/mount.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 <security/mac/mac_framework.h>
50
51 #include <vm/vm.h>
52 #include <vm/vm_param.h>
53 #include <vm/vm_object.h>
54 #include <vm/vm_kern.h>
55 #include <vm/vm_extern.h>
56 #include <vm/pmap.h>
57 #include <vm/vm_map.h>
58
59 #include <sys/link_elf.h>
60
61 #include "linker_if.h"
62
63 typedef struct {
64 void *addr;
65 Elf_Off size;
66 int flags;
67 int sec; /* Original section */
68 char *name;
69 } Elf_progent;
70
71 typedef struct {
72 Elf_Rel *rel;
73 int nrel;
74 int sec;
75 } Elf_relent;
76
77 typedef struct {
78 Elf_Rela *rela;
79 int nrela;
80 int sec;
81 } Elf_relaent;
82
83
84 typedef struct elf_file {
85 struct linker_file lf; /* Common fields */
86
87 int preloaded;
88 caddr_t address; /* Relocation address */
89 vm_object_t object; /* VM object to hold file pages */
90 Elf_Shdr *e_shdr;
91
92 Elf_progent *progtab;
93 int nprogtab;
94
95 Elf_relaent *relatab;
96 int nrela;
97
98 Elf_relent *reltab;
99 int nrel;
100
101 Elf_Sym *ddbsymtab; /* The symbol table we are using */
102 long ddbsymcnt; /* Number of symbols */
103 caddr_t ddbstrtab; /* String table */
104 long ddbstrcnt; /* number of bytes in string table */
105
106 caddr_t shstrtab; /* Section name string table */
107 long shstrcnt; /* number of bytes in string table */
108
109 } *elf_file_t;
110
111 static int link_elf_link_preload(linker_class_t cls,
112 const char *, linker_file_t *);
113 static int link_elf_link_preload_finish(linker_file_t);
114 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *);
115 static int link_elf_lookup_symbol(linker_file_t, const char *,
116 c_linker_sym_t *);
117 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
118 linker_symval_t *);
119 static int link_elf_search_symbol(linker_file_t, caddr_t value,
120 c_linker_sym_t *sym, long *diffp);
121
122 static void link_elf_unload_file(linker_file_t);
123 static int link_elf_lookup_set(linker_file_t, const char *,
124 void ***, void ***, int *);
125 static int link_elf_each_function_name(linker_file_t,
126 int (*)(const char *, void *), void *);
127 static void link_elf_reloc_local(linker_file_t);
128
129 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
130
131 static kobj_method_t link_elf_methods[] = {
132 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
133 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
134 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
135 KOBJMETHOD(linker_unload, link_elf_unload_file),
136 KOBJMETHOD(linker_load_file, link_elf_load_file),
137 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
138 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
139 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
140 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
141 { 0, 0 }
142 };
143
144 static struct linker_class link_elf_class = {
145 #if ELF_TARG_CLASS == ELFCLASS32
146 "elf32_obj",
147 #else
148 "elf64_obj",
149 #endif
150 link_elf_methods, sizeof(struct elf_file)
151 };
152
153 static int relocate_file(elf_file_t ef);
154
155 static void
156 link_elf_error(const char *s)
157 {
158 printf("kldload: %s\n", s);
159 }
160
161 static void
162 link_elf_init(void *arg)
163 {
164
165 linker_add_class(&link_elf_class);
166 }
167
168 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
169
170 static int
171 link_elf_link_preload(linker_class_t cls, const char *filename,
172 linker_file_t *result)
173 {
174 Elf_Ehdr *hdr;
175 Elf_Shdr *shdr;
176 Elf_Sym *es;
177 void *modptr, *baseptr, *sizeptr;
178 char *type;
179 elf_file_t ef;
180 linker_file_t lf;
181 Elf_Addr off;
182 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
183
184 /* Look to see if we have the file preloaded */
185 modptr = preload_search_by_name(filename);
186 if (modptr == NULL)
187 return ENOENT;
188
189 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
190 baseptr = preload_search_info(modptr, MODINFO_ADDR);
191 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
192 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
193 MODINFOMD_ELFHDR);
194 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
195 MODINFOMD_SHDR);
196 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
197 " obj module") != 0 &&
198 strcmp(type, "elf obj module") != 0)) {
199 return (EFTYPE);
200 }
201 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
202 shdr == NULL)
203 return (EINVAL);
204
205 lf = linker_make_file(filename, &link_elf_class);
206 if (lf == NULL)
207 return (ENOMEM);
208
209 ef = (elf_file_t)lf;
210 ef->preloaded = 1;
211 ef->address = *(caddr_t *)baseptr;
212 lf->address = *(caddr_t *)baseptr;
213 lf->size = *(size_t *)sizeptr;
214
215 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
216 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
217 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
218 hdr->e_version != EV_CURRENT ||
219 hdr->e_type != ET_REL ||
220 hdr->e_machine != ELF_TARG_MACH) {
221 error = EFTYPE;
222 goto out;
223 }
224 ef->e_shdr = shdr;
225
226 /* Scan the section header for information and table sizing. */
227 symtabindex = -1;
228 symstrindex = -1;
229 for (i = 0; i < hdr->e_shnum; i++) {
230 switch (shdr[i].sh_type) {
231 case SHT_PROGBITS:
232 case SHT_NOBITS:
233 ef->nprogtab++;
234 break;
235 case SHT_SYMTAB:
236 symtabindex = i;
237 symstrindex = shdr[i].sh_link;
238 break;
239 case SHT_REL:
240 ef->nrel++;
241 break;
242 case SHT_RELA:
243 ef->nrela++;
244 break;
245 }
246 }
247
248 shstrindex = hdr->e_shstrndx;
249 if (ef->nprogtab == 0 || symstrindex < 0 ||
250 symstrindex >= hdr->e_shnum ||
251 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
252 shstrindex >= hdr->e_shnum ||
253 shdr[shstrindex].sh_type != SHT_STRTAB) {
254 printf("%s: bad/missing section headers\n", filename);
255 error = ENOEXEC;
256 goto out;
257 }
258
259 /* Allocate space for tracking the load chunks */
260 if (ef->nprogtab != 0)
261 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
262 M_LINKER, M_WAITOK | M_ZERO);
263 if (ef->nrel != 0)
264 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER,
265 M_WAITOK | M_ZERO);
266 if (ef->nrela != 0)
267 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER,
268 M_WAITOK | M_ZERO);
269 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
270 (ef->nrel != 0 && ef->reltab == NULL) ||
271 (ef->nrela != 0 && ef->relatab == NULL)) {
272 error = ENOMEM;
273 goto out;
274 }
275
276 /* XXX, relocate the sh_addr fields saved by the loader. */
277 off = 0;
278 for (i = 0; i < hdr->e_shnum; i++) {
279 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
280 off = shdr[i].sh_addr;
281 }
282 for (i = 0; i < hdr->e_shnum; i++) {
283 if (shdr[i].sh_addr != 0)
284 shdr[i].sh_addr = shdr[i].sh_addr - off +
285 (Elf_Addr)ef->address;
286 }
287
288 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
289 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
290 ef->ddbstrcnt = shdr[symstrindex].sh_size;
291 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
292 ef->shstrcnt = shdr[shstrindex].sh_size;
293 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
294
295 /* Now fill out progtab and the relocation tables. */
296 pb = 0;
297 rl = 0;
298 ra = 0;
299 for (i = 0; i < hdr->e_shnum; i++) {
300 switch (shdr[i].sh_type) {
301 case SHT_PROGBITS:
302 case SHT_NOBITS:
303 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
304 if (shdr[i].sh_type == SHT_PROGBITS)
305 ef->progtab[pb].name = "<<PROGBITS>>";
306 else
307 ef->progtab[pb].name = "<<NOBITS>>";
308 ef->progtab[pb].size = shdr[i].sh_size;
309 ef->progtab[pb].sec = i;
310 if (ef->shstrtab && shdr[i].sh_name != 0)
311 ef->progtab[pb].name =
312 ef->shstrtab + shdr[i].sh_name;
313
314 /* Update all symbol values with the offset. */
315 for (j = 0; j < ef->ddbsymcnt; j++) {
316 es = &ef->ddbsymtab[j];
317 if (es->st_shndx != i)
318 continue;
319 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
320 }
321 pb++;
322 break;
323 case SHT_REL:
324 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
325 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
326 ef->reltab[rl].sec = shdr[i].sh_info;
327 rl++;
328 break;
329 case SHT_RELA:
330 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
331 ef->relatab[ra].nrela =
332 shdr[i].sh_size / sizeof(Elf_Rela);
333 ef->relatab[ra].sec = shdr[i].sh_info;
334 ra++;
335 break;
336 }
337 }
338 if (pb != ef->nprogtab)
339 panic("lost progbits");
340 if (rl != ef->nrel)
341 panic("lost rel");
342 if (ra != ef->nrela)
343 panic("lost rela");
344
345 /* Local intra-module relocations */
346 link_elf_reloc_local(lf);
347
348 *result = lf;
349 return (0);
350
351 out:
352 /* preload not done this way */
353 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
354 return (error);
355 }
356
357 static int
358 link_elf_link_preload_finish(linker_file_t lf)
359 {
360 elf_file_t ef;
361 int error;
362
363 ef = (elf_file_t)lf;
364 error = relocate_file(ef);
365 if (error)
366 return error;
367
368 /* Notify MD code that a module is being loaded. */
369 error = elf_cpu_load_file(lf);
370 if (error)
371 return (error);
372
373 return (0);
374 }
375
376 static int
377 link_elf_load_file(linker_class_t cls, const char *filename,
378 linker_file_t *result)
379 {
380 struct nameidata nd;
381 struct thread *td = curthread; /* XXX */
382 Elf_Ehdr *hdr;
383 Elf_Shdr *shdr;
384 Elf_Sym *es;
385 int nbytes, i, j;
386 vm_offset_t mapbase;
387 size_t mapsize;
388 int error = 0;
389 int resid, flags;
390 elf_file_t ef;
391 linker_file_t lf;
392 int symtabindex;
393 int symstrindex;
394 int shstrindex;
395 int nsym;
396 int pb, rl, ra;
397 int alignmask;
398 int vfslocked;
399
400 shdr = NULL;
401 lf = NULL;
402 mapsize = 0;
403 hdr = NULL;
404
405 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
406 flags = FREAD;
407 error = vn_open(&nd, &flags, 0, NULL);
408 if (error)
409 return error;
410 vfslocked = NDHASGIANT(&nd);
411 NDFREE(&nd, NDF_ONLY_PNBUF);
412 #ifdef MAC
413 error = mac_check_kld_load(td->td_ucred, nd.ni_vp);
414 if (error) {
415 goto out;
416 }
417 #endif
418
419 /* Read the elf header from the file. */
420 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
421 if (hdr == NULL) {
422 error = ENOMEM;
423 goto out;
424 }
425 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
426 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
427 &resid, td);
428 if (error)
429 goto out;
430 if (resid != 0){
431 error = ENOEXEC;
432 goto out;
433 }
434
435 if (!IS_ELF(*hdr)) {
436 error = ENOEXEC;
437 goto out;
438 }
439
440 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
441 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
442 link_elf_error("Unsupported file layout");
443 error = ENOEXEC;
444 goto out;
445 }
446 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
447 || hdr->e_version != EV_CURRENT) {
448 link_elf_error("Unsupported file version");
449 error = ENOEXEC;
450 goto out;
451 }
452 if (hdr->e_type != ET_REL) {
453 link_elf_error("Unsupported file type");
454 error = ENOEXEC;
455 goto out;
456 }
457 if (hdr->e_machine != ELF_TARG_MACH) {
458 link_elf_error("Unsupported machine");
459 error = ENOEXEC;
460 goto out;
461 }
462
463 lf = linker_make_file(filename, &link_elf_class);
464 if (!lf) {
465 error = ENOMEM;
466 goto out;
467 }
468 ef = (elf_file_t) lf;
469 ef->nprogtab = 0;
470 ef->e_shdr = 0;
471 ef->nrel = 0;
472 ef->nrela = 0;
473
474 /* Allocate and read in the section header */
475 nbytes = hdr->e_shnum * hdr->e_shentsize;
476 if (nbytes == 0 || hdr->e_shoff == 0 ||
477 hdr->e_shentsize != sizeof(Elf_Shdr)) {
478 error = ENOEXEC;
479 goto out;
480 }
481 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
482 if (shdr == NULL) {
483 error = ENOMEM;
484 goto out;
485 }
486 ef->e_shdr = shdr;
487 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
488 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
489 if (error)
490 goto out;
491 if (resid) {
492 error = ENOEXEC;
493 goto out;
494 }
495
496 /* Scan the section header for information and table sizing. */
497 nsym = 0;
498 symtabindex = -1;
499 symstrindex = -1;
500 for (i = 0; i < hdr->e_shnum; i++) {
501 switch (shdr[i].sh_type) {
502 case SHT_PROGBITS:
503 case SHT_NOBITS:
504 ef->nprogtab++;
505 break;
506 case SHT_SYMTAB:
507 nsym++;
508 symtabindex = i;
509 symstrindex = shdr[i].sh_link;
510 break;
511 case SHT_REL:
512 ef->nrel++;
513 break;
514 case SHT_RELA:
515 ef->nrela++;
516 break;
517 case SHT_STRTAB:
518 break;
519 }
520 }
521 if (ef->nprogtab == 0) {
522 link_elf_error("file has no contents");
523 error = ENOEXEC;
524 goto out;
525 }
526 if (nsym != 1) {
527 /* Only allow one symbol table for now */
528 link_elf_error("file has no valid symbol table");
529 error = ENOEXEC;
530 goto out;
531 }
532 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
533 shdr[symstrindex].sh_type != SHT_STRTAB) {
534 link_elf_error("file has invalid symbol strings");
535 error = ENOEXEC;
536 goto out;
537 }
538
539 /* Allocate space for tracking the load chunks */
540 if (ef->nprogtab != 0)
541 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
542 M_LINKER, M_WAITOK | M_ZERO);
543 if (ef->nrel != 0)
544 ef->reltab = malloc(ef->nrel * sizeof(*ef->reltab), M_LINKER,
545 M_WAITOK | M_ZERO);
546 if (ef->nrela != 0)
547 ef->relatab = malloc(ef->nrela * sizeof(*ef->relatab), M_LINKER,
548 M_WAITOK | M_ZERO);
549 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
550 (ef->nrel != 0 && ef->reltab == NULL) ||
551 (ef->nrela != 0 && ef->relatab == NULL)) {
552 error = ENOMEM;
553 goto out;
554 }
555
556 if (symtabindex == -1)
557 panic("lost symbol table index");
558 /* Allocate space for and load the symbol table */
559 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
560 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
561 if (ef->ddbsymtab == NULL) {
562 error = ENOMEM;
563 goto out;
564 }
565 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
566 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
567 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
568 &resid, td);
569 if (error)
570 goto out;
571 if (resid != 0){
572 error = EINVAL;
573 goto out;
574 }
575
576 if (symstrindex == -1)
577 panic("lost symbol string index");
578 /* Allocate space for and load the symbol strings */
579 ef->ddbstrcnt = shdr[symstrindex].sh_size;
580 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
581 if (ef->ddbstrtab == NULL) {
582 error = ENOMEM;
583 goto out;
584 }
585 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
586 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
587 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
588 &resid, td);
589 if (error)
590 goto out;
591 if (resid != 0){
592 error = EINVAL;
593 goto out;
594 }
595
596 /* Do we have a string table for the section names? */
597 shstrindex = -1;
598 if (hdr->e_shstrndx != 0 &&
599 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
600 shstrindex = hdr->e_shstrndx;
601 ef->shstrcnt = shdr[shstrindex].sh_size;
602 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
603 M_WAITOK);
604 if (ef->shstrtab == NULL) {
605 error = ENOMEM;
606 goto out;
607 }
608 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
609 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
610 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
611 &resid, td);
612 if (error)
613 goto out;
614 if (resid != 0){
615 error = EINVAL;
616 goto out;
617 }
618 }
619
620 /* Size up code/data(progbits) and bss(nobits). */
621 alignmask = 0;
622 for (i = 0; i < hdr->e_shnum; i++) {
623 switch (shdr[i].sh_type) {
624 case SHT_PROGBITS:
625 case SHT_NOBITS:
626 alignmask = shdr[i].sh_addralign - 1;
627 mapsize += alignmask;
628 mapsize &= ~alignmask;
629 mapsize += shdr[i].sh_size;
630 break;
631 }
632 }
633
634 /*
635 * We know how much space we need for the text/data/bss/etc.
636 * This stuff needs to be in a single chunk so that profiling etc
637 * can get the bounds and gdb can associate offsets with modules
638 */
639 ef->object = vm_object_allocate(OBJT_DEFAULT,
640 round_page(mapsize) >> PAGE_SHIFT);
641 if (ef->object == NULL) {
642 error = ENOMEM;
643 goto out;
644 }
645 ef->address = (caddr_t) vm_map_min(kernel_map);
646 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
647 round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
648 if (error) {
649 vm_object_deallocate(ef->object);
650 ef->object = 0;
651 goto out;
652 }
653
654 /* Wire the pages */
655 error = vm_map_wire(kernel_map, mapbase,
656 mapbase + round_page(mapsize),
657 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
658 if (error != KERN_SUCCESS) {
659 error = ENOMEM;
660 goto out;
661 }
662
663 /* Inform the kld system about the situation */
664 lf->address = ef->address = (caddr_t)mapbase;
665 lf->size = mapsize;
666
667 /*
668 * Now load code/data(progbits), zero bss(nobits), allocate space for
669 * and load relocs
670 */
671 pb = 0;
672 rl = 0;
673 ra = 0;
674 alignmask = 0;
675 for (i = 0; i < hdr->e_shnum; i++) {
676 switch (shdr[i].sh_type) {
677 case SHT_PROGBITS:
678 case SHT_NOBITS:
679 alignmask = shdr[i].sh_addralign - 1;
680 mapbase += alignmask;
681 mapbase &= ~alignmask;
682 ef->progtab[pb].addr = (void *)(uintptr_t)mapbase;
683 if (shdr[i].sh_type == SHT_PROGBITS) {
684 ef->progtab[pb].name = "<<PROGBITS>>";
685 error = vn_rdwr(UIO_READ, nd.ni_vp,
686 ef->progtab[pb].addr,
687 shdr[i].sh_size, shdr[i].sh_offset,
688 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
689 NOCRED, &resid, td);
690 if (error)
691 goto out;
692 if (resid != 0){
693 error = EINVAL;
694 goto out;
695 }
696 } else {
697 ef->progtab[pb].name = "<<NOBITS>>";
698 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
699 }
700 ef->progtab[pb].size = shdr[i].sh_size;
701 ef->progtab[pb].sec = i;
702 if (ef->shstrtab && shdr[i].sh_name != 0)
703 ef->progtab[pb].name =
704 ef->shstrtab + shdr[i].sh_name;
705
706 /* Update all symbol values with the offset. */
707 for (j = 0; j < ef->ddbsymcnt; j++) {
708 es = &ef->ddbsymtab[j];
709 if (es->st_shndx != i)
710 continue;
711 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
712 }
713 mapbase += shdr[i].sh_size;
714 pb++;
715 break;
716 case SHT_REL:
717 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
718 M_WAITOK);
719 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
720 ef->reltab[rl].sec = shdr[i].sh_info;
721 error = vn_rdwr(UIO_READ, nd.ni_vp,
722 (void *)ef->reltab[rl].rel,
723 shdr[i].sh_size, shdr[i].sh_offset,
724 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
725 &resid, td);
726 if (error)
727 goto out;
728 if (resid != 0){
729 error = EINVAL;
730 goto out;
731 }
732 rl++;
733 break;
734 case SHT_RELA:
735 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
736 M_WAITOK);
737 ef->relatab[ra].nrela =
738 shdr[i].sh_size / sizeof(Elf_Rela);
739 ef->relatab[ra].sec = shdr[i].sh_info;
740 error = vn_rdwr(UIO_READ, nd.ni_vp,
741 (void *)ef->relatab[ra].rela,
742 shdr[i].sh_size, shdr[i].sh_offset,
743 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
744 &resid, td);
745 if (error)
746 goto out;
747 if (resid != 0){
748 error = EINVAL;
749 goto out;
750 }
751 ra++;
752 break;
753 }
754 }
755 if (pb != ef->nprogtab)
756 panic("lost progbits");
757 if (rl != ef->nrel)
758 panic("lost rel");
759 if (ra != ef->nrela)
760 panic("lost rela");
761 if (mapbase != (vm_offset_t)ef->address + mapsize)
762 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
763 mapbase, ef->address, mapsize,
764 (vm_offset_t)ef->address + mapsize);
765
766 /* Local intra-module relocations */
767 link_elf_reloc_local(lf);
768
769 /* Pull in dependencies */
770 error = linker_load_dependencies(lf);
771 if (error)
772 goto out;
773
774 /* External relocations */
775 error = relocate_file(ef);
776 if (error)
777 goto out;
778
779 /* Notify MD code that a module is being loaded. */
780 error = elf_cpu_load_file(lf);
781 if (error)
782 goto out;
783
784 *result = lf;
785
786 out:
787 if (error && lf)
788 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
789 if (hdr)
790 free(hdr, M_LINKER);
791 VOP_UNLOCK(nd.ni_vp, 0, td);
792 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
793 VFS_UNLOCK_GIANT(vfslocked);
794
795 return error;
796 }
797
798 static void
799 link_elf_unload_file(linker_file_t file)
800 {
801 elf_file_t ef = (elf_file_t) file;
802 int i;
803
804 /* Notify MD code that a module is being unloaded. */
805 elf_cpu_unload_file(file);
806
807 if (ef->preloaded) {
808 if (ef->reltab)
809 free(ef->reltab, M_LINKER);
810 if (ef->relatab)
811 free(ef->relatab, M_LINKER);
812 if (ef->progtab)
813 free(ef->progtab, M_LINKER);
814 if (file->filename != NULL)
815 preload_delete_name(file->filename);
816 /* XXX reclaim module memory? */
817 return;
818 }
819
820 for (i = 0; i < ef->nrel; i++)
821 if (ef->reltab[i].rel)
822 free(ef->reltab[i].rel, M_LINKER);
823 for (i = 0; i < ef->nrela; i++)
824 if (ef->relatab[i].rela)
825 free(ef->relatab[i].rela, M_LINKER);
826 if (ef->reltab)
827 free(ef->reltab, M_LINKER);
828 if (ef->relatab)
829 free(ef->relatab, M_LINKER);
830 if (ef->progtab)
831 free(ef->progtab, M_LINKER);
832
833 if (ef->object) {
834 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
835 (vm_offset_t) ef->address +
836 (ef->object->size << PAGE_SHIFT));
837 }
838 if (ef->e_shdr)
839 free(ef->e_shdr, M_LINKER);
840 if (ef->ddbsymtab)
841 free(ef->ddbsymtab, M_LINKER);
842 if (ef->ddbstrtab)
843 free(ef->ddbstrtab, M_LINKER);
844 if (ef->shstrtab)
845 free(ef->shstrtab, M_LINKER);
846 }
847
848 static const char *
849 symbol_name(elf_file_t ef, Elf_Size r_info)
850 {
851 const Elf_Sym *ref;
852
853 if (ELF_R_SYM(r_info)) {
854 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
855 return ef->ddbstrtab + ref->st_name;
856 } else
857 return NULL;
858 }
859
860 static Elf_Addr
861 findbase(elf_file_t ef, int sec)
862 {
863 int i;
864 Elf_Addr base = 0;
865
866 for (i = 0; i < ef->nprogtab; i++) {
867 if (sec == ef->progtab[i].sec) {
868 base = (Elf_Addr)ef->progtab[i].addr;
869 break;
870 }
871 }
872 return base;
873 }
874
875 static int
876 relocate_file(elf_file_t ef)
877 {
878 const Elf_Rel *rellim;
879 const Elf_Rel *rel;
880 const Elf_Rela *relalim;
881 const Elf_Rela *rela;
882 const char *symname;
883 const Elf_Sym *sym;
884 int i;
885 Elf_Size symidx;
886 Elf_Addr base;
887
888
889 /* Perform relocations without addend if there are any: */
890 for (i = 0; i < ef->nrel; i++) {
891 rel = ef->reltab[i].rel;
892 if (rel == NULL)
893 panic("lost a reltab!");
894 rellim = rel + ef->reltab[i].nrel;
895 base = findbase(ef, ef->reltab[i].sec);
896 if (base == 0)
897 panic("lost base for reltab");
898 for ( ; rel < rellim; rel++) {
899 symidx = ELF_R_SYM(rel->r_info);
900 if (symidx >= ef->ddbsymcnt)
901 continue;
902 sym = ef->ddbsymtab + symidx;
903 /* Local relocs are already done */
904 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
905 continue;
906 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
907 elf_obj_lookup)) {
908 symname = symbol_name(ef, rel->r_info);
909 printf("link_elf_obj: symbol %s undefined\n",
910 symname);
911 return ENOENT;
912 }
913 }
914 }
915
916 /* Perform relocations with addend if there are any: */
917 for (i = 0; i < ef->nrela; i++) {
918 rela = ef->relatab[i].rela;
919 if (rela == NULL)
920 panic("lost a relatab!");
921 relalim = rela + ef->relatab[i].nrela;
922 base = findbase(ef, ef->relatab[i].sec);
923 if (base == 0)
924 panic("lost base for relatab");
925 for ( ; rela < relalim; rela++) {
926 symidx = ELF_R_SYM(rela->r_info);
927 if (symidx >= ef->ddbsymcnt)
928 continue;
929 sym = ef->ddbsymtab + symidx;
930 /* Local relocs are already done */
931 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
932 continue;
933 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
934 elf_obj_lookup)) {
935 symname = symbol_name(ef, rela->r_info);
936 printf("link_elf_obj: symbol %s undefined\n",
937 symname);
938 return ENOENT;
939 }
940 }
941 }
942
943 return 0;
944 }
945
946 static int
947 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
948 {
949 elf_file_t ef = (elf_file_t) lf;
950 const Elf_Sym *symp;
951 const char *strp;
952 int i;
953
954 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
955 strp = ef->ddbstrtab + symp->st_name;
956 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
957 *sym = (c_linker_sym_t) symp;
958 return 0;
959 }
960 }
961 return ENOENT;
962 }
963
964 static int
965 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
966 linker_symval_t *symval)
967 {
968 elf_file_t ef = (elf_file_t) lf;
969 const Elf_Sym *es = (const Elf_Sym*) sym;
970
971 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
972 symval->name = ef->ddbstrtab + es->st_name;
973 symval->value = (caddr_t)es->st_value;
974 symval->size = es->st_size;
975 return 0;
976 }
977 return ENOENT;
978 }
979
980 static int
981 link_elf_search_symbol(linker_file_t lf, caddr_t value,
982 c_linker_sym_t *sym, long *diffp)
983 {
984 elf_file_t ef = (elf_file_t) lf;
985 u_long off = (uintptr_t) (void *) value;
986 u_long diff = off;
987 u_long st_value;
988 const Elf_Sym *es;
989 const Elf_Sym *best = 0;
990 int i;
991
992 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
993 if (es->st_name == 0)
994 continue;
995 st_value = es->st_value;
996 if (off >= st_value) {
997 if (off - st_value < diff) {
998 diff = off - st_value;
999 best = es;
1000 if (diff == 0)
1001 break;
1002 } else if (off - st_value == diff) {
1003 best = es;
1004 }
1005 }
1006 }
1007 if (best == 0)
1008 *diffp = off;
1009 else
1010 *diffp = diff;
1011 *sym = (c_linker_sym_t) best;
1012
1013 return 0;
1014 }
1015
1016 /*
1017 * Look up a linker set on an ELF system.
1018 */
1019 static int
1020 link_elf_lookup_set(linker_file_t lf, const char *name,
1021 void ***startp, void ***stopp, int *countp)
1022 {
1023 elf_file_t ef = (elf_file_t)lf;
1024 void **start, **stop;
1025 int i, count;
1026
1027 /* Relative to section number */
1028 for (i = 0; i < ef->nprogtab; i++) {
1029 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1030 strcmp(ef->progtab[i].name + 4, name) == 0) {
1031 start = (void **)ef->progtab[i].addr;
1032 stop = (void **)((char *)ef->progtab[i].addr +
1033 ef->progtab[i].size);
1034 count = stop - start;
1035 if (startp)
1036 *startp = start;
1037 if (stopp)
1038 *stopp = stop;
1039 if (countp)
1040 *countp = count;
1041 return (0);
1042 }
1043 }
1044 return (ESRCH);
1045 }
1046
1047 static int
1048 link_elf_each_function_name(linker_file_t file,
1049 int (*callback)(const char *, void *), void *opaque)
1050 {
1051 elf_file_t ef = (elf_file_t)file;
1052 const Elf_Sym *symp;
1053 int i, error;
1054
1055 /* Exhaustive search */
1056 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1057 if (symp->st_value != 0 &&
1058 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1059 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1060 if (error)
1061 return (error);
1062 }
1063 }
1064 return (0);
1065 }
1066
1067 /*
1068 * Symbol lookup function that can be used when the symbol index is known (ie
1069 * in relocations). It uses the symbol index instead of doing a fully fledged
1070 * hash table based lookup when such is valid. For example for local symbols.
1071 * This is not only more efficient, it's also more correct. It's not always
1072 * the case that the symbol can be found through the hash table.
1073 */
1074 static Elf_Addr
1075 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1076 {
1077 elf_file_t ef = (elf_file_t)lf;
1078 const Elf_Sym *sym;
1079 const char *symbol;
1080 Elf_Addr ret;
1081
1082 /* Don't even try to lookup the symbol if the index is bogus. */
1083 if (symidx >= ef->ddbsymcnt)
1084 return (0);
1085
1086 sym = ef->ddbsymtab + symidx;
1087
1088 /* Quick answer if there is a definition included. */
1089 if (sym->st_shndx != SHN_UNDEF)
1090 return (sym->st_value);
1091
1092 /* If we get here, then it is undefined and needs a lookup. */
1093 switch (ELF_ST_BIND(sym->st_info)) {
1094 case STB_LOCAL:
1095 /* Local, but undefined? huh? */
1096 return (0);
1097
1098 case STB_GLOBAL:
1099 /* Relative to Data or Function name */
1100 symbol = ef->ddbstrtab + sym->st_name;
1101
1102 /* Force a lookup failure if the symbol name is bogus. */
1103 if (*symbol == 0)
1104 return (0);
1105 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1106 return ret;
1107
1108 case STB_WEAK:
1109 printf("link_elf_obj: Weak symbols not supported\n");
1110 return (0);
1111
1112 default:
1113 return (0);
1114 }
1115 }
1116
1117 static void
1118 link_elf_fix_link_set(elf_file_t ef)
1119 {
1120 static const char startn[] = "__start_";
1121 static const char stopn[] = "__stop_";
1122 Elf_Sym *sym;
1123 const char *sym_name, *linkset_name;
1124 Elf_Addr startp, stopp;
1125 Elf_Size symidx;
1126 int start, i;
1127
1128 startp = stopp = 0;
1129 for (symidx = 1 /* zero entry is special */;
1130 symidx < ef->ddbsymcnt; symidx++) {
1131 sym = ef->ddbsymtab + symidx;
1132 if (sym->st_shndx != SHN_UNDEF)
1133 continue;
1134
1135 sym_name = ef->ddbstrtab + sym->st_name;
1136 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1137 start = 1;
1138 linkset_name = sym_name + sizeof(startn) - 1;
1139 }
1140 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1141 start = 0;
1142 linkset_name = sym_name + sizeof(stopn) - 1;
1143 }
1144 else
1145 continue;
1146
1147 for (i = 0; i < ef->nprogtab; i++) {
1148 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1149 startp = (Elf_Addr)ef->progtab[i].addr;
1150 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1151 break;
1152 }
1153 }
1154 if (i == ef->nprogtab)
1155 continue;
1156
1157 sym->st_value = start ? startp : stopp;
1158 sym->st_shndx = i;
1159 }
1160 }
1161
1162 static void
1163 link_elf_reloc_local(linker_file_t lf)
1164 {
1165 elf_file_t ef = (elf_file_t)lf;
1166 const Elf_Rel *rellim;
1167 const Elf_Rel *rel;
1168 const Elf_Rela *relalim;
1169 const Elf_Rela *rela;
1170 const Elf_Sym *sym;
1171 Elf_Addr base;
1172 int i;
1173 Elf_Size symidx;
1174
1175 link_elf_fix_link_set(ef);
1176
1177 /* Perform relocations without addend if there are any: */
1178 for (i = 0; i < ef->nrel; i++) {
1179 rel = ef->reltab[i].rel;
1180 if (rel == NULL)
1181 panic("lost a reltab!");
1182 rellim = rel + ef->reltab[i].nrel;
1183 base = findbase(ef, ef->reltab[i].sec);
1184 if (base == 0)
1185 panic("lost base for reltab");
1186 for ( ; rel < rellim; rel++) {
1187 symidx = ELF_R_SYM(rel->r_info);
1188 if (symidx >= ef->ddbsymcnt)
1189 continue;
1190 sym = ef->ddbsymtab + symidx;
1191 /* Only do local relocs */
1192 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1193 continue;
1194 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1195 elf_obj_lookup);
1196 }
1197 }
1198
1199 /* Perform relocations with addend if there are any: */
1200 for (i = 0; i < ef->nrela; i++) {
1201 rela = ef->relatab[i].rela;
1202 if (rela == NULL)
1203 panic("lost a relatab!");
1204 relalim = rela + ef->relatab[i].nrela;
1205 base = findbase(ef, ef->relatab[i].sec);
1206 if (base == 0)
1207 panic("lost base for relatab");
1208 for ( ; rela < relalim; rela++) {
1209 symidx = ELF_R_SYM(rela->r_info);
1210 if (symidx >= ef->ddbsymcnt)
1211 continue;
1212 sym = ef->ddbsymtab + symidx;
1213 /* Only do local relocs */
1214 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1215 continue;
1216 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1217 elf_obj_lookup);
1218 }
1219 }
1220 }
Cache object: b68cb24db1e93ada20ffcc09032e4c31
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