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/11.0/sys/kern/link_elf_obj.c 298819 2016-04-29 22:15:33Z pfg $");
30
31 #include "opt_ddb.h"
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/mount.h>
40 #include <sys/proc.h>
41 #include <sys/namei.h>
42 #include <sys/fcntl.h>
43 #include <sys/vnode.h>
44 #include <sys/linker.h>
45
46 #include <machine/elf.h>
47
48 #include <net/vnet.h>
49
50 #include <security/mac/mac_framework.h>
51
52 #include <vm/vm.h>
53 #include <vm/vm_param.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_kern.h>
56 #include <vm/vm_extern.h>
57 #include <vm/pmap.h>
58 #include <vm/vm_map.h>
59
60 #include <sys/link_elf.h>
61
62 #ifdef DDB_CTF
63 #include <sys/zlib.h>
64 #endif
65
66 #include "linker_if.h"
67
68 typedef struct {
69 void *addr;
70 Elf_Off size;
71 int flags;
72 int sec; /* Original section */
73 char *name;
74 } Elf_progent;
75
76 typedef struct {
77 Elf_Rel *rel;
78 int nrel;
79 int sec;
80 } Elf_relent;
81
82 typedef struct {
83 Elf_Rela *rela;
84 int nrela;
85 int sec;
86 } Elf_relaent;
87
88
89 typedef struct elf_file {
90 struct linker_file lf; /* Common fields */
91
92 int preloaded;
93 caddr_t address; /* Relocation address */
94 vm_object_t object; /* VM object to hold file pages */
95 Elf_Shdr *e_shdr;
96
97 Elf_progent *progtab;
98 int nprogtab;
99
100 Elf_relaent *relatab;
101 int nrelatab;
102
103 Elf_relent *reltab;
104 int nreltab;
105
106 Elf_Sym *ddbsymtab; /* The symbol table we are using */
107 long ddbsymcnt; /* Number of symbols */
108 caddr_t ddbstrtab; /* String table */
109 long ddbstrcnt; /* number of bytes in string table */
110
111 caddr_t shstrtab; /* Section name string table */
112 long shstrcnt; /* number of bytes in string table */
113
114 caddr_t ctftab; /* CTF table */
115 long ctfcnt; /* number of bytes in CTF table */
116 caddr_t ctfoff; /* CTF offset table */
117 caddr_t typoff; /* Type offset table */
118 long typlen; /* Number of type entries. */
119
120 } *elf_file_t;
121
122 #include <kern/kern_ctf.c>
123
124 static int link_elf_link_preload(linker_class_t cls,
125 const char *, linker_file_t *);
126 static int link_elf_link_preload_finish(linker_file_t);
127 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *);
128 static int link_elf_lookup_symbol(linker_file_t, const char *,
129 c_linker_sym_t *);
130 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
131 linker_symval_t *);
132 static int link_elf_search_symbol(linker_file_t, caddr_t value,
133 c_linker_sym_t *sym, long *diffp);
134
135 static void link_elf_unload_file(linker_file_t);
136 static int link_elf_lookup_set(linker_file_t, const char *,
137 void ***, void ***, int *);
138 static int link_elf_each_function_name(linker_file_t,
139 int (*)(const char *, void *), void *);
140 static int link_elf_each_function_nameval(linker_file_t,
141 linker_function_nameval_callback_t,
142 void *);
143 static int link_elf_reloc_local(linker_file_t);
144 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
145 static long link_elf_strtab_get(linker_file_t, caddr_t *);
146
147 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
148 Elf_Addr *);
149
150 static kobj_method_t link_elf_methods[] = {
151 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
152 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
153 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
154 KOBJMETHOD(linker_unload, link_elf_unload_file),
155 KOBJMETHOD(linker_load_file, link_elf_load_file),
156 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
157 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
158 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
159 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
160 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
161 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
162 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
163 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
164 { 0, 0 }
165 };
166
167 static struct linker_class link_elf_class = {
168 #if ELF_TARG_CLASS == ELFCLASS32
169 "elf32_obj",
170 #else
171 "elf64_obj",
172 #endif
173 link_elf_methods, sizeof(struct elf_file)
174 };
175
176 static int relocate_file(elf_file_t ef);
177 static void elf_obj_cleanup_globals_cache(elf_file_t);
178
179 static void
180 link_elf_error(const char *filename, const char *s)
181 {
182 if (filename == NULL)
183 printf("kldload: %s\n", s);
184 else
185 printf("kldload: %s: %s\n", filename, s);
186 }
187
188 static void
189 link_elf_init(void *arg)
190 {
191
192 linker_add_class(&link_elf_class);
193 }
194
195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
196
197 static int
198 link_elf_link_preload(linker_class_t cls, const char *filename,
199 linker_file_t *result)
200 {
201 Elf_Ehdr *hdr;
202 Elf_Shdr *shdr;
203 Elf_Sym *es;
204 void *modptr, *baseptr, *sizeptr;
205 char *type;
206 elf_file_t ef;
207 linker_file_t lf;
208 Elf_Addr off;
209 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
210
211 /* Look to see if we have the file preloaded */
212 modptr = preload_search_by_name(filename);
213 if (modptr == NULL)
214 return ENOENT;
215
216 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
217 baseptr = preload_search_info(modptr, MODINFO_ADDR);
218 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
219 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
220 MODINFOMD_ELFHDR);
221 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
222 MODINFOMD_SHDR);
223 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
224 " obj module") != 0 &&
225 strcmp(type, "elf obj module") != 0)) {
226 return (EFTYPE);
227 }
228 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
229 shdr == NULL)
230 return (EINVAL);
231
232 lf = linker_make_file(filename, &link_elf_class);
233 if (lf == NULL)
234 return (ENOMEM);
235
236 ef = (elf_file_t)lf;
237 ef->preloaded = 1;
238 ef->address = *(caddr_t *)baseptr;
239 lf->address = *(caddr_t *)baseptr;
240 lf->size = *(size_t *)sizeptr;
241
242 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
243 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
244 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
245 hdr->e_version != EV_CURRENT ||
246 hdr->e_type != ET_REL ||
247 hdr->e_machine != ELF_TARG_MACH) {
248 error = EFTYPE;
249 goto out;
250 }
251 ef->e_shdr = shdr;
252
253 /* Scan the section header for information and table sizing. */
254 symtabindex = -1;
255 symstrindex = -1;
256 for (i = 0; i < hdr->e_shnum; i++) {
257 switch (shdr[i].sh_type) {
258 case SHT_PROGBITS:
259 case SHT_NOBITS:
260 #ifdef __amd64__
261 case SHT_X86_64_UNWIND:
262 #endif
263 ef->nprogtab++;
264 break;
265 case SHT_SYMTAB:
266 symtabindex = i;
267 symstrindex = shdr[i].sh_link;
268 break;
269 case SHT_REL:
270 ef->nreltab++;
271 break;
272 case SHT_RELA:
273 ef->nrelatab++;
274 break;
275 }
276 }
277
278 shstrindex = hdr->e_shstrndx;
279 if (ef->nprogtab == 0 || symstrindex < 0 ||
280 symstrindex >= hdr->e_shnum ||
281 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
282 shstrindex >= hdr->e_shnum ||
283 shdr[shstrindex].sh_type != SHT_STRTAB) {
284 printf("%s: bad/missing section headers\n", filename);
285 error = ENOEXEC;
286 goto out;
287 }
288
289 /* Allocate space for tracking the load chunks */
290 if (ef->nprogtab != 0)
291 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
292 M_LINKER, M_WAITOK | M_ZERO);
293 if (ef->nreltab != 0)
294 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
295 M_LINKER, M_WAITOK | M_ZERO);
296 if (ef->nrelatab != 0)
297 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
298 M_LINKER, M_WAITOK | M_ZERO);
299 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
300 (ef->nreltab != 0 && ef->reltab == NULL) ||
301 (ef->nrelatab != 0 && ef->relatab == NULL)) {
302 error = ENOMEM;
303 goto out;
304 }
305
306 /* XXX, relocate the sh_addr fields saved by the loader. */
307 off = 0;
308 for (i = 0; i < hdr->e_shnum; i++) {
309 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
310 off = shdr[i].sh_addr;
311 }
312 for (i = 0; i < hdr->e_shnum; i++) {
313 if (shdr[i].sh_addr != 0)
314 shdr[i].sh_addr = shdr[i].sh_addr - off +
315 (Elf_Addr)ef->address;
316 }
317
318 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
319 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
320 ef->ddbstrcnt = shdr[symstrindex].sh_size;
321 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
322 ef->shstrcnt = shdr[shstrindex].sh_size;
323 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
324
325 /* Now fill out progtab and the relocation tables. */
326 pb = 0;
327 rl = 0;
328 ra = 0;
329 for (i = 0; i < hdr->e_shnum; i++) {
330 switch (shdr[i].sh_type) {
331 case SHT_PROGBITS:
332 case SHT_NOBITS:
333 #ifdef __amd64__
334 case SHT_X86_64_UNWIND:
335 #endif
336 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
337 if (shdr[i].sh_type == SHT_PROGBITS)
338 ef->progtab[pb].name = "<<PROGBITS>>";
339 #ifdef __amd64__
340 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
341 ef->progtab[pb].name = "<<UNWIND>>";
342 #endif
343 else
344 ef->progtab[pb].name = "<<NOBITS>>";
345 ef->progtab[pb].size = shdr[i].sh_size;
346 ef->progtab[pb].sec = i;
347 if (ef->shstrtab && shdr[i].sh_name != 0)
348 ef->progtab[pb].name =
349 ef->shstrtab + shdr[i].sh_name;
350 if (ef->progtab[pb].name != NULL &&
351 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
352 void *dpcpu;
353
354 dpcpu = dpcpu_alloc(shdr[i].sh_size);
355 if (dpcpu == NULL) {
356 error = ENOSPC;
357 goto out;
358 }
359 memcpy(dpcpu, ef->progtab[pb].addr,
360 ef->progtab[pb].size);
361 dpcpu_copy(dpcpu, shdr[i].sh_size);
362 ef->progtab[pb].addr = dpcpu;
363 #ifdef VIMAGE
364 } else if (ef->progtab[pb].name != NULL &&
365 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
366 void *vnet_data;
367
368 vnet_data = vnet_data_alloc(shdr[i].sh_size);
369 if (vnet_data == NULL) {
370 error = ENOSPC;
371 goto out;
372 }
373 memcpy(vnet_data, ef->progtab[pb].addr,
374 ef->progtab[pb].size);
375 vnet_data_copy(vnet_data, shdr[i].sh_size);
376 ef->progtab[pb].addr = vnet_data;
377 #endif
378 } else if (ef->progtab[pb].name != NULL &&
379 !strcmp(ef->progtab[pb].name, ".ctors")) {
380 lf->ctors_addr = ef->progtab[pb].addr;
381 lf->ctors_size = shdr[i].sh_size;
382 }
383
384 /* Update all symbol values with the offset. */
385 for (j = 0; j < ef->ddbsymcnt; j++) {
386 es = &ef->ddbsymtab[j];
387 if (es->st_shndx != i)
388 continue;
389 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
390 }
391 pb++;
392 break;
393 case SHT_REL:
394 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
395 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
396 ef->reltab[rl].sec = shdr[i].sh_info;
397 rl++;
398 break;
399 case SHT_RELA:
400 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
401 ef->relatab[ra].nrela =
402 shdr[i].sh_size / sizeof(Elf_Rela);
403 ef->relatab[ra].sec = shdr[i].sh_info;
404 ra++;
405 break;
406 }
407 }
408 if (pb != ef->nprogtab) {
409 printf("%s: lost progbits\n", filename);
410 error = ENOEXEC;
411 goto out;
412 }
413 if (rl != ef->nreltab) {
414 printf("%s: lost reltab\n", filename);
415 error = ENOEXEC;
416 goto out;
417 }
418 if (ra != ef->nrelatab) {
419 printf("%s: lost relatab\n", filename);
420 error = ENOEXEC;
421 goto out;
422 }
423
424 /* Local intra-module relocations */
425 error = link_elf_reloc_local(lf);
426 if (error != 0)
427 goto out;
428
429 *result = lf;
430 return (0);
431
432 out:
433 /* preload not done this way */
434 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
435 return (error);
436 }
437
438 static void
439 link_elf_invoke_ctors(caddr_t addr, size_t size)
440 {
441 void (**ctor)(void);
442 size_t i, cnt;
443
444 if (addr == NULL || size == 0)
445 return;
446 cnt = size / sizeof(*ctor);
447 ctor = (void *)addr;
448 for (i = 0; i < cnt; i++) {
449 if (ctor[i] != NULL)
450 (*ctor[i])();
451 }
452 }
453
454 static int
455 link_elf_link_preload_finish(linker_file_t lf)
456 {
457 elf_file_t ef;
458 int error;
459
460 ef = (elf_file_t)lf;
461 error = relocate_file(ef);
462 if (error)
463 return error;
464
465 /* Notify MD code that a module is being loaded. */
466 error = elf_cpu_load_file(lf);
467 if (error)
468 return (error);
469
470 /* Invoke .ctors */
471 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
472 return (0);
473 }
474
475 static int
476 link_elf_load_file(linker_class_t cls, const char *filename,
477 linker_file_t *result)
478 {
479 struct nameidata nd;
480 struct thread *td = curthread; /* XXX */
481 Elf_Ehdr *hdr;
482 Elf_Shdr *shdr;
483 Elf_Sym *es;
484 int nbytes, i, j;
485 vm_offset_t mapbase;
486 size_t mapsize;
487 int error = 0;
488 ssize_t resid;
489 int flags;
490 elf_file_t ef;
491 linker_file_t lf;
492 int symtabindex;
493 int symstrindex;
494 int shstrindex;
495 int nsym;
496 int pb, rl, ra;
497 int alignmask;
498
499 shdr = NULL;
500 lf = NULL;
501 mapsize = 0;
502 hdr = NULL;
503
504 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
505 flags = FREAD;
506 error = vn_open(&nd, &flags, 0, NULL);
507 if (error)
508 return error;
509 NDFREE(&nd, NDF_ONLY_PNBUF);
510 if (nd.ni_vp->v_type != VREG) {
511 error = ENOEXEC;
512 goto out;
513 }
514 #ifdef MAC
515 error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
516 if (error) {
517 goto out;
518 }
519 #endif
520
521 /* Read the elf header from the file. */
522 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
523 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
524 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
525 &resid, td);
526 if (error)
527 goto out;
528 if (resid != 0){
529 error = ENOEXEC;
530 goto out;
531 }
532
533 if (!IS_ELF(*hdr)) {
534 error = ENOEXEC;
535 goto out;
536 }
537
538 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
539 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
540 link_elf_error(filename, "Unsupported file layout");
541 error = ENOEXEC;
542 goto out;
543 }
544 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
545 || hdr->e_version != EV_CURRENT) {
546 link_elf_error(filename, "Unsupported file version");
547 error = ENOEXEC;
548 goto out;
549 }
550 if (hdr->e_type != ET_REL) {
551 error = ENOSYS;
552 goto out;
553 }
554 if (hdr->e_machine != ELF_TARG_MACH) {
555 link_elf_error(filename, "Unsupported machine");
556 error = ENOEXEC;
557 goto out;
558 }
559
560 lf = linker_make_file(filename, &link_elf_class);
561 if (!lf) {
562 error = ENOMEM;
563 goto out;
564 }
565 ef = (elf_file_t) lf;
566 ef->nprogtab = 0;
567 ef->e_shdr = 0;
568 ef->nreltab = 0;
569 ef->nrelatab = 0;
570
571 /* Allocate and read in the section header */
572 nbytes = hdr->e_shnum * hdr->e_shentsize;
573 if (nbytes == 0 || hdr->e_shoff == 0 ||
574 hdr->e_shentsize != sizeof(Elf_Shdr)) {
575 error = ENOEXEC;
576 goto out;
577 }
578 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
579 ef->e_shdr = shdr;
580 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
581 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
582 if (error)
583 goto out;
584 if (resid) {
585 error = ENOEXEC;
586 goto out;
587 }
588
589 /* Scan the section header for information and table sizing. */
590 nsym = 0;
591 symtabindex = -1;
592 symstrindex = -1;
593 for (i = 0; i < hdr->e_shnum; i++) {
594 if (shdr[i].sh_size == 0)
595 continue;
596 switch (shdr[i].sh_type) {
597 case SHT_PROGBITS:
598 case SHT_NOBITS:
599 #ifdef __amd64__
600 case SHT_X86_64_UNWIND:
601 #endif
602 ef->nprogtab++;
603 break;
604 case SHT_SYMTAB:
605 nsym++;
606 symtabindex = i;
607 symstrindex = shdr[i].sh_link;
608 break;
609 case SHT_REL:
610 ef->nreltab++;
611 break;
612 case SHT_RELA:
613 ef->nrelatab++;
614 break;
615 case SHT_STRTAB:
616 break;
617 }
618 }
619 if (ef->nprogtab == 0) {
620 link_elf_error(filename, "file has no contents");
621 error = ENOEXEC;
622 goto out;
623 }
624 if (nsym != 1) {
625 /* Only allow one symbol table for now */
626 link_elf_error(filename, "file has no valid symbol table");
627 error = ENOEXEC;
628 goto out;
629 }
630 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
631 shdr[symstrindex].sh_type != SHT_STRTAB) {
632 link_elf_error(filename, "file has invalid symbol strings");
633 error = ENOEXEC;
634 goto out;
635 }
636
637 /* Allocate space for tracking the load chunks */
638 if (ef->nprogtab != 0)
639 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
640 M_LINKER, M_WAITOK | M_ZERO);
641 if (ef->nreltab != 0)
642 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
643 M_LINKER, M_WAITOK | M_ZERO);
644 if (ef->nrelatab != 0)
645 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
646 M_LINKER, M_WAITOK | M_ZERO);
647
648 if (symtabindex == -1) {
649 link_elf_error(filename, "lost symbol table index");
650 error = ENOEXEC;
651 goto out;
652 }
653 /* Allocate space for and load the symbol table */
654 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
655 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
656 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
657 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
658 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
659 &resid, td);
660 if (error)
661 goto out;
662 if (resid != 0){
663 error = EINVAL;
664 goto out;
665 }
666
667 if (symstrindex == -1) {
668 link_elf_error(filename, "lost symbol string index");
669 error = ENOEXEC;
670 goto out;
671 }
672 /* Allocate space for and load the symbol strings */
673 ef->ddbstrcnt = shdr[symstrindex].sh_size;
674 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
675 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
676 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
677 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
678 &resid, td);
679 if (error)
680 goto out;
681 if (resid != 0){
682 error = EINVAL;
683 goto out;
684 }
685
686 /* Do we have a string table for the section names? */
687 shstrindex = -1;
688 if (hdr->e_shstrndx != 0 &&
689 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
690 shstrindex = hdr->e_shstrndx;
691 ef->shstrcnt = shdr[shstrindex].sh_size;
692 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
693 M_WAITOK);
694 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
695 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
696 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
697 &resid, td);
698 if (error)
699 goto out;
700 if (resid != 0){
701 error = EINVAL;
702 goto out;
703 }
704 }
705
706 /* Size up code/data(progbits) and bss(nobits). */
707 alignmask = 0;
708 for (i = 0; i < hdr->e_shnum; i++) {
709 if (shdr[i].sh_size == 0)
710 continue;
711 switch (shdr[i].sh_type) {
712 case SHT_PROGBITS:
713 case SHT_NOBITS:
714 #ifdef __amd64__
715 case SHT_X86_64_UNWIND:
716 #endif
717 alignmask = shdr[i].sh_addralign - 1;
718 mapsize += alignmask;
719 mapsize &= ~alignmask;
720 mapsize += shdr[i].sh_size;
721 break;
722 }
723 }
724
725 /*
726 * We know how much space we need for the text/data/bss/etc.
727 * This stuff needs to be in a single chunk so that profiling etc
728 * can get the bounds and gdb can associate offsets with modules
729 */
730 ef->object = vm_object_allocate(OBJT_DEFAULT,
731 round_page(mapsize) >> PAGE_SHIFT);
732 if (ef->object == NULL) {
733 error = ENOMEM;
734 goto out;
735 }
736 ef->address = (caddr_t) vm_map_min(kernel_map);
737
738 /*
739 * In order to satisfy amd64's architectural requirements on the
740 * location of code and data in the kernel's address space, request a
741 * mapping that is above the kernel.
742 */
743 #ifdef __amd64__
744 mapbase = KERNBASE;
745 #else
746 mapbase = VM_MIN_KERNEL_ADDRESS;
747 #endif
748 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
749 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
750 VM_PROT_ALL, 0);
751 if (error) {
752 vm_object_deallocate(ef->object);
753 ef->object = 0;
754 goto out;
755 }
756
757 /* Wire the pages */
758 error = vm_map_wire(kernel_map, mapbase,
759 mapbase + round_page(mapsize),
760 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
761 if (error != KERN_SUCCESS) {
762 error = ENOMEM;
763 goto out;
764 }
765
766 /* Inform the kld system about the situation */
767 lf->address = ef->address = (caddr_t)mapbase;
768 lf->size = mapsize;
769
770 /*
771 * Now load code/data(progbits), zero bss(nobits), allocate space for
772 * and load relocs
773 */
774 pb = 0;
775 rl = 0;
776 ra = 0;
777 alignmask = 0;
778 for (i = 0; i < hdr->e_shnum; i++) {
779 if (shdr[i].sh_size == 0)
780 continue;
781 switch (shdr[i].sh_type) {
782 case SHT_PROGBITS:
783 case SHT_NOBITS:
784 #ifdef __amd64__
785 case SHT_X86_64_UNWIND:
786 #endif
787 alignmask = shdr[i].sh_addralign - 1;
788 mapbase += alignmask;
789 mapbase &= ~alignmask;
790 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
791 ef->progtab[pb].name =
792 ef->shstrtab + shdr[i].sh_name;
793 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
794 lf->ctors_addr = (caddr_t)mapbase;
795 lf->ctors_size = shdr[i].sh_size;
796 }
797 } else if (shdr[i].sh_type == SHT_PROGBITS)
798 ef->progtab[pb].name = "<<PROGBITS>>";
799 #ifdef __amd64__
800 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
801 ef->progtab[pb].name = "<<UNWIND>>";
802 #endif
803 else
804 ef->progtab[pb].name = "<<NOBITS>>";
805 if (ef->progtab[pb].name != NULL &&
806 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
807 ef->progtab[pb].addr =
808 dpcpu_alloc(shdr[i].sh_size);
809 #ifdef VIMAGE
810 else if (ef->progtab[pb].name != NULL &&
811 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
812 ef->progtab[pb].addr =
813 vnet_data_alloc(shdr[i].sh_size);
814 #endif
815 else
816 ef->progtab[pb].addr =
817 (void *)(uintptr_t)mapbase;
818 if (ef->progtab[pb].addr == NULL) {
819 error = ENOSPC;
820 goto out;
821 }
822 ef->progtab[pb].size = shdr[i].sh_size;
823 ef->progtab[pb].sec = i;
824 if (shdr[i].sh_type == SHT_PROGBITS
825 #ifdef __amd64__
826 || shdr[i].sh_type == SHT_X86_64_UNWIND
827 #endif
828 ) {
829 error = vn_rdwr(UIO_READ, nd.ni_vp,
830 ef->progtab[pb].addr,
831 shdr[i].sh_size, shdr[i].sh_offset,
832 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
833 NOCRED, &resid, td);
834 if (error)
835 goto out;
836 if (resid != 0){
837 error = EINVAL;
838 goto out;
839 }
840 /* Initialize the per-cpu or vnet area. */
841 if (ef->progtab[pb].addr != (void *)mapbase &&
842 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
843 dpcpu_copy(ef->progtab[pb].addr,
844 shdr[i].sh_size);
845 #ifdef VIMAGE
846 else if (ef->progtab[pb].addr !=
847 (void *)mapbase &&
848 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
849 vnet_data_copy(ef->progtab[pb].addr,
850 shdr[i].sh_size);
851 #endif
852 } else
853 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
854
855 /* Update all symbol values with the offset. */
856 for (j = 0; j < ef->ddbsymcnt; j++) {
857 es = &ef->ddbsymtab[j];
858 if (es->st_shndx != i)
859 continue;
860 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
861 }
862 mapbase += shdr[i].sh_size;
863 pb++;
864 break;
865 case SHT_REL:
866 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
867 M_WAITOK);
868 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
869 ef->reltab[rl].sec = shdr[i].sh_info;
870 error = vn_rdwr(UIO_READ, nd.ni_vp,
871 (void *)ef->reltab[rl].rel,
872 shdr[i].sh_size, shdr[i].sh_offset,
873 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
874 &resid, td);
875 if (error)
876 goto out;
877 if (resid != 0){
878 error = EINVAL;
879 goto out;
880 }
881 rl++;
882 break;
883 case SHT_RELA:
884 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
885 M_WAITOK);
886 ef->relatab[ra].nrela =
887 shdr[i].sh_size / sizeof(Elf_Rela);
888 ef->relatab[ra].sec = shdr[i].sh_info;
889 error = vn_rdwr(UIO_READ, nd.ni_vp,
890 (void *)ef->relatab[ra].rela,
891 shdr[i].sh_size, shdr[i].sh_offset,
892 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
893 &resid, td);
894 if (error)
895 goto out;
896 if (resid != 0){
897 error = EINVAL;
898 goto out;
899 }
900 ra++;
901 break;
902 }
903 }
904 if (pb != ef->nprogtab) {
905 link_elf_error(filename, "lost progbits");
906 error = ENOEXEC;
907 goto out;
908 }
909 if (rl != ef->nreltab) {
910 link_elf_error(filename, "lost reltab");
911 error = ENOEXEC;
912 goto out;
913 }
914 if (ra != ef->nrelatab) {
915 link_elf_error(filename, "lost relatab");
916 error = ENOEXEC;
917 goto out;
918 }
919 if (mapbase != (vm_offset_t)ef->address + mapsize) {
920 printf(
921 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
922 filename != NULL ? filename : "<none>",
923 (u_long)mapbase, ef->address, (u_long)mapsize,
924 (u_long)(vm_offset_t)ef->address + mapsize);
925 error = ENOMEM;
926 goto out;
927 }
928
929 /* Local intra-module relocations */
930 error = link_elf_reloc_local(lf);
931 if (error != 0)
932 goto out;
933
934 /* Pull in dependencies */
935 VOP_UNLOCK(nd.ni_vp, 0);
936 error = linker_load_dependencies(lf);
937 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
938 if (error)
939 goto out;
940
941 /* External relocations */
942 error = relocate_file(ef);
943 if (error)
944 goto out;
945
946 /* Notify MD code that a module is being loaded. */
947 error = elf_cpu_load_file(lf);
948 if (error)
949 goto out;
950
951 /* Invoke .ctors */
952 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
953
954 *result = lf;
955
956 out:
957 VOP_UNLOCK(nd.ni_vp, 0);
958 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
959 if (error && lf)
960 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
961 free(hdr, M_LINKER);
962
963 return error;
964 }
965
966 static void
967 link_elf_unload_file(linker_file_t file)
968 {
969 elf_file_t ef = (elf_file_t) file;
970 int i;
971
972 /* Notify MD code that a module is being unloaded. */
973 elf_cpu_unload_file(file);
974
975 if (ef->progtab) {
976 for (i = 0; i < ef->nprogtab; i++) {
977 if (ef->progtab[i].size == 0)
978 continue;
979 if (ef->progtab[i].name == NULL)
980 continue;
981 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
982 dpcpu_free(ef->progtab[i].addr,
983 ef->progtab[i].size);
984 #ifdef VIMAGE
985 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
986 vnet_data_free(ef->progtab[i].addr,
987 ef->progtab[i].size);
988 #endif
989 }
990 }
991 if (ef->preloaded) {
992 free(ef->reltab, M_LINKER);
993 free(ef->relatab, M_LINKER);
994 free(ef->progtab, M_LINKER);
995 free(ef->ctftab, M_LINKER);
996 free(ef->ctfoff, M_LINKER);
997 free(ef->typoff, M_LINKER);
998 if (file->filename != NULL)
999 preload_delete_name(file->filename);
1000 /* XXX reclaim module memory? */
1001 return;
1002 }
1003
1004 for (i = 0; i < ef->nreltab; i++)
1005 free(ef->reltab[i].rel, M_LINKER);
1006 for (i = 0; i < ef->nrelatab; i++)
1007 free(ef->relatab[i].rela, M_LINKER);
1008 free(ef->reltab, M_LINKER);
1009 free(ef->relatab, M_LINKER);
1010 free(ef->progtab, M_LINKER);
1011
1012 if (ef->object) {
1013 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1014 (vm_offset_t) ef->address +
1015 (ef->object->size << PAGE_SHIFT));
1016 }
1017 free(ef->e_shdr, M_LINKER);
1018 free(ef->ddbsymtab, M_LINKER);
1019 free(ef->ddbstrtab, M_LINKER);
1020 free(ef->shstrtab, M_LINKER);
1021 free(ef->ctftab, M_LINKER);
1022 free(ef->ctfoff, M_LINKER);
1023 free(ef->typoff, M_LINKER);
1024 }
1025
1026 static const char *
1027 symbol_name(elf_file_t ef, Elf_Size r_info)
1028 {
1029 const Elf_Sym *ref;
1030
1031 if (ELF_R_SYM(r_info)) {
1032 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1033 return ef->ddbstrtab + ref->st_name;
1034 } else
1035 return NULL;
1036 }
1037
1038 static Elf_Addr
1039 findbase(elf_file_t ef, int sec)
1040 {
1041 int i;
1042 Elf_Addr base = 0;
1043
1044 for (i = 0; i < ef->nprogtab; i++) {
1045 if (sec == ef->progtab[i].sec) {
1046 base = (Elf_Addr)ef->progtab[i].addr;
1047 break;
1048 }
1049 }
1050 return base;
1051 }
1052
1053 static int
1054 relocate_file(elf_file_t ef)
1055 {
1056 const Elf_Rel *rellim;
1057 const Elf_Rel *rel;
1058 const Elf_Rela *relalim;
1059 const Elf_Rela *rela;
1060 const char *symname;
1061 const Elf_Sym *sym;
1062 int i;
1063 Elf_Size symidx;
1064 Elf_Addr base;
1065
1066
1067 /* Perform relocations without addend if there are any: */
1068 for (i = 0; i < ef->nreltab; i++) {
1069 rel = ef->reltab[i].rel;
1070 if (rel == NULL) {
1071 link_elf_error(ef->lf.filename, "lost a reltab!");
1072 return (ENOEXEC);
1073 }
1074 rellim = rel + ef->reltab[i].nrel;
1075 base = findbase(ef, ef->reltab[i].sec);
1076 if (base == 0) {
1077 link_elf_error(ef->lf.filename, "lost base for reltab");
1078 return (ENOEXEC);
1079 }
1080 for ( ; rel < rellim; rel++) {
1081 symidx = ELF_R_SYM(rel->r_info);
1082 if (symidx >= ef->ddbsymcnt)
1083 continue;
1084 sym = ef->ddbsymtab + symidx;
1085 /* Local relocs are already done */
1086 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1087 continue;
1088 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1089 elf_obj_lookup)) {
1090 symname = symbol_name(ef, rel->r_info);
1091 printf("link_elf_obj: symbol %s undefined\n",
1092 symname);
1093 return (ENOENT);
1094 }
1095 }
1096 }
1097
1098 /* Perform relocations with addend if there are any: */
1099 for (i = 0; i < ef->nrelatab; i++) {
1100 rela = ef->relatab[i].rela;
1101 if (rela == NULL) {
1102 link_elf_error(ef->lf.filename, "lost a relatab!");
1103 return (ENOEXEC);
1104 }
1105 relalim = rela + ef->relatab[i].nrela;
1106 base = findbase(ef, ef->relatab[i].sec);
1107 if (base == 0) {
1108 link_elf_error(ef->lf.filename,
1109 "lost base for relatab");
1110 return (ENOEXEC);
1111 }
1112 for ( ; rela < relalim; rela++) {
1113 symidx = ELF_R_SYM(rela->r_info);
1114 if (symidx >= ef->ddbsymcnt)
1115 continue;
1116 sym = ef->ddbsymtab + symidx;
1117 /* Local relocs are already done */
1118 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1119 continue;
1120 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1121 elf_obj_lookup)) {
1122 symname = symbol_name(ef, rela->r_info);
1123 printf("link_elf_obj: symbol %s undefined\n",
1124 symname);
1125 return (ENOENT);
1126 }
1127 }
1128 }
1129
1130 /*
1131 * Only clean SHN_FBSD_CACHED for successful return. If we
1132 * modified symbol table for the object but found an
1133 * unresolved symbol, there is no reason to roll back.
1134 */
1135 elf_obj_cleanup_globals_cache(ef);
1136
1137 return (0);
1138 }
1139
1140 static int
1141 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1142 {
1143 elf_file_t ef = (elf_file_t) lf;
1144 const Elf_Sym *symp;
1145 const char *strp;
1146 int i;
1147
1148 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1149 strp = ef->ddbstrtab + symp->st_name;
1150 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1151 *sym = (c_linker_sym_t) symp;
1152 return 0;
1153 }
1154 }
1155 return ENOENT;
1156 }
1157
1158 static int
1159 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1160 linker_symval_t *symval)
1161 {
1162 elf_file_t ef = (elf_file_t) lf;
1163 const Elf_Sym *es = (const Elf_Sym*) sym;
1164
1165 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1166 symval->name = ef->ddbstrtab + es->st_name;
1167 symval->value = (caddr_t)es->st_value;
1168 symval->size = es->st_size;
1169 return 0;
1170 }
1171 return ENOENT;
1172 }
1173
1174 static int
1175 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1176 c_linker_sym_t *sym, long *diffp)
1177 {
1178 elf_file_t ef = (elf_file_t) lf;
1179 u_long off = (uintptr_t) (void *) value;
1180 u_long diff = off;
1181 u_long st_value;
1182 const Elf_Sym *es;
1183 const Elf_Sym *best = NULL;
1184 int i;
1185
1186 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1187 if (es->st_name == 0)
1188 continue;
1189 st_value = es->st_value;
1190 if (off >= st_value) {
1191 if (off - st_value < diff) {
1192 diff = off - st_value;
1193 best = es;
1194 if (diff == 0)
1195 break;
1196 } else if (off - st_value == diff) {
1197 best = es;
1198 }
1199 }
1200 }
1201 if (best == NULL)
1202 *diffp = off;
1203 else
1204 *diffp = diff;
1205 *sym = (c_linker_sym_t) best;
1206
1207 return 0;
1208 }
1209
1210 /*
1211 * Look up a linker set on an ELF system.
1212 */
1213 static int
1214 link_elf_lookup_set(linker_file_t lf, const char *name,
1215 void ***startp, void ***stopp, int *countp)
1216 {
1217 elf_file_t ef = (elf_file_t)lf;
1218 void **start, **stop;
1219 int i, count;
1220
1221 /* Relative to section number */
1222 for (i = 0; i < ef->nprogtab; i++) {
1223 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1224 strcmp(ef->progtab[i].name + 4, name) == 0) {
1225 start = (void **)ef->progtab[i].addr;
1226 stop = (void **)((char *)ef->progtab[i].addr +
1227 ef->progtab[i].size);
1228 count = stop - start;
1229 if (startp)
1230 *startp = start;
1231 if (stopp)
1232 *stopp = stop;
1233 if (countp)
1234 *countp = count;
1235 return (0);
1236 }
1237 }
1238 return (ESRCH);
1239 }
1240
1241 static int
1242 link_elf_each_function_name(linker_file_t file,
1243 int (*callback)(const char *, void *), void *opaque)
1244 {
1245 elf_file_t ef = (elf_file_t)file;
1246 const Elf_Sym *symp;
1247 int i, error;
1248
1249 /* Exhaustive search */
1250 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1251 if (symp->st_value != 0 &&
1252 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1253 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1254 if (error)
1255 return (error);
1256 }
1257 }
1258 return (0);
1259 }
1260
1261 static int
1262 link_elf_each_function_nameval(linker_file_t file,
1263 linker_function_nameval_callback_t callback, void *opaque)
1264 {
1265 linker_symval_t symval;
1266 elf_file_t ef = (elf_file_t)file;
1267 const Elf_Sym* symp;
1268 int i, error;
1269
1270 /* Exhaustive search */
1271 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1272 if (symp->st_value != 0 &&
1273 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1274 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1275 if (error)
1276 return (error);
1277 error = callback(file, i, &symval, opaque);
1278 if (error)
1279 return (error);
1280 }
1281 }
1282 return (0);
1283 }
1284
1285 static void
1286 elf_obj_cleanup_globals_cache(elf_file_t ef)
1287 {
1288 Elf_Sym *sym;
1289 Elf_Size i;
1290
1291 for (i = 0; i < ef->ddbsymcnt; i++) {
1292 sym = ef->ddbsymtab + i;
1293 if (sym->st_shndx == SHN_FBSD_CACHED) {
1294 sym->st_shndx = SHN_UNDEF;
1295 sym->st_value = 0;
1296 }
1297 }
1298 }
1299
1300 /*
1301 * Symbol lookup function that can be used when the symbol index is known (ie
1302 * in relocations). It uses the symbol index instead of doing a fully fledged
1303 * hash table based lookup when such is valid. For example for local symbols.
1304 * This is not only more efficient, it's also more correct. It's not always
1305 * the case that the symbol can be found through the hash table.
1306 */
1307 static int
1308 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1309 {
1310 elf_file_t ef = (elf_file_t)lf;
1311 Elf_Sym *sym;
1312 const char *symbol;
1313 Elf_Addr res1;
1314
1315 /* Don't even try to lookup the symbol if the index is bogus. */
1316 if (symidx >= ef->ddbsymcnt) {
1317 *res = 0;
1318 return (EINVAL);
1319 }
1320
1321 sym = ef->ddbsymtab + symidx;
1322
1323 /* Quick answer if there is a definition included. */
1324 if (sym->st_shndx != SHN_UNDEF) {
1325 *res = sym->st_value;
1326 return (0);
1327 }
1328
1329 /* If we get here, then it is undefined and needs a lookup. */
1330 switch (ELF_ST_BIND(sym->st_info)) {
1331 case STB_LOCAL:
1332 /* Local, but undefined? huh? */
1333 *res = 0;
1334 return (EINVAL);
1335
1336 case STB_GLOBAL:
1337 case STB_WEAK:
1338 /* Relative to Data or Function name */
1339 symbol = ef->ddbstrtab + sym->st_name;
1340
1341 /* Force a lookup failure if the symbol name is bogus. */
1342 if (*symbol == 0) {
1343 *res = 0;
1344 return (EINVAL);
1345 }
1346 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1347
1348 /*
1349 * Cache global lookups during module relocation. The failure
1350 * case is particularly expensive for callers, who must scan
1351 * through the entire globals table doing strcmp(). Cache to
1352 * avoid doing such work repeatedly.
1353 *
1354 * After relocation is complete, undefined globals will be
1355 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1356 * above.
1357 */
1358 if (res1 != 0) {
1359 sym->st_shndx = SHN_FBSD_CACHED;
1360 sym->st_value = res1;
1361 *res = res1;
1362 return (0);
1363 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1364 sym->st_value = 0;
1365 *res = 0;
1366 return (0);
1367 }
1368 return (EINVAL);
1369
1370 default:
1371 return (EINVAL);
1372 }
1373 }
1374
1375 static void
1376 link_elf_fix_link_set(elf_file_t ef)
1377 {
1378 static const char startn[] = "__start_";
1379 static const char stopn[] = "__stop_";
1380 Elf_Sym *sym;
1381 const char *sym_name, *linkset_name;
1382 Elf_Addr startp, stopp;
1383 Elf_Size symidx;
1384 int start, i;
1385
1386 startp = stopp = 0;
1387 for (symidx = 1 /* zero entry is special */;
1388 symidx < ef->ddbsymcnt; symidx++) {
1389 sym = ef->ddbsymtab + symidx;
1390 if (sym->st_shndx != SHN_UNDEF)
1391 continue;
1392
1393 sym_name = ef->ddbstrtab + sym->st_name;
1394 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1395 start = 1;
1396 linkset_name = sym_name + sizeof(startn) - 1;
1397 }
1398 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1399 start = 0;
1400 linkset_name = sym_name + sizeof(stopn) - 1;
1401 }
1402 else
1403 continue;
1404
1405 for (i = 0; i < ef->nprogtab; i++) {
1406 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1407 startp = (Elf_Addr)ef->progtab[i].addr;
1408 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1409 break;
1410 }
1411 }
1412 if (i == ef->nprogtab)
1413 continue;
1414
1415 sym->st_value = start ? startp : stopp;
1416 sym->st_shndx = i;
1417 }
1418 }
1419
1420 static int
1421 link_elf_reloc_local(linker_file_t lf)
1422 {
1423 elf_file_t ef = (elf_file_t)lf;
1424 const Elf_Rel *rellim;
1425 const Elf_Rel *rel;
1426 const Elf_Rela *relalim;
1427 const Elf_Rela *rela;
1428 const Elf_Sym *sym;
1429 Elf_Addr base;
1430 int i;
1431 Elf_Size symidx;
1432
1433 link_elf_fix_link_set(ef);
1434
1435 /* Perform relocations without addend if there are any: */
1436 for (i = 0; i < ef->nreltab; i++) {
1437 rel = ef->reltab[i].rel;
1438 if (rel == NULL) {
1439 link_elf_error(ef->lf.filename, "lost a reltab");
1440 return (ENOEXEC);
1441 }
1442 rellim = rel + ef->reltab[i].nrel;
1443 base = findbase(ef, ef->reltab[i].sec);
1444 if (base == 0) {
1445 link_elf_error(ef->lf.filename, "lost base for reltab");
1446 return (ENOEXEC);
1447 }
1448 for ( ; rel < rellim; rel++) {
1449 symidx = ELF_R_SYM(rel->r_info);
1450 if (symidx >= ef->ddbsymcnt)
1451 continue;
1452 sym = ef->ddbsymtab + symidx;
1453 /* Only do local relocs */
1454 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1455 continue;
1456 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1457 elf_obj_lookup);
1458 }
1459 }
1460
1461 /* Perform relocations with addend if there are any: */
1462 for (i = 0; i < ef->nrelatab; i++) {
1463 rela = ef->relatab[i].rela;
1464 if (rela == NULL) {
1465 link_elf_error(ef->lf.filename, "lost a relatab!");
1466 return (ENOEXEC);
1467 }
1468 relalim = rela + ef->relatab[i].nrela;
1469 base = findbase(ef, ef->relatab[i].sec);
1470 if (base == 0) {
1471 link_elf_error(ef->lf.filename, "lost base for reltab");
1472 return (ENOEXEC);
1473 }
1474 for ( ; rela < relalim; rela++) {
1475 symidx = ELF_R_SYM(rela->r_info);
1476 if (symidx >= ef->ddbsymcnt)
1477 continue;
1478 sym = ef->ddbsymtab + symidx;
1479 /* Only do local relocs */
1480 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1481 continue;
1482 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1483 elf_obj_lookup);
1484 }
1485 }
1486 return (0);
1487 }
1488
1489 static long
1490 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1491 {
1492 elf_file_t ef = (elf_file_t)lf;
1493
1494 *symtab = ef->ddbsymtab;
1495
1496 if (*symtab == NULL)
1497 return (0);
1498
1499 return (ef->ddbsymcnt);
1500 }
1501
1502 static long
1503 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1504 {
1505 elf_file_t ef = (elf_file_t)lf;
1506
1507 *strtab = ef->ddbstrtab;
1508
1509 if (*strtab == NULL)
1510 return (0);
1511
1512 return (ef->ddbstrcnt);
1513 }
Cache object: 1f01c21ef7acaaf894035beaf82b394a
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