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/11.2/sys/kern/link_elf_obj.c 333720 2018-05-17 15:24:53Z kib $");
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 /* Ignore sections not loaded by the loader. */
264 if (shdr[i].sh_addr == 0)
265 break;
266 ef->nprogtab++;
267 break;
268 case SHT_SYMTAB:
269 symtabindex = i;
270 symstrindex = shdr[i].sh_link;
271 break;
272 case SHT_REL:
273 /*
274 * Ignore relocation tables for sections not
275 * loaded by the loader.
276 */
277 if (shdr[shdr[i].sh_info].sh_addr == 0)
278 break;
279 ef->nreltab++;
280 break;
281 case SHT_RELA:
282 if (shdr[shdr[i].sh_info].sh_addr == 0)
283 break;
284 ef->nrelatab++;
285 break;
286 }
287 }
288
289 shstrindex = hdr->e_shstrndx;
290 if (ef->nprogtab == 0 || symstrindex < 0 ||
291 symstrindex >= hdr->e_shnum ||
292 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
293 shstrindex >= hdr->e_shnum ||
294 shdr[shstrindex].sh_type != SHT_STRTAB) {
295 printf("%s: bad/missing section headers\n", filename);
296 error = ENOEXEC;
297 goto out;
298 }
299
300 /* Allocate space for tracking the load chunks */
301 if (ef->nprogtab != 0)
302 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
303 M_LINKER, M_WAITOK | M_ZERO);
304 if (ef->nreltab != 0)
305 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
306 M_LINKER, M_WAITOK | M_ZERO);
307 if (ef->nrelatab != 0)
308 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
309 M_LINKER, M_WAITOK | M_ZERO);
310 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
311 (ef->nreltab != 0 && ef->reltab == NULL) ||
312 (ef->nrelatab != 0 && ef->relatab == NULL)) {
313 error = ENOMEM;
314 goto out;
315 }
316
317 /* XXX, relocate the sh_addr fields saved by the loader. */
318 off = 0;
319 for (i = 0; i < hdr->e_shnum; i++) {
320 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
321 off = shdr[i].sh_addr;
322 }
323 for (i = 0; i < hdr->e_shnum; i++) {
324 if (shdr[i].sh_addr != 0)
325 shdr[i].sh_addr = shdr[i].sh_addr - off +
326 (Elf_Addr)ef->address;
327 }
328
329 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
330 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
331 ef->ddbstrcnt = shdr[symstrindex].sh_size;
332 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
333 ef->shstrcnt = shdr[shstrindex].sh_size;
334 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
335
336 /* Now fill out progtab and the relocation tables. */
337 pb = 0;
338 rl = 0;
339 ra = 0;
340 for (i = 0; i < hdr->e_shnum; i++) {
341 switch (shdr[i].sh_type) {
342 case SHT_PROGBITS:
343 case SHT_NOBITS:
344 #ifdef __amd64__
345 case SHT_X86_64_UNWIND:
346 #endif
347 if (shdr[i].sh_addr == 0)
348 break;
349 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
350 if (shdr[i].sh_type == SHT_PROGBITS)
351 ef->progtab[pb].name = "<<PROGBITS>>";
352 #ifdef __amd64__
353 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
354 ef->progtab[pb].name = "<<UNWIND>>";
355 #endif
356 else
357 ef->progtab[pb].name = "<<NOBITS>>";
358 ef->progtab[pb].size = shdr[i].sh_size;
359 ef->progtab[pb].sec = i;
360 if (ef->shstrtab && shdr[i].sh_name != 0)
361 ef->progtab[pb].name =
362 ef->shstrtab + shdr[i].sh_name;
363 if (ef->progtab[pb].name != NULL &&
364 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
365 void *dpcpu;
366
367 dpcpu = dpcpu_alloc(shdr[i].sh_size);
368 if (dpcpu == NULL) {
369 error = ENOSPC;
370 goto out;
371 }
372 memcpy(dpcpu, ef->progtab[pb].addr,
373 ef->progtab[pb].size);
374 dpcpu_copy(dpcpu, shdr[i].sh_size);
375 ef->progtab[pb].addr = dpcpu;
376 #ifdef VIMAGE
377 } else if (ef->progtab[pb].name != NULL &&
378 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
379 void *vnet_data;
380
381 vnet_data = vnet_data_alloc(shdr[i].sh_size);
382 if (vnet_data == NULL) {
383 error = ENOSPC;
384 goto out;
385 }
386 memcpy(vnet_data, ef->progtab[pb].addr,
387 ef->progtab[pb].size);
388 vnet_data_copy(vnet_data, shdr[i].sh_size);
389 ef->progtab[pb].addr = vnet_data;
390 #endif
391 } else if (ef->progtab[pb].name != NULL &&
392 !strcmp(ef->progtab[pb].name, ".ctors")) {
393 lf->ctors_addr = ef->progtab[pb].addr;
394 lf->ctors_size = shdr[i].sh_size;
395 }
396
397 /* Update all symbol values with the offset. */
398 for (j = 0; j < ef->ddbsymcnt; j++) {
399 es = &ef->ddbsymtab[j];
400 if (es->st_shndx != i)
401 continue;
402 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
403 }
404 pb++;
405 break;
406 case SHT_REL:
407 if (shdr[shdr[i].sh_info].sh_addr == 0)
408 break;
409 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
410 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
411 ef->reltab[rl].sec = shdr[i].sh_info;
412 rl++;
413 break;
414 case SHT_RELA:
415 if (shdr[shdr[i].sh_info].sh_addr == 0)
416 break;
417 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
418 ef->relatab[ra].nrela =
419 shdr[i].sh_size / sizeof(Elf_Rela);
420 ef->relatab[ra].sec = shdr[i].sh_info;
421 ra++;
422 break;
423 }
424 }
425 if (pb != ef->nprogtab) {
426 printf("%s: lost progbits\n", filename);
427 error = ENOEXEC;
428 goto out;
429 }
430 if (rl != ef->nreltab) {
431 printf("%s: lost reltab\n", filename);
432 error = ENOEXEC;
433 goto out;
434 }
435 if (ra != ef->nrelatab) {
436 printf("%s: lost relatab\n", filename);
437 error = ENOEXEC;
438 goto out;
439 }
440
441 /* Local intra-module relocations */
442 error = link_elf_reloc_local(lf);
443 if (error != 0)
444 goto out;
445
446 *result = lf;
447 return (0);
448
449 out:
450 /* preload not done this way */
451 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
452 return (error);
453 }
454
455 static void
456 link_elf_invoke_ctors(caddr_t addr, size_t size)
457 {
458 void (**ctor)(void);
459 size_t i, cnt;
460
461 if (addr == NULL || size == 0)
462 return;
463 cnt = size / sizeof(*ctor);
464 ctor = (void *)addr;
465 for (i = 0; i < cnt; i++) {
466 if (ctor[i] != NULL)
467 (*ctor[i])();
468 }
469 }
470
471 static int
472 link_elf_link_preload_finish(linker_file_t lf)
473 {
474 elf_file_t ef;
475 int error;
476
477 ef = (elf_file_t)lf;
478 error = relocate_file(ef);
479 if (error)
480 return error;
481
482 /* Notify MD code that a module is being loaded. */
483 error = elf_cpu_load_file(lf);
484 if (error)
485 return (error);
486
487 /* Invoke .ctors */
488 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
489 return (0);
490 }
491
492 static int
493 link_elf_load_file(linker_class_t cls, const char *filename,
494 linker_file_t *result)
495 {
496 struct nameidata nd;
497 struct thread *td = curthread; /* XXX */
498 Elf_Ehdr *hdr;
499 Elf_Shdr *shdr;
500 Elf_Sym *es;
501 int nbytes, i, j;
502 vm_offset_t mapbase;
503 size_t mapsize;
504 int error = 0;
505 ssize_t resid;
506 int flags;
507 elf_file_t ef;
508 linker_file_t lf;
509 int symtabindex;
510 int symstrindex;
511 int shstrindex;
512 int nsym;
513 int pb, rl, ra;
514 int alignmask;
515
516 shdr = NULL;
517 lf = NULL;
518 mapsize = 0;
519 hdr = NULL;
520
521 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
522 flags = FREAD;
523 error = vn_open(&nd, &flags, 0, NULL);
524 if (error)
525 return error;
526 NDFREE(&nd, NDF_ONLY_PNBUF);
527 if (nd.ni_vp->v_type != VREG) {
528 error = ENOEXEC;
529 goto out;
530 }
531 #ifdef MAC
532 error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
533 if (error) {
534 goto out;
535 }
536 #endif
537
538 /* Read the elf header from the file. */
539 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
540 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
541 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
542 &resid, td);
543 if (error)
544 goto out;
545 if (resid != 0){
546 error = ENOEXEC;
547 goto out;
548 }
549
550 if (!IS_ELF(*hdr)) {
551 error = ENOEXEC;
552 goto out;
553 }
554
555 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
556 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
557 link_elf_error(filename, "Unsupported file layout");
558 error = ENOEXEC;
559 goto out;
560 }
561 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
562 || hdr->e_version != EV_CURRENT) {
563 link_elf_error(filename, "Unsupported file version");
564 error = ENOEXEC;
565 goto out;
566 }
567 if (hdr->e_type != ET_REL) {
568 error = ENOSYS;
569 goto out;
570 }
571 if (hdr->e_machine != ELF_TARG_MACH) {
572 link_elf_error(filename, "Unsupported machine");
573 error = ENOEXEC;
574 goto out;
575 }
576
577 lf = linker_make_file(filename, &link_elf_class);
578 if (!lf) {
579 error = ENOMEM;
580 goto out;
581 }
582 ef = (elf_file_t) lf;
583 ef->nprogtab = 0;
584 ef->e_shdr = 0;
585 ef->nreltab = 0;
586 ef->nrelatab = 0;
587
588 /* Allocate and read in the section header */
589 nbytes = hdr->e_shnum * hdr->e_shentsize;
590 if (nbytes == 0 || hdr->e_shoff == 0 ||
591 hdr->e_shentsize != sizeof(Elf_Shdr)) {
592 error = ENOEXEC;
593 goto out;
594 }
595 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
596 ef->e_shdr = shdr;
597 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
598 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
599 if (error)
600 goto out;
601 if (resid) {
602 error = ENOEXEC;
603 goto out;
604 }
605
606 /* Scan the section header for information and table sizing. */
607 nsym = 0;
608 symtabindex = -1;
609 symstrindex = -1;
610 for (i = 0; i < hdr->e_shnum; i++) {
611 if (shdr[i].sh_size == 0)
612 continue;
613 switch (shdr[i].sh_type) {
614 case SHT_PROGBITS:
615 case SHT_NOBITS:
616 #ifdef __amd64__
617 case SHT_X86_64_UNWIND:
618 #endif
619 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
620 break;
621 ef->nprogtab++;
622 break;
623 case SHT_SYMTAB:
624 nsym++;
625 symtabindex = i;
626 symstrindex = shdr[i].sh_link;
627 break;
628 case SHT_REL:
629 /*
630 * Ignore relocation tables for unallocated
631 * sections.
632 */
633 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
634 break;
635 ef->nreltab++;
636 break;
637 case SHT_RELA:
638 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
639 break;
640 ef->nrelatab++;
641 break;
642 case SHT_STRTAB:
643 break;
644 }
645 }
646 if (ef->nprogtab == 0) {
647 link_elf_error(filename, "file has no contents");
648 error = ENOEXEC;
649 goto out;
650 }
651 if (nsym != 1) {
652 /* Only allow one symbol table for now */
653 link_elf_error(filename, "file has no valid symbol table");
654 error = ENOEXEC;
655 goto out;
656 }
657 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
658 shdr[symstrindex].sh_type != SHT_STRTAB) {
659 link_elf_error(filename, "file has invalid symbol strings");
660 error = ENOEXEC;
661 goto out;
662 }
663
664 /* Allocate space for tracking the load chunks */
665 if (ef->nprogtab != 0)
666 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
667 M_LINKER, M_WAITOK | M_ZERO);
668 if (ef->nreltab != 0)
669 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
670 M_LINKER, M_WAITOK | M_ZERO);
671 if (ef->nrelatab != 0)
672 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
673 M_LINKER, M_WAITOK | M_ZERO);
674
675 if (symtabindex == -1) {
676 link_elf_error(filename, "lost symbol table index");
677 error = ENOEXEC;
678 goto out;
679 }
680 /* Allocate space for and load the symbol table */
681 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
682 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
683 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
684 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
685 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
686 &resid, td);
687 if (error)
688 goto out;
689 if (resid != 0){
690 error = EINVAL;
691 goto out;
692 }
693
694 if (symstrindex == -1) {
695 link_elf_error(filename, "lost symbol string index");
696 error = ENOEXEC;
697 goto out;
698 }
699 /* Allocate space for and load the symbol strings */
700 ef->ddbstrcnt = shdr[symstrindex].sh_size;
701 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
702 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
703 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
704 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
705 &resid, td);
706 if (error)
707 goto out;
708 if (resid != 0){
709 error = EINVAL;
710 goto out;
711 }
712
713 /* Do we have a string table for the section names? */
714 shstrindex = -1;
715 if (hdr->e_shstrndx != 0 &&
716 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
717 shstrindex = hdr->e_shstrndx;
718 ef->shstrcnt = shdr[shstrindex].sh_size;
719 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
720 M_WAITOK);
721 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
722 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
723 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
724 &resid, td);
725 if (error)
726 goto out;
727 if (resid != 0){
728 error = EINVAL;
729 goto out;
730 }
731 }
732
733 /* Size up code/data(progbits) and bss(nobits). */
734 alignmask = 0;
735 for (i = 0; i < hdr->e_shnum; i++) {
736 if (shdr[i].sh_size == 0)
737 continue;
738 switch (shdr[i].sh_type) {
739 case SHT_PROGBITS:
740 case SHT_NOBITS:
741 #ifdef __amd64__
742 case SHT_X86_64_UNWIND:
743 #endif
744 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
745 break;
746 alignmask = shdr[i].sh_addralign - 1;
747 mapsize += alignmask;
748 mapsize &= ~alignmask;
749 mapsize += shdr[i].sh_size;
750 break;
751 }
752 }
753
754 /*
755 * We know how much space we need for the text/data/bss/etc.
756 * This stuff needs to be in a single chunk so that profiling etc
757 * can get the bounds and gdb can associate offsets with modules
758 */
759 ef->object = vm_object_allocate(OBJT_DEFAULT,
760 round_page(mapsize) >> PAGE_SHIFT);
761 if (ef->object == NULL) {
762 error = ENOMEM;
763 goto out;
764 }
765 ef->address = (caddr_t) vm_map_min(kernel_map);
766
767 /*
768 * In order to satisfy amd64's architectural requirements on the
769 * location of code and data in the kernel's address space, request a
770 * mapping that is above the kernel.
771 */
772 #ifdef __amd64__
773 mapbase = KERNBASE;
774 #else
775 mapbase = VM_MIN_KERNEL_ADDRESS;
776 #endif
777 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
778 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
779 VM_PROT_ALL, 0);
780 if (error) {
781 vm_object_deallocate(ef->object);
782 ef->object = 0;
783 goto out;
784 }
785
786 /* Wire the pages */
787 error = vm_map_wire(kernel_map, mapbase,
788 mapbase + round_page(mapsize),
789 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
790 if (error != KERN_SUCCESS) {
791 error = ENOMEM;
792 goto out;
793 }
794
795 /* Inform the kld system about the situation */
796 lf->address = ef->address = (caddr_t)mapbase;
797 lf->size = mapsize;
798
799 /*
800 * Now load code/data(progbits), zero bss(nobits), allocate space for
801 * and load relocs
802 */
803 pb = 0;
804 rl = 0;
805 ra = 0;
806 alignmask = 0;
807 for (i = 0; i < hdr->e_shnum; i++) {
808 if (shdr[i].sh_size == 0)
809 continue;
810 switch (shdr[i].sh_type) {
811 case SHT_PROGBITS:
812 case SHT_NOBITS:
813 #ifdef __amd64__
814 case SHT_X86_64_UNWIND:
815 #endif
816 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
817 break;
818 alignmask = shdr[i].sh_addralign - 1;
819 mapbase += alignmask;
820 mapbase &= ~alignmask;
821 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
822 ef->progtab[pb].name =
823 ef->shstrtab + shdr[i].sh_name;
824 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
825 lf->ctors_addr = (caddr_t)mapbase;
826 lf->ctors_size = shdr[i].sh_size;
827 }
828 } else if (shdr[i].sh_type == SHT_PROGBITS)
829 ef->progtab[pb].name = "<<PROGBITS>>";
830 #ifdef __amd64__
831 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
832 ef->progtab[pb].name = "<<UNWIND>>";
833 #endif
834 else
835 ef->progtab[pb].name = "<<NOBITS>>";
836 if (ef->progtab[pb].name != NULL &&
837 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
838 ef->progtab[pb].addr =
839 dpcpu_alloc(shdr[i].sh_size);
840 #ifdef VIMAGE
841 else if (ef->progtab[pb].name != NULL &&
842 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
843 ef->progtab[pb].addr =
844 vnet_data_alloc(shdr[i].sh_size);
845 #endif
846 else
847 ef->progtab[pb].addr =
848 (void *)(uintptr_t)mapbase;
849 if (ef->progtab[pb].addr == NULL) {
850 error = ENOSPC;
851 goto out;
852 }
853 ef->progtab[pb].size = shdr[i].sh_size;
854 ef->progtab[pb].sec = i;
855 if (shdr[i].sh_type == SHT_PROGBITS
856 #ifdef __amd64__
857 || shdr[i].sh_type == SHT_X86_64_UNWIND
858 #endif
859 ) {
860 error = vn_rdwr(UIO_READ, nd.ni_vp,
861 ef->progtab[pb].addr,
862 shdr[i].sh_size, shdr[i].sh_offset,
863 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
864 NOCRED, &resid, td);
865 if (error)
866 goto out;
867 if (resid != 0){
868 error = EINVAL;
869 goto out;
870 }
871 /* Initialize the per-cpu or vnet area. */
872 if (ef->progtab[pb].addr != (void *)mapbase &&
873 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
874 dpcpu_copy(ef->progtab[pb].addr,
875 shdr[i].sh_size);
876 #ifdef VIMAGE
877 else if (ef->progtab[pb].addr !=
878 (void *)mapbase &&
879 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
880 vnet_data_copy(ef->progtab[pb].addr,
881 shdr[i].sh_size);
882 #endif
883 } else
884 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
885
886 /* Update all symbol values with the offset. */
887 for (j = 0; j < ef->ddbsymcnt; j++) {
888 es = &ef->ddbsymtab[j];
889 if (es->st_shndx != i)
890 continue;
891 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
892 }
893 mapbase += shdr[i].sh_size;
894 pb++;
895 break;
896 case SHT_REL:
897 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
898 break;
899 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
900 M_WAITOK);
901 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
902 ef->reltab[rl].sec = shdr[i].sh_info;
903 error = vn_rdwr(UIO_READ, nd.ni_vp,
904 (void *)ef->reltab[rl].rel,
905 shdr[i].sh_size, shdr[i].sh_offset,
906 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
907 &resid, td);
908 if (error)
909 goto out;
910 if (resid != 0){
911 error = EINVAL;
912 goto out;
913 }
914 rl++;
915 break;
916 case SHT_RELA:
917 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
918 break;
919 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
920 M_WAITOK);
921 ef->relatab[ra].nrela =
922 shdr[i].sh_size / sizeof(Elf_Rela);
923 ef->relatab[ra].sec = shdr[i].sh_info;
924 error = vn_rdwr(UIO_READ, nd.ni_vp,
925 (void *)ef->relatab[ra].rela,
926 shdr[i].sh_size, shdr[i].sh_offset,
927 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
928 &resid, td);
929 if (error)
930 goto out;
931 if (resid != 0){
932 error = EINVAL;
933 goto out;
934 }
935 ra++;
936 break;
937 }
938 }
939 if (pb != ef->nprogtab) {
940 link_elf_error(filename, "lost progbits");
941 error = ENOEXEC;
942 goto out;
943 }
944 if (rl != ef->nreltab) {
945 link_elf_error(filename, "lost reltab");
946 error = ENOEXEC;
947 goto out;
948 }
949 if (ra != ef->nrelatab) {
950 link_elf_error(filename, "lost relatab");
951 error = ENOEXEC;
952 goto out;
953 }
954 if (mapbase != (vm_offset_t)ef->address + mapsize) {
955 printf(
956 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
957 filename != NULL ? filename : "<none>",
958 (u_long)mapbase, ef->address, (u_long)mapsize,
959 (u_long)(vm_offset_t)ef->address + mapsize);
960 error = ENOMEM;
961 goto out;
962 }
963
964 /* Local intra-module relocations */
965 error = link_elf_reloc_local(lf);
966 if (error != 0)
967 goto out;
968
969 /* Pull in dependencies */
970 VOP_UNLOCK(nd.ni_vp, 0);
971 error = linker_load_dependencies(lf);
972 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
973 if (error)
974 goto out;
975
976 /* External relocations */
977 error = relocate_file(ef);
978 if (error)
979 goto out;
980
981 /* Notify MD code that a module is being loaded. */
982 error = elf_cpu_load_file(lf);
983 if (error)
984 goto out;
985
986 /* Invoke .ctors */
987 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
988
989 *result = lf;
990
991 out:
992 VOP_UNLOCK(nd.ni_vp, 0);
993 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
994 if (error && lf)
995 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
996 free(hdr, M_LINKER);
997
998 return error;
999 }
1000
1001 static void
1002 link_elf_unload_file(linker_file_t file)
1003 {
1004 elf_file_t ef = (elf_file_t) file;
1005 int i;
1006
1007 /* Notify MD code that a module is being unloaded. */
1008 elf_cpu_unload_file(file);
1009
1010 if (ef->progtab) {
1011 for (i = 0; i < ef->nprogtab; i++) {
1012 if (ef->progtab[i].size == 0)
1013 continue;
1014 if (ef->progtab[i].name == NULL)
1015 continue;
1016 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1017 dpcpu_free(ef->progtab[i].addr,
1018 ef->progtab[i].size);
1019 #ifdef VIMAGE
1020 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1021 vnet_data_free(ef->progtab[i].addr,
1022 ef->progtab[i].size);
1023 #endif
1024 }
1025 }
1026 if (ef->preloaded) {
1027 free(ef->reltab, M_LINKER);
1028 free(ef->relatab, M_LINKER);
1029 free(ef->progtab, M_LINKER);
1030 free(ef->ctftab, M_LINKER);
1031 free(ef->ctfoff, M_LINKER);
1032 free(ef->typoff, M_LINKER);
1033 if (file->filename != NULL)
1034 preload_delete_name(file->filename);
1035 /* XXX reclaim module memory? */
1036 return;
1037 }
1038
1039 for (i = 0; i < ef->nreltab; i++)
1040 free(ef->reltab[i].rel, M_LINKER);
1041 for (i = 0; i < ef->nrelatab; i++)
1042 free(ef->relatab[i].rela, M_LINKER);
1043 free(ef->reltab, M_LINKER);
1044 free(ef->relatab, M_LINKER);
1045 free(ef->progtab, M_LINKER);
1046
1047 if (ef->object) {
1048 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1049 (vm_offset_t) ef->address +
1050 (ef->object->size << PAGE_SHIFT));
1051 }
1052 free(ef->e_shdr, M_LINKER);
1053 free(ef->ddbsymtab, M_LINKER);
1054 free(ef->ddbstrtab, M_LINKER);
1055 free(ef->shstrtab, M_LINKER);
1056 free(ef->ctftab, M_LINKER);
1057 free(ef->ctfoff, M_LINKER);
1058 free(ef->typoff, M_LINKER);
1059 }
1060
1061 static const char *
1062 symbol_name(elf_file_t ef, Elf_Size r_info)
1063 {
1064 const Elf_Sym *ref;
1065
1066 if (ELF_R_SYM(r_info)) {
1067 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1068 return ef->ddbstrtab + ref->st_name;
1069 } else
1070 return NULL;
1071 }
1072
1073 static Elf_Addr
1074 findbase(elf_file_t ef, int sec)
1075 {
1076 int i;
1077 Elf_Addr base = 0;
1078
1079 for (i = 0; i < ef->nprogtab; i++) {
1080 if (sec == ef->progtab[i].sec) {
1081 base = (Elf_Addr)ef->progtab[i].addr;
1082 break;
1083 }
1084 }
1085 return base;
1086 }
1087
1088 static int
1089 relocate_file(elf_file_t ef)
1090 {
1091 const Elf_Rel *rellim;
1092 const Elf_Rel *rel;
1093 const Elf_Rela *relalim;
1094 const Elf_Rela *rela;
1095 const char *symname;
1096 const Elf_Sym *sym;
1097 int i;
1098 Elf_Size symidx;
1099 Elf_Addr base;
1100
1101
1102 /* Perform relocations without addend if there are any: */
1103 for (i = 0; i < ef->nreltab; i++) {
1104 rel = ef->reltab[i].rel;
1105 if (rel == NULL) {
1106 link_elf_error(ef->lf.filename, "lost a reltab!");
1107 return (ENOEXEC);
1108 }
1109 rellim = rel + ef->reltab[i].nrel;
1110 base = findbase(ef, ef->reltab[i].sec);
1111 if (base == 0) {
1112 link_elf_error(ef->lf.filename, "lost base for reltab");
1113 return (ENOEXEC);
1114 }
1115 for ( ; rel < rellim; rel++) {
1116 symidx = ELF_R_SYM(rel->r_info);
1117 if (symidx >= ef->ddbsymcnt)
1118 continue;
1119 sym = ef->ddbsymtab + symidx;
1120 /* Local relocs are already done */
1121 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1122 continue;
1123 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1124 elf_obj_lookup)) {
1125 symname = symbol_name(ef, rel->r_info);
1126 printf("link_elf_obj: symbol %s undefined\n",
1127 symname);
1128 return (ENOENT);
1129 }
1130 }
1131 }
1132
1133 /* Perform relocations with addend if there are any: */
1134 for (i = 0; i < ef->nrelatab; i++) {
1135 rela = ef->relatab[i].rela;
1136 if (rela == NULL) {
1137 link_elf_error(ef->lf.filename, "lost a relatab!");
1138 return (ENOEXEC);
1139 }
1140 relalim = rela + ef->relatab[i].nrela;
1141 base = findbase(ef, ef->relatab[i].sec);
1142 if (base == 0) {
1143 link_elf_error(ef->lf.filename,
1144 "lost base for relatab");
1145 return (ENOEXEC);
1146 }
1147 for ( ; rela < relalim; rela++) {
1148 symidx = ELF_R_SYM(rela->r_info);
1149 if (symidx >= ef->ddbsymcnt)
1150 continue;
1151 sym = ef->ddbsymtab + symidx;
1152 /* Local relocs are already done */
1153 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1154 continue;
1155 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1156 elf_obj_lookup)) {
1157 symname = symbol_name(ef, rela->r_info);
1158 printf("link_elf_obj: symbol %s undefined\n",
1159 symname);
1160 return (ENOENT);
1161 }
1162 }
1163 }
1164
1165 /*
1166 * Only clean SHN_FBSD_CACHED for successful return. If we
1167 * modified symbol table for the object but found an
1168 * unresolved symbol, there is no reason to roll back.
1169 */
1170 elf_obj_cleanup_globals_cache(ef);
1171
1172 return (0);
1173 }
1174
1175 static int
1176 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1177 {
1178 elf_file_t ef = (elf_file_t) lf;
1179 const Elf_Sym *symp;
1180 const char *strp;
1181 int i;
1182
1183 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1184 strp = ef->ddbstrtab + symp->st_name;
1185 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1186 *sym = (c_linker_sym_t) symp;
1187 return 0;
1188 }
1189 }
1190 return ENOENT;
1191 }
1192
1193 static int
1194 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1195 linker_symval_t *symval)
1196 {
1197 elf_file_t ef;
1198 const Elf_Sym *es;
1199 caddr_t val;
1200
1201 ef = (elf_file_t) lf;
1202 es = (const Elf_Sym*) sym;
1203 val = (caddr_t)es->st_value;
1204 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1205 symval->name = ef->ddbstrtab + es->st_name;
1206 val = (caddr_t)es->st_value;
1207 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1208 val = ((caddr_t (*)(void))val)();
1209 symval->value = val;
1210 symval->size = es->st_size;
1211 return 0;
1212 }
1213 return ENOENT;
1214 }
1215
1216 static int
1217 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1218 c_linker_sym_t *sym, long *diffp)
1219 {
1220 elf_file_t ef = (elf_file_t) lf;
1221 u_long off = (uintptr_t) (void *) value;
1222 u_long diff = off;
1223 u_long st_value;
1224 const Elf_Sym *es;
1225 const Elf_Sym *best = NULL;
1226 int i;
1227
1228 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1229 if (es->st_name == 0)
1230 continue;
1231 st_value = es->st_value;
1232 if (off >= st_value) {
1233 if (off - st_value < diff) {
1234 diff = off - st_value;
1235 best = es;
1236 if (diff == 0)
1237 break;
1238 } else if (off - st_value == diff) {
1239 best = es;
1240 }
1241 }
1242 }
1243 if (best == NULL)
1244 *diffp = off;
1245 else
1246 *diffp = diff;
1247 *sym = (c_linker_sym_t) best;
1248
1249 return 0;
1250 }
1251
1252 /*
1253 * Look up a linker set on an ELF system.
1254 */
1255 static int
1256 link_elf_lookup_set(linker_file_t lf, const char *name,
1257 void ***startp, void ***stopp, int *countp)
1258 {
1259 elf_file_t ef = (elf_file_t)lf;
1260 void **start, **stop;
1261 int i, count;
1262
1263 /* Relative to section number */
1264 for (i = 0; i < ef->nprogtab; i++) {
1265 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1266 strcmp(ef->progtab[i].name + 4, name) == 0) {
1267 start = (void **)ef->progtab[i].addr;
1268 stop = (void **)((char *)ef->progtab[i].addr +
1269 ef->progtab[i].size);
1270 count = stop - start;
1271 if (startp)
1272 *startp = start;
1273 if (stopp)
1274 *stopp = stop;
1275 if (countp)
1276 *countp = count;
1277 return (0);
1278 }
1279 }
1280 return (ESRCH);
1281 }
1282
1283 static int
1284 link_elf_each_function_name(linker_file_t file,
1285 int (*callback)(const char *, void *), void *opaque)
1286 {
1287 elf_file_t ef = (elf_file_t)file;
1288 const Elf_Sym *symp;
1289 int i, error;
1290
1291 /* Exhaustive search */
1292 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1293 if (symp->st_value != 0 &&
1294 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1295 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1296 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1297 if (error)
1298 return (error);
1299 }
1300 }
1301 return (0);
1302 }
1303
1304 static int
1305 link_elf_each_function_nameval(linker_file_t file,
1306 linker_function_nameval_callback_t callback, void *opaque)
1307 {
1308 linker_symval_t symval;
1309 elf_file_t ef = (elf_file_t)file;
1310 const Elf_Sym* symp;
1311 int i, error;
1312
1313 /* Exhaustive search */
1314 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1315 if (symp->st_value != 0 &&
1316 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1317 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1318 error = link_elf_symbol_values(file,
1319 (c_linker_sym_t)symp, &symval);
1320 if (error)
1321 return (error);
1322 error = callback(file, i, &symval, opaque);
1323 if (error)
1324 return (error);
1325 }
1326 }
1327 return (0);
1328 }
1329
1330 static void
1331 elf_obj_cleanup_globals_cache(elf_file_t ef)
1332 {
1333 Elf_Sym *sym;
1334 Elf_Size i;
1335
1336 for (i = 0; i < ef->ddbsymcnt; i++) {
1337 sym = ef->ddbsymtab + i;
1338 if (sym->st_shndx == SHN_FBSD_CACHED) {
1339 sym->st_shndx = SHN_UNDEF;
1340 sym->st_value = 0;
1341 }
1342 }
1343 }
1344
1345 /*
1346 * Symbol lookup function that can be used when the symbol index is known (ie
1347 * in relocations). It uses the symbol index instead of doing a fully fledged
1348 * hash table based lookup when such is valid. For example for local symbols.
1349 * This is not only more efficient, it's also more correct. It's not always
1350 * the case that the symbol can be found through the hash table.
1351 */
1352 static int
1353 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1354 {
1355 elf_file_t ef = (elf_file_t)lf;
1356 Elf_Sym *sym;
1357 const char *symbol;
1358 Elf_Addr res1;
1359
1360 /* Don't even try to lookup the symbol if the index is bogus. */
1361 if (symidx >= ef->ddbsymcnt) {
1362 *res = 0;
1363 return (EINVAL);
1364 }
1365
1366 sym = ef->ddbsymtab + symidx;
1367
1368 /* Quick answer if there is a definition included. */
1369 if (sym->st_shndx != SHN_UNDEF) {
1370 *res = sym->st_value;
1371 return (0);
1372 }
1373
1374 /* If we get here, then it is undefined and needs a lookup. */
1375 switch (ELF_ST_BIND(sym->st_info)) {
1376 case STB_LOCAL:
1377 /* Local, but undefined? huh? */
1378 *res = 0;
1379 return (EINVAL);
1380
1381 case STB_GLOBAL:
1382 case STB_WEAK:
1383 /* Relative to Data or Function name */
1384 symbol = ef->ddbstrtab + sym->st_name;
1385
1386 /* Force a lookup failure if the symbol name is bogus. */
1387 if (*symbol == 0) {
1388 *res = 0;
1389 return (EINVAL);
1390 }
1391 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1392
1393 /*
1394 * Cache global lookups during module relocation. The failure
1395 * case is particularly expensive for callers, who must scan
1396 * through the entire globals table doing strcmp(). Cache to
1397 * avoid doing such work repeatedly.
1398 *
1399 * After relocation is complete, undefined globals will be
1400 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1401 * above.
1402 */
1403 if (res1 != 0) {
1404 sym->st_shndx = SHN_FBSD_CACHED;
1405 sym->st_value = res1;
1406 *res = res1;
1407 return (0);
1408 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1409 sym->st_value = 0;
1410 *res = 0;
1411 return (0);
1412 }
1413 return (EINVAL);
1414
1415 default:
1416 return (EINVAL);
1417 }
1418 }
1419
1420 static void
1421 link_elf_fix_link_set(elf_file_t ef)
1422 {
1423 static const char startn[] = "__start_";
1424 static const char stopn[] = "__stop_";
1425 Elf_Sym *sym;
1426 const char *sym_name, *linkset_name;
1427 Elf_Addr startp, stopp;
1428 Elf_Size symidx;
1429 int start, i;
1430
1431 startp = stopp = 0;
1432 for (symidx = 1 /* zero entry is special */;
1433 symidx < ef->ddbsymcnt; symidx++) {
1434 sym = ef->ddbsymtab + symidx;
1435 if (sym->st_shndx != SHN_UNDEF)
1436 continue;
1437
1438 sym_name = ef->ddbstrtab + sym->st_name;
1439 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1440 start = 1;
1441 linkset_name = sym_name + sizeof(startn) - 1;
1442 }
1443 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1444 start = 0;
1445 linkset_name = sym_name + sizeof(stopn) - 1;
1446 }
1447 else
1448 continue;
1449
1450 for (i = 0; i < ef->nprogtab; i++) {
1451 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1452 startp = (Elf_Addr)ef->progtab[i].addr;
1453 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1454 break;
1455 }
1456 }
1457 if (i == ef->nprogtab)
1458 continue;
1459
1460 sym->st_value = start ? startp : stopp;
1461 sym->st_shndx = i;
1462 }
1463 }
1464
1465 static int
1466 link_elf_reloc_local(linker_file_t lf)
1467 {
1468 elf_file_t ef = (elf_file_t)lf;
1469 const Elf_Rel *rellim;
1470 const Elf_Rel *rel;
1471 const Elf_Rela *relalim;
1472 const Elf_Rela *rela;
1473 const Elf_Sym *sym;
1474 Elf_Addr base;
1475 int i;
1476 Elf_Size symidx;
1477
1478 link_elf_fix_link_set(ef);
1479
1480 /* Perform relocations without addend if there are any: */
1481 for (i = 0; i < ef->nreltab; i++) {
1482 rel = ef->reltab[i].rel;
1483 if (rel == NULL) {
1484 link_elf_error(ef->lf.filename, "lost a reltab");
1485 return (ENOEXEC);
1486 }
1487 rellim = rel + ef->reltab[i].nrel;
1488 base = findbase(ef, ef->reltab[i].sec);
1489 if (base == 0) {
1490 link_elf_error(ef->lf.filename, "lost base for reltab");
1491 return (ENOEXEC);
1492 }
1493 for ( ; rel < rellim; rel++) {
1494 symidx = ELF_R_SYM(rel->r_info);
1495 if (symidx >= ef->ddbsymcnt)
1496 continue;
1497 sym = ef->ddbsymtab + symidx;
1498 /* Only do local relocs */
1499 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1500 continue;
1501 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1502 elf_obj_lookup);
1503 }
1504 }
1505
1506 /* Perform relocations with addend if there are any: */
1507 for (i = 0; i < ef->nrelatab; i++) {
1508 rela = ef->relatab[i].rela;
1509 if (rela == NULL) {
1510 link_elf_error(ef->lf.filename, "lost a relatab!");
1511 return (ENOEXEC);
1512 }
1513 relalim = rela + ef->relatab[i].nrela;
1514 base = findbase(ef, ef->relatab[i].sec);
1515 if (base == 0) {
1516 link_elf_error(ef->lf.filename, "lost base for reltab");
1517 return (ENOEXEC);
1518 }
1519 for ( ; rela < relalim; rela++) {
1520 symidx = ELF_R_SYM(rela->r_info);
1521 if (symidx >= ef->ddbsymcnt)
1522 continue;
1523 sym = ef->ddbsymtab + symidx;
1524 /* Only do local relocs */
1525 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1526 continue;
1527 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1528 elf_obj_lookup);
1529 }
1530 }
1531 return (0);
1532 }
1533
1534 static long
1535 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1536 {
1537 elf_file_t ef = (elf_file_t)lf;
1538
1539 *symtab = ef->ddbsymtab;
1540
1541 if (*symtab == NULL)
1542 return (0);
1543
1544 return (ef->ddbsymcnt);
1545 }
1546
1547 static long
1548 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1549 {
1550 elf_file_t ef = (elf_file_t)lf;
1551
1552 *strtab = ef->ddbstrtab;
1553
1554 if (*strtab == NULL)
1555 return (0);
1556
1557 return (ef->ddbstrcnt);
1558 }
Cache object: fb971442b91579bf6b01580405ef9378
|