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/10.4/sys/kern/link_elf_obj.c 302234 2016-06-27 21:50:30Z bdrewery $");
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 <net/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_AMD64_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_AMD64_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_AMD64_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 }
379
380 /* Update all symbol values with the offset. */
381 for (j = 0; j < ef->ddbsymcnt; j++) {
382 es = &ef->ddbsymtab[j];
383 if (es->st_shndx != i)
384 continue;
385 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
386 }
387 pb++;
388 break;
389 case SHT_REL:
390 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
391 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
392 ef->reltab[rl].sec = shdr[i].sh_info;
393 rl++;
394 break;
395 case SHT_RELA:
396 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
397 ef->relatab[ra].nrela =
398 shdr[i].sh_size / sizeof(Elf_Rela);
399 ef->relatab[ra].sec = shdr[i].sh_info;
400 ra++;
401 break;
402 }
403 }
404 if (pb != ef->nprogtab) {
405 printf("%s: lost progbits\n", filename);
406 error = ENOEXEC;
407 goto out;
408 }
409 if (rl != ef->nreltab) {
410 printf("%s: lost reltab\n", filename);
411 error = ENOEXEC;
412 goto out;
413 }
414 if (ra != ef->nrelatab) {
415 printf("%s: lost relatab\n", filename);
416 error = ENOEXEC;
417 goto out;
418 }
419
420 /* Local intra-module relocations */
421 error = link_elf_reloc_local(lf);
422 if (error != 0)
423 goto out;
424
425 *result = lf;
426 return (0);
427
428 out:
429 /* preload not done this way */
430 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
431 return (error);
432 }
433
434 static int
435 link_elf_link_preload_finish(linker_file_t lf)
436 {
437 elf_file_t ef;
438 int error;
439
440 ef = (elf_file_t)lf;
441 error = relocate_file(ef);
442 if (error)
443 return error;
444
445 /* Notify MD code that a module is being loaded. */
446 error = elf_cpu_load_file(lf);
447 if (error)
448 return (error);
449
450 return (0);
451 }
452
453 static int
454 link_elf_load_file(linker_class_t cls, const char *filename,
455 linker_file_t *result)
456 {
457 struct nameidata nd;
458 struct thread *td = curthread; /* XXX */
459 Elf_Ehdr *hdr;
460 Elf_Shdr *shdr;
461 Elf_Sym *es;
462 int nbytes, i, j;
463 vm_offset_t mapbase;
464 size_t mapsize;
465 int error = 0;
466 ssize_t resid;
467 int flags;
468 elf_file_t ef;
469 linker_file_t lf;
470 int symtabindex;
471 int symstrindex;
472 int shstrindex;
473 int nsym;
474 int pb, rl, ra;
475 int alignmask;
476
477 shdr = NULL;
478 lf = NULL;
479 mapsize = 0;
480 hdr = NULL;
481
482 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
483 flags = FREAD;
484 error = vn_open(&nd, &flags, 0, NULL);
485 if (error)
486 return error;
487 NDFREE(&nd, NDF_ONLY_PNBUF);
488 if (nd.ni_vp->v_type != VREG) {
489 error = ENOEXEC;
490 goto out;
491 }
492 #ifdef MAC
493 error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
494 if (error) {
495 goto out;
496 }
497 #endif
498
499 /* Read the elf header from the file. */
500 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
501 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
502 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
503 &resid, td);
504 if (error)
505 goto out;
506 if (resid != 0){
507 error = ENOEXEC;
508 goto out;
509 }
510
511 if (!IS_ELF(*hdr)) {
512 error = ENOEXEC;
513 goto out;
514 }
515
516 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
517 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
518 link_elf_error(filename, "Unsupported file layout");
519 error = ENOEXEC;
520 goto out;
521 }
522 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
523 || hdr->e_version != EV_CURRENT) {
524 link_elf_error(filename, "Unsupported file version");
525 error = ENOEXEC;
526 goto out;
527 }
528 if (hdr->e_type != ET_REL) {
529 error = ENOSYS;
530 goto out;
531 }
532 if (hdr->e_machine != ELF_TARG_MACH) {
533 link_elf_error(filename, "Unsupported machine");
534 error = ENOEXEC;
535 goto out;
536 }
537
538 lf = linker_make_file(filename, &link_elf_class);
539 if (!lf) {
540 error = ENOMEM;
541 goto out;
542 }
543 ef = (elf_file_t) lf;
544 ef->nprogtab = 0;
545 ef->e_shdr = 0;
546 ef->nreltab = 0;
547 ef->nrelatab = 0;
548
549 /* Allocate and read in the section header */
550 nbytes = hdr->e_shnum * hdr->e_shentsize;
551 if (nbytes == 0 || hdr->e_shoff == 0 ||
552 hdr->e_shentsize != sizeof(Elf_Shdr)) {
553 error = ENOEXEC;
554 goto out;
555 }
556 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
557 ef->e_shdr = shdr;
558 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
559 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
560 if (error)
561 goto out;
562 if (resid) {
563 error = ENOEXEC;
564 goto out;
565 }
566
567 /* Scan the section header for information and table sizing. */
568 nsym = 0;
569 symtabindex = -1;
570 symstrindex = -1;
571 for (i = 0; i < hdr->e_shnum; i++) {
572 if (shdr[i].sh_size == 0)
573 continue;
574 switch (shdr[i].sh_type) {
575 case SHT_PROGBITS:
576 case SHT_NOBITS:
577 #ifdef __amd64__
578 case SHT_AMD64_UNWIND:
579 #endif
580 ef->nprogtab++;
581 break;
582 case SHT_SYMTAB:
583 nsym++;
584 symtabindex = i;
585 symstrindex = shdr[i].sh_link;
586 break;
587 case SHT_REL:
588 ef->nreltab++;
589 break;
590 case SHT_RELA:
591 ef->nrelatab++;
592 break;
593 case SHT_STRTAB:
594 break;
595 }
596 }
597 if (ef->nprogtab == 0) {
598 link_elf_error(filename, "file has no contents");
599 error = ENOEXEC;
600 goto out;
601 }
602 if (nsym != 1) {
603 /* Only allow one symbol table for now */
604 link_elf_error(filename, "file has no valid symbol table");
605 error = ENOEXEC;
606 goto out;
607 }
608 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
609 shdr[symstrindex].sh_type != SHT_STRTAB) {
610 link_elf_error(filename, "file has invalid symbol strings");
611 error = ENOEXEC;
612 goto out;
613 }
614
615 /* Allocate space for tracking the load chunks */
616 if (ef->nprogtab != 0)
617 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
618 M_LINKER, M_WAITOK | M_ZERO);
619 if (ef->nreltab != 0)
620 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
621 M_LINKER, M_WAITOK | M_ZERO);
622 if (ef->nrelatab != 0)
623 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
624 M_LINKER, M_WAITOK | M_ZERO);
625
626 if (symtabindex == -1) {
627 link_elf_error(filename, "lost symbol table index");
628 error = ENOEXEC;
629 goto out;
630 }
631 /* Allocate space for and load the symbol table */
632 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
633 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
634 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
635 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
636 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
637 &resid, td);
638 if (error)
639 goto out;
640 if (resid != 0){
641 error = EINVAL;
642 goto out;
643 }
644
645 if (symstrindex == -1) {
646 link_elf_error(filename, "lost symbol string index");
647 error = ENOEXEC;
648 goto out;
649 }
650 /* Allocate space for and load the symbol strings */
651 ef->ddbstrcnt = shdr[symstrindex].sh_size;
652 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
653 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
654 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
655 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
656 &resid, td);
657 if (error)
658 goto out;
659 if (resid != 0){
660 error = EINVAL;
661 goto out;
662 }
663
664 /* Do we have a string table for the section names? */
665 shstrindex = -1;
666 if (hdr->e_shstrndx != 0 &&
667 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
668 shstrindex = hdr->e_shstrndx;
669 ef->shstrcnt = shdr[shstrindex].sh_size;
670 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
671 M_WAITOK);
672 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
673 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
674 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
675 &resid, td);
676 if (error)
677 goto out;
678 if (resid != 0){
679 error = EINVAL;
680 goto out;
681 }
682 }
683
684 /* Size up code/data(progbits) and bss(nobits). */
685 alignmask = 0;
686 for (i = 0; i < hdr->e_shnum; i++) {
687 if (shdr[i].sh_size == 0)
688 continue;
689 switch (shdr[i].sh_type) {
690 case SHT_PROGBITS:
691 case SHT_NOBITS:
692 #ifdef __amd64__
693 case SHT_AMD64_UNWIND:
694 #endif
695 alignmask = shdr[i].sh_addralign - 1;
696 mapsize += alignmask;
697 mapsize &= ~alignmask;
698 mapsize += shdr[i].sh_size;
699 break;
700 }
701 }
702
703 /*
704 * We know how much space we need for the text/data/bss/etc.
705 * This stuff needs to be in a single chunk so that profiling etc
706 * can get the bounds and gdb can associate offsets with modules
707 */
708 ef->object = vm_object_allocate(OBJT_DEFAULT,
709 round_page(mapsize) >> PAGE_SHIFT);
710 if (ef->object == NULL) {
711 error = ENOMEM;
712 goto out;
713 }
714 ef->address = (caddr_t) vm_map_min(kernel_map);
715
716 /*
717 * In order to satisfy amd64's architectural requirements on the
718 * location of code and data in the kernel's address space, request a
719 * mapping that is above the kernel.
720 */
721 #ifdef __amd64__
722 mapbase = KERNBASE;
723 #else
724 mapbase = VM_MIN_KERNEL_ADDRESS;
725 #endif
726 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
727 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
728 VM_PROT_ALL, 0);
729 if (error) {
730 vm_object_deallocate(ef->object);
731 ef->object = 0;
732 goto out;
733 }
734
735 /* Wire the pages */
736 error = vm_map_wire(kernel_map, mapbase,
737 mapbase + round_page(mapsize),
738 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
739 if (error != KERN_SUCCESS) {
740 error = ENOMEM;
741 goto out;
742 }
743
744 /* Inform the kld system about the situation */
745 lf->address = ef->address = (caddr_t)mapbase;
746 lf->size = mapsize;
747
748 /*
749 * Now load code/data(progbits), zero bss(nobits), allocate space for
750 * and load relocs
751 */
752 pb = 0;
753 rl = 0;
754 ra = 0;
755 alignmask = 0;
756 for (i = 0; i < hdr->e_shnum; i++) {
757 if (shdr[i].sh_size == 0)
758 continue;
759 switch (shdr[i].sh_type) {
760 case SHT_PROGBITS:
761 case SHT_NOBITS:
762 #ifdef __amd64__
763 case SHT_AMD64_UNWIND:
764 #endif
765 alignmask = shdr[i].sh_addralign - 1;
766 mapbase += alignmask;
767 mapbase &= ~alignmask;
768 if (ef->shstrtab && shdr[i].sh_name != 0)
769 ef->progtab[pb].name =
770 ef->shstrtab + shdr[i].sh_name;
771 else if (shdr[i].sh_type == SHT_PROGBITS)
772 ef->progtab[pb].name = "<<PROGBITS>>";
773 #ifdef __amd64__
774 else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
775 ef->progtab[pb].name = "<<UNWIND>>";
776 #endif
777 else
778 ef->progtab[pb].name = "<<NOBITS>>";
779 if (ef->progtab[pb].name != NULL &&
780 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
781 ef->progtab[pb].addr =
782 dpcpu_alloc(shdr[i].sh_size);
783 #ifdef VIMAGE
784 else if (ef->progtab[pb].name != NULL &&
785 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
786 ef->progtab[pb].addr =
787 vnet_data_alloc(shdr[i].sh_size);
788 #endif
789 else
790 ef->progtab[pb].addr =
791 (void *)(uintptr_t)mapbase;
792 if (ef->progtab[pb].addr == NULL) {
793 error = ENOSPC;
794 goto out;
795 }
796 ef->progtab[pb].size = shdr[i].sh_size;
797 ef->progtab[pb].sec = i;
798 if (shdr[i].sh_type == SHT_PROGBITS
799 #ifdef __amd64__
800 || shdr[i].sh_type == SHT_AMD64_UNWIND
801 #endif
802 ) {
803 error = vn_rdwr(UIO_READ, nd.ni_vp,
804 ef->progtab[pb].addr,
805 shdr[i].sh_size, shdr[i].sh_offset,
806 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
807 NOCRED, &resid, td);
808 if (error)
809 goto out;
810 if (resid != 0){
811 error = EINVAL;
812 goto out;
813 }
814 /* Initialize the per-cpu or vnet area. */
815 if (ef->progtab[pb].addr != (void *)mapbase &&
816 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
817 dpcpu_copy(ef->progtab[pb].addr,
818 shdr[i].sh_size);
819 #ifdef VIMAGE
820 else if (ef->progtab[pb].addr !=
821 (void *)mapbase &&
822 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
823 vnet_data_copy(ef->progtab[pb].addr,
824 shdr[i].sh_size);
825 #endif
826 } else
827 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
828
829 /* Update all symbol values with the offset. */
830 for (j = 0; j < ef->ddbsymcnt; j++) {
831 es = &ef->ddbsymtab[j];
832 if (es->st_shndx != i)
833 continue;
834 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
835 }
836 mapbase += shdr[i].sh_size;
837 pb++;
838 break;
839 case SHT_REL:
840 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
841 M_WAITOK);
842 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
843 ef->reltab[rl].sec = shdr[i].sh_info;
844 error = vn_rdwr(UIO_READ, nd.ni_vp,
845 (void *)ef->reltab[rl].rel,
846 shdr[i].sh_size, shdr[i].sh_offset,
847 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
848 &resid, td);
849 if (error)
850 goto out;
851 if (resid != 0){
852 error = EINVAL;
853 goto out;
854 }
855 rl++;
856 break;
857 case SHT_RELA:
858 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
859 M_WAITOK);
860 ef->relatab[ra].nrela =
861 shdr[i].sh_size / sizeof(Elf_Rela);
862 ef->relatab[ra].sec = shdr[i].sh_info;
863 error = vn_rdwr(UIO_READ, nd.ni_vp,
864 (void *)ef->relatab[ra].rela,
865 shdr[i].sh_size, shdr[i].sh_offset,
866 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
867 &resid, td);
868 if (error)
869 goto out;
870 if (resid != 0){
871 error = EINVAL;
872 goto out;
873 }
874 ra++;
875 break;
876 }
877 }
878 if (pb != ef->nprogtab) {
879 link_elf_error(filename, "lost progbits");
880 error = ENOEXEC;
881 goto out;
882 }
883 if (rl != ef->nreltab) {
884 link_elf_error(filename, "lost reltab");
885 error = ENOEXEC;
886 goto out;
887 }
888 if (ra != ef->nrelatab) {
889 link_elf_error(filename, "lost relatab");
890 error = ENOEXEC;
891 goto out;
892 }
893 if (mapbase != (vm_offset_t)ef->address + mapsize) {
894 printf(
895 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
896 filename != NULL ? filename : "<none>",
897 (u_long)mapbase, ef->address, (u_long)mapsize,
898 (u_long)(vm_offset_t)ef->address + mapsize);
899 error = ENOMEM;
900 goto out;
901 }
902
903 /* Local intra-module relocations */
904 error = link_elf_reloc_local(lf);
905 if (error != 0)
906 goto out;
907
908 /* Pull in dependencies */
909 VOP_UNLOCK(nd.ni_vp, 0);
910 error = linker_load_dependencies(lf);
911 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
912 if (error)
913 goto out;
914
915 /* External relocations */
916 error = relocate_file(ef);
917 if (error)
918 goto out;
919
920 /* Notify MD code that a module is being loaded. */
921 error = elf_cpu_load_file(lf);
922 if (error)
923 goto out;
924
925 *result = lf;
926
927 out:
928 VOP_UNLOCK(nd.ni_vp, 0);
929 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
930 if (error && lf)
931 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
932 free(hdr, M_LINKER);
933
934 return error;
935 }
936
937 static void
938 link_elf_unload_file(linker_file_t file)
939 {
940 elf_file_t ef = (elf_file_t) file;
941 int i;
942
943 /* Notify MD code that a module is being unloaded. */
944 elf_cpu_unload_file(file);
945
946 if (ef->progtab) {
947 for (i = 0; i < ef->nprogtab; i++) {
948 if (ef->progtab[i].size == 0)
949 continue;
950 if (ef->progtab[i].name == NULL)
951 continue;
952 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
953 dpcpu_free(ef->progtab[i].addr,
954 ef->progtab[i].size);
955 #ifdef VIMAGE
956 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
957 vnet_data_free(ef->progtab[i].addr,
958 ef->progtab[i].size);
959 #endif
960 }
961 }
962 if (ef->preloaded) {
963 free(ef->reltab, M_LINKER);
964 free(ef->relatab, M_LINKER);
965 free(ef->progtab, M_LINKER);
966 free(ef->ctftab, M_LINKER);
967 free(ef->ctfoff, M_LINKER);
968 free(ef->typoff, M_LINKER);
969 if (file->filename != NULL)
970 preload_delete_name(file->filename);
971 /* XXX reclaim module memory? */
972 return;
973 }
974
975 for (i = 0; i < ef->nreltab; i++)
976 free(ef->reltab[i].rel, M_LINKER);
977 for (i = 0; i < ef->nrelatab; i++)
978 free(ef->relatab[i].rela, M_LINKER);
979 free(ef->reltab, M_LINKER);
980 free(ef->relatab, M_LINKER);
981 free(ef->progtab, M_LINKER);
982
983 if (ef->object) {
984 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
985 (vm_offset_t) ef->address +
986 (ef->object->size << PAGE_SHIFT));
987 }
988 free(ef->e_shdr, M_LINKER);
989 free(ef->ddbsymtab, M_LINKER);
990 free(ef->ddbstrtab, M_LINKER);
991 free(ef->shstrtab, M_LINKER);
992 free(ef->ctftab, M_LINKER);
993 free(ef->ctfoff, M_LINKER);
994 free(ef->typoff, M_LINKER);
995 }
996
997 static const char *
998 symbol_name(elf_file_t ef, Elf_Size r_info)
999 {
1000 const Elf_Sym *ref;
1001
1002 if (ELF_R_SYM(r_info)) {
1003 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1004 return ef->ddbstrtab + ref->st_name;
1005 } else
1006 return NULL;
1007 }
1008
1009 static Elf_Addr
1010 findbase(elf_file_t ef, int sec)
1011 {
1012 int i;
1013 Elf_Addr base = 0;
1014
1015 for (i = 0; i < ef->nprogtab; i++) {
1016 if (sec == ef->progtab[i].sec) {
1017 base = (Elf_Addr)ef->progtab[i].addr;
1018 break;
1019 }
1020 }
1021 return base;
1022 }
1023
1024 static int
1025 relocate_file(elf_file_t ef)
1026 {
1027 const Elf_Rel *rellim;
1028 const Elf_Rel *rel;
1029 const Elf_Rela *relalim;
1030 const Elf_Rela *rela;
1031 const char *symname;
1032 const Elf_Sym *sym;
1033 int i;
1034 Elf_Size symidx;
1035 Elf_Addr base;
1036
1037
1038 /* Perform relocations without addend if there are any: */
1039 for (i = 0; i < ef->nreltab; i++) {
1040 rel = ef->reltab[i].rel;
1041 if (rel == NULL) {
1042 link_elf_error(ef->lf.filename, "lost a reltab!");
1043 return (ENOEXEC);
1044 }
1045 rellim = rel + ef->reltab[i].nrel;
1046 base = findbase(ef, ef->reltab[i].sec);
1047 if (base == 0) {
1048 link_elf_error(ef->lf.filename, "lost base for reltab");
1049 return (ENOEXEC);
1050 }
1051 for ( ; rel < rellim; rel++) {
1052 symidx = ELF_R_SYM(rel->r_info);
1053 if (symidx >= ef->ddbsymcnt)
1054 continue;
1055 sym = ef->ddbsymtab + symidx;
1056 /* Local relocs are already done */
1057 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1058 continue;
1059 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1060 elf_obj_lookup)) {
1061 symname = symbol_name(ef, rel->r_info);
1062 printf("link_elf_obj: symbol %s undefined\n",
1063 symname);
1064 return (ENOENT);
1065 }
1066 }
1067 }
1068
1069 /* Perform relocations with addend if there are any: */
1070 for (i = 0; i < ef->nrelatab; i++) {
1071 rela = ef->relatab[i].rela;
1072 if (rela == NULL) {
1073 link_elf_error(ef->lf.filename, "lost a relatab!");
1074 return (ENOEXEC);
1075 }
1076 relalim = rela + ef->relatab[i].nrela;
1077 base = findbase(ef, ef->relatab[i].sec);
1078 if (base == 0) {
1079 link_elf_error(ef->lf.filename,
1080 "lost base for relatab");
1081 return (ENOEXEC);
1082 }
1083 for ( ; rela < relalim; rela++) {
1084 symidx = ELF_R_SYM(rela->r_info);
1085 if (symidx >= ef->ddbsymcnt)
1086 continue;
1087 sym = ef->ddbsymtab + symidx;
1088 /* Local relocs are already done */
1089 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1090 continue;
1091 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1092 elf_obj_lookup)) {
1093 symname = symbol_name(ef, rela->r_info);
1094 printf("link_elf_obj: symbol %s undefined\n",
1095 symname);
1096 return (ENOENT);
1097 }
1098 }
1099 }
1100
1101 /*
1102 * Only clean SHN_FBSD_CACHED for successful return. If we
1103 * modified symbol table for the object but found an
1104 * unresolved symbol, there is no reason to roll back.
1105 */
1106 elf_obj_cleanup_globals_cache(ef);
1107
1108 return (0);
1109 }
1110
1111 static int
1112 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1113 {
1114 elf_file_t ef = (elf_file_t) lf;
1115 const Elf_Sym *symp;
1116 const char *strp;
1117 int i;
1118
1119 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1120 strp = ef->ddbstrtab + symp->st_name;
1121 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1122 *sym = (c_linker_sym_t) symp;
1123 return 0;
1124 }
1125 }
1126 return ENOENT;
1127 }
1128
1129 static int
1130 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1131 linker_symval_t *symval)
1132 {
1133 elf_file_t ef = (elf_file_t) lf;
1134 const Elf_Sym *es = (const Elf_Sym*) sym;
1135
1136 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1137 symval->name = ef->ddbstrtab + es->st_name;
1138 symval->value = (caddr_t)es->st_value;
1139 symval->size = es->st_size;
1140 return 0;
1141 }
1142 return ENOENT;
1143 }
1144
1145 static int
1146 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1147 c_linker_sym_t *sym, long *diffp)
1148 {
1149 elf_file_t ef = (elf_file_t) lf;
1150 u_long off = (uintptr_t) (void *) value;
1151 u_long diff = off;
1152 u_long st_value;
1153 const Elf_Sym *es;
1154 const Elf_Sym *best = 0;
1155 int i;
1156
1157 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1158 if (es->st_name == 0)
1159 continue;
1160 st_value = es->st_value;
1161 if (off >= st_value) {
1162 if (off - st_value < diff) {
1163 diff = off - st_value;
1164 best = es;
1165 if (diff == 0)
1166 break;
1167 } else if (off - st_value == diff) {
1168 best = es;
1169 }
1170 }
1171 }
1172 if (best == 0)
1173 *diffp = off;
1174 else
1175 *diffp = diff;
1176 *sym = (c_linker_sym_t) best;
1177
1178 return 0;
1179 }
1180
1181 /*
1182 * Look up a linker set on an ELF system.
1183 */
1184 static int
1185 link_elf_lookup_set(linker_file_t lf, const char *name,
1186 void ***startp, void ***stopp, int *countp)
1187 {
1188 elf_file_t ef = (elf_file_t)lf;
1189 void **start, **stop;
1190 int i, count;
1191
1192 /* Relative to section number */
1193 for (i = 0; i < ef->nprogtab; i++) {
1194 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1195 strcmp(ef->progtab[i].name + 4, name) == 0) {
1196 start = (void **)ef->progtab[i].addr;
1197 stop = (void **)((char *)ef->progtab[i].addr +
1198 ef->progtab[i].size);
1199 count = stop - start;
1200 if (startp)
1201 *startp = start;
1202 if (stopp)
1203 *stopp = stop;
1204 if (countp)
1205 *countp = count;
1206 return (0);
1207 }
1208 }
1209 return (ESRCH);
1210 }
1211
1212 static int
1213 link_elf_each_function_name(linker_file_t file,
1214 int (*callback)(const char *, void *), void *opaque)
1215 {
1216 elf_file_t ef = (elf_file_t)file;
1217 const Elf_Sym *symp;
1218 int i, error;
1219
1220 /* Exhaustive search */
1221 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1222 if (symp->st_value != 0 &&
1223 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1224 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1225 if (error)
1226 return (error);
1227 }
1228 }
1229 return (0);
1230 }
1231
1232 static int
1233 link_elf_each_function_nameval(linker_file_t file,
1234 linker_function_nameval_callback_t callback, void *opaque)
1235 {
1236 linker_symval_t symval;
1237 elf_file_t ef = (elf_file_t)file;
1238 const Elf_Sym* symp;
1239 int i, error;
1240
1241 /* Exhaustive search */
1242 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1243 if (symp->st_value != 0 &&
1244 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1245 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1246 if (error)
1247 return (error);
1248 error = callback(file, i, &symval, opaque);
1249 if (error)
1250 return (error);
1251 }
1252 }
1253 return (0);
1254 }
1255
1256 static void
1257 elf_obj_cleanup_globals_cache(elf_file_t ef)
1258 {
1259 Elf_Sym *sym;
1260 Elf_Size i;
1261
1262 for (i = 0; i < ef->ddbsymcnt; i++) {
1263 sym = ef->ddbsymtab + i;
1264 if (sym->st_shndx == SHN_FBSD_CACHED) {
1265 sym->st_shndx = SHN_UNDEF;
1266 sym->st_value = 0;
1267 }
1268 }
1269 }
1270
1271 /*
1272 * Symbol lookup function that can be used when the symbol index is known (ie
1273 * in relocations). It uses the symbol index instead of doing a fully fledged
1274 * hash table based lookup when such is valid. For example for local symbols.
1275 * This is not only more efficient, it's also more correct. It's not always
1276 * the case that the symbol can be found through the hash table.
1277 */
1278 static int
1279 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1280 {
1281 elf_file_t ef = (elf_file_t)lf;
1282 Elf_Sym *sym;
1283 const char *symbol;
1284 Elf_Addr res1;
1285
1286 /* Don't even try to lookup the symbol if the index is bogus. */
1287 if (symidx >= ef->ddbsymcnt) {
1288 *res = 0;
1289 return (EINVAL);
1290 }
1291
1292 sym = ef->ddbsymtab + symidx;
1293
1294 /* Quick answer if there is a definition included. */
1295 if (sym->st_shndx != SHN_UNDEF) {
1296 *res = sym->st_value;
1297 return (0);
1298 }
1299
1300 /* If we get here, then it is undefined and needs a lookup. */
1301 switch (ELF_ST_BIND(sym->st_info)) {
1302 case STB_LOCAL:
1303 /* Local, but undefined? huh? */
1304 *res = 0;
1305 return (EINVAL);
1306
1307 case STB_GLOBAL:
1308 case STB_WEAK:
1309 /* Relative to Data or Function name */
1310 symbol = ef->ddbstrtab + sym->st_name;
1311
1312 /* Force a lookup failure if the symbol name is bogus. */
1313 if (*symbol == 0) {
1314 *res = 0;
1315 return (EINVAL);
1316 }
1317 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1318
1319 /*
1320 * Cache global lookups during module relocation. The failure
1321 * case is particularly expensive for callers, who must scan
1322 * through the entire globals table doing strcmp(). Cache to
1323 * avoid doing such work repeatedly.
1324 *
1325 * After relocation is complete, undefined globals will be
1326 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1327 * above.
1328 */
1329 if (res1 != 0) {
1330 sym->st_shndx = SHN_FBSD_CACHED;
1331 sym->st_value = res1;
1332 *res = res1;
1333 return (0);
1334 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1335 sym->st_value = 0;
1336 *res = 0;
1337 return (0);
1338 }
1339 return (EINVAL);
1340
1341 default:
1342 return (EINVAL);
1343 }
1344 }
1345
1346 static void
1347 link_elf_fix_link_set(elf_file_t ef)
1348 {
1349 static const char startn[] = "__start_";
1350 static const char stopn[] = "__stop_";
1351 Elf_Sym *sym;
1352 const char *sym_name, *linkset_name;
1353 Elf_Addr startp, stopp;
1354 Elf_Size symidx;
1355 int start, i;
1356
1357 startp = stopp = 0;
1358 for (symidx = 1 /* zero entry is special */;
1359 symidx < ef->ddbsymcnt; symidx++) {
1360 sym = ef->ddbsymtab + symidx;
1361 if (sym->st_shndx != SHN_UNDEF)
1362 continue;
1363
1364 sym_name = ef->ddbstrtab + sym->st_name;
1365 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1366 start = 1;
1367 linkset_name = sym_name + sizeof(startn) - 1;
1368 }
1369 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1370 start = 0;
1371 linkset_name = sym_name + sizeof(stopn) - 1;
1372 }
1373 else
1374 continue;
1375
1376 for (i = 0; i < ef->nprogtab; i++) {
1377 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1378 startp = (Elf_Addr)ef->progtab[i].addr;
1379 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1380 break;
1381 }
1382 }
1383 if (i == ef->nprogtab)
1384 continue;
1385
1386 sym->st_value = start ? startp : stopp;
1387 sym->st_shndx = i;
1388 }
1389 }
1390
1391 static int
1392 link_elf_reloc_local(linker_file_t lf)
1393 {
1394 elf_file_t ef = (elf_file_t)lf;
1395 const Elf_Rel *rellim;
1396 const Elf_Rel *rel;
1397 const Elf_Rela *relalim;
1398 const Elf_Rela *rela;
1399 const Elf_Sym *sym;
1400 Elf_Addr base;
1401 int i;
1402 Elf_Size symidx;
1403
1404 link_elf_fix_link_set(ef);
1405
1406 /* Perform relocations without addend if there are any: */
1407 for (i = 0; i < ef->nreltab; i++) {
1408 rel = ef->reltab[i].rel;
1409 if (rel == NULL) {
1410 link_elf_error(ef->lf.filename, "lost a reltab");
1411 return (ENOEXEC);
1412 }
1413 rellim = rel + ef->reltab[i].nrel;
1414 base = findbase(ef, ef->reltab[i].sec);
1415 if (base == 0) {
1416 link_elf_error(ef->lf.filename, "lost base for reltab");
1417 return (ENOEXEC);
1418 }
1419 for ( ; rel < rellim; rel++) {
1420 symidx = ELF_R_SYM(rel->r_info);
1421 if (symidx >= ef->ddbsymcnt)
1422 continue;
1423 sym = ef->ddbsymtab + symidx;
1424 /* Only do local relocs */
1425 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1426 continue;
1427 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1428 elf_obj_lookup);
1429 }
1430 }
1431
1432 /* Perform relocations with addend if there are any: */
1433 for (i = 0; i < ef->nrelatab; i++) {
1434 rela = ef->relatab[i].rela;
1435 if (rela == NULL) {
1436 link_elf_error(ef->lf.filename, "lost a relatab!");
1437 return (ENOEXEC);
1438 }
1439 relalim = rela + ef->relatab[i].nrela;
1440 base = findbase(ef, ef->relatab[i].sec);
1441 if (base == 0) {
1442 link_elf_error(ef->lf.filename, "lost base for reltab");
1443 return (ENOEXEC);
1444 }
1445 for ( ; rela < relalim; rela++) {
1446 symidx = ELF_R_SYM(rela->r_info);
1447 if (symidx >= ef->ddbsymcnt)
1448 continue;
1449 sym = ef->ddbsymtab + symidx;
1450 /* Only do local relocs */
1451 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1452 continue;
1453 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1454 elf_obj_lookup);
1455 }
1456 }
1457 return (0);
1458 }
1459
1460 static long
1461 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1462 {
1463 elf_file_t ef = (elf_file_t)lf;
1464
1465 *symtab = ef->ddbsymtab;
1466
1467 if (*symtab == NULL)
1468 return (0);
1469
1470 return (ef->ddbsymcnt);
1471 }
1472
1473 static long
1474 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1475 {
1476 elf_file_t ef = (elf_file_t)lf;
1477
1478 *strtab = ef->ddbstrtab;
1479
1480 if (*strtab == NULL)
1481 return (0);
1482
1483 return (ef->ddbstrcnt);
1484 }
Cache object: 37430e6638d2416d2e86e9a77be2e2b9
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