FreeBSD/Linux Kernel Cross Reference
sys/kern/link_elf.c
1 /*-
2 * Copyright (c) 1998-2000 Doug Rabson
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/8.3/sys/kern/link_elf.c 222880 2011-06-08 21:36:36Z dchagin $");
29
30 #include "opt_ddb.h"
31 #include "opt_gdb.h"
32
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #ifdef GPROF
36 #include <sys/gmon.h>
37 #endif
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/mount.h>
43 #include <sys/pcpu.h>
44 #include <sys/proc.h>
45 #include <sys/namei.h>
46 #include <sys/fcntl.h>
47 #include <sys/vnode.h>
48 #include <sys/linker.h>
49
50 #include <machine/elf.h>
51
52 #include <net/vnet.h>
53
54 #include <security/mac/mac_framework.h>
55
56 #include <vm/vm.h>
57 #include <vm/vm_param.h>
58 #ifdef SPARSE_MAPPING
59 #include <vm/vm_object.h>
60 #include <vm/vm_kern.h>
61 #include <vm/vm_extern.h>
62 #endif
63 #include <vm/pmap.h>
64 #include <vm/vm_map.h>
65
66 #include <sys/link_elf.h>
67
68 #ifdef DDB_CTF
69 #include <net/zlib.h>
70 #endif
71
72 #include "linker_if.h"
73
74 #define MAXSEGS 4
75
76 typedef struct elf_file {
77 struct linker_file lf; /* Common fields */
78 int preloaded; /* Was file pre-loaded */
79 caddr_t address; /* Relocation address */
80 #ifdef SPARSE_MAPPING
81 vm_object_t object; /* VM object to hold file pages */
82 #endif
83 Elf_Dyn *dynamic; /* Symbol table etc. */
84 Elf_Hashelt nbuckets; /* DT_HASH info */
85 Elf_Hashelt nchains;
86 const Elf_Hashelt *buckets;
87 const Elf_Hashelt *chains;
88 caddr_t hash;
89 caddr_t strtab; /* DT_STRTAB */
90 int strsz; /* DT_STRSZ */
91 const Elf_Sym *symtab; /* DT_SYMTAB */
92 Elf_Addr *got; /* DT_PLTGOT */
93 const Elf_Rel *pltrel; /* DT_JMPREL */
94 int pltrelsize; /* DT_PLTRELSZ */
95 const Elf_Rela *pltrela; /* DT_JMPREL */
96 int pltrelasize; /* DT_PLTRELSZ */
97 const Elf_Rel *rel; /* DT_REL */
98 int relsize; /* DT_RELSZ */
99 const Elf_Rela *rela; /* DT_RELA */
100 int relasize; /* DT_RELASZ */
101 caddr_t modptr;
102 const Elf_Sym *ddbsymtab; /* The symbol table we are using */
103 long ddbsymcnt; /* Number of symbols */
104 caddr_t ddbstrtab; /* String table */
105 long ddbstrcnt; /* number of bytes in string table */
106 caddr_t symbase; /* malloc'ed symbold base */
107 caddr_t strbase; /* malloc'ed string base */
108 caddr_t ctftab; /* CTF table */
109 long ctfcnt; /* number of bytes in CTF table */
110 caddr_t ctfoff; /* CTF offset table */
111 caddr_t typoff; /* Type offset table */
112 long typlen; /* Number of type entries. */
113 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */
114 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */
115 Elf_Addr pcpu_base; /* Relocated pcpu set address. */
116 #ifdef VIMAGE
117 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */
118 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */
119 Elf_Addr vnet_base; /* Relocated vnet set address. */
120 #endif
121 #ifdef GDB
122 struct link_map gdb; /* hooks for gdb */
123 #endif
124 } *elf_file_t;
125
126 #include <kern/kern_ctf.c>
127
128 static int link_elf_link_common_finish(linker_file_t);
129 static int link_elf_link_preload(linker_class_t cls,
130 const char *, linker_file_t *);
131 static int link_elf_link_preload_finish(linker_file_t);
132 static int link_elf_load_file(linker_class_t, const char *,
133 linker_file_t *);
134 static int link_elf_lookup_symbol(linker_file_t, const char *,
135 c_linker_sym_t *);
136 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
137 linker_symval_t *);
138 static int link_elf_search_symbol(linker_file_t, caddr_t,
139 c_linker_sym_t *, long *);
140
141 static void link_elf_unload_file(linker_file_t);
142 static void link_elf_unload_preload(linker_file_t);
143 static int link_elf_lookup_set(linker_file_t, const char *,
144 void ***, void ***, int *);
145 static int link_elf_each_function_name(linker_file_t,
146 int (*)(const char *, void *), void *);
147 static int link_elf_each_function_nameval(linker_file_t,
148 linker_function_nameval_callback_t, void *);
149 static void link_elf_reloc_local(linker_file_t);
150 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
151 static long link_elf_strtab_get(linker_file_t, caddr_t *);
152 static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int);
153
154 static kobj_method_t link_elf_methods[] = {
155 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
156 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
157 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
158 KOBJMETHOD(linker_unload, link_elf_unload_file),
159 KOBJMETHOD(linker_load_file, link_elf_load_file),
160 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
161 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
162 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
163 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
164 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
165 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
166 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
167 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
168 { 0, 0 }
169 };
170
171 static struct linker_class link_elf_class = {
172 #if ELF_TARG_CLASS == ELFCLASS32
173 "elf32",
174 #else
175 "elf64",
176 #endif
177 link_elf_methods, sizeof(struct elf_file)
178 };
179
180 static int parse_dynamic(elf_file_t);
181 static int relocate_file(elf_file_t);
182 static int link_elf_preload_parse_symbols(elf_file_t);
183
184 #ifdef GDB
185 static void r_debug_state(struct r_debug *, struct link_map *);
186
187 /*
188 * A list of loaded modules for GDB to use for loading symbols.
189 */
190 struct r_debug r_debug;
191
192 #define GDB_STATE(s) do { \
193 r_debug.r_state = s; r_debug_state(NULL, NULL); \
194 } while (0)
195
196 /*
197 * Function for the debugger to set a breakpoint on to gain control.
198 */
199 static void
200 r_debug_state(struct r_debug *dummy_one __unused,
201 struct link_map *dummy_two __unused)
202 {
203 }
204
205 static void
206 link_elf_add_gdb(struct link_map *l)
207 {
208 struct link_map *prev;
209
210 l->l_next = NULL;
211
212 if (r_debug.r_map == NULL) {
213 /* Add first. */
214 l->l_prev = NULL;
215 r_debug.r_map = l;
216 } else {
217 /* Append to list. */
218 for (prev = r_debug.r_map;
219 prev->l_next != NULL;
220 prev = prev->l_next)
221 ;
222 l->l_prev = prev;
223 prev->l_next = l;
224 }
225 }
226
227 static void
228 link_elf_delete_gdb(struct link_map *l)
229 {
230 if (l->l_prev == NULL) {
231 /* Remove first. */
232 if ((r_debug.r_map = l->l_next) != NULL)
233 l->l_next->l_prev = NULL;
234 } else {
235 /* Remove any but first. */
236 if ((l->l_prev->l_next = l->l_next) != NULL)
237 l->l_next->l_prev = l->l_prev;
238 }
239 }
240 #endif /* GDB */
241
242 #ifdef __ia64__
243 Elf_Addr link_elf_get_gp(linker_file_t);
244 #endif
245
246 /*
247 * The kernel symbol table starts here.
248 */
249 extern struct _dynamic _DYNAMIC;
250
251 static void
252 link_elf_error(const char *filename, const char *s)
253 {
254 if (filename == NULL)
255 printf("kldload: %s\n", s);
256 else
257 printf("kldload: %s: %s\n", filename, s);
258 }
259
260 /*
261 * Actions performed after linking/loading both the preloaded kernel and any
262 * modules; whether preloaded or dynamicly loaded.
263 */
264 static int
265 link_elf_link_common_finish(linker_file_t lf)
266 {
267 #ifdef GDB
268 elf_file_t ef = (elf_file_t)lf;
269 char *newfilename;
270 #endif
271 int error;
272
273 /* Notify MD code that a module is being loaded. */
274 error = elf_cpu_load_file(lf);
275 if (error != 0)
276 return (error);
277
278 #ifdef GDB
279 GDB_STATE(RT_ADD);
280 ef->gdb.l_addr = lf->address;
281 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
282 strcpy(newfilename, lf->filename);
283 ef->gdb.l_name = newfilename;
284 ef->gdb.l_ld = ef->dynamic;
285 link_elf_add_gdb(&ef->gdb);
286 GDB_STATE(RT_CONSISTENT);
287 #endif
288
289 return (0);
290 }
291
292 static void
293 link_elf_init(void* arg)
294 {
295 Elf_Dyn *dp;
296 caddr_t modptr, baseptr, sizeptr;
297 elf_file_t ef;
298 char *modname;
299
300 linker_add_class(&link_elf_class);
301
302 dp = (Elf_Dyn *)&_DYNAMIC;
303 modname = NULL;
304 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
305 if (modptr == NULL)
306 modptr = preload_search_by_type("elf kernel");
307 if (modptr != NULL)
308 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
309 if (modname == NULL)
310 modname = "kernel";
311 linker_kernel_file = linker_make_file(modname, &link_elf_class);
312 if (linker_kernel_file == NULL)
313 panic("%s: Can't create linker structures for kernel",
314 __func__);
315
316 ef = (elf_file_t) linker_kernel_file;
317 ef->preloaded = 1;
318 ef->address = 0;
319 #ifdef SPARSE_MAPPING
320 ef->object = 0;
321 #endif
322 ef->dynamic = dp;
323
324 if (dp != NULL)
325 parse_dynamic(ef);
326 linker_kernel_file->address = (caddr_t) KERNBASE;
327 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
328
329 if (modptr != NULL) {
330 ef->modptr = modptr;
331 baseptr = preload_search_info(modptr, MODINFO_ADDR);
332 if (baseptr != NULL)
333 linker_kernel_file->address = *(caddr_t *)baseptr;
334 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
335 if (sizeptr != NULL)
336 linker_kernel_file->size = *(size_t *)sizeptr;
337 }
338 (void)link_elf_preload_parse_symbols(ef);
339
340 #ifdef GDB
341 r_debug.r_map = NULL;
342 r_debug.r_brk = r_debug_state;
343 r_debug.r_state = RT_CONSISTENT;
344 #endif
345
346 (void)link_elf_link_common_finish(linker_kernel_file);
347 linker_kernel_file->flags |= LINKER_FILE_LINKED;
348 }
349
350 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0);
351
352 static int
353 link_elf_preload_parse_symbols(elf_file_t ef)
354 {
355 caddr_t pointer;
356 caddr_t ssym, esym, base;
357 caddr_t strtab;
358 int strcnt;
359 Elf_Sym *symtab;
360 int symcnt;
361
362 if (ef->modptr == NULL)
363 return (0);
364 pointer = preload_search_info(ef->modptr,
365 MODINFO_METADATA | MODINFOMD_SSYM);
366 if (pointer == NULL)
367 return (0);
368 ssym = *(caddr_t *)pointer;
369 pointer = preload_search_info(ef->modptr,
370 MODINFO_METADATA | MODINFOMD_ESYM);
371 if (pointer == NULL)
372 return (0);
373 esym = *(caddr_t *)pointer;
374
375 base = ssym;
376
377 symcnt = *(long *)base;
378 base += sizeof(long);
379 symtab = (Elf_Sym *)base;
380 base += roundup(symcnt, sizeof(long));
381
382 if (base > esym || base < ssym) {
383 printf("Symbols are corrupt!\n");
384 return (EINVAL);
385 }
386
387 strcnt = *(long *)base;
388 base += sizeof(long);
389 strtab = base;
390 base += roundup(strcnt, sizeof(long));
391
392 if (base > esym || base < ssym) {
393 printf("Symbols are corrupt!\n");
394 return (EINVAL);
395 }
396
397 ef->ddbsymtab = symtab;
398 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
399 ef->ddbstrtab = strtab;
400 ef->ddbstrcnt = strcnt;
401
402 return (0);
403 }
404
405 static int
406 parse_dynamic(elf_file_t ef)
407 {
408 Elf_Dyn *dp;
409 int plttype = DT_REL;
410
411 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
412 switch (dp->d_tag) {
413 case DT_HASH:
414 {
415 /* From src/libexec/rtld-elf/rtld.c */
416 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
417 (ef->address + dp->d_un.d_ptr);
418 ef->nbuckets = hashtab[0];
419 ef->nchains = hashtab[1];
420 ef->buckets = hashtab + 2;
421 ef->chains = ef->buckets + ef->nbuckets;
422 break;
423 }
424 case DT_STRTAB:
425 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
426 break;
427 case DT_STRSZ:
428 ef->strsz = dp->d_un.d_val;
429 break;
430 case DT_SYMTAB:
431 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
432 break;
433 case DT_SYMENT:
434 if (dp->d_un.d_val != sizeof(Elf_Sym))
435 return (ENOEXEC);
436 break;
437 case DT_PLTGOT:
438 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
439 break;
440 case DT_REL:
441 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
442 break;
443 case DT_RELSZ:
444 ef->relsize = dp->d_un.d_val;
445 break;
446 case DT_RELENT:
447 if (dp->d_un.d_val != sizeof(Elf_Rel))
448 return (ENOEXEC);
449 break;
450 case DT_JMPREL:
451 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
452 break;
453 case DT_PLTRELSZ:
454 ef->pltrelsize = dp->d_un.d_val;
455 break;
456 case DT_RELA:
457 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
458 break;
459 case DT_RELASZ:
460 ef->relasize = dp->d_un.d_val;
461 break;
462 case DT_RELAENT:
463 if (dp->d_un.d_val != sizeof(Elf_Rela))
464 return (ENOEXEC);
465 break;
466 case DT_PLTREL:
467 plttype = dp->d_un.d_val;
468 if (plttype != DT_REL && plttype != DT_RELA)
469 return (ENOEXEC);
470 break;
471 #ifdef GDB
472 case DT_DEBUG:
473 dp->d_un.d_ptr = (Elf_Addr)&r_debug;
474 break;
475 #endif
476 }
477 }
478
479 if (plttype == DT_RELA) {
480 ef->pltrela = (const Elf_Rela *)ef->pltrel;
481 ef->pltrel = NULL;
482 ef->pltrelasize = ef->pltrelsize;
483 ef->pltrelsize = 0;
484 }
485
486 ef->ddbsymtab = ef->symtab;
487 ef->ddbsymcnt = ef->nchains;
488 ef->ddbstrtab = ef->strtab;
489 ef->ddbstrcnt = ef->strsz;
490
491 return (0);
492 }
493
494 static int
495 parse_dpcpu(elf_file_t ef)
496 {
497 int count;
498 int error;
499
500 ef->pcpu_start = 0;
501 ef->pcpu_stop = 0;
502 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
503 (void ***)&ef->pcpu_stop, &count);
504 /* Error just means there is no pcpu set to relocate. */
505 if (error != 0)
506 return (0);
507 count *= sizeof(void *);
508 /*
509 * Allocate space in the primary pcpu area. Copy in our
510 * initialization from the data section and then initialize
511 * all per-cpu storage from that.
512 */
513 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count);
514 if (ef->pcpu_base == 0)
515 return (ENOSPC);
516 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count);
517 dpcpu_copy((void *)ef->pcpu_base, count);
518
519 return (0);
520 }
521
522 #ifdef VIMAGE
523 static int
524 parse_vnet(elf_file_t ef)
525 {
526 int count;
527 int error;
528
529 ef->vnet_start = 0;
530 ef->vnet_stop = 0;
531 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
532 (void ***)&ef->vnet_stop, &count);
533 /* Error just means there is no vnet data set to relocate. */
534 if (error != 0)
535 return (0);
536 count *= sizeof(void *);
537 /*
538 * Allocate space in the primary vnet area. Copy in our
539 * initialization from the data section and then initialize
540 * all per-vnet storage from that.
541 */
542 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count);
543 if (ef->vnet_base == 0)
544 return (ENOSPC);
545 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count);
546 vnet_data_copy((void *)ef->vnet_base, count);
547
548 return (0);
549 }
550 #endif
551
552 static int
553 link_elf_link_preload(linker_class_t cls,
554 const char* filename, linker_file_t *result)
555 {
556 caddr_t modptr, baseptr, sizeptr, dynptr;
557 char *type;
558 elf_file_t ef;
559 linker_file_t lf;
560 int error;
561 vm_offset_t dp;
562
563 /* Look to see if we have the file preloaded */
564 modptr = preload_search_by_name(filename);
565 if (modptr == NULL)
566 return (ENOENT);
567
568 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
569 baseptr = preload_search_info(modptr, MODINFO_ADDR);
570 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
571 dynptr = preload_search_info(modptr,
572 MODINFO_METADATA | MODINFOMD_DYNAMIC);
573 if (type == NULL ||
574 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
575 strcmp(type, "elf module") != 0))
576 return (EFTYPE);
577 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
578 return (EINVAL);
579
580 lf = linker_make_file(filename, &link_elf_class);
581 if (lf == NULL)
582 return (ENOMEM);
583
584 ef = (elf_file_t) lf;
585 ef->preloaded = 1;
586 ef->modptr = modptr;
587 ef->address = *(caddr_t *)baseptr;
588 #ifdef SPARSE_MAPPING
589 ef->object = 0;
590 #endif
591 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
592 ef->dynamic = (Elf_Dyn *)dp;
593 lf->address = ef->address;
594 lf->size = *(size_t *)sizeptr;
595
596 error = parse_dynamic(ef);
597 if (error == 0)
598 error = parse_dpcpu(ef);
599 #ifdef VIMAGE
600 if (error == 0)
601 error = parse_vnet(ef);
602 #endif
603 if (error != 0) {
604 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
605 return (error);
606 }
607 link_elf_reloc_local(lf);
608 *result = lf;
609 return (0);
610 }
611
612 static int
613 link_elf_link_preload_finish(linker_file_t lf)
614 {
615 elf_file_t ef;
616 int error;
617
618 ef = (elf_file_t) lf;
619 #if 0 /* this will be more trouble than it's worth for now */
620 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
621 if (dp->d_tag != DT_NEEDED)
622 continue;
623 modname = ef->strtab + dp->d_un.d_val;
624 error = linker_load_module(modname, lf);
625 if (error != 0)
626 goto out;
627 }
628 #endif
629 error = relocate_file(ef);
630 if (error != 0)
631 return (error);
632 (void)link_elf_preload_parse_symbols(ef);
633
634 return (link_elf_link_common_finish(lf));
635 }
636
637 static int
638 link_elf_load_file(linker_class_t cls, const char* filename,
639 linker_file_t* result)
640 {
641 struct nameidata nd;
642 struct thread* td = curthread; /* XXX */
643 Elf_Ehdr *hdr;
644 caddr_t firstpage;
645 int nbytes, i;
646 Elf_Phdr *phdr;
647 Elf_Phdr *phlimit;
648 Elf_Phdr *segs[MAXSEGS];
649 int nsegs;
650 Elf_Phdr *phdyn;
651 Elf_Phdr *phphdr;
652 caddr_t mapbase;
653 size_t mapsize;
654 Elf_Off base_offset;
655 Elf_Addr base_vaddr;
656 Elf_Addr base_vlimit;
657 int error = 0;
658 int resid, flags;
659 elf_file_t ef;
660 linker_file_t lf;
661 Elf_Shdr *shdr;
662 int symtabindex;
663 int symstrindex;
664 int symcnt;
665 int strcnt;
666 int vfslocked;
667
668 shdr = NULL;
669 lf = NULL;
670
671 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
672 flags = FREAD;
673 error = vn_open(&nd, &flags, 0, NULL);
674 if (error != 0)
675 return (error);
676 vfslocked = NDHASGIANT(&nd);
677 NDFREE(&nd, NDF_ONLY_PNBUF);
678 if (nd.ni_vp->v_type != VREG) {
679 error = ENOEXEC;
680 firstpage = NULL;
681 goto out;
682 }
683 #ifdef MAC
684 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
685 if (error != 0) {
686 firstpage = NULL;
687 goto out;
688 }
689 #endif
690
691 /*
692 * Read the elf header from the file.
693 */
694 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
695 hdr = (Elf_Ehdr *)firstpage;
696 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
697 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
698 &resid, td);
699 nbytes = PAGE_SIZE - resid;
700 if (error != 0)
701 goto out;
702
703 if (!IS_ELF(*hdr)) {
704 error = ENOEXEC;
705 goto out;
706 }
707
708 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
709 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
710 link_elf_error(filename, "Unsupported file layout");
711 error = ENOEXEC;
712 goto out;
713 }
714 if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
715 hdr->e_version != EV_CURRENT) {
716 link_elf_error(filename, "Unsupported file version");
717 error = ENOEXEC;
718 goto out;
719 }
720 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
721 error = ENOSYS;
722 goto out;
723 }
724 if (hdr->e_machine != ELF_TARG_MACH) {
725 link_elf_error(filename, "Unsupported machine");
726 error = ENOEXEC;
727 goto out;
728 }
729
730 /*
731 * We rely on the program header being in the first page.
732 * This is not strictly required by the ABI specification, but
733 * it seems to always true in practice. And, it simplifies
734 * things considerably.
735 */
736 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
737 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
738 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
739 link_elf_error(filename, "Unreadable program headers");
740
741 /*
742 * Scan the program header entries, and save key information.
743 *
744 * We rely on there being exactly two load segments, text and data,
745 * in that order.
746 */
747 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
748 phlimit = phdr + hdr->e_phnum;
749 nsegs = 0;
750 phdyn = NULL;
751 phphdr = NULL;
752 while (phdr < phlimit) {
753 switch (phdr->p_type) {
754 case PT_LOAD:
755 if (nsegs == MAXSEGS) {
756 link_elf_error(filename, "Too many sections");
757 error = ENOEXEC;
758 goto out;
759 }
760 /*
761 * XXX: We just trust they come in right order ??
762 */
763 segs[nsegs] = phdr;
764 ++nsegs;
765 break;
766
767 case PT_PHDR:
768 phphdr = phdr;
769 break;
770
771 case PT_DYNAMIC:
772 phdyn = phdr;
773 break;
774
775 case PT_INTERP:
776 error = ENOSYS;
777 goto out;
778 }
779
780 ++phdr;
781 }
782 if (phdyn == NULL) {
783 link_elf_error(filename, "Object is not dynamically-linked");
784 error = ENOEXEC;
785 goto out;
786 }
787 if (nsegs == 0) {
788 link_elf_error(filename, "No sections");
789 error = ENOEXEC;
790 goto out;
791 }
792
793 /*
794 * Allocate the entire address space of the object, to stake
795 * out our contiguous region, and to establish the base
796 * address for relocation.
797 */
798 base_offset = trunc_page(segs[0]->p_offset);
799 base_vaddr = trunc_page(segs[0]->p_vaddr);
800 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
801 segs[nsegs - 1]->p_memsz);
802 mapsize = base_vlimit - base_vaddr;
803
804 lf = linker_make_file(filename, &link_elf_class);
805 if (lf == NULL) {
806 error = ENOMEM;
807 goto out;
808 }
809
810 ef = (elf_file_t) lf;
811 #ifdef SPARSE_MAPPING
812 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
813 if (ef->object == NULL) {
814 error = ENOMEM;
815 goto out;
816 }
817 ef->address = (caddr_t) vm_map_min(kernel_map);
818 error = vm_map_find(kernel_map, ef->object, 0,
819 (vm_offset_t *) &ef->address, mapsize, 1,
820 VM_PROT_ALL, VM_PROT_ALL, 0);
821 if (error != 0) {
822 vm_object_deallocate(ef->object);
823 ef->object = 0;
824 goto out;
825 }
826 #else
827 ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
828 #endif
829 mapbase = ef->address;
830
831 /*
832 * Read the text and data sections and zero the bss.
833 */
834 for (i = 0; i < nsegs; i++) {
835 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
836 error = vn_rdwr(UIO_READ, nd.ni_vp,
837 segbase, segs[i]->p_filesz, segs[i]->p_offset,
838 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
839 &resid, td);
840 if (error != 0)
841 goto out;
842 bzero(segbase + segs[i]->p_filesz,
843 segs[i]->p_memsz - segs[i]->p_filesz);
844
845 #ifdef SPARSE_MAPPING
846 /*
847 * Wire down the pages
848 */
849 error = vm_map_wire(kernel_map,
850 (vm_offset_t) segbase,
851 (vm_offset_t) segbase + segs[i]->p_memsz,
852 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
853 if (error != KERN_SUCCESS) {
854 error = ENOMEM;
855 goto out;
856 }
857 #endif
858 }
859
860 #ifdef GPROF
861 /* Update profiling information with the new text segment. */
862 mtx_lock(&Giant);
863 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
864 segs[0]->p_memsz));
865 mtx_unlock(&Giant);
866 #endif
867
868 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
869
870 lf->address = ef->address;
871 lf->size = mapsize;
872
873 error = parse_dynamic(ef);
874 if (error != 0)
875 goto out;
876 error = parse_dpcpu(ef);
877 if (error != 0)
878 goto out;
879 #ifdef VIMAGE
880 error = parse_vnet(ef);
881 if (error != 0)
882 goto out;
883 #endif
884 link_elf_reloc_local(lf);
885
886 VOP_UNLOCK(nd.ni_vp, 0);
887 error = linker_load_dependencies(lf);
888 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
889 if (error != 0)
890 goto out;
891 #if 0 /* this will be more trouble than it's worth for now */
892 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
893 if (dp->d_tag != DT_NEEDED)
894 continue;
895 modname = ef->strtab + dp->d_un.d_val;
896 error = linker_load_module(modname, lf);
897 if (error != 0)
898 goto out;
899 }
900 #endif
901 error = relocate_file(ef);
902 if (error != 0)
903 goto out;
904
905 /*
906 * Try and load the symbol table if it's present. (you can
907 * strip it!)
908 */
909 nbytes = hdr->e_shnum * hdr->e_shentsize;
910 if (nbytes == 0 || hdr->e_shoff == 0)
911 goto nosyms;
912 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
913 error = vn_rdwr(UIO_READ, nd.ni_vp,
914 (caddr_t)shdr, nbytes, hdr->e_shoff,
915 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
916 &resid, td);
917 if (error != 0)
918 goto out;
919 symtabindex = -1;
920 symstrindex = -1;
921 for (i = 0; i < hdr->e_shnum; i++) {
922 if (shdr[i].sh_type == SHT_SYMTAB) {
923 symtabindex = i;
924 symstrindex = shdr[i].sh_link;
925 }
926 }
927 if (symtabindex < 0 || symstrindex < 0)
928 goto nosyms;
929
930 symcnt = shdr[symtabindex].sh_size;
931 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
932 strcnt = shdr[symstrindex].sh_size;
933 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
934
935 error = vn_rdwr(UIO_READ, nd.ni_vp,
936 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
937 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
938 &resid, td);
939 if (error != 0)
940 goto out;
941 error = vn_rdwr(UIO_READ, nd.ni_vp,
942 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
943 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
944 &resid, td);
945 if (error != 0)
946 goto out;
947
948 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
949 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
950 ef->ddbstrcnt = strcnt;
951 ef->ddbstrtab = ef->strbase;
952
953 error = link_elf_link_common_finish(lf);
954 if (error != 0)
955 goto out;
956
957 nosyms:
958 *result = lf;
959
960 out:
961 VOP_UNLOCK(nd.ni_vp, 0);
962 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
963 VFS_UNLOCK_GIANT(vfslocked);
964 if (error != 0 && lf != NULL)
965 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
966 if (shdr != NULL)
967 free(shdr, M_LINKER);
968 if (firstpage != NULL)
969 free(firstpage, M_LINKER);
970
971 return (error);
972 }
973
974 Elf_Addr
975 elf_relocaddr(linker_file_t lf, Elf_Addr x)
976 {
977 elf_file_t ef;
978
979 ef = (elf_file_t)lf;
980 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
981 return ((x - ef->pcpu_start) + ef->pcpu_base);
982 #ifdef VIMAGE
983 if (x >= ef->vnet_start && x < ef->vnet_stop)
984 return ((x - ef->vnet_start) + ef->vnet_base);
985 #endif
986 return (x);
987 }
988
989
990 static void
991 link_elf_unload_file(linker_file_t file)
992 {
993 elf_file_t ef = (elf_file_t) file;
994
995 if (ef->pcpu_base != 0) {
996 dpcpu_free((void *)ef->pcpu_base,
997 ef->pcpu_stop - ef->pcpu_start);
998 }
999 #ifdef VIMAGE
1000 if (ef->vnet_base != 0) {
1001 vnet_data_free((void *)ef->vnet_base,
1002 ef->vnet_stop - ef->vnet_start);
1003 }
1004 #endif
1005 #ifdef GDB
1006 if (ef->gdb.l_ld != NULL) {
1007 GDB_STATE(RT_DELETE);
1008 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1009 link_elf_delete_gdb(&ef->gdb);
1010 GDB_STATE(RT_CONSISTENT);
1011 }
1012 #endif
1013
1014 /* Notify MD code that a module is being unloaded. */
1015 elf_cpu_unload_file(file);
1016
1017 if (ef->preloaded) {
1018 link_elf_unload_preload(file);
1019 return;
1020 }
1021
1022 #ifdef SPARSE_MAPPING
1023 if (ef->object != NULL) {
1024 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1025 (vm_offset_t) ef->address
1026 + (ef->object->size << PAGE_SHIFT));
1027 }
1028 #else
1029 if (ef->address != NULL)
1030 free(ef->address, M_LINKER);
1031 #endif
1032 if (ef->symbase != NULL)
1033 free(ef->symbase, M_LINKER);
1034 if (ef->strbase != NULL)
1035 free(ef->strbase, M_LINKER);
1036 if (ef->ctftab != NULL)
1037 free(ef->ctftab, M_LINKER);
1038 if (ef->ctfoff != NULL)
1039 free(ef->ctfoff, M_LINKER);
1040 if (ef->typoff != NULL)
1041 free(ef->typoff, M_LINKER);
1042 }
1043
1044 static void
1045 link_elf_unload_preload(linker_file_t file)
1046 {
1047 if (file->filename != NULL)
1048 preload_delete_name(file->filename);
1049 }
1050
1051 static const char *
1052 symbol_name(elf_file_t ef, Elf_Size r_info)
1053 {
1054 const Elf_Sym *ref;
1055
1056 if (ELF_R_SYM(r_info)) {
1057 ref = ef->symtab + ELF_R_SYM(r_info);
1058 return (ef->strtab + ref->st_name);
1059 }
1060 return (NULL);
1061 }
1062
1063 static int
1064 relocate_file(elf_file_t ef)
1065 {
1066 const Elf_Rel *rellim;
1067 const Elf_Rel *rel;
1068 const Elf_Rela *relalim;
1069 const Elf_Rela *rela;
1070 const char *symname;
1071
1072 /* Perform relocations without addend if there are any: */
1073 rel = ef->rel;
1074 if (rel != NULL) {
1075 rellim = (const Elf_Rel *)
1076 ((const char *)ef->rel + ef->relsize);
1077 while (rel < rellim) {
1078 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1079 ELF_RELOC_REL, elf_lookup)) {
1080 symname = symbol_name(ef, rel->r_info);
1081 printf("link_elf: symbol %s undefined\n", symname);
1082 return (ENOENT);
1083 }
1084 rel++;
1085 }
1086 }
1087
1088 /* Perform relocations with addend if there are any: */
1089 rela = ef->rela;
1090 if (rela != NULL) {
1091 relalim = (const Elf_Rela *)
1092 ((const char *)ef->rela + ef->relasize);
1093 while (rela < relalim) {
1094 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1095 ELF_RELOC_RELA, elf_lookup)) {
1096 symname = symbol_name(ef, rela->r_info);
1097 printf("link_elf: symbol %s undefined\n",
1098 symname);
1099 return (ENOENT);
1100 }
1101 rela++;
1102 }
1103 }
1104
1105 /* Perform PLT relocations without addend if there are any: */
1106 rel = ef->pltrel;
1107 if (rel != NULL) {
1108 rellim = (const Elf_Rel *)
1109 ((const char *)ef->pltrel + ef->pltrelsize);
1110 while (rel < rellim) {
1111 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1112 ELF_RELOC_REL, elf_lookup)) {
1113 symname = symbol_name(ef, rel->r_info);
1114 printf("link_elf: symbol %s undefined\n",
1115 symname);
1116 return (ENOENT);
1117 }
1118 rel++;
1119 }
1120 }
1121
1122 /* Perform relocations with addend if there are any: */
1123 rela = ef->pltrela;
1124 if (rela != NULL) {
1125 relalim = (const Elf_Rela *)
1126 ((const char *)ef->pltrela + ef->pltrelasize);
1127 while (rela < relalim) {
1128 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1129 ELF_RELOC_RELA, elf_lookup)) {
1130 symname = symbol_name(ef, rela->r_info);
1131 printf("link_elf: symbol %s undefined\n",
1132 symname);
1133 return (ENOENT);
1134 }
1135 rela++;
1136 }
1137 }
1138
1139 return (0);
1140 }
1141
1142 /*
1143 * Hash function for symbol table lookup. Don't even think about changing
1144 * this. It is specified by the System V ABI.
1145 */
1146 static unsigned long
1147 elf_hash(const char *name)
1148 {
1149 const unsigned char *p = (const unsigned char *) name;
1150 unsigned long h = 0;
1151 unsigned long g;
1152
1153 while (*p != '\0') {
1154 h = (h << 4) + *p++;
1155 if ((g = h & 0xf0000000) != 0)
1156 h ^= g >> 24;
1157 h &= ~g;
1158 }
1159 return (h);
1160 }
1161
1162 static int
1163 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1164 {
1165 elf_file_t ef = (elf_file_t) lf;
1166 unsigned long symnum;
1167 const Elf_Sym* symp;
1168 const char *strp;
1169 unsigned long hash;
1170 int i;
1171
1172 /* If we don't have a hash, bail. */
1173 if (ef->buckets == NULL || ef->nbuckets == 0) {
1174 printf("link_elf_lookup_symbol: missing symbol hash table\n");
1175 return (ENOENT);
1176 }
1177
1178 /* First, search hashed global symbols */
1179 hash = elf_hash(name);
1180 symnum = ef->buckets[hash % ef->nbuckets];
1181
1182 while (symnum != STN_UNDEF) {
1183 if (symnum >= ef->nchains) {
1184 printf("%s: corrupt symbol table\n", __func__);
1185 return (ENOENT);
1186 }
1187
1188 symp = ef->symtab + symnum;
1189 if (symp->st_name == 0) {
1190 printf("%s: corrupt symbol table\n", __func__);
1191 return (ENOENT);
1192 }
1193
1194 strp = ef->strtab + symp->st_name;
1195
1196 if (strcmp(name, strp) == 0) {
1197 if (symp->st_shndx != SHN_UNDEF ||
1198 (symp->st_value != 0 &&
1199 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1200 *sym = (c_linker_sym_t) symp;
1201 return (0);
1202 }
1203 return (ENOENT);
1204 }
1205
1206 symnum = ef->chains[symnum];
1207 }
1208
1209 /* If we have not found it, look at the full table (if loaded) */
1210 if (ef->symtab == ef->ddbsymtab)
1211 return (ENOENT);
1212
1213 /* Exhaustive search */
1214 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1215 strp = ef->ddbstrtab + symp->st_name;
1216 if (strcmp(name, strp) == 0) {
1217 if (symp->st_shndx != SHN_UNDEF ||
1218 (symp->st_value != 0 &&
1219 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1220 *sym = (c_linker_sym_t) symp;
1221 return (0);
1222 }
1223 return (ENOENT);
1224 }
1225 }
1226
1227 return (ENOENT);
1228 }
1229
1230 static int
1231 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1232 linker_symval_t *symval)
1233 {
1234 elf_file_t ef = (elf_file_t) lf;
1235 const Elf_Sym* es = (const Elf_Sym*) sym;
1236
1237 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1238 symval->name = ef->strtab + es->st_name;
1239 symval->value = (caddr_t) ef->address + es->st_value;
1240 symval->size = es->st_size;
1241 return (0);
1242 }
1243 if (ef->symtab == ef->ddbsymtab)
1244 return (ENOENT);
1245 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1246 symval->name = ef->ddbstrtab + es->st_name;
1247 symval->value = (caddr_t) ef->address + es->st_value;
1248 symval->size = es->st_size;
1249 return (0);
1250 }
1251 return (ENOENT);
1252 }
1253
1254 static int
1255 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1256 c_linker_sym_t *sym, long *diffp)
1257 {
1258 elf_file_t ef = (elf_file_t) lf;
1259 u_long off = (uintptr_t) (void *) value;
1260 u_long diff = off;
1261 u_long st_value;
1262 const Elf_Sym* es;
1263 const Elf_Sym* best = 0;
1264 int i;
1265
1266 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1267 if (es->st_name == 0)
1268 continue;
1269 st_value = es->st_value + (uintptr_t) (void *) ef->address;
1270 if (off >= st_value) {
1271 if (off - st_value < diff) {
1272 diff = off - st_value;
1273 best = es;
1274 if (diff == 0)
1275 break;
1276 } else if (off - st_value == diff) {
1277 best = es;
1278 }
1279 }
1280 }
1281 if (best == 0)
1282 *diffp = off;
1283 else
1284 *diffp = diff;
1285 *sym = (c_linker_sym_t) best;
1286
1287 return (0);
1288 }
1289
1290 /*
1291 * Look up a linker set on an ELF system.
1292 */
1293 static int
1294 link_elf_lookup_set(linker_file_t lf, const char *name,
1295 void ***startp, void ***stopp, int *countp)
1296 {
1297 c_linker_sym_t sym;
1298 linker_symval_t symval;
1299 char *setsym;
1300 void **start, **stop;
1301 int len, error = 0, count;
1302
1303 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1304 setsym = malloc(len, M_LINKER, M_WAITOK);
1305
1306 /* get address of first entry */
1307 snprintf(setsym, len, "%s%s", "__start_set_", name);
1308 error = link_elf_lookup_symbol(lf, setsym, &sym);
1309 if (error != 0)
1310 goto out;
1311 link_elf_symbol_values(lf, sym, &symval);
1312 if (symval.value == 0) {
1313 error = ESRCH;
1314 goto out;
1315 }
1316 start = (void **)symval.value;
1317
1318 /* get address of last entry */
1319 snprintf(setsym, len, "%s%s", "__stop_set_", name);
1320 error = link_elf_lookup_symbol(lf, setsym, &sym);
1321 if (error != 0)
1322 goto out;
1323 link_elf_symbol_values(lf, sym, &symval);
1324 if (symval.value == 0) {
1325 error = ESRCH;
1326 goto out;
1327 }
1328 stop = (void **)symval.value;
1329
1330 /* and the number of entries */
1331 count = stop - start;
1332
1333 /* and copy out */
1334 if (startp != NULL)
1335 *startp = start;
1336 if (stopp != NULL)
1337 *stopp = stop;
1338 if (countp != NULL)
1339 *countp = count;
1340
1341 out:
1342 free(setsym, M_LINKER);
1343 return (error);
1344 }
1345
1346 static int
1347 link_elf_each_function_name(linker_file_t file,
1348 int (*callback)(const char *, void *), void *opaque)
1349 {
1350 elf_file_t ef = (elf_file_t)file;
1351 const Elf_Sym *symp;
1352 int i, error;
1353
1354 /* Exhaustive search */
1355 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1356 if (symp->st_value != 0 &&
1357 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1358 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1359 if (error != 0)
1360 return (error);
1361 }
1362 }
1363 return (0);
1364 }
1365
1366 static int
1367 link_elf_each_function_nameval(linker_file_t file,
1368 linker_function_nameval_callback_t callback, void *opaque)
1369 {
1370 linker_symval_t symval;
1371 elf_file_t ef = (elf_file_t)file;
1372 const Elf_Sym* symp;
1373 int i, error;
1374
1375 /* Exhaustive search */
1376 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1377 if (symp->st_value != 0 &&
1378 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1379 error = link_elf_symbol_values(file,
1380 (c_linker_sym_t) symp, &symval);
1381 if (error != 0)
1382 return (error);
1383 error = callback(file, i, &symval, opaque);
1384 if (error != 0)
1385 return (error);
1386 }
1387 }
1388 return (0);
1389 }
1390
1391 #ifdef __ia64__
1392 /*
1393 * Each KLD has its own GP. The GP value for each load module is given by
1394 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1395 * don't have direct access to the ELF file structure. The link_elf_get_gp()
1396 * function returns the GP given a pointer to a generic linker file struct.
1397 */
1398 Elf_Addr
1399 link_elf_get_gp(linker_file_t lf)
1400 {
1401 elf_file_t ef = (elf_file_t)lf;
1402 return ((Elf_Addr)ef->got);
1403 }
1404 #endif
1405
1406 const Elf_Sym *
1407 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1408 {
1409 elf_file_t ef = (elf_file_t)lf;
1410
1411 if (symidx >= ef->nchains)
1412 return (NULL);
1413 return (ef->symtab + symidx);
1414 }
1415
1416 const char *
1417 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1418 {
1419 elf_file_t ef = (elf_file_t)lf;
1420 const Elf_Sym *sym;
1421
1422 if (symidx >= ef->nchains)
1423 return (NULL);
1424 sym = ef->symtab + symidx;
1425 return (ef->strtab + sym->st_name);
1426 }
1427
1428 /*
1429 * Symbol lookup function that can be used when the symbol index is known (ie
1430 * in relocations). It uses the symbol index instead of doing a fully fledged
1431 * hash table based lookup when such is valid. For example for local symbols.
1432 * This is not only more efficient, it's also more correct. It's not always
1433 * the case that the symbol can be found through the hash table.
1434 */
1435 static Elf_Addr
1436 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1437 {
1438 elf_file_t ef = (elf_file_t)lf;
1439 const Elf_Sym *sym;
1440 const char *symbol;
1441
1442 /* Don't even try to lookup the symbol if the index is bogus. */
1443 if (symidx >= ef->nchains)
1444 return (0);
1445
1446 sym = ef->symtab + symidx;
1447
1448 /*
1449 * Don't do a full lookup when the symbol is local. It may even
1450 * fail because it may not be found through the hash table.
1451 */
1452 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1453 /* Force lookup failure when we have an insanity. */
1454 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1455 return (0);
1456 return ((Elf_Addr)ef->address + sym->st_value);
1457 }
1458
1459 /*
1460 * XXX we can avoid doing a hash table based lookup for global
1461 * symbols as well. This however is not always valid, so we'll
1462 * just do it the hard way for now. Performance tweaks can
1463 * always be added.
1464 */
1465
1466 symbol = ef->strtab + sym->st_name;
1467
1468 /* Force a lookup failure if the symbol name is bogus. */
1469 if (*symbol == 0)
1470 return (0);
1471
1472 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1473 }
1474
1475 static void
1476 link_elf_reloc_local(linker_file_t lf)
1477 {
1478 const Elf_Rel *rellim;
1479 const Elf_Rel *rel;
1480 const Elf_Rela *relalim;
1481 const Elf_Rela *rela;
1482 elf_file_t ef = (elf_file_t)lf;
1483
1484 /* Perform relocations without addend if there are any: */
1485 if ((rel = ef->rel) != NULL) {
1486 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1487 while (rel < rellim) {
1488 elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1489 ELF_RELOC_REL, elf_lookup);
1490 rel++;
1491 }
1492 }
1493
1494 /* Perform relocations with addend if there are any: */
1495 if ((rela = ef->rela) != NULL) {
1496 relalim = (const Elf_Rela *)
1497 ((const char *)ef->rela + ef->relasize);
1498 while (rela < relalim) {
1499 elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1500 ELF_RELOC_RELA, elf_lookup);
1501 rela++;
1502 }
1503 }
1504 }
1505
1506 static long
1507 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1508 {
1509 elf_file_t ef = (elf_file_t)lf;
1510
1511 *symtab = ef->ddbsymtab;
1512
1513 if (*symtab == NULL)
1514 return (0);
1515
1516 return (ef->ddbsymcnt);
1517 }
1518
1519 static long
1520 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1521 {
1522 elf_file_t ef = (elf_file_t)lf;
1523
1524 *strtab = ef->ddbstrtab;
1525
1526 if (*strtab == NULL)
1527 return (0);
1528
1529 return (ef->ddbstrcnt);
1530 }
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