1/* $NetBSD: subr_kobj.c,v 1.59 2016/08/02 12:23:08 martin Exp $ */
2
3/*-
4 * Copyright (c) 2008 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software developed for The NetBSD Foundation
8 * by Andrew Doran.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*-
33 * Copyright (c) 1998-2000 Doug Rabson
34 * Copyright (c) 2004 Peter Wemm
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 *
46 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
47 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
48 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
49 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
50 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
51 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
52 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
53 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
54 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
55 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
56 * SUCH DAMAGE.
57 */
58
59/*
60 * Kernel loader for ELF objects.
61 *
62 * TODO: adjust kmem_alloc() calls to avoid needless fragmentation.
63 */
64
65#include <sys/cdefs.h>
66__KERNEL_RCSID(0, "$NetBSD: subr_kobj.c,v 1.59 2016/08/02 12:23:08 martin Exp $");
67
68#ifdef _KERNEL_OPT
69#include "opt_modular.h"
70#endif
71
72#include <sys/kobj_impl.h>
73
74#ifdef MODULAR
75
76#include <sys/param.h>
77#include <sys/kernel.h>
78#include <sys/kmem.h>
79#include <sys/proc.h>
80#include <sys/ksyms.h>
81#include <sys/module.h>
82
83#include <uvm/uvm_extern.h>
84
85#define kobj_error(_kobj, ...) \
86 kobj_out(__func__, __LINE__, _kobj, __VA_ARGS__)
87
88static int kobj_relocate(kobj_t, bool);
89static int kobj_checksyms(kobj_t, bool);
90static void kobj_out(const char *, int, kobj_t, const char *, ...)
91 __printflike(4, 5);
92static void kobj_jettison(kobj_t);
93static void kobj_free(kobj_t, void *, size_t);
94static void kobj_close(kobj_t);
95static int kobj_read_mem(kobj_t, void **, size_t, off_t, bool);
96static void kobj_close_mem(kobj_t);
97
98extern struct vm_map *module_map;
99
100/*
101 * kobj_load_mem:
102 *
103 * Load an object already resident in memory. If size is not -1,
104 * the complete size of the object is known.
105 */
106int
107kobj_load_mem(kobj_t *kop, const char *name, void *base, ssize_t size)
108{
109 kobj_t ko;
110
111 ko = kmem_zalloc(sizeof(*ko), KM_SLEEP);
112 if (ko == NULL) {
113 return ENOMEM;
114 }
115
116 ko->ko_type = KT_MEMORY;
117 kobj_setname(ko, name);
118 ko->ko_source = base;
119 ko->ko_memsize = size;
120 ko->ko_read = kobj_read_mem;
121 ko->ko_close = kobj_close_mem;
122
123 *kop = ko;
124 return kobj_load(ko);
125}
126
127/*
128 * kobj_close:
129 *
130 * Close an open ELF object.
131 */
132static void
133kobj_close(kobj_t ko)
134{
135
136 if (ko->ko_source == NULL) {
137 return;
138 }
139
140 ko->ko_close(ko);
141 ko->ko_source = NULL;
142}
143
144static void
145kobj_close_mem(kobj_t ko)
146{
147
148 return;
149}
150
151/*
152 * kobj_load:
153 *
154 * Load an ELF object and prepare to link into the running kernel
155 * image.
156 */
157int
158kobj_load(kobj_t ko)
159{
160 Elf_Ehdr *hdr;
161 Elf_Shdr *shdr;
162 Elf_Sym *es;
163 vaddr_t map_text_base;
164 vaddr_t map_data_base;
165 vaddr_t map_rodata_base;
166 size_t map_text_size;
167 size_t map_data_size;
168 size_t map_rodata_size;
169 int error;
170 int symtabindex;
171 int symstrindex;
172 int nsym;
173 int pb, rl, ra;
174 int alignmask;
175 int i, j;
176 void *addr;
177
178 KASSERT(ko->ko_type != KT_UNSET);
179 KASSERT(ko->ko_source != NULL);
180
181 shdr = NULL;
182 error = 0;
183 hdr = NULL;
184
185 /*
186 * Read the elf header from the file.
187 */
188 error = ko->ko_read(ko, (void **)&hdr, sizeof(*hdr), 0, true);
189 if (error != 0) {
190 kobj_error(ko, "read failed %d", error);
191 goto out;
192 }
193 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0) {
194 kobj_error(ko, "not an ELF object");
195 error = ENOEXEC;
196 goto out;
197 }
198
199 if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
200 hdr->e_version != EV_CURRENT) {
201 kobj_error(ko, "unsupported file version %d",
202 hdr->e_ident[EI_VERSION]);
203 error = ENOEXEC;
204 goto out;
205 }
206 if (hdr->e_type != ET_REL) {
207 kobj_error(ko, "unsupported file type %d", hdr->e_type);
208 error = ENOEXEC;
209 goto out;
210 }
211 switch (hdr->e_machine) {
212#if ELFSIZE == 32
213 ELF32_MACHDEP_ID_CASES
214#elif ELFSIZE == 64
215 ELF64_MACHDEP_ID_CASES
216#else
217#error not defined
218#endif
219 default:
220 kobj_error(ko, "unsupported machine %d", hdr->e_machine);
221 error = ENOEXEC;
222 goto out;
223 }
224
225 ko->ko_nprogtab = 0;
226 ko->ko_shdr = 0;
227 ko->ko_nrel = 0;
228 ko->ko_nrela = 0;
229
230 /*
231 * Allocate and read in the section header.
232 */
233 if (hdr->e_shnum == 0 || hdr->e_shnum > ELF_MAXSHNUM ||
234 hdr->e_shoff == 0 || hdr->e_shentsize != sizeof(Elf_Shdr)) {
235 kobj_error(ko, "bad sizes");
236 error = ENOEXEC;
237 goto out;
238 }
239 ko->ko_shdrsz = hdr->e_shnum * sizeof(Elf_Shdr);
240 error = ko->ko_read(ko, (void **)&shdr, ko->ko_shdrsz, hdr->e_shoff,
241 true);
242 if (error != 0) {
243 kobj_error(ko, "read failed %d", error);
244 goto out;
245 }
246 ko->ko_shdr = shdr;
247
248 /*
249 * Scan the section header for information and table sizing.
250 */
251 nsym = 0;
252 symtabindex = symstrindex = -1;
253 for (i = 0; i < hdr->e_shnum; i++) {
254 switch (shdr[i].sh_type) {
255 case SHT_PROGBITS:
256 case SHT_NOBITS:
257 ko->ko_nprogtab++;
258 break;
259 case SHT_SYMTAB:
260 nsym++;
261 symtabindex = i;
262 symstrindex = shdr[i].sh_link;
263 break;
264 case SHT_REL:
265 if (shdr[shdr[i].sh_info].sh_type != SHT_PROGBITS)
266 continue;
267 ko->ko_nrel++;
268 break;
269 case SHT_RELA:
270 if (shdr[shdr[i].sh_info].sh_type != SHT_PROGBITS)
271 continue;
272 ko->ko_nrela++;
273 break;
274 case SHT_STRTAB:
275 break;
276 }
277 }
278 if (ko->ko_nprogtab == 0) {
279 kobj_error(ko, "file has no contents");
280 error = ENOEXEC;
281 goto out;
282 }
283 if (nsym != 1) {
284 /* Only allow one symbol table for now */
285 kobj_error(ko, "file has no valid symbol table");
286 error = ENOEXEC;
287 goto out;
288 }
289 KASSERT(symtabindex != -1);
290 KASSERT(symstrindex != -1);
291
292 if (symstrindex == SHN_UNDEF || symstrindex >= hdr->e_shnum ||
293 shdr[symstrindex].sh_type != SHT_STRTAB) {
294 kobj_error(ko, "file has invalid symbol strings");
295 error = ENOEXEC;
296 goto out;
297 }
298
299 /*
300 * Allocate space for tracking the load chunks.
301 */
302 if (ko->ko_nprogtab != 0) {
303 ko->ko_progtab = kmem_zalloc(ko->ko_nprogtab *
304 sizeof(*ko->ko_progtab), KM_SLEEP);
305 if (ko->ko_progtab == NULL) {
306 error = ENOMEM;
307 kobj_error(ko, "out of memory");
308 goto out;
309 }
310 }
311 if (ko->ko_nrel != 0) {
312 ko->ko_reltab = kmem_zalloc(ko->ko_nrel *
313 sizeof(*ko->ko_reltab), KM_SLEEP);
314 if (ko->ko_reltab == NULL) {
315 error = ENOMEM;
316 kobj_error(ko, "out of memory");
317 goto out;
318 }
319 }
320 if (ko->ko_nrela != 0) {
321 ko->ko_relatab = kmem_zalloc(ko->ko_nrela *
322 sizeof(*ko->ko_relatab), KM_SLEEP);
323 if (ko->ko_relatab == NULL) {
324 error = ENOMEM;
325 kobj_error(ko, "out of memory");
326 goto out;
327 }
328 }
329
330 /*
331 * Allocate space for and load the symbol table.
332 */
333 ko->ko_symcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
334 if (ko->ko_symcnt == 0) {
335 kobj_error(ko, "no symbol table");
336 error = ENOEXEC;
337 goto out;
338 }
339 error = ko->ko_read(ko, (void **)&ko->ko_symtab,
340 ko->ko_symcnt * sizeof(Elf_Sym),
341 shdr[symtabindex].sh_offset, true);
342 if (error != 0) {
343 kobj_error(ko, "read failed %d", error);
344 goto out;
345 }
346
347 /*
348 * Allocate space for and load the symbol strings.
349 */
350 ko->ko_strtabsz = shdr[symstrindex].sh_size;
351 if (ko->ko_strtabsz == 0) {
352 kobj_error(ko, "no symbol strings");
353 error = ENOEXEC;
354 goto out;
355 }
356 error = ko->ko_read(ko, (void *)&ko->ko_strtab, ko->ko_strtabsz,
357 shdr[symstrindex].sh_offset, true);
358 if (error != 0) {
359 kobj_error(ko, "read failed %d", error);
360 goto out;
361 }
362
363 /*
364 * Adjust module symbol namespace, if necessary (e.g. with rump)
365 */
366 error = kobj_renamespace(ko->ko_symtab, ko->ko_symcnt,
367 &ko->ko_strtab, &ko->ko_strtabsz);
368 if (error != 0) {
369 kobj_error(ko, "renamespace failed %d", error);
370 goto out;
371 }
372
373 /*
374 * Do we have a string table for the section names?
375 */
376 if (hdr->e_shstrndx != SHN_UNDEF) {
377 if (hdr->e_shstrndx >= hdr->e_shnum) {
378 kobj_error(ko, "bad shstrndx");
379 error = ENOEXEC;
380 goto out;
381 }
382 if (shdr[hdr->e_shstrndx].sh_size != 0 &&
383 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
384 ko->ko_shstrtabsz = shdr[hdr->e_shstrndx].sh_size;
385 error = ko->ko_read(ko, (void **)&ko->ko_shstrtab,
386 shdr[hdr->e_shstrndx].sh_size,
387 shdr[hdr->e_shstrndx].sh_offset, true);
388 if (error != 0) {
389 kobj_error(ko, "read failed %d", error);
390 goto out;
391 }
392 }
393 }
394
395 /*
396 * Size up code/data(progbits) and bss(nobits).
397 */
398 alignmask = 0;
399 map_text_size = 0;
400 map_data_size = 0;
401 map_rodata_size = 0;
402 for (i = 0; i < hdr->e_shnum; i++) {
403 if (shdr[i].sh_type != SHT_PROGBITS &&
404 shdr[i].sh_type != SHT_NOBITS)
405 continue;
406 alignmask = shdr[i].sh_addralign - 1;
407 if ((shdr[i].sh_flags & SHF_EXECINSTR)) {
408 map_text_size += alignmask;
409 map_text_size &= ~alignmask;
410 map_text_size += shdr[i].sh_size;
411 } else if (!(shdr[i].sh_flags & SHF_WRITE)) {
412 map_rodata_size += alignmask;
413 map_rodata_size &= ~alignmask;
414 map_rodata_size += shdr[i].sh_size;
415 } else {
416 map_data_size += alignmask;
417 map_data_size &= ~alignmask;
418 map_data_size += shdr[i].sh_size;
419 }
420 }
421
422 if (map_text_size == 0) {
423 kobj_error(ko, "no text");
424 error = ENOEXEC;
425 goto out;
426 }
427
428 if (map_data_size != 0) {
429 map_data_base = uvm_km_alloc(module_map, round_page(map_data_size),
430 0, UVM_KMF_WIRED);
431 if (map_data_base == 0) {
432 kobj_error(ko, "out of memory");
433 error = ENOMEM;
434 goto out;
435 }
436 ko->ko_data_address = map_data_base;
437 ko->ko_data_size = map_data_size;
438 } else {
439 map_data_base = 0;
440 ko->ko_data_address = 0;
441 ko->ko_data_size = 0;
442 }
443
444 if (map_rodata_size != 0) {
445 map_rodata_base = uvm_km_alloc(module_map, round_page(map_rodata_size),
446 0, UVM_KMF_WIRED);
447 if (map_rodata_base == 0) {
448 kobj_error(ko, "out of memory");
449 error = ENOMEM;
450 goto out;
451 }
452 ko->ko_rodata_address = map_rodata_base;
453 ko->ko_rodata_size = map_rodata_size;
454 } else {
455 map_rodata_base = 0;
456 ko->ko_rodata_address = 0;
457 ko->ko_rodata_size = 0;
458 }
459
460 map_text_base = uvm_km_alloc(module_map, round_page(map_text_size),
461 0, UVM_KMF_WIRED | UVM_KMF_EXEC);
462 if (map_text_base == 0) {
463 kobj_error(ko, "out of memory");
464 error = ENOMEM;
465 goto out;
466 }
467 ko->ko_text_address = map_text_base;
468 ko->ko_text_size = map_text_size;
469
470 /*
471 * Now load code/data(progbits), zero bss(nobits), allocate space
472 * for and load relocs
473 */
474 pb = 0;
475 rl = 0;
476 ra = 0;
477 alignmask = 0;
478 for (i = 0; i < hdr->e_shnum; i++) {
479 switch (shdr[i].sh_type) {
480 case SHT_PROGBITS:
481 case SHT_NOBITS:
482 alignmask = shdr[i].sh_addralign - 1;
483 if ((shdr[i].sh_flags & SHF_EXECINSTR)) {
484 map_text_base += alignmask;
485 map_text_base &= ~alignmask;
486 addr = (void *)map_text_base;
487 map_text_base += shdr[i].sh_size;
488 } else if (!(shdr[i].sh_flags & SHF_WRITE)) {
489 map_rodata_base += alignmask;
490 map_rodata_base &= ~alignmask;
491 addr = (void *)map_rodata_base;
492 map_rodata_base += shdr[i].sh_size;
493 } else {
494 map_data_base += alignmask;
495 map_data_base &= ~alignmask;
496 addr = (void *)map_data_base;
497 map_data_base += shdr[i].sh_size;
498 }
499
500 ko->ko_progtab[pb].addr = addr;
501 if (shdr[i].sh_type == SHT_PROGBITS) {
502 ko->ko_progtab[pb].name = "<<PROGBITS>>";
503 error = ko->ko_read(ko, &addr,
504 shdr[i].sh_size, shdr[i].sh_offset, false);
505 if (error != 0) {
506 kobj_error(ko, "read failed %d", error);
507 goto out;
508 }
509 } else { /* SHT_NOBITS */
510 ko->ko_progtab[pb].name = "<<NOBITS>>";
511 memset(addr, 0, shdr[i].sh_size);
512 }
513
514 ko->ko_progtab[pb].size = shdr[i].sh_size;
515 ko->ko_progtab[pb].sec = i;
516 if (ko->ko_shstrtab != NULL && shdr[i].sh_name != 0) {
517 ko->ko_progtab[pb].name =
518 ko->ko_shstrtab + shdr[i].sh_name;
519 }
520
521 /* Update all symbol values with the offset. */
522 for (j = 0; j < ko->ko_symcnt; j++) {
523 es = &ko->ko_symtab[j];
524 if (es->st_shndx != i) {
525 continue;
526 }
527 es->st_value += (Elf_Addr)addr;
528 }
529 pb++;
530 break;
531 case SHT_REL:
532 if (shdr[shdr[i].sh_info].sh_type != SHT_PROGBITS)
533 break;
534 ko->ko_reltab[rl].size = shdr[i].sh_size;
535 ko->ko_reltab[rl].size -=
536 shdr[i].sh_size % sizeof(Elf_Rel);
537 if (ko->ko_reltab[rl].size != 0) {
538 ko->ko_reltab[rl].nrel =
539 shdr[i].sh_size / sizeof(Elf_Rel);
540 ko->ko_reltab[rl].sec = shdr[i].sh_info;
541 error = ko->ko_read(ko,
542 (void **)&ko->ko_reltab[rl].rel,
543 ko->ko_reltab[rl].size,
544 shdr[i].sh_offset, true);
545 if (error != 0) {
546 kobj_error(ko, "read failed %d",
547 error);
548 goto out;
549 }
550 }
551 rl++;
552 break;
553 case SHT_RELA:
554 if (shdr[shdr[i].sh_info].sh_type != SHT_PROGBITS)
555 break;
556 ko->ko_relatab[ra].size = shdr[i].sh_size;
557 ko->ko_relatab[ra].size -=
558 shdr[i].sh_size % sizeof(Elf_Rela);
559 if (ko->ko_relatab[ra].size != 0) {
560 ko->ko_relatab[ra].nrela =
561 shdr[i].sh_size / sizeof(Elf_Rela);
562 ko->ko_relatab[ra].sec = shdr[i].sh_info;
563 error = ko->ko_read(ko,
564 (void **)&ko->ko_relatab[ra].rela,
565 shdr[i].sh_size,
566 shdr[i].sh_offset, true);
567 if (error != 0) {
568 kobj_error(ko, "read failed %d", error);
569 goto out;
570 }
571 }
572 ra++;
573 break;
574 default:
575 break;
576 }
577 }
578 if (pb != ko->ko_nprogtab) {
579 panic("%s:%d: %s: lost progbits", __func__, __LINE__,
580 ko->ko_name);
581 }
582 if (rl != ko->ko_nrel) {
583 panic("%s:%d: %s: lost rel", __func__, __LINE__,
584 ko->ko_name);
585 }
586 if (ra != ko->ko_nrela) {
587 panic("%s:%d: %s: lost rela", __func__, __LINE__,
588 ko->ko_name);
589 }
590 if (map_text_base != ko->ko_text_address + map_text_size) {
591 panic("%s:%d: %s: map_text_base 0x%lx != address %lx "
592 "+ map_text_size %ld (0x%lx)\n",
593 __func__, __LINE__, ko->ko_name, (long)map_text_base,
594 (long)ko->ko_text_address, (long)map_text_size,
595 (long)ko->ko_text_address + map_text_size);
596 }
597 if (map_data_base != ko->ko_data_address + map_data_size) {
598 panic("%s:%d: %s: map_data_base 0x%lx != address %lx "
599 "+ map_data_size %ld (0x%lx)\n",
600 __func__, __LINE__, ko->ko_name, (long)map_data_base,
601 (long)ko->ko_data_address, (long)map_data_size,
602 (long)ko->ko_data_address + map_data_size);
603 }
604 if (map_rodata_base != ko->ko_rodata_address + map_rodata_size) {
605 panic("%s:%d: %s: map_rodata_base 0x%lx != address %lx "
606 "+ map_rodata_size %ld (0x%lx)\n",
607 __func__, __LINE__, ko->ko_name, (long)map_rodata_base,
608 (long)ko->ko_rodata_address, (long)map_rodata_size,
609 (long)ko->ko_rodata_address + map_rodata_size);
610 }
611
612 /*
613 * Perform local relocations only. Relocations relating to global
614 * symbols will be done by kobj_affix().
615 */
616 error = kobj_checksyms(ko, false);
617 if (error == 0) {
618 error = kobj_relocate(ko, true);
619 }
620 out:
621 if (hdr != NULL) {
622 kobj_free(ko, hdr, sizeof(*hdr));
623 }
624 kobj_close(ko);
625 if (error != 0) {
626 kobj_unload(ko);
627 }
628
629 return error;
630}
631
632/*
633 * kobj_unload:
634 *
635 * Unload an object previously loaded by kobj_load().
636 */
637void
638kobj_unload(kobj_t ko)
639{
640 int error;
641
642 kobj_close(ko);
643 kobj_jettison(ko);
644
645 /*
646 * Notify MD code that a module has been unloaded.
647 */
648 if (ko->ko_loaded) {
649 error = kobj_machdep(ko, (void *)ko->ko_text_address,
650 ko->ko_text_size, false);
651 if (error != 0)
652 kobj_error(ko, "machine dependent deinit failed (text) %d",
653 error);
654
655 if (ko->ko_data_address != 0) {
656 error = kobj_machdep(ko, (void *)ko->ko_data_address,
657 ko->ko_data_size, false);
658 if (error != 0)
659 kobj_error(ko, "machine dependent deinit failed"
660 "(data) %d", error);
661 }
662
663 if (ko->ko_rodata_address != 0) {
664 error = kobj_machdep(ko, (void *)ko->ko_rodata_address,
665 ko->ko_rodata_size, false);
666 if (error != 0)
667 kobj_error(ko, "machine dependent deinit failed"
668 "(rodata) %d", error);
669 }
670 }
671 if (ko->ko_text_address != 0) {
672 uvm_km_free(module_map, ko->ko_text_address,
673 round_page(ko->ko_text_size), UVM_KMF_WIRED);
674 }
675 if (ko->ko_data_address != 0) {
676 uvm_km_free(module_map, ko->ko_data_address,
677 round_page(ko->ko_data_size), UVM_KMF_WIRED);
678 }
679 if (ko->ko_rodata_address != 0) {
680 uvm_km_free(module_map, ko->ko_rodata_address,
681 round_page(ko->ko_rodata_size), UVM_KMF_WIRED);
682 }
683 if (ko->ko_ksyms == true) {
684 ksyms_modunload(ko->ko_name);
685 }
686 if (ko->ko_symtab != NULL) {
687 kobj_free(ko, ko->ko_symtab, ko->ko_symcnt * sizeof(Elf_Sym));
688 }
689 if (ko->ko_strtab != NULL) {
690 kobj_free(ko, ko->ko_strtab, ko->ko_strtabsz);
691 }
692 if (ko->ko_progtab != NULL) {
693 kobj_free(ko, ko->ko_progtab, ko->ko_nprogtab *
694 sizeof(*ko->ko_progtab));
695 ko->ko_progtab = NULL;
696 }
697 if (ko->ko_shstrtab) {
698 kobj_free(ko, ko->ko_shstrtab, ko->ko_shstrtabsz);
699 ko->ko_shstrtab = NULL;
700 }
701
702 kmem_free(ko, sizeof(*ko));
703}
704
705/*
706 * kobj_stat:
707 *
708 * Return size and load address of an object.
709 */
710int
711kobj_stat(kobj_t ko, vaddr_t *address, size_t *size)
712{
713
714 if (address != NULL) {
715 *address = ko->ko_text_address;
716 }
717 if (size != NULL) {
718 *size = ko->ko_text_size;
719 }
720 return 0;
721}
722
723/*
724 * kobj_affix:
725 *
726 * Set an object's name and perform global relocs. May only be
727 * called after the module and any requisite modules are loaded.
728 */
729int
730kobj_affix(kobj_t ko, const char *name)
731{
732 int error;
733
734 KASSERT(ko->ko_ksyms == false);
735 KASSERT(ko->ko_loaded == false);
736
737 kobj_setname(ko, name);
738
739 /* Cache addresses of undefined symbols. */
740 error = kobj_checksyms(ko, true);
741
742 /* Now do global relocations. */
743 if (error == 0)
744 error = kobj_relocate(ko, false);
745
746 /*
747 * Now that we know the name, register the symbol table.
748 * Do after global relocations because ksyms will pack
749 * the table.
750 */
751 if (error == 0) {
752 ksyms_modload(ko->ko_name, ko->ko_symtab, ko->ko_symcnt *
753 sizeof(Elf_Sym), ko->ko_strtab, ko->ko_strtabsz);
754 ko->ko_ksyms = true;
755 }
756
757 /* Jettison unneeded memory post-link. */
758 kobj_jettison(ko);
759
760 /*
761 * Notify MD code that a module has been loaded.
762 *
763 * Most architectures use this opportunity to flush their caches.
764 */
765 if (error == 0) {
766 error = kobj_machdep(ko, (void *)ko->ko_text_address,
767 ko->ko_text_size, true);
768 if (error != 0)
769 kobj_error(ko, "machine dependent init failed (text) %d",
770 error);
771
772 if (ko->ko_data_address != 0) {
773 error = kobj_machdep(ko, (void *)ko->ko_data_address,
774 ko->ko_data_size, true);
775 if (error != 0)
776 kobj_error(ko, "machine dependent init failed"
777 "(data) %d", error);
778 }
779
780 if (ko->ko_rodata_address != 0) {
781 error = kobj_machdep(ko, (void *)ko->ko_rodata_address,
782 ko->ko_rodata_size, true);
783 if (error != 0)
784 kobj_error(ko, "machine dependent init failed"
785 "(rodata) %d", error);
786 }
787
788 ko->ko_loaded = true;
789 }
790
791 if (error == 0) {
792 /* Change the memory protections, when needed. */
793 uvm_km_protect(module_map, ko->ko_text_address,
794 ko->ko_text_size, VM_PROT_READ|VM_PROT_EXECUTE);
795 if (ko->ko_rodata_address != 0) {
796 uvm_km_protect(module_map, ko->ko_rodata_address,
797 ko->ko_rodata_size, VM_PROT_READ);
798 }
799 } else {
800 /* If there was an error, destroy the whole object. */
801 kobj_unload(ko);
802 }
803
804 return error;
805}
806
807/*
808 * kobj_find_section:
809 *
810 * Given a section name, search the loaded object and return
811 * virtual address if present and loaded.
812 */
813int
814kobj_find_section(kobj_t ko, const char *name, void **addr, size_t *size)
815{
816 int i;
817
818 KASSERT(ko->ko_progtab != NULL);
819
820 for (i = 0; i < ko->ko_nprogtab; i++) {
821 if (strcmp(ko->ko_progtab[i].name, name) == 0) {
822 if (addr != NULL) {
823 *addr = ko->ko_progtab[i].addr;
824 }
825 if (size != NULL) {
826 *size = ko->ko_progtab[i].size;
827 }
828 return 0;
829 }
830 }
831
832 return ENOENT;
833}
834
835/*
836 * kobj_jettison:
837 *
838 * Release object data not needed after performing relocations.
839 */
840static void
841kobj_jettison(kobj_t ko)
842{
843 int i;
844
845 if (ko->ko_reltab != NULL) {
846 for (i = 0; i < ko->ko_nrel; i++) {
847 if (ko->ko_reltab[i].rel) {
848 kobj_free(ko, ko->ko_reltab[i].rel,
849 ko->ko_reltab[i].size);
850 }
851 }
852 kobj_free(ko, ko->ko_reltab, ko->ko_nrel *
853 sizeof(*ko->ko_reltab));
854 ko->ko_reltab = NULL;
855 ko->ko_nrel = 0;
856 }
857 if (ko->ko_relatab != NULL) {
858 for (i = 0; i < ko->ko_nrela; i++) {
859 if (ko->ko_relatab[i].rela) {
860 kobj_free(ko, ko->ko_relatab[i].rela,
861 ko->ko_relatab[i].size);
862 }
863 }
864 kobj_free(ko, ko->ko_relatab, ko->ko_nrela *
865 sizeof(*ko->ko_relatab));
866 ko->ko_relatab = NULL;
867 ko->ko_nrela = 0;
868 }
869 if (ko->ko_shdr != NULL) {
870 kobj_free(ko, ko->ko_shdr, ko->ko_shdrsz);
871 ko->ko_shdr = NULL;
872 }
873}
874
875/*
876 * kobj_sym_lookup:
877 *
878 * Symbol lookup function to be used when the symbol index
879 * is known (ie during relocation).
880 */
881uintptr_t
882kobj_sym_lookup(kobj_t ko, uintptr_t symidx)
883{
884 const Elf_Sym *sym;
885 const char *symbol;
886
887 /* Don't even try to lookup the symbol if the index is bogus. */
888 if (symidx >= ko->ko_symcnt)
889 return 0;
890
891 sym = ko->ko_symtab + symidx;
892
893 /* Quick answer if there is a definition included. */
894 if (sym->st_shndx != SHN_UNDEF) {
895 return (uintptr_t)sym->st_value;
896 }
897
898 /* If we get here, then it is undefined and needs a lookup. */
899 switch (ELF_ST_BIND(sym->st_info)) {
900 case STB_LOCAL:
901 /* Local, but undefined? huh? */
902 kobj_error(ko, "local symbol undefined");
903 return 0;
904
905 case STB_GLOBAL:
906 /* Relative to Data or Function name */
907 symbol = ko->ko_strtab + sym->st_name;
908
909 /* Force a lookup failure if the symbol name is bogus. */
910 if (*symbol == 0) {
911 kobj_error(ko, "bad symbol name");
912 return 0;
913 }
914
915 return (uintptr_t)sym->st_value;
916
917 case STB_WEAK:
918 kobj_error(ko, "weak symbols not supported");
919 return 0;
920
921 default:
922 return 0;
923 }
924}
925
926/*
927 * kobj_findbase:
928 *
929 * Return base address of the given section.
930 */
931static uintptr_t
932kobj_findbase(kobj_t ko, int sec)
933{
934 int i;
935
936 for (i = 0; i < ko->ko_nprogtab; i++) {
937 if (sec == ko->ko_progtab[i].sec) {
938 return (uintptr_t)ko->ko_progtab[i].addr;
939 }
940 }
941 return 0;
942}
943
944/*
945 * kobj_checksyms:
946 *
947 * Scan symbol table for duplicates or resolve references to
948 * exernal symbols.
949 */
950static int
951kobj_checksyms(kobj_t ko, bool undefined)
952{
953 unsigned long rval;
954 Elf_Sym *sym, *ms;
955 const char *name;
956 int error;
957
958 error = 0;
959
960 for (ms = (sym = ko->ko_symtab) + ko->ko_symcnt; sym < ms; sym++) {
961 /* Check validity of the symbol. */
962 if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL ||
963 sym->st_name == 0)
964 continue;
965 if (undefined != (sym->st_shndx == SHN_UNDEF)) {
966 continue;
967 }
968
969 /*
970 * Look it up. Don't need to lock, as it is known that
971 * the symbol tables aren't going to change (we hold
972 * module_lock).
973 */
974 name = ko->ko_strtab + sym->st_name;
975 if (ksyms_getval_unlocked(NULL, name, &rval,
976 KSYMS_EXTERN) != 0) {
977 if (undefined) {
978 kobj_error(ko, "symbol `%s' not found",
979 name);
980 error = ENOEXEC;
981 }
982 continue;
983 }
984
985 /* Save values of undefined globals. */
986 if (undefined) {
987 sym->st_value = (Elf_Addr)rval;
988 continue;
989 }
990
991 /* Check (and complain) about differing values. */
992 if (sym->st_value == rval) {
993 continue;
994 }
995 if (strcmp(name, "_bss_start") == 0 ||
996 strcmp(name, "__bss_start") == 0 ||
997 strcmp(name, "_bss_end__") == 0 ||
998 strcmp(name, "__bss_end__") == 0 ||
999 strcmp(name, "_edata") == 0 ||
1000 strcmp(name, "_end") == 0 ||
1001 strcmp(name, "__end") == 0 ||
1002 strcmp(name, "__end__") == 0 ||
1003 strncmp(name, "__start_link_set_", 17) == 0 ||
1004 strncmp(name, "__stop_link_set_", 16) == 0) {
1005 continue;
1006 }
1007 kobj_error(ko, "global symbol `%s' redefined",
1008 name);
1009 error = ENOEXEC;
1010 }
1011
1012 return error;
1013}
1014
1015/*
1016 * kobj_relocate:
1017 *
1018 * Resolve relocations for the loaded object.
1019 */
1020static int
1021kobj_relocate(kobj_t ko, bool local)
1022{
1023 const Elf_Rel *rellim;
1024 const Elf_Rel *rel;
1025 const Elf_Rela *relalim;
1026 const Elf_Rela *rela;
1027 const Elf_Sym *sym;
1028 uintptr_t base;
1029 int i, error;
1030 uintptr_t symidx;
1031
1032 /*
1033 * Perform relocations without addend if there are any.
1034 */
1035 for (i = 0; i < ko->ko_nrel; i++) {
1036 rel = ko->ko_reltab[i].rel;
1037 if (rel == NULL) {
1038 continue;
1039 }
1040 rellim = rel + ko->ko_reltab[i].nrel;
1041 base = kobj_findbase(ko, ko->ko_reltab[i].sec);
1042 if (base == 0) {
1043 panic("%s:%d: %s: lost base for e_reltab[%d] sec %d",
1044 __func__, __LINE__, ko->ko_name, i,
1045 ko->ko_reltab[i].sec);
1046 }
1047 for (; rel < rellim; rel++) {
1048 symidx = ELF_R_SYM(rel->r_info);
1049 if (symidx >= ko->ko_symcnt) {
1050 continue;
1051 }
1052 sym = ko->ko_symtab + symidx;
1053 if (local != (ELF_ST_BIND(sym->st_info) == STB_LOCAL)) {
1054 continue;
1055 }
1056 error = kobj_reloc(ko, base, rel, false, local);
1057 if (error != 0) {
1058 return ENOENT;
1059 }
1060 }
1061 }
1062
1063 /*
1064 * Perform relocations with addend if there are any.
1065 */
1066 for (i = 0; i < ko->ko_nrela; i++) {
1067 rela = ko->ko_relatab[i].rela;
1068 if (rela == NULL) {
1069 continue;
1070 }
1071 relalim = rela + ko->ko_relatab[i].nrela;
1072 base = kobj_findbase(ko, ko->ko_relatab[i].sec);
1073 if (base == 0) {
1074 panic("%s:%d: %s: lost base for e_relatab[%d] sec %d",
1075 __func__, __LINE__, ko->ko_name, i,
1076 ko->ko_relatab[i].sec);
1077 }
1078 for (; rela < relalim; rela++) {
1079 symidx = ELF_R_SYM(rela->r_info);
1080 if (symidx >= ko->ko_symcnt) {
1081 continue;
1082 }
1083 sym = ko->ko_symtab + symidx;
1084 if (local != (ELF_ST_BIND(sym->st_info) == STB_LOCAL)) {
1085 continue;
1086 }
1087 error = kobj_reloc(ko, base, rela, true, local);
1088 if (error != 0) {
1089 return ENOENT;
1090 }
1091 }
1092 }
1093
1094 return 0;
1095}
1096
1097/*
1098 * kobj_out:
1099 *
1100 * Utility function: log an error.
1101 */
1102static void
1103kobj_out(const char *fname, int lnum, kobj_t ko, const char *fmt, ...)
1104{
1105 va_list ap;
1106
1107 printf("%s, %d: [%s]: linker error: ", fname, lnum, ko->ko_name);
1108 va_start(ap, fmt);
1109 vprintf(fmt, ap);
1110 va_end(ap);
1111 printf("\n");
1112}
1113
1114static int
1115kobj_read_mem(kobj_t ko, void **basep, size_t size, off_t off,
1116 bool allocate)
1117{
1118 void *base = *basep;
1119 int error;
1120
1121 KASSERT(ko->ko_source != NULL);
1122
1123 if (ko->ko_memsize != -1 && off + size > ko->ko_memsize) {
1124 kobj_error(ko, "preloaded object short");
1125 error = EINVAL;
1126 base = NULL;
1127 } else if (allocate) {
1128 base = kmem_alloc(size, KM_SLEEP);
1129 error = 0;
1130 } else {
1131 error = 0;
1132 }
1133
1134 if (error == 0) {
1135 /* Copy the section */
1136 memcpy(base, (uint8_t *)ko->ko_source + off, size);
1137 }
1138
1139 if (allocate && error != 0) {
1140 kmem_free(base, size);
1141 base = NULL;
1142 }
1143
1144 if (allocate)
1145 *basep = base;
1146
1147 return error;
1148}
1149
1150/*
1151 * kobj_free:
1152 *
1153 * Utility function: free memory if it was allocated from the heap.
1154 */
1155static void
1156kobj_free(kobj_t ko, void *base, size_t size)
1157{
1158
1159 kmem_free(base, size);
1160}
1161
1162extern char module_base[];
1163
1164void
1165kobj_setname(kobj_t ko, const char *name)
1166{
1167 const char *d = name, *dots = "";
1168 size_t len, dlen;
1169
1170 for (char *s = module_base; *d == *s; d++, s++)
1171 continue;
1172
1173 if (d == name)
1174 name = "";
1175 else
1176 name = "%M";
1177 dlen = strlen(d);
1178 len = dlen + strlen(name);
1179 if (len >= sizeof(ko->ko_name)) {
1180 len = (len - sizeof(ko->ko_name)) + 5; /* dots + NUL */
1181 if (dlen >= len) {
1182 d += len;
1183 dots = "/...";
1184 }
1185 }
1186 snprintf(ko->ko_name, sizeof(ko->ko_name), "%s%s%s", name, dots, d);
1187}
1188
1189#else /* MODULAR */
1190
1191int
1192kobj_load_mem(kobj_t *kop, const char *name, void *base, ssize_t size)
1193{
1194
1195 return ENOSYS;
1196}
1197
1198void
1199kobj_unload(kobj_t ko)
1200{
1201
1202 panic("not modular");
1203}
1204
1205int
1206kobj_stat(kobj_t ko, vaddr_t *base, size_t *size)
1207{
1208
1209 return ENOSYS;
1210}
1211
1212int
1213kobj_affix(kobj_t ko, const char *name)
1214{
1215
1216 panic("not modular");
1217}
1218
1219int
1220kobj_find_section(kobj_t ko, const char *name, void **addr, size_t *size)
1221{
1222
1223 panic("not modular");
1224}
1225
1226void
1227kobj_setname(kobj_t ko, const char *name)
1228{
1229
1230 panic("not modular");
1231}
1232
1233#endif /* MODULAR */
1234