1 /*-
2 * Copyright (c) 1998 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 * $FreeBSD: src/sys/kern/link_elf.c,v 1.24 1999/12/24 15:33:36 bde Exp $
28 */
29
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/malloc.h>
34 #include <sys/proc.h>
35 #include <sys/nlookup.h>
36 #include <sys/fcntl.h>
37 #include <sys/vnode.h>
38 #include <sys/linker.h>
39 #include <machine/elf.h>
40
41 #include <vm/vm.h>
42 #include <vm/vm_param.h>
43 #include <vm/vm_zone.h>
44 #include <vm/vm_object.h>
45 #include <vm/vm_kern.h>
46 #include <vm/vm_extern.h>
47 #include <sys/lock.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50
51 static int link_elf_obj_preload_file(const char *, linker_file_t *);
52 static int link_elf_obj_preload_finish(linker_file_t);
53 static int link_elf_obj_load_file(const char *, linker_file_t *);
54 static int
55 link_elf_obj_lookup_symbol(linker_file_t, const char *,
56 c_linker_sym_t *);
57 static int link_elf_obj_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t *);
58 static int
59 link_elf_obj_search_symbol(linker_file_t, caddr_t value,
60 c_linker_sym_t * sym, long *diffp);
61
62 static void link_elf_obj_unload_file(linker_file_t);
63 static int
64 link_elf_obj_lookup_set(linker_file_t, const char *,
65 void ***, void ***, int *);
66 static void link_elf_obj_reloc_local(linker_file_t lf);
67 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *);
68
69 static struct linker_class_ops link_elf_obj_class_ops = {
70 link_elf_obj_load_file,
71 link_elf_obj_preload_file,
72 };
73
74 static struct linker_file_ops link_elf_obj_file_ops = {
75 .lookup_symbol = link_elf_obj_lookup_symbol,
76 .symbol_values = link_elf_obj_symbol_values,
77 .search_symbol = link_elf_obj_search_symbol,
78 .preload_finish = link_elf_obj_preload_finish,
79 .unload = link_elf_obj_unload_file,
80 .lookup_set = link_elf_obj_lookup_set,
81 };
82
83 typedef struct {
84 void *addr;
85 Elf_Off size;
86 int flags;
87 int sec; /* Original section */
88 char *name;
89 } Elf_progent;
90
91 typedef struct {
92 Elf_Rel *rel;
93 int nrel;
94 int sec;
95 } Elf_relent;
96
97 typedef struct {
98 Elf_Rela *rela;
99 int nrela;
100 int sec;
101 } Elf_relaent;
102
103
104 typedef struct elf_file {
105 int preloaded;
106
107 caddr_t address; /* Relocation address */
108 size_t bytes; /* Chunk size in bytes */
109 vm_object_t object; /* VM object to hold file pages */
110 Elf_Shdr *e_shdr;
111
112 Elf_progent *progtab;
113 int nprogtab;
114
115 Elf_relaent *relatab;
116 int nrelatab;
117
118 Elf_relent *reltab;
119 int nreltab;
120
121 Elf_Sym *ddbsymtab; /* The symbol table we are using */
122 long ddbsymcnt; /* Number of symbols */
123 caddr_t ddbstrtab; /* String table */
124 long ddbstrcnt; /* number of bytes in string table */
125
126 caddr_t shstrtab; /* Section name string table */
127 long shstrcnt; /* number of bytes in string table */
128
129 caddr_t ctftab; /* CTF table */
130 long ctfcnt; /* number of bytes in CTF table */
131 caddr_t ctfoff; /* CTF offset table */
132 caddr_t typoff; /* Type offset table */
133 long typlen; /* Number of type entries. */
134
135 } *elf_file_t;
136
137 static int relocate_file(linker_file_t lf);
138
139 /*
140 * The kernel symbol table starts here.
141 */
142 extern struct _dynamic _DYNAMIC;
143
144 static void
145 link_elf_obj_init(void *arg)
146 {
147 #if ELF_TARG_CLASS == ELFCLASS32
148 linker_add_class("elf32", NULL, &link_elf_obj_class_ops);
149 #else
150 linker_add_class("elf64", NULL, &link_elf_obj_class_ops);
151 #endif
152 }
153
154 SYSINIT(link_elf, SI_BOOT2_KLD, SI_ORDER_SECOND, link_elf_obj_init, 0);
155
156 static void
157 link_elf_obj_error(const char *file, const char *s)
158 {
159 kprintf("kldload: %s: %s\n", file, s);
160 }
161
162 static int
163 link_elf_obj_preload_file(const char *filename, linker_file_t *result)
164 {
165 Elf_Ehdr *hdr;
166 Elf_Shdr *shdr;
167 Elf_Sym *es;
168 caddr_t modptr, baseptr, sizeptr;
169 char *type;
170 elf_file_t ef;
171 linker_file_t lf;
172 Elf_Addr off;
173 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
174
175 /*
176 * Look to see if we have the module preloaded.
177 */
178 modptr = preload_search_by_name(filename);
179 if (modptr == NULL)
180 return ENOENT;
181
182 /* It's preloaded, check we can handle it and collect information */
183 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
184 baseptr = preload_search_info(modptr, MODINFO_ADDR);
185 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
186 hdr = (Elf_Ehdr *) preload_search_info(modptr, MODINFO_METADATA |
187 MODINFOMD_ELFHDR);
188 shdr = (Elf_Shdr *) preload_search_info(modptr, MODINFO_METADATA |
189 MODINFOMD_SHDR);
190 if (type == NULL ||
191 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " obj module") != 0 &&
192 strcmp(type, "elf obj module") != 0)) {
193 return (EFTYPE);
194 }
195 if (baseptr == NULL || sizeptr == NULL || hdr == NULL || shdr == NULL)
196 return (EINVAL);
197
198 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
199 ef->preloaded = 1;
200 ef->address = *(caddr_t *) baseptr;
201 ef->bytes = 0;
202 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops);
203 if (lf == NULL) {
204 kfree(ef, M_LINKER);
205 return ENOMEM;
206 }
207 lf->address = ef->address;
208 lf->size = *(size_t *) sizeptr;
209
210 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
211 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
212 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
213 hdr->e_version != EV_CURRENT ||
214 hdr->e_type != ET_REL ||
215 hdr->e_machine != ELF_TARG_MACH) {
216 error = EFTYPE;
217 goto out;
218 }
219 ef->e_shdr = shdr;
220
221 /* Scan the section header for information and table sizing. */
222 symtabindex = -1;
223 symstrindex = -1;
224 for (i = 0; i < hdr->e_shnum; i++) {
225 switch (shdr[i].sh_type) {
226 case SHT_PROGBITS:
227 case SHT_NOBITS:
228 ef->nprogtab++;
229 break;
230 case SHT_SYMTAB:
231 symtabindex = i;
232 symstrindex = shdr[i].sh_link;
233 break;
234 case SHT_REL:
235 ef->nreltab++;
236 break;
237 case SHT_RELA:
238 ef->nrelatab++;
239 break;
240 }
241 }
242
243 shstrindex = hdr->e_shstrndx;
244 if (ef->nprogtab == 0 || symstrindex < 0 ||
245 symstrindex >= hdr->e_shnum ||
246 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
247 shstrindex >= hdr->e_shnum ||
248 shdr[shstrindex].sh_type != SHT_STRTAB) {
249 error = ENOEXEC;
250 goto out;
251 }
252 /* Allocate space for tracking the load chunks */
253 if (ef->nprogtab != 0)
254 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab),
255 M_LINKER, M_WAITOK | M_ZERO);
256 if (ef->nreltab != 0)
257 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab),
258 M_LINKER, M_WAITOK | M_ZERO);
259 if (ef->nrelatab != 0)
260 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab),
261 M_LINKER, M_WAITOK | M_ZERO);
262 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
263 (ef->nreltab != 0 && ef->reltab == NULL) ||
264 (ef->nrelatab != 0 && ef->relatab == NULL)) {
265 error = ENOMEM;
266 goto out;
267 }
268 /* XXX, relocate the sh_addr fields saved by the loader. */
269 off = 0;
270 for (i = 0; i < hdr->e_shnum; i++) {
271 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
272 off = shdr[i].sh_addr;
273 }
274 for (i = 0; i < hdr->e_shnum; i++) {
275 if (shdr[i].sh_addr != 0)
276 shdr[i].sh_addr = shdr[i].sh_addr - off +
277 (Elf_Addr) ef->address;
278 }
279
280 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
281 ef->ddbsymtab = (Elf_Sym *) shdr[symtabindex].sh_addr;
282 ef->ddbstrcnt = shdr[symstrindex].sh_size;
283 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
284 ef->shstrcnt = shdr[shstrindex].sh_size;
285 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
286
287 /* Now fill out progtab and the relocation tables. */
288 pb = 0;
289 rl = 0;
290 ra = 0;
291 for (i = 0; i < hdr->e_shnum; i++) {
292 switch (shdr[i].sh_type) {
293 case SHT_PROGBITS:
294 case SHT_NOBITS:
295 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
296 if (shdr[i].sh_type == SHT_PROGBITS)
297 ef->progtab[pb].name = "<<PROGBITS>>";
298 else
299 ef->progtab[pb].name = "<<NOBITS>>";
300 ef->progtab[pb].size = shdr[i].sh_size;
301 ef->progtab[pb].sec = i;
302 if (ef->shstrtab && shdr[i].sh_name != 0)
303 ef->progtab[pb].name =
304 ef->shstrtab + shdr[i].sh_name;
305 #if 0
306 if (ef->progtab[pb].name != NULL &&
307 !strcmp(ef->progtab[pb].name, "set_pcpu")) {
308 void *dpcpu;
309
310 dpcpu = dpcpu_alloc(shdr[i].sh_size);
311 if (dpcpu == NULL) {
312 error = ENOSPC;
313 goto out;
314 }
315 memcpy(dpcpu, ef->progtab[pb].addr,
316 ef->progtab[pb].size);
317 dpcpu_copy(dpcpu, shdr[i].sh_size);
318 ef->progtab[pb].addr = dpcpu;
319 #ifdef VIMAGE
320 } else if (ef->progtab[pb].name != NULL &&
321 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
322 void *vnet_data;
323
324 vnet_data = vnet_data_alloc(shdr[i].sh_size);
325 if (vnet_data == NULL) {
326 error = ENOSPC;
327 goto out;
328 }
329 memcpy(vnet_data, ef->progtab[pb].addr,
330 ef->progtab[pb].size);
331 vnet_data_copy(vnet_data, shdr[i].sh_size);
332 ef->progtab[pb].addr = vnet_data;
333 #endif
334 }
335 #endif
336 /* Update all symbol values with the offset. */
337 for (j = 0; j < ef->ddbsymcnt; j++) {
338 es = &ef->ddbsymtab[j];
339 if (es->st_shndx != i)
340 continue;
341 es->st_value += (Elf_Addr) ef->progtab[pb].addr;
342 }
343 pb++;
344 break;
345 case SHT_REL:
346 ef->reltab[rl].rel = (Elf_Rel *) shdr[i].sh_addr;
347 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
348 ef->reltab[rl].sec = shdr[i].sh_info;
349 rl++;
350 break;
351 case SHT_RELA:
352 ef->relatab[ra].rela = (Elf_Rela *) shdr[i].sh_addr;
353 ef->relatab[ra].nrela =
354 shdr[i].sh_size / sizeof(Elf_Rela);
355 ef->relatab[ra].sec = shdr[i].sh_info;
356 ra++;
357 break;
358 }
359 }
360 if (pb != ef->nprogtab)
361 panic("lost progbits");
362 if (rl != ef->nreltab)
363 panic("lost reltab");
364 if (ra != ef->nrelatab)
365 panic("lost relatab");
366
367 /* Local intra-module relocations */
368 link_elf_obj_reloc_local(lf);
369
370 *result = lf;
371 return (0);
372
373 out:
374 /* preload not done this way */
375 linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
376 return (error);
377 }
378
379 static int
380 link_elf_obj_preload_finish(linker_file_t lf)
381 {
382 int error;
383
384 error = relocate_file(lf);
385
386 return (error);
387 }
388
389 static int
390 link_elf_obj_load_file(const char *filename, linker_file_t * result)
391 {
392 struct nlookupdata nd;
393 struct thread *td = curthread; /* XXX */
394 struct proc *p = td->td_proc;
395 char *pathname;
396 struct vnode *vp;
397 Elf_Ehdr *hdr;
398 Elf_Shdr *shdr;
399 Elf_Sym *es;
400 int nbytes, i, j;
401 vm_offset_t mapbase;
402 size_t mapsize;
403 int error = 0;
404 int resid;
405 elf_file_t ef;
406 linker_file_t lf;
407 int symtabindex;
408 int symstrindex;
409 int shstrindex;
410 int nsym;
411 int pb, rl, ra;
412 int alignmask;
413
414 /* XXX Hack for firmware loading where p == NULL */
415 if (p == NULL) {
416 p = &proc0;
417 }
418
419 KKASSERT(p != NULL);
420 if (p->p_ucred == NULL) {
421 kprintf("link_elf_obj_load_file: cannot load '%s' from filesystem"
422 " this early\n", filename);
423 return ENOENT;
424 }
425 shdr = NULL;
426 lf = NULL;
427 mapsize = 0;
428 hdr = NULL;
429 pathname = linker_search_path(filename);
430 if (pathname == NULL)
431 return ENOENT;
432
433 error = nlookup_init(&nd, pathname, UIO_SYSSPACE, NLC_FOLLOW | NLC_LOCKVP);
434 if (error == 0)
435 error = vn_open(&nd, NULL, FREAD, 0);
436 kfree(pathname, M_LINKER);
437 if (error) {
438 nlookup_done(&nd);
439 return error;
440 }
441 vp = nd.nl_open_vp;
442 nd.nl_open_vp = NULL;
443 nlookup_done(&nd);
444
445 /*
446 * Read the elf header from the file.
447 */
448 hdr = kmalloc(sizeof(*hdr), M_LINKER, M_WAITOK);
449 error = vn_rdwr(UIO_READ, vp, (void *)hdr, sizeof(*hdr), 0,
450 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
451 if (error)
452 goto out;
453 if (resid != 0) {
454 error = ENOEXEC;
455 goto out;
456 }
457 if (!IS_ELF(*hdr)) {
458 error = ENOEXEC;
459 goto out;
460 }
461
462 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
463 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
464 link_elf_obj_error(filename, "Unsupported file layout");
465 error = ENOEXEC;
466 goto out;
467 }
468 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
469 || hdr->e_version != EV_CURRENT) {
470 link_elf_obj_error(filename, "Unsupported file version");
471 error = ENOEXEC;
472 goto out;
473 }
474 if (hdr->e_type != ET_REL) {
475 error = ENOSYS;
476 goto out;
477 }
478 if (hdr->e_machine != ELF_TARG_MACH) {
479 link_elf_obj_error(filename, "Unsupported machine");
480 error = ENOEXEC;
481 goto out;
482 }
483
484 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
485 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops);
486 if (lf == NULL) {
487 kfree(ef, M_LINKER);
488 error = ENOMEM;
489 goto out;
490 }
491 ef->nprogtab = 0;
492 ef->e_shdr = NULL;
493 ef->nreltab = 0;
494 ef->nrelatab = 0;
495
496 /* Allocate and read in the section header */
497 nbytes = hdr->e_shnum * hdr->e_shentsize;
498 if (nbytes == 0 || hdr->e_shoff == 0 ||
499 hdr->e_shentsize != sizeof(Elf_Shdr)) {
500 error = ENOEXEC;
501 goto out;
502 }
503 shdr = kmalloc(nbytes, M_LINKER, M_WAITOK);
504 ef->e_shdr = shdr;
505 error = vn_rdwr(UIO_READ, vp, (caddr_t) shdr, nbytes, hdr->e_shoff,
506 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
507 if (error)
508 goto out;
509 if (resid) {
510 error = ENOEXEC;
511 goto out;
512 }
513 /* Scan the section header for information and table sizing. */
514 nsym = 0;
515 symtabindex = -1;
516 symstrindex = -1;
517 for (i = 0; i < hdr->e_shnum; i++) {
518 switch (shdr[i].sh_type) {
519 case SHT_PROGBITS:
520 case SHT_NOBITS:
521 ef->nprogtab++;
522 break;
523 case SHT_SYMTAB:
524 nsym++;
525 symtabindex = i;
526 symstrindex = shdr[i].sh_link;
527 break;
528 case SHT_REL:
529 ef->nreltab++;
530 break;
531 case SHT_RELA:
532 ef->nrelatab++;
533 break;
534 case SHT_STRTAB:
535 break;
536 }
537 }
538 if (ef->nprogtab == 0) {
539 link_elf_obj_error(filename, "file has no contents");
540 error = ENOEXEC;
541 goto out;
542 }
543 if (nsym != 1) {
544 /* Only allow one symbol table for now */
545 link_elf_obj_error(filename, "file has no valid symbol table");
546 error = ENOEXEC;
547 goto out;
548 }
549 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
550 shdr[symstrindex].sh_type != SHT_STRTAB) {
551 link_elf_obj_error(filename, "file has invalid symbol strings");
552 error = ENOEXEC;
553 goto out;
554 }
555 /* Allocate space for tracking the load chunks */
556 if (ef->nprogtab != 0)
557 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab),
558 M_LINKER, M_WAITOK | M_ZERO);
559 if (ef->nreltab != 0)
560 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab),
561 M_LINKER, M_WAITOK | M_ZERO);
562 if (ef->nrelatab != 0)
563 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab),
564 M_LINKER, M_WAITOK | M_ZERO);
565 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
566 (ef->nreltab != 0 && ef->reltab == NULL) ||
567 (ef->nrelatab != 0 && ef->relatab == NULL)) {
568 error = ENOMEM;
569 goto out;
570 }
571 if (symtabindex == -1)
572 panic("lost symbol table index");
573 /* Allocate space for and load the symbol table */
574 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
575 ef->ddbsymtab = kmalloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
576 error = vn_rdwr(UIO_READ, vp, (void *)ef->ddbsymtab,
577 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
578 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
579 if (error)
580 goto out;
581 if (resid != 0) {
582 error = EINVAL;
583 goto out;
584 }
585 if (symstrindex == -1)
586 panic("lost symbol string index");
587 /* Allocate space for and load the symbol strings */
588 ef->ddbstrcnt = shdr[symstrindex].sh_size;
589 ef->ddbstrtab = kmalloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
590 error = vn_rdwr(UIO_READ, vp, ef->ddbstrtab,
591 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
592 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
593 if (error)
594 goto out;
595 if (resid != 0) {
596 error = EINVAL;
597 goto out;
598 }
599 /* Do we have a string table for the section names? */
600 shstrindex = -1;
601 if (hdr->e_shstrndx != 0 &&
602 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
603 shstrindex = hdr->e_shstrndx;
604 ef->shstrcnt = shdr[shstrindex].sh_size;
605 ef->shstrtab = kmalloc(shdr[shstrindex].sh_size, M_LINKER,
606 M_WAITOK);
607 error = vn_rdwr(UIO_READ, vp, ef->shstrtab,
608 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
609 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
610 if (error)
611 goto out;
612 if (resid != 0) {
613 error = EINVAL;
614 goto out;
615 }
616 }
617 /* Size up code/data(progbits) and bss(nobits). */
618 alignmask = 0;
619 for (i = 0; i < hdr->e_shnum; i++) {
620 switch (shdr[i].sh_type) {
621 case SHT_PROGBITS:
622 case SHT_NOBITS:
623 alignmask = shdr[i].sh_addralign - 1;
624 mapsize += alignmask;
625 mapsize &= ~alignmask;
626 mapsize += shdr[i].sh_size;
627 break;
628 }
629 }
630
631 /*
632 * We know how much space we need for the text/data/bss/etc. This
633 * stuff needs to be in a single chunk so that profiling etc can get
634 * the bounds and gdb can associate offsets with modules
635 */
636 ef->object = vm_object_allocate(OBJT_DEFAULT,
637 round_page(mapsize) >> PAGE_SHIFT);
638 if (ef->object == NULL) {
639 error = ENOMEM;
640 goto out;
641 }
642 vm_object_hold(ef->object);
643 vm_object_reference_locked(ef->object);
644 ef->address = (caddr_t) vm_map_min(&kernel_map);
645 ef->bytes = 0;
646
647 /*
648 * In order to satisfy x86_64's architectural requirements on the
649 * location of code and data in the kernel's address space, request a
650 * mapping that is above the kernel.
651 *
652 * vkernel64's text+data is outside the managed VM space entirely.
653 */
654 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL)
655 error = vkernel_module_memory_alloc(&mapbase, round_page(mapsize));
656 vm_object_drop(ef->object);
657 #else
658 mapbase = KERNBASE;
659 error = vm_map_find(&kernel_map, ef->object, 0, &mapbase,
660 round_page(mapsize), PAGE_SIZE,
661 TRUE, VM_MAPTYPE_NORMAL,
662 VM_PROT_ALL, VM_PROT_ALL, FALSE);
663 vm_object_drop(ef->object);
664 if (error) {
665 vm_object_deallocate(ef->object);
666 ef->object = NULL;
667 goto out;
668 }
669 /* Wire the pages */
670 error = vm_map_wire(&kernel_map, mapbase,
671 mapbase + round_page(mapsize), 0);
672 #endif
673 if (error != KERN_SUCCESS) {
674 error = ENOMEM;
675 goto out;
676 }
677 /* Inform the kld system about the situation */
678 lf->address = ef->address = (caddr_t) mapbase;
679 lf->size = round_page(mapsize);
680 ef->bytes = mapsize;
681
682 /*
683 * Now load code/data(progbits), zero bss(nobits), allocate space for
684 * and load relocs
685 */
686 pb = 0;
687 rl = 0;
688 ra = 0;
689 alignmask = 0;
690 for (i = 0; i < hdr->e_shnum; i++) {
691 switch (shdr[i].sh_type) {
692 case SHT_PROGBITS:
693 case SHT_NOBITS:
694 alignmask = shdr[i].sh_addralign - 1;
695 mapbase += alignmask;
696 mapbase &= ~alignmask;
697 if (ef->shstrtab && shdr[i].sh_name != 0)
698 ef->progtab[pb].name =
699 ef->shstrtab + shdr[i].sh_name;
700 else if (shdr[i].sh_type == SHT_PROGBITS)
701 ef->progtab[pb].name = "<<PROGBITS>>";
702 else
703 ef->progtab[pb].name = "<<NOBITS>>";
704 #if 0
705 if (ef->progtab[pb].name != NULL &&
706 !strcmp(ef->progtab[pb].name, "set_pcpu"))
707 ef->progtab[pb].addr =
708 dpcpu_alloc(shdr[i].sh_size);
709 #ifdef VIMAGE
710 else if (ef->progtab[pb].name != NULL &&
711 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
712 ef->progtab[pb].addr =
713 vnet_data_alloc(shdr[i].sh_size);
714 #endif
715 else
716 #endif
717 ef->progtab[pb].addr =
718 (void *)(uintptr_t) mapbase;
719 if (ef->progtab[pb].addr == NULL) {
720 error = ENOSPC;
721 goto out;
722 }
723 ef->progtab[pb].size = shdr[i].sh_size;
724 ef->progtab[pb].sec = i;
725 if (shdr[i].sh_type == SHT_PROGBITS) {
726 error = vn_rdwr(UIO_READ, vp,
727 ef->progtab[pb].addr,
728 shdr[i].sh_size, shdr[i].sh_offset,
729 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
730 &resid);
731 if (error)
732 goto out;
733 if (resid != 0) {
734 error = EINVAL;
735 goto out;
736 }
737 #if 0
738 /* Initialize the per-cpu or vnet area. */
739 if (ef->progtab[pb].addr != (void *)mapbase &&
740 !strcmp(ef->progtab[pb].name, "set_pcpu"))
741 dpcpu_copy(ef->progtab[pb].addr,
742 shdr[i].sh_size);
743 #ifdef VIMAGE
744 else if (ef->progtab[pb].addr !=
745 (void *)mapbase &&
746 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
747 vnet_data_copy(ef->progtab[pb].addr,
748 shdr[i].sh_size);
749 #endif
750 #endif
751 } else
752 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
753
754 /* Update all symbol values with the offset. */
755 for (j = 0; j < ef->ddbsymcnt; j++) {
756 es = &ef->ddbsymtab[j];
757 if (es->st_shndx != i)
758 continue;
759 es->st_value += (Elf_Addr) ef->progtab[pb].addr;
760 }
761 mapbase += shdr[i].sh_size;
762 pb++;
763 break;
764 case SHT_REL:
765 ef->reltab[rl].rel = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
766 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
767 ef->reltab[rl].sec = shdr[i].sh_info;
768 error = vn_rdwr(UIO_READ, vp,
769 (void *)ef->reltab[rl].rel,
770 shdr[i].sh_size, shdr[i].sh_offset,
771 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
772 if (error)
773 goto out;
774 if (resid != 0) {
775 error = EINVAL;
776 goto out;
777 }
778 rl++;
779 break;
780 case SHT_RELA:
781 ef->relatab[ra].rela = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
782 ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela);
783 ef->relatab[ra].sec = shdr[i].sh_info;
784 error = vn_rdwr(UIO_READ, vp,
785 (void *)ef->relatab[ra].rela,
786 shdr[i].sh_size, shdr[i].sh_offset,
787 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
788 if (error)
789 goto out;
790 if (resid != 0) {
791 error = EINVAL;
792 goto out;
793 }
794 ra++;
795 break;
796 }
797 }
798 if (pb != ef->nprogtab)
799 panic("lost progbits");
800 if (rl != ef->nreltab)
801 panic("lost reltab");
802 if (ra != ef->nrelatab)
803 panic("lost relatab");
804 if (mapbase != (vm_offset_t) ef->address + mapsize)
805 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)",
806 mapbase, ef->address, mapsize,
807 (vm_offset_t) ef->address + mapsize);
808
809 /* Local intra-module relocations */
810 link_elf_obj_reloc_local(lf);
811
812 /* Pull in dependencies */
813 error = linker_load_dependencies(lf);
814 if (error)
815 goto out;
816
817 /* External relocations */
818 error = relocate_file(lf);
819 if (error)
820 goto out;
821
822 *result = lf;
823
824 out:
825 if (error && lf)
826 linker_file_unload(lf /*, LINKER_UNLOAD_FORCE */);
827 if (hdr)
828 kfree(hdr, M_LINKER);
829 vn_unlock(vp);
830 vn_close(vp, FREAD);
831
832 return error;
833 }
834
835 static void
836 link_elf_obj_unload_file(linker_file_t file)
837 {
838 elf_file_t ef = file->priv;
839 int i;
840
841 if (ef->progtab) {
842 for (i = 0; i < ef->nprogtab; i++) {
843 if (ef->progtab[i].size == 0)
844 continue;
845 if (ef->progtab[i].name == NULL)
846 continue;
847 #if 0
848 if (!strcmp(ef->progtab[i].name, "set_pcpu"))
849 dpcpu_free(ef->progtab[i].addr,
850 ef->progtab[i].size);
851 #ifdef VIMAGE
852 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
853 vnet_data_free(ef->progtab[i].addr,
854 ef->progtab[i].size);
855 #endif
856 #endif
857 }
858 }
859 if (ef->preloaded) {
860 if (ef->reltab)
861 kfree(ef->reltab, M_LINKER);
862 if (ef->relatab)
863 kfree(ef->relatab, M_LINKER);
864 if (ef->progtab)
865 kfree(ef->progtab, M_LINKER);
866 if (ef->ctftab)
867 kfree(ef->ctftab, M_LINKER);
868 if (ef->ctfoff)
869 kfree(ef->ctfoff, M_LINKER);
870 if (ef->typoff)
871 kfree(ef->typoff, M_LINKER);
872 if (file->filename != NULL)
873 preload_delete_name(file->filename);
874 kfree(ef, M_LINKER);
875 /* XXX reclaim module memory? */
876 return;
877 }
878
879 for (i = 0; i < ef->nreltab; i++)
880 if (ef->reltab[i].rel)
881 kfree(ef->reltab[i].rel, M_LINKER);
882 for (i = 0; i < ef->nrelatab; i++)
883 if (ef->relatab[i].rela)
884 kfree(ef->relatab[i].rela, M_LINKER);
885 if (ef->reltab)
886 kfree(ef->reltab, M_LINKER);
887 if (ef->relatab)
888 kfree(ef->relatab, M_LINKER);
889 if (ef->progtab)
890 kfree(ef->progtab, M_LINKER);
891
892 if (ef->object) {
893 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL)
894 vkernel_module_memory_free((vm_offset_t)ef->address, ef->bytes);
895 #else
896 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
897 (vm_offset_t) ef->address +
898 (ef->object->size << PAGE_SHIFT));
899 #endif
900 vm_object_deallocate(ef->object);
901 ef->object = NULL;
902 }
903 if (ef->e_shdr)
904 kfree(ef->e_shdr, M_LINKER);
905 if (ef->ddbsymtab)
906 kfree(ef->ddbsymtab, M_LINKER);
907 if (ef->ddbstrtab)
908 kfree(ef->ddbstrtab, M_LINKER);
909 if (ef->shstrtab)
910 kfree(ef->shstrtab, M_LINKER);
911 if (ef->ctftab)
912 kfree(ef->ctftab, M_LINKER);
913 if (ef->ctfoff)
914 kfree(ef->ctfoff, M_LINKER);
915 if (ef->typoff)
916 kfree(ef->typoff, M_LINKER);
917 kfree(ef, M_LINKER);
918 }
919
920 static const char *
921 symbol_name(elf_file_t ef, Elf_Size r_info)
922 {
923 const Elf_Sym *ref;
924
925 if (ELF_R_SYM(r_info)) {
926 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
927 return ef->ddbstrtab + ref->st_name;
928 } else
929 return NULL;
930 }
931
932 static Elf_Addr
933 findbase(elf_file_t ef, int sec)
934 {
935 int i;
936 Elf_Addr base = 0;
937
938 for (i = 0; i < ef->nprogtab; i++) {
939 if (sec == ef->progtab[i].sec) {
940 base = (Elf_Addr)ef->progtab[i].addr;
941 break;
942 }
943 }
944 return base;
945 }
946
947 static int
948 relocate_file(linker_file_t lf)
949 {
950 elf_file_t ef = lf->priv;
951 const Elf_Rel *rellim;
952 const Elf_Rel *rel;
953 const Elf_Rela *relalim;
954 const Elf_Rela *rela;
955 const char *symname;
956 const Elf_Sym *sym;
957 int i;
958 Elf_Size symidx;
959 Elf_Addr base;
960
961 /* Perform relocations without addend if there are any: */
962 for (i = 0; i < ef->nreltab; i++) {
963 rel = ef->reltab[i].rel;
964 if (rel == NULL)
965 panic("lost a reltab!");
966 rellim = rel + ef->reltab[i].nrel;
967 base = findbase(ef, ef->reltab[i].sec);
968 if (base == 0)
969 panic("lost base for reltab");
970 for ( ; rel < rellim; rel++) {
971 symidx = ELF_R_SYM(rel->r_info);
972 if (symidx >= ef->ddbsymcnt)
973 continue;
974 sym = ef->ddbsymtab + symidx;
975 /* Local relocs are already done */
976 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
977 continue;
978 if (elf_reloc(lf, base, rel, ELF_RELOC_REL,
979 elf_obj_lookup)) {
980 symname = symbol_name(ef, rel->r_info);
981 kprintf("link_elf_obj_obj: symbol %s undefined\n",
982 symname);
983 return ENOENT;
984 }
985 }
986 }
987
988 /* Perform relocations with addend if there are any: */
989 for (i = 0; i < ef->nrelatab; i++) {
990 rela = ef->relatab[i].rela;
991 if (rela == NULL)
992 panic("lost a relatab!");
993 relalim = rela + ef->relatab[i].nrela;
994 base = findbase(ef, ef->relatab[i].sec);
995 if (base == 0)
996 panic("lost base for relatab");
997 for ( ; rela < relalim; rela++) {
998 symidx = ELF_R_SYM(rela->r_info);
999 if (symidx >= ef->ddbsymcnt)
1000 continue;
1001 sym = ef->ddbsymtab + symidx;
1002 /* Local relocs are already done */
1003 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1004 continue;
1005 if (elf_reloc(lf, base, rela, ELF_RELOC_RELA,
1006 elf_obj_lookup)) {
1007 symname = symbol_name(ef, rela->r_info);
1008 kprintf("link_elf_obj_obj: symbol %s undefined\n",
1009 symname);
1010 return ENOENT;
1011 }
1012 }
1013 }
1014
1015 return 0;
1016 }
1017
1018 static int
1019 link_elf_obj_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1020 {
1021 elf_file_t ef = lf->priv;
1022 const Elf_Sym *symp;
1023 const char *strp;
1024 int i;
1025
1026 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1027 strp = ef->ddbstrtab + symp->st_name;
1028 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1029 *sym = (c_linker_sym_t) symp;
1030 return 0;
1031 }
1032 }
1033 return ENOENT;
1034 }
1035
1036 static int
1037 link_elf_obj_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1038 linker_symval_t *symval)
1039 {
1040 elf_file_t ef = lf->priv;
1041 const Elf_Sym *es = (const Elf_Sym*) sym;
1042
1043 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1044 symval->name = ef->ddbstrtab + es->st_name;
1045 symval->value = (caddr_t)es->st_value;
1046 symval->size = es->st_size;
1047 return 0;
1048 }
1049 return ENOENT;
1050 }
1051
1052 static int
1053 link_elf_obj_search_symbol(linker_file_t lf, caddr_t value,
1054 c_linker_sym_t *sym, long *diffp)
1055 {
1056 elf_file_t ef = lf->priv;
1057 u_long off = (uintptr_t) (void *) value;
1058 u_long diff = off;
1059 u_long st_value;
1060 const Elf_Sym *es;
1061 const Elf_Sym *best = NULL;
1062 int i;
1063
1064 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1065 if (es->st_name == 0)
1066 continue;
1067 st_value = es->st_value;
1068 if (off >= st_value) {
1069 if (off - st_value < diff) {
1070 diff = off - st_value;
1071 best = es;
1072 if (diff == 0)
1073 break;
1074 } else if (off - st_value == diff) {
1075 best = es;
1076 }
1077 }
1078 }
1079 if (best == NULL)
1080 *diffp = off;
1081 else
1082 *diffp = diff;
1083 *sym = (c_linker_sym_t) best;
1084
1085 return 0;
1086 }
1087
1088 /*
1089 * Look up a linker set on an ELF system.
1090 */
1091 static int
1092 link_elf_obj_lookup_set(linker_file_t lf, const char *name,
1093 void ***startp, void ***stopp, int *countp)
1094 {
1095 elf_file_t ef = lf->priv;
1096 void **start, **stop;
1097 int i, count;
1098
1099 /* Relative to section number */
1100 for (i = 0; i < ef->nprogtab; i++) {
1101 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1102 strcmp(ef->progtab[i].name + 4, name) == 0) {
1103 start = (void **)ef->progtab[i].addr;
1104 stop = (void **)((char *)ef->progtab[i].addr +
1105 ef->progtab[i].size);
1106 count = stop - start;
1107 if (startp)
1108 *startp = start;
1109 if (stopp)
1110 *stopp = stop;
1111 if (countp)
1112 *countp = count;
1113 return (0);
1114 }
1115 }
1116 return (ESRCH);
1117 }
1118
1119 /*
1120 * Symbol lookup function that can be used when the symbol index is known (ie
1121 * in relocations). It uses the symbol index instead of doing a fully fledged
1122 * hash table based lookup when such is valid. For example for local symbols.
1123 * This is not only more efficient, it's also more correct. It's not always
1124 * the case that the symbol can be found through the hash table.
1125 */
1126 static int
1127 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result)
1128 {
1129 elf_file_t ef = lf->priv;
1130 const Elf_Sym *sym;
1131 const char *symbol;
1132
1133 /* Don't even try to lookup the symbol if the index is bogus. */
1134 if (symidx >= ef->ddbsymcnt)
1135 return (ENOENT);
1136
1137 sym = ef->ddbsymtab + symidx;
1138
1139 /* Quick answer if there is a definition included. */
1140 if (sym->st_shndx != SHN_UNDEF) {
1141 *result = sym->st_value;
1142 return (0);
1143 }
1144
1145 /* If we get here, then it is undefined and needs a lookup. */
1146 switch (ELF_ST_BIND(sym->st_info)) {
1147 case STB_LOCAL:
1148 /* Local, but undefined? huh? */
1149 return (ENOENT);
1150
1151 case STB_GLOBAL:
1152 /* Relative to Data or Function name */
1153 symbol = ef->ddbstrtab + sym->st_name;
1154
1155 /* Force a lookup failure if the symbol name is bogus. */
1156 if (*symbol == 0)
1157 return (ENOENT);
1158 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result));
1159
1160 case STB_WEAK:
1161 kprintf("link_elf_obj_obj: Weak symbols not supported\n");
1162 return (ENOENT);
1163
1164 default:
1165 return (ENOENT);
1166 }
1167 }
1168
1169 static void
1170 link_elf_obj_fix_link_set(elf_file_t ef)
1171 {
1172 static const char startn[] = "__start_";
1173 static const char stopn[] = "__stop_";
1174 Elf_Sym *sym;
1175 const char *sym_name, *linkset_name;
1176 Elf_Addr startp, stopp;
1177 Elf_Size symidx;
1178 int start, i;
1179
1180 startp = stopp = 0;
1181 for (symidx = 1 /* zero entry is special */;
1182 symidx < ef->ddbsymcnt; symidx++) {
1183 sym = ef->ddbsymtab + symidx;
1184 if (sym->st_shndx != SHN_UNDEF)
1185 continue;
1186
1187 sym_name = ef->ddbstrtab + sym->st_name;
1188 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1189 start = 1;
1190 linkset_name = sym_name + sizeof(startn) - 1;
1191 }
1192 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1193 start = 0;
1194 linkset_name = sym_name + sizeof(stopn) - 1;
1195 }
1196 else
1197 continue;
1198
1199 for (i = 0; i < ef->nprogtab; i++) {
1200 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1201 startp = (Elf_Addr)ef->progtab[i].addr;
1202 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1203 break;
1204 }
1205 }
1206 if (i == ef->nprogtab)
1207 continue;
1208
1209 sym->st_value = start ? startp : stopp;
1210 sym->st_shndx = i;
1211 }
1212 }
1213
1214 static void
1215 link_elf_obj_reloc_local(linker_file_t lf)
1216 {
1217 elf_file_t ef = lf->priv;
1218 const Elf_Rel *rellim;
1219 const Elf_Rel *rel;
1220 const Elf_Rela *relalim;
1221 const Elf_Rela *rela;
1222 const Elf_Sym *sym;
1223 Elf_Addr base;
1224 int i;
1225 Elf_Size symidx;
1226
1227 link_elf_obj_fix_link_set(ef);
1228
1229 /* Perform relocations without addend if there are any: */
1230 for (i = 0; i < ef->nreltab; i++) {
1231 rel = ef->reltab[i].rel;
1232 if (rel == NULL)
1233 panic("lost a reltab!");
1234 rellim = rel + ef->reltab[i].nrel;
1235 base = findbase(ef, ef->reltab[i].sec);
1236 if (base == 0)
1237 panic("lost base for reltab");
1238 for ( ; rel < rellim; rel++) {
1239 symidx = ELF_R_SYM(rel->r_info);
1240 if (symidx >= ef->ddbsymcnt)
1241 continue;
1242 sym = ef->ddbsymtab + symidx;
1243 /* Only do local relocs */
1244 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1245 continue;
1246 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1247 elf_obj_lookup);
1248 }
1249 }
1250
1251 /* Perform relocations with addend if there are any: */
1252 for (i = 0; i < ef->nrelatab; i++) {
1253 rela = ef->relatab[i].rela;
1254 if (rela == NULL)
1255 panic("lost a relatab!");
1256 relalim = rela + ef->relatab[i].nrela;
1257 base = findbase(ef, ef->relatab[i].sec);
1258 if (base == 0)
1259 panic("lost base for relatab");
1260 for ( ; rela < relalim; rela++) {
1261 symidx = ELF_R_SYM(rela->r_info);
1262 if (symidx >= ef->ddbsymcnt)
1263 continue;
1264 sym = ef->ddbsymtab + symidx;
1265 /* Only do local relocs */
1266 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1267 continue;
1268 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1269 elf_obj_lookup);
1270 }
1271 }
1272 }
Cache object: 6e4288231ba6e45a8af523a48c79c8cb
|