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iscontrol(8): Fix synopsis, sync usage() & improve markup
[dragonfly.git] / sys / kern / link_elf_obj.c
blobfbc9e9fc969f88b666b4737d625d48babf452766
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 * $DragonFly: src/sys/kern/link_elf.c,v 1.29 2008/08/01 23:11:16 dillon Exp $
29 */
30
31 #include <sys/param.h>
32 #include <sys/kernel.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/proc.h>
36 #include <sys/nlookup.h>
37 #include <sys/fcntl.h>
38 #include <sys/vnode.h>
39 #include <sys/linker.h>
40 #include <machine/elf.h>
41
42 #include <vm/vm.h>
43 #include <vm/vm_param.h>
44 #include <vm/vm_zone.h>
45 #include <vm/vm_object.h>
46 #include <vm/vm_kern.h>
47 #include <vm/vm_extern.h>
48 #include <sys/lock.h>
49 #include <vm/pmap.h>
50 #include <vm/vm_map.h>
51
52 static int link_elf_obj_preload_file(const char *, linker_file_t *);
53 static int link_elf_obj_preload_finish(linker_file_t);
54 static int link_elf_obj_load_file(const char *, linker_file_t *);
55 static int
56 link_elf_obj_lookup_symbol(linker_file_t, const char *,
57 c_linker_sym_t *);
58 static int link_elf_obj_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t *);
59 static int
60 link_elf_obj_search_symbol(linker_file_t, caddr_t value,
61 c_linker_sym_t * sym, long *diffp);
62
63 static void link_elf_obj_unload_file(linker_file_t);
64 static int
65 link_elf_obj_lookup_set(linker_file_t, const char *,
66 void ***, void ***, int *);
67 static void link_elf_obj_reloc_local(linker_file_t lf);
68 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *);
69
70 static struct linker_class_ops link_elf_obj_class_ops = {
71 link_elf_obj_load_file,
72 link_elf_obj_preload_file,
73 };
74
75 static struct linker_file_ops link_elf_obj_file_ops = {
76 .lookup_symbol = link_elf_obj_lookup_symbol,
77 .symbol_values = link_elf_obj_symbol_values,
78 .search_symbol = link_elf_obj_search_symbol,
79 .preload_finish = link_elf_obj_preload_finish,
80 .unload = link_elf_obj_unload_file,
81 .lookup_set = link_elf_obj_lookup_set,
82 };
83
84 typedef struct {
85 void *addr;
86 Elf_Off size;
87 int flags;
88 int sec; /* Original section */
89 char *name;
90 } Elf_progent;
91
92 typedef struct {
93 Elf_Rel *rel;
94 int nrel;
95 int sec;
96 } Elf_relent;
97
98 typedef struct {
99 Elf_Rela *rela;
100 int nrela;
101 int sec;
102 } Elf_relaent;
103
104
105 typedef struct elf_file {
106 int preloaded;
107
108 caddr_t address; /* Relocation address */
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 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops);
202 if (lf == NULL) {
203 kfree(ef, M_LINKER);
204 return ENOMEM;
205 }
206 lf->address = ef->address;
207 lf->size = *(size_t *) sizeptr;
208
209 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
210 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
211 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
212 hdr->e_version != EV_CURRENT ||
213 hdr->e_type != ET_REL ||
214 hdr->e_machine != ELF_TARG_MACH) {
215 error = EFTYPE;
216 goto out;
217 }
218 ef->e_shdr = shdr;
219
220 /* Scan the section header for information and table sizing. */
221 symtabindex = -1;
222 symstrindex = -1;
223 for (i = 0; i < hdr->e_shnum; i++) {
224 switch (shdr[i].sh_type) {
225 case SHT_PROGBITS:
226 case SHT_NOBITS:
227 ef->nprogtab++;
228 break;
229 case SHT_SYMTAB:
230 symtabindex = i;
231 symstrindex = shdr[i].sh_link;
232 break;
233 case SHT_REL:
234 ef->nreltab++;
235 break;
236 case SHT_RELA:
237 ef->nrelatab++;
238 break;
239 }
240 }
241
242 shstrindex = hdr->e_shstrndx;
243 if (ef->nprogtab == 0 || symstrindex < 0 ||
244 symstrindex >= hdr->e_shnum ||
245 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
246 shstrindex >= hdr->e_shnum ||
247 shdr[shstrindex].sh_type != SHT_STRTAB) {
248 error = ENOEXEC;
249 goto out;
250 }
251 /* Allocate space for tracking the load chunks */
252 if (ef->nprogtab != 0)
253 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab),
254 M_LINKER, M_WAITOK | M_ZERO);
255 if (ef->nreltab != 0)
256 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab),
257 M_LINKER, M_WAITOK | M_ZERO);
258 if (ef->nrelatab != 0)
259 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab),
260 M_LINKER, M_WAITOK | M_ZERO);
261 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
262 (ef->nreltab != 0 && ef->reltab == NULL) ||
263 (ef->nrelatab != 0 && ef->relatab == NULL)) {
264 error = ENOMEM;
265 goto out;
266 }
267 /* XXX, relocate the sh_addr fields saved by the loader. */
268 off = 0;
269 for (i = 0; i < hdr->e_shnum; i++) {
270 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
271 off = shdr[i].sh_addr;
272 }
273 for (i = 0; i < hdr->e_shnum; i++) {
274 if (shdr[i].sh_addr != 0)
275 shdr[i].sh_addr = shdr[i].sh_addr - off +
276 (Elf_Addr) ef->address;
277 }
278
279 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
280 ef->ddbsymtab = (Elf_Sym *) shdr[symtabindex].sh_addr;
281 ef->ddbstrcnt = shdr[symstrindex].sh_size;
282 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
283 ef->shstrcnt = shdr[shstrindex].sh_size;
284 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
285
286 /* Now fill out progtab and the relocation tables. */
287 pb = 0;
288 rl = 0;
289 ra = 0;
290 for (i = 0; i < hdr->e_shnum; i++) {
291 switch (shdr[i].sh_type) {
292 case SHT_PROGBITS:
293 case SHT_NOBITS:
294 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
295 if (shdr[i].sh_type == SHT_PROGBITS)
296 ef->progtab[pb].name = "<<PROGBITS>>";
297 else
298 ef->progtab[pb].name = "<<NOBITS>>";
299 ef->progtab[pb].size = shdr[i].sh_size;
300 ef->progtab[pb].sec = i;
301 if (ef->shstrtab && shdr[i].sh_name != 0)
302 ef->progtab[pb].name =
303 ef->shstrtab + shdr[i].sh_name;
304 #if 0
305 if (ef->progtab[pb].name != NULL &&
306 !strcmp(ef->progtab[pb].name, "set_pcpu")) {
307 void *dpcpu;
308
309 dpcpu = dpcpu_alloc(shdr[i].sh_size);
310 if (dpcpu == NULL) {
311 error = ENOSPC;
312 goto out;
313 }
314 memcpy(dpcpu, ef->progtab[pb].addr,
315 ef->progtab[pb].size);
316 dpcpu_copy(dpcpu, shdr[i].sh_size);
317 ef->progtab[pb].addr = dpcpu;
318 #ifdef VIMAGE
319 } else if (ef->progtab[pb].name != NULL &&
320 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
321 void *vnet_data;
322
323 vnet_data = vnet_data_alloc(shdr[i].sh_size);
324 if (vnet_data == NULL) {
325 error = ENOSPC;
326 goto out;
327 }
328 memcpy(vnet_data, ef->progtab[pb].addr,
329 ef->progtab[pb].size);
330 vnet_data_copy(vnet_data, shdr[i].sh_size);
331 ef->progtab[pb].addr = vnet_data;
332 #endif
333 }
334 #endif
335 /* Update all symbol values with the offset. */
336 for (j = 0; j < ef->ddbsymcnt; j++) {
337 es = &ef->ddbsymtab[j];
338 if (es->st_shndx != i)
339 continue;
340 es->st_value += (Elf_Addr) ef->progtab[pb].addr;
341 }
342 pb++;
343 break;
344 case SHT_REL:
345 ef->reltab[rl].rel = (Elf_Rel *) shdr[i].sh_addr;
346 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
347 ef->reltab[rl].sec = shdr[i].sh_info;
348 rl++;
349 break;
350 case SHT_RELA:
351 ef->relatab[ra].rela = (Elf_Rela *) shdr[i].sh_addr;
352 ef->relatab[ra].nrela =
353 shdr[i].sh_size / sizeof(Elf_Rela);
354 ef->relatab[ra].sec = shdr[i].sh_info;
355 ra++;
356 break;
357 }
358 }
359 if (pb != ef->nprogtab)
360 panic("lost progbits");
361 if (rl != ef->nreltab)
362 panic("lost reltab");
363 if (ra != ef->nrelatab)
364 panic("lost relatab");
365
366 /* Local intra-module relocations */
367 link_elf_obj_reloc_local(lf);
368
369 *result = lf;
370 return (0);
371
372 out:
373 /* preload not done this way */
374 linker_file_unload(lf /* , LINKER_UNLOAD_FORCE */ );
375 return (error);
376 }
377
378 static int
379 link_elf_obj_preload_finish(linker_file_t lf)
380 {
381 int error;
382
383 error = relocate_file(lf);
384
385 return (error);
386 }
387
388 static int
389 link_elf_obj_load_file(const char *filename, linker_file_t * result)
390 {
391 struct nlookupdata nd;
392 struct thread *td = curthread; /* XXX */
393 struct proc *p = td->td_proc;
394 char *pathname;
395 struct vnode *vp;
396 Elf_Ehdr *hdr;
397 Elf_Shdr *shdr;
398 Elf_Sym *es;
399 int nbytes, i, j;
400 vm_offset_t mapbase;
401 size_t mapsize;
402 int error = 0;
403 int resid;
404 elf_file_t ef;
405 linker_file_t lf;
406 int symtabindex;
407 int symstrindex;
408 int shstrindex;
409 int nsym;
410 int pb, rl, ra;
411 int alignmask;
412
413 KKASSERT(p != NULL);
414 if (p->p_ucred == NULL) {
415 kprintf("link_elf_obj_load_file: cannot load '%s' from filesystem"
416 " this early\n", filename);
417 return ENOENT;
418 }
419 shdr = NULL;
420 lf = NULL;
421 mapsize = 0;
422 hdr = NULL;
423 pathname = linker_search_path(filename);
424 if (pathname == NULL)
425 return ENOENT;
426
427 error = nlookup_init(&nd, pathname, UIO_SYSSPACE, NLC_FOLLOW | NLC_LOCKVP);
428 if (error == 0)
429 error = vn_open(&nd, NULL, FREAD, 0);
430 kfree(pathname, M_LINKER);
431 if (error) {
432 nlookup_done(&nd);
433 return error;
434 }
435 vp = nd.nl_open_vp;
436 nd.nl_open_vp = NULL;
437 nlookup_done(&nd);
438
439 /*
440 * Read the elf header from the file.
441 */
442 hdr = kmalloc(sizeof(*hdr), M_LINKER, M_WAITOK);
443 if (hdr == NULL) {
444 error = ENOMEM;
445 goto out;
446 }
447 error = vn_rdwr(UIO_READ, vp, (void *)hdr, sizeof(*hdr), 0,
448 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
449 if (error)
450 goto out;
451 if (resid != 0) {
452 error = ENOEXEC;
453 goto out;
454 }
455 if (!IS_ELF(*hdr)) {
456 error = ENOEXEC;
457 goto out;
458 }
459
460 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
461 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
462 link_elf_obj_error(filename, "Unsupported file layout");
463 error = ENOEXEC;
464 goto out;
465 }
466 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
467 || hdr->e_version != EV_CURRENT) {
468 link_elf_obj_error(filename, "Unsupported file version");
469 error = ENOEXEC;
470 goto out;
471 }
472 if (hdr->e_type != ET_REL) {
473 error = ENOSYS;
474 goto out;
475 }
476 if (hdr->e_machine != ELF_TARG_MACH) {
477 link_elf_obj_error(filename, "Unsupported machine");
478 error = ENOEXEC;
479 goto out;
480 }
481
482 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
483 lf = linker_make_file(filename, ef, &link_elf_obj_file_ops);
484 if (lf == NULL) {
485 kfree(ef, M_LINKER);
486 error = ENOMEM;
487 goto out;
488 }
489 ef->nprogtab = 0;
490 ef->e_shdr = 0;
491 ef->nreltab = 0;
492 ef->nrelatab = 0;
493
494 /* Allocate and read in the section header */
495 nbytes = hdr->e_shnum * hdr->e_shentsize;
496 if (nbytes == 0 || hdr->e_shoff == 0 ||
497 hdr->e_shentsize != sizeof(Elf_Shdr)) {
498 error = ENOEXEC;
499 goto out;
500 }
501 shdr = kmalloc(nbytes, M_LINKER, M_WAITOK);
502 if (shdr == NULL) {
503 error = ENOMEM;
504 goto out;
505 }
506 ef->e_shdr = shdr;
507 error = vn_rdwr(UIO_READ, vp, (caddr_t) shdr, nbytes, hdr->e_shoff,
508 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
509 if (error)
510 goto out;
511 if (resid) {
512 error = ENOEXEC;
513 goto out;
514 }
515 /* Scan the section header for information and table sizing. */
516 nsym = 0;
517 symtabindex = -1;
518 symstrindex = -1;
519 for (i = 0; i < hdr->e_shnum; i++) {
520 switch (shdr[i].sh_type) {
521 case SHT_PROGBITS:
522 case SHT_NOBITS:
523 ef->nprogtab++;
524 break;
525 case SHT_SYMTAB:
526 nsym++;
527 symtabindex = i;
528 symstrindex = shdr[i].sh_link;
529 break;
530 case SHT_REL:
531 ef->nreltab++;
532 break;
533 case SHT_RELA:
534 ef->nrelatab++;
535 break;
536 case SHT_STRTAB:
537 break;
538 }
539 }
540 if (ef->nprogtab == 0) {
541 link_elf_obj_error(filename, "file has no contents");
542 error = ENOEXEC;
543 goto out;
544 }
545 if (nsym != 1) {
546 /* Only allow one symbol table for now */
547 link_elf_obj_error(filename, "file has no valid symbol table");
548 error = ENOEXEC;
549 goto out;
550 }
551 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
552 shdr[symstrindex].sh_type != SHT_STRTAB) {
553 link_elf_obj_error(filename, "file has invalid symbol strings");
554 error = ENOEXEC;
555 goto out;
556 }
557 /* Allocate space for tracking the load chunks */
558 if (ef->nprogtab != 0)
559 ef->progtab = kmalloc(ef->nprogtab * sizeof(*ef->progtab),
560 M_LINKER, M_WAITOK | M_ZERO);
561 if (ef->nreltab != 0)
562 ef->reltab = kmalloc(ef->nreltab * sizeof(*ef->reltab),
563 M_LINKER, M_WAITOK | M_ZERO);
564 if (ef->nrelatab != 0)
565 ef->relatab = kmalloc(ef->nrelatab * sizeof(*ef->relatab),
566 M_LINKER, M_WAITOK | M_ZERO);
567 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
568 (ef->nreltab != 0 && ef->reltab == NULL) ||
569 (ef->nrelatab != 0 && ef->relatab == NULL)) {
570 error = ENOMEM;
571 goto out;
572 }
573 if (symtabindex == -1)
574 panic("lost symbol table index");
575 /* Allocate space for and load the symbol table */
576 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
577 ef->ddbsymtab = kmalloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
578 if (ef->ddbsymtab == NULL) {
579 error = ENOMEM;
580 goto out;
581 }
582 error = vn_rdwr(UIO_READ, vp, (void *)ef->ddbsymtab,
583 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
584 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
585 if (error)
586 goto out;
587 if (resid != 0) {
588 error = EINVAL;
589 goto out;
590 }
591 if (symstrindex == -1)
592 panic("lost symbol string index");
593 /* Allocate space for and load the symbol strings */
594 ef->ddbstrcnt = shdr[symstrindex].sh_size;
595 ef->ddbstrtab = kmalloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
596 if (ef->ddbstrtab == NULL) {
597 error = ENOMEM;
598 goto out;
599 }
600 error = vn_rdwr(UIO_READ, vp, ef->ddbstrtab,
601 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
602 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
603 if (error)
604 goto out;
605 if (resid != 0) {
606 error = EINVAL;
607 goto out;
608 }
609 /* Do we have a string table for the section names? */
610 shstrindex = -1;
611 if (hdr->e_shstrndx != 0 &&
612 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
613 shstrindex = hdr->e_shstrndx;
614 ef->shstrcnt = shdr[shstrindex].sh_size;
615 ef->shstrtab = kmalloc(shdr[shstrindex].sh_size, M_LINKER,
616 M_WAITOK);
617 if (ef->shstrtab == NULL) {
618 error = ENOMEM;
619 goto out;
620 }
621 error = vn_rdwr(UIO_READ, vp, ef->shstrtab,
622 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
623 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
624 if (error)
625 goto out;
626 if (resid != 0) {
627 error = EINVAL;
628 goto out;
629 }
630 }
631 /* Size up code/data(progbits) and bss(nobits). */
632 alignmask = 0;
633 for (i = 0; i < hdr->e_shnum; i++) {
634 switch (shdr[i].sh_type) {
635 case SHT_PROGBITS:
636 case SHT_NOBITS:
637 alignmask = shdr[i].sh_addralign - 1;
638 mapsize += alignmask;
639 mapsize &= ~alignmask;
640 mapsize += shdr[i].sh_size;
641 break;
642 }
643 }
644
645 /*
646 * We know how much space we need for the text/data/bss/etc. This
647 * stuff needs to be in a single chunk so that profiling etc can get
648 * the bounds and gdb can associate offsets with modules
649 */
650 ef->object = vm_object_allocate(OBJT_DEFAULT,
651 round_page(mapsize) >> PAGE_SHIFT);
652 if (ef->object == NULL) {
653 error = ENOMEM;
654 goto out;
655 }
656 ef->address = (caddr_t) vm_map_min(&kernel_map);
657
658 /*
659 * In order to satisfy amd64's architectural requirements on the
660 * location of code and data in the kernel's address space, request a
661 * mapping that is above the kernel.
662 */
663 mapbase = KERNBASE;
664 error = vm_map_find(&kernel_map, ef->object, 0, &mapbase,
665 round_page(mapsize), TRUE, VM_MAPTYPE_NORMAL,
666 VM_PROT_ALL, VM_PROT_ALL, FALSE);
667 if (error) {
668 vm_object_deallocate(ef->object);
669 ef->object = 0;
670 goto out;
671 }
672 /* Wire the pages */
673 error = vm_map_wire(&kernel_map, mapbase,
674 mapbase + round_page(mapsize), 0);
675 if (error != KERN_SUCCESS) {
676 error = ENOMEM;
677 goto out;
678 }
679 /* Inform the kld system about the situation */
680 lf->address = ef->address = (caddr_t) mapbase;
681 lf->size = mapsize;
682
683 /*
684 * Now load code/data(progbits), zero bss(nobits), allocate space for
685 * and load relocs
686 */
687 pb = 0;
688 rl = 0;
689 ra = 0;
690 alignmask = 0;
691 for (i = 0; i < hdr->e_shnum; i++) {
692 switch (shdr[i].sh_type) {
693 case SHT_PROGBITS:
694 case SHT_NOBITS:
695 alignmask = shdr[i].sh_addralign - 1;
696 mapbase += alignmask;
697 mapbase &= ~alignmask;
698 if (ef->shstrtab && shdr[i].sh_name != 0)
699 ef->progtab[pb].name =
700 ef->shstrtab + shdr[i].sh_name;
701 else if (shdr[i].sh_type == SHT_PROGBITS)
702 ef->progtab[pb].name = "<<PROGBITS>>";
703 else
704 ef->progtab[pb].name = "<<NOBITS>>";
705 #if 0
706 if (ef->progtab[pb].name != NULL &&
707 !strcmp(ef->progtab[pb].name, "set_pcpu"))
708 ef->progtab[pb].addr =
709 dpcpu_alloc(shdr[i].sh_size);
710 #ifdef VIMAGE
711 else if (ef->progtab[pb].name != NULL &&
712 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
713 ef->progtab[pb].addr =
714 vnet_data_alloc(shdr[i].sh_size);
715 #endif
716 else
717 #endif
718 ef->progtab[pb].addr =
719 (void *)(uintptr_t) mapbase;
720 if (ef->progtab[pb].addr == NULL) {
721 error = ENOSPC;
722 goto out;
723 }
724 ef->progtab[pb].size = shdr[i].sh_size;
725 ef->progtab[pb].sec = i;
726 if (shdr[i].sh_type == SHT_PROGBITS) {
727 error = vn_rdwr(UIO_READ, vp,
728 ef->progtab[pb].addr,
729 shdr[i].sh_size, shdr[i].sh_offset,
730 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
731 &resid);
732 if (error)
733 goto out;
734 if (resid != 0) {
735 error = EINVAL;
736 goto out;
737 }
738 #if 0
739 /* Initialize the per-cpu or vnet area. */
740 if (ef->progtab[pb].addr != (void *)mapbase &&
741 !strcmp(ef->progtab[pb].name, "set_pcpu"))
742 dpcpu_copy(ef->progtab[pb].addr,
743 shdr[i].sh_size);
744 #ifdef VIMAGE
745 else if (ef->progtab[pb].addr !=
746 (void *)mapbase &&
747 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
748 vnet_data_copy(ef->progtab[pb].addr,
749 shdr[i].sh_size);
750 #endif
751 #endif
752 } else
753 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
754
755 /* Update all symbol values with the offset. */
756 for (j = 0; j < ef->ddbsymcnt; j++) {
757 es = &ef->ddbsymtab[j];
758 if (es->st_shndx != i)
759 continue;
760 es->st_value += (Elf_Addr) ef->progtab[pb].addr;
761 }
762 mapbase += shdr[i].sh_size;
763 pb++;
764 break;
765 case SHT_REL:
766 ef->reltab[rl].rel = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
767 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
768 ef->reltab[rl].sec = shdr[i].sh_info;
769 error = vn_rdwr(UIO_READ, vp,
770 (void *)ef->reltab[rl].rel,
771 shdr[i].sh_size, shdr[i].sh_offset,
772 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
773 if (error)
774 goto out;
775 if (resid != 0) {
776 error = EINVAL;
777 goto out;
778 }
779 rl++;
780 break;
781 case SHT_RELA:
782 ef->relatab[ra].rela = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
783 ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela);
784 ef->relatab[ra].sec = shdr[i].sh_info;
785 error = vn_rdwr(UIO_READ, vp,
786 (void *)ef->relatab[ra].rela,
787 shdr[i].sh_size, shdr[i].sh_offset,
788 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
789 if (error)
790 goto out;
791 if (resid != 0) {
792 error = EINVAL;
793 goto out;
794 }
795 ra++;
796 break;
797 }
798 }
799 if (pb != ef->nprogtab)
800 panic("lost progbits");
801 if (rl != ef->nreltab)
802 panic("lost reltab");
803 if (ra != ef->nrelatab)
804 panic("lost relatab");
805 if (mapbase != (vm_offset_t) ef->address + mapsize)
806 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
807 mapbase, ef->address, mapsize,
808 (vm_offset_t) ef->address + mapsize);
809
810 /* Local intra-module relocations */
811 link_elf_obj_reloc_local(lf);
812
813 /* Pull in dependencies */
814 error = linker_load_dependencies(lf);
815 if (error)
816 goto out;
817
818 /* External relocations */
819 error = relocate_file(lf);
820 if (error)
821 goto out;
822
823 *result = lf;
824
825 out:
826 if (error && lf)
827 linker_file_unload(lf /*, LINKER_UNLOAD_FORCE */);
828 if (hdr)
829 kfree(hdr, M_LINKER);
830 vn_unlock(vp);
831 vn_close(vp, FREAD);
832
833 return error;
834 }
835
836 static void
837 link_elf_obj_unload_file(linker_file_t file)
838 {
839 elf_file_t ef = file->priv;
840 int i;
841
842 if (ef->progtab) {
843 for (i = 0; i < ef->nprogtab; i++) {
844 if (ef->progtab[i].size == 0)
845 continue;
846 if (ef->progtab[i].name == NULL)
847 continue;
848 #if 0
849 if (!strcmp(ef->progtab[i].name, "set_pcpu"))
850 dpcpu_free(ef->progtab[i].addr,
851 ef->progtab[i].size);
852 #ifdef VIMAGE
853 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
854 vnet_data_free(ef->progtab[i].addr,
855 ef->progtab[i].size);
856 #endif
857 #endif
858 }
859 }
860 if (ef->preloaded) {
861 if (ef->reltab)
862 kfree(ef->reltab, M_LINKER);
863 if (ef->relatab)
864 kfree(ef->relatab, M_LINKER);
865 if (ef->progtab)
866 kfree(ef->progtab, M_LINKER);
867 if (ef->ctftab)
868 kfree(ef->ctftab, M_LINKER);
869 if (ef->ctfoff)
870 kfree(ef->ctfoff, M_LINKER);
871 if (ef->typoff)
872 kfree(ef->typoff, M_LINKER);
873 if (file->filename != NULL)
874 preload_delete_name(file->filename);
875 kfree(ef, M_LINKER);
876 /* XXX reclaim module memory? */
877 return;
878 }
879
880 for (i = 0; i < ef->nreltab; i++)
881 if (ef->reltab[i].rel)
882 kfree(ef->reltab[i].rel, M_LINKER);
883 for (i = 0; i < ef->nrelatab; i++)
884 if (ef->relatab[i].rela)
885 kfree(ef->relatab[i].rela, M_LINKER);
886 if (ef->reltab)
887 kfree(ef->reltab, M_LINKER);
888 if (ef->relatab)
889 kfree(ef->relatab, M_LINKER);
890 if (ef->progtab)
891 kfree(ef->progtab, M_LINKER);
892
893 if (ef->object) {
894 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
895 (vm_offset_t) ef->address +
896 (ef->object->size << PAGE_SHIFT));
897 }
898 if (ef->e_shdr)
899 kfree(ef->e_shdr, M_LINKER);
900 if (ef->ddbsymtab)
901 kfree(ef->ddbsymtab, M_LINKER);
902 if (ef->ddbstrtab)
903 kfree(ef->ddbstrtab, M_LINKER);
904 if (ef->shstrtab)
905 kfree(ef->shstrtab, M_LINKER);
906 if (ef->ctftab)
907 kfree(ef->ctftab, M_LINKER);
908 if (ef->ctfoff)
909 kfree(ef->ctfoff, M_LINKER);
910 if (ef->typoff)
911 kfree(ef->typoff, M_LINKER);
912 kfree(ef, M_LINKER);
913 }
914
915 static const char *
916 symbol_name(elf_file_t ef, Elf_Size r_info)
917 {
918 const Elf_Sym *ref;
919
920 if (ELF_R_SYM(r_info)) {
921 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
922 return ef->ddbstrtab + ref->st_name;
923 } else
924 return NULL;
925 }
926
927 static Elf_Addr
928 findbase(elf_file_t ef, int sec)
929 {
930 int i;
931 Elf_Addr base = 0;
932
933 for (i = 0; i < ef->nprogtab; i++) {
934 if (sec == ef->progtab[i].sec) {
935 base = (Elf_Addr)ef->progtab[i].addr;
936 break;
937 }
938 }
939 return base;
940 }
941
942 static int
943 relocate_file(linker_file_t lf)
944 {
945 elf_file_t ef = lf->priv;
946 const Elf_Rel *rellim;
947 const Elf_Rel *rel;
948 const Elf_Rela *relalim;
949 const Elf_Rela *rela;
950 const char *symname;
951 const Elf_Sym *sym;
952 int i;
953 Elf_Size symidx;
954 Elf_Addr base;
955
956 /* Perform relocations without addend if there are any: */
957 for (i = 0; i < ef->nreltab; i++) {
958 rel = ef->reltab[i].rel;
959 if (rel == NULL)
960 panic("lost a reltab!");
961 rellim = rel + ef->reltab[i].nrel;
962 base = findbase(ef, ef->reltab[i].sec);
963 if (base == 0)
964 panic("lost base for reltab");
965 for ( ; rel < rellim; rel++) {
966 symidx = ELF_R_SYM(rel->r_info);
967 if (symidx >= ef->ddbsymcnt)
968 continue;
969 sym = ef->ddbsymtab + symidx;
970 /* Local relocs are already done */
971 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
972 continue;
973 if (elf_reloc(lf, base, rel, ELF_RELOC_REL,
974 elf_obj_lookup)) {
975 symname = symbol_name(ef, rel->r_info);
976 kprintf("link_elf_obj_obj: symbol %s undefined\n",
977 symname);
978 return ENOENT;
979 }
980 }
981 }
982
983 /* Perform relocations with addend if there are any: */
984 for (i = 0; i < ef->nrelatab; i++) {
985 rela = ef->relatab[i].rela;
986 if (rela == NULL)
987 panic("lost a relatab!");
988 relalim = rela + ef->relatab[i].nrela;
989 base = findbase(ef, ef->relatab[i].sec);
990 if (base == 0)
991 panic("lost base for relatab");
992 for ( ; rela < relalim; rela++) {
993 symidx = ELF_R_SYM(rela->r_info);
994 if (symidx >= ef->ddbsymcnt)
995 continue;
996 sym = ef->ddbsymtab + symidx;
997 /* Local relocs are already done */
998 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
999 continue;
1000 if (elf_reloc(lf, base, rela, ELF_RELOC_RELA,
1001 elf_obj_lookup)) {
1002 symname = symbol_name(ef, rela->r_info);
1003 kprintf("link_elf_obj_obj: symbol %s undefined\n",
1004 symname);
1005 return ENOENT;
1006 }
1007 }
1008 }
1009
1010 return 0;
1011 }
1012
1013 static int
1014 link_elf_obj_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1015 {
1016 elf_file_t ef = lf->priv;
1017 const Elf_Sym *symp;
1018 const char *strp;
1019 int i;
1020
1021 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1022 strp = ef->ddbstrtab + symp->st_name;
1023 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1024 *sym = (c_linker_sym_t) symp;
1025 return 0;
1026 }
1027 }
1028 return ENOENT;
1029 }
1030
1031 static int
1032 link_elf_obj_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1033 linker_symval_t *symval)
1034 {
1035 elf_file_t ef = lf->priv;
1036 const Elf_Sym *es = (const Elf_Sym*) sym;
1037
1038 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1039 symval->name = ef->ddbstrtab + es->st_name;
1040 symval->value = (caddr_t)es->st_value;
1041 symval->size = es->st_size;
1042 return 0;
1043 }
1044 return ENOENT;
1045 }
1046
1047 static int
1048 link_elf_obj_search_symbol(linker_file_t lf, caddr_t value,
1049 c_linker_sym_t *sym, long *diffp)
1050 {
1051 elf_file_t ef = lf->priv;
1052 u_long off = (uintptr_t) (void *) value;
1053 u_long diff = off;
1054 u_long st_value;
1055 const Elf_Sym *es;
1056 const Elf_Sym *best = 0;
1057 int i;
1058
1059 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1060 if (es->st_name == 0)
1061 continue;
1062 st_value = es->st_value;
1063 if (off >= st_value) {
1064 if (off - st_value < diff) {
1065 diff = off - st_value;
1066 best = es;
1067 if (diff == 0)
1068 break;
1069 } else if (off - st_value == diff) {
1070 best = es;
1071 }
1072 }
1073 }
1074 if (best == 0)
1075 *diffp = off;
1076 else
1077 *diffp = diff;
1078 *sym = (c_linker_sym_t) best;
1079
1080 return 0;
1081 }
1082
1083 /*
1084 * Look up a linker set on an ELF system.
1085 */
1086 static int
1087 link_elf_obj_lookup_set(linker_file_t lf, const char *name,
1088 void ***startp, void ***stopp, int *countp)
1089 {
1090 elf_file_t ef = lf->priv;
1091 void **start, **stop;
1092 int i, count;
1093
1094 /* Relative to section number */
1095 for (i = 0; i < ef->nprogtab; i++) {
1096 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1097 strcmp(ef->progtab[i].name + 4, name) == 0) {
1098 start = (void **)ef->progtab[i].addr;
1099 stop = (void **)((char *)ef->progtab[i].addr +
1100 ef->progtab[i].size);
1101 count = stop - start;
1102 if (startp)
1103 *startp = start;
1104 if (stopp)
1105 *stopp = stop;
1106 if (countp)
1107 *countp = count;
1108 return (0);
1109 }
1110 }
1111 return (ESRCH);
1112 }
1113
1114 /*
1115 * Symbol lookup function that can be used when the symbol index is known (ie
1116 * in relocations). It uses the symbol index instead of doing a fully fledged
1117 * hash table based lookup when such is valid. For example for local symbols.
1118 * This is not only more efficient, it's also more correct. It's not always
1119 * the case that the symbol can be found through the hash table.
1120 */
1121 static int
1122 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result)
1123 {
1124 elf_file_t ef = lf->priv;
1125 const Elf_Sym *sym;
1126 const char *symbol;
1127
1128 /* Don't even try to lookup the symbol if the index is bogus. */
1129 if (symidx >= ef->ddbsymcnt)
1130 return (ENOENT);
1131
1132 sym = ef->ddbsymtab + symidx;
1133
1134 /* Quick answer if there is a definition included. */
1135 if (sym->st_shndx != SHN_UNDEF) {
1136 *result = sym->st_value;
1137 return (0);
1138 }
1139
1140 /* If we get here, then it is undefined and needs a lookup. */
1141 switch (ELF_ST_BIND(sym->st_info)) {
1142 case STB_LOCAL:
1143 /* Local, but undefined? huh? */
1144 return (ENOENT);
1145
1146 case STB_GLOBAL:
1147 /* Relative to Data or Function name */
1148 symbol = ef->ddbstrtab + sym->st_name;
1149
1150 /* Force a lookup failure if the symbol name is bogus. */
1151 if (*symbol == 0)
1152 return (ENOENT);
1153 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result));
1154
1155 case STB_WEAK:
1156 kprintf("link_elf_obj_obj: Weak symbols not supported\n");
1157 return (ENOENT);
1158
1159 default:
1160 return (ENOENT);
1161 }
1162 }
1163
1164 static void
1165 link_elf_obj_fix_link_set(elf_file_t ef)
1166 {
1167 static const char startn[] = "__start_";
1168 static const char stopn[] = "__stop_";
1169 Elf_Sym *sym;
1170 const char *sym_name, *linkset_name;
1171 Elf_Addr startp, stopp;
1172 Elf_Size symidx;
1173 int start, i;
1174
1175 startp = stopp = 0;
1176 for (symidx = 1 /* zero entry is special */;
1177 symidx < ef->ddbsymcnt; symidx++) {
1178 sym = ef->ddbsymtab + symidx;
1179 if (sym->st_shndx != SHN_UNDEF)
1180 continue;
1181
1182 sym_name = ef->ddbstrtab + sym->st_name;
1183 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1184 start = 1;
1185 linkset_name = sym_name + sizeof(startn) - 1;
1186 }
1187 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1188 start = 0;
1189 linkset_name = sym_name + sizeof(stopn) - 1;
1190 }
1191 else
1192 continue;
1193
1194 for (i = 0; i < ef->nprogtab; i++) {
1195 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1196 startp = (Elf_Addr)ef->progtab[i].addr;
1197 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1198 break;
1199 }
1200 }
1201 if (i == ef->nprogtab)
1202 continue;
1203
1204 sym->st_value = start ? startp : stopp;
1205 sym->st_shndx = i;
1206 }
1207 }
1208
1209 static void
1210 link_elf_obj_reloc_local(linker_file_t lf)
1211 {
1212 elf_file_t ef = lf->priv;
1213 const Elf_Rel *rellim;
1214 const Elf_Rel *rel;
1215 const Elf_Rela *relalim;
1216 const Elf_Rela *rela;
1217 const Elf_Sym *sym;
1218 Elf_Addr base;
1219 int i;
1220 Elf_Size symidx;
1221
1222 link_elf_obj_fix_link_set(ef);
1223
1224 /* Perform relocations without addend if there are any: */
1225 for (i = 0; i < ef->nreltab; i++) {
1226 rel = ef->reltab[i].rel;
1227 if (rel == NULL)
1228 panic("lost a reltab!");
1229 rellim = rel + ef->reltab[i].nrel;
1230 base = findbase(ef, ef->reltab[i].sec);
1231 if (base == 0)
1232 panic("lost base for reltab");
1233 for ( ; rel < rellim; rel++) {
1234 symidx = ELF_R_SYM(rel->r_info);
1235 if (symidx >= ef->ddbsymcnt)
1236 continue;
1237 sym = ef->ddbsymtab + symidx;
1238 /* Only do local relocs */
1239 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1240 continue;
1241 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1242 elf_obj_lookup);
1243 }
1244 }
1245
1246 /* Perform relocations with addend if there are any: */
1247 for (i = 0; i < ef->nrelatab; i++) {
1248 rela = ef->relatab[i].rela;
1249 if (rela == NULL)
1250 panic("lost a relatab!");
1251 relalim = rela + ef->relatab[i].nrela;
1252 base = findbase(ef, ef->relatab[i].sec);
1253 if (base == 0)
1254 panic("lost base for relatab");
1255 for ( ; rela < relalim; rela++) {
1256 symidx = ELF_R_SYM(rela->r_info);
1257 if (symidx >= ef->ddbsymcnt)
1258 continue;
1259 sym = ef->ddbsymtab + symidx;
1260 /* Only do local relocs */
1261 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1262 continue;
1263 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1264 elf_obj_lookup);
1265 }
1266 }
1267 }
DragonFly BSD