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kernel - Fix rare allproc scan vs p_ucred race
[dragonfly.git] / sys / kern / link_elf_obj.c
blob69bfe48f350ea0d7f51843d795e2af99cc979fa4
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 if (shdr[i].sh_size == 0)
519 continue;
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 error = vn_rdwr(UIO_READ, vp, (void *)ef->ddbsymtab,
579 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
580 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
581 if (error)
582 goto out;
583 if (resid != 0) {
584 error = EINVAL;
585 goto out;
586 }
587 if (symstrindex == -1)
588 panic("lost symbol string index");
589 /* Allocate space for and load the symbol strings */
590 ef->ddbstrcnt = shdr[symstrindex].sh_size;
591 ef->ddbstrtab = kmalloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
592 error = vn_rdwr(UIO_READ, vp, ef->ddbstrtab,
593 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
594 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
595 if (error)
596 goto out;
597 if (resid != 0) {
598 error = EINVAL;
599 goto out;
600 }
601 /* Do we have a string table for the section names? */
602 shstrindex = -1;
603 if (hdr->e_shstrndx != 0 &&
604 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
605 shstrindex = hdr->e_shstrndx;
606 ef->shstrcnt = shdr[shstrindex].sh_size;
607 ef->shstrtab = kmalloc(shdr[shstrindex].sh_size, M_LINKER,
608 M_WAITOK);
609 error = vn_rdwr(UIO_READ, vp, ef->shstrtab,
610 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
611 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
612 if (error)
613 goto out;
614 if (resid != 0) {
615 error = EINVAL;
616 goto out;
617 }
618 }
619 /* Size up code/data(progbits) and bss(nobits). */
620 alignmask = 0;
621 for (i = 0; i < hdr->e_shnum; i++) {
622 if (shdr[i].sh_size == 0)
623 continue;
624 switch (shdr[i].sh_type) {
625 case SHT_PROGBITS:
626 case SHT_NOBITS:
627 alignmask = shdr[i].sh_addralign - 1;
628 mapsize += alignmask;
629 mapsize &= ~alignmask;
630 mapsize += shdr[i].sh_size;
631 break;
632 }
633 }
634
635 /*
636 * We know how much space we need for the text/data/bss/etc. This
637 * stuff needs to be in a single chunk so that profiling etc can get
638 * the bounds and gdb can associate offsets with modules
639 */
640 ef->object = vm_object_allocate(OBJT_DEFAULT,
641 round_page(mapsize) >> PAGE_SHIFT);
642 if (ef->object == NULL) {
643 error = ENOMEM;
644 goto out;
645 }
646 vm_object_hold(ef->object);
647 vm_object_reference_locked(ef->object);
648 ef->address = (caddr_t) vm_map_min(&kernel_map);
649 ef->bytes = 0;
650
651 /*
652 * In order to satisfy x86_64's architectural requirements on the
653 * location of code and data in the kernel's address space, request a
654 * mapping that is above the kernel.
655 *
656 * vkernel64's text+data is outside the managed VM space entirely.
657 */
658 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL)
659 error = vkernel_module_memory_alloc(&mapbase, round_page(mapsize));
660 vm_object_drop(ef->object);
661 #else
662 mapbase = KERNBASE;
663 error = vm_map_find(&kernel_map, ef->object, NULL,
664 0, &mapbase, round_page(mapsize),
665 PAGE_SIZE, TRUE,
666 VM_MAPTYPE_NORMAL, VM_SUBSYS_IMGACT,
667 VM_PROT_ALL, VM_PROT_ALL, FALSE);
668 vm_object_drop(ef->object);
669 if (error) {
670 vm_object_deallocate(ef->object);
671 ef->object = NULL;
672 goto out;
673 }
674 /* Wire the pages */
675 error = vm_map_wire(&kernel_map, mapbase,
676 mapbase + round_page(mapsize), 0);
677 #endif
678 if (error != KERN_SUCCESS) {
679 error = ENOMEM;
680 goto out;
681 }
682 /* Inform the kld system about the situation */
683 lf->address = ef->address = (caddr_t) mapbase;
684 lf->size = round_page(mapsize);
685 ef->bytes = mapsize;
686
687 /*
688 * Now load code/data(progbits), zero bss(nobits), allocate space for
689 * and load relocs
690 */
691 pb = 0;
692 rl = 0;
693 ra = 0;
694 alignmask = 0;
695 for (i = 0; i < hdr->e_shnum; i++) {
696 if (shdr[i].sh_size == 0)
697 continue;
698 switch (shdr[i].sh_type) {
699 case SHT_PROGBITS:
700 case SHT_NOBITS:
701 alignmask = shdr[i].sh_addralign - 1;
702 mapbase += alignmask;
703 mapbase &= ~alignmask;
704 if (ef->shstrtab && shdr[i].sh_name != 0)
705 ef->progtab[pb].name =
706 ef->shstrtab + shdr[i].sh_name;
707 else if (shdr[i].sh_type == SHT_PROGBITS)
708 ef->progtab[pb].name = "<<PROGBITS>>";
709 else
710 ef->progtab[pb].name = "<<NOBITS>>";
711 #if 0
712 if (ef->progtab[pb].name != NULL &&
713 !strcmp(ef->progtab[pb].name, "set_pcpu"))
714 ef->progtab[pb].addr =
715 dpcpu_alloc(shdr[i].sh_size);
716 #ifdef VIMAGE
717 else if (ef->progtab[pb].name != NULL &&
718 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
719 ef->progtab[pb].addr =
720 vnet_data_alloc(shdr[i].sh_size);
721 #endif
722 else
723 #endif
724 ef->progtab[pb].addr =
725 (void *)(uintptr_t) mapbase;
726 if (ef->progtab[pb].addr == NULL) {
727 error = ENOSPC;
728 goto out;
729 }
730 ef->progtab[pb].size = shdr[i].sh_size;
731 ef->progtab[pb].sec = i;
732 if (shdr[i].sh_type == SHT_PROGBITS) {
733 error = vn_rdwr(UIO_READ, vp,
734 ef->progtab[pb].addr,
735 shdr[i].sh_size, shdr[i].sh_offset,
736 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred,
737 &resid);
738 if (error)
739 goto out;
740 if (resid != 0) {
741 error = EINVAL;
742 goto out;
743 }
744 #if 0
745 /* Initialize the per-cpu or vnet area. */
746 if (ef->progtab[pb].addr != (void *)mapbase &&
747 !strcmp(ef->progtab[pb].name, "set_pcpu"))
748 dpcpu_copy(ef->progtab[pb].addr,
749 shdr[i].sh_size);
750 #ifdef VIMAGE
751 else if (ef->progtab[pb].addr !=
752 (void *)mapbase &&
753 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
754 vnet_data_copy(ef->progtab[pb].addr,
755 shdr[i].sh_size);
756 #endif
757 #endif
758 } else
759 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
760
761 /* Update all symbol values with the offset. */
762 for (j = 0; j < ef->ddbsymcnt; j++) {
763 es = &ef->ddbsymtab[j];
764 if (es->st_shndx != i)
765 continue;
766 es->st_value += (Elf_Addr) ef->progtab[pb].addr;
767 }
768 mapbase += shdr[i].sh_size;
769 pb++;
770 break;
771 case SHT_REL:
772 ef->reltab[rl].rel = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
773 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
774 ef->reltab[rl].sec = shdr[i].sh_info;
775 error = vn_rdwr(UIO_READ, vp,
776 (void *)ef->reltab[rl].rel,
777 shdr[i].sh_size, shdr[i].sh_offset,
778 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
779 if (error)
780 goto out;
781 if (resid != 0) {
782 error = EINVAL;
783 goto out;
784 }
785 rl++;
786 break;
787 case SHT_RELA:
788 ef->relatab[ra].rela = kmalloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
789 ef->relatab[ra].nrela = shdr[i].sh_size / sizeof(Elf_Rela);
790 ef->relatab[ra].sec = shdr[i].sh_info;
791 error = vn_rdwr(UIO_READ, vp,
792 (void *)ef->relatab[ra].rela,
793 shdr[i].sh_size, shdr[i].sh_offset,
794 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
795 if (error)
796 goto out;
797 if (resid != 0) {
798 error = EINVAL;
799 goto out;
800 }
801 ra++;
802 break;
803 }
804 }
805 if (pb != ef->nprogtab)
806 panic("lost progbits");
807 if (rl != ef->nreltab)
808 panic("lost reltab");
809 if (ra != ef->nrelatab)
810 panic("lost relatab");
811 if (mapbase != (vm_offset_t) ef->address + mapsize)
812 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)",
813 mapbase, ef->address, mapsize,
814 (vm_offset_t) ef->address + mapsize);
815
816 /* Local intra-module relocations */
817 link_elf_obj_reloc_local(lf);
818
819 /* Pull in dependencies */
820 error = linker_load_dependencies(lf);
821 if (error)
822 goto out;
823
824 /* External relocations */
825 error = relocate_file(lf);
826 if (error)
827 goto out;
828
829 *result = lf;
830
831 out:
832 if (error && lf)
833 linker_file_unload(lf /*, LINKER_UNLOAD_FORCE */);
834 if (hdr)
835 kfree(hdr, M_LINKER);
836 vn_unlock(vp);
837 vn_close(vp, FREAD, NULL);
838
839 return error;
840 }
841
842 static void
843 link_elf_obj_unload_file(linker_file_t file)
844 {
845 elf_file_t ef = file->priv;
846 int i;
847
848 if (ef->progtab) {
849 for (i = 0; i < ef->nprogtab; i++) {
850 if (ef->progtab[i].size == 0)
851 continue;
852 if (ef->progtab[i].name == NULL)
853 continue;
854 #if 0
855 if (!strcmp(ef->progtab[i].name, "set_pcpu"))
856 dpcpu_free(ef->progtab[i].addr,
857 ef->progtab[i].size);
858 #ifdef VIMAGE
859 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
860 vnet_data_free(ef->progtab[i].addr,
861 ef->progtab[i].size);
862 #endif
863 #endif
864 }
865 }
866 if (ef->preloaded) {
867 if (ef->reltab)
868 kfree(ef->reltab, M_LINKER);
869 if (ef->relatab)
870 kfree(ef->relatab, M_LINKER);
871 if (ef->progtab)
872 kfree(ef->progtab, M_LINKER);
873 if (ef->ctftab)
874 kfree(ef->ctftab, M_LINKER);
875 if (ef->ctfoff)
876 kfree(ef->ctfoff, M_LINKER);
877 if (ef->typoff)
878 kfree(ef->typoff, M_LINKER);
879 if (file->filename != NULL)
880 preload_delete_name(file->filename);
881 kfree(ef, M_LINKER);
882 /* XXX reclaim module memory? */
883 return;
884 }
885
886 for (i = 0; i < ef->nreltab; i++)
887 if (ef->reltab[i].rel)
888 kfree(ef->reltab[i].rel, M_LINKER);
889 for (i = 0; i < ef->nrelatab; i++)
890 if (ef->relatab[i].rela)
891 kfree(ef->relatab[i].rela, M_LINKER);
892 if (ef->reltab)
893 kfree(ef->reltab, M_LINKER);
894 if (ef->relatab)
895 kfree(ef->relatab, M_LINKER);
896 if (ef->progtab)
897 kfree(ef->progtab, M_LINKER);
898
899 if (ef->object) {
900 #if defined(__x86_64__) && defined(_KERNEL_VIRTUAL)
901 vkernel_module_memory_free((vm_offset_t)ef->address, ef->bytes);
902 #else
903 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
904 (vm_offset_t) ef->address +
905 (ef->object->size << PAGE_SHIFT));
906 #endif
907 vm_object_deallocate(ef->object);
908 ef->object = NULL;
909 }
910 if (ef->e_shdr)
911 kfree(ef->e_shdr, M_LINKER);
912 if (ef->ddbsymtab)
913 kfree(ef->ddbsymtab, M_LINKER);
914 if (ef->ddbstrtab)
915 kfree(ef->ddbstrtab, M_LINKER);
916 if (ef->shstrtab)
917 kfree(ef->shstrtab, M_LINKER);
918 if (ef->ctftab)
919 kfree(ef->ctftab, M_LINKER);
920 if (ef->ctfoff)
921 kfree(ef->ctfoff, M_LINKER);
922 if (ef->typoff)
923 kfree(ef->typoff, M_LINKER);
924 kfree(ef, M_LINKER);
925 }
926
927 static const char *
928 symbol_name(elf_file_t ef, Elf_Size r_info)
929 {
930 const Elf_Sym *ref;
931
932 if (ELF_R_SYM(r_info)) {
933 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
934 return ef->ddbstrtab + ref->st_name;
935 } else
936 return NULL;
937 }
938
939 static Elf_Addr
940 findbase(elf_file_t ef, int sec)
941 {
942 int i;
943 Elf_Addr base = 0;
944
945 for (i = 0; i < ef->nprogtab; i++) {
946 if (sec == ef->progtab[i].sec) {
947 base = (Elf_Addr)ef->progtab[i].addr;
948 break;
949 }
950 }
951 return base;
952 }
953
954 static int
955 relocate_file(linker_file_t lf)
956 {
957 elf_file_t ef = lf->priv;
958 const Elf_Rel *rellim;
959 const Elf_Rel *rel;
960 const Elf_Rela *relalim;
961 const Elf_Rela *rela;
962 const char *symname;
963 const Elf_Sym *sym;
964 int i;
965 Elf_Size symidx;
966 Elf_Addr base;
967
968 /* Perform relocations without addend if there are any: */
969 for (i = 0; i < ef->nreltab; i++) {
970 rel = ef->reltab[i].rel;
971 if (rel == NULL)
972 panic("lost a reltab!");
973 rellim = rel + ef->reltab[i].nrel;
974 base = findbase(ef, ef->reltab[i].sec);
975 if (base == 0)
976 panic("lost base for reltab");
977 for ( ; rel < rellim; rel++) {
978 symidx = ELF_R_SYM(rel->r_info);
979 if (symidx >= ef->ddbsymcnt)
980 continue;
981 sym = ef->ddbsymtab + symidx;
982 /* Local relocs are already done */
983 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
984 continue;
985 if (elf_reloc(lf, base, rel, ELF_RELOC_REL,
986 elf_obj_lookup)) {
987 symname = symbol_name(ef, rel->r_info);
988 kprintf("link_elf_obj_obj: symbol %s undefined\n",
989 symname);
990 return ENOENT;
991 }
992 }
993 }
994
995 /* Perform relocations with addend if there are any: */
996 for (i = 0; i < ef->nrelatab; i++) {
997 rela = ef->relatab[i].rela;
998 if (rela == NULL)
999 panic("lost a relatab!");
1000 relalim = rela + ef->relatab[i].nrela;
1001 base = findbase(ef, ef->relatab[i].sec);
1002 if (base == 0)
1003 panic("lost base for relatab");
1004 for ( ; rela < relalim; rela++) {
1005 symidx = ELF_R_SYM(rela->r_info);
1006 if (symidx >= ef->ddbsymcnt)
1007 continue;
1008 sym = ef->ddbsymtab + symidx;
1009 /* Local relocs are already done */
1010 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1011 continue;
1012 if (elf_reloc(lf, base, rela, ELF_RELOC_RELA,
1013 elf_obj_lookup)) {
1014 symname = symbol_name(ef, rela->r_info);
1015 kprintf("link_elf_obj_obj: symbol %s undefined\n",
1016 symname);
1017 return ENOENT;
1018 }
1019 }
1020 }
1021
1022 return 0;
1023 }
1024
1025 static int
1026 link_elf_obj_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1027 {
1028 elf_file_t ef = lf->priv;
1029 const Elf_Sym *symp;
1030 const char *strp;
1031 int i;
1032
1033 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1034 strp = ef->ddbstrtab + symp->st_name;
1035 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1036 *sym = (c_linker_sym_t) symp;
1037 return 0;
1038 }
1039 }
1040 return ENOENT;
1041 }
1042
1043 static int
1044 link_elf_obj_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1045 linker_symval_t *symval)
1046 {
1047 elf_file_t ef = lf->priv;
1048 const Elf_Sym *es = (const Elf_Sym*) sym;
1049
1050 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1051 symval->name = ef->ddbstrtab + es->st_name;
1052 symval->value = (caddr_t)es->st_value;
1053 symval->size = es->st_size;
1054 return 0;
1055 }
1056 return ENOENT;
1057 }
1058
1059 static int
1060 link_elf_obj_search_symbol(linker_file_t lf, caddr_t value,
1061 c_linker_sym_t *sym, long *diffp)
1062 {
1063 elf_file_t ef = lf->priv;
1064 u_long off = (uintptr_t) (void *) value;
1065 u_long diff = off;
1066 u_long st_value;
1067 const Elf_Sym *es;
1068 const Elf_Sym *best = NULL;
1069 int i;
1070
1071 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1072 if (es->st_name == 0)
1073 continue;
1074 st_value = es->st_value;
1075 if (off >= st_value) {
1076 if (off - st_value < diff) {
1077 diff = off - st_value;
1078 best = es;
1079 if (diff == 0)
1080 break;
1081 } else if (off - st_value == diff) {
1082 best = es;
1083 }
1084 }
1085 }
1086 if (best == NULL)
1087 *diffp = off;
1088 else
1089 *diffp = diff;
1090 *sym = (c_linker_sym_t) best;
1091
1092 return 0;
1093 }
1094
1095 /*
1096 * Look up a linker set on an ELF system.
1097 */
1098 static int
1099 link_elf_obj_lookup_set(linker_file_t lf, const char *name,
1100 void ***startp, void ***stopp, int *countp)
1101 {
1102 elf_file_t ef = lf->priv;
1103 void **start, **stop;
1104 int i, count;
1105
1106 /* Relative to section number */
1107 for (i = 0; i < ef->nprogtab; i++) {
1108 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1109 strcmp(ef->progtab[i].name + 4, name) == 0) {
1110 start = (void **)ef->progtab[i].addr;
1111 stop = (void **)((char *)ef->progtab[i].addr +
1112 ef->progtab[i].size);
1113 count = stop - start;
1114 if (startp)
1115 *startp = start;
1116 if (stopp)
1117 *stopp = stop;
1118 if (countp)
1119 *countp = count;
1120 return (0);
1121 }
1122 }
1123 return (ESRCH);
1124 }
1125
1126 /*
1127 * Symbol lookup function that can be used when the symbol index is known (ie
1128 * in relocations). It uses the symbol index instead of doing a fully fledged
1129 * hash table based lookup when such is valid. For example for local symbols.
1130 * This is not only more efficient, it's also more correct. It's not always
1131 * the case that the symbol can be found through the hash table.
1132 */
1133 static int
1134 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result)
1135 {
1136 elf_file_t ef = lf->priv;
1137 const Elf_Sym *sym;
1138 const char *symbol;
1139
1140 /* Don't even try to lookup the symbol if the index is bogus. */
1141 if (symidx >= ef->ddbsymcnt)
1142 return (ENOENT);
1143
1144 sym = ef->ddbsymtab + symidx;
1145
1146 /* Quick answer if there is a definition included. */
1147 if (sym->st_shndx != SHN_UNDEF) {
1148 *result = sym->st_value;
1149 return (0);
1150 }
1151
1152 /* If we get here, then it is undefined and needs a lookup. */
1153 switch (ELF_ST_BIND(sym->st_info)) {
1154 case STB_LOCAL:
1155 /* Local, but undefined? huh? */
1156 return (ENOENT);
1157
1158 case STB_GLOBAL:
1159 /* Relative to Data or Function name */
1160 symbol = ef->ddbstrtab + sym->st_name;
1161
1162 /* Force a lookup failure if the symbol name is bogus. */
1163 if (*symbol == 0)
1164 return (ENOENT);
1165 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result));
1166
1167 case STB_WEAK:
1168 kprintf("link_elf_obj_obj: Weak symbols not supported\n");
1169 return (ENOENT);
1170
1171 default:
1172 return (ENOENT);
1173 }
1174 }
1175
1176 static void
1177 link_elf_obj_fix_link_set(elf_file_t ef)
1178 {
1179 static const char startn[] = "__start_";
1180 static const char stopn[] = "__stop_";
1181 Elf_Sym *sym;
1182 const char *sym_name, *linkset_name;
1183 Elf_Addr startp, stopp;
1184 Elf_Size symidx;
1185 int start, i;
1186
1187 startp = stopp = 0;
1188 for (symidx = 1 /* zero entry is special */;
1189 symidx < ef->ddbsymcnt; symidx++) {
1190 sym = ef->ddbsymtab + symidx;
1191 if (sym->st_shndx != SHN_UNDEF)
1192 continue;
1193
1194 sym_name = ef->ddbstrtab + sym->st_name;
1195 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1196 start = 1;
1197 linkset_name = sym_name + sizeof(startn) - 1;
1198 }
1199 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1200 start = 0;
1201 linkset_name = sym_name + sizeof(stopn) - 1;
1202 }
1203 else
1204 continue;
1205
1206 for (i = 0; i < ef->nprogtab; i++) {
1207 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1208 startp = (Elf_Addr)ef->progtab[i].addr;
1209 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1210 break;
1211 }
1212 }
1213 if (i == ef->nprogtab)
1214 continue;
1215
1216 sym->st_value = start ? startp : stopp;
1217 sym->st_shndx = i;
1218 }
1219 }
1220
1221 static void
1222 link_elf_obj_reloc_local(linker_file_t lf)
1223 {
1224 elf_file_t ef = lf->priv;
1225 const Elf_Rel *rellim;
1226 const Elf_Rel *rel;
1227 const Elf_Rela *relalim;
1228 const Elf_Rela *rela;
1229 const Elf_Sym *sym;
1230 Elf_Addr base;
1231 int i;
1232 Elf_Size symidx;
1233
1234 link_elf_obj_fix_link_set(ef);
1235
1236 /* Perform relocations without addend if there are any: */
1237 for (i = 0; i < ef->nreltab; i++) {
1238 rel = ef->reltab[i].rel;
1239 if (rel == NULL)
1240 panic("lost a reltab!");
1241 rellim = rel + ef->reltab[i].nrel;
1242 base = findbase(ef, ef->reltab[i].sec);
1243 if (base == 0)
1244 panic("lost base for reltab");
1245 for ( ; rel < rellim; rel++) {
1246 symidx = ELF_R_SYM(rel->r_info);
1247 if (symidx >= ef->ddbsymcnt)
1248 continue;
1249 sym = ef->ddbsymtab + symidx;
1250 /* Only do local relocs */
1251 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1252 continue;
1253 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1254 elf_obj_lookup);
1255 }
1256 }
1257
1258 /* Perform relocations with addend if there are any: */
1259 for (i = 0; i < ef->nrelatab; i++) {
1260 rela = ef->relatab[i].rela;
1261 if (rela == NULL)
1262 panic("lost a relatab!");
1263 relalim = rela + ef->relatab[i].nrela;
1264 base = findbase(ef, ef->relatab[i].sec);
1265 if (base == 0)
1266 panic("lost base for relatab");
1267 for ( ; rela < relalim; rela++) {
1268 symidx = ELF_R_SYM(rela->r_info);
1269 if (symidx >= ef->ddbsymcnt)
1270 continue;
1271 sym = ef->ddbsymtab + symidx;
1272 /* Only do local relocs */
1273 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1274 continue;
1275 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1276 elf_obj_lookup);
1277 }
1278 }
1279 }
DragonFly BSD