xref: /freebsd/sys/kern/link_elf_obj.c (revision ddd5b8e9b4d8957fce018c520657cdfa4ecffad3)
1 /*-
2  * Copyright (c) 1998-2000 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 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include "opt_ddb.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/mount.h>
40 #include <sys/proc.h>
41 #include <sys/namei.h>
42 #include <sys/fcntl.h>
43 #include <sys/vnode.h>
44 #include <sys/linker.h>
45 
46 #include <machine/elf.h>
47 
48 #include <net/vnet.h>
49 
50 #include <security/mac/mac_framework.h>
51 
52 #include <vm/vm.h>
53 #include <vm/vm_param.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_kern.h>
56 #include <vm/vm_extern.h>
57 #include <vm/pmap.h>
58 #include <vm/vm_map.h>
59 
60 #include <sys/link_elf.h>
61 
62 #ifdef DDB_CTF
63 #include <net/zlib.h>
64 #endif
65 
66 #include "linker_if.h"
67 
68 typedef struct {
69 	void		*addr;
70 	Elf_Off		size;
71 	int		flags;
72 	int		sec;	/* Original section */
73 	char		*name;
74 } Elf_progent;
75 
76 typedef struct {
77 	Elf_Rel		*rel;
78 	int		nrel;
79 	int		sec;
80 } Elf_relent;
81 
82 typedef struct {
83 	Elf_Rela	*rela;
84 	int		nrela;
85 	int		sec;
86 } Elf_relaent;
87 
88 
89 typedef struct elf_file {
90 	struct linker_file lf;		/* Common fields */
91 
92 	int		preloaded;
93 	caddr_t		address;	/* Relocation address */
94 	vm_object_t	object;		/* VM object to hold file pages */
95 	Elf_Shdr	*e_shdr;
96 
97 	Elf_progent	*progtab;
98 	int		nprogtab;
99 
100 	Elf_relaent	*relatab;
101 	int		nrelatab;
102 
103 	Elf_relent	*reltab;
104 	int		nreltab;
105 
106 	Elf_Sym		*ddbsymtab;	/* The symbol table we are using */
107 	long		ddbsymcnt;	/* Number of symbols */
108 	caddr_t		ddbstrtab;	/* String table */
109 	long		ddbstrcnt;	/* number of bytes in string table */
110 
111 	caddr_t		shstrtab;	/* Section name string table */
112 	long		shstrcnt;	/* number of bytes in string table */
113 
114 	caddr_t		ctftab;		/* CTF table */
115 	long		ctfcnt;		/* number of bytes in CTF table */
116 	caddr_t		ctfoff;		/* CTF offset table */
117 	caddr_t		typoff;		/* Type offset table */
118 	long		typlen;		/* Number of type entries. */
119 
120 } *elf_file_t;
121 
122 #include <kern/kern_ctf.c>
123 
124 static int	link_elf_link_preload(linker_class_t cls,
125 		    const char *, linker_file_t *);
126 static int	link_elf_link_preload_finish(linker_file_t);
127 static int	link_elf_load_file(linker_class_t, const char *, linker_file_t *);
128 static int	link_elf_lookup_symbol(linker_file_t, const char *,
129 		    c_linker_sym_t *);
130 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
131 		    linker_symval_t *);
132 static int	link_elf_search_symbol(linker_file_t, caddr_t value,
133 		    c_linker_sym_t *sym, long *diffp);
134 
135 static void	link_elf_unload_file(linker_file_t);
136 static int	link_elf_lookup_set(linker_file_t, const char *,
137 		    void ***, void ***, int *);
138 static int	link_elf_each_function_name(linker_file_t,
139 		    int (*)(const char *, void *), void *);
140 static int	link_elf_each_function_nameval(linker_file_t,
141 				linker_function_nameval_callback_t,
142 				void *);
143 static void	link_elf_reloc_local(linker_file_t);
144 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
145 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
146 
147 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
148 
149 static kobj_method_t link_elf_methods[] = {
150 	KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
151 	KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
152 	KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
153 	KOBJMETHOD(linker_unload,		link_elf_unload_file),
154 	KOBJMETHOD(linker_load_file,		link_elf_load_file),
155 	KOBJMETHOD(linker_link_preload,		link_elf_link_preload),
156 	KOBJMETHOD(linker_link_preload_finish,	link_elf_link_preload_finish),
157 	KOBJMETHOD(linker_lookup_set,		link_elf_lookup_set),
158 	KOBJMETHOD(linker_each_function_name,	link_elf_each_function_name),
159 	KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
160 	KOBJMETHOD(linker_ctf_get,		link_elf_ctf_get),
161 	KOBJMETHOD(linker_symtab_get, 		link_elf_symtab_get),
162 	KOBJMETHOD(linker_strtab_get, 		link_elf_strtab_get),
163 	{ 0, 0 }
164 };
165 
166 static struct linker_class link_elf_class = {
167 #if ELF_TARG_CLASS == ELFCLASS32
168 	"elf32_obj",
169 #else
170 	"elf64_obj",
171 #endif
172 	link_elf_methods, sizeof(struct elf_file)
173 };
174 
175 static int	relocate_file(elf_file_t ef);
176 
177 static void
178 link_elf_error(const char *filename, const char *s)
179 {
180 	if (filename == NULL)
181 		printf("kldload: %s\n", s);
182 	else
183 		printf("kldload: %s: %s\n", filename, s);
184 }
185 
186 static void
187 link_elf_init(void *arg)
188 {
189 
190 	linker_add_class(&link_elf_class);
191 }
192 
193 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
194 
195 static int
196 link_elf_link_preload(linker_class_t cls, const char *filename,
197     linker_file_t *result)
198 {
199 	Elf_Ehdr *hdr;
200 	Elf_Shdr *shdr;
201 	Elf_Sym *es;
202 	void *modptr, *baseptr, *sizeptr;
203 	char *type;
204 	elf_file_t ef;
205 	linker_file_t lf;
206 	Elf_Addr off;
207 	int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
208 
209 	/* Look to see if we have the file preloaded */
210 	modptr = preload_search_by_name(filename);
211 	if (modptr == NULL)
212 		return ENOENT;
213 
214 	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
215 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
216 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
217 	hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
218 	    MODINFOMD_ELFHDR);
219 	shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
220 	    MODINFOMD_SHDR);
221 	if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
222 	    " obj module") != 0 &&
223 	    strcmp(type, "elf obj module") != 0)) {
224 		return (EFTYPE);
225 	}
226 	if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
227 	    shdr == NULL)
228 		return (EINVAL);
229 
230 	lf = linker_make_file(filename, &link_elf_class);
231 	if (lf == NULL)
232 		return (ENOMEM);
233 
234 	ef = (elf_file_t)lf;
235 	ef->preloaded = 1;
236 	ef->address = *(caddr_t *)baseptr;
237 	lf->address = *(caddr_t *)baseptr;
238 	lf->size = *(size_t *)sizeptr;
239 
240 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
241 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
242 	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||
243 	    hdr->e_version != EV_CURRENT ||
244 	    hdr->e_type != ET_REL ||
245 	    hdr->e_machine != ELF_TARG_MACH) {
246 		error = EFTYPE;
247 		goto out;
248 	}
249 	ef->e_shdr = shdr;
250 
251 	/* Scan the section header for information and table sizing. */
252 	symtabindex = -1;
253 	symstrindex = -1;
254 	for (i = 0; i < hdr->e_shnum; i++) {
255 		switch (shdr[i].sh_type) {
256 		case SHT_PROGBITS:
257 		case SHT_NOBITS:
258 			ef->nprogtab++;
259 			break;
260 		case SHT_SYMTAB:
261 			symtabindex = i;
262 			symstrindex = shdr[i].sh_link;
263 			break;
264 		case SHT_REL:
265 			ef->nreltab++;
266 			break;
267 		case SHT_RELA:
268 			ef->nrelatab++;
269 			break;
270 		}
271 	}
272 
273 	shstrindex = hdr->e_shstrndx;
274 	if (ef->nprogtab == 0 || symstrindex < 0 ||
275 	    symstrindex >= hdr->e_shnum ||
276 	    shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
277 	    shstrindex >= hdr->e_shnum ||
278 	    shdr[shstrindex].sh_type != SHT_STRTAB) {
279 		printf("%s: bad/missing section headers\n", filename);
280 		error = ENOEXEC;
281 		goto out;
282 	}
283 
284 	/* Allocate space for tracking the load chunks */
285 	if (ef->nprogtab != 0)
286 		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
287 		    M_LINKER, M_WAITOK | M_ZERO);
288 	if (ef->nreltab != 0)
289 		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
290 		    M_LINKER, M_WAITOK | M_ZERO);
291 	if (ef->nrelatab != 0)
292 		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
293 		    M_LINKER, M_WAITOK | M_ZERO);
294 	if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
295 	    (ef->nreltab != 0 && ef->reltab == NULL) ||
296 	    (ef->nrelatab != 0 && ef->relatab == NULL)) {
297 		error = ENOMEM;
298 		goto out;
299 	}
300 
301 	/* XXX, relocate the sh_addr fields saved by the loader. */
302 	off = 0;
303 	for (i = 0; i < hdr->e_shnum; i++) {
304 		if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
305 			off = shdr[i].sh_addr;
306 	}
307 	for (i = 0; i < hdr->e_shnum; i++) {
308 		if (shdr[i].sh_addr != 0)
309 			shdr[i].sh_addr = shdr[i].sh_addr - off +
310 			    (Elf_Addr)ef->address;
311 	}
312 
313 	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
314 	ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
315 	ef->ddbstrcnt = shdr[symstrindex].sh_size;
316 	ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
317 	ef->shstrcnt = shdr[shstrindex].sh_size;
318 	ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
319 
320 	/* Now fill out progtab and the relocation tables. */
321 	pb = 0;
322 	rl = 0;
323 	ra = 0;
324 	for (i = 0; i < hdr->e_shnum; i++) {
325 		switch (shdr[i].sh_type) {
326 		case SHT_PROGBITS:
327 		case SHT_NOBITS:
328 			ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
329 			if (shdr[i].sh_type == SHT_PROGBITS)
330 				ef->progtab[pb].name = "<<PROGBITS>>";
331 			else
332 				ef->progtab[pb].name = "<<NOBITS>>";
333 			ef->progtab[pb].size = shdr[i].sh_size;
334 			ef->progtab[pb].sec = i;
335 			if (ef->shstrtab && shdr[i].sh_name != 0)
336 				ef->progtab[pb].name =
337 				    ef->shstrtab + shdr[i].sh_name;
338 			if (ef->progtab[pb].name != NULL &&
339 			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
340 				void *dpcpu;
341 
342 				dpcpu = dpcpu_alloc(shdr[i].sh_size);
343 				if (dpcpu == NULL) {
344 					error = ENOSPC;
345 					goto out;
346 				}
347 				memcpy(dpcpu, ef->progtab[pb].addr,
348 				    ef->progtab[pb].size);
349 				dpcpu_copy(dpcpu, shdr[i].sh_size);
350 				ef->progtab[pb].addr = dpcpu;
351 #ifdef VIMAGE
352 			} else if (ef->progtab[pb].name != NULL &&
353 			    !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
354 				void *vnet_data;
355 
356 				vnet_data = vnet_data_alloc(shdr[i].sh_size);
357 				if (vnet_data == NULL) {
358 					error = ENOSPC;
359 					goto out;
360 				}
361 				memcpy(vnet_data, ef->progtab[pb].addr,
362 				    ef->progtab[pb].size);
363 				vnet_data_copy(vnet_data, shdr[i].sh_size);
364 				ef->progtab[pb].addr = vnet_data;
365 #endif
366 			}
367 
368 			/* Update all symbol values with the offset. */
369 			for (j = 0; j < ef->ddbsymcnt; j++) {
370 				es = &ef->ddbsymtab[j];
371 				if (es->st_shndx != i)
372 					continue;
373 				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
374 			}
375 			pb++;
376 			break;
377 		case SHT_REL:
378 			ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
379 			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
380 			ef->reltab[rl].sec = shdr[i].sh_info;
381 			rl++;
382 			break;
383 		case SHT_RELA:
384 			ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
385 			ef->relatab[ra].nrela =
386 			    shdr[i].sh_size / sizeof(Elf_Rela);
387 			ef->relatab[ra].sec = shdr[i].sh_info;
388 			ra++;
389 			break;
390 		}
391 	}
392 	if (pb != ef->nprogtab)
393 		panic("lost progbits");
394 	if (rl != ef->nreltab)
395 		panic("lost reltab");
396 	if (ra != ef->nrelatab)
397 		panic("lost relatab");
398 
399 	/* Local intra-module relocations */
400 	link_elf_reloc_local(lf);
401 
402 	*result = lf;
403 	return (0);
404 
405 out:
406 	/* preload not done this way */
407 	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
408 	return (error);
409 }
410 
411 static int
412 link_elf_link_preload_finish(linker_file_t lf)
413 {
414 	elf_file_t ef;
415 	int error;
416 
417 	ef = (elf_file_t)lf;
418 	error = relocate_file(ef);
419 	if (error)
420 		return error;
421 
422 	/* Notify MD code that a module is being loaded. */
423 	error = elf_cpu_load_file(lf);
424 	if (error)
425 		return (error);
426 
427 	return (0);
428 }
429 
430 static int
431 link_elf_load_file(linker_class_t cls, const char *filename,
432     linker_file_t *result)
433 {
434 	struct nameidata nd;
435 	struct thread *td = curthread;	/* XXX */
436 	Elf_Ehdr *hdr;
437 	Elf_Shdr *shdr;
438 	Elf_Sym *es;
439 	int nbytes, i, j;
440 	vm_offset_t mapbase;
441 	size_t mapsize;
442 	int error = 0;
443 	ssize_t resid;
444 	int flags;
445 	elf_file_t ef;
446 	linker_file_t lf;
447 	int symtabindex;
448 	int symstrindex;
449 	int shstrindex;
450 	int nsym;
451 	int pb, rl, ra;
452 	int alignmask;
453 
454 	shdr = NULL;
455 	lf = NULL;
456 	mapsize = 0;
457 	hdr = NULL;
458 
459 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
460 	flags = FREAD;
461 	error = vn_open(&nd, &flags, 0, NULL);
462 	if (error)
463 		return error;
464 	NDFREE(&nd, NDF_ONLY_PNBUF);
465 	if (nd.ni_vp->v_type != VREG) {
466 		error = ENOEXEC;
467 		goto out;
468 	}
469 #ifdef MAC
470 	error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
471 	if (error) {
472 		goto out;
473 	}
474 #endif
475 
476 	/* Read the elf header from the file. */
477 	hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
478 	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
479 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
480 	    &resid, td);
481 	if (error)
482 		goto out;
483 	if (resid != 0){
484 		error = ENOEXEC;
485 		goto out;
486 	}
487 
488 	if (!IS_ELF(*hdr)) {
489 		error = ENOEXEC;
490 		goto out;
491 	}
492 
493 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
494 	    || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
495 		link_elf_error(filename, "Unsupported file layout");
496 		error = ENOEXEC;
497 		goto out;
498 	}
499 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT
500 	    || hdr->e_version != EV_CURRENT) {
501 		link_elf_error(filename, "Unsupported file version");
502 		error = ENOEXEC;
503 		goto out;
504 	}
505 	if (hdr->e_type != ET_REL) {
506 		error = ENOSYS;
507 		goto out;
508 	}
509 	if (hdr->e_machine != ELF_TARG_MACH) {
510 		link_elf_error(filename, "Unsupported machine");
511 		error = ENOEXEC;
512 		goto out;
513 	}
514 
515 	lf = linker_make_file(filename, &link_elf_class);
516 	if (!lf) {
517 		error = ENOMEM;
518 		goto out;
519 	}
520 	ef = (elf_file_t) lf;
521 	ef->nprogtab = 0;
522 	ef->e_shdr = 0;
523 	ef->nreltab = 0;
524 	ef->nrelatab = 0;
525 
526 	/* Allocate and read in the section header */
527 	nbytes = hdr->e_shnum * hdr->e_shentsize;
528 	if (nbytes == 0 || hdr->e_shoff == 0 ||
529 	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
530 		error = ENOEXEC;
531 		goto out;
532 	}
533 	shdr = malloc(nbytes, M_LINKER, M_WAITOK);
534 	ef->e_shdr = shdr;
535 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
536 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
537 	if (error)
538 		goto out;
539 	if (resid) {
540 		error = ENOEXEC;
541 		goto out;
542 	}
543 
544 	/* Scan the section header for information and table sizing. */
545 	nsym = 0;
546 	symtabindex = -1;
547 	symstrindex = -1;
548 	for (i = 0; i < hdr->e_shnum; i++) {
549 		if (shdr[i].sh_size == 0)
550 			continue;
551 		switch (shdr[i].sh_type) {
552 		case SHT_PROGBITS:
553 		case SHT_NOBITS:
554 			ef->nprogtab++;
555 			break;
556 		case SHT_SYMTAB:
557 			nsym++;
558 			symtabindex = i;
559 			symstrindex = shdr[i].sh_link;
560 			break;
561 		case SHT_REL:
562 			ef->nreltab++;
563 			break;
564 		case SHT_RELA:
565 			ef->nrelatab++;
566 			break;
567 		case SHT_STRTAB:
568 			break;
569 		}
570 	}
571 	if (ef->nprogtab == 0) {
572 		link_elf_error(filename, "file has no contents");
573 		error = ENOEXEC;
574 		goto out;
575 	}
576 	if (nsym != 1) {
577 		/* Only allow one symbol table for now */
578 		link_elf_error(filename, "file has no valid symbol table");
579 		error = ENOEXEC;
580 		goto out;
581 	}
582 	if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
583 	    shdr[symstrindex].sh_type != SHT_STRTAB) {
584 		link_elf_error(filename, "file has invalid symbol strings");
585 		error = ENOEXEC;
586 		goto out;
587 	}
588 
589 	/* Allocate space for tracking the load chunks */
590 	if (ef->nprogtab != 0)
591 		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
592 		    M_LINKER, M_WAITOK | M_ZERO);
593 	if (ef->nreltab != 0)
594 		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
595 		    M_LINKER, M_WAITOK | M_ZERO);
596 	if (ef->nrelatab != 0)
597 		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
598 		    M_LINKER, M_WAITOK | M_ZERO);
599 
600 	if (symtabindex == -1)
601 		panic("lost symbol table index");
602 	/* Allocate space for and load the symbol table */
603 	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
604 	ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
605 	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
606 	    shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
607 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
608 	    &resid, td);
609 	if (error)
610 		goto out;
611 	if (resid != 0){
612 		error = EINVAL;
613 		goto out;
614 	}
615 
616 	if (symstrindex == -1)
617 		panic("lost symbol string index");
618 	/* Allocate space for and load the symbol strings */
619 	ef->ddbstrcnt = shdr[symstrindex].sh_size;
620 	ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
621 	error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
622 	    shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
623 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
624 	    &resid, td);
625 	if (error)
626 		goto out;
627 	if (resid != 0){
628 		error = EINVAL;
629 		goto out;
630 	}
631 
632 	/* Do we have a string table for the section names?  */
633 	shstrindex = -1;
634 	if (hdr->e_shstrndx != 0 &&
635 	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
636 		shstrindex = hdr->e_shstrndx;
637 		ef->shstrcnt = shdr[shstrindex].sh_size;
638 		ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
639 		    M_WAITOK);
640 		error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
641 		    shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
642 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
643 		    &resid, td);
644 		if (error)
645 			goto out;
646 		if (resid != 0){
647 			error = EINVAL;
648 			goto out;
649 		}
650 	}
651 
652 	/* Size up code/data(progbits) and bss(nobits). */
653 	alignmask = 0;
654 	for (i = 0; i < hdr->e_shnum; i++) {
655 		if (shdr[i].sh_size == 0)
656 			continue;
657 		switch (shdr[i].sh_type) {
658 		case SHT_PROGBITS:
659 		case SHT_NOBITS:
660 			alignmask = shdr[i].sh_addralign - 1;
661 			mapsize += alignmask;
662 			mapsize &= ~alignmask;
663 			mapsize += shdr[i].sh_size;
664 			break;
665 		}
666 	}
667 
668 	/*
669 	 * We know how much space we need for the text/data/bss/etc.
670 	 * This stuff needs to be in a single chunk so that profiling etc
671 	 * can get the bounds and gdb can associate offsets with modules
672 	 */
673 	ef->object = vm_object_allocate(OBJT_DEFAULT,
674 	    round_page(mapsize) >> PAGE_SHIFT);
675 	if (ef->object == NULL) {
676 		error = ENOMEM;
677 		goto out;
678 	}
679 	ef->address = (caddr_t) vm_map_min(kernel_map);
680 
681 	/*
682 	 * In order to satisfy amd64's architectural requirements on the
683 	 * location of code and data in the kernel's address space, request a
684 	 * mapping that is above the kernel.
685 	 */
686 #ifdef __amd64__
687 	mapbase = KERNBASE;
688 #else
689 	mapbase = VM_MIN_KERNEL_ADDRESS;
690 #endif
691 	error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
692 	    round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
693 	if (error) {
694 		vm_object_deallocate(ef->object);
695 		ef->object = 0;
696 		goto out;
697 	}
698 
699 	/* Wire the pages */
700 	error = vm_map_wire(kernel_map, mapbase,
701 	    mapbase + round_page(mapsize),
702 	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
703 	if (error != KERN_SUCCESS) {
704 		error = ENOMEM;
705 		goto out;
706 	}
707 
708 	/* Inform the kld system about the situation */
709 	lf->address = ef->address = (caddr_t)mapbase;
710 	lf->size = mapsize;
711 
712 	/*
713 	 * Now load code/data(progbits), zero bss(nobits), allocate space for
714 	 * and load relocs
715 	 */
716 	pb = 0;
717 	rl = 0;
718 	ra = 0;
719 	alignmask = 0;
720 	for (i = 0; i < hdr->e_shnum; i++) {
721 		if (shdr[i].sh_size == 0)
722 			continue;
723 		switch (shdr[i].sh_type) {
724 		case SHT_PROGBITS:
725 		case SHT_NOBITS:
726 			alignmask = shdr[i].sh_addralign - 1;
727 			mapbase += alignmask;
728 			mapbase &= ~alignmask;
729 			if (ef->shstrtab && shdr[i].sh_name != 0)
730 				ef->progtab[pb].name =
731 				    ef->shstrtab + shdr[i].sh_name;
732 			else if (shdr[i].sh_type == SHT_PROGBITS)
733 				ef->progtab[pb].name = "<<PROGBITS>>";
734 			else
735 				ef->progtab[pb].name = "<<NOBITS>>";
736 			if (ef->progtab[pb].name != NULL &&
737 			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
738 				ef->progtab[pb].addr =
739 				    dpcpu_alloc(shdr[i].sh_size);
740 #ifdef VIMAGE
741 			else if (ef->progtab[pb].name != NULL &&
742 			    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
743 				ef->progtab[pb].addr =
744 				    vnet_data_alloc(shdr[i].sh_size);
745 #endif
746 			else
747 				ef->progtab[pb].addr =
748 				    (void *)(uintptr_t)mapbase;
749 			if (ef->progtab[pb].addr == NULL) {
750 				error = ENOSPC;
751 				goto out;
752 			}
753 			ef->progtab[pb].size = shdr[i].sh_size;
754 			ef->progtab[pb].sec = i;
755 			if (shdr[i].sh_type == SHT_PROGBITS) {
756 				error = vn_rdwr(UIO_READ, nd.ni_vp,
757 				    ef->progtab[pb].addr,
758 				    shdr[i].sh_size, shdr[i].sh_offset,
759 				    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
760 				    NOCRED, &resid, td);
761 				if (error)
762 					goto out;
763 				if (resid != 0){
764 					error = EINVAL;
765 					goto out;
766 				}
767 				/* Initialize the per-cpu or vnet area. */
768 				if (ef->progtab[pb].addr != (void *)mapbase &&
769 				    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
770 					dpcpu_copy(ef->progtab[pb].addr,
771 					    shdr[i].sh_size);
772 #ifdef VIMAGE
773 				else if (ef->progtab[pb].addr !=
774 				    (void *)mapbase &&
775 				    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
776 					vnet_data_copy(ef->progtab[pb].addr,
777 					    shdr[i].sh_size);
778 #endif
779 			} else
780 				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
781 
782 			/* Update all symbol values with the offset. */
783 			for (j = 0; j < ef->ddbsymcnt; j++) {
784 				es = &ef->ddbsymtab[j];
785 				if (es->st_shndx != i)
786 					continue;
787 				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
788 			}
789 			mapbase += shdr[i].sh_size;
790 			pb++;
791 			break;
792 		case SHT_REL:
793 			ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
794 			    M_WAITOK);
795 			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
796 			ef->reltab[rl].sec = shdr[i].sh_info;
797 			error = vn_rdwr(UIO_READ, nd.ni_vp,
798 			    (void *)ef->reltab[rl].rel,
799 			    shdr[i].sh_size, shdr[i].sh_offset,
800 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
801 			    &resid, td);
802 			if (error)
803 				goto out;
804 			if (resid != 0){
805 				error = EINVAL;
806 				goto out;
807 			}
808 			rl++;
809 			break;
810 		case SHT_RELA:
811 			ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
812 			    M_WAITOK);
813 			ef->relatab[ra].nrela =
814 			    shdr[i].sh_size / sizeof(Elf_Rela);
815 			ef->relatab[ra].sec = shdr[i].sh_info;
816 			error = vn_rdwr(UIO_READ, nd.ni_vp,
817 			    (void *)ef->relatab[ra].rela,
818 			    shdr[i].sh_size, shdr[i].sh_offset,
819 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
820 			    &resid, td);
821 			if (error)
822 				goto out;
823 			if (resid != 0){
824 				error = EINVAL;
825 				goto out;
826 			}
827 			ra++;
828 			break;
829 		}
830 	}
831 	if (pb != ef->nprogtab)
832 		panic("lost progbits");
833 	if (rl != ef->nreltab)
834 		panic("lost reltab");
835 	if (ra != ef->nrelatab)
836 		panic("lost relatab");
837 	if (mapbase != (vm_offset_t)ef->address + mapsize)
838 		panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
839 		    (u_long)mapbase, ef->address, (u_long)mapsize,
840 		    (u_long)(vm_offset_t)ef->address + mapsize);
841 
842 	/* Local intra-module relocations */
843 	link_elf_reloc_local(lf);
844 
845 	/* Pull in dependencies */
846 	VOP_UNLOCK(nd.ni_vp, 0);
847 	error = linker_load_dependencies(lf);
848 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
849 	if (error)
850 		goto out;
851 
852 	/* External relocations */
853 	error = relocate_file(ef);
854 	if (error)
855 		goto out;
856 
857 	/* Notify MD code that a module is being loaded. */
858 	error = elf_cpu_load_file(lf);
859 	if (error)
860 		goto out;
861 
862 	*result = lf;
863 
864 out:
865 	VOP_UNLOCK(nd.ni_vp, 0);
866 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
867 	if (error && lf)
868 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
869 	if (hdr)
870 		free(hdr, M_LINKER);
871 
872 	return error;
873 }
874 
875 static void
876 link_elf_unload_file(linker_file_t file)
877 {
878 	elf_file_t ef = (elf_file_t) file;
879 	int i;
880 
881 	/* Notify MD code that a module is being unloaded. */
882 	elf_cpu_unload_file(file);
883 
884 	if (ef->progtab) {
885 		for (i = 0; i < ef->nprogtab; i++) {
886 			if (ef->progtab[i].size == 0)
887 				continue;
888 			if (ef->progtab[i].name == NULL)
889 				continue;
890 			if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
891 				dpcpu_free(ef->progtab[i].addr,
892 				    ef->progtab[i].size);
893 #ifdef VIMAGE
894 			else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
895 				vnet_data_free(ef->progtab[i].addr,
896 				    ef->progtab[i].size);
897 #endif
898 		}
899 	}
900 	if (ef->preloaded) {
901 		if (ef->reltab)
902 			free(ef->reltab, M_LINKER);
903 		if (ef->relatab)
904 			free(ef->relatab, M_LINKER);
905 		if (ef->progtab)
906 			free(ef->progtab, M_LINKER);
907 		if (ef->ctftab)
908 			free(ef->ctftab, M_LINKER);
909 		if (ef->ctfoff)
910 			free(ef->ctfoff, M_LINKER);
911 		if (ef->typoff)
912 			free(ef->typoff, M_LINKER);
913 		if (file->filename != NULL)
914 			preload_delete_name(file->filename);
915 		/* XXX reclaim module memory? */
916 		return;
917 	}
918 
919 	for (i = 0; i < ef->nreltab; i++)
920 		if (ef->reltab[i].rel)
921 			free(ef->reltab[i].rel, M_LINKER);
922 	for (i = 0; i < ef->nrelatab; i++)
923 		if (ef->relatab[i].rela)
924 			free(ef->relatab[i].rela, M_LINKER);
925 	if (ef->reltab)
926 		free(ef->reltab, M_LINKER);
927 	if (ef->relatab)
928 		free(ef->relatab, M_LINKER);
929 	if (ef->progtab)
930 		free(ef->progtab, M_LINKER);
931 
932 	if (ef->object) {
933 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
934 		    (vm_offset_t) ef->address +
935 		    (ef->object->size << PAGE_SHIFT));
936 	}
937 	if (ef->e_shdr)
938 		free(ef->e_shdr, M_LINKER);
939 	if (ef->ddbsymtab)
940 		free(ef->ddbsymtab, M_LINKER);
941 	if (ef->ddbstrtab)
942 		free(ef->ddbstrtab, M_LINKER);
943 	if (ef->shstrtab)
944 		free(ef->shstrtab, M_LINKER);
945 	if (ef->ctftab)
946 		free(ef->ctftab, M_LINKER);
947 	if (ef->ctfoff)
948 		free(ef->ctfoff, M_LINKER);
949 	if (ef->typoff)
950 		free(ef->typoff, M_LINKER);
951 }
952 
953 static const char *
954 symbol_name(elf_file_t ef, Elf_Size r_info)
955 {
956 	const Elf_Sym *ref;
957 
958 	if (ELF_R_SYM(r_info)) {
959 		ref = ef->ddbsymtab + ELF_R_SYM(r_info);
960 		return ef->ddbstrtab + ref->st_name;
961 	} else
962 		return NULL;
963 }
964 
965 static Elf_Addr
966 findbase(elf_file_t ef, int sec)
967 {
968 	int i;
969 	Elf_Addr base = 0;
970 
971 	for (i = 0; i < ef->nprogtab; i++) {
972 		if (sec == ef->progtab[i].sec) {
973 			base = (Elf_Addr)ef->progtab[i].addr;
974 			break;
975 		}
976 	}
977 	return base;
978 }
979 
980 static int
981 relocate_file(elf_file_t ef)
982 {
983 	const Elf_Rel *rellim;
984 	const Elf_Rel *rel;
985 	const Elf_Rela *relalim;
986 	const Elf_Rela *rela;
987 	const char *symname;
988 	const Elf_Sym *sym;
989 	int i;
990 	Elf_Size symidx;
991 	Elf_Addr base;
992 
993 
994 	/* Perform relocations without addend if there are any: */
995 	for (i = 0; i < ef->nreltab; i++) {
996 		rel = ef->reltab[i].rel;
997 		if (rel == NULL)
998 			panic("lost a reltab!");
999 		rellim = rel + ef->reltab[i].nrel;
1000 		base = findbase(ef, ef->reltab[i].sec);
1001 		if (base == 0)
1002 			panic("lost base for reltab");
1003 		for ( ; rel < rellim; rel++) {
1004 			symidx = ELF_R_SYM(rel->r_info);
1005 			if (symidx >= ef->ddbsymcnt)
1006 				continue;
1007 			sym = ef->ddbsymtab + symidx;
1008 			/* Local relocs are already done */
1009 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1010 				continue;
1011 			if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1012 			    elf_obj_lookup)) {
1013 				symname = symbol_name(ef, rel->r_info);
1014 				printf("link_elf_obj: symbol %s undefined\n",
1015 				    symname);
1016 				return ENOENT;
1017 			}
1018 		}
1019 	}
1020 
1021 	/* Perform relocations with addend if there are any: */
1022 	for (i = 0; i < ef->nrelatab; i++) {
1023 		rela = ef->relatab[i].rela;
1024 		if (rela == NULL)
1025 			panic("lost a relatab!");
1026 		relalim = rela + ef->relatab[i].nrela;
1027 		base = findbase(ef, ef->relatab[i].sec);
1028 		if (base == 0)
1029 			panic("lost base for relatab");
1030 		for ( ; rela < relalim; rela++) {
1031 			symidx = ELF_R_SYM(rela->r_info);
1032 			if (symidx >= ef->ddbsymcnt)
1033 				continue;
1034 			sym = ef->ddbsymtab + symidx;
1035 			/* Local relocs are already done */
1036 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1037 				continue;
1038 			if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1039 			    elf_obj_lookup)) {
1040 				symname = symbol_name(ef, rela->r_info);
1041 				printf("link_elf_obj: symbol %s undefined\n",
1042 				    symname);
1043 				return ENOENT;
1044 			}
1045 		}
1046 	}
1047 
1048 	return 0;
1049 }
1050 
1051 static int
1052 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1053 {
1054 	elf_file_t ef = (elf_file_t) lf;
1055 	const Elf_Sym *symp;
1056 	const char *strp;
1057 	int i;
1058 
1059 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1060 		strp = ef->ddbstrtab + symp->st_name;
1061 		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1062 			*sym = (c_linker_sym_t) symp;
1063 			return 0;
1064 		}
1065 	}
1066 	return ENOENT;
1067 }
1068 
1069 static int
1070 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1071     linker_symval_t *symval)
1072 {
1073 	elf_file_t ef = (elf_file_t) lf;
1074 	const Elf_Sym *es = (const Elf_Sym*) sym;
1075 
1076 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1077 		symval->name = ef->ddbstrtab + es->st_name;
1078 		symval->value = (caddr_t)es->st_value;
1079 		symval->size = es->st_size;
1080 		return 0;
1081 	}
1082 	return ENOENT;
1083 }
1084 
1085 static int
1086 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1087     c_linker_sym_t *sym, long *diffp)
1088 {
1089 	elf_file_t ef = (elf_file_t) lf;
1090 	u_long off = (uintptr_t) (void *) value;
1091 	u_long diff = off;
1092 	u_long st_value;
1093 	const Elf_Sym *es;
1094 	const Elf_Sym *best = 0;
1095 	int i;
1096 
1097 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1098 		if (es->st_name == 0)
1099 			continue;
1100 		st_value = es->st_value;
1101 		if (off >= st_value) {
1102 			if (off - st_value < diff) {
1103 				diff = off - st_value;
1104 				best = es;
1105 				if (diff == 0)
1106 					break;
1107 			} else if (off - st_value == diff) {
1108 				best = es;
1109 			}
1110 		}
1111 	}
1112 	if (best == 0)
1113 		*diffp = off;
1114 	else
1115 		*diffp = diff;
1116 	*sym = (c_linker_sym_t) best;
1117 
1118 	return 0;
1119 }
1120 
1121 /*
1122  * Look up a linker set on an ELF system.
1123  */
1124 static int
1125 link_elf_lookup_set(linker_file_t lf, const char *name,
1126     void ***startp, void ***stopp, int *countp)
1127 {
1128 	elf_file_t ef = (elf_file_t)lf;
1129 	void **start, **stop;
1130 	int i, count;
1131 
1132 	/* Relative to section number */
1133 	for (i = 0; i < ef->nprogtab; i++) {
1134 		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1135 		    strcmp(ef->progtab[i].name + 4, name) == 0) {
1136 			start  = (void **)ef->progtab[i].addr;
1137 			stop = (void **)((char *)ef->progtab[i].addr +
1138 			    ef->progtab[i].size);
1139 			count = stop - start;
1140 			if (startp)
1141 				*startp = start;
1142 			if (stopp)
1143 				*stopp = stop;
1144 			if (countp)
1145 				*countp = count;
1146 			return (0);
1147 		}
1148 	}
1149 	return (ESRCH);
1150 }
1151 
1152 static int
1153 link_elf_each_function_name(linker_file_t file,
1154     int (*callback)(const char *, void *), void *opaque)
1155 {
1156 	elf_file_t ef = (elf_file_t)file;
1157 	const Elf_Sym *symp;
1158 	int i, error;
1159 
1160 	/* Exhaustive search */
1161 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1162 		if (symp->st_value != 0 &&
1163 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1164 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1165 			if (error)
1166 				return (error);
1167 		}
1168 	}
1169 	return (0);
1170 }
1171 
1172 static int
1173 link_elf_each_function_nameval(linker_file_t file,
1174     linker_function_nameval_callback_t callback, void *opaque)
1175 {
1176 	linker_symval_t symval;
1177 	elf_file_t ef = (elf_file_t)file;
1178 	const Elf_Sym* symp;
1179 	int i, error;
1180 
1181 	/* Exhaustive search */
1182 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1183 		if (symp->st_value != 0 &&
1184 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1185 			error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1186 			if (error)
1187 				return (error);
1188 			error = callback(file, i, &symval, opaque);
1189 			if (error)
1190 				return (error);
1191 		}
1192 	}
1193 	return (0);
1194 }
1195 
1196 /*
1197  * Symbol lookup function that can be used when the symbol index is known (ie
1198  * in relocations). It uses the symbol index instead of doing a fully fledged
1199  * hash table based lookup when such is valid. For example for local symbols.
1200  * This is not only more efficient, it's also more correct. It's not always
1201  * the case that the symbol can be found through the hash table.
1202  */
1203 static Elf_Addr
1204 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1205 {
1206 	elf_file_t ef = (elf_file_t)lf;
1207 	const Elf_Sym *sym;
1208 	const char *symbol;
1209 	Elf_Addr ret;
1210 
1211 	/* Don't even try to lookup the symbol if the index is bogus. */
1212 	if (symidx >= ef->ddbsymcnt)
1213 		return (0);
1214 
1215 	sym = ef->ddbsymtab + symidx;
1216 
1217 	/* Quick answer if there is a definition included. */
1218 	if (sym->st_shndx != SHN_UNDEF)
1219 		return (sym->st_value);
1220 
1221 	/* If we get here, then it is undefined and needs a lookup. */
1222 	switch (ELF_ST_BIND(sym->st_info)) {
1223 	case STB_LOCAL:
1224 		/* Local, but undefined? huh? */
1225 		return (0);
1226 
1227 	case STB_GLOBAL:
1228 		/* Relative to Data or Function name */
1229 		symbol = ef->ddbstrtab + sym->st_name;
1230 
1231 		/* Force a lookup failure if the symbol name is bogus. */
1232 		if (*symbol == 0)
1233 			return (0);
1234 		ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1235 		return ret;
1236 
1237 	case STB_WEAK:
1238 		printf("link_elf_obj: Weak symbols not supported\n");
1239 		return (0);
1240 
1241 	default:
1242 		return (0);
1243 	}
1244 }
1245 
1246 static void
1247 link_elf_fix_link_set(elf_file_t ef)
1248 {
1249 	static const char startn[] = "__start_";
1250 	static const char stopn[] = "__stop_";
1251 	Elf_Sym *sym;
1252 	const char *sym_name, *linkset_name;
1253 	Elf_Addr startp, stopp;
1254 	Elf_Size symidx;
1255 	int start, i;
1256 
1257 	startp = stopp = 0;
1258 	for (symidx = 1 /* zero entry is special */;
1259 		symidx < ef->ddbsymcnt; symidx++) {
1260 		sym = ef->ddbsymtab + symidx;
1261 		if (sym->st_shndx != SHN_UNDEF)
1262 			continue;
1263 
1264 		sym_name = ef->ddbstrtab + sym->st_name;
1265 		if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1266 			start = 1;
1267 			linkset_name = sym_name + sizeof(startn) - 1;
1268 		}
1269 		else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1270 			start = 0;
1271 			linkset_name = sym_name + sizeof(stopn) - 1;
1272 		}
1273 		else
1274 			continue;
1275 
1276 		for (i = 0; i < ef->nprogtab; i++) {
1277 			if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1278 				startp = (Elf_Addr)ef->progtab[i].addr;
1279 				stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1280 				break;
1281 			}
1282 		}
1283 		if (i == ef->nprogtab)
1284 			continue;
1285 
1286 		sym->st_value = start ? startp : stopp;
1287 		sym->st_shndx = i;
1288 	}
1289 }
1290 
1291 static void
1292 link_elf_reloc_local(linker_file_t lf)
1293 {
1294 	elf_file_t ef = (elf_file_t)lf;
1295 	const Elf_Rel *rellim;
1296 	const Elf_Rel *rel;
1297 	const Elf_Rela *relalim;
1298 	const Elf_Rela *rela;
1299 	const Elf_Sym *sym;
1300 	Elf_Addr base;
1301 	int i;
1302 	Elf_Size symidx;
1303 
1304 	link_elf_fix_link_set(ef);
1305 
1306 	/* Perform relocations without addend if there are any: */
1307 	for (i = 0; i < ef->nreltab; i++) {
1308 		rel = ef->reltab[i].rel;
1309 		if (rel == NULL)
1310 			panic("lost a reltab!");
1311 		rellim = rel + ef->reltab[i].nrel;
1312 		base = findbase(ef, ef->reltab[i].sec);
1313 		if (base == 0)
1314 			panic("lost base for reltab");
1315 		for ( ; rel < rellim; rel++) {
1316 			symidx = ELF_R_SYM(rel->r_info);
1317 			if (symidx >= ef->ddbsymcnt)
1318 				continue;
1319 			sym = ef->ddbsymtab + symidx;
1320 			/* Only do local relocs */
1321 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1322 				continue;
1323 			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1324 			    elf_obj_lookup);
1325 		}
1326 	}
1327 
1328 	/* Perform relocations with addend if there are any: */
1329 	for (i = 0; i < ef->nrelatab; i++) {
1330 		rela = ef->relatab[i].rela;
1331 		if (rela == NULL)
1332 			panic("lost a relatab!");
1333 		relalim = rela + ef->relatab[i].nrela;
1334 		base = findbase(ef, ef->relatab[i].sec);
1335 		if (base == 0)
1336 			panic("lost base for relatab");
1337 		for ( ; rela < relalim; rela++) {
1338 			symidx = ELF_R_SYM(rela->r_info);
1339 			if (symidx >= ef->ddbsymcnt)
1340 				continue;
1341 			sym = ef->ddbsymtab + symidx;
1342 			/* Only do local relocs */
1343 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1344 				continue;
1345 			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1346 			    elf_obj_lookup);
1347 		}
1348 	}
1349 }
1350 
1351 static long
1352 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1353 {
1354     elf_file_t ef = (elf_file_t)lf;
1355 
1356     *symtab = ef->ddbsymtab;
1357 
1358     if (*symtab == NULL)
1359         return (0);
1360 
1361     return (ef->ddbsymcnt);
1362 }
1363 
1364 static long
1365 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1366 {
1367     elf_file_t ef = (elf_file_t)lf;
1368 
1369     *strtab = ef->ddbstrtab;
1370 
1371     if (*strtab == NULL)
1372         return (0);
1373 
1374     return (ef->ddbstrcnt);
1375 }
1376