xref: /freebsd/sys/kern/link_elf_obj.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 	int resid, flags;
444 	elf_file_t ef;
445 	linker_file_t lf;
446 	int symtabindex;
447 	int symstrindex;
448 	int shstrindex;
449 	int nsym;
450 	int pb, rl, ra;
451 	int alignmask;
452 	int vfslocked;
453 
454 	shdr = NULL;
455 	lf = NULL;
456 	mapsize = 0;
457 	hdr = NULL;
458 
459 	NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
460 	flags = FREAD;
461 	error = vn_open(&nd, &flags, 0, NULL);
462 	if (error)
463 		return error;
464 	vfslocked = NDHASGIANT(&nd);
465 	NDFREE(&nd, NDF_ONLY_PNBUF);
466 	if (nd.ni_vp->v_type != VREG) {
467 		error = ENOEXEC;
468 		goto out;
469 	}
470 #ifdef MAC
471 	error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
472 	if (error) {
473 		goto out;
474 	}
475 #endif
476 
477 	/* Read the elf header from the file. */
478 	hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
479 	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
480 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
481 	    &resid, td);
482 	if (error)
483 		goto out;
484 	if (resid != 0){
485 		error = ENOEXEC;
486 		goto out;
487 	}
488 
489 	if (!IS_ELF(*hdr)) {
490 		error = ENOEXEC;
491 		goto out;
492 	}
493 
494 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
495 	    || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
496 		link_elf_error(filename, "Unsupported file layout");
497 		error = ENOEXEC;
498 		goto out;
499 	}
500 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT
501 	    || hdr->e_version != EV_CURRENT) {
502 		link_elf_error(filename, "Unsupported file version");
503 		error = ENOEXEC;
504 		goto out;
505 	}
506 	if (hdr->e_type != ET_REL) {
507 		error = ENOSYS;
508 		goto out;
509 	}
510 	if (hdr->e_machine != ELF_TARG_MACH) {
511 		link_elf_error(filename, "Unsupported machine");
512 		error = ENOEXEC;
513 		goto out;
514 	}
515 
516 	lf = linker_make_file(filename, &link_elf_class);
517 	if (!lf) {
518 		error = ENOMEM;
519 		goto out;
520 	}
521 	ef = (elf_file_t) lf;
522 	ef->nprogtab = 0;
523 	ef->e_shdr = 0;
524 	ef->nreltab = 0;
525 	ef->nrelatab = 0;
526 
527 	/* Allocate and read in the section header */
528 	nbytes = hdr->e_shnum * hdr->e_shentsize;
529 	if (nbytes == 0 || hdr->e_shoff == 0 ||
530 	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
531 		error = ENOEXEC;
532 		goto out;
533 	}
534 	shdr = malloc(nbytes, M_LINKER, M_WAITOK);
535 	ef->e_shdr = shdr;
536 	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
537 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
538 	if (error)
539 		goto out;
540 	if (resid) {
541 		error = ENOEXEC;
542 		goto out;
543 	}
544 
545 	/* Scan the section header for information and table sizing. */
546 	nsym = 0;
547 	symtabindex = -1;
548 	symstrindex = -1;
549 	for (i = 0; i < hdr->e_shnum; i++) {
550 		if (shdr[i].sh_size == 0)
551 			continue;
552 		switch (shdr[i].sh_type) {
553 		case SHT_PROGBITS:
554 		case SHT_NOBITS:
555 			ef->nprogtab++;
556 			break;
557 		case SHT_SYMTAB:
558 			nsym++;
559 			symtabindex = i;
560 			symstrindex = shdr[i].sh_link;
561 			break;
562 		case SHT_REL:
563 			ef->nreltab++;
564 			break;
565 		case SHT_RELA:
566 			ef->nrelatab++;
567 			break;
568 		case SHT_STRTAB:
569 			break;
570 		}
571 	}
572 	if (ef->nprogtab == 0) {
573 		link_elf_error(filename, "file has no contents");
574 		error = ENOEXEC;
575 		goto out;
576 	}
577 	if (nsym != 1) {
578 		/* Only allow one symbol table for now */
579 		link_elf_error(filename, "file has no valid symbol table");
580 		error = ENOEXEC;
581 		goto out;
582 	}
583 	if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
584 	    shdr[symstrindex].sh_type != SHT_STRTAB) {
585 		link_elf_error(filename, "file has invalid symbol strings");
586 		error = ENOEXEC;
587 		goto out;
588 	}
589 
590 	/* Allocate space for tracking the load chunks */
591 	if (ef->nprogtab != 0)
592 		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
593 		    M_LINKER, M_WAITOK | M_ZERO);
594 	if (ef->nreltab != 0)
595 		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
596 		    M_LINKER, M_WAITOK | M_ZERO);
597 	if (ef->nrelatab != 0)
598 		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
599 		    M_LINKER, M_WAITOK | M_ZERO);
600 
601 	if (symtabindex == -1)
602 		panic("lost symbol table index");
603 	/* Allocate space for and load the symbol table */
604 	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
605 	ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
606 	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
607 	    shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
608 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
609 	    &resid, td);
610 	if (error)
611 		goto out;
612 	if (resid != 0){
613 		error = EINVAL;
614 		goto out;
615 	}
616 
617 	if (symstrindex == -1)
618 		panic("lost symbol string index");
619 	/* Allocate space for and load the symbol strings */
620 	ef->ddbstrcnt = shdr[symstrindex].sh_size;
621 	ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
622 	error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
623 	    shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
624 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
625 	    &resid, td);
626 	if (error)
627 		goto out;
628 	if (resid != 0){
629 		error = EINVAL;
630 		goto out;
631 	}
632 
633 	/* Do we have a string table for the section names?  */
634 	shstrindex = -1;
635 	if (hdr->e_shstrndx != 0 &&
636 	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
637 		shstrindex = hdr->e_shstrndx;
638 		ef->shstrcnt = shdr[shstrindex].sh_size;
639 		ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
640 		    M_WAITOK);
641 		error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
642 		    shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
643 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
644 		    &resid, td);
645 		if (error)
646 			goto out;
647 		if (resid != 0){
648 			error = EINVAL;
649 			goto out;
650 		}
651 	}
652 
653 	/* Size up code/data(progbits) and bss(nobits). */
654 	alignmask = 0;
655 	for (i = 0; i < hdr->e_shnum; i++) {
656 		if (shdr[i].sh_size == 0)
657 			continue;
658 		switch (shdr[i].sh_type) {
659 		case SHT_PROGBITS:
660 		case SHT_NOBITS:
661 			alignmask = shdr[i].sh_addralign - 1;
662 			mapsize += alignmask;
663 			mapsize &= ~alignmask;
664 			mapsize += shdr[i].sh_size;
665 			break;
666 		}
667 	}
668 
669 	/*
670 	 * We know how much space we need for the text/data/bss/etc.
671 	 * This stuff needs to be in a single chunk so that profiling etc
672 	 * can get the bounds and gdb can associate offsets with modules
673 	 */
674 	ef->object = vm_object_allocate(OBJT_DEFAULT,
675 	    round_page(mapsize) >> PAGE_SHIFT);
676 	if (ef->object == NULL) {
677 		error = ENOMEM;
678 		goto out;
679 	}
680 	ef->address = (caddr_t) vm_map_min(kernel_map);
681 
682 	/*
683 	 * In order to satisfy amd64's architectural requirements on the
684 	 * location of code and data in the kernel's address space, request a
685 	 * mapping that is above the kernel.
686 	 */
687 	mapbase = KERNBASE;
688 	error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
689 	    round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
690 	if (error) {
691 		vm_object_deallocate(ef->object);
692 		ef->object = 0;
693 		goto out;
694 	}
695 
696 	/* Wire the pages */
697 	error = vm_map_wire(kernel_map, mapbase,
698 	    mapbase + round_page(mapsize),
699 	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
700 	if (error != KERN_SUCCESS) {
701 		error = ENOMEM;
702 		goto out;
703 	}
704 
705 	/* Inform the kld system about the situation */
706 	lf->address = ef->address = (caddr_t)mapbase;
707 	lf->size = mapsize;
708 
709 	/*
710 	 * Now load code/data(progbits), zero bss(nobits), allocate space for
711 	 * and load relocs
712 	 */
713 	pb = 0;
714 	rl = 0;
715 	ra = 0;
716 	alignmask = 0;
717 	for (i = 0; i < hdr->e_shnum; i++) {
718 		if (shdr[i].sh_size == 0)
719 			continue;
720 		switch (shdr[i].sh_type) {
721 		case SHT_PROGBITS:
722 		case SHT_NOBITS:
723 			alignmask = shdr[i].sh_addralign - 1;
724 			mapbase += alignmask;
725 			mapbase &= ~alignmask;
726 			if (ef->shstrtab && shdr[i].sh_name != 0)
727 				ef->progtab[pb].name =
728 				    ef->shstrtab + shdr[i].sh_name;
729 			else if (shdr[i].sh_type == SHT_PROGBITS)
730 				ef->progtab[pb].name = "<<PROGBITS>>";
731 			else
732 				ef->progtab[pb].name = "<<NOBITS>>";
733 			if (ef->progtab[pb].name != NULL &&
734 			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
735 				ef->progtab[pb].addr =
736 				    dpcpu_alloc(shdr[i].sh_size);
737 #ifdef VIMAGE
738 			else if (ef->progtab[pb].name != NULL &&
739 			    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
740 				ef->progtab[pb].addr =
741 				    vnet_data_alloc(shdr[i].sh_size);
742 #endif
743 			else
744 				ef->progtab[pb].addr =
745 				    (void *)(uintptr_t)mapbase;
746 			if (ef->progtab[pb].addr == NULL) {
747 				error = ENOSPC;
748 				goto out;
749 			}
750 			ef->progtab[pb].size = shdr[i].sh_size;
751 			ef->progtab[pb].sec = i;
752 			if (shdr[i].sh_type == SHT_PROGBITS) {
753 				error = vn_rdwr(UIO_READ, nd.ni_vp,
754 				    ef->progtab[pb].addr,
755 				    shdr[i].sh_size, shdr[i].sh_offset,
756 				    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
757 				    NOCRED, &resid, td);
758 				if (error)
759 					goto out;
760 				if (resid != 0){
761 					error = EINVAL;
762 					goto out;
763 				}
764 				/* Initialize the per-cpu or vnet area. */
765 				if (ef->progtab[pb].addr != (void *)mapbase &&
766 				    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
767 					dpcpu_copy(ef->progtab[pb].addr,
768 					    shdr[i].sh_size);
769 #ifdef VIMAGE
770 				else if (ef->progtab[pb].addr !=
771 				    (void *)mapbase &&
772 				    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
773 					vnet_data_copy(ef->progtab[pb].addr,
774 					    shdr[i].sh_size);
775 #endif
776 			} else
777 				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
778 
779 			/* Update all symbol values with the offset. */
780 			for (j = 0; j < ef->ddbsymcnt; j++) {
781 				es = &ef->ddbsymtab[j];
782 				if (es->st_shndx != i)
783 					continue;
784 				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
785 			}
786 			mapbase += shdr[i].sh_size;
787 			pb++;
788 			break;
789 		case SHT_REL:
790 			ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
791 			    M_WAITOK);
792 			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
793 			ef->reltab[rl].sec = shdr[i].sh_info;
794 			error = vn_rdwr(UIO_READ, nd.ni_vp,
795 			    (void *)ef->reltab[rl].rel,
796 			    shdr[i].sh_size, shdr[i].sh_offset,
797 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
798 			    &resid, td);
799 			if (error)
800 				goto out;
801 			if (resid != 0){
802 				error = EINVAL;
803 				goto out;
804 			}
805 			rl++;
806 			break;
807 		case SHT_RELA:
808 			ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
809 			    M_WAITOK);
810 			ef->relatab[ra].nrela =
811 			    shdr[i].sh_size / sizeof(Elf_Rela);
812 			ef->relatab[ra].sec = shdr[i].sh_info;
813 			error = vn_rdwr(UIO_READ, nd.ni_vp,
814 			    (void *)ef->relatab[ra].rela,
815 			    shdr[i].sh_size, shdr[i].sh_offset,
816 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
817 			    &resid, td);
818 			if (error)
819 				goto out;
820 			if (resid != 0){
821 				error = EINVAL;
822 				goto out;
823 			}
824 			ra++;
825 			break;
826 		}
827 	}
828 	if (pb != ef->nprogtab)
829 		panic("lost progbits");
830 	if (rl != ef->nreltab)
831 		panic("lost reltab");
832 	if (ra != ef->nrelatab)
833 		panic("lost relatab");
834 	if (mapbase != (vm_offset_t)ef->address + mapsize)
835 		panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
836 		    (u_long)mapbase, ef->address, (u_long)mapsize,
837 		    (u_long)(vm_offset_t)ef->address + mapsize);
838 
839 	/* Local intra-module relocations */
840 	link_elf_reloc_local(lf);
841 
842 	/* Pull in dependencies */
843 	VOP_UNLOCK(nd.ni_vp, 0);
844 	error = linker_load_dependencies(lf);
845 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
846 	if (error)
847 		goto out;
848 
849 	/* External relocations */
850 	error = relocate_file(ef);
851 	if (error)
852 		goto out;
853 
854 	/* Notify MD code that a module is being loaded. */
855 	error = elf_cpu_load_file(lf);
856 	if (error)
857 		goto out;
858 
859 	*result = lf;
860 
861 out:
862 	VOP_UNLOCK(nd.ni_vp, 0);
863 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
864 	VFS_UNLOCK_GIANT(vfslocked);
865 	if (error && lf)
866 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
867 	if (hdr)
868 		free(hdr, M_LINKER);
869 
870 	return error;
871 }
872 
873 static void
874 link_elf_unload_file(linker_file_t file)
875 {
876 	elf_file_t ef = (elf_file_t) file;
877 	int i;
878 
879 	/* Notify MD code that a module is being unloaded. */
880 	elf_cpu_unload_file(file);
881 
882 	if (ef->progtab) {
883 		for (i = 0; i < ef->nprogtab; i++) {
884 			if (ef->progtab[i].size == 0)
885 				continue;
886 			if (ef->progtab[i].name == NULL)
887 				continue;
888 			if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
889 				dpcpu_free(ef->progtab[i].addr,
890 				    ef->progtab[i].size);
891 #ifdef VIMAGE
892 			else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
893 				vnet_data_free(ef->progtab[i].addr,
894 				    ef->progtab[i].size);
895 #endif
896 		}
897 	}
898 	if (ef->preloaded) {
899 		if (ef->reltab)
900 			free(ef->reltab, M_LINKER);
901 		if (ef->relatab)
902 			free(ef->relatab, M_LINKER);
903 		if (ef->progtab)
904 			free(ef->progtab, M_LINKER);
905 		if (ef->ctftab)
906 			free(ef->ctftab, M_LINKER);
907 		if (ef->ctfoff)
908 			free(ef->ctfoff, M_LINKER);
909 		if (ef->typoff)
910 			free(ef->typoff, M_LINKER);
911 		if (file->filename != NULL)
912 			preload_delete_name(file->filename);
913 		/* XXX reclaim module memory? */
914 		return;
915 	}
916 
917 	for (i = 0; i < ef->nreltab; i++)
918 		if (ef->reltab[i].rel)
919 			free(ef->reltab[i].rel, M_LINKER);
920 	for (i = 0; i < ef->nrelatab; i++)
921 		if (ef->relatab[i].rela)
922 			free(ef->relatab[i].rela, M_LINKER);
923 	if (ef->reltab)
924 		free(ef->reltab, M_LINKER);
925 	if (ef->relatab)
926 		free(ef->relatab, M_LINKER);
927 	if (ef->progtab)
928 		free(ef->progtab, M_LINKER);
929 
930 	if (ef->object) {
931 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
932 		    (vm_offset_t) ef->address +
933 		    (ef->object->size << PAGE_SHIFT));
934 	}
935 	if (ef->e_shdr)
936 		free(ef->e_shdr, M_LINKER);
937 	if (ef->ddbsymtab)
938 		free(ef->ddbsymtab, M_LINKER);
939 	if (ef->ddbstrtab)
940 		free(ef->ddbstrtab, M_LINKER);
941 	if (ef->shstrtab)
942 		free(ef->shstrtab, M_LINKER);
943 	if (ef->ctftab)
944 		free(ef->ctftab, M_LINKER);
945 	if (ef->ctfoff)
946 		free(ef->ctfoff, M_LINKER);
947 	if (ef->typoff)
948 		free(ef->typoff, M_LINKER);
949 }
950 
951 static const char *
952 symbol_name(elf_file_t ef, Elf_Size r_info)
953 {
954 	const Elf_Sym *ref;
955 
956 	if (ELF_R_SYM(r_info)) {
957 		ref = ef->ddbsymtab + ELF_R_SYM(r_info);
958 		return ef->ddbstrtab + ref->st_name;
959 	} else
960 		return NULL;
961 }
962 
963 static Elf_Addr
964 findbase(elf_file_t ef, int sec)
965 {
966 	int i;
967 	Elf_Addr base = 0;
968 
969 	for (i = 0; i < ef->nprogtab; i++) {
970 		if (sec == ef->progtab[i].sec) {
971 			base = (Elf_Addr)ef->progtab[i].addr;
972 			break;
973 		}
974 	}
975 	return base;
976 }
977 
978 static int
979 relocate_file(elf_file_t ef)
980 {
981 	const Elf_Rel *rellim;
982 	const Elf_Rel *rel;
983 	const Elf_Rela *relalim;
984 	const Elf_Rela *rela;
985 	const char *symname;
986 	const Elf_Sym *sym;
987 	int i;
988 	Elf_Size symidx;
989 	Elf_Addr base;
990 
991 
992 	/* Perform relocations without addend if there are any: */
993 	for (i = 0; i < ef->nreltab; i++) {
994 		rel = ef->reltab[i].rel;
995 		if (rel == NULL)
996 			panic("lost a reltab!");
997 		rellim = rel + ef->reltab[i].nrel;
998 		base = findbase(ef, ef->reltab[i].sec);
999 		if (base == 0)
1000 			panic("lost base for reltab");
1001 		for ( ; rel < rellim; rel++) {
1002 			symidx = ELF_R_SYM(rel->r_info);
1003 			if (symidx >= ef->ddbsymcnt)
1004 				continue;
1005 			sym = ef->ddbsymtab + symidx;
1006 			/* Local relocs are already done */
1007 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1008 				continue;
1009 			if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1010 			    elf_obj_lookup)) {
1011 				symname = symbol_name(ef, rel->r_info);
1012 				printf("link_elf_obj: symbol %s undefined\n",
1013 				    symname);
1014 				return ENOENT;
1015 			}
1016 		}
1017 	}
1018 
1019 	/* Perform relocations with addend if there are any: */
1020 	for (i = 0; i < ef->nrelatab; i++) {
1021 		rela = ef->relatab[i].rela;
1022 		if (rela == NULL)
1023 			panic("lost a relatab!");
1024 		relalim = rela + ef->relatab[i].nrela;
1025 		base = findbase(ef, ef->relatab[i].sec);
1026 		if (base == 0)
1027 			panic("lost base for relatab");
1028 		for ( ; rela < relalim; rela++) {
1029 			symidx = ELF_R_SYM(rela->r_info);
1030 			if (symidx >= ef->ddbsymcnt)
1031 				continue;
1032 			sym = ef->ddbsymtab + symidx;
1033 			/* Local relocs are already done */
1034 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1035 				continue;
1036 			if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1037 			    elf_obj_lookup)) {
1038 				symname = symbol_name(ef, rela->r_info);
1039 				printf("link_elf_obj: symbol %s undefined\n",
1040 				    symname);
1041 				return ENOENT;
1042 			}
1043 		}
1044 	}
1045 
1046 	return 0;
1047 }
1048 
1049 static int
1050 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1051 {
1052 	elf_file_t ef = (elf_file_t) lf;
1053 	const Elf_Sym *symp;
1054 	const char *strp;
1055 	int i;
1056 
1057 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1058 		strp = ef->ddbstrtab + symp->st_name;
1059 		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1060 			*sym = (c_linker_sym_t) symp;
1061 			return 0;
1062 		}
1063 	}
1064 	return ENOENT;
1065 }
1066 
1067 static int
1068 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1069     linker_symval_t *symval)
1070 {
1071 	elf_file_t ef = (elf_file_t) lf;
1072 	const Elf_Sym *es = (const Elf_Sym*) sym;
1073 
1074 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1075 		symval->name = ef->ddbstrtab + es->st_name;
1076 		symval->value = (caddr_t)es->st_value;
1077 		symval->size = es->st_size;
1078 		return 0;
1079 	}
1080 	return ENOENT;
1081 }
1082 
1083 static int
1084 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1085     c_linker_sym_t *sym, long *diffp)
1086 {
1087 	elf_file_t ef = (elf_file_t) lf;
1088 	u_long off = (uintptr_t) (void *) value;
1089 	u_long diff = off;
1090 	u_long st_value;
1091 	const Elf_Sym *es;
1092 	const Elf_Sym *best = 0;
1093 	int i;
1094 
1095 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1096 		if (es->st_name == 0)
1097 			continue;
1098 		st_value = es->st_value;
1099 		if (off >= st_value) {
1100 			if (off - st_value < diff) {
1101 				diff = off - st_value;
1102 				best = es;
1103 				if (diff == 0)
1104 					break;
1105 			} else if (off - st_value == diff) {
1106 				best = es;
1107 			}
1108 		}
1109 	}
1110 	if (best == 0)
1111 		*diffp = off;
1112 	else
1113 		*diffp = diff;
1114 	*sym = (c_linker_sym_t) best;
1115 
1116 	return 0;
1117 }
1118 
1119 /*
1120  * Look up a linker set on an ELF system.
1121  */
1122 static int
1123 link_elf_lookup_set(linker_file_t lf, const char *name,
1124     void ***startp, void ***stopp, int *countp)
1125 {
1126 	elf_file_t ef = (elf_file_t)lf;
1127 	void **start, **stop;
1128 	int i, count;
1129 
1130 	/* Relative to section number */
1131 	for (i = 0; i < ef->nprogtab; i++) {
1132 		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1133 		    strcmp(ef->progtab[i].name + 4, name) == 0) {
1134 			start  = (void **)ef->progtab[i].addr;
1135 			stop = (void **)((char *)ef->progtab[i].addr +
1136 			    ef->progtab[i].size);
1137 			count = stop - start;
1138 			if (startp)
1139 				*startp = start;
1140 			if (stopp)
1141 				*stopp = stop;
1142 			if (countp)
1143 				*countp = count;
1144 			return (0);
1145 		}
1146 	}
1147 	return (ESRCH);
1148 }
1149 
1150 static int
1151 link_elf_each_function_name(linker_file_t file,
1152     int (*callback)(const char *, void *), void *opaque)
1153 {
1154 	elf_file_t ef = (elf_file_t)file;
1155 	const Elf_Sym *symp;
1156 	int i, error;
1157 
1158 	/* Exhaustive search */
1159 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1160 		if (symp->st_value != 0 &&
1161 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1162 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1163 			if (error)
1164 				return (error);
1165 		}
1166 	}
1167 	return (0);
1168 }
1169 
1170 static int
1171 link_elf_each_function_nameval(linker_file_t file,
1172     linker_function_nameval_callback_t callback, void *opaque)
1173 {
1174 	linker_symval_t symval;
1175 	elf_file_t ef = (elf_file_t)file;
1176 	const Elf_Sym* symp;
1177 	int i, error;
1178 
1179 	/* Exhaustive search */
1180 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1181 		if (symp->st_value != 0 &&
1182 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1183 			error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1184 			if (error)
1185 				return (error);
1186 			error = callback(file, i, &symval, opaque);
1187 			if (error)
1188 				return (error);
1189 		}
1190 	}
1191 	return (0);
1192 }
1193 
1194 /*
1195  * Symbol lookup function that can be used when the symbol index is known (ie
1196  * in relocations). It uses the symbol index instead of doing a fully fledged
1197  * hash table based lookup when such is valid. For example for local symbols.
1198  * This is not only more efficient, it's also more correct. It's not always
1199  * the case that the symbol can be found through the hash table.
1200  */
1201 static Elf_Addr
1202 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1203 {
1204 	elf_file_t ef = (elf_file_t)lf;
1205 	const Elf_Sym *sym;
1206 	const char *symbol;
1207 	Elf_Addr ret;
1208 
1209 	/* Don't even try to lookup the symbol if the index is bogus. */
1210 	if (symidx >= ef->ddbsymcnt)
1211 		return (0);
1212 
1213 	sym = ef->ddbsymtab + symidx;
1214 
1215 	/* Quick answer if there is a definition included. */
1216 	if (sym->st_shndx != SHN_UNDEF)
1217 		return (sym->st_value);
1218 
1219 	/* If we get here, then it is undefined and needs a lookup. */
1220 	switch (ELF_ST_BIND(sym->st_info)) {
1221 	case STB_LOCAL:
1222 		/* Local, but undefined? huh? */
1223 		return (0);
1224 
1225 	case STB_GLOBAL:
1226 		/* Relative to Data or Function name */
1227 		symbol = ef->ddbstrtab + sym->st_name;
1228 
1229 		/* Force a lookup failure if the symbol name is bogus. */
1230 		if (*symbol == 0)
1231 			return (0);
1232 		ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1233 		return ret;
1234 
1235 	case STB_WEAK:
1236 		printf("link_elf_obj: Weak symbols not supported\n");
1237 		return (0);
1238 
1239 	default:
1240 		return (0);
1241 	}
1242 }
1243 
1244 static void
1245 link_elf_fix_link_set(elf_file_t ef)
1246 {
1247 	static const char startn[] = "__start_";
1248 	static const char stopn[] = "__stop_";
1249 	Elf_Sym *sym;
1250 	const char *sym_name, *linkset_name;
1251 	Elf_Addr startp, stopp;
1252 	Elf_Size symidx;
1253 	int start, i;
1254 
1255 	startp = stopp = 0;
1256 	for (symidx = 1 /* zero entry is special */;
1257 		symidx < ef->ddbsymcnt; symidx++) {
1258 		sym = ef->ddbsymtab + symidx;
1259 		if (sym->st_shndx != SHN_UNDEF)
1260 			continue;
1261 
1262 		sym_name = ef->ddbstrtab + sym->st_name;
1263 		if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1264 			start = 1;
1265 			linkset_name = sym_name + sizeof(startn) - 1;
1266 		}
1267 		else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1268 			start = 0;
1269 			linkset_name = sym_name + sizeof(stopn) - 1;
1270 		}
1271 		else
1272 			continue;
1273 
1274 		for (i = 0; i < ef->nprogtab; i++) {
1275 			if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1276 				startp = (Elf_Addr)ef->progtab[i].addr;
1277 				stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1278 				break;
1279 			}
1280 		}
1281 		if (i == ef->nprogtab)
1282 			continue;
1283 
1284 		sym->st_value = start ? startp : stopp;
1285 		sym->st_shndx = i;
1286 	}
1287 }
1288 
1289 static void
1290 link_elf_reloc_local(linker_file_t lf)
1291 {
1292 	elf_file_t ef = (elf_file_t)lf;
1293 	const Elf_Rel *rellim;
1294 	const Elf_Rel *rel;
1295 	const Elf_Rela *relalim;
1296 	const Elf_Rela *rela;
1297 	const Elf_Sym *sym;
1298 	Elf_Addr base;
1299 	int i;
1300 	Elf_Size symidx;
1301 
1302 	link_elf_fix_link_set(ef);
1303 
1304 	/* Perform relocations without addend if there are any: */
1305 	for (i = 0; i < ef->nreltab; i++) {
1306 		rel = ef->reltab[i].rel;
1307 		if (rel == NULL)
1308 			panic("lost a reltab!");
1309 		rellim = rel + ef->reltab[i].nrel;
1310 		base = findbase(ef, ef->reltab[i].sec);
1311 		if (base == 0)
1312 			panic("lost base for reltab");
1313 		for ( ; rel < rellim; rel++) {
1314 			symidx = ELF_R_SYM(rel->r_info);
1315 			if (symidx >= ef->ddbsymcnt)
1316 				continue;
1317 			sym = ef->ddbsymtab + symidx;
1318 			/* Only do local relocs */
1319 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1320 				continue;
1321 			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1322 			    elf_obj_lookup);
1323 		}
1324 	}
1325 
1326 	/* Perform relocations with addend if there are any: */
1327 	for (i = 0; i < ef->nrelatab; i++) {
1328 		rela = ef->relatab[i].rela;
1329 		if (rela == NULL)
1330 			panic("lost a relatab!");
1331 		relalim = rela + ef->relatab[i].nrela;
1332 		base = findbase(ef, ef->relatab[i].sec);
1333 		if (base == 0)
1334 			panic("lost base for relatab");
1335 		for ( ; rela < relalim; rela++) {
1336 			symidx = ELF_R_SYM(rela->r_info);
1337 			if (symidx >= ef->ddbsymcnt)
1338 				continue;
1339 			sym = ef->ddbsymtab + symidx;
1340 			/* Only do local relocs */
1341 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1342 				continue;
1343 			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1344 			    elf_obj_lookup);
1345 		}
1346 	}
1347 }
1348 
1349 static long
1350 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1351 {
1352     elf_file_t ef = (elf_file_t)lf;
1353 
1354     *symtab = ef->ddbsymtab;
1355 
1356     if (*symtab == NULL)
1357         return (0);
1358 
1359     return (ef->ddbsymcnt);
1360 }
1361 
1362 static long
1363 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1364 {
1365     elf_file_t ef = (elf_file_t)lf;
1366 
1367     *strtab = ef->ddbstrtab;
1368 
1369     if (*strtab == NULL)
1370         return (0);
1371 
1372     return (ef->ddbstrcnt);
1373 }
1374