xref: /freebsd/sys/kern/link_elf_obj.c (revision b7c60aadbbd5c846a250c05791fe7406d6d78bf4)
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 #ifdef __amd64__
688 	mapbase = KERNBASE;
689 #else
690 	mapbase = VM_MIN_KERNEL_ADDRESS;
691 #endif
692 	error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
693 	    round_page(mapsize), TRUE, VM_PROT_ALL, VM_PROT_ALL, FALSE);
694 	if (error) {
695 		vm_object_deallocate(ef->object);
696 		ef->object = 0;
697 		goto out;
698 	}
699 
700 	/* Wire the pages */
701 	error = vm_map_wire(kernel_map, mapbase,
702 	    mapbase + round_page(mapsize),
703 	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
704 	if (error != KERN_SUCCESS) {
705 		error = ENOMEM;
706 		goto out;
707 	}
708 
709 	/* Inform the kld system about the situation */
710 	lf->address = ef->address = (caddr_t)mapbase;
711 	lf->size = mapsize;
712 
713 	/*
714 	 * Now load code/data(progbits), zero bss(nobits), allocate space for
715 	 * and load relocs
716 	 */
717 	pb = 0;
718 	rl = 0;
719 	ra = 0;
720 	alignmask = 0;
721 	for (i = 0; i < hdr->e_shnum; i++) {
722 		if (shdr[i].sh_size == 0)
723 			continue;
724 		switch (shdr[i].sh_type) {
725 		case SHT_PROGBITS:
726 		case SHT_NOBITS:
727 			alignmask = shdr[i].sh_addralign - 1;
728 			mapbase += alignmask;
729 			mapbase &= ~alignmask;
730 			if (ef->shstrtab && shdr[i].sh_name != 0)
731 				ef->progtab[pb].name =
732 				    ef->shstrtab + shdr[i].sh_name;
733 			else if (shdr[i].sh_type == SHT_PROGBITS)
734 				ef->progtab[pb].name = "<<PROGBITS>>";
735 			else
736 				ef->progtab[pb].name = "<<NOBITS>>";
737 			if (ef->progtab[pb].name != NULL &&
738 			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
739 				ef->progtab[pb].addr =
740 				    dpcpu_alloc(shdr[i].sh_size);
741 #ifdef VIMAGE
742 			else if (ef->progtab[pb].name != NULL &&
743 			    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
744 				ef->progtab[pb].addr =
745 				    vnet_data_alloc(shdr[i].sh_size);
746 #endif
747 			else
748 				ef->progtab[pb].addr =
749 				    (void *)(uintptr_t)mapbase;
750 			if (ef->progtab[pb].addr == NULL) {
751 				error = ENOSPC;
752 				goto out;
753 			}
754 			ef->progtab[pb].size = shdr[i].sh_size;
755 			ef->progtab[pb].sec = i;
756 			if (shdr[i].sh_type == SHT_PROGBITS) {
757 				error = vn_rdwr(UIO_READ, nd.ni_vp,
758 				    ef->progtab[pb].addr,
759 				    shdr[i].sh_size, shdr[i].sh_offset,
760 				    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
761 				    NOCRED, &resid, td);
762 				if (error)
763 					goto out;
764 				if (resid != 0){
765 					error = EINVAL;
766 					goto out;
767 				}
768 				/* Initialize the per-cpu or vnet area. */
769 				if (ef->progtab[pb].addr != (void *)mapbase &&
770 				    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
771 					dpcpu_copy(ef->progtab[pb].addr,
772 					    shdr[i].sh_size);
773 #ifdef VIMAGE
774 				else if (ef->progtab[pb].addr !=
775 				    (void *)mapbase &&
776 				    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
777 					vnet_data_copy(ef->progtab[pb].addr,
778 					    shdr[i].sh_size);
779 #endif
780 			} else
781 				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
782 
783 			/* Update all symbol values with the offset. */
784 			for (j = 0; j < ef->ddbsymcnt; j++) {
785 				es = &ef->ddbsymtab[j];
786 				if (es->st_shndx != i)
787 					continue;
788 				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
789 			}
790 			mapbase += shdr[i].sh_size;
791 			pb++;
792 			break;
793 		case SHT_REL:
794 			ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
795 			    M_WAITOK);
796 			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
797 			ef->reltab[rl].sec = shdr[i].sh_info;
798 			error = vn_rdwr(UIO_READ, nd.ni_vp,
799 			    (void *)ef->reltab[rl].rel,
800 			    shdr[i].sh_size, shdr[i].sh_offset,
801 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
802 			    &resid, td);
803 			if (error)
804 				goto out;
805 			if (resid != 0){
806 				error = EINVAL;
807 				goto out;
808 			}
809 			rl++;
810 			break;
811 		case SHT_RELA:
812 			ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
813 			    M_WAITOK);
814 			ef->relatab[ra].nrela =
815 			    shdr[i].sh_size / sizeof(Elf_Rela);
816 			ef->relatab[ra].sec = shdr[i].sh_info;
817 			error = vn_rdwr(UIO_READ, nd.ni_vp,
818 			    (void *)ef->relatab[ra].rela,
819 			    shdr[i].sh_size, shdr[i].sh_offset,
820 			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
821 			    &resid, td);
822 			if (error)
823 				goto out;
824 			if (resid != 0){
825 				error = EINVAL;
826 				goto out;
827 			}
828 			ra++;
829 			break;
830 		}
831 	}
832 	if (pb != ef->nprogtab)
833 		panic("lost progbits");
834 	if (rl != ef->nreltab)
835 		panic("lost reltab");
836 	if (ra != ef->nrelatab)
837 		panic("lost relatab");
838 	if (mapbase != (vm_offset_t)ef->address + mapsize)
839 		panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
840 		    (u_long)mapbase, ef->address, (u_long)mapsize,
841 		    (u_long)(vm_offset_t)ef->address + mapsize);
842 
843 	/* Local intra-module relocations */
844 	link_elf_reloc_local(lf);
845 
846 	/* Pull in dependencies */
847 	VOP_UNLOCK(nd.ni_vp, 0);
848 	error = linker_load_dependencies(lf);
849 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
850 	if (error)
851 		goto out;
852 
853 	/* External relocations */
854 	error = relocate_file(ef);
855 	if (error)
856 		goto out;
857 
858 	/* Notify MD code that a module is being loaded. */
859 	error = elf_cpu_load_file(lf);
860 	if (error)
861 		goto out;
862 
863 	*result = lf;
864 
865 out:
866 	VOP_UNLOCK(nd.ni_vp, 0);
867 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
868 	VFS_UNLOCK_GIANT(vfslocked);
869 	if (error && lf)
870 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
871 	if (hdr)
872 		free(hdr, M_LINKER);
873 
874 	return error;
875 }
876 
877 static void
878 link_elf_unload_file(linker_file_t file)
879 {
880 	elf_file_t ef = (elf_file_t) file;
881 	int i;
882 
883 	/* Notify MD code that a module is being unloaded. */
884 	elf_cpu_unload_file(file);
885 
886 	if (ef->progtab) {
887 		for (i = 0; i < ef->nprogtab; i++) {
888 			if (ef->progtab[i].size == 0)
889 				continue;
890 			if (ef->progtab[i].name == NULL)
891 				continue;
892 			if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
893 				dpcpu_free(ef->progtab[i].addr,
894 				    ef->progtab[i].size);
895 #ifdef VIMAGE
896 			else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
897 				vnet_data_free(ef->progtab[i].addr,
898 				    ef->progtab[i].size);
899 #endif
900 		}
901 	}
902 	if (ef->preloaded) {
903 		if (ef->reltab)
904 			free(ef->reltab, M_LINKER);
905 		if (ef->relatab)
906 			free(ef->relatab, M_LINKER);
907 		if (ef->progtab)
908 			free(ef->progtab, M_LINKER);
909 		if (ef->ctftab)
910 			free(ef->ctftab, M_LINKER);
911 		if (ef->ctfoff)
912 			free(ef->ctfoff, M_LINKER);
913 		if (ef->typoff)
914 			free(ef->typoff, M_LINKER);
915 		if (file->filename != NULL)
916 			preload_delete_name(file->filename);
917 		/* XXX reclaim module memory? */
918 		return;
919 	}
920 
921 	for (i = 0; i < ef->nreltab; i++)
922 		if (ef->reltab[i].rel)
923 			free(ef->reltab[i].rel, M_LINKER);
924 	for (i = 0; i < ef->nrelatab; i++)
925 		if (ef->relatab[i].rela)
926 			free(ef->relatab[i].rela, M_LINKER);
927 	if (ef->reltab)
928 		free(ef->reltab, M_LINKER);
929 	if (ef->relatab)
930 		free(ef->relatab, M_LINKER);
931 	if (ef->progtab)
932 		free(ef->progtab, M_LINKER);
933 
934 	if (ef->object) {
935 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
936 		    (vm_offset_t) ef->address +
937 		    (ef->object->size << PAGE_SHIFT));
938 	}
939 	if (ef->e_shdr)
940 		free(ef->e_shdr, M_LINKER);
941 	if (ef->ddbsymtab)
942 		free(ef->ddbsymtab, M_LINKER);
943 	if (ef->ddbstrtab)
944 		free(ef->ddbstrtab, M_LINKER);
945 	if (ef->shstrtab)
946 		free(ef->shstrtab, M_LINKER);
947 	if (ef->ctftab)
948 		free(ef->ctftab, M_LINKER);
949 	if (ef->ctfoff)
950 		free(ef->ctfoff, M_LINKER);
951 	if (ef->typoff)
952 		free(ef->typoff, M_LINKER);
953 }
954 
955 static const char *
956 symbol_name(elf_file_t ef, Elf_Size r_info)
957 {
958 	const Elf_Sym *ref;
959 
960 	if (ELF_R_SYM(r_info)) {
961 		ref = ef->ddbsymtab + ELF_R_SYM(r_info);
962 		return ef->ddbstrtab + ref->st_name;
963 	} else
964 		return NULL;
965 }
966 
967 static Elf_Addr
968 findbase(elf_file_t ef, int sec)
969 {
970 	int i;
971 	Elf_Addr base = 0;
972 
973 	for (i = 0; i < ef->nprogtab; i++) {
974 		if (sec == ef->progtab[i].sec) {
975 			base = (Elf_Addr)ef->progtab[i].addr;
976 			break;
977 		}
978 	}
979 	return base;
980 }
981 
982 static int
983 relocate_file(elf_file_t ef)
984 {
985 	const Elf_Rel *rellim;
986 	const Elf_Rel *rel;
987 	const Elf_Rela *relalim;
988 	const Elf_Rela *rela;
989 	const char *symname;
990 	const Elf_Sym *sym;
991 	int i;
992 	Elf_Size symidx;
993 	Elf_Addr base;
994 
995 
996 	/* Perform relocations without addend if there are any: */
997 	for (i = 0; i < ef->nreltab; i++) {
998 		rel = ef->reltab[i].rel;
999 		if (rel == NULL)
1000 			panic("lost a reltab!");
1001 		rellim = rel + ef->reltab[i].nrel;
1002 		base = findbase(ef, ef->reltab[i].sec);
1003 		if (base == 0)
1004 			panic("lost base for reltab");
1005 		for ( ; rel < rellim; rel++) {
1006 			symidx = ELF_R_SYM(rel->r_info);
1007 			if (symidx >= ef->ddbsymcnt)
1008 				continue;
1009 			sym = ef->ddbsymtab + symidx;
1010 			/* Local relocs are already done */
1011 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1012 				continue;
1013 			if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1014 			    elf_obj_lookup)) {
1015 				symname = symbol_name(ef, rel->r_info);
1016 				printf("link_elf_obj: symbol %s undefined\n",
1017 				    symname);
1018 				return ENOENT;
1019 			}
1020 		}
1021 	}
1022 
1023 	/* Perform relocations with addend if there are any: */
1024 	for (i = 0; i < ef->nrelatab; i++) {
1025 		rela = ef->relatab[i].rela;
1026 		if (rela == NULL)
1027 			panic("lost a relatab!");
1028 		relalim = rela + ef->relatab[i].nrela;
1029 		base = findbase(ef, ef->relatab[i].sec);
1030 		if (base == 0)
1031 			panic("lost base for relatab");
1032 		for ( ; rela < relalim; rela++) {
1033 			symidx = ELF_R_SYM(rela->r_info);
1034 			if (symidx >= ef->ddbsymcnt)
1035 				continue;
1036 			sym = ef->ddbsymtab + symidx;
1037 			/* Local relocs are already done */
1038 			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1039 				continue;
1040 			if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1041 			    elf_obj_lookup)) {
1042 				symname = symbol_name(ef, rela->r_info);
1043 				printf("link_elf_obj: symbol %s undefined\n",
1044 				    symname);
1045 				return ENOENT;
1046 			}
1047 		}
1048 	}
1049 
1050 	return 0;
1051 }
1052 
1053 static int
1054 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1055 {
1056 	elf_file_t ef = (elf_file_t) lf;
1057 	const Elf_Sym *symp;
1058 	const char *strp;
1059 	int i;
1060 
1061 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1062 		strp = ef->ddbstrtab + symp->st_name;
1063 		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1064 			*sym = (c_linker_sym_t) symp;
1065 			return 0;
1066 		}
1067 	}
1068 	return ENOENT;
1069 }
1070 
1071 static int
1072 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1073     linker_symval_t *symval)
1074 {
1075 	elf_file_t ef = (elf_file_t) lf;
1076 	const Elf_Sym *es = (const Elf_Sym*) sym;
1077 
1078 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1079 		symval->name = ef->ddbstrtab + es->st_name;
1080 		symval->value = (caddr_t)es->st_value;
1081 		symval->size = es->st_size;
1082 		return 0;
1083 	}
1084 	return ENOENT;
1085 }
1086 
1087 static int
1088 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1089     c_linker_sym_t *sym, long *diffp)
1090 {
1091 	elf_file_t ef = (elf_file_t) lf;
1092 	u_long off = (uintptr_t) (void *) value;
1093 	u_long diff = off;
1094 	u_long st_value;
1095 	const Elf_Sym *es;
1096 	const Elf_Sym *best = 0;
1097 	int i;
1098 
1099 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1100 		if (es->st_name == 0)
1101 			continue;
1102 		st_value = es->st_value;
1103 		if (off >= st_value) {
1104 			if (off - st_value < diff) {
1105 				diff = off - st_value;
1106 				best = es;
1107 				if (diff == 0)
1108 					break;
1109 			} else if (off - st_value == diff) {
1110 				best = es;
1111 			}
1112 		}
1113 	}
1114 	if (best == 0)
1115 		*diffp = off;
1116 	else
1117 		*diffp = diff;
1118 	*sym = (c_linker_sym_t) best;
1119 
1120 	return 0;
1121 }
1122 
1123 /*
1124  * Look up a linker set on an ELF system.
1125  */
1126 static int
1127 link_elf_lookup_set(linker_file_t lf, const char *name,
1128     void ***startp, void ***stopp, int *countp)
1129 {
1130 	elf_file_t ef = (elf_file_t)lf;
1131 	void **start, **stop;
1132 	int i, count;
1133 
1134 	/* Relative to section number */
1135 	for (i = 0; i < ef->nprogtab; i++) {
1136 		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1137 		    strcmp(ef->progtab[i].name + 4, name) == 0) {
1138 			start  = (void **)ef->progtab[i].addr;
1139 			stop = (void **)((char *)ef->progtab[i].addr +
1140 			    ef->progtab[i].size);
1141 			count = stop - start;
1142 			if (startp)
1143 				*startp = start;
1144 			if (stopp)
1145 				*stopp = stop;
1146 			if (countp)
1147 				*countp = count;
1148 			return (0);
1149 		}
1150 	}
1151 	return (ESRCH);
1152 }
1153 
1154 static int
1155 link_elf_each_function_name(linker_file_t file,
1156     int (*callback)(const char *, void *), void *opaque)
1157 {
1158 	elf_file_t ef = (elf_file_t)file;
1159 	const Elf_Sym *symp;
1160 	int i, error;
1161 
1162 	/* Exhaustive search */
1163 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1164 		if (symp->st_value != 0 &&
1165 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1166 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1167 			if (error)
1168 				return (error);
1169 		}
1170 	}
1171 	return (0);
1172 }
1173 
1174 static int
1175 link_elf_each_function_nameval(linker_file_t file,
1176     linker_function_nameval_callback_t callback, void *opaque)
1177 {
1178 	linker_symval_t symval;
1179 	elf_file_t ef = (elf_file_t)file;
1180 	const Elf_Sym* symp;
1181 	int i, error;
1182 
1183 	/* Exhaustive search */
1184 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1185 		if (symp->st_value != 0 &&
1186 		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1187 			error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1188 			if (error)
1189 				return (error);
1190 			error = callback(file, i, &symval, opaque);
1191 			if (error)
1192 				return (error);
1193 		}
1194 	}
1195 	return (0);
1196 }
1197 
1198 /*
1199  * Symbol lookup function that can be used when the symbol index is known (ie
1200  * in relocations). It uses the symbol index instead of doing a fully fledged
1201  * hash table based lookup when such is valid. For example for local symbols.
1202  * This is not only more efficient, it's also more correct. It's not always
1203  * the case that the symbol can be found through the hash table.
1204  */
1205 static Elf_Addr
1206 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1207 {
1208 	elf_file_t ef = (elf_file_t)lf;
1209 	const Elf_Sym *sym;
1210 	const char *symbol;
1211 	Elf_Addr ret;
1212 
1213 	/* Don't even try to lookup the symbol if the index is bogus. */
1214 	if (symidx >= ef->ddbsymcnt)
1215 		return (0);
1216 
1217 	sym = ef->ddbsymtab + symidx;
1218 
1219 	/* Quick answer if there is a definition included. */
1220 	if (sym->st_shndx != SHN_UNDEF)
1221 		return (sym->st_value);
1222 
1223 	/* If we get here, then it is undefined and needs a lookup. */
1224 	switch (ELF_ST_BIND(sym->st_info)) {
1225 	case STB_LOCAL:
1226 		/* Local, but undefined? huh? */
1227 		return (0);
1228 
1229 	case STB_GLOBAL:
1230 		/* Relative to Data or Function name */
1231 		symbol = ef->ddbstrtab + sym->st_name;
1232 
1233 		/* Force a lookup failure if the symbol name is bogus. */
1234 		if (*symbol == 0)
1235 			return (0);
1236 		ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1237 		return ret;
1238 
1239 	case STB_WEAK:
1240 		printf("link_elf_obj: Weak symbols not supported\n");
1241 		return (0);
1242 
1243 	default:
1244 		return (0);
1245 	}
1246 }
1247 
1248 static void
1249 link_elf_fix_link_set(elf_file_t ef)
1250 {
1251 	static const char startn[] = "__start_";
1252 	static const char stopn[] = "__stop_";
1253 	Elf_Sym *sym;
1254 	const char *sym_name, *linkset_name;
1255 	Elf_Addr startp, stopp;
1256 	Elf_Size symidx;
1257 	int start, i;
1258 
1259 	startp = stopp = 0;
1260 	for (symidx = 1 /* zero entry is special */;
1261 		symidx < ef->ddbsymcnt; symidx++) {
1262 		sym = ef->ddbsymtab + symidx;
1263 		if (sym->st_shndx != SHN_UNDEF)
1264 			continue;
1265 
1266 		sym_name = ef->ddbstrtab + sym->st_name;
1267 		if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1268 			start = 1;
1269 			linkset_name = sym_name + sizeof(startn) - 1;
1270 		}
1271 		else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1272 			start = 0;
1273 			linkset_name = sym_name + sizeof(stopn) - 1;
1274 		}
1275 		else
1276 			continue;
1277 
1278 		for (i = 0; i < ef->nprogtab; i++) {
1279 			if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1280 				startp = (Elf_Addr)ef->progtab[i].addr;
1281 				stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1282 				break;
1283 			}
1284 		}
1285 		if (i == ef->nprogtab)
1286 			continue;
1287 
1288 		sym->st_value = start ? startp : stopp;
1289 		sym->st_shndx = i;
1290 	}
1291 }
1292 
1293 static void
1294 link_elf_reloc_local(linker_file_t lf)
1295 {
1296 	elf_file_t ef = (elf_file_t)lf;
1297 	const Elf_Rel *rellim;
1298 	const Elf_Rel *rel;
1299 	const Elf_Rela *relalim;
1300 	const Elf_Rela *rela;
1301 	const Elf_Sym *sym;
1302 	Elf_Addr base;
1303 	int i;
1304 	Elf_Size symidx;
1305 
1306 	link_elf_fix_link_set(ef);
1307 
1308 	/* Perform relocations without addend if there are any: */
1309 	for (i = 0; i < ef->nreltab; i++) {
1310 		rel = ef->reltab[i].rel;
1311 		if (rel == NULL)
1312 			panic("lost a reltab!");
1313 		rellim = rel + ef->reltab[i].nrel;
1314 		base = findbase(ef, ef->reltab[i].sec);
1315 		if (base == 0)
1316 			panic("lost base for reltab");
1317 		for ( ; rel < rellim; rel++) {
1318 			symidx = ELF_R_SYM(rel->r_info);
1319 			if (symidx >= ef->ddbsymcnt)
1320 				continue;
1321 			sym = ef->ddbsymtab + symidx;
1322 			/* Only do local relocs */
1323 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1324 				continue;
1325 			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1326 			    elf_obj_lookup);
1327 		}
1328 	}
1329 
1330 	/* Perform relocations with addend if there are any: */
1331 	for (i = 0; i < ef->nrelatab; i++) {
1332 		rela = ef->relatab[i].rela;
1333 		if (rela == NULL)
1334 			panic("lost a relatab!");
1335 		relalim = rela + ef->relatab[i].nrela;
1336 		base = findbase(ef, ef->relatab[i].sec);
1337 		if (base == 0)
1338 			panic("lost base for relatab");
1339 		for ( ; rela < relalim; rela++) {
1340 			symidx = ELF_R_SYM(rela->r_info);
1341 			if (symidx >= ef->ddbsymcnt)
1342 				continue;
1343 			sym = ef->ddbsymtab + symidx;
1344 			/* Only do local relocs */
1345 			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1346 				continue;
1347 			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1348 			    elf_obj_lookup);
1349 		}
1350 	}
1351 }
1352 
1353 static long
1354 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1355 {
1356     elf_file_t ef = (elf_file_t)lf;
1357 
1358     *symtab = ef->ddbsymtab;
1359 
1360     if (*symtab == NULL)
1361         return (0);
1362 
1363     return (ef->ddbsymcnt);
1364 }
1365 
1366 static long
1367 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1368 {
1369     elf_file_t ef = (elf_file_t)lf;
1370 
1371     *strtab = ef->ddbstrtab;
1372 
1373     if (*strtab == NULL)
1374         return (0);
1375 
1376     return (ef->ddbstrcnt);
1377 }
1378