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
68typedef struct {
69	void		*addr;
70	Elf_Off		size;
71	int		flags;
72	int		sec;	/* Original section */
73	char		*name;
74} Elf_progent;
75
76typedef struct {
77	Elf_Rel		*rel;
78	int		nrel;
79	int		sec;
80} Elf_relent;
81
82typedef struct {
83	Elf_Rela	*rela;
84	int		nrela;
85	int		sec;
86} Elf_relaent;
87
88
89typedef 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
124static int	link_elf_link_preload(linker_class_t cls,
125		    const char *, linker_file_t *);
126static int	link_elf_link_preload_finish(linker_file_t);
127static int	link_elf_load_file(linker_class_t, const char *, linker_file_t *);
128static int	link_elf_lookup_symbol(linker_file_t, const char *,
129		    c_linker_sym_t *);
130static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
131		    linker_symval_t *);
132static int	link_elf_search_symbol(linker_file_t, caddr_t value,
133		    c_linker_sym_t *sym, long *diffp);
134
135static void	link_elf_unload_file(linker_file_t);
136static int	link_elf_lookup_set(linker_file_t, const char *,
137		    void ***, void ***, int *);
138static int	link_elf_each_function_name(linker_file_t,
139		    int (*)(const char *, void *), void *);
140static int	link_elf_each_function_nameval(linker_file_t,
141				linker_function_nameval_callback_t,
142				void *);
143static int	link_elf_reloc_local(linker_file_t);
144static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
145static long	link_elf_strtab_get(linker_file_t, caddr_t *);
146
147static int	elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
148		    Elf_Addr *);
149
150static kobj_method_t link_elf_methods[] = {
151	KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
152	KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
153	KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
154	KOBJMETHOD(linker_unload,		link_elf_unload_file),
155	KOBJMETHOD(linker_load_file,		link_elf_load_file),
156	KOBJMETHOD(linker_link_preload,		link_elf_link_preload),
157	KOBJMETHOD(linker_link_preload_finish,	link_elf_link_preload_finish),
158	KOBJMETHOD(linker_lookup_set,		link_elf_lookup_set),
159	KOBJMETHOD(linker_each_function_name,	link_elf_each_function_name),
160	KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
161	KOBJMETHOD(linker_ctf_get,		link_elf_ctf_get),
162	KOBJMETHOD(linker_symtab_get, 		link_elf_symtab_get),
163	KOBJMETHOD(linker_strtab_get, 		link_elf_strtab_get),
164	{ 0, 0 }
165};
166
167static struct linker_class link_elf_class = {
168#if ELF_TARG_CLASS == ELFCLASS32
169	"elf32_obj",
170#else
171	"elf64_obj",
172#endif
173	link_elf_methods, sizeof(struct elf_file)
174};
175
176static int	relocate_file(elf_file_t ef);
177static void	elf_obj_cleanup_globals_cache(elf_file_t);
178
179static void
180link_elf_error(const char *filename, const char *s)
181{
182	if (filename == NULL)
183		printf("kldload: %s\n", s);
184	else
185		printf("kldload: %s: %s\n", filename, s);
186}
187
188static void
189link_elf_init(void *arg)
190{
191
192	linker_add_class(&link_elf_class);
193}
194
195SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
196
197static int
198link_elf_link_preload(linker_class_t cls, const char *filename,
199    linker_file_t *result)
200{
201	Elf_Ehdr *hdr;
202	Elf_Shdr *shdr;
203	Elf_Sym *es;
204	void *modptr, *baseptr, *sizeptr;
205	char *type;
206	elf_file_t ef;
207	linker_file_t lf;
208	Elf_Addr off;
209	int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
210
211	/* Look to see if we have the file preloaded */
212	modptr = preload_search_by_name(filename);
213	if (modptr == NULL)
214		return ENOENT;
215
216	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
217	baseptr = preload_search_info(modptr, MODINFO_ADDR);
218	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
219	hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
220	    MODINFOMD_ELFHDR);
221	shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
222	    MODINFOMD_SHDR);
223	if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
224	    " obj module") != 0 &&
225	    strcmp(type, "elf obj module") != 0)) {
226		return (EFTYPE);
227	}
228	if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
229	    shdr == NULL)
230		return (EINVAL);
231
232	lf = linker_make_file(filename, &link_elf_class);
233	if (lf == NULL)
234		return (ENOMEM);
235
236	ef = (elf_file_t)lf;
237	ef->preloaded = 1;
238	ef->address = *(caddr_t *)baseptr;
239	lf->address = *(caddr_t *)baseptr;
240	lf->size = *(size_t *)sizeptr;
241
242	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
243	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
244	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||
245	    hdr->e_version != EV_CURRENT ||
246	    hdr->e_type != ET_REL ||
247	    hdr->e_machine != ELF_TARG_MACH) {
248		error = EFTYPE;
249		goto out;
250	}
251	ef->e_shdr = shdr;
252
253	/* Scan the section header for information and table sizing. */
254	symtabindex = -1;
255	symstrindex = -1;
256	for (i = 0; i < hdr->e_shnum; i++) {
257		switch (shdr[i].sh_type) {
258		case SHT_PROGBITS:
259		case SHT_NOBITS:
260#ifdef __amd64__
261		case SHT_AMD64_UNWIND:
262#endif
263			ef->nprogtab++;
264			break;
265		case SHT_SYMTAB:
266			symtabindex = i;
267			symstrindex = shdr[i].sh_link;
268			break;
269		case SHT_REL:
270			ef->nreltab++;
271			break;
272		case SHT_RELA:
273			ef->nrelatab++;
274			break;
275		}
276	}
277
278	shstrindex = hdr->e_shstrndx;
279	if (ef->nprogtab == 0 || symstrindex < 0 ||
280	    symstrindex >= hdr->e_shnum ||
281	    shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
282	    shstrindex >= hdr->e_shnum ||
283	    shdr[shstrindex].sh_type != SHT_STRTAB) {
284		printf("%s: bad/missing section headers\n", filename);
285		error = ENOEXEC;
286		goto out;
287	}
288
289	/* Allocate space for tracking the load chunks */
290	if (ef->nprogtab != 0)
291		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
292		    M_LINKER, M_WAITOK | M_ZERO);
293	if (ef->nreltab != 0)
294		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
295		    M_LINKER, M_WAITOK | M_ZERO);
296	if (ef->nrelatab != 0)
297		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
298		    M_LINKER, M_WAITOK | M_ZERO);
299	if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
300	    (ef->nreltab != 0 && ef->reltab == NULL) ||
301	    (ef->nrelatab != 0 && ef->relatab == NULL)) {
302		error = ENOMEM;
303		goto out;
304	}
305
306	/* XXX, relocate the sh_addr fields saved by the loader. */
307	off = 0;
308	for (i = 0; i < hdr->e_shnum; i++) {
309		if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
310			off = shdr[i].sh_addr;
311	}
312	for (i = 0; i < hdr->e_shnum; i++) {
313		if (shdr[i].sh_addr != 0)
314			shdr[i].sh_addr = shdr[i].sh_addr - off +
315			    (Elf_Addr)ef->address;
316	}
317
318	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
319	ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
320	ef->ddbstrcnt = shdr[symstrindex].sh_size;
321	ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
322	ef->shstrcnt = shdr[shstrindex].sh_size;
323	ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
324
325	/* Now fill out progtab and the relocation tables. */
326	pb = 0;
327	rl = 0;
328	ra = 0;
329	for (i = 0; i < hdr->e_shnum; i++) {
330		switch (shdr[i].sh_type) {
331		case SHT_PROGBITS:
332		case SHT_NOBITS:
333#ifdef __amd64__
334		case SHT_AMD64_UNWIND:
335#endif
336			ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
337			if (shdr[i].sh_type == SHT_PROGBITS)
338				ef->progtab[pb].name = "<<PROGBITS>>";
339#ifdef __amd64__
340			else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
341				ef->progtab[pb].name = "<<UNWIND>>";
342#endif
343			else
344				ef->progtab[pb].name = "<<NOBITS>>";
345			ef->progtab[pb].size = shdr[i].sh_size;
346			ef->progtab[pb].sec = i;
347			if (ef->shstrtab && shdr[i].sh_name != 0)
348				ef->progtab[pb].name =
349				    ef->shstrtab + shdr[i].sh_name;
350			if (ef->progtab[pb].name != NULL &&
351			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
352				void *dpcpu;
353
354				dpcpu = dpcpu_alloc(shdr[i].sh_size);
355				if (dpcpu == NULL) {
356					error = ENOSPC;
357					goto out;
358				}
359				memcpy(dpcpu, ef->progtab[pb].addr,
360				    ef->progtab[pb].size);
361				dpcpu_copy(dpcpu, shdr[i].sh_size);
362				ef->progtab[pb].addr = dpcpu;
363#ifdef VIMAGE
364			} else if (ef->progtab[pb].name != NULL &&
365			    !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
366				void *vnet_data;
367
368				vnet_data = vnet_data_alloc(shdr[i].sh_size);
369				if (vnet_data == NULL) {
370					error = ENOSPC;
371					goto out;
372				}
373				memcpy(vnet_data, ef->progtab[pb].addr,
374				    ef->progtab[pb].size);
375				vnet_data_copy(vnet_data, shdr[i].sh_size);
376				ef->progtab[pb].addr = vnet_data;
377#endif
378			}
379
380			/* Update all symbol values with the offset. */
381			for (j = 0; j < ef->ddbsymcnt; j++) {
382				es = &ef->ddbsymtab[j];
383				if (es->st_shndx != i)
384					continue;
385				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
386			}
387			pb++;
388			break;
389		case SHT_REL:
390			ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
391			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
392			ef->reltab[rl].sec = shdr[i].sh_info;
393			rl++;
394			break;
395		case SHT_RELA:
396			ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
397			ef->relatab[ra].nrela =
398			    shdr[i].sh_size / sizeof(Elf_Rela);
399			ef->relatab[ra].sec = shdr[i].sh_info;
400			ra++;
401			break;
402		}
403	}
404	if (pb != ef->nprogtab) {
405		printf("%s: lost progbits\n", filename);
406		error = ENOEXEC;
407		goto out;
408	}
409	if (rl != ef->nreltab) {
410		printf("%s: lost reltab\n", filename);
411		error = ENOEXEC;
412		goto out;
413	}
414	if (ra != ef->nrelatab) {
415		printf("%s: lost relatab\n", filename);
416		error = ENOEXEC;
417		goto out;
418	}
419
420	/* Local intra-module relocations */
421	error = link_elf_reloc_local(lf);
422	if (error != 0)
423		goto out;
424
425	*result = lf;
426	return (0);
427
428out:
429	/* preload not done this way */
430	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
431	return (error);
432}
433
434static int
435link_elf_link_preload_finish(linker_file_t lf)
436{
437	elf_file_t ef;
438	int error;
439
440	ef = (elf_file_t)lf;
441	error = relocate_file(ef);
442	if (error)
443		return error;
444
445	/* Notify MD code that a module is being loaded. */
446	error = elf_cpu_load_file(lf);
447	if (error)
448		return (error);
449
450	return (0);
451}
452
453static int
454link_elf_load_file(linker_class_t cls, const char *filename,
455    linker_file_t *result)
456{
457	struct nameidata nd;
458	struct thread *td = curthread;	/* XXX */
459	Elf_Ehdr *hdr;
460	Elf_Shdr *shdr;
461	Elf_Sym *es;
462	int nbytes, i, j;
463	vm_offset_t mapbase;
464	size_t mapsize;
465	int error = 0;
466	ssize_t resid;
467	int flags;
468	elf_file_t ef;
469	linker_file_t lf;
470	int symtabindex;
471	int symstrindex;
472	int shstrindex;
473	int nsym;
474	int pb, rl, ra;
475	int alignmask;
476
477	shdr = NULL;
478	lf = NULL;
479	mapsize = 0;
480	hdr = NULL;
481
482	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
483	flags = FREAD;
484	error = vn_open(&nd, &flags, 0, NULL);
485	if (error)
486		return error;
487	NDFREE(&nd, NDF_ONLY_PNBUF);
488	if (nd.ni_vp->v_type != VREG) {
489		error = ENOEXEC;
490		goto out;
491	}
492#ifdef MAC
493	error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
494	if (error) {
495		goto out;
496	}
497#endif
498
499	/* Read the elf header from the file. */
500	hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
501	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
502	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
503	    &resid, td);
504	if (error)
505		goto out;
506	if (resid != 0){
507		error = ENOEXEC;
508		goto out;
509	}
510
511	if (!IS_ELF(*hdr)) {
512		error = ENOEXEC;
513		goto out;
514	}
515
516	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
517	    || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
518		link_elf_error(filename, "Unsupported file layout");
519		error = ENOEXEC;
520		goto out;
521	}
522	if (hdr->e_ident[EI_VERSION] != EV_CURRENT
523	    || hdr->e_version != EV_CURRENT) {
524		link_elf_error(filename, "Unsupported file version");
525		error = ENOEXEC;
526		goto out;
527	}
528	if (hdr->e_type != ET_REL) {
529		error = ENOSYS;
530		goto out;
531	}
532	if (hdr->e_machine != ELF_TARG_MACH) {
533		link_elf_error(filename, "Unsupported machine");
534		error = ENOEXEC;
535		goto out;
536	}
537
538	lf = linker_make_file(filename, &link_elf_class);
539	if (!lf) {
540		error = ENOMEM;
541		goto out;
542	}
543	ef = (elf_file_t) lf;
544	ef->nprogtab = 0;
545	ef->e_shdr = 0;
546	ef->nreltab = 0;
547	ef->nrelatab = 0;
548
549	/* Allocate and read in the section header */
550	nbytes = hdr->e_shnum * hdr->e_shentsize;
551	if (nbytes == 0 || hdr->e_shoff == 0 ||
552	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
553		error = ENOEXEC;
554		goto out;
555	}
556	shdr = malloc(nbytes, M_LINKER, M_WAITOK);
557	ef->e_shdr = shdr;
558	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
559	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
560	if (error)
561		goto out;
562	if (resid) {
563		error = ENOEXEC;
564		goto out;
565	}
566
567	/* Scan the section header for information and table sizing. */
568	nsym = 0;
569	symtabindex = -1;
570	symstrindex = -1;
571	for (i = 0; i < hdr->e_shnum; i++) {
572		if (shdr[i].sh_size == 0)
573			continue;
574		switch (shdr[i].sh_type) {
575		case SHT_PROGBITS:
576		case SHT_NOBITS:
577#ifdef __amd64__
578		case SHT_AMD64_UNWIND:
579#endif
580			ef->nprogtab++;
581			break;
582		case SHT_SYMTAB:
583			nsym++;
584			symtabindex = i;
585			symstrindex = shdr[i].sh_link;
586			break;
587		case SHT_REL:
588			ef->nreltab++;
589			break;
590		case SHT_RELA:
591			ef->nrelatab++;
592			break;
593		case SHT_STRTAB:
594			break;
595		}
596	}
597	if (ef->nprogtab == 0) {
598		link_elf_error(filename, "file has no contents");
599		error = ENOEXEC;
600		goto out;
601	}
602	if (nsym != 1) {
603		/* Only allow one symbol table for now */
604		link_elf_error(filename, "file has no valid symbol table");
605		error = ENOEXEC;
606		goto out;
607	}
608	if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
609	    shdr[symstrindex].sh_type != SHT_STRTAB) {
610		link_elf_error(filename, "file has invalid symbol strings");
611		error = ENOEXEC;
612		goto out;
613	}
614
615	/* Allocate space for tracking the load chunks */
616	if (ef->nprogtab != 0)
617		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
618		    M_LINKER, M_WAITOK | M_ZERO);
619	if (ef->nreltab != 0)
620		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
621		    M_LINKER, M_WAITOK | M_ZERO);
622	if (ef->nrelatab != 0)
623		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
624		    M_LINKER, M_WAITOK | M_ZERO);
625
626	if (symtabindex == -1) {
627		link_elf_error(filename, "lost symbol table index");
628		error = ENOEXEC;
629		goto out;
630	}
631	/* Allocate space for and load the symbol table */
632	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
633	ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
634	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
635	    shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
636	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
637	    &resid, td);
638	if (error)
639		goto out;
640	if (resid != 0){
641		error = EINVAL;
642		goto out;
643	}
644
645	if (symstrindex == -1) {
646		link_elf_error(filename, "lost symbol string index");
647		error = ENOEXEC;
648		goto out;
649	}
650	/* Allocate space for and load the symbol strings */
651	ef->ddbstrcnt = shdr[symstrindex].sh_size;
652	ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
653	error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
654	    shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
655	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
656	    &resid, td);
657	if (error)
658		goto out;
659	if (resid != 0){
660		error = EINVAL;
661		goto out;
662	}
663
664	/* Do we have a string table for the section names?  */
665	shstrindex = -1;
666	if (hdr->e_shstrndx != 0 &&
667	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
668		shstrindex = hdr->e_shstrndx;
669		ef->shstrcnt = shdr[shstrindex].sh_size;
670		ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
671		    M_WAITOK);
672		error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
673		    shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
674		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
675		    &resid, td);
676		if (error)
677			goto out;
678		if (resid != 0){
679			error = EINVAL;
680			goto out;
681		}
682	}
683
684	/* Size up code/data(progbits) and bss(nobits). */
685	alignmask = 0;
686	for (i = 0; i < hdr->e_shnum; i++) {
687		if (shdr[i].sh_size == 0)
688			continue;
689		switch (shdr[i].sh_type) {
690		case SHT_PROGBITS:
691		case SHT_NOBITS:
692#ifdef __amd64__
693		case SHT_AMD64_UNWIND:
694#endif
695			alignmask = shdr[i].sh_addralign - 1;
696			mapsize += alignmask;
697			mapsize &= ~alignmask;
698			mapsize += shdr[i].sh_size;
699			break;
700		}
701	}
702
703	/*
704	 * We know how much space we need for the text/data/bss/etc.
705	 * This stuff needs to be in a single chunk so that profiling etc
706	 * can get the bounds and gdb can associate offsets with modules
707	 */
708	ef->object = vm_object_allocate(OBJT_DEFAULT,
709	    round_page(mapsize) >> PAGE_SHIFT);
710	if (ef->object == NULL) {
711		error = ENOMEM;
712		goto out;
713	}
714	ef->address = (caddr_t) vm_map_min(kernel_map);
715
716	/*
717	 * In order to satisfy amd64's architectural requirements on the
718	 * location of code and data in the kernel's address space, request a
719	 * mapping that is above the kernel.
720	 */
721#ifdef __amd64__
722	mapbase = KERNBASE;
723#else
724	mapbase = VM_MIN_KERNEL_ADDRESS;
725#endif
726	error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
727	    round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
728	    VM_PROT_ALL, 0);
729	if (error) {
730		vm_object_deallocate(ef->object);
731		ef->object = 0;
732		goto out;
733	}
734
735	/* Wire the pages */
736	error = vm_map_wire(kernel_map, mapbase,
737	    mapbase + round_page(mapsize),
738	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
739	if (error != KERN_SUCCESS) {
740		error = ENOMEM;
741		goto out;
742	}
743
744	/* Inform the kld system about the situation */
745	lf->address = ef->address = (caddr_t)mapbase;
746	lf->size = mapsize;
747
748	/*
749	 * Now load code/data(progbits), zero bss(nobits), allocate space for
750	 * and load relocs
751	 */
752	pb = 0;
753	rl = 0;
754	ra = 0;
755	alignmask = 0;
756	for (i = 0; i < hdr->e_shnum; i++) {
757		if (shdr[i].sh_size == 0)
758			continue;
759		switch (shdr[i].sh_type) {
760		case SHT_PROGBITS:
761		case SHT_NOBITS:
762#ifdef __amd64__
763		case SHT_AMD64_UNWIND:
764#endif
765			alignmask = shdr[i].sh_addralign - 1;
766			mapbase += alignmask;
767			mapbase &= ~alignmask;
768			if (ef->shstrtab && shdr[i].sh_name != 0)
769				ef->progtab[pb].name =
770				    ef->shstrtab + shdr[i].sh_name;
771			else if (shdr[i].sh_type == SHT_PROGBITS)
772				ef->progtab[pb].name = "<<PROGBITS>>";
773#ifdef __amd64__
774			else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
775				ef->progtab[pb].name = "<<UNWIND>>";
776#endif
777			else
778				ef->progtab[pb].name = "<<NOBITS>>";
779			if (ef->progtab[pb].name != NULL &&
780			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
781				ef->progtab[pb].addr =
782				    dpcpu_alloc(shdr[i].sh_size);
783#ifdef VIMAGE
784			else if (ef->progtab[pb].name != NULL &&
785			    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
786				ef->progtab[pb].addr =
787				    vnet_data_alloc(shdr[i].sh_size);
788#endif
789			else
790				ef->progtab[pb].addr =
791				    (void *)(uintptr_t)mapbase;
792			if (ef->progtab[pb].addr == NULL) {
793				error = ENOSPC;
794				goto out;
795			}
796			ef->progtab[pb].size = shdr[i].sh_size;
797			ef->progtab[pb].sec = i;
798			if (shdr[i].sh_type == SHT_PROGBITS
799#ifdef __amd64__
800			    || shdr[i].sh_type == SHT_AMD64_UNWIND
801#endif
802			    ) {
803				error = vn_rdwr(UIO_READ, nd.ni_vp,
804				    ef->progtab[pb].addr,
805				    shdr[i].sh_size, shdr[i].sh_offset,
806				    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
807				    NOCRED, &resid, td);
808				if (error)
809					goto out;
810				if (resid != 0){
811					error = EINVAL;
812					goto out;
813				}
814				/* Initialize the per-cpu or vnet area. */
815				if (ef->progtab[pb].addr != (void *)mapbase &&
816				    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
817					dpcpu_copy(ef->progtab[pb].addr,
818					    shdr[i].sh_size);
819#ifdef VIMAGE
820				else if (ef->progtab[pb].addr !=
821				    (void *)mapbase &&
822				    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
823					vnet_data_copy(ef->progtab[pb].addr,
824					    shdr[i].sh_size);
825#endif
826			} else
827				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
828
829			/* Update all symbol values with the offset. */
830			for (j = 0; j < ef->ddbsymcnt; j++) {
831				es = &ef->ddbsymtab[j];
832				if (es->st_shndx != i)
833					continue;
834				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
835			}
836			mapbase += shdr[i].sh_size;
837			pb++;
838			break;
839		case SHT_REL:
840			ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
841			    M_WAITOK);
842			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
843			ef->reltab[rl].sec = shdr[i].sh_info;
844			error = vn_rdwr(UIO_READ, nd.ni_vp,
845			    (void *)ef->reltab[rl].rel,
846			    shdr[i].sh_size, shdr[i].sh_offset,
847			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
848			    &resid, td);
849			if (error)
850				goto out;
851			if (resid != 0){
852				error = EINVAL;
853				goto out;
854			}
855			rl++;
856			break;
857		case SHT_RELA:
858			ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
859			    M_WAITOK);
860			ef->relatab[ra].nrela =
861			    shdr[i].sh_size / sizeof(Elf_Rela);
862			ef->relatab[ra].sec = shdr[i].sh_info;
863			error = vn_rdwr(UIO_READ, nd.ni_vp,
864			    (void *)ef->relatab[ra].rela,
865			    shdr[i].sh_size, shdr[i].sh_offset,
866			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
867			    &resid, td);
868			if (error)
869				goto out;
870			if (resid != 0){
871				error = EINVAL;
872				goto out;
873			}
874			ra++;
875			break;
876		}
877	}
878	if (pb != ef->nprogtab) {
879		link_elf_error(filename, "lost progbits");
880		error = ENOEXEC;
881		goto out;
882	}
883	if (rl != ef->nreltab) {
884		link_elf_error(filename, "lost reltab");
885		error = ENOEXEC;
886		goto out;
887	}
888	if (ra != ef->nrelatab) {
889		link_elf_error(filename, "lost relatab");
890		error = ENOEXEC;
891		goto out;
892	}
893	if (mapbase != (vm_offset_t)ef->address + mapsize) {
894		printf(
895		    "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
896		    filename != NULL ? filename : "<none>",
897		    (u_long)mapbase, ef->address, (u_long)mapsize,
898		    (u_long)(vm_offset_t)ef->address + mapsize);
899		error = ENOMEM;
900		goto out;
901	}
902
903	/* Local intra-module relocations */
904	error = link_elf_reloc_local(lf);
905	if (error != 0)
906		goto out;
907
908	/* Pull in dependencies */
909	VOP_UNLOCK(nd.ni_vp, 0);
910	error = linker_load_dependencies(lf);
911	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
912	if (error)
913		goto out;
914
915	/* External relocations */
916	error = relocate_file(ef);
917	if (error)
918		goto out;
919
920	/* Notify MD code that a module is being loaded. */
921	error = elf_cpu_load_file(lf);
922	if (error)
923		goto out;
924
925	*result = lf;
926
927out:
928	VOP_UNLOCK(nd.ni_vp, 0);
929	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
930	if (error && lf)
931		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
932	free(hdr, M_LINKER);
933
934	return error;
935}
936
937static void
938link_elf_unload_file(linker_file_t file)
939{
940	elf_file_t ef = (elf_file_t) file;
941	int i;
942
943	/* Notify MD code that a module is being unloaded. */
944	elf_cpu_unload_file(file);
945
946	if (ef->progtab) {
947		for (i = 0; i < ef->nprogtab; i++) {
948			if (ef->progtab[i].size == 0)
949				continue;
950			if (ef->progtab[i].name == NULL)
951				continue;
952			if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
953				dpcpu_free(ef->progtab[i].addr,
954				    ef->progtab[i].size);
955#ifdef VIMAGE
956			else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
957				vnet_data_free(ef->progtab[i].addr,
958				    ef->progtab[i].size);
959#endif
960		}
961	}
962	if (ef->preloaded) {
963		free(ef->reltab, M_LINKER);
964		free(ef->relatab, M_LINKER);
965		free(ef->progtab, M_LINKER);
966		free(ef->ctftab, M_LINKER);
967		free(ef->ctfoff, M_LINKER);
968		free(ef->typoff, M_LINKER);
969		if (file->filename != NULL)
970			preload_delete_name(file->filename);
971		/* XXX reclaim module memory? */
972		return;
973	}
974
975	for (i = 0; i < ef->nreltab; i++)
976		free(ef->reltab[i].rel, M_LINKER);
977	for (i = 0; i < ef->nrelatab; i++)
978		free(ef->relatab[i].rela, M_LINKER);
979	free(ef->reltab, M_LINKER);
980	free(ef->relatab, M_LINKER);
981	free(ef->progtab, M_LINKER);
982
983	if (ef->object) {
984		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
985		    (vm_offset_t) ef->address +
986		    (ef->object->size << PAGE_SHIFT));
987	}
988	free(ef->e_shdr, M_LINKER);
989	free(ef->ddbsymtab, M_LINKER);
990	free(ef->ddbstrtab, M_LINKER);
991	free(ef->shstrtab, M_LINKER);
992	free(ef->ctftab, M_LINKER);
993	free(ef->ctfoff, M_LINKER);
994	free(ef->typoff, M_LINKER);
995}
996
997static const char *
998symbol_name(elf_file_t ef, Elf_Size r_info)
999{
1000	const Elf_Sym *ref;
1001
1002	if (ELF_R_SYM(r_info)) {
1003		ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1004		return ef->ddbstrtab + ref->st_name;
1005	} else
1006		return NULL;
1007}
1008
1009static Elf_Addr
1010findbase(elf_file_t ef, int sec)
1011{
1012	int i;
1013	Elf_Addr base = 0;
1014
1015	for (i = 0; i < ef->nprogtab; i++) {
1016		if (sec == ef->progtab[i].sec) {
1017			base = (Elf_Addr)ef->progtab[i].addr;
1018			break;
1019		}
1020	}
1021	return base;
1022}
1023
1024static int
1025relocate_file(elf_file_t ef)
1026{
1027	const Elf_Rel *rellim;
1028	const Elf_Rel *rel;
1029	const Elf_Rela *relalim;
1030	const Elf_Rela *rela;
1031	const char *symname;
1032	const Elf_Sym *sym;
1033	int i;
1034	Elf_Size symidx;
1035	Elf_Addr base;
1036
1037
1038	/* Perform relocations without addend if there are any: */
1039	for (i = 0; i < ef->nreltab; i++) {
1040		rel = ef->reltab[i].rel;
1041		if (rel == NULL) {
1042			link_elf_error(ef->lf.filename, "lost a reltab!");
1043			return (ENOEXEC);
1044		}
1045		rellim = rel + ef->reltab[i].nrel;
1046		base = findbase(ef, ef->reltab[i].sec);
1047		if (base == 0) {
1048			link_elf_error(ef->lf.filename, "lost base for reltab");
1049			return (ENOEXEC);
1050		}
1051		for ( ; rel < rellim; rel++) {
1052			symidx = ELF_R_SYM(rel->r_info);
1053			if (symidx >= ef->ddbsymcnt)
1054				continue;
1055			sym = ef->ddbsymtab + symidx;
1056			/* Local relocs are already done */
1057			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1058				continue;
1059			if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1060			    elf_obj_lookup)) {
1061				symname = symbol_name(ef, rel->r_info);
1062				printf("link_elf_obj: symbol %s undefined\n",
1063				    symname);
1064				return (ENOENT);
1065			}
1066		}
1067	}
1068
1069	/* Perform relocations with addend if there are any: */
1070	for (i = 0; i < ef->nrelatab; i++) {
1071		rela = ef->relatab[i].rela;
1072		if (rela == NULL) {
1073			link_elf_error(ef->lf.filename, "lost a relatab!");
1074			return (ENOEXEC);
1075		}
1076		relalim = rela + ef->relatab[i].nrela;
1077		base = findbase(ef, ef->relatab[i].sec);
1078		if (base == 0) {
1079			link_elf_error(ef->lf.filename,
1080			    "lost base for relatab");
1081			return (ENOEXEC);
1082		}
1083		for ( ; rela < relalim; rela++) {
1084			symidx = ELF_R_SYM(rela->r_info);
1085			if (symidx >= ef->ddbsymcnt)
1086				continue;
1087			sym = ef->ddbsymtab + symidx;
1088			/* Local relocs are already done */
1089			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1090				continue;
1091			if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1092			    elf_obj_lookup)) {
1093				symname = symbol_name(ef, rela->r_info);
1094				printf("link_elf_obj: symbol %s undefined\n",
1095				    symname);
1096				return (ENOENT);
1097			}
1098		}
1099	}
1100
1101	/*
1102	 * Only clean SHN_FBSD_CACHED for successful return.  If we
1103	 * modified symbol table for the object but found an
1104	 * unresolved symbol, there is no reason to roll back.
1105	 */
1106	elf_obj_cleanup_globals_cache(ef);
1107
1108	return (0);
1109}
1110
1111static int
1112link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1113{
1114	elf_file_t ef = (elf_file_t) lf;
1115	const Elf_Sym *symp;
1116	const char *strp;
1117	int i;
1118
1119	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1120		strp = ef->ddbstrtab + symp->st_name;
1121		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1122			*sym = (c_linker_sym_t) symp;
1123			return 0;
1124		}
1125	}
1126	return ENOENT;
1127}
1128
1129static int
1130link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1131    linker_symval_t *symval)
1132{
1133	elf_file_t ef = (elf_file_t) lf;
1134	const Elf_Sym *es = (const Elf_Sym*) sym;
1135
1136	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1137		symval->name = ef->ddbstrtab + es->st_name;
1138		symval->value = (caddr_t)es->st_value;
1139		symval->size = es->st_size;
1140		return 0;
1141	}
1142	return ENOENT;
1143}
1144
1145static int
1146link_elf_search_symbol(linker_file_t lf, caddr_t value,
1147    c_linker_sym_t *sym, long *diffp)
1148{
1149	elf_file_t ef = (elf_file_t) lf;
1150	u_long off = (uintptr_t) (void *) value;
1151	u_long diff = off;
1152	u_long st_value;
1153	const Elf_Sym *es;
1154	const Elf_Sym *best = 0;
1155	int i;
1156
1157	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1158		if (es->st_name == 0)
1159			continue;
1160		st_value = es->st_value;
1161		if (off >= st_value) {
1162			if (off - st_value < diff) {
1163				diff = off - st_value;
1164				best = es;
1165				if (diff == 0)
1166					break;
1167			} else if (off - st_value == diff) {
1168				best = es;
1169			}
1170		}
1171	}
1172	if (best == 0)
1173		*diffp = off;
1174	else
1175		*diffp = diff;
1176	*sym = (c_linker_sym_t) best;
1177
1178	return 0;
1179}
1180
1181/*
1182 * Look up a linker set on an ELF system.
1183 */
1184static int
1185link_elf_lookup_set(linker_file_t lf, const char *name,
1186    void ***startp, void ***stopp, int *countp)
1187{
1188	elf_file_t ef = (elf_file_t)lf;
1189	void **start, **stop;
1190	int i, count;
1191
1192	/* Relative to section number */
1193	for (i = 0; i < ef->nprogtab; i++) {
1194		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1195		    strcmp(ef->progtab[i].name + 4, name) == 0) {
1196			start  = (void **)ef->progtab[i].addr;
1197			stop = (void **)((char *)ef->progtab[i].addr +
1198			    ef->progtab[i].size);
1199			count = stop - start;
1200			if (startp)
1201				*startp = start;
1202			if (stopp)
1203				*stopp = stop;
1204			if (countp)
1205				*countp = count;
1206			return (0);
1207		}
1208	}
1209	return (ESRCH);
1210}
1211
1212static int
1213link_elf_each_function_name(linker_file_t file,
1214    int (*callback)(const char *, void *), void *opaque)
1215{
1216	elf_file_t ef = (elf_file_t)file;
1217	const Elf_Sym *symp;
1218	int i, error;
1219
1220	/* Exhaustive search */
1221	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1222		if (symp->st_value != 0 &&
1223		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1224			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1225			if (error)
1226				return (error);
1227		}
1228	}
1229	return (0);
1230}
1231
1232static int
1233link_elf_each_function_nameval(linker_file_t file,
1234    linker_function_nameval_callback_t callback, void *opaque)
1235{
1236	linker_symval_t symval;
1237	elf_file_t ef = (elf_file_t)file;
1238	const Elf_Sym* symp;
1239	int i, error;
1240
1241	/* Exhaustive search */
1242	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1243		if (symp->st_value != 0 &&
1244		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1245			error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1246			if (error)
1247				return (error);
1248			error = callback(file, i, &symval, opaque);
1249			if (error)
1250				return (error);
1251		}
1252	}
1253	return (0);
1254}
1255
1256static void
1257elf_obj_cleanup_globals_cache(elf_file_t ef)
1258{
1259	Elf_Sym *sym;
1260	Elf_Size i;
1261
1262	for (i = 0; i < ef->ddbsymcnt; i++) {
1263		sym = ef->ddbsymtab + i;
1264		if (sym->st_shndx == SHN_FBSD_CACHED) {
1265			sym->st_shndx = SHN_UNDEF;
1266			sym->st_value = 0;
1267		}
1268	}
1269}
1270
1271/*
1272 * Symbol lookup function that can be used when the symbol index is known (ie
1273 * in relocations). It uses the symbol index instead of doing a fully fledged
1274 * hash table based lookup when such is valid. For example for local symbols.
1275 * This is not only more efficient, it's also more correct. It's not always
1276 * the case that the symbol can be found through the hash table.
1277 */
1278static int
1279elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1280{
1281	elf_file_t ef = (elf_file_t)lf;
1282	Elf_Sym *sym;
1283	const char *symbol;
1284	Elf_Addr res1;
1285
1286	/* Don't even try to lookup the symbol if the index is bogus. */
1287	if (symidx >= ef->ddbsymcnt) {
1288		*res = 0;
1289		return (EINVAL);
1290	}
1291
1292	sym = ef->ddbsymtab + symidx;
1293
1294	/* Quick answer if there is a definition included. */
1295	if (sym->st_shndx != SHN_UNDEF) {
1296		*res = sym->st_value;
1297		return (0);
1298	}
1299
1300	/* If we get here, then it is undefined and needs a lookup. */
1301	switch (ELF_ST_BIND(sym->st_info)) {
1302	case STB_LOCAL:
1303		/* Local, but undefined? huh? */
1304		*res = 0;
1305		return (EINVAL);
1306
1307	case STB_GLOBAL:
1308	case STB_WEAK:
1309		/* Relative to Data or Function name */
1310		symbol = ef->ddbstrtab + sym->st_name;
1311
1312		/* Force a lookup failure if the symbol name is bogus. */
1313		if (*symbol == 0) {
1314			*res = 0;
1315			return (EINVAL);
1316		}
1317		res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1318
1319		/*
1320		 * Cache global lookups during module relocation. The failure
1321		 * case is particularly expensive for callers, who must scan
1322		 * through the entire globals table doing strcmp(). Cache to
1323		 * avoid doing such work repeatedly.
1324		 *
1325		 * After relocation is complete, undefined globals will be
1326		 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1327		 * above.
1328		 */
1329		if (res1 != 0) {
1330			sym->st_shndx = SHN_FBSD_CACHED;
1331			sym->st_value = res1;
1332			*res = res1;
1333			return (0);
1334		} else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1335			sym->st_value = 0;
1336			*res = 0;
1337			return (0);
1338		}
1339		return (EINVAL);
1340
1341	default:
1342		return (EINVAL);
1343	}
1344}
1345
1346static void
1347link_elf_fix_link_set(elf_file_t ef)
1348{
1349	static const char startn[] = "__start_";
1350	static const char stopn[] = "__stop_";
1351	Elf_Sym *sym;
1352	const char *sym_name, *linkset_name;
1353	Elf_Addr startp, stopp;
1354	Elf_Size symidx;
1355	int start, i;
1356
1357	startp = stopp = 0;
1358	for (symidx = 1 /* zero entry is special */;
1359		symidx < ef->ddbsymcnt; symidx++) {
1360		sym = ef->ddbsymtab + symidx;
1361		if (sym->st_shndx != SHN_UNDEF)
1362			continue;
1363
1364		sym_name = ef->ddbstrtab + sym->st_name;
1365		if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1366			start = 1;
1367			linkset_name = sym_name + sizeof(startn) - 1;
1368		}
1369		else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1370			start = 0;
1371			linkset_name = sym_name + sizeof(stopn) - 1;
1372		}
1373		else
1374			continue;
1375
1376		for (i = 0; i < ef->nprogtab; i++) {
1377			if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1378				startp = (Elf_Addr)ef->progtab[i].addr;
1379				stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1380				break;
1381			}
1382		}
1383		if (i == ef->nprogtab)
1384			continue;
1385
1386		sym->st_value = start ? startp : stopp;
1387		sym->st_shndx = i;
1388	}
1389}
1390
1391static int
1392link_elf_reloc_local(linker_file_t lf)
1393{
1394	elf_file_t ef = (elf_file_t)lf;
1395	const Elf_Rel *rellim;
1396	const Elf_Rel *rel;
1397	const Elf_Rela *relalim;
1398	const Elf_Rela *rela;
1399	const Elf_Sym *sym;
1400	Elf_Addr base;
1401	int i;
1402	Elf_Size symidx;
1403
1404	link_elf_fix_link_set(ef);
1405
1406	/* Perform relocations without addend if there are any: */
1407	for (i = 0; i < ef->nreltab; i++) {
1408		rel = ef->reltab[i].rel;
1409		if (rel == NULL) {
1410			link_elf_error(ef->lf.filename, "lost a reltab");
1411			return (ENOEXEC);
1412		}
1413		rellim = rel + ef->reltab[i].nrel;
1414		base = findbase(ef, ef->reltab[i].sec);
1415		if (base == 0) {
1416			link_elf_error(ef->lf.filename, "lost base for reltab");
1417			return (ENOEXEC);
1418		}
1419		for ( ; rel < rellim; rel++) {
1420			symidx = ELF_R_SYM(rel->r_info);
1421			if (symidx >= ef->ddbsymcnt)
1422				continue;
1423			sym = ef->ddbsymtab + symidx;
1424			/* Only do local relocs */
1425			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1426				continue;
1427			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1428			    elf_obj_lookup);
1429		}
1430	}
1431
1432	/* Perform relocations with addend if there are any: */
1433	for (i = 0; i < ef->nrelatab; i++) {
1434		rela = ef->relatab[i].rela;
1435		if (rela == NULL) {
1436			link_elf_error(ef->lf.filename, "lost a relatab!");
1437			return (ENOEXEC);
1438		}
1439		relalim = rela + ef->relatab[i].nrela;
1440		base = findbase(ef, ef->relatab[i].sec);
1441		if (base == 0) {
1442			link_elf_error(ef->lf.filename, "lost base for reltab");
1443			return (ENOEXEC);
1444		}
1445		for ( ; rela < relalim; rela++) {
1446			symidx = ELF_R_SYM(rela->r_info);
1447			if (symidx >= ef->ddbsymcnt)
1448				continue;
1449			sym = ef->ddbsymtab + symidx;
1450			/* Only do local relocs */
1451			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1452				continue;
1453			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1454			    elf_obj_lookup);
1455		}
1456	}
1457	return (0);
1458}
1459
1460static long
1461link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1462{
1463    elf_file_t ef = (elf_file_t)lf;
1464
1465    *symtab = ef->ddbsymtab;
1466
1467    if (*symtab == NULL)
1468        return (0);
1469
1470    return (ef->ddbsymcnt);
1471}
1472
1473static long
1474link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1475{
1476    elf_file_t ef = (elf_file_t)lf;
1477
1478    *strtab = ef->ddbstrtab;
1479
1480    if (*strtab == NULL)
1481        return (0);
1482
1483    return (ef->ddbstrcnt);
1484}
1485