link_elf_obj.c revision 296438 
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: stable/10/sys/kern/link_elf_obj.c 296438 2016-03-07 07:54:48Z dim $");
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 void	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		panic("lost progbits");
406	if (rl != ef->nreltab)
407		panic("lost reltab");
408	if (ra != ef->nrelatab)
409		panic("lost relatab");
410
411	/* Local intra-module relocations */
412	link_elf_reloc_local(lf);
413
414	*result = lf;
415	return (0);
416
417out:
418	/* preload not done this way */
419	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
420	return (error);
421}
422
423static int
424link_elf_link_preload_finish(linker_file_t lf)
425{
426	elf_file_t ef;
427	int error;
428
429	ef = (elf_file_t)lf;
430	error = relocate_file(ef);
431	if (error)
432		return error;
433
434	/* Notify MD code that a module is being loaded. */
435	error = elf_cpu_load_file(lf);
436	if (error)
437		return (error);
438
439	return (0);
440}
441
442static int
443link_elf_load_file(linker_class_t cls, const char *filename,
444    linker_file_t *result)
445{
446	struct nameidata nd;
447	struct thread *td = curthread;	/* XXX */
448	Elf_Ehdr *hdr;
449	Elf_Shdr *shdr;
450	Elf_Sym *es;
451	int nbytes, i, j;
452	vm_offset_t mapbase;
453	size_t mapsize;
454	int error = 0;
455	ssize_t resid;
456	int flags;
457	elf_file_t ef;
458	linker_file_t lf;
459	int symtabindex;
460	int symstrindex;
461	int shstrindex;
462	int nsym;
463	int pb, rl, ra;
464	int alignmask;
465
466	shdr = NULL;
467	lf = NULL;
468	mapsize = 0;
469	hdr = NULL;
470
471	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
472	flags = FREAD;
473	error = vn_open(&nd, &flags, 0, NULL);
474	if (error)
475		return error;
476	NDFREE(&nd, NDF_ONLY_PNBUF);
477	if (nd.ni_vp->v_type != VREG) {
478		error = ENOEXEC;
479		goto out;
480	}
481#ifdef MAC
482	error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
483	if (error) {
484		goto out;
485	}
486#endif
487
488	/* Read the elf header from the file. */
489	hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
490	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
491	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
492	    &resid, td);
493	if (error)
494		goto out;
495	if (resid != 0){
496		error = ENOEXEC;
497		goto out;
498	}
499
500	if (!IS_ELF(*hdr)) {
501		error = ENOEXEC;
502		goto out;
503	}
504
505	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
506	    || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
507		link_elf_error(filename, "Unsupported file layout");
508		error = ENOEXEC;
509		goto out;
510	}
511	if (hdr->e_ident[EI_VERSION] != EV_CURRENT
512	    || hdr->e_version != EV_CURRENT) {
513		link_elf_error(filename, "Unsupported file version");
514		error = ENOEXEC;
515		goto out;
516	}
517	if (hdr->e_type != ET_REL) {
518		error = ENOSYS;
519		goto out;
520	}
521	if (hdr->e_machine != ELF_TARG_MACH) {
522		link_elf_error(filename, "Unsupported machine");
523		error = ENOEXEC;
524		goto out;
525	}
526
527	lf = linker_make_file(filename, &link_elf_class);
528	if (!lf) {
529		error = ENOMEM;
530		goto out;
531	}
532	ef = (elf_file_t) lf;
533	ef->nprogtab = 0;
534	ef->e_shdr = 0;
535	ef->nreltab = 0;
536	ef->nrelatab = 0;
537
538	/* Allocate and read in the section header */
539	nbytes = hdr->e_shnum * hdr->e_shentsize;
540	if (nbytes == 0 || hdr->e_shoff == 0 ||
541	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
542		error = ENOEXEC;
543		goto out;
544	}
545	shdr = malloc(nbytes, M_LINKER, M_WAITOK);
546	ef->e_shdr = shdr;
547	error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
548	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
549	if (error)
550		goto out;
551	if (resid) {
552		error = ENOEXEC;
553		goto out;
554	}
555
556	/* Scan the section header for information and table sizing. */
557	nsym = 0;
558	symtabindex = -1;
559	symstrindex = -1;
560	for (i = 0; i < hdr->e_shnum; i++) {
561		if (shdr[i].sh_size == 0)
562			continue;
563		switch (shdr[i].sh_type) {
564		case SHT_PROGBITS:
565		case SHT_NOBITS:
566#ifdef __amd64__
567		case SHT_AMD64_UNWIND:
568#endif
569			ef->nprogtab++;
570			break;
571		case SHT_SYMTAB:
572			nsym++;
573			symtabindex = i;
574			symstrindex = shdr[i].sh_link;
575			break;
576		case SHT_REL:
577			ef->nreltab++;
578			break;
579		case SHT_RELA:
580			ef->nrelatab++;
581			break;
582		case SHT_STRTAB:
583			break;
584		}
585	}
586	if (ef->nprogtab == 0) {
587		link_elf_error(filename, "file has no contents");
588		error = ENOEXEC;
589		goto out;
590	}
591	if (nsym != 1) {
592		/* Only allow one symbol table for now */
593		link_elf_error(filename, "file has no valid symbol table");
594		error = ENOEXEC;
595		goto out;
596	}
597	if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
598	    shdr[symstrindex].sh_type != SHT_STRTAB) {
599		link_elf_error(filename, "file has invalid symbol strings");
600		error = ENOEXEC;
601		goto out;
602	}
603
604	/* Allocate space for tracking the load chunks */
605	if (ef->nprogtab != 0)
606		ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
607		    M_LINKER, M_WAITOK | M_ZERO);
608	if (ef->nreltab != 0)
609		ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
610		    M_LINKER, M_WAITOK | M_ZERO);
611	if (ef->nrelatab != 0)
612		ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
613		    M_LINKER, M_WAITOK | M_ZERO);
614
615	if (symtabindex == -1)
616		panic("lost symbol table index");
617	/* Allocate space for and load the symbol table */
618	ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
619	ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
620	error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
621	    shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
622	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
623	    &resid, td);
624	if (error)
625		goto out;
626	if (resid != 0){
627		error = EINVAL;
628		goto out;
629	}
630
631	if (symstrindex == -1)
632		panic("lost symbol string index");
633	/* Allocate space for and load the symbol strings */
634	ef->ddbstrcnt = shdr[symstrindex].sh_size;
635	ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
636	error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
637	    shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
638	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
639	    &resid, td);
640	if (error)
641		goto out;
642	if (resid != 0){
643		error = EINVAL;
644		goto out;
645	}
646
647	/* Do we have a string table for the section names?  */
648	shstrindex = -1;
649	if (hdr->e_shstrndx != 0 &&
650	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
651		shstrindex = hdr->e_shstrndx;
652		ef->shstrcnt = shdr[shstrindex].sh_size;
653		ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
654		    M_WAITOK);
655		error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
656		    shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
657		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
658		    &resid, td);
659		if (error)
660			goto out;
661		if (resid != 0){
662			error = EINVAL;
663			goto out;
664		}
665	}
666
667	/* Size up code/data(progbits) and bss(nobits). */
668	alignmask = 0;
669	for (i = 0; i < hdr->e_shnum; i++) {
670		if (shdr[i].sh_size == 0)
671			continue;
672		switch (shdr[i].sh_type) {
673		case SHT_PROGBITS:
674		case SHT_NOBITS:
675#ifdef __amd64__
676		case SHT_AMD64_UNWIND:
677#endif
678			alignmask = shdr[i].sh_addralign - 1;
679			mapsize += alignmask;
680			mapsize &= ~alignmask;
681			mapsize += shdr[i].sh_size;
682			break;
683		}
684	}
685
686	/*
687	 * We know how much space we need for the text/data/bss/etc.
688	 * This stuff needs to be in a single chunk so that profiling etc
689	 * can get the bounds and gdb can associate offsets with modules
690	 */
691	ef->object = vm_object_allocate(OBJT_DEFAULT,
692	    round_page(mapsize) >> PAGE_SHIFT);
693	if (ef->object == NULL) {
694		error = ENOMEM;
695		goto out;
696	}
697	ef->address = (caddr_t) vm_map_min(kernel_map);
698
699	/*
700	 * In order to satisfy amd64's architectural requirements on the
701	 * location of code and data in the kernel's address space, request a
702	 * mapping that is above the kernel.
703	 */
704#ifdef __amd64__
705	mapbase = KERNBASE;
706#else
707	mapbase = VM_MIN_KERNEL_ADDRESS;
708#endif
709	error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
710	    round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
711	    VM_PROT_ALL, 0);
712	if (error) {
713		vm_object_deallocate(ef->object);
714		ef->object = 0;
715		goto out;
716	}
717
718	/* Wire the pages */
719	error = vm_map_wire(kernel_map, mapbase,
720	    mapbase + round_page(mapsize),
721	    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
722	if (error != KERN_SUCCESS) {
723		error = ENOMEM;
724		goto out;
725	}
726
727	/* Inform the kld system about the situation */
728	lf->address = ef->address = (caddr_t)mapbase;
729	lf->size = mapsize;
730
731	/*
732	 * Now load code/data(progbits), zero bss(nobits), allocate space for
733	 * and load relocs
734	 */
735	pb = 0;
736	rl = 0;
737	ra = 0;
738	alignmask = 0;
739	for (i = 0; i < hdr->e_shnum; i++) {
740		if (shdr[i].sh_size == 0)
741			continue;
742		switch (shdr[i].sh_type) {
743		case SHT_PROGBITS:
744		case SHT_NOBITS:
745#ifdef __amd64__
746		case SHT_AMD64_UNWIND:
747#endif
748			alignmask = shdr[i].sh_addralign - 1;
749			mapbase += alignmask;
750			mapbase &= ~alignmask;
751			if (ef->shstrtab && shdr[i].sh_name != 0)
752				ef->progtab[pb].name =
753				    ef->shstrtab + shdr[i].sh_name;
754			else if (shdr[i].sh_type == SHT_PROGBITS)
755				ef->progtab[pb].name = "<<PROGBITS>>";
756#ifdef __amd64__
757			else if (shdr[i].sh_type == SHT_AMD64_UNWIND)
758				ef->progtab[pb].name = "<<UNWIND>>";
759#endif
760			else
761				ef->progtab[pb].name = "<<NOBITS>>";
762			if (ef->progtab[pb].name != NULL &&
763			    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
764				ef->progtab[pb].addr =
765				    dpcpu_alloc(shdr[i].sh_size);
766#ifdef VIMAGE
767			else if (ef->progtab[pb].name != NULL &&
768			    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
769				ef->progtab[pb].addr =
770				    vnet_data_alloc(shdr[i].sh_size);
771#endif
772			else
773				ef->progtab[pb].addr =
774				    (void *)(uintptr_t)mapbase;
775			if (ef->progtab[pb].addr == NULL) {
776				error = ENOSPC;
777				goto out;
778			}
779			ef->progtab[pb].size = shdr[i].sh_size;
780			ef->progtab[pb].sec = i;
781			if (shdr[i].sh_type == SHT_PROGBITS
782#ifdef __amd64__
783			    || shdr[i].sh_type == SHT_AMD64_UNWIND
784#endif
785			    ) {
786				error = vn_rdwr(UIO_READ, nd.ni_vp,
787				    ef->progtab[pb].addr,
788				    shdr[i].sh_size, shdr[i].sh_offset,
789				    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
790				    NOCRED, &resid, td);
791				if (error)
792					goto out;
793				if (resid != 0){
794					error = EINVAL;
795					goto out;
796				}
797				/* Initialize the per-cpu or vnet area. */
798				if (ef->progtab[pb].addr != (void *)mapbase &&
799				    !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
800					dpcpu_copy(ef->progtab[pb].addr,
801					    shdr[i].sh_size);
802#ifdef VIMAGE
803				else if (ef->progtab[pb].addr !=
804				    (void *)mapbase &&
805				    !strcmp(ef->progtab[pb].name, VNET_SETNAME))
806					vnet_data_copy(ef->progtab[pb].addr,
807					    shdr[i].sh_size);
808#endif
809			} else
810				bzero(ef->progtab[pb].addr, shdr[i].sh_size);
811
812			/* Update all symbol values with the offset. */
813			for (j = 0; j < ef->ddbsymcnt; j++) {
814				es = &ef->ddbsymtab[j];
815				if (es->st_shndx != i)
816					continue;
817				es->st_value += (Elf_Addr)ef->progtab[pb].addr;
818			}
819			mapbase += shdr[i].sh_size;
820			pb++;
821			break;
822		case SHT_REL:
823			ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
824			    M_WAITOK);
825			ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
826			ef->reltab[rl].sec = shdr[i].sh_info;
827			error = vn_rdwr(UIO_READ, nd.ni_vp,
828			    (void *)ef->reltab[rl].rel,
829			    shdr[i].sh_size, shdr[i].sh_offset,
830			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
831			    &resid, td);
832			if (error)
833				goto out;
834			if (resid != 0){
835				error = EINVAL;
836				goto out;
837			}
838			rl++;
839			break;
840		case SHT_RELA:
841			ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
842			    M_WAITOK);
843			ef->relatab[ra].nrela =
844			    shdr[i].sh_size / sizeof(Elf_Rela);
845			ef->relatab[ra].sec = shdr[i].sh_info;
846			error = vn_rdwr(UIO_READ, nd.ni_vp,
847			    (void *)ef->relatab[ra].rela,
848			    shdr[i].sh_size, shdr[i].sh_offset,
849			    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
850			    &resid, td);
851			if (error)
852				goto out;
853			if (resid != 0){
854				error = EINVAL;
855				goto out;
856			}
857			ra++;
858			break;
859		}
860	}
861	if (pb != ef->nprogtab)
862		panic("lost progbits");
863	if (rl != ef->nreltab)
864		panic("lost reltab");
865	if (ra != ef->nrelatab)
866		panic("lost relatab");
867	if (mapbase != (vm_offset_t)ef->address + mapsize)
868		panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
869		    (u_long)mapbase, ef->address, (u_long)mapsize,
870		    (u_long)(vm_offset_t)ef->address + mapsize);
871
872	/* Local intra-module relocations */
873	link_elf_reloc_local(lf);
874
875	/* Pull in dependencies */
876	VOP_UNLOCK(nd.ni_vp, 0);
877	error = linker_load_dependencies(lf);
878	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
879	if (error)
880		goto out;
881
882	/* External relocations */
883	error = relocate_file(ef);
884	if (error)
885		goto out;
886
887	/* Notify MD code that a module is being loaded. */
888	error = elf_cpu_load_file(lf);
889	if (error)
890		goto out;
891
892	*result = lf;
893
894out:
895	VOP_UNLOCK(nd.ni_vp, 0);
896	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
897	if (error && lf)
898		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
899	if (hdr)
900		free(hdr, M_LINKER);
901
902	return error;
903}
904
905static void
906link_elf_unload_file(linker_file_t file)
907{
908	elf_file_t ef = (elf_file_t) file;
909	int i;
910
911	/* Notify MD code that a module is being unloaded. */
912	elf_cpu_unload_file(file);
913
914	if (ef->progtab) {
915		for (i = 0; i < ef->nprogtab; i++) {
916			if (ef->progtab[i].size == 0)
917				continue;
918			if (ef->progtab[i].name == NULL)
919				continue;
920			if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
921				dpcpu_free(ef->progtab[i].addr,
922				    ef->progtab[i].size);
923#ifdef VIMAGE
924			else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
925				vnet_data_free(ef->progtab[i].addr,
926				    ef->progtab[i].size);
927#endif
928		}
929	}
930	if (ef->preloaded) {
931		if (ef->reltab)
932			free(ef->reltab, M_LINKER);
933		if (ef->relatab)
934			free(ef->relatab, M_LINKER);
935		if (ef->progtab)
936			free(ef->progtab, M_LINKER);
937		if (ef->ctftab)
938			free(ef->ctftab, M_LINKER);
939		if (ef->ctfoff)
940			free(ef->ctfoff, M_LINKER);
941		if (ef->typoff)
942			free(ef->typoff, M_LINKER);
943		if (file->filename != NULL)
944			preload_delete_name(file->filename);
945		/* XXX reclaim module memory? */
946		return;
947	}
948
949	for (i = 0; i < ef->nreltab; i++)
950		if (ef->reltab[i].rel)
951			free(ef->reltab[i].rel, M_LINKER);
952	for (i = 0; i < ef->nrelatab; i++)
953		if (ef->relatab[i].rela)
954			free(ef->relatab[i].rela, M_LINKER);
955	if (ef->reltab)
956		free(ef->reltab, M_LINKER);
957	if (ef->relatab)
958		free(ef->relatab, M_LINKER);
959	if (ef->progtab)
960		free(ef->progtab, M_LINKER);
961
962	if (ef->object) {
963		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
964		    (vm_offset_t) ef->address +
965		    (ef->object->size << PAGE_SHIFT));
966	}
967	if (ef->e_shdr)
968		free(ef->e_shdr, M_LINKER);
969	if (ef->ddbsymtab)
970		free(ef->ddbsymtab, M_LINKER);
971	if (ef->ddbstrtab)
972		free(ef->ddbstrtab, M_LINKER);
973	if (ef->shstrtab)
974		free(ef->shstrtab, M_LINKER);
975	if (ef->ctftab)
976		free(ef->ctftab, M_LINKER);
977	if (ef->ctfoff)
978		free(ef->ctfoff, M_LINKER);
979	if (ef->typoff)
980		free(ef->typoff, M_LINKER);
981}
982
983static const char *
984symbol_name(elf_file_t ef, Elf_Size r_info)
985{
986	const Elf_Sym *ref;
987
988	if (ELF_R_SYM(r_info)) {
989		ref = ef->ddbsymtab + ELF_R_SYM(r_info);
990		return ef->ddbstrtab + ref->st_name;
991	} else
992		return NULL;
993}
994
995static Elf_Addr
996findbase(elf_file_t ef, int sec)
997{
998	int i;
999	Elf_Addr base = 0;
1000
1001	for (i = 0; i < ef->nprogtab; i++) {
1002		if (sec == ef->progtab[i].sec) {
1003			base = (Elf_Addr)ef->progtab[i].addr;
1004			break;
1005		}
1006	}
1007	return base;
1008}
1009
1010static int
1011relocate_file(elf_file_t ef)
1012{
1013	const Elf_Rel *rellim;
1014	const Elf_Rel *rel;
1015	const Elf_Rela *relalim;
1016	const Elf_Rela *rela;
1017	const char *symname;
1018	const Elf_Sym *sym;
1019	int i;
1020	Elf_Size symidx;
1021	Elf_Addr base;
1022
1023
1024	/* Perform relocations without addend if there are any: */
1025	for (i = 0; i < ef->nreltab; i++) {
1026		rel = ef->reltab[i].rel;
1027		if (rel == NULL)
1028			panic("lost a reltab!");
1029		rellim = rel + ef->reltab[i].nrel;
1030		base = findbase(ef, ef->reltab[i].sec);
1031		if (base == 0)
1032			panic("lost base for reltab");
1033		for ( ; rel < rellim; rel++) {
1034			symidx = ELF_R_SYM(rel->r_info);
1035			if (symidx >= ef->ddbsymcnt)
1036				continue;
1037			sym = ef->ddbsymtab + symidx;
1038			/* Local relocs are already done */
1039			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1040				continue;
1041			if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1042			    elf_obj_lookup)) {
1043				symname = symbol_name(ef, rel->r_info);
1044				printf("link_elf_obj: symbol %s undefined\n",
1045				    symname);
1046				return ENOENT;
1047			}
1048		}
1049	}
1050
1051	/* Perform relocations with addend if there are any: */
1052	for (i = 0; i < ef->nrelatab; i++) {
1053		rela = ef->relatab[i].rela;
1054		if (rela == NULL)
1055			panic("lost a relatab!");
1056		relalim = rela + ef->relatab[i].nrela;
1057		base = findbase(ef, ef->relatab[i].sec);
1058		if (base == 0)
1059			panic("lost base for relatab");
1060		for ( ; rela < relalim; rela++) {
1061			symidx = ELF_R_SYM(rela->r_info);
1062			if (symidx >= ef->ddbsymcnt)
1063				continue;
1064			sym = ef->ddbsymtab + symidx;
1065			/* Local relocs are already done */
1066			if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1067				continue;
1068			if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1069			    elf_obj_lookup)) {
1070				symname = symbol_name(ef, rela->r_info);
1071				printf("link_elf_obj: symbol %s undefined\n",
1072				    symname);
1073				return ENOENT;
1074			}
1075		}
1076	}
1077
1078	/*
1079	 * Only clean SHN_FBSD_CACHED for successfull return.  If we
1080	 * modified symbol table for the object but found an
1081	 * unresolved symbol, there is no reason to roll back.
1082	 */
1083	elf_obj_cleanup_globals_cache(ef);
1084
1085	return 0;
1086}
1087
1088static int
1089link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1090{
1091	elf_file_t ef = (elf_file_t) lf;
1092	const Elf_Sym *symp;
1093	const char *strp;
1094	int i;
1095
1096	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1097		strp = ef->ddbstrtab + symp->st_name;
1098		if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1099			*sym = (c_linker_sym_t) symp;
1100			return 0;
1101		}
1102	}
1103	return ENOENT;
1104}
1105
1106static int
1107link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1108    linker_symval_t *symval)
1109{
1110	elf_file_t ef = (elf_file_t) lf;
1111	const Elf_Sym *es = (const Elf_Sym*) sym;
1112
1113	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1114		symval->name = ef->ddbstrtab + es->st_name;
1115		symval->value = (caddr_t)es->st_value;
1116		symval->size = es->st_size;
1117		return 0;
1118	}
1119	return ENOENT;
1120}
1121
1122static int
1123link_elf_search_symbol(linker_file_t lf, caddr_t value,
1124    c_linker_sym_t *sym, long *diffp)
1125{
1126	elf_file_t ef = (elf_file_t) lf;
1127	u_long off = (uintptr_t) (void *) value;
1128	u_long diff = off;
1129	u_long st_value;
1130	const Elf_Sym *es;
1131	const Elf_Sym *best = 0;
1132	int i;
1133
1134	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1135		if (es->st_name == 0)
1136			continue;
1137		st_value = es->st_value;
1138		if (off >= st_value) {
1139			if (off - st_value < diff) {
1140				diff = off - st_value;
1141				best = es;
1142				if (diff == 0)
1143					break;
1144			} else if (off - st_value == diff) {
1145				best = es;
1146			}
1147		}
1148	}
1149	if (best == 0)
1150		*diffp = off;
1151	else
1152		*diffp = diff;
1153	*sym = (c_linker_sym_t) best;
1154
1155	return 0;
1156}
1157
1158/*
1159 * Look up a linker set on an ELF system.
1160 */
1161static int
1162link_elf_lookup_set(linker_file_t lf, const char *name,
1163    void ***startp, void ***stopp, int *countp)
1164{
1165	elf_file_t ef = (elf_file_t)lf;
1166	void **start, **stop;
1167	int i, count;
1168
1169	/* Relative to section number */
1170	for (i = 0; i < ef->nprogtab; i++) {
1171		if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1172		    strcmp(ef->progtab[i].name + 4, name) == 0) {
1173			start  = (void **)ef->progtab[i].addr;
1174			stop = (void **)((char *)ef->progtab[i].addr +
1175			    ef->progtab[i].size);
1176			count = stop - start;
1177			if (startp)
1178				*startp = start;
1179			if (stopp)
1180				*stopp = stop;
1181			if (countp)
1182				*countp = count;
1183			return (0);
1184		}
1185	}
1186	return (ESRCH);
1187}
1188
1189static int
1190link_elf_each_function_name(linker_file_t file,
1191    int (*callback)(const char *, void *), void *opaque)
1192{
1193	elf_file_t ef = (elf_file_t)file;
1194	const Elf_Sym *symp;
1195	int i, error;
1196
1197	/* Exhaustive search */
1198	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1199		if (symp->st_value != 0 &&
1200		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1201			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1202			if (error)
1203				return (error);
1204		}
1205	}
1206	return (0);
1207}
1208
1209static int
1210link_elf_each_function_nameval(linker_file_t file,
1211    linker_function_nameval_callback_t callback, void *opaque)
1212{
1213	linker_symval_t symval;
1214	elf_file_t ef = (elf_file_t)file;
1215	const Elf_Sym* symp;
1216	int i, error;
1217
1218	/* Exhaustive search */
1219	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1220		if (symp->st_value != 0 &&
1221		    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1222			error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1223			if (error)
1224				return (error);
1225			error = callback(file, i, &symval, opaque);
1226			if (error)
1227				return (error);
1228		}
1229	}
1230	return (0);
1231}
1232
1233static void
1234elf_obj_cleanup_globals_cache(elf_file_t ef)
1235{
1236	Elf_Sym *sym;
1237	Elf_Size i;
1238
1239	for (i = 0; i < ef->ddbsymcnt; i++) {
1240		sym = ef->ddbsymtab + i;
1241		if (sym->st_shndx == SHN_FBSD_CACHED) {
1242			sym->st_shndx = SHN_UNDEF;
1243			sym->st_value = 0;
1244		}
1245	}
1246}
1247
1248/*
1249 * Symbol lookup function that can be used when the symbol index is known (ie
1250 * in relocations). It uses the symbol index instead of doing a fully fledged
1251 * hash table based lookup when such is valid. For example for local symbols.
1252 * This is not only more efficient, it's also more correct. It's not always
1253 * the case that the symbol can be found through the hash table.
1254 */
1255static int
1256elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1257{
1258	elf_file_t ef = (elf_file_t)lf;
1259	Elf_Sym *sym;
1260	const char *symbol;
1261	Elf_Addr res1;
1262
1263	/* Don't even try to lookup the symbol if the index is bogus. */
1264	if (symidx >= ef->ddbsymcnt) {
1265		*res = 0;
1266		return (EINVAL);
1267	}
1268
1269	sym = ef->ddbsymtab + symidx;
1270
1271	/* Quick answer if there is a definition included. */
1272	if (sym->st_shndx != SHN_UNDEF) {
1273		*res = sym->st_value;
1274		return (0);
1275	}
1276
1277	/* If we get here, then it is undefined and needs a lookup. */
1278	switch (ELF_ST_BIND(sym->st_info)) {
1279	case STB_LOCAL:
1280		/* Local, but undefined? huh? */
1281		*res = 0;
1282		return (EINVAL);
1283
1284	case STB_GLOBAL:
1285	case STB_WEAK:
1286		/* Relative to Data or Function name */
1287		symbol = ef->ddbstrtab + sym->st_name;
1288
1289		/* Force a lookup failure if the symbol name is bogus. */
1290		if (*symbol == 0) {
1291			*res = 0;
1292			return (EINVAL);
1293		}
1294		res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1295
1296		/*
1297		 * Cache global lookups during module relocation. The failure
1298		 * case is particularly expensive for callers, who must scan
1299		 * through the entire globals table doing strcmp(). Cache to
1300		 * avoid doing such work repeatedly.
1301		 *
1302		 * After relocation is complete, undefined globals will be
1303		 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1304		 * above.
1305		 */
1306		if (res1 != 0) {
1307			sym->st_shndx = SHN_FBSD_CACHED;
1308			sym->st_value = res1;
1309			*res = res1;
1310			return (0);
1311		} else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1312			sym->st_value = 0;
1313			*res = 0;
1314			return (0);
1315		}
1316		return (EINVAL);
1317
1318	default:
1319		return (EINVAL);
1320	}
1321}
1322
1323static void
1324link_elf_fix_link_set(elf_file_t ef)
1325{
1326	static const char startn[] = "__start_";
1327	static const char stopn[] = "__stop_";
1328	Elf_Sym *sym;
1329	const char *sym_name, *linkset_name;
1330	Elf_Addr startp, stopp;
1331	Elf_Size symidx;
1332	int start, i;
1333
1334	startp = stopp = 0;
1335	for (symidx = 1 /* zero entry is special */;
1336		symidx < ef->ddbsymcnt; symidx++) {
1337		sym = ef->ddbsymtab + symidx;
1338		if (sym->st_shndx != SHN_UNDEF)
1339			continue;
1340
1341		sym_name = ef->ddbstrtab + sym->st_name;
1342		if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1343			start = 1;
1344			linkset_name = sym_name + sizeof(startn) - 1;
1345		}
1346		else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1347			start = 0;
1348			linkset_name = sym_name + sizeof(stopn) - 1;
1349		}
1350		else
1351			continue;
1352
1353		for (i = 0; i < ef->nprogtab; i++) {
1354			if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1355				startp = (Elf_Addr)ef->progtab[i].addr;
1356				stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1357				break;
1358			}
1359		}
1360		if (i == ef->nprogtab)
1361			continue;
1362
1363		sym->st_value = start ? startp : stopp;
1364		sym->st_shndx = i;
1365	}
1366}
1367
1368static void
1369link_elf_reloc_local(linker_file_t lf)
1370{
1371	elf_file_t ef = (elf_file_t)lf;
1372	const Elf_Rel *rellim;
1373	const Elf_Rel *rel;
1374	const Elf_Rela *relalim;
1375	const Elf_Rela *rela;
1376	const Elf_Sym *sym;
1377	Elf_Addr base;
1378	int i;
1379	Elf_Size symidx;
1380
1381	link_elf_fix_link_set(ef);
1382
1383	/* Perform relocations without addend if there are any: */
1384	for (i = 0; i < ef->nreltab; i++) {
1385		rel = ef->reltab[i].rel;
1386		if (rel == NULL)
1387			panic("lost a reltab!");
1388		rellim = rel + ef->reltab[i].nrel;
1389		base = findbase(ef, ef->reltab[i].sec);
1390		if (base == 0)
1391			panic("lost base for reltab");
1392		for ( ; rel < rellim; rel++) {
1393			symidx = ELF_R_SYM(rel->r_info);
1394			if (symidx >= ef->ddbsymcnt)
1395				continue;
1396			sym = ef->ddbsymtab + symidx;
1397			/* Only do local relocs */
1398			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1399				continue;
1400			elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1401			    elf_obj_lookup);
1402		}
1403	}
1404
1405	/* Perform relocations with addend if there are any: */
1406	for (i = 0; i < ef->nrelatab; i++) {
1407		rela = ef->relatab[i].rela;
1408		if (rela == NULL)
1409			panic("lost a relatab!");
1410		relalim = rela + ef->relatab[i].nrela;
1411		base = findbase(ef, ef->relatab[i].sec);
1412		if (base == 0)
1413			panic("lost base for relatab");
1414		for ( ; rela < relalim; rela++) {
1415			symidx = ELF_R_SYM(rela->r_info);
1416			if (symidx >= ef->ddbsymcnt)
1417				continue;
1418			sym = ef->ddbsymtab + symidx;
1419			/* Only do local relocs */
1420			if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1421				continue;
1422			elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1423			    elf_obj_lookup);
1424		}
1425	}
1426}
1427
1428static long
1429link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1430{
1431    elf_file_t ef = (elf_file_t)lf;
1432
1433    *symtab = ef->ddbsymtab;
1434
1435    if (*symtab == NULL)
1436        return (0);
1437
1438    return (ef->ddbsymcnt);
1439}
1440
1441static long
1442link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1443{
1444    elf_file_t ef = (elf_file_t)lf;
1445
1446    *strtab = ef->ddbstrtab;
1447
1448    if (*strtab == NULL)
1449        return (0);
1450
1451    return (ef->ddbstrcnt);
1452}
1453