xref: /freebsd/sys/kern/link_elf.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /*-
2  * Copyright (c) 1998-2000 Doug Rabson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_gdb.h"
31 #include "opt_mac.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #ifdef GPROF
36 #include <sys/gmon.h>
37 #endif
38 #include <sys/kernel.h>
39 #include <sys/lock.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/mount.h>
43 #include <sys/proc.h>
44 #include <sys/namei.h>
45 #include <sys/fcntl.h>
46 #include <sys/vnode.h>
47 #include <sys/linker.h>
48 
49 #include <machine/elf.h>
50 
51 #include <security/mac/mac_framework.h>
52 
53 #include <vm/vm.h>
54 #include <vm/vm_param.h>
55 #ifdef SPARSE_MAPPING
56 #include <vm/vm_object.h>
57 #include <vm/vm_kern.h>
58 #include <vm/vm_extern.h>
59 #endif
60 #include <vm/pmap.h>
61 #include <vm/vm_map.h>
62 
63 #include <sys/link_elf.h>
64 
65 #include "linker_if.h"
66 
67 #define MAXSEGS 4
68 
69 typedef struct elf_file {
70     struct linker_file	lf;		/* Common fields */
71     int			preloaded;	/* Was file pre-loaded */
72     caddr_t		address;	/* Relocation address */
73 #ifdef SPARSE_MAPPING
74     vm_object_t		object;		/* VM object to hold file pages */
75 #endif
76     Elf_Dyn*		dynamic;	/* Symbol table etc. */
77     Elf_Hashelt		nbuckets;	/* DT_HASH info */
78     Elf_Hashelt		nchains;
79     const Elf_Hashelt*	buckets;
80     const Elf_Hashelt*	chains;
81     caddr_t		hash;
82     caddr_t		strtab;		/* DT_STRTAB */
83     int			strsz;		/* DT_STRSZ */
84     const Elf_Sym*	symtab;		/* DT_SYMTAB */
85     Elf_Addr*		got;		/* DT_PLTGOT */
86     const Elf_Rel*	pltrel;		/* DT_JMPREL */
87     int			pltrelsize;	/* DT_PLTRELSZ */
88     const Elf_Rela*	pltrela;	/* DT_JMPREL */
89     int			pltrelasize;	/* DT_PLTRELSZ */
90     const Elf_Rel*	rel;		/* DT_REL */
91     int			relsize;	/* DT_RELSZ */
92     const Elf_Rela*	rela;		/* DT_RELA */
93     int			relasize;	/* DT_RELASZ */
94     caddr_t		modptr;
95     const Elf_Sym*	ddbsymtab;	/* The symbol table we are using */
96     long		ddbsymcnt;	/* Number of symbols */
97     caddr_t		ddbstrtab;	/* String table */
98     long		ddbstrcnt;	/* number of bytes in string table */
99     caddr_t		symbase;	/* malloc'ed symbold base */
100     caddr_t		strbase;	/* malloc'ed string base */
101 #ifdef GDB
102     struct link_map	gdb;		/* hooks for gdb */
103 #endif
104 } *elf_file_t;
105 
106 static int	link_elf_link_common_finish(linker_file_t);
107 static int	link_elf_link_preload(linker_class_t cls,
108 				      const char*, linker_file_t*);
109 static int	link_elf_link_preload_finish(linker_file_t);
110 static int	link_elf_load_file(linker_class_t, const char*, linker_file_t*);
111 static int	link_elf_lookup_symbol(linker_file_t, const char*,
112 				       c_linker_sym_t*);
113 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t*);
114 static int	link_elf_search_symbol(linker_file_t, caddr_t value,
115 				       c_linker_sym_t* sym, long* diffp);
116 
117 static void	link_elf_unload_file(linker_file_t);
118 static void	link_elf_unload_preload(linker_file_t);
119 static int	link_elf_lookup_set(linker_file_t, const char *,
120 				    void ***, void ***, int *);
121 static int	link_elf_each_function_name(linker_file_t,
122 				int (*)(const char *, void *),
123 				void *);
124 static void	link_elf_reloc_local(linker_file_t);
125 static Elf_Addr	elf_lookup(linker_file_t lf, Elf_Size symidx, int deps);
126 
127 static kobj_method_t link_elf_methods[] = {
128     KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
129     KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
130     KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
131     KOBJMETHOD(linker_unload,		link_elf_unload_file),
132     KOBJMETHOD(linker_load_file,	link_elf_load_file),
133     KOBJMETHOD(linker_link_preload,	link_elf_link_preload),
134     KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
135     KOBJMETHOD(linker_lookup_set,	link_elf_lookup_set),
136     KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
137     { 0, 0 }
138 };
139 
140 static struct linker_class link_elf_class = {
141 #if ELF_TARG_CLASS == ELFCLASS32
142     "elf32",
143 #else
144     "elf64",
145 #endif
146     link_elf_methods, sizeof(struct elf_file)
147 };
148 
149 static int		parse_dynamic(elf_file_t ef);
150 static int		relocate_file(elf_file_t ef);
151 static int		link_elf_preload_parse_symbols(elf_file_t ef);
152 
153 #ifdef GDB
154 static void		r_debug_state(struct r_debug *dummy_one,
155 				      struct link_map *dummy_two);
156 
157 /*
158  * A list of loaded modules for GDB to use for loading symbols.
159  */
160 struct r_debug r_debug;
161 
162 #define GDB_STATE(s)	r_debug.r_state = s; r_debug_state(NULL, NULL);
163 
164 /*
165  * Function for the debugger to set a breakpoint on to gain control.
166  */
167 static void
168 r_debug_state(struct r_debug *dummy_one __unused,
169 	      struct link_map *dummy_two __unused)
170 {
171 }
172 
173 static void
174 link_elf_add_gdb(struct link_map *l)
175 {
176     struct link_map *prev;
177 
178     l->l_next = NULL;
179 
180     if (r_debug.r_map == NULL) {
181 	/* Add first. */
182 	l->l_prev = NULL;
183 	r_debug.r_map = l;
184     } else {
185 	/* Append to list. */
186 	for (prev = r_debug.r_map; prev->l_next != NULL; prev = prev->l_next)
187 	    ;
188 	l->l_prev = prev;
189 	prev->l_next = l;
190     }
191 }
192 
193 static void
194 link_elf_delete_gdb(struct link_map *l)
195 {
196     if (l->l_prev == NULL) {
197 	/* Remove first. */
198 	if ((r_debug.r_map = l->l_next) != NULL)
199 	    l->l_next->l_prev = NULL;
200     } else {
201 	/* Remove any but first. */
202 	if ((l->l_prev->l_next = l->l_next) != NULL)
203 	    l->l_next->l_prev = l->l_prev;
204     }
205 }
206 #endif /* GDB */
207 
208 #ifdef __ia64__
209 Elf_Addr link_elf_get_gp(linker_file_t);
210 #endif
211 
212 /*
213  * The kernel symbol table starts here.
214  */
215 extern struct _dynamic _DYNAMIC;
216 
217 static void
218 link_elf_error(const char *s)
219 {
220     printf("kldload: %s\n", s);
221 }
222 
223 /*
224  * Actions performed after linking/loading both the preloaded kernel and any
225  * modules; whether preloaded or dynamicly loaded.
226  */
227 static int
228 link_elf_link_common_finish(linker_file_t lf)
229 {
230 #ifdef GDB
231     elf_file_t ef = (elf_file_t)lf;
232     char *newfilename;
233 #endif
234     int error;
235 
236     /* Notify MD code that a module is being loaded. */
237     error = elf_cpu_load_file(lf);
238     if (error)
239 	return (error);
240 
241 #ifdef GDB
242     GDB_STATE(RT_ADD);
243     ef->gdb.l_addr = lf->address;
244     newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
245     strcpy(newfilename, lf->filename);
246     ef->gdb.l_name = newfilename;
247     ef->gdb.l_ld = ef->dynamic;
248     link_elf_add_gdb(&ef->gdb);
249     GDB_STATE(RT_CONSISTENT);
250 #endif
251 
252     return (0);
253 }
254 
255 static void
256 link_elf_init(void* arg)
257 {
258     Elf_Dyn	*dp;
259     caddr_t	modptr, baseptr, sizeptr;
260     elf_file_t	ef;
261     char	*modname;
262 
263     linker_add_class(&link_elf_class);
264 
265     dp = (Elf_Dyn*) &_DYNAMIC;
266     modname = NULL;
267     modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
268     if (modptr == NULL)
269 	modptr = preload_search_by_type("elf kernel");
270     if (modptr)
271 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
272     if (modname == NULL)
273 	modname = "kernel";
274     linker_kernel_file = linker_make_file(modname, &link_elf_class);
275     if (linker_kernel_file == NULL)
276 	panic("link_elf_init: Can't create linker structures for kernel");
277 
278     ef = (elf_file_t) linker_kernel_file;
279     ef->preloaded = 1;
280     ef->address = 0;
281 #ifdef SPARSE_MAPPING
282     ef->object = 0;
283 #endif
284     ef->dynamic = dp;
285 
286     if (dp)
287 	parse_dynamic(ef);
288     linker_kernel_file->address = (caddr_t) KERNBASE;
289     linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
290 
291     if (modptr) {
292 	ef->modptr = modptr;
293 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
294 	if (baseptr)
295 	    linker_kernel_file->address = *(caddr_t *)baseptr;
296 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
297 	if (sizeptr)
298 	    linker_kernel_file->size = *(size_t *)sizeptr;
299     }
300     (void)link_elf_preload_parse_symbols(ef);
301 
302 #ifdef GDB
303     r_debug.r_map = NULL;
304     r_debug.r_brk = r_debug_state;
305     r_debug.r_state = RT_CONSISTENT;
306 #endif
307 
308     (void)link_elf_link_common_finish(linker_kernel_file);
309     linker_kernel_file->flags |= LINKER_FILE_LINKED;
310 }
311 
312 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0);
313 
314 static int
315 link_elf_preload_parse_symbols(elf_file_t ef)
316 {
317     caddr_t	pointer;
318     caddr_t	ssym, esym, base;
319     caddr_t	strtab;
320     int		strcnt;
321     Elf_Sym*	symtab;
322     int		symcnt;
323 
324     if (ef->modptr == NULL)
325 	return 0;
326     pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_SSYM);
327     if (pointer == NULL)
328 	return 0;
329     ssym = *(caddr_t *)pointer;
330     pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_ESYM);
331     if (pointer == NULL)
332 	return 0;
333     esym = *(caddr_t *)pointer;
334 
335     base = ssym;
336 
337     symcnt = *(long *)base;
338     base += sizeof(long);
339     symtab = (Elf_Sym *)base;
340     base += roundup(symcnt, sizeof(long));
341 
342     if (base > esym || base < ssym) {
343 	printf("Symbols are corrupt!\n");
344 	return EINVAL;
345     }
346 
347     strcnt = *(long *)base;
348     base += sizeof(long);
349     strtab = base;
350     base += roundup(strcnt, sizeof(long));
351 
352     if (base > esym || base < ssym) {
353 	printf("Symbols are corrupt!\n");
354 	return EINVAL;
355     }
356 
357     ef->ddbsymtab = symtab;
358     ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
359     ef->ddbstrtab = strtab;
360     ef->ddbstrcnt = strcnt;
361 
362     return 0;
363 }
364 
365 static int
366 parse_dynamic(elf_file_t ef)
367 {
368     Elf_Dyn *dp;
369     int plttype = DT_REL;
370 
371     for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
372 	switch (dp->d_tag) {
373 	case DT_HASH:
374 	{
375 	    /* From src/libexec/rtld-elf/rtld.c */
376 	    const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
377 		(ef->address + dp->d_un.d_ptr);
378 	    ef->nbuckets = hashtab[0];
379 	    ef->nchains = hashtab[1];
380 	    ef->buckets = hashtab + 2;
381 	    ef->chains = ef->buckets + ef->nbuckets;
382 	    break;
383 	}
384 	case DT_STRTAB:
385 	    ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
386 	    break;
387 	case DT_STRSZ:
388 	    ef->strsz = dp->d_un.d_val;
389 	    break;
390 	case DT_SYMTAB:
391 	    ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
392 	    break;
393 	case DT_SYMENT:
394 	    if (dp->d_un.d_val != sizeof(Elf_Sym))
395 		return ENOEXEC;
396 	    break;
397 	case DT_PLTGOT:
398 	    ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
399 	    break;
400 	case DT_REL:
401 	    ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
402 	    break;
403 	case DT_RELSZ:
404 	    ef->relsize = dp->d_un.d_val;
405 	    break;
406 	case DT_RELENT:
407 	    if (dp->d_un.d_val != sizeof(Elf_Rel))
408 		return ENOEXEC;
409 	    break;
410 	case DT_JMPREL:
411 	    ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
412 	    break;
413 	case DT_PLTRELSZ:
414 	    ef->pltrelsize = dp->d_un.d_val;
415 	    break;
416 	case DT_RELA:
417 	    ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
418 	    break;
419 	case DT_RELASZ:
420 	    ef->relasize = dp->d_un.d_val;
421 	    break;
422 	case DT_RELAENT:
423 	    if (dp->d_un.d_val != sizeof(Elf_Rela))
424 		return ENOEXEC;
425 	    break;
426 	case DT_PLTREL:
427 	    plttype = dp->d_un.d_val;
428 	    if (plttype != DT_REL && plttype != DT_RELA)
429 		return ENOEXEC;
430 	    break;
431 #ifdef GDB
432 	case DT_DEBUG:
433 	    dp->d_un.d_ptr = (Elf_Addr) &r_debug;
434 	    break;
435 #endif
436 	}
437     }
438 
439     if (plttype == DT_RELA) {
440 	ef->pltrela = (const Elf_Rela *) ef->pltrel;
441 	ef->pltrel = NULL;
442 	ef->pltrelasize = ef->pltrelsize;
443 	ef->pltrelsize = 0;
444     }
445 
446     ef->ddbsymtab = ef->symtab;
447     ef->ddbsymcnt = ef->nchains;
448     ef->ddbstrtab = ef->strtab;
449     ef->ddbstrcnt = ef->strsz;
450 
451     return 0;
452 }
453 
454 static int
455 link_elf_link_preload(linker_class_t cls,
456 		      const char* filename, linker_file_t *result)
457 {
458     caddr_t		modptr, baseptr, sizeptr, dynptr;
459     char		*type;
460     elf_file_t		ef;
461     linker_file_t	lf;
462     int			error;
463     vm_offset_t		dp;
464 
465     /* Look to see if we have the file preloaded */
466     modptr = preload_search_by_name(filename);
467     if (modptr == NULL)
468 	return ENOENT;
469 
470     type = (char *)preload_search_info(modptr, MODINFO_TYPE);
471     baseptr = preload_search_info(modptr, MODINFO_ADDR);
472     sizeptr = preload_search_info(modptr, MODINFO_SIZE);
473     dynptr = preload_search_info(modptr, MODINFO_METADATA|MODINFOMD_DYNAMIC);
474     if (type == NULL ||
475 	(strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
476 	 strcmp(type, "elf module") != 0))
477 	return (EFTYPE);
478     if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
479 	return (EINVAL);
480 
481     lf = linker_make_file(filename, &link_elf_class);
482     if (lf == NULL) {
483 	return ENOMEM;
484     }
485 
486     ef = (elf_file_t) lf;
487     ef->preloaded = 1;
488     ef->modptr = modptr;
489     ef->address = *(caddr_t *)baseptr;
490 #ifdef SPARSE_MAPPING
491     ef->object = 0;
492 #endif
493     dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
494     ef->dynamic = (Elf_Dyn *)dp;
495     lf->address = ef->address;
496     lf->size = *(size_t *)sizeptr;
497 
498     error = parse_dynamic(ef);
499     if (error) {
500 	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
501 	return error;
502     }
503     link_elf_reloc_local(lf);
504     *result = lf;
505     return (0);
506 }
507 
508 static int
509 link_elf_link_preload_finish(linker_file_t lf)
510 {
511     elf_file_t		ef;
512     int error;
513 
514     ef = (elf_file_t) lf;
515 #if 0	/* this will be more trouble than it's worth for now */
516     for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
517 	if (dp->d_tag != DT_NEEDED)
518 	    continue;
519 	modname = ef->strtab + dp->d_un.d_val;
520 	error = linker_load_module(modname, lf);
521 	if (error)
522 	    goto out;
523     }
524 #endif
525     error = relocate_file(ef);
526     if (error)
527 	return error;
528     (void)link_elf_preload_parse_symbols(ef);
529 
530     return (link_elf_link_common_finish(lf));
531 }
532 
533 static int
534 link_elf_load_file(linker_class_t cls, const char* filename,
535 	linker_file_t* result)
536 {
537     struct nameidata nd;
538     struct thread* td = curthread;	/* XXX */
539     Elf_Ehdr *hdr;
540     caddr_t firstpage;
541     int nbytes, i;
542     Elf_Phdr *phdr;
543     Elf_Phdr *phlimit;
544     Elf_Phdr *segs[MAXSEGS];
545     int nsegs;
546     Elf_Phdr *phdyn;
547     Elf_Phdr *phphdr;
548     caddr_t mapbase;
549     size_t mapsize;
550     Elf_Off base_offset;
551     Elf_Addr base_vaddr;
552     Elf_Addr base_vlimit;
553     int error = 0;
554     int resid, flags;
555     elf_file_t ef;
556     linker_file_t lf;
557     Elf_Shdr *shdr;
558     int symtabindex;
559     int symstrindex;
560     int symcnt;
561     int strcnt;
562     int vfslocked;
563 
564     shdr = NULL;
565     lf = NULL;
566 
567     NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
568     flags = FREAD;
569     error = vn_open(&nd, &flags, 0, NULL);
570     if (error)
571 	return error;
572     vfslocked = NDHASGIANT(&nd);
573     NDFREE(&nd, NDF_ONLY_PNBUF);
574 #ifdef MAC
575     error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
576     if (error) {
577 	firstpage = NULL;
578 	goto out;
579     }
580 #endif
581 
582     /*
583      * Read the elf header from the file.
584      */
585     firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
586     if (firstpage == NULL) {
587 	error = ENOMEM;
588 	goto out;
589     }
590     hdr = (Elf_Ehdr *)firstpage;
591     error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
592 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
593 		    &resid, td);
594     nbytes = PAGE_SIZE - resid;
595     if (error)
596 	goto out;
597 
598     if (!IS_ELF(*hdr)) {
599 	error = ENOEXEC;
600 	goto out;
601     }
602 
603     if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
604       || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
605 	link_elf_error("Unsupported file layout");
606 	error = ENOEXEC;
607 	goto out;
608     }
609     if (hdr->e_ident[EI_VERSION] != EV_CURRENT
610       || hdr->e_version != EV_CURRENT) {
611 	link_elf_error("Unsupported file version");
612 	error = ENOEXEC;
613 	goto out;
614     }
615     if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
616 	link_elf_error("Unsupported file type");
617 	error = ENOEXEC;
618 	goto out;
619     }
620     if (hdr->e_machine != ELF_TARG_MACH) {
621 	link_elf_error("Unsupported machine");
622 	error = ENOEXEC;
623 	goto out;
624     }
625 
626     /*
627      * We rely on the program header being in the first page.  This is
628      * not strictly required by the ABI specification, but it seems to
629      * always true in practice.  And, it simplifies things considerably.
630      */
631     if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
632 	  (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
633 	  (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
634 	link_elf_error("Unreadable program headers");
635 
636     /*
637      * Scan the program header entries, and save key information.
638      *
639      * We rely on there being exactly two load segments, text and data,
640      * in that order.
641      */
642     phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
643     phlimit = phdr + hdr->e_phnum;
644     nsegs = 0;
645     phdyn = NULL;
646     phphdr = NULL;
647     while (phdr < phlimit) {
648 	switch (phdr->p_type) {
649 
650 	case PT_LOAD:
651 	    if (nsegs == MAXSEGS) {
652 		link_elf_error("Too many sections");
653 		error = ENOEXEC;
654 		goto out;
655 	    }
656 	    /*
657 	     * XXX: We just trust they come in right order ??
658 	     */
659 	    segs[nsegs] = phdr;
660 	    ++nsegs;
661 	    break;
662 
663 	case PT_PHDR:
664 	    phphdr = phdr;
665 	    break;
666 
667 	case PT_DYNAMIC:
668 	    phdyn = phdr;
669 	    break;
670 
671 	case PT_INTERP:
672 	    link_elf_error("Unsupported file type");
673 	    error = ENOEXEC;
674 	    goto out;
675 	}
676 
677 	++phdr;
678     }
679     if (phdyn == NULL) {
680 	link_elf_error("Object is not dynamically-linked");
681 	error = ENOEXEC;
682 	goto out;
683     }
684     if (nsegs == 0) {
685 	link_elf_error("No sections");
686 	error = ENOEXEC;
687 	goto out;
688     }
689 
690     /*
691      * Allocate the entire address space of the object, to stake out our
692      * contiguous region, and to establish the base address for relocation.
693      */
694     base_offset = trunc_page(segs[0]->p_offset);
695     base_vaddr = trunc_page(segs[0]->p_vaddr);
696     base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
697 	segs[nsegs - 1]->p_memsz);
698     mapsize = base_vlimit - base_vaddr;
699 
700     lf = linker_make_file(filename, &link_elf_class);
701     if (!lf) {
702 	error = ENOMEM;
703 	goto out;
704     }
705 
706     ef = (elf_file_t) lf;
707 #ifdef SPARSE_MAPPING
708     ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
709     if (ef->object == NULL) {
710 	error = ENOMEM;
711 	goto out;
712     }
713     ef->address = (caddr_t) vm_map_min(kernel_map);
714     error = vm_map_find(kernel_map, ef->object, 0,
715 			(vm_offset_t *) &ef->address,
716 			mapsize, 1,
717 			VM_PROT_ALL, VM_PROT_ALL, 0);
718     if (error) {
719 	vm_object_deallocate(ef->object);
720 	ef->object = 0;
721 	goto out;
722     }
723 #else
724     ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
725     if (!ef->address) {
726 	error = ENOMEM;
727 	goto out;
728     }
729 #endif
730     mapbase = ef->address;
731 
732     /*
733      * Read the text and data sections and zero the bss.
734      */
735     for (i = 0; i < nsegs; i++) {
736 	caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
737 	error = vn_rdwr(UIO_READ, nd.ni_vp,
738 			segbase, segs[i]->p_filesz, segs[i]->p_offset,
739 			UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
740 			&resid, td);
741 	if (error) {
742 	    goto out;
743 	}
744 	bzero(segbase + segs[i]->p_filesz,
745 	      segs[i]->p_memsz - segs[i]->p_filesz);
746 
747 #ifdef SPARSE_MAPPING
748 	/*
749 	 * Wire down the pages
750 	 */
751 	error = vm_map_wire(kernel_map,
752 		    (vm_offset_t) segbase,
753 		    (vm_offset_t) segbase + segs[i]->p_memsz,
754 		    VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
755 	if (error != KERN_SUCCESS) {
756 	    error = ENOMEM;
757 	    goto out;
758 	}
759 #endif
760     }
761 
762 #ifdef GPROF
763     /* Update profiling information with the new text segment. */
764     mtx_lock(&Giant);
765     kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
766 	segs[0]->p_memsz));
767     mtx_unlock(&Giant);
768 #endif
769 
770     ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
771 
772     lf->address = ef->address;
773     lf->size = mapsize;
774 
775     error = parse_dynamic(ef);
776     if (error)
777 	goto out;
778     link_elf_reloc_local(lf);
779 
780     error = linker_load_dependencies(lf);
781     if (error)
782 	goto out;
783 #if 0	/* this will be more trouble than it's worth for now */
784     for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
785 	if (dp->d_tag != DT_NEEDED)
786 	    continue;
787 	modname = ef->strtab + dp->d_un.d_val;
788 	error = linker_load_module(modname, lf);
789 	if (error)
790 	    goto out;
791     }
792 #endif
793     error = relocate_file(ef);
794     if (error)
795 	goto out;
796 
797     /* Try and load the symbol table if it's present.  (you can strip it!) */
798     nbytes = hdr->e_shnum * hdr->e_shentsize;
799     if (nbytes == 0 || hdr->e_shoff == 0)
800 	goto nosyms;
801     shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
802     if (shdr == NULL) {
803 	error = ENOMEM;
804 	goto out;
805     }
806     error = vn_rdwr(UIO_READ, nd.ni_vp,
807 		    (caddr_t)shdr, nbytes, hdr->e_shoff,
808 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
809 		    &resid, td);
810     if (error)
811 	goto out;
812     symtabindex = -1;
813     symstrindex = -1;
814     for (i = 0; i < hdr->e_shnum; i++) {
815 	if (shdr[i].sh_type == SHT_SYMTAB) {
816 	    symtabindex = i;
817 	    symstrindex = shdr[i].sh_link;
818 	}
819     }
820     if (symtabindex < 0 || symstrindex < 0)
821 	goto nosyms;
822 
823     symcnt = shdr[symtabindex].sh_size;
824     ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
825     strcnt = shdr[symstrindex].sh_size;
826     ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
827 
828     if (ef->symbase == NULL || ef->strbase == NULL) {
829 	error = ENOMEM;
830 	goto out;
831     }
832     error = vn_rdwr(UIO_READ, nd.ni_vp,
833 		    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
834 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
835 		    &resid, td);
836     if (error)
837 	goto out;
838     error = vn_rdwr(UIO_READ, nd.ni_vp,
839 		    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
840 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
841 		    &resid, td);
842     if (error)
843 	goto out;
844 
845     ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
846     ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
847     ef->ddbstrcnt = strcnt;
848     ef->ddbstrtab = ef->strbase;
849 
850     error = link_elf_link_common_finish(lf);
851     if (error)
852 	goto out;
853 
854 nosyms:
855 
856     *result = lf;
857 
858 out:
859     if (error && lf)
860 	linker_file_unload(lf, LINKER_UNLOAD_FORCE);
861     if (shdr)
862 	free(shdr, M_LINKER);
863     if (firstpage)
864 	free(firstpage, M_LINKER);
865     VOP_UNLOCK(nd.ni_vp, 0);
866     vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
867     VFS_UNLOCK_GIANT(vfslocked);
868 
869     return error;
870 }
871 
872 static void
873 link_elf_unload_file(linker_file_t file)
874 {
875     elf_file_t ef = (elf_file_t) file;
876 
877 #ifdef GDB
878     if (ef->gdb.l_ld) {
879 	GDB_STATE(RT_DELETE);
880 	free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
881 	link_elf_delete_gdb(&ef->gdb);
882 	GDB_STATE(RT_CONSISTENT);
883     }
884 #endif
885 
886     /* Notify MD code that a module is being unloaded. */
887     elf_cpu_unload_file(file);
888 
889     if (ef->preloaded) {
890 	link_elf_unload_preload(file);
891 	return;
892     }
893 
894 #ifdef SPARSE_MAPPING
895     if (ef->object) {
896 	vm_map_remove(kernel_map, (vm_offset_t) ef->address,
897 		      (vm_offset_t) ef->address
898 		      + (ef->object->size << PAGE_SHIFT));
899     }
900 #else
901     if (ef->address)
902 	free(ef->address, M_LINKER);
903 #endif
904     if (ef->symbase)
905 	free(ef->symbase, M_LINKER);
906     if (ef->strbase)
907 	free(ef->strbase, M_LINKER);
908 }
909 
910 static void
911 link_elf_unload_preload(linker_file_t file)
912 {
913     if (file->filename)
914 	preload_delete_name(file->filename);
915 }
916 
917 static const char *
918 symbol_name(elf_file_t ef, Elf_Size r_info)
919 {
920     const Elf_Sym *ref;
921 
922     if (ELF_R_SYM(r_info)) {
923 	ref = ef->symtab + ELF_R_SYM(r_info);
924 	return ef->strtab + ref->st_name;
925     } else
926 	return NULL;
927 }
928 
929 static int
930 relocate_file(elf_file_t ef)
931 {
932     const Elf_Rel *rellim;
933     const Elf_Rel *rel;
934     const Elf_Rela *relalim;
935     const Elf_Rela *rela;
936     const char *symname;
937 
938     /* Perform relocations without addend if there are any: */
939     rel = ef->rel;
940     if (rel) {
941 	rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
942 	while (rel < rellim) {
943 	    if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
944 			  elf_lookup)) {
945 		symname = symbol_name(ef, rel->r_info);
946 		printf("link_elf: symbol %s undefined\n", symname);
947 		return ENOENT;
948 	    }
949 	    rel++;
950 	}
951     }
952 
953     /* Perform relocations with addend if there are any: */
954     rela = ef->rela;
955     if (rela) {
956 	relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
957 	while (rela < relalim) {
958 	    if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
959 			  elf_lookup)) {
960 		symname = symbol_name(ef, rela->r_info);
961 		printf("link_elf: symbol %s undefined\n", symname);
962 		return ENOENT;
963 	    }
964 	    rela++;
965 	}
966     }
967 
968     /* Perform PLT relocations without addend if there are any: */
969     rel = ef->pltrel;
970     if (rel) {
971 	rellim = (const Elf_Rel *)((const char *)ef->pltrel + ef->pltrelsize);
972 	while (rel < rellim) {
973 	    if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
974 			  elf_lookup)) {
975 		symname = symbol_name(ef, rel->r_info);
976 		printf("link_elf: symbol %s undefined\n", symname);
977 		return ENOENT;
978 	    }
979 	    rel++;
980 	}
981     }
982 
983     /* Perform relocations with addend if there are any: */
984     rela = ef->pltrela;
985     if (rela) {
986 	relalim = (const Elf_Rela *)((const char *)ef->pltrela + ef->pltrelasize);
987 	while (rela < relalim) {
988 	    if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
989 			  elf_lookup)) {
990 		symname = symbol_name(ef, rela->r_info);
991 		printf("link_elf: symbol %s undefined\n", symname);
992 		return ENOENT;
993 	    }
994 	    rela++;
995 	}
996     }
997 
998     return 0;
999 }
1000 
1001 /*
1002  * Hash function for symbol table lookup.  Don't even think about changing
1003  * this.  It is specified by the System V ABI.
1004  */
1005 static unsigned long
1006 elf_hash(const char *name)
1007 {
1008     const unsigned char *p = (const unsigned char *) name;
1009     unsigned long h = 0;
1010     unsigned long g;
1011 
1012     while (*p != '\0') {
1013 	h = (h << 4) + *p++;
1014 	if ((g = h & 0xf0000000) != 0)
1015 	    h ^= g >> 24;
1016 	h &= ~g;
1017     }
1018     return h;
1019 }
1020 
1021 static int
1022 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1023 {
1024     elf_file_t ef = (elf_file_t) lf;
1025     unsigned long symnum;
1026     const Elf_Sym* symp;
1027     const char *strp;
1028     unsigned long hash;
1029     int i;
1030 
1031     /* If we don't have a hash, bail. */
1032     if (ef->buckets == NULL || ef->nbuckets == 0) {
1033 	printf("link_elf_lookup_symbol: missing symbol hash table\n");
1034 	return ENOENT;
1035     }
1036 
1037     /* First, search hashed global symbols */
1038     hash = elf_hash(name);
1039     symnum = ef->buckets[hash % ef->nbuckets];
1040 
1041     while (symnum != STN_UNDEF) {
1042 	if (symnum >= ef->nchains) {
1043 	    printf("link_elf_lookup_symbol: corrupt symbol table\n");
1044 	    return ENOENT;
1045 	}
1046 
1047 	symp = ef->symtab + symnum;
1048 	if (symp->st_name == 0) {
1049 	    printf("link_elf_lookup_symbol: corrupt symbol table\n");
1050 	    return ENOENT;
1051 	}
1052 
1053 	strp = ef->strtab + symp->st_name;
1054 
1055 	if (strcmp(name, strp) == 0) {
1056 	    if (symp->st_shndx != SHN_UNDEF ||
1057 		(symp->st_value != 0 &&
1058 		 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1059 		*sym = (c_linker_sym_t) symp;
1060 		return 0;
1061 	    } else
1062 		return ENOENT;
1063 	}
1064 
1065 	symnum = ef->chains[symnum];
1066     }
1067 
1068     /* If we have not found it, look at the full table (if loaded) */
1069     if (ef->symtab == ef->ddbsymtab)
1070 	return ENOENT;
1071 
1072     /* Exhaustive search */
1073     for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1074 	strp = ef->ddbstrtab + symp->st_name;
1075 	if (strcmp(name, strp) == 0) {
1076 	    if (symp->st_shndx != SHN_UNDEF ||
1077 		(symp->st_value != 0 &&
1078 		 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1079 		*sym = (c_linker_sym_t) symp;
1080 		return 0;
1081 	    } else
1082 		return ENOENT;
1083 	}
1084     }
1085 
1086     return ENOENT;
1087 }
1088 
1089 static int
1090 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t* symval)
1091 {
1092 	elf_file_t ef = (elf_file_t) lf;
1093 	const Elf_Sym* es = (const Elf_Sym*) sym;
1094 
1095 	if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1096 	    symval->name = ef->strtab + es->st_name;
1097 	    symval->value = (caddr_t) ef->address + es->st_value;
1098 	    symval->size = es->st_size;
1099 	    return 0;
1100 	}
1101 	if (ef->symtab == ef->ddbsymtab)
1102 	    return ENOENT;
1103 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1104 	    symval->name = ef->ddbstrtab + es->st_name;
1105 	    symval->value = (caddr_t) ef->address + es->st_value;
1106 	    symval->size = es->st_size;
1107 	    return 0;
1108 	}
1109 	return ENOENT;
1110 }
1111 
1112 static int
1113 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1114 		       c_linker_sym_t* sym, long* diffp)
1115 {
1116 	elf_file_t ef = (elf_file_t) lf;
1117 	u_long off = (uintptr_t) (void *) value;
1118 	u_long diff = off;
1119 	u_long st_value;
1120 	const Elf_Sym* es;
1121 	const Elf_Sym* best = 0;
1122 	int i;
1123 
1124 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1125 		if (es->st_name == 0)
1126 			continue;
1127 		st_value = es->st_value + (uintptr_t) (void *) ef->address;
1128 		if (off >= st_value) {
1129 			if (off - st_value < diff) {
1130 				diff = off - st_value;
1131 				best = es;
1132 				if (diff == 0)
1133 					break;
1134 			} else if (off - st_value == diff) {
1135 				best = es;
1136 			}
1137 		}
1138 	}
1139 	if (best == 0)
1140 		*diffp = off;
1141 	else
1142 		*diffp = diff;
1143 	*sym = (c_linker_sym_t) best;
1144 
1145 	return 0;
1146 }
1147 
1148 /*
1149  * Look up a linker set on an ELF system.
1150  */
1151 static int
1152 link_elf_lookup_set(linker_file_t lf, const char *name,
1153 		    void ***startp, void ***stopp, int *countp)
1154 {
1155 	c_linker_sym_t sym;
1156 	linker_symval_t symval;
1157 	char *setsym;
1158 	void **start, **stop;
1159 	int len, error = 0, count;
1160 
1161 	len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1162 	setsym = malloc(len, M_LINKER, M_WAITOK);
1163 	if (setsym == NULL)
1164 		return ENOMEM;
1165 
1166 	/* get address of first entry */
1167 	snprintf(setsym, len, "%s%s", "__start_set_", name);
1168 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1169 	if (error)
1170 		goto out;
1171 	link_elf_symbol_values(lf, sym, &symval);
1172 	if (symval.value == 0) {
1173 		error = ESRCH;
1174 		goto out;
1175 	}
1176 	start = (void **)symval.value;
1177 
1178 	/* get address of last entry */
1179 	snprintf(setsym, len, "%s%s", "__stop_set_", name);
1180 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1181 	if (error)
1182 		goto out;
1183 	link_elf_symbol_values(lf, sym, &symval);
1184 	if (symval.value == 0) {
1185 		error = ESRCH;
1186 		goto out;
1187 	}
1188 	stop = (void **)symval.value;
1189 
1190 	/* and the number of entries */
1191 	count = stop - start;
1192 
1193 	/* and copy out */
1194 	if (startp)
1195 		*startp = start;
1196 	if (stopp)
1197 		*stopp = stop;
1198 	if (countp)
1199 		*countp = count;
1200 
1201 out:
1202 	free(setsym, M_LINKER);
1203 	return error;
1204 }
1205 
1206 static int
1207 link_elf_each_function_name(linker_file_t file,
1208   int (*callback)(const char *, void *), void *opaque) {
1209     elf_file_t ef = (elf_file_t)file;
1210     const Elf_Sym* symp;
1211     int i, error;
1212 
1213     /* Exhaustive search */
1214     for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1215 	if (symp->st_value != 0 &&
1216 	    ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1217 		error = callback(ef->ddbstrtab + symp->st_name, opaque);
1218 		if (error)
1219 		    return (error);
1220 	}
1221     }
1222     return (0);
1223 }
1224 
1225 #ifdef __ia64__
1226 /*
1227  * Each KLD has its own GP. The GP value for each load module is given by
1228  * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1229  * don't have direct access to the ELF file structure. The link_elf_get_gp()
1230  * function returns the GP given a pointer to a generic linker file struct.
1231  */
1232 Elf_Addr
1233 link_elf_get_gp(linker_file_t lf)
1234 {
1235 	elf_file_t ef = (elf_file_t)lf;
1236 	return (Elf_Addr)ef->got;
1237 }
1238 #endif
1239 
1240 const Elf_Sym *
1241 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1242 {
1243 	elf_file_t ef = (elf_file_t)lf;
1244 
1245 	if (symidx >= ef->nchains)
1246 		return (NULL);
1247 	return (ef->symtab + symidx);
1248 }
1249 
1250 const char *
1251 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1252 {
1253 	elf_file_t ef = (elf_file_t)lf;
1254 	const Elf_Sym *sym;
1255 
1256 	if (symidx >= ef->nchains)
1257 		return (NULL);
1258 	sym = ef->symtab + symidx;
1259 	return (ef->strtab + sym->st_name);
1260 }
1261 
1262 /*
1263  * Symbol lookup function that can be used when the symbol index is known (ie
1264  * in relocations). It uses the symbol index instead of doing a fully fledged
1265  * hash table based lookup when such is valid. For example for local symbols.
1266  * This is not only more efficient, it's also more correct. It's not always
1267  * the case that the symbol can be found through the hash table.
1268  */
1269 static Elf_Addr
1270 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1271 {
1272 	elf_file_t ef = (elf_file_t)lf;
1273 	const Elf_Sym *sym;
1274 	const char *symbol;
1275 
1276 	/* Don't even try to lookup the symbol if the index is bogus. */
1277 	if (symidx >= ef->nchains)
1278 		return (0);
1279 
1280 	sym = ef->symtab + symidx;
1281 
1282 	/*
1283 	 * Don't do a full lookup when the symbol is local. It may even
1284 	 * fail because it may not be found through the hash table.
1285 	 */
1286 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1287 		/* Force lookup failure when we have an insanity. */
1288 		if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1289 			return (0);
1290 		return ((Elf_Addr)ef->address + sym->st_value);
1291 	}
1292 
1293 	/*
1294 	 * XXX we can avoid doing a hash table based lookup for global
1295 	 * symbols as well. This however is not always valid, so we'll
1296 	 * just do it the hard way for now. Performance tweaks can
1297 	 * always be added.
1298 	 */
1299 
1300 	symbol = ef->strtab + sym->st_name;
1301 
1302 	/* Force a lookup failure if the symbol name is bogus. */
1303 	if (*symbol == 0)
1304 		return (0);
1305 
1306 	return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1307 }
1308 
1309 static void
1310 link_elf_reloc_local(linker_file_t lf)
1311 {
1312     const Elf_Rel *rellim;
1313     const Elf_Rel *rel;
1314     const Elf_Rela *relalim;
1315     const Elf_Rela *rela;
1316     elf_file_t ef = (elf_file_t)lf;
1317 
1318     /* Perform relocations without addend if there are any: */
1319     if ((rel = ef->rel) != NULL) {
1320 	rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1321 	while (rel < rellim) {
1322 	    elf_reloc_local(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
1323 			    elf_lookup);
1324 	    rel++;
1325 	}
1326     }
1327 
1328     /* Perform relocations with addend if there are any: */
1329     if ((rela = ef->rela) != NULL) {
1330 	relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
1331 	while (rela < relalim) {
1332 	    elf_reloc_local(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
1333 			    elf_lookup);
1334 	    rela++;
1335 	}
1336     }
1337 }
1338