xref: /freebsd/sys/kern/link_elf.c (revision 657729a89dd578d8cfc70d6616f5c65a48a8b33a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1998-2000 Doug Rabson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_ddb.h"
33 #include "opt_gdb.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #ifdef SPARSE_MAPPING
41 #include <sys/mman.h>
42 #endif
43 #include <sys/mutex.h>
44 #include <sys/mount.h>
45 #include <sys/pcpu.h>
46 #include <sys/proc.h>
47 #include <sys/namei.h>
48 #include <sys/fcntl.h>
49 #include <sys/vnode.h>
50 #include <sys/linker.h>
51 #include <sys/sysctl.h>
52 
53 #include <machine/elf.h>
54 
55 #include <net/vnet.h>
56 
57 #include <security/mac/mac_framework.h>
58 
59 #include <vm/vm.h>
60 #include <vm/vm_param.h>
61 #ifdef SPARSE_MAPPING
62 #include <vm/vm_object.h>
63 #include <vm/vm_kern.h>
64 #include <vm/vm_extern.h>
65 #endif
66 #include <vm/pmap.h>
67 #include <vm/vm_map.h>
68 
69 #include <sys/link_elf.h>
70 
71 #include "linker_if.h"
72 
73 #define MAXSEGS 4
74 
75 typedef struct elf_file {
76 	struct linker_file lf;		/* Common fields */
77 	int		preloaded;	/* Was file pre-loaded */
78 	caddr_t		address;	/* Relocation address */
79 #ifdef SPARSE_MAPPING
80 	vm_object_t	object;		/* VM object to hold file pages */
81 #endif
82 	Elf_Dyn		*dynamic;	/* Symbol table etc. */
83 	Elf_Hashelt	nbuckets;	/* DT_HASH info */
84 	Elf_Hashelt	nchains;
85 	const Elf_Hashelt *buckets;
86 	const Elf_Hashelt *chains;
87 	caddr_t		hash;
88 	caddr_t		strtab;		/* DT_STRTAB */
89 	int		strsz;		/* DT_STRSZ */
90 	const Elf_Sym	*symtab;		/* DT_SYMTAB */
91 	Elf_Addr	*got;		/* DT_PLTGOT */
92 	const Elf_Rel	*pltrel;	/* DT_JMPREL */
93 	int		pltrelsize;	/* DT_PLTRELSZ */
94 	const Elf_Rela	*pltrela;	/* DT_JMPREL */
95 	int		pltrelasize;	/* DT_PLTRELSZ */
96 	const Elf_Rel	*rel;		/* DT_REL */
97 	int		relsize;	/* DT_RELSZ */
98 	const Elf_Rela	*rela;		/* DT_RELA */
99 	int		relasize;	/* DT_RELASZ */
100 	caddr_t		modptr;
101 	const Elf_Sym	*ddbsymtab;	/* The symbol table we are using */
102 	long		ddbsymcnt;	/* Number of symbols */
103 	caddr_t		ddbstrtab;	/* String table */
104 	long		ddbstrcnt;	/* number of bytes in string table */
105 	caddr_t		symbase;	/* malloc'ed symbold base */
106 	caddr_t		strbase;	/* malloc'ed string base */
107 	caddr_t		ctftab;		/* CTF table */
108 	long		ctfcnt;		/* number of bytes in CTF table */
109 	caddr_t		ctfoff;		/* CTF offset table */
110 	caddr_t		typoff;		/* Type offset table */
111 	long		typlen;		/* Number of type entries. */
112 	Elf_Addr	pcpu_start;	/* Pre-relocation pcpu set start. */
113 	Elf_Addr	pcpu_stop;	/* Pre-relocation pcpu set stop. */
114 	Elf_Addr	pcpu_base;	/* Relocated pcpu set address. */
115 #ifdef VIMAGE
116 	Elf_Addr	vnet_start;	/* Pre-relocation vnet set start. */
117 	Elf_Addr	vnet_stop;	/* Pre-relocation vnet set stop. */
118 	Elf_Addr	vnet_base;	/* Relocated vnet set address. */
119 #endif
120 #ifdef GDB
121 	struct link_map	gdb;		/* hooks for gdb */
122 #endif
123 } *elf_file_t;
124 
125 struct elf_set {
126 	Elf_Addr	es_start;
127 	Elf_Addr	es_stop;
128 	Elf_Addr	es_base;
129 	TAILQ_ENTRY(elf_set)	es_link;
130 };
131 
132 TAILQ_HEAD(elf_set_head, elf_set);
133 
134 #include <kern/kern_ctf.c>
135 
136 static int	link_elf_link_common_finish(linker_file_t);
137 static int	link_elf_link_preload(linker_class_t cls,
138 				      const char *, linker_file_t *);
139 static int	link_elf_link_preload_finish(linker_file_t);
140 static int	link_elf_load_file(linker_class_t, const char *,
141 		    linker_file_t *);
142 static int	link_elf_lookup_symbol(linker_file_t, const char *,
143 		    c_linker_sym_t *);
144 static int	link_elf_lookup_debug_symbol(linker_file_t, const char *,
145 		    c_linker_sym_t *);
146 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
147 		    linker_symval_t *);
148 static int	link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t,
149 		    linker_symval_t*);
150 static int	link_elf_search_symbol(linker_file_t, caddr_t,
151 		    c_linker_sym_t *, long *);
152 
153 static void	link_elf_unload_file(linker_file_t);
154 static void	link_elf_unload_preload(linker_file_t);
155 static int	link_elf_lookup_set(linker_file_t, const char *,
156 		    void ***, void ***, int *);
157 static int	link_elf_each_function_name(linker_file_t,
158 		    int (*)(const char *, void *), void *);
159 static int	link_elf_each_function_nameval(linker_file_t,
160 		    linker_function_nameval_callback_t, void *);
161 static void	link_elf_reloc_local(linker_file_t);
162 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
163 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
164 static int	elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *);
165 
166 static kobj_method_t link_elf_methods[] = {
167 	KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
168 	KOBJMETHOD(linker_lookup_debug_symbol,	link_elf_lookup_debug_symbol),
169 	KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
170 	KOBJMETHOD(linker_debug_symbol_values,	link_elf_debug_symbol_values),
171 	KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
172 	KOBJMETHOD(linker_unload,		link_elf_unload_file),
173 	KOBJMETHOD(linker_load_file,		link_elf_load_file),
174 	KOBJMETHOD(linker_link_preload,		link_elf_link_preload),
175 	KOBJMETHOD(linker_link_preload_finish,	link_elf_link_preload_finish),
176 	KOBJMETHOD(linker_lookup_set,		link_elf_lookup_set),
177 	KOBJMETHOD(linker_each_function_name,	link_elf_each_function_name),
178 	KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
179 	KOBJMETHOD(linker_ctf_get,		link_elf_ctf_get),
180 	KOBJMETHOD(linker_symtab_get,		link_elf_symtab_get),
181 	KOBJMETHOD(linker_strtab_get,		link_elf_strtab_get),
182 	KOBJMETHOD_END
183 };
184 
185 static struct linker_class link_elf_class = {
186 #if ELF_TARG_CLASS == ELFCLASS32
187 	"elf32",
188 #else
189 	"elf64",
190 #endif
191 	link_elf_methods, sizeof(struct elf_file)
192 };
193 
194 static bool link_elf_leak_locals = true;
195 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_leak_locals,
196     CTLFLAG_RWTUN, &link_elf_leak_locals, 0,
197     "Allow local symbols to participate in global module symbol resolution");
198 
199 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase,
200     const void *data, int type, elf_lookup_fn lookup);
201 
202 static int	parse_dynamic(elf_file_t);
203 static int	relocate_file(elf_file_t);
204 static int	relocate_file1(elf_file_t ef, elf_lookup_fn lookup,
205 		    elf_reloc_fn reloc, bool ifuncs);
206 static int	link_elf_preload_parse_symbols(elf_file_t);
207 
208 static struct elf_set_head set_pcpu_list;
209 #ifdef VIMAGE
210 static struct elf_set_head set_vnet_list;
211 #endif
212 
213 static void
214 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
215 {
216 	struct elf_set *set, *iter;
217 
218 	set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
219 	set->es_start = start;
220 	set->es_stop = stop;
221 	set->es_base = base;
222 
223 	TAILQ_FOREACH(iter, list, es_link) {
224 		KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
225 		    (set->es_start > iter->es_start && set->es_stop > iter->es_stop),
226 		    ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
227 		    (uintmax_t)set->es_start, (uintmax_t)set->es_stop,
228 		    (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
229 
230 		if (iter->es_start > set->es_start) {
231 			TAILQ_INSERT_BEFORE(iter, set, es_link);
232 			break;
233 		}
234 	}
235 
236 	if (iter == NULL)
237 		TAILQ_INSERT_TAIL(list, set, es_link);
238 }
239 
240 static int
241 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
242 {
243 	struct elf_set *set;
244 
245 	TAILQ_FOREACH(set, list, es_link) {
246 		if (addr < set->es_start)
247 			return (0);
248 		if (addr < set->es_stop) {
249 			*start = set->es_start;
250 			*base = set->es_base;
251 			return (1);
252 		}
253 	}
254 
255 	return (0);
256 }
257 
258 static void
259 elf_set_delete(struct elf_set_head *list, Elf_Addr start)
260 {
261 	struct elf_set *set;
262 
263 	TAILQ_FOREACH(set, list, es_link) {
264 		if (start < set->es_start)
265 			break;
266 		if (start == set->es_start) {
267 			TAILQ_REMOVE(list, set, es_link);
268 			free(set, M_LINKER);
269 			return;
270 		}
271 	}
272 	KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
273 	    (uintmax_t)start));
274 }
275 
276 #ifdef GDB
277 static void	r_debug_state(struct r_debug *, struct link_map *);
278 
279 /*
280  * A list of loaded modules for GDB to use for loading symbols.
281  */
282 struct r_debug r_debug;
283 
284 #define GDB_STATE(s) do {				\
285 	r_debug.r_state = s; r_debug_state(NULL, NULL);	\
286 } while (0)
287 
288 /*
289  * Function for the debugger to set a breakpoint on to gain control.
290  */
291 static void
292 r_debug_state(struct r_debug *dummy_one __unused,
293 	      struct link_map *dummy_two __unused)
294 {
295 }
296 
297 static void
298 link_elf_add_gdb(struct link_map *l)
299 {
300 	struct link_map *prev;
301 
302 	l->l_next = NULL;
303 
304 	if (r_debug.r_map == NULL) {
305 		/* Add first. */
306 		l->l_prev = NULL;
307 		r_debug.r_map = l;
308 	} else {
309 		/* Append to list. */
310 		for (prev = r_debug.r_map;
311 		    prev->l_next != NULL;
312 		    prev = prev->l_next)
313 			;
314 		l->l_prev = prev;
315 		prev->l_next = l;
316 	}
317 }
318 
319 static void
320 link_elf_delete_gdb(struct link_map *l)
321 {
322 	if (l->l_prev == NULL) {
323 		/* Remove first. */
324 		if ((r_debug.r_map = l->l_next) != NULL)
325 			l->l_next->l_prev = NULL;
326 	} else {
327 		/* Remove any but first. */
328 		if ((l->l_prev->l_next = l->l_next) != NULL)
329 			l->l_next->l_prev = l->l_prev;
330 	}
331 }
332 #endif /* GDB */
333 
334 /*
335  * The kernel symbol table starts here.
336  */
337 extern struct _dynamic _DYNAMIC;
338 
339 static void
340 link_elf_error(const char *filename, const char *s)
341 {
342 	if (filename == NULL)
343 		printf("kldload: %s\n", s);
344 	else
345 		printf("kldload: %s: %s\n", filename, s);
346 }
347 
348 static void
349 link_elf_invoke_ctors(caddr_t addr, size_t size)
350 {
351 	void (**ctor)(void);
352 	size_t i, cnt;
353 
354 	if (addr == NULL || size == 0)
355 		return;
356 	cnt = size / sizeof(*ctor);
357 	ctor = (void *)addr;
358 	for (i = 0; i < cnt; i++) {
359 		if (ctor[i] != NULL)
360 			(*ctor[i])();
361 	}
362 }
363 
364 /*
365  * Actions performed after linking/loading both the preloaded kernel and any
366  * modules; whether preloaded or dynamicly loaded.
367  */
368 static int
369 link_elf_link_common_finish(linker_file_t lf)
370 {
371 #ifdef GDB
372 	elf_file_t ef = (elf_file_t)lf;
373 	char *newfilename;
374 #endif
375 	int error;
376 
377 	/* Notify MD code that a module is being loaded. */
378 	error = elf_cpu_load_file(lf);
379 	if (error != 0)
380 		return (error);
381 
382 #ifdef GDB
383 	GDB_STATE(RT_ADD);
384 	ef->gdb.l_addr = lf->address;
385 	newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
386 	strcpy(newfilename, lf->filename);
387 	ef->gdb.l_name = newfilename;
388 	ef->gdb.l_ld = ef->dynamic;
389 	link_elf_add_gdb(&ef->gdb);
390 	GDB_STATE(RT_CONSISTENT);
391 #endif
392 
393 	/* Invoke .ctors */
394 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
395 	return (0);
396 }
397 
398 #ifdef RELOCATABLE_KERNEL
399 /*
400  * __startkernel and __endkernel are symbols set up as relocation canaries.
401  *
402  * They are defined in locore to reference linker script symbols at the
403  * beginning and end of the LOAD area. This has the desired side effect of
404  * giving us variables that have relative relocations pointing at them, so
405  * relocation of the kernel object will cause the variables to be updated
406  * automatically by the runtime linker when we initialize.
407  *
408  * There are two main reasons to relocate the kernel:
409  * 1) If the loader needed to load the kernel at an alternate load address.
410  * 2) If the kernel is switching address spaces on machines like POWER9
411  *    under Radix where the high bits of the effective address are used to
412  *    differentiate between hypervisor, host, guest, and problem state.
413  */
414 extern vm_offset_t __startkernel, __endkernel;
415 #endif
416 
417 static unsigned long kern_relbase = KERNBASE;
418 
419 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD,
420 	SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address");
421 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD,
422 	&kern_relbase, 0, "Kernel relocated base address");
423 
424 static void
425 link_elf_init(void* arg)
426 {
427 	Elf_Dyn *dp;
428 	Elf_Addr *ctors_addrp;
429 	Elf_Size *ctors_sizep;
430 	caddr_t modptr, baseptr, sizeptr;
431 	elf_file_t ef;
432 	const char *modname;
433 
434 	linker_add_class(&link_elf_class);
435 
436 	dp = (Elf_Dyn *)&_DYNAMIC;
437 	modname = NULL;
438 	modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
439 	if (modptr == NULL)
440 		modptr = preload_search_by_type("elf kernel");
441 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
442 	if (modname == NULL)
443 		modname = "kernel";
444 	linker_kernel_file = linker_make_file(modname, &link_elf_class);
445 	if (linker_kernel_file == NULL)
446 		panic("%s: Can't create linker structures for kernel",
447 		    __func__);
448 
449 	ef = (elf_file_t) linker_kernel_file;
450 	ef->preloaded = 1;
451 #ifdef RELOCATABLE_KERNEL
452 	/* Compute relative displacement */
453 	ef->address = (caddr_t) (__startkernel - KERNBASE);
454 #else
455 	ef->address = 0;
456 #endif
457 #ifdef SPARSE_MAPPING
458 	ef->object = NULL;
459 #endif
460 	ef->dynamic = dp;
461 
462 	if (dp != NULL)
463 		parse_dynamic(ef);
464 #ifdef RELOCATABLE_KERNEL
465 	linker_kernel_file->address = (caddr_t)__startkernel;
466 	linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
467 	kern_relbase = (unsigned long)__startkernel;
468 #else
469 	linker_kernel_file->address += KERNBASE;
470 	linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
471 #endif
472 
473 	if (modptr != NULL) {
474 		ef->modptr = modptr;
475 		baseptr = preload_search_info(modptr, MODINFO_ADDR);
476 		if (baseptr != NULL)
477 			linker_kernel_file->address = *(caddr_t *)baseptr;
478 		sizeptr = preload_search_info(modptr, MODINFO_SIZE);
479 		if (sizeptr != NULL)
480 			linker_kernel_file->size = *(size_t *)sizeptr;
481 		ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
482 			MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
483 		ctors_sizep = (Elf_Size *)preload_search_info(modptr,
484 			MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
485 		if (ctors_addrp != NULL && ctors_sizep != NULL) {
486 			linker_kernel_file->ctors_addr = ef->address +
487 			    *ctors_addrp;
488 			linker_kernel_file->ctors_size = *ctors_sizep;
489 		}
490 	}
491 	(void)link_elf_preload_parse_symbols(ef);
492 
493 #ifdef GDB
494 	r_debug.r_map = NULL;
495 	r_debug.r_brk = r_debug_state;
496 	r_debug.r_state = RT_CONSISTENT;
497 #endif
498 
499 	(void)link_elf_link_common_finish(linker_kernel_file);
500 	linker_kernel_file->flags |= LINKER_FILE_LINKED;
501 	TAILQ_INIT(&set_pcpu_list);
502 #ifdef VIMAGE
503 	TAILQ_INIT(&set_vnet_list);
504 #endif
505 }
506 
507 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL);
508 
509 static int
510 link_elf_preload_parse_symbols(elf_file_t ef)
511 {
512 	caddr_t pointer;
513 	caddr_t ssym, esym, base;
514 	caddr_t strtab;
515 	int strcnt;
516 	Elf_Sym *symtab;
517 	int symcnt;
518 
519 	if (ef->modptr == NULL)
520 		return (0);
521 	pointer = preload_search_info(ef->modptr,
522 	    MODINFO_METADATA | MODINFOMD_SSYM);
523 	if (pointer == NULL)
524 		return (0);
525 	ssym = *(caddr_t *)pointer;
526 	pointer = preload_search_info(ef->modptr,
527 	    MODINFO_METADATA | MODINFOMD_ESYM);
528 	if (pointer == NULL)
529 		return (0);
530 	esym = *(caddr_t *)pointer;
531 
532 	base = ssym;
533 
534 	symcnt = *(long *)base;
535 	base += sizeof(long);
536 	symtab = (Elf_Sym *)base;
537 	base += roundup(symcnt, sizeof(long));
538 
539 	if (base > esym || base < ssym) {
540 		printf("Symbols are corrupt!\n");
541 		return (EINVAL);
542 	}
543 
544 	strcnt = *(long *)base;
545 	base += sizeof(long);
546 	strtab = base;
547 	base += roundup(strcnt, sizeof(long));
548 
549 	if (base > esym || base < ssym) {
550 		printf("Symbols are corrupt!\n");
551 		return (EINVAL);
552 	}
553 
554 	ef->ddbsymtab = symtab;
555 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
556 	ef->ddbstrtab = strtab;
557 	ef->ddbstrcnt = strcnt;
558 
559 	return (0);
560 }
561 
562 static int
563 parse_dynamic(elf_file_t ef)
564 {
565 	Elf_Dyn *dp;
566 	int plttype = DT_REL;
567 
568 	for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
569 		switch (dp->d_tag) {
570 		case DT_HASH:
571 		{
572 			/* From src/libexec/rtld-elf/rtld.c */
573 			const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
574 			    (ef->address + dp->d_un.d_ptr);
575 			ef->nbuckets = hashtab[0];
576 			ef->nchains = hashtab[1];
577 			ef->buckets = hashtab + 2;
578 			ef->chains = ef->buckets + ef->nbuckets;
579 			break;
580 		}
581 		case DT_STRTAB:
582 			ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
583 			break;
584 		case DT_STRSZ:
585 			ef->strsz = dp->d_un.d_val;
586 			break;
587 		case DT_SYMTAB:
588 			ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
589 			break;
590 		case DT_SYMENT:
591 			if (dp->d_un.d_val != sizeof(Elf_Sym))
592 				return (ENOEXEC);
593 			break;
594 		case DT_PLTGOT:
595 			ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
596 			break;
597 		case DT_REL:
598 			ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
599 			break;
600 		case DT_RELSZ:
601 			ef->relsize = dp->d_un.d_val;
602 			break;
603 		case DT_RELENT:
604 			if (dp->d_un.d_val != sizeof(Elf_Rel))
605 				return (ENOEXEC);
606 			break;
607 		case DT_JMPREL:
608 			ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
609 			break;
610 		case DT_PLTRELSZ:
611 			ef->pltrelsize = dp->d_un.d_val;
612 			break;
613 		case DT_RELA:
614 			ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
615 			break;
616 		case DT_RELASZ:
617 			ef->relasize = dp->d_un.d_val;
618 			break;
619 		case DT_RELAENT:
620 			if (dp->d_un.d_val != sizeof(Elf_Rela))
621 				return (ENOEXEC);
622 			break;
623 		case DT_PLTREL:
624 			plttype = dp->d_un.d_val;
625 			if (plttype != DT_REL && plttype != DT_RELA)
626 				return (ENOEXEC);
627 			break;
628 #ifdef GDB
629 		case DT_DEBUG:
630 			dp->d_un.d_ptr = (Elf_Addr)&r_debug;
631 			break;
632 #endif
633 		}
634 	}
635 
636 	if (plttype == DT_RELA) {
637 		ef->pltrela = (const Elf_Rela *)ef->pltrel;
638 		ef->pltrel = NULL;
639 		ef->pltrelasize = ef->pltrelsize;
640 		ef->pltrelsize = 0;
641 	}
642 
643 	ef->ddbsymtab = ef->symtab;
644 	ef->ddbsymcnt = ef->nchains;
645 	ef->ddbstrtab = ef->strtab;
646 	ef->ddbstrcnt = ef->strsz;
647 
648 	return elf_cpu_parse_dynamic(ef->address, ef->dynamic);
649 }
650 
651 #define	LS_PADDING	0x90909090
652 static int
653 parse_dpcpu(elf_file_t ef)
654 {
655 	int error, size;
656 #if defined(__i386__)
657 	uint32_t pad;
658 #endif
659 
660 	ef->pcpu_start = 0;
661 	ef->pcpu_stop = 0;
662 	error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
663 	    (void ***)&ef->pcpu_stop, NULL);
664 	/* Error just means there is no pcpu set to relocate. */
665 	if (error != 0)
666 		return (0);
667 	size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start;
668 	/* Empty set? */
669 	if (size < 1)
670 		return (0);
671 #if defined(__i386__)
672 	/* In case we do find __start/stop_set_ symbols double-check. */
673 	if (size < 4) {
674 		uprintf("Kernel module '%s' must be recompiled with "
675 		    "linker script\n", ef->lf.pathname);
676 		return (ENOEXEC);
677 	}
678 
679 	/* Padding from linker-script correct? */
680 	pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad));
681 	if (pad != LS_PADDING) {
682 		uprintf("Kernel module '%s' must be recompiled with "
683 		    "linker script, invalid padding %#04x (%#04x)\n",
684 		    ef->lf.pathname, pad, LS_PADDING);
685 		return (ENOEXEC);
686 	}
687 	/* If we only have valid padding, nothing to do. */
688 	if (size == 4)
689 		return (0);
690 #endif
691 	/*
692 	 * Allocate space in the primary pcpu area.  Copy in our
693 	 * initialization from the data section and then initialize
694 	 * all per-cpu storage from that.
695 	 */
696 	ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size);
697 	if (ef->pcpu_base == 0) {
698 		printf("%s: pcpu module space is out of space; "
699 		    "cannot allocate %d for %s\n",
700 		    __func__, size, ef->lf.pathname);
701 		return (ENOSPC);
702 	}
703 	memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size);
704 	dpcpu_copy((void *)ef->pcpu_base, size);
705 	elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
706 	    ef->pcpu_base);
707 
708 	return (0);
709 }
710 
711 #ifdef VIMAGE
712 static int
713 parse_vnet(elf_file_t ef)
714 {
715 	int error, size;
716 #if defined(__i386__)
717 	uint32_t pad;
718 #endif
719 
720 	ef->vnet_start = 0;
721 	ef->vnet_stop = 0;
722 	error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
723 	    (void ***)&ef->vnet_stop, NULL);
724 	/* Error just means there is no vnet data set to relocate. */
725 	if (error != 0)
726 		return (0);
727 	size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
728 	/* Empty set? */
729 	if (size < 1)
730 		return (0);
731 #if defined(__i386__)
732 	/* In case we do find __start/stop_set_ symbols double-check. */
733 	if (size < 4) {
734 		uprintf("Kernel module '%s' must be recompiled with "
735 		    "linker script\n", ef->lf.pathname);
736 		return (ENOEXEC);
737 	}
738 
739 	/* Padding from linker-script correct? */
740 	pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad));
741 	if (pad != LS_PADDING) {
742 		uprintf("Kernel module '%s' must be recompiled with "
743 		    "linker script, invalid padding %#04x (%#04x)\n",
744 		    ef->lf.pathname, pad, LS_PADDING);
745 		return (ENOEXEC);
746 	}
747 	/* If we only have valid padding, nothing to do. */
748 	if (size == 4)
749 		return (0);
750 #endif
751 	/*
752 	 * Allocate space in the primary vnet area.  Copy in our
753 	 * initialization from the data section and then initialize
754 	 * all per-vnet storage from that.
755 	 */
756 	ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size);
757 	if (ef->vnet_base == 0) {
758 		printf("%s: vnet module space is out of space; "
759 		    "cannot allocate %d for %s\n",
760 		    __func__, size, ef->lf.pathname);
761 		return (ENOSPC);
762 	}
763 	memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size);
764 	vnet_data_copy((void *)ef->vnet_base, size);
765 	elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
766 	    ef->vnet_base);
767 
768 	return (0);
769 }
770 #endif
771 #undef LS_PADDING
772 
773 /*
774  * Apply the specified protection to the loadable segments of a preloaded linker
775  * file.
776  */
777 static int
778 preload_protect(elf_file_t ef, vm_prot_t prot)
779 {
780 #if defined(__aarch64__) || defined(__amd64__)
781 	Elf_Ehdr *hdr;
782 	Elf_Phdr *phdr, *phlimit;
783 	vm_prot_t nprot;
784 	int error;
785 
786 	error = 0;
787 	hdr = (Elf_Ehdr *)ef->address;
788 	phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff);
789 	phlimit = phdr + hdr->e_phnum;
790 	for (; phdr < phlimit; phdr++) {
791 		if (phdr->p_type != PT_LOAD)
792 			continue;
793 
794 		nprot = prot | VM_PROT_READ;
795 		if ((phdr->p_flags & PF_W) != 0)
796 			nprot |= VM_PROT_WRITE;
797 		if ((phdr->p_flags & PF_X) != 0)
798 			nprot |= VM_PROT_EXECUTE;
799 		error = pmap_change_prot((vm_offset_t)ef->address +
800 		    phdr->p_vaddr, round_page(phdr->p_memsz), nprot);
801 		if (error != 0)
802 			break;
803 	}
804 	return (error);
805 #else
806 	return (0);
807 #endif
808 }
809 
810 #ifdef __arm__
811 /*
812  * Locate the ARM exception/unwind table info for DDB and stack(9) use by
813  * searching for the section header that describes it.  There may be no unwind
814  * info, for example in a module containing only data.
815  */
816 static void
817 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr)
818 {
819 	int i;
820 
821 	for (i = 0; i < nhdr; i++) {
822 		if (shdr[i].sh_type == SHT_ARM_EXIDX) {
823 			lf->exidx_addr = shdr[i].sh_addr + lf->address;
824 			lf->exidx_size = shdr[i].sh_size;
825 			break;
826 		}
827 	}
828 }
829 
830 /*
831  * Locate the section headers metadata in a preloaded module, then use it to
832  * locate the exception/unwind table in the module.  The size of the metadata
833  * block is stored in a uint32 word immediately before the data itself, and a
834  * comment in preload_search_info() says it is safe to rely on that.
835  */
836 static void
837 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr)
838 {
839 	uint32_t *modinfo;
840 	Elf_Shdr *shdr;
841 	uint32_t  nhdr;
842 
843 	modinfo = (uint32_t *)preload_search_info(modptr,
844 	    MODINFO_METADATA | MODINFOMD_SHDR);
845 	if (modinfo != NULL) {
846 		shdr = (Elf_Shdr *)modinfo;
847 		nhdr = modinfo[-1] / sizeof(Elf_Shdr);
848 		link_elf_locate_exidx(lf, shdr, nhdr);
849 	}
850 }
851 
852 #endif /* __arm__ */
853 
854 static int
855 link_elf_link_preload(linker_class_t cls, const char *filename,
856     linker_file_t *result)
857 {
858 	Elf_Addr *ctors_addrp;
859 	Elf_Size *ctors_sizep;
860 	caddr_t modptr, baseptr, sizeptr, dynptr;
861 	char *type;
862 	elf_file_t ef;
863 	linker_file_t lf;
864 	int error;
865 	vm_offset_t dp;
866 
867 	/* Look to see if we have the file preloaded */
868 	modptr = preload_search_by_name(filename);
869 	if (modptr == NULL)
870 		return (ENOENT);
871 
872 	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
873 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
874 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
875 	dynptr = preload_search_info(modptr,
876 	    MODINFO_METADATA | MODINFOMD_DYNAMIC);
877 	if (type == NULL ||
878 	    (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
879 	     strcmp(type, "elf module") != 0))
880 		return (EFTYPE);
881 	if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
882 		return (EINVAL);
883 
884 	lf = linker_make_file(filename, &link_elf_class);
885 	if (lf == NULL)
886 		return (ENOMEM);
887 
888 	ef = (elf_file_t) lf;
889 	ef->preloaded = 1;
890 	ef->modptr = modptr;
891 	ef->address = *(caddr_t *)baseptr;
892 #ifdef SPARSE_MAPPING
893 	ef->object = NULL;
894 #endif
895 	dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
896 	ef->dynamic = (Elf_Dyn *)dp;
897 	lf->address = ef->address;
898 	lf->size = *(size_t *)sizeptr;
899 
900 	ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
901 	    MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
902 	ctors_sizep = (Elf_Size *)preload_search_info(modptr,
903 	    MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
904 	if (ctors_addrp != NULL && ctors_sizep != NULL) {
905 		lf->ctors_addr = ef->address + *ctors_addrp;
906 		lf->ctors_size = *ctors_sizep;
907 	}
908 
909 #ifdef __arm__
910 	link_elf_locate_exidx_preload(lf, modptr);
911 #endif
912 
913 	error = parse_dynamic(ef);
914 	if (error == 0)
915 		error = parse_dpcpu(ef);
916 #ifdef VIMAGE
917 	if (error == 0)
918 		error = parse_vnet(ef);
919 #endif
920 	if (error == 0)
921 		error = preload_protect(ef, VM_PROT_ALL);
922 	if (error != 0) {
923 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
924 		return (error);
925 	}
926 	link_elf_reloc_local(lf);
927 	*result = lf;
928 	return (0);
929 }
930 
931 static int
932 link_elf_link_preload_finish(linker_file_t lf)
933 {
934 	elf_file_t ef;
935 	int error;
936 
937 	ef = (elf_file_t) lf;
938 	error = relocate_file(ef);
939 	if (error == 0)
940 		error = preload_protect(ef, VM_PROT_NONE);
941 	if (error != 0)
942 		return (error);
943 	(void)link_elf_preload_parse_symbols(ef);
944 
945 	return (link_elf_link_common_finish(lf));
946 }
947 
948 static int
949 link_elf_load_file(linker_class_t cls, const char* filename,
950     linker_file_t* result)
951 {
952 	struct nameidata nd;
953 	struct thread* td = curthread;	/* XXX */
954 	Elf_Ehdr *hdr;
955 	caddr_t firstpage, segbase;
956 	int nbytes, i;
957 	Elf_Phdr *phdr;
958 	Elf_Phdr *phlimit;
959 	Elf_Phdr *segs[MAXSEGS];
960 	int nsegs;
961 	Elf_Phdr *phdyn;
962 	caddr_t mapbase;
963 	size_t mapsize;
964 	Elf_Addr base_vaddr;
965 	Elf_Addr base_vlimit;
966 	int error = 0;
967 	ssize_t resid;
968 	int flags;
969 	elf_file_t ef;
970 	linker_file_t lf;
971 	Elf_Shdr *shdr;
972 	int symtabindex;
973 	int symstrindex;
974 	int shstrindex;
975 	int symcnt;
976 	int strcnt;
977 	char *shstrs;
978 
979 	shdr = NULL;
980 	lf = NULL;
981 	shstrs = NULL;
982 
983 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename);
984 	flags = FREAD;
985 	error = vn_open(&nd, &flags, 0, NULL);
986 	if (error != 0)
987 		return (error);
988 	NDFREE_PNBUF(&nd);
989 	if (nd.ni_vp->v_type != VREG) {
990 		error = ENOEXEC;
991 		firstpage = NULL;
992 		goto out;
993 	}
994 #ifdef MAC
995 	error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
996 	if (error != 0) {
997 		firstpage = NULL;
998 		goto out;
999 	}
1000 #endif
1001 
1002 	/*
1003 	 * Read the elf header from the file.
1004 	 */
1005 	firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
1006 	hdr = (Elf_Ehdr *)firstpage;
1007 	error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
1008 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1009 	    &resid, td);
1010 	nbytes = PAGE_SIZE - resid;
1011 	if (error != 0)
1012 		goto out;
1013 
1014 	if (!IS_ELF(*hdr)) {
1015 		error = ENOEXEC;
1016 		goto out;
1017 	}
1018 
1019 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
1020 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
1021 		link_elf_error(filename, "Unsupported file layout");
1022 		error = ENOEXEC;
1023 		goto out;
1024 	}
1025 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
1026 	    hdr->e_version != EV_CURRENT) {
1027 		link_elf_error(filename, "Unsupported file version");
1028 		error = ENOEXEC;
1029 		goto out;
1030 	}
1031 	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
1032 		error = ENOSYS;
1033 		goto out;
1034 	}
1035 	if (hdr->e_machine != ELF_TARG_MACH) {
1036 		link_elf_error(filename, "Unsupported machine");
1037 		error = ENOEXEC;
1038 		goto out;
1039 	}
1040 
1041 	/*
1042 	 * We rely on the program header being in the first page.
1043 	 * This is not strictly required by the ABI specification, but
1044 	 * it seems to always true in practice.  And, it simplifies
1045 	 * things considerably.
1046 	 */
1047 	if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
1048 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
1049 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
1050 		link_elf_error(filename, "Unreadable program headers");
1051 
1052 	/*
1053 	 * Scan the program header entries, and save key information.
1054 	 *
1055 	 * We rely on there being exactly two load segments, text and data,
1056 	 * in that order.
1057 	 */
1058 	phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
1059 	phlimit = phdr + hdr->e_phnum;
1060 	nsegs = 0;
1061 	phdyn = NULL;
1062 	while (phdr < phlimit) {
1063 		switch (phdr->p_type) {
1064 		case PT_LOAD:
1065 			if (nsegs == MAXSEGS) {
1066 				link_elf_error(filename, "Too many sections");
1067 				error = ENOEXEC;
1068 				goto out;
1069 			}
1070 			/*
1071 			 * XXX: We just trust they come in right order ??
1072 			 */
1073 			segs[nsegs] = phdr;
1074 			++nsegs;
1075 			break;
1076 
1077 		case PT_DYNAMIC:
1078 			phdyn = phdr;
1079 			break;
1080 
1081 		case PT_INTERP:
1082 			error = ENOSYS;
1083 			goto out;
1084 		}
1085 
1086 		++phdr;
1087 	}
1088 	if (phdyn == NULL) {
1089 		link_elf_error(filename, "Object is not dynamically-linked");
1090 		error = ENOEXEC;
1091 		goto out;
1092 	}
1093 	if (nsegs == 0) {
1094 		link_elf_error(filename, "No sections");
1095 		error = ENOEXEC;
1096 		goto out;
1097 	}
1098 
1099 	/*
1100 	 * Allocate the entire address space of the object, to stake
1101 	 * out our contiguous region, and to establish the base
1102 	 * address for relocation.
1103 	 */
1104 	base_vaddr = trunc_page(segs[0]->p_vaddr);
1105 	base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
1106 	    segs[nsegs - 1]->p_memsz);
1107 	mapsize = base_vlimit - base_vaddr;
1108 
1109 	lf = linker_make_file(filename, &link_elf_class);
1110 	if (lf == NULL) {
1111 		error = ENOMEM;
1112 		goto out;
1113 	}
1114 
1115 	ef = (elf_file_t) lf;
1116 #ifdef SPARSE_MAPPING
1117 	ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL,
1118 	    0, thread0.td_ucred);
1119 	if (ef->object == NULL) {
1120 		error = ENOMEM;
1121 		goto out;
1122 	}
1123 #ifdef __amd64__
1124 	mapbase = (caddr_t)KERNBASE;
1125 #else
1126 	mapbase = (caddr_t)vm_map_min(kernel_map);
1127 #endif
1128 	/*
1129 	 * Mapping protections are downgraded after relocation processing.
1130 	 */
1131 	error = vm_map_find(kernel_map, ef->object, 0,
1132 	    (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE,
1133 	    VM_PROT_ALL, VM_PROT_ALL, 0);
1134 	if (error != 0) {
1135 		vm_object_deallocate(ef->object);
1136 		ef->object = NULL;
1137 		goto out;
1138 	}
1139 #else
1140 	mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK);
1141 #endif
1142 	ef->address = mapbase;
1143 
1144 	/*
1145 	 * Read the text and data sections and zero the bss.
1146 	 */
1147 	for (i = 0; i < nsegs; i++) {
1148 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1149 
1150 #ifdef SPARSE_MAPPING
1151 		/*
1152 		 * Consecutive segments may have different mapping permissions,
1153 		 * so be strict and verify that their mappings do not overlap.
1154 		 */
1155 		if (((vm_offset_t)segbase & PAGE_MASK) != 0) {
1156 			error = EINVAL;
1157 			goto out;
1158 		}
1159 
1160 		error = vm_map_wire(kernel_map,
1161 		    (vm_offset_t)segbase,
1162 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1163 		    VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
1164 		if (error != KERN_SUCCESS) {
1165 			error = ENOMEM;
1166 			goto out;
1167 		}
1168 #endif
1169 
1170 		error = vn_rdwr(UIO_READ, nd.ni_vp,
1171 		    segbase, segs[i]->p_filesz, segs[i]->p_offset,
1172 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1173 		    &resid, td);
1174 		if (error != 0)
1175 			goto out;
1176 		bzero(segbase + segs[i]->p_filesz,
1177 		    segs[i]->p_memsz - segs[i]->p_filesz);
1178 	}
1179 
1180 	ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
1181 
1182 	lf->address = ef->address;
1183 	lf->size = mapsize;
1184 
1185 	error = parse_dynamic(ef);
1186 	if (error != 0)
1187 		goto out;
1188 	error = parse_dpcpu(ef);
1189 	if (error != 0)
1190 		goto out;
1191 #ifdef VIMAGE
1192 	error = parse_vnet(ef);
1193 	if (error != 0)
1194 		goto out;
1195 #endif
1196 	link_elf_reloc_local(lf);
1197 
1198 	VOP_UNLOCK(nd.ni_vp);
1199 	error = linker_load_dependencies(lf);
1200 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1201 	if (error != 0)
1202 		goto out;
1203 	error = relocate_file(ef);
1204 	if (error != 0)
1205 		goto out;
1206 
1207 #ifdef SPARSE_MAPPING
1208 	/*
1209 	 * Downgrade permissions on text segment mappings now that relocation
1210 	 * processing is complete.  Restrict permissions on read-only segments.
1211 	 */
1212 	for (i = 0; i < nsegs; i++) {
1213 		vm_prot_t prot;
1214 
1215 		if (segs[i]->p_type != PT_LOAD)
1216 			continue;
1217 
1218 		prot = VM_PROT_READ;
1219 		if ((segs[i]->p_flags & PF_W) != 0)
1220 			prot |= VM_PROT_WRITE;
1221 		if ((segs[i]->p_flags & PF_X) != 0)
1222 			prot |= VM_PROT_EXECUTE;
1223 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1224 		error = vm_map_protect(kernel_map,
1225 		    (vm_offset_t)segbase,
1226 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1227 		    prot, 0, VM_MAP_PROTECT_SET_PROT);
1228 		if (error != KERN_SUCCESS) {
1229 			error = ENOMEM;
1230 			goto out;
1231 		}
1232 	}
1233 #endif
1234 
1235 	/*
1236 	 * Try and load the symbol table if it's present.  (you can
1237 	 * strip it!)
1238 	 */
1239 	nbytes = hdr->e_shnum * hdr->e_shentsize;
1240 	if (nbytes == 0 || hdr->e_shoff == 0)
1241 		goto nosyms;
1242 	shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1243 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1244 	    (caddr_t)shdr, nbytes, hdr->e_shoff,
1245 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1246 	    &resid, td);
1247 	if (error != 0)
1248 		goto out;
1249 
1250 	/* Read section string table */
1251 	shstrindex = hdr->e_shstrndx;
1252 	if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB &&
1253 	    shdr[shstrindex].sh_size != 0) {
1254 		nbytes = shdr[shstrindex].sh_size;
1255 		shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1256 		error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes,
1257 		    shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
1258 		    td->td_ucred, NOCRED, &resid, td);
1259 		if (error)
1260 			goto out;
1261 	}
1262 
1263 	symtabindex = -1;
1264 	symstrindex = -1;
1265 	for (i = 0; i < hdr->e_shnum; i++) {
1266 		if (shdr[i].sh_type == SHT_SYMTAB) {
1267 			symtabindex = i;
1268 			symstrindex = shdr[i].sh_link;
1269 		} else if (shstrs != NULL && shdr[i].sh_name != 0 &&
1270 		    strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) {
1271 			/* Record relocated address and size of .ctors. */
1272 			lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr;
1273 			lf->ctors_size = shdr[i].sh_size;
1274 		}
1275 	}
1276 	if (symtabindex < 0 || symstrindex < 0)
1277 		goto nosyms;
1278 
1279 	symcnt = shdr[symtabindex].sh_size;
1280 	ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
1281 	strcnt = shdr[symstrindex].sh_size;
1282 	ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
1283 
1284 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1285 	    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
1286 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1287 	    &resid, td);
1288 	if (error != 0)
1289 		goto out;
1290 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1291 	    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
1292 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1293 	    &resid, td);
1294 	if (error != 0)
1295 		goto out;
1296 
1297 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
1298 	ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
1299 	ef->ddbstrcnt = strcnt;
1300 	ef->ddbstrtab = ef->strbase;
1301 
1302 nosyms:
1303 
1304 #ifdef __arm__
1305 	link_elf_locate_exidx(lf, shdr, hdr->e_shnum);
1306 #endif
1307 
1308 	error = link_elf_link_common_finish(lf);
1309 	if (error != 0)
1310 		goto out;
1311 
1312 	*result = lf;
1313 
1314 out:
1315 	VOP_UNLOCK(nd.ni_vp);
1316 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1317 	if (error != 0 && lf != NULL)
1318 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1319 	free(shdr, M_LINKER);
1320 	free(firstpage, M_LINKER);
1321 	free(shstrs, M_LINKER);
1322 
1323 	return (error);
1324 }
1325 
1326 Elf_Addr
1327 elf_relocaddr(linker_file_t lf, Elf_Addr x)
1328 {
1329 	elf_file_t ef;
1330 
1331 	KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class,
1332 	    ("elf_relocaddr: unexpected linker file %p", lf));
1333 
1334 	ef = (elf_file_t)lf;
1335 	if (x >= ef->pcpu_start && x < ef->pcpu_stop)
1336 		return ((x - ef->pcpu_start) + ef->pcpu_base);
1337 #ifdef VIMAGE
1338 	if (x >= ef->vnet_start && x < ef->vnet_stop)
1339 		return ((x - ef->vnet_start) + ef->vnet_base);
1340 #endif
1341 	return (x);
1342 }
1343 
1344 static void
1345 link_elf_unload_file(linker_file_t file)
1346 {
1347 	elf_file_t ef = (elf_file_t) file;
1348 
1349 	if (ef->pcpu_base != 0) {
1350 		dpcpu_free((void *)ef->pcpu_base,
1351 		    ef->pcpu_stop - ef->pcpu_start);
1352 		elf_set_delete(&set_pcpu_list, ef->pcpu_start);
1353 	}
1354 #ifdef VIMAGE
1355 	if (ef->vnet_base != 0) {
1356 		vnet_data_free((void *)ef->vnet_base,
1357 		    ef->vnet_stop - ef->vnet_start);
1358 		elf_set_delete(&set_vnet_list, ef->vnet_start);
1359 	}
1360 #endif
1361 #ifdef GDB
1362 	if (ef->gdb.l_ld != NULL) {
1363 		GDB_STATE(RT_DELETE);
1364 		free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1365 		link_elf_delete_gdb(&ef->gdb);
1366 		GDB_STATE(RT_CONSISTENT);
1367 	}
1368 #endif
1369 
1370 	/* Notify MD code that a module is being unloaded. */
1371 	elf_cpu_unload_file(file);
1372 
1373 	if (ef->preloaded) {
1374 		link_elf_unload_preload(file);
1375 		return;
1376 	}
1377 
1378 #ifdef SPARSE_MAPPING
1379 	if (ef->object != NULL) {
1380 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1381 		    (vm_offset_t) ef->address
1382 		    + (ef->object->size << PAGE_SHIFT));
1383 	}
1384 #else
1385 	free(ef->address, M_LINKER);
1386 #endif
1387 	free(ef->symbase, M_LINKER);
1388 	free(ef->strbase, M_LINKER);
1389 	free(ef->ctftab, M_LINKER);
1390 	free(ef->ctfoff, M_LINKER);
1391 	free(ef->typoff, M_LINKER);
1392 }
1393 
1394 static void
1395 link_elf_unload_preload(linker_file_t file)
1396 {
1397 
1398 	if (file->pathname != NULL)
1399 		preload_delete_name(file->pathname);
1400 }
1401 
1402 static const char *
1403 symbol_name(elf_file_t ef, Elf_Size r_info)
1404 {
1405 	const Elf_Sym *ref;
1406 
1407 	if (ELF_R_SYM(r_info)) {
1408 		ref = ef->symtab + ELF_R_SYM(r_info);
1409 		return (ef->strtab + ref->st_name);
1410 	}
1411 	return (NULL);
1412 }
1413 
1414 static int
1415 symbol_type(elf_file_t ef, Elf_Size r_info)
1416 {
1417 	const Elf_Sym *ref;
1418 
1419 	if (ELF_R_SYM(r_info)) {
1420 		ref = ef->symtab + ELF_R_SYM(r_info);
1421 		return (ELF_ST_TYPE(ref->st_info));
1422 	}
1423 	return (STT_NOTYPE);
1424 }
1425 
1426 static int
1427 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc,
1428     bool ifuncs)
1429 {
1430 	const Elf_Rel *rel;
1431 	const Elf_Rela *rela;
1432 	const char *symname;
1433 
1434 #define	APPLY_RELOCS(iter, tbl, tblsize, type) do {			\
1435 	for ((iter) = (tbl); (iter) != NULL &&				\
1436 	    (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) {	\
1437 		if ((symbol_type(ef, (iter)->r_info) ==			\
1438 		    STT_GNU_IFUNC ||					\
1439 		    elf_is_ifunc_reloc((iter)->r_info)) != ifuncs)	\
1440 			continue;					\
1441 		if (reloc(&ef->lf, (Elf_Addr)ef->address,		\
1442 		    (iter), (type), lookup)) {				\
1443 			symname = symbol_name(ef, (iter)->r_info);	\
1444 			printf("link_elf: symbol %s undefined\n",	\
1445 			    symname);					\
1446 			return (ENOENT);				\
1447 		}							\
1448 	}								\
1449 } while (0)
1450 
1451 	APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL);
1452 	APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA);
1453 	APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL);
1454 	APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA);
1455 
1456 #undef APPLY_RELOCS
1457 
1458 	return (0);
1459 }
1460 
1461 static int
1462 relocate_file(elf_file_t ef)
1463 {
1464 	int error;
1465 
1466 	error = relocate_file1(ef, elf_lookup, elf_reloc, false);
1467 	if (error == 0)
1468 		error = relocate_file1(ef, elf_lookup, elf_reloc, true);
1469 	return (error);
1470 }
1471 
1472 /*
1473  * Hash function for symbol table lookup.  Don't even think about changing
1474  * this.  It is specified by the System V ABI.
1475  */
1476 static unsigned long
1477 elf_hash(const char *name)
1478 {
1479 	const unsigned char *p = (const unsigned char *) name;
1480 	unsigned long h = 0;
1481 	unsigned long g;
1482 
1483 	while (*p != '\0') {
1484 		h = (h << 4) + *p++;
1485 		if ((g = h & 0xf0000000) != 0)
1486 			h ^= g >> 24;
1487 		h &= ~g;
1488 	}
1489 	return (h);
1490 }
1491 
1492 static int
1493 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym,
1494     bool see_local)
1495 {
1496 	elf_file_t ef = (elf_file_t) lf;
1497 	unsigned long symnum;
1498 	const Elf_Sym* symp;
1499 	const char *strp;
1500 	unsigned long hash;
1501 
1502 	/* If we don't have a hash, bail. */
1503 	if (ef->buckets == NULL || ef->nbuckets == 0) {
1504 		printf("link_elf_lookup_symbol: missing symbol hash table\n");
1505 		return (ENOENT);
1506 	}
1507 
1508 	/* First, search hashed global symbols */
1509 	hash = elf_hash(name);
1510 	symnum = ef->buckets[hash % ef->nbuckets];
1511 
1512 	while (symnum != STN_UNDEF) {
1513 		if (symnum >= ef->nchains) {
1514 			printf("%s: corrupt symbol table\n", __func__);
1515 			return (ENOENT);
1516 		}
1517 
1518 		symp = ef->symtab + symnum;
1519 		if (symp->st_name == 0) {
1520 			printf("%s: corrupt symbol table\n", __func__);
1521 			return (ENOENT);
1522 		}
1523 
1524 		strp = ef->strtab + symp->st_name;
1525 
1526 		if (strcmp(name, strp) == 0) {
1527 			if (symp->st_shndx != SHN_UNDEF ||
1528 			    (symp->st_value != 0 &&
1529 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1530 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1531 				if (see_local ||
1532 				    ELF_ST_BIND(symp->st_info) != STB_LOCAL) {
1533 					*sym = (c_linker_sym_t) symp;
1534 					return (0);
1535 				}
1536 			}
1537 			return (ENOENT);
1538 		}
1539 
1540 		symnum = ef->chains[symnum];
1541 	}
1542 
1543 	return (ENOENT);
1544 }
1545 
1546 static int
1547 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1548 {
1549 	if (link_elf_leak_locals)
1550 		return (link_elf_lookup_debug_symbol(lf, name, sym));
1551 	return (link_elf_lookup_symbol1(lf, name, sym, false));
1552 }
1553 
1554 static int
1555 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name,
1556     c_linker_sym_t *sym)
1557 {
1558 	elf_file_t ef = (elf_file_t)lf;
1559 	const Elf_Sym* symp;
1560 	const char *strp;
1561 	int i;
1562 
1563 	if (link_elf_lookup_symbol1(lf, name, sym, true) == 0)
1564 		return (0);
1565 
1566 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1567 		strp = ef->ddbstrtab + symp->st_name;
1568 		if (strcmp(name, strp) == 0) {
1569 			if (symp->st_shndx != SHN_UNDEF ||
1570 			    (symp->st_value != 0 &&
1571 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1572 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1573 				*sym = (c_linker_sym_t) symp;
1574 				return (0);
1575 			}
1576 			return (ENOENT);
1577 		}
1578 	}
1579 
1580 	return (ENOENT);
1581 }
1582 
1583 static int
1584 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym,
1585     linker_symval_t *symval, bool see_local)
1586 {
1587 	elf_file_t ef;
1588 	const Elf_Sym *es;
1589 	caddr_t val;
1590 
1591 	ef = (elf_file_t)lf;
1592 	es = (const Elf_Sym *)sym;
1593 	if (es >= ef->symtab && es < ef->symtab + ef->nchains) {
1594 		if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL)
1595 			return (ENOENT);
1596 		symval->name = ef->strtab + es->st_name;
1597 		val = (caddr_t)ef->address + es->st_value;
1598 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1599 			val = ((caddr_t (*)(void))val)();
1600 		symval->value = val;
1601 		symval->size = es->st_size;
1602 		return (0);
1603 	}
1604 	return (ENOENT);
1605 }
1606 
1607 static int
1608 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1609     linker_symval_t *symval)
1610 {
1611 	if (link_elf_leak_locals)
1612 		return (link_elf_debug_symbol_values(lf, sym, symval));
1613 	return (link_elf_symbol_values1(lf, sym, symval, false));
1614 }
1615 
1616 static int
1617 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1618     linker_symval_t *symval)
1619 {
1620 	elf_file_t ef = (elf_file_t)lf;
1621 	const Elf_Sym *es = (const Elf_Sym *)sym;
1622 	caddr_t val;
1623 
1624 	if (link_elf_symbol_values1(lf, sym, symval, true) == 0)
1625 		return (0);
1626 	if (ef->symtab == ef->ddbsymtab)
1627 		return (ENOENT);
1628 
1629 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1630 		symval->name = ef->ddbstrtab + es->st_name;
1631 		val = (caddr_t)ef->address + es->st_value;
1632 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1633 			val = ((caddr_t (*)(void))val)();
1634 		symval->value = val;
1635 		symval->size = es->st_size;
1636 		return (0);
1637 	}
1638 	return (ENOENT);
1639 }
1640 
1641 static int
1642 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1643     c_linker_sym_t *sym, long *diffp)
1644 {
1645 	elf_file_t ef = (elf_file_t)lf;
1646 	u_long off = (uintptr_t)(void *)value;
1647 	u_long diff = off;
1648 	u_long st_value;
1649 	const Elf_Sym *es;
1650 	const Elf_Sym *best = NULL;
1651 	int i;
1652 
1653 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1654 		if (es->st_name == 0)
1655 			continue;
1656 		st_value = es->st_value + (uintptr_t) (void *) ef->address;
1657 		if (off >= st_value) {
1658 			if (off - st_value < diff) {
1659 				diff = off - st_value;
1660 				best = es;
1661 				if (diff == 0)
1662 					break;
1663 			} else if (off - st_value == diff) {
1664 				best = es;
1665 			}
1666 		}
1667 	}
1668 	if (best == NULL)
1669 		*diffp = off;
1670 	else
1671 		*diffp = diff;
1672 	*sym = (c_linker_sym_t) best;
1673 
1674 	return (0);
1675 }
1676 
1677 /*
1678  * Look up a linker set on an ELF system.
1679  */
1680 static int
1681 link_elf_lookup_set(linker_file_t lf, const char *name,
1682     void ***startp, void ***stopp, int *countp)
1683 {
1684 	c_linker_sym_t sym;
1685 	linker_symval_t symval;
1686 	char *setsym;
1687 	void **start, **stop;
1688 	int len, error = 0, count;
1689 
1690 	len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1691 	setsym = malloc(len, M_LINKER, M_WAITOK);
1692 
1693 	/* get address of first entry */
1694 	snprintf(setsym, len, "%s%s", "__start_set_", name);
1695 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1696 	if (error != 0)
1697 		goto out;
1698 	link_elf_symbol_values(lf, sym, &symval);
1699 	if (symval.value == 0) {
1700 		error = ESRCH;
1701 		goto out;
1702 	}
1703 	start = (void **)symval.value;
1704 
1705 	/* get address of last entry */
1706 	snprintf(setsym, len, "%s%s", "__stop_set_", name);
1707 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1708 	if (error != 0)
1709 		goto out;
1710 	link_elf_symbol_values(lf, sym, &symval);
1711 	if (symval.value == 0) {
1712 		error = ESRCH;
1713 		goto out;
1714 	}
1715 	stop = (void **)symval.value;
1716 
1717 	/* and the number of entries */
1718 	count = stop - start;
1719 
1720 	/* and copy out */
1721 	if (startp != NULL)
1722 		*startp = start;
1723 	if (stopp != NULL)
1724 		*stopp = stop;
1725 	if (countp != NULL)
1726 		*countp = count;
1727 
1728 out:
1729 	free(setsym, M_LINKER);
1730 	return (error);
1731 }
1732 
1733 static int
1734 link_elf_each_function_name(linker_file_t file,
1735   int (*callback)(const char *, void *), void *opaque)
1736 {
1737 	elf_file_t ef = (elf_file_t)file;
1738 	const Elf_Sym *symp;
1739 	int i, error;
1740 
1741 	/* Exhaustive search */
1742 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1743 		if (symp->st_value != 0 &&
1744 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1745 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1746 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1747 			if (error != 0)
1748 				return (error);
1749 		}
1750 	}
1751 	return (0);
1752 }
1753 
1754 static int
1755 link_elf_each_function_nameval(linker_file_t file,
1756     linker_function_nameval_callback_t callback, void *opaque)
1757 {
1758 	linker_symval_t symval;
1759 	elf_file_t ef = (elf_file_t)file;
1760 	const Elf_Sym *symp;
1761 	int i, error;
1762 
1763 	/* Exhaustive search */
1764 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1765 		if (symp->st_value != 0 &&
1766 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1767 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1768 			error = link_elf_debug_symbol_values(file,
1769 			    (c_linker_sym_t) symp, &symval);
1770 			if (error == 0)
1771 				error = callback(file, i, &symval, opaque);
1772 			if (error != 0)
1773 				return (error);
1774 		}
1775 	}
1776 	return (0);
1777 }
1778 
1779 const Elf_Sym *
1780 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1781 {
1782 	elf_file_t ef = (elf_file_t)lf;
1783 
1784 	if (symidx >= ef->nchains)
1785 		return (NULL);
1786 	return (ef->symtab + symidx);
1787 }
1788 
1789 const char *
1790 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1791 {
1792 	elf_file_t ef = (elf_file_t)lf;
1793 	const Elf_Sym *sym;
1794 
1795 	if (symidx >= ef->nchains)
1796 		return (NULL);
1797 	sym = ef->symtab + symidx;
1798 	return (ef->strtab + sym->st_name);
1799 }
1800 
1801 /*
1802  * Symbol lookup function that can be used when the symbol index is known (ie
1803  * in relocations). It uses the symbol index instead of doing a fully fledged
1804  * hash table based lookup when such is valid. For example for local symbols.
1805  * This is not only more efficient, it's also more correct. It's not always
1806  * the case that the symbol can be found through the hash table.
1807  */
1808 static int
1809 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1810 {
1811 	elf_file_t ef = (elf_file_t)lf;
1812 	const Elf_Sym *sym;
1813 	const char *symbol;
1814 	Elf_Addr addr, start, base;
1815 
1816 	/* Don't even try to lookup the symbol if the index is bogus. */
1817 	if (symidx >= ef->nchains) {
1818 		*res = 0;
1819 		return (EINVAL);
1820 	}
1821 
1822 	sym = ef->symtab + symidx;
1823 
1824 	/*
1825 	 * Don't do a full lookup when the symbol is local. It may even
1826 	 * fail because it may not be found through the hash table.
1827 	 */
1828 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1829 		/* Force lookup failure when we have an insanity. */
1830 		if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) {
1831 			*res = 0;
1832 			return (EINVAL);
1833 		}
1834 		*res = ((Elf_Addr)ef->address + sym->st_value);
1835 		return (0);
1836 	}
1837 
1838 	/*
1839 	 * XXX we can avoid doing a hash table based lookup for global
1840 	 * symbols as well. This however is not always valid, so we'll
1841 	 * just do it the hard way for now. Performance tweaks can
1842 	 * always be added.
1843 	 */
1844 
1845 	symbol = ef->strtab + sym->st_name;
1846 
1847 	/* Force a lookup failure if the symbol name is bogus. */
1848 	if (*symbol == 0) {
1849 		*res = 0;
1850 		return (EINVAL);
1851 	}
1852 
1853 	addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1854 	if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1855 		*res = 0;
1856 		return (EINVAL);
1857 	}
1858 
1859 	if (elf_set_find(&set_pcpu_list, addr, &start, &base))
1860 		addr = addr - start + base;
1861 #ifdef VIMAGE
1862 	else if (elf_set_find(&set_vnet_list, addr, &start, &base))
1863 		addr = addr - start + base;
1864 #endif
1865 	*res = addr;
1866 	return (0);
1867 }
1868 
1869 static void
1870 link_elf_reloc_local(linker_file_t lf)
1871 {
1872 	const Elf_Rel *rellim;
1873 	const Elf_Rel *rel;
1874 	const Elf_Rela *relalim;
1875 	const Elf_Rela *rela;
1876 	elf_file_t ef = (elf_file_t)lf;
1877 
1878 	/* Perform relocations without addend if there are any: */
1879 	if ((rel = ef->rel) != NULL) {
1880 		rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1881 		while (rel < rellim) {
1882 			elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1883 			    ELF_RELOC_REL, elf_lookup);
1884 			rel++;
1885 		}
1886 	}
1887 
1888 	/* Perform relocations with addend if there are any: */
1889 	if ((rela = ef->rela) != NULL) {
1890 		relalim = (const Elf_Rela *)
1891 		    ((const char *)ef->rela + ef->relasize);
1892 		while (rela < relalim) {
1893 			elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1894 			    ELF_RELOC_RELA, elf_lookup);
1895 			rela++;
1896 		}
1897 	}
1898 }
1899 
1900 static long
1901 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1902 {
1903 	elf_file_t ef = (elf_file_t)lf;
1904 
1905 	*symtab = ef->ddbsymtab;
1906 
1907 	if (*symtab == NULL)
1908 		return (0);
1909 
1910 	return (ef->ddbsymcnt);
1911 }
1912 
1913 static long
1914 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1915 {
1916 	elf_file_t ef = (elf_file_t)lf;
1917 
1918 	*strtab = ef->ddbstrtab;
1919 
1920 	if (*strtab == NULL)
1921 		return (0);
1922 
1923 	return (ef->ddbstrcnt);
1924 }
1925 
1926 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__)
1927 /*
1928  * Use this lookup routine when performing relocations early during boot.
1929  * The generic lookup routine depends on kobj, which is not initialized
1930  * at that point.
1931  */
1932 static int
1933 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused,
1934     Elf_Addr *res)
1935 {
1936 	elf_file_t ef;
1937 	const Elf_Sym *symp;
1938 	caddr_t val;
1939 
1940 	ef = (elf_file_t)lf;
1941 	symp = ef->symtab + symidx;
1942 	if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) {
1943 		val = (caddr_t)ef->address + symp->st_value;
1944 		*res = ((Elf_Addr (*)(void))val)();
1945 		return (0);
1946 	}
1947 	return (ENOENT);
1948 }
1949 
1950 void
1951 link_elf_ireloc(caddr_t kmdp)
1952 {
1953 	struct elf_file eff;
1954 	elf_file_t ef;
1955 
1956 	ef = &eff;
1957 
1958 	bzero_early(ef, sizeof(*ef));
1959 
1960 	ef->modptr = kmdp;
1961 	ef->dynamic = (Elf_Dyn *)&_DYNAMIC;
1962 
1963 #ifdef RELOCATABLE_KERNEL
1964 	ef->address = (caddr_t) (__startkernel - KERNBASE);
1965 #else
1966 	ef->address = 0;
1967 #endif
1968 	parse_dynamic(ef);
1969 
1970 	link_elf_preload_parse_symbols(ef);
1971 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true);
1972 }
1973 
1974 #if defined(__aarch64__) || defined(__amd64__)
1975 void
1976 link_elf_late_ireloc(void)
1977 {
1978 	elf_file_t ef;
1979 
1980 	KASSERT(linker_kernel_file != NULL,
1981 	    ("link_elf_late_ireloc: No kernel linker file found"));
1982 	ef = (elf_file_t)linker_kernel_file;
1983 
1984 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true);
1985 }
1986 #endif
1987 #endif
1988