xref: /freebsd/sys/kern/link_elf.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #include <sys/tslog.h>
53 
54 #include <machine/elf.h>
55 
56 #include <net/vnet.h>
57 
58 #include <security/mac/mac_framework.h>
59 
60 #include <vm/vm.h>
61 #include <vm/vm_param.h>
62 #ifdef SPARSE_MAPPING
63 #include <vm/vm_object.h>
64 #include <vm/vm_kern.h>
65 #include <vm/vm_extern.h>
66 #endif
67 #include <vm/pmap.h>
68 #include <vm/vm_map.h>
69 
70 #include <sys/link_elf.h>
71 
72 #include "linker_if.h"
73 
74 #define MAXSEGS 4
75 
76 typedef struct elf_file {
77 	struct linker_file lf;		/* Common fields */
78 	int		preloaded;	/* Was file pre-loaded */
79 	caddr_t		address;	/* Relocation address */
80 #ifdef SPARSE_MAPPING
81 	vm_object_t	object;		/* VM object to hold file pages */
82 #endif
83 	Elf_Dyn		*dynamic;	/* Symbol table etc. */
84 	Elf_Hashelt	nbuckets;	/* DT_HASH info */
85 	Elf_Hashelt	nchains;
86 	const Elf_Hashelt *buckets;
87 	const Elf_Hashelt *chains;
88 	caddr_t		hash;
89 	caddr_t		strtab;		/* DT_STRTAB */
90 	int		strsz;		/* DT_STRSZ */
91 	const Elf_Sym	*symtab;		/* DT_SYMTAB */
92 	Elf_Addr	*got;		/* DT_PLTGOT */
93 	const Elf_Rel	*pltrel;	/* DT_JMPREL */
94 	int		pltrelsize;	/* DT_PLTRELSZ */
95 	const Elf_Rela	*pltrela;	/* DT_JMPREL */
96 	int		pltrelasize;	/* DT_PLTRELSZ */
97 	const Elf_Rel	*rel;		/* DT_REL */
98 	int		relsize;	/* DT_RELSZ */
99 	const Elf_Rela	*rela;		/* DT_RELA */
100 	int		relasize;	/* DT_RELASZ */
101 	caddr_t		modptr;
102 	const Elf_Sym	*ddbsymtab;	/* The symbol table we are using */
103 	long		ddbsymcnt;	/* Number of symbols */
104 	caddr_t		ddbstrtab;	/* String table */
105 	long		ddbstrcnt;	/* number of bytes in string table */
106 	caddr_t		symbase;	/* malloc'ed symbold base */
107 	caddr_t		strbase;	/* malloc'ed string base */
108 	caddr_t		ctftab;		/* CTF table */
109 	long		ctfcnt;		/* number of bytes in CTF table */
110 	caddr_t		ctfoff;		/* CTF offset table */
111 	caddr_t		typoff;		/* Type offset table */
112 	long		typlen;		/* Number of type entries. */
113 	Elf_Addr	pcpu_start;	/* Pre-relocation pcpu set start. */
114 	Elf_Addr	pcpu_stop;	/* Pre-relocation pcpu set stop. */
115 	Elf_Addr	pcpu_base;	/* Relocated pcpu set address. */
116 #ifdef VIMAGE
117 	Elf_Addr	vnet_start;	/* Pre-relocation vnet set start. */
118 	Elf_Addr	vnet_stop;	/* Pre-relocation vnet set stop. */
119 	Elf_Addr	vnet_base;	/* Relocated vnet set address. */
120 #endif
121 #ifdef GDB
122 	struct link_map	gdb;		/* hooks for gdb */
123 #endif
124 } *elf_file_t;
125 
126 struct elf_set {
127 	Elf_Addr	es_start;
128 	Elf_Addr	es_stop;
129 	Elf_Addr	es_base;
130 	TAILQ_ENTRY(elf_set)	es_link;
131 };
132 
133 TAILQ_HEAD(elf_set_head, elf_set);
134 
135 #include <kern/kern_ctf.c>
136 
137 static int	link_elf_link_common_finish(linker_file_t);
138 static int	link_elf_link_preload(linker_class_t cls,
139 				      const char *, linker_file_t *);
140 static int	link_elf_link_preload_finish(linker_file_t);
141 static int	link_elf_load_file(linker_class_t, const char *,
142 		    linker_file_t *);
143 static int	link_elf_lookup_symbol(linker_file_t, const char *,
144 		    c_linker_sym_t *);
145 static int	link_elf_lookup_debug_symbol(linker_file_t, const char *,
146 		    c_linker_sym_t *);
147 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
148 		    linker_symval_t *);
149 static int	link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t,
150 		    linker_symval_t*);
151 static int	link_elf_search_symbol(linker_file_t, caddr_t,
152 		    c_linker_sym_t *, long *);
153 
154 static void	link_elf_unload_file(linker_file_t);
155 static void	link_elf_unload_preload(linker_file_t);
156 static int	link_elf_lookup_set(linker_file_t, const char *,
157 		    void ***, void ***, int *);
158 static int	link_elf_each_function_name(linker_file_t,
159 		    int (*)(const char *, void *), void *);
160 static int	link_elf_each_function_nameval(linker_file_t,
161 		    linker_function_nameval_callback_t, void *);
162 static void	link_elf_reloc_local(linker_file_t);
163 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
164 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
165 static int	elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *);
166 
167 static kobj_method_t link_elf_methods[] = {
168 	KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
169 	KOBJMETHOD(linker_lookup_debug_symbol,	link_elf_lookup_debug_symbol),
170 	KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
171 	KOBJMETHOD(linker_debug_symbol_values,	link_elf_debug_symbol_values),
172 	KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
173 	KOBJMETHOD(linker_unload,		link_elf_unload_file),
174 	KOBJMETHOD(linker_load_file,		link_elf_load_file),
175 	KOBJMETHOD(linker_link_preload,		link_elf_link_preload),
176 	KOBJMETHOD(linker_link_preload_finish,	link_elf_link_preload_finish),
177 	KOBJMETHOD(linker_lookup_set,		link_elf_lookup_set),
178 	KOBJMETHOD(linker_each_function_name,	link_elf_each_function_name),
179 	KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
180 	KOBJMETHOD(linker_ctf_get,		link_elf_ctf_get),
181 	KOBJMETHOD(linker_symtab_get,		link_elf_symtab_get),
182 	KOBJMETHOD(linker_strtab_get,		link_elf_strtab_get),
183 	KOBJMETHOD_END
184 };
185 
186 static struct linker_class link_elf_class = {
187 #if ELF_TARG_CLASS == ELFCLASS32
188 	"elf32",
189 #else
190 	"elf64",
191 #endif
192 	link_elf_methods, sizeof(struct elf_file)
193 };
194 
195 static bool link_elf_leak_locals = true;
196 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_leak_locals,
197     CTLFLAG_RWTUN, &link_elf_leak_locals, 0,
198     "Allow local symbols to participate in global module symbol resolution");
199 
200 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase,
201     const void *data, int type, elf_lookup_fn lookup);
202 
203 static int	parse_dynamic(elf_file_t);
204 static int	relocate_file(elf_file_t);
205 static int	relocate_file1(elf_file_t ef, elf_lookup_fn lookup,
206 		    elf_reloc_fn reloc, bool ifuncs);
207 static int	link_elf_preload_parse_symbols(elf_file_t);
208 
209 static struct elf_set_head set_pcpu_list;
210 #ifdef VIMAGE
211 static struct elf_set_head set_vnet_list;
212 #endif
213 
214 static void
215 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
216 {
217 	struct elf_set *set, *iter;
218 
219 	set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
220 	set->es_start = start;
221 	set->es_stop = stop;
222 	set->es_base = base;
223 
224 	TAILQ_FOREACH(iter, list, es_link) {
225 		KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
226 		    (set->es_start > iter->es_start && set->es_stop > iter->es_stop),
227 		    ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
228 		    (uintmax_t)set->es_start, (uintmax_t)set->es_stop,
229 		    (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
230 
231 		if (iter->es_start > set->es_start) {
232 			TAILQ_INSERT_BEFORE(iter, set, es_link);
233 			break;
234 		}
235 	}
236 
237 	if (iter == NULL)
238 		TAILQ_INSERT_TAIL(list, set, es_link);
239 }
240 
241 static int
242 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
243 {
244 	struct elf_set *set;
245 
246 	TAILQ_FOREACH(set, list, es_link) {
247 		if (addr < set->es_start)
248 			return (0);
249 		if (addr < set->es_stop) {
250 			*start = set->es_start;
251 			*base = set->es_base;
252 			return (1);
253 		}
254 	}
255 
256 	return (0);
257 }
258 
259 static void
260 elf_set_delete(struct elf_set_head *list, Elf_Addr start)
261 {
262 	struct elf_set *set;
263 
264 	TAILQ_FOREACH(set, list, es_link) {
265 		if (start < set->es_start)
266 			break;
267 		if (start == set->es_start) {
268 			TAILQ_REMOVE(list, set, es_link);
269 			free(set, M_LINKER);
270 			return;
271 		}
272 	}
273 	KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
274 	    (uintmax_t)start));
275 }
276 
277 #ifdef GDB
278 static void	r_debug_state(struct r_debug *, struct link_map *);
279 
280 /*
281  * A list of loaded modules for GDB to use for loading symbols.
282  */
283 struct r_debug r_debug;
284 
285 #define GDB_STATE(s) do {				\
286 	r_debug.r_state = s; r_debug_state(NULL, NULL);	\
287 } while (0)
288 
289 /*
290  * Function for the debugger to set a breakpoint on to gain control.
291  */
292 static void
293 r_debug_state(struct r_debug *dummy_one __unused,
294 	      struct link_map *dummy_two __unused)
295 {
296 }
297 
298 static void
299 link_elf_add_gdb(struct link_map *l)
300 {
301 	struct link_map *prev;
302 
303 	l->l_next = NULL;
304 
305 	if (r_debug.r_map == NULL) {
306 		/* Add first. */
307 		l->l_prev = NULL;
308 		r_debug.r_map = l;
309 	} else {
310 		/* Append to list. */
311 		for (prev = r_debug.r_map;
312 		    prev->l_next != NULL;
313 		    prev = prev->l_next)
314 			;
315 		l->l_prev = prev;
316 		prev->l_next = l;
317 	}
318 }
319 
320 static void
321 link_elf_delete_gdb(struct link_map *l)
322 {
323 	if (l->l_prev == NULL) {
324 		/* Remove first. */
325 		if ((r_debug.r_map = l->l_next) != NULL)
326 			l->l_next->l_prev = NULL;
327 	} else {
328 		/* Remove any but first. */
329 		if ((l->l_prev->l_next = l->l_next) != NULL)
330 			l->l_next->l_prev = l->l_prev;
331 	}
332 }
333 #endif /* GDB */
334 
335 /*
336  * The kernel symbol table starts here.
337  */
338 extern struct _dynamic _DYNAMIC;
339 
340 static void
341 link_elf_error(const char *filename, const char *s)
342 {
343 	if (filename == NULL)
344 		printf("kldload: %s\n", s);
345 	else
346 		printf("kldload: %s: %s\n", filename, s);
347 }
348 
349 static void
350 link_elf_invoke_ctors(caddr_t addr, size_t size)
351 {
352 	void (**ctor)(void);
353 	size_t i, cnt;
354 
355 	if (addr == NULL || size == 0)
356 		return;
357 	cnt = size / sizeof(*ctor);
358 	ctor = (void *)addr;
359 	for (i = 0; i < cnt; i++) {
360 		if (ctor[i] != NULL)
361 			(*ctor[i])();
362 	}
363 }
364 
365 /*
366  * Actions performed after linking/loading both the preloaded kernel and any
367  * modules; whether preloaded or dynamicly loaded.
368  */
369 static int
370 link_elf_link_common_finish(linker_file_t lf)
371 {
372 #ifdef GDB
373 	elf_file_t ef = (elf_file_t)lf;
374 	char *newfilename;
375 #endif
376 	int error;
377 
378 	/* Notify MD code that a module is being loaded. */
379 	error = elf_cpu_load_file(lf);
380 	if (error != 0)
381 		return (error);
382 
383 #ifdef GDB
384 	GDB_STATE(RT_ADD);
385 	ef->gdb.l_addr = lf->address;
386 	newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
387 	strcpy(newfilename, lf->filename);
388 	ef->gdb.l_name = newfilename;
389 	ef->gdb.l_ld = ef->dynamic;
390 	link_elf_add_gdb(&ef->gdb);
391 	GDB_STATE(RT_CONSISTENT);
392 #endif
393 
394 	/* Invoke .ctors */
395 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
396 	return (0);
397 }
398 
399 #ifdef RELOCATABLE_KERNEL
400 /*
401  * __startkernel and __endkernel are symbols set up as relocation canaries.
402  *
403  * They are defined in locore to reference linker script symbols at the
404  * beginning and end of the LOAD area. This has the desired side effect of
405  * giving us variables that have relative relocations pointing at them, so
406  * relocation of the kernel object will cause the variables to be updated
407  * automatically by the runtime linker when we initialize.
408  *
409  * There are two main reasons to relocate the kernel:
410  * 1) If the loader needed to load the kernel at an alternate load address.
411  * 2) If the kernel is switching address spaces on machines like POWER9
412  *    under Radix where the high bits of the effective address are used to
413  *    differentiate between hypervisor, host, guest, and problem state.
414  */
415 extern vm_offset_t __startkernel, __endkernel;
416 #endif
417 
418 static unsigned long kern_relbase = KERNBASE;
419 
420 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD,
421 	SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address");
422 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD,
423 	&kern_relbase, 0, "Kernel relocated base address");
424 
425 static void
426 link_elf_init(void* arg)
427 {
428 	Elf_Dyn *dp;
429 	Elf_Addr *ctors_addrp;
430 	Elf_Size *ctors_sizep;
431 	caddr_t modptr, baseptr, sizeptr;
432 	elf_file_t ef;
433 	const char *modname;
434 
435 	linker_add_class(&link_elf_class);
436 
437 	dp = (Elf_Dyn *)&_DYNAMIC;
438 	modname = NULL;
439 	modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
440 	if (modptr == NULL)
441 		modptr = preload_search_by_type("elf kernel");
442 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
443 	if (modname == NULL)
444 		modname = "kernel";
445 	linker_kernel_file = linker_make_file(modname, &link_elf_class);
446 	if (linker_kernel_file == NULL)
447 		panic("%s: Can't create linker structures for kernel",
448 		    __func__);
449 
450 	ef = (elf_file_t) linker_kernel_file;
451 	ef->preloaded = 1;
452 #ifdef RELOCATABLE_KERNEL
453 	/* Compute relative displacement */
454 	ef->address = (caddr_t) (__startkernel - KERNBASE);
455 #else
456 	ef->address = 0;
457 #endif
458 #ifdef SPARSE_MAPPING
459 	ef->object = NULL;
460 #endif
461 	ef->dynamic = dp;
462 
463 	if (dp != NULL)
464 		parse_dynamic(ef);
465 #ifdef RELOCATABLE_KERNEL
466 	linker_kernel_file->address = (caddr_t)__startkernel;
467 	linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
468 	kern_relbase = (unsigned long)__startkernel;
469 #else
470 	linker_kernel_file->address += KERNBASE;
471 	linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
472 #endif
473 
474 	if (modptr != NULL) {
475 		ef->modptr = modptr;
476 		baseptr = preload_search_info(modptr, MODINFO_ADDR);
477 		if (baseptr != NULL)
478 			linker_kernel_file->address = *(caddr_t *)baseptr;
479 		sizeptr = preload_search_info(modptr, MODINFO_SIZE);
480 		if (sizeptr != NULL)
481 			linker_kernel_file->size = *(size_t *)sizeptr;
482 		ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
483 			MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
484 		ctors_sizep = (Elf_Size *)preload_search_info(modptr,
485 			MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
486 		if (ctors_addrp != NULL && ctors_sizep != NULL) {
487 			linker_kernel_file->ctors_addr = ef->address +
488 			    *ctors_addrp;
489 			linker_kernel_file->ctors_size = *ctors_sizep;
490 		}
491 	}
492 	(void)link_elf_preload_parse_symbols(ef);
493 
494 #ifdef GDB
495 	r_debug.r_map = NULL;
496 	r_debug.r_brk = r_debug_state;
497 	r_debug.r_state = RT_CONSISTENT;
498 #endif
499 
500 	(void)link_elf_link_common_finish(linker_kernel_file);
501 	linker_kernel_file->flags |= LINKER_FILE_LINKED;
502 	TAILQ_INIT(&set_pcpu_list);
503 #ifdef VIMAGE
504 	TAILQ_INIT(&set_vnet_list);
505 #endif
506 }
507 
508 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL);
509 
510 static int
511 link_elf_preload_parse_symbols(elf_file_t ef)
512 {
513 	caddr_t pointer;
514 	caddr_t ssym, esym, base;
515 	caddr_t strtab;
516 	int strcnt;
517 	Elf_Sym *symtab;
518 	int symcnt;
519 
520 	if (ef->modptr == NULL)
521 		return (0);
522 	pointer = preload_search_info(ef->modptr,
523 	    MODINFO_METADATA | MODINFOMD_SSYM);
524 	if (pointer == NULL)
525 		return (0);
526 	ssym = *(caddr_t *)pointer;
527 	pointer = preload_search_info(ef->modptr,
528 	    MODINFO_METADATA | MODINFOMD_ESYM);
529 	if (pointer == NULL)
530 		return (0);
531 	esym = *(caddr_t *)pointer;
532 
533 	base = ssym;
534 
535 	symcnt = *(long *)base;
536 	base += sizeof(long);
537 	symtab = (Elf_Sym *)base;
538 	base += roundup(symcnt, sizeof(long));
539 
540 	if (base > esym || base < ssym) {
541 		printf("Symbols are corrupt!\n");
542 		return (EINVAL);
543 	}
544 
545 	strcnt = *(long *)base;
546 	base += sizeof(long);
547 	strtab = base;
548 	base += roundup(strcnt, sizeof(long));
549 
550 	if (base > esym || base < ssym) {
551 		printf("Symbols are corrupt!\n");
552 		return (EINVAL);
553 	}
554 
555 	ef->ddbsymtab = symtab;
556 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
557 	ef->ddbstrtab = strtab;
558 	ef->ddbstrcnt = strcnt;
559 
560 	return (0);
561 }
562 
563 static int
564 parse_dynamic(elf_file_t ef)
565 {
566 	Elf_Dyn *dp;
567 	int plttype = DT_REL;
568 
569 	for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
570 		switch (dp->d_tag) {
571 		case DT_HASH:
572 		{
573 			/* From src/libexec/rtld-elf/rtld.c */
574 			const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
575 			    (ef->address + dp->d_un.d_ptr);
576 			ef->nbuckets = hashtab[0];
577 			ef->nchains = hashtab[1];
578 			ef->buckets = hashtab + 2;
579 			ef->chains = ef->buckets + ef->nbuckets;
580 			break;
581 		}
582 		case DT_STRTAB:
583 			ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
584 			break;
585 		case DT_STRSZ:
586 			ef->strsz = dp->d_un.d_val;
587 			break;
588 		case DT_SYMTAB:
589 			ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
590 			break;
591 		case DT_SYMENT:
592 			if (dp->d_un.d_val != sizeof(Elf_Sym))
593 				return (ENOEXEC);
594 			break;
595 		case DT_PLTGOT:
596 			ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
597 			break;
598 		case DT_REL:
599 			ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
600 			break;
601 		case DT_RELSZ:
602 			ef->relsize = dp->d_un.d_val;
603 			break;
604 		case DT_RELENT:
605 			if (dp->d_un.d_val != sizeof(Elf_Rel))
606 				return (ENOEXEC);
607 			break;
608 		case DT_JMPREL:
609 			ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
610 			break;
611 		case DT_PLTRELSZ:
612 			ef->pltrelsize = dp->d_un.d_val;
613 			break;
614 		case DT_RELA:
615 			ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
616 			break;
617 		case DT_RELASZ:
618 			ef->relasize = dp->d_un.d_val;
619 			break;
620 		case DT_RELAENT:
621 			if (dp->d_un.d_val != sizeof(Elf_Rela))
622 				return (ENOEXEC);
623 			break;
624 		case DT_PLTREL:
625 			plttype = dp->d_un.d_val;
626 			if (plttype != DT_REL && plttype != DT_RELA)
627 				return (ENOEXEC);
628 			break;
629 #ifdef GDB
630 		case DT_DEBUG:
631 			dp->d_un.d_ptr = (Elf_Addr)&r_debug;
632 			break;
633 #endif
634 		}
635 	}
636 
637 	if (plttype == DT_RELA) {
638 		ef->pltrela = (const Elf_Rela *)ef->pltrel;
639 		ef->pltrel = NULL;
640 		ef->pltrelasize = ef->pltrelsize;
641 		ef->pltrelsize = 0;
642 	}
643 
644 	ef->ddbsymtab = ef->symtab;
645 	ef->ddbsymcnt = ef->nchains;
646 	ef->ddbstrtab = ef->strtab;
647 	ef->ddbstrcnt = ef->strsz;
648 
649 	return elf_cpu_parse_dynamic(ef->address, ef->dynamic);
650 }
651 
652 #define	LS_PADDING	0x90909090
653 static int
654 parse_dpcpu(elf_file_t ef)
655 {
656 	int error, size;
657 #if defined(__i386__)
658 	uint32_t pad;
659 #endif
660 
661 	ef->pcpu_start = 0;
662 	ef->pcpu_stop = 0;
663 	error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
664 	    (void ***)&ef->pcpu_stop, NULL);
665 	/* Error just means there is no pcpu set to relocate. */
666 	if (error != 0)
667 		return (0);
668 	size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start;
669 	/* Empty set? */
670 	if (size < 1)
671 		return (0);
672 #if defined(__i386__)
673 	/* In case we do find __start/stop_set_ symbols double-check. */
674 	if (size < 4) {
675 		uprintf("Kernel module '%s' must be recompiled with "
676 		    "linker script\n", ef->lf.pathname);
677 		return (ENOEXEC);
678 	}
679 
680 	/* Padding from linker-script correct? */
681 	pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad));
682 	if (pad != LS_PADDING) {
683 		uprintf("Kernel module '%s' must be recompiled with "
684 		    "linker script, invalid padding %#04x (%#04x)\n",
685 		    ef->lf.pathname, pad, LS_PADDING);
686 		return (ENOEXEC);
687 	}
688 	/* If we only have valid padding, nothing to do. */
689 	if (size == 4)
690 		return (0);
691 #endif
692 	/*
693 	 * Allocate space in the primary pcpu area.  Copy in our
694 	 * initialization from the data section and then initialize
695 	 * all per-cpu storage from that.
696 	 */
697 	ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size);
698 	if (ef->pcpu_base == 0) {
699 		printf("%s: pcpu module space is out of space; "
700 		    "cannot allocate %d for %s\n",
701 		    __func__, size, ef->lf.pathname);
702 		return (ENOSPC);
703 	}
704 	memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size);
705 	dpcpu_copy((void *)ef->pcpu_base, size);
706 	elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
707 	    ef->pcpu_base);
708 
709 	return (0);
710 }
711 
712 #ifdef VIMAGE
713 static int
714 parse_vnet(elf_file_t ef)
715 {
716 	int error, size;
717 #if defined(__i386__)
718 	uint32_t pad;
719 #endif
720 
721 	ef->vnet_start = 0;
722 	ef->vnet_stop = 0;
723 	error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
724 	    (void ***)&ef->vnet_stop, NULL);
725 	/* Error just means there is no vnet data set to relocate. */
726 	if (error != 0)
727 		return (0);
728 	size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
729 	/* Empty set? */
730 	if (size < 1)
731 		return (0);
732 #if defined(__i386__)
733 	/* In case we do find __start/stop_set_ symbols double-check. */
734 	if (size < 4) {
735 		uprintf("Kernel module '%s' must be recompiled with "
736 		    "linker script\n", ef->lf.pathname);
737 		return (ENOEXEC);
738 	}
739 
740 	/* Padding from linker-script correct? */
741 	pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad));
742 	if (pad != LS_PADDING) {
743 		uprintf("Kernel module '%s' must be recompiled with "
744 		    "linker script, invalid padding %#04x (%#04x)\n",
745 		    ef->lf.pathname, pad, LS_PADDING);
746 		return (ENOEXEC);
747 	}
748 	/* If we only have valid padding, nothing to do. */
749 	if (size == 4)
750 		return (0);
751 #endif
752 	/*
753 	 * Allocate space in the primary vnet area.  Copy in our
754 	 * initialization from the data section and then initialize
755 	 * all per-vnet storage from that.
756 	 */
757 	ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size);
758 	if (ef->vnet_base == 0) {
759 		printf("%s: vnet module space is out of space; "
760 		    "cannot allocate %d for %s\n",
761 		    __func__, size, ef->lf.pathname);
762 		return (ENOSPC);
763 	}
764 	memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size);
765 	vnet_data_copy((void *)ef->vnet_base, size);
766 	elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
767 	    ef->vnet_base);
768 
769 	return (0);
770 }
771 #endif
772 #undef LS_PADDING
773 
774 /*
775  * Apply the specified protection to the loadable segments of a preloaded linker
776  * file.
777  */
778 static int
779 preload_protect(elf_file_t ef, vm_prot_t prot)
780 {
781 #if defined(__aarch64__) || defined(__amd64__)
782 	Elf_Ehdr *hdr;
783 	Elf_Phdr *phdr, *phlimit;
784 	vm_prot_t nprot;
785 	int error;
786 
787 	error = 0;
788 	hdr = (Elf_Ehdr *)ef->address;
789 	phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff);
790 	phlimit = phdr + hdr->e_phnum;
791 	for (; phdr < phlimit; phdr++) {
792 		if (phdr->p_type != PT_LOAD)
793 			continue;
794 
795 		nprot = prot | VM_PROT_READ;
796 		if ((phdr->p_flags & PF_W) != 0)
797 			nprot |= VM_PROT_WRITE;
798 		if ((phdr->p_flags & PF_X) != 0)
799 			nprot |= VM_PROT_EXECUTE;
800 		error = pmap_change_prot((vm_offset_t)ef->address +
801 		    phdr->p_vaddr, round_page(phdr->p_memsz), nprot);
802 		if (error != 0)
803 			break;
804 	}
805 	return (error);
806 #else
807 	return (0);
808 #endif
809 }
810 
811 #ifdef __arm__
812 /*
813  * Locate the ARM exception/unwind table info for DDB and stack(9) use by
814  * searching for the section header that describes it.  There may be no unwind
815  * info, for example in a module containing only data.
816  */
817 static void
818 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr)
819 {
820 	int i;
821 
822 	for (i = 0; i < nhdr; i++) {
823 		if (shdr[i].sh_type == SHT_ARM_EXIDX) {
824 			lf->exidx_addr = shdr[i].sh_addr + lf->address;
825 			lf->exidx_size = shdr[i].sh_size;
826 			break;
827 		}
828 	}
829 }
830 
831 /*
832  * Locate the section headers metadata in a preloaded module, then use it to
833  * locate the exception/unwind table in the module.  The size of the metadata
834  * block is stored in a uint32 word immediately before the data itself, and a
835  * comment in preload_search_info() says it is safe to rely on that.
836  */
837 static void
838 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr)
839 {
840 	uint32_t *modinfo;
841 	Elf_Shdr *shdr;
842 	uint32_t  nhdr;
843 
844 	modinfo = (uint32_t *)preload_search_info(modptr,
845 	    MODINFO_METADATA | MODINFOMD_SHDR);
846 	if (modinfo != NULL) {
847 		shdr = (Elf_Shdr *)modinfo;
848 		nhdr = modinfo[-1] / sizeof(Elf_Shdr);
849 		link_elf_locate_exidx(lf, shdr, nhdr);
850 	}
851 }
852 
853 #endif /* __arm__ */
854 
855 static int
856 link_elf_link_preload(linker_class_t cls, const char *filename,
857     linker_file_t *result)
858 {
859 	Elf_Addr *ctors_addrp;
860 	Elf_Size *ctors_sizep;
861 	caddr_t modptr, baseptr, sizeptr, dynptr;
862 	char *type;
863 	elf_file_t ef;
864 	linker_file_t lf;
865 	int error;
866 	vm_offset_t dp;
867 
868 	/* Look to see if we have the file preloaded */
869 	modptr = preload_search_by_name(filename);
870 	if (modptr == NULL)
871 		return (ENOENT);
872 
873 	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
874 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
875 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
876 	dynptr = preload_search_info(modptr,
877 	    MODINFO_METADATA | MODINFOMD_DYNAMIC);
878 	if (type == NULL ||
879 	    (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
880 	     strcmp(type, "elf module") != 0))
881 		return (EFTYPE);
882 	if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
883 		return (EINVAL);
884 
885 	lf = linker_make_file(filename, &link_elf_class);
886 	if (lf == NULL)
887 		return (ENOMEM);
888 
889 	ef = (elf_file_t) lf;
890 	ef->preloaded = 1;
891 	ef->modptr = modptr;
892 	ef->address = *(caddr_t *)baseptr;
893 #ifdef SPARSE_MAPPING
894 	ef->object = NULL;
895 #endif
896 	dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
897 	ef->dynamic = (Elf_Dyn *)dp;
898 	lf->address = ef->address;
899 	lf->size = *(size_t *)sizeptr;
900 
901 	ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
902 	    MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
903 	ctors_sizep = (Elf_Size *)preload_search_info(modptr,
904 	    MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
905 	if (ctors_addrp != NULL && ctors_sizep != NULL) {
906 		lf->ctors_addr = ef->address + *ctors_addrp;
907 		lf->ctors_size = *ctors_sizep;
908 	}
909 
910 #ifdef __arm__
911 	link_elf_locate_exidx_preload(lf, modptr);
912 #endif
913 
914 	error = parse_dynamic(ef);
915 	if (error == 0)
916 		error = parse_dpcpu(ef);
917 #ifdef VIMAGE
918 	if (error == 0)
919 		error = parse_vnet(ef);
920 #endif
921 	if (error == 0)
922 		error = preload_protect(ef, VM_PROT_ALL);
923 	if (error != 0) {
924 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
925 		return (error);
926 	}
927 	link_elf_reloc_local(lf);
928 	*result = lf;
929 	return (0);
930 }
931 
932 static int
933 link_elf_link_preload_finish(linker_file_t lf)
934 {
935 	elf_file_t ef;
936 	int error;
937 
938 	ef = (elf_file_t) lf;
939 	error = relocate_file(ef);
940 	if (error == 0)
941 		error = preload_protect(ef, VM_PROT_NONE);
942 	if (error != 0)
943 		return (error);
944 	(void)link_elf_preload_parse_symbols(ef);
945 
946 	return (link_elf_link_common_finish(lf));
947 }
948 
949 static int
950 link_elf_load_file(linker_class_t cls, const char* filename,
951     linker_file_t* result)
952 {
953 	struct nameidata nd;
954 	struct thread* td = curthread;	/* XXX */
955 	Elf_Ehdr *hdr;
956 	caddr_t firstpage, segbase;
957 	int nbytes, i;
958 	Elf_Phdr *phdr;
959 	Elf_Phdr *phlimit;
960 	Elf_Phdr *segs[MAXSEGS];
961 	int nsegs;
962 	Elf_Phdr *phdyn;
963 	caddr_t mapbase;
964 	size_t mapsize;
965 	Elf_Addr base_vaddr;
966 	Elf_Addr base_vlimit;
967 	int error = 0;
968 	ssize_t resid;
969 	int flags;
970 	elf_file_t ef;
971 	linker_file_t lf;
972 	Elf_Shdr *shdr;
973 	int symtabindex;
974 	int symstrindex;
975 	int shstrindex;
976 	int symcnt;
977 	int strcnt;
978 	char *shstrs;
979 
980 	shdr = NULL;
981 	lf = NULL;
982 	shstrs = NULL;
983 
984 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename);
985 	flags = FREAD;
986 	error = vn_open(&nd, &flags, 0, NULL);
987 	if (error != 0)
988 		return (error);
989 	NDFREE_PNBUF(&nd);
990 	if (nd.ni_vp->v_type != VREG) {
991 		error = ENOEXEC;
992 		firstpage = NULL;
993 		goto out;
994 	}
995 #ifdef MAC
996 	error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
997 	if (error != 0) {
998 		firstpage = NULL;
999 		goto out;
1000 	}
1001 #endif
1002 
1003 	/*
1004 	 * Read the elf header from the file.
1005 	 */
1006 	firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
1007 	hdr = (Elf_Ehdr *)firstpage;
1008 	error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
1009 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1010 	    &resid, td);
1011 	nbytes = PAGE_SIZE - resid;
1012 	if (error != 0)
1013 		goto out;
1014 
1015 	if (!IS_ELF(*hdr)) {
1016 		error = ENOEXEC;
1017 		goto out;
1018 	}
1019 
1020 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
1021 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
1022 		link_elf_error(filename, "Unsupported file layout");
1023 		error = ENOEXEC;
1024 		goto out;
1025 	}
1026 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
1027 	    hdr->e_version != EV_CURRENT) {
1028 		link_elf_error(filename, "Unsupported file version");
1029 		error = ENOEXEC;
1030 		goto out;
1031 	}
1032 	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
1033 		error = ENOSYS;
1034 		goto out;
1035 	}
1036 	if (hdr->e_machine != ELF_TARG_MACH) {
1037 		link_elf_error(filename, "Unsupported machine");
1038 		error = ENOEXEC;
1039 		goto out;
1040 	}
1041 
1042 	/*
1043 	 * We rely on the program header being in the first page.
1044 	 * This is not strictly required by the ABI specification, but
1045 	 * it seems to always true in practice.  And, it simplifies
1046 	 * things considerably.
1047 	 */
1048 	if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
1049 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
1050 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
1051 		link_elf_error(filename, "Unreadable program headers");
1052 
1053 	/*
1054 	 * Scan the program header entries, and save key information.
1055 	 *
1056 	 * We rely on there being exactly two load segments, text and data,
1057 	 * in that order.
1058 	 */
1059 	phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
1060 	phlimit = phdr + hdr->e_phnum;
1061 	nsegs = 0;
1062 	phdyn = NULL;
1063 	while (phdr < phlimit) {
1064 		switch (phdr->p_type) {
1065 		case PT_LOAD:
1066 			if (nsegs == MAXSEGS) {
1067 				link_elf_error(filename, "Too many sections");
1068 				error = ENOEXEC;
1069 				goto out;
1070 			}
1071 			/*
1072 			 * XXX: We just trust they come in right order ??
1073 			 */
1074 			segs[nsegs] = phdr;
1075 			++nsegs;
1076 			break;
1077 
1078 		case PT_DYNAMIC:
1079 			phdyn = phdr;
1080 			break;
1081 
1082 		case PT_INTERP:
1083 			error = ENOSYS;
1084 			goto out;
1085 		}
1086 
1087 		++phdr;
1088 	}
1089 	if (phdyn == NULL) {
1090 		link_elf_error(filename, "Object is not dynamically-linked");
1091 		error = ENOEXEC;
1092 		goto out;
1093 	}
1094 	if (nsegs == 0) {
1095 		link_elf_error(filename, "No sections");
1096 		error = ENOEXEC;
1097 		goto out;
1098 	}
1099 
1100 	/*
1101 	 * Allocate the entire address space of the object, to stake
1102 	 * out our contiguous region, and to establish the base
1103 	 * address for relocation.
1104 	 */
1105 	base_vaddr = trunc_page(segs[0]->p_vaddr);
1106 	base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
1107 	    segs[nsegs - 1]->p_memsz);
1108 	mapsize = base_vlimit - base_vaddr;
1109 
1110 	lf = linker_make_file(filename, &link_elf_class);
1111 	if (lf == NULL) {
1112 		error = ENOMEM;
1113 		goto out;
1114 	}
1115 
1116 	ef = (elf_file_t) lf;
1117 #ifdef SPARSE_MAPPING
1118 	ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL,
1119 	    0, thread0.td_ucred);
1120 	if (ef->object == NULL) {
1121 		error = ENOMEM;
1122 		goto out;
1123 	}
1124 #ifdef __amd64__
1125 	mapbase = (caddr_t)KERNBASE;
1126 #else
1127 	mapbase = (caddr_t)vm_map_min(kernel_map);
1128 #endif
1129 	/*
1130 	 * Mapping protections are downgraded after relocation processing.
1131 	 */
1132 	error = vm_map_find(kernel_map, ef->object, 0,
1133 	    (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE,
1134 	    VM_PROT_ALL, VM_PROT_ALL, 0);
1135 	if (error != 0) {
1136 		vm_object_deallocate(ef->object);
1137 		ef->object = NULL;
1138 		goto out;
1139 	}
1140 #else
1141 	mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK);
1142 #endif
1143 	ef->address = mapbase;
1144 
1145 	/*
1146 	 * Read the text and data sections and zero the bss.
1147 	 */
1148 	for (i = 0; i < nsegs; i++) {
1149 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1150 
1151 #ifdef SPARSE_MAPPING
1152 		/*
1153 		 * Consecutive segments may have different mapping permissions,
1154 		 * so be strict and verify that their mappings do not overlap.
1155 		 */
1156 		if (((vm_offset_t)segbase & PAGE_MASK) != 0) {
1157 			error = EINVAL;
1158 			goto out;
1159 		}
1160 
1161 		error = vm_map_wire(kernel_map,
1162 		    (vm_offset_t)segbase,
1163 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1164 		    VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
1165 		if (error != KERN_SUCCESS) {
1166 			error = ENOMEM;
1167 			goto out;
1168 		}
1169 #endif
1170 
1171 		error = vn_rdwr(UIO_READ, nd.ni_vp,
1172 		    segbase, segs[i]->p_filesz, segs[i]->p_offset,
1173 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1174 		    &resid, td);
1175 		if (error != 0)
1176 			goto out;
1177 		bzero(segbase + segs[i]->p_filesz,
1178 		    segs[i]->p_memsz - segs[i]->p_filesz);
1179 	}
1180 
1181 	ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
1182 
1183 	lf->address = ef->address;
1184 	lf->size = mapsize;
1185 
1186 	error = parse_dynamic(ef);
1187 	if (error != 0)
1188 		goto out;
1189 	error = parse_dpcpu(ef);
1190 	if (error != 0)
1191 		goto out;
1192 #ifdef VIMAGE
1193 	error = parse_vnet(ef);
1194 	if (error != 0)
1195 		goto out;
1196 #endif
1197 	link_elf_reloc_local(lf);
1198 
1199 	VOP_UNLOCK(nd.ni_vp);
1200 	error = linker_load_dependencies(lf);
1201 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1202 	if (error != 0)
1203 		goto out;
1204 	error = relocate_file(ef);
1205 	if (error != 0)
1206 		goto out;
1207 
1208 #ifdef SPARSE_MAPPING
1209 	/*
1210 	 * Downgrade permissions on text segment mappings now that relocation
1211 	 * processing is complete.  Restrict permissions on read-only segments.
1212 	 */
1213 	for (i = 0; i < nsegs; i++) {
1214 		vm_prot_t prot;
1215 
1216 		if (segs[i]->p_type != PT_LOAD)
1217 			continue;
1218 
1219 		prot = VM_PROT_READ;
1220 		if ((segs[i]->p_flags & PF_W) != 0)
1221 			prot |= VM_PROT_WRITE;
1222 		if ((segs[i]->p_flags & PF_X) != 0)
1223 			prot |= VM_PROT_EXECUTE;
1224 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1225 		error = vm_map_protect(kernel_map,
1226 		    (vm_offset_t)segbase,
1227 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1228 		    prot, 0, VM_MAP_PROTECT_SET_PROT);
1229 		if (error != KERN_SUCCESS) {
1230 			error = ENOMEM;
1231 			goto out;
1232 		}
1233 	}
1234 #endif
1235 
1236 	/*
1237 	 * Try and load the symbol table if it's present.  (you can
1238 	 * strip it!)
1239 	 */
1240 	nbytes = hdr->e_shnum * hdr->e_shentsize;
1241 	if (nbytes == 0 || hdr->e_shoff == 0)
1242 		goto nosyms;
1243 	shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1244 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1245 	    (caddr_t)shdr, nbytes, hdr->e_shoff,
1246 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1247 	    &resid, td);
1248 	if (error != 0)
1249 		goto out;
1250 
1251 	/* Read section string table */
1252 	shstrindex = hdr->e_shstrndx;
1253 	if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB &&
1254 	    shdr[shstrindex].sh_size != 0) {
1255 		nbytes = shdr[shstrindex].sh_size;
1256 		shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1257 		error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes,
1258 		    shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
1259 		    td->td_ucred, NOCRED, &resid, td);
1260 		if (error)
1261 			goto out;
1262 	}
1263 
1264 	symtabindex = -1;
1265 	symstrindex = -1;
1266 	for (i = 0; i < hdr->e_shnum; i++) {
1267 		if (shdr[i].sh_type == SHT_SYMTAB) {
1268 			symtabindex = i;
1269 			symstrindex = shdr[i].sh_link;
1270 		} else if (shstrs != NULL && shdr[i].sh_name != 0 &&
1271 		    strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) {
1272 			/* Record relocated address and size of .ctors. */
1273 			lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr;
1274 			lf->ctors_size = shdr[i].sh_size;
1275 		}
1276 	}
1277 	if (symtabindex < 0 || symstrindex < 0)
1278 		goto nosyms;
1279 
1280 	symcnt = shdr[symtabindex].sh_size;
1281 	ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
1282 	strcnt = shdr[symstrindex].sh_size;
1283 	ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
1284 
1285 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1286 	    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
1287 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1288 	    &resid, td);
1289 	if (error != 0)
1290 		goto out;
1291 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1292 	    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
1293 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1294 	    &resid, td);
1295 	if (error != 0)
1296 		goto out;
1297 
1298 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
1299 	ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
1300 	ef->ddbstrcnt = strcnt;
1301 	ef->ddbstrtab = ef->strbase;
1302 
1303 nosyms:
1304 
1305 #ifdef __arm__
1306 	link_elf_locate_exidx(lf, shdr, hdr->e_shnum);
1307 #endif
1308 
1309 	error = link_elf_link_common_finish(lf);
1310 	if (error != 0)
1311 		goto out;
1312 
1313 	*result = lf;
1314 
1315 out:
1316 	VOP_UNLOCK(nd.ni_vp);
1317 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1318 	if (error != 0 && lf != NULL)
1319 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1320 	free(shdr, M_LINKER);
1321 	free(firstpage, M_LINKER);
1322 	free(shstrs, M_LINKER);
1323 
1324 	return (error);
1325 }
1326 
1327 Elf_Addr
1328 elf_relocaddr(linker_file_t lf, Elf_Addr x)
1329 {
1330 	elf_file_t ef;
1331 
1332 	KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class,
1333 	    ("elf_relocaddr: unexpected linker file %p", lf));
1334 
1335 	ef = (elf_file_t)lf;
1336 	if (x >= ef->pcpu_start && x < ef->pcpu_stop)
1337 		return ((x - ef->pcpu_start) + ef->pcpu_base);
1338 #ifdef VIMAGE
1339 	if (x >= ef->vnet_start && x < ef->vnet_stop)
1340 		return ((x - ef->vnet_start) + ef->vnet_base);
1341 #endif
1342 	return (x);
1343 }
1344 
1345 static void
1346 link_elf_unload_file(linker_file_t file)
1347 {
1348 	elf_file_t ef = (elf_file_t) file;
1349 
1350 	if (ef->pcpu_base != 0) {
1351 		dpcpu_free((void *)ef->pcpu_base,
1352 		    ef->pcpu_stop - ef->pcpu_start);
1353 		elf_set_delete(&set_pcpu_list, ef->pcpu_start);
1354 	}
1355 #ifdef VIMAGE
1356 	if (ef->vnet_base != 0) {
1357 		vnet_data_free((void *)ef->vnet_base,
1358 		    ef->vnet_stop - ef->vnet_start);
1359 		elf_set_delete(&set_vnet_list, ef->vnet_start);
1360 	}
1361 #endif
1362 #ifdef GDB
1363 	if (ef->gdb.l_ld != NULL) {
1364 		GDB_STATE(RT_DELETE);
1365 		free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1366 		link_elf_delete_gdb(&ef->gdb);
1367 		GDB_STATE(RT_CONSISTENT);
1368 	}
1369 #endif
1370 
1371 	/* Notify MD code that a module is being unloaded. */
1372 	elf_cpu_unload_file(file);
1373 
1374 	if (ef->preloaded) {
1375 		link_elf_unload_preload(file);
1376 		return;
1377 	}
1378 
1379 #ifdef SPARSE_MAPPING
1380 	if (ef->object != NULL) {
1381 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1382 		    (vm_offset_t) ef->address
1383 		    + (ef->object->size << PAGE_SHIFT));
1384 	}
1385 #else
1386 	free(ef->address, M_LINKER);
1387 #endif
1388 	free(ef->symbase, M_LINKER);
1389 	free(ef->strbase, M_LINKER);
1390 	free(ef->ctftab, M_LINKER);
1391 	free(ef->ctfoff, M_LINKER);
1392 	free(ef->typoff, M_LINKER);
1393 }
1394 
1395 static void
1396 link_elf_unload_preload(linker_file_t file)
1397 {
1398 
1399 	if (file->pathname != NULL)
1400 		preload_delete_name(file->pathname);
1401 }
1402 
1403 static const char *
1404 symbol_name(elf_file_t ef, Elf_Size r_info)
1405 {
1406 	const Elf_Sym *ref;
1407 
1408 	if (ELF_R_SYM(r_info)) {
1409 		ref = ef->symtab + ELF_R_SYM(r_info);
1410 		return (ef->strtab + ref->st_name);
1411 	}
1412 	return (NULL);
1413 }
1414 
1415 static int
1416 symbol_type(elf_file_t ef, Elf_Size r_info)
1417 {
1418 	const Elf_Sym *ref;
1419 
1420 	if (ELF_R_SYM(r_info)) {
1421 		ref = ef->symtab + ELF_R_SYM(r_info);
1422 		return (ELF_ST_TYPE(ref->st_info));
1423 	}
1424 	return (STT_NOTYPE);
1425 }
1426 
1427 static int
1428 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc,
1429     bool ifuncs)
1430 {
1431 	const Elf_Rel *rel;
1432 	const Elf_Rela *rela;
1433 	const char *symname;
1434 
1435 	TSENTER();
1436 #define	APPLY_RELOCS(iter, tbl, tblsize, type) do {			\
1437 	for ((iter) = (tbl); (iter) != NULL &&				\
1438 	    (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) {	\
1439 		if ((symbol_type(ef, (iter)->r_info) ==			\
1440 		    STT_GNU_IFUNC ||					\
1441 		    elf_is_ifunc_reloc((iter)->r_info)) != ifuncs)	\
1442 			continue;					\
1443 		if (reloc(&ef->lf, (Elf_Addr)ef->address,		\
1444 		    (iter), (type), lookup)) {				\
1445 			symname = symbol_name(ef, (iter)->r_info);	\
1446 			printf("link_elf: symbol %s undefined\n",	\
1447 			    symname);					\
1448 			return (ENOENT);				\
1449 		}							\
1450 	}								\
1451 } while (0)
1452 
1453 	APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL);
1454 	TSENTER2("ef->rela");
1455 	APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA);
1456 	TSEXIT2("ef->rela");
1457 	APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL);
1458 	APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA);
1459 
1460 #undef APPLY_RELOCS
1461 
1462 	TSEXIT();
1463 	return (0);
1464 }
1465 
1466 static int
1467 relocate_file(elf_file_t ef)
1468 {
1469 	int error;
1470 
1471 	error = relocate_file1(ef, elf_lookup, elf_reloc, false);
1472 	if (error == 0)
1473 		error = relocate_file1(ef, elf_lookup, elf_reloc, true);
1474 	return (error);
1475 }
1476 
1477 /*
1478  * SysV hash function for symbol table lookup.  It is specified by the
1479  * System V ABI.
1480  */
1481 static Elf32_Word
1482 elf_hash(const char *name)
1483 {
1484 	const unsigned char *p = (const unsigned char *)name;
1485 	Elf32_Word h = 0;
1486 
1487 	while (*p != '\0') {
1488 		h = (h << 4) + *p++;
1489 		h ^= (h >> 24) & 0xf0;
1490 	}
1491 	return (h & 0x0fffffff);
1492 }
1493 
1494 static int
1495 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym,
1496     bool see_local)
1497 {
1498 	elf_file_t ef = (elf_file_t) lf;
1499 	unsigned long symnum;
1500 	const Elf_Sym* symp;
1501 	const char *strp;
1502 	Elf32_Word hash;
1503 
1504 	/* If we don't have a hash, bail. */
1505 	if (ef->buckets == NULL || ef->nbuckets == 0) {
1506 		printf("link_elf_lookup_symbol: missing symbol hash table\n");
1507 		return (ENOENT);
1508 	}
1509 
1510 	/* First, search hashed global symbols */
1511 	hash = elf_hash(name);
1512 	symnum = ef->buckets[hash % ef->nbuckets];
1513 
1514 	while (symnum != STN_UNDEF) {
1515 		if (symnum >= ef->nchains) {
1516 			printf("%s: corrupt symbol table\n", __func__);
1517 			return (ENOENT);
1518 		}
1519 
1520 		symp = ef->symtab + symnum;
1521 		if (symp->st_name == 0) {
1522 			printf("%s: corrupt symbol table\n", __func__);
1523 			return (ENOENT);
1524 		}
1525 
1526 		strp = ef->strtab + symp->st_name;
1527 
1528 		if (strcmp(name, strp) == 0) {
1529 			if (symp->st_shndx != SHN_UNDEF ||
1530 			    (symp->st_value != 0 &&
1531 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1532 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1533 				if (see_local ||
1534 				    ELF_ST_BIND(symp->st_info) != STB_LOCAL) {
1535 					*sym = (c_linker_sym_t) symp;
1536 					return (0);
1537 				}
1538 			}
1539 			return (ENOENT);
1540 		}
1541 
1542 		symnum = ef->chains[symnum];
1543 	}
1544 
1545 	return (ENOENT);
1546 }
1547 
1548 static int
1549 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1550 {
1551 	if (link_elf_leak_locals)
1552 		return (link_elf_lookup_debug_symbol(lf, name, sym));
1553 	return (link_elf_lookup_symbol1(lf, name, sym, false));
1554 }
1555 
1556 static int
1557 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name,
1558     c_linker_sym_t *sym)
1559 {
1560 	elf_file_t ef = (elf_file_t)lf;
1561 	const Elf_Sym* symp;
1562 	const char *strp;
1563 	int i;
1564 
1565 	if (link_elf_lookup_symbol1(lf, name, sym, true) == 0)
1566 		return (0);
1567 
1568 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1569 		strp = ef->ddbstrtab + symp->st_name;
1570 		if (strcmp(name, strp) == 0) {
1571 			if (symp->st_shndx != SHN_UNDEF ||
1572 			    (symp->st_value != 0 &&
1573 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1574 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1575 				*sym = (c_linker_sym_t) symp;
1576 				return (0);
1577 			}
1578 			return (ENOENT);
1579 		}
1580 	}
1581 
1582 	return (ENOENT);
1583 }
1584 
1585 static int
1586 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym,
1587     linker_symval_t *symval, bool see_local)
1588 {
1589 	elf_file_t ef;
1590 	const Elf_Sym *es;
1591 	caddr_t val;
1592 
1593 	ef = (elf_file_t)lf;
1594 	es = (const Elf_Sym *)sym;
1595 	if (es >= ef->symtab && es < ef->symtab + ef->nchains) {
1596 		if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL)
1597 			return (ENOENT);
1598 		symval->name = ef->strtab + es->st_name;
1599 		val = (caddr_t)ef->address + es->st_value;
1600 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1601 			val = ((caddr_t (*)(void))val)();
1602 		symval->value = val;
1603 		symval->size = es->st_size;
1604 		return (0);
1605 	}
1606 	return (ENOENT);
1607 }
1608 
1609 static int
1610 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1611     linker_symval_t *symval)
1612 {
1613 	if (link_elf_leak_locals)
1614 		return (link_elf_debug_symbol_values(lf, sym, symval));
1615 	return (link_elf_symbol_values1(lf, sym, symval, false));
1616 }
1617 
1618 static int
1619 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1620     linker_symval_t *symval)
1621 {
1622 	elf_file_t ef = (elf_file_t)lf;
1623 	const Elf_Sym *es = (const Elf_Sym *)sym;
1624 	caddr_t val;
1625 
1626 	if (link_elf_symbol_values1(lf, sym, symval, true) == 0)
1627 		return (0);
1628 	if (ef->symtab == ef->ddbsymtab)
1629 		return (ENOENT);
1630 
1631 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1632 		symval->name = ef->ddbstrtab + es->st_name;
1633 		val = (caddr_t)ef->address + es->st_value;
1634 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1635 			val = ((caddr_t (*)(void))val)();
1636 		symval->value = val;
1637 		symval->size = es->st_size;
1638 		return (0);
1639 	}
1640 	return (ENOENT);
1641 }
1642 
1643 static int
1644 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1645     c_linker_sym_t *sym, long *diffp)
1646 {
1647 	elf_file_t ef = (elf_file_t)lf;
1648 	u_long off = (uintptr_t)(void *)value;
1649 	u_long diff = off;
1650 	u_long st_value;
1651 	const Elf_Sym *es;
1652 	const Elf_Sym *best = NULL;
1653 	int i;
1654 
1655 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1656 		if (es->st_name == 0)
1657 			continue;
1658 		st_value = es->st_value + (uintptr_t) (void *) ef->address;
1659 		if (off >= st_value) {
1660 			if (off - st_value < diff) {
1661 				diff = off - st_value;
1662 				best = es;
1663 				if (diff == 0)
1664 					break;
1665 			} else if (off - st_value == diff) {
1666 				best = es;
1667 			}
1668 		}
1669 	}
1670 	if (best == NULL)
1671 		*diffp = off;
1672 	else
1673 		*diffp = diff;
1674 	*sym = (c_linker_sym_t) best;
1675 
1676 	return (0);
1677 }
1678 
1679 /*
1680  * Look up a linker set on an ELF system.
1681  */
1682 static int
1683 link_elf_lookup_set(linker_file_t lf, const char *name,
1684     void ***startp, void ***stopp, int *countp)
1685 {
1686 	c_linker_sym_t sym;
1687 	linker_symval_t symval;
1688 	char *setsym;
1689 	void **start, **stop;
1690 	int len, error = 0, count;
1691 
1692 	len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1693 	setsym = malloc(len, M_LINKER, M_WAITOK);
1694 
1695 	/* get address of first entry */
1696 	snprintf(setsym, len, "%s%s", "__start_set_", name);
1697 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1698 	if (error != 0)
1699 		goto out;
1700 	link_elf_symbol_values(lf, sym, &symval);
1701 	if (symval.value == 0) {
1702 		error = ESRCH;
1703 		goto out;
1704 	}
1705 	start = (void **)symval.value;
1706 
1707 	/* get address of last entry */
1708 	snprintf(setsym, len, "%s%s", "__stop_set_", name);
1709 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1710 	if (error != 0)
1711 		goto out;
1712 	link_elf_symbol_values(lf, sym, &symval);
1713 	if (symval.value == 0) {
1714 		error = ESRCH;
1715 		goto out;
1716 	}
1717 	stop = (void **)symval.value;
1718 
1719 	/* and the number of entries */
1720 	count = stop - start;
1721 
1722 	/* and copy out */
1723 	if (startp != NULL)
1724 		*startp = start;
1725 	if (stopp != NULL)
1726 		*stopp = stop;
1727 	if (countp != NULL)
1728 		*countp = count;
1729 
1730 out:
1731 	free(setsym, M_LINKER);
1732 	return (error);
1733 }
1734 
1735 static int
1736 link_elf_each_function_name(linker_file_t file,
1737   int (*callback)(const char *, void *), void *opaque)
1738 {
1739 	elf_file_t ef = (elf_file_t)file;
1740 	const Elf_Sym *symp;
1741 	int i, error;
1742 
1743 	/* Exhaustive search */
1744 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1745 		if (symp->st_value != 0 &&
1746 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1747 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1748 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1749 			if (error != 0)
1750 				return (error);
1751 		}
1752 	}
1753 	return (0);
1754 }
1755 
1756 static int
1757 link_elf_each_function_nameval(linker_file_t file,
1758     linker_function_nameval_callback_t callback, void *opaque)
1759 {
1760 	linker_symval_t symval;
1761 	elf_file_t ef = (elf_file_t)file;
1762 	const Elf_Sym *symp;
1763 	int i, error;
1764 
1765 	/* Exhaustive search */
1766 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1767 		if (symp->st_value != 0 &&
1768 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1769 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1770 			error = link_elf_debug_symbol_values(file,
1771 			    (c_linker_sym_t) symp, &symval);
1772 			if (error == 0)
1773 				error = callback(file, i, &symval, opaque);
1774 			if (error != 0)
1775 				return (error);
1776 		}
1777 	}
1778 	return (0);
1779 }
1780 
1781 const Elf_Sym *
1782 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1783 {
1784 	elf_file_t ef = (elf_file_t)lf;
1785 
1786 	if (symidx >= ef->nchains)
1787 		return (NULL);
1788 	return (ef->symtab + symidx);
1789 }
1790 
1791 const char *
1792 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1793 {
1794 	elf_file_t ef = (elf_file_t)lf;
1795 	const Elf_Sym *sym;
1796 
1797 	if (symidx >= ef->nchains)
1798 		return (NULL);
1799 	sym = ef->symtab + symidx;
1800 	return (ef->strtab + sym->st_name);
1801 }
1802 
1803 /*
1804  * Symbol lookup function that can be used when the symbol index is known (ie
1805  * in relocations). It uses the symbol index instead of doing a fully fledged
1806  * hash table based lookup when such is valid. For example for local symbols.
1807  * This is not only more efficient, it's also more correct. It's not always
1808  * the case that the symbol can be found through the hash table.
1809  */
1810 static int
1811 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1812 {
1813 	elf_file_t ef = (elf_file_t)lf;
1814 	const Elf_Sym *sym;
1815 	const char *symbol;
1816 	Elf_Addr addr, start, base;
1817 
1818 	/* Don't even try to lookup the symbol if the index is bogus. */
1819 	if (symidx >= ef->nchains) {
1820 		*res = 0;
1821 		return (EINVAL);
1822 	}
1823 
1824 	sym = ef->symtab + symidx;
1825 
1826 	/*
1827 	 * Don't do a full lookup when the symbol is local. It may even
1828 	 * fail because it may not be found through the hash table.
1829 	 */
1830 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1831 		/* Force lookup failure when we have an insanity. */
1832 		if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) {
1833 			*res = 0;
1834 			return (EINVAL);
1835 		}
1836 		*res = ((Elf_Addr)ef->address + sym->st_value);
1837 		return (0);
1838 	}
1839 
1840 	/*
1841 	 * XXX we can avoid doing a hash table based lookup for global
1842 	 * symbols as well. This however is not always valid, so we'll
1843 	 * just do it the hard way for now. Performance tweaks can
1844 	 * always be added.
1845 	 */
1846 
1847 	symbol = ef->strtab + sym->st_name;
1848 
1849 	/* Force a lookup failure if the symbol name is bogus. */
1850 	if (*symbol == 0) {
1851 		*res = 0;
1852 		return (EINVAL);
1853 	}
1854 
1855 	addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1856 	if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1857 		*res = 0;
1858 		return (EINVAL);
1859 	}
1860 
1861 	if (elf_set_find(&set_pcpu_list, addr, &start, &base))
1862 		addr = addr - start + base;
1863 #ifdef VIMAGE
1864 	else if (elf_set_find(&set_vnet_list, addr, &start, &base))
1865 		addr = addr - start + base;
1866 #endif
1867 	*res = addr;
1868 	return (0);
1869 }
1870 
1871 static void
1872 link_elf_reloc_local(linker_file_t lf)
1873 {
1874 	const Elf_Rel *rellim;
1875 	const Elf_Rel *rel;
1876 	const Elf_Rela *relalim;
1877 	const Elf_Rela *rela;
1878 	elf_file_t ef = (elf_file_t)lf;
1879 
1880 	/* Perform relocations without addend if there are any: */
1881 	if ((rel = ef->rel) != NULL) {
1882 		rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1883 		while (rel < rellim) {
1884 			elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1885 			    ELF_RELOC_REL, elf_lookup);
1886 			rel++;
1887 		}
1888 	}
1889 
1890 	/* Perform relocations with addend if there are any: */
1891 	if ((rela = ef->rela) != NULL) {
1892 		relalim = (const Elf_Rela *)
1893 		    ((const char *)ef->rela + ef->relasize);
1894 		while (rela < relalim) {
1895 			elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1896 			    ELF_RELOC_RELA, elf_lookup);
1897 			rela++;
1898 		}
1899 	}
1900 }
1901 
1902 static long
1903 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1904 {
1905 	elf_file_t ef = (elf_file_t)lf;
1906 
1907 	*symtab = ef->ddbsymtab;
1908 
1909 	if (*symtab == NULL)
1910 		return (0);
1911 
1912 	return (ef->ddbsymcnt);
1913 }
1914 
1915 static long
1916 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1917 {
1918 	elf_file_t ef = (elf_file_t)lf;
1919 
1920 	*strtab = ef->ddbstrtab;
1921 
1922 	if (*strtab == NULL)
1923 		return (0);
1924 
1925 	return (ef->ddbstrcnt);
1926 }
1927 
1928 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__)
1929 /*
1930  * Use this lookup routine when performing relocations early during boot.
1931  * The generic lookup routine depends on kobj, which is not initialized
1932  * at that point.
1933  */
1934 static int
1935 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused,
1936     Elf_Addr *res)
1937 {
1938 	elf_file_t ef;
1939 	const Elf_Sym *symp;
1940 	caddr_t val;
1941 
1942 	ef = (elf_file_t)lf;
1943 	symp = ef->symtab + symidx;
1944 	if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) {
1945 		val = (caddr_t)ef->address + symp->st_value;
1946 		*res = ((Elf_Addr (*)(void))val)();
1947 		return (0);
1948 	}
1949 	return (ENOENT);
1950 }
1951 
1952 void
1953 link_elf_ireloc(caddr_t kmdp)
1954 {
1955 	struct elf_file eff;
1956 	elf_file_t ef;
1957 
1958 	TSENTER();
1959 	ef = &eff;
1960 
1961 	bzero_early(ef, sizeof(*ef));
1962 
1963 	ef->modptr = kmdp;
1964 	ef->dynamic = (Elf_Dyn *)&_DYNAMIC;
1965 
1966 #ifdef RELOCATABLE_KERNEL
1967 	ef->address = (caddr_t) (__startkernel - KERNBASE);
1968 #else
1969 	ef->address = 0;
1970 #endif
1971 	parse_dynamic(ef);
1972 
1973 	link_elf_preload_parse_symbols(ef);
1974 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true);
1975 	TSEXIT();
1976 }
1977 
1978 #if defined(__aarch64__) || defined(__amd64__)
1979 void
1980 link_elf_late_ireloc(void)
1981 {
1982 	elf_file_t ef;
1983 
1984 	KASSERT(linker_kernel_file != NULL,
1985 	    ("link_elf_late_ireloc: No kernel linker file found"));
1986 	ef = (elf_file_t)linker_kernel_file;
1987 
1988 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true);
1989 }
1990 #endif
1991 #endif
1992