xref: /freebsd/sys/kern/link_elf.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
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 #include "opt_ddb.h"
31 #include "opt_gdb.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #ifdef SPARSE_MAPPING
39 #include <sys/mman.h>
40 #endif
41 #include <sys/mutex.h>
42 #include <sys/mount.h>
43 #include <sys/pcpu.h>
44 #include <sys/proc.h>
45 #include <sys/namei.h>
46 #include <sys/fcntl.h>
47 #include <sys/vnode.h>
48 #include <sys/linker.h>
49 #include <sys/sysctl.h>
50 #include <sys/tslog.h>
51 
52 #include <machine/elf.h>
53 
54 #include <net/vnet.h>
55 
56 #include <security/mac/mac_framework.h>
57 
58 #include <vm/vm.h>
59 #include <vm/vm_param.h>
60 #ifdef SPARSE_MAPPING
61 #include <vm/vm_object.h>
62 #include <vm/vm_kern.h>
63 #include <vm/vm_extern.h>
64 #endif
65 #include <vm/pmap.h>
66 #include <vm/vm_map.h>
67 
68 #include <sys/link_elf.h>
69 
70 #include "linker_if.h"
71 
72 #define MAXSEGS 4
73 
74 typedef struct elf_file {
75 	struct linker_file lf;		/* Common fields */
76 	int		preloaded;	/* Was file pre-loaded */
77 	caddr_t		address;	/* Relocation address */
78 #ifdef SPARSE_MAPPING
79 	vm_object_t	object;		/* VM object to hold file pages */
80 #endif
81 	Elf_Dyn		*dynamic;	/* Symbol table etc. */
82 	Elf_Hashelt	nbuckets;	/* DT_HASH info */
83 	Elf_Hashelt	nchains;
84 	const Elf_Hashelt *buckets;
85 	const Elf_Hashelt *chains;
86 	caddr_t		hash;
87 	caddr_t		strtab;		/* DT_STRTAB */
88 	int		strsz;		/* DT_STRSZ */
89 	const Elf_Sym	*symtab;		/* DT_SYMTAB */
90 	Elf_Addr	*got;		/* DT_PLTGOT */
91 	const Elf_Rel	*pltrel;	/* DT_JMPREL */
92 	int		pltrelsize;	/* DT_PLTRELSZ */
93 	const Elf_Rela	*pltrela;	/* DT_JMPREL */
94 	int		pltrelasize;	/* DT_PLTRELSZ */
95 	const Elf_Rel	*rel;		/* DT_REL */
96 	int		relsize;	/* DT_RELSZ */
97 	const Elf_Rela	*rela;		/* DT_RELA */
98 	int		relasize;	/* DT_RELASZ */
99 	caddr_t		modptr;
100 	const Elf_Sym	*ddbsymtab;	/* The symbol table we are using */
101 	long		ddbsymcnt;	/* Number of symbols */
102 	caddr_t		ddbstrtab;	/* String table */
103 	long		ddbstrcnt;	/* number of bytes in string table */
104 	caddr_t		symbase;	/* malloc'ed symbold base */
105 	caddr_t		strbase;	/* malloc'ed string base */
106 	caddr_t		ctftab;		/* CTF table */
107 	long		ctfcnt;		/* number of bytes in CTF table */
108 	caddr_t		ctfoff;		/* CTF offset table */
109 	caddr_t		typoff;		/* Type offset table */
110 	long		typlen;		/* Number of type entries. */
111 	Elf_Addr	pcpu_start;	/* Pre-relocation pcpu set start. */
112 	Elf_Addr	pcpu_stop;	/* Pre-relocation pcpu set stop. */
113 	Elf_Addr	pcpu_base;	/* Relocated pcpu set address. */
114 #ifdef VIMAGE
115 	Elf_Addr	vnet_start;	/* Pre-relocation vnet set start. */
116 	Elf_Addr	vnet_stop;	/* Pre-relocation vnet set stop. */
117 	Elf_Addr	vnet_base;	/* Relocated vnet set address. */
118 #endif
119 #ifdef GDB
120 	struct link_map	gdb;		/* hooks for gdb */
121 #endif
122 } *elf_file_t;
123 
124 struct elf_set {
125 	Elf_Addr	es_start;
126 	Elf_Addr	es_stop;
127 	Elf_Addr	es_base;
128 	TAILQ_ENTRY(elf_set)	es_link;
129 };
130 
131 TAILQ_HEAD(elf_set_head, elf_set);
132 
133 #include <kern/kern_ctf.c>
134 
135 static int	link_elf_link_common_finish(linker_file_t);
136 static int	link_elf_link_preload(linker_class_t cls,
137 				      const char *, linker_file_t *);
138 static int	link_elf_link_preload_finish(linker_file_t);
139 static int	link_elf_load_file(linker_class_t, const char *,
140 		    linker_file_t *);
141 static int	link_elf_lookup_symbol(linker_file_t, const char *,
142 		    c_linker_sym_t *);
143 static int	link_elf_lookup_debug_symbol(linker_file_t, const char *,
144 		    c_linker_sym_t *);
145 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
146 		    linker_symval_t *);
147 static int	link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t,
148 		    linker_symval_t*);
149 static int	link_elf_search_symbol(linker_file_t, caddr_t,
150 		    c_linker_sym_t *, long *);
151 
152 static void	link_elf_unload_file(linker_file_t);
153 static void	link_elf_unload_preload(linker_file_t);
154 static int	link_elf_lookup_set(linker_file_t, const char *,
155 		    void ***, void ***, int *);
156 static int	link_elf_each_function_name(linker_file_t,
157 		    int (*)(const char *, void *), void *);
158 static int	link_elf_each_function_nameval(linker_file_t,
159 		    linker_function_nameval_callback_t, void *);
160 static void	link_elf_reloc_local(linker_file_t);
161 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
162 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
163 static int	elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *);
164 
165 static kobj_method_t link_elf_methods[] = {
166 	KOBJMETHOD(linker_lookup_symbol,	link_elf_lookup_symbol),
167 	KOBJMETHOD(linker_lookup_debug_symbol,	link_elf_lookup_debug_symbol),
168 	KOBJMETHOD(linker_symbol_values,	link_elf_symbol_values),
169 	KOBJMETHOD(linker_debug_symbol_values,	link_elf_debug_symbol_values),
170 	KOBJMETHOD(linker_search_symbol,	link_elf_search_symbol),
171 	KOBJMETHOD(linker_unload,		link_elf_unload_file),
172 	KOBJMETHOD(linker_load_file,		link_elf_load_file),
173 	KOBJMETHOD(linker_link_preload,		link_elf_link_preload),
174 	KOBJMETHOD(linker_link_preload_finish,	link_elf_link_preload_finish),
175 	KOBJMETHOD(linker_lookup_set,		link_elf_lookup_set),
176 	KOBJMETHOD(linker_each_function_name,	link_elf_each_function_name),
177 	KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
178 	KOBJMETHOD(linker_ctf_get,		link_elf_ctf_get),
179 	KOBJMETHOD(linker_symtab_get,		link_elf_symtab_get),
180 	KOBJMETHOD(linker_strtab_get,		link_elf_strtab_get),
181 	KOBJMETHOD_END
182 };
183 
184 static struct linker_class link_elf_class = {
185 #if ELF_TARG_CLASS == ELFCLASS32
186 	"elf32",
187 #else
188 	"elf64",
189 #endif
190 	link_elf_methods, sizeof(struct elf_file)
191 };
192 
193 static bool link_elf_leak_locals = true;
194 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_leak_locals,
195     CTLFLAG_RWTUN, &link_elf_leak_locals, 0,
196     "Allow local symbols to participate in global module symbol resolution");
197 
198 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase,
199     const void *data, int type, elf_lookup_fn lookup);
200 
201 static int	parse_dynamic(elf_file_t);
202 static int	relocate_file(elf_file_t);
203 static int	relocate_file1(elf_file_t ef, elf_lookup_fn lookup,
204 		    elf_reloc_fn reloc, bool ifuncs);
205 static int	link_elf_preload_parse_symbols(elf_file_t);
206 
207 static struct elf_set_head set_pcpu_list;
208 #ifdef VIMAGE
209 static struct elf_set_head set_vnet_list;
210 #endif
211 
212 static void
213 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
214 {
215 	struct elf_set *set, *iter;
216 
217 	set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
218 	set->es_start = start;
219 	set->es_stop = stop;
220 	set->es_base = base;
221 
222 	TAILQ_FOREACH(iter, list, es_link) {
223 		KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
224 		    (set->es_start > iter->es_start && set->es_stop > iter->es_stop),
225 		    ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
226 		    (uintmax_t)set->es_start, (uintmax_t)set->es_stop,
227 		    (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
228 
229 		if (iter->es_start > set->es_start) {
230 			TAILQ_INSERT_BEFORE(iter, set, es_link);
231 			break;
232 		}
233 	}
234 
235 	if (iter == NULL)
236 		TAILQ_INSERT_TAIL(list, set, es_link);
237 }
238 
239 static int
240 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
241 {
242 	struct elf_set *set;
243 
244 	TAILQ_FOREACH(set, list, es_link) {
245 		if (addr < set->es_start)
246 			return (0);
247 		if (addr < set->es_stop) {
248 			*start = set->es_start;
249 			*base = set->es_base;
250 			return (1);
251 		}
252 	}
253 
254 	return (0);
255 }
256 
257 static void
258 elf_set_delete(struct elf_set_head *list, Elf_Addr start)
259 {
260 	struct elf_set *set;
261 
262 	TAILQ_FOREACH(set, list, es_link) {
263 		if (start < set->es_start)
264 			break;
265 		if (start == set->es_start) {
266 			TAILQ_REMOVE(list, set, es_link);
267 			free(set, M_LINKER);
268 			return;
269 		}
270 	}
271 	KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
272 	    (uintmax_t)start));
273 }
274 
275 #ifdef GDB
276 static void	r_debug_state(struct r_debug *, struct link_map *);
277 
278 /*
279  * A list of loaded modules for GDB to use for loading symbols.
280  */
281 struct r_debug r_debug;
282 
283 #define GDB_STATE(s) do {				\
284 	r_debug.r_state = s; r_debug_state(NULL, NULL);	\
285 } while (0)
286 
287 /*
288  * Function for the debugger to set a breakpoint on to gain control.
289  */
290 static void
291 r_debug_state(struct r_debug *dummy_one __unused,
292 	      struct link_map *dummy_two __unused)
293 {
294 }
295 
296 static void
297 link_elf_add_gdb(struct link_map *l)
298 {
299 	struct link_map *prev;
300 
301 	l->l_next = NULL;
302 
303 	if (r_debug.r_map == NULL) {
304 		/* Add first. */
305 		l->l_prev = NULL;
306 		r_debug.r_map = l;
307 	} else {
308 		/* Append to list. */
309 		for (prev = r_debug.r_map;
310 		    prev->l_next != NULL;
311 		    prev = prev->l_next)
312 			;
313 		l->l_prev = prev;
314 		prev->l_next = l;
315 	}
316 }
317 
318 static void
319 link_elf_delete_gdb(struct link_map *l)
320 {
321 	if (l->l_prev == NULL) {
322 		/* Remove first. */
323 		if ((r_debug.r_map = l->l_next) != NULL)
324 			l->l_next->l_prev = NULL;
325 	} else {
326 		/* Remove any but first. */
327 		if ((l->l_prev->l_next = l->l_next) != NULL)
328 			l->l_next->l_prev = l->l_prev;
329 	}
330 }
331 #endif /* GDB */
332 
333 /*
334  * The kernel symbol table starts here.
335  */
336 extern struct _dynamic _DYNAMIC;
337 
338 static void
339 link_elf_error(const char *filename, const char *s)
340 {
341 	if (filename == NULL)
342 		printf("kldload: %s\n", s);
343 	else
344 		printf("kldload: %s: %s\n", filename, s);
345 }
346 
347 static void
348 link_elf_invoke_ctors(caddr_t addr, size_t size)
349 {
350 	void (**ctor)(void);
351 	size_t i, cnt;
352 
353 	if (addr == NULL || size == 0)
354 		return;
355 	cnt = size / sizeof(*ctor);
356 	ctor = (void *)addr;
357 	for (i = 0; i < cnt; i++) {
358 		if (ctor[i] != NULL)
359 			(*ctor[i])();
360 	}
361 }
362 
363 /*
364  * Actions performed after linking/loading both the preloaded kernel and any
365  * modules; whether preloaded or dynamicly loaded.
366  */
367 static int
368 link_elf_link_common_finish(linker_file_t lf)
369 {
370 #ifdef GDB
371 	elf_file_t ef = (elf_file_t)lf;
372 	char *newfilename;
373 #endif
374 	int error;
375 
376 	/* Notify MD code that a module is being loaded. */
377 	error = elf_cpu_load_file(lf);
378 	if (error != 0)
379 		return (error);
380 
381 #ifdef GDB
382 	GDB_STATE(RT_ADD);
383 	ef->gdb.l_addr = lf->address;
384 	newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
385 	strcpy(newfilename, lf->filename);
386 	ef->gdb.l_name = newfilename;
387 	ef->gdb.l_ld = ef->dynamic;
388 	link_elf_add_gdb(&ef->gdb);
389 	GDB_STATE(RT_CONSISTENT);
390 #endif
391 
392 	/* Invoke .ctors */
393 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
394 	return (0);
395 }
396 
397 #ifdef RELOCATABLE_KERNEL
398 /*
399  * __startkernel and __endkernel are symbols set up as relocation canaries.
400  *
401  * They are defined in locore to reference linker script symbols at the
402  * beginning and end of the LOAD area. This has the desired side effect of
403  * giving us variables that have relative relocations pointing at them, so
404  * relocation of the kernel object will cause the variables to be updated
405  * automatically by the runtime linker when we initialize.
406  *
407  * There are two main reasons to relocate the kernel:
408  * 1) If the loader needed to load the kernel at an alternate load address.
409  * 2) If the kernel is switching address spaces on machines like POWER9
410  *    under Radix where the high bits of the effective address are used to
411  *    differentiate between hypervisor, host, guest, and problem state.
412  */
413 extern vm_offset_t __startkernel, __endkernel;
414 #endif
415 
416 static unsigned long kern_relbase = KERNBASE;
417 
418 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD,
419 	SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address");
420 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD,
421 	&kern_relbase, 0, "Kernel relocated base address");
422 
423 static void
424 link_elf_init(void* arg)
425 {
426 	Elf_Dyn *dp;
427 	Elf_Addr *ctors_addrp;
428 	Elf_Size *ctors_sizep;
429 	caddr_t modptr, baseptr, sizeptr;
430 	elf_file_t ef;
431 	const char *modname;
432 
433 	linker_add_class(&link_elf_class);
434 
435 	dp = (Elf_Dyn *)&_DYNAMIC;
436 	modname = NULL;
437 	modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
438 	if (modptr == NULL)
439 		modptr = preload_search_by_type("elf kernel");
440 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
441 	if (modname == NULL)
442 		modname = "kernel";
443 	linker_kernel_file = linker_make_file(modname, &link_elf_class);
444 	if (linker_kernel_file == NULL)
445 		panic("%s: Can't create linker structures for kernel",
446 		    __func__);
447 
448 	ef = (elf_file_t) linker_kernel_file;
449 	ef->preloaded = 1;
450 #ifdef RELOCATABLE_KERNEL
451 	/* Compute relative displacement */
452 	ef->address = (caddr_t) (__startkernel - KERNBASE);
453 #else
454 	ef->address = 0;
455 #endif
456 #ifdef SPARSE_MAPPING
457 	ef->object = NULL;
458 #endif
459 	ef->dynamic = dp;
460 
461 	if (dp != NULL)
462 		parse_dynamic(ef);
463 #ifdef RELOCATABLE_KERNEL
464 	linker_kernel_file->address = (caddr_t)__startkernel;
465 	linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
466 	kern_relbase = (unsigned long)__startkernel;
467 #else
468 	linker_kernel_file->address += KERNBASE;
469 	linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
470 #endif
471 
472 	if (modptr != NULL) {
473 		ef->modptr = modptr;
474 		baseptr = preload_search_info(modptr, MODINFO_ADDR);
475 		if (baseptr != NULL)
476 			linker_kernel_file->address = *(caddr_t *)baseptr;
477 		sizeptr = preload_search_info(modptr, MODINFO_SIZE);
478 		if (sizeptr != NULL)
479 			linker_kernel_file->size = *(size_t *)sizeptr;
480 		ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
481 			MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
482 		ctors_sizep = (Elf_Size *)preload_search_info(modptr,
483 			MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
484 		if (ctors_addrp != NULL && ctors_sizep != NULL) {
485 			linker_kernel_file->ctors_addr = ef->address +
486 			    *ctors_addrp;
487 			linker_kernel_file->ctors_size = *ctors_sizep;
488 		}
489 	}
490 	(void)link_elf_preload_parse_symbols(ef);
491 
492 #ifdef GDB
493 	r_debug.r_map = NULL;
494 	r_debug.r_brk = r_debug_state;
495 	r_debug.r_state = RT_CONSISTENT;
496 #endif
497 
498 	(void)link_elf_link_common_finish(linker_kernel_file);
499 	linker_kernel_file->flags |= LINKER_FILE_LINKED;
500 	TAILQ_INIT(&set_pcpu_list);
501 #ifdef VIMAGE
502 	TAILQ_INIT(&set_vnet_list);
503 #endif
504 }
505 
506 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL);
507 
508 static int
509 link_elf_preload_parse_symbols(elf_file_t ef)
510 {
511 	caddr_t pointer;
512 	caddr_t ssym, esym, base;
513 	caddr_t strtab;
514 	int strcnt;
515 	Elf_Sym *symtab;
516 	int symcnt;
517 
518 	if (ef->modptr == NULL)
519 		return (0);
520 	pointer = preload_search_info(ef->modptr,
521 	    MODINFO_METADATA | MODINFOMD_SSYM);
522 	if (pointer == NULL)
523 		return (0);
524 	ssym = *(caddr_t *)pointer;
525 	pointer = preload_search_info(ef->modptr,
526 	    MODINFO_METADATA | MODINFOMD_ESYM);
527 	if (pointer == NULL)
528 		return (0);
529 	esym = *(caddr_t *)pointer;
530 
531 	base = ssym;
532 
533 	symcnt = *(long *)base;
534 	base += sizeof(long);
535 	symtab = (Elf_Sym *)base;
536 	base += roundup(symcnt, sizeof(long));
537 
538 	if (base > esym || base < ssym) {
539 		printf("Symbols are corrupt!\n");
540 		return (EINVAL);
541 	}
542 
543 	strcnt = *(long *)base;
544 	base += sizeof(long);
545 	strtab = base;
546 	base += roundup(strcnt, sizeof(long));
547 
548 	if (base > esym || base < ssym) {
549 		printf("Symbols are corrupt!\n");
550 		return (EINVAL);
551 	}
552 
553 	ef->ddbsymtab = symtab;
554 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
555 	ef->ddbstrtab = strtab;
556 	ef->ddbstrcnt = strcnt;
557 
558 	return (0);
559 }
560 
561 static int
562 parse_dynamic(elf_file_t ef)
563 {
564 	Elf_Dyn *dp;
565 	int plttype = DT_REL;
566 
567 	for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
568 		switch (dp->d_tag) {
569 		case DT_HASH:
570 		{
571 			/* From src/libexec/rtld-elf/rtld.c */
572 			const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
573 			    (ef->address + dp->d_un.d_ptr);
574 			ef->nbuckets = hashtab[0];
575 			ef->nchains = hashtab[1];
576 			ef->buckets = hashtab + 2;
577 			ef->chains = ef->buckets + ef->nbuckets;
578 			break;
579 		}
580 		case DT_STRTAB:
581 			ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
582 			break;
583 		case DT_STRSZ:
584 			ef->strsz = dp->d_un.d_val;
585 			break;
586 		case DT_SYMTAB:
587 			ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
588 			break;
589 		case DT_SYMENT:
590 			if (dp->d_un.d_val != sizeof(Elf_Sym))
591 				return (ENOEXEC);
592 			break;
593 		case DT_PLTGOT:
594 			ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
595 			break;
596 		case DT_REL:
597 			ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
598 			break;
599 		case DT_RELSZ:
600 			ef->relsize = dp->d_un.d_val;
601 			break;
602 		case DT_RELENT:
603 			if (dp->d_un.d_val != sizeof(Elf_Rel))
604 				return (ENOEXEC);
605 			break;
606 		case DT_JMPREL:
607 			ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
608 			break;
609 		case DT_PLTRELSZ:
610 			ef->pltrelsize = dp->d_un.d_val;
611 			break;
612 		case DT_RELA:
613 			ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
614 			break;
615 		case DT_RELASZ:
616 			ef->relasize = dp->d_un.d_val;
617 			break;
618 		case DT_RELAENT:
619 			if (dp->d_un.d_val != sizeof(Elf_Rela))
620 				return (ENOEXEC);
621 			break;
622 		case DT_PLTREL:
623 			plttype = dp->d_un.d_val;
624 			if (plttype != DT_REL && plttype != DT_RELA)
625 				return (ENOEXEC);
626 			break;
627 #ifdef GDB
628 		case DT_DEBUG:
629 			dp->d_un.d_ptr = (Elf_Addr)&r_debug;
630 			break;
631 #endif
632 		}
633 	}
634 
635 	if (plttype == DT_RELA) {
636 		ef->pltrela = (const Elf_Rela *)ef->pltrel;
637 		ef->pltrel = NULL;
638 		ef->pltrelasize = ef->pltrelsize;
639 		ef->pltrelsize = 0;
640 	}
641 
642 	ef->ddbsymtab = ef->symtab;
643 	ef->ddbsymcnt = ef->nchains;
644 	ef->ddbstrtab = ef->strtab;
645 	ef->ddbstrcnt = ef->strsz;
646 
647 	return elf_cpu_parse_dynamic(ef->address, ef->dynamic);
648 }
649 
650 #define	LS_PADDING	0x90909090
651 static int
652 parse_dpcpu(elf_file_t ef)
653 {
654 	int error, size;
655 #if defined(__i386__)
656 	uint32_t pad;
657 #endif
658 
659 	ef->pcpu_start = 0;
660 	ef->pcpu_stop = 0;
661 	error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
662 	    (void ***)&ef->pcpu_stop, NULL);
663 	/* Error just means there is no pcpu set to relocate. */
664 	if (error != 0)
665 		return (0);
666 	size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start;
667 	/* Empty set? */
668 	if (size < 1)
669 		return (0);
670 #if defined(__i386__)
671 	/* In case we do find __start/stop_set_ symbols double-check. */
672 	if (size < 4) {
673 		uprintf("Kernel module '%s' must be recompiled with "
674 		    "linker script\n", ef->lf.pathname);
675 		return (ENOEXEC);
676 	}
677 
678 	/* Padding from linker-script correct? */
679 	pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad));
680 	if (pad != LS_PADDING) {
681 		uprintf("Kernel module '%s' must be recompiled with "
682 		    "linker script, invalid padding %#04x (%#04x)\n",
683 		    ef->lf.pathname, pad, LS_PADDING);
684 		return (ENOEXEC);
685 	}
686 	/* If we only have valid padding, nothing to do. */
687 	if (size == 4)
688 		return (0);
689 #endif
690 	/*
691 	 * Allocate space in the primary pcpu area.  Copy in our
692 	 * initialization from the data section and then initialize
693 	 * all per-cpu storage from that.
694 	 */
695 	ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size);
696 	if (ef->pcpu_base == 0) {
697 		printf("%s: pcpu module space is out of space; "
698 		    "cannot allocate %d for %s\n",
699 		    __func__, size, ef->lf.pathname);
700 		return (ENOSPC);
701 	}
702 	memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size);
703 	dpcpu_copy((void *)ef->pcpu_base, size);
704 	elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
705 	    ef->pcpu_base);
706 
707 	return (0);
708 }
709 
710 #ifdef VIMAGE
711 static int
712 parse_vnet(elf_file_t ef)
713 {
714 	int error, size;
715 #if defined(__i386__)
716 	uint32_t pad;
717 #endif
718 
719 	ef->vnet_start = 0;
720 	ef->vnet_stop = 0;
721 	error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
722 	    (void ***)&ef->vnet_stop, NULL);
723 	/* Error just means there is no vnet data set to relocate. */
724 	if (error != 0)
725 		return (0);
726 	size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
727 	/* Empty set? */
728 	if (size < 1)
729 		return (0);
730 #if defined(__i386__)
731 	/* In case we do find __start/stop_set_ symbols double-check. */
732 	if (size < 4) {
733 		uprintf("Kernel module '%s' must be recompiled with "
734 		    "linker script\n", ef->lf.pathname);
735 		return (ENOEXEC);
736 	}
737 
738 	/* Padding from linker-script correct? */
739 	pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad));
740 	if (pad != LS_PADDING) {
741 		uprintf("Kernel module '%s' must be recompiled with "
742 		    "linker script, invalid padding %#04x (%#04x)\n",
743 		    ef->lf.pathname, pad, LS_PADDING);
744 		return (ENOEXEC);
745 	}
746 	/* If we only have valid padding, nothing to do. */
747 	if (size == 4)
748 		return (0);
749 #endif
750 	/*
751 	 * Allocate space in the primary vnet area.  Copy in our
752 	 * initialization from the data section and then initialize
753 	 * all per-vnet storage from that.
754 	 */
755 	ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size);
756 	if (ef->vnet_base == 0) {
757 		printf("%s: vnet module space is out of space; "
758 		    "cannot allocate %d for %s\n",
759 		    __func__, size, ef->lf.pathname);
760 		return (ENOSPC);
761 	}
762 	memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size);
763 	vnet_data_copy((void *)ef->vnet_base, size);
764 	elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
765 	    ef->vnet_base);
766 
767 	return (0);
768 }
769 #endif
770 #undef LS_PADDING
771 
772 /*
773  * Apply the specified protection to the loadable segments of a preloaded linker
774  * file.
775  */
776 static int
777 preload_protect(elf_file_t ef, vm_prot_t prot)
778 {
779 #if defined(__aarch64__) || defined(__amd64__)
780 	Elf_Ehdr *hdr;
781 	Elf_Phdr *phdr, *phlimit;
782 	vm_prot_t nprot;
783 	int error;
784 
785 	error = 0;
786 	hdr = (Elf_Ehdr *)ef->address;
787 	phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff);
788 	phlimit = phdr + hdr->e_phnum;
789 	for (; phdr < phlimit; phdr++) {
790 		if (phdr->p_type != PT_LOAD)
791 			continue;
792 
793 		nprot = prot | VM_PROT_READ;
794 		if ((phdr->p_flags & PF_W) != 0)
795 			nprot |= VM_PROT_WRITE;
796 		if ((phdr->p_flags & PF_X) != 0)
797 			nprot |= VM_PROT_EXECUTE;
798 		error = pmap_change_prot((vm_offset_t)ef->address +
799 		    phdr->p_vaddr, round_page(phdr->p_memsz), nprot);
800 		if (error != 0)
801 			break;
802 	}
803 	return (error);
804 #else
805 	return (0);
806 #endif
807 }
808 
809 #ifdef __arm__
810 /*
811  * Locate the ARM exception/unwind table info for DDB and stack(9) use by
812  * searching for the section header that describes it.  There may be no unwind
813  * info, for example in a module containing only data.
814  */
815 static void
816 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr)
817 {
818 	int i;
819 
820 	for (i = 0; i < nhdr; i++) {
821 		if (shdr[i].sh_type == SHT_ARM_EXIDX) {
822 			lf->exidx_addr = shdr[i].sh_addr + lf->address;
823 			lf->exidx_size = shdr[i].sh_size;
824 			break;
825 		}
826 	}
827 }
828 
829 /*
830  * Locate the section headers metadata in a preloaded module, then use it to
831  * locate the exception/unwind table in the module.  The size of the metadata
832  * block is stored in a uint32 word immediately before the data itself, and a
833  * comment in preload_search_info() says it is safe to rely on that.
834  */
835 static void
836 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr)
837 {
838 	uint32_t *modinfo;
839 	Elf_Shdr *shdr;
840 	uint32_t  nhdr;
841 
842 	modinfo = (uint32_t *)preload_search_info(modptr,
843 	    MODINFO_METADATA | MODINFOMD_SHDR);
844 	if (modinfo != NULL) {
845 		shdr = (Elf_Shdr *)modinfo;
846 		nhdr = modinfo[-1] / sizeof(Elf_Shdr);
847 		link_elf_locate_exidx(lf, shdr, nhdr);
848 	}
849 }
850 
851 #endif /* __arm__ */
852 
853 static int
854 link_elf_link_preload(linker_class_t cls, const char *filename,
855     linker_file_t *result)
856 {
857 	Elf_Addr *ctors_addrp;
858 	Elf_Size *ctors_sizep;
859 	caddr_t modptr, baseptr, sizeptr, dynptr;
860 	char *type;
861 	elf_file_t ef;
862 	linker_file_t lf;
863 	int error;
864 	vm_offset_t dp;
865 
866 	/* Look to see if we have the file preloaded */
867 	modptr = preload_search_by_name(filename);
868 	if (modptr == NULL)
869 		return (ENOENT);
870 
871 	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
872 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
873 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
874 	dynptr = preload_search_info(modptr,
875 	    MODINFO_METADATA | MODINFOMD_DYNAMIC);
876 	if (type == NULL ||
877 	    (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
878 	     strcmp(type, "elf module") != 0))
879 		return (EFTYPE);
880 	if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
881 		return (EINVAL);
882 
883 	lf = linker_make_file(filename, &link_elf_class);
884 	if (lf == NULL)
885 		return (ENOMEM);
886 
887 	ef = (elf_file_t) lf;
888 	ef->preloaded = 1;
889 	ef->modptr = modptr;
890 	ef->address = *(caddr_t *)baseptr;
891 #ifdef SPARSE_MAPPING
892 	ef->object = NULL;
893 #endif
894 	dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
895 	ef->dynamic = (Elf_Dyn *)dp;
896 	lf->address = ef->address;
897 	lf->size = *(size_t *)sizeptr;
898 
899 	ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
900 	    MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
901 	ctors_sizep = (Elf_Size *)preload_search_info(modptr,
902 	    MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
903 	if (ctors_addrp != NULL && ctors_sizep != NULL) {
904 		lf->ctors_addr = ef->address + *ctors_addrp;
905 		lf->ctors_size = *ctors_sizep;
906 	}
907 
908 #ifdef __arm__
909 	link_elf_locate_exidx_preload(lf, modptr);
910 #endif
911 
912 	error = parse_dynamic(ef);
913 	if (error == 0)
914 		error = parse_dpcpu(ef);
915 #ifdef VIMAGE
916 	if (error == 0)
917 		error = parse_vnet(ef);
918 #endif
919 	if (error == 0)
920 		error = preload_protect(ef, VM_PROT_ALL);
921 	if (error != 0) {
922 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
923 		return (error);
924 	}
925 	link_elf_reloc_local(lf);
926 	*result = lf;
927 	return (0);
928 }
929 
930 static int
931 link_elf_link_preload_finish(linker_file_t lf)
932 {
933 	elf_file_t ef;
934 	int error;
935 
936 	ef = (elf_file_t) lf;
937 	error = relocate_file(ef);
938 	if (error == 0)
939 		error = preload_protect(ef, VM_PROT_NONE);
940 	if (error != 0)
941 		return (error);
942 	(void)link_elf_preload_parse_symbols(ef);
943 
944 	return (link_elf_link_common_finish(lf));
945 }
946 
947 static int
948 link_elf_load_file(linker_class_t cls, const char* filename,
949     linker_file_t* result)
950 {
951 	struct nameidata nd;
952 	struct thread* td = curthread;	/* XXX */
953 	Elf_Ehdr *hdr;
954 	caddr_t firstpage, segbase;
955 	int nbytes, i;
956 	Elf_Phdr *phdr;
957 	Elf_Phdr *phlimit;
958 	Elf_Phdr *segs[MAXSEGS];
959 	int nsegs;
960 	Elf_Phdr *phdyn;
961 	caddr_t mapbase;
962 	size_t mapsize;
963 	Elf_Addr base_vaddr;
964 	Elf_Addr base_vlimit;
965 	int error = 0;
966 	ssize_t resid;
967 	int flags;
968 	elf_file_t ef;
969 	linker_file_t lf;
970 	Elf_Shdr *shdr;
971 	int symtabindex;
972 	int symstrindex;
973 	int shstrindex;
974 	int symcnt;
975 	int strcnt;
976 	char *shstrs;
977 
978 	shdr = NULL;
979 	lf = NULL;
980 	shstrs = NULL;
981 
982 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename);
983 	flags = FREAD;
984 	error = vn_open(&nd, &flags, 0, NULL);
985 	if (error != 0)
986 		return (error);
987 	NDFREE_PNBUF(&nd);
988 	if (nd.ni_vp->v_type != VREG) {
989 		error = ENOEXEC;
990 		firstpage = NULL;
991 		goto out;
992 	}
993 #ifdef MAC
994 	error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
995 	if (error != 0) {
996 		firstpage = NULL;
997 		goto out;
998 	}
999 #endif
1000 
1001 	/*
1002 	 * Read the elf header from the file.
1003 	 */
1004 	firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
1005 	hdr = (Elf_Ehdr *)firstpage;
1006 	error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
1007 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1008 	    &resid, td);
1009 	nbytes = PAGE_SIZE - resid;
1010 	if (error != 0)
1011 		goto out;
1012 
1013 	if (!IS_ELF(*hdr)) {
1014 		error = ENOEXEC;
1015 		goto out;
1016 	}
1017 
1018 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
1019 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
1020 		link_elf_error(filename, "Unsupported file layout");
1021 		error = ENOEXEC;
1022 		goto out;
1023 	}
1024 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
1025 	    hdr->e_version != EV_CURRENT) {
1026 		link_elf_error(filename, "Unsupported file version");
1027 		error = ENOEXEC;
1028 		goto out;
1029 	}
1030 	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
1031 		error = ENOSYS;
1032 		goto out;
1033 	}
1034 	if (hdr->e_machine != ELF_TARG_MACH) {
1035 		link_elf_error(filename, "Unsupported machine");
1036 		error = ENOEXEC;
1037 		goto out;
1038 	}
1039 
1040 	/*
1041 	 * We rely on the program header being in the first page.
1042 	 * This is not strictly required by the ABI specification, but
1043 	 * it seems to always true in practice.  And, it simplifies
1044 	 * things considerably.
1045 	 */
1046 	if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
1047 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
1048 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
1049 		link_elf_error(filename, "Unreadable program headers");
1050 
1051 	/*
1052 	 * Scan the program header entries, and save key information.
1053 	 *
1054 	 * We rely on there being exactly two load segments, text and data,
1055 	 * in that order.
1056 	 */
1057 	phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
1058 	phlimit = phdr + hdr->e_phnum;
1059 	nsegs = 0;
1060 	phdyn = NULL;
1061 	while (phdr < phlimit) {
1062 		switch (phdr->p_type) {
1063 		case PT_LOAD:
1064 			if (nsegs == MAXSEGS) {
1065 				link_elf_error(filename, "Too many sections");
1066 				error = ENOEXEC;
1067 				goto out;
1068 			}
1069 			/*
1070 			 * XXX: We just trust they come in right order ??
1071 			 */
1072 			segs[nsegs] = phdr;
1073 			++nsegs;
1074 			break;
1075 
1076 		case PT_DYNAMIC:
1077 			phdyn = phdr;
1078 			break;
1079 
1080 		case PT_INTERP:
1081 			error = ENOSYS;
1082 			goto out;
1083 		}
1084 
1085 		++phdr;
1086 	}
1087 	if (phdyn == NULL) {
1088 		link_elf_error(filename, "Object is not dynamically-linked");
1089 		error = ENOEXEC;
1090 		goto out;
1091 	}
1092 	if (nsegs == 0) {
1093 		link_elf_error(filename, "No sections");
1094 		error = ENOEXEC;
1095 		goto out;
1096 	}
1097 
1098 	/*
1099 	 * Allocate the entire address space of the object, to stake
1100 	 * out our contiguous region, and to establish the base
1101 	 * address for relocation.
1102 	 */
1103 	base_vaddr = trunc_page(segs[0]->p_vaddr);
1104 	base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
1105 	    segs[nsegs - 1]->p_memsz);
1106 	mapsize = base_vlimit - base_vaddr;
1107 
1108 	lf = linker_make_file(filename, &link_elf_class);
1109 	if (lf == NULL) {
1110 		error = ENOMEM;
1111 		goto out;
1112 	}
1113 
1114 	ef = (elf_file_t) lf;
1115 #ifdef SPARSE_MAPPING
1116 	ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL,
1117 	    0, thread0.td_ucred);
1118 	if (ef->object == NULL) {
1119 		error = ENOMEM;
1120 		goto out;
1121 	}
1122 #ifdef __amd64__
1123 	mapbase = (caddr_t)KERNBASE;
1124 #else
1125 	mapbase = (caddr_t)vm_map_min(kernel_map);
1126 #endif
1127 	/*
1128 	 * Mapping protections are downgraded after relocation processing.
1129 	 */
1130 	error = vm_map_find(kernel_map, ef->object, 0,
1131 	    (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE,
1132 	    VM_PROT_ALL, VM_PROT_ALL, 0);
1133 	if (error != 0) {
1134 		vm_object_deallocate(ef->object);
1135 		ef->object = NULL;
1136 		goto out;
1137 	}
1138 #else
1139 	mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK);
1140 #endif
1141 	ef->address = mapbase;
1142 
1143 	/*
1144 	 * Read the text and data sections and zero the bss.
1145 	 */
1146 	for (i = 0; i < nsegs; i++) {
1147 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1148 
1149 #ifdef SPARSE_MAPPING
1150 		/*
1151 		 * Consecutive segments may have different mapping permissions,
1152 		 * so be strict and verify that their mappings do not overlap.
1153 		 */
1154 		if (((vm_offset_t)segbase & PAGE_MASK) != 0) {
1155 			error = EINVAL;
1156 			goto out;
1157 		}
1158 
1159 		error = vm_map_wire(kernel_map,
1160 		    (vm_offset_t)segbase,
1161 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1162 		    VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
1163 		if (error != KERN_SUCCESS) {
1164 			error = ENOMEM;
1165 			goto out;
1166 		}
1167 #endif
1168 
1169 		error = vn_rdwr(UIO_READ, nd.ni_vp,
1170 		    segbase, segs[i]->p_filesz, segs[i]->p_offset,
1171 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1172 		    &resid, td);
1173 		if (error != 0)
1174 			goto out;
1175 		bzero(segbase + segs[i]->p_filesz,
1176 		    segs[i]->p_memsz - segs[i]->p_filesz);
1177 	}
1178 
1179 	ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
1180 
1181 	lf->address = ef->address;
1182 	lf->size = mapsize;
1183 
1184 	error = parse_dynamic(ef);
1185 	if (error != 0)
1186 		goto out;
1187 	error = parse_dpcpu(ef);
1188 	if (error != 0)
1189 		goto out;
1190 #ifdef VIMAGE
1191 	error = parse_vnet(ef);
1192 	if (error != 0)
1193 		goto out;
1194 #endif
1195 	link_elf_reloc_local(lf);
1196 
1197 	VOP_UNLOCK(nd.ni_vp);
1198 	error = linker_load_dependencies(lf);
1199 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1200 	if (error != 0)
1201 		goto out;
1202 	error = relocate_file(ef);
1203 	if (error != 0)
1204 		goto out;
1205 
1206 #ifdef SPARSE_MAPPING
1207 	/*
1208 	 * Downgrade permissions on text segment mappings now that relocation
1209 	 * processing is complete.  Restrict permissions on read-only segments.
1210 	 */
1211 	for (i = 0; i < nsegs; i++) {
1212 		vm_prot_t prot;
1213 
1214 		if (segs[i]->p_type != PT_LOAD)
1215 			continue;
1216 
1217 		prot = VM_PROT_READ;
1218 		if ((segs[i]->p_flags & PF_W) != 0)
1219 			prot |= VM_PROT_WRITE;
1220 		if ((segs[i]->p_flags & PF_X) != 0)
1221 			prot |= VM_PROT_EXECUTE;
1222 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1223 		error = vm_map_protect(kernel_map,
1224 		    (vm_offset_t)segbase,
1225 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1226 		    prot, 0, VM_MAP_PROTECT_SET_PROT);
1227 		if (error != KERN_SUCCESS) {
1228 			error = ENOMEM;
1229 			goto out;
1230 		}
1231 	}
1232 #endif
1233 
1234 	/*
1235 	 * Try and load the symbol table if it's present.  (you can
1236 	 * strip it!)
1237 	 */
1238 	nbytes = hdr->e_shnum * hdr->e_shentsize;
1239 	if (nbytes == 0 || hdr->e_shoff == 0)
1240 		goto nosyms;
1241 	shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1242 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1243 	    (caddr_t)shdr, nbytes, hdr->e_shoff,
1244 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1245 	    &resid, td);
1246 	if (error != 0)
1247 		goto out;
1248 
1249 	/* Read section string table */
1250 	shstrindex = hdr->e_shstrndx;
1251 	if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB &&
1252 	    shdr[shstrindex].sh_size != 0) {
1253 		nbytes = shdr[shstrindex].sh_size;
1254 		shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1255 		error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes,
1256 		    shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
1257 		    td->td_ucred, NOCRED, &resid, td);
1258 		if (error)
1259 			goto out;
1260 	}
1261 
1262 	symtabindex = -1;
1263 	symstrindex = -1;
1264 	for (i = 0; i < hdr->e_shnum; i++) {
1265 		if (shdr[i].sh_type == SHT_SYMTAB) {
1266 			symtabindex = i;
1267 			symstrindex = shdr[i].sh_link;
1268 		} else if (shstrs != NULL && shdr[i].sh_name != 0 &&
1269 		    strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) {
1270 			/* Record relocated address and size of .ctors. */
1271 			lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr;
1272 			lf->ctors_size = shdr[i].sh_size;
1273 		}
1274 	}
1275 	if (symtabindex < 0 || symstrindex < 0)
1276 		goto nosyms;
1277 
1278 	symcnt = shdr[symtabindex].sh_size;
1279 	ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
1280 	strcnt = shdr[symstrindex].sh_size;
1281 	ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
1282 
1283 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1284 	    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
1285 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1286 	    &resid, td);
1287 	if (error != 0)
1288 		goto out;
1289 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1290 	    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
1291 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1292 	    &resid, td);
1293 	if (error != 0)
1294 		goto out;
1295 
1296 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
1297 	ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
1298 	ef->ddbstrcnt = strcnt;
1299 	ef->ddbstrtab = ef->strbase;
1300 
1301 nosyms:
1302 
1303 #ifdef __arm__
1304 	link_elf_locate_exidx(lf, shdr, hdr->e_shnum);
1305 #endif
1306 
1307 	error = link_elf_link_common_finish(lf);
1308 	if (error != 0)
1309 		goto out;
1310 
1311 	*result = lf;
1312 
1313 out:
1314 	VOP_UNLOCK(nd.ni_vp);
1315 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1316 	if (error != 0 && lf != NULL)
1317 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1318 	free(shdr, M_LINKER);
1319 	free(firstpage, M_LINKER);
1320 	free(shstrs, M_LINKER);
1321 
1322 	return (error);
1323 }
1324 
1325 Elf_Addr
1326 elf_relocaddr(linker_file_t lf, Elf_Addr x)
1327 {
1328 	elf_file_t ef;
1329 
1330 	KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class,
1331 	    ("elf_relocaddr: unexpected linker file %p", lf));
1332 
1333 	ef = (elf_file_t)lf;
1334 	if (x >= ef->pcpu_start && x < ef->pcpu_stop)
1335 		return ((x - ef->pcpu_start) + ef->pcpu_base);
1336 #ifdef VIMAGE
1337 	if (x >= ef->vnet_start && x < ef->vnet_stop)
1338 		return ((x - ef->vnet_start) + ef->vnet_base);
1339 #endif
1340 	return (x);
1341 }
1342 
1343 static void
1344 link_elf_unload_file(linker_file_t file)
1345 {
1346 	elf_file_t ef = (elf_file_t) file;
1347 
1348 	if (ef->pcpu_base != 0) {
1349 		dpcpu_free((void *)ef->pcpu_base,
1350 		    ef->pcpu_stop - ef->pcpu_start);
1351 		elf_set_delete(&set_pcpu_list, ef->pcpu_start);
1352 	}
1353 #ifdef VIMAGE
1354 	if (ef->vnet_base != 0) {
1355 		vnet_data_free((void *)ef->vnet_base,
1356 		    ef->vnet_stop - ef->vnet_start);
1357 		elf_set_delete(&set_vnet_list, ef->vnet_start);
1358 	}
1359 #endif
1360 #ifdef GDB
1361 	if (ef->gdb.l_ld != NULL) {
1362 		GDB_STATE(RT_DELETE);
1363 		free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1364 		link_elf_delete_gdb(&ef->gdb);
1365 		GDB_STATE(RT_CONSISTENT);
1366 	}
1367 #endif
1368 
1369 	/* Notify MD code that a module is being unloaded. */
1370 	elf_cpu_unload_file(file);
1371 
1372 	if (ef->preloaded) {
1373 		link_elf_unload_preload(file);
1374 		return;
1375 	}
1376 
1377 #ifdef SPARSE_MAPPING
1378 	if (ef->object != NULL) {
1379 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1380 		    (vm_offset_t) ef->address
1381 		    + (ef->object->size << PAGE_SHIFT));
1382 	}
1383 #else
1384 	free(ef->address, M_LINKER);
1385 #endif
1386 	free(ef->symbase, M_LINKER);
1387 	free(ef->strbase, M_LINKER);
1388 	free(ef->ctftab, M_LINKER);
1389 	free(ef->ctfoff, M_LINKER);
1390 	free(ef->typoff, M_LINKER);
1391 }
1392 
1393 static void
1394 link_elf_unload_preload(linker_file_t file)
1395 {
1396 
1397 	if (file->pathname != NULL)
1398 		preload_delete_name(file->pathname);
1399 }
1400 
1401 static const char *
1402 symbol_name(elf_file_t ef, Elf_Size r_info)
1403 {
1404 	const Elf_Sym *ref;
1405 
1406 	if (ELF_R_SYM(r_info)) {
1407 		ref = ef->symtab + ELF_R_SYM(r_info);
1408 		return (ef->strtab + ref->st_name);
1409 	}
1410 	return (NULL);
1411 }
1412 
1413 static int
1414 symbol_type(elf_file_t ef, Elf_Size r_info)
1415 {
1416 	const Elf_Sym *ref;
1417 
1418 	if (ELF_R_SYM(r_info)) {
1419 		ref = ef->symtab + ELF_R_SYM(r_info);
1420 		return (ELF_ST_TYPE(ref->st_info));
1421 	}
1422 	return (STT_NOTYPE);
1423 }
1424 
1425 static int
1426 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc,
1427     bool ifuncs)
1428 {
1429 	const Elf_Rel *rel;
1430 	const Elf_Rela *rela;
1431 	const char *symname;
1432 
1433 	TSENTER();
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 	TSENTER2("ef->rela");
1453 	APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA);
1454 	TSEXIT2("ef->rela");
1455 	APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL);
1456 	APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA);
1457 
1458 #undef APPLY_RELOCS
1459 
1460 	TSEXIT();
1461 	return (0);
1462 }
1463 
1464 static int
1465 relocate_file(elf_file_t ef)
1466 {
1467 	int error;
1468 
1469 	error = relocate_file1(ef, elf_lookup, elf_reloc, false);
1470 	if (error == 0)
1471 		error = relocate_file1(ef, elf_lookup, elf_reloc, true);
1472 	return (error);
1473 }
1474 
1475 /*
1476  * SysV hash function for symbol table lookup.  It is specified by the
1477  * System V ABI.
1478  */
1479 static Elf32_Word
1480 elf_hash(const char *name)
1481 {
1482 	const unsigned char *p = (const unsigned char *)name;
1483 	Elf32_Word h = 0;
1484 
1485 	while (*p != '\0') {
1486 		h = (h << 4) + *p++;
1487 		h ^= (h >> 24) & 0xf0;
1488 	}
1489 	return (h & 0x0fffffff);
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 	Elf32_Word 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 	TSENTER();
1957 	ef = &eff;
1958 
1959 	bzero_early(ef, sizeof(*ef));
1960 
1961 	ef->modptr = kmdp;
1962 	ef->dynamic = (Elf_Dyn *)&_DYNAMIC;
1963 
1964 #ifdef RELOCATABLE_KERNEL
1965 	ef->address = (caddr_t) (__startkernel - KERNBASE);
1966 #else
1967 	ef->address = 0;
1968 #endif
1969 	parse_dynamic(ef);
1970 
1971 	link_elf_preload_parse_symbols(ef);
1972 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true);
1973 	TSEXIT();
1974 }
1975 
1976 #if defined(__aarch64__) || defined(__amd64__)
1977 void
1978 link_elf_late_ireloc(void)
1979 {
1980 	elf_file_t ef;
1981 
1982 	KASSERT(linker_kernel_file != NULL,
1983 	    ("link_elf_late_ireloc: No kernel linker file found"));
1984 	ef = (elf_file_t)linker_kernel_file;
1985 
1986 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true);
1987 }
1988 #endif
1989 #endif
1990