xref: /freebsd/sys/kern/link_elf.c (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
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 "opt_ddb.h"
30 #include "opt_gdb.h"
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #ifdef SPARSE_MAPPING
38 #include <sys/mman.h>
39 #endif
40 #include <sys/mutex.h>
41 #include <sys/mount.h>
42 #include <sys/pcpu.h>
43 #include <sys/proc.h>
44 #include <sys/namei.h>
45 #include <sys/fcntl.h>
46 #include <sys/vnode.h>
47 #include <sys/linker.h>
48 #include <sys/sysctl.h>
49 #include <sys/tslog.h>
50 
51 #include <machine/elf.h>
52 
53 #include <net/vnet.h>
54 
55 #include <security/mac/mac_framework.h>
56 
57 #include <vm/vm.h>
58 #include <vm/vm_param.h>
59 #ifdef SPARSE_MAPPING
60 #include <vm/vm_object.h>
61 #include <vm/vm_kern.h>
62 #include <vm/vm_extern.h>
63 #endif
64 #include <vm/pmap.h>
65 #include <vm/vm_map.h>
66 
67 #include <sys/link_elf.h>
68 
69 #include "linker_if.h"
70 
71 #define MAXSEGS 4
72 
73 typedef struct elf_file {
74 	struct linker_file lf;		/* Common fields */
75 	int		preloaded;	/* Was file pre-loaded */
76 	caddr_t		address;	/* Relocation address */
77 #ifdef SPARSE_MAPPING
78 	vm_object_t	object;		/* VM object to hold file pages */
79 #endif
80 	Elf_Dyn		*dynamic;	/* Symbol table etc. */
81 	Elf_Hashelt	nbuckets;	/* DT_HASH info */
82 	Elf_Hashelt	nchains;
83 	const Elf_Hashelt *buckets;
84 	const Elf_Hashelt *chains;
85 	caddr_t		hash;
86 	caddr_t		strtab;		/* DT_STRTAB */
87 	int		strsz;		/* DT_STRSZ */
88 	const Elf_Sym	*symtab;		/* DT_SYMTAB */
89 	Elf_Addr	*got;		/* DT_PLTGOT */
90 	const Elf_Rel	*pltrel;	/* DT_JMPREL */
91 	int		pltrelsize;	/* DT_PLTRELSZ */
92 	const Elf_Rela	*pltrela;	/* DT_JMPREL */
93 	int		pltrelasize;	/* DT_PLTRELSZ */
94 	const Elf_Rel	*rel;		/* DT_REL */
95 	int		relsize;	/* DT_RELSZ */
96 	const Elf_Rela	*rela;		/* DT_RELA */
97 	int		relasize;	/* DT_RELASZ */
98 	caddr_t		modptr;
99 	const Elf_Sym	*ddbsymtab;	/* The symbol table we are using */
100 	long		ddbsymcnt;	/* Number of symbols */
101 	caddr_t		ddbstrtab;	/* String table */
102 	long		ddbstrcnt;	/* number of bytes in string table */
103 	caddr_t		symbase;	/* malloc'ed symbold base */
104 	caddr_t		strbase;	/* malloc'ed string base */
105 	caddr_t		ctftab;		/* CTF table */
106 	long		ctfcnt;		/* number of bytes in CTF table */
107 	caddr_t		ctfoff;		/* CTF offset table */
108 	caddr_t		typoff;		/* Type offset table */
109 	long		typlen;		/* Number of type entries. */
110 	Elf_Addr	pcpu_start;	/* Pre-relocation pcpu set start. */
111 	Elf_Addr	pcpu_stop;	/* Pre-relocation pcpu set stop. */
112 	Elf_Addr	pcpu_base;	/* Relocated pcpu set address. */
113 #ifdef VIMAGE
114 	Elf_Addr	vnet_start;	/* Pre-relocation vnet set start. */
115 	Elf_Addr	vnet_stop;	/* Pre-relocation vnet set stop. */
116 	Elf_Addr	vnet_base;	/* Relocated vnet set address. */
117 #endif
118 #ifdef GDB
119 	struct link_map	gdb;		/* hooks for gdb */
120 #endif
121 } *elf_file_t;
122 
123 struct elf_set {
124 	Elf_Addr	es_start;
125 	Elf_Addr	es_stop;
126 	Elf_Addr	es_base;
127 	TAILQ_ENTRY(elf_set)	es_link;
128 };
129 
130 TAILQ_HEAD(elf_set_head, elf_set);
131 
132 #include <kern/kern_ctf.c>
133 
134 static int	link_elf_link_common_finish(linker_file_t);
135 static int	link_elf_link_preload(linker_class_t cls,
136 				      const char *, linker_file_t *);
137 static int	link_elf_link_preload_finish(linker_file_t);
138 static int	link_elf_load_file(linker_class_t, const char *,
139 		    linker_file_t *);
140 static int	link_elf_lookup_symbol(linker_file_t, const char *,
141 		    c_linker_sym_t *);
142 static int	link_elf_lookup_debug_symbol(linker_file_t, const char *,
143 		    c_linker_sym_t *);
144 static int	link_elf_symbol_values(linker_file_t, c_linker_sym_t,
145 		    linker_symval_t *);
146 static int	link_elf_debug_symbol_values(linker_file_t, c_linker_sym_t,
147 		    linker_symval_t*);
148 static int	link_elf_search_symbol(linker_file_t, caddr_t,
149 		    c_linker_sym_t *, long *);
150 
151 static void	link_elf_unload_file(linker_file_t);
152 static void	link_elf_unload_preload(linker_file_t);
153 static int	link_elf_lookup_set(linker_file_t, const char *,
154 		    void ***, void ***, int *);
155 static int	link_elf_each_function_name(linker_file_t,
156 		    int (*)(const char *, void *), void *);
157 static int	link_elf_each_function_nameval(linker_file_t,
158 		    linker_function_nameval_callback_t, void *);
159 static void	link_elf_reloc_local(linker_file_t);
160 static long	link_elf_symtab_get(linker_file_t, const Elf_Sym **);
161 static long	link_elf_strtab_get(linker_file_t, caddr_t *);
162 #ifdef VIMAGE
163 static void	link_elf_propagate_vnets(linker_file_t);
164 #endif
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 #ifdef VIMAGE
184 	KOBJMETHOD(linker_propagate_vnets,	link_elf_propagate_vnets),
185 #endif
186 	KOBJMETHOD_END
187 };
188 
189 static struct linker_class link_elf_class = {
190 #if ELF_TARG_CLASS == ELFCLASS32
191 	"elf32",
192 #else
193 	"elf64",
194 #endif
195 	link_elf_methods, sizeof(struct elf_file)
196 };
197 
198 static bool link_elf_leak_locals = true;
199 SYSCTL_BOOL(_debug, OID_AUTO, link_elf_leak_locals,
200     CTLFLAG_RWTUN, &link_elf_leak_locals, 0,
201     "Allow local symbols to participate in global module symbol resolution");
202 
203 typedef int (*elf_reloc_fn)(linker_file_t lf, Elf_Addr relocbase,
204     const void *data, int type, elf_lookup_fn lookup);
205 
206 static int	parse_dynamic(elf_file_t);
207 static int	relocate_file(elf_file_t);
208 static int	relocate_file1(elf_file_t ef, elf_lookup_fn lookup,
209 		    elf_reloc_fn reloc, bool ifuncs);
210 static int	link_elf_preload_parse_symbols(elf_file_t);
211 
212 static struct elf_set_head set_pcpu_list;
213 #ifdef VIMAGE
214 static struct elf_set_head set_vnet_list;
215 #endif
216 
217 static void
218 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
219 {
220 	struct elf_set *set, *iter;
221 
222 	set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
223 	set->es_start = start;
224 	set->es_stop = stop;
225 	set->es_base = base;
226 
227 	TAILQ_FOREACH(iter, list, es_link) {
228 		KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
229 		    (set->es_start > iter->es_start && set->es_stop > iter->es_stop),
230 		    ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
231 		    (uintmax_t)set->es_start, (uintmax_t)set->es_stop,
232 		    (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
233 
234 		if (iter->es_start > set->es_start) {
235 			TAILQ_INSERT_BEFORE(iter, set, es_link);
236 			break;
237 		}
238 	}
239 
240 	if (iter == NULL)
241 		TAILQ_INSERT_TAIL(list, set, es_link);
242 }
243 
244 static int
245 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
246 {
247 	struct elf_set *set;
248 
249 	TAILQ_FOREACH(set, list, es_link) {
250 		if (addr < set->es_start)
251 			return (0);
252 		if (addr < set->es_stop) {
253 			*start = set->es_start;
254 			*base = set->es_base;
255 			return (1);
256 		}
257 	}
258 
259 	return (0);
260 }
261 
262 static void
263 elf_set_delete(struct elf_set_head *list, Elf_Addr start)
264 {
265 	struct elf_set *set;
266 
267 	TAILQ_FOREACH(set, list, es_link) {
268 		if (start < set->es_start)
269 			break;
270 		if (start == set->es_start) {
271 			TAILQ_REMOVE(list, set, es_link);
272 			free(set, M_LINKER);
273 			return;
274 		}
275 	}
276 	KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
277 	    (uintmax_t)start));
278 }
279 
280 #ifdef GDB
281 static void	r_debug_state(struct r_debug *, struct link_map *);
282 
283 /*
284  * A list of loaded modules for GDB to use for loading symbols.
285  */
286 struct r_debug r_debug;
287 
288 #define GDB_STATE(s) do {				\
289 	r_debug.r_state = s; r_debug_state(NULL, NULL);	\
290 } while (0)
291 
292 /*
293  * Function for the debugger to set a breakpoint on to gain control.
294  */
295 static void
296 r_debug_state(struct r_debug *dummy_one __unused,
297 	      struct link_map *dummy_two __unused)
298 {
299 }
300 
301 static void
302 link_elf_add_gdb(struct link_map *l)
303 {
304 	struct link_map *prev;
305 
306 	l->l_next = NULL;
307 
308 	if (r_debug.r_map == NULL) {
309 		/* Add first. */
310 		l->l_prev = NULL;
311 		r_debug.r_map = l;
312 	} else {
313 		/* Append to list. */
314 		for (prev = r_debug.r_map;
315 		    prev->l_next != NULL;
316 		    prev = prev->l_next)
317 			;
318 		l->l_prev = prev;
319 		prev->l_next = l;
320 	}
321 }
322 
323 static void
324 link_elf_delete_gdb(struct link_map *l)
325 {
326 	if (l->l_prev == NULL) {
327 		/* Remove first. */
328 		if ((r_debug.r_map = l->l_next) != NULL)
329 			l->l_next->l_prev = NULL;
330 	} else {
331 		/* Remove any but first. */
332 		if ((l->l_prev->l_next = l->l_next) != NULL)
333 			l->l_next->l_prev = l->l_prev;
334 	}
335 }
336 #endif /* GDB */
337 
338 /*
339  * The kernel symbol table starts here.
340  */
341 extern struct _dynamic _DYNAMIC;
342 
343 static void
344 link_elf_error(const char *filename, const char *s)
345 {
346 	if (filename == NULL)
347 		printf("kldload: %s\n", s);
348 	else
349 		printf("kldload: %s: %s\n", filename, s);
350 }
351 
352 static void
353 link_elf_invoke_ctors(caddr_t addr, size_t size)
354 {
355 	void (**ctor)(void);
356 	size_t i, cnt;
357 
358 	if (addr == NULL || size == 0)
359 		return;
360 	cnt = size / sizeof(*ctor);
361 	ctor = (void *)addr;
362 	for (i = 0; i < cnt; i++) {
363 		if (ctor[i] != NULL)
364 			(*ctor[i])();
365 	}
366 }
367 
368 /*
369  * Actions performed after linking/loading both the preloaded kernel and any
370  * modules; whether preloaded or dynamicly loaded.
371  */
372 static int
373 link_elf_link_common_finish(linker_file_t lf)
374 {
375 #ifdef GDB
376 	elf_file_t ef = (elf_file_t)lf;
377 	char *newfilename;
378 #endif
379 	int error;
380 
381 	/* Notify MD code that a module is being loaded. */
382 	error = elf_cpu_load_file(lf);
383 	if (error != 0)
384 		return (error);
385 
386 #ifdef GDB
387 	GDB_STATE(RT_ADD);
388 	ef->gdb.l_addr = lf->address;
389 	newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
390 	strcpy(newfilename, lf->filename);
391 	ef->gdb.l_name = newfilename;
392 	ef->gdb.l_ld = ef->dynamic;
393 	link_elf_add_gdb(&ef->gdb);
394 	GDB_STATE(RT_CONSISTENT);
395 #endif
396 
397 	/* Invoke .ctors */
398 	link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
399 	return (0);
400 }
401 
402 #ifdef RELOCATABLE_KERNEL
403 /*
404  * __startkernel and __endkernel are symbols set up as relocation canaries.
405  *
406  * They are defined in locore to reference linker script symbols at the
407  * beginning and end of the LOAD area. This has the desired side effect of
408  * giving us variables that have relative relocations pointing at them, so
409  * relocation of the kernel object will cause the variables to be updated
410  * automatically by the runtime linker when we initialize.
411  *
412  * There are two main reasons to relocate the kernel:
413  * 1) If the loader needed to load the kernel at an alternate load address.
414  * 2) If the kernel is switching address spaces on machines like POWER9
415  *    under Radix where the high bits of the effective address are used to
416  *    differentiate between hypervisor, host, guest, and problem state.
417  */
418 extern vm_offset_t __startkernel, __endkernel;
419 #endif
420 
421 static unsigned long kern_relbase = KERNBASE;
422 
423 SYSCTL_ULONG(_kern, OID_AUTO, base_address, CTLFLAG_RD,
424 	SYSCTL_NULL_ULONG_PTR, KERNBASE, "Kernel base address");
425 SYSCTL_ULONG(_kern, OID_AUTO, relbase_address, CTLFLAG_RD,
426 	&kern_relbase, 0, "Kernel relocated base address");
427 
428 static void
429 link_elf_init(void* arg)
430 {
431 	Elf_Dyn *dp;
432 	Elf_Addr *ctors_addrp;
433 	Elf_Size *ctors_sizep;
434 	caddr_t modptr, baseptr, sizeptr;
435 	elf_file_t ef;
436 	const char *modname;
437 
438 	linker_add_class(&link_elf_class);
439 
440 	dp = (Elf_Dyn *)&_DYNAMIC;
441 	modname = NULL;
442 	modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
443 	if (modptr == NULL)
444 		modptr = preload_search_by_type("elf kernel");
445 	modname = (char *)preload_search_info(modptr, MODINFO_NAME);
446 	if (modname == NULL)
447 		modname = "kernel";
448 	linker_kernel_file = linker_make_file(modname, &link_elf_class);
449 	if (linker_kernel_file == NULL)
450 		panic("%s: Can't create linker structures for kernel",
451 		    __func__);
452 
453 	ef = (elf_file_t) linker_kernel_file;
454 	ef->preloaded = 1;
455 #ifdef RELOCATABLE_KERNEL
456 	/* Compute relative displacement */
457 	ef->address = (caddr_t) (__startkernel - KERNBASE);
458 #else
459 	ef->address = 0;
460 #endif
461 #ifdef SPARSE_MAPPING
462 	ef->object = NULL;
463 #endif
464 	ef->dynamic = dp;
465 
466 	if (dp != NULL)
467 		parse_dynamic(ef);
468 #ifdef RELOCATABLE_KERNEL
469 	linker_kernel_file->address = (caddr_t)__startkernel;
470 	linker_kernel_file->size = (intptr_t)(__endkernel - __startkernel);
471 	kern_relbase = (unsigned long)__startkernel;
472 #else
473 	linker_kernel_file->address += KERNBASE;
474 	linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
475 #endif
476 
477 	if (modptr != NULL) {
478 		ef->modptr = modptr;
479 		baseptr = preload_search_info(modptr, MODINFO_ADDR);
480 		if (baseptr != NULL)
481 			linker_kernel_file->address = *(caddr_t *)baseptr;
482 		sizeptr = preload_search_info(modptr, MODINFO_SIZE);
483 		if (sizeptr != NULL)
484 			linker_kernel_file->size = *(size_t *)sizeptr;
485 		ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
486 			MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
487 		ctors_sizep = (Elf_Size *)preload_search_info(modptr,
488 			MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
489 		if (ctors_addrp != NULL && ctors_sizep != NULL) {
490 			linker_kernel_file->ctors_addr = ef->address +
491 			    *ctors_addrp;
492 			linker_kernel_file->ctors_size = *ctors_sizep;
493 		}
494 	}
495 	(void)link_elf_preload_parse_symbols(ef);
496 
497 #ifdef GDB
498 	r_debug.r_map = NULL;
499 	r_debug.r_brk = r_debug_state;
500 	r_debug.r_state = RT_CONSISTENT;
501 #endif
502 
503 	(void)link_elf_link_common_finish(linker_kernel_file);
504 	linker_kernel_file->flags |= LINKER_FILE_LINKED;
505 	TAILQ_INIT(&set_pcpu_list);
506 #ifdef VIMAGE
507 	TAILQ_INIT(&set_vnet_list);
508 	vnet_save_init((void *)VNET_START, VNET_STOP - VNET_START);
509 #endif
510 }
511 
512 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, NULL);
513 
514 static int
515 link_elf_preload_parse_symbols(elf_file_t ef)
516 {
517 	caddr_t pointer;
518 	caddr_t ssym, esym, base;
519 	caddr_t strtab;
520 	int strcnt;
521 	Elf_Sym *symtab;
522 	int symcnt;
523 
524 	if (ef->modptr == NULL)
525 		return (0);
526 	pointer = preload_search_info(ef->modptr,
527 	    MODINFO_METADATA | MODINFOMD_SSYM);
528 	if (pointer == NULL)
529 		return (0);
530 	ssym = *(caddr_t *)pointer;
531 	pointer = preload_search_info(ef->modptr,
532 	    MODINFO_METADATA | MODINFOMD_ESYM);
533 	if (pointer == NULL)
534 		return (0);
535 	esym = *(caddr_t *)pointer;
536 
537 	base = ssym;
538 
539 	symcnt = *(long *)base;
540 	base += sizeof(long);
541 	symtab = (Elf_Sym *)base;
542 	base += roundup(symcnt, sizeof(long));
543 
544 	if (base > esym || base < ssym) {
545 		printf("Symbols are corrupt!\n");
546 		return (EINVAL);
547 	}
548 
549 	strcnt = *(long *)base;
550 	base += sizeof(long);
551 	strtab = base;
552 	base += roundup(strcnt, sizeof(long));
553 
554 	if (base > esym || base < ssym) {
555 		printf("Symbols are corrupt!\n");
556 		return (EINVAL);
557 	}
558 
559 	ef->ddbsymtab = symtab;
560 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
561 	ef->ddbstrtab = strtab;
562 	ef->ddbstrcnt = strcnt;
563 
564 	return (0);
565 }
566 
567 static int
568 parse_dynamic(elf_file_t ef)
569 {
570 	Elf_Dyn *dp;
571 	int plttype = DT_REL;
572 
573 	for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
574 		switch (dp->d_tag) {
575 		case DT_HASH:
576 		{
577 			/* From src/libexec/rtld-elf/rtld.c */
578 			const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
579 			    (ef->address + dp->d_un.d_ptr);
580 			ef->nbuckets = hashtab[0];
581 			ef->nchains = hashtab[1];
582 			ef->buckets = hashtab + 2;
583 			ef->chains = ef->buckets + ef->nbuckets;
584 			break;
585 		}
586 		case DT_STRTAB:
587 			ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
588 			break;
589 		case DT_STRSZ:
590 			ef->strsz = dp->d_un.d_val;
591 			break;
592 		case DT_SYMTAB:
593 			ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
594 			break;
595 		case DT_SYMENT:
596 			if (dp->d_un.d_val != sizeof(Elf_Sym))
597 				return (ENOEXEC);
598 			break;
599 		case DT_PLTGOT:
600 			ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
601 			break;
602 		case DT_REL:
603 			ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
604 			break;
605 		case DT_RELSZ:
606 			ef->relsize = dp->d_un.d_val;
607 			break;
608 		case DT_RELENT:
609 			if (dp->d_un.d_val != sizeof(Elf_Rel))
610 				return (ENOEXEC);
611 			break;
612 		case DT_JMPREL:
613 			ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
614 			break;
615 		case DT_PLTRELSZ:
616 			ef->pltrelsize = dp->d_un.d_val;
617 			break;
618 		case DT_RELA:
619 			ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
620 			break;
621 		case DT_RELASZ:
622 			ef->relasize = dp->d_un.d_val;
623 			break;
624 		case DT_RELAENT:
625 			if (dp->d_un.d_val != sizeof(Elf_Rela))
626 				return (ENOEXEC);
627 			break;
628 		case DT_PLTREL:
629 			plttype = dp->d_un.d_val;
630 			if (plttype != DT_REL && plttype != DT_RELA)
631 				return (ENOEXEC);
632 			break;
633 #ifdef GDB
634 		case DT_DEBUG:
635 			dp->d_un.d_ptr = (Elf_Addr)&r_debug;
636 			break;
637 #endif
638 		}
639 	}
640 
641 	if (plttype == DT_RELA) {
642 		ef->pltrela = (const Elf_Rela *)ef->pltrel;
643 		ef->pltrel = NULL;
644 		ef->pltrelasize = ef->pltrelsize;
645 		ef->pltrelsize = 0;
646 	}
647 
648 	ef->ddbsymtab = ef->symtab;
649 	ef->ddbsymcnt = ef->nchains;
650 	ef->ddbstrtab = ef->strtab;
651 	ef->ddbstrcnt = ef->strsz;
652 
653 	return elf_cpu_parse_dynamic(ef->address, ef->dynamic);
654 }
655 
656 #define	LS_PADDING	0x90909090
657 static int
658 parse_dpcpu(elf_file_t ef)
659 {
660 	int error, size;
661 #if defined(__i386__)
662 	uint32_t pad;
663 #endif
664 
665 	ef->pcpu_start = 0;
666 	ef->pcpu_stop = 0;
667 	error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
668 	    (void ***)&ef->pcpu_stop, NULL);
669 	/* Error just means there is no pcpu set to relocate. */
670 	if (error != 0)
671 		return (0);
672 	size = (uintptr_t)ef->pcpu_stop - (uintptr_t)ef->pcpu_start;
673 	/* Empty set? */
674 	if (size < 1)
675 		return (0);
676 #if defined(__i386__)
677 	/* In case we do find __start/stop_set_ symbols double-check. */
678 	if (size < 4) {
679 		uprintf("Kernel module '%s' must be recompiled with "
680 		    "linker script\n", ef->lf.pathname);
681 		return (ENOEXEC);
682 	}
683 
684 	/* Padding from linker-script correct? */
685 	pad = *(uint32_t *)((uintptr_t)ef->pcpu_stop - sizeof(pad));
686 	if (pad != LS_PADDING) {
687 		uprintf("Kernel module '%s' must be recompiled with "
688 		    "linker script, invalid padding %#04x (%#04x)\n",
689 		    ef->lf.pathname, pad, LS_PADDING);
690 		return (ENOEXEC);
691 	}
692 	/* If we only have valid padding, nothing to do. */
693 	if (size == 4)
694 		return (0);
695 #endif
696 	/*
697 	 * Allocate space in the primary pcpu area.  Copy in our
698 	 * initialization from the data section and then initialize
699 	 * all per-cpu storage from that.
700 	 */
701 	ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(size);
702 	if (ef->pcpu_base == 0) {
703 		printf("%s: pcpu module space is out of space; "
704 		    "cannot allocate %d for %s\n",
705 		    __func__, size, ef->lf.pathname);
706 		return (ENOSPC);
707 	}
708 	memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, size);
709 	dpcpu_copy((void *)ef->pcpu_base, size);
710 	elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
711 	    ef->pcpu_base);
712 
713 	return (0);
714 }
715 
716 #ifdef VIMAGE
717 static int
718 parse_vnet(elf_file_t ef)
719 {
720 	int error, size;
721 #if defined(__i386__)
722 	uint32_t pad;
723 #endif
724 
725 	ef->vnet_start = 0;
726 	ef->vnet_stop = 0;
727 	ef->vnet_base = 0;
728 	error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
729 	    (void ***)&ef->vnet_stop, NULL);
730 	/* Error just means there is no vnet data set to relocate. */
731 	if (error != 0)
732 		return (0);
733 	size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
734 	/* Empty set? */
735 	if (size < 1)
736 		return (0);
737 #if defined(__i386__)
738 	/* In case we do find __start/stop_set_ symbols double-check. */
739 	if (size < 4) {
740 		uprintf("Kernel module '%s' must be recompiled with "
741 		    "linker script\n", ef->lf.pathname);
742 		return (ENOEXEC);
743 	}
744 
745 	/* Padding from linker-script correct? */
746 	pad = *(uint32_t *)((uintptr_t)ef->vnet_stop - sizeof(pad));
747 	if (pad != LS_PADDING) {
748 		uprintf("Kernel module '%s' must be recompiled with "
749 		    "linker script, invalid padding %#04x (%#04x)\n",
750 		    ef->lf.pathname, pad, LS_PADDING);
751 		return (ENOEXEC);
752 	}
753 	/* If we only have valid padding, nothing to do. */
754 	if (size == 4)
755 		return (0);
756 #endif
757 	/*
758 	 * Allocate space in the primary vnet area.  Copy in our
759 	 * initialization from the data section and then initialize
760 	 * all per-vnet storage from that.
761 	 */
762 	ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(size);
763 	if (ef->vnet_base == 0) {
764 		printf("%s: vnet module space is out of space; "
765 		    "cannot allocate %d for %s\n",
766 		    __func__, size, ef->lf.pathname);
767 		return (ENOSPC);
768 	}
769 	memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, size);
770 	vnet_save_init((void *)ef->vnet_base, size);
771 	elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
772 	    ef->vnet_base);
773 
774 	return (0);
775 }
776 #endif
777 #undef LS_PADDING
778 
779 /*
780  * Apply the specified protection to the loadable segments of a preloaded linker
781  * file.
782  */
783 static int
784 preload_protect(elf_file_t ef, vm_prot_t prot)
785 {
786 #if defined(__aarch64__) || defined(__amd64__)
787 	Elf_Ehdr *hdr;
788 	Elf_Phdr *phdr, *phlimit;
789 	vm_prot_t nprot;
790 	int error;
791 
792 	error = 0;
793 	hdr = (Elf_Ehdr *)ef->address;
794 	phdr = (Elf_Phdr *)(ef->address + hdr->e_phoff);
795 	phlimit = phdr + hdr->e_phnum;
796 	for (; phdr < phlimit; phdr++) {
797 		if (phdr->p_type != PT_LOAD)
798 			continue;
799 
800 		nprot = prot | VM_PROT_READ;
801 		if ((phdr->p_flags & PF_W) != 0)
802 			nprot |= VM_PROT_WRITE;
803 		if ((phdr->p_flags & PF_X) != 0)
804 			nprot |= VM_PROT_EXECUTE;
805 		error = pmap_change_prot((vm_offset_t)ef->address +
806 		    phdr->p_vaddr, round_page(phdr->p_memsz), nprot);
807 		if (error != 0)
808 			break;
809 	}
810 	return (error);
811 #else
812 	return (0);
813 #endif
814 }
815 
816 #ifdef __arm__
817 /*
818  * Locate the ARM exception/unwind table info for DDB and stack(9) use by
819  * searching for the section header that describes it.  There may be no unwind
820  * info, for example in a module containing only data.
821  */
822 static void
823 link_elf_locate_exidx(linker_file_t lf, Elf_Shdr *shdr, int nhdr)
824 {
825 	int i;
826 
827 	for (i = 0; i < nhdr; i++) {
828 		if (shdr[i].sh_type == SHT_ARM_EXIDX) {
829 			lf->exidx_addr = shdr[i].sh_addr + lf->address;
830 			lf->exidx_size = shdr[i].sh_size;
831 			break;
832 		}
833 	}
834 }
835 
836 /*
837  * Locate the section headers metadata in a preloaded module, then use it to
838  * locate the exception/unwind table in the module.  The size of the metadata
839  * block is stored in a uint32 word immediately before the data itself, and a
840  * comment in preload_search_info() says it is safe to rely on that.
841  */
842 static void
843 link_elf_locate_exidx_preload(struct linker_file *lf, caddr_t modptr)
844 {
845 	uint32_t *modinfo;
846 	Elf_Shdr *shdr;
847 	uint32_t  nhdr;
848 
849 	modinfo = (uint32_t *)preload_search_info(modptr,
850 	    MODINFO_METADATA | MODINFOMD_SHDR);
851 	if (modinfo != NULL) {
852 		shdr = (Elf_Shdr *)modinfo;
853 		nhdr = modinfo[-1] / sizeof(Elf_Shdr);
854 		link_elf_locate_exidx(lf, shdr, nhdr);
855 	}
856 }
857 
858 #endif /* __arm__ */
859 
860 static int
861 link_elf_link_preload(linker_class_t cls, const char *filename,
862     linker_file_t *result)
863 {
864 	Elf_Addr *ctors_addrp;
865 	Elf_Size *ctors_sizep;
866 	caddr_t modptr, baseptr, sizeptr, dynptr;
867 	char *type;
868 	elf_file_t ef;
869 	linker_file_t lf;
870 	int error;
871 	vm_offset_t dp;
872 
873 	/* Look to see if we have the file preloaded */
874 	modptr = preload_search_by_name(filename);
875 	if (modptr == NULL)
876 		return (ENOENT);
877 
878 	type = (char *)preload_search_info(modptr, MODINFO_TYPE);
879 	baseptr = preload_search_info(modptr, MODINFO_ADDR);
880 	sizeptr = preload_search_info(modptr, MODINFO_SIZE);
881 	dynptr = preload_search_info(modptr,
882 	    MODINFO_METADATA | MODINFOMD_DYNAMIC);
883 	if (type == NULL ||
884 	    (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
885 	     strcmp(type, "elf module") != 0))
886 		return (EFTYPE);
887 	if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
888 		return (EINVAL);
889 
890 	lf = linker_make_file(filename, &link_elf_class);
891 	if (lf == NULL)
892 		return (ENOMEM);
893 
894 	ef = (elf_file_t) lf;
895 	ef->preloaded = 1;
896 	ef->modptr = modptr;
897 	ef->address = *(caddr_t *)baseptr;
898 #ifdef SPARSE_MAPPING
899 	ef->object = NULL;
900 #endif
901 	dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
902 	ef->dynamic = (Elf_Dyn *)dp;
903 	lf->address = ef->address;
904 	lf->size = *(size_t *)sizeptr;
905 
906 	ctors_addrp = (Elf_Addr *)preload_search_info(modptr,
907 	    MODINFO_METADATA | MODINFOMD_CTORS_ADDR);
908 	ctors_sizep = (Elf_Size *)preload_search_info(modptr,
909 	    MODINFO_METADATA | MODINFOMD_CTORS_SIZE);
910 	if (ctors_addrp != NULL && ctors_sizep != NULL) {
911 		lf->ctors_addr = ef->address + *ctors_addrp;
912 		lf->ctors_size = *ctors_sizep;
913 	}
914 
915 #ifdef __arm__
916 	link_elf_locate_exidx_preload(lf, modptr);
917 #endif
918 
919 	error = parse_dynamic(ef);
920 	if (error == 0)
921 		error = parse_dpcpu(ef);
922 #ifdef VIMAGE
923 	if (error == 0)
924 		error = parse_vnet(ef);
925 #endif
926 	if (error == 0)
927 		error = preload_protect(ef, VM_PROT_ALL);
928 	if (error != 0) {
929 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
930 		return (error);
931 	}
932 	link_elf_reloc_local(lf);
933 	*result = lf;
934 	return (0);
935 }
936 
937 static int
938 link_elf_link_preload_finish(linker_file_t lf)
939 {
940 	elf_file_t ef;
941 	int error;
942 
943 	ef = (elf_file_t) lf;
944 	error = relocate_file(ef);
945 	if (error == 0)
946 		error = preload_protect(ef, VM_PROT_NONE);
947 	if (error != 0)
948 		return (error);
949 	(void)link_elf_preload_parse_symbols(ef);
950 
951 	return (link_elf_link_common_finish(lf));
952 }
953 
954 static int
955 link_elf_load_file(linker_class_t cls, const char* filename,
956     linker_file_t* result)
957 {
958 	struct nameidata nd;
959 	struct thread* td = curthread;	/* XXX */
960 	Elf_Ehdr *hdr;
961 	caddr_t firstpage, segbase;
962 	int nbytes, i;
963 	Elf_Phdr *phdr;
964 	Elf_Phdr *phlimit;
965 	Elf_Phdr *segs[MAXSEGS];
966 	int nsegs;
967 	Elf_Phdr *phdyn;
968 	caddr_t mapbase;
969 	size_t mapsize;
970 	Elf_Addr base_vaddr;
971 	Elf_Addr base_vlimit;
972 	int error = 0;
973 	ssize_t resid;
974 	int flags;
975 	elf_file_t ef;
976 	linker_file_t lf;
977 	Elf_Shdr *shdr;
978 	int symtabindex;
979 	int symstrindex;
980 	int shstrindex;
981 	int symcnt;
982 	int strcnt;
983 	char *shstrs;
984 
985 	shdr = NULL;
986 	lf = NULL;
987 	shstrs = NULL;
988 
989 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename);
990 	flags = FREAD;
991 	error = vn_open(&nd, &flags, 0, NULL);
992 	if (error != 0)
993 		return (error);
994 	NDFREE_PNBUF(&nd);
995 	if (nd.ni_vp->v_type != VREG) {
996 		error = ENOEXEC;
997 		firstpage = NULL;
998 		goto out;
999 	}
1000 #ifdef MAC
1001 	error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
1002 	if (error != 0) {
1003 		firstpage = NULL;
1004 		goto out;
1005 	}
1006 #endif
1007 
1008 	/*
1009 	 * Read the elf header from the file.
1010 	 */
1011 	firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
1012 	hdr = (Elf_Ehdr *)firstpage;
1013 	error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
1014 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1015 	    &resid, td);
1016 	nbytes = PAGE_SIZE - resid;
1017 	if (error != 0)
1018 		goto out;
1019 
1020 	if (!IS_ELF(*hdr)) {
1021 		error = ENOEXEC;
1022 		goto out;
1023 	}
1024 
1025 	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
1026 	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
1027 		link_elf_error(filename, "Unsupported file layout");
1028 		error = ENOEXEC;
1029 		goto out;
1030 	}
1031 	if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
1032 	    hdr->e_version != EV_CURRENT) {
1033 		link_elf_error(filename, "Unsupported file version");
1034 		error = ENOEXEC;
1035 		goto out;
1036 	}
1037 	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
1038 		error = ENOSYS;
1039 		goto out;
1040 	}
1041 	if (hdr->e_machine != ELF_TARG_MACH) {
1042 		link_elf_error(filename, "Unsupported machine");
1043 		error = ENOEXEC;
1044 		goto out;
1045 	}
1046 
1047 	/*
1048 	 * We rely on the program header being in the first page.
1049 	 * This is not strictly required by the ABI specification, but
1050 	 * it seems to always true in practice.  And, it simplifies
1051 	 * things considerably.
1052 	 */
1053 	if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
1054 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
1055 	      (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
1056 		link_elf_error(filename, "Unreadable program headers");
1057 
1058 	/*
1059 	 * Scan the program header entries, and save key information.
1060 	 *
1061 	 * We rely on there being exactly two load segments, text and data,
1062 	 * in that order.
1063 	 */
1064 	phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
1065 	phlimit = phdr + hdr->e_phnum;
1066 	nsegs = 0;
1067 	phdyn = NULL;
1068 	while (phdr < phlimit) {
1069 		switch (phdr->p_type) {
1070 		case PT_LOAD:
1071 			if (nsegs == MAXSEGS) {
1072 				link_elf_error(filename, "Too many sections");
1073 				error = ENOEXEC;
1074 				goto out;
1075 			}
1076 			/*
1077 			 * XXX: We just trust they come in right order ??
1078 			 */
1079 			segs[nsegs] = phdr;
1080 			++nsegs;
1081 			break;
1082 
1083 		case PT_DYNAMIC:
1084 			phdyn = phdr;
1085 			break;
1086 
1087 		case PT_INTERP:
1088 			error = ENOSYS;
1089 			goto out;
1090 		}
1091 
1092 		++phdr;
1093 	}
1094 	if (phdyn == NULL) {
1095 		link_elf_error(filename, "Object is not dynamically-linked");
1096 		error = ENOEXEC;
1097 		goto out;
1098 	}
1099 	if (nsegs == 0) {
1100 		link_elf_error(filename, "No sections");
1101 		error = ENOEXEC;
1102 		goto out;
1103 	}
1104 
1105 	/*
1106 	 * Allocate the entire address space of the object, to stake
1107 	 * out our contiguous region, and to establish the base
1108 	 * address for relocation.
1109 	 */
1110 	base_vaddr = trunc_page(segs[0]->p_vaddr);
1111 	base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
1112 	    segs[nsegs - 1]->p_memsz);
1113 	mapsize = base_vlimit - base_vaddr;
1114 
1115 	lf = linker_make_file(filename, &link_elf_class);
1116 	if (lf == NULL) {
1117 		error = ENOMEM;
1118 		goto out;
1119 	}
1120 
1121 	ef = (elf_file_t) lf;
1122 #ifdef SPARSE_MAPPING
1123 	ef->object = vm_pager_allocate(OBJT_PHYS, NULL, mapsize, VM_PROT_ALL,
1124 	    0, thread0.td_ucred);
1125 	if (ef->object == NULL) {
1126 		error = ENOMEM;
1127 		goto out;
1128 	}
1129 #ifdef __amd64__
1130 	mapbase = (caddr_t)KERNBASE;
1131 #else
1132 	mapbase = (caddr_t)vm_map_min(kernel_map);
1133 #endif
1134 	/*
1135 	 * Mapping protections are downgraded after relocation processing.
1136 	 */
1137 	error = vm_map_find(kernel_map, ef->object, 0,
1138 	    (vm_offset_t *)&mapbase, mapsize, 0, VMFS_OPTIMAL_SPACE,
1139 	    VM_PROT_ALL, VM_PROT_ALL, 0);
1140 	if (error != 0) {
1141 		vm_object_deallocate(ef->object);
1142 		ef->object = NULL;
1143 		goto out;
1144 	}
1145 #else
1146 	mapbase = malloc_exec(mapsize, M_LINKER, M_WAITOK);
1147 #endif
1148 	ef->address = mapbase;
1149 
1150 	/*
1151 	 * Read the text and data sections and zero the bss.
1152 	 */
1153 	for (i = 0; i < nsegs; i++) {
1154 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1155 
1156 #ifdef SPARSE_MAPPING
1157 		/*
1158 		 * Consecutive segments may have different mapping permissions,
1159 		 * so be strict and verify that their mappings do not overlap.
1160 		 */
1161 		if (((vm_offset_t)segbase & PAGE_MASK) != 0) {
1162 			error = EINVAL;
1163 			goto out;
1164 		}
1165 
1166 		error = vm_map_wire(kernel_map,
1167 		    (vm_offset_t)segbase,
1168 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1169 		    VM_MAP_WIRE_SYSTEM | VM_MAP_WIRE_NOHOLES);
1170 		if (error != KERN_SUCCESS) {
1171 			error = ENOMEM;
1172 			goto out;
1173 		}
1174 #endif
1175 
1176 		error = vn_rdwr(UIO_READ, nd.ni_vp,
1177 		    segbase, segs[i]->p_filesz, segs[i]->p_offset,
1178 		    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1179 		    &resid, td);
1180 		if (error != 0)
1181 			goto out;
1182 		bzero(segbase + segs[i]->p_filesz,
1183 		    segs[i]->p_memsz - segs[i]->p_filesz);
1184 	}
1185 
1186 	ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
1187 
1188 	lf->address = ef->address;
1189 	lf->size = mapsize;
1190 
1191 	error = parse_dynamic(ef);
1192 	if (error != 0)
1193 		goto out;
1194 	error = parse_dpcpu(ef);
1195 	if (error != 0)
1196 		goto out;
1197 #ifdef VIMAGE
1198 	error = parse_vnet(ef);
1199 	if (error != 0)
1200 		goto out;
1201 #endif
1202 	link_elf_reloc_local(lf);
1203 
1204 	VOP_UNLOCK(nd.ni_vp);
1205 	error = linker_load_dependencies(lf);
1206 	vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1207 	if (error != 0)
1208 		goto out;
1209 	error = relocate_file(ef);
1210 	if (error != 0)
1211 		goto out;
1212 
1213 #ifdef SPARSE_MAPPING
1214 	/*
1215 	 * Downgrade permissions on text segment mappings now that relocation
1216 	 * processing is complete.  Restrict permissions on read-only segments.
1217 	 */
1218 	for (i = 0; i < nsegs; i++) {
1219 		vm_prot_t prot;
1220 
1221 		if (segs[i]->p_type != PT_LOAD)
1222 			continue;
1223 
1224 		prot = VM_PROT_READ;
1225 		if ((segs[i]->p_flags & PF_W) != 0)
1226 			prot |= VM_PROT_WRITE;
1227 		if ((segs[i]->p_flags & PF_X) != 0)
1228 			prot |= VM_PROT_EXECUTE;
1229 		segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
1230 		error = vm_map_protect(kernel_map,
1231 		    (vm_offset_t)segbase,
1232 		    (vm_offset_t)segbase + round_page(segs[i]->p_memsz),
1233 		    prot, 0, VM_MAP_PROTECT_SET_PROT);
1234 		if (error != KERN_SUCCESS) {
1235 			error = ENOMEM;
1236 			goto out;
1237 		}
1238 	}
1239 #endif
1240 
1241 	/*
1242 	 * Try and load the symbol table if it's present.  (you can
1243 	 * strip it!)
1244 	 */
1245 	nbytes = hdr->e_shnum * hdr->e_shentsize;
1246 	if (nbytes == 0 || hdr->e_shoff == 0)
1247 		goto nosyms;
1248 	shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1249 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1250 	    (caddr_t)shdr, nbytes, hdr->e_shoff,
1251 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1252 	    &resid, td);
1253 	if (error != 0)
1254 		goto out;
1255 
1256 	/* Read section string table */
1257 	shstrindex = hdr->e_shstrndx;
1258 	if (shstrindex != 0 && shdr[shstrindex].sh_type == SHT_STRTAB &&
1259 	    shdr[shstrindex].sh_size != 0) {
1260 		nbytes = shdr[shstrindex].sh_size;
1261 		shstrs = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
1262 		error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shstrs, nbytes,
1263 		    shdr[shstrindex].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
1264 		    td->td_ucred, NOCRED, &resid, td);
1265 		if (error)
1266 			goto out;
1267 	}
1268 
1269 	symtabindex = -1;
1270 	symstrindex = -1;
1271 	for (i = 0; i < hdr->e_shnum; i++) {
1272 		if (shdr[i].sh_type == SHT_SYMTAB) {
1273 			symtabindex = i;
1274 			symstrindex = shdr[i].sh_link;
1275 		} else if (shstrs != NULL && shdr[i].sh_name != 0 &&
1276 		    strcmp(shstrs + shdr[i].sh_name, ".ctors") == 0) {
1277 			/* Record relocated address and size of .ctors. */
1278 			lf->ctors_addr = mapbase + shdr[i].sh_addr - base_vaddr;
1279 			lf->ctors_size = shdr[i].sh_size;
1280 		}
1281 	}
1282 	if (symtabindex < 0 || symstrindex < 0)
1283 		goto nosyms;
1284 
1285 	symcnt = shdr[symtabindex].sh_size;
1286 	ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
1287 	strcnt = shdr[symstrindex].sh_size;
1288 	ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
1289 
1290 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1291 	    ef->symbase, symcnt, shdr[symtabindex].sh_offset,
1292 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1293 	    &resid, td);
1294 	if (error != 0)
1295 		goto out;
1296 	error = vn_rdwr(UIO_READ, nd.ni_vp,
1297 	    ef->strbase, strcnt, shdr[symstrindex].sh_offset,
1298 	    UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1299 	    &resid, td);
1300 	if (error != 0)
1301 		goto out;
1302 
1303 	ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
1304 	ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
1305 	ef->ddbstrcnt = strcnt;
1306 	ef->ddbstrtab = ef->strbase;
1307 
1308 nosyms:
1309 
1310 #ifdef __arm__
1311 	link_elf_locate_exidx(lf, shdr, hdr->e_shnum);
1312 #endif
1313 
1314 	error = link_elf_link_common_finish(lf);
1315 	if (error != 0)
1316 		goto out;
1317 
1318 	*result = lf;
1319 
1320 out:
1321 	VOP_UNLOCK(nd.ni_vp);
1322 	vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1323 	if (error != 0 && lf != NULL)
1324 		linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1325 	free(shdr, M_LINKER);
1326 	free(firstpage, M_LINKER);
1327 	free(shstrs, M_LINKER);
1328 
1329 	return (error);
1330 }
1331 
1332 Elf_Addr
1333 elf_relocaddr(linker_file_t lf, Elf_Addr x)
1334 {
1335 	elf_file_t ef;
1336 
1337 	KASSERT(lf->ops->cls == (kobj_class_t)&link_elf_class,
1338 	    ("elf_relocaddr: unexpected linker file %p", lf));
1339 
1340 	ef = (elf_file_t)lf;
1341 	if (x >= ef->pcpu_start && x < ef->pcpu_stop)
1342 		return ((x - ef->pcpu_start) + ef->pcpu_base);
1343 #ifdef VIMAGE
1344 	if (x >= ef->vnet_start && x < ef->vnet_stop)
1345 		return ((x - ef->vnet_start) + ef->vnet_base);
1346 #endif
1347 	return (x);
1348 }
1349 
1350 static void
1351 link_elf_unload_file(linker_file_t file)
1352 {
1353 	elf_file_t ef = (elf_file_t) file;
1354 
1355 	if (ef->pcpu_base != 0) {
1356 		dpcpu_free((void *)ef->pcpu_base,
1357 		    ef->pcpu_stop - ef->pcpu_start);
1358 		elf_set_delete(&set_pcpu_list, ef->pcpu_start);
1359 	}
1360 #ifdef VIMAGE
1361 	if (ef->vnet_base != 0) {
1362 		vnet_data_free((void *)ef->vnet_base,
1363 		    ef->vnet_stop - ef->vnet_start);
1364 		elf_set_delete(&set_vnet_list, ef->vnet_start);
1365 	}
1366 #endif
1367 #ifdef GDB
1368 	if (ef->gdb.l_ld != NULL) {
1369 		GDB_STATE(RT_DELETE);
1370 		free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1371 		link_elf_delete_gdb(&ef->gdb);
1372 		GDB_STATE(RT_CONSISTENT);
1373 	}
1374 #endif
1375 
1376 	/* Notify MD code that a module is being unloaded. */
1377 	elf_cpu_unload_file(file);
1378 
1379 	if (ef->preloaded) {
1380 		link_elf_unload_preload(file);
1381 		return;
1382 	}
1383 
1384 #ifdef SPARSE_MAPPING
1385 	if (ef->object != NULL) {
1386 		vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1387 		    (vm_offset_t) ef->address
1388 		    + (ef->object->size << PAGE_SHIFT));
1389 	}
1390 #else
1391 	free(ef->address, M_LINKER);
1392 #endif
1393 	free(ef->symbase, M_LINKER);
1394 	free(ef->strbase, M_LINKER);
1395 	free(ef->ctftab, M_LINKER);
1396 	free(ef->ctfoff, M_LINKER);
1397 	free(ef->typoff, M_LINKER);
1398 }
1399 
1400 static void
1401 link_elf_unload_preload(linker_file_t file)
1402 {
1403 
1404 	if (file->pathname != NULL)
1405 		preload_delete_name(file->pathname);
1406 }
1407 
1408 static const char *
1409 symbol_name(elf_file_t ef, Elf_Size r_info)
1410 {
1411 	const Elf_Sym *ref;
1412 
1413 	if (ELF_R_SYM(r_info)) {
1414 		ref = ef->symtab + ELF_R_SYM(r_info);
1415 		return (ef->strtab + ref->st_name);
1416 	}
1417 	return (NULL);
1418 }
1419 
1420 static int
1421 symbol_type(elf_file_t ef, Elf_Size r_info)
1422 {
1423 	const Elf_Sym *ref;
1424 
1425 	if (ELF_R_SYM(r_info)) {
1426 		ref = ef->symtab + ELF_R_SYM(r_info);
1427 		return (ELF_ST_TYPE(ref->st_info));
1428 	}
1429 	return (STT_NOTYPE);
1430 }
1431 
1432 static int
1433 relocate_file1(elf_file_t ef, elf_lookup_fn lookup, elf_reloc_fn reloc,
1434     bool ifuncs)
1435 {
1436 	const Elf_Rel *rel;
1437 	const Elf_Rela *rela;
1438 	const char *symname;
1439 
1440 	TSENTER();
1441 #define	APPLY_RELOCS(iter, tbl, tblsize, type) do {			\
1442 	for ((iter) = (tbl); (iter) != NULL &&				\
1443 	    (iter) < (tbl) + (tblsize) / sizeof(*(iter)); (iter)++) {	\
1444 		if ((symbol_type(ef, (iter)->r_info) ==			\
1445 		    STT_GNU_IFUNC ||					\
1446 		    elf_is_ifunc_reloc((iter)->r_info)) != ifuncs)	\
1447 			continue;					\
1448 		if (reloc(&ef->lf, (Elf_Addr)ef->address,		\
1449 		    (iter), (type), lookup)) {				\
1450 			symname = symbol_name(ef, (iter)->r_info);	\
1451 			printf("link_elf: symbol %s undefined\n",	\
1452 			    symname);					\
1453 			return (ENOENT);				\
1454 		}							\
1455 	}								\
1456 } while (0)
1457 
1458 	APPLY_RELOCS(rel, ef->rel, ef->relsize, ELF_RELOC_REL);
1459 	TSENTER2("ef->rela");
1460 	APPLY_RELOCS(rela, ef->rela, ef->relasize, ELF_RELOC_RELA);
1461 	TSEXIT2("ef->rela");
1462 	APPLY_RELOCS(rel, ef->pltrel, ef->pltrelsize, ELF_RELOC_REL);
1463 	APPLY_RELOCS(rela, ef->pltrela, ef->pltrelasize, ELF_RELOC_RELA);
1464 
1465 #undef APPLY_RELOCS
1466 
1467 	TSEXIT();
1468 	return (0);
1469 }
1470 
1471 static int
1472 relocate_file(elf_file_t ef)
1473 {
1474 	int error;
1475 
1476 	error = relocate_file1(ef, elf_lookup, elf_reloc, false);
1477 	if (error == 0)
1478 		error = relocate_file1(ef, elf_lookup, elf_reloc, true);
1479 	return (error);
1480 }
1481 
1482 /*
1483  * SysV hash function for symbol table lookup.  It is specified by the
1484  * System V ABI.
1485  */
1486 static Elf32_Word
1487 elf_hash(const char *name)
1488 {
1489 	const unsigned char *p = (const unsigned char *)name;
1490 	Elf32_Word h = 0;
1491 
1492 	while (*p != '\0') {
1493 		h = (h << 4) + *p++;
1494 		h ^= (h >> 24) & 0xf0;
1495 	}
1496 	return (h & 0x0fffffff);
1497 }
1498 
1499 static int
1500 link_elf_lookup_symbol1(linker_file_t lf, const char *name, c_linker_sym_t *sym,
1501     bool see_local)
1502 {
1503 	elf_file_t ef = (elf_file_t) lf;
1504 	unsigned long symnum;
1505 	const Elf_Sym* symp;
1506 	const char *strp;
1507 	Elf32_Word hash;
1508 
1509 	/* If we don't have a hash, bail. */
1510 	if (ef->buckets == NULL || ef->nbuckets == 0) {
1511 		printf("link_elf_lookup_symbol: missing symbol hash table\n");
1512 		return (ENOENT);
1513 	}
1514 
1515 	/* First, search hashed global symbols */
1516 	hash = elf_hash(name);
1517 	symnum = ef->buckets[hash % ef->nbuckets];
1518 
1519 	while (symnum != STN_UNDEF) {
1520 		if (symnum >= ef->nchains) {
1521 			printf("%s: corrupt symbol table\n", __func__);
1522 			return (ENOENT);
1523 		}
1524 
1525 		symp = ef->symtab + symnum;
1526 		if (symp->st_name == 0) {
1527 			printf("%s: corrupt symbol table\n", __func__);
1528 			return (ENOENT);
1529 		}
1530 
1531 		strp = ef->strtab + symp->st_name;
1532 
1533 		if (strcmp(name, strp) == 0) {
1534 			if (symp->st_shndx != SHN_UNDEF ||
1535 			    (symp->st_value != 0 &&
1536 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1537 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1538 				if (see_local ||
1539 				    ELF_ST_BIND(symp->st_info) != STB_LOCAL) {
1540 					*sym = (c_linker_sym_t) symp;
1541 					return (0);
1542 				}
1543 			}
1544 			return (ENOENT);
1545 		}
1546 
1547 		symnum = ef->chains[symnum];
1548 	}
1549 
1550 	return (ENOENT);
1551 }
1552 
1553 static int
1554 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1555 {
1556 	if (link_elf_leak_locals)
1557 		return (link_elf_lookup_debug_symbol(lf, name, sym));
1558 	return (link_elf_lookup_symbol1(lf, name, sym, false));
1559 }
1560 
1561 static int
1562 link_elf_lookup_debug_symbol(linker_file_t lf, const char *name,
1563     c_linker_sym_t *sym)
1564 {
1565 	elf_file_t ef = (elf_file_t)lf;
1566 	const Elf_Sym* symp;
1567 	const char *strp;
1568 	int i;
1569 
1570 	if (link_elf_lookup_symbol1(lf, name, sym, true) == 0)
1571 		return (0);
1572 
1573 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1574 		strp = ef->ddbstrtab + symp->st_name;
1575 		if (strcmp(name, strp) == 0) {
1576 			if (symp->st_shndx != SHN_UNDEF ||
1577 			    (symp->st_value != 0 &&
1578 			    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1579 			    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC))) {
1580 				*sym = (c_linker_sym_t) symp;
1581 				return (0);
1582 			}
1583 			return (ENOENT);
1584 		}
1585 	}
1586 
1587 	return (ENOENT);
1588 }
1589 
1590 static int
1591 link_elf_symbol_values1(linker_file_t lf, c_linker_sym_t sym,
1592     linker_symval_t *symval, bool see_local)
1593 {
1594 	elf_file_t ef;
1595 	const Elf_Sym *es;
1596 	caddr_t val;
1597 
1598 	ef = (elf_file_t)lf;
1599 	es = (const Elf_Sym *)sym;
1600 	if (es >= ef->symtab && es < ef->symtab + ef->nchains) {
1601 		if (!see_local && ELF_ST_BIND(es->st_info) == STB_LOCAL)
1602 			return (ENOENT);
1603 		symval->name = ef->strtab + es->st_name;
1604 		val = (caddr_t)ef->address + es->st_value;
1605 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1606 			val = ((caddr_t (*)(void))val)();
1607 		symval->value = val;
1608 		symval->size = es->st_size;
1609 		return (0);
1610 	}
1611 	return (ENOENT);
1612 }
1613 
1614 static int
1615 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1616     linker_symval_t *symval)
1617 {
1618 	if (link_elf_leak_locals)
1619 		return (link_elf_debug_symbol_values(lf, sym, symval));
1620 	return (link_elf_symbol_values1(lf, sym, symval, false));
1621 }
1622 
1623 static int
1624 link_elf_debug_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1625     linker_symval_t *symval)
1626 {
1627 	elf_file_t ef = (elf_file_t)lf;
1628 	const Elf_Sym *es = (const Elf_Sym *)sym;
1629 	caddr_t val;
1630 
1631 	if (link_elf_symbol_values1(lf, sym, symval, true) == 0)
1632 		return (0);
1633 	if (ef->symtab == ef->ddbsymtab)
1634 		return (ENOENT);
1635 
1636 	if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1637 		symval->name = ef->ddbstrtab + es->st_name;
1638 		val = (caddr_t)ef->address + es->st_value;
1639 		if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1640 			val = ((caddr_t (*)(void))val)();
1641 		symval->value = val;
1642 		symval->size = es->st_size;
1643 		return (0);
1644 	}
1645 	return (ENOENT);
1646 }
1647 
1648 static int
1649 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1650     c_linker_sym_t *sym, long *diffp)
1651 {
1652 	elf_file_t ef = (elf_file_t)lf;
1653 	u_long off = (uintptr_t)(void *)value;
1654 	u_long diff = off;
1655 	u_long st_value;
1656 	const Elf_Sym *es;
1657 	const Elf_Sym *best = NULL;
1658 	int i;
1659 
1660 	for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1661 		if (es->st_name == 0)
1662 			continue;
1663 		st_value = es->st_value + (uintptr_t) (void *) ef->address;
1664 		if (off >= st_value) {
1665 			if (off - st_value < diff) {
1666 				diff = off - st_value;
1667 				best = es;
1668 				if (diff == 0)
1669 					break;
1670 			} else if (off - st_value == diff) {
1671 				best = es;
1672 			}
1673 		}
1674 	}
1675 	if (best == NULL)
1676 		*diffp = off;
1677 	else
1678 		*diffp = diff;
1679 	*sym = (c_linker_sym_t) best;
1680 
1681 	return (0);
1682 }
1683 
1684 /*
1685  * Look up a linker set on an ELF system.
1686  */
1687 static int
1688 link_elf_lookup_set(linker_file_t lf, const char *name,
1689     void ***startp, void ***stopp, int *countp)
1690 {
1691 	c_linker_sym_t sym;
1692 	linker_symval_t symval;
1693 	char *setsym;
1694 	void **start, **stop;
1695 	int len, error = 0, count;
1696 
1697 	len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1698 	setsym = malloc(len, M_LINKER, M_WAITOK);
1699 
1700 	/* get address of first entry */
1701 	snprintf(setsym, len, "%s%s", "__start_set_", name);
1702 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1703 	if (error != 0)
1704 		goto out;
1705 	link_elf_symbol_values(lf, sym, &symval);
1706 	if (symval.value == 0) {
1707 		error = ESRCH;
1708 		goto out;
1709 	}
1710 	start = (void **)symval.value;
1711 
1712 	/* get address of last entry */
1713 	snprintf(setsym, len, "%s%s", "__stop_set_", name);
1714 	error = link_elf_lookup_symbol(lf, setsym, &sym);
1715 	if (error != 0)
1716 		goto out;
1717 	link_elf_symbol_values(lf, sym, &symval);
1718 	if (symval.value == 0) {
1719 		error = ESRCH;
1720 		goto out;
1721 	}
1722 	stop = (void **)symval.value;
1723 
1724 	/* and the number of entries */
1725 	count = stop - start;
1726 
1727 	/* and copy out */
1728 	if (startp != NULL)
1729 		*startp = start;
1730 	if (stopp != NULL)
1731 		*stopp = stop;
1732 	if (countp != NULL)
1733 		*countp = count;
1734 
1735 out:
1736 	free(setsym, M_LINKER);
1737 	return (error);
1738 }
1739 
1740 static int
1741 link_elf_each_function_name(linker_file_t file,
1742   int (*callback)(const char *, void *), void *opaque)
1743 {
1744 	elf_file_t ef = (elf_file_t)file;
1745 	const Elf_Sym *symp;
1746 	int i, error;
1747 
1748 	/* Exhaustive search */
1749 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1750 		if (symp->st_value != 0 &&
1751 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1752 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1753 			error = callback(ef->ddbstrtab + symp->st_name, opaque);
1754 			if (error != 0)
1755 				return (error);
1756 		}
1757 	}
1758 	return (0);
1759 }
1760 
1761 static int
1762 link_elf_each_function_nameval(linker_file_t file,
1763     linker_function_nameval_callback_t callback, void *opaque)
1764 {
1765 	linker_symval_t symval;
1766 	elf_file_t ef = (elf_file_t)file;
1767 	const Elf_Sym *symp;
1768 	int i, error;
1769 
1770 	/* Exhaustive search */
1771 	for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1772 		if (symp->st_value != 0 &&
1773 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1774 		    ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1775 			error = link_elf_debug_symbol_values(file,
1776 			    (c_linker_sym_t) symp, &symval);
1777 			if (error == 0)
1778 				error = callback(file, i, &symval, opaque);
1779 			if (error != 0)
1780 				return (error);
1781 		}
1782 	}
1783 	return (0);
1784 }
1785 
1786 const Elf_Sym *
1787 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1788 {
1789 	elf_file_t ef = (elf_file_t)lf;
1790 
1791 	if (symidx >= ef->nchains)
1792 		return (NULL);
1793 	return (ef->symtab + symidx);
1794 }
1795 
1796 const char *
1797 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1798 {
1799 	elf_file_t ef = (elf_file_t)lf;
1800 	const Elf_Sym *sym;
1801 
1802 	if (symidx >= ef->nchains)
1803 		return (NULL);
1804 	sym = ef->symtab + symidx;
1805 	return (ef->strtab + sym->st_name);
1806 }
1807 
1808 /*
1809  * Symbol lookup function that can be used when the symbol index is known (ie
1810  * in relocations). It uses the symbol index instead of doing a fully fledged
1811  * hash table based lookup when such is valid. For example for local symbols.
1812  * This is not only more efficient, it's also more correct. It's not always
1813  * the case that the symbol can be found through the hash table.
1814  */
1815 static int
1816 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1817 {
1818 	elf_file_t ef = (elf_file_t)lf;
1819 	const Elf_Sym *sym;
1820 	const char *symbol;
1821 	Elf_Addr addr, start, base;
1822 
1823 	/* Don't even try to lookup the symbol if the index is bogus. */
1824 	if (symidx >= ef->nchains) {
1825 		*res = 0;
1826 		return (EINVAL);
1827 	}
1828 
1829 	sym = ef->symtab + symidx;
1830 
1831 	/*
1832 	 * Don't do a full lookup when the symbol is local. It may even
1833 	 * fail because it may not be found through the hash table.
1834 	 */
1835 	if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1836 		/* Force lookup failure when we have an insanity. */
1837 		if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) {
1838 			*res = 0;
1839 			return (EINVAL);
1840 		}
1841 		*res = ((Elf_Addr)ef->address + sym->st_value);
1842 		return (0);
1843 	}
1844 
1845 	/*
1846 	 * XXX we can avoid doing a hash table based lookup for global
1847 	 * symbols as well. This however is not always valid, so we'll
1848 	 * just do it the hard way for now. Performance tweaks can
1849 	 * always be added.
1850 	 */
1851 
1852 	symbol = ef->strtab + sym->st_name;
1853 
1854 	/* Force a lookup failure if the symbol name is bogus. */
1855 	if (*symbol == 0) {
1856 		*res = 0;
1857 		return (EINVAL);
1858 	}
1859 
1860 	addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1861 	if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1862 		*res = 0;
1863 		return (EINVAL);
1864 	}
1865 
1866 	if (elf_set_find(&set_pcpu_list, addr, &start, &base))
1867 		addr = addr - start + base;
1868 #ifdef VIMAGE
1869 	else if (elf_set_find(&set_vnet_list, addr, &start, &base))
1870 		addr = addr - start + base;
1871 #endif
1872 	*res = addr;
1873 	return (0);
1874 }
1875 
1876 static void
1877 link_elf_reloc_local(linker_file_t lf)
1878 {
1879 	const Elf_Rel *rellim;
1880 	const Elf_Rel *rel;
1881 	const Elf_Rela *relalim;
1882 	const Elf_Rela *rela;
1883 	elf_file_t ef = (elf_file_t)lf;
1884 
1885 	/* Perform relocations without addend if there are any: */
1886 	if ((rel = ef->rel) != NULL) {
1887 		rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1888 		while (rel < rellim) {
1889 			elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1890 			    ELF_RELOC_REL, elf_lookup);
1891 			rel++;
1892 		}
1893 	}
1894 
1895 	/* Perform relocations with addend if there are any: */
1896 	if ((rela = ef->rela) != NULL) {
1897 		relalim = (const Elf_Rela *)
1898 		    ((const char *)ef->rela + ef->relasize);
1899 		while (rela < relalim) {
1900 			elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1901 			    ELF_RELOC_RELA, elf_lookup);
1902 			rela++;
1903 		}
1904 	}
1905 }
1906 
1907 static long
1908 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1909 {
1910 	elf_file_t ef = (elf_file_t)lf;
1911 
1912 	*symtab = ef->ddbsymtab;
1913 
1914 	if (*symtab == NULL)
1915 		return (0);
1916 
1917 	return (ef->ddbsymcnt);
1918 }
1919 
1920 static long
1921 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1922 {
1923 	elf_file_t ef = (elf_file_t)lf;
1924 
1925 	*strtab = ef->ddbstrtab;
1926 
1927 	if (*strtab == NULL)
1928 		return (0);
1929 
1930 	return (ef->ddbstrcnt);
1931 }
1932 
1933 #ifdef VIMAGE
1934 static void
1935 link_elf_propagate_vnets(linker_file_t lf)
1936 {
1937 	elf_file_t ef = (elf_file_t)lf;
1938 	int size;
1939 
1940 	if (ef->vnet_base != 0) {
1941 		size = (uintptr_t)ef->vnet_stop - (uintptr_t)ef->vnet_start;
1942 		vnet_data_copy((void *)ef->vnet_base, size);
1943 	}
1944 }
1945 #endif
1946 
1947 #if defined(__i386__) || defined(__amd64__) || defined(__aarch64__) || defined(__powerpc__)
1948 /*
1949  * Use this lookup routine when performing relocations early during boot.
1950  * The generic lookup routine depends on kobj, which is not initialized
1951  * at that point.
1952  */
1953 static int
1954 elf_lookup_ifunc(linker_file_t lf, Elf_Size symidx, int deps __unused,
1955     Elf_Addr *res)
1956 {
1957 	elf_file_t ef;
1958 	const Elf_Sym *symp;
1959 	caddr_t val;
1960 
1961 	ef = (elf_file_t)lf;
1962 	symp = ef->symtab + symidx;
1963 	if (ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC) {
1964 		val = (caddr_t)ef->address + symp->st_value;
1965 		*res = ((Elf_Addr (*)(void))val)();
1966 		return (0);
1967 	}
1968 	return (ENOENT);
1969 }
1970 
1971 void
1972 link_elf_ireloc(caddr_t kmdp)
1973 {
1974 	struct elf_file eff;
1975 	elf_file_t ef;
1976 
1977 	TSENTER();
1978 	ef = &eff;
1979 
1980 	bzero_early(ef, sizeof(*ef));
1981 
1982 	ef->modptr = kmdp;
1983 	ef->dynamic = (Elf_Dyn *)&_DYNAMIC;
1984 
1985 #ifdef RELOCATABLE_KERNEL
1986 	ef->address = (caddr_t) (__startkernel - KERNBASE);
1987 #else
1988 	ef->address = 0;
1989 #endif
1990 	parse_dynamic(ef);
1991 
1992 	link_elf_preload_parse_symbols(ef);
1993 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc, true);
1994 	TSEXIT();
1995 }
1996 
1997 #if defined(__aarch64__) || defined(__amd64__)
1998 void
1999 link_elf_late_ireloc(void)
2000 {
2001 	elf_file_t ef;
2002 
2003 	KASSERT(linker_kernel_file != NULL,
2004 	    ("link_elf_late_ireloc: No kernel linker file found"));
2005 	ef = (elf_file_t)linker_kernel_file;
2006 
2007 	relocate_file1(ef, elf_lookup_ifunc, elf_reloc_late, true);
2008 }
2009 #endif
2010 #endif
2011