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