2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1998-2000 Doug Rabson
5 * Copyright (c) 2004 Peter Wemm
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
41 #include <sys/mount.h>
43 #include <sys/namei.h>
44 #include <sys/fcntl.h>
45 #include <sys/vnode.h>
46 #include <sys/linker.h>
48 #include <machine/elf.h>
52 #include <security/mac/mac_framework.h>
55 #include <vm/vm_param.h>
56 #include <vm/vm_object.h>
57 #include <vm/vm_kern.h>
58 #include <vm/vm_extern.h>
60 #include <vm/vm_map.h>
62 #include <sys/link_elf.h>
68 #include "linker_if.h"
74 int sec; /* Original section */
91 typedef struct elf_file {
92 struct linker_file lf; /* Common fields */
95 caddr_t address; /* Relocation address */
96 vm_object_t object; /* VM object to hold file pages */
102 Elf_relaent *relatab;
108 Elf_Sym *ddbsymtab; /* The symbol table we are using */
109 long ddbsymcnt; /* Number of symbols */
110 caddr_t ddbstrtab; /* String table */
111 long ddbstrcnt; /* number of bytes in string table */
113 caddr_t shstrtab; /* Section name string table */
114 long shstrcnt; /* number of bytes in string table */
116 caddr_t ctftab; /* CTF table */
117 long ctfcnt; /* number of bytes in CTF table */
118 caddr_t ctfoff; /* CTF offset table */
119 caddr_t typoff; /* Type offset table */
120 long typlen; /* Number of type entries. */
124 #include <kern/kern_ctf.c>
126 static int link_elf_link_preload(linker_class_t cls,
127 const char *, linker_file_t *);
128 static int link_elf_link_preload_finish(linker_file_t);
129 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *);
130 static int link_elf_lookup_symbol(linker_file_t, const char *,
132 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
134 static int link_elf_search_symbol(linker_file_t, caddr_t value,
135 c_linker_sym_t *sym, long *diffp);
137 static void link_elf_unload_file(linker_file_t);
138 static int link_elf_lookup_set(linker_file_t, const char *,
139 void ***, void ***, int *);
140 static int link_elf_each_function_name(linker_file_t,
141 int (*)(const char *, void *), void *);
142 static int link_elf_each_function_nameval(linker_file_t,
143 linker_function_nameval_callback_t,
145 static int link_elf_reloc_local(linker_file_t);
146 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
147 static long link_elf_strtab_get(linker_file_t, caddr_t *);
149 static int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
152 static kobj_method_t link_elf_methods[] = {
153 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
154 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
155 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
156 KOBJMETHOD(linker_unload, link_elf_unload_file),
157 KOBJMETHOD(linker_load_file, link_elf_load_file),
158 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
159 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
160 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
161 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
162 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
163 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
164 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
165 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
169 static struct linker_class link_elf_class = {
170 #if ELF_TARG_CLASS == ELFCLASS32
175 link_elf_methods, sizeof(struct elf_file)
178 static int relocate_file(elf_file_t ef);
179 static void elf_obj_cleanup_globals_cache(elf_file_t);
182 link_elf_error(const char *filename, const char *s)
184 if (filename == NULL)
185 printf("kldload: %s\n", s);
187 printf("kldload: %s: %s\n", filename, s);
191 link_elf_init(void *arg)
194 linker_add_class(&link_elf_class);
197 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
200 link_elf_link_preload(linker_class_t cls, const char *filename,
201 linker_file_t *result)
206 void *modptr, *baseptr, *sizeptr;
211 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
213 /* Look to see if we have the file preloaded */
214 modptr = preload_search_by_name(filename);
218 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
219 baseptr = preload_search_info(modptr, MODINFO_ADDR);
220 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
221 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
223 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
225 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
226 " obj module") != 0 &&
227 strcmp(type, "elf obj module") != 0)) {
230 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
234 lf = linker_make_file(filename, &link_elf_class);
240 ef->address = *(caddr_t *)baseptr;
241 lf->address = *(caddr_t *)baseptr;
242 lf->size = *(size_t *)sizeptr;
244 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
245 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
246 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
247 hdr->e_version != EV_CURRENT ||
248 hdr->e_type != ET_REL ||
249 hdr->e_machine != ELF_TARG_MACH) {
255 /* Scan the section header for information and table sizing. */
258 for (i = 0; i < hdr->e_shnum; i++) {
259 switch (shdr[i].sh_type) {
263 case SHT_X86_64_UNWIND:
269 symstrindex = shdr[i].sh_link;
280 shstrindex = hdr->e_shstrndx;
281 if (ef->nprogtab == 0 || symstrindex < 0 ||
282 symstrindex >= hdr->e_shnum ||
283 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
284 shstrindex >= hdr->e_shnum ||
285 shdr[shstrindex].sh_type != SHT_STRTAB) {
286 printf("%s: bad/missing section headers\n", filename);
291 /* Allocate space for tracking the load chunks */
292 if (ef->nprogtab != 0)
293 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
294 M_LINKER, M_WAITOK | M_ZERO);
295 if (ef->nreltab != 0)
296 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
297 M_LINKER, M_WAITOK | M_ZERO);
298 if (ef->nrelatab != 0)
299 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
300 M_LINKER, M_WAITOK | M_ZERO);
301 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
302 (ef->nreltab != 0 && ef->reltab == NULL) ||
303 (ef->nrelatab != 0 && ef->relatab == NULL)) {
308 /* XXX, relocate the sh_addr fields saved by the loader. */
310 for (i = 0; i < hdr->e_shnum; i++) {
311 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
312 off = shdr[i].sh_addr;
314 for (i = 0; i < hdr->e_shnum; i++) {
315 if (shdr[i].sh_addr != 0)
316 shdr[i].sh_addr = shdr[i].sh_addr - off +
317 (Elf_Addr)ef->address;
320 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
321 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
322 ef->ddbstrcnt = shdr[symstrindex].sh_size;
323 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
324 ef->shstrcnt = shdr[shstrindex].sh_size;
325 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
327 /* Now fill out progtab and the relocation tables. */
331 for (i = 0; i < hdr->e_shnum; i++) {
332 switch (shdr[i].sh_type) {
336 case SHT_X86_64_UNWIND:
338 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
339 if (shdr[i].sh_type == SHT_PROGBITS)
340 ef->progtab[pb].name = "<<PROGBITS>>";
342 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
343 ef->progtab[pb].name = "<<UNWIND>>";
346 ef->progtab[pb].name = "<<NOBITS>>";
347 ef->progtab[pb].size = shdr[i].sh_size;
348 ef->progtab[pb].sec = i;
349 if (ef->shstrtab && shdr[i].sh_name != 0)
350 ef->progtab[pb].name =
351 ef->shstrtab + shdr[i].sh_name;
352 if (ef->progtab[pb].name != NULL &&
353 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
356 dpcpu = dpcpu_alloc(shdr[i].sh_size);
361 memcpy(dpcpu, ef->progtab[pb].addr,
362 ef->progtab[pb].size);
363 dpcpu_copy(dpcpu, shdr[i].sh_size);
364 ef->progtab[pb].addr = dpcpu;
366 } else if (ef->progtab[pb].name != NULL &&
367 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
370 vnet_data = vnet_data_alloc(shdr[i].sh_size);
371 if (vnet_data == NULL) {
375 memcpy(vnet_data, ef->progtab[pb].addr,
376 ef->progtab[pb].size);
377 vnet_data_copy(vnet_data, shdr[i].sh_size);
378 ef->progtab[pb].addr = vnet_data;
380 } else if (ef->progtab[pb].name != NULL &&
381 !strcmp(ef->progtab[pb].name, ".ctors")) {
382 lf->ctors_addr = ef->progtab[pb].addr;
383 lf->ctors_size = shdr[i].sh_size;
386 /* Update all symbol values with the offset. */
387 for (j = 0; j < ef->ddbsymcnt; j++) {
388 es = &ef->ddbsymtab[j];
389 if (es->st_shndx != i)
391 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
396 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
397 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
398 ef->reltab[rl].sec = shdr[i].sh_info;
402 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
403 ef->relatab[ra].nrela =
404 shdr[i].sh_size / sizeof(Elf_Rela);
405 ef->relatab[ra].sec = shdr[i].sh_info;
410 if (pb != ef->nprogtab) {
411 printf("%s: lost progbits\n", filename);
415 if (rl != ef->nreltab) {
416 printf("%s: lost reltab\n", filename);
420 if (ra != ef->nrelatab) {
421 printf("%s: lost relatab\n", filename);
426 /* Local intra-module relocations */
427 error = link_elf_reloc_local(lf);
435 /* preload not done this way */
436 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
441 link_elf_invoke_ctors(caddr_t addr, size_t size)
446 if (addr == NULL || size == 0)
448 cnt = size / sizeof(*ctor);
450 for (i = 0; i < cnt; i++) {
457 link_elf_link_preload_finish(linker_file_t lf)
463 error = relocate_file(ef);
467 /* Notify MD code that a module is being loaded. */
468 error = elf_cpu_load_file(lf);
473 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
478 link_elf_load_file(linker_class_t cls, const char *filename,
479 linker_file_t *result)
481 struct nameidata *nd;
482 struct thread *td = curthread; /* XXX */
506 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
507 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
509 error = vn_open(nd, &flags, 0, NULL);
514 NDFREE(nd, NDF_ONLY_PNBUF);
515 if (nd->ni_vp->v_type != VREG) {
520 error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
526 /* Read the elf header from the file. */
527 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
528 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
529 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
543 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
544 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
545 link_elf_error(filename, "Unsupported file layout");
549 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
550 || hdr->e_version != EV_CURRENT) {
551 link_elf_error(filename, "Unsupported file version");
555 if (hdr->e_type != ET_REL) {
559 if (hdr->e_machine != ELF_TARG_MACH) {
560 link_elf_error(filename, "Unsupported machine");
565 lf = linker_make_file(filename, &link_elf_class);
570 ef = (elf_file_t) lf;
576 /* Allocate and read in the section header */
577 nbytes = hdr->e_shnum * hdr->e_shentsize;
578 if (nbytes == 0 || hdr->e_shoff == 0 ||
579 hdr->e_shentsize != sizeof(Elf_Shdr)) {
583 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
585 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
586 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
595 /* Scan the section header for information and table sizing. */
599 for (i = 0; i < hdr->e_shnum; i++) {
600 if (shdr[i].sh_size == 0)
602 switch (shdr[i].sh_type) {
606 case SHT_X86_64_UNWIND:
613 symstrindex = shdr[i].sh_link;
625 if (ef->nprogtab == 0) {
626 link_elf_error(filename, "file has no contents");
631 /* Only allow one symbol table for now */
632 link_elf_error(filename, "file has no valid symbol table");
636 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
637 shdr[symstrindex].sh_type != SHT_STRTAB) {
638 link_elf_error(filename, "file has invalid symbol strings");
643 /* Allocate space for tracking the load chunks */
644 if (ef->nprogtab != 0)
645 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
646 M_LINKER, M_WAITOK | M_ZERO);
647 if (ef->nreltab != 0)
648 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
649 M_LINKER, M_WAITOK | M_ZERO);
650 if (ef->nrelatab != 0)
651 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
652 M_LINKER, M_WAITOK | M_ZERO);
654 if (symtabindex == -1) {
655 link_elf_error(filename, "lost symbol table index");
659 /* Allocate space for and load the symbol table */
660 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
661 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
662 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
663 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
664 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
673 if (symstrindex == -1) {
674 link_elf_error(filename, "lost symbol string index");
678 /* Allocate space for and load the symbol strings */
679 ef->ddbstrcnt = shdr[symstrindex].sh_size;
680 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
681 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
682 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
683 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
692 /* Do we have a string table for the section names? */
694 if (hdr->e_shstrndx != 0 &&
695 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
696 shstrindex = hdr->e_shstrndx;
697 ef->shstrcnt = shdr[shstrindex].sh_size;
698 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
700 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
701 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
702 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
712 /* Size up code/data(progbits) and bss(nobits). */
714 for (i = 0; i < hdr->e_shnum; i++) {
715 if (shdr[i].sh_size == 0)
717 switch (shdr[i].sh_type) {
721 case SHT_X86_64_UNWIND:
723 alignmask = shdr[i].sh_addralign - 1;
724 mapsize += alignmask;
725 mapsize &= ~alignmask;
726 mapsize += shdr[i].sh_size;
732 * We know how much space we need for the text/data/bss/etc.
733 * This stuff needs to be in a single chunk so that profiling etc
734 * can get the bounds and gdb can associate offsets with modules
736 ef->object = vm_object_allocate(OBJT_DEFAULT,
737 round_page(mapsize) >> PAGE_SHIFT);
738 if (ef->object == NULL) {
742 ef->address = (caddr_t) vm_map_min(kernel_map);
745 * In order to satisfy amd64's architectural requirements on the
746 * location of code and data in the kernel's address space, request a
747 * mapping that is above the kernel.
752 mapbase = VM_MIN_KERNEL_ADDRESS;
754 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
755 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
758 vm_object_deallocate(ef->object);
764 error = vm_map_wire(kernel_map, mapbase,
765 mapbase + round_page(mapsize),
766 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
767 if (error != KERN_SUCCESS) {
772 /* Inform the kld system about the situation */
773 lf->address = ef->address = (caddr_t)mapbase;
777 * Now load code/data(progbits), zero bss(nobits), allocate space for
784 for (i = 0; i < hdr->e_shnum; i++) {
785 if (shdr[i].sh_size == 0)
787 switch (shdr[i].sh_type) {
791 case SHT_X86_64_UNWIND:
793 alignmask = shdr[i].sh_addralign - 1;
794 mapbase += alignmask;
795 mapbase &= ~alignmask;
796 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
797 ef->progtab[pb].name =
798 ef->shstrtab + shdr[i].sh_name;
799 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
800 lf->ctors_addr = (caddr_t)mapbase;
801 lf->ctors_size = shdr[i].sh_size;
803 } else if (shdr[i].sh_type == SHT_PROGBITS)
804 ef->progtab[pb].name = "<<PROGBITS>>";
806 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
807 ef->progtab[pb].name = "<<UNWIND>>";
810 ef->progtab[pb].name = "<<NOBITS>>";
811 if (ef->progtab[pb].name != NULL &&
812 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
813 ef->progtab[pb].addr =
814 dpcpu_alloc(shdr[i].sh_size);
816 else if (ef->progtab[pb].name != NULL &&
817 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
818 ef->progtab[pb].addr =
819 vnet_data_alloc(shdr[i].sh_size);
822 ef->progtab[pb].addr =
823 (void *)(uintptr_t)mapbase;
824 if (ef->progtab[pb].addr == NULL) {
828 ef->progtab[pb].size = shdr[i].sh_size;
829 ef->progtab[pb].sec = i;
830 if (shdr[i].sh_type == SHT_PROGBITS
832 || shdr[i].sh_type == SHT_X86_64_UNWIND
835 error = vn_rdwr(UIO_READ, nd->ni_vp,
836 ef->progtab[pb].addr,
837 shdr[i].sh_size, shdr[i].sh_offset,
838 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
846 /* Initialize the per-cpu or vnet area. */
847 if (ef->progtab[pb].addr != (void *)mapbase &&
848 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
849 dpcpu_copy(ef->progtab[pb].addr,
852 else if (ef->progtab[pb].addr !=
854 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
855 vnet_data_copy(ef->progtab[pb].addr,
859 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
861 /* Update all symbol values with the offset. */
862 for (j = 0; j < ef->ddbsymcnt; j++) {
863 es = &ef->ddbsymtab[j];
864 if (es->st_shndx != i)
866 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
868 mapbase += shdr[i].sh_size;
872 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
874 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
875 ef->reltab[rl].sec = shdr[i].sh_info;
876 error = vn_rdwr(UIO_READ, nd->ni_vp,
877 (void *)ef->reltab[rl].rel,
878 shdr[i].sh_size, shdr[i].sh_offset,
879 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
890 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
892 ef->relatab[ra].nrela =
893 shdr[i].sh_size / sizeof(Elf_Rela);
894 ef->relatab[ra].sec = shdr[i].sh_info;
895 error = vn_rdwr(UIO_READ, nd->ni_vp,
896 (void *)ef->relatab[ra].rela,
897 shdr[i].sh_size, shdr[i].sh_offset,
898 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
910 if (pb != ef->nprogtab) {
911 link_elf_error(filename, "lost progbits");
915 if (rl != ef->nreltab) {
916 link_elf_error(filename, "lost reltab");
920 if (ra != ef->nrelatab) {
921 link_elf_error(filename, "lost relatab");
925 if (mapbase != (vm_offset_t)ef->address + mapsize) {
927 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
928 filename != NULL ? filename : "<none>",
929 (u_long)mapbase, ef->address, (u_long)mapsize,
930 (u_long)(vm_offset_t)ef->address + mapsize);
935 /* Local intra-module relocations */
936 error = link_elf_reloc_local(lf);
940 /* Pull in dependencies */
941 VOP_UNLOCK(nd->ni_vp, 0);
942 error = linker_load_dependencies(lf);
943 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
947 /* External relocations */
948 error = relocate_file(ef);
952 /* Notify MD code that a module is being loaded. */
953 error = elf_cpu_load_file(lf);
958 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
963 VOP_UNLOCK(nd->ni_vp, 0);
964 vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
967 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
974 link_elf_unload_file(linker_file_t file)
976 elf_file_t ef = (elf_file_t) file;
979 /* Notify MD code that a module is being unloaded. */
980 elf_cpu_unload_file(file);
983 for (i = 0; i < ef->nprogtab; i++) {
984 if (ef->progtab[i].size == 0)
986 if (ef->progtab[i].name == NULL)
988 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
989 dpcpu_free(ef->progtab[i].addr,
990 ef->progtab[i].size);
992 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
993 vnet_data_free(ef->progtab[i].addr,
994 ef->progtab[i].size);
999 free(ef->reltab, M_LINKER);
1000 free(ef->relatab, M_LINKER);
1001 free(ef->progtab, M_LINKER);
1002 free(ef->ctftab, M_LINKER);
1003 free(ef->ctfoff, M_LINKER);
1004 free(ef->typoff, M_LINKER);
1005 if (file->filename != NULL)
1006 preload_delete_name(file->filename);
1007 /* XXX reclaim module memory? */
1011 for (i = 0; i < ef->nreltab; i++)
1012 free(ef->reltab[i].rel, M_LINKER);
1013 for (i = 0; i < ef->nrelatab; i++)
1014 free(ef->relatab[i].rela, M_LINKER);
1015 free(ef->reltab, M_LINKER);
1016 free(ef->relatab, M_LINKER);
1017 free(ef->progtab, M_LINKER);
1020 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1021 (vm_offset_t) ef->address +
1022 (ef->object->size << PAGE_SHIFT));
1024 free(ef->e_shdr, M_LINKER);
1025 free(ef->ddbsymtab, M_LINKER);
1026 free(ef->ddbstrtab, M_LINKER);
1027 free(ef->shstrtab, M_LINKER);
1028 free(ef->ctftab, M_LINKER);
1029 free(ef->ctfoff, M_LINKER);
1030 free(ef->typoff, M_LINKER);
1034 symbol_name(elf_file_t ef, Elf_Size r_info)
1038 if (ELF_R_SYM(r_info)) {
1039 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1040 return ef->ddbstrtab + ref->st_name;
1046 findbase(elf_file_t ef, int sec)
1051 for (i = 0; i < ef->nprogtab; i++) {
1052 if (sec == ef->progtab[i].sec) {
1053 base = (Elf_Addr)ef->progtab[i].addr;
1061 relocate_file(elf_file_t ef)
1063 const Elf_Rel *rellim;
1065 const Elf_Rela *relalim;
1066 const Elf_Rela *rela;
1067 const char *symname;
1074 /* Perform relocations without addend if there are any: */
1075 for (i = 0; i < ef->nreltab; i++) {
1076 rel = ef->reltab[i].rel;
1078 link_elf_error(ef->lf.filename, "lost a reltab!");
1081 rellim = rel + ef->reltab[i].nrel;
1082 base = findbase(ef, ef->reltab[i].sec);
1084 link_elf_error(ef->lf.filename, "lost base for reltab");
1087 for ( ; rel < rellim; rel++) {
1088 symidx = ELF_R_SYM(rel->r_info);
1089 if (symidx >= ef->ddbsymcnt)
1091 sym = ef->ddbsymtab + symidx;
1092 /* Local relocs are already done */
1093 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1095 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1097 symname = symbol_name(ef, rel->r_info);
1098 printf("link_elf_obj: symbol %s undefined\n",
1105 /* Perform relocations with addend if there are any: */
1106 for (i = 0; i < ef->nrelatab; i++) {
1107 rela = ef->relatab[i].rela;
1109 link_elf_error(ef->lf.filename, "lost a relatab!");
1112 relalim = rela + ef->relatab[i].nrela;
1113 base = findbase(ef, ef->relatab[i].sec);
1115 link_elf_error(ef->lf.filename,
1116 "lost base for relatab");
1119 for ( ; rela < relalim; rela++) {
1120 symidx = ELF_R_SYM(rela->r_info);
1121 if (symidx >= ef->ddbsymcnt)
1123 sym = ef->ddbsymtab + symidx;
1124 /* Local relocs are already done */
1125 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1127 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1129 symname = symbol_name(ef, rela->r_info);
1130 printf("link_elf_obj: symbol %s undefined\n",
1138 * Only clean SHN_FBSD_CACHED for successful return. If we
1139 * modified symbol table for the object but found an
1140 * unresolved symbol, there is no reason to roll back.
1142 elf_obj_cleanup_globals_cache(ef);
1148 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1150 elf_file_t ef = (elf_file_t) lf;
1151 const Elf_Sym *symp;
1155 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1156 strp = ef->ddbstrtab + symp->st_name;
1157 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1158 *sym = (c_linker_sym_t) symp;
1166 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1167 linker_symval_t *symval)
1169 elf_file_t ef = (elf_file_t) lf;
1170 const Elf_Sym *es = (const Elf_Sym*) sym;
1172 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1173 symval->name = ef->ddbstrtab + es->st_name;
1174 symval->value = (caddr_t)es->st_value;
1175 symval->size = es->st_size;
1182 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1183 c_linker_sym_t *sym, long *diffp)
1185 elf_file_t ef = (elf_file_t) lf;
1186 u_long off = (uintptr_t) (void *) value;
1190 const Elf_Sym *best = NULL;
1193 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1194 if (es->st_name == 0)
1196 st_value = es->st_value;
1197 if (off >= st_value) {
1198 if (off - st_value < diff) {
1199 diff = off - st_value;
1203 } else if (off - st_value == diff) {
1212 *sym = (c_linker_sym_t) best;
1218 * Look up a linker set on an ELF system.
1221 link_elf_lookup_set(linker_file_t lf, const char *name,
1222 void ***startp, void ***stopp, int *countp)
1224 elf_file_t ef = (elf_file_t)lf;
1225 void **start, **stop;
1228 /* Relative to section number */
1229 for (i = 0; i < ef->nprogtab; i++) {
1230 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1231 strcmp(ef->progtab[i].name + 4, name) == 0) {
1232 start = (void **)ef->progtab[i].addr;
1233 stop = (void **)((char *)ef->progtab[i].addr +
1234 ef->progtab[i].size);
1235 count = stop - start;
1249 link_elf_each_function_name(linker_file_t file,
1250 int (*callback)(const char *, void *), void *opaque)
1252 elf_file_t ef = (elf_file_t)file;
1253 const Elf_Sym *symp;
1256 /* Exhaustive search */
1257 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1258 if (symp->st_value != 0 &&
1259 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1260 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1269 link_elf_each_function_nameval(linker_file_t file,
1270 linker_function_nameval_callback_t callback, void *opaque)
1272 linker_symval_t symval;
1273 elf_file_t ef = (elf_file_t)file;
1274 const Elf_Sym* symp;
1277 /* Exhaustive search */
1278 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1279 if (symp->st_value != 0 &&
1280 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1281 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1284 error = callback(file, i, &symval, opaque);
1293 elf_obj_cleanup_globals_cache(elf_file_t ef)
1298 for (i = 0; i < ef->ddbsymcnt; i++) {
1299 sym = ef->ddbsymtab + i;
1300 if (sym->st_shndx == SHN_FBSD_CACHED) {
1301 sym->st_shndx = SHN_UNDEF;
1308 * Symbol lookup function that can be used when the symbol index is known (ie
1309 * in relocations). It uses the symbol index instead of doing a fully fledged
1310 * hash table based lookup when such is valid. For example for local symbols.
1311 * This is not only more efficient, it's also more correct. It's not always
1312 * the case that the symbol can be found through the hash table.
1315 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1317 elf_file_t ef = (elf_file_t)lf;
1322 /* Don't even try to lookup the symbol if the index is bogus. */
1323 if (symidx >= ef->ddbsymcnt) {
1328 sym = ef->ddbsymtab + symidx;
1330 /* Quick answer if there is a definition included. */
1331 if (sym->st_shndx != SHN_UNDEF) {
1332 *res = sym->st_value;
1336 /* If we get here, then it is undefined and needs a lookup. */
1337 switch (ELF_ST_BIND(sym->st_info)) {
1339 /* Local, but undefined? huh? */
1345 /* Relative to Data or Function name */
1346 symbol = ef->ddbstrtab + sym->st_name;
1348 /* Force a lookup failure if the symbol name is bogus. */
1353 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1356 * Cache global lookups during module relocation. The failure
1357 * case is particularly expensive for callers, who must scan
1358 * through the entire globals table doing strcmp(). Cache to
1359 * avoid doing such work repeatedly.
1361 * After relocation is complete, undefined globals will be
1362 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1366 sym->st_shndx = SHN_FBSD_CACHED;
1367 sym->st_value = res1;
1370 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1383 link_elf_fix_link_set(elf_file_t ef)
1385 static const char startn[] = "__start_";
1386 static const char stopn[] = "__stop_";
1388 const char *sym_name, *linkset_name;
1389 Elf_Addr startp, stopp;
1394 for (symidx = 1 /* zero entry is special */;
1395 symidx < ef->ddbsymcnt; symidx++) {
1396 sym = ef->ddbsymtab + symidx;
1397 if (sym->st_shndx != SHN_UNDEF)
1400 sym_name = ef->ddbstrtab + sym->st_name;
1401 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1403 linkset_name = sym_name + sizeof(startn) - 1;
1405 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1407 linkset_name = sym_name + sizeof(stopn) - 1;
1412 for (i = 0; i < ef->nprogtab; i++) {
1413 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1414 startp = (Elf_Addr)ef->progtab[i].addr;
1415 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1419 if (i == ef->nprogtab)
1422 sym->st_value = start ? startp : stopp;
1428 link_elf_reloc_local(linker_file_t lf)
1430 elf_file_t ef = (elf_file_t)lf;
1431 const Elf_Rel *rellim;
1433 const Elf_Rela *relalim;
1434 const Elf_Rela *rela;
1440 link_elf_fix_link_set(ef);
1442 /* Perform relocations without addend if there are any: */
1443 for (i = 0; i < ef->nreltab; i++) {
1444 rel = ef->reltab[i].rel;
1446 link_elf_error(ef->lf.filename, "lost a reltab");
1449 rellim = rel + ef->reltab[i].nrel;
1450 base = findbase(ef, ef->reltab[i].sec);
1452 link_elf_error(ef->lf.filename, "lost base for reltab");
1455 for ( ; rel < rellim; rel++) {
1456 symidx = ELF_R_SYM(rel->r_info);
1457 if (symidx >= ef->ddbsymcnt)
1459 sym = ef->ddbsymtab + symidx;
1460 /* Only do local relocs */
1461 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1463 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1468 /* Perform relocations with addend if there are any: */
1469 for (i = 0; i < ef->nrelatab; i++) {
1470 rela = ef->relatab[i].rela;
1472 link_elf_error(ef->lf.filename, "lost a relatab!");
1475 relalim = rela + ef->relatab[i].nrela;
1476 base = findbase(ef, ef->relatab[i].sec);
1478 link_elf_error(ef->lf.filename, "lost base for reltab");
1481 for ( ; rela < relalim; rela++) {
1482 symidx = ELF_R_SYM(rela->r_info);
1483 if (symidx >= ef->ddbsymcnt)
1485 sym = ef->ddbsymtab + symidx;
1486 /* Only do local relocs */
1487 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1489 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1497 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1499 elf_file_t ef = (elf_file_t)lf;
1501 *symtab = ef->ddbsymtab;
1503 if (*symtab == NULL)
1506 return (ef->ddbsymcnt);
1510 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1512 elf_file_t ef = (elf_file_t)lf;
1514 *strtab = ef->ddbstrtab;
1516 if (*strtab == NULL)
1519 return (ef->ddbstrcnt);