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:
265 /* Ignore sections not loaded by the loader. */
266 if (shdr[i].sh_addr == 0)
272 symstrindex = shdr[i].sh_link;
283 shstrindex = hdr->e_shstrndx;
284 if (ef->nprogtab == 0 || symstrindex < 0 ||
285 symstrindex >= hdr->e_shnum ||
286 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
287 shstrindex >= hdr->e_shnum ||
288 shdr[shstrindex].sh_type != SHT_STRTAB) {
289 printf("%s: bad/missing section headers\n", filename);
294 /* Allocate space for tracking the load chunks */
295 if (ef->nprogtab != 0)
296 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
297 M_LINKER, M_WAITOK | M_ZERO);
298 if (ef->nreltab != 0)
299 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
300 M_LINKER, M_WAITOK | M_ZERO);
301 if (ef->nrelatab != 0)
302 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
303 M_LINKER, M_WAITOK | M_ZERO);
304 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
305 (ef->nreltab != 0 && ef->reltab == NULL) ||
306 (ef->nrelatab != 0 && ef->relatab == NULL)) {
311 /* XXX, relocate the sh_addr fields saved by the loader. */
313 for (i = 0; i < hdr->e_shnum; i++) {
314 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
315 off = shdr[i].sh_addr;
317 for (i = 0; i < hdr->e_shnum; i++) {
318 if (shdr[i].sh_addr != 0)
319 shdr[i].sh_addr = shdr[i].sh_addr - off +
320 (Elf_Addr)ef->address;
323 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
324 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
325 ef->ddbstrcnt = shdr[symstrindex].sh_size;
326 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
327 ef->shstrcnt = shdr[shstrindex].sh_size;
328 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
330 /* Now fill out progtab and the relocation tables. */
334 for (i = 0; i < hdr->e_shnum; i++) {
335 switch (shdr[i].sh_type) {
339 case SHT_X86_64_UNWIND:
341 if (shdr[i].sh_addr == 0)
343 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
344 if (shdr[i].sh_type == SHT_PROGBITS)
345 ef->progtab[pb].name = "<<PROGBITS>>";
347 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
348 ef->progtab[pb].name = "<<UNWIND>>";
351 ef->progtab[pb].name = "<<NOBITS>>";
352 ef->progtab[pb].size = shdr[i].sh_size;
353 ef->progtab[pb].sec = i;
354 if (ef->shstrtab && shdr[i].sh_name != 0)
355 ef->progtab[pb].name =
356 ef->shstrtab + shdr[i].sh_name;
357 if (ef->progtab[pb].name != NULL &&
358 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
361 dpcpu = dpcpu_alloc(shdr[i].sh_size);
366 memcpy(dpcpu, ef->progtab[pb].addr,
367 ef->progtab[pb].size);
368 dpcpu_copy(dpcpu, shdr[i].sh_size);
369 ef->progtab[pb].addr = dpcpu;
371 } else if (ef->progtab[pb].name != NULL &&
372 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
375 vnet_data = vnet_data_alloc(shdr[i].sh_size);
376 if (vnet_data == NULL) {
380 memcpy(vnet_data, ef->progtab[pb].addr,
381 ef->progtab[pb].size);
382 vnet_data_copy(vnet_data, shdr[i].sh_size);
383 ef->progtab[pb].addr = vnet_data;
385 } else if (ef->progtab[pb].name != NULL &&
386 !strcmp(ef->progtab[pb].name, ".ctors")) {
387 lf->ctors_addr = ef->progtab[pb].addr;
388 lf->ctors_size = shdr[i].sh_size;
391 /* Update all symbol values with the offset. */
392 for (j = 0; j < ef->ddbsymcnt; j++) {
393 es = &ef->ddbsymtab[j];
394 if (es->st_shndx != i)
396 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
401 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
402 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
403 ef->reltab[rl].sec = shdr[i].sh_info;
407 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
408 ef->relatab[ra].nrela =
409 shdr[i].sh_size / sizeof(Elf_Rela);
410 ef->relatab[ra].sec = shdr[i].sh_info;
415 if (pb != ef->nprogtab) {
416 printf("%s: lost progbits\n", filename);
420 if (rl != ef->nreltab) {
421 printf("%s: lost reltab\n", filename);
425 if (ra != ef->nrelatab) {
426 printf("%s: lost relatab\n", filename);
431 /* Local intra-module relocations */
432 error = link_elf_reloc_local(lf);
440 /* preload not done this way */
441 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
446 link_elf_invoke_ctors(caddr_t addr, size_t size)
451 if (addr == NULL || size == 0)
453 cnt = size / sizeof(*ctor);
455 for (i = 0; i < cnt; i++) {
462 link_elf_link_preload_finish(linker_file_t lf)
468 error = relocate_file(ef);
472 /* Notify MD code that a module is being loaded. */
473 error = elf_cpu_load_file(lf);
478 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
483 link_elf_load_file(linker_class_t cls, const char *filename,
484 linker_file_t *result)
486 struct nameidata *nd;
487 struct thread *td = curthread; /* XXX */
511 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
512 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
514 error = vn_open(nd, &flags, 0, NULL);
519 NDFREE(nd, NDF_ONLY_PNBUF);
520 if (nd->ni_vp->v_type != VREG) {
525 error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
531 /* Read the elf header from the file. */
532 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
533 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
534 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
548 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
549 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
550 link_elf_error(filename, "Unsupported file layout");
554 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
555 || hdr->e_version != EV_CURRENT) {
556 link_elf_error(filename, "Unsupported file version");
560 if (hdr->e_type != ET_REL) {
564 if (hdr->e_machine != ELF_TARG_MACH) {
565 link_elf_error(filename, "Unsupported machine");
570 lf = linker_make_file(filename, &link_elf_class);
575 ef = (elf_file_t) lf;
581 /* Allocate and read in the section header */
582 nbytes = hdr->e_shnum * hdr->e_shentsize;
583 if (nbytes == 0 || hdr->e_shoff == 0 ||
584 hdr->e_shentsize != sizeof(Elf_Shdr)) {
588 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
590 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
591 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
600 /* Scan the section header for information and table sizing. */
604 for (i = 0; i < hdr->e_shnum; i++) {
605 if (shdr[i].sh_size == 0)
607 switch (shdr[i].sh_type) {
611 case SHT_X86_64_UNWIND:
613 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
620 symstrindex = shdr[i].sh_link;
632 if (ef->nprogtab == 0) {
633 link_elf_error(filename, "file has no contents");
638 /* Only allow one symbol table for now */
639 link_elf_error(filename, "file has no valid symbol table");
643 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
644 shdr[symstrindex].sh_type != SHT_STRTAB) {
645 link_elf_error(filename, "file has invalid symbol strings");
650 /* Allocate space for tracking the load chunks */
651 if (ef->nprogtab != 0)
652 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
653 M_LINKER, M_WAITOK | M_ZERO);
654 if (ef->nreltab != 0)
655 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
656 M_LINKER, M_WAITOK | M_ZERO);
657 if (ef->nrelatab != 0)
658 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
659 M_LINKER, M_WAITOK | M_ZERO);
661 if (symtabindex == -1) {
662 link_elf_error(filename, "lost symbol table index");
666 /* Allocate space for and load the symbol table */
667 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
668 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
669 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
670 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
671 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
680 if (symstrindex == -1) {
681 link_elf_error(filename, "lost symbol string index");
685 /* Allocate space for and load the symbol strings */
686 ef->ddbstrcnt = shdr[symstrindex].sh_size;
687 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
688 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
689 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
690 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
699 /* Do we have a string table for the section names? */
701 if (hdr->e_shstrndx != 0 &&
702 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
703 shstrindex = hdr->e_shstrndx;
704 ef->shstrcnt = shdr[shstrindex].sh_size;
705 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
707 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
708 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
709 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
719 /* Size up code/data(progbits) and bss(nobits). */
721 for (i = 0; i < hdr->e_shnum; i++) {
722 if (shdr[i].sh_size == 0)
724 switch (shdr[i].sh_type) {
728 case SHT_X86_64_UNWIND:
730 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
732 alignmask = shdr[i].sh_addralign - 1;
733 mapsize += alignmask;
734 mapsize &= ~alignmask;
735 mapsize += shdr[i].sh_size;
741 * We know how much space we need for the text/data/bss/etc.
742 * This stuff needs to be in a single chunk so that profiling etc
743 * can get the bounds and gdb can associate offsets with modules
745 ef->object = vm_object_allocate(OBJT_DEFAULT,
746 round_page(mapsize) >> PAGE_SHIFT);
747 if (ef->object == NULL) {
751 ef->address = (caddr_t) vm_map_min(kernel_map);
754 * In order to satisfy amd64's architectural requirements on the
755 * location of code and data in the kernel's address space, request a
756 * mapping that is above the kernel.
761 mapbase = VM_MIN_KERNEL_ADDRESS;
763 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
764 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
767 vm_object_deallocate(ef->object);
773 error = vm_map_wire(kernel_map, mapbase,
774 mapbase + round_page(mapsize),
775 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
776 if (error != KERN_SUCCESS) {
781 /* Inform the kld system about the situation */
782 lf->address = ef->address = (caddr_t)mapbase;
786 * Now load code/data(progbits), zero bss(nobits), allocate space for
793 for (i = 0; i < hdr->e_shnum; i++) {
794 if (shdr[i].sh_size == 0)
796 switch (shdr[i].sh_type) {
800 case SHT_X86_64_UNWIND:
802 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
804 alignmask = shdr[i].sh_addralign - 1;
805 mapbase += alignmask;
806 mapbase &= ~alignmask;
807 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
808 ef->progtab[pb].name =
809 ef->shstrtab + shdr[i].sh_name;
810 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
811 lf->ctors_addr = (caddr_t)mapbase;
812 lf->ctors_size = shdr[i].sh_size;
814 } else if (shdr[i].sh_type == SHT_PROGBITS)
815 ef->progtab[pb].name = "<<PROGBITS>>";
817 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
818 ef->progtab[pb].name = "<<UNWIND>>";
821 ef->progtab[pb].name = "<<NOBITS>>";
822 if (ef->progtab[pb].name != NULL &&
823 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
824 ef->progtab[pb].addr =
825 dpcpu_alloc(shdr[i].sh_size);
827 else if (ef->progtab[pb].name != NULL &&
828 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
829 ef->progtab[pb].addr =
830 vnet_data_alloc(shdr[i].sh_size);
833 ef->progtab[pb].addr =
834 (void *)(uintptr_t)mapbase;
835 if (ef->progtab[pb].addr == NULL) {
839 ef->progtab[pb].size = shdr[i].sh_size;
840 ef->progtab[pb].sec = i;
841 if (shdr[i].sh_type == SHT_PROGBITS
843 || shdr[i].sh_type == SHT_X86_64_UNWIND
846 error = vn_rdwr(UIO_READ, nd->ni_vp,
847 ef->progtab[pb].addr,
848 shdr[i].sh_size, shdr[i].sh_offset,
849 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
857 /* Initialize the per-cpu or vnet area. */
858 if (ef->progtab[pb].addr != (void *)mapbase &&
859 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
860 dpcpu_copy(ef->progtab[pb].addr,
863 else if (ef->progtab[pb].addr !=
865 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
866 vnet_data_copy(ef->progtab[pb].addr,
870 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
872 /* Update all symbol values with the offset. */
873 for (j = 0; j < ef->ddbsymcnt; j++) {
874 es = &ef->ddbsymtab[j];
875 if (es->st_shndx != i)
877 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
879 mapbase += shdr[i].sh_size;
883 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
885 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
886 ef->reltab[rl].sec = shdr[i].sh_info;
887 error = vn_rdwr(UIO_READ, nd->ni_vp,
888 (void *)ef->reltab[rl].rel,
889 shdr[i].sh_size, shdr[i].sh_offset,
890 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
901 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
903 ef->relatab[ra].nrela =
904 shdr[i].sh_size / sizeof(Elf_Rela);
905 ef->relatab[ra].sec = shdr[i].sh_info;
906 error = vn_rdwr(UIO_READ, nd->ni_vp,
907 (void *)ef->relatab[ra].rela,
908 shdr[i].sh_size, shdr[i].sh_offset,
909 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
921 if (pb != ef->nprogtab) {
922 link_elf_error(filename, "lost progbits");
926 if (rl != ef->nreltab) {
927 link_elf_error(filename, "lost reltab");
931 if (ra != ef->nrelatab) {
932 link_elf_error(filename, "lost relatab");
936 if (mapbase != (vm_offset_t)ef->address + mapsize) {
938 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
939 filename != NULL ? filename : "<none>",
940 (u_long)mapbase, ef->address, (u_long)mapsize,
941 (u_long)(vm_offset_t)ef->address + mapsize);
946 /* Local intra-module relocations */
947 error = link_elf_reloc_local(lf);
951 /* Pull in dependencies */
952 VOP_UNLOCK(nd->ni_vp, 0);
953 error = linker_load_dependencies(lf);
954 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
958 /* External relocations */
959 error = relocate_file(ef);
963 /* Notify MD code that a module is being loaded. */
964 error = elf_cpu_load_file(lf);
969 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
974 VOP_UNLOCK(nd->ni_vp, 0);
975 vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
978 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
985 link_elf_unload_file(linker_file_t file)
987 elf_file_t ef = (elf_file_t) file;
990 /* Notify MD code that a module is being unloaded. */
991 elf_cpu_unload_file(file);
994 for (i = 0; i < ef->nprogtab; i++) {
995 if (ef->progtab[i].size == 0)
997 if (ef->progtab[i].name == NULL)
999 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1000 dpcpu_free(ef->progtab[i].addr,
1001 ef->progtab[i].size);
1003 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1004 vnet_data_free(ef->progtab[i].addr,
1005 ef->progtab[i].size);
1009 if (ef->preloaded) {
1010 free(ef->reltab, M_LINKER);
1011 free(ef->relatab, M_LINKER);
1012 free(ef->progtab, M_LINKER);
1013 free(ef->ctftab, M_LINKER);
1014 free(ef->ctfoff, M_LINKER);
1015 free(ef->typoff, M_LINKER);
1016 if (file->filename != NULL)
1017 preload_delete_name(file->filename);
1018 /* XXX reclaim module memory? */
1022 for (i = 0; i < ef->nreltab; i++)
1023 free(ef->reltab[i].rel, M_LINKER);
1024 for (i = 0; i < ef->nrelatab; i++)
1025 free(ef->relatab[i].rela, M_LINKER);
1026 free(ef->reltab, M_LINKER);
1027 free(ef->relatab, M_LINKER);
1028 free(ef->progtab, M_LINKER);
1031 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1032 (vm_offset_t) ef->address +
1033 (ef->object->size << PAGE_SHIFT));
1035 free(ef->e_shdr, M_LINKER);
1036 free(ef->ddbsymtab, M_LINKER);
1037 free(ef->ddbstrtab, M_LINKER);
1038 free(ef->shstrtab, M_LINKER);
1039 free(ef->ctftab, M_LINKER);
1040 free(ef->ctfoff, M_LINKER);
1041 free(ef->typoff, M_LINKER);
1045 symbol_name(elf_file_t ef, Elf_Size r_info)
1049 if (ELF_R_SYM(r_info)) {
1050 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1051 return ef->ddbstrtab + ref->st_name;
1057 findbase(elf_file_t ef, int sec)
1062 for (i = 0; i < ef->nprogtab; i++) {
1063 if (sec == ef->progtab[i].sec) {
1064 base = (Elf_Addr)ef->progtab[i].addr;
1072 relocate_file(elf_file_t ef)
1074 const Elf_Rel *rellim;
1076 const Elf_Rela *relalim;
1077 const Elf_Rela *rela;
1078 const char *symname;
1085 /* Perform relocations without addend if there are any: */
1086 for (i = 0; i < ef->nreltab; i++) {
1087 rel = ef->reltab[i].rel;
1089 link_elf_error(ef->lf.filename, "lost a reltab!");
1092 rellim = rel + ef->reltab[i].nrel;
1093 base = findbase(ef, ef->reltab[i].sec);
1095 link_elf_error(ef->lf.filename, "lost base for reltab");
1098 for ( ; rel < rellim; rel++) {
1099 symidx = ELF_R_SYM(rel->r_info);
1100 if (symidx >= ef->ddbsymcnt)
1102 sym = ef->ddbsymtab + symidx;
1103 /* Local relocs are already done */
1104 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1106 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1108 symname = symbol_name(ef, rel->r_info);
1109 printf("link_elf_obj: symbol %s undefined\n",
1116 /* Perform relocations with addend if there are any: */
1117 for (i = 0; i < ef->nrelatab; i++) {
1118 rela = ef->relatab[i].rela;
1120 link_elf_error(ef->lf.filename, "lost a relatab!");
1123 relalim = rela + ef->relatab[i].nrela;
1124 base = findbase(ef, ef->relatab[i].sec);
1126 link_elf_error(ef->lf.filename,
1127 "lost base for relatab");
1130 for ( ; rela < relalim; rela++) {
1131 symidx = ELF_R_SYM(rela->r_info);
1132 if (symidx >= ef->ddbsymcnt)
1134 sym = ef->ddbsymtab + symidx;
1135 /* Local relocs are already done */
1136 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1138 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1140 symname = symbol_name(ef, rela->r_info);
1141 printf("link_elf_obj: symbol %s undefined\n",
1149 * Only clean SHN_FBSD_CACHED for successful return. If we
1150 * modified symbol table for the object but found an
1151 * unresolved symbol, there is no reason to roll back.
1153 elf_obj_cleanup_globals_cache(ef);
1159 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1161 elf_file_t ef = (elf_file_t) lf;
1162 const Elf_Sym *symp;
1166 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1167 strp = ef->ddbstrtab + symp->st_name;
1168 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1169 *sym = (c_linker_sym_t) symp;
1177 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1178 linker_symval_t *symval)
1180 elf_file_t ef = (elf_file_t) lf;
1181 const Elf_Sym *es = (const Elf_Sym*) sym;
1183 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1184 symval->name = ef->ddbstrtab + es->st_name;
1185 symval->value = (caddr_t)es->st_value;
1186 symval->size = es->st_size;
1193 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1194 c_linker_sym_t *sym, long *diffp)
1196 elf_file_t ef = (elf_file_t) lf;
1197 u_long off = (uintptr_t) (void *) value;
1201 const Elf_Sym *best = NULL;
1204 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1205 if (es->st_name == 0)
1207 st_value = es->st_value;
1208 if (off >= st_value) {
1209 if (off - st_value < diff) {
1210 diff = off - st_value;
1214 } else if (off - st_value == diff) {
1223 *sym = (c_linker_sym_t) best;
1229 * Look up a linker set on an ELF system.
1232 link_elf_lookup_set(linker_file_t lf, const char *name,
1233 void ***startp, void ***stopp, int *countp)
1235 elf_file_t ef = (elf_file_t)lf;
1236 void **start, **stop;
1239 /* Relative to section number */
1240 for (i = 0; i < ef->nprogtab; i++) {
1241 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1242 strcmp(ef->progtab[i].name + 4, name) == 0) {
1243 start = (void **)ef->progtab[i].addr;
1244 stop = (void **)((char *)ef->progtab[i].addr +
1245 ef->progtab[i].size);
1246 count = stop - start;
1260 link_elf_each_function_name(linker_file_t file,
1261 int (*callback)(const char *, void *), void *opaque)
1263 elf_file_t ef = (elf_file_t)file;
1264 const Elf_Sym *symp;
1267 /* Exhaustive search */
1268 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1269 if (symp->st_value != 0 &&
1270 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1271 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1280 link_elf_each_function_nameval(linker_file_t file,
1281 linker_function_nameval_callback_t callback, void *opaque)
1283 linker_symval_t symval;
1284 elf_file_t ef = (elf_file_t)file;
1285 const Elf_Sym* symp;
1288 /* Exhaustive search */
1289 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1290 if (symp->st_value != 0 &&
1291 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1292 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1295 error = callback(file, i, &symval, opaque);
1304 elf_obj_cleanup_globals_cache(elf_file_t ef)
1309 for (i = 0; i < ef->ddbsymcnt; i++) {
1310 sym = ef->ddbsymtab + i;
1311 if (sym->st_shndx == SHN_FBSD_CACHED) {
1312 sym->st_shndx = SHN_UNDEF;
1319 * Symbol lookup function that can be used when the symbol index is known (ie
1320 * in relocations). It uses the symbol index instead of doing a fully fledged
1321 * hash table based lookup when such is valid. For example for local symbols.
1322 * This is not only more efficient, it's also more correct. It's not always
1323 * the case that the symbol can be found through the hash table.
1326 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1328 elf_file_t ef = (elf_file_t)lf;
1333 /* Don't even try to lookup the symbol if the index is bogus. */
1334 if (symidx >= ef->ddbsymcnt) {
1339 sym = ef->ddbsymtab + symidx;
1341 /* Quick answer if there is a definition included. */
1342 if (sym->st_shndx != SHN_UNDEF) {
1343 *res = sym->st_value;
1347 /* If we get here, then it is undefined and needs a lookup. */
1348 switch (ELF_ST_BIND(sym->st_info)) {
1350 /* Local, but undefined? huh? */
1356 /* Relative to Data or Function name */
1357 symbol = ef->ddbstrtab + sym->st_name;
1359 /* Force a lookup failure if the symbol name is bogus. */
1364 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1367 * Cache global lookups during module relocation. The failure
1368 * case is particularly expensive for callers, who must scan
1369 * through the entire globals table doing strcmp(). Cache to
1370 * avoid doing such work repeatedly.
1372 * After relocation is complete, undefined globals will be
1373 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1377 sym->st_shndx = SHN_FBSD_CACHED;
1378 sym->st_value = res1;
1381 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1394 link_elf_fix_link_set(elf_file_t ef)
1396 static const char startn[] = "__start_";
1397 static const char stopn[] = "__stop_";
1399 const char *sym_name, *linkset_name;
1400 Elf_Addr startp, stopp;
1405 for (symidx = 1 /* zero entry is special */;
1406 symidx < ef->ddbsymcnt; symidx++) {
1407 sym = ef->ddbsymtab + symidx;
1408 if (sym->st_shndx != SHN_UNDEF)
1411 sym_name = ef->ddbstrtab + sym->st_name;
1412 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1414 linkset_name = sym_name + sizeof(startn) - 1;
1416 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1418 linkset_name = sym_name + sizeof(stopn) - 1;
1423 for (i = 0; i < ef->nprogtab; i++) {
1424 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1425 startp = (Elf_Addr)ef->progtab[i].addr;
1426 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1430 if (i == ef->nprogtab)
1433 sym->st_value = start ? startp : stopp;
1439 link_elf_reloc_local(linker_file_t lf)
1441 elf_file_t ef = (elf_file_t)lf;
1442 const Elf_Rel *rellim;
1444 const Elf_Rela *relalim;
1445 const Elf_Rela *rela;
1451 link_elf_fix_link_set(ef);
1453 /* Perform relocations without addend if there are any: */
1454 for (i = 0; i < ef->nreltab; i++) {
1455 rel = ef->reltab[i].rel;
1457 link_elf_error(ef->lf.filename, "lost a reltab");
1460 rellim = rel + ef->reltab[i].nrel;
1461 base = findbase(ef, ef->reltab[i].sec);
1463 link_elf_error(ef->lf.filename, "lost base for reltab");
1466 for ( ; rel < rellim; rel++) {
1467 symidx = ELF_R_SYM(rel->r_info);
1468 if (symidx >= ef->ddbsymcnt)
1470 sym = ef->ddbsymtab + symidx;
1471 /* Only do local relocs */
1472 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1474 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1479 /* Perform relocations with addend if there are any: */
1480 for (i = 0; i < ef->nrelatab; i++) {
1481 rela = ef->relatab[i].rela;
1483 link_elf_error(ef->lf.filename, "lost a relatab!");
1486 relalim = rela + ef->relatab[i].nrela;
1487 base = findbase(ef, ef->relatab[i].sec);
1489 link_elf_error(ef->lf.filename, "lost base for reltab");
1492 for ( ; rela < relalim; rela++) {
1493 symidx = ELF_R_SYM(rela->r_info);
1494 if (symidx >= ef->ddbsymcnt)
1496 sym = ef->ddbsymtab + symidx;
1497 /* Only do local relocs */
1498 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1500 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1508 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1510 elf_file_t ef = (elf_file_t)lf;
1512 *symtab = ef->ddbsymtab;
1514 if (*symtab == NULL)
1517 return (ef->ddbsymcnt);
1521 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1523 elf_file_t ef = (elf_file_t)lf;
1525 *strtab = ef->ddbstrtab;
1527 if (*strtab == NULL)
1530 return (ef->ddbstrcnt);