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, bool);
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, NULL);
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;
276 * Ignore relocation tables for sections not
277 * loaded by the loader.
279 if (shdr[shdr[i].sh_info].sh_addr == 0)
284 if (shdr[shdr[i].sh_info].sh_addr == 0)
291 shstrindex = hdr->e_shstrndx;
292 if (ef->nprogtab == 0 || symstrindex < 0 ||
293 symstrindex >= hdr->e_shnum ||
294 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
295 shstrindex >= hdr->e_shnum ||
296 shdr[shstrindex].sh_type != SHT_STRTAB) {
297 printf("%s: bad/missing section headers\n", filename);
302 /* Allocate space for tracking the load chunks */
303 if (ef->nprogtab != 0)
304 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
305 M_LINKER, M_WAITOK | M_ZERO);
306 if (ef->nreltab != 0)
307 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
308 M_LINKER, M_WAITOK | M_ZERO);
309 if (ef->nrelatab != 0)
310 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
311 M_LINKER, M_WAITOK | M_ZERO);
312 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
313 (ef->nreltab != 0 && ef->reltab == NULL) ||
314 (ef->nrelatab != 0 && ef->relatab == NULL)) {
319 /* XXX, relocate the sh_addr fields saved by the loader. */
321 for (i = 0; i < hdr->e_shnum; i++) {
322 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
323 off = shdr[i].sh_addr;
325 for (i = 0; i < hdr->e_shnum; i++) {
326 if (shdr[i].sh_addr != 0)
327 shdr[i].sh_addr = shdr[i].sh_addr - off +
328 (Elf_Addr)ef->address;
331 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
332 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
333 ef->ddbstrcnt = shdr[symstrindex].sh_size;
334 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
335 ef->shstrcnt = shdr[shstrindex].sh_size;
336 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
338 /* Now fill out progtab and the relocation tables. */
342 for (i = 0; i < hdr->e_shnum; i++) {
343 switch (shdr[i].sh_type) {
347 case SHT_X86_64_UNWIND:
349 if (shdr[i].sh_addr == 0)
351 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
352 if (shdr[i].sh_type == SHT_PROGBITS)
353 ef->progtab[pb].name = "<<PROGBITS>>";
355 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
356 ef->progtab[pb].name = "<<UNWIND>>";
359 ef->progtab[pb].name = "<<NOBITS>>";
360 ef->progtab[pb].size = shdr[i].sh_size;
361 ef->progtab[pb].sec = i;
362 if (ef->shstrtab && shdr[i].sh_name != 0)
363 ef->progtab[pb].name =
364 ef->shstrtab + shdr[i].sh_name;
365 if (ef->progtab[pb].name != NULL &&
366 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
369 dpcpu = dpcpu_alloc(shdr[i].sh_size);
371 printf("%s: pcpu module space is out "
372 "of space; cannot allocate %#jx "
373 "for %s\n", __func__,
374 (uintmax_t)shdr[i].sh_size,
379 memcpy(dpcpu, ef->progtab[pb].addr,
380 ef->progtab[pb].size);
381 dpcpu_copy(dpcpu, shdr[i].sh_size);
382 ef->progtab[pb].addr = dpcpu;
384 } else if (ef->progtab[pb].name != NULL &&
385 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
388 vnet_data = vnet_data_alloc(shdr[i].sh_size);
389 if (vnet_data == NULL) {
390 printf("%s: vnet module space is out "
391 "of space; cannot allocate %#jx "
392 "for %s\n", __func__,
393 (uintmax_t)shdr[i].sh_size,
398 memcpy(vnet_data, ef->progtab[pb].addr,
399 ef->progtab[pb].size);
400 vnet_data_copy(vnet_data, shdr[i].sh_size);
401 ef->progtab[pb].addr = vnet_data;
403 } else if (ef->progtab[pb].name != NULL &&
404 !strcmp(ef->progtab[pb].name, ".ctors")) {
405 lf->ctors_addr = ef->progtab[pb].addr;
406 lf->ctors_size = shdr[i].sh_size;
409 /* Update all symbol values with the offset. */
410 for (j = 0; j < ef->ddbsymcnt; j++) {
411 es = &ef->ddbsymtab[j];
412 if (es->st_shndx != i)
414 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
419 if (shdr[shdr[i].sh_info].sh_addr == 0)
421 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
422 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
423 ef->reltab[rl].sec = shdr[i].sh_info;
427 if (shdr[shdr[i].sh_info].sh_addr == 0)
429 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
430 ef->relatab[ra].nrela =
431 shdr[i].sh_size / sizeof(Elf_Rela);
432 ef->relatab[ra].sec = shdr[i].sh_info;
437 if (pb != ef->nprogtab) {
438 printf("%s: lost progbits\n", filename);
442 if (rl != ef->nreltab) {
443 printf("%s: lost reltab\n", filename);
447 if (ra != ef->nrelatab) {
448 printf("%s: lost relatab\n", filename);
453 /* Local intra-module relocations */
454 error = link_elf_reloc_local(lf, false);
461 /* preload not done this way */
462 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
467 link_elf_invoke_ctors(caddr_t addr, size_t size)
472 if (addr == NULL || size == 0)
474 cnt = size / sizeof(*ctor);
476 for (i = 0; i < cnt; i++) {
483 link_elf_link_preload_finish(linker_file_t lf)
489 error = relocate_file(ef);
493 /* Notify MD code that a module is being loaded. */
494 error = elf_cpu_load_file(lf);
498 #if defined(__i386__) || defined(__amd64__)
500 error = link_elf_reloc_local(lf, true);
506 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
511 link_elf_load_file(linker_class_t cls, const char *filename,
512 linker_file_t *result)
514 struct nameidata *nd;
515 struct thread *td = curthread; /* XXX */
539 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
540 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
542 error = vn_open(nd, &flags, 0, NULL);
547 NDFREE(nd, NDF_ONLY_PNBUF);
548 if (nd->ni_vp->v_type != VREG) {
553 error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
559 /* Read the elf header from the file. */
560 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
561 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
562 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
576 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
577 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
578 link_elf_error(filename, "Unsupported file layout");
582 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
583 || hdr->e_version != EV_CURRENT) {
584 link_elf_error(filename, "Unsupported file version");
588 if (hdr->e_type != ET_REL) {
592 if (hdr->e_machine != ELF_TARG_MACH) {
593 link_elf_error(filename, "Unsupported machine");
598 lf = linker_make_file(filename, &link_elf_class);
603 ef = (elf_file_t) lf;
609 /* Allocate and read in the section header */
610 nbytes = hdr->e_shnum * hdr->e_shentsize;
611 if (nbytes == 0 || hdr->e_shoff == 0 ||
612 hdr->e_shentsize != sizeof(Elf_Shdr)) {
616 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
618 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
619 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
628 /* Scan the section header for information and table sizing. */
632 for (i = 0; i < hdr->e_shnum; i++) {
633 if (shdr[i].sh_size == 0)
635 switch (shdr[i].sh_type) {
639 case SHT_X86_64_UNWIND:
641 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
648 symstrindex = shdr[i].sh_link;
652 * Ignore relocation tables for unallocated
655 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
660 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
668 if (ef->nprogtab == 0) {
669 link_elf_error(filename, "file has no contents");
674 /* Only allow one symbol table for now */
675 link_elf_error(filename,
676 "file must have exactly one symbol table");
680 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
681 shdr[symstrindex].sh_type != SHT_STRTAB) {
682 link_elf_error(filename, "file has invalid symbol strings");
687 /* Allocate space for tracking the load chunks */
688 if (ef->nprogtab != 0)
689 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
690 M_LINKER, M_WAITOK | M_ZERO);
691 if (ef->nreltab != 0)
692 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
693 M_LINKER, M_WAITOK | M_ZERO);
694 if (ef->nrelatab != 0)
695 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
696 M_LINKER, M_WAITOK | M_ZERO);
698 if (symtabindex == -1) {
699 link_elf_error(filename, "lost symbol table index");
703 /* Allocate space for and load the symbol table */
704 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
705 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
706 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
707 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
708 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
717 if (symstrindex == -1) {
718 link_elf_error(filename, "lost symbol string index");
722 /* Allocate space for and load the symbol strings */
723 ef->ddbstrcnt = shdr[symstrindex].sh_size;
724 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
725 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
726 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
727 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
736 /* Do we have a string table for the section names? */
738 if (hdr->e_shstrndx != 0 &&
739 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
740 shstrindex = hdr->e_shstrndx;
741 ef->shstrcnt = shdr[shstrindex].sh_size;
742 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
744 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
745 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
746 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
756 /* Size up code/data(progbits) and bss(nobits). */
758 for (i = 0; i < hdr->e_shnum; i++) {
759 if (shdr[i].sh_size == 0)
761 switch (shdr[i].sh_type) {
765 case SHT_X86_64_UNWIND:
767 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
769 alignmask = shdr[i].sh_addralign - 1;
770 mapsize += alignmask;
771 mapsize &= ~alignmask;
772 mapsize += shdr[i].sh_size;
778 * We know how much space we need for the text/data/bss/etc.
779 * This stuff needs to be in a single chunk so that profiling etc
780 * can get the bounds and gdb can associate offsets with modules
782 ef->object = vm_object_allocate(OBJT_DEFAULT,
783 round_page(mapsize) >> PAGE_SHIFT);
784 if (ef->object == NULL) {
788 ef->address = (caddr_t) vm_map_min(kernel_map);
791 * In order to satisfy amd64's architectural requirements on the
792 * location of code and data in the kernel's address space, request a
793 * mapping that is above the kernel.
798 mapbase = VM_MIN_KERNEL_ADDRESS;
800 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
801 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
804 vm_object_deallocate(ef->object);
810 error = vm_map_wire(kernel_map, mapbase,
811 mapbase + round_page(mapsize),
812 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
813 if (error != KERN_SUCCESS) {
818 /* Inform the kld system about the situation */
819 lf->address = ef->address = (caddr_t)mapbase;
823 * Now load code/data(progbits), zero bss(nobits), allocate space for
830 for (i = 0; i < hdr->e_shnum; i++) {
831 if (shdr[i].sh_size == 0)
833 switch (shdr[i].sh_type) {
837 case SHT_X86_64_UNWIND:
839 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
841 alignmask = shdr[i].sh_addralign - 1;
842 mapbase += alignmask;
843 mapbase &= ~alignmask;
844 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
845 ef->progtab[pb].name =
846 ef->shstrtab + shdr[i].sh_name;
847 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
848 lf->ctors_addr = (caddr_t)mapbase;
849 lf->ctors_size = shdr[i].sh_size;
851 } else if (shdr[i].sh_type == SHT_PROGBITS)
852 ef->progtab[pb].name = "<<PROGBITS>>";
854 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
855 ef->progtab[pb].name = "<<UNWIND>>";
858 ef->progtab[pb].name = "<<NOBITS>>";
859 if (ef->progtab[pb].name != NULL &&
860 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
861 ef->progtab[pb].addr =
862 dpcpu_alloc(shdr[i].sh_size);
863 if (ef->progtab[pb].addr == NULL) {
864 printf("%s: pcpu module space is out "
865 "of space; cannot allocate %#jx "
866 "for %s\n", __func__,
867 (uintmax_t)shdr[i].sh_size,
872 else if (ef->progtab[pb].name != NULL &&
873 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
874 ef->progtab[pb].addr =
875 vnet_data_alloc(shdr[i].sh_size);
876 if (ef->progtab[pb].addr == NULL) {
877 printf("%s: vnet module space is out "
878 "of space; cannot allocate %#jx "
879 "for %s\n", __func__,
880 (uintmax_t)shdr[i].sh_size,
886 ef->progtab[pb].addr =
887 (void *)(uintptr_t)mapbase;
888 if (ef->progtab[pb].addr == NULL) {
892 ef->progtab[pb].size = shdr[i].sh_size;
893 ef->progtab[pb].sec = i;
894 if (shdr[i].sh_type == SHT_PROGBITS
896 || shdr[i].sh_type == SHT_X86_64_UNWIND
899 error = vn_rdwr(UIO_READ, nd->ni_vp,
900 ef->progtab[pb].addr,
901 shdr[i].sh_size, shdr[i].sh_offset,
902 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
910 /* Initialize the per-cpu or vnet area. */
911 if (ef->progtab[pb].addr != (void *)mapbase &&
912 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
913 dpcpu_copy(ef->progtab[pb].addr,
916 else if (ef->progtab[pb].addr !=
918 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
919 vnet_data_copy(ef->progtab[pb].addr,
923 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
925 /* Update all symbol values with the offset. */
926 for (j = 0; j < ef->ddbsymcnt; j++) {
927 es = &ef->ddbsymtab[j];
928 if (es->st_shndx != i)
930 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
932 mapbase += shdr[i].sh_size;
936 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
938 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
940 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
941 ef->reltab[rl].sec = shdr[i].sh_info;
942 error = vn_rdwr(UIO_READ, nd->ni_vp,
943 (void *)ef->reltab[rl].rel,
944 shdr[i].sh_size, shdr[i].sh_offset,
945 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
956 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
958 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
960 ef->relatab[ra].nrela =
961 shdr[i].sh_size / sizeof(Elf_Rela);
962 ef->relatab[ra].sec = shdr[i].sh_info;
963 error = vn_rdwr(UIO_READ, nd->ni_vp,
964 (void *)ef->relatab[ra].rela,
965 shdr[i].sh_size, shdr[i].sh_offset,
966 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
978 if (pb != ef->nprogtab) {
979 link_elf_error(filename, "lost progbits");
983 if (rl != ef->nreltab) {
984 link_elf_error(filename, "lost reltab");
988 if (ra != ef->nrelatab) {
989 link_elf_error(filename, "lost relatab");
993 if (mapbase != (vm_offset_t)ef->address + mapsize) {
995 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
996 filename != NULL ? filename : "<none>",
997 (u_long)mapbase, ef->address, (u_long)mapsize,
998 (u_long)(vm_offset_t)ef->address + mapsize);
1003 /* Local intra-module relocations */
1004 error = link_elf_reloc_local(lf, false);
1008 /* Pull in dependencies */
1009 VOP_UNLOCK(nd->ni_vp, 0);
1010 error = linker_load_dependencies(lf);
1011 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1015 /* External relocations */
1016 error = relocate_file(ef);
1020 /* Notify MD code that a module is being loaded. */
1021 error = elf_cpu_load_file(lf);
1025 #if defined(__i386__) || defined(__amd64__)
1027 error = link_elf_reloc_local(lf, true);
1033 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1038 VOP_UNLOCK(nd->ni_vp, 0);
1039 vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1042 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1043 free(hdr, M_LINKER);
1049 link_elf_unload_file(linker_file_t file)
1051 elf_file_t ef = (elf_file_t) file;
1054 /* Notify MD code that a module is being unloaded. */
1055 elf_cpu_unload_file(file);
1058 for (i = 0; i < ef->nprogtab; i++) {
1059 if (ef->progtab[i].size == 0)
1061 if (ef->progtab[i].name == NULL)
1063 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1064 dpcpu_free(ef->progtab[i].addr,
1065 ef->progtab[i].size);
1067 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1068 vnet_data_free(ef->progtab[i].addr,
1069 ef->progtab[i].size);
1073 if (ef->preloaded) {
1074 free(ef->reltab, M_LINKER);
1075 free(ef->relatab, M_LINKER);
1076 free(ef->progtab, M_LINKER);
1077 free(ef->ctftab, M_LINKER);
1078 free(ef->ctfoff, M_LINKER);
1079 free(ef->typoff, M_LINKER);
1080 if (file->pathname != NULL)
1081 preload_delete_name(file->pathname);
1085 for (i = 0; i < ef->nreltab; i++)
1086 free(ef->reltab[i].rel, M_LINKER);
1087 for (i = 0; i < ef->nrelatab; i++)
1088 free(ef->relatab[i].rela, M_LINKER);
1089 free(ef->reltab, M_LINKER);
1090 free(ef->relatab, M_LINKER);
1091 free(ef->progtab, M_LINKER);
1094 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1095 (vm_offset_t) ef->address +
1096 (ef->object->size << PAGE_SHIFT));
1098 free(ef->e_shdr, M_LINKER);
1099 free(ef->ddbsymtab, M_LINKER);
1100 free(ef->ddbstrtab, M_LINKER);
1101 free(ef->shstrtab, M_LINKER);
1102 free(ef->ctftab, M_LINKER);
1103 free(ef->ctfoff, M_LINKER);
1104 free(ef->typoff, M_LINKER);
1108 symbol_name(elf_file_t ef, Elf_Size r_info)
1112 if (ELF_R_SYM(r_info)) {
1113 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1114 return ef->ddbstrtab + ref->st_name;
1120 findbase(elf_file_t ef, int sec)
1125 for (i = 0; i < ef->nprogtab; i++) {
1126 if (sec == ef->progtab[i].sec) {
1127 base = (Elf_Addr)ef->progtab[i].addr;
1135 relocate_file(elf_file_t ef)
1137 const Elf_Rel *rellim;
1139 const Elf_Rela *relalim;
1140 const Elf_Rela *rela;
1141 const char *symname;
1148 /* Perform relocations without addend if there are any: */
1149 for (i = 0; i < ef->nreltab; i++) {
1150 rel = ef->reltab[i].rel;
1152 link_elf_error(ef->lf.filename, "lost a reltab!");
1155 rellim = rel + ef->reltab[i].nrel;
1156 base = findbase(ef, ef->reltab[i].sec);
1158 link_elf_error(ef->lf.filename, "lost base for reltab");
1161 for ( ; rel < rellim; rel++) {
1162 symidx = ELF_R_SYM(rel->r_info);
1163 if (symidx >= ef->ddbsymcnt)
1165 sym = ef->ddbsymtab + symidx;
1166 /* Local relocs are already done */
1167 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1169 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1171 symname = symbol_name(ef, rel->r_info);
1172 printf("link_elf_obj: symbol %s undefined\n",
1179 /* Perform relocations with addend if there are any: */
1180 for (i = 0; i < ef->nrelatab; i++) {
1181 rela = ef->relatab[i].rela;
1183 link_elf_error(ef->lf.filename, "lost a relatab!");
1186 relalim = rela + ef->relatab[i].nrela;
1187 base = findbase(ef, ef->relatab[i].sec);
1189 link_elf_error(ef->lf.filename,
1190 "lost base for relatab");
1193 for ( ; rela < relalim; rela++) {
1194 symidx = ELF_R_SYM(rela->r_info);
1195 if (symidx >= ef->ddbsymcnt)
1197 sym = ef->ddbsymtab + symidx;
1198 /* Local relocs are already done */
1199 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1201 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1203 symname = symbol_name(ef, rela->r_info);
1204 printf("link_elf_obj: symbol %s undefined\n",
1212 * Only clean SHN_FBSD_CACHED for successful return. If we
1213 * modified symbol table for the object but found an
1214 * unresolved symbol, there is no reason to roll back.
1216 elf_obj_cleanup_globals_cache(ef);
1222 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1224 elf_file_t ef = (elf_file_t) lf;
1225 const Elf_Sym *symp;
1229 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1230 strp = ef->ddbstrtab + symp->st_name;
1231 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1232 *sym = (c_linker_sym_t) symp;
1240 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1241 linker_symval_t *symval)
1247 ef = (elf_file_t) lf;
1248 es = (const Elf_Sym*) sym;
1249 val = (caddr_t)es->st_value;
1250 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1251 symval->name = ef->ddbstrtab + es->st_name;
1252 val = (caddr_t)es->st_value;
1253 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1254 val = ((caddr_t (*)(void))val)();
1255 symval->value = val;
1256 symval->size = es->st_size;
1263 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1264 c_linker_sym_t *sym, long *diffp)
1266 elf_file_t ef = (elf_file_t) lf;
1267 u_long off = (uintptr_t) (void *) value;
1271 const Elf_Sym *best = NULL;
1274 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1275 if (es->st_name == 0)
1277 st_value = es->st_value;
1278 if (off >= st_value) {
1279 if (off - st_value < diff) {
1280 diff = off - st_value;
1284 } else if (off - st_value == diff) {
1293 *sym = (c_linker_sym_t) best;
1299 * Look up a linker set on an ELF system.
1302 link_elf_lookup_set(linker_file_t lf, const char *name,
1303 void ***startp, void ***stopp, int *countp)
1305 elf_file_t ef = (elf_file_t)lf;
1306 void **start, **stop;
1309 /* Relative to section number */
1310 for (i = 0; i < ef->nprogtab; i++) {
1311 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1312 strcmp(ef->progtab[i].name + 4, name) == 0) {
1313 start = (void **)ef->progtab[i].addr;
1314 stop = (void **)((char *)ef->progtab[i].addr +
1315 ef->progtab[i].size);
1316 count = stop - start;
1330 link_elf_each_function_name(linker_file_t file,
1331 int (*callback)(const char *, void *), void *opaque)
1333 elf_file_t ef = (elf_file_t)file;
1334 const Elf_Sym *symp;
1337 /* Exhaustive search */
1338 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1339 if (symp->st_value != 0 &&
1340 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1341 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1342 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1351 link_elf_each_function_nameval(linker_file_t file,
1352 linker_function_nameval_callback_t callback, void *opaque)
1354 linker_symval_t symval;
1355 elf_file_t ef = (elf_file_t)file;
1356 const Elf_Sym* symp;
1359 /* Exhaustive search */
1360 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1361 if (symp->st_value != 0 &&
1362 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1363 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1364 error = link_elf_symbol_values(file,
1365 (c_linker_sym_t)symp, &symval);
1368 error = callback(file, i, &symval, opaque);
1377 elf_obj_cleanup_globals_cache(elf_file_t ef)
1382 for (i = 0; i < ef->ddbsymcnt; i++) {
1383 sym = ef->ddbsymtab + i;
1384 if (sym->st_shndx == SHN_FBSD_CACHED) {
1385 sym->st_shndx = SHN_UNDEF;
1392 * Symbol lookup function that can be used when the symbol index is known (ie
1393 * in relocations). It uses the symbol index instead of doing a fully fledged
1394 * hash table based lookup when such is valid. For example for local symbols.
1395 * This is not only more efficient, it's also more correct. It's not always
1396 * the case that the symbol can be found through the hash table.
1399 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1401 elf_file_t ef = (elf_file_t)lf;
1406 /* Don't even try to lookup the symbol if the index is bogus. */
1407 if (symidx >= ef->ddbsymcnt) {
1412 sym = ef->ddbsymtab + symidx;
1414 /* Quick answer if there is a definition included. */
1415 if (sym->st_shndx != SHN_UNDEF) {
1416 res1 = (Elf_Addr)sym->st_value;
1417 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1418 res1 = ((Elf_Addr (*)(void))res1)();
1423 /* If we get here, then it is undefined and needs a lookup. */
1424 switch (ELF_ST_BIND(sym->st_info)) {
1426 /* Local, but undefined? huh? */
1432 /* Relative to Data or Function name */
1433 symbol = ef->ddbstrtab + sym->st_name;
1435 /* Force a lookup failure if the symbol name is bogus. */
1440 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1443 * Cache global lookups during module relocation. The failure
1444 * case is particularly expensive for callers, who must scan
1445 * through the entire globals table doing strcmp(). Cache to
1446 * avoid doing such work repeatedly.
1448 * After relocation is complete, undefined globals will be
1449 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1453 sym->st_shndx = SHN_FBSD_CACHED;
1454 sym->st_value = res1;
1457 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1470 link_elf_fix_link_set(elf_file_t ef)
1472 static const char startn[] = "__start_";
1473 static const char stopn[] = "__stop_";
1475 const char *sym_name, *linkset_name;
1476 Elf_Addr startp, stopp;
1481 for (symidx = 1 /* zero entry is special */;
1482 symidx < ef->ddbsymcnt; symidx++) {
1483 sym = ef->ddbsymtab + symidx;
1484 if (sym->st_shndx != SHN_UNDEF)
1487 sym_name = ef->ddbstrtab + sym->st_name;
1488 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1490 linkset_name = sym_name + sizeof(startn) - 1;
1492 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1494 linkset_name = sym_name + sizeof(stopn) - 1;
1499 for (i = 0; i < ef->nprogtab; i++) {
1500 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1501 startp = (Elf_Addr)ef->progtab[i].addr;
1502 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1506 if (i == ef->nprogtab)
1509 sym->st_value = start ? startp : stopp;
1515 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1517 elf_file_t ef = (elf_file_t)lf;
1518 const Elf_Rel *rellim;
1520 const Elf_Rela *relalim;
1521 const Elf_Rela *rela;
1527 link_elf_fix_link_set(ef);
1529 /* Perform relocations without addend if there are any: */
1530 for (i = 0; i < ef->nreltab; i++) {
1531 rel = ef->reltab[i].rel;
1533 link_elf_error(ef->lf.filename, "lost a reltab");
1536 rellim = rel + ef->reltab[i].nrel;
1537 base = findbase(ef, ef->reltab[i].sec);
1539 link_elf_error(ef->lf.filename, "lost base for reltab");
1542 for ( ; rel < rellim; rel++) {
1543 symidx = ELF_R_SYM(rel->r_info);
1544 if (symidx >= ef->ddbsymcnt)
1546 sym = ef->ddbsymtab + symidx;
1547 /* Only do local relocs */
1548 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1550 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1551 elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1552 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1557 /* Perform relocations with addend if there are any: */
1558 for (i = 0; i < ef->nrelatab; i++) {
1559 rela = ef->relatab[i].rela;
1561 link_elf_error(ef->lf.filename, "lost a relatab!");
1564 relalim = rela + ef->relatab[i].nrela;
1565 base = findbase(ef, ef->relatab[i].sec);
1567 link_elf_error(ef->lf.filename, "lost base for reltab");
1570 for ( ; rela < relalim; rela++) {
1571 symidx = ELF_R_SYM(rela->r_info);
1572 if (symidx >= ef->ddbsymcnt)
1574 sym = ef->ddbsymtab + symidx;
1575 /* Only do local relocs */
1576 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1578 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1579 elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1580 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1588 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1590 elf_file_t ef = (elf_file_t)lf;
1592 *symtab = ef->ddbsymtab;
1594 if (*symtab == NULL)
1597 return (ef->ddbsymcnt);
1601 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1603 elf_file_t ef = (elf_file_t)lf;
1605 *strtab = ef->ddbstrtab;
1607 if (*strtab == NULL)
1610 return (ef->ddbstrcnt);