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>
65 #include <contrib/zlib/zlib.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 /* Allocate space for and load the symbol strings */
718 ef->ddbstrcnt = shdr[symstrindex].sh_size;
719 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
720 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
721 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
722 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
731 /* Do we have a string table for the section names? */
733 if (hdr->e_shstrndx != 0 &&
734 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
735 shstrindex = hdr->e_shstrndx;
736 ef->shstrcnt = shdr[shstrindex].sh_size;
737 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
739 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
740 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
741 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
751 /* Size up code/data(progbits) and bss(nobits). */
753 for (i = 0; i < hdr->e_shnum; i++) {
754 if (shdr[i].sh_size == 0)
756 switch (shdr[i].sh_type) {
760 case SHT_X86_64_UNWIND:
762 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
764 alignmask = shdr[i].sh_addralign - 1;
765 mapsize += alignmask;
766 mapsize &= ~alignmask;
767 mapsize += shdr[i].sh_size;
773 * We know how much space we need for the text/data/bss/etc.
774 * This stuff needs to be in a single chunk so that profiling etc
775 * can get the bounds and gdb can associate offsets with modules
777 ef->object = vm_object_allocate(OBJT_DEFAULT,
778 round_page(mapsize) >> PAGE_SHIFT);
779 if (ef->object == NULL) {
783 ef->address = (caddr_t) vm_map_min(kernel_map);
786 * In order to satisfy amd64's architectural requirements on the
787 * location of code and data in the kernel's address space, request a
788 * mapping that is above the kernel.
793 mapbase = VM_MIN_KERNEL_ADDRESS;
795 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
796 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
799 vm_object_deallocate(ef->object);
805 error = vm_map_wire(kernel_map, mapbase,
806 mapbase + round_page(mapsize),
807 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
808 if (error != KERN_SUCCESS) {
813 /* Inform the kld system about the situation */
814 lf->address = ef->address = (caddr_t)mapbase;
818 * Now load code/data(progbits), zero bss(nobits), allocate space for
825 for (i = 0; i < hdr->e_shnum; i++) {
826 if (shdr[i].sh_size == 0)
828 switch (shdr[i].sh_type) {
832 case SHT_X86_64_UNWIND:
834 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
836 alignmask = shdr[i].sh_addralign - 1;
837 mapbase += alignmask;
838 mapbase &= ~alignmask;
839 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
840 ef->progtab[pb].name =
841 ef->shstrtab + shdr[i].sh_name;
842 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
843 lf->ctors_addr = (caddr_t)mapbase;
844 lf->ctors_size = shdr[i].sh_size;
846 } else if (shdr[i].sh_type == SHT_PROGBITS)
847 ef->progtab[pb].name = "<<PROGBITS>>";
849 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
850 ef->progtab[pb].name = "<<UNWIND>>";
853 ef->progtab[pb].name = "<<NOBITS>>";
854 if (ef->progtab[pb].name != NULL &&
855 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
856 ef->progtab[pb].addr =
857 dpcpu_alloc(shdr[i].sh_size);
858 if (ef->progtab[pb].addr == NULL) {
859 printf("%s: pcpu module space is out "
860 "of space; cannot allocate %#jx "
861 "for %s\n", __func__,
862 (uintmax_t)shdr[i].sh_size,
867 else if (ef->progtab[pb].name != NULL &&
868 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
869 ef->progtab[pb].addr =
870 vnet_data_alloc(shdr[i].sh_size);
871 if (ef->progtab[pb].addr == NULL) {
872 printf("%s: vnet module space is out "
873 "of space; cannot allocate %#jx "
874 "for %s\n", __func__,
875 (uintmax_t)shdr[i].sh_size,
881 ef->progtab[pb].addr =
882 (void *)(uintptr_t)mapbase;
883 if (ef->progtab[pb].addr == NULL) {
887 ef->progtab[pb].size = shdr[i].sh_size;
888 ef->progtab[pb].sec = i;
889 if (shdr[i].sh_type == SHT_PROGBITS
891 || shdr[i].sh_type == SHT_X86_64_UNWIND
894 error = vn_rdwr(UIO_READ, nd->ni_vp,
895 ef->progtab[pb].addr,
896 shdr[i].sh_size, shdr[i].sh_offset,
897 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
905 /* Initialize the per-cpu or vnet area. */
906 if (ef->progtab[pb].addr != (void *)mapbase &&
907 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
908 dpcpu_copy(ef->progtab[pb].addr,
911 else if (ef->progtab[pb].addr !=
913 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
914 vnet_data_copy(ef->progtab[pb].addr,
918 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
920 /* Update all symbol values with the offset. */
921 for (j = 0; j < ef->ddbsymcnt; j++) {
922 es = &ef->ddbsymtab[j];
923 if (es->st_shndx != i)
925 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
927 mapbase += shdr[i].sh_size;
931 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
933 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
935 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
936 ef->reltab[rl].sec = shdr[i].sh_info;
937 error = vn_rdwr(UIO_READ, nd->ni_vp,
938 (void *)ef->reltab[rl].rel,
939 shdr[i].sh_size, shdr[i].sh_offset,
940 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
951 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
953 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
955 ef->relatab[ra].nrela =
956 shdr[i].sh_size / sizeof(Elf_Rela);
957 ef->relatab[ra].sec = shdr[i].sh_info;
958 error = vn_rdwr(UIO_READ, nd->ni_vp,
959 (void *)ef->relatab[ra].rela,
960 shdr[i].sh_size, shdr[i].sh_offset,
961 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
973 if (pb != ef->nprogtab) {
974 link_elf_error(filename, "lost progbits");
978 if (rl != ef->nreltab) {
979 link_elf_error(filename, "lost reltab");
983 if (ra != ef->nrelatab) {
984 link_elf_error(filename, "lost relatab");
988 if (mapbase != (vm_offset_t)ef->address + mapsize) {
990 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
991 filename != NULL ? filename : "<none>",
992 (u_long)mapbase, ef->address, (u_long)mapsize,
993 (u_long)(vm_offset_t)ef->address + mapsize);
998 /* Local intra-module relocations */
999 error = link_elf_reloc_local(lf, false);
1003 /* Pull in dependencies */
1004 VOP_UNLOCK(nd->ni_vp, 0);
1005 error = linker_load_dependencies(lf);
1006 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
1010 /* External relocations */
1011 error = relocate_file(ef);
1015 /* Notify MD code that a module is being loaded. */
1016 error = elf_cpu_load_file(lf);
1020 #if defined(__i386__) || defined(__amd64__)
1022 error = link_elf_reloc_local(lf, true);
1028 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1033 VOP_UNLOCK(nd->ni_vp, 0);
1034 vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1037 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1038 free(hdr, M_LINKER);
1044 link_elf_unload_file(linker_file_t file)
1046 elf_file_t ef = (elf_file_t) file;
1049 /* Notify MD code that a module is being unloaded. */
1050 elf_cpu_unload_file(file);
1053 for (i = 0; i < ef->nprogtab; i++) {
1054 if (ef->progtab[i].size == 0)
1056 if (ef->progtab[i].name == NULL)
1058 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1059 dpcpu_free(ef->progtab[i].addr,
1060 ef->progtab[i].size);
1062 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1063 vnet_data_free(ef->progtab[i].addr,
1064 ef->progtab[i].size);
1068 if (ef->preloaded) {
1069 free(ef->reltab, M_LINKER);
1070 free(ef->relatab, M_LINKER);
1071 free(ef->progtab, M_LINKER);
1072 free(ef->ctftab, M_LINKER);
1073 free(ef->ctfoff, M_LINKER);
1074 free(ef->typoff, M_LINKER);
1075 if (file->pathname != NULL)
1076 preload_delete_name(file->pathname);
1080 for (i = 0; i < ef->nreltab; i++)
1081 free(ef->reltab[i].rel, M_LINKER);
1082 for (i = 0; i < ef->nrelatab; i++)
1083 free(ef->relatab[i].rela, M_LINKER);
1084 free(ef->reltab, M_LINKER);
1085 free(ef->relatab, M_LINKER);
1086 free(ef->progtab, M_LINKER);
1089 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1090 (vm_offset_t) ef->address +
1091 (ef->object->size << PAGE_SHIFT));
1093 free(ef->e_shdr, M_LINKER);
1094 free(ef->ddbsymtab, M_LINKER);
1095 free(ef->ddbstrtab, M_LINKER);
1096 free(ef->shstrtab, M_LINKER);
1097 free(ef->ctftab, M_LINKER);
1098 free(ef->ctfoff, M_LINKER);
1099 free(ef->typoff, M_LINKER);
1103 symbol_name(elf_file_t ef, Elf_Size r_info)
1107 if (ELF_R_SYM(r_info)) {
1108 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1109 return ef->ddbstrtab + ref->st_name;
1115 findbase(elf_file_t ef, int sec)
1120 for (i = 0; i < ef->nprogtab; i++) {
1121 if (sec == ef->progtab[i].sec) {
1122 base = (Elf_Addr)ef->progtab[i].addr;
1130 relocate_file(elf_file_t ef)
1132 const Elf_Rel *rellim;
1134 const Elf_Rela *relalim;
1135 const Elf_Rela *rela;
1136 const char *symname;
1143 /* Perform relocations without addend if there are any: */
1144 for (i = 0; i < ef->nreltab; i++) {
1145 rel = ef->reltab[i].rel;
1147 link_elf_error(ef->lf.filename, "lost a reltab!");
1150 rellim = rel + ef->reltab[i].nrel;
1151 base = findbase(ef, ef->reltab[i].sec);
1153 link_elf_error(ef->lf.filename, "lost base for reltab");
1156 for ( ; rel < rellim; rel++) {
1157 symidx = ELF_R_SYM(rel->r_info);
1158 if (symidx >= ef->ddbsymcnt)
1160 sym = ef->ddbsymtab + symidx;
1161 /* Local relocs are already done */
1162 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1164 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1166 symname = symbol_name(ef, rel->r_info);
1167 printf("link_elf_obj: symbol %s undefined\n",
1174 /* Perform relocations with addend if there are any: */
1175 for (i = 0; i < ef->nrelatab; i++) {
1176 rela = ef->relatab[i].rela;
1178 link_elf_error(ef->lf.filename, "lost a relatab!");
1181 relalim = rela + ef->relatab[i].nrela;
1182 base = findbase(ef, ef->relatab[i].sec);
1184 link_elf_error(ef->lf.filename,
1185 "lost base for relatab");
1188 for ( ; rela < relalim; rela++) {
1189 symidx = ELF_R_SYM(rela->r_info);
1190 if (symidx >= ef->ddbsymcnt)
1192 sym = ef->ddbsymtab + symidx;
1193 /* Local relocs are already done */
1194 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1196 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1198 symname = symbol_name(ef, rela->r_info);
1199 printf("link_elf_obj: symbol %s undefined\n",
1207 * Only clean SHN_FBSD_CACHED for successful return. If we
1208 * modified symbol table for the object but found an
1209 * unresolved symbol, there is no reason to roll back.
1211 elf_obj_cleanup_globals_cache(ef);
1217 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1219 elf_file_t ef = (elf_file_t) lf;
1220 const Elf_Sym *symp;
1224 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1225 strp = ef->ddbstrtab + symp->st_name;
1226 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1227 *sym = (c_linker_sym_t) symp;
1235 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1236 linker_symval_t *symval)
1242 ef = (elf_file_t) lf;
1243 es = (const Elf_Sym*) sym;
1244 val = (caddr_t)es->st_value;
1245 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1246 symval->name = ef->ddbstrtab + es->st_name;
1247 val = (caddr_t)es->st_value;
1248 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1249 val = ((caddr_t (*)(void))val)();
1250 symval->value = val;
1251 symval->size = es->st_size;
1258 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1259 c_linker_sym_t *sym, long *diffp)
1261 elf_file_t ef = (elf_file_t) lf;
1262 u_long off = (uintptr_t) (void *) value;
1266 const Elf_Sym *best = NULL;
1269 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1270 if (es->st_name == 0)
1272 st_value = es->st_value;
1273 if (off >= st_value) {
1274 if (off - st_value < diff) {
1275 diff = off - st_value;
1279 } else if (off - st_value == diff) {
1288 *sym = (c_linker_sym_t) best;
1294 * Look up a linker set on an ELF system.
1297 link_elf_lookup_set(linker_file_t lf, const char *name,
1298 void ***startp, void ***stopp, int *countp)
1300 elf_file_t ef = (elf_file_t)lf;
1301 void **start, **stop;
1304 /* Relative to section number */
1305 for (i = 0; i < ef->nprogtab; i++) {
1306 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1307 strcmp(ef->progtab[i].name + 4, name) == 0) {
1308 start = (void **)ef->progtab[i].addr;
1309 stop = (void **)((char *)ef->progtab[i].addr +
1310 ef->progtab[i].size);
1311 count = stop - start;
1325 link_elf_each_function_name(linker_file_t file,
1326 int (*callback)(const char *, void *), void *opaque)
1328 elf_file_t ef = (elf_file_t)file;
1329 const Elf_Sym *symp;
1332 /* Exhaustive search */
1333 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1334 if (symp->st_value != 0 &&
1335 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1336 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1337 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1346 link_elf_each_function_nameval(linker_file_t file,
1347 linker_function_nameval_callback_t callback, void *opaque)
1349 linker_symval_t symval;
1350 elf_file_t ef = (elf_file_t)file;
1351 const Elf_Sym* symp;
1354 /* Exhaustive search */
1355 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1356 if (symp->st_value != 0 &&
1357 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1358 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1359 error = link_elf_symbol_values(file,
1360 (c_linker_sym_t)symp, &symval);
1363 error = callback(file, i, &symval, opaque);
1372 elf_obj_cleanup_globals_cache(elf_file_t ef)
1377 for (i = 0; i < ef->ddbsymcnt; i++) {
1378 sym = ef->ddbsymtab + i;
1379 if (sym->st_shndx == SHN_FBSD_CACHED) {
1380 sym->st_shndx = SHN_UNDEF;
1387 * Symbol lookup function that can be used when the symbol index is known (ie
1388 * in relocations). It uses the symbol index instead of doing a fully fledged
1389 * hash table based lookup when such is valid. For example for local symbols.
1390 * This is not only more efficient, it's also more correct. It's not always
1391 * the case that the symbol can be found through the hash table.
1394 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1396 elf_file_t ef = (elf_file_t)lf;
1401 /* Don't even try to lookup the symbol if the index is bogus. */
1402 if (symidx >= ef->ddbsymcnt) {
1407 sym = ef->ddbsymtab + symidx;
1409 /* Quick answer if there is a definition included. */
1410 if (sym->st_shndx != SHN_UNDEF) {
1411 res1 = (Elf_Addr)sym->st_value;
1412 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1413 res1 = ((Elf_Addr (*)(void))res1)();
1418 /* If we get here, then it is undefined and needs a lookup. */
1419 switch (ELF_ST_BIND(sym->st_info)) {
1421 /* Local, but undefined? huh? */
1427 /* Relative to Data or Function name */
1428 symbol = ef->ddbstrtab + sym->st_name;
1430 /* Force a lookup failure if the symbol name is bogus. */
1435 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1438 * Cache global lookups during module relocation. The failure
1439 * case is particularly expensive for callers, who must scan
1440 * through the entire globals table doing strcmp(). Cache to
1441 * avoid doing such work repeatedly.
1443 * After relocation is complete, undefined globals will be
1444 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1448 sym->st_shndx = SHN_FBSD_CACHED;
1449 sym->st_value = res1;
1452 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1465 link_elf_fix_link_set(elf_file_t ef)
1467 static const char startn[] = "__start_";
1468 static const char stopn[] = "__stop_";
1470 const char *sym_name, *linkset_name;
1471 Elf_Addr startp, stopp;
1476 for (symidx = 1 /* zero entry is special */;
1477 symidx < ef->ddbsymcnt; symidx++) {
1478 sym = ef->ddbsymtab + symidx;
1479 if (sym->st_shndx != SHN_UNDEF)
1482 sym_name = ef->ddbstrtab + sym->st_name;
1483 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1485 linkset_name = sym_name + sizeof(startn) - 1;
1487 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1489 linkset_name = sym_name + sizeof(stopn) - 1;
1494 for (i = 0; i < ef->nprogtab; i++) {
1495 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1496 startp = (Elf_Addr)ef->progtab[i].addr;
1497 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1501 if (i == ef->nprogtab)
1504 sym->st_value = start ? startp : stopp;
1510 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1512 elf_file_t ef = (elf_file_t)lf;
1513 const Elf_Rel *rellim;
1515 const Elf_Rela *relalim;
1516 const Elf_Rela *rela;
1522 link_elf_fix_link_set(ef);
1524 /* Perform relocations without addend if there are any: */
1525 for (i = 0; i < ef->nreltab; i++) {
1526 rel = ef->reltab[i].rel;
1528 link_elf_error(ef->lf.filename, "lost a reltab");
1531 rellim = rel + ef->reltab[i].nrel;
1532 base = findbase(ef, ef->reltab[i].sec);
1534 link_elf_error(ef->lf.filename, "lost base for reltab");
1537 for ( ; rel < rellim; rel++) {
1538 symidx = ELF_R_SYM(rel->r_info);
1539 if (symidx >= ef->ddbsymcnt)
1541 sym = ef->ddbsymtab + symidx;
1542 /* Only do local relocs */
1543 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1545 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1546 elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1547 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1552 /* Perform relocations with addend if there are any: */
1553 for (i = 0; i < ef->nrelatab; i++) {
1554 rela = ef->relatab[i].rela;
1556 link_elf_error(ef->lf.filename, "lost a relatab!");
1559 relalim = rela + ef->relatab[i].nrela;
1560 base = findbase(ef, ef->relatab[i].sec);
1562 link_elf_error(ef->lf.filename, "lost base for reltab");
1565 for ( ; rela < relalim; rela++) {
1566 symidx = ELF_R_SYM(rela->r_info);
1567 if (symidx >= ef->ddbsymcnt)
1569 sym = ef->ddbsymtab + symidx;
1570 /* Only do local relocs */
1571 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1573 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1574 elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1575 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1583 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1585 elf_file_t ef = (elf_file_t)lf;
1587 *symtab = ef->ddbsymtab;
1589 if (*symtab == NULL)
1592 return (ef->ddbsymcnt);
1596 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1598 elf_file_t ef = (elf_file_t)lf;
1600 *strtab = ef->ddbstrtab;
1602 if (*strtab == NULL)
1605 return (ef->ddbstrcnt);