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);
374 memcpy(dpcpu, ef->progtab[pb].addr,
375 ef->progtab[pb].size);
376 dpcpu_copy(dpcpu, shdr[i].sh_size);
377 ef->progtab[pb].addr = dpcpu;
379 } else if (ef->progtab[pb].name != NULL &&
380 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
383 vnet_data = vnet_data_alloc(shdr[i].sh_size);
384 if (vnet_data == NULL) {
388 memcpy(vnet_data, ef->progtab[pb].addr,
389 ef->progtab[pb].size);
390 vnet_data_copy(vnet_data, shdr[i].sh_size);
391 ef->progtab[pb].addr = vnet_data;
393 } else if (ef->progtab[pb].name != NULL &&
394 !strcmp(ef->progtab[pb].name, ".ctors")) {
395 lf->ctors_addr = ef->progtab[pb].addr;
396 lf->ctors_size = shdr[i].sh_size;
399 /* Update all symbol values with the offset. */
400 for (j = 0; j < ef->ddbsymcnt; j++) {
401 es = &ef->ddbsymtab[j];
402 if (es->st_shndx != i)
404 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
409 if (shdr[shdr[i].sh_info].sh_addr == 0)
411 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
412 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
413 ef->reltab[rl].sec = shdr[i].sh_info;
417 if (shdr[shdr[i].sh_info].sh_addr == 0)
419 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
420 ef->relatab[ra].nrela =
421 shdr[i].sh_size / sizeof(Elf_Rela);
422 ef->relatab[ra].sec = shdr[i].sh_info;
427 if (pb != ef->nprogtab) {
428 printf("%s: lost progbits\n", filename);
432 if (rl != ef->nreltab) {
433 printf("%s: lost reltab\n", filename);
437 if (ra != ef->nrelatab) {
438 printf("%s: lost relatab\n", filename);
443 /* Local intra-module relocations */
444 error = link_elf_reloc_local(lf, false);
451 /* preload not done this way */
452 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
457 link_elf_invoke_ctors(caddr_t addr, size_t size)
462 if (addr == NULL || size == 0)
464 cnt = size / sizeof(*ctor);
466 for (i = 0; i < cnt; i++) {
473 link_elf_link_preload_finish(linker_file_t lf)
479 error = relocate_file(ef);
483 /* Notify MD code that a module is being loaded. */
484 error = elf_cpu_load_file(lf);
488 #if defined(__i386__) || defined(__amd64__)
490 error = link_elf_reloc_local(lf, true);
496 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
501 link_elf_load_file(linker_class_t cls, const char *filename,
502 linker_file_t *result)
504 struct nameidata *nd;
505 struct thread *td = curthread; /* XXX */
529 nd = malloc(sizeof(struct nameidata), M_TEMP, M_WAITOK);
530 NDINIT(nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
532 error = vn_open(nd, &flags, 0, NULL);
537 NDFREE(nd, NDF_ONLY_PNBUF);
538 if (nd->ni_vp->v_type != VREG) {
543 error = mac_kld_check_load(td->td_ucred, nd->ni_vp);
549 /* Read the elf header from the file. */
550 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
551 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)hdr, sizeof(*hdr), 0,
552 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
566 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
567 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
568 link_elf_error(filename, "Unsupported file layout");
572 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
573 || hdr->e_version != EV_CURRENT) {
574 link_elf_error(filename, "Unsupported file version");
578 if (hdr->e_type != ET_REL) {
582 if (hdr->e_machine != ELF_TARG_MACH) {
583 link_elf_error(filename, "Unsupported machine");
588 lf = linker_make_file(filename, &link_elf_class);
593 ef = (elf_file_t) lf;
599 /* Allocate and read in the section header */
600 nbytes = hdr->e_shnum * hdr->e_shentsize;
601 if (nbytes == 0 || hdr->e_shoff == 0 ||
602 hdr->e_shentsize != sizeof(Elf_Shdr)) {
606 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
608 error = vn_rdwr(UIO_READ, nd->ni_vp, (caddr_t)shdr, nbytes,
609 hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
618 /* Scan the section header for information and table sizing. */
622 for (i = 0; i < hdr->e_shnum; i++) {
623 if (shdr[i].sh_size == 0)
625 switch (shdr[i].sh_type) {
629 case SHT_X86_64_UNWIND:
631 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
638 symstrindex = shdr[i].sh_link;
642 * Ignore relocation tables for unallocated
645 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
650 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
658 if (ef->nprogtab == 0) {
659 link_elf_error(filename, "file has no contents");
664 /* Only allow one symbol table for now */
665 link_elf_error(filename,
666 "file must have exactly one symbol table");
670 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
671 shdr[symstrindex].sh_type != SHT_STRTAB) {
672 link_elf_error(filename, "file has invalid symbol strings");
677 /* Allocate space for tracking the load chunks */
678 if (ef->nprogtab != 0)
679 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
680 M_LINKER, M_WAITOK | M_ZERO);
681 if (ef->nreltab != 0)
682 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
683 M_LINKER, M_WAITOK | M_ZERO);
684 if (ef->nrelatab != 0)
685 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
686 M_LINKER, M_WAITOK | M_ZERO);
688 if (symtabindex == -1) {
689 link_elf_error(filename, "lost symbol table index");
693 /* Allocate space for and load the symbol table */
694 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
695 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
696 error = vn_rdwr(UIO_READ, nd->ni_vp, (void *)ef->ddbsymtab,
697 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
698 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
707 if (symstrindex == -1) {
708 link_elf_error(filename, "lost symbol string index");
712 /* Allocate space for and load the symbol strings */
713 ef->ddbstrcnt = shdr[symstrindex].sh_size;
714 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
715 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->ddbstrtab,
716 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
717 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
726 /* Do we have a string table for the section names? */
728 if (hdr->e_shstrndx != 0 &&
729 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
730 shstrindex = hdr->e_shstrndx;
731 ef->shstrcnt = shdr[shstrindex].sh_size;
732 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
734 error = vn_rdwr(UIO_READ, nd->ni_vp, ef->shstrtab,
735 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
736 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
746 /* Size up code/data(progbits) and bss(nobits). */
748 for (i = 0; i < hdr->e_shnum; i++) {
749 if (shdr[i].sh_size == 0)
751 switch (shdr[i].sh_type) {
755 case SHT_X86_64_UNWIND:
757 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
759 alignmask = shdr[i].sh_addralign - 1;
760 mapsize += alignmask;
761 mapsize &= ~alignmask;
762 mapsize += shdr[i].sh_size;
768 * We know how much space we need for the text/data/bss/etc.
769 * This stuff needs to be in a single chunk so that profiling etc
770 * can get the bounds and gdb can associate offsets with modules
772 ef->object = vm_object_allocate(OBJT_DEFAULT,
773 round_page(mapsize) >> PAGE_SHIFT);
774 if (ef->object == NULL) {
778 ef->address = (caddr_t) vm_map_min(kernel_map);
781 * In order to satisfy amd64's architectural requirements on the
782 * location of code and data in the kernel's address space, request a
783 * mapping that is above the kernel.
788 mapbase = VM_MIN_KERNEL_ADDRESS;
790 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
791 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
794 vm_object_deallocate(ef->object);
800 error = vm_map_wire(kernel_map, mapbase,
801 mapbase + round_page(mapsize),
802 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
803 if (error != KERN_SUCCESS) {
808 /* Inform the kld system about the situation */
809 lf->address = ef->address = (caddr_t)mapbase;
813 * Now load code/data(progbits), zero bss(nobits), allocate space for
820 for (i = 0; i < hdr->e_shnum; i++) {
821 if (shdr[i].sh_size == 0)
823 switch (shdr[i].sh_type) {
827 case SHT_X86_64_UNWIND:
829 if ((shdr[i].sh_flags & SHF_ALLOC) == 0)
831 alignmask = shdr[i].sh_addralign - 1;
832 mapbase += alignmask;
833 mapbase &= ~alignmask;
834 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
835 ef->progtab[pb].name =
836 ef->shstrtab + shdr[i].sh_name;
837 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
838 lf->ctors_addr = (caddr_t)mapbase;
839 lf->ctors_size = shdr[i].sh_size;
841 } else if (shdr[i].sh_type == SHT_PROGBITS)
842 ef->progtab[pb].name = "<<PROGBITS>>";
844 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
845 ef->progtab[pb].name = "<<UNWIND>>";
848 ef->progtab[pb].name = "<<NOBITS>>";
849 if (ef->progtab[pb].name != NULL &&
850 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
851 ef->progtab[pb].addr =
852 dpcpu_alloc(shdr[i].sh_size);
854 else if (ef->progtab[pb].name != NULL &&
855 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
856 ef->progtab[pb].addr =
857 vnet_data_alloc(shdr[i].sh_size);
860 ef->progtab[pb].addr =
861 (void *)(uintptr_t)mapbase;
862 if (ef->progtab[pb].addr == NULL) {
866 ef->progtab[pb].size = shdr[i].sh_size;
867 ef->progtab[pb].sec = i;
868 if (shdr[i].sh_type == SHT_PROGBITS
870 || shdr[i].sh_type == SHT_X86_64_UNWIND
873 error = vn_rdwr(UIO_READ, nd->ni_vp,
874 ef->progtab[pb].addr,
875 shdr[i].sh_size, shdr[i].sh_offset,
876 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
884 /* Initialize the per-cpu or vnet area. */
885 if (ef->progtab[pb].addr != (void *)mapbase &&
886 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
887 dpcpu_copy(ef->progtab[pb].addr,
890 else if (ef->progtab[pb].addr !=
892 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
893 vnet_data_copy(ef->progtab[pb].addr,
897 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
899 /* Update all symbol values with the offset. */
900 for (j = 0; j < ef->ddbsymcnt; j++) {
901 es = &ef->ddbsymtab[j];
902 if (es->st_shndx != i)
904 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
906 mapbase += shdr[i].sh_size;
910 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
912 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
914 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
915 ef->reltab[rl].sec = shdr[i].sh_info;
916 error = vn_rdwr(UIO_READ, nd->ni_vp,
917 (void *)ef->reltab[rl].rel,
918 shdr[i].sh_size, shdr[i].sh_offset,
919 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
930 if ((shdr[shdr[i].sh_info].sh_flags & SHF_ALLOC) == 0)
932 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
934 ef->relatab[ra].nrela =
935 shdr[i].sh_size / sizeof(Elf_Rela);
936 ef->relatab[ra].sec = shdr[i].sh_info;
937 error = vn_rdwr(UIO_READ, nd->ni_vp,
938 (void *)ef->relatab[ra].rela,
939 shdr[i].sh_size, shdr[i].sh_offset,
940 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
952 if (pb != ef->nprogtab) {
953 link_elf_error(filename, "lost progbits");
957 if (rl != ef->nreltab) {
958 link_elf_error(filename, "lost reltab");
962 if (ra != ef->nrelatab) {
963 link_elf_error(filename, "lost relatab");
967 if (mapbase != (vm_offset_t)ef->address + mapsize) {
969 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
970 filename != NULL ? filename : "<none>",
971 (u_long)mapbase, ef->address, (u_long)mapsize,
972 (u_long)(vm_offset_t)ef->address + mapsize);
977 /* Local intra-module relocations */
978 error = link_elf_reloc_local(lf, false);
982 /* Pull in dependencies */
983 VOP_UNLOCK(nd->ni_vp, 0);
984 error = linker_load_dependencies(lf);
985 vn_lock(nd->ni_vp, LK_EXCLUSIVE | LK_RETRY);
989 /* External relocations */
990 error = relocate_file(ef);
994 /* Notify MD code that a module is being loaded. */
995 error = elf_cpu_load_file(lf);
999 #if defined(__i386__) || defined(__amd64__)
1001 error = link_elf_reloc_local(lf, true);
1007 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
1012 VOP_UNLOCK(nd->ni_vp, 0);
1013 vn_close(nd->ni_vp, FREAD, td->td_ucred, td);
1016 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1017 free(hdr, M_LINKER);
1023 link_elf_unload_file(linker_file_t file)
1025 elf_file_t ef = (elf_file_t) file;
1028 /* Notify MD code that a module is being unloaded. */
1029 elf_cpu_unload_file(file);
1032 for (i = 0; i < ef->nprogtab; i++) {
1033 if (ef->progtab[i].size == 0)
1035 if (ef->progtab[i].name == NULL)
1037 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
1038 dpcpu_free(ef->progtab[i].addr,
1039 ef->progtab[i].size);
1041 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
1042 vnet_data_free(ef->progtab[i].addr,
1043 ef->progtab[i].size);
1047 if (ef->preloaded) {
1048 free(ef->reltab, M_LINKER);
1049 free(ef->relatab, M_LINKER);
1050 free(ef->progtab, M_LINKER);
1051 free(ef->ctftab, M_LINKER);
1052 free(ef->ctfoff, M_LINKER);
1053 free(ef->typoff, M_LINKER);
1054 if (file->pathname != NULL)
1055 preload_delete_name(file->pathname);
1059 for (i = 0; i < ef->nreltab; i++)
1060 free(ef->reltab[i].rel, M_LINKER);
1061 for (i = 0; i < ef->nrelatab; i++)
1062 free(ef->relatab[i].rela, M_LINKER);
1063 free(ef->reltab, M_LINKER);
1064 free(ef->relatab, M_LINKER);
1065 free(ef->progtab, M_LINKER);
1068 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1069 (vm_offset_t) ef->address +
1070 (ef->object->size << PAGE_SHIFT));
1072 free(ef->e_shdr, M_LINKER);
1073 free(ef->ddbsymtab, M_LINKER);
1074 free(ef->ddbstrtab, M_LINKER);
1075 free(ef->shstrtab, M_LINKER);
1076 free(ef->ctftab, M_LINKER);
1077 free(ef->ctfoff, M_LINKER);
1078 free(ef->typoff, M_LINKER);
1082 symbol_name(elf_file_t ef, Elf_Size r_info)
1086 if (ELF_R_SYM(r_info)) {
1087 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1088 return ef->ddbstrtab + ref->st_name;
1094 findbase(elf_file_t ef, int sec)
1099 for (i = 0; i < ef->nprogtab; i++) {
1100 if (sec == ef->progtab[i].sec) {
1101 base = (Elf_Addr)ef->progtab[i].addr;
1109 relocate_file(elf_file_t ef)
1111 const Elf_Rel *rellim;
1113 const Elf_Rela *relalim;
1114 const Elf_Rela *rela;
1115 const char *symname;
1122 /* Perform relocations without addend if there are any: */
1123 for (i = 0; i < ef->nreltab; i++) {
1124 rel = ef->reltab[i].rel;
1126 link_elf_error(ef->lf.filename, "lost a reltab!");
1129 rellim = rel + ef->reltab[i].nrel;
1130 base = findbase(ef, ef->reltab[i].sec);
1132 link_elf_error(ef->lf.filename, "lost base for reltab");
1135 for ( ; rel < rellim; rel++) {
1136 symidx = ELF_R_SYM(rel->r_info);
1137 if (symidx >= ef->ddbsymcnt)
1139 sym = ef->ddbsymtab + symidx;
1140 /* Local relocs are already done */
1141 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1143 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1145 symname = symbol_name(ef, rel->r_info);
1146 printf("link_elf_obj: symbol %s undefined\n",
1153 /* Perform relocations with addend if there are any: */
1154 for (i = 0; i < ef->nrelatab; i++) {
1155 rela = ef->relatab[i].rela;
1157 link_elf_error(ef->lf.filename, "lost a relatab!");
1160 relalim = rela + ef->relatab[i].nrela;
1161 base = findbase(ef, ef->relatab[i].sec);
1163 link_elf_error(ef->lf.filename,
1164 "lost base for relatab");
1167 for ( ; rela < relalim; rela++) {
1168 symidx = ELF_R_SYM(rela->r_info);
1169 if (symidx >= ef->ddbsymcnt)
1171 sym = ef->ddbsymtab + symidx;
1172 /* Local relocs are already done */
1173 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1175 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1177 symname = symbol_name(ef, rela->r_info);
1178 printf("link_elf_obj: symbol %s undefined\n",
1186 * Only clean SHN_FBSD_CACHED for successful return. If we
1187 * modified symbol table for the object but found an
1188 * unresolved symbol, there is no reason to roll back.
1190 elf_obj_cleanup_globals_cache(ef);
1196 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1198 elf_file_t ef = (elf_file_t) lf;
1199 const Elf_Sym *symp;
1203 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1204 strp = ef->ddbstrtab + symp->st_name;
1205 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1206 *sym = (c_linker_sym_t) symp;
1214 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1215 linker_symval_t *symval)
1221 ef = (elf_file_t) lf;
1222 es = (const Elf_Sym*) sym;
1223 val = (caddr_t)es->st_value;
1224 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1225 symval->name = ef->ddbstrtab + es->st_name;
1226 val = (caddr_t)es->st_value;
1227 if (ELF_ST_TYPE(es->st_info) == STT_GNU_IFUNC)
1228 val = ((caddr_t (*)(void))val)();
1229 symval->value = val;
1230 symval->size = es->st_size;
1237 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1238 c_linker_sym_t *sym, long *diffp)
1240 elf_file_t ef = (elf_file_t) lf;
1241 u_long off = (uintptr_t) (void *) value;
1245 const Elf_Sym *best = NULL;
1248 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1249 if (es->st_name == 0)
1251 st_value = es->st_value;
1252 if (off >= st_value) {
1253 if (off - st_value < diff) {
1254 diff = off - st_value;
1258 } else if (off - st_value == diff) {
1267 *sym = (c_linker_sym_t) best;
1273 * Look up a linker set on an ELF system.
1276 link_elf_lookup_set(linker_file_t lf, const char *name,
1277 void ***startp, void ***stopp, int *countp)
1279 elf_file_t ef = (elf_file_t)lf;
1280 void **start, **stop;
1283 /* Relative to section number */
1284 for (i = 0; i < ef->nprogtab; i++) {
1285 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1286 strcmp(ef->progtab[i].name + 4, name) == 0) {
1287 start = (void **)ef->progtab[i].addr;
1288 stop = (void **)((char *)ef->progtab[i].addr +
1289 ef->progtab[i].size);
1290 count = stop - start;
1304 link_elf_each_function_name(linker_file_t file,
1305 int (*callback)(const char *, void *), void *opaque)
1307 elf_file_t ef = (elf_file_t)file;
1308 const Elf_Sym *symp;
1311 /* Exhaustive search */
1312 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1313 if (symp->st_value != 0 &&
1314 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1315 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1316 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1325 link_elf_each_function_nameval(linker_file_t file,
1326 linker_function_nameval_callback_t callback, void *opaque)
1328 linker_symval_t symval;
1329 elf_file_t ef = (elf_file_t)file;
1330 const Elf_Sym* symp;
1333 /* Exhaustive search */
1334 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1335 if (symp->st_value != 0 &&
1336 (ELF_ST_TYPE(symp->st_info) == STT_FUNC ||
1337 ELF_ST_TYPE(symp->st_info) == STT_GNU_IFUNC)) {
1338 error = link_elf_symbol_values(file,
1339 (c_linker_sym_t)symp, &symval);
1342 error = callback(file, i, &symval, opaque);
1351 elf_obj_cleanup_globals_cache(elf_file_t ef)
1356 for (i = 0; i < ef->ddbsymcnt; i++) {
1357 sym = ef->ddbsymtab + i;
1358 if (sym->st_shndx == SHN_FBSD_CACHED) {
1359 sym->st_shndx = SHN_UNDEF;
1366 * Symbol lookup function that can be used when the symbol index is known (ie
1367 * in relocations). It uses the symbol index instead of doing a fully fledged
1368 * hash table based lookup when such is valid. For example for local symbols.
1369 * This is not only more efficient, it's also more correct. It's not always
1370 * the case that the symbol can be found through the hash table.
1373 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1375 elf_file_t ef = (elf_file_t)lf;
1380 /* Don't even try to lookup the symbol if the index is bogus. */
1381 if (symidx >= ef->ddbsymcnt) {
1386 sym = ef->ddbsymtab + symidx;
1388 /* Quick answer if there is a definition included. */
1389 if (sym->st_shndx != SHN_UNDEF) {
1390 res1 = (Elf_Addr)sym->st_value;
1391 if (ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC)
1392 res1 = ((Elf_Addr (*)(void))res1)();
1397 /* If we get here, then it is undefined and needs a lookup. */
1398 switch (ELF_ST_BIND(sym->st_info)) {
1400 /* Local, but undefined? huh? */
1406 /* Relative to Data or Function name */
1407 symbol = ef->ddbstrtab + sym->st_name;
1409 /* Force a lookup failure if the symbol name is bogus. */
1414 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1417 * Cache global lookups during module relocation. The failure
1418 * case is particularly expensive for callers, who must scan
1419 * through the entire globals table doing strcmp(). Cache to
1420 * avoid doing such work repeatedly.
1422 * After relocation is complete, undefined globals will be
1423 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1427 sym->st_shndx = SHN_FBSD_CACHED;
1428 sym->st_value = res1;
1431 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1444 link_elf_fix_link_set(elf_file_t ef)
1446 static const char startn[] = "__start_";
1447 static const char stopn[] = "__stop_";
1449 const char *sym_name, *linkset_name;
1450 Elf_Addr startp, stopp;
1455 for (symidx = 1 /* zero entry is special */;
1456 symidx < ef->ddbsymcnt; symidx++) {
1457 sym = ef->ddbsymtab + symidx;
1458 if (sym->st_shndx != SHN_UNDEF)
1461 sym_name = ef->ddbstrtab + sym->st_name;
1462 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1464 linkset_name = sym_name + sizeof(startn) - 1;
1466 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1468 linkset_name = sym_name + sizeof(stopn) - 1;
1473 for (i = 0; i < ef->nprogtab; i++) {
1474 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1475 startp = (Elf_Addr)ef->progtab[i].addr;
1476 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1480 if (i == ef->nprogtab)
1483 sym->st_value = start ? startp : stopp;
1489 link_elf_reloc_local(linker_file_t lf, bool ifuncs)
1491 elf_file_t ef = (elf_file_t)lf;
1492 const Elf_Rel *rellim;
1494 const Elf_Rela *relalim;
1495 const Elf_Rela *rela;
1501 link_elf_fix_link_set(ef);
1503 /* Perform relocations without addend if there are any: */
1504 for (i = 0; i < ef->nreltab; i++) {
1505 rel = ef->reltab[i].rel;
1507 link_elf_error(ef->lf.filename, "lost a reltab");
1510 rellim = rel + ef->reltab[i].nrel;
1511 base = findbase(ef, ef->reltab[i].sec);
1513 link_elf_error(ef->lf.filename, "lost base for reltab");
1516 for ( ; rel < rellim; rel++) {
1517 symidx = ELF_R_SYM(rel->r_info);
1518 if (symidx >= ef->ddbsymcnt)
1520 sym = ef->ddbsymtab + symidx;
1521 /* Only do local relocs */
1522 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1524 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1525 elf_is_ifunc_reloc(rel->r_info)) == ifuncs)
1526 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1531 /* Perform relocations with addend if there are any: */
1532 for (i = 0; i < ef->nrelatab; i++) {
1533 rela = ef->relatab[i].rela;
1535 link_elf_error(ef->lf.filename, "lost a relatab!");
1538 relalim = rela + ef->relatab[i].nrela;
1539 base = findbase(ef, ef->relatab[i].sec);
1541 link_elf_error(ef->lf.filename, "lost base for reltab");
1544 for ( ; rela < relalim; rela++) {
1545 symidx = ELF_R_SYM(rela->r_info);
1546 if (symidx >= ef->ddbsymcnt)
1548 sym = ef->ddbsymtab + symidx;
1549 /* Only do local relocs */
1550 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1552 if ((ELF_ST_TYPE(sym->st_info) == STT_GNU_IFUNC ||
1553 elf_is_ifunc_reloc(rela->r_info)) == ifuncs)
1554 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1562 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1564 elf_file_t ef = (elf_file_t)lf;
1566 *symtab = ef->ddbsymtab;
1568 if (*symtab == NULL)
1571 return (ef->ddbsymcnt);
1575 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1577 elf_file_t ef = (elf_file_t)lf;
1579 *strtab = ef->ddbstrtab;
1581 if (*strtab == NULL)
1584 return (ef->ddbstrcnt);