2 * Copyright (c) 1998-2000 Doug Rabson
3 * Copyright (c) 2004 Peter Wemm
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/mount.h>
41 #include <sys/namei.h>
42 #include <sys/fcntl.h>
43 #include <sys/vnode.h>
44 #include <sys/linker.h>
46 #include <machine/elf.h>
50 #include <security/mac/mac_framework.h>
53 #include <vm/vm_param.h>
54 #include <vm/vm_object.h>
55 #include <vm/vm_kern.h>
56 #include <vm/vm_extern.h>
58 #include <vm/vm_map.h>
60 #include <sys/link_elf.h>
66 #include "linker_if.h"
72 int sec; /* Original section */
89 typedef struct elf_file {
90 struct linker_file lf; /* Common fields */
93 caddr_t address; /* Relocation address */
94 vm_object_t object; /* VM object to hold file pages */
100 Elf_relaent *relatab;
106 Elf_Sym *ddbsymtab; /* The symbol table we are using */
107 long ddbsymcnt; /* Number of symbols */
108 caddr_t ddbstrtab; /* String table */
109 long ddbstrcnt; /* number of bytes in string table */
111 caddr_t shstrtab; /* Section name string table */
112 long shstrcnt; /* number of bytes in string table */
114 caddr_t ctftab; /* CTF table */
115 long ctfcnt; /* number of bytes in CTF table */
116 caddr_t ctfoff; /* CTF offset table */
117 caddr_t typoff; /* Type offset table */
118 long typlen; /* Number of type entries. */
122 #include <kern/kern_ctf.c>
124 static int link_elf_link_preload(linker_class_t cls,
125 const char *, linker_file_t *);
126 static int link_elf_link_preload_finish(linker_file_t);
127 static int link_elf_load_file(linker_class_t, const char *, linker_file_t *);
128 static int link_elf_lookup_symbol(linker_file_t, const char *,
130 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
132 static int link_elf_search_symbol(linker_file_t, caddr_t value,
133 c_linker_sym_t *sym, long *diffp);
135 static void link_elf_unload_file(linker_file_t);
136 static int link_elf_lookup_set(linker_file_t, const char *,
137 void ***, void ***, int *);
138 static int link_elf_each_function_name(linker_file_t,
139 int (*)(const char *, void *), void *);
140 static int link_elf_each_function_nameval(linker_file_t,
141 linker_function_nameval_callback_t,
143 static void link_elf_reloc_local(linker_file_t);
144 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
145 static long link_elf_strtab_get(linker_file_t, caddr_t *);
147 static Elf_Addr elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps);
149 static kobj_method_t link_elf_methods[] = {
150 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
151 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
152 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
153 KOBJMETHOD(linker_unload, link_elf_unload_file),
154 KOBJMETHOD(linker_load_file, link_elf_load_file),
155 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
156 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
157 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
158 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
159 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
160 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
161 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
162 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
166 static struct linker_class link_elf_class = {
167 #if ELF_TARG_CLASS == ELFCLASS32
172 link_elf_methods, sizeof(struct elf_file)
175 static int relocate_file(elf_file_t ef);
176 static void elf_obj_cleanup_globals_cache(elf_file_t);
179 link_elf_error(const char *filename, const char *s)
181 if (filename == NULL)
182 printf("kldload: %s\n", s);
184 printf("kldload: %s: %s\n", filename, s);
188 link_elf_init(void *arg)
191 linker_add_class(&link_elf_class);
194 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
197 link_elf_link_preload(linker_class_t cls, const char *filename,
198 linker_file_t *result)
203 void *modptr, *baseptr, *sizeptr;
208 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
210 /* Look to see if we have the file preloaded */
211 modptr = preload_search_by_name(filename);
215 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
216 baseptr = preload_search_info(modptr, MODINFO_ADDR);
217 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
218 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
220 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
222 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
223 " obj module") != 0 &&
224 strcmp(type, "elf obj module") != 0)) {
227 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
231 lf = linker_make_file(filename, &link_elf_class);
237 ef->address = *(caddr_t *)baseptr;
238 lf->address = *(caddr_t *)baseptr;
239 lf->size = *(size_t *)sizeptr;
241 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
242 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
243 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
244 hdr->e_version != EV_CURRENT ||
245 hdr->e_type != ET_REL ||
246 hdr->e_machine != ELF_TARG_MACH) {
252 /* Scan the section header for information and table sizing. */
255 for (i = 0; i < hdr->e_shnum; i++) {
256 switch (shdr[i].sh_type) {
263 symstrindex = shdr[i].sh_link;
274 shstrindex = hdr->e_shstrndx;
275 if (ef->nprogtab == 0 || symstrindex < 0 ||
276 symstrindex >= hdr->e_shnum ||
277 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
278 shstrindex >= hdr->e_shnum ||
279 shdr[shstrindex].sh_type != SHT_STRTAB) {
280 printf("%s: bad/missing section headers\n", filename);
285 /* Allocate space for tracking the load chunks */
286 if (ef->nprogtab != 0)
287 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
288 M_LINKER, M_WAITOK | M_ZERO);
289 if (ef->nreltab != 0)
290 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
291 M_LINKER, M_WAITOK | M_ZERO);
292 if (ef->nrelatab != 0)
293 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
294 M_LINKER, M_WAITOK | M_ZERO);
295 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
296 (ef->nreltab != 0 && ef->reltab == NULL) ||
297 (ef->nrelatab != 0 && ef->relatab == NULL)) {
302 /* XXX, relocate the sh_addr fields saved by the loader. */
304 for (i = 0; i < hdr->e_shnum; i++) {
305 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
306 off = shdr[i].sh_addr;
308 for (i = 0; i < hdr->e_shnum; i++) {
309 if (shdr[i].sh_addr != 0)
310 shdr[i].sh_addr = shdr[i].sh_addr - off +
311 (Elf_Addr)ef->address;
314 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
315 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
316 ef->ddbstrcnt = shdr[symstrindex].sh_size;
317 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
318 ef->shstrcnt = shdr[shstrindex].sh_size;
319 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
321 /* Now fill out progtab and the relocation tables. */
325 for (i = 0; i < hdr->e_shnum; i++) {
326 switch (shdr[i].sh_type) {
329 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
330 if (shdr[i].sh_type == SHT_PROGBITS)
331 ef->progtab[pb].name = "<<PROGBITS>>";
333 ef->progtab[pb].name = "<<NOBITS>>";
334 ef->progtab[pb].size = shdr[i].sh_size;
335 ef->progtab[pb].sec = i;
336 if (ef->shstrtab && shdr[i].sh_name != 0)
337 ef->progtab[pb].name =
338 ef->shstrtab + shdr[i].sh_name;
339 if (ef->progtab[pb].name != NULL &&
340 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
343 dpcpu = dpcpu_alloc(shdr[i].sh_size);
348 memcpy(dpcpu, ef->progtab[pb].addr,
349 ef->progtab[pb].size);
350 dpcpu_copy(dpcpu, shdr[i].sh_size);
351 ef->progtab[pb].addr = dpcpu;
353 } else if (ef->progtab[pb].name != NULL &&
354 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
357 vnet_data = vnet_data_alloc(shdr[i].sh_size);
358 if (vnet_data == NULL) {
362 memcpy(vnet_data, ef->progtab[pb].addr,
363 ef->progtab[pb].size);
364 vnet_data_copy(vnet_data, shdr[i].sh_size);
365 ef->progtab[pb].addr = vnet_data;
367 } else if (ef->progtab[pb].name != NULL &&
368 !strcmp(ef->progtab[pb].name, ".ctors")) {
369 lf->ctors_addr = ef->progtab[pb].addr;
370 lf->ctors_size = shdr[i].sh_size;
373 /* Update all symbol values with the offset. */
374 for (j = 0; j < ef->ddbsymcnt; j++) {
375 es = &ef->ddbsymtab[j];
376 if (es->st_shndx != i)
378 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
383 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
384 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
385 ef->reltab[rl].sec = shdr[i].sh_info;
389 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
390 ef->relatab[ra].nrela =
391 shdr[i].sh_size / sizeof(Elf_Rela);
392 ef->relatab[ra].sec = shdr[i].sh_info;
397 if (pb != ef->nprogtab)
398 panic("lost progbits");
399 if (rl != ef->nreltab)
400 panic("lost reltab");
401 if (ra != ef->nrelatab)
402 panic("lost relatab");
404 /* Local intra-module relocations */
405 link_elf_reloc_local(lf);
411 /* preload not done this way */
412 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
417 link_elf_invoke_ctors(caddr_t addr, size_t size)
422 if (addr == NULL || size == 0)
424 cnt = size / sizeof(*ctor);
426 for (i = 0; i < cnt; i++) {
433 link_elf_link_preload_finish(linker_file_t lf)
439 error = relocate_file(ef);
443 /* Notify MD code that a module is being loaded. */
444 error = elf_cpu_load_file(lf);
449 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
454 link_elf_load_file(linker_class_t cls, const char *filename,
455 linker_file_t *result)
458 struct thread *td = curthread; /* XXX */
482 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
484 error = vn_open(&nd, &flags, 0, NULL);
487 NDFREE(&nd, NDF_ONLY_PNBUF);
488 if (nd.ni_vp->v_type != VREG) {
493 error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
499 /* Read the elf header from the file. */
500 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
501 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
502 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
516 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
517 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
518 link_elf_error(filename, "Unsupported file layout");
522 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
523 || hdr->e_version != EV_CURRENT) {
524 link_elf_error(filename, "Unsupported file version");
528 if (hdr->e_type != ET_REL) {
532 if (hdr->e_machine != ELF_TARG_MACH) {
533 link_elf_error(filename, "Unsupported machine");
538 lf = linker_make_file(filename, &link_elf_class);
543 ef = (elf_file_t) lf;
549 /* Allocate and read in the section header */
550 nbytes = hdr->e_shnum * hdr->e_shentsize;
551 if (nbytes == 0 || hdr->e_shoff == 0 ||
552 hdr->e_shentsize != sizeof(Elf_Shdr)) {
556 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
558 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
559 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
567 /* Scan the section header for information and table sizing. */
571 for (i = 0; i < hdr->e_shnum; i++) {
572 if (shdr[i].sh_size == 0)
574 switch (shdr[i].sh_type) {
582 symstrindex = shdr[i].sh_link;
594 if (ef->nprogtab == 0) {
595 link_elf_error(filename, "file has no contents");
600 /* Only allow one symbol table for now */
601 link_elf_error(filename, "file has no valid symbol table");
605 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
606 shdr[symstrindex].sh_type != SHT_STRTAB) {
607 link_elf_error(filename, "file has invalid symbol strings");
612 /* Allocate space for tracking the load chunks */
613 if (ef->nprogtab != 0)
614 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
615 M_LINKER, M_WAITOK | M_ZERO);
616 if (ef->nreltab != 0)
617 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
618 M_LINKER, M_WAITOK | M_ZERO);
619 if (ef->nrelatab != 0)
620 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
621 M_LINKER, M_WAITOK | M_ZERO);
623 if (symtabindex == -1)
624 panic("lost symbol table index");
625 /* Allocate space for and load the symbol table */
626 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
627 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
628 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
629 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
630 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
639 if (symstrindex == -1)
640 panic("lost symbol string index");
641 /* Allocate space for and load the symbol strings */
642 ef->ddbstrcnt = shdr[symstrindex].sh_size;
643 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
644 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
645 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
646 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
655 /* Do we have a string table for the section names? */
657 if (hdr->e_shstrndx != 0 &&
658 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
659 shstrindex = hdr->e_shstrndx;
660 ef->shstrcnt = shdr[shstrindex].sh_size;
661 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
663 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
664 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
665 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
675 /* Size up code/data(progbits) and bss(nobits). */
677 for (i = 0; i < hdr->e_shnum; i++) {
678 if (shdr[i].sh_size == 0)
680 switch (shdr[i].sh_type) {
683 alignmask = shdr[i].sh_addralign - 1;
684 mapsize += alignmask;
685 mapsize &= ~alignmask;
686 mapsize += shdr[i].sh_size;
692 * We know how much space we need for the text/data/bss/etc.
693 * This stuff needs to be in a single chunk so that profiling etc
694 * can get the bounds and gdb can associate offsets with modules
696 ef->object = vm_object_allocate(OBJT_DEFAULT,
697 round_page(mapsize) >> PAGE_SHIFT);
698 if (ef->object == NULL) {
702 ef->address = (caddr_t) vm_map_min(kernel_map);
705 * In order to satisfy amd64's architectural requirements on the
706 * location of code and data in the kernel's address space, request a
707 * mapping that is above the kernel.
712 mapbase = VM_MIN_KERNEL_ADDRESS;
714 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
715 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
718 vm_object_deallocate(ef->object);
724 error = vm_map_wire(kernel_map, mapbase,
725 mapbase + round_page(mapsize),
726 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
727 if (error != KERN_SUCCESS) {
732 /* Inform the kld system about the situation */
733 lf->address = ef->address = (caddr_t)mapbase;
737 * Now load code/data(progbits), zero bss(nobits), allocate space for
744 for (i = 0; i < hdr->e_shnum; i++) {
745 if (shdr[i].sh_size == 0)
747 switch (shdr[i].sh_type) {
750 alignmask = shdr[i].sh_addralign - 1;
751 mapbase += alignmask;
752 mapbase &= ~alignmask;
753 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
754 ef->progtab[pb].name =
755 ef->shstrtab + shdr[i].sh_name;
756 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
757 lf->ctors_addr = (caddr_t)mapbase;
758 lf->ctors_size = shdr[i].sh_size;
760 } else if (shdr[i].sh_type == SHT_PROGBITS)
761 ef->progtab[pb].name = "<<PROGBITS>>";
763 ef->progtab[pb].name = "<<NOBITS>>";
764 if (ef->progtab[pb].name != NULL &&
765 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
766 ef->progtab[pb].addr =
767 dpcpu_alloc(shdr[i].sh_size);
769 else if (ef->progtab[pb].name != NULL &&
770 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
771 ef->progtab[pb].addr =
772 vnet_data_alloc(shdr[i].sh_size);
775 ef->progtab[pb].addr =
776 (void *)(uintptr_t)mapbase;
777 if (ef->progtab[pb].addr == NULL) {
781 ef->progtab[pb].size = shdr[i].sh_size;
782 ef->progtab[pb].sec = i;
783 if (shdr[i].sh_type == SHT_PROGBITS) {
784 error = vn_rdwr(UIO_READ, nd.ni_vp,
785 ef->progtab[pb].addr,
786 shdr[i].sh_size, shdr[i].sh_offset,
787 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
795 /* Initialize the per-cpu or vnet area. */
796 if (ef->progtab[pb].addr != (void *)mapbase &&
797 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
798 dpcpu_copy(ef->progtab[pb].addr,
801 else if (ef->progtab[pb].addr !=
803 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
804 vnet_data_copy(ef->progtab[pb].addr,
808 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
810 /* Update all symbol values with the offset. */
811 for (j = 0; j < ef->ddbsymcnt; j++) {
812 es = &ef->ddbsymtab[j];
813 if (es->st_shndx != i)
815 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
817 mapbase += shdr[i].sh_size;
821 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
823 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
824 ef->reltab[rl].sec = shdr[i].sh_info;
825 error = vn_rdwr(UIO_READ, nd.ni_vp,
826 (void *)ef->reltab[rl].rel,
827 shdr[i].sh_size, shdr[i].sh_offset,
828 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
839 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
841 ef->relatab[ra].nrela =
842 shdr[i].sh_size / sizeof(Elf_Rela);
843 ef->relatab[ra].sec = shdr[i].sh_info;
844 error = vn_rdwr(UIO_READ, nd.ni_vp,
845 (void *)ef->relatab[ra].rela,
846 shdr[i].sh_size, shdr[i].sh_offset,
847 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
859 if (pb != ef->nprogtab)
860 panic("lost progbits");
861 if (rl != ef->nreltab)
862 panic("lost reltab");
863 if (ra != ef->nrelatab)
864 panic("lost relatab");
865 if (mapbase != (vm_offset_t)ef->address + mapsize)
866 panic("mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
867 (u_long)mapbase, ef->address, (u_long)mapsize,
868 (u_long)(vm_offset_t)ef->address + mapsize);
870 /* Local intra-module relocations */
871 link_elf_reloc_local(lf);
873 /* Pull in dependencies */
874 VOP_UNLOCK(nd.ni_vp, 0);
875 error = linker_load_dependencies(lf);
876 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
880 /* External relocations */
881 error = relocate_file(ef);
885 /* Notify MD code that a module is being loaded. */
886 error = elf_cpu_load_file(lf);
891 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
896 VOP_UNLOCK(nd.ni_vp, 0);
897 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
899 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
907 link_elf_unload_file(linker_file_t file)
909 elf_file_t ef = (elf_file_t) file;
912 /* Notify MD code that a module is being unloaded. */
913 elf_cpu_unload_file(file);
916 for (i = 0; i < ef->nprogtab; i++) {
917 if (ef->progtab[i].size == 0)
919 if (ef->progtab[i].name == NULL)
921 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
922 dpcpu_free(ef->progtab[i].addr,
923 ef->progtab[i].size);
925 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
926 vnet_data_free(ef->progtab[i].addr,
927 ef->progtab[i].size);
933 free(ef->reltab, M_LINKER);
935 free(ef->relatab, M_LINKER);
937 free(ef->progtab, M_LINKER);
939 free(ef->ctftab, M_LINKER);
941 free(ef->ctfoff, M_LINKER);
943 free(ef->typoff, M_LINKER);
944 if (file->filename != NULL)
945 preload_delete_name(file->filename);
946 /* XXX reclaim module memory? */
950 for (i = 0; i < ef->nreltab; i++)
951 if (ef->reltab[i].rel)
952 free(ef->reltab[i].rel, M_LINKER);
953 for (i = 0; i < ef->nrelatab; i++)
954 if (ef->relatab[i].rela)
955 free(ef->relatab[i].rela, M_LINKER);
957 free(ef->reltab, M_LINKER);
959 free(ef->relatab, M_LINKER);
961 free(ef->progtab, M_LINKER);
964 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
965 (vm_offset_t) ef->address +
966 (ef->object->size << PAGE_SHIFT));
969 free(ef->e_shdr, M_LINKER);
971 free(ef->ddbsymtab, M_LINKER);
973 free(ef->ddbstrtab, M_LINKER);
975 free(ef->shstrtab, M_LINKER);
977 free(ef->ctftab, M_LINKER);
979 free(ef->ctfoff, M_LINKER);
981 free(ef->typoff, M_LINKER);
985 symbol_name(elf_file_t ef, Elf_Size r_info)
989 if (ELF_R_SYM(r_info)) {
990 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
991 return ef->ddbstrtab + ref->st_name;
997 findbase(elf_file_t ef, int sec)
1002 for (i = 0; i < ef->nprogtab; i++) {
1003 if (sec == ef->progtab[i].sec) {
1004 base = (Elf_Addr)ef->progtab[i].addr;
1012 relocate_file(elf_file_t ef)
1014 const Elf_Rel *rellim;
1016 const Elf_Rela *relalim;
1017 const Elf_Rela *rela;
1018 const char *symname;
1025 /* Perform relocations without addend if there are any: */
1026 for (i = 0; i < ef->nreltab; i++) {
1027 rel = ef->reltab[i].rel;
1029 panic("lost a reltab!");
1030 rellim = rel + ef->reltab[i].nrel;
1031 base = findbase(ef, ef->reltab[i].sec);
1033 panic("lost base for reltab");
1034 for ( ; rel < rellim; rel++) {
1035 symidx = ELF_R_SYM(rel->r_info);
1036 if (symidx >= ef->ddbsymcnt)
1038 sym = ef->ddbsymtab + symidx;
1039 /* Local relocs are already done */
1040 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1042 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1044 symname = symbol_name(ef, rel->r_info);
1045 printf("link_elf_obj: symbol %s undefined\n",
1052 /* Perform relocations with addend if there are any: */
1053 for (i = 0; i < ef->nrelatab; i++) {
1054 rela = ef->relatab[i].rela;
1056 panic("lost a relatab!");
1057 relalim = rela + ef->relatab[i].nrela;
1058 base = findbase(ef, ef->relatab[i].sec);
1060 panic("lost base for relatab");
1061 for ( ; rela < relalim; rela++) {
1062 symidx = ELF_R_SYM(rela->r_info);
1063 if (symidx >= ef->ddbsymcnt)
1065 sym = ef->ddbsymtab + symidx;
1066 /* Local relocs are already done */
1067 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1069 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1071 symname = symbol_name(ef, rela->r_info);
1072 printf("link_elf_obj: symbol %s undefined\n",
1080 * Only clean SHN_FBSD_CACHED for successfull return. If we
1081 * modified symbol table for the object but found an
1082 * unresolved symbol, there is no reason to roll back.
1084 elf_obj_cleanup_globals_cache(ef);
1090 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1092 elf_file_t ef = (elf_file_t) lf;
1093 const Elf_Sym *symp;
1097 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1098 strp = ef->ddbstrtab + symp->st_name;
1099 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1100 *sym = (c_linker_sym_t) symp;
1108 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1109 linker_symval_t *symval)
1111 elf_file_t ef = (elf_file_t) lf;
1112 const Elf_Sym *es = (const Elf_Sym*) sym;
1114 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1115 symval->name = ef->ddbstrtab + es->st_name;
1116 symval->value = (caddr_t)es->st_value;
1117 symval->size = es->st_size;
1124 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1125 c_linker_sym_t *sym, long *diffp)
1127 elf_file_t ef = (elf_file_t) lf;
1128 u_long off = (uintptr_t) (void *) value;
1132 const Elf_Sym *best = 0;
1135 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1136 if (es->st_name == 0)
1138 st_value = es->st_value;
1139 if (off >= st_value) {
1140 if (off - st_value < diff) {
1141 diff = off - st_value;
1145 } else if (off - st_value == diff) {
1154 *sym = (c_linker_sym_t) best;
1160 * Look up a linker set on an ELF system.
1163 link_elf_lookup_set(linker_file_t lf, const char *name,
1164 void ***startp, void ***stopp, int *countp)
1166 elf_file_t ef = (elf_file_t)lf;
1167 void **start, **stop;
1170 /* Relative to section number */
1171 for (i = 0; i < ef->nprogtab; i++) {
1172 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1173 strcmp(ef->progtab[i].name + 4, name) == 0) {
1174 start = (void **)ef->progtab[i].addr;
1175 stop = (void **)((char *)ef->progtab[i].addr +
1176 ef->progtab[i].size);
1177 count = stop - start;
1191 link_elf_each_function_name(linker_file_t file,
1192 int (*callback)(const char *, void *), void *opaque)
1194 elf_file_t ef = (elf_file_t)file;
1195 const Elf_Sym *symp;
1198 /* Exhaustive search */
1199 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1200 if (symp->st_value != 0 &&
1201 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1202 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1211 link_elf_each_function_nameval(linker_file_t file,
1212 linker_function_nameval_callback_t callback, void *opaque)
1214 linker_symval_t symval;
1215 elf_file_t ef = (elf_file_t)file;
1216 const Elf_Sym* symp;
1219 /* Exhaustive search */
1220 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1221 if (symp->st_value != 0 &&
1222 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1223 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1226 error = callback(file, i, &symval, opaque);
1235 elf_obj_cleanup_globals_cache(elf_file_t ef)
1240 for (i = 0; i < ef->ddbsymcnt; i++) {
1241 sym = ef->ddbsymtab + i;
1242 if (sym->st_shndx == SHN_FBSD_CACHED) {
1243 sym->st_shndx = SHN_UNDEF;
1250 * Symbol lookup function that can be used when the symbol index is known (ie
1251 * in relocations). It uses the symbol index instead of doing a fully fledged
1252 * hash table based lookup when such is valid. For example for local symbols.
1253 * This is not only more efficient, it's also more correct. It's not always
1254 * the case that the symbol can be found through the hash table.
1257 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1259 elf_file_t ef = (elf_file_t)lf;
1264 /* Don't even try to lookup the symbol if the index is bogus. */
1265 if (symidx >= ef->ddbsymcnt)
1268 sym = ef->ddbsymtab + symidx;
1270 /* Quick answer if there is a definition included. */
1271 if (sym->st_shndx != SHN_UNDEF)
1272 return (sym->st_value);
1274 /* If we get here, then it is undefined and needs a lookup. */
1275 switch (ELF_ST_BIND(sym->st_info)) {
1277 /* Local, but undefined? huh? */
1281 /* Relative to Data or Function name */
1282 symbol = ef->ddbstrtab + sym->st_name;
1284 /* Force a lookup failure if the symbol name is bogus. */
1287 ret = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1290 * Cache global lookups during module relocation. The failure
1291 * case is particularly expensive for callers, who must scan
1292 * through the entire globals table doing strcmp(). Cache to
1293 * avoid doing such work repeatedly.
1295 * After relocation is complete, undefined globals will be
1296 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1300 sym->st_shndx = SHN_FBSD_CACHED;
1301 sym->st_value = ret;
1306 printf("link_elf_obj: Weak symbols not supported\n");
1315 link_elf_fix_link_set(elf_file_t ef)
1317 static const char startn[] = "__start_";
1318 static const char stopn[] = "__stop_";
1320 const char *sym_name, *linkset_name;
1321 Elf_Addr startp, stopp;
1326 for (symidx = 1 /* zero entry is special */;
1327 symidx < ef->ddbsymcnt; symidx++) {
1328 sym = ef->ddbsymtab + symidx;
1329 if (sym->st_shndx != SHN_UNDEF)
1332 sym_name = ef->ddbstrtab + sym->st_name;
1333 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1335 linkset_name = sym_name + sizeof(startn) - 1;
1337 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1339 linkset_name = sym_name + sizeof(stopn) - 1;
1344 for (i = 0; i < ef->nprogtab; i++) {
1345 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1346 startp = (Elf_Addr)ef->progtab[i].addr;
1347 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1351 if (i == ef->nprogtab)
1354 sym->st_value = start ? startp : stopp;
1360 link_elf_reloc_local(linker_file_t lf)
1362 elf_file_t ef = (elf_file_t)lf;
1363 const Elf_Rel *rellim;
1365 const Elf_Rela *relalim;
1366 const Elf_Rela *rela;
1372 link_elf_fix_link_set(ef);
1374 /* Perform relocations without addend if there are any: */
1375 for (i = 0; i < ef->nreltab; i++) {
1376 rel = ef->reltab[i].rel;
1378 panic("lost a reltab!");
1379 rellim = rel + ef->reltab[i].nrel;
1380 base = findbase(ef, ef->reltab[i].sec);
1382 panic("lost base for reltab");
1383 for ( ; rel < rellim; rel++) {
1384 symidx = ELF_R_SYM(rel->r_info);
1385 if (symidx >= ef->ddbsymcnt)
1387 sym = ef->ddbsymtab + symidx;
1388 /* Only do local relocs */
1389 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1391 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1396 /* Perform relocations with addend if there are any: */
1397 for (i = 0; i < ef->nrelatab; i++) {
1398 rela = ef->relatab[i].rela;
1400 panic("lost a relatab!");
1401 relalim = rela + ef->relatab[i].nrela;
1402 base = findbase(ef, ef->relatab[i].sec);
1404 panic("lost base for relatab");
1405 for ( ; rela < relalim; rela++) {
1406 symidx = ELF_R_SYM(rela->r_info);
1407 if (symidx >= ef->ddbsymcnt)
1409 sym = ef->ddbsymtab + symidx;
1410 /* Only do local relocs */
1411 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1413 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1420 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1422 elf_file_t ef = (elf_file_t)lf;
1424 *symtab = ef->ddbsymtab;
1426 if (*symtab == NULL)
1429 return (ef->ddbsymcnt);
1433 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1435 elf_file_t ef = (elf_file_t)lf;
1437 *strtab = ef->ddbstrtab;
1439 if (*strtab == NULL)
1442 return (ef->ddbstrcnt);