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 int 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 int elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps,
150 static kobj_method_t link_elf_methods[] = {
151 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
152 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
153 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
154 KOBJMETHOD(linker_unload, link_elf_unload_file),
155 KOBJMETHOD(linker_load_file, link_elf_load_file),
156 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
157 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
158 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
159 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
160 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
161 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
162 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
163 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
167 static struct linker_class link_elf_class = {
168 #if ELF_TARG_CLASS == ELFCLASS32
173 link_elf_methods, sizeof(struct elf_file)
176 static int relocate_file(elf_file_t ef);
177 static void elf_obj_cleanup_globals_cache(elf_file_t);
180 link_elf_error(const char *filename, const char *s)
182 if (filename == NULL)
183 printf("kldload: %s\n", s);
185 printf("kldload: %s: %s\n", filename, s);
189 link_elf_init(void *arg)
192 linker_add_class(&link_elf_class);
195 SYSINIT(link_elf_obj, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
198 link_elf_link_preload(linker_class_t cls, const char *filename,
199 linker_file_t *result)
204 void *modptr, *baseptr, *sizeptr;
209 int error, i, j, pb, ra, rl, shstrindex, symstrindex, symtabindex;
211 /* Look to see if we have the file preloaded */
212 modptr = preload_search_by_name(filename);
216 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
217 baseptr = preload_search_info(modptr, MODINFO_ADDR);
218 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
219 hdr = (Elf_Ehdr *)preload_search_info(modptr, MODINFO_METADATA |
221 shdr = (Elf_Shdr *)preload_search_info(modptr, MODINFO_METADATA |
223 if (type == NULL || (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE)
224 " obj module") != 0 &&
225 strcmp(type, "elf obj module") != 0)) {
228 if (baseptr == NULL || sizeptr == NULL || hdr == NULL ||
232 lf = linker_make_file(filename, &link_elf_class);
238 ef->address = *(caddr_t *)baseptr;
239 lf->address = *(caddr_t *)baseptr;
240 lf->size = *(size_t *)sizeptr;
242 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
243 hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
244 hdr->e_ident[EI_VERSION] != EV_CURRENT ||
245 hdr->e_version != EV_CURRENT ||
246 hdr->e_type != ET_REL ||
247 hdr->e_machine != ELF_TARG_MACH) {
253 /* Scan the section header for information and table sizing. */
256 for (i = 0; i < hdr->e_shnum; i++) {
257 switch (shdr[i].sh_type) {
261 case SHT_X86_64_UNWIND:
267 symstrindex = shdr[i].sh_link;
278 shstrindex = hdr->e_shstrndx;
279 if (ef->nprogtab == 0 || symstrindex < 0 ||
280 symstrindex >= hdr->e_shnum ||
281 shdr[symstrindex].sh_type != SHT_STRTAB || shstrindex == 0 ||
282 shstrindex >= hdr->e_shnum ||
283 shdr[shstrindex].sh_type != SHT_STRTAB) {
284 printf("%s: bad/missing section headers\n", filename);
289 /* Allocate space for tracking the load chunks */
290 if (ef->nprogtab != 0)
291 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
292 M_LINKER, M_WAITOK | M_ZERO);
293 if (ef->nreltab != 0)
294 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
295 M_LINKER, M_WAITOK | M_ZERO);
296 if (ef->nrelatab != 0)
297 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
298 M_LINKER, M_WAITOK | M_ZERO);
299 if ((ef->nprogtab != 0 && ef->progtab == NULL) ||
300 (ef->nreltab != 0 && ef->reltab == NULL) ||
301 (ef->nrelatab != 0 && ef->relatab == NULL)) {
306 /* XXX, relocate the sh_addr fields saved by the loader. */
308 for (i = 0; i < hdr->e_shnum; i++) {
309 if (shdr[i].sh_addr != 0 && (off == 0 || shdr[i].sh_addr < off))
310 off = shdr[i].sh_addr;
312 for (i = 0; i < hdr->e_shnum; i++) {
313 if (shdr[i].sh_addr != 0)
314 shdr[i].sh_addr = shdr[i].sh_addr - off +
315 (Elf_Addr)ef->address;
318 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
319 ef->ddbsymtab = (Elf_Sym *)shdr[symtabindex].sh_addr;
320 ef->ddbstrcnt = shdr[symstrindex].sh_size;
321 ef->ddbstrtab = (char *)shdr[symstrindex].sh_addr;
322 ef->shstrcnt = shdr[shstrindex].sh_size;
323 ef->shstrtab = (char *)shdr[shstrindex].sh_addr;
325 /* Now fill out progtab and the relocation tables. */
329 for (i = 0; i < hdr->e_shnum; i++) {
330 switch (shdr[i].sh_type) {
334 case SHT_X86_64_UNWIND:
336 ef->progtab[pb].addr = (void *)shdr[i].sh_addr;
337 if (shdr[i].sh_type == SHT_PROGBITS)
338 ef->progtab[pb].name = "<<PROGBITS>>";
340 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
341 ef->progtab[pb].name = "<<UNWIND>>";
344 ef->progtab[pb].name = "<<NOBITS>>";
345 ef->progtab[pb].size = shdr[i].sh_size;
346 ef->progtab[pb].sec = i;
347 if (ef->shstrtab && shdr[i].sh_name != 0)
348 ef->progtab[pb].name =
349 ef->shstrtab + shdr[i].sh_name;
350 if (ef->progtab[pb].name != NULL &&
351 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME)) {
354 dpcpu = dpcpu_alloc(shdr[i].sh_size);
359 memcpy(dpcpu, ef->progtab[pb].addr,
360 ef->progtab[pb].size);
361 dpcpu_copy(dpcpu, shdr[i].sh_size);
362 ef->progtab[pb].addr = dpcpu;
364 } else if (ef->progtab[pb].name != NULL &&
365 !strcmp(ef->progtab[pb].name, VNET_SETNAME)) {
368 vnet_data = vnet_data_alloc(shdr[i].sh_size);
369 if (vnet_data == NULL) {
373 memcpy(vnet_data, ef->progtab[pb].addr,
374 ef->progtab[pb].size);
375 vnet_data_copy(vnet_data, shdr[i].sh_size);
376 ef->progtab[pb].addr = vnet_data;
378 } else if (ef->progtab[pb].name != NULL &&
379 !strcmp(ef->progtab[pb].name, ".ctors")) {
380 lf->ctors_addr = ef->progtab[pb].addr;
381 lf->ctors_size = shdr[i].sh_size;
384 /* Update all symbol values with the offset. */
385 for (j = 0; j < ef->ddbsymcnt; j++) {
386 es = &ef->ddbsymtab[j];
387 if (es->st_shndx != i)
389 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
394 ef->reltab[rl].rel = (Elf_Rel *)shdr[i].sh_addr;
395 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
396 ef->reltab[rl].sec = shdr[i].sh_info;
400 ef->relatab[ra].rela = (Elf_Rela *)shdr[i].sh_addr;
401 ef->relatab[ra].nrela =
402 shdr[i].sh_size / sizeof(Elf_Rela);
403 ef->relatab[ra].sec = shdr[i].sh_info;
408 if (pb != ef->nprogtab) {
409 printf("%s: lost progbits\n", filename);
413 if (rl != ef->nreltab) {
414 printf("%s: lost reltab\n", filename);
418 if (ra != ef->nrelatab) {
419 printf("%s: lost relatab\n", filename);
424 /* Local intra-module relocations */
425 error = link_elf_reloc_local(lf);
433 /* preload not done this way */
434 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
439 link_elf_invoke_ctors(caddr_t addr, size_t size)
444 if (addr == NULL || size == 0)
446 cnt = size / sizeof(*ctor);
448 for (i = 0; i < cnt; i++) {
455 link_elf_link_preload_finish(linker_file_t lf)
461 error = relocate_file(ef);
465 /* Notify MD code that a module is being loaded. */
466 error = elf_cpu_load_file(lf);
471 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
476 link_elf_load_file(linker_class_t cls, const char *filename,
477 linker_file_t *result)
480 struct thread *td = curthread; /* XXX */
504 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
506 error = vn_open(&nd, &flags, 0, NULL);
509 NDFREE(&nd, NDF_ONLY_PNBUF);
510 if (nd.ni_vp->v_type != VREG) {
515 error = mac_kld_check_load(td->td_ucred, nd.ni_vp);
521 /* Read the elf header from the file. */
522 hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
523 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)hdr, sizeof(*hdr), 0,
524 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
538 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
539 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
540 link_elf_error(filename, "Unsupported file layout");
544 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
545 || hdr->e_version != EV_CURRENT) {
546 link_elf_error(filename, "Unsupported file version");
550 if (hdr->e_type != ET_REL) {
554 if (hdr->e_machine != ELF_TARG_MACH) {
555 link_elf_error(filename, "Unsupported machine");
560 lf = linker_make_file(filename, &link_elf_class);
565 ef = (elf_file_t) lf;
571 /* Allocate and read in the section header */
572 nbytes = hdr->e_shnum * hdr->e_shentsize;
573 if (nbytes == 0 || hdr->e_shoff == 0 ||
574 hdr->e_shentsize != sizeof(Elf_Shdr)) {
578 shdr = malloc(nbytes, M_LINKER, M_WAITOK);
580 error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes, hdr->e_shoff,
581 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid, td);
589 /* Scan the section header for information and table sizing. */
593 for (i = 0; i < hdr->e_shnum; i++) {
594 if (shdr[i].sh_size == 0)
596 switch (shdr[i].sh_type) {
600 case SHT_X86_64_UNWIND:
607 symstrindex = shdr[i].sh_link;
619 if (ef->nprogtab == 0) {
620 link_elf_error(filename, "file has no contents");
625 /* Only allow one symbol table for now */
626 link_elf_error(filename, "file has no valid symbol table");
630 if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
631 shdr[symstrindex].sh_type != SHT_STRTAB) {
632 link_elf_error(filename, "file has invalid symbol strings");
637 /* Allocate space for tracking the load chunks */
638 if (ef->nprogtab != 0)
639 ef->progtab = malloc(ef->nprogtab * sizeof(*ef->progtab),
640 M_LINKER, M_WAITOK | M_ZERO);
641 if (ef->nreltab != 0)
642 ef->reltab = malloc(ef->nreltab * sizeof(*ef->reltab),
643 M_LINKER, M_WAITOK | M_ZERO);
644 if (ef->nrelatab != 0)
645 ef->relatab = malloc(ef->nrelatab * sizeof(*ef->relatab),
646 M_LINKER, M_WAITOK | M_ZERO);
648 if (symtabindex == -1) {
649 link_elf_error(filename, "lost symbol table index");
653 /* Allocate space for and load the symbol table */
654 ef->ddbsymcnt = shdr[symtabindex].sh_size / sizeof(Elf_Sym);
655 ef->ddbsymtab = malloc(shdr[symtabindex].sh_size, M_LINKER, M_WAITOK);
656 error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ef->ddbsymtab,
657 shdr[symtabindex].sh_size, shdr[symtabindex].sh_offset,
658 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
667 if (symstrindex == -1) {
668 link_elf_error(filename, "lost symbol string index");
672 /* Allocate space for and load the symbol strings */
673 ef->ddbstrcnt = shdr[symstrindex].sh_size;
674 ef->ddbstrtab = malloc(shdr[symstrindex].sh_size, M_LINKER, M_WAITOK);
675 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->ddbstrtab,
676 shdr[symstrindex].sh_size, shdr[symstrindex].sh_offset,
677 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
686 /* Do we have a string table for the section names? */
688 if (hdr->e_shstrndx != 0 &&
689 shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
690 shstrindex = hdr->e_shstrndx;
691 ef->shstrcnt = shdr[shstrindex].sh_size;
692 ef->shstrtab = malloc(shdr[shstrindex].sh_size, M_LINKER,
694 error = vn_rdwr(UIO_READ, nd.ni_vp, ef->shstrtab,
695 shdr[shstrindex].sh_size, shdr[shstrindex].sh_offset,
696 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
706 /* Size up code/data(progbits) and bss(nobits). */
708 for (i = 0; i < hdr->e_shnum; i++) {
709 if (shdr[i].sh_size == 0)
711 switch (shdr[i].sh_type) {
715 case SHT_X86_64_UNWIND:
717 alignmask = shdr[i].sh_addralign - 1;
718 mapsize += alignmask;
719 mapsize &= ~alignmask;
720 mapsize += shdr[i].sh_size;
726 * We know how much space we need for the text/data/bss/etc.
727 * This stuff needs to be in a single chunk so that profiling etc
728 * can get the bounds and gdb can associate offsets with modules
730 ef->object = vm_object_allocate(OBJT_DEFAULT,
731 round_page(mapsize) >> PAGE_SHIFT);
732 if (ef->object == NULL) {
736 ef->address = (caddr_t) vm_map_min(kernel_map);
739 * In order to satisfy amd64's architectural requirements on the
740 * location of code and data in the kernel's address space, request a
741 * mapping that is above the kernel.
746 mapbase = VM_MIN_KERNEL_ADDRESS;
748 error = vm_map_find(kernel_map, ef->object, 0, &mapbase,
749 round_page(mapsize), 0, VMFS_OPTIMAL_SPACE, VM_PROT_ALL,
752 vm_object_deallocate(ef->object);
758 error = vm_map_wire(kernel_map, mapbase,
759 mapbase + round_page(mapsize),
760 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
761 if (error != KERN_SUCCESS) {
766 /* Inform the kld system about the situation */
767 lf->address = ef->address = (caddr_t)mapbase;
771 * Now load code/data(progbits), zero bss(nobits), allocate space for
778 for (i = 0; i < hdr->e_shnum; i++) {
779 if (shdr[i].sh_size == 0)
781 switch (shdr[i].sh_type) {
785 case SHT_X86_64_UNWIND:
787 alignmask = shdr[i].sh_addralign - 1;
788 mapbase += alignmask;
789 mapbase &= ~alignmask;
790 if (ef->shstrtab != NULL && shdr[i].sh_name != 0) {
791 ef->progtab[pb].name =
792 ef->shstrtab + shdr[i].sh_name;
793 if (!strcmp(ef->progtab[pb].name, ".ctors")) {
794 lf->ctors_addr = (caddr_t)mapbase;
795 lf->ctors_size = shdr[i].sh_size;
797 } else if (shdr[i].sh_type == SHT_PROGBITS)
798 ef->progtab[pb].name = "<<PROGBITS>>";
800 else if (shdr[i].sh_type == SHT_X86_64_UNWIND)
801 ef->progtab[pb].name = "<<UNWIND>>";
804 ef->progtab[pb].name = "<<NOBITS>>";
805 if (ef->progtab[pb].name != NULL &&
806 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
807 ef->progtab[pb].addr =
808 dpcpu_alloc(shdr[i].sh_size);
810 else if (ef->progtab[pb].name != NULL &&
811 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
812 ef->progtab[pb].addr =
813 vnet_data_alloc(shdr[i].sh_size);
816 ef->progtab[pb].addr =
817 (void *)(uintptr_t)mapbase;
818 if (ef->progtab[pb].addr == NULL) {
822 ef->progtab[pb].size = shdr[i].sh_size;
823 ef->progtab[pb].sec = i;
824 if (shdr[i].sh_type == SHT_PROGBITS
826 || shdr[i].sh_type == SHT_X86_64_UNWIND
829 error = vn_rdwr(UIO_READ, nd.ni_vp,
830 ef->progtab[pb].addr,
831 shdr[i].sh_size, shdr[i].sh_offset,
832 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
840 /* Initialize the per-cpu or vnet area. */
841 if (ef->progtab[pb].addr != (void *)mapbase &&
842 !strcmp(ef->progtab[pb].name, DPCPU_SETNAME))
843 dpcpu_copy(ef->progtab[pb].addr,
846 else if (ef->progtab[pb].addr !=
848 !strcmp(ef->progtab[pb].name, VNET_SETNAME))
849 vnet_data_copy(ef->progtab[pb].addr,
853 bzero(ef->progtab[pb].addr, shdr[i].sh_size);
855 /* Update all symbol values with the offset. */
856 for (j = 0; j < ef->ddbsymcnt; j++) {
857 es = &ef->ddbsymtab[j];
858 if (es->st_shndx != i)
860 es->st_value += (Elf_Addr)ef->progtab[pb].addr;
862 mapbase += shdr[i].sh_size;
866 ef->reltab[rl].rel = malloc(shdr[i].sh_size, M_LINKER,
868 ef->reltab[rl].nrel = shdr[i].sh_size / sizeof(Elf_Rel);
869 ef->reltab[rl].sec = shdr[i].sh_info;
870 error = vn_rdwr(UIO_READ, nd.ni_vp,
871 (void *)ef->reltab[rl].rel,
872 shdr[i].sh_size, shdr[i].sh_offset,
873 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
884 ef->relatab[ra].rela = malloc(shdr[i].sh_size, M_LINKER,
886 ef->relatab[ra].nrela =
887 shdr[i].sh_size / sizeof(Elf_Rela);
888 ef->relatab[ra].sec = shdr[i].sh_info;
889 error = vn_rdwr(UIO_READ, nd.ni_vp,
890 (void *)ef->relatab[ra].rela,
891 shdr[i].sh_size, shdr[i].sh_offset,
892 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
904 if (pb != ef->nprogtab) {
905 link_elf_error(filename, "lost progbits");
909 if (rl != ef->nreltab) {
910 link_elf_error(filename, "lost reltab");
914 if (ra != ef->nrelatab) {
915 link_elf_error(filename, "lost relatab");
919 if (mapbase != (vm_offset_t)ef->address + mapsize) {
921 "%s: mapbase 0x%lx != address %p + mapsize 0x%lx (0x%lx)\n",
922 filename != NULL ? filename : "<none>",
923 (u_long)mapbase, ef->address, (u_long)mapsize,
924 (u_long)(vm_offset_t)ef->address + mapsize);
929 /* Local intra-module relocations */
930 error = link_elf_reloc_local(lf);
934 /* Pull in dependencies */
935 VOP_UNLOCK(nd.ni_vp, 0);
936 error = linker_load_dependencies(lf);
937 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
941 /* External relocations */
942 error = relocate_file(ef);
946 /* Notify MD code that a module is being loaded. */
947 error = elf_cpu_load_file(lf);
952 link_elf_invoke_ctors(lf->ctors_addr, lf->ctors_size);
957 VOP_UNLOCK(nd.ni_vp, 0);
958 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
960 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
967 link_elf_unload_file(linker_file_t file)
969 elf_file_t ef = (elf_file_t) file;
972 /* Notify MD code that a module is being unloaded. */
973 elf_cpu_unload_file(file);
976 for (i = 0; i < ef->nprogtab; i++) {
977 if (ef->progtab[i].size == 0)
979 if (ef->progtab[i].name == NULL)
981 if (!strcmp(ef->progtab[i].name, DPCPU_SETNAME))
982 dpcpu_free(ef->progtab[i].addr,
983 ef->progtab[i].size);
985 else if (!strcmp(ef->progtab[i].name, VNET_SETNAME))
986 vnet_data_free(ef->progtab[i].addr,
987 ef->progtab[i].size);
992 free(ef->reltab, M_LINKER);
993 free(ef->relatab, M_LINKER);
994 free(ef->progtab, M_LINKER);
995 free(ef->ctftab, M_LINKER);
996 free(ef->ctfoff, M_LINKER);
997 free(ef->typoff, M_LINKER);
998 if (file->filename != NULL)
999 preload_delete_name(file->filename);
1000 /* XXX reclaim module memory? */
1004 for (i = 0; i < ef->nreltab; i++)
1005 free(ef->reltab[i].rel, M_LINKER);
1006 for (i = 0; i < ef->nrelatab; i++)
1007 free(ef->relatab[i].rela, M_LINKER);
1008 free(ef->reltab, M_LINKER);
1009 free(ef->relatab, M_LINKER);
1010 free(ef->progtab, M_LINKER);
1013 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1014 (vm_offset_t) ef->address +
1015 (ef->object->size << PAGE_SHIFT));
1017 free(ef->e_shdr, M_LINKER);
1018 free(ef->ddbsymtab, M_LINKER);
1019 free(ef->ddbstrtab, M_LINKER);
1020 free(ef->shstrtab, M_LINKER);
1021 free(ef->ctftab, M_LINKER);
1022 free(ef->ctfoff, M_LINKER);
1023 free(ef->typoff, M_LINKER);
1027 symbol_name(elf_file_t ef, Elf_Size r_info)
1031 if (ELF_R_SYM(r_info)) {
1032 ref = ef->ddbsymtab + ELF_R_SYM(r_info);
1033 return ef->ddbstrtab + ref->st_name;
1039 findbase(elf_file_t ef, int sec)
1044 for (i = 0; i < ef->nprogtab; i++) {
1045 if (sec == ef->progtab[i].sec) {
1046 base = (Elf_Addr)ef->progtab[i].addr;
1054 relocate_file(elf_file_t ef)
1056 const Elf_Rel *rellim;
1058 const Elf_Rela *relalim;
1059 const Elf_Rela *rela;
1060 const char *symname;
1067 /* Perform relocations without addend if there are any: */
1068 for (i = 0; i < ef->nreltab; i++) {
1069 rel = ef->reltab[i].rel;
1071 link_elf_error(ef->lf.filename, "lost a reltab!");
1074 rellim = rel + ef->reltab[i].nrel;
1075 base = findbase(ef, ef->reltab[i].sec);
1077 link_elf_error(ef->lf.filename, "lost base for reltab");
1080 for ( ; rel < rellim; rel++) {
1081 symidx = ELF_R_SYM(rel->r_info);
1082 if (symidx >= ef->ddbsymcnt)
1084 sym = ef->ddbsymtab + symidx;
1085 /* Local relocs are already done */
1086 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1088 if (elf_reloc(&ef->lf, base, rel, ELF_RELOC_REL,
1090 symname = symbol_name(ef, rel->r_info);
1091 printf("link_elf_obj: symbol %s undefined\n",
1098 /* Perform relocations with addend if there are any: */
1099 for (i = 0; i < ef->nrelatab; i++) {
1100 rela = ef->relatab[i].rela;
1102 link_elf_error(ef->lf.filename, "lost a relatab!");
1105 relalim = rela + ef->relatab[i].nrela;
1106 base = findbase(ef, ef->relatab[i].sec);
1108 link_elf_error(ef->lf.filename,
1109 "lost base for relatab");
1112 for ( ; rela < relalim; rela++) {
1113 symidx = ELF_R_SYM(rela->r_info);
1114 if (symidx >= ef->ddbsymcnt)
1116 sym = ef->ddbsymtab + symidx;
1117 /* Local relocs are already done */
1118 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL)
1120 if (elf_reloc(&ef->lf, base, rela, ELF_RELOC_RELA,
1122 symname = symbol_name(ef, rela->r_info);
1123 printf("link_elf_obj: symbol %s undefined\n",
1131 * Only clean SHN_FBSD_CACHED for successful return. If we
1132 * modified symbol table for the object but found an
1133 * unresolved symbol, there is no reason to roll back.
1135 elf_obj_cleanup_globals_cache(ef);
1141 link_elf_lookup_symbol(linker_file_t lf, const char *name, c_linker_sym_t *sym)
1143 elf_file_t ef = (elf_file_t) lf;
1144 const Elf_Sym *symp;
1148 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1149 strp = ef->ddbstrtab + symp->st_name;
1150 if (symp->st_shndx != SHN_UNDEF && strcmp(name, strp) == 0) {
1151 *sym = (c_linker_sym_t) symp;
1159 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1160 linker_symval_t *symval)
1162 elf_file_t ef = (elf_file_t) lf;
1163 const Elf_Sym *es = (const Elf_Sym*) sym;
1165 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1166 symval->name = ef->ddbstrtab + es->st_name;
1167 symval->value = (caddr_t)es->st_value;
1168 symval->size = es->st_size;
1175 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1176 c_linker_sym_t *sym, long *diffp)
1178 elf_file_t ef = (elf_file_t) lf;
1179 u_long off = (uintptr_t) (void *) value;
1183 const Elf_Sym *best = NULL;
1186 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1187 if (es->st_name == 0)
1189 st_value = es->st_value;
1190 if (off >= st_value) {
1191 if (off - st_value < diff) {
1192 diff = off - st_value;
1196 } else if (off - st_value == diff) {
1205 *sym = (c_linker_sym_t) best;
1211 * Look up a linker set on an ELF system.
1214 link_elf_lookup_set(linker_file_t lf, const char *name,
1215 void ***startp, void ***stopp, int *countp)
1217 elf_file_t ef = (elf_file_t)lf;
1218 void **start, **stop;
1221 /* Relative to section number */
1222 for (i = 0; i < ef->nprogtab; i++) {
1223 if ((strncmp(ef->progtab[i].name, "set_", 4) == 0) &&
1224 strcmp(ef->progtab[i].name + 4, name) == 0) {
1225 start = (void **)ef->progtab[i].addr;
1226 stop = (void **)((char *)ef->progtab[i].addr +
1227 ef->progtab[i].size);
1228 count = stop - start;
1242 link_elf_each_function_name(linker_file_t file,
1243 int (*callback)(const char *, void *), void *opaque)
1245 elf_file_t ef = (elf_file_t)file;
1246 const Elf_Sym *symp;
1249 /* Exhaustive search */
1250 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1251 if (symp->st_value != 0 &&
1252 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1253 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1262 link_elf_each_function_nameval(linker_file_t file,
1263 linker_function_nameval_callback_t callback, void *opaque)
1265 linker_symval_t symval;
1266 elf_file_t ef = (elf_file_t)file;
1267 const Elf_Sym* symp;
1270 /* Exhaustive search */
1271 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1272 if (symp->st_value != 0 &&
1273 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1274 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1277 error = callback(file, i, &symval, opaque);
1286 elf_obj_cleanup_globals_cache(elf_file_t ef)
1291 for (i = 0; i < ef->ddbsymcnt; i++) {
1292 sym = ef->ddbsymtab + i;
1293 if (sym->st_shndx == SHN_FBSD_CACHED) {
1294 sym->st_shndx = SHN_UNDEF;
1301 * Symbol lookup function that can be used when the symbol index is known (ie
1302 * in relocations). It uses the symbol index instead of doing a fully fledged
1303 * hash table based lookup when such is valid. For example for local symbols.
1304 * This is not only more efficient, it's also more correct. It's not always
1305 * the case that the symbol can be found through the hash table.
1308 elf_obj_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1310 elf_file_t ef = (elf_file_t)lf;
1315 /* Don't even try to lookup the symbol if the index is bogus. */
1316 if (symidx >= ef->ddbsymcnt) {
1321 sym = ef->ddbsymtab + symidx;
1323 /* Quick answer if there is a definition included. */
1324 if (sym->st_shndx != SHN_UNDEF) {
1325 *res = sym->st_value;
1329 /* If we get here, then it is undefined and needs a lookup. */
1330 switch (ELF_ST_BIND(sym->st_info)) {
1332 /* Local, but undefined? huh? */
1338 /* Relative to Data or Function name */
1339 symbol = ef->ddbstrtab + sym->st_name;
1341 /* Force a lookup failure if the symbol name is bogus. */
1346 res1 = (Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps);
1349 * Cache global lookups during module relocation. The failure
1350 * case is particularly expensive for callers, who must scan
1351 * through the entire globals table doing strcmp(). Cache to
1352 * avoid doing such work repeatedly.
1354 * After relocation is complete, undefined globals will be
1355 * restored to SHN_UNDEF in elf_obj_cleanup_globals_cache(),
1359 sym->st_shndx = SHN_FBSD_CACHED;
1360 sym->st_value = res1;
1363 } else if (ELF_ST_BIND(sym->st_info) == STB_WEAK) {
1376 link_elf_fix_link_set(elf_file_t ef)
1378 static const char startn[] = "__start_";
1379 static const char stopn[] = "__stop_";
1381 const char *sym_name, *linkset_name;
1382 Elf_Addr startp, stopp;
1387 for (symidx = 1 /* zero entry is special */;
1388 symidx < ef->ddbsymcnt; symidx++) {
1389 sym = ef->ddbsymtab + symidx;
1390 if (sym->st_shndx != SHN_UNDEF)
1393 sym_name = ef->ddbstrtab + sym->st_name;
1394 if (strncmp(sym_name, startn, sizeof(startn) - 1) == 0) {
1396 linkset_name = sym_name + sizeof(startn) - 1;
1398 else if (strncmp(sym_name, stopn, sizeof(stopn) - 1) == 0) {
1400 linkset_name = sym_name + sizeof(stopn) - 1;
1405 for (i = 0; i < ef->nprogtab; i++) {
1406 if (strcmp(ef->progtab[i].name, linkset_name) == 0) {
1407 startp = (Elf_Addr)ef->progtab[i].addr;
1408 stopp = (Elf_Addr)(startp + ef->progtab[i].size);
1412 if (i == ef->nprogtab)
1415 sym->st_value = start ? startp : stopp;
1421 link_elf_reloc_local(linker_file_t lf)
1423 elf_file_t ef = (elf_file_t)lf;
1424 const Elf_Rel *rellim;
1426 const Elf_Rela *relalim;
1427 const Elf_Rela *rela;
1433 link_elf_fix_link_set(ef);
1435 /* Perform relocations without addend if there are any: */
1436 for (i = 0; i < ef->nreltab; i++) {
1437 rel = ef->reltab[i].rel;
1439 link_elf_error(ef->lf.filename, "lost a reltab");
1442 rellim = rel + ef->reltab[i].nrel;
1443 base = findbase(ef, ef->reltab[i].sec);
1445 link_elf_error(ef->lf.filename, "lost base for reltab");
1448 for ( ; rel < rellim; rel++) {
1449 symidx = ELF_R_SYM(rel->r_info);
1450 if (symidx >= ef->ddbsymcnt)
1452 sym = ef->ddbsymtab + symidx;
1453 /* Only do local relocs */
1454 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1456 elf_reloc_local(lf, base, rel, ELF_RELOC_REL,
1461 /* Perform relocations with addend if there are any: */
1462 for (i = 0; i < ef->nrelatab; i++) {
1463 rela = ef->relatab[i].rela;
1465 link_elf_error(ef->lf.filename, "lost a relatab!");
1468 relalim = rela + ef->relatab[i].nrela;
1469 base = findbase(ef, ef->relatab[i].sec);
1471 link_elf_error(ef->lf.filename, "lost base for reltab");
1474 for ( ; rela < relalim; rela++) {
1475 symidx = ELF_R_SYM(rela->r_info);
1476 if (symidx >= ef->ddbsymcnt)
1478 sym = ef->ddbsymtab + symidx;
1479 /* Only do local relocs */
1480 if (ELF_ST_BIND(sym->st_info) != STB_LOCAL)
1482 elf_reloc_local(lf, base, rela, ELF_RELOC_RELA,
1490 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1492 elf_file_t ef = (elf_file_t)lf;
1494 *symtab = ef->ddbsymtab;
1496 if (*symtab == NULL)
1499 return (ef->ddbsymcnt);
1503 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1505 elf_file_t ef = (elf_file_t)lf;
1507 *strtab = ef->ddbstrtab;
1509 if (*strtab == NULL)
1512 return (ef->ddbstrcnt);