2 * Copyright (c) 1998 Doug Rabson
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * $FreeBSD: src/sys/kern/link_elf.c,v 1.24 1999/12/24 15:33:36 bde Exp $
27 * $DragonFly: src/sys/kern/link_elf.c,v 1.29 2008/08/01 23:11:16 dillon Exp $
30 #include <sys/param.h>
31 #include <sys/kernel.h>
32 #include <sys/systm.h>
33 #include <sys/malloc.h>
35 #include <sys/nlookup.h>
36 #include <sys/fcntl.h>
37 #include <sys/vnode.h>
38 #include <sys/linker.h>
39 #include <machine/elf.h>
42 #include <vm/vm_param.h>
43 #include <vm/vm_zone.h>
46 #include <vm/vm_object.h>
47 #include <vm/vm_kern.h>
48 #include <vm/vm_extern.h>
51 #include <vm/vm_map.h>
53 static int link_elf_preload_file(const char *, linker_file_t *);
54 static int link_elf_preload_finish(linker_file_t);
55 static int link_elf_load_file(const char*, linker_file_t*);
56 static int link_elf_lookup_symbol(linker_file_t, const char*,
58 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t*);
59 static int link_elf_search_symbol(linker_file_t, caddr_t value,
60 c_linker_sym_t* sym, long* diffp);
62 static void link_elf_unload_file(linker_file_t);
63 static void link_elf_unload_module(linker_file_t);
64 static int link_elf_lookup_set(linker_file_t, const char *,
65 void ***, void ***, int *);
66 static int elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *);
67 static void link_elf_reloc_local(linker_file_t lf);
69 static struct linker_class_ops link_elf_class_ops = {
71 link_elf_preload_file,
74 static struct linker_file_ops link_elf_file_ops = {
75 .lookup_symbol = link_elf_lookup_symbol,
76 .symbol_values = link_elf_symbol_values,
77 .search_symbol = link_elf_search_symbol,
78 .unload = link_elf_unload_file,
79 .lookup_set = link_elf_lookup_set
82 static struct linker_file_ops link_elf_module_ops = {
83 .lookup_symbol = link_elf_lookup_symbol,
84 .symbol_values = link_elf_symbol_values,
85 .search_symbol = link_elf_search_symbol,
86 .preload_finish = link_elf_preload_finish,
87 .unload = link_elf_unload_module,
88 .lookup_set = link_elf_lookup_set,
91 typedef struct elf_file {
92 caddr_t address; /* Relocation address */
94 vm_object_t object; /* VM object to hold file pages */
96 const Elf_Dyn* dynamic; /* Symbol table etc. */
97 Elf_Hashelt nbuckets; /* DT_HASH info */
99 const Elf_Hashelt* buckets;
100 const Elf_Hashelt* chains;
102 caddr_t strtab; /* DT_STRTAB */
103 int strsz; /* DT_STRSZ */
104 const Elf_Sym* symtab; /* DT_SYMTAB */
105 Elf_Addr* got; /* DT_PLTGOT */
106 const Elf_Rel* pltrel; /* DT_JMPREL */
107 int pltrelsize; /* DT_PLTRELSZ */
108 const Elf_Rela* pltrela; /* DT_JMPREL */
109 int pltrelasize; /* DT_PLTRELSZ */
110 const Elf_Rel* rel; /* DT_REL */
111 int relsize; /* DT_RELSZ */
112 const Elf_Rela* rela; /* DT_RELA */
113 int relasize; /* DT_RELASZ */
115 const Elf_Sym* ddbsymtab; /* The symbol table we are using */
116 long ddbsymcnt; /* Number of symbols */
117 caddr_t ddbstrtab; /* String table */
118 long ddbstrcnt; /* number of bytes in string table */
119 caddr_t symbase; /* malloc'ed symbold base */
120 caddr_t strbase; /* malloc'ed string base */
123 static int parse_dynamic(linker_file_t lf);
124 static int relocate_file(linker_file_t lf);
125 static int parse_module_symbols(linker_file_t lf);
128 * The kernel symbol table starts here.
130 extern struct _dynamic _DYNAMIC;
133 link_elf_init(void* arg)
136 caddr_t modptr, baseptr, sizeptr;
140 #if ELF_TARG_CLASS == ELFCLASS32
141 linker_add_class("elf32", NULL, &link_elf_class_ops);
143 linker_add_class("elf64", NULL, &link_elf_class_ops);
146 dp = (Elf_Dyn*) &_DYNAMIC;
148 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_INTWAIT | M_ZERO);
150 #ifdef SPARSE_MAPPING
155 modptr = preload_search_by_type("elf kernel");
157 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
160 linker_kernel_file = linker_make_file(modname, ef, &link_elf_file_ops);
161 if (linker_kernel_file == NULL)
162 panic("link_elf_init: Can't create linker structures for kernel");
163 parse_dynamic(linker_kernel_file);
164 linker_kernel_file->address = (caddr_t) KERNBASE;
165 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
169 baseptr = preload_search_info(modptr, MODINFO_ADDR);
171 linker_kernel_file->address = *(caddr_t *)baseptr;
172 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
174 linker_kernel_file->size = *(size_t *)sizeptr;
176 parse_module_symbols(linker_kernel_file);
177 linker_current_file = linker_kernel_file;
178 linker_kernel_file->flags |= LINKER_FILE_LINKED;
182 SYSINIT(link_elf, SI_BOOT2_KLD, SI_ORDER_SECOND, link_elf_init, 0);
185 parse_module_symbols(linker_file_t lf)
187 elf_file_t ef = lf->priv;
189 caddr_t ssym, esym, base;
195 if (ef->modptr == NULL)
197 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_SSYM);
200 ssym = *(caddr_t *)pointer;
201 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_ESYM);
204 esym = *(caddr_t *)pointer;
208 symcnt = *(long *)base;
209 base += sizeof(long);
210 symtab = (Elf_Sym *)base;
211 base += roundup(symcnt, sizeof(long));
213 if (base > esym || base < ssym) {
214 kprintf("Symbols are corrupt!\n");
218 strcnt = *(long *)base;
219 base += sizeof(long);
221 base += roundup(strcnt, sizeof(long));
223 if (base > esym || base < ssym) {
224 kprintf("Symbols are corrupt!\n");
228 ef->ddbsymtab = symtab;
229 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
230 ef->ddbstrtab = strtab;
231 ef->ddbstrcnt = strcnt;
237 parse_dynamic(linker_file_t lf)
239 elf_file_t ef = lf->priv;
241 int plttype = DT_REL;
243 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
247 /* From src/libexec/rtld-elf/rtld.c */
248 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
249 (ef->address + dp->d_un.d_ptr);
250 ef->nbuckets = hashtab[0];
251 ef->nchains = hashtab[1];
252 ef->buckets = hashtab + 2;
253 ef->chains = ef->buckets + ef->nbuckets;
257 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
260 ef->strsz = dp->d_un.d_val;
263 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
266 if (dp->d_un.d_val != sizeof(Elf_Sym))
270 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
273 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
276 ef->relsize = dp->d_un.d_val;
279 if (dp->d_un.d_val != sizeof(Elf_Rel))
283 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
286 ef->pltrelsize = dp->d_un.d_val;
289 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
292 ef->relasize = dp->d_un.d_val;
295 if (dp->d_un.d_val != sizeof(Elf_Rela))
299 plttype = dp->d_un.d_val;
300 if (plttype != DT_REL && plttype != DT_RELA)
306 if (plttype == DT_RELA) {
307 ef->pltrela = (const Elf_Rela *) ef->pltrel;
309 ef->pltrelasize = ef->pltrelsize;
313 ef->ddbsymtab = ef->symtab;
314 ef->ddbsymcnt = ef->nchains;
315 ef->ddbstrtab = ef->strtab;
316 ef->ddbstrcnt = ef->strsz;
322 link_elf_error(const char *s)
324 kprintf("kldload: %s\n", s);
328 link_elf_preload_file(const char *filename, linker_file_t *result)
330 caddr_t modptr, baseptr, sizeptr, dynptr;
338 * Look to see if we have the module preloaded.
340 modptr = preload_search_by_name(filename);
344 /* It's preloaded, check we can handle it and collect information */
345 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
346 baseptr = preload_search_info(modptr, MODINFO_ADDR);
347 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
348 dynptr = preload_search_info(modptr, MODINFO_METADATA|MODINFOMD_DYNAMIC);
350 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
351 strcmp(type, "elf module") != 0))
353 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
356 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
358 ef->address = *(caddr_t *)baseptr;
359 #ifdef SPARSE_MAPPING
362 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
363 ef->dynamic = (Elf_Dyn *)dp;
364 lf = linker_make_file(filename, ef, &link_elf_module_ops);
369 lf->address = ef->address;
370 lf->size = *(size_t *)sizeptr;
372 error = parse_dynamic(lf);
374 linker_file_unload(lf);
377 link_elf_reloc_local(lf);
383 link_elf_preload_finish(linker_file_t lf)
387 error = relocate_file(lf);
390 parse_module_symbols(lf);
396 link_elf_load_file(const char* filename, linker_file_t* result)
398 struct nlookupdata nd;
399 struct thread *td = curthread; /* XXX */
400 struct proc *p = td->td_proc;
415 Elf_Addr base_vlimit;
428 if (p->p_ucred == NULL) {
429 kprintf("link_elf_load_file: cannot load '%s' from filesystem"
430 " this early\n", filename);
435 pathname = linker_search_path(filename);
436 if (pathname == NULL)
439 error = nlookup_init(&nd, pathname, UIO_SYSSPACE, NLC_FOLLOW|NLC_LOCKVP);
441 error = vn_open(&nd, NULL, FREAD, 0);
442 kfree(pathname, M_LINKER);
448 nd.nl_open_vp = NULL;
452 * Read the elf header from the file.
454 firstpage = kmalloc(PAGE_SIZE, M_LINKER, M_WAITOK);
455 hdr = (Elf_Ehdr *)firstpage;
456 error = vn_rdwr(UIO_READ, vp, firstpage, PAGE_SIZE, 0,
457 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
458 nbytes = PAGE_SIZE - resid;
467 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
468 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
469 link_elf_error("Unsupported file layout");
473 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
474 || hdr->e_version != EV_CURRENT) {
475 link_elf_error("Unsupported file version");
479 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
483 if (hdr->e_machine != ELF_TARG_MACH) {
484 link_elf_error("Unsupported machine");
490 * We rely on the program header being in the first page. This is
491 * not strictly required by the ABI specification, but it seems to
492 * always true in practice. And, it simplifies things considerably.
494 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
495 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
496 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
497 link_elf_error("Unreadable program headers");
500 * Scan the program header entries, and save key information.
502 * We rely on there being exactly two load segments, text and data,
505 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
506 phlimit = phdr + hdr->e_phnum;
510 while (phdr < phlimit) {
511 switch (phdr->p_type) {
515 link_elf_error("Too many sections");
539 link_elf_error("Object is not dynamically-linked");
545 * Allocate the entire address space of the object, to stake out our
546 * contiguous region, and to establish the base address for relocation.
548 base_offset = trunc_page(segs[0]->p_offset);
549 base_vaddr = trunc_page(segs[0]->p_vaddr);
550 base_vlimit = round_page(segs[1]->p_vaddr + segs[1]->p_memsz);
551 mapsize = base_vlimit - base_vaddr;
553 ef = kmalloc(sizeof(struct elf_file), M_LINKER, M_WAITOK | M_ZERO);
554 #ifdef SPARSE_MAPPING
555 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
556 if (ef->object == NULL) {
561 vm_object_reference(ef->object);
562 ef->address = (caddr_t)vm_map_min(&kernel_map);
563 error = vm_map_find(&kernel_map, ef->object, 0,
564 (vm_offset_t *)&ef->address, mapsize,
567 VM_PROT_ALL, VM_PROT_ALL,
570 vm_object_deallocate(ef->object);
575 ef->address = kmalloc(mapsize, M_LINKER, M_WAITOK);
577 mapbase = ef->address;
580 * Read the text and data sections and zero the bss.
582 for (i = 0; i < 2; i++) {
583 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
584 error = vn_rdwr(UIO_READ, vp,
585 segbase, segs[i]->p_filesz, segs[i]->p_offset,
586 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
588 #ifdef SPARSE_MAPPING
589 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
590 (vm_offset_t) ef->address
591 + (ef->object->size << PAGE_SHIFT));
592 vm_object_deallocate(ef->object);
594 kfree(ef->address, M_LINKER);
599 bzero(segbase + segs[i]->p_filesz,
600 segs[i]->p_memsz - segs[i]->p_filesz);
602 #ifdef SPARSE_MAPPING
604 * Wire down the pages
606 vm_map_wire(&kernel_map,
607 (vm_offset_t) segbase,
608 (vm_offset_t) segbase + segs[i]->p_memsz,
613 ef->dynamic = (const Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
615 lf = linker_make_file(filename, ef, &link_elf_file_ops);
617 #ifdef SPARSE_MAPPING
618 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
619 (vm_offset_t) ef->address
620 + (ef->object->size << PAGE_SHIFT));
621 vm_object_deallocate(ef->object);
623 kfree(ef->address, M_LINKER);
629 lf->address = ef->address;
632 error = parse_dynamic(lf);
635 link_elf_reloc_local(lf);
636 error = linker_load_dependencies(lf);
639 error = relocate_file(lf);
643 /* Try and load the symbol table if it's present. (you can strip it!) */
644 nbytes = hdr->e_shnum * hdr->e_shentsize;
645 if (nbytes == 0 || hdr->e_shoff == 0)
647 shdr = kmalloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
648 error = vn_rdwr(UIO_READ, vp,
649 (caddr_t)shdr, nbytes, hdr->e_shoff,
650 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
655 for (i = 0; i < hdr->e_shnum; i++) {
656 if (shdr[i].sh_type == SHT_SYMTAB) {
658 symstrindex = shdr[i].sh_link;
661 if (symtabindex < 0 || symstrindex < 0)
664 symcnt = shdr[symtabindex].sh_size;
665 ef->symbase = kmalloc(symcnt, M_LINKER, M_WAITOK);
666 strcnt = shdr[symstrindex].sh_size;
667 ef->strbase = kmalloc(strcnt, M_LINKER, M_WAITOK);
668 error = vn_rdwr(UIO_READ, vp,
669 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
670 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
673 error = vn_rdwr(UIO_READ, vp,
674 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
675 UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid);
679 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
680 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
681 ef->ddbstrcnt = strcnt;
682 ef->ddbstrtab = ef->strbase;
690 linker_file_unload(lf);
692 kfree(shdr, M_LINKER);
694 kfree(firstpage, M_LINKER);
702 elf_relocaddr(linker_file_t lf, Elf_Addr x)
708 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
709 return ((x - ef->pcpu_start) + ef->pcpu_base);
711 if (x >= ef->vnet_start && x < ef->vnet_stop)
712 return ((x - ef->vnet_start) + ef->vnet_base);
719 link_elf_unload_file(linker_file_t file)
721 elf_file_t ef = file->priv;
724 #ifdef SPARSE_MAPPING
726 vm_map_remove(&kernel_map, (vm_offset_t) ef->address,
727 (vm_offset_t) ef->address
728 + (ef->object->size << PAGE_SHIFT));
729 vm_object_deallocate(ef->object);
733 kfree(ef->address, M_LINKER);
736 kfree(ef->symbase, M_LINKER);
738 kfree(ef->strbase, M_LINKER);
744 link_elf_unload_module(linker_file_t file)
746 elf_file_t ef = file->priv;
751 preload_delete_name(file->filename);
755 symbol_name(elf_file_t ef, Elf_Size r_info)
759 if (ELF_R_SYM(r_info)) {
760 ref = ef->symtab + ELF_R_SYM(r_info);
761 return ef->strtab + ref->st_name;
767 relocate_file(linker_file_t lf)
769 elf_file_t ef = lf->priv;
770 const Elf_Rel *rellim;
772 const Elf_Rela *relalim;
773 const Elf_Rela *rela;
776 /* Perform relocations without addend if there are any: */
779 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
780 while (rel < rellim) {
781 if (elf_reloc(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL, elf_lookup)) {
782 symname = symbol_name(ef, rel->r_info);
783 kprintf("link_elf: symbol %s undefined\n", symname);
790 /* Perform relocations with addend if there are any: */
793 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
794 while (rela < relalim) {
795 if (elf_reloc(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA, elf_lookup)) {
796 symname = symbol_name(ef, rela->r_info);
797 kprintf("link_elf: symbol %s undefined\n", symname);
804 /* Perform PLT relocations without addend if there are any: */
807 rellim = (const Elf_Rel *)((const char *)ef->pltrel + ef->pltrelsize);
808 while (rel < rellim) {
809 if (elf_reloc(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL, elf_lookup)) {
810 symname = symbol_name(ef, rel->r_info);
811 kprintf("link_elf: symbol %s undefined\n", symname);
818 /* Perform relocations with addend if there are any: */
821 relalim = (const Elf_Rela *)((const char *)ef->pltrela + ef->pltrelasize);
822 while (rela < relalim) {
823 symname = symbol_name(ef, rela->r_info);
824 if (elf_reloc(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA, elf_lookup)) {
825 kprintf("link_elf: symbol %s undefined\n", symname);
836 * Hash function for symbol table lookup. Don't even think about changing
837 * this. It is specified by the System V ABI.
840 elf_hash(const char *name)
842 const unsigned char *p = (const unsigned char *) name;
848 if ((g = h & 0xf0000000) != 0)
856 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
858 elf_file_t ef = lf->priv;
859 unsigned long symnum;
865 /* If we don't have a hash, bail. */
866 if (ef->buckets == NULL || ef->nbuckets == 0) {
867 kprintf("link_elf_lookup_symbol: missing symbol hash table\n");
871 /* First, search hashed global symbols */
872 hash = elf_hash(name);
873 symnum = ef->buckets[hash % ef->nbuckets];
875 while (symnum != STN_UNDEF) {
876 if (symnum >= ef->nchains) {
877 kprintf("link_elf_lookup_symbol: corrupt symbol table\n");
881 symp = ef->symtab + symnum;
882 if (symp->st_name == 0) {
883 kprintf("link_elf_lookup_symbol: corrupt symbol table\n");
887 strp = ef->strtab + symp->st_name;
889 if (strcmp(name, strp) == 0) {
890 if (symp->st_shndx != SHN_UNDEF ||
891 (symp->st_value != 0 &&
892 ELF_ST_TYPE(symp->st_info) == STT_FUNC)
894 *sym = (c_linker_sym_t) symp;
901 symnum = ef->chains[symnum];
904 /* If we have not found it, look at the full table (if loaded) */
905 if (ef->symtab == ef->ddbsymtab)
908 /* Exhaustive search */
909 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
910 strp = ef->ddbstrtab + symp->st_name;
911 if (strcmp(name, strp) == 0) {
912 if (symp->st_shndx != SHN_UNDEF ||
913 (symp->st_value != 0 &&
914 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
915 *sym = (c_linker_sym_t) symp;
926 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t *symval)
928 elf_file_t ef = lf->priv;
929 const Elf_Sym *es = (const Elf_Sym *)sym;
931 if (es >= ef->symtab && ((es - ef->symtab) < ef->nchains)) {
932 symval->name = ef->strtab + es->st_name;
933 symval->value = (caddr_t) ef->address + es->st_value;
934 symval->size = es->st_size;
937 if (ef->symtab == ef->ddbsymtab)
939 if (es >= ef->ddbsymtab && ((es - ef->ddbsymtab) < ef->ddbsymcnt)) {
940 symval->name = ef->ddbstrtab + es->st_name;
941 symval->value = (caddr_t) ef->address + es->st_value;
942 symval->size = es->st_size;
949 link_elf_search_symbol(linker_file_t lf, caddr_t value,
950 c_linker_sym_t *sym, long *diffp)
952 elf_file_t ef = lf->priv;
953 u_long off = (uintptr_t)(void *)value;
957 const Elf_Sym *best = 0;
960 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
961 if (es->st_name == 0)
963 st_value = es->st_value + (uintptr_t)(void *)ef->address;
964 if (off >= st_value) {
965 if (off - st_value < diff) {
966 diff = off - st_value;
970 } else if (off - st_value == diff) {
979 *sym = (c_linker_sym_t) best;
985 * Look up a linker set on an ELF system.
988 link_elf_lookup_set(linker_file_t lf, const char *name,
989 void ***startp, void ***stopp, int *countp)
992 linker_symval_t symval;
994 void **start, **stop;
995 int len, error = 0, count;
997 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
998 setsym = kmalloc(len, M_LINKER, M_WAITOK);
1000 /* get address of first entry */
1001 ksnprintf(setsym, len, "%s%s", "__start_set_", name);
1002 error = link_elf_lookup_symbol(lf, setsym, &sym);
1005 link_elf_symbol_values(lf, sym, &symval);
1006 if (symval.value == 0) {
1010 start = (void **)symval.value;
1012 /* get address of last entry */
1013 ksnprintf(setsym, len, "%s%s", "__stop_set_", name);
1014 error = link_elf_lookup_symbol(lf, setsym, &sym);
1017 link_elf_symbol_values(lf, sym, &symval);
1018 if (symval.value == 0) {
1022 stop = (void **)symval.value;
1024 /* and the number of entries */
1025 count = stop - start;
1036 kfree(setsym, M_LINKER);
1041 * Symbol lookup function that can be used when the symbol index is known (ie
1042 * in relocations). It uses the symbol index instead of doing a fully fledged
1043 * hash table based lookup when such is valid. For example for local symbols.
1044 * This is not only more efficient, it's also more correct. It's not always
1045 * the case that the symbol can be found through the hash table.
1048 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *result)
1050 elf_file_t ef = lf->priv;
1054 /* Don't even try to lookup the symbol if the index is bogus. */
1055 if (symidx >= ef->nchains)
1058 sym = ef->symtab + symidx;
1061 * Don't do a full lookup when the symbol is local. It may even
1062 * fail because it may not be found through the hash table.
1064 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1065 /* Force lookup failure when we have an insanity. */
1066 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1068 return ((Elf_Addr) ef->address + sym->st_value);
1071 * XXX we can avoid doing a hash table based lookup for global
1072 * symbols as well. This however is not always valid, so we'll
1073 * just do it the hard way for now. Performance tweaks can
1077 symbol = ef->strtab + sym->st_name;
1079 /* Force a lookup failure if the symbol name is bogus. */
1083 return (linker_file_lookup_symbol(lf, symbol, deps, (caddr_t *)result));
1086 link_elf_reloc_local(linker_file_t lf)
1088 elf_file_t ef = lf->priv;
1089 const Elf_Rel *rellim;
1091 const Elf_Rela *relalim;
1092 const Elf_Rela *rela;
1094 /* Perform relocations without addend if there are any: */
1095 if ((rel = ef->rel) != NULL) {
1096 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1097 while (rel < rellim) {
1098 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
1104 /* Perform relocations with addend if there are any: */
1105 if ((rela = ef->rela) != NULL) {
1106 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
1107 while (rela < relalim) {
1108 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,