2 * Copyright (c) 1998-2000 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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
38 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mutex.h>
42 #include <sys/mount.h>
45 #include <sys/namei.h>
46 #include <sys/fcntl.h>
47 #include <sys/vnode.h>
48 #include <sys/linker.h>
50 #include <machine/elf.h>
52 #include <security/mac/mac_framework.h>
55 #include <vm/vm_param.h>
57 #include <vm/vm_object.h>
58 #include <vm/vm_kern.h>
59 #include <vm/vm_extern.h>
62 #include <vm/vm_map.h>
64 #include <sys/link_elf.h>
70 #include "linker_if.h"
74 typedef struct elf_file {
75 struct linker_file lf; /* Common fields */
76 int preloaded; /* Was file pre-loaded */
77 caddr_t address; /* Relocation address */
79 vm_object_t object; /* VM object to hold file pages */
81 Elf_Dyn* dynamic; /* Symbol table etc. */
82 Elf_Hashelt nbuckets; /* DT_HASH info */
84 const Elf_Hashelt* buckets;
85 const Elf_Hashelt* chains;
87 caddr_t strtab; /* DT_STRTAB */
88 int strsz; /* DT_STRSZ */
89 const Elf_Sym* symtab; /* DT_SYMTAB */
90 Elf_Addr* got; /* DT_PLTGOT */
91 const Elf_Rel* pltrel; /* DT_JMPREL */
92 int pltrelsize; /* DT_PLTRELSZ */
93 const Elf_Rela* pltrela; /* DT_JMPREL */
94 int pltrelasize; /* DT_PLTRELSZ */
95 const Elf_Rel* rel; /* DT_REL */
96 int relsize; /* DT_RELSZ */
97 const Elf_Rela* rela; /* DT_RELA */
98 int relasize; /* DT_RELASZ */
100 const Elf_Sym* ddbsymtab; /* The symbol table we are using */
101 long ddbsymcnt; /* Number of symbols */
102 caddr_t ddbstrtab; /* String table */
103 long ddbstrcnt; /* number of bytes in string table */
104 caddr_t symbase; /* malloc'ed symbold base */
105 caddr_t strbase; /* malloc'ed string base */
106 caddr_t ctftab; /* CTF table */
107 long ctfcnt; /* number of bytes in CTF table */
108 caddr_t ctfoff; /* CTF offset table */
109 caddr_t typoff; /* Type offset table */
110 long typlen; /* Number of type entries. */
111 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */
112 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */
113 Elf_Addr pcpu_base; /* Relocated pcpu set address. */
115 struct link_map gdb; /* hooks for gdb */
119 #include <kern/kern_ctf.c>
121 static int link_elf_link_common_finish(linker_file_t);
122 static int link_elf_link_preload(linker_class_t cls,
123 const char*, linker_file_t*);
124 static int link_elf_link_preload_finish(linker_file_t);
125 static int link_elf_load_file(linker_class_t, const char*, linker_file_t*);
126 static int link_elf_lookup_symbol(linker_file_t, const char*,
128 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t*);
129 static int link_elf_search_symbol(linker_file_t, caddr_t value,
130 c_linker_sym_t* sym, long* diffp);
132 static void link_elf_unload_file(linker_file_t);
133 static void link_elf_unload_preload(linker_file_t);
134 static int link_elf_lookup_set(linker_file_t, const char *,
135 void ***, void ***, int *);
136 static int link_elf_each_function_name(linker_file_t,
137 int (*)(const char *, void *),
139 static int link_elf_each_function_nameval(linker_file_t,
140 linker_function_nameval_callback_t,
142 static void link_elf_reloc_local(linker_file_t);
143 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
144 static long link_elf_strtab_get(linker_file_t, caddr_t *);
145 static Elf_Addr elf_lookup(linker_file_t lf, Elf_Size symidx, int deps);
147 static kobj_method_t link_elf_methods[] = {
148 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
149 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
150 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
151 KOBJMETHOD(linker_unload, link_elf_unload_file),
152 KOBJMETHOD(linker_load_file, link_elf_load_file),
153 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
154 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
155 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
156 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
157 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
158 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
159 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
160 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
164 static struct linker_class link_elf_class = {
165 #if ELF_TARG_CLASS == ELFCLASS32
170 link_elf_methods, sizeof(struct elf_file)
173 static int parse_dynamic(elf_file_t ef);
174 static int relocate_file(elf_file_t ef);
175 static int link_elf_preload_parse_symbols(elf_file_t ef);
178 static void r_debug_state(struct r_debug *dummy_one,
179 struct link_map *dummy_two);
182 * A list of loaded modules for GDB to use for loading symbols.
184 struct r_debug r_debug;
186 #define GDB_STATE(s) r_debug.r_state = s; r_debug_state(NULL, NULL);
189 * Function for the debugger to set a breakpoint on to gain control.
192 r_debug_state(struct r_debug *dummy_one __unused,
193 struct link_map *dummy_two __unused)
198 link_elf_add_gdb(struct link_map *l)
200 struct link_map *prev;
204 if (r_debug.r_map == NULL) {
209 /* Append to list. */
210 for (prev = r_debug.r_map; prev->l_next != NULL; prev = prev->l_next)
218 link_elf_delete_gdb(struct link_map *l)
220 if (l->l_prev == NULL) {
222 if ((r_debug.r_map = l->l_next) != NULL)
223 l->l_next->l_prev = NULL;
225 /* Remove any but first. */
226 if ((l->l_prev->l_next = l->l_next) != NULL)
227 l->l_next->l_prev = l->l_prev;
233 Elf_Addr link_elf_get_gp(linker_file_t);
237 * The kernel symbol table starts here.
239 extern struct _dynamic _DYNAMIC;
242 link_elf_error(const char *filename, const char *s)
244 if (filename == NULL)
245 printf("kldload: %s\n", s);
247 printf("kldload: %s: %s\n", filename, s);
251 * Actions performed after linking/loading both the preloaded kernel and any
252 * modules; whether preloaded or dynamicly loaded.
255 link_elf_link_common_finish(linker_file_t lf)
258 elf_file_t ef = (elf_file_t)lf;
263 /* Notify MD code that a module is being loaded. */
264 error = elf_cpu_load_file(lf);
270 ef->gdb.l_addr = lf->address;
271 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
272 strcpy(newfilename, lf->filename);
273 ef->gdb.l_name = newfilename;
274 ef->gdb.l_ld = ef->dynamic;
275 link_elf_add_gdb(&ef->gdb);
276 GDB_STATE(RT_CONSISTENT);
283 link_elf_init(void* arg)
286 caddr_t modptr, baseptr, sizeptr;
290 linker_add_class(&link_elf_class);
292 dp = (Elf_Dyn*) &_DYNAMIC;
294 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
296 modptr = preload_search_by_type("elf kernel");
298 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
301 linker_kernel_file = linker_make_file(modname, &link_elf_class);
302 if (linker_kernel_file == NULL)
303 panic("link_elf_init: Can't create linker structures for kernel");
305 ef = (elf_file_t) linker_kernel_file;
308 #ifdef SPARSE_MAPPING
315 linker_kernel_file->address = (caddr_t) KERNBASE;
316 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
320 baseptr = preload_search_info(modptr, MODINFO_ADDR);
322 linker_kernel_file->address = *(caddr_t *)baseptr;
323 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
325 linker_kernel_file->size = *(size_t *)sizeptr;
327 (void)link_elf_preload_parse_symbols(ef);
330 r_debug.r_map = NULL;
331 r_debug.r_brk = r_debug_state;
332 r_debug.r_state = RT_CONSISTENT;
335 (void)link_elf_link_common_finish(linker_kernel_file);
336 linker_kernel_file->flags |= LINKER_FILE_LINKED;
339 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0);
342 link_elf_preload_parse_symbols(elf_file_t ef)
345 caddr_t ssym, esym, base;
351 if (ef->modptr == NULL)
353 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_SSYM);
356 ssym = *(caddr_t *)pointer;
357 pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_ESYM);
360 esym = *(caddr_t *)pointer;
364 symcnt = *(long *)base;
365 base += sizeof(long);
366 symtab = (Elf_Sym *)base;
367 base += roundup(symcnt, sizeof(long));
369 if (base > esym || base < ssym) {
370 printf("Symbols are corrupt!\n");
374 strcnt = *(long *)base;
375 base += sizeof(long);
377 base += roundup(strcnt, sizeof(long));
379 if (base > esym || base < ssym) {
380 printf("Symbols are corrupt!\n");
384 ef->ddbsymtab = symtab;
385 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
386 ef->ddbstrtab = strtab;
387 ef->ddbstrcnt = strcnt;
393 parse_dynamic(elf_file_t ef)
396 int plttype = DT_REL;
398 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
402 /* From src/libexec/rtld-elf/rtld.c */
403 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
404 (ef->address + dp->d_un.d_ptr);
405 ef->nbuckets = hashtab[0];
406 ef->nchains = hashtab[1];
407 ef->buckets = hashtab + 2;
408 ef->chains = ef->buckets + ef->nbuckets;
412 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
415 ef->strsz = dp->d_un.d_val;
418 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
421 if (dp->d_un.d_val != sizeof(Elf_Sym))
425 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
428 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
431 ef->relsize = dp->d_un.d_val;
434 if (dp->d_un.d_val != sizeof(Elf_Rel))
438 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
441 ef->pltrelsize = dp->d_un.d_val;
444 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
447 ef->relasize = dp->d_un.d_val;
450 if (dp->d_un.d_val != sizeof(Elf_Rela))
454 plttype = dp->d_un.d_val;
455 if (plttype != DT_REL && plttype != DT_RELA)
460 dp->d_un.d_ptr = (Elf_Addr) &r_debug;
466 if (plttype == DT_RELA) {
467 ef->pltrela = (const Elf_Rela *) ef->pltrel;
469 ef->pltrelasize = ef->pltrelsize;
473 ef->ddbsymtab = ef->symtab;
474 ef->ddbsymcnt = ef->nchains;
475 ef->ddbstrtab = ef->strtab;
476 ef->ddbstrcnt = ef->strsz;
482 parse_dpcpu(elf_file_t ef)
489 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
490 (void ***)&ef->pcpu_stop, &count);
491 /* Error just means there is no pcpu set to relocate. */
494 count *= sizeof(void *);
496 * Allocate space in the primary pcpu area. Copy in our initialization
497 * from the data section and then initialize all per-cpu storage from
500 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count);
501 if (ef->pcpu_base == (Elf_Addr)NULL)
503 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count);
504 dpcpu_copy((void *)ef->pcpu_base, count);
510 link_elf_link_preload(linker_class_t cls,
511 const char* filename, linker_file_t *result)
513 caddr_t modptr, baseptr, sizeptr, dynptr;
520 /* Look to see if we have the file preloaded */
521 modptr = preload_search_by_name(filename);
525 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
526 baseptr = preload_search_info(modptr, MODINFO_ADDR);
527 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
528 dynptr = preload_search_info(modptr, MODINFO_METADATA|MODINFOMD_DYNAMIC);
530 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
531 strcmp(type, "elf module") != 0))
533 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
536 lf = linker_make_file(filename, &link_elf_class);
541 ef = (elf_file_t) lf;
544 ef->address = *(caddr_t *)baseptr;
545 #ifdef SPARSE_MAPPING
548 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
549 ef->dynamic = (Elf_Dyn *)dp;
550 lf->address = ef->address;
551 lf->size = *(size_t *)sizeptr;
553 error = parse_dynamic(ef);
555 error = parse_dpcpu(ef);
557 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
560 link_elf_reloc_local(lf);
566 link_elf_link_preload_finish(linker_file_t lf)
571 ef = (elf_file_t) lf;
572 #if 0 /* this will be more trouble than it's worth for now */
573 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
574 if (dp->d_tag != DT_NEEDED)
576 modname = ef->strtab + dp->d_un.d_val;
577 error = linker_load_module(modname, lf);
582 error = relocate_file(ef);
585 (void)link_elf_preload_parse_symbols(ef);
587 return (link_elf_link_common_finish(lf));
591 link_elf_load_file(linker_class_t cls, const char* filename,
592 linker_file_t* result)
595 struct thread* td = curthread; /* XXX */
601 Elf_Phdr *segs[MAXSEGS];
609 Elf_Addr base_vlimit;
624 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
626 error = vn_open(&nd, &flags, 0, NULL);
629 vfslocked = NDHASGIANT(&nd);
630 NDFREE(&nd, NDF_ONLY_PNBUF);
631 if (nd.ni_vp->v_type != VREG) {
637 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
645 * Read the elf header from the file.
647 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
648 if (firstpage == NULL) {
652 hdr = (Elf_Ehdr *)firstpage;
653 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
654 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
656 nbytes = PAGE_SIZE - resid;
665 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
666 || hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
667 link_elf_error(filename, "Unsupported file layout");
671 if (hdr->e_ident[EI_VERSION] != EV_CURRENT
672 || hdr->e_version != EV_CURRENT) {
673 link_elf_error(filename, "Unsupported file version");
677 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
681 if (hdr->e_machine != ELF_TARG_MACH) {
682 link_elf_error(filename, "Unsupported machine");
688 * We rely on the program header being in the first page. This is
689 * not strictly required by the ABI specification, but it seems to
690 * always true in practice. And, it simplifies things considerably.
692 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
693 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
694 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
695 link_elf_error(filename, "Unreadable program headers");
698 * Scan the program header entries, and save key information.
700 * We rely on there being exactly two load segments, text and data,
703 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
704 phlimit = phdr + hdr->e_phnum;
708 while (phdr < phlimit) {
709 switch (phdr->p_type) {
712 if (nsegs == MAXSEGS) {
713 link_elf_error(filename, "Too many sections");
718 * XXX: We just trust they come in right order ??
740 link_elf_error(filename, "Object is not dynamically-linked");
745 link_elf_error(filename, "No sections");
751 * Allocate the entire address space of the object, to stake out our
752 * contiguous region, and to establish the base address for relocation.
754 base_offset = trunc_page(segs[0]->p_offset);
755 base_vaddr = trunc_page(segs[0]->p_vaddr);
756 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
757 segs[nsegs - 1]->p_memsz);
758 mapsize = base_vlimit - base_vaddr;
760 lf = linker_make_file(filename, &link_elf_class);
766 ef = (elf_file_t) lf;
767 #ifdef SPARSE_MAPPING
768 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
769 if (ef->object == NULL) {
773 ef->address = (caddr_t) vm_map_min(kernel_map);
774 error = vm_map_find(kernel_map, ef->object, 0,
775 (vm_offset_t *) &ef->address,
777 VM_PROT_ALL, VM_PROT_ALL, 0);
779 vm_object_deallocate(ef->object);
784 ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
790 mapbase = ef->address;
793 * Read the text and data sections and zero the bss.
795 for (i = 0; i < nsegs; i++) {
796 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
797 error = vn_rdwr(UIO_READ, nd.ni_vp,
798 segbase, segs[i]->p_filesz, segs[i]->p_offset,
799 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
804 bzero(segbase + segs[i]->p_filesz,
805 segs[i]->p_memsz - segs[i]->p_filesz);
807 #ifdef SPARSE_MAPPING
809 * Wire down the pages
811 error = vm_map_wire(kernel_map,
812 (vm_offset_t) segbase,
813 (vm_offset_t) segbase + segs[i]->p_memsz,
814 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
815 if (error != KERN_SUCCESS) {
823 /* Update profiling information with the new text segment. */
825 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
830 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
832 lf->address = ef->address;
835 error = parse_dynamic(ef);
838 error = parse_dpcpu(ef);
841 link_elf_reloc_local(lf);
843 VOP_UNLOCK(nd.ni_vp, 0);
844 error = linker_load_dependencies(lf);
845 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
848 #if 0 /* this will be more trouble than it's worth for now */
849 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
850 if (dp->d_tag != DT_NEEDED)
852 modname = ef->strtab + dp->d_un.d_val;
853 error = linker_load_module(modname, lf);
858 error = relocate_file(ef);
862 /* Try and load the symbol table if it's present. (you can strip it!) */
863 nbytes = hdr->e_shnum * hdr->e_shentsize;
864 if (nbytes == 0 || hdr->e_shoff == 0)
866 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
871 error = vn_rdwr(UIO_READ, nd.ni_vp,
872 (caddr_t)shdr, nbytes, hdr->e_shoff,
873 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
879 for (i = 0; i < hdr->e_shnum; i++) {
880 if (shdr[i].sh_type == SHT_SYMTAB) {
882 symstrindex = shdr[i].sh_link;
885 if (symtabindex < 0 || symstrindex < 0)
888 symcnt = shdr[symtabindex].sh_size;
889 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
890 strcnt = shdr[symstrindex].sh_size;
891 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
893 if (ef->symbase == NULL || ef->strbase == NULL) {
897 error = vn_rdwr(UIO_READ, nd.ni_vp,
898 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
899 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
903 error = vn_rdwr(UIO_READ, nd.ni_vp,
904 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
905 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
910 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
911 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
912 ef->ddbstrcnt = strcnt;
913 ef->ddbstrtab = ef->strbase;
915 error = link_elf_link_common_finish(lf);
925 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
927 free(shdr, M_LINKER);
929 free(firstpage, M_LINKER);
930 VOP_UNLOCK(nd.ni_vp, 0);
931 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
932 VFS_UNLOCK_GIANT(vfslocked);
938 elf_relocaddr(linker_file_t lf, Elf_Addr x)
943 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
944 return ((x - ef->pcpu_start) + ef->pcpu_base);
950 link_elf_unload_file(linker_file_t file)
952 elf_file_t ef = (elf_file_t) file;
955 dpcpu_free((void *)ef->pcpu_base, ef->pcpu_stop - ef->pcpu_start);
959 GDB_STATE(RT_DELETE);
960 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
961 link_elf_delete_gdb(&ef->gdb);
962 GDB_STATE(RT_CONSISTENT);
966 /* Notify MD code that a module is being unloaded. */
967 elf_cpu_unload_file(file);
970 link_elf_unload_preload(file);
974 #ifdef SPARSE_MAPPING
976 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
977 (vm_offset_t) ef->address
978 + (ef->object->size << PAGE_SHIFT));
982 free(ef->address, M_LINKER);
985 free(ef->symbase, M_LINKER);
987 free(ef->strbase, M_LINKER);
989 free(ef->ctftab, M_LINKER);
991 free(ef->ctfoff, M_LINKER);
993 free(ef->typoff, M_LINKER);
997 link_elf_unload_preload(linker_file_t file)
1000 preload_delete_name(file->filename);
1004 symbol_name(elf_file_t ef, Elf_Size r_info)
1008 if (ELF_R_SYM(r_info)) {
1009 ref = ef->symtab + ELF_R_SYM(r_info);
1010 return ef->strtab + ref->st_name;
1016 relocate_file(elf_file_t ef)
1018 const Elf_Rel *rellim;
1020 const Elf_Rela *relalim;
1021 const Elf_Rela *rela;
1022 const char *symname;
1024 /* Perform relocations without addend if there are any: */
1027 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1028 while (rel < rellim) {
1029 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
1031 symname = symbol_name(ef, rel->r_info);
1032 printf("link_elf: symbol %s undefined\n", symname);
1039 /* Perform relocations with addend if there are any: */
1042 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
1043 while (rela < relalim) {
1044 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
1046 symname = symbol_name(ef, rela->r_info);
1047 printf("link_elf: symbol %s undefined\n", symname);
1054 /* Perform PLT relocations without addend if there are any: */
1057 rellim = (const Elf_Rel *)((const char *)ef->pltrel + ef->pltrelsize);
1058 while (rel < rellim) {
1059 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
1061 symname = symbol_name(ef, rel->r_info);
1062 printf("link_elf: symbol %s undefined\n", symname);
1069 /* Perform relocations with addend if there are any: */
1072 relalim = (const Elf_Rela *)((const char *)ef->pltrela + ef->pltrelasize);
1073 while (rela < relalim) {
1074 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
1076 symname = symbol_name(ef, rela->r_info);
1077 printf("link_elf: symbol %s undefined\n", symname);
1088 * Hash function for symbol table lookup. Don't even think about changing
1089 * this. It is specified by the System V ABI.
1091 static unsigned long
1092 elf_hash(const char *name)
1094 const unsigned char *p = (const unsigned char *) name;
1095 unsigned long h = 0;
1098 while (*p != '\0') {
1099 h = (h << 4) + *p++;
1100 if ((g = h & 0xf0000000) != 0)
1108 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1110 elf_file_t ef = (elf_file_t) lf;
1111 unsigned long symnum;
1112 const Elf_Sym* symp;
1117 /* If we don't have a hash, bail. */
1118 if (ef->buckets == NULL || ef->nbuckets == 0) {
1119 printf("link_elf_lookup_symbol: missing symbol hash table\n");
1123 /* First, search hashed global symbols */
1124 hash = elf_hash(name);
1125 symnum = ef->buckets[hash % ef->nbuckets];
1127 while (symnum != STN_UNDEF) {
1128 if (symnum >= ef->nchains) {
1129 printf("link_elf_lookup_symbol: corrupt symbol table\n");
1133 symp = ef->symtab + symnum;
1134 if (symp->st_name == 0) {
1135 printf("link_elf_lookup_symbol: corrupt symbol table\n");
1139 strp = ef->strtab + symp->st_name;
1141 if (strcmp(name, strp) == 0) {
1142 if (symp->st_shndx != SHN_UNDEF ||
1143 (symp->st_value != 0 &&
1144 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1145 *sym = (c_linker_sym_t) symp;
1151 symnum = ef->chains[symnum];
1154 /* If we have not found it, look at the full table (if loaded) */
1155 if (ef->symtab == ef->ddbsymtab)
1158 /* Exhaustive search */
1159 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1160 strp = ef->ddbstrtab + symp->st_name;
1161 if (strcmp(name, strp) == 0) {
1162 if (symp->st_shndx != SHN_UNDEF ||
1163 (symp->st_value != 0 &&
1164 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1165 *sym = (c_linker_sym_t) symp;
1176 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t* symval)
1178 elf_file_t ef = (elf_file_t) lf;
1179 const Elf_Sym* es = (const Elf_Sym*) sym;
1181 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1182 symval->name = ef->strtab + es->st_name;
1183 symval->value = (caddr_t) ef->address + es->st_value;
1184 symval->size = es->st_size;
1187 if (ef->symtab == ef->ddbsymtab)
1189 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1190 symval->name = ef->ddbstrtab + es->st_name;
1191 symval->value = (caddr_t) ef->address + es->st_value;
1192 symval->size = es->st_size;
1199 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1200 c_linker_sym_t* sym, long* diffp)
1202 elf_file_t ef = (elf_file_t) lf;
1203 u_long off = (uintptr_t) (void *) value;
1207 const Elf_Sym* best = 0;
1210 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1211 if (es->st_name == 0)
1213 st_value = es->st_value + (uintptr_t) (void *) ef->address;
1214 if (off >= st_value) {
1215 if (off - st_value < diff) {
1216 diff = off - st_value;
1220 } else if (off - st_value == diff) {
1229 *sym = (c_linker_sym_t) best;
1235 * Look up a linker set on an ELF system.
1238 link_elf_lookup_set(linker_file_t lf, const char *name,
1239 void ***startp, void ***stopp, int *countp)
1242 linker_symval_t symval;
1244 void **start, **stop;
1245 int len, error = 0, count;
1247 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1248 setsym = malloc(len, M_LINKER, M_WAITOK);
1252 /* get address of first entry */
1253 snprintf(setsym, len, "%s%s", "__start_set_", name);
1254 error = link_elf_lookup_symbol(lf, setsym, &sym);
1257 link_elf_symbol_values(lf, sym, &symval);
1258 if (symval.value == 0) {
1262 start = (void **)symval.value;
1264 /* get address of last entry */
1265 snprintf(setsym, len, "%s%s", "__stop_set_", name);
1266 error = link_elf_lookup_symbol(lf, setsym, &sym);
1269 link_elf_symbol_values(lf, sym, &symval);
1270 if (symval.value == 0) {
1274 stop = (void **)symval.value;
1276 /* and the number of entries */
1277 count = stop - start;
1288 free(setsym, M_LINKER);
1293 link_elf_each_function_name(linker_file_t file,
1294 int (*callback)(const char *, void *), void *opaque) {
1295 elf_file_t ef = (elf_file_t)file;
1296 const Elf_Sym* symp;
1299 /* Exhaustive search */
1300 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1301 if (symp->st_value != 0 &&
1302 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1303 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1312 link_elf_each_function_nameval(linker_file_t file,
1313 linker_function_nameval_callback_t callback, void *opaque)
1315 linker_symval_t symval;
1316 elf_file_t ef = (elf_file_t)file;
1317 const Elf_Sym* symp;
1320 /* Exhaustive search */
1321 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1322 if (symp->st_value != 0 &&
1323 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1324 error = link_elf_symbol_values(file, (c_linker_sym_t) symp, &symval);
1327 error = callback(file, i, &symval, opaque);
1337 * Each KLD has its own GP. The GP value for each load module is given by
1338 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1339 * don't have direct access to the ELF file structure. The link_elf_get_gp()
1340 * function returns the GP given a pointer to a generic linker file struct.
1343 link_elf_get_gp(linker_file_t lf)
1345 elf_file_t ef = (elf_file_t)lf;
1346 return (Elf_Addr)ef->got;
1351 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1353 elf_file_t ef = (elf_file_t)lf;
1355 if (symidx >= ef->nchains)
1357 return (ef->symtab + symidx);
1361 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1363 elf_file_t ef = (elf_file_t)lf;
1366 if (symidx >= ef->nchains)
1368 sym = ef->symtab + symidx;
1369 return (ef->strtab + sym->st_name);
1373 * Symbol lookup function that can be used when the symbol index is known (ie
1374 * in relocations). It uses the symbol index instead of doing a fully fledged
1375 * hash table based lookup when such is valid. For example for local symbols.
1376 * This is not only more efficient, it's also more correct. It's not always
1377 * the case that the symbol can be found through the hash table.
1380 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1382 elf_file_t ef = (elf_file_t)lf;
1386 /* Don't even try to lookup the symbol if the index is bogus. */
1387 if (symidx >= ef->nchains)
1390 sym = ef->symtab + symidx;
1393 * Don't do a full lookup when the symbol is local. It may even
1394 * fail because it may not be found through the hash table.
1396 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1397 /* Force lookup failure when we have an insanity. */
1398 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1400 return ((Elf_Addr)ef->address + sym->st_value);
1404 * XXX we can avoid doing a hash table based lookup for global
1405 * symbols as well. This however is not always valid, so we'll
1406 * just do it the hard way for now. Performance tweaks can
1410 symbol = ef->strtab + sym->st_name;
1412 /* Force a lookup failure if the symbol name is bogus. */
1416 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1420 link_elf_reloc_local(linker_file_t lf)
1422 const Elf_Rel *rellim;
1424 const Elf_Rela *relalim;
1425 const Elf_Rela *rela;
1426 elf_file_t ef = (elf_file_t)lf;
1428 /* Perform relocations without addend if there are any: */
1429 if ((rel = ef->rel) != NULL) {
1430 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1431 while (rel < rellim) {
1432 elf_reloc_local(lf, (Elf_Addr)ef->address, rel, ELF_RELOC_REL,
1438 /* Perform relocations with addend if there are any: */
1439 if ((rela = ef->rela) != NULL) {
1440 relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
1441 while (rela < relalim) {
1442 elf_reloc_local(lf, (Elf_Addr)ef->address, rela, ELF_RELOC_RELA,
1450 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1452 elf_file_t ef = (elf_file_t)lf;
1454 *symtab = ef->ddbsymtab;
1456 if (*symtab == NULL)
1459 return (ef->ddbsymcnt);
1463 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1465 elf_file_t ef = (elf_file_t)lf;
1467 *strtab = ef->ddbstrtab;
1469 if (*strtab == NULL)
1472 return (ef->ddbstrcnt);