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>
54 #include <security/mac/mac_framework.h>
57 #include <vm/vm_param.h>
59 #include <vm/vm_object.h>
60 #include <vm/vm_kern.h>
61 #include <vm/vm_extern.h>
64 #include <vm/vm_map.h>
66 #include <sys/link_elf.h>
72 #include "linker_if.h"
76 typedef struct elf_file {
77 struct linker_file lf; /* Common fields */
78 int preloaded; /* Was file pre-loaded */
79 caddr_t address; /* Relocation address */
81 vm_object_t object; /* VM object to hold file pages */
83 Elf_Dyn *dynamic; /* Symbol table etc. */
84 Elf_Hashelt nbuckets; /* DT_HASH info */
86 const Elf_Hashelt *buckets;
87 const Elf_Hashelt *chains;
89 caddr_t strtab; /* DT_STRTAB */
90 int strsz; /* DT_STRSZ */
91 const Elf_Sym *symtab; /* DT_SYMTAB */
92 Elf_Addr *got; /* DT_PLTGOT */
93 const Elf_Rel *pltrel; /* DT_JMPREL */
94 int pltrelsize; /* DT_PLTRELSZ */
95 const Elf_Rela *pltrela; /* DT_JMPREL */
96 int pltrelasize; /* DT_PLTRELSZ */
97 const Elf_Rel *rel; /* DT_REL */
98 int relsize; /* DT_RELSZ */
99 const Elf_Rela *rela; /* DT_RELA */
100 int relasize; /* DT_RELASZ */
102 const Elf_Sym *ddbsymtab; /* The symbol table we are using */
103 long ddbsymcnt; /* Number of symbols */
104 caddr_t ddbstrtab; /* String table */
105 long ddbstrcnt; /* number of bytes in string table */
106 caddr_t symbase; /* malloc'ed symbold base */
107 caddr_t strbase; /* malloc'ed string base */
108 caddr_t ctftab; /* CTF table */
109 long ctfcnt; /* number of bytes in CTF table */
110 caddr_t ctfoff; /* CTF offset table */
111 caddr_t typoff; /* Type offset table */
112 long typlen; /* Number of type entries. */
113 Elf_Addr pcpu_start; /* Pre-relocation pcpu set start. */
114 Elf_Addr pcpu_stop; /* Pre-relocation pcpu set stop. */
115 Elf_Addr pcpu_base; /* Relocated pcpu set address. */
117 Elf_Addr vnet_start; /* Pre-relocation vnet set start. */
118 Elf_Addr vnet_stop; /* Pre-relocation vnet set stop. */
119 Elf_Addr vnet_base; /* Relocated vnet set address. */
122 struct link_map gdb; /* hooks for gdb */
126 #include <kern/kern_ctf.c>
128 static int link_elf_link_common_finish(linker_file_t);
129 static int link_elf_link_preload(linker_class_t cls,
130 const char *, linker_file_t *);
131 static int link_elf_link_preload_finish(linker_file_t);
132 static int link_elf_load_file(linker_class_t, const char *,
134 static int link_elf_lookup_symbol(linker_file_t, const char *,
136 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
138 static int link_elf_search_symbol(linker_file_t, caddr_t,
139 c_linker_sym_t *, long *);
141 static void link_elf_unload_file(linker_file_t);
142 static void link_elf_unload_preload(linker_file_t);
143 static int link_elf_lookup_set(linker_file_t, const char *,
144 void ***, void ***, int *);
145 static int link_elf_each_function_name(linker_file_t,
146 int (*)(const char *, void *), void *);
147 static int link_elf_each_function_nameval(linker_file_t,
148 linker_function_nameval_callback_t, void *);
149 static void link_elf_reloc_local(linker_file_t);
150 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
151 static long link_elf_strtab_get(linker_file_t, caddr_t *);
152 static Elf_Addr elf_lookup(linker_file_t, Elf_Size, int);
154 static kobj_method_t link_elf_methods[] = {
155 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
156 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
157 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
158 KOBJMETHOD(linker_unload, link_elf_unload_file),
159 KOBJMETHOD(linker_load_file, link_elf_load_file),
160 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
161 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
162 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
163 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
164 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
165 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
166 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
167 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
171 static struct linker_class link_elf_class = {
172 #if ELF_TARG_CLASS == ELFCLASS32
177 link_elf_methods, sizeof(struct elf_file)
180 static int parse_dynamic(elf_file_t);
181 static int relocate_file(elf_file_t);
182 static int link_elf_preload_parse_symbols(elf_file_t);
185 static void r_debug_state(struct r_debug *, struct link_map *);
188 * A list of loaded modules for GDB to use for loading symbols.
190 struct r_debug r_debug;
192 #define GDB_STATE(s) do { \
193 r_debug.r_state = s; r_debug_state(NULL, NULL); \
197 * Function for the debugger to set a breakpoint on to gain control.
200 r_debug_state(struct r_debug *dummy_one __unused,
201 struct link_map *dummy_two __unused)
206 link_elf_add_gdb(struct link_map *l)
208 struct link_map *prev;
212 if (r_debug.r_map == NULL) {
217 /* Append to list. */
218 for (prev = r_debug.r_map;
219 prev->l_next != NULL;
228 link_elf_delete_gdb(struct link_map *l)
230 if (l->l_prev == NULL) {
232 if ((r_debug.r_map = l->l_next) != NULL)
233 l->l_next->l_prev = NULL;
235 /* Remove any but first. */
236 if ((l->l_prev->l_next = l->l_next) != NULL)
237 l->l_next->l_prev = l->l_prev;
243 Elf_Addr link_elf_get_gp(linker_file_t);
247 * The kernel symbol table starts here.
249 extern struct _dynamic _DYNAMIC;
252 link_elf_error(const char *filename, const char *s)
254 if (filename == NULL)
255 printf("kldload: %s\n", s);
257 printf("kldload: %s: %s\n", filename, s);
261 * Actions performed after linking/loading both the preloaded kernel and any
262 * modules; whether preloaded or dynamicly loaded.
265 link_elf_link_common_finish(linker_file_t lf)
268 elf_file_t ef = (elf_file_t)lf;
273 /* Notify MD code that a module is being loaded. */
274 error = elf_cpu_load_file(lf);
280 ef->gdb.l_addr = lf->address;
281 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
282 strcpy(newfilename, lf->filename);
283 ef->gdb.l_name = newfilename;
284 ef->gdb.l_ld = ef->dynamic;
285 link_elf_add_gdb(&ef->gdb);
286 GDB_STATE(RT_CONSISTENT);
293 link_elf_init(void* arg)
296 caddr_t modptr, baseptr, sizeptr;
300 linker_add_class(&link_elf_class);
302 dp = (Elf_Dyn *)&_DYNAMIC;
304 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
306 modptr = preload_search_by_type("elf kernel");
308 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
311 linker_kernel_file = linker_make_file(modname, &link_elf_class);
312 if (linker_kernel_file == NULL)
313 panic("%s: Can't create linker structures for kernel",
316 ef = (elf_file_t) linker_kernel_file;
319 #ifdef SPARSE_MAPPING
326 linker_kernel_file->address = (caddr_t) KERNBASE;
327 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
329 if (modptr != NULL) {
331 baseptr = preload_search_info(modptr, MODINFO_ADDR);
333 linker_kernel_file->address = *(caddr_t *)baseptr;
334 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
336 linker_kernel_file->size = *(size_t *)sizeptr;
338 (void)link_elf_preload_parse_symbols(ef);
341 r_debug.r_map = NULL;
342 r_debug.r_brk = r_debug_state;
343 r_debug.r_state = RT_CONSISTENT;
346 (void)link_elf_link_common_finish(linker_kernel_file);
347 linker_kernel_file->flags |= LINKER_FILE_LINKED;
350 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0);
353 link_elf_preload_parse_symbols(elf_file_t ef)
356 caddr_t ssym, esym, base;
362 if (ef->modptr == NULL)
364 pointer = preload_search_info(ef->modptr,
365 MODINFO_METADATA | MODINFOMD_SSYM);
368 ssym = *(caddr_t *)pointer;
369 pointer = preload_search_info(ef->modptr,
370 MODINFO_METADATA | MODINFOMD_ESYM);
373 esym = *(caddr_t *)pointer;
377 symcnt = *(long *)base;
378 base += sizeof(long);
379 symtab = (Elf_Sym *)base;
380 base += roundup(symcnt, sizeof(long));
382 if (base > esym || base < ssym) {
383 printf("Symbols are corrupt!\n");
387 strcnt = *(long *)base;
388 base += sizeof(long);
390 base += roundup(strcnt, sizeof(long));
392 if (base > esym || base < ssym) {
393 printf("Symbols are corrupt!\n");
397 ef->ddbsymtab = symtab;
398 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
399 ef->ddbstrtab = strtab;
400 ef->ddbstrcnt = strcnt;
406 parse_dynamic(elf_file_t ef)
409 int plttype = DT_REL;
411 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
415 /* From src/libexec/rtld-elf/rtld.c */
416 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
417 (ef->address + dp->d_un.d_ptr);
418 ef->nbuckets = hashtab[0];
419 ef->nchains = hashtab[1];
420 ef->buckets = hashtab + 2;
421 ef->chains = ef->buckets + ef->nbuckets;
425 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
428 ef->strsz = dp->d_un.d_val;
431 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
434 if (dp->d_un.d_val != sizeof(Elf_Sym))
438 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
441 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
444 ef->relsize = dp->d_un.d_val;
447 if (dp->d_un.d_val != sizeof(Elf_Rel))
451 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
454 ef->pltrelsize = dp->d_un.d_val;
457 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
460 ef->relasize = dp->d_un.d_val;
463 if (dp->d_un.d_val != sizeof(Elf_Rela))
467 plttype = dp->d_un.d_val;
468 if (plttype != DT_REL && plttype != DT_RELA)
473 dp->d_un.d_ptr = (Elf_Addr)&r_debug;
479 if (plttype == DT_RELA) {
480 ef->pltrela = (const Elf_Rela *)ef->pltrel;
482 ef->pltrelasize = ef->pltrelsize;
486 ef->ddbsymtab = ef->symtab;
487 ef->ddbsymcnt = ef->nchains;
488 ef->ddbstrtab = ef->strtab;
489 ef->ddbstrcnt = ef->strsz;
495 parse_dpcpu(elf_file_t ef)
502 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
503 (void ***)&ef->pcpu_stop, &count);
504 /* Error just means there is no pcpu set to relocate. */
507 count *= sizeof(void *);
509 * Allocate space in the primary pcpu area. Copy in our
510 * initialization from the data section and then initialize
511 * all per-cpu storage from that.
513 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count);
514 if (ef->pcpu_base == 0)
516 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count);
517 dpcpu_copy((void *)ef->pcpu_base, count);
524 parse_vnet(elf_file_t ef)
531 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
532 (void ***)&ef->vnet_stop, &count);
533 /* Error just means there is no vnet data set to relocate. */
536 count *= sizeof(void *);
538 * Allocate space in the primary vnet area. Copy in our
539 * initialization from the data section and then initialize
540 * all per-vnet storage from that.
542 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count);
543 if (ef->vnet_base == 0)
545 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count);
546 vnet_data_copy((void *)ef->vnet_base, count);
553 link_elf_link_preload(linker_class_t cls,
554 const char* filename, linker_file_t *result)
556 caddr_t modptr, baseptr, sizeptr, dynptr;
563 /* Look to see if we have the file preloaded */
564 modptr = preload_search_by_name(filename);
568 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
569 baseptr = preload_search_info(modptr, MODINFO_ADDR);
570 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
571 dynptr = preload_search_info(modptr,
572 MODINFO_METADATA | MODINFOMD_DYNAMIC);
574 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
575 strcmp(type, "elf module") != 0))
577 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
580 lf = linker_make_file(filename, &link_elf_class);
584 ef = (elf_file_t) lf;
587 ef->address = *(caddr_t *)baseptr;
588 #ifdef SPARSE_MAPPING
591 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
592 ef->dynamic = (Elf_Dyn *)dp;
593 lf->address = ef->address;
594 lf->size = *(size_t *)sizeptr;
596 error = parse_dynamic(ef);
598 error = parse_dpcpu(ef);
601 error = parse_vnet(ef);
604 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
607 link_elf_reloc_local(lf);
613 link_elf_link_preload_finish(linker_file_t lf)
618 ef = (elf_file_t) lf;
619 #if 0 /* this will be more trouble than it's worth for now */
620 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
621 if (dp->d_tag != DT_NEEDED)
623 modname = ef->strtab + dp->d_un.d_val;
624 error = linker_load_module(modname, lf);
629 error = relocate_file(ef);
632 (void)link_elf_preload_parse_symbols(ef);
634 return (link_elf_link_common_finish(lf));
638 link_elf_load_file(linker_class_t cls, const char* filename,
639 linker_file_t* result)
642 struct thread* td = curthread; /* XXX */
648 Elf_Phdr *segs[MAXSEGS];
656 Elf_Addr base_vlimit;
671 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
673 error = vn_open(&nd, &flags, 0, NULL);
676 vfslocked = NDHASGIANT(&nd);
677 NDFREE(&nd, NDF_ONLY_PNBUF);
678 if (nd.ni_vp->v_type != VREG) {
684 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
692 * Read the elf header from the file.
694 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
695 if (firstpage == NULL) {
699 hdr = (Elf_Ehdr *)firstpage;
700 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
701 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
703 nbytes = PAGE_SIZE - resid;
712 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
713 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
714 link_elf_error(filename, "Unsupported file layout");
718 if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
719 hdr->e_version != EV_CURRENT) {
720 link_elf_error(filename, "Unsupported file version");
724 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
728 if (hdr->e_machine != ELF_TARG_MACH) {
729 link_elf_error(filename, "Unsupported machine");
735 * We rely on the program header being in the first page.
736 * This is not strictly required by the ABI specification, but
737 * it seems to always true in practice. And, it simplifies
738 * things considerably.
740 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
741 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
742 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
743 link_elf_error(filename, "Unreadable program headers");
746 * Scan the program header entries, and save key information.
748 * We rely on there being exactly two load segments, text and data,
751 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
752 phlimit = phdr + hdr->e_phnum;
756 while (phdr < phlimit) {
757 switch (phdr->p_type) {
759 if (nsegs == MAXSEGS) {
760 link_elf_error(filename, "Too many sections");
765 * XXX: We just trust they come in right order ??
787 link_elf_error(filename, "Object is not dynamically-linked");
792 link_elf_error(filename, "No sections");
798 * Allocate the entire address space of the object, to stake
799 * out our contiguous region, and to establish the base
800 * address for relocation.
802 base_offset = trunc_page(segs[0]->p_offset);
803 base_vaddr = trunc_page(segs[0]->p_vaddr);
804 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
805 segs[nsegs - 1]->p_memsz);
806 mapsize = base_vlimit - base_vaddr;
808 lf = linker_make_file(filename, &link_elf_class);
814 ef = (elf_file_t) lf;
815 #ifdef SPARSE_MAPPING
816 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
817 if (ef->object == NULL) {
821 ef->address = (caddr_t) vm_map_min(kernel_map);
822 error = vm_map_find(kernel_map, ef->object, 0,
823 (vm_offset_t *) &ef->address, mapsize, 1,
824 VM_PROT_ALL, VM_PROT_ALL, 0);
826 vm_object_deallocate(ef->object);
831 ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
832 if (ef->address == NULL) {
837 mapbase = ef->address;
840 * Read the text and data sections and zero the bss.
842 for (i = 0; i < nsegs; i++) {
843 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
844 error = vn_rdwr(UIO_READ, nd.ni_vp,
845 segbase, segs[i]->p_filesz, segs[i]->p_offset,
846 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
850 bzero(segbase + segs[i]->p_filesz,
851 segs[i]->p_memsz - segs[i]->p_filesz);
853 #ifdef SPARSE_MAPPING
855 * Wire down the pages
857 error = vm_map_wire(kernel_map,
858 (vm_offset_t) segbase,
859 (vm_offset_t) segbase + segs[i]->p_memsz,
860 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
861 if (error != KERN_SUCCESS) {
869 /* Update profiling information with the new text segment. */
871 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
876 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
878 lf->address = ef->address;
881 error = parse_dynamic(ef);
884 error = parse_dpcpu(ef);
888 error = parse_vnet(ef);
892 link_elf_reloc_local(lf);
894 VOP_UNLOCK(nd.ni_vp, 0);
895 error = linker_load_dependencies(lf);
896 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
899 #if 0 /* this will be more trouble than it's worth for now */
900 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
901 if (dp->d_tag != DT_NEEDED)
903 modname = ef->strtab + dp->d_un.d_val;
904 error = linker_load_module(modname, lf);
909 error = relocate_file(ef);
914 * Try and load the symbol table if it's present. (you can
917 nbytes = hdr->e_shnum * hdr->e_shentsize;
918 if (nbytes == 0 || hdr->e_shoff == 0)
920 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
925 error = vn_rdwr(UIO_READ, nd.ni_vp,
926 (caddr_t)shdr, nbytes, hdr->e_shoff,
927 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
933 for (i = 0; i < hdr->e_shnum; i++) {
934 if (shdr[i].sh_type == SHT_SYMTAB) {
936 symstrindex = shdr[i].sh_link;
939 if (symtabindex < 0 || symstrindex < 0)
942 symcnt = shdr[symtabindex].sh_size;
943 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
944 strcnt = shdr[symstrindex].sh_size;
945 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
947 if (ef->symbase == NULL || ef->strbase == NULL) {
951 error = vn_rdwr(UIO_READ, nd.ni_vp,
952 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
953 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
957 error = vn_rdwr(UIO_READ, nd.ni_vp,
958 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
959 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
964 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
965 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
966 ef->ddbstrcnt = strcnt;
967 ef->ddbstrtab = ef->strbase;
969 error = link_elf_link_common_finish(lf);
977 VOP_UNLOCK(nd.ni_vp, 0);
978 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
979 VFS_UNLOCK_GIANT(vfslocked);
980 if (error != 0 && lf != NULL)
981 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
983 free(shdr, M_LINKER);
984 if (firstpage != NULL)
985 free(firstpage, M_LINKER);
991 elf_relocaddr(linker_file_t lf, Elf_Addr x)
996 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
997 return ((x - ef->pcpu_start) + ef->pcpu_base);
999 if (x >= ef->vnet_start && x < ef->vnet_stop)
1000 return ((x - ef->vnet_start) + ef->vnet_base);
1007 link_elf_unload_file(linker_file_t file)
1009 elf_file_t ef = (elf_file_t) file;
1011 if (ef->pcpu_base != 0) {
1012 dpcpu_free((void *)ef->pcpu_base,
1013 ef->pcpu_stop - ef->pcpu_start);
1016 if (ef->vnet_base != 0) {
1017 vnet_data_free((void *)ef->vnet_base,
1018 ef->vnet_stop - ef->vnet_start);
1022 if (ef->gdb.l_ld != NULL) {
1023 GDB_STATE(RT_DELETE);
1024 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1025 link_elf_delete_gdb(&ef->gdb);
1026 GDB_STATE(RT_CONSISTENT);
1030 /* Notify MD code that a module is being unloaded. */
1031 elf_cpu_unload_file(file);
1033 if (ef->preloaded) {
1034 link_elf_unload_preload(file);
1038 #ifdef SPARSE_MAPPING
1039 if (ef->object != NULL) {
1040 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1041 (vm_offset_t) ef->address
1042 + (ef->object->size << PAGE_SHIFT));
1045 if (ef->address != NULL)
1046 free(ef->address, M_LINKER);
1048 if (ef->symbase != NULL)
1049 free(ef->symbase, M_LINKER);
1050 if (ef->strbase != NULL)
1051 free(ef->strbase, M_LINKER);
1052 if (ef->ctftab != NULL)
1053 free(ef->ctftab, M_LINKER);
1054 if (ef->ctfoff != NULL)
1055 free(ef->ctfoff, M_LINKER);
1056 if (ef->typoff != NULL)
1057 free(ef->typoff, M_LINKER);
1061 link_elf_unload_preload(linker_file_t file)
1063 if (file->filename != NULL)
1064 preload_delete_name(file->filename);
1068 symbol_name(elf_file_t ef, Elf_Size r_info)
1072 if (ELF_R_SYM(r_info)) {
1073 ref = ef->symtab + ELF_R_SYM(r_info);
1074 return (ef->strtab + ref->st_name);
1080 relocate_file(elf_file_t ef)
1082 const Elf_Rel *rellim;
1084 const Elf_Rela *relalim;
1085 const Elf_Rela *rela;
1086 const char *symname;
1088 /* Perform relocations without addend if there are any: */
1091 rellim = (const Elf_Rel *)
1092 ((const char *)ef->rel + ef->relsize);
1093 while (rel < rellim) {
1094 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1095 ELF_RELOC_REL, elf_lookup)) {
1096 symname = symbol_name(ef, rel->r_info);
1097 printf("link_elf: symbol %s undefined\n", symname);
1104 /* Perform relocations with addend if there are any: */
1107 relalim = (const Elf_Rela *)
1108 ((const char *)ef->rela + ef->relasize);
1109 while (rela < relalim) {
1110 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1111 ELF_RELOC_RELA, elf_lookup)) {
1112 symname = symbol_name(ef, rela->r_info);
1113 printf("link_elf: symbol %s undefined\n",
1121 /* Perform PLT relocations without addend if there are any: */
1124 rellim = (const Elf_Rel *)
1125 ((const char *)ef->pltrel + ef->pltrelsize);
1126 while (rel < rellim) {
1127 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1128 ELF_RELOC_REL, elf_lookup)) {
1129 symname = symbol_name(ef, rel->r_info);
1130 printf("link_elf: symbol %s undefined\n",
1138 /* Perform relocations with addend if there are any: */
1141 relalim = (const Elf_Rela *)
1142 ((const char *)ef->pltrela + ef->pltrelasize);
1143 while (rela < relalim) {
1144 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1145 ELF_RELOC_RELA, elf_lookup)) {
1146 symname = symbol_name(ef, rela->r_info);
1147 printf("link_elf: symbol %s undefined\n",
1159 * Hash function for symbol table lookup. Don't even think about changing
1160 * this. It is specified by the System V ABI.
1162 static unsigned long
1163 elf_hash(const char *name)
1165 const unsigned char *p = (const unsigned char *) name;
1166 unsigned long h = 0;
1169 while (*p != '\0') {
1170 h = (h << 4) + *p++;
1171 if ((g = h & 0xf0000000) != 0)
1179 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1181 elf_file_t ef = (elf_file_t) lf;
1182 unsigned long symnum;
1183 const Elf_Sym* symp;
1188 /* If we don't have a hash, bail. */
1189 if (ef->buckets == NULL || ef->nbuckets == 0) {
1190 printf("link_elf_lookup_symbol: missing symbol hash table\n");
1194 /* First, search hashed global symbols */
1195 hash = elf_hash(name);
1196 symnum = ef->buckets[hash % ef->nbuckets];
1198 while (symnum != STN_UNDEF) {
1199 if (symnum >= ef->nchains) {
1200 printf("%s: corrupt symbol table\n", __func__);
1204 symp = ef->symtab + symnum;
1205 if (symp->st_name == 0) {
1206 printf("%s: corrupt symbol table\n", __func__);
1210 strp = ef->strtab + symp->st_name;
1212 if (strcmp(name, strp) == 0) {
1213 if (symp->st_shndx != SHN_UNDEF ||
1214 (symp->st_value != 0 &&
1215 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1216 *sym = (c_linker_sym_t) symp;
1222 symnum = ef->chains[symnum];
1225 /* If we have not found it, look at the full table (if loaded) */
1226 if (ef->symtab == ef->ddbsymtab)
1229 /* Exhaustive search */
1230 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1231 strp = ef->ddbstrtab + symp->st_name;
1232 if (strcmp(name, strp) == 0) {
1233 if (symp->st_shndx != SHN_UNDEF ||
1234 (symp->st_value != 0 &&
1235 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1236 *sym = (c_linker_sym_t) symp;
1247 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1248 linker_symval_t *symval)
1250 elf_file_t ef = (elf_file_t) lf;
1251 const Elf_Sym* es = (const Elf_Sym*) sym;
1253 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1254 symval->name = ef->strtab + es->st_name;
1255 symval->value = (caddr_t) ef->address + es->st_value;
1256 symval->size = es->st_size;
1259 if (ef->symtab == ef->ddbsymtab)
1261 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1262 symval->name = ef->ddbstrtab + es->st_name;
1263 symval->value = (caddr_t) ef->address + es->st_value;
1264 symval->size = es->st_size;
1271 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1272 c_linker_sym_t *sym, long *diffp)
1274 elf_file_t ef = (elf_file_t) lf;
1275 u_long off = (uintptr_t) (void *) value;
1279 const Elf_Sym* best = 0;
1282 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1283 if (es->st_name == 0)
1285 st_value = es->st_value + (uintptr_t) (void *) ef->address;
1286 if (off >= st_value) {
1287 if (off - st_value < diff) {
1288 diff = off - st_value;
1292 } else if (off - st_value == diff) {
1301 *sym = (c_linker_sym_t) best;
1307 * Look up a linker set on an ELF system.
1310 link_elf_lookup_set(linker_file_t lf, const char *name,
1311 void ***startp, void ***stopp, int *countp)
1314 linker_symval_t symval;
1316 void **start, **stop;
1317 int len, error = 0, count;
1319 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1320 setsym = malloc(len, M_LINKER, M_WAITOK);
1324 /* get address of first entry */
1325 snprintf(setsym, len, "%s%s", "__start_set_", name);
1326 error = link_elf_lookup_symbol(lf, setsym, &sym);
1329 link_elf_symbol_values(lf, sym, &symval);
1330 if (symval.value == 0) {
1334 start = (void **)symval.value;
1336 /* get address of last entry */
1337 snprintf(setsym, len, "%s%s", "__stop_set_", name);
1338 error = link_elf_lookup_symbol(lf, setsym, &sym);
1341 link_elf_symbol_values(lf, sym, &symval);
1342 if (symval.value == 0) {
1346 stop = (void **)symval.value;
1348 /* and the number of entries */
1349 count = stop - start;
1360 free(setsym, M_LINKER);
1365 link_elf_each_function_name(linker_file_t file,
1366 int (*callback)(const char *, void *), void *opaque)
1368 elf_file_t ef = (elf_file_t)file;
1369 const Elf_Sym *symp;
1372 /* Exhaustive search */
1373 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1374 if (symp->st_value != 0 &&
1375 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1376 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1385 link_elf_each_function_nameval(linker_file_t file,
1386 linker_function_nameval_callback_t callback, void *opaque)
1388 linker_symval_t symval;
1389 elf_file_t ef = (elf_file_t)file;
1390 const Elf_Sym* symp;
1393 /* Exhaustive search */
1394 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1395 if (symp->st_value != 0 &&
1396 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1397 error = link_elf_symbol_values(file,
1398 (c_linker_sym_t) symp, &symval);
1401 error = callback(file, i, &symval, opaque);
1411 * Each KLD has its own GP. The GP value for each load module is given by
1412 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1413 * don't have direct access to the ELF file structure. The link_elf_get_gp()
1414 * function returns the GP given a pointer to a generic linker file struct.
1417 link_elf_get_gp(linker_file_t lf)
1419 elf_file_t ef = (elf_file_t)lf;
1420 return ((Elf_Addr)ef->got);
1425 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1427 elf_file_t ef = (elf_file_t)lf;
1429 if (symidx >= ef->nchains)
1431 return (ef->symtab + symidx);
1435 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1437 elf_file_t ef = (elf_file_t)lf;
1440 if (symidx >= ef->nchains)
1442 sym = ef->symtab + symidx;
1443 return (ef->strtab + sym->st_name);
1447 * Symbol lookup function that can be used when the symbol index is known (ie
1448 * in relocations). It uses the symbol index instead of doing a fully fledged
1449 * hash table based lookup when such is valid. For example for local symbols.
1450 * This is not only more efficient, it's also more correct. It's not always
1451 * the case that the symbol can be found through the hash table.
1454 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1456 elf_file_t ef = (elf_file_t)lf;
1460 /* Don't even try to lookup the symbol if the index is bogus. */
1461 if (symidx >= ef->nchains)
1464 sym = ef->symtab + symidx;
1467 * Don't do a full lookup when the symbol is local. It may even
1468 * fail because it may not be found through the hash table.
1470 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1471 /* Force lookup failure when we have an insanity. */
1472 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1474 return ((Elf_Addr)ef->address + sym->st_value);
1478 * XXX we can avoid doing a hash table based lookup for global
1479 * symbols as well. This however is not always valid, so we'll
1480 * just do it the hard way for now. Performance tweaks can
1484 symbol = ef->strtab + sym->st_name;
1486 /* Force a lookup failure if the symbol name is bogus. */
1490 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1494 link_elf_reloc_local(linker_file_t lf)
1496 const Elf_Rel *rellim;
1498 const Elf_Rela *relalim;
1499 const Elf_Rela *rela;
1500 elf_file_t ef = (elf_file_t)lf;
1502 /* Perform relocations without addend if there are any: */
1503 if ((rel = ef->rel) != NULL) {
1504 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1505 while (rel < rellim) {
1506 elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1507 ELF_RELOC_REL, elf_lookup);
1512 /* Perform relocations with addend if there are any: */
1513 if ((rela = ef->rela) != NULL) {
1514 relalim = (const Elf_Rela *)
1515 ((const char *)ef->rela + ef->relasize);
1516 while (rela < relalim) {
1517 elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1518 ELF_RELOC_RELA, elf_lookup);
1525 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1527 elf_file_t ef = (elf_file_t)lf;
1529 *symtab = ef->ddbsymtab;
1531 if (*symtab == NULL)
1534 return (ef->ddbsymcnt);
1538 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1540 elf_file_t ef = (elf_file_t)lf;
1542 *strtab = ef->ddbstrtab;
1544 if (*strtab == NULL)
1547 return (ef->ddbstrcnt);