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;
672 NDINIT(&nd, LOOKUP, FOLLOW | MPSAFE, UIO_SYSSPACE, filename, td);
674 error = vn_open(&nd, &flags, 0, NULL);
677 vfslocked = NDHASGIANT(&nd);
678 NDFREE(&nd, NDF_ONLY_PNBUF);
679 if (nd.ni_vp->v_type != VREG) {
685 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
693 * Read the elf header from the file.
695 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
696 hdr = (Elf_Ehdr *)firstpage;
697 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
698 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
700 nbytes = PAGE_SIZE - resid;
709 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
710 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
711 link_elf_error(filename, "Unsupported file layout");
715 if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
716 hdr->e_version != EV_CURRENT) {
717 link_elf_error(filename, "Unsupported file version");
721 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
725 if (hdr->e_machine != ELF_TARG_MACH) {
726 link_elf_error(filename, "Unsupported machine");
732 * We rely on the program header being in the first page.
733 * This is not strictly required by the ABI specification, but
734 * it seems to always true in practice. And, it simplifies
735 * things considerably.
737 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
738 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
739 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
740 link_elf_error(filename, "Unreadable program headers");
743 * Scan the program header entries, and save key information.
745 * We rely on there being exactly two load segments, text and data,
748 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
749 phlimit = phdr + hdr->e_phnum;
753 while (phdr < phlimit) {
754 switch (phdr->p_type) {
756 if (nsegs == MAXSEGS) {
757 link_elf_error(filename, "Too many sections");
762 * XXX: We just trust they come in right order ??
784 link_elf_error(filename, "Object is not dynamically-linked");
789 link_elf_error(filename, "No sections");
795 * Allocate the entire address space of the object, to stake
796 * out our contiguous region, and to establish the base
797 * address for relocation.
799 base_offset = trunc_page(segs[0]->p_offset);
800 base_vaddr = trunc_page(segs[0]->p_vaddr);
801 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
802 segs[nsegs - 1]->p_memsz);
803 mapsize = base_vlimit - base_vaddr;
805 lf = linker_make_file(filename, &link_elf_class);
811 ef = (elf_file_t) lf;
812 #ifdef SPARSE_MAPPING
813 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
814 if (ef->object == NULL) {
818 ef->address = (caddr_t) vm_map_min(kernel_map);
819 error = vm_map_find(kernel_map, ef->object, 0,
820 (vm_offset_t *) &ef->address, mapsize, 1,
821 VM_PROT_ALL, VM_PROT_ALL, 0);
823 vm_object_deallocate(ef->object);
828 ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
830 mapbase = ef->address;
833 * Read the text and data sections and zero the bss.
835 for (i = 0; i < nsegs; i++) {
836 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
837 error = vn_rdwr(UIO_READ, nd.ni_vp,
838 segbase, segs[i]->p_filesz, segs[i]->p_offset,
839 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
843 bzero(segbase + segs[i]->p_filesz,
844 segs[i]->p_memsz - segs[i]->p_filesz);
846 #ifdef SPARSE_MAPPING
848 * Wire down the pages
850 error = vm_map_wire(kernel_map,
851 (vm_offset_t) segbase,
852 (vm_offset_t) segbase + segs[i]->p_memsz,
853 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
854 if (error != KERN_SUCCESS) {
862 /* Update profiling information with the new text segment. */
864 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
869 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
871 lf->address = ef->address;
874 error = parse_dynamic(ef);
877 error = parse_dpcpu(ef);
881 error = parse_vnet(ef);
885 link_elf_reloc_local(lf);
887 VOP_UNLOCK(nd.ni_vp, 0);
888 error = linker_load_dependencies(lf);
889 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
892 #if 0 /* this will be more trouble than it's worth for now */
893 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
894 if (dp->d_tag != DT_NEEDED)
896 modname = ef->strtab + dp->d_un.d_val;
897 error = linker_load_module(modname, lf);
902 error = relocate_file(ef);
907 * Try and load the symbol table if it's present. (you can
910 nbytes = hdr->e_shnum * hdr->e_shentsize;
911 if (nbytes == 0 || hdr->e_shoff == 0)
913 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
914 error = vn_rdwr(UIO_READ, nd.ni_vp,
915 (caddr_t)shdr, nbytes, hdr->e_shoff,
916 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
922 for (i = 0; i < hdr->e_shnum; i++) {
923 if (shdr[i].sh_type == SHT_SYMTAB) {
925 symstrindex = shdr[i].sh_link;
928 if (symtabindex < 0 || symstrindex < 0)
931 symcnt = shdr[symtabindex].sh_size;
932 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
933 strcnt = shdr[symstrindex].sh_size;
934 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
936 error = vn_rdwr(UIO_READ, nd.ni_vp,
937 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
938 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
942 error = vn_rdwr(UIO_READ, nd.ni_vp,
943 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
944 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
949 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
950 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
951 ef->ddbstrcnt = strcnt;
952 ef->ddbstrtab = ef->strbase;
955 error = link_elf_link_common_finish(lf);
962 VOP_UNLOCK(nd.ni_vp, 0);
963 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
964 VFS_UNLOCK_GIANT(vfslocked);
965 if (error != 0 && lf != NULL)
966 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
968 free(shdr, M_LINKER);
969 if (firstpage != NULL)
970 free(firstpage, M_LINKER);
976 elf_relocaddr(linker_file_t lf, Elf_Addr x)
981 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
982 return ((x - ef->pcpu_start) + ef->pcpu_base);
984 if (x >= ef->vnet_start && x < ef->vnet_stop)
985 return ((x - ef->vnet_start) + ef->vnet_base);
992 link_elf_unload_file(linker_file_t file)
994 elf_file_t ef = (elf_file_t) file;
996 if (ef->pcpu_base != 0) {
997 dpcpu_free((void *)ef->pcpu_base,
998 ef->pcpu_stop - ef->pcpu_start);
1001 if (ef->vnet_base != 0) {
1002 vnet_data_free((void *)ef->vnet_base,
1003 ef->vnet_stop - ef->vnet_start);
1007 if (ef->gdb.l_ld != NULL) {
1008 GDB_STATE(RT_DELETE);
1009 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1010 link_elf_delete_gdb(&ef->gdb);
1011 GDB_STATE(RT_CONSISTENT);
1015 /* Notify MD code that a module is being unloaded. */
1016 elf_cpu_unload_file(file);
1018 if (ef->preloaded) {
1019 link_elf_unload_preload(file);
1023 #ifdef SPARSE_MAPPING
1024 if (ef->object != NULL) {
1025 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1026 (vm_offset_t) ef->address
1027 + (ef->object->size << PAGE_SHIFT));
1030 if (ef->address != NULL)
1031 free(ef->address, M_LINKER);
1033 if (ef->symbase != NULL)
1034 free(ef->symbase, M_LINKER);
1035 if (ef->strbase != NULL)
1036 free(ef->strbase, M_LINKER);
1037 if (ef->ctftab != NULL)
1038 free(ef->ctftab, M_LINKER);
1039 if (ef->ctfoff != NULL)
1040 free(ef->ctfoff, M_LINKER);
1041 if (ef->typoff != NULL)
1042 free(ef->typoff, M_LINKER);
1046 link_elf_unload_preload(linker_file_t file)
1048 if (file->filename != NULL)
1049 preload_delete_name(file->filename);
1053 symbol_name(elf_file_t ef, Elf_Size r_info)
1057 if (ELF_R_SYM(r_info)) {
1058 ref = ef->symtab + ELF_R_SYM(r_info);
1059 return (ef->strtab + ref->st_name);
1065 relocate_file(elf_file_t ef)
1067 const Elf_Rel *rellim;
1069 const Elf_Rela *relalim;
1070 const Elf_Rela *rela;
1071 const char *symname;
1073 /* Perform relocations without addend if there are any: */
1076 rellim = (const Elf_Rel *)
1077 ((const char *)ef->rel + ef->relsize);
1078 while (rel < rellim) {
1079 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1080 ELF_RELOC_REL, elf_lookup)) {
1081 symname = symbol_name(ef, rel->r_info);
1082 printf("link_elf: symbol %s undefined\n", symname);
1089 /* Perform relocations with addend if there are any: */
1092 relalim = (const Elf_Rela *)
1093 ((const char *)ef->rela + ef->relasize);
1094 while (rela < relalim) {
1095 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1096 ELF_RELOC_RELA, elf_lookup)) {
1097 symname = symbol_name(ef, rela->r_info);
1098 printf("link_elf: symbol %s undefined\n",
1106 /* Perform PLT relocations without addend if there are any: */
1109 rellim = (const Elf_Rel *)
1110 ((const char *)ef->pltrel + ef->pltrelsize);
1111 while (rel < rellim) {
1112 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1113 ELF_RELOC_REL, elf_lookup)) {
1114 symname = symbol_name(ef, rel->r_info);
1115 printf("link_elf: symbol %s undefined\n",
1123 /* Perform relocations with addend if there are any: */
1126 relalim = (const Elf_Rela *)
1127 ((const char *)ef->pltrela + ef->pltrelasize);
1128 while (rela < relalim) {
1129 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1130 ELF_RELOC_RELA, elf_lookup)) {
1131 symname = symbol_name(ef, rela->r_info);
1132 printf("link_elf: symbol %s undefined\n",
1144 * Hash function for symbol table lookup. Don't even think about changing
1145 * this. It is specified by the System V ABI.
1147 static unsigned long
1148 elf_hash(const char *name)
1150 const unsigned char *p = (const unsigned char *) name;
1151 unsigned long h = 0;
1154 while (*p != '\0') {
1155 h = (h << 4) + *p++;
1156 if ((g = h & 0xf0000000) != 0)
1164 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1166 elf_file_t ef = (elf_file_t) lf;
1167 unsigned long symnum;
1168 const Elf_Sym* symp;
1173 /* If we don't have a hash, bail. */
1174 if (ef->buckets == NULL || ef->nbuckets == 0) {
1175 printf("link_elf_lookup_symbol: missing symbol hash table\n");
1179 /* First, search hashed global symbols */
1180 hash = elf_hash(name);
1181 symnum = ef->buckets[hash % ef->nbuckets];
1183 while (symnum != STN_UNDEF) {
1184 if (symnum >= ef->nchains) {
1185 printf("%s: corrupt symbol table\n", __func__);
1189 symp = ef->symtab + symnum;
1190 if (symp->st_name == 0) {
1191 printf("%s: corrupt symbol table\n", __func__);
1195 strp = ef->strtab + symp->st_name;
1197 if (strcmp(name, strp) == 0) {
1198 if (symp->st_shndx != SHN_UNDEF ||
1199 (symp->st_value != 0 &&
1200 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1201 *sym = (c_linker_sym_t) symp;
1207 symnum = ef->chains[symnum];
1210 /* If we have not found it, look at the full table (if loaded) */
1211 if (ef->symtab == ef->ddbsymtab)
1214 /* Exhaustive search */
1215 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1216 strp = ef->ddbstrtab + symp->st_name;
1217 if (strcmp(name, strp) == 0) {
1218 if (symp->st_shndx != SHN_UNDEF ||
1219 (symp->st_value != 0 &&
1220 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1221 *sym = (c_linker_sym_t) symp;
1232 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1233 linker_symval_t *symval)
1235 elf_file_t ef = (elf_file_t) lf;
1236 const Elf_Sym* es = (const Elf_Sym*) sym;
1238 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1239 symval->name = ef->strtab + es->st_name;
1240 symval->value = (caddr_t) ef->address + es->st_value;
1241 symval->size = es->st_size;
1244 if (ef->symtab == ef->ddbsymtab)
1246 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1247 symval->name = ef->ddbstrtab + es->st_name;
1248 symval->value = (caddr_t) ef->address + es->st_value;
1249 symval->size = es->st_size;
1256 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1257 c_linker_sym_t *sym, long *diffp)
1259 elf_file_t ef = (elf_file_t) lf;
1260 u_long off = (uintptr_t) (void *) value;
1264 const Elf_Sym* best = 0;
1267 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1268 if (es->st_name == 0)
1270 st_value = es->st_value + (uintptr_t) (void *) ef->address;
1271 if (off >= st_value) {
1272 if (off - st_value < diff) {
1273 diff = off - st_value;
1277 } else if (off - st_value == diff) {
1286 *sym = (c_linker_sym_t) best;
1292 * Look up a linker set on an ELF system.
1295 link_elf_lookup_set(linker_file_t lf, const char *name,
1296 void ***startp, void ***stopp, int *countp)
1299 linker_symval_t symval;
1301 void **start, **stop;
1302 int len, error = 0, count;
1304 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1305 setsym = malloc(len, M_LINKER, M_WAITOK);
1307 /* get address of first entry */
1308 snprintf(setsym, len, "%s%s", "__start_set_", name);
1309 error = link_elf_lookup_symbol(lf, setsym, &sym);
1312 link_elf_symbol_values(lf, sym, &symval);
1313 if (symval.value == 0) {
1317 start = (void **)symval.value;
1319 /* get address of last entry */
1320 snprintf(setsym, len, "%s%s", "__stop_set_", name);
1321 error = link_elf_lookup_symbol(lf, setsym, &sym);
1324 link_elf_symbol_values(lf, sym, &symval);
1325 if (symval.value == 0) {
1329 stop = (void **)symval.value;
1331 /* and the number of entries */
1332 count = stop - start;
1343 free(setsym, M_LINKER);
1348 link_elf_each_function_name(linker_file_t file,
1349 int (*callback)(const char *, void *), void *opaque)
1351 elf_file_t ef = (elf_file_t)file;
1352 const Elf_Sym *symp;
1355 /* Exhaustive search */
1356 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1357 if (symp->st_value != 0 &&
1358 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1359 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1368 link_elf_each_function_nameval(linker_file_t file,
1369 linker_function_nameval_callback_t callback, void *opaque)
1371 linker_symval_t symval;
1372 elf_file_t ef = (elf_file_t)file;
1373 const Elf_Sym* symp;
1376 /* Exhaustive search */
1377 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1378 if (symp->st_value != 0 &&
1379 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1380 error = link_elf_symbol_values(file,
1381 (c_linker_sym_t) symp, &symval);
1384 error = callback(file, i, &symval, opaque);
1394 * Each KLD has its own GP. The GP value for each load module is given by
1395 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1396 * don't have direct access to the ELF file structure. The link_elf_get_gp()
1397 * function returns the GP given a pointer to a generic linker file struct.
1400 link_elf_get_gp(linker_file_t lf)
1402 elf_file_t ef = (elf_file_t)lf;
1403 return ((Elf_Addr)ef->got);
1408 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1410 elf_file_t ef = (elf_file_t)lf;
1412 if (symidx >= ef->nchains)
1414 return (ef->symtab + symidx);
1418 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1420 elf_file_t ef = (elf_file_t)lf;
1423 if (symidx >= ef->nchains)
1425 sym = ef->symtab + symidx;
1426 return (ef->strtab + sym->st_name);
1430 * Symbol lookup function that can be used when the symbol index is known (ie
1431 * in relocations). It uses the symbol index instead of doing a fully fledged
1432 * hash table based lookup when such is valid. For example for local symbols.
1433 * This is not only more efficient, it's also more correct. It's not always
1434 * the case that the symbol can be found through the hash table.
1437 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps)
1439 elf_file_t ef = (elf_file_t)lf;
1443 /* Don't even try to lookup the symbol if the index is bogus. */
1444 if (symidx >= ef->nchains)
1447 sym = ef->symtab + symidx;
1450 * Don't do a full lookup when the symbol is local. It may even
1451 * fail because it may not be found through the hash table.
1453 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1454 /* Force lookup failure when we have an insanity. */
1455 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0)
1457 return ((Elf_Addr)ef->address + sym->st_value);
1461 * XXX we can avoid doing a hash table based lookup for global
1462 * symbols as well. This however is not always valid, so we'll
1463 * just do it the hard way for now. Performance tweaks can
1467 symbol = ef->strtab + sym->st_name;
1469 /* Force a lookup failure if the symbol name is bogus. */
1473 return ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1477 link_elf_reloc_local(linker_file_t lf)
1479 const Elf_Rel *rellim;
1481 const Elf_Rela *relalim;
1482 const Elf_Rela *rela;
1483 elf_file_t ef = (elf_file_t)lf;
1485 /* Perform relocations without addend if there are any: */
1486 if ((rel = ef->rel) != NULL) {
1487 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1488 while (rel < rellim) {
1489 elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1490 ELF_RELOC_REL, elf_lookup);
1495 /* Perform relocations with addend if there are any: */
1496 if ((rela = ef->rela) != NULL) {
1497 relalim = (const Elf_Rela *)
1498 ((const char *)ef->rela + ef->relasize);
1499 while (rela < relalim) {
1500 elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1501 ELF_RELOC_RELA, elf_lookup);
1508 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1510 elf_file_t ef = (elf_file_t)lf;
1512 *symtab = ef->ddbsymtab;
1514 if (*symtab == NULL)
1517 return (ef->ddbsymcnt);
1521 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1523 elf_file_t ef = (elf_file_t)lf;
1525 *strtab = ef->ddbstrtab;
1527 if (*strtab == NULL)
1530 return (ef->ddbstrcnt);