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 */
130 TAILQ_ENTRY(elf_set) es_link;
133 TAILQ_HEAD(elf_set_head, elf_set);
135 #include <kern/kern_ctf.c>
137 static int link_elf_link_common_finish(linker_file_t);
138 static int link_elf_link_preload(linker_class_t cls,
139 const char *, linker_file_t *);
140 static int link_elf_link_preload_finish(linker_file_t);
141 static int link_elf_load_file(linker_class_t, const char *,
143 static int link_elf_lookup_symbol(linker_file_t, const char *,
145 static int link_elf_symbol_values(linker_file_t, c_linker_sym_t,
147 static int link_elf_search_symbol(linker_file_t, caddr_t,
148 c_linker_sym_t *, long *);
150 static void link_elf_unload_file(linker_file_t);
151 static void link_elf_unload_preload(linker_file_t);
152 static int link_elf_lookup_set(linker_file_t, const char *,
153 void ***, void ***, int *);
154 static int link_elf_each_function_name(linker_file_t,
155 int (*)(const char *, void *), void *);
156 static int link_elf_each_function_nameval(linker_file_t,
157 linker_function_nameval_callback_t, void *);
158 static void link_elf_reloc_local(linker_file_t);
159 static long link_elf_symtab_get(linker_file_t, const Elf_Sym **);
160 static long link_elf_strtab_get(linker_file_t, caddr_t *);
161 static int elf_lookup(linker_file_t, Elf_Size, int, Elf_Addr *);
163 static kobj_method_t link_elf_methods[] = {
164 KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
165 KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
166 KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
167 KOBJMETHOD(linker_unload, link_elf_unload_file),
168 KOBJMETHOD(linker_load_file, link_elf_load_file),
169 KOBJMETHOD(linker_link_preload, link_elf_link_preload),
170 KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
171 KOBJMETHOD(linker_lookup_set, link_elf_lookup_set),
172 KOBJMETHOD(linker_each_function_name, link_elf_each_function_name),
173 KOBJMETHOD(linker_each_function_nameval, link_elf_each_function_nameval),
174 KOBJMETHOD(linker_ctf_get, link_elf_ctf_get),
175 KOBJMETHOD(linker_symtab_get, link_elf_symtab_get),
176 KOBJMETHOD(linker_strtab_get, link_elf_strtab_get),
180 static struct linker_class link_elf_class = {
181 #if ELF_TARG_CLASS == ELFCLASS32
186 link_elf_methods, sizeof(struct elf_file)
189 static int parse_dynamic(elf_file_t);
190 static int relocate_file(elf_file_t);
191 static int link_elf_preload_parse_symbols(elf_file_t);
193 static struct elf_set_head set_pcpu_list;
195 static struct elf_set_head set_vnet_list;
199 elf_set_add(struct elf_set_head *list, Elf_Addr start, Elf_Addr stop, Elf_Addr base)
201 struct elf_set *set, *iter;
203 set = malloc(sizeof(*set), M_LINKER, M_WAITOK);
204 set->es_start = start;
208 TAILQ_FOREACH(iter, list, es_link) {
210 KASSERT((set->es_start < iter->es_start && set->es_stop < iter->es_stop) ||
211 (set->es_start > iter->es_start && set->es_stop > iter->es_stop),
212 ("linker sets intersection: to insert: 0x%jx-0x%jx; inserted: 0x%jx-0x%jx",
213 (uintmax_t)set->es_start, (uintmax_t)set->es_stop,
214 (uintmax_t)iter->es_start, (uintmax_t)iter->es_stop));
216 if (iter->es_start > set->es_start) {
217 TAILQ_INSERT_BEFORE(iter, set, es_link);
223 TAILQ_INSERT_TAIL(list, set, es_link);
227 elf_set_find(struct elf_set_head *list, Elf_Addr addr, Elf_Addr *start, Elf_Addr *base)
231 TAILQ_FOREACH(set, list, es_link) {
232 if (addr < set->es_start)
234 if (addr < set->es_stop) {
235 *start = set->es_start;
236 *base = set->es_base;
245 elf_set_delete(struct elf_set_head *list, Elf_Addr start)
249 TAILQ_FOREACH(set, list, es_link) {
250 if (start < set->es_start)
252 if (start == set->es_start) {
253 TAILQ_REMOVE(list, set, es_link);
258 KASSERT(0, ("deleting unknown linker set (start = 0x%jx)",
263 static void r_debug_state(struct r_debug *, struct link_map *);
266 * A list of loaded modules for GDB to use for loading symbols.
268 struct r_debug r_debug;
270 #define GDB_STATE(s) do { \
271 r_debug.r_state = s; r_debug_state(NULL, NULL); \
275 * Function for the debugger to set a breakpoint on to gain control.
278 r_debug_state(struct r_debug *dummy_one __unused,
279 struct link_map *dummy_two __unused)
284 link_elf_add_gdb(struct link_map *l)
286 struct link_map *prev;
290 if (r_debug.r_map == NULL) {
295 /* Append to list. */
296 for (prev = r_debug.r_map;
297 prev->l_next != NULL;
306 link_elf_delete_gdb(struct link_map *l)
308 if (l->l_prev == NULL) {
310 if ((r_debug.r_map = l->l_next) != NULL)
311 l->l_next->l_prev = NULL;
313 /* Remove any but first. */
314 if ((l->l_prev->l_next = l->l_next) != NULL)
315 l->l_next->l_prev = l->l_prev;
321 Elf_Addr link_elf_get_gp(linker_file_t);
325 * The kernel symbol table starts here.
327 extern struct _dynamic _DYNAMIC;
330 link_elf_error(const char *filename, const char *s)
332 if (filename == NULL)
333 printf("kldload: %s\n", s);
335 printf("kldload: %s: %s\n", filename, s);
339 * Actions performed after linking/loading both the preloaded kernel and any
340 * modules; whether preloaded or dynamicly loaded.
343 link_elf_link_common_finish(linker_file_t lf)
346 elf_file_t ef = (elf_file_t)lf;
351 /* Notify MD code that a module is being loaded. */
352 error = elf_cpu_load_file(lf);
358 ef->gdb.l_addr = lf->address;
359 newfilename = malloc(strlen(lf->filename) + 1, M_LINKER, M_WAITOK);
360 strcpy(newfilename, lf->filename);
361 ef->gdb.l_name = newfilename;
362 ef->gdb.l_ld = ef->dynamic;
363 link_elf_add_gdb(&ef->gdb);
364 GDB_STATE(RT_CONSISTENT);
371 link_elf_init(void* arg)
374 caddr_t modptr, baseptr, sizeptr;
378 linker_add_class(&link_elf_class);
380 dp = (Elf_Dyn *)&_DYNAMIC;
382 modptr = preload_search_by_type("elf" __XSTRING(__ELF_WORD_SIZE) " kernel");
384 modptr = preload_search_by_type("elf kernel");
386 modname = (char *)preload_search_info(modptr, MODINFO_NAME);
389 linker_kernel_file = linker_make_file(modname, &link_elf_class);
390 if (linker_kernel_file == NULL)
391 panic("%s: Can't create linker structures for kernel",
394 ef = (elf_file_t) linker_kernel_file;
397 #ifdef SPARSE_MAPPING
404 linker_kernel_file->address = (caddr_t) KERNBASE;
405 linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
407 if (modptr != NULL) {
409 baseptr = preload_search_info(modptr, MODINFO_ADDR);
411 linker_kernel_file->address = *(caddr_t *)baseptr;
412 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
414 linker_kernel_file->size = *(size_t *)sizeptr;
416 (void)link_elf_preload_parse_symbols(ef);
419 r_debug.r_map = NULL;
420 r_debug.r_brk = r_debug_state;
421 r_debug.r_state = RT_CONSISTENT;
424 (void)link_elf_link_common_finish(linker_kernel_file);
425 linker_kernel_file->flags |= LINKER_FILE_LINKED;
426 TAILQ_INIT(&set_pcpu_list);
428 TAILQ_INIT(&set_vnet_list);
432 SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_THIRD, link_elf_init, 0);
435 link_elf_preload_parse_symbols(elf_file_t ef)
438 caddr_t ssym, esym, base;
444 if (ef->modptr == NULL)
446 pointer = preload_search_info(ef->modptr,
447 MODINFO_METADATA | MODINFOMD_SSYM);
450 ssym = *(caddr_t *)pointer;
451 pointer = preload_search_info(ef->modptr,
452 MODINFO_METADATA | MODINFOMD_ESYM);
455 esym = *(caddr_t *)pointer;
459 symcnt = *(long *)base;
460 base += sizeof(long);
461 symtab = (Elf_Sym *)base;
462 base += roundup(symcnt, sizeof(long));
464 if (base > esym || base < ssym) {
465 printf("Symbols are corrupt!\n");
469 strcnt = *(long *)base;
470 base += sizeof(long);
472 base += roundup(strcnt, sizeof(long));
474 if (base > esym || base < ssym) {
475 printf("Symbols are corrupt!\n");
479 ef->ddbsymtab = symtab;
480 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
481 ef->ddbstrtab = strtab;
482 ef->ddbstrcnt = strcnt;
488 parse_dynamic(elf_file_t ef)
491 int plttype = DT_REL;
493 for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
497 /* From src/libexec/rtld-elf/rtld.c */
498 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
499 (ef->address + dp->d_un.d_ptr);
500 ef->nbuckets = hashtab[0];
501 ef->nchains = hashtab[1];
502 ef->buckets = hashtab + 2;
503 ef->chains = ef->buckets + ef->nbuckets;
507 ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
510 ef->strsz = dp->d_un.d_val;
513 ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
516 if (dp->d_un.d_val != sizeof(Elf_Sym))
520 ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
523 ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
526 ef->relsize = dp->d_un.d_val;
529 if (dp->d_un.d_val != sizeof(Elf_Rel))
533 ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
536 ef->pltrelsize = dp->d_un.d_val;
539 ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
542 ef->relasize = dp->d_un.d_val;
545 if (dp->d_un.d_val != sizeof(Elf_Rela))
549 plttype = dp->d_un.d_val;
550 if (plttype != DT_REL && plttype != DT_RELA)
555 dp->d_un.d_ptr = (Elf_Addr)&r_debug;
561 if (plttype == DT_RELA) {
562 ef->pltrela = (const Elf_Rela *)ef->pltrel;
564 ef->pltrelasize = ef->pltrelsize;
568 ef->ddbsymtab = ef->symtab;
569 ef->ddbsymcnt = ef->nchains;
570 ef->ddbstrtab = ef->strtab;
571 ef->ddbstrcnt = ef->strsz;
577 parse_dpcpu(elf_file_t ef)
584 error = link_elf_lookup_set(&ef->lf, "pcpu", (void ***)&ef->pcpu_start,
585 (void ***)&ef->pcpu_stop, &count);
586 /* Error just means there is no pcpu set to relocate. */
589 count *= sizeof(void *);
591 * Allocate space in the primary pcpu area. Copy in our
592 * initialization from the data section and then initialize
593 * all per-cpu storage from that.
595 ef->pcpu_base = (Elf_Addr)(uintptr_t)dpcpu_alloc(count);
596 if (ef->pcpu_base == 0)
598 memcpy((void *)ef->pcpu_base, (void *)ef->pcpu_start, count);
599 dpcpu_copy((void *)ef->pcpu_base, count);
600 elf_set_add(&set_pcpu_list, ef->pcpu_start, ef->pcpu_stop,
608 parse_vnet(elf_file_t ef)
615 error = link_elf_lookup_set(&ef->lf, "vnet", (void ***)&ef->vnet_start,
616 (void ***)&ef->vnet_stop, &count);
617 /* Error just means there is no vnet data set to relocate. */
620 count *= sizeof(void *);
622 * Allocate space in the primary vnet area. Copy in our
623 * initialization from the data section and then initialize
624 * all per-vnet storage from that.
626 ef->vnet_base = (Elf_Addr)(uintptr_t)vnet_data_alloc(count);
627 if (ef->vnet_base == 0)
629 memcpy((void *)ef->vnet_base, (void *)ef->vnet_start, count);
630 vnet_data_copy((void *)ef->vnet_base, count);
631 elf_set_add(&set_vnet_list, ef->vnet_start, ef->vnet_stop,
639 link_elf_link_preload(linker_class_t cls,
640 const char* filename, linker_file_t *result)
642 caddr_t modptr, baseptr, sizeptr, dynptr;
649 /* Look to see if we have the file preloaded */
650 modptr = preload_search_by_name(filename);
654 type = (char *)preload_search_info(modptr, MODINFO_TYPE);
655 baseptr = preload_search_info(modptr, MODINFO_ADDR);
656 sizeptr = preload_search_info(modptr, MODINFO_SIZE);
657 dynptr = preload_search_info(modptr,
658 MODINFO_METADATA | MODINFOMD_DYNAMIC);
660 (strcmp(type, "elf" __XSTRING(__ELF_WORD_SIZE) " module") != 0 &&
661 strcmp(type, "elf module") != 0))
663 if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
666 lf = linker_make_file(filename, &link_elf_class);
670 ef = (elf_file_t) lf;
673 ef->address = *(caddr_t *)baseptr;
674 #ifdef SPARSE_MAPPING
677 dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
678 ef->dynamic = (Elf_Dyn *)dp;
679 lf->address = ef->address;
680 lf->size = *(size_t *)sizeptr;
682 error = parse_dynamic(ef);
684 error = parse_dpcpu(ef);
687 error = parse_vnet(ef);
690 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
693 link_elf_reloc_local(lf);
699 link_elf_link_preload_finish(linker_file_t lf)
704 ef = (elf_file_t) lf;
705 error = relocate_file(ef);
708 (void)link_elf_preload_parse_symbols(ef);
710 return (link_elf_link_common_finish(lf));
714 link_elf_load_file(linker_class_t cls, const char* filename,
715 linker_file_t* result)
718 struct thread* td = curthread; /* XXX */
724 Elf_Phdr *segs[MAXSEGS];
732 Elf_Addr base_vlimit;
747 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, td);
749 error = vn_open(&nd, &flags, 0, NULL);
752 NDFREE(&nd, NDF_ONLY_PNBUF);
753 if (nd.ni_vp->v_type != VREG) {
759 error = mac_kld_check_load(curthread->td_ucred, nd.ni_vp);
767 * Read the elf header from the file.
769 firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
770 hdr = (Elf_Ehdr *)firstpage;
771 error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
772 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
774 nbytes = PAGE_SIZE - resid;
783 if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
784 hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
785 link_elf_error(filename, "Unsupported file layout");
789 if (hdr->e_ident[EI_VERSION] != EV_CURRENT ||
790 hdr->e_version != EV_CURRENT) {
791 link_elf_error(filename, "Unsupported file version");
795 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
799 if (hdr->e_machine != ELF_TARG_MACH) {
800 link_elf_error(filename, "Unsupported machine");
806 * We rely on the program header being in the first page.
807 * This is not strictly required by the ABI specification, but
808 * it seems to always true in practice. And, it simplifies
809 * things considerably.
811 if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
812 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
813 (hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
814 link_elf_error(filename, "Unreadable program headers");
817 * Scan the program header entries, and save key information.
819 * We rely on there being exactly two load segments, text and data,
822 phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
823 phlimit = phdr + hdr->e_phnum;
827 while (phdr < phlimit) {
828 switch (phdr->p_type) {
830 if (nsegs == MAXSEGS) {
831 link_elf_error(filename, "Too many sections");
836 * XXX: We just trust they come in right order ??
858 link_elf_error(filename, "Object is not dynamically-linked");
863 link_elf_error(filename, "No sections");
869 * Allocate the entire address space of the object, to stake
870 * out our contiguous region, and to establish the base
871 * address for relocation.
873 base_offset = trunc_page(segs[0]->p_offset);
874 base_vaddr = trunc_page(segs[0]->p_vaddr);
875 base_vlimit = round_page(segs[nsegs - 1]->p_vaddr +
876 segs[nsegs - 1]->p_memsz);
877 mapsize = base_vlimit - base_vaddr;
879 lf = linker_make_file(filename, &link_elf_class);
885 ef = (elf_file_t) lf;
886 #ifdef SPARSE_MAPPING
887 ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
888 if (ef->object == NULL) {
892 ef->address = (caddr_t) vm_map_min(kernel_map);
893 error = vm_map_find(kernel_map, ef->object, 0,
894 (vm_offset_t *) &ef->address, mapsize, 0, VMFS_OPTIMAL_SPACE,
895 VM_PROT_ALL, VM_PROT_ALL, 0);
897 vm_object_deallocate(ef->object);
902 ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
904 mapbase = ef->address;
907 * Read the text and data sections and zero the bss.
909 for (i = 0; i < nsegs; i++) {
910 caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
911 error = vn_rdwr(UIO_READ, nd.ni_vp,
912 segbase, segs[i]->p_filesz, segs[i]->p_offset,
913 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
917 bzero(segbase + segs[i]->p_filesz,
918 segs[i]->p_memsz - segs[i]->p_filesz);
920 #ifdef SPARSE_MAPPING
922 * Wire down the pages
924 error = vm_map_wire(kernel_map,
925 (vm_offset_t) segbase,
926 (vm_offset_t) segbase + segs[i]->p_memsz,
927 VM_MAP_WIRE_SYSTEM|VM_MAP_WIRE_NOHOLES);
928 if (error != KERN_SUCCESS) {
936 /* Update profiling information with the new text segment. */
938 kmupetext((uintfptr_t)(mapbase + segs[0]->p_vaddr - base_vaddr +
943 ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
945 lf->address = ef->address;
948 error = parse_dynamic(ef);
951 error = parse_dpcpu(ef);
955 error = parse_vnet(ef);
959 link_elf_reloc_local(lf);
961 VOP_UNLOCK(nd.ni_vp, 0);
962 error = linker_load_dependencies(lf);
963 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
966 error = relocate_file(ef);
971 * Try and load the symbol table if it's present. (you can
974 nbytes = hdr->e_shnum * hdr->e_shentsize;
975 if (nbytes == 0 || hdr->e_shoff == 0)
977 shdr = malloc(nbytes, M_LINKER, M_WAITOK | M_ZERO);
978 error = vn_rdwr(UIO_READ, nd.ni_vp,
979 (caddr_t)shdr, nbytes, hdr->e_shoff,
980 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
986 for (i = 0; i < hdr->e_shnum; i++) {
987 if (shdr[i].sh_type == SHT_SYMTAB) {
989 symstrindex = shdr[i].sh_link;
992 if (symtabindex < 0 || symstrindex < 0)
995 symcnt = shdr[symtabindex].sh_size;
996 ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
997 strcnt = shdr[symstrindex].sh_size;
998 ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
1000 error = vn_rdwr(UIO_READ, nd.ni_vp,
1001 ef->symbase, symcnt, shdr[symtabindex].sh_offset,
1002 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1006 error = vn_rdwr(UIO_READ, nd.ni_vp,
1007 ef->strbase, strcnt, shdr[symstrindex].sh_offset,
1008 UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
1013 ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
1014 ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
1015 ef->ddbstrcnt = strcnt;
1016 ef->ddbstrtab = ef->strbase;
1019 error = link_elf_link_common_finish(lf);
1026 VOP_UNLOCK(nd.ni_vp, 0);
1027 vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
1028 if (error != 0 && lf != NULL)
1029 linker_file_unload(lf, LINKER_UNLOAD_FORCE);
1030 free(shdr, M_LINKER);
1031 free(firstpage, M_LINKER);
1037 elf_relocaddr(linker_file_t lf, Elf_Addr x)
1041 ef = (elf_file_t)lf;
1042 if (x >= ef->pcpu_start && x < ef->pcpu_stop)
1043 return ((x - ef->pcpu_start) + ef->pcpu_base);
1045 if (x >= ef->vnet_start && x < ef->vnet_stop)
1046 return ((x - ef->vnet_start) + ef->vnet_base);
1053 link_elf_unload_file(linker_file_t file)
1055 elf_file_t ef = (elf_file_t) file;
1057 if (ef->pcpu_base != 0) {
1058 dpcpu_free((void *)ef->pcpu_base,
1059 ef->pcpu_stop - ef->pcpu_start);
1060 elf_set_delete(&set_pcpu_list, ef->pcpu_start);
1063 if (ef->vnet_base != 0) {
1064 vnet_data_free((void *)ef->vnet_base,
1065 ef->vnet_stop - ef->vnet_start);
1066 elf_set_delete(&set_vnet_list, ef->vnet_start);
1070 if (ef->gdb.l_ld != NULL) {
1071 GDB_STATE(RT_DELETE);
1072 free((void *)(uintptr_t)ef->gdb.l_name, M_LINKER);
1073 link_elf_delete_gdb(&ef->gdb);
1074 GDB_STATE(RT_CONSISTENT);
1078 /* Notify MD code that a module is being unloaded. */
1079 elf_cpu_unload_file(file);
1081 if (ef->preloaded) {
1082 link_elf_unload_preload(file);
1086 #ifdef SPARSE_MAPPING
1087 if (ef->object != NULL) {
1088 vm_map_remove(kernel_map, (vm_offset_t) ef->address,
1089 (vm_offset_t) ef->address
1090 + (ef->object->size << PAGE_SHIFT));
1093 free(ef->address, M_LINKER);
1095 free(ef->symbase, M_LINKER);
1096 free(ef->strbase, M_LINKER);
1097 free(ef->ctftab, M_LINKER);
1098 free(ef->ctfoff, M_LINKER);
1099 free(ef->typoff, M_LINKER);
1103 link_elf_unload_preload(linker_file_t file)
1105 if (file->filename != NULL)
1106 preload_delete_name(file->filename);
1110 symbol_name(elf_file_t ef, Elf_Size r_info)
1114 if (ELF_R_SYM(r_info)) {
1115 ref = ef->symtab + ELF_R_SYM(r_info);
1116 return (ef->strtab + ref->st_name);
1122 relocate_file(elf_file_t ef)
1124 const Elf_Rel *rellim;
1126 const Elf_Rela *relalim;
1127 const Elf_Rela *rela;
1128 const char *symname;
1130 /* Perform relocations without addend if there are any: */
1133 rellim = (const Elf_Rel *)
1134 ((const char *)ef->rel + ef->relsize);
1135 while (rel < rellim) {
1136 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1137 ELF_RELOC_REL, elf_lookup)) {
1138 symname = symbol_name(ef, rel->r_info);
1139 printf("link_elf: symbol %s undefined\n", symname);
1146 /* Perform relocations with addend if there are any: */
1149 relalim = (const Elf_Rela *)
1150 ((const char *)ef->rela + ef->relasize);
1151 while (rela < relalim) {
1152 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1153 ELF_RELOC_RELA, elf_lookup)) {
1154 symname = symbol_name(ef, rela->r_info);
1155 printf("link_elf: symbol %s undefined\n",
1163 /* Perform PLT relocations without addend if there are any: */
1166 rellim = (const Elf_Rel *)
1167 ((const char *)ef->pltrel + ef->pltrelsize);
1168 while (rel < rellim) {
1169 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rel,
1170 ELF_RELOC_REL, elf_lookup)) {
1171 symname = symbol_name(ef, rel->r_info);
1172 printf("link_elf: symbol %s undefined\n",
1180 /* Perform relocations with addend if there are any: */
1183 relalim = (const Elf_Rela *)
1184 ((const char *)ef->pltrela + ef->pltrelasize);
1185 while (rela < relalim) {
1186 if (elf_reloc(&ef->lf, (Elf_Addr)ef->address, rela,
1187 ELF_RELOC_RELA, elf_lookup)) {
1188 symname = symbol_name(ef, rela->r_info);
1189 printf("link_elf: symbol %s undefined\n",
1201 * Hash function for symbol table lookup. Don't even think about changing
1202 * this. It is specified by the System V ABI.
1204 static unsigned long
1205 elf_hash(const char *name)
1207 const unsigned char *p = (const unsigned char *) name;
1208 unsigned long h = 0;
1211 while (*p != '\0') {
1212 h = (h << 4) + *p++;
1213 if ((g = h & 0xf0000000) != 0)
1221 link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
1223 elf_file_t ef = (elf_file_t) lf;
1224 unsigned long symnum;
1225 const Elf_Sym* symp;
1230 /* If we don't have a hash, bail. */
1231 if (ef->buckets == NULL || ef->nbuckets == 0) {
1232 printf("link_elf_lookup_symbol: missing symbol hash table\n");
1236 /* First, search hashed global symbols */
1237 hash = elf_hash(name);
1238 symnum = ef->buckets[hash % ef->nbuckets];
1240 while (symnum != STN_UNDEF) {
1241 if (symnum >= ef->nchains) {
1242 printf("%s: corrupt symbol table\n", __func__);
1246 symp = ef->symtab + symnum;
1247 if (symp->st_name == 0) {
1248 printf("%s: corrupt symbol table\n", __func__);
1252 strp = ef->strtab + symp->st_name;
1254 if (strcmp(name, strp) == 0) {
1255 if (symp->st_shndx != SHN_UNDEF ||
1256 (symp->st_value != 0 &&
1257 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1258 *sym = (c_linker_sym_t) symp;
1264 symnum = ef->chains[symnum];
1267 /* If we have not found it, look at the full table (if loaded) */
1268 if (ef->symtab == ef->ddbsymtab)
1271 /* Exhaustive search */
1272 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1273 strp = ef->ddbstrtab + symp->st_name;
1274 if (strcmp(name, strp) == 0) {
1275 if (symp->st_shndx != SHN_UNDEF ||
1276 (symp->st_value != 0 &&
1277 ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
1278 *sym = (c_linker_sym_t) symp;
1289 link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym,
1290 linker_symval_t *symval)
1292 elf_file_t ef = (elf_file_t) lf;
1293 const Elf_Sym* es = (const Elf_Sym*) sym;
1295 if (es >= ef->symtab && es < (ef->symtab + ef->nchains)) {
1296 symval->name = ef->strtab + es->st_name;
1297 symval->value = (caddr_t) ef->address + es->st_value;
1298 symval->size = es->st_size;
1301 if (ef->symtab == ef->ddbsymtab)
1303 if (es >= ef->ddbsymtab && es < (ef->ddbsymtab + ef->ddbsymcnt)) {
1304 symval->name = ef->ddbstrtab + es->st_name;
1305 symval->value = (caddr_t) ef->address + es->st_value;
1306 symval->size = es->st_size;
1313 link_elf_search_symbol(linker_file_t lf, caddr_t value,
1314 c_linker_sym_t *sym, long *diffp)
1316 elf_file_t ef = (elf_file_t) lf;
1317 u_long off = (uintptr_t) (void *) value;
1321 const Elf_Sym* best = 0;
1324 for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
1325 if (es->st_name == 0)
1327 st_value = es->st_value + (uintptr_t) (void *) ef->address;
1328 if (off >= st_value) {
1329 if (off - st_value < diff) {
1330 diff = off - st_value;
1334 } else if (off - st_value == diff) {
1343 *sym = (c_linker_sym_t) best;
1349 * Look up a linker set on an ELF system.
1352 link_elf_lookup_set(linker_file_t lf, const char *name,
1353 void ***startp, void ***stopp, int *countp)
1356 linker_symval_t symval;
1358 void **start, **stop;
1359 int len, error = 0, count;
1361 len = strlen(name) + sizeof("__start_set_"); /* sizeof includes \0 */
1362 setsym = malloc(len, M_LINKER, M_WAITOK);
1364 /* get address of first entry */
1365 snprintf(setsym, len, "%s%s", "__start_set_", name);
1366 error = link_elf_lookup_symbol(lf, setsym, &sym);
1369 link_elf_symbol_values(lf, sym, &symval);
1370 if (symval.value == 0) {
1374 start = (void **)symval.value;
1376 /* get address of last entry */
1377 snprintf(setsym, len, "%s%s", "__stop_set_", name);
1378 error = link_elf_lookup_symbol(lf, setsym, &sym);
1381 link_elf_symbol_values(lf, sym, &symval);
1382 if (symval.value == 0) {
1386 stop = (void **)symval.value;
1388 /* and the number of entries */
1389 count = stop - start;
1400 free(setsym, M_LINKER);
1405 link_elf_each_function_name(linker_file_t file,
1406 int (*callback)(const char *, void *), void *opaque)
1408 elf_file_t ef = (elf_file_t)file;
1409 const Elf_Sym *symp;
1412 /* Exhaustive search */
1413 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1414 if (symp->st_value != 0 &&
1415 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1416 error = callback(ef->ddbstrtab + symp->st_name, opaque);
1425 link_elf_each_function_nameval(linker_file_t file,
1426 linker_function_nameval_callback_t callback, void *opaque)
1428 linker_symval_t symval;
1429 elf_file_t ef = (elf_file_t)file;
1430 const Elf_Sym* symp;
1433 /* Exhaustive search */
1434 for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
1435 if (symp->st_value != 0 &&
1436 ELF_ST_TYPE(symp->st_info) == STT_FUNC) {
1437 error = link_elf_symbol_values(file,
1438 (c_linker_sym_t) symp, &symval);
1441 error = callback(file, i, &symval, opaque);
1451 * Each KLD has its own GP. The GP value for each load module is given by
1452 * DT_PLTGOT on ia64. We need GP to construct function descriptors, but
1453 * don't have direct access to the ELF file structure. The link_elf_get_gp()
1454 * function returns the GP given a pointer to a generic linker file struct.
1457 link_elf_get_gp(linker_file_t lf)
1459 elf_file_t ef = (elf_file_t)lf;
1460 return ((Elf_Addr)ef->got);
1465 elf_get_sym(linker_file_t lf, Elf_Size symidx)
1467 elf_file_t ef = (elf_file_t)lf;
1469 if (symidx >= ef->nchains)
1471 return (ef->symtab + symidx);
1475 elf_get_symname(linker_file_t lf, Elf_Size symidx)
1477 elf_file_t ef = (elf_file_t)lf;
1480 if (symidx >= ef->nchains)
1482 sym = ef->symtab + symidx;
1483 return (ef->strtab + sym->st_name);
1487 * Symbol lookup function that can be used when the symbol index is known (ie
1488 * in relocations). It uses the symbol index instead of doing a fully fledged
1489 * hash table based lookup when such is valid. For example for local symbols.
1490 * This is not only more efficient, it's also more correct. It's not always
1491 * the case that the symbol can be found through the hash table.
1494 elf_lookup(linker_file_t lf, Elf_Size symidx, int deps, Elf_Addr *res)
1496 elf_file_t ef = (elf_file_t)lf;
1499 Elf_Addr addr, start, base;
1501 /* Don't even try to lookup the symbol if the index is bogus. */
1502 if (symidx >= ef->nchains) {
1507 sym = ef->symtab + symidx;
1510 * Don't do a full lookup when the symbol is local. It may even
1511 * fail because it may not be found through the hash table.
1513 if (ELF_ST_BIND(sym->st_info) == STB_LOCAL) {
1514 /* Force lookup failure when we have an insanity. */
1515 if (sym->st_shndx == SHN_UNDEF || sym->st_value == 0) {
1519 *res = ((Elf_Addr)ef->address + sym->st_value);
1524 * XXX we can avoid doing a hash table based lookup for global
1525 * symbols as well. This however is not always valid, so we'll
1526 * just do it the hard way for now. Performance tweaks can
1530 symbol = ef->strtab + sym->st_name;
1532 /* Force a lookup failure if the symbol name is bogus. */
1538 addr = ((Elf_Addr)linker_file_lookup_symbol(lf, symbol, deps));
1539 if (addr == 0 && ELF_ST_BIND(sym->st_info) != STB_WEAK) {
1544 if (elf_set_find(&set_pcpu_list, addr, &start, &base))
1545 addr = addr - start + base;
1547 else if (elf_set_find(&set_vnet_list, addr, &start, &base))
1548 addr = addr - start + base;
1555 link_elf_reloc_local(linker_file_t lf)
1557 const Elf_Rel *rellim;
1559 const Elf_Rela *relalim;
1560 const Elf_Rela *rela;
1561 elf_file_t ef = (elf_file_t)lf;
1563 /* Perform relocations without addend if there are any: */
1564 if ((rel = ef->rel) != NULL) {
1565 rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
1566 while (rel < rellim) {
1567 elf_reloc_local(lf, (Elf_Addr)ef->address, rel,
1568 ELF_RELOC_REL, elf_lookup);
1573 /* Perform relocations with addend if there are any: */
1574 if ((rela = ef->rela) != NULL) {
1575 relalim = (const Elf_Rela *)
1576 ((const char *)ef->rela + ef->relasize);
1577 while (rela < relalim) {
1578 elf_reloc_local(lf, (Elf_Addr)ef->address, rela,
1579 ELF_RELOC_RELA, elf_lookup);
1586 link_elf_symtab_get(linker_file_t lf, const Elf_Sym **symtab)
1588 elf_file_t ef = (elf_file_t)lf;
1590 *symtab = ef->ddbsymtab;
1592 if (*symtab == NULL)
1595 return (ef->ddbsymcnt);
1599 link_elf_strtab_get(linker_file_t lf, caddr_t *strtab)
1601 elf_file_t ef = (elf_file_t)lf;
1603 *strtab = ef->ddbstrtab;
1605 if (*strtab == NULL)
1608 return (ef->ddbstrcnt);