1050 lines
26 KiB
C
1050 lines
26 KiB
C
/*-
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* Copyright (c) 1998-2000 Doug Rabson
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include "opt_ddb.h"
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/proc.h>
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#include <sys/namei.h>
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#include <sys/fcntl.h>
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#include <sys/vnode.h>
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#include <sys/linker.h>
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#include <machine/elf.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <sys/lock.h>
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#ifdef SPARSE_MAPPING
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#include <vm/vm_object.h>
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#include <vm/vm_kern.h>
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#include <vm/vm_extern.h>
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#endif
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#include <vm/pmap.h>
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#include <vm/vm_map.h>
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#include <link.h>
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#include "linker_if.h"
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typedef struct elf_file {
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struct linker_file lf; /* Common fields */
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int preloaded; /* Was file pre-loaded */
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caddr_t address; /* Relocation address */
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#ifdef SPARSE_MAPPING
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vm_object_t object; /* VM object to hold file pages */
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#endif
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Elf_Dyn* dynamic; /* Symbol table etc. */
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Elf_Off nbuckets; /* DT_HASH info */
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Elf_Off nchains;
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const Elf_Off* buckets;
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const Elf_Off* chains;
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caddr_t hash;
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caddr_t strtab; /* DT_STRTAB */
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int strsz; /* DT_STRSZ */
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const Elf_Sym* symtab; /* DT_SYMTAB */
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Elf_Addr* got; /* DT_PLTGOT */
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const Elf_Rel* pltrel; /* DT_JMPREL */
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int pltrelsize; /* DT_PLTRELSZ */
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const Elf_Rela* pltrela; /* DT_JMPREL */
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int pltrelasize; /* DT_PLTRELSZ */
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const Elf_Rel* rel; /* DT_REL */
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int relsize; /* DT_RELSZ */
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const Elf_Rela* rela; /* DT_RELA */
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int relasize; /* DT_RELASZ */
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caddr_t modptr;
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const Elf_Sym* ddbsymtab; /* The symbol table we are using */
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long ddbsymcnt; /* Number of symbols */
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caddr_t ddbstrtab; /* String table */
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long ddbstrcnt; /* number of bytes in string table */
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caddr_t symbase; /* malloc'ed symbold base */
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caddr_t strbase; /* malloc'ed string base */
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#ifdef DDB
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struct link_map gdb; /* hooks for gdb */
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#endif
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} *elf_file_t;
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static int link_elf_link_preload(linker_class_t cls,
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const char*, linker_file_t*);
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static int link_elf_link_preload_finish(linker_file_t);
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static int link_elf_load_file(linker_class_t, const char*, linker_file_t*);
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static int link_elf_lookup_symbol(linker_file_t, const char*,
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c_linker_sym_t*);
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static int link_elf_symbol_values(linker_file_t, c_linker_sym_t, linker_symval_t*);
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static int link_elf_search_symbol(linker_file_t, caddr_t value,
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c_linker_sym_t* sym, long* diffp);
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static void link_elf_unload_file(linker_file_t);
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static void link_elf_unload_preload(linker_file_t);
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static kobj_method_t link_elf_methods[] = {
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KOBJMETHOD(linker_lookup_symbol, link_elf_lookup_symbol),
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KOBJMETHOD(linker_symbol_values, link_elf_symbol_values),
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KOBJMETHOD(linker_search_symbol, link_elf_search_symbol),
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KOBJMETHOD(linker_unload, link_elf_unload_file),
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KOBJMETHOD(linker_load_file, link_elf_load_file),
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KOBJMETHOD(linker_link_preload, link_elf_link_preload),
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KOBJMETHOD(linker_link_preload_finish, link_elf_link_preload_finish),
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{ 0, 0 }
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};
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static struct linker_class link_elf_class = {
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#if ELF_TARG_CLASS == ELFCLASS32
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"elf32",
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#else
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"elf64",
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#endif
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link_elf_methods, sizeof(struct elf_file)
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};
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static int parse_dynamic(elf_file_t ef);
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static int relocate_file(elf_file_t ef);
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static int link_elf_preload_parse_symbols(elf_file_t ef);
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#ifdef DDB
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/*
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* A list of loaded modules for GDB to use for loading symbols.
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*/
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struct r_debug r_debug;
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#define GDB_STATE(s) r_debug.r_state = s; r_debug_state();
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/*
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* Function for the debugger to set a breakpoint on to gain control.
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*/
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void
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r_debug_state(void)
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{
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}
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#endif
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/*
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* The kernel symbol table starts here.
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*/
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extern struct _dynamic _DYNAMIC;
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static void
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link_elf_init(void* arg)
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{
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#ifdef __ELF__
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Elf_Dyn *dp;
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caddr_t modptr, baseptr, sizeptr;
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elf_file_t ef;
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char *modname;
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#endif
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linker_add_class(&link_elf_class);
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#ifdef __ELF__
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dp = (Elf_Dyn*) &_DYNAMIC;
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if (dp) {
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modname = NULL;
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modptr = preload_search_by_type("elf kernel");
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if (modptr)
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modname = (char *)preload_search_info(modptr, MODINFO_NAME);
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if (modname == NULL)
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modname = "kernel";
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linker_kernel_file = linker_make_file(modname, &link_elf_class);
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if (linker_kernel_file == NULL)
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panic("link_elf_init: Can't create linker structures for kernel");
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ef = (elf_file_t) linker_kernel_file;
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ef->preloaded = 1;
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ef->address = 0;
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#ifdef SPARSE_MAPPING
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ef->object = 0;
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#endif
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ef->dynamic = dp;
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parse_dynamic(ef);
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linker_kernel_file->address = (caddr_t) KERNBASE;
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linker_kernel_file->size = -(intptr_t)linker_kernel_file->address;
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if (modptr) {
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ef->modptr = modptr;
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baseptr = preload_search_info(modptr, MODINFO_ADDR);
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if (baseptr)
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linker_kernel_file->address = *(caddr_t *)baseptr;
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sizeptr = preload_search_info(modptr, MODINFO_SIZE);
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if (sizeptr)
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linker_kernel_file->size = *(size_t *)sizeptr;
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}
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(void)link_elf_preload_parse_symbols(ef);
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#ifdef DDB
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ef->gdb.l_addr = linker_kernel_file->address;
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ef->gdb.l_name = modname;
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ef->gdb.l_ld = dp;
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ef->gdb.l_prev = 0;
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ef->gdb.l_next = 0;
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r_debug.r_map = &ef->gdb;
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r_debug.r_brk = r_debug_state;
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r_debug.r_state = RT_CONSISTENT;
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r_debug_state(); /* say hello to gdb! */
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#endif
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}
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#endif
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}
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SYSINIT(link_elf, SI_SUB_KLD, SI_ORDER_SECOND, link_elf_init, 0);
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static int
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link_elf_preload_parse_symbols(elf_file_t ef)
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{
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caddr_t pointer;
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caddr_t ssym, esym, base;
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caddr_t strtab;
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int strcnt;
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Elf_Sym* symtab;
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int symcnt;
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if (ef->modptr == NULL)
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return 0;
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pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_SSYM);
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if (pointer == NULL)
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return 0;
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ssym = *(caddr_t *)pointer;
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pointer = preload_search_info(ef->modptr, MODINFO_METADATA|MODINFOMD_ESYM);
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if (pointer == NULL)
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return 0;
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esym = *(caddr_t *)pointer;
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base = ssym;
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symcnt = *(long *)base;
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base += sizeof(long);
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symtab = (Elf_Sym *)base;
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base += roundup(symcnt, sizeof(long));
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if (base > esym || base < ssym) {
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printf("Symbols are corrupt!\n");
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return EINVAL;
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}
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strcnt = *(long *)base;
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base += sizeof(long);
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strtab = base;
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base += roundup(strcnt, sizeof(long));
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if (base > esym || base < ssym) {
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printf("Symbols are corrupt!\n");
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return EINVAL;
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}
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ef->ddbsymtab = symtab;
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ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
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ef->ddbstrtab = strtab;
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ef->ddbstrcnt = strcnt;
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return 0;
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}
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static int
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parse_dynamic(elf_file_t ef)
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{
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Elf_Dyn *dp;
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int plttype = DT_REL;
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for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
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switch (dp->d_tag) {
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case DT_HASH:
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{
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/* From src/libexec/rtld-elf/rtld.c */
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const Elf_Off *hashtab = (const Elf_Off *)
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(ef->address + dp->d_un.d_ptr);
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ef->nbuckets = hashtab[0];
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ef->nchains = hashtab[1];
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ef->buckets = hashtab + 2;
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ef->chains = ef->buckets + ef->nbuckets;
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break;
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}
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case DT_STRTAB:
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ef->strtab = (caddr_t) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_STRSZ:
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ef->strsz = dp->d_un.d_val;
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break;
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case DT_SYMTAB:
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ef->symtab = (Elf_Sym*) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_SYMENT:
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if (dp->d_un.d_val != sizeof(Elf_Sym))
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return ENOEXEC;
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break;
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case DT_PLTGOT:
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ef->got = (Elf_Addr *) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_REL:
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ef->rel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_RELSZ:
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ef->relsize = dp->d_un.d_val;
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break;
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case DT_RELENT:
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if (dp->d_un.d_val != sizeof(Elf_Rel))
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return ENOEXEC;
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break;
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case DT_JMPREL:
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ef->pltrel = (const Elf_Rel *) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_PLTRELSZ:
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ef->pltrelsize = dp->d_un.d_val;
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break;
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case DT_RELA:
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ef->rela = (const Elf_Rela *) (ef->address + dp->d_un.d_ptr);
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break;
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case DT_RELASZ:
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ef->relasize = dp->d_un.d_val;
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break;
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case DT_RELAENT:
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if (dp->d_un.d_val != sizeof(Elf_Rela))
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return ENOEXEC;
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break;
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case DT_PLTREL:
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plttype = dp->d_un.d_val;
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if (plttype != DT_REL && plttype != DT_RELA)
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return ENOEXEC;
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break;
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#ifdef DDB
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case DT_DEBUG:
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dp->d_un.d_ptr = (Elf_Addr) &r_debug;
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break;
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#endif
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}
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}
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if (plttype == DT_RELA) {
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ef->pltrela = (const Elf_Rela *) ef->pltrel;
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ef->pltrel = NULL;
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ef->pltrelasize = ef->pltrelsize;
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ef->pltrelsize = 0;
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}
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ef->ddbsymtab = ef->symtab;
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ef->ddbsymcnt = ef->nchains;
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ef->ddbstrtab = ef->strtab;
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ef->ddbstrcnt = ef->strsz;
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return 0;
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}
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static void
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link_elf_error(const char *s)
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{
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printf("kldload: %s\n", s);
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}
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#ifdef DDB
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static void
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link_elf_add_gdb(struct link_map *l)
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{
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struct link_map *prev;
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/*
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* Scan to the end of the list.
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*/
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for (prev = r_debug.r_map; prev->l_next != NULL; prev = prev->l_next)
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;
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/* Link in the new entry. */
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l->l_prev = prev;
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l->l_next = prev->l_next;
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prev->l_next = l;
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}
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static void
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link_elf_delete_gdb(struct link_map *l)
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{
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if (l->l_prev == NULL) {
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if ((r_debug.r_map = l->l_next) != NULL)
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l->l_next->l_prev = NULL;
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return;
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}
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if ((l->l_prev->l_next = l->l_next) != NULL)
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l->l_next->l_prev = l->l_prev;
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}
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#endif /* DDB */
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static int
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link_elf_link_preload(linker_class_t cls,
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const char* filename, linker_file_t *result)
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{
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caddr_t modptr, baseptr, sizeptr, dynptr;
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char *type;
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elf_file_t ef;
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linker_file_t lf;
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int error;
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vm_offset_t dp;
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/* Look to see if we have the file preloaded */
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modptr = preload_search_by_name(filename);
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if (modptr == NULL)
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return ENOENT;
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type = (char *)preload_search_info(modptr, MODINFO_TYPE);
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baseptr = preload_search_info(modptr, MODINFO_ADDR);
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sizeptr = preload_search_info(modptr, MODINFO_SIZE);
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dynptr = preload_search_info(modptr, MODINFO_METADATA|MODINFOMD_DYNAMIC);
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if (type == NULL || strcmp(type, "elf module") != 0)
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return (EFTYPE);
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if (baseptr == NULL || sizeptr == NULL || dynptr == NULL)
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return (EINVAL);
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lf = linker_make_file(filename, &link_elf_class);
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if (lf == NULL) {
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return ENOMEM;
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}
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ef = (elf_file_t) lf;
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ef->preloaded = 1;
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ef->modptr = modptr;
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ef->address = *(caddr_t *)baseptr;
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#ifdef SPARSE_MAPPING
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ef->object = 0;
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#endif
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dp = (vm_offset_t)ef->address + *(vm_offset_t *)dynptr;
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ef->dynamic = (Elf_Dyn *)dp;
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lf->address = ef->address;
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lf->size = *(size_t *)sizeptr;
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error = parse_dynamic(ef);
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if (error) {
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linker_file_unload(lf);
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return error;
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}
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*result = lf;
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return (0);
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}
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|
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static int
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link_elf_link_preload_finish(linker_file_t lf)
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{
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elf_file_t ef;
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int error;
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ef = (elf_file_t) lf;
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#if 0 /* this will be more trouble than it's worth for now */
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for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
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if (dp->d_tag != DT_NEEDED)
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continue;
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modname = ef->strtab + dp->d_un.d_val;
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error = linker_load_module(modname, lf);
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if (error)
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goto out;
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}
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#endif
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error = relocate_file(ef);
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if (error)
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return error;
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(void)link_elf_preload_parse_symbols(ef);
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#ifdef DDB
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GDB_STATE(RT_ADD);
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ef->gdb.l_addr = lf->address;
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ef->gdb.l_name = lf->filename;
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ef->gdb.l_ld = ef->dynamic;
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link_elf_add_gdb(&ef->gdb);
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GDB_STATE(RT_CONSISTENT);
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#endif
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return (0);
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}
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static int
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link_elf_load_file(linker_class_t cls, const char* filename, linker_file_t* result)
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{
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struct nameidata nd;
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struct proc* p = curproc; /* XXX */
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Elf_Ehdr *hdr;
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caddr_t firstpage;
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int nbytes, i;
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Elf_Phdr *phdr;
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Elf_Phdr *phlimit;
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Elf_Phdr *segs[2];
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int nsegs;
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Elf_Phdr *phdyn;
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Elf_Phdr *phphdr;
|
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caddr_t mapbase;
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size_t mapsize;
|
|
Elf_Off base_offset;
|
|
Elf_Addr base_vaddr;
|
|
Elf_Addr base_vlimit;
|
|
int error = 0;
|
|
int resid;
|
|
elf_file_t ef;
|
|
linker_file_t lf;
|
|
Elf_Shdr *shdr;
|
|
int symtabindex;
|
|
int symstrindex;
|
|
int symcnt;
|
|
int strcnt;
|
|
|
|
shdr = NULL;
|
|
lf = NULL;
|
|
|
|
NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, filename, p);
|
|
error = vn_open(&nd, FREAD, 0);
|
|
if (error)
|
|
return error;
|
|
NDFREE(&nd, NDF_ONLY_PNBUF);
|
|
|
|
/*
|
|
* Read the elf header from the file.
|
|
*/
|
|
firstpage = malloc(PAGE_SIZE, M_LINKER, M_WAITOK);
|
|
if (firstpage == NULL) {
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
hdr = (Elf_Ehdr *)firstpage;
|
|
error = vn_rdwr(UIO_READ, nd.ni_vp, firstpage, PAGE_SIZE, 0,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
nbytes = PAGE_SIZE - resid;
|
|
if (error)
|
|
goto out;
|
|
|
|
if (!IS_ELF(*hdr)) {
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
|
|
if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS
|
|
|| hdr->e_ident[EI_DATA] != ELF_TARG_DATA) {
|
|
link_elf_error("Unsupported file layout");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
if (hdr->e_ident[EI_VERSION] != EV_CURRENT
|
|
|| hdr->e_version != EV_CURRENT) {
|
|
link_elf_error("Unsupported file version");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN) {
|
|
link_elf_error("Unsupported file type");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
if (hdr->e_machine != ELF_TARG_MACH) {
|
|
link_elf_error("Unsupported machine");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* We rely on the program header being in the first page. This is
|
|
* not strictly required by the ABI specification, but it seems to
|
|
* always true in practice. And, it simplifies things considerably.
|
|
*/
|
|
if (!((hdr->e_phentsize == sizeof(Elf_Phdr)) &&
|
|
(hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= PAGE_SIZE) &&
|
|
(hdr->e_phoff + hdr->e_phnum*sizeof(Elf_Phdr) <= nbytes)))
|
|
link_elf_error("Unreadable program headers");
|
|
|
|
/*
|
|
* Scan the program header entries, and save key information.
|
|
*
|
|
* We rely on there being exactly two load segments, text and data,
|
|
* in that order.
|
|
*/
|
|
phdr = (Elf_Phdr *) (firstpage + hdr->e_phoff);
|
|
phlimit = phdr + hdr->e_phnum;
|
|
nsegs = 0;
|
|
phdyn = NULL;
|
|
phphdr = NULL;
|
|
while (phdr < phlimit) {
|
|
switch (phdr->p_type) {
|
|
|
|
case PT_LOAD:
|
|
if (nsegs == 2) {
|
|
link_elf_error("Too many sections");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
segs[nsegs] = phdr;
|
|
++nsegs;
|
|
break;
|
|
|
|
case PT_PHDR:
|
|
phphdr = phdr;
|
|
break;
|
|
|
|
case PT_DYNAMIC:
|
|
phdyn = phdr;
|
|
break;
|
|
}
|
|
|
|
++phdr;
|
|
}
|
|
if (phdyn == NULL) {
|
|
link_elf_error("Object is not dynamically-linked");
|
|
error = ENOEXEC;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Allocate the entire address space of the object, to stake out our
|
|
* contiguous region, and to establish the base address for relocation.
|
|
*/
|
|
base_offset = trunc_page(segs[0]->p_offset);
|
|
base_vaddr = trunc_page(segs[0]->p_vaddr);
|
|
base_vlimit = round_page(segs[1]->p_vaddr + segs[1]->p_memsz);
|
|
mapsize = base_vlimit - base_vaddr;
|
|
|
|
lf = linker_make_file(filename, &link_elf_class);
|
|
if (!lf) {
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ef = (elf_file_t) lf;
|
|
#ifdef SPARSE_MAPPING
|
|
ef->object = vm_object_allocate(OBJT_DEFAULT, mapsize >> PAGE_SHIFT);
|
|
if (ef->object == NULL) {
|
|
free(ef, M_LINKER);
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
vm_object_reference(ef->object);
|
|
ef->address = (caddr_t) vm_map_min(kernel_map);
|
|
error = vm_map_find(kernel_map, ef->object, 0,
|
|
(vm_offset_t *) &ef->address,
|
|
mapsize, 1,
|
|
VM_PROT_ALL, VM_PROT_ALL, 0);
|
|
if (error) {
|
|
vm_object_deallocate(ef->object);
|
|
ef->object = 0;
|
|
goto out;
|
|
}
|
|
#else
|
|
ef->address = malloc(mapsize, M_LINKER, M_WAITOK);
|
|
if (!ef->address) {
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
#endif
|
|
mapbase = ef->address;
|
|
|
|
/*
|
|
* Read the text and data sections and zero the bss.
|
|
*/
|
|
for (i = 0; i < 2; i++) {
|
|
caddr_t segbase = mapbase + segs[i]->p_vaddr - base_vaddr;
|
|
error = vn_rdwr(UIO_READ, nd.ni_vp,
|
|
segbase, segs[i]->p_filesz, segs[i]->p_offset,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
if (error) {
|
|
goto out;
|
|
}
|
|
bzero(segbase + segs[i]->p_filesz,
|
|
segs[i]->p_memsz - segs[i]->p_filesz);
|
|
|
|
#ifdef SPARSE_MAPPING
|
|
/*
|
|
* Wire down the pages
|
|
*/
|
|
vm_map_pageable(kernel_map,
|
|
(vm_offset_t) segbase,
|
|
(vm_offset_t) segbase + segs[i]->p_memsz,
|
|
FALSE);
|
|
#endif
|
|
}
|
|
|
|
ef->dynamic = (Elf_Dyn *) (mapbase + phdyn->p_vaddr - base_vaddr);
|
|
|
|
lf->address = ef->address;
|
|
lf->size = mapsize;
|
|
|
|
error = parse_dynamic(ef);
|
|
if (error)
|
|
goto out;
|
|
error = linker_load_dependancies(lf);
|
|
if (error)
|
|
goto out;
|
|
#if 0 /* this will be more trouble than it's worth for now */
|
|
for (dp = ef->dynamic; dp->d_tag != DT_NULL; dp++) {
|
|
if (dp->d_tag != DT_NEEDED)
|
|
continue;
|
|
modname = ef->strtab + dp->d_un.d_val;
|
|
error = linker_load_module(modname, lf);
|
|
if (error)
|
|
goto out;
|
|
}
|
|
#endif
|
|
error = relocate_file(ef);
|
|
if (error)
|
|
goto out;
|
|
|
|
/* Try and load the symbol table if it's present. (you can strip it!) */
|
|
nbytes = hdr->e_shnum * hdr->e_shentsize;
|
|
if (nbytes == 0 || hdr->e_shoff == 0)
|
|
goto nosyms;
|
|
shdr = malloc(nbytes, M_LINKER, M_WAITOK);
|
|
if (shdr == NULL) {
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
bzero(shdr, nbytes);
|
|
error = vn_rdwr(UIO_READ, nd.ni_vp,
|
|
(caddr_t)shdr, nbytes, hdr->e_shoff,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
if (error)
|
|
goto out;
|
|
symtabindex = -1;
|
|
symstrindex = -1;
|
|
for (i = 0; i < hdr->e_shnum; i++) {
|
|
if (shdr[i].sh_type == SHT_SYMTAB) {
|
|
symtabindex = i;
|
|
symstrindex = shdr[i].sh_link;
|
|
}
|
|
}
|
|
if (symtabindex < 0 || symstrindex < 0)
|
|
goto nosyms;
|
|
|
|
symcnt = shdr[symtabindex].sh_size;
|
|
ef->symbase = malloc(symcnt, M_LINKER, M_WAITOK);
|
|
strcnt = shdr[symstrindex].sh_size;
|
|
ef->strbase = malloc(strcnt, M_LINKER, M_WAITOK);
|
|
|
|
if (ef->symbase == NULL || ef->strbase == NULL) {
|
|
error = ENOMEM;
|
|
goto out;
|
|
}
|
|
error = vn_rdwr(UIO_READ, nd.ni_vp,
|
|
ef->symbase, symcnt, shdr[symtabindex].sh_offset,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
if (error)
|
|
goto out;
|
|
error = vn_rdwr(UIO_READ, nd.ni_vp,
|
|
ef->strbase, strcnt, shdr[symstrindex].sh_offset,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
if (error)
|
|
goto out;
|
|
|
|
ef->ddbsymcnt = symcnt / sizeof(Elf_Sym);
|
|
ef->ddbsymtab = (const Elf_Sym *)ef->symbase;
|
|
ef->ddbstrcnt = strcnt;
|
|
ef->ddbstrtab = ef->strbase;
|
|
|
|
#ifdef DDB
|
|
GDB_STATE(RT_ADD);
|
|
ef->gdb.l_addr = lf->address;
|
|
ef->gdb.l_name = filename;
|
|
ef->gdb.l_ld = ef->dynamic;
|
|
link_elf_add_gdb(&ef->gdb);
|
|
GDB_STATE(RT_CONSISTENT);
|
|
#endif
|
|
|
|
nosyms:
|
|
|
|
*result = lf;
|
|
|
|
out:
|
|
if (error && lf)
|
|
linker_file_unload(lf);
|
|
if (shdr)
|
|
free(shdr, M_LINKER);
|
|
if (firstpage)
|
|
free(firstpage, M_LINKER);
|
|
VOP_UNLOCK(nd.ni_vp, 0, p);
|
|
vn_close(nd.ni_vp, FREAD, p->p_ucred, p);
|
|
|
|
return error;
|
|
}
|
|
|
|
static void
|
|
link_elf_unload_file(linker_file_t file)
|
|
{
|
|
elf_file_t ef = (elf_file_t) file;
|
|
|
|
#ifdef DDB
|
|
if (ef->gdb.l_ld) {
|
|
GDB_STATE(RT_DELETE);
|
|
link_elf_delete_gdb(&ef->gdb);
|
|
GDB_STATE(RT_CONSISTENT);
|
|
}
|
|
#endif
|
|
|
|
if (ef->preloaded) {
|
|
link_elf_unload_preload(file);
|
|
return;
|
|
}
|
|
#ifdef SPARSE_MAPPING
|
|
if (ef->object) {
|
|
vm_map_remove(kernel_map, (vm_offset_t) ef->address,
|
|
(vm_offset_t) ef->address
|
|
+ (ef->object->size << PAGE_SHIFT));
|
|
vm_object_deallocate(ef->object);
|
|
}
|
|
#else
|
|
if (ef->address)
|
|
free(ef->address, M_LINKER);
|
|
#endif
|
|
if (ef->symbase)
|
|
free(ef->symbase, M_LINKER);
|
|
if (ef->strbase)
|
|
free(ef->strbase, M_LINKER);
|
|
}
|
|
|
|
static void
|
|
link_elf_unload_preload(linker_file_t file)
|
|
{
|
|
if (file->filename)
|
|
preload_delete_name(file->filename);
|
|
}
|
|
|
|
static const char *
|
|
symbol_name(elf_file_t ef, Elf_Word r_info)
|
|
{
|
|
const Elf_Sym *ref;
|
|
|
|
if (ELF_R_SYM(r_info)) {
|
|
ref = ef->symtab + ELF_R_SYM(r_info);
|
|
return ef->strtab + ref->st_name;
|
|
} else
|
|
return NULL;
|
|
}
|
|
|
|
static int
|
|
relocate_file(elf_file_t ef)
|
|
{
|
|
const Elf_Rel *rellim;
|
|
const Elf_Rel *rel;
|
|
const Elf_Rela *relalim;
|
|
const Elf_Rela *rela;
|
|
const char *symname;
|
|
|
|
/* Perform relocations without addend if there are any: */
|
|
rel = ef->rel;
|
|
if (rel) {
|
|
rellim = (const Elf_Rel *)((const char *)ef->rel + ef->relsize);
|
|
while (rel < rellim) {
|
|
symname = symbol_name(ef, rel->r_info);
|
|
if (elf_reloc(&ef->lf, rel, ELF_RELOC_REL, symname)) {
|
|
printf("link_elf: symbol %s undefined\n", symname);
|
|
return ENOENT;
|
|
}
|
|
rel++;
|
|
}
|
|
}
|
|
|
|
/* Perform relocations with addend if there are any: */
|
|
rela = ef->rela;
|
|
if (rela) {
|
|
relalim = (const Elf_Rela *)((const char *)ef->rela + ef->relasize);
|
|
while (rela < relalim) {
|
|
symname = symbol_name(ef, rela->r_info);
|
|
if (elf_reloc(&ef->lf, rela, ELF_RELOC_RELA, symname)) {
|
|
printf("link_elf: symbol %s undefined\n", symname);
|
|
return ENOENT;
|
|
}
|
|
rela++;
|
|
}
|
|
}
|
|
|
|
/* Perform PLT relocations without addend if there are any: */
|
|
rel = ef->pltrel;
|
|
if (rel) {
|
|
rellim = (const Elf_Rel *)((const char *)ef->pltrel + ef->pltrelsize);
|
|
while (rel < rellim) {
|
|
symname = symbol_name(ef, rel->r_info);
|
|
if (elf_reloc(&ef->lf, rel, ELF_RELOC_REL, symname)) {
|
|
printf("link_elf: symbol %s undefined\n", symname);
|
|
return ENOENT;
|
|
}
|
|
rel++;
|
|
}
|
|
}
|
|
|
|
/* Perform relocations with addend if there are any: */
|
|
rela = ef->pltrela;
|
|
if (rela) {
|
|
relalim = (const Elf_Rela *)((const char *)ef->pltrela + ef->pltrelasize);
|
|
while (rela < relalim) {
|
|
symname = symbol_name(ef, rela->r_info);
|
|
if (elf_reloc(&ef->lf, rela, ELF_RELOC_RELA, symname)) {
|
|
printf("link_elf: symbol %s undefined\n", symname);
|
|
return ENOENT;
|
|
}
|
|
rela++;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Hash function for symbol table lookup. Don't even think about changing
|
|
* this. It is specified by the System V ABI.
|
|
*/
|
|
static unsigned long
|
|
elf_hash(const char *name)
|
|
{
|
|
const unsigned char *p = (const unsigned char *) name;
|
|
unsigned long h = 0;
|
|
unsigned long g;
|
|
|
|
while (*p != '\0') {
|
|
h = (h << 4) + *p++;
|
|
if ((g = h & 0xf0000000) != 0)
|
|
h ^= g >> 24;
|
|
h &= ~g;
|
|
}
|
|
return h;
|
|
}
|
|
|
|
int
|
|
link_elf_lookup_symbol(linker_file_t lf, const char* name, c_linker_sym_t* sym)
|
|
{
|
|
elf_file_t ef = (elf_file_t) lf;
|
|
unsigned long symnum;
|
|
const Elf_Sym* symp;
|
|
const char *strp;
|
|
unsigned long hash;
|
|
int i;
|
|
|
|
/* First, search hashed global symbols */
|
|
hash = elf_hash(name);
|
|
symnum = ef->buckets[hash % ef->nbuckets];
|
|
|
|
while (symnum != STN_UNDEF) {
|
|
if (symnum >= ef->nchains) {
|
|
printf("link_elf_lookup_symbol: corrupt symbol table\n");
|
|
return ENOENT;
|
|
}
|
|
|
|
symp = ef->symtab + symnum;
|
|
if (symp->st_name == 0) {
|
|
printf("link_elf_lookup_symbol: corrupt symbol table\n");
|
|
return ENOENT;
|
|
}
|
|
|
|
strp = ef->strtab + symp->st_name;
|
|
|
|
if (strcmp(name, strp) == 0) {
|
|
if (symp->st_shndx != SHN_UNDEF ||
|
|
(symp->st_value != 0 &&
|
|
ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
|
|
*sym = (c_linker_sym_t) symp;
|
|
return 0;
|
|
} else
|
|
return ENOENT;
|
|
}
|
|
|
|
symnum = ef->chains[symnum];
|
|
}
|
|
|
|
/* If we have not found it, look at the full table (if loaded) */
|
|
if (ef->symtab == ef->ddbsymtab)
|
|
return ENOENT;
|
|
|
|
/* Exhaustive search */
|
|
for (i = 0, symp = ef->ddbsymtab; i < ef->ddbsymcnt; i++, symp++) {
|
|
strp = ef->ddbstrtab + symp->st_name;
|
|
if (strcmp(name, strp) == 0) {
|
|
if (symp->st_shndx != SHN_UNDEF ||
|
|
(symp->st_value != 0 &&
|
|
ELF_ST_TYPE(symp->st_info) == STT_FUNC)) {
|
|
*sym = (c_linker_sym_t) symp;
|
|
return 0;
|
|
} else
|
|
return ENOENT;
|
|
}
|
|
}
|
|
|
|
return ENOENT;
|
|
}
|
|
|
|
static int
|
|
link_elf_symbol_values(linker_file_t lf, c_linker_sym_t sym, linker_symval_t* symval)
|
|
{
|
|
elf_file_t ef = (elf_file_t) lf;
|
|
const Elf_Sym* es = (const Elf_Sym*) sym;
|
|
|
|
if (es >= ef->symtab && ((es - ef->symtab) < ef->nchains)) {
|
|
symval->name = ef->strtab + es->st_name;
|
|
symval->value = (caddr_t) ef->address + es->st_value;
|
|
symval->size = es->st_size;
|
|
return 0;
|
|
}
|
|
if (ef->symtab == ef->ddbsymtab)
|
|
return ENOENT;
|
|
if (es >= ef->ddbsymtab && ((es - ef->ddbsymtab) < ef->ddbsymcnt)) {
|
|
symval->name = ef->ddbstrtab + es->st_name;
|
|
symval->value = (caddr_t) ef->address + es->st_value;
|
|
symval->size = es->st_size;
|
|
return 0;
|
|
}
|
|
return ENOENT;
|
|
}
|
|
|
|
static int
|
|
link_elf_search_symbol(linker_file_t lf, caddr_t value,
|
|
c_linker_sym_t* sym, long* diffp)
|
|
{
|
|
elf_file_t ef = (elf_file_t) lf;
|
|
u_long off = (uintptr_t) (void *) value;
|
|
u_long diff = off;
|
|
u_long st_value;
|
|
const Elf_Sym* es;
|
|
const Elf_Sym* best = 0;
|
|
int i;
|
|
|
|
for (i = 0, es = ef->ddbsymtab; i < ef->ddbsymcnt; i++, es++) {
|
|
if (es->st_name == 0)
|
|
continue;
|
|
st_value = es->st_value + (uintptr_t) (void *) ef->address;
|
|
if (off >= st_value) {
|
|
if (off - st_value < diff) {
|
|
diff = off - st_value;
|
|
best = es;
|
|
if (diff == 0)
|
|
break;
|
|
} else if (off - st_value == diff) {
|
|
best = es;
|
|
}
|
|
}
|
|
}
|
|
if (best == 0)
|
|
*diffp = off;
|
|
else
|
|
*diffp = diff;
|
|
*sym = (c_linker_sym_t) best;
|
|
|
|
return 0;
|
|
}
|