1/* $NetBSD: lookup_elf32.c,v 1.2 2010/02/10 23:33:56 martin Exp $ */ 2 3/*- 4 * Copyright (c) 2010 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Martin Husemann. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32/* If not included by lookup_elf64.c, ELFSIZE won't be defined. */ 33#ifndef ELFSIZE 34#define ELFSIZE 32 35#endif 36 37#include <lib/libkern/libkern.h> 38#include <sys/param.h> 39#include <sys/exec_elf.h> 40 41#if ((ELFSIZE == 32) && defined(BOOT_ELF32)) || \ 42 ((ELFSIZE == 64) && defined(BOOT_ELF64)) 43 44void * ELFNAMEEND(lookup_symbol)(const char *, void *, void *); 45 46void * 47ELFNAMEEND(lookup_symbol)(const char *symname, void *sstab, void *estab) 48{ 49 Elf_Ehdr *elf; 50 Elf_Shdr *shp; 51 Elf_Sym *symtab_start, *symtab_end, *sp; 52 char *strtab_start, *strtab_end; 53 int i, j; 54 55 elf = sstab; 56 if (elf->e_shoff == 0) 57 return NULL; 58 59 switch (elf->e_machine) { 60 ELFDEFNNAME(MACHDEP_ID_CASES) 61 default: 62 return NULL; 63 } 64 65 symtab_start = symtab_end = NULL; 66 strtab_start = strtab_end = NULL; 67 68 shp = (Elf_Shdr *)((char *)sstab + elf->e_shoff); 69 for (i = 0; i < elf->e_shnum; i++) { 70 if (shp[i].sh_type != SHT_SYMTAB) 71 continue; 72 if (shp[i].sh_offset == 0) 73 continue; 74 symtab_start = (Elf_Sym*)((char*)sstab + shp[i].sh_offset); 75 symtab_end = (Elf_Sym*)((char*)sstab + shp[i].sh_offset 76 + shp[i].sh_size); 77 j = shp[i].sh_link; 78 if (shp[j].sh_offset == 0) 79 continue; 80 strtab_start = (char*)sstab + shp[j].sh_offset; 81 strtab_end = (char*)sstab + shp[j].sh_offset + shp[j].sh_size; 82 break; 83 } 84 85 if (!symtab_start || !strtab_start) 86 return NULL; 87 88 for (sp = symtab_start; sp < symtab_end; sp++) 89 if (sp->st_name != 0 && 90 strcmp(strtab_start + sp->st_name, symname) == 0) 91 return (void*)(uintptr_t)sp->st_value; 92 93 return NULL; 94} 95 96#endif /* (ELFSIZE == 32 && BOOT_ELF32) || (ELFSIZE == 64 && BOOT_ELF64) */ 97