1 /* Common definitions for handling files in memory or only on disk. 2 Copyright (C) 1998, 1999, 2000, 2002, 2005, 2008 Red Hat, Inc. 3 This file is part of Red Hat elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 1998. 5 6 Red Hat elfutils is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by the 8 Free Software Foundation; version 2 of the License. 9 10 Red Hat elfutils is distributed in the hope that it will be useful, but 11 WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 General Public License for more details. 14 15 You should have received a copy of the GNU General Public License along 16 with Red Hat elfutils; if not, write to the Free Software Foundation, 17 Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. 18 19 In addition, as a special exception, Red Hat, Inc. gives You the 20 additional right to link the code of Red Hat elfutils with code licensed 21 under any Open Source Initiative certified open source license 22 (http://www.opensource.org/licenses/index.php) which requires the 23 distribution of source code with any binary distribution and to 24 distribute linked combinations of the two. Non-GPL Code permitted under 25 this exception must only link to the code of Red Hat elfutils through 26 those well defined interfaces identified in the file named EXCEPTION 27 found in the source code files (the "Approved Interfaces"). The files 28 of Non-GPL Code may instantiate templates or use macros or inline 29 functions from the Approved Interfaces without causing the resulting 30 work to be covered by the GNU General Public License. Only Red Hat, 31 Inc. may make changes or additions to the list of Approved Interfaces. 32 Red Hat's grant of this exception is conditioned upon your not adding 33 any new exceptions. If you wish to add a new Approved Interface or 34 exception, please contact Red Hat. You must obey the GNU General Public 35 License in all respects for all of the Red Hat elfutils code and other 36 code used in conjunction with Red Hat elfutils except the Non-GPL Code 37 covered by this exception. If you modify this file, you may extend this 38 exception to your version of the file, but you are not obligated to do 39 so. If you do not wish to provide this exception without modification, 40 you must delete this exception statement from your version and license 41 this file solely under the GPL without exception. 42 43 Red Hat elfutils is an included package of the Open Invention Network. 44 An included package of the Open Invention Network is a package for which 45 Open Invention Network licensees cross-license their patents. No patent 46 license is granted, either expressly or impliedly, by designation as an 47 included package. Should you wish to participate in the Open Invention 48 Network licensing program, please visit www.openinventionnetwork.com 49 <http://www.openinventionnetwork.com>. */ 50 51 #ifndef _COMMON_H 52 #define _COMMON_H 1 53 54 #include <ar.h> 55 #include <byteswap.h> 56 #include <endian.h> 57 #include <stdlib.h> 58 #include <string.h> 59 60 #include "libelfP.h" 61 62 static inline Elf_Kind 63 __attribute__ ((unused)) 64 determine_kind (void *buf, size_t len) 65 { 66 /* First test for an archive. */ 67 if (len >= SARMAG && memcmp (buf, ARMAG, SARMAG) == 0) 68 return ELF_K_AR; 69 70 /* Next try ELF files. */ 71 if (len >= EI_NIDENT && memcmp (buf, ELFMAG, SELFMAG) == 0) 72 { 73 /* Could be an ELF file. */ 74 int eclass = (int) ((unsigned char *) buf)[EI_CLASS]; 75 int data = (int) ((unsigned char *) buf)[EI_DATA]; 76 int version = (int) ((unsigned char *) buf)[EI_VERSION]; 77 78 if (eclass > ELFCLASSNONE && eclass < ELFCLASSNUM 79 && data > ELFDATANONE && data < ELFDATANUM 80 && version > EV_NONE && version < EV_NUM) 81 return ELF_K_ELF; 82 } 83 84 /* We do not know this file type. */ 85 return ELF_K_NONE; 86 } 87 88 89 /* Allocate an Elf descriptor and fill in the generic information. */ 90 static inline Elf * 91 __attribute__ ((unused)) 92 allocate_elf (int fildes, void *map_address, off_t offset, size_t maxsize, 93 Elf_Cmd cmd, Elf *parent, Elf_Kind kind, size_t extra) 94 { 95 Elf *result = (Elf *) calloc (1, sizeof (Elf) + extra); 96 if (result == NULL) 97 __libelf_seterrno (ELF_E_NOMEM); 98 else 99 { 100 result->kind = kind; 101 result->ref_count = 1; 102 result->cmd = cmd; 103 result->fildes = fildes; 104 result->start_offset = offset; 105 result->maximum_size = maxsize; 106 result->map_address = map_address; 107 result->parent = parent; 108 109 rwlock_init (result->lock); 110 } 111 112 return result; 113 } 114 115 116 /* Acquire lock for the descriptor and all children. */ 117 static void 118 __attribute__ ((unused)) 119 libelf_acquire_all (Elf *elf) 120 { 121 rwlock_wrlock (elf->lock); 122 123 if (elf->kind == ELF_K_AR) 124 { 125 Elf *child = elf->state.ar.children; 126 127 while (child != NULL) 128 { 129 if (child->ref_count != 0) 130 libelf_acquire_all (child); 131 child = child->next; 132 } 133 } 134 } 135 136 /* Release own lock and those of the children. */ 137 static void 138 __attribute__ ((unused)) 139 libelf_release_all (Elf *elf) 140 { 141 if (elf->kind == ELF_K_AR) 142 { 143 Elf *child = elf->state.ar.children; 144 145 while (child != NULL) 146 { 147 if (child->ref_count != 0) 148 libelf_release_all (child); 149 child = child->next; 150 } 151 } 152 153 rwlock_unlock (elf->lock); 154 } 155 156 157 /* Macro to convert endianess in place. It determines the function it 158 has to use itself. */ 159 #define CONVERT(Var) \ 160 (Var) = (sizeof (Var) == 1 \ 161 ? (unsigned char) (Var) \ 162 : (sizeof (Var) == 2 \ 163 ? bswap_16 (Var) \ 164 : (sizeof (Var) == 4 \ 165 ? bswap_32 (Var) \ 166 : bswap_64 (Var)))) 167 168 #define CONVERT_TO(Dst, Var) \ 169 (Dst) = (sizeof (Var) == 1 \ 170 ? (unsigned char) (Var) \ 171 : (sizeof (Var) == 2 \ 172 ? bswap_16 (Var) \ 173 : (sizeof (Var) == 4 \ 174 ? bswap_32 (Var) \ 175 : bswap_64 (Var)))) 176 177 178 #if __BYTE_ORDER == __LITTLE_ENDIAN 179 # define MY_ELFDATA ELFDATA2LSB 180 #else 181 # define MY_ELFDATA ELFDATA2MSB 182 #endif 183 184 #endif /* common.h */ 185
