1 /* Convert from memory to file representation. 2 Copyright (C) 1998, 1999, 2000, 2002, 2015 Red Hat, Inc. 3 This file is part of elfutils. 4 Written by Ulrich Drepper <drepper (at) redhat.com>, 1998. 5 6 This file is free software; you can redistribute it and/or modify 7 it under the terms of either 8 9 * the GNU Lesser General Public License as published by the Free 10 Software Foundation; either version 3 of the License, or (at 11 your option) any later version 12 13 or 14 15 * the GNU General Public License as published by the Free 16 Software Foundation; either version 2 of the License, or (at 17 your option) any later version 18 19 or both in parallel, as here. 20 21 elfutils is distributed in the hope that it will be useful, but 22 WITHOUT ANY WARRANTY; without even the implied warranty of 23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 24 General Public License for more details. 25 26 You should have received copies of the GNU General Public License and 27 the GNU Lesser General Public License along with this program. If 28 not, see <http://www.gnu.org/licenses/>. */ 29 30 #ifdef HAVE_CONFIG_H 31 # include <config.h> 32 #endif 33 34 #include <assert.h> 35 #include <endian.h> 36 #include <string.h> 37 38 #include "libelfP.h" 39 40 #ifndef LIBELFBITS 41 # define LIBELFBITS 32 42 #endif 43 44 45 Elf_Data * 46 elfw2(LIBELFBITS, xlatetof) (Elf_Data *dest, const Elf_Data *src, 47 unsigned int encode) 48 { 49 /* First test whether the input data is really suitable for this 50 type. This means, whether there is an integer number of records. 51 Note that for this implementation the memory and file size of the 52 data types are identical. */ 53 #if EV_NUM != 2 54 size_t recsize = __libelf_type_sizes[src->d_version - 1][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type]; 55 #else 56 size_t recsize = __libelf_type_sizes[0][ELFW(ELFCLASS,LIBELFBITS) - 1][src->d_type]; 57 #endif 58 59 if (src->d_size % recsize != 0) 60 { 61 __libelf_seterrno (ELF_E_INVALID_DATA); 62 return NULL; 63 } 64 65 /* Next see whether the converted data fits in the output buffer. */ 66 if (src->d_size > dest->d_size) 67 { 68 __libelf_seterrno (ELF_E_DEST_SIZE); 69 return NULL; 70 } 71 72 /* Test the encode parameter. */ 73 if (encode != ELFDATA2LSB && encode != ELFDATA2MSB) 74 { 75 __libelf_seterrno (ELF_E_INVALID_ENCODING); 76 return NULL; 77 } 78 79 /* Determine the translation function to use. 80 81 At this point we make an assumption which is valid for all 82 existing implementations so far: the memory and file sizes are 83 the same. This has very important consequences: 84 a) The requirement that the source and destination buffer can 85 overlap can easily be fulfilled. 86 b) We need only one function to convert from and memory to file 87 and vice versa since the function only has to copy and/or 88 change the byte order. 89 */ 90 if ((__BYTE_ORDER == __LITTLE_ENDIAN && encode == ELFDATA2LSB) 91 || (__BYTE_ORDER == __BIG_ENDIAN && encode == ELFDATA2MSB)) 92 { 93 /* We simply have to copy since the byte order is the same. */ 94 if (src->d_buf != dest->d_buf) 95 memmove (dest->d_buf, src->d_buf, src->d_size); 96 } 97 else 98 { 99 xfct_t fctp; 100 101 /* Get a pointer to the transformation functions. The `#ifdef' is 102 a small optimization since we don't anticipate another ELF 103 version and so would waste "precious" code. */ 104 #if EV_NUM != 2 105 fctp = __elf_xfctstom[dest->d_version - 1][src->d_version - 1][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type]; 106 #else 107 fctp = __elf_xfctstom[0][0][ELFW(ELFCLASS, LIBELFBITS) - 1][src->d_type]; 108 #endif 109 110 /* Do the real work. */ 111 (*fctp) (dest->d_buf, src->d_buf, src->d_size, 1); 112 } 113 114 /* Now set the real destination type and length since the operation was 115 successful. */ 116 dest->d_type = src->d_type; 117 dest->d_size = src->d_size; 118 119 return dest; 120 } 121 INTDEF(elfw2(LIBELFBITS, xlatetof)) 122
