1 /* Transformation functions for ELF data types. 2 Copyright (C) 1998,1999,2000,2002,2004,2005,2006,2007,2015 Red Hat, Inc. 3 Copyright (C) 2022 Mark J. Wielaard <mark@klomp.org> 4 This file is part of elfutils. 5 Written by Ulrich Drepper <drepper@redhat.com>, 1998. 6 7 This file is free software; you can redistribute it and/or modify 8 it under the terms of either 9 10 * the GNU Lesser General Public License as published by the Free 11 Software Foundation; either version 3 of the License, or (at 12 your option) any later version 13 14 or 15 16 * the GNU General Public License as published by the Free 17 Software Foundation; either version 2 of the License, or (at 18 your option) any later version 19 20 or both in parallel, as here. 21 22 elfutils is distributed in the hope that it will be useful, but 23 WITHOUT ANY WARRANTY; without even the implied warranty of 24 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 25 General Public License for more details. 26 27 You should have received copies of the GNU General Public License and 28 the GNU Lesser General Public License along with this program. If 29 not, see <http://www.gnu.org/licenses/>. */ 30 31 #ifdef HAVE_CONFIG_H 32 # include <config.h> 33 #endif 34 35 #include <stdint.h> 36 #include <string.h> 37 #include <stdlib.h> 38 39 #include "libelfP.h" 40 41 #ifndef LIBELFBITS 42 # define LIBELFBITS 32 43 #endif 44 45 46 /* Well, what shall I say. Nothing to do here. */ 47 #define elf_cvt_Byte(dest, src, n) \ 48 (__builtin_constant_p (n) && (n) == 1 \ 49 ? (void) (*((char *) (dest)) = *((char *) (src))) \ 50 : Elf32_cvt_Byte (dest, src, n)) 51 static void 52 (elf_cvt_Byte) (void *dest, const void *src, size_t n, 53 int encode __attribute__ ((unused))) 54 { 55 if (n != 0) 56 memmove (dest, src, n); 57 } 58 59 60 /* We'll optimize the definition of the conversion functions here a 61 bit. We need only functions for 16, 32, and 64 bits. The 62 functions referenced in the table will be aliases for one of these 63 functions. Which one is decided by the ELFxx_FSZ_type. */ 64 65 #if ALLOW_UNALIGNED 66 67 #define FETCH(Bits, ptr) (*(const uint##Bits##_t *) ptr) 68 #define STORE(Bits, ptr, val) (*(uint##Bits##_t *) ptr = val) 69 70 #else 71 72 union unaligned 73 { 74 uint16_t u16; 75 uint32_t u32; 76 uint64_t u64; 77 } attribute_packed; 78 79 #define FETCH(Bits, ptr) (((const union unaligned *) ptr)->u##Bits) 80 #define STORE(Bits, ptr, val) (((union unaligned *) ptr)->u##Bits = val) 81 82 #endif 83 84 /* Now define the conversion functions for the basic types. We use here 85 the fact that file and memory types are the same and that we have the 86 ELFxx_FSZ_* macros. 87 88 At the same time we define inline functions which we will use to 89 convert the complex types. */ 90 #define FUNDAMENTAL(NAME, Name, Bits) \ 91 INLINE2 (ELFW2(Bits,FSZ_##NAME), ElfW2(Bits,cvt_##Name), ElfW2(Bits,Name)) 92 #define INLINE2(Bytes, FName, TName) \ 93 INLINE3 (Bytes, FName, TName) 94 #define INLINE3(Bytes, FName, TName) \ 95 static inline void FName##1 (void *dest, const void *ptr) \ 96 { \ 97 switch (Bytes) \ 98 { \ 99 case 2: STORE (16, dest, bswap_16 (FETCH (16, ptr))); break; \ 100 case 4: STORE (32, dest, bswap_32 (FETCH (32, ptr))); break; \ 101 case 8: STORE (64, dest, bswap_64 (FETCH (64, ptr))); break; \ 102 default: \ 103 abort (); \ 104 } \ 105 } \ 106 \ 107 static void FName (void *dest, const void *ptr, size_t len, \ 108 int encode __attribute__ ((unused))) \ 109 { \ 110 size_t n = len / sizeof (TName); \ 111 if (dest < ptr) \ 112 while (n-- > 0) \ 113 { \ 114 FName##1 (dest, ptr); \ 115 dest += Bytes; \ 116 ptr += Bytes; \ 117 } \ 118 else \ 119 { \ 120 dest += len; \ 121 ptr += len; \ 122 while (n-- > 0) \ 123 { \ 124 ptr -= Bytes; \ 125 dest -= Bytes; \ 126 FName##1 (dest, ptr); \ 127 } \ 128 } \ 129 } 130 131 132 /* Now the tricky part: define the transformation functions for the 133 complex types. We will use the definitions of the types in 134 abstract.h. */ 135 #define START(Bits, Name, EName) \ 136 static void \ 137 ElfW2 (Bits, cvt_##Name) (void *dest, const void *src, size_t len, \ 138 int encode __attribute__ ((unused))) \ 139 { ElfW2(Bits, Name) *tdest = (ElfW2(Bits, Name) *) dest; \ 140 ElfW2(Bits, Name) *tsrc = (ElfW2(Bits, Name) *) src; \ 141 size_t sz = sizeof (ElfW2(Bits, Name)); \ 142 size_t n; \ 143 for (n = len / sz; n > 0; ++tdest, ++tsrc, --n) { 144 #define END(Bits, Name) \ 145 } \ 146 if (len % sz > 0) /* Cannot convert partial structures, just copy. */ \ 147 memmove (dest, src, len % sz); \ 148 } 149 #define TYPE_EXTRA(Code) 150 #define TYPE_XLATE(Code) Code 151 #define TYPE_NAME(Type, Name) TYPE_NAME2 (Type, Name) 152 #define TYPE_NAME2(Type, Name) Type##1 (&tdest->Name, &tsrc->Name); 153 #define TYPE(Name, Bits) TYPE2 (Name, Bits) 154 #define TYPE2(Name, Bits) TYPE3 (Name##Bits) 155 #define TYPE3(Name) Name (cvt_) 156 157 /* Signal that we are generating conversion functions. */ 158 #define GENERATE_CONVERSION 159 160 /* First generate the 32-bit conversion functions. */ 161 #define LIBELFBITS 32 162 #include "gelf_xlate.h" 163 164 /* Now generate the 64-bit conversion functions. */ 165 #define LIBELFBITS 64 166 #include "gelf_xlate.h" 167 168 169 /* We have a few functions which we must create by hand since the sections 170 do not contain records of only one type. */ 171 #include "version_xlate.h" 172 #include "gnuhash_xlate.h" 173 #include "note_xlate.h" 174 #include "chdr_xlate.h" 175 176 177 /* Now the externally visible table with the function pointers. */ 178 const xfct_t __elf_xfctstom[ELFCLASSNUM - 1][ELF_T_NUM] = 179 { 180 [ELFCLASS32 - 1] = { 181 #define define_xfcts(Bits) \ 182 [ELF_T_BYTE] = elf_cvt_Byte, \ 183 [ELF_T_ADDR] = ElfW2(Bits, cvt_Addr), \ 184 [ELF_T_DYN] = ElfW2(Bits, cvt_Dyn), \ 185 [ELF_T_EHDR] = ElfW2(Bits, cvt_Ehdr), \ 186 [ELF_T_HALF] = ElfW2(Bits, cvt_Half), \ 187 [ELF_T_OFF] = ElfW2(Bits, cvt_Off), \ 188 [ELF_T_PHDR] = ElfW2(Bits, cvt_Phdr), \ 189 [ELF_T_RELA] = ElfW2(Bits, cvt_Rela), \ 190 [ELF_T_REL] = ElfW2(Bits, cvt_Rel), \ 191 [ELF_T_SHDR] = ElfW2(Bits, cvt_Shdr), \ 192 [ELF_T_SWORD] = ElfW2(Bits, cvt_Sword), \ 193 [ELF_T_SYM] = ElfW2(Bits, cvt_Sym), \ 194 [ELF_T_WORD] = ElfW2(Bits, cvt_Word), \ 195 [ELF_T_XWORD] = ElfW2(Bits, cvt_Xword), \ 196 [ELF_T_SXWORD] = ElfW2(Bits, cvt_Sxword), \ 197 [ELF_T_VDEF] = elf_cvt_Verdef, \ 198 [ELF_T_VDAUX] = elf_cvt_Verdef, \ 199 [ELF_T_VNEED] = elf_cvt_Verneed, \ 200 [ELF_T_VNAUX] = elf_cvt_Verneed, \ 201 [ELF_T_NHDR] = elf_cvt_note4, \ 202 [ELF_T_NHDR8] = elf_cvt_note8, \ 203 [ELF_T_SYMINFO] = ElfW2(Bits, cvt_Syminfo), \ 204 [ELF_T_MOVE] = ElfW2(Bits, cvt_Move), \ 205 [ELF_T_LIB] = ElfW2(Bits, cvt_Lib), \ 206 [ELF_T_AUXV] = ElfW2(Bits, cvt_auxv_t), \ 207 [ELF_T_CHDR] = ElfW2(Bits, cvt_chdr) 208 define_xfcts (32), 209 [ELF_T_GNUHASH] = Elf32_cvt_Word 210 }, 211 [ELFCLASS64 - 1] = { 212 define_xfcts (64), 213 [ELF_T_GNUHASH] = elf_cvt_gnuhash 214 } 215 }; 216