1 /*- 2 * Copyright (c) 2006,2008 Joseph Koshy 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 #include <sys/types.h> 28 29 #include <libelf.h> 30 31 #include "_libelf.h" 32 33 ELFTC_VCSID("$Id: libelf_align.c 3174 2015-03-27 17:13:41Z emaste $"); 34 35 struct align { 36 unsigned int a32; 37 unsigned int a64; 38 }; 39 40 #ifdef __GNUC__ 41 #define MALIGN(N) { \ 42 .a32 = __alignof__(Elf32_##N), \ 43 .a64 = __alignof__(Elf64_##N) \ 44 } 45 #define MALIGN64(V) { \ 46 .a32 = 0, \ 47 .a64 = __alignof__(Elf64_##V) \ 48 } 49 #define MALIGN_WORD() { \ 50 .a32 = __alignof__(int32_t), \ 51 .a64 = __alignof__(int64_t) \ 52 } 53 #else 54 #error Need the __alignof__ builtin. 55 #endif 56 #define UNSUPPORTED() { \ 57 .a32 = 0, \ 58 .a64 = 0 \ 59 } 60 61 static struct align malign[ELF_T_NUM] = { 62 [ELF_T_ADDR] = MALIGN(Addr), 63 [ELF_T_BYTE] = { .a32 = 1, .a64 = 1 }, 64 [ELF_T_CAP] = MALIGN(Cap), 65 [ELF_T_DYN] = MALIGN(Dyn), 66 [ELF_T_EHDR] = MALIGN(Ehdr), 67 [ELF_T_HALF] = MALIGN(Half), 68 [ELF_T_LWORD] = MALIGN(Lword), 69 [ELF_T_MOVE] = MALIGN(Move), 70 [ELF_T_MOVEP] = UNSUPPORTED(), 71 [ELF_T_NOTE] = MALIGN(Nhdr), 72 [ELF_T_OFF] = MALIGN(Off), 73 [ELF_T_PHDR] = MALIGN(Phdr), 74 [ELF_T_REL] = MALIGN(Rel), 75 [ELF_T_RELA] = MALIGN(Rela), 76 [ELF_T_SHDR] = MALIGN(Shdr), 77 [ELF_T_SWORD] = MALIGN(Sword), 78 [ELF_T_SXWORD] = MALIGN64(Sxword), 79 [ELF_T_SYM] = MALIGN(Sym), 80 [ELF_T_SYMINFO] = MALIGN(Syminfo), 81 [ELF_T_VDEF] = MALIGN(Verdef), 82 [ELF_T_VNEED] = MALIGN(Verneed), 83 [ELF_T_WORD] = MALIGN(Word), 84 [ELF_T_XWORD] = MALIGN64(Xword), 85 [ELF_T_GNUHASH] = MALIGN_WORD() 86 }; 87 88 unsigned int 89 _libelf_malign(Elf_Type t, int elfclass) 90 { 91 if (t >= ELF_T_NUM || (int) t < 0) 92 return (0); 93 94 return (elfclass == ELFCLASS32 ? malign[t].a32 : 95 malign[t].a64); 96 } 97 98 #define FALIGN(A32,A64) { .a32 = (A32), .a64 = (A64) } 99 100 static struct align falign[ELF_T_NUM] = { 101 [ELF_T_ADDR] = FALIGN(4,8), 102 [ELF_T_BYTE] = FALIGN(1,1), 103 [ELF_T_CAP] = FALIGN(4,8), 104 [ELF_T_DYN] = FALIGN(4,8), 105 [ELF_T_EHDR] = FALIGN(4,8), 106 [ELF_T_HALF] = FALIGN(2,2), 107 [ELF_T_LWORD] = FALIGN(8,8), 108 [ELF_T_MOVE] = FALIGN(8,8), 109 [ELF_T_MOVEP] = UNSUPPORTED(), 110 [ELF_T_NOTE] = FALIGN(1,1), 111 [ELF_T_OFF] = FALIGN(4,8), 112 [ELF_T_PHDR] = FALIGN(4,8), 113 [ELF_T_REL] = FALIGN(4,8), 114 [ELF_T_RELA] = FALIGN(4,8), 115 [ELF_T_SHDR] = FALIGN(4,8), 116 [ELF_T_SWORD] = FALIGN(4,4), 117 [ELF_T_SXWORD] = FALIGN(0,8), 118 [ELF_T_SYM] = FALIGN(4,8), 119 [ELF_T_SYMINFO] = FALIGN(2,2), 120 [ELF_T_VDEF] = FALIGN(4,4), 121 [ELF_T_VNEED] = FALIGN(4,4), 122 [ELF_T_WORD] = FALIGN(4,4), 123 [ELF_T_XWORD] = FALIGN(0,8), 124 [ELF_T_GNUHASH] = FALIGN(4,8) 125 }; 126 127 unsigned int 128 _libelf_falign(Elf_Type t, int elfclass) 129 { 130 if (t >= ELF_T_NUM || (int) t < 0) 131 return (0); 132 133 return (elfclass == ELFCLASS32 ? falign[t].a32 : 134 falign[t].a64); 135 } 136