1 /* $NetBSD: libelf_align.c,v 1.6 2024/03/03 17:37:34 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 2006,2008 Joseph Koshy 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #if HAVE_NBTOOL_CONFIG_H 30 # include "nbtool_config.h" 31 #endif 32 33 #include <sys/cdefs.h> 34 35 #include <sys/types.h> 36 37 #include <libelf.h> 38 39 #include "_libelf.h" 40 41 __RCSID("$NetBSD: libelf_align.c,v 1.6 2024/03/03 17:37:34 christos Exp $"); 42 ELFTC_VCSID("Id: libelf_align.c 3977 2022-05-01 06:45:34Z jkoshy"); 43 44 struct align { 45 unsigned int a32; 46 unsigned int a64; 47 }; 48 49 #if defined(__GNUC__) || defined(__lint__) 50 #define MALIGN(N) { \ 51 .a32 = __alignof__(Elf32_##N), \ 52 .a64 = __alignof__(Elf64_##N) \ 53 } 54 #define MALIGN64(V) { \ 55 .a32 = 0, \ 56 .a64 = __alignof__(Elf64_##V) \ 57 } 58 #define MALIGN_WORD() { \ 59 .a32 = __alignof__(int32_t), \ 60 .a64 = __alignof__(int64_t) \ 61 } 62 #elif defined(__lint__) 63 #define MALIGN(N) { .a32 = 0, .a64 = 0 } 64 #define MALIGN64(N) { .a32 = 0, .a64 = 0 } 65 #define MALIGN_WORD(N) { .a32 = 0, .a64 = 0 } 66 #else 67 #error Need the __alignof__ builtin. 68 #endif 69 #define UNSUPPORTED() { \ 70 .a32 = 0, \ 71 .a64 = 0 \ 72 } 73 74 static struct align malign[ELF_T_NUM] = { 75 [ELF_T_ADDR] = MALIGN(Addr), 76 [ELF_T_BYTE] = { .a32 = 1, .a64 = 1 }, 77 [ELF_T_CAP] = MALIGN(Cap), 78 [ELF_T_DYN] = MALIGN(Dyn), 79 [ELF_T_EHDR] = MALIGN(Ehdr), 80 [ELF_T_HALF] = MALIGN(Half), 81 [ELF_T_LWORD] = MALIGN(Lword), 82 [ELF_T_MOVE] = MALIGN(Move), 83 [ELF_T_MOVEP] = UNSUPPORTED(), 84 [ELF_T_NOTE] = MALIGN(Nhdr), 85 [ELF_T_OFF] = MALIGN(Off), 86 [ELF_T_PHDR] = MALIGN(Phdr), 87 [ELF_T_REL] = MALIGN(Rel), 88 [ELF_T_RELA] = MALIGN(Rela), 89 [ELF_T_SHDR] = MALIGN(Shdr), 90 [ELF_T_SWORD] = MALIGN(Sword), 91 [ELF_T_SXWORD] = MALIGN64(Sxword), 92 [ELF_T_SYM] = MALIGN(Sym), 93 [ELF_T_SYMINFO] = MALIGN(Syminfo), 94 [ELF_T_VDEF] = MALIGN(Verdef), 95 [ELF_T_VNEED] = MALIGN(Verneed), 96 [ELF_T_WORD] = MALIGN(Word), 97 [ELF_T_XWORD] = MALIGN64(Xword), 98 [ELF_T_GNUHASH] = MALIGN_WORD() 99 }; 100 101 unsigned int 102 _libelf_malign(Elf_Type t, int elfclass) 103 { 104 if (t >= ELF_T_NUM || (int) t < 0) 105 return (0); 106 107 return (elfclass == ELFCLASS32 ? malign[t].a32 : 108 malign[t].a64); 109 } 110 111 #define FALIGN(A32,A64) { .a32 = (A32), .a64 = (A64) } 112 113 static struct align falign[ELF_T_NUM] = { 114 [ELF_T_ADDR] = FALIGN(4,8), 115 [ELF_T_BYTE] = FALIGN(1,1), 116 [ELF_T_CAP] = FALIGN(4,8), 117 [ELF_T_DYN] = FALIGN(4,8), 118 [ELF_T_EHDR] = FALIGN(4,8), 119 [ELF_T_HALF] = FALIGN(2,2), 120 [ELF_T_LWORD] = FALIGN(8,8), 121 [ELF_T_MOVE] = FALIGN(8,8), 122 [ELF_T_MOVEP] = UNSUPPORTED(), 123 [ELF_T_NOTE] = FALIGN(4,4), 124 [ELF_T_OFF] = FALIGN(4,8), 125 [ELF_T_PHDR] = FALIGN(4,8), 126 [ELF_T_REL] = FALIGN(4,8), 127 [ELF_T_RELA] = FALIGN(4,8), 128 [ELF_T_SHDR] = FALIGN(4,8), 129 [ELF_T_SWORD] = FALIGN(4,4), 130 [ELF_T_SXWORD] = FALIGN(0,8), 131 [ELF_T_SYM] = FALIGN(4,8), 132 [ELF_T_SYMINFO] = FALIGN(2,2), 133 [ELF_T_VDEF] = FALIGN(4,4), 134 [ELF_T_VNEED] = FALIGN(4,4), 135 [ELF_T_WORD] = FALIGN(4,4), 136 [ELF_T_XWORD] = FALIGN(0,8), 137 [ELF_T_GNUHASH] = FALIGN(4,8) 138 }; 139 140 unsigned int 141 _libelf_falign(Elf_Type t, int elfclass) 142 { 143 if (t >= ELF_T_NUM || (int) t < 0) 144 return (0); 145 146 return (elfclass == ELFCLASS32 ? falign[t].a32 : 147 falign[t].a64); 148 } 149