1 /* BFD support for the Intel 386 architecture. 2 Copyright (C) 1992-2020 Free Software Foundation, Inc. 3 4 This file is part of BFD, the Binary File Descriptor library. 5 6 This program is free software; you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program; if not, write to the Free Software 18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21 #include "sysdep.h" 22 #include "bfd.h" 23 #include "libbfd.h" 24 #include "libiberty.h" 25 26 extern void * bfd_arch_i386_short_nop_fill (bfd_size_type, bfd_boolean, 27 bfd_boolean); 28 29 static const bfd_arch_info_type * 30 bfd_i386_compatible (const bfd_arch_info_type *a, 31 const bfd_arch_info_type *b) 32 { 33 const bfd_arch_info_type *compat = bfd_default_compatible (a, b); 34 35 /* Don't allow mixing x64_32 with x86_64. */ 36 if (compat 37 && (a->mach & bfd_mach_x64_32) != (b->mach & bfd_mach_x64_32)) 38 compat = NULL; 39 40 return compat; 41 } 42 43 /* Fill the buffer with zero or nop instruction if CODE is TRUE. Use 44 multi byte nop instructions if LONG_NOP is TRUE. */ 45 46 static void * 47 bfd_arch_i386_fill (bfd_size_type count, bfd_boolean code, 48 bfd_boolean long_nop) 49 { 50 /* nop */ 51 static const char nop_1[] = { 0x90 }; 52 /* xchg %ax,%ax */ 53 static const char nop_2[] = { 0x66, 0x90 }; 54 /* nopl (%[re]ax) */ 55 static const char nop_3[] = { 0x0f, 0x1f, 0x00 }; 56 /* nopl 0(%[re]ax) */ 57 static const char nop_4[] = { 0x0f, 0x1f, 0x40, 0x00 }; 58 /* nopl 0(%[re]ax,%[re]ax,1) */ 59 static const char nop_5[] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 }; 60 /* nopw 0(%[re]ax,%[re]ax,1) */ 61 static const char nop_6[] = { 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 }; 62 /* nopl 0L(%[re]ax) */ 63 static const char nop_7[] = { 0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00 }; 64 /* nopl 0L(%[re]ax,%[re]ax,1) */ 65 static const char nop_8[] = 66 { 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00}; 67 /* nopw 0L(%[re]ax,%[re]ax,1) */ 68 static const char nop_9[] = 69 { 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 }; 70 /* nopw %cs:0L(%[re]ax,%[re]ax,1) */ 71 static const char nop_10[] = 72 { 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 }; 73 static const char *const nops[] = 74 { nop_1, nop_2, nop_3, nop_4, nop_5, 75 nop_6, nop_7, nop_8, nop_9, nop_10 }; 76 bfd_size_type nop_size = long_nop ? ARRAY_SIZE (nops) : 2; 77 78 void *fill = bfd_malloc (count); 79 if (fill == NULL) 80 return fill; 81 82 if (code) 83 { 84 bfd_byte *p = fill; 85 while (count >= nop_size) 86 { 87 memcpy (p, nops[nop_size - 1], nop_size); 88 p += nop_size; 89 count -= nop_size; 90 } 91 if (count != 0) 92 memcpy (p, nops[count - 1], count); 93 } 94 else 95 memset (fill, 0, count); 96 97 return fill; 98 } 99 100 /* Fill the buffer with zero or short nop instruction if CODE is TRUE. */ 101 102 void * 103 bfd_arch_i386_short_nop_fill (bfd_size_type count, 104 bfd_boolean is_bigendian ATTRIBUTE_UNUSED, 105 bfd_boolean code) 106 { 107 return bfd_arch_i386_fill (count, code, FALSE); 108 } 109 110 /* Fill the buffer with zero or long nop instruction if CODE is TRUE. */ 111 112 static void * 113 bfd_arch_i386_long_nop_fill (bfd_size_type count, 114 bfd_boolean is_bigendian ATTRIBUTE_UNUSED, 115 bfd_boolean code) 116 { 117 return bfd_arch_i386_fill (count, code, TRUE); 118 } 119 120 /* Fill the buffer with zero, or one-byte nop instructions if CODE is TRUE. */ 121 122 static void * 123 bfd_arch_i386_onebyte_nop_fill (bfd_size_type count, 124 bfd_boolean is_bigendian ATTRIBUTE_UNUSED, 125 bfd_boolean code) 126 { 127 void *fill = bfd_malloc (count); 128 if (fill != NULL) 129 memset (fill, code ? 0x90 : 0, count); 130 return fill; 131 } 132 133 #define N(BITS, MACH, NAME, PRINT, DEF, FILL, NEXT) \ 134 { BITS, /* Bits in a word. */ \ 135 BITS, /* Bits in an address. */ \ 136 8, /* Bits in a byte. */ \ 137 bfd_arch_i386, \ 138 MACH, /* Machine number. */ \ 139 NAME, \ 140 PRINT, \ 141 3, /* Section alignment power. */ \ 142 DEF, /* Default architecture version ? */ \ 143 bfd_i386_compatible, \ 144 bfd_default_scan, \ 145 FILL, \ 146 NEXT, \ 147 0 /* Maximum instruction length. */ \ 148 } 149 150 151 static const bfd_arch_info_type bfd_x64_32_nacl_arch = 152 N (64, bfd_mach_x64_32_nacl, "i386", "i386:x64-32:nacl", 153 FALSE, bfd_arch_i386_onebyte_nop_fill, NULL); 154 155 static const bfd_arch_info_type bfd_x86_64_nacl_arch = 156 N (64, bfd_mach_x86_64_nacl, "i386", "i386:x86-64:nacl", 157 FALSE, bfd_arch_i386_onebyte_nop_fill, &bfd_x64_32_nacl_arch); 158 159 const bfd_arch_info_type bfd_i386_nacl_arch = 160 N (32, bfd_mach_i386_i386_nacl, "i386", "i386:nacl", 161 TRUE, bfd_arch_i386_onebyte_nop_fill, &bfd_x86_64_nacl_arch); 162 163 164 static const bfd_arch_info_type bfd_x64_32_arch_intel_syntax = 165 N (64, bfd_mach_x64_32_intel_syntax, "i386:intel", "i386:x64-32:intel", 166 FALSE, bfd_arch_i386_long_nop_fill, &bfd_i386_nacl_arch); 167 168 static const bfd_arch_info_type bfd_x86_64_arch_intel_syntax = 169 N (64, bfd_mach_x86_64_intel_syntax, "i386:intel", "i386:x86-64:intel", 170 FALSE, bfd_arch_i386_long_nop_fill, &bfd_x64_32_arch_intel_syntax); 171 172 static const bfd_arch_info_type bfd_i386_arch_intel_syntax = 173 N (32, bfd_mach_i386_i386_intel_syntax, "i386:intel", "i386:intel", 174 TRUE, bfd_arch_i386_short_nop_fill, &bfd_x86_64_arch_intel_syntax); 175 176 177 static const bfd_arch_info_type i8086_arch = 178 N (32, bfd_mach_i386_i8086, "i8086", "i8086", 179 FALSE, bfd_arch_i386_short_nop_fill, &bfd_i386_arch_intel_syntax); 180 181 static const bfd_arch_info_type bfd_x64_32_arch = 182 N (64, bfd_mach_x64_32, "i386", "i386:x64-32", 183 FALSE, bfd_arch_i386_long_nop_fill, &i8086_arch); 184 185 static const bfd_arch_info_type bfd_x86_64_arch = 186 N (64, bfd_mach_x86_64, "i386", "i386:x86-64", 187 FALSE, bfd_arch_i386_long_nop_fill, &bfd_x64_32_arch); 188 189 const bfd_arch_info_type bfd_i386_arch = 190 N (32, bfd_mach_i386_i386, "i386", "i386", 191 TRUE, bfd_arch_i386_short_nop_fill, &bfd_x86_64_arch); 192