1 /* Native-dependent code for AMD64. 2 3 Copyright (C) 2003-2017 Free Software Foundation, Inc. 4 5 This file is part of GDB. 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with this program. If not, see <http://www.gnu.org/licenses/>. */ 19 20 #include "defs.h" 21 #include "gdbarch.h" 22 #include "regcache.h" 23 24 #include "i386-tdep.h" 25 #include "amd64-tdep.h" 26 #include "amd64-nat.h" 27 28 /* The following bits of code help with implementing debugging 32-bit 29 code natively on AMD64. The idea is to define two mappings between 30 the register number as used by GDB and the register set used by the 31 host to represent the general-purpose registers; one for 32-bit 32 code and one for 64-bit code. The mappings are specified by the 33 follwing variables and consist of an array of offsets within the 34 register set indexed by register number, and the number of 35 registers supported by the mapping. We don't need mappings for the 36 floating-point and SSE registers, since the difference between 37 64-bit and 32-bit variants are negligable. The difference in the 38 number of SSE registers is already handled by the target code. */ 39 40 /* General-purpose register mapping for native 32-bit code. */ 41 int *amd64_native_gregset32_reg_offset; 42 int amd64_native_gregset32_num_regs = I386_NUM_GREGS; 43 44 /* General-purpose register mapping for native 64-bit code. */ 45 int *amd64_native_gregset64_reg_offset; 46 int amd64_native_gregset64_num_regs = AMD64_NUM_GREGS; 47 48 /* Return the offset of REGNUM within the appropriate native 49 general-purpose register set. */ 50 51 static int 52 amd64_native_gregset_reg_offset (struct gdbarch *gdbarch, int regnum) 53 { 54 int *reg_offset = amd64_native_gregset64_reg_offset; 55 int num_regs = amd64_native_gregset64_num_regs; 56 57 gdb_assert (regnum >= 0); 58 59 if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32) 60 { 61 reg_offset = amd64_native_gregset32_reg_offset; 62 num_regs = amd64_native_gregset32_num_regs; 63 } 64 65 if (num_regs > gdbarch_num_regs (gdbarch)) 66 num_regs = gdbarch_num_regs (gdbarch); 67 68 if (regnum >= num_regs) 69 return -1; 70 71 /* Kernels that predate Linux 2.6.25 don't provide access to 72 these segment registers in user_regs_struct. */ 73 #ifndef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE 74 if (regnum == AMD64_FSBASE_REGNUM || regnum == AMD64_GSBASE_REGNUM) 75 return -1; 76 #endif 77 78 return reg_offset[regnum]; 79 } 80 81 /* Return whether the native general-purpose register set supplies 82 register REGNUM. */ 83 84 int 85 amd64_native_gregset_supplies_p (struct gdbarch *gdbarch, int regnum) 86 { 87 return (amd64_native_gregset_reg_offset (gdbarch, regnum) != -1); 88 } 89 90 91 /* Supply register REGNUM, whose contents are stored in GREGS, to 92 REGCACHE. If REGNUM is -1, supply all appropriate registers. */ 93 94 void 95 amd64_supply_native_gregset (struct regcache *regcache, 96 const void *gregs, int regnum) 97 { 98 const char *regs = (const char *) gregs; 99 struct gdbarch *gdbarch = get_regcache_arch (regcache); 100 int num_regs = amd64_native_gregset64_num_regs; 101 int i; 102 103 if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32) 104 num_regs = amd64_native_gregset32_num_regs; 105 106 if (num_regs > gdbarch_num_regs (gdbarch)) 107 num_regs = gdbarch_num_regs (gdbarch); 108 109 for (i = 0; i < num_regs; i++) 110 { 111 if (regnum == -1 || regnum == i) 112 { 113 int offset = amd64_native_gregset_reg_offset (gdbarch, i); 114 115 if (offset != -1) 116 regcache_raw_supply (regcache, i, regs + offset); 117 } 118 } 119 } 120 121 /* Collect register REGNUM from REGCACHE and store its contents in 122 GREGS. If REGNUM is -1, collect and store all appropriate 123 registers. */ 124 125 void 126 amd64_collect_native_gregset (const struct regcache *regcache, 127 void *gregs, int regnum) 128 { 129 char *regs = (char *) gregs; 130 struct gdbarch *gdbarch = get_regcache_arch (regcache); 131 int num_regs = amd64_native_gregset64_num_regs; 132 int i; 133 134 if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32) 135 { 136 num_regs = amd64_native_gregset32_num_regs; 137 138 /* Make sure %eax, %ebx, %ecx, %edx, %esi, %edi, %ebp, %esp and 139 %eip get zero-extended to 64 bits. */ 140 for (i = 0; i <= I386_EIP_REGNUM; i++) 141 { 142 if (regnum == -1 || regnum == i) 143 memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8); 144 } 145 /* Ditto for %cs, %ss, %ds, %es, %fs, and %gs. */ 146 for (i = I386_CS_REGNUM; i <= I386_GS_REGNUM; i++) 147 { 148 if (regnum == -1 || regnum == i) 149 memset (regs + amd64_native_gregset_reg_offset (gdbarch, i), 0, 8); 150 } 151 } 152 153 if (num_regs > gdbarch_num_regs (gdbarch)) 154 num_regs = gdbarch_num_regs (gdbarch); 155 156 for (i = 0; i < num_regs; i++) 157 { 158 if (regnum == -1 || regnum == i) 159 { 160 int offset = amd64_native_gregset_reg_offset (gdbarch, i); 161 162 if (offset != -1) 163 regcache_raw_collect (regcache, i, regs + offset); 164 } 165 } 166 } 167