| 1 | /* Native-dependent code for AMD64. |
| 2 | |
| 3 | Copyright (C) 2003-2019 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 = regcache->arch (); |
| 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 (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 = regcache->arch (); |
| 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 (i, regs + offset); |
| 164 | } |
| 165 | } |
| 166 | } |