gdbserver/linux-x86-tdesc.cc

   1 /* GNU/Linux/x86-64 specific target description, for the remote server
   2    for GDB.
   3    Copyright (C) 2017-2020 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 "server.h"
  21 #include "tdesc.h"
  22 #include "linux-x86-tdesc.h"
  23 #include "arch/i386.h"
  24 #include "gdbsupport/x86-xstate.h"
  25 #ifdef __x86_64__
  26 #include "arch/amd64.h"
  27 #endif
  28 #include "x86-tdesc.h"
  29
  30 /* Return the right x86_linux_tdesc index for a given XCR0.  Return
  31    X86_TDESC_LAST if can't find a match.  */
  32
  33 static enum x86_linux_tdesc
  34 xcr0_to_tdesc_idx (uint64_t xcr0, bool is_x32)
  35 {
  36   if (xcr0 & X86_XSTATE_PKRU)
  37     {
  38       if (is_x32)
  39         {
  40           /* No x32 MPX and PKU, fall back to avx_avx512.  */
  41           return X86_TDESC_AVX_AVX512;
  42         }
  43       else
  44         return X86_TDESC_AVX_MPX_AVX512_PKU;
  45     }
  46   else if (xcr0 & X86_XSTATE_AVX512)
  47     return X86_TDESC_AVX_AVX512;
  48   else if ((xcr0 & X86_XSTATE_AVX_MPX_MASK) == X86_XSTATE_AVX_MPX_MASK)
  49     {
  50       if (is_x32) /* No MPX on x32.  */
  51         return X86_TDESC_AVX;
  52       else
  53         return X86_TDESC_AVX_MPX;
  54     }
  55   else if (xcr0 & X86_XSTATE_MPX)
  56     {
  57       if (is_x32) /* No MPX on x32.  */
  58         return X86_TDESC_AVX;
  59       else
  60         return X86_TDESC_MPX;
  61     }
  62   else if (xcr0 & X86_XSTATE_AVX)
  63     return X86_TDESC_AVX;
  64   else if (xcr0 & X86_XSTATE_SSE)
  65     return X86_TDESC_SSE;
  66   else if (xcr0 & X86_XSTATE_X87)
  67     return X86_TDESC_MMX;
  68   else
  69     return X86_TDESC_LAST;
  70 }
  71
  72 #if defined __i386__ || !defined IN_PROCESS_AGENT
  73
  74 static struct target_desc *i386_tdescs[X86_TDESC_LAST] = { };
  75
  76 /* Return the target description according to XCR0.  */
  77
  78 const struct target_desc *
  79 i386_linux_read_description (uint64_t xcr0)
  80 {
  81   enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, false);
  82
  83   if (idx == X86_TDESC_LAST)
  84     return NULL;
  85
  86   struct target_desc **tdesc = &i386_tdescs[idx];
  87
  88   if (*tdesc == NULL)
  89     {
  90       *tdesc = i386_create_target_description (xcr0, true, false);
  91
  92       init_target_desc (*tdesc, i386_expedite_regs);
  93     }
  94
  95   return *tdesc;;
  96 }
  97 #endif
  98
  99 #ifdef __x86_64__
 100
 101 static target_desc *amd64_tdescs[X86_TDESC_LAST] = { };
 102 static target_desc *x32_tdescs[X86_TDESC_LAST] = { };
 103
 104 const struct target_desc *
 105 amd64_linux_read_description (uint64_t xcr0, bool is_x32)
 106 {
 107   enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, is_x32);
 108
 109   if (idx == X86_TDESC_LAST)
 110     return NULL;
 111
 112   struct target_desc **tdesc = NULL;
 113
 114   if (is_x32)
 115     tdesc = &x32_tdescs[idx];
 116   else
 117     tdesc = &amd64_tdescs[idx];
 118
 119   if (*tdesc == NULL)
 120     {
 121       *tdesc = amd64_create_target_description (xcr0, is_x32, true, true);
 122
 123       init_target_desc (*tdesc, amd64_expedite_regs);
 124     }
 125   return *tdesc;
 126 }
 127
 128 #endif
 129
 130 #ifndef IN_PROCESS_AGENT
 131
 132 int
 133 i386_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 134 {
 135   for (int i = 0; i < X86_TDESC_LAST; i++)
 136     {
 137       if (tdesc == i386_tdescs[i])
 138         return i;
 139     }
 140
 141   /* If none tdesc is found, return the one with minimum features.  */
 142   return X86_TDESC_MMX;
 143 }
 144
 145 #if defined __x86_64__
 146 int
 147 amd64_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 148 {
 149   for (int i = 0; i < X86_TDESC_LAST; i++)
 150     {
 151       if (tdesc == amd64_tdescs[i])
 152         return i;
 153     }
 154   for (int i = 0; i < X86_TDESC_LAST; i++)
 155     {
 156       if (tdesc == x32_tdescs[i])
 157         return i;
 158     }
 159
 160   return X86_TDESC_SSE;
 161 }
 162
 163 #endif
 164 #endif