gdbserver/linux-x86-tdesc.cc

   1 /* GNU/Linux/x86-64 specific target description, for the remote server
   2    for GDB.
   3    Copyright (C) 2017-2024 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 "tdesc.h"
  21 #include "linux-x86-tdesc.h"
  22 #include "arch/i386.h"
  23 #include "gdbsupport/x86-xstate.h"
  24 #ifdef __x86_64__
  25 #include "arch/amd64.h"
  26 #endif
  27 #include "x86-tdesc.h"
  28
  29 /* Return the right x86_linux_tdesc index for a given XCR0.  Return
  30    X86_TDESC_LAST if can't find a match.  */
  31
  32 static enum x86_linux_tdesc
  33 xcr0_to_tdesc_idx (uint64_t xcr0, bool is_x32)
  34 {
  35   if (xcr0 & X86_XSTATE_PKRU)
  36     {
  37       if (is_x32)
  38         {
  39           /* No x32 MPX and PKU, fall back to avx_avx512.  */
  40           return X86_TDESC_AVX_AVX512;
  41         }
  42       else
  43         return X86_TDESC_AVX_MPX_AVX512_PKU;
  44     }
  45   else if (xcr0 & X86_XSTATE_AVX512)
  46     return X86_TDESC_AVX_AVX512;
  47   else if ((xcr0 & X86_XSTATE_AVX_MPX_MASK) == X86_XSTATE_AVX_MPX_MASK)
  48     {
  49       if (is_x32) /* No MPX on x32.  */
  50         return X86_TDESC_AVX;
  51       else
  52         return X86_TDESC_AVX_MPX;
  53     }
  54   else if (xcr0 & X86_XSTATE_MPX)
  55     {
  56       if (is_x32) /* No MPX on x32.  */
  57         return X86_TDESC_AVX;
  58       else
  59         return X86_TDESC_MPX;
  60     }
  61   else if (xcr0 & X86_XSTATE_AVX)
  62     return X86_TDESC_AVX;
  63   else if (xcr0 & X86_XSTATE_SSE)
  64     return X86_TDESC_SSE;
  65   else if (xcr0 & X86_XSTATE_X87)
  66     return X86_TDESC_MMX;
  67   else
  68     return X86_TDESC_LAST;
  69 }
  70
  71 #if defined __i386__ || !defined IN_PROCESS_AGENT
  72
  73 static struct target_desc *i386_tdescs[X86_TDESC_LAST] = { };
  74
  75 /* Return the target description according to XCR0.  */
  76
  77 const struct target_desc *
  78 i386_linux_read_description (uint64_t xcr0)
  79 {
  80   enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, false);
  81
  82   if (idx == X86_TDESC_LAST)
  83     return NULL;
  84
  85   struct target_desc **tdesc = &i386_tdescs[idx];
  86
  87   if (*tdesc == NULL)
  88     {
  89       *tdesc = i386_create_target_description (xcr0, true, false);
  90
  91       init_target_desc (*tdesc, i386_expedite_regs);
  92     }
  93
  94   return *tdesc;;
  95 }
  96 #endif
  97
  98 #ifdef __x86_64__
  99
 100 static target_desc *amd64_tdescs[X86_TDESC_LAST] = { };
 101 static target_desc *x32_tdescs[X86_TDESC_LAST] = { };
 102
 103 const struct target_desc *
 104 amd64_linux_read_description (uint64_t xcr0, bool is_x32)
 105 {
 106   enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, is_x32);
 107
 108   if (idx == X86_TDESC_LAST)
 109     return NULL;
 110
 111   struct target_desc **tdesc = NULL;
 112
 113   if (is_x32)
 114     tdesc = &x32_tdescs[idx];
 115   else
 116     tdesc = &amd64_tdescs[idx];
 117
 118   if (*tdesc == NULL)
 119     {
 120       *tdesc = amd64_create_target_description (xcr0, is_x32, true, true);
 121
 122       init_target_desc (*tdesc, amd64_expedite_regs);
 123     }
 124   return *tdesc;
 125 }
 126
 127 #endif
 128
 129 #ifndef IN_PROCESS_AGENT
 130
 131 int
 132 i386_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 133 {
 134   for (int i = 0; i < X86_TDESC_LAST; i++)
 135     {
 136       if (tdesc == i386_tdescs[i])
 137         return i;
 138     }
 139
 140   /* If none tdesc is found, return the one with minimum features.  */
 141   return X86_TDESC_MMX;
 142 }
 143
 144 #if defined __x86_64__
 145 int
 146 amd64_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 147 {
 148   for (int i = 0; i < X86_TDESC_LAST; i++)
 149     {
 150       if (tdesc == amd64_tdescs[i])
 151         return i;
 152     }
 153   for (int i = 0; i < X86_TDESC_LAST; i++)
 154     {
 155       if (tdesc == x32_tdescs[i])
 156         return i;
 157     }
 158
 159   return X86_TDESC_SSE;
 160 }
 161
 162 #endif
 163 #endif