gdb/gdbserver/linux-x86-tdesc.c

   1 /* GNU/Linux/x86-64 specific target description, for the remote server
   2    for GDB.
   3    Copyright (C) 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 "server.h"
  21 #include "tdesc.h"
  22 #include "linux-x86-tdesc.h"
  23 #include "arch/i386.h"
  24 #include "common/x86-xstate.h"
  25 #ifdef __x86_64__
  26 #include "arch/amd64.h"
  27 #endif
  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 static struct target_desc *i386_tdescs[X86_TDESC_LAST] = { };
  72
  73 #if defined __i386__ || !defined IN_PROCESS_AGENT
  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);
  90
  91       init_target_desc (*tdesc);
  92
  93 #ifndef IN_PROCESS_AGENT
  94       static const char *expedite_regs_i386[] = { "ebp", "esp", "eip", NULL };
  95       (*tdesc)->expedite_regs = expedite_regs_i386;
  96 #endif
  97     }
  98
  99   return *tdesc;;
 100 }
 101 #endif
 102
 103 #ifdef __x86_64__
 104
 105 static target_desc *amd64_tdescs[X86_TDESC_LAST] = { };
 106 static target_desc *x32_tdescs[X86_TDESC_LAST] = { };
 107
 108 const struct target_desc *
 109 amd64_linux_read_description (uint64_t xcr0, bool is_x32)
 110 {
 111   enum x86_linux_tdesc idx = xcr0_to_tdesc_idx (xcr0, is_x32);
 112
 113   if (idx == X86_TDESC_LAST)
 114     return NULL;
 115
 116   struct target_desc **tdesc = NULL;
 117
 118   if (is_x32)
 119     tdesc = &x32_tdescs[idx];
 120   else
 121     tdesc = &amd64_tdescs[idx];
 122
 123   if (*tdesc == NULL)
 124     {
 125       *tdesc = amd64_create_target_description (xcr0, is_x32);
 126
 127       init_target_desc (*tdesc);
 128
 129 #ifndef IN_PROCESS_AGENT
 130       static const char *expedite_regs_amd64[] = { "rbp", "rsp", "rip", NULL };
 131       (*tdesc)->expedite_regs = expedite_regs_amd64;
 132 #endif
 133     }
 134   return *tdesc;
 135 }
 136
 137 #endif
 138
 139 #ifndef IN_PROCESS_AGENT
 140
 141 int
 142 i386_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 143 {
 144   for (int i = 0; i < X86_TDESC_LAST; i++)
 145     {
 146       if (tdesc == i386_tdescs[i])
 147         return i;
 148     }
 149
 150   /* If none tdesc is found, return the one with minimum features.  */
 151   return X86_TDESC_MMX;
 152 }
 153
 154 #if defined __x86_64__
 155 int
 156 amd64_get_ipa_tdesc_idx (const struct target_desc *tdesc)
 157 {
 158   for (int i = 0; i < X86_TDESC_LAST; i++)
 159     {
 160       if (tdesc == amd64_tdescs[i])
 161         return i;
 162     }
 163   for (int i = 0; i < X86_TDESC_LAST; i++)
 164     {
 165       if (tdesc == x32_tdescs[i])
 166         return i;
 167     }
 168
 169   return X86_TDESC_SSE;
 170 }
 171
 172 #endif
 173 #endif