xref: /netbsd-src/external/gpl3/gdb/dist/gdbserver/linux-x86-tdesc.cc (revision 64f917f5a88990e32dd65fcd4348042fa7f852b9)
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
164