1 /* BFD support for the Intel 386 architecture.
2 Copyright (C) 1992-2016 Free Software Foundation, Inc.
3
4 This file is part of BFD, the Binary File Descriptor library.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #include "sysdep.h"
22 #include "bfd.h"
23 #include "libbfd.h"
24 #include "libiberty.h"
25
26 extern void * bfd_arch_i386_short_nop_fill (bfd_size_type, bfd_boolean,
27 bfd_boolean);
28
29 static const bfd_arch_info_type *
bfd_i386_compatible(const bfd_arch_info_type * a,const bfd_arch_info_type * b)30 bfd_i386_compatible (const bfd_arch_info_type *a,
31 const bfd_arch_info_type *b)
32 {
33 const bfd_arch_info_type *compat = bfd_default_compatible (a, b);
34
35 /* Don't allow mixing x64_32 with x86_64. */
36 if (compat
37 && (a->mach & bfd_mach_x64_32) != (b->mach & bfd_mach_x64_32))
38 compat = NULL;
39
40 return compat;
41 }
42
43 /* Fill the buffer with zero or nop instruction if CODE is TRUE. Use
44 multi byte nop instructions if LONG_NOP is TRUE. */
45
46 static void *
bfd_arch_i386_fill(bfd_size_type count,bfd_boolean code,bfd_boolean long_nop)47 bfd_arch_i386_fill (bfd_size_type count, bfd_boolean code,
48 bfd_boolean long_nop)
49 {
50 /* nop */
51 static const char nop_1[] = { 0x90 };
52 /* xchg %ax,%ax */
53 static const char nop_2[] = { 0x66, 0x90 };
54 /* nopl (%[re]ax) */
55 static const char nop_3[] = { 0x0f, 0x1f, 0x00 };
56 /* nopl 0(%[re]ax) */
57 static const char nop_4[] = { 0x0f, 0x1f, 0x40, 0x00 };
58 /* nopl 0(%[re]ax,%[re]ax,1) */
59 static const char nop_5[] = { 0x0f, 0x1f, 0x44, 0x00, 0x00 };
60 /* nopw 0(%[re]ax,%[re]ax,1) */
61 static const char nop_6[] = { 0x66, 0x0f, 0x1f, 0x44, 0x00, 0x00 };
62 /* nopl 0L(%[re]ax) */
63 static const char nop_7[] = { 0x0f, 0x1f, 0x80, 0x00, 0x00, 0x00, 0x00 };
64 /* nopl 0L(%[re]ax,%[re]ax,1) */
65 static const char nop_8[] =
66 { 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00};
67 /* nopw 0L(%[re]ax,%[re]ax,1) */
68 static const char nop_9[] =
69 { 0x66, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 };
70 /* nopw %cs:0L(%[re]ax,%[re]ax,1) */
71 static const char nop_10[] =
72 { 0x66, 0x2e, 0x0f, 0x1f, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 };
73 static const char *const nops[] =
74 { nop_1, nop_2, nop_3, nop_4, nop_5,
75 nop_6, nop_7, nop_8, nop_9, nop_10 };
76 bfd_size_type nop_size = long_nop ? ARRAY_SIZE (nops) : 2;
77
78 void *fill = bfd_malloc (count);
79 if (fill == NULL)
80 return fill;
81
82 if (code)
83 {
84 bfd_byte *p = fill;
85 while (count >= nop_size)
86 {
87 memcpy (p, nops[nop_size - 1], nop_size);
88 p += nop_size;
89 count -= nop_size;
90 }
91 if (count != 0)
92 memcpy (p, nops[count - 1], count);
93 }
94 else
95 memset (fill, 0, count);
96
97 return fill;
98 }
99
100 /* Fill the buffer with zero or short nop instruction if CODE is TRUE. */
101
102 void *
bfd_arch_i386_short_nop_fill(bfd_size_type count,bfd_boolean is_bigendian ATTRIBUTE_UNUSED,bfd_boolean code)103 bfd_arch_i386_short_nop_fill (bfd_size_type count,
104 bfd_boolean is_bigendian ATTRIBUTE_UNUSED,
105 bfd_boolean code)
106 {
107 return bfd_arch_i386_fill (count, code, FALSE);
108 }
109
110 /* Fill the buffer with zero or long nop instruction if CODE is TRUE. */
111
112 static void *
bfd_arch_i386_long_nop_fill(bfd_size_type count,bfd_boolean is_bigendian ATTRIBUTE_UNUSED,bfd_boolean code)113 bfd_arch_i386_long_nop_fill (bfd_size_type count,
114 bfd_boolean is_bigendian ATTRIBUTE_UNUSED,
115 bfd_boolean code)
116 {
117 return bfd_arch_i386_fill (count, code, TRUE);
118 }
119
120 /* Fill the buffer with zero, or one-byte nop instructions if CODE is TRUE. */
121
122 static void *
bfd_arch_i386_onebyte_nop_fill(bfd_size_type count,bfd_boolean is_bigendian ATTRIBUTE_UNUSED,bfd_boolean code)123 bfd_arch_i386_onebyte_nop_fill (bfd_size_type count,
124 bfd_boolean is_bigendian ATTRIBUTE_UNUSED,
125 bfd_boolean code)
126 {
127 void *fill = bfd_malloc (count);
128 if (fill != NULL)
129 memset (fill, code ? 0x90 : 0, count);
130 return fill;
131 }
132
133
134 static const bfd_arch_info_type bfd_x64_32_nacl_arch =
135 {
136 64, /* 64 bits in a word */
137 64, /* 64 bits in an address */
138 8, /* 8 bits in a byte */
139 bfd_arch_i386,
140 bfd_mach_x64_32_nacl,
141 "i386",
142 "i386:x64-32:nacl",
143 3,
144 FALSE,
145 bfd_i386_compatible,
146 bfd_default_scan,
147 bfd_arch_i386_onebyte_nop_fill,
148 NULL
149 };
150
151 static const bfd_arch_info_type bfd_x86_64_nacl_arch =
152 {
153 64, /* 64 bits in a word */
154 64, /* 64 bits in an address */
155 8, /* 8 bits in a byte */
156 bfd_arch_i386,
157 bfd_mach_x86_64_nacl,
158 "i386",
159 "i386:x86-64:nacl",
160 3,
161 FALSE,
162 bfd_i386_compatible,
163 bfd_default_scan,
164 bfd_arch_i386_onebyte_nop_fill,
165 &bfd_x64_32_nacl_arch
166 };
167
168 const bfd_arch_info_type bfd_i386_nacl_arch =
169 {
170 32, /* 32 bits in a word */
171 32, /* 32 bits in an address */
172 8, /* 8 bits in a byte */
173 bfd_arch_i386,
174 bfd_mach_i386_i386_nacl,
175 "i386",
176 "i386:nacl",
177 3,
178 TRUE,
179 bfd_i386_compatible,
180 bfd_default_scan,
181 bfd_arch_i386_onebyte_nop_fill,
182 &bfd_x86_64_nacl_arch
183 };
184
185 static const bfd_arch_info_type bfd_x64_32_arch_intel_syntax =
186 {
187 64, /* 64 bits in a word */
188 64, /* 64 bits in an address */
189 8, /* 8 bits in a byte */
190 bfd_arch_i386,
191 bfd_mach_x64_32_intel_syntax,
192 "i386:intel",
193 "i386:x64-32:intel",
194 3,
195 FALSE,
196 bfd_i386_compatible,
197 bfd_default_scan,
198 bfd_arch_i386_long_nop_fill,
199 &bfd_i386_nacl_arch
200 };
201
202 static const bfd_arch_info_type bfd_x86_64_arch_intel_syntax =
203 {
204 64, /* 64 bits in a word */
205 64, /* 64 bits in an address */
206 8, /* 8 bits in a byte */
207 bfd_arch_i386,
208 bfd_mach_x86_64_intel_syntax,
209 "i386:intel",
210 "i386:x86-64:intel",
211 3,
212 FALSE,
213 bfd_i386_compatible,
214 bfd_default_scan,
215 bfd_arch_i386_long_nop_fill,
216 &bfd_x64_32_arch_intel_syntax,
217 };
218
219 static const bfd_arch_info_type bfd_i386_arch_intel_syntax =
220 {
221 32, /* 32 bits in a word */
222 32, /* 32 bits in an address */
223 8, /* 8 bits in a byte */
224 bfd_arch_i386,
225 bfd_mach_i386_i386_intel_syntax,
226 "i386:intel",
227 "i386:intel",
228 3,
229 TRUE,
230 bfd_i386_compatible,
231 bfd_default_scan,
232 bfd_arch_i386_short_nop_fill,
233 &bfd_x86_64_arch_intel_syntax
234 };
235
236 static const bfd_arch_info_type i8086_arch =
237 {
238 32, /* 32 bits in a word */
239 32, /* 32 bits in an address (well, not really) */
240 8, /* 8 bits in a byte */
241 bfd_arch_i386,
242 bfd_mach_i386_i8086,
243 "i8086",
244 "i8086",
245 3,
246 FALSE,
247 bfd_i386_compatible,
248 bfd_default_scan,
249 bfd_arch_i386_short_nop_fill,
250 &bfd_i386_arch_intel_syntax
251 };
252
253 static const bfd_arch_info_type bfd_x64_32_arch =
254 {
255 64, /* 64 bits in a word */
256 64, /* 64 bits in an address */
257 8, /* 8 bits in a byte */
258 bfd_arch_i386,
259 bfd_mach_x64_32,
260 "i386",
261 "i386:x64-32",
262 3,
263 FALSE,
264 bfd_i386_compatible,
265 bfd_default_scan,
266 bfd_arch_i386_long_nop_fill,
267 &i8086_arch
268 };
269
270 static const bfd_arch_info_type bfd_x86_64_arch =
271 {
272 64, /* 64 bits in a word */
273 64, /* 64 bits in an address */
274 8, /* 8 bits in a byte */
275 bfd_arch_i386,
276 bfd_mach_x86_64,
277 "i386",
278 "i386:x86-64",
279 3,
280 FALSE,
281 bfd_i386_compatible,
282 bfd_default_scan,
283 bfd_arch_i386_long_nop_fill,
284 &bfd_x64_32_arch
285 };
286
287 const bfd_arch_info_type bfd_i386_arch =
288 {
289 32, /* 32 bits in a word */
290 32, /* 32 bits in an address */
291 8, /* 8 bits in a byte */
292 bfd_arch_i386,
293 bfd_mach_i386_i386,
294 "i386",
295 "i386",
296 3,
297 TRUE,
298 bfd_i386_compatible,
299 bfd_default_scan,
300 bfd_arch_i386_short_nop_fill,
301 &bfd_x86_64_arch
302 };
303