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8a96bc77 MK |
1 | /* Target-dependent code for FreeBSD/i386. |
2 | ||
32d0add0 | 3 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
8a96bc77 MK |
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 | |
a9762ec7 | 9 | the Free Software Foundation; either version 3 of the License, or |
8a96bc77 MK |
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 | |
a9762ec7 | 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
8a96bc77 MK |
19 | |
20 | #include "defs.h" | |
21 | #include "arch-utils.h" | |
fa565c2b | 22 | #include "gdbcore.h" |
8a96bc77 | 23 | #include "osabi.h" |
fa565c2b MK |
24 | #include "regcache.h" |
25 | ||
8a96bc77 MK |
26 | #include "i386-tdep.h" |
27 | #include "i387-tdep.h" | |
fa565c2b | 28 | #include "bsd-uthread.h" |
490496c3 | 29 | #include "fbsd-tdep.h" |
7e654c37 | 30 | #include "solib-svr4.h" |
8a96bc77 | 31 | |
cf424aef JB |
32 | /* Support for signal handlers. */ |
33 | ||
34 | /* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp | |
35 | routine. */ | |
36 | ||
37 | /* FreeBSD/i386 supports three different signal trampolines, one for | |
38 | versions before 4.0, a second for 4.x, and a third for 5.0 and | |
39 | later. To complicate matters, FreeBSD/i386 binaries running under | |
40 | an amd64 kernel use a different set of trampolines. These | |
41 | trampolines differ from the i386 kernel trampolines in that they | |
42 | omit a middle section that conditionally restores %gs. */ | |
43 | ||
44 | static const gdb_byte i386fbsd_sigtramp_start[] = | |
45 | { | |
46 | 0x8d, 0x44, 0x24, 0x20, /* lea SIGF_UC(%esp),%eax */ | |
47 | 0x50 /* pushl %eax */ | |
48 | }; | |
49 | ||
50 | static const gdb_byte i386fbsd_sigtramp_middle[] = | |
51 | { | |
52 | 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00, | |
53 | /* testl $PSL_VM,UC_EFLAGS(%eax) */ | |
54 | 0x75, 0x03, /* jne +3 */ | |
55 | 0x8e, 0x68, 0x14 /* mov UC_GS(%eax),%gs */ | |
56 | }; | |
57 | ||
58 | static const gdb_byte i386fbsd_sigtramp_end[] = | |
59 | { | |
60 | 0xb8, 0xa1, 0x01, 0x00, 0x00, /* movl $SYS_sigreturn,%eax */ | |
61 | 0x50, /* pushl %eax */ | |
62 | 0xcd, 0x80 /* int $0x80 */ | |
63 | }; | |
64 | ||
65 | static const gdb_byte i386fbsd_freebsd4_sigtramp_start[] = | |
66 | { | |
67 | 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_UC4(%esp),%eax */ | |
68 | 0x50 /* pushl %eax */ | |
69 | }; | |
70 | ||
71 | static const gdb_byte i386fbsd_freebsd4_sigtramp_middle[] = | |
72 | { | |
73 | 0xf7, 0x40, 0x54, 0x00, 0x00, 0x02, 0x00, | |
74 | /* testl $PSL_VM,UC4_EFLAGS(%eax) */ | |
75 | 0x75, 0x03, /* jne +3 */ | |
76 | 0x8e, 0x68, 0x14 /* mov UC4_GS(%eax),%gs */ | |
77 | }; | |
78 | ||
79 | static const gdb_byte i386fbsd_freebsd4_sigtramp_end[] = | |
80 | { | |
81 | 0xb8, 0x58, 0x01, 0x00, 0x00, /* movl $344,%eax */ | |
82 | 0x50, /* pushl %eax */ | |
83 | 0xcd, 0x80 /* int $0x80 */ | |
84 | }; | |
85 | ||
86 | static const gdb_byte i386fbsd_osigtramp_start[] = | |
87 | { | |
88 | 0x8d, 0x44, 0x24, 0x14, /* lea SIGF_SC(%esp),%eax */ | |
89 | 0x50 /* pushl %eax */ | |
90 | }; | |
91 | ||
92 | static const gdb_byte i386fbsd_osigtramp_middle[] = | |
93 | { | |
94 | 0xf7, 0x40, 0x18, 0x00, 0x00, 0x02, 0x00, | |
95 | /* testl $PSL_VM,SC_PS(%eax) */ | |
96 | 0x75, 0x03, /* jne +3 */ | |
97 | 0x8e, 0x68, 0x44 /* mov SC_GS(%eax),%gs */ | |
98 | }; | |
99 | ||
100 | static const gdb_byte i386fbsd_osigtramp_end[] = | |
101 | { | |
102 | 0xb8, 0x67, 0x00, 0x00, 0x00, /* movl $103,%eax */ | |
103 | 0x50, /* pushl %eax */ | |
104 | 0xcd, 0x80 /* int $0x80 */ | |
105 | }; | |
106 | ||
107 | /* The three different trampolines are all the same size. */ | |
108 | gdb_static_assert (sizeof i386fbsd_sigtramp_start == | |
109 | sizeof i386fbsd_freebsd4_sigtramp_start); | |
110 | gdb_static_assert (sizeof i386fbsd_sigtramp_start == | |
111 | sizeof i386fbsd_osigtramp_start); | |
112 | gdb_static_assert (sizeof i386fbsd_sigtramp_middle == | |
113 | sizeof i386fbsd_freebsd4_sigtramp_middle); | |
114 | gdb_static_assert (sizeof i386fbsd_sigtramp_middle == | |
115 | sizeof i386fbsd_osigtramp_middle); | |
116 | gdb_static_assert (sizeof i386fbsd_sigtramp_end == | |
117 | sizeof i386fbsd_freebsd4_sigtramp_end); | |
118 | gdb_static_assert (sizeof i386fbsd_sigtramp_end == | |
119 | sizeof i386fbsd_osigtramp_end); | |
120 | ||
121 | /* We assume that the middle is the largest chunk below. */ | |
122 | gdb_static_assert (sizeof i386fbsd_sigtramp_middle > | |
123 | sizeof i386fbsd_sigtramp_start); | |
124 | gdb_static_assert (sizeof i386fbsd_sigtramp_middle > | |
125 | sizeof i386fbsd_sigtramp_end); | |
126 | ||
127 | static int | |
128 | i386fbsd_sigtramp_p (struct frame_info *this_frame) | |
129 | { | |
130 | CORE_ADDR pc = get_frame_pc (this_frame); | |
131 | gdb_byte buf[sizeof i386fbsd_sigtramp_middle]; | |
132 | const gdb_byte *middle, *end; | |
133 | ||
134 | /* Look for a matching start. */ | |
135 | if (!safe_frame_unwind_memory (this_frame, pc, buf, | |
136 | sizeof i386fbsd_sigtramp_start)) | |
137 | return 0; | |
138 | if (memcmp (buf, i386fbsd_sigtramp_start, sizeof i386fbsd_sigtramp_start) == | |
139 | 0) { | |
140 | middle = i386fbsd_sigtramp_middle; | |
141 | end = i386fbsd_sigtramp_end; | |
142 | } else if (memcmp (buf, i386fbsd_freebsd4_sigtramp_start, | |
143 | sizeof i386fbsd_freebsd4_sigtramp_start) == 0) { | |
144 | middle = i386fbsd_freebsd4_sigtramp_middle; | |
145 | end = i386fbsd_freebsd4_sigtramp_end; | |
146 | } else if (memcmp (buf, i386fbsd_osigtramp_start, | |
147 | sizeof i386fbsd_osigtramp_start) == 0) { | |
148 | middle = i386fbsd_osigtramp_middle; | |
149 | end = i386fbsd_osigtramp_end; | |
150 | } else | |
151 | return 0; | |
152 | ||
153 | /* Since the end is shorter than the middle, check for a matching end | |
154 | next. */ | |
155 | pc += sizeof i386fbsd_sigtramp_start; | |
156 | if (!safe_frame_unwind_memory (this_frame, pc, buf, | |
157 | sizeof i386fbsd_sigtramp_end)) | |
158 | return 0; | |
159 | if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) == 0) | |
160 | return 1; | |
161 | ||
162 | /* If the end didn't match, check for a matching middle. */ | |
163 | if (!safe_frame_unwind_memory (this_frame, pc, buf, | |
164 | sizeof i386fbsd_sigtramp_middle)) | |
165 | return 0; | |
166 | if (memcmp (buf, middle, sizeof i386fbsd_sigtramp_middle) != 0) | |
167 | return 0; | |
168 | ||
169 | /* The middle matched, check for a matching end. */ | |
170 | pc += sizeof i386fbsd_sigtramp_middle; | |
171 | if (!safe_frame_unwind_memory (this_frame, pc, buf, | |
172 | sizeof i386fbsd_sigtramp_end)) | |
173 | return 0; | |
174 | if (memcmp (buf, end, sizeof i386fbsd_sigtramp_end) != 0) | |
175 | return 0; | |
176 | ||
177 | return 1; | |
178 | } | |
179 | ||
8a96bc77 MK |
180 | /* FreeBSD 3.0-RELEASE or later. */ |
181 | ||
182 | /* From <machine/reg.h>. */ | |
183 | static int i386fbsd_r_reg_offset[] = | |
184 | { | |
185 | 9 * 4, 8 * 4, 7 * 4, 6 * 4, /* %eax, %ecx, %edx, %ebx */ | |
186 | 15 * 4, 4 * 4, /* %esp, %ebp */ | |
187 | 3 * 4, 2 * 4, /* %esi, %edi */ | |
188 | 12 * 4, 14 * 4, /* %eip, %eflags */ | |
189 | 13 * 4, 16 * 4, /* %cs, %ss */ | |
190 | 1 * 4, 0 * 4, -1, -1 /* %ds, %es, %fs, %gs */ | |
191 | }; | |
192 | ||
5d93ae8c | 193 | /* Sigtramp routine location. */ |
cf424aef JB |
194 | CORE_ADDR i386fbsd_sigtramp_start_addr; |
195 | CORE_ADDR i386fbsd_sigtramp_end_addr; | |
8a96bc77 MK |
196 | |
197 | /* From <machine/signal.h>. */ | |
abfcdd21 | 198 | int i386fbsd_sc_reg_offset[] = |
8a96bc77 MK |
199 | { |
200 | 8 + 14 * 4, /* %eax */ | |
201 | 8 + 13 * 4, /* %ecx */ | |
202 | 8 + 12 * 4, /* %edx */ | |
203 | 8 + 11 * 4, /* %ebx */ | |
204 | 8 + 0 * 4, /* %esp */ | |
205 | 8 + 1 * 4, /* %ebp */ | |
206 | 8 + 10 * 4, /* %esi */ | |
207 | 8 + 9 * 4, /* %edi */ | |
208 | 8 + 3 * 4, /* %eip */ | |
209 | 8 + 4 * 4, /* %eflags */ | |
210 | 8 + 7 * 4, /* %cs */ | |
211 | 8 + 8 * 4, /* %ss */ | |
212 | 8 + 6 * 4, /* %ds */ | |
213 | 8 + 5 * 4, /* %es */ | |
214 | 8 + 15 * 4, /* %fs */ | |
215 | 8 + 16 * 4 /* %gs */ | |
216 | }; | |
217 | ||
1c02b2a5 | 218 | /* From /usr/src/lib/libc/i386/gen/_setjmp.S. */ |
fa565c2b MK |
219 | static int i386fbsd_jmp_buf_reg_offset[] = |
220 | { | |
221 | -1, /* %eax */ | |
222 | -1, /* %ecx */ | |
223 | -1, /* %edx */ | |
224 | 1 * 4, /* %ebx */ | |
225 | 2 * 4, /* %esp */ | |
226 | 3 * 4, /* %ebp */ | |
227 | 4 * 4, /* %esi */ | |
228 | 5 * 4, /* %edi */ | |
229 | 0 * 4 /* %eip */ | |
230 | }; | |
231 | ||
232 | static void | |
233 | i386fbsd_supply_uthread (struct regcache *regcache, | |
234 | int regnum, CORE_ADDR addr) | |
235 | { | |
e362b510 | 236 | gdb_byte buf[4]; |
fa565c2b MK |
237 | int i; |
238 | ||
239 | gdb_assert (regnum >= -1); | |
240 | ||
241 | for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++) | |
242 | { | |
243 | if (i386fbsd_jmp_buf_reg_offset[i] != -1 | |
244 | && (regnum == -1 || regnum == i)) | |
245 | { | |
246 | read_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4); | |
247 | regcache_raw_supply (regcache, i, buf); | |
248 | } | |
249 | } | |
250 | } | |
251 | ||
252 | static void | |
253 | i386fbsd_collect_uthread (const struct regcache *regcache, | |
254 | int regnum, CORE_ADDR addr) | |
255 | { | |
e362b510 | 256 | gdb_byte buf[4]; |
fa565c2b MK |
257 | int i; |
258 | ||
259 | gdb_assert (regnum >= -1); | |
260 | ||
261 | for (i = 0; i < ARRAY_SIZE (i386fbsd_jmp_buf_reg_offset); i++) | |
262 | { | |
263 | if (i386fbsd_jmp_buf_reg_offset[i] != -1 | |
264 | && (regnum == -1 || regnum == i)) | |
265 | { | |
266 | regcache_raw_collect (regcache, i, buf); | |
267 | write_memory (addr + i386fbsd_jmp_buf_reg_offset[i], buf, 4); | |
268 | } | |
269 | } | |
270 | } | |
271 | ||
8a96bc77 MK |
272 | static void |
273 | i386fbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
274 | { | |
275 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
276 | ||
277 | /* Obviously FreeBSD is BSD-based. */ | |
278 | i386bsd_init_abi (info, gdbarch); | |
279 | ||
280 | /* FreeBSD has a different `struct reg', and reserves some space for | |
281 | its FPU emulator in `struct fpreg'. */ | |
282 | tdep->gregset_reg_offset = i386fbsd_r_reg_offset; | |
283 | tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd_r_reg_offset); | |
284 | tdep->sizeof_gregset = 18 * 4; | |
285 | tdep->sizeof_fpregset = 176; | |
286 | ||
287 | /* FreeBSD uses -freg-struct-return by default. */ | |
288 | tdep->struct_return = reg_struct_return; | |
289 | ||
cf424aef JB |
290 | tdep->sigtramp_p = i386fbsd_sigtramp_p; |
291 | ||
8a96bc77 | 292 | /* FreeBSD uses a different memory layout. */ |
5d93ae8c MK |
293 | tdep->sigtramp_start = i386fbsd_sigtramp_start_addr; |
294 | tdep->sigtramp_end = i386fbsd_sigtramp_end_addr; | |
8a96bc77 MK |
295 | |
296 | /* FreeBSD has a more complete `struct sigcontext'. */ | |
297 | tdep->sc_reg_offset = i386fbsd_sc_reg_offset; | |
298 | tdep->sc_num_regs = ARRAY_SIZE (i386fbsd_sc_reg_offset); | |
fa565c2b MK |
299 | |
300 | /* FreeBSD provides a user-level threads implementation. */ | |
301 | bsd_uthread_set_supply_uthread (gdbarch, i386fbsd_supply_uthread); | |
302 | bsd_uthread_set_collect_uthread (gdbarch, i386fbsd_collect_uthread); | |
8a96bc77 MK |
303 | } |
304 | ||
305 | static void | |
306 | i386fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
307 | { | |
308 | /* It's almost identical to FreeBSD a.out. */ | |
309 | i386fbsdaout_init_abi (info, gdbarch); | |
310 | ||
311 | /* Except that it uses ELF. */ | |
312 | i386_elf_init_abi (info, gdbarch); | |
313 | ||
314 | /* FreeBSD ELF uses SVR4-style shared libraries. */ | |
7e654c37 MK |
315 | set_solib_svr4_fetch_link_map_offsets |
316 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); | |
8a96bc77 MK |
317 | } |
318 | ||
319 | /* FreeBSD 4.0-RELEASE or later. */ | |
320 | ||
321 | /* From <machine/reg.h>. */ | |
322 | static int i386fbsd4_r_reg_offset[] = | |
323 | { | |
324 | 10 * 4, 9 * 4, 8 * 4, 7 * 4, /* %eax, %ecx, %edx, %ebx */ | |
325 | 16 * 4, 5 * 4, /* %esp, %ebp */ | |
326 | 4 * 4, 3 * 4, /* %esi, %edi */ | |
327 | 13 * 4, 15 * 4, /* %eip, %eflags */ | |
328 | 14 * 4, 17 * 4, /* %cs, %ss */ | |
329 | 2 * 4, 1 * 4, 0 * 4, 18 * 4 /* %ds, %es, %fs, %gs */ | |
330 | }; | |
331 | ||
332 | /* From <machine/signal.h>. */ | |
333 | int i386fbsd4_sc_reg_offset[] = | |
334 | { | |
335 | 20 + 11 * 4, /* %eax */ | |
336 | 20 + 10 * 4, /* %ecx */ | |
337 | 20 + 9 * 4, /* %edx */ | |
338 | 20 + 8 * 4, /* %ebx */ | |
339 | 20 + 17 * 4, /* %esp */ | |
340 | 20 + 6 * 4, /* %ebp */ | |
341 | 20 + 5 * 4, /* %esi */ | |
342 | 20 + 4 * 4, /* %edi */ | |
343 | 20 + 14 * 4, /* %eip */ | |
344 | 20 + 16 * 4, /* %eflags */ | |
345 | 20 + 15 * 4, /* %cs */ | |
346 | 20 + 18 * 4, /* %ss */ | |
347 | 20 + 3 * 4, /* %ds */ | |
348 | 20 + 2 * 4, /* %es */ | |
349 | 20 + 1 * 4, /* %fs */ | |
350 | 20 + 0 * 4 /* %gs */ | |
351 | }; | |
352 | ||
353 | static void | |
354 | i386fbsd4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
355 | { | |
356 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
357 | ||
490496c3 AA |
358 | /* Generic FreeBSD support. */ |
359 | fbsd_init_abi (info, gdbarch); | |
360 | ||
8a96bc77 MK |
361 | /* Inherit stuff from older releases. We assume that FreeBSD |
362 | 4.0-RELEASE always uses ELF. */ | |
363 | i386fbsd_init_abi (info, gdbarch); | |
364 | ||
365 | /* FreeBSD 4.0 introduced a new `struct reg'. */ | |
366 | tdep->gregset_reg_offset = i386fbsd4_r_reg_offset; | |
367 | tdep->gregset_num_regs = ARRAY_SIZE (i386fbsd4_r_reg_offset); | |
368 | tdep->sizeof_gregset = 19 * 4; | |
369 | ||
370 | /* FreeBSD 4.0 introduced a new `struct sigcontext'. */ | |
371 | tdep->sc_reg_offset = i386fbsd4_sc_reg_offset; | |
372 | tdep->sc_num_regs = ARRAY_SIZE (i386fbsd4_sc_reg_offset); | |
373 | } | |
374 | ||
375 | \f | |
376 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
377 | void _initialize_i386fbsd_tdep (void); | |
378 | ||
379 | void | |
380 | _initialize_i386fbsd_tdep (void) | |
381 | { | |
382 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_AOUT, | |
383 | i386fbsdaout_init_abi); | |
384 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_FREEBSD_ELF, | |
385 | i386fbsd4_init_abi); | |
386 | } |