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0fc93e6b | 1 | /* Target-dependent code for NetBSD/i386, for GDB. |
4be87837 | 2 | Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003 |
0fc93e6b C |
3 | 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 2 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, write to the Free Software | |
19 | Foundation, Inc., 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "defs.h" | |
23 | #include "gdbtypes.h" | |
dfe6eb1f JT |
24 | #include "gdbcore.h" |
25 | #include "regcache.h" | |
3cac699e | 26 | #include "arch-utils.h" |
4be87837 | 27 | #include "osabi.h" |
0fc93e6b | 28 | |
3cac699e | 29 | #include "i386-tdep.h" |
dfe6eb1f | 30 | #include "i387-tdep.h" |
3cac699e | 31 | #include "nbsd-tdep.h" |
dfe6eb1f | 32 | |
7d400e77 JT |
33 | #include "solib-svr4.h" |
34 | ||
dfe6eb1f JT |
35 | /* Map a GDB register number to an offset in the reg structure. */ |
36 | static int regmap[] = | |
37 | { | |
38 | ( 0 * 4), /* %eax */ | |
39 | ( 1 * 4), /* %ecx */ | |
40 | ( 2 * 4), /* %edx */ | |
41 | ( 3 * 4), /* %ebx */ | |
42 | ( 4 * 4), /* %esp */ | |
43 | ( 5 * 4), /* %epb */ | |
44 | ( 6 * 4), /* %esi */ | |
45 | ( 7 * 4), /* %edi */ | |
46 | ( 8 * 4), /* %eip */ | |
47 | ( 9 * 4), /* %eflags */ | |
48 | (10 * 4), /* %cs */ | |
49 | (11 * 4), /* %ss */ | |
50 | (12 * 4), /* %ds */ | |
51 | (13 * 4), /* %es */ | |
52 | (14 * 4), /* %fs */ | |
53 | (15 * 4), /* %gs */ | |
54 | }; | |
55 | ||
56 | #define SIZEOF_STRUCT_REG (16 * 4) | |
57 | ||
58 | static void | |
59 | i386nbsd_supply_reg (char *regs, int regno) | |
60 | { | |
61 | int i; | |
62 | ||
63 | for (i = 0; i <= 15; i++) | |
64 | if (regno == i || regno == -1) | |
65 | supply_register (i, regs + regmap[i]); | |
66 | } | |
67 | ||
68 | static void | |
69 | fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, | |
70 | CORE_ADDR ignore) | |
71 | { | |
72 | char *regs, *fsave; | |
73 | ||
74 | /* We get everything from one section. */ | |
75 | if (which != 0) | |
76 | return; | |
77 | ||
78 | if (core_reg_size < (SIZEOF_STRUCT_REG + 108)) | |
79 | { | |
80 | warning ("Wrong size register set in core file."); | |
81 | return; | |
82 | } | |
83 | ||
84 | regs = core_reg_sect; | |
85 | fsave = core_reg_sect + SIZEOF_STRUCT_REG; | |
86 | ||
87 | /* Integer registers. */ | |
88 | i386nbsd_supply_reg (regs, -1); | |
89 | ||
90 | /* Floating point registers. */ | |
91 | i387_supply_fsave (fsave); | |
92 | } | |
93 | ||
94 | static void | |
6f558d74 MK |
95 | fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, |
96 | int which, CORE_ADDR ignore) | |
dfe6eb1f JT |
97 | { |
98 | switch (which) | |
99 | { | |
100 | case 0: /* Integer registers. */ | |
101 | if (core_reg_size != SIZEOF_STRUCT_REG) | |
102 | warning ("Wrong size register set in core file."); | |
103 | else | |
104 | i386nbsd_supply_reg (core_reg_sect, -1); | |
105 | break; | |
106 | ||
107 | case 2: /* Floating point registers. */ | |
108 | if (core_reg_size != 108) | |
109 | warning ("Wrong size FP register set in core file."); | |
110 | else | |
111 | i387_supply_fsave (core_reg_sect); | |
112 | break; | |
113 | ||
114 | case 3: /* "Extended" floating point registers. This is gdb-speak | |
115 | for SSE/SSE2. */ | |
116 | if (core_reg_size != 512) | |
117 | warning ("Wrong size XMM register set in core file."); | |
118 | else | |
119 | i387_supply_fxsave (core_reg_sect); | |
120 | break; | |
121 | ||
122 | default: | |
123 | /* Don't know what kind of register request this is; just ignore it. */ | |
124 | break; | |
125 | } | |
126 | } | |
127 | ||
128 | static struct core_fns i386nbsd_core_fns = | |
129 | { | |
130 | bfd_target_unknown_flavour, /* core_flavour */ | |
131 | default_check_format, /* check_format */ | |
132 | default_core_sniffer, /* core_sniffer */ | |
133 | fetch_core_registers, /* core_read_registers */ | |
134 | NULL /* next */ | |
135 | }; | |
136 | ||
137 | static struct core_fns i386nbsd_elfcore_fns = | |
138 | { | |
139 | bfd_target_elf_flavour, /* core_flavour */ | |
140 | default_check_format, /* check_format */ | |
141 | default_core_sniffer, /* core_sniffer */ | |
142 | fetch_elfcore_registers, /* core_read_registers */ | |
143 | NULL /* next */ | |
144 | }; | |
145 | ||
d66198e1 JT |
146 | /* Under NetBSD/i386, signal handler invocations can be identified by the |
147 | designated code sequence that is used to return from a signal handler. | |
148 | In particular, the return address of a signal handler points to the | |
149 | following code sequence: | |
150 | ||
151 | leal 0x10(%esp), %eax | |
152 | pushl %eax | |
153 | pushl %eax | |
154 | movl $0x127, %eax # __sigreturn14 | |
155 | int $0x80 | |
156 | ||
157 | Each instruction has a unique encoding, so we simply attempt to match | |
158 | the instruction the PC is pointing to with any of the above instructions. | |
159 | If there is a hit, we know the offset to the start of the designated | |
160 | sequence and can then check whether we really are executing in the | |
161 | signal trampoline. If not, -1 is returned, otherwise the offset from the | |
162 | start of the return sequence is returned. */ | |
163 | #define RETCODE_INSN1 0x8d | |
164 | #define RETCODE_INSN2 0x50 | |
165 | #define RETCODE_INSN3 0x50 | |
166 | #define RETCODE_INSN4 0xb8 | |
167 | #define RETCODE_INSN5 0xcd | |
168 | ||
169 | #define RETCODE_INSN2_OFF 4 | |
170 | #define RETCODE_INSN3_OFF 5 | |
171 | #define RETCODE_INSN4_OFF 6 | |
172 | #define RETCODE_INSN5_OFF 11 | |
173 | ||
174 | static const unsigned char sigtramp_retcode[] = | |
3cac699e | 175 | { |
d66198e1 JT |
176 | RETCODE_INSN1, 0x44, 0x24, 0x10, |
177 | RETCODE_INSN2, | |
178 | RETCODE_INSN3, | |
179 | RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00, | |
180 | RETCODE_INSN5, 0x80, | |
181 | }; | |
182 | ||
183 | static LONGEST | |
184 | i386nbsd_sigtramp_offset (CORE_ADDR pc) | |
185 | { | |
186 | unsigned char ret[sizeof(sigtramp_retcode)], insn; | |
187 | LONGEST off; | |
188 | int i; | |
189 | ||
190 | if (read_memory_nobpt (pc, &insn, 1) != 0) | |
191 | return -1; | |
192 | ||
193 | switch (insn) | |
194 | { | |
195 | case RETCODE_INSN1: | |
196 | off = 0; | |
197 | break; | |
198 | ||
199 | case RETCODE_INSN2: | |
200 | /* INSN2 and INSN3 are the same. Read at the location of PC+1 | |
201 | to determine if we're actually looking at INSN2 or INSN3. */ | |
202 | if (read_memory_nobpt (pc + 1, &insn, 1) != 0) | |
203 | return -1; | |
204 | ||
205 | if (insn == RETCODE_INSN3) | |
206 | off = RETCODE_INSN2_OFF; | |
207 | else | |
208 | off = RETCODE_INSN3_OFF; | |
209 | break; | |
3cac699e | 210 | |
d66198e1 JT |
211 | case RETCODE_INSN4: |
212 | off = RETCODE_INSN4_OFF; | |
213 | break; | |
214 | ||
215 | case RETCODE_INSN5: | |
216 | off = RETCODE_INSN5_OFF; | |
217 | break; | |
218 | ||
219 | default: | |
220 | return -1; | |
221 | } | |
222 | ||
223 | pc -= off; | |
3cac699e | 224 | |
d66198e1 JT |
225 | if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
226 | return -1; | |
3cac699e | 227 | |
d66198e1 JT |
228 | if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
229 | return off; | |
230 | ||
231 | return -1; | |
3cac699e JT |
232 | } |
233 | ||
d66198e1 JT |
234 | static int |
235 | i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
236 | { | |
d66198e1 JT |
237 | return (nbsd_pc_in_sigtramp (pc, name) |
238 | || i386nbsd_sigtramp_offset (pc) >= 0); | |
239 | } | |
3cac699e JT |
240 | |
241 | /* From <machine/signal.h>. */ | |
a3386186 MK |
242 | int i386nbsd_sc_reg_offset[I386_NUM_GREGS] = |
243 | { | |
244 | 10 * 4, /* %eax */ | |
245 | 9 * 4, /* %ecx */ | |
246 | 8 * 4, /* %edx */ | |
247 | 7 * 4, /* %ebx */ | |
248 | 14 * 4, /* %esp */ | |
249 | 6 * 4, /* %ebp */ | |
250 | 5 * 4, /* %esi */ | |
251 | 4 * 4, /* %edi */ | |
252 | 11 * 4, /* %eip */ | |
253 | 13 * 4, /* %eflags */ | |
254 | 12 * 4, /* %cs */ | |
255 | 15 * 4, /* %ss */ | |
256 | 3 * 4, /* %ds */ | |
257 | 2 * 4, /* %es */ | |
258 | 1 * 4, /* %fs */ | |
259 | 0 * 4 /* %gs */ | |
260 | }; | |
3cac699e JT |
261 | |
262 | static void | |
263 | i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
264 | { | |
265 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
266 | ||
267 | /* Obviously NetBSD is BSD-based. */ | |
268 | i386bsd_init_abi (info, gdbarch); | |
269 | ||
270 | /* NetBSD has different signal trampoline conventions. */ | |
271 | set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp); | |
4b218c18 MK |
272 | /* FIXME: kettenis/20020906: We should probably provide |
273 | NetBSD-specific versions of these functions if we want to | |
274 | recognize signal trampolines that live on the stack. */ | |
275 | set_gdbarch_sigtramp_start (gdbarch, NULL); | |
276 | set_gdbarch_sigtramp_end (gdbarch, NULL); | |
3cac699e JT |
277 | |
278 | /* NetBSD uses -freg-struct-return by default. */ | |
279 | tdep->struct_return = reg_struct_return; | |
280 | ||
3cac699e JT |
281 | /* NetBSD has a `struct sigcontext' that's different from the |
282 | origional 4.3 BSD. */ | |
a3386186 MK |
283 | tdep->sc_reg_offset = i386nbsd_sc_reg_offset; |
284 | tdep->sc_num_regs = I386_NUM_GREGS; | |
3cac699e JT |
285 | } |
286 | ||
287 | /* NetBSD ELF. */ | |
288 | static void | |
289 | i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
290 | { | |
291 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
292 | ||
293 | /* It's still NetBSD. */ | |
294 | i386nbsd_init_abi (info, gdbarch); | |
295 | ||
296 | /* But ELF-based. */ | |
297 | i386_elf_init_abi (info, gdbarch); | |
298 | ||
299 | /* NetBSD ELF uses SVR4-style shared libraries. */ | |
300 | set_gdbarch_in_solib_call_trampoline (gdbarch, | |
301 | generic_in_solib_call_trampoline); | |
7d400e77 JT |
302 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
303 | nbsd_ilp32_solib_svr4_fetch_link_map_offsets); | |
3cac699e JT |
304 | |
305 | /* NetBSD ELF uses -fpcc-struct-return by default. */ | |
306 | tdep->struct_return = pcc_struct_return; | |
307 | ||
308 | /* We support the SSE registers on NetBSD ELF. */ | |
309 | tdep->num_xmm_regs = I386_NUM_XREGS - 1; | |
310 | set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS | |
311 | + I386_NUM_XREGS); | |
312 | } | |
313 | ||
dfe6eb1f JT |
314 | void |
315 | _initialize_i386nbsd_tdep (void) | |
316 | { | |
317 | add_core_fns (&i386nbsd_core_fns); | |
318 | add_core_fns (&i386nbsd_elfcore_fns); | |
3cac699e | 319 | |
05816f70 | 320 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT, |
3cac699e | 321 | i386nbsd_init_abi); |
05816f70 | 322 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF, |
3cac699e | 323 | i386nbsdelf_init_abi); |
dfe6eb1f | 324 | } |