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0fc93e6b | 1 | /* Target-dependent code for NetBSD/i386, for GDB. |
dfe6eb1f | 2 | Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002 |
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" |
0fc93e6b | 27 | |
3cac699e | 28 | #include "i386-tdep.h" |
dfe6eb1f | 29 | #include "i387-tdep.h" |
3cac699e | 30 | #include "nbsd-tdep.h" |
dfe6eb1f | 31 | |
7d400e77 JT |
32 | #include "solib-svr4.h" |
33 | ||
dfe6eb1f JT |
34 | /* Map a GDB register number to an offset in the reg structure. */ |
35 | static int regmap[] = | |
36 | { | |
37 | ( 0 * 4), /* %eax */ | |
38 | ( 1 * 4), /* %ecx */ | |
39 | ( 2 * 4), /* %edx */ | |
40 | ( 3 * 4), /* %ebx */ | |
41 | ( 4 * 4), /* %esp */ | |
42 | ( 5 * 4), /* %epb */ | |
43 | ( 6 * 4), /* %esi */ | |
44 | ( 7 * 4), /* %edi */ | |
45 | ( 8 * 4), /* %eip */ | |
46 | ( 9 * 4), /* %eflags */ | |
47 | (10 * 4), /* %cs */ | |
48 | (11 * 4), /* %ss */ | |
49 | (12 * 4), /* %ds */ | |
50 | (13 * 4), /* %es */ | |
51 | (14 * 4), /* %fs */ | |
52 | (15 * 4), /* %gs */ | |
53 | }; | |
54 | ||
55 | #define SIZEOF_STRUCT_REG (16 * 4) | |
56 | ||
57 | static void | |
58 | i386nbsd_supply_reg (char *regs, int regno) | |
59 | { | |
60 | int i; | |
61 | ||
62 | for (i = 0; i <= 15; i++) | |
63 | if (regno == i || regno == -1) | |
64 | supply_register (i, regs + regmap[i]); | |
65 | } | |
66 | ||
67 | static void | |
68 | fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which, | |
69 | CORE_ADDR ignore) | |
70 | { | |
71 | char *regs, *fsave; | |
72 | ||
73 | /* We get everything from one section. */ | |
74 | if (which != 0) | |
75 | return; | |
76 | ||
77 | if (core_reg_size < (SIZEOF_STRUCT_REG + 108)) | |
78 | { | |
79 | warning ("Wrong size register set in core file."); | |
80 | return; | |
81 | } | |
82 | ||
83 | regs = core_reg_sect; | |
84 | fsave = core_reg_sect + SIZEOF_STRUCT_REG; | |
85 | ||
86 | /* Integer registers. */ | |
87 | i386nbsd_supply_reg (regs, -1); | |
88 | ||
89 | /* Floating point registers. */ | |
90 | i387_supply_fsave (fsave); | |
91 | } | |
92 | ||
93 | static void | |
6f558d74 MK |
94 | fetch_elfcore_registers (char *core_reg_sect, unsigned core_reg_size, |
95 | int which, CORE_ADDR ignore) | |
dfe6eb1f JT |
96 | { |
97 | switch (which) | |
98 | { | |
99 | case 0: /* Integer registers. */ | |
100 | if (core_reg_size != SIZEOF_STRUCT_REG) | |
101 | warning ("Wrong size register set in core file."); | |
102 | else | |
103 | i386nbsd_supply_reg (core_reg_sect, -1); | |
104 | break; | |
105 | ||
106 | case 2: /* Floating point registers. */ | |
107 | if (core_reg_size != 108) | |
108 | warning ("Wrong size FP register set in core file."); | |
109 | else | |
110 | i387_supply_fsave (core_reg_sect); | |
111 | break; | |
112 | ||
113 | case 3: /* "Extended" floating point registers. This is gdb-speak | |
114 | for SSE/SSE2. */ | |
115 | if (core_reg_size != 512) | |
116 | warning ("Wrong size XMM register set in core file."); | |
117 | else | |
118 | i387_supply_fxsave (core_reg_sect); | |
119 | break; | |
120 | ||
121 | default: | |
122 | /* Don't know what kind of register request this is; just ignore it. */ | |
123 | break; | |
124 | } | |
125 | } | |
126 | ||
127 | static struct core_fns i386nbsd_core_fns = | |
128 | { | |
129 | bfd_target_unknown_flavour, /* core_flavour */ | |
130 | default_check_format, /* check_format */ | |
131 | default_core_sniffer, /* core_sniffer */ | |
132 | fetch_core_registers, /* core_read_registers */ | |
133 | NULL /* next */ | |
134 | }; | |
135 | ||
136 | static struct core_fns i386nbsd_elfcore_fns = | |
137 | { | |
138 | bfd_target_elf_flavour, /* core_flavour */ | |
139 | default_check_format, /* check_format */ | |
140 | default_core_sniffer, /* core_sniffer */ | |
141 | fetch_elfcore_registers, /* core_read_registers */ | |
142 | NULL /* next */ | |
143 | }; | |
144 | ||
d66198e1 JT |
145 | /* Under NetBSD/i386, signal handler invocations can be identified by the |
146 | designated code sequence that is used to return from a signal handler. | |
147 | In particular, the return address of a signal handler points to the | |
148 | following code sequence: | |
149 | ||
150 | leal 0x10(%esp), %eax | |
151 | pushl %eax | |
152 | pushl %eax | |
153 | movl $0x127, %eax # __sigreturn14 | |
154 | int $0x80 | |
155 | ||
156 | Each instruction has a unique encoding, so we simply attempt to match | |
157 | the instruction the PC is pointing to with any of the above instructions. | |
158 | If there is a hit, we know the offset to the start of the designated | |
159 | sequence and can then check whether we really are executing in the | |
160 | signal trampoline. If not, -1 is returned, otherwise the offset from the | |
161 | start of the return sequence is returned. */ | |
162 | #define RETCODE_INSN1 0x8d | |
163 | #define RETCODE_INSN2 0x50 | |
164 | #define RETCODE_INSN3 0x50 | |
165 | #define RETCODE_INSN4 0xb8 | |
166 | #define RETCODE_INSN5 0xcd | |
167 | ||
168 | #define RETCODE_INSN2_OFF 4 | |
169 | #define RETCODE_INSN3_OFF 5 | |
170 | #define RETCODE_INSN4_OFF 6 | |
171 | #define RETCODE_INSN5_OFF 11 | |
172 | ||
173 | static const unsigned char sigtramp_retcode[] = | |
3cac699e | 174 | { |
d66198e1 JT |
175 | RETCODE_INSN1, 0x44, 0x24, 0x10, |
176 | RETCODE_INSN2, | |
177 | RETCODE_INSN3, | |
178 | RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00, | |
179 | RETCODE_INSN5, 0x80, | |
180 | }; | |
181 | ||
182 | static LONGEST | |
183 | i386nbsd_sigtramp_offset (CORE_ADDR pc) | |
184 | { | |
185 | unsigned char ret[sizeof(sigtramp_retcode)], insn; | |
186 | LONGEST off; | |
187 | int i; | |
188 | ||
189 | if (read_memory_nobpt (pc, &insn, 1) != 0) | |
190 | return -1; | |
191 | ||
192 | switch (insn) | |
193 | { | |
194 | case RETCODE_INSN1: | |
195 | off = 0; | |
196 | break; | |
197 | ||
198 | case RETCODE_INSN2: | |
199 | /* INSN2 and INSN3 are the same. Read at the location of PC+1 | |
200 | to determine if we're actually looking at INSN2 or INSN3. */ | |
201 | if (read_memory_nobpt (pc + 1, &insn, 1) != 0) | |
202 | return -1; | |
203 | ||
204 | if (insn == RETCODE_INSN3) | |
205 | off = RETCODE_INSN2_OFF; | |
206 | else | |
207 | off = RETCODE_INSN3_OFF; | |
208 | break; | |
3cac699e | 209 | |
d66198e1 JT |
210 | case RETCODE_INSN4: |
211 | off = RETCODE_INSN4_OFF; | |
212 | break; | |
213 | ||
214 | case RETCODE_INSN5: | |
215 | off = RETCODE_INSN5_OFF; | |
216 | break; | |
217 | ||
218 | default: | |
219 | return -1; | |
220 | } | |
221 | ||
222 | pc -= off; | |
3cac699e | 223 | |
d66198e1 JT |
224 | if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
225 | return -1; | |
3cac699e | 226 | |
d66198e1 JT |
227 | if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
228 | return off; | |
229 | ||
230 | return -1; | |
3cac699e JT |
231 | } |
232 | ||
d66198e1 JT |
233 | static int |
234 | i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
235 | { | |
d66198e1 JT |
236 | return (nbsd_pc_in_sigtramp (pc, name) |
237 | || i386nbsd_sigtramp_offset (pc) >= 0); | |
238 | } | |
3cac699e JT |
239 | |
240 | /* From <machine/signal.h>. */ | |
241 | int i386nbsd_sc_pc_offset = 44; | |
242 | int i386nbsd_sc_sp_offset = 56; | |
243 | ||
244 | static void | |
245 | i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
246 | { | |
247 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
248 | ||
249 | /* Obviously NetBSD is BSD-based. */ | |
250 | i386bsd_init_abi (info, gdbarch); | |
251 | ||
252 | /* NetBSD has different signal trampoline conventions. */ | |
253 | set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp); | |
4b218c18 MK |
254 | /* FIXME: kettenis/20020906: We should probably provide |
255 | NetBSD-specific versions of these functions if we want to | |
256 | recognize signal trampolines that live on the stack. */ | |
257 | set_gdbarch_sigtramp_start (gdbarch, NULL); | |
258 | set_gdbarch_sigtramp_end (gdbarch, NULL); | |
3cac699e JT |
259 | |
260 | /* NetBSD uses -freg-struct-return by default. */ | |
261 | tdep->struct_return = reg_struct_return; | |
262 | ||
3cac699e JT |
263 | /* NetBSD has a `struct sigcontext' that's different from the |
264 | origional 4.3 BSD. */ | |
265 | tdep->sc_pc_offset = i386nbsd_sc_pc_offset; | |
266 | tdep->sc_sp_offset = i386nbsd_sc_sp_offset; | |
267 | } | |
268 | ||
269 | /* NetBSD ELF. */ | |
270 | static void | |
271 | i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
272 | { | |
273 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
274 | ||
275 | /* It's still NetBSD. */ | |
276 | i386nbsd_init_abi (info, gdbarch); | |
277 | ||
278 | /* But ELF-based. */ | |
279 | i386_elf_init_abi (info, gdbarch); | |
280 | ||
281 | /* NetBSD ELF uses SVR4-style shared libraries. */ | |
282 | set_gdbarch_in_solib_call_trampoline (gdbarch, | |
283 | generic_in_solib_call_trampoline); | |
7d400e77 JT |
284 | set_solib_svr4_fetch_link_map_offsets (gdbarch, |
285 | nbsd_ilp32_solib_svr4_fetch_link_map_offsets); | |
3cac699e JT |
286 | |
287 | /* NetBSD ELF uses -fpcc-struct-return by default. */ | |
288 | tdep->struct_return = pcc_struct_return; | |
289 | ||
290 | /* We support the SSE registers on NetBSD ELF. */ | |
291 | tdep->num_xmm_regs = I386_NUM_XREGS - 1; | |
292 | set_gdbarch_num_regs (gdbarch, I386_NUM_GREGS + I386_NUM_FREGS | |
293 | + I386_NUM_XREGS); | |
294 | } | |
295 | ||
dfe6eb1f JT |
296 | void |
297 | _initialize_i386nbsd_tdep (void) | |
298 | { | |
299 | add_core_fns (&i386nbsd_core_fns); | |
300 | add_core_fns (&i386nbsd_elfcore_fns); | |
3cac699e JT |
301 | |
302 | gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_AOUT, | |
303 | i386nbsd_init_abi); | |
304 | gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_NETBSD_ELF, | |
305 | i386nbsdelf_init_abi); | |
dfe6eb1f | 306 | } |