Commit | Line | Data |
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ed504bdf MK |
1 | /* Target-dependent code for NetBSD/i386. |
2 | ||
7e654c37 MK |
3 | Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, |
4 | 2003, 2004 | |
0fc93e6b C |
5 | Free Software Foundation, Inc. |
6 | ||
7 | This file is part of GDB. | |
8 | ||
9 | This program is free software; you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 2 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | This program is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with this program; if not, write to the Free Software | |
21 | Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | Boston, MA 02111-1307, USA. */ | |
23 | ||
24 | #include "defs.h" | |
13739f4d | 25 | #include "arch-utils.h" |
dfe6eb1f JT |
26 | #include "gdbcore.h" |
27 | #include "regcache.h" | |
13739f4d | 28 | #include "regset.h" |
4be87837 | 29 | #include "osabi.h" |
0fc93e6b | 30 | |
13739f4d MK |
31 | #include "gdb_assert.h" |
32 | #include "gdb_string.h" | |
33 | ||
3cac699e | 34 | #include "i386-tdep.h" |
dfe6eb1f | 35 | #include "i387-tdep.h" |
3cac699e | 36 | #include "nbsd-tdep.h" |
7d400e77 JT |
37 | #include "solib-svr4.h" |
38 | ||
13739f4d MK |
39 | /* From <machine/reg.h>. */ |
40 | static int i386nbsd_r_reg_offset[] = | |
dfe6eb1f | 41 | { |
13739f4d MK |
42 | 0 * 4, /* %eax */ |
43 | 1 * 4, /* %ecx */ | |
44 | 2 * 4, /* %edx */ | |
45 | 3 * 4, /* %ebx */ | |
46 | 4 * 4, /* %esp */ | |
47 | 5 * 4, /* %ebp */ | |
48 | 6 * 4, /* %esi */ | |
49 | 7 * 4, /* %edi */ | |
50 | 8 * 4, /* %eip */ | |
51 | 9 * 4, /* %eflags */ | |
52 | 10 * 4, /* %cs */ | |
53 | 11 * 4, /* %ss */ | |
54 | 12 * 4, /* %ds */ | |
55 | 13 * 4, /* %es */ | |
56 | 14 * 4, /* %fs */ | |
57 | 15 * 4 /* %gs */ | |
dfe6eb1f JT |
58 | }; |
59 | ||
dfe6eb1f | 60 | static void |
13739f4d MK |
61 | i386nbsd_aout_supply_regset (const struct regset *regset, |
62 | struct regcache *regcache, int regnum, | |
63 | const void *regs, size_t len) | |
dfe6eb1f | 64 | { |
13739f4d MK |
65 | const struct gdbarch_tdep *tdep = regset->descr; |
66 | ||
67 | gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE); | |
dfe6eb1f | 68 | |
13739f4d MK |
69 | i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); |
70 | i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset); | |
dfe6eb1f JT |
71 | } |
72 | ||
49cfa46f | 73 | static const struct regset * |
13739f4d MK |
74 | i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch, |
75 | const char *sect_name, | |
76 | size_t sect_size) | |
dfe6eb1f | 77 | { |
13739f4d | 78 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
dfe6eb1f | 79 | |
13739f4d MK |
80 | /* NetBSD a.out core dumps don't use seperate register sets for the |
81 | general-purpose and floating-point registers. */ | |
dfe6eb1f | 82 | |
13739f4d MK |
83 | if (strcmp (sect_name, ".reg") == 0 |
84 | && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE) | |
dfe6eb1f | 85 | { |
13739f4d MK |
86 | if (tdep->gregset == NULL) |
87 | { | |
88 | tdep->gregset = XMALLOC (struct regset); | |
89 | tdep->gregset->descr = tdep; | |
90 | tdep->gregset->supply_regset = i386nbsd_aout_supply_regset; | |
91 | } | |
92 | return tdep->gregset; | |
dfe6eb1f JT |
93 | } |
94 | ||
13739f4d | 95 | return NULL; |
dfe6eb1f JT |
96 | } |
97 | ||
d66198e1 JT |
98 | /* Under NetBSD/i386, signal handler invocations can be identified by the |
99 | designated code sequence that is used to return from a signal handler. | |
100 | In particular, the return address of a signal handler points to the | |
101 | following code sequence: | |
102 | ||
103 | leal 0x10(%esp), %eax | |
104 | pushl %eax | |
105 | pushl %eax | |
106 | movl $0x127, %eax # __sigreturn14 | |
107 | int $0x80 | |
108 | ||
109 | Each instruction has a unique encoding, so we simply attempt to match | |
110 | the instruction the PC is pointing to with any of the above instructions. | |
111 | If there is a hit, we know the offset to the start of the designated | |
112 | sequence and can then check whether we really are executing in the | |
113 | signal trampoline. If not, -1 is returned, otherwise the offset from the | |
114 | start of the return sequence is returned. */ | |
115 | #define RETCODE_INSN1 0x8d | |
116 | #define RETCODE_INSN2 0x50 | |
117 | #define RETCODE_INSN3 0x50 | |
118 | #define RETCODE_INSN4 0xb8 | |
119 | #define RETCODE_INSN5 0xcd | |
120 | ||
121 | #define RETCODE_INSN2_OFF 4 | |
122 | #define RETCODE_INSN3_OFF 5 | |
123 | #define RETCODE_INSN4_OFF 6 | |
124 | #define RETCODE_INSN5_OFF 11 | |
125 | ||
126 | static const unsigned char sigtramp_retcode[] = | |
3cac699e | 127 | { |
d66198e1 JT |
128 | RETCODE_INSN1, 0x44, 0x24, 0x10, |
129 | RETCODE_INSN2, | |
130 | RETCODE_INSN3, | |
131 | RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00, | |
132 | RETCODE_INSN5, 0x80, | |
133 | }; | |
134 | ||
135 | static LONGEST | |
136 | i386nbsd_sigtramp_offset (CORE_ADDR pc) | |
137 | { | |
138 | unsigned char ret[sizeof(sigtramp_retcode)], insn; | |
139 | LONGEST off; | |
140 | int i; | |
141 | ||
142 | if (read_memory_nobpt (pc, &insn, 1) != 0) | |
143 | return -1; | |
144 | ||
145 | switch (insn) | |
146 | { | |
147 | case RETCODE_INSN1: | |
148 | off = 0; | |
149 | break; | |
150 | ||
151 | case RETCODE_INSN2: | |
152 | /* INSN2 and INSN3 are the same. Read at the location of PC+1 | |
153 | to determine if we're actually looking at INSN2 or INSN3. */ | |
154 | if (read_memory_nobpt (pc + 1, &insn, 1) != 0) | |
155 | return -1; | |
156 | ||
157 | if (insn == RETCODE_INSN3) | |
158 | off = RETCODE_INSN2_OFF; | |
159 | else | |
160 | off = RETCODE_INSN3_OFF; | |
161 | break; | |
3cac699e | 162 | |
d66198e1 JT |
163 | case RETCODE_INSN4: |
164 | off = RETCODE_INSN4_OFF; | |
165 | break; | |
166 | ||
167 | case RETCODE_INSN5: | |
168 | off = RETCODE_INSN5_OFF; | |
169 | break; | |
170 | ||
171 | default: | |
172 | return -1; | |
173 | } | |
174 | ||
175 | pc -= off; | |
3cac699e | 176 | |
d66198e1 JT |
177 | if (read_memory_nobpt (pc, (char *) ret, sizeof (ret)) != 0) |
178 | return -1; | |
3cac699e | 179 | |
d66198e1 JT |
180 | if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
181 | return off; | |
182 | ||
183 | return -1; | |
3cac699e JT |
184 | } |
185 | ||
d66198e1 JT |
186 | static int |
187 | i386nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
188 | { | |
d66198e1 JT |
189 | return (nbsd_pc_in_sigtramp (pc, name) |
190 | || i386nbsd_sigtramp_offset (pc) >= 0); | |
191 | } | |
3cac699e JT |
192 | |
193 | /* From <machine/signal.h>. */ | |
13739f4d | 194 | int i386nbsd_sc_reg_offset[] = |
a3386186 MK |
195 | { |
196 | 10 * 4, /* %eax */ | |
197 | 9 * 4, /* %ecx */ | |
198 | 8 * 4, /* %edx */ | |
199 | 7 * 4, /* %ebx */ | |
200 | 14 * 4, /* %esp */ | |
201 | 6 * 4, /* %ebp */ | |
202 | 5 * 4, /* %esi */ | |
203 | 4 * 4, /* %edi */ | |
204 | 11 * 4, /* %eip */ | |
205 | 13 * 4, /* %eflags */ | |
206 | 12 * 4, /* %cs */ | |
207 | 15 * 4, /* %ss */ | |
208 | 3 * 4, /* %ds */ | |
209 | 2 * 4, /* %es */ | |
210 | 1 * 4, /* %fs */ | |
211 | 0 * 4 /* %gs */ | |
212 | }; | |
3cac699e JT |
213 | |
214 | static void | |
215 | i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
216 | { | |
217 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
218 | ||
219 | /* Obviously NetBSD is BSD-based. */ | |
220 | i386bsd_init_abi (info, gdbarch); | |
221 | ||
13739f4d MK |
222 | /* NetBSD has a different `struct reg'. */ |
223 | tdep->gregset_reg_offset = i386nbsd_r_reg_offset; | |
224 | tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset); | |
225 | tdep->sizeof_gregset = 16 * 4; | |
226 | ||
3cac699e JT |
227 | /* NetBSD has different signal trampoline conventions. */ |
228 | set_gdbarch_pc_in_sigtramp (gdbarch, i386nbsd_pc_in_sigtramp); | |
4b218c18 MK |
229 | /* FIXME: kettenis/20020906: We should probably provide |
230 | NetBSD-specific versions of these functions if we want to | |
231 | recognize signal trampolines that live on the stack. */ | |
232 | set_gdbarch_sigtramp_start (gdbarch, NULL); | |
233 | set_gdbarch_sigtramp_end (gdbarch, NULL); | |
3cac699e JT |
234 | |
235 | /* NetBSD uses -freg-struct-return by default. */ | |
236 | tdep->struct_return = reg_struct_return; | |
237 | ||
3cac699e JT |
238 | /* NetBSD has a `struct sigcontext' that's different from the |
239 | origional 4.3 BSD. */ | |
a3386186 | 240 | tdep->sc_reg_offset = i386nbsd_sc_reg_offset; |
13739f4d MK |
241 | tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset); |
242 | } | |
243 | ||
244 | /* NetBSD a.out. */ | |
245 | ||
246 | static void | |
247 | i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
248 | { | |
249 | i386nbsd_init_abi (info, gdbarch); | |
250 | ||
251 | /* NetBSD a.out has a single register set. */ | |
252 | set_gdbarch_regset_from_core_section | |
253 | (gdbarch, i386nbsd_aout_regset_from_core_section); | |
3cac699e JT |
254 | } |
255 | ||
256 | /* NetBSD ELF. */ | |
13739f4d | 257 | |
3cac699e JT |
258 | static void |
259 | i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
260 | { | |
261 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
262 | ||
263 | /* It's still NetBSD. */ | |
264 | i386nbsd_init_abi (info, gdbarch); | |
265 | ||
266 | /* But ELF-based. */ | |
267 | i386_elf_init_abi (info, gdbarch); | |
268 | ||
269 | /* NetBSD ELF uses SVR4-style shared libraries. */ | |
7e654c37 MK |
270 | set_gdbarch_in_solib_call_trampoline |
271 | (gdbarch, generic_in_solib_call_trampoline); | |
13739f4d | 272 | set_solib_svr4_fetch_link_map_offsets |
7e654c37 | 273 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
3cac699e JT |
274 | |
275 | /* NetBSD ELF uses -fpcc-struct-return by default. */ | |
276 | tdep->struct_return = pcc_struct_return; | |
3cac699e JT |
277 | } |
278 | ||
dfe6eb1f JT |
279 | void |
280 | _initialize_i386nbsd_tdep (void) | |
281 | { | |
05816f70 | 282 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT, |
13739f4d | 283 | i386nbsdaout_init_abi); |
05816f70 | 284 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF, |
3cac699e | 285 | i386nbsdelf_init_abi); |
dfe6eb1f | 286 | } |