Commit | Line | Data |
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ed504bdf MK |
1 | /* Target-dependent code for NetBSD/i386. |
2 | ||
6aba47ca DJ |
3 | Copyright (C) 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003, |
4 | 2004, 2007 Free Software Foundation, Inc. | |
0fc93e6b C |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
197e01b6 EZ |
20 | Foundation, Inc., 51 Franklin Street, Fifth Floor, |
21 | Boston, MA 02110-1301, USA. */ | |
0fc93e6b C |
22 | |
23 | #include "defs.h" | |
13739f4d | 24 | #include "arch-utils.h" |
911bc6ee | 25 | #include "frame.h" |
dfe6eb1f JT |
26 | #include "gdbcore.h" |
27 | #include "regcache.h" | |
13739f4d | 28 | #include "regset.h" |
4be87837 | 29 | #include "osabi.h" |
911bc6ee | 30 | #include "symtab.h" |
0fc93e6b | 31 | |
13739f4d MK |
32 | #include "gdb_assert.h" |
33 | #include "gdb_string.h" | |
34 | ||
3cac699e | 35 | #include "i386-tdep.h" |
dfe6eb1f | 36 | #include "i387-tdep.h" |
3cac699e | 37 | #include "nbsd-tdep.h" |
7d400e77 JT |
38 | #include "solib-svr4.h" |
39 | ||
13739f4d MK |
40 | /* From <machine/reg.h>. */ |
41 | static int i386nbsd_r_reg_offset[] = | |
dfe6eb1f | 42 | { |
13739f4d MK |
43 | 0 * 4, /* %eax */ |
44 | 1 * 4, /* %ecx */ | |
45 | 2 * 4, /* %edx */ | |
46 | 3 * 4, /* %ebx */ | |
47 | 4 * 4, /* %esp */ | |
48 | 5 * 4, /* %ebp */ | |
49 | 6 * 4, /* %esi */ | |
50 | 7 * 4, /* %edi */ | |
51 | 8 * 4, /* %eip */ | |
52 | 9 * 4, /* %eflags */ | |
53 | 10 * 4, /* %cs */ | |
54 | 11 * 4, /* %ss */ | |
55 | 12 * 4, /* %ds */ | |
56 | 13 * 4, /* %es */ | |
57 | 14 * 4, /* %fs */ | |
58 | 15 * 4 /* %gs */ | |
dfe6eb1f JT |
59 | }; |
60 | ||
dfe6eb1f | 61 | static void |
13739f4d MK |
62 | i386nbsd_aout_supply_regset (const struct regset *regset, |
63 | struct regcache *regcache, int regnum, | |
64 | const void *regs, size_t len) | |
dfe6eb1f | 65 | { |
9ea75c57 | 66 | const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch); |
13739f4d MK |
67 | |
68 | gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE); | |
dfe6eb1f | 69 | |
13739f4d MK |
70 | i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset); |
71 | i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset); | |
dfe6eb1f JT |
72 | } |
73 | ||
49cfa46f | 74 | static const struct regset * |
13739f4d MK |
75 | i386nbsd_aout_regset_from_core_section (struct gdbarch *gdbarch, |
76 | const char *sect_name, | |
77 | size_t sect_size) | |
dfe6eb1f | 78 | { |
13739f4d | 79 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
dfe6eb1f | 80 | |
13739f4d MK |
81 | /* NetBSD a.out core dumps don't use seperate register sets for the |
82 | general-purpose and floating-point registers. */ | |
dfe6eb1f | 83 | |
13739f4d MK |
84 | if (strcmp (sect_name, ".reg") == 0 |
85 | && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE) | |
dfe6eb1f | 86 | { |
13739f4d | 87 | if (tdep->gregset == NULL) |
9ea75c57 MK |
88 | tdep->gregset = |
89 | regset_alloc (gdbarch, i386nbsd_aout_supply_regset, NULL); | |
13739f4d | 90 | return tdep->gregset; |
dfe6eb1f JT |
91 | } |
92 | ||
13739f4d | 93 | return NULL; |
dfe6eb1f JT |
94 | } |
95 | ||
d66198e1 JT |
96 | /* Under NetBSD/i386, signal handler invocations can be identified by the |
97 | designated code sequence that is used to return from a signal handler. | |
98 | In particular, the return address of a signal handler points to the | |
99 | following code sequence: | |
100 | ||
101 | leal 0x10(%esp), %eax | |
102 | pushl %eax | |
103 | pushl %eax | |
104 | movl $0x127, %eax # __sigreturn14 | |
105 | int $0x80 | |
106 | ||
107 | Each instruction has a unique encoding, so we simply attempt to match | |
108 | the instruction the PC is pointing to with any of the above instructions. | |
109 | If there is a hit, we know the offset to the start of the designated | |
110 | sequence and can then check whether we really are executing in the | |
111 | signal trampoline. If not, -1 is returned, otherwise the offset from the | |
112 | start of the return sequence is returned. */ | |
113 | #define RETCODE_INSN1 0x8d | |
114 | #define RETCODE_INSN2 0x50 | |
115 | #define RETCODE_INSN3 0x50 | |
116 | #define RETCODE_INSN4 0xb8 | |
117 | #define RETCODE_INSN5 0xcd | |
118 | ||
119 | #define RETCODE_INSN2_OFF 4 | |
120 | #define RETCODE_INSN3_OFF 5 | |
121 | #define RETCODE_INSN4_OFF 6 | |
122 | #define RETCODE_INSN5_OFF 11 | |
123 | ||
124 | static const unsigned char sigtramp_retcode[] = | |
3cac699e | 125 | { |
d66198e1 JT |
126 | RETCODE_INSN1, 0x44, 0x24, 0x10, |
127 | RETCODE_INSN2, | |
128 | RETCODE_INSN3, | |
129 | RETCODE_INSN4, 0x27, 0x01, 0x00, 0x00, | |
130 | RETCODE_INSN5, 0x80, | |
131 | }; | |
132 | ||
133 | static LONGEST | |
24f9f5e3 | 134 | i386nbsd_sigtramp_offset (struct frame_info *next_frame) |
d66198e1 | 135 | { |
24f9f5e3 | 136 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
d66198e1 JT |
137 | unsigned char ret[sizeof(sigtramp_retcode)], insn; |
138 | LONGEST off; | |
139 | int i; | |
140 | ||
24f9f5e3 | 141 | if (!safe_frame_unwind_memory (next_frame, pc, &insn, 1)) |
d66198e1 JT |
142 | return -1; |
143 | ||
144 | switch (insn) | |
145 | { | |
146 | case RETCODE_INSN1: | |
147 | off = 0; | |
148 | break; | |
149 | ||
150 | case RETCODE_INSN2: | |
151 | /* INSN2 and INSN3 are the same. Read at the location of PC+1 | |
152 | to determine if we're actually looking at INSN2 or INSN3. */ | |
24f9f5e3 | 153 | if (!safe_frame_unwind_memory (next_frame, pc + 1, &insn, 1)) |
d66198e1 JT |
154 | return -1; |
155 | ||
156 | if (insn == RETCODE_INSN3) | |
157 | off = RETCODE_INSN2_OFF; | |
158 | else | |
159 | off = RETCODE_INSN3_OFF; | |
160 | break; | |
3cac699e | 161 | |
d66198e1 JT |
162 | case RETCODE_INSN4: |
163 | off = RETCODE_INSN4_OFF; | |
164 | break; | |
165 | ||
166 | case RETCODE_INSN5: | |
167 | off = RETCODE_INSN5_OFF; | |
168 | break; | |
169 | ||
170 | default: | |
171 | return -1; | |
172 | } | |
173 | ||
174 | pc -= off; | |
3cac699e | 175 | |
24f9f5e3 | 176 | if (!safe_frame_unwind_memory (next_frame, pc, ret, sizeof (ret))) |
d66198e1 | 177 | return -1; |
3cac699e | 178 | |
d66198e1 JT |
179 | if (memcmp (ret, sigtramp_retcode, sizeof (ret)) == 0) |
180 | return off; | |
181 | ||
182 | return -1; | |
3cac699e JT |
183 | } |
184 | ||
377d9ebd | 185 | /* Return whether the frame preceding NEXT_FRAME corresponds to a |
911bc6ee MK |
186 | NetBSD sigtramp routine. */ |
187 | ||
d66198e1 | 188 | static int |
911bc6ee | 189 | i386nbsd_sigtramp_p (struct frame_info *next_frame) |
d66198e1 | 190 | { |
911bc6ee MK |
191 | CORE_ADDR pc = frame_pc_unwind (next_frame); |
192 | char *name; | |
193 | ||
194 | find_pc_partial_function (pc, &name, NULL, NULL); | |
d66198e1 | 195 | return (nbsd_pc_in_sigtramp (pc, name) |
24f9f5e3 | 196 | || i386nbsd_sigtramp_offset (next_frame) >= 0); |
d66198e1 | 197 | } |
3cac699e JT |
198 | |
199 | /* From <machine/signal.h>. */ | |
13739f4d | 200 | int i386nbsd_sc_reg_offset[] = |
a3386186 MK |
201 | { |
202 | 10 * 4, /* %eax */ | |
203 | 9 * 4, /* %ecx */ | |
204 | 8 * 4, /* %edx */ | |
205 | 7 * 4, /* %ebx */ | |
206 | 14 * 4, /* %esp */ | |
207 | 6 * 4, /* %ebp */ | |
208 | 5 * 4, /* %esi */ | |
209 | 4 * 4, /* %edi */ | |
210 | 11 * 4, /* %eip */ | |
211 | 13 * 4, /* %eflags */ | |
212 | 12 * 4, /* %cs */ | |
213 | 15 * 4, /* %ss */ | |
214 | 3 * 4, /* %ds */ | |
215 | 2 * 4, /* %es */ | |
216 | 1 * 4, /* %fs */ | |
217 | 0 * 4 /* %gs */ | |
218 | }; | |
3cac699e JT |
219 | |
220 | static void | |
221 | i386nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
222 | { | |
223 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
224 | ||
225 | /* Obviously NetBSD is BSD-based. */ | |
226 | i386bsd_init_abi (info, gdbarch); | |
227 | ||
13739f4d MK |
228 | /* NetBSD has a different `struct reg'. */ |
229 | tdep->gregset_reg_offset = i386nbsd_r_reg_offset; | |
230 | tdep->gregset_num_regs = ARRAY_SIZE (i386nbsd_r_reg_offset); | |
231 | tdep->sizeof_gregset = 16 * 4; | |
232 | ||
3cac699e | 233 | /* NetBSD has different signal trampoline conventions. */ |
911bc6ee MK |
234 | tdep->sigtramp_start = 0; |
235 | tdep->sigtramp_end = 0; | |
236 | tdep->sigtramp_p = i386nbsd_sigtramp_p; | |
3cac699e JT |
237 | |
238 | /* NetBSD uses -freg-struct-return by default. */ | |
239 | tdep->struct_return = reg_struct_return; | |
240 | ||
3cac699e | 241 | /* NetBSD has a `struct sigcontext' that's different from the |
f2e7c15d | 242 | original 4.3 BSD. */ |
a3386186 | 243 | tdep->sc_reg_offset = i386nbsd_sc_reg_offset; |
13739f4d MK |
244 | tdep->sc_num_regs = ARRAY_SIZE (i386nbsd_sc_reg_offset); |
245 | } | |
246 | ||
247 | /* NetBSD a.out. */ | |
248 | ||
249 | static void | |
250 | i386nbsdaout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
251 | { | |
252 | i386nbsd_init_abi (info, gdbarch); | |
253 | ||
254 | /* NetBSD a.out has a single register set. */ | |
255 | set_gdbarch_regset_from_core_section | |
256 | (gdbarch, i386nbsd_aout_regset_from_core_section); | |
3cac699e JT |
257 | } |
258 | ||
259 | /* NetBSD ELF. */ | |
13739f4d | 260 | |
3cac699e JT |
261 | static void |
262 | i386nbsdelf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
263 | { | |
264 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
265 | ||
266 | /* It's still NetBSD. */ | |
267 | i386nbsd_init_abi (info, gdbarch); | |
268 | ||
269 | /* But ELF-based. */ | |
270 | i386_elf_init_abi (info, gdbarch); | |
271 | ||
272 | /* NetBSD ELF uses SVR4-style shared libraries. */ | |
13739f4d | 273 | set_solib_svr4_fetch_link_map_offsets |
7e654c37 | 274 | (gdbarch, svr4_ilp32_fetch_link_map_offsets); |
3cac699e JT |
275 | |
276 | /* NetBSD ELF uses -fpcc-struct-return by default. */ | |
277 | tdep->struct_return = pcc_struct_return; | |
3cac699e JT |
278 | } |
279 | ||
dfe6eb1f JT |
280 | void |
281 | _initialize_i386nbsd_tdep (void) | |
282 | { | |
05816f70 | 283 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_AOUT, |
13739f4d | 284 | i386nbsdaout_init_abi); |
05816f70 | 285 | gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_NETBSD_ELF, |
3cac699e | 286 | i386nbsdelf_init_abi); |
dfe6eb1f | 287 | } |