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1e067c66 MK |
1 | /* Target-dependent code for OpenBSD/sparc64. |
2 | ||
3 | Copyright 2004 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 "frame.h" | |
24 | #include "frame-unwind.h" | |
25 | #include "osabi.h" | |
26 | #include "regset.h" | |
27 | #include "symtab.h" | |
28 | #include "solib-svr4.h" | |
29 | #include "trad-frame.h" | |
30 | ||
31 | #include "gdb_assert.h" | |
32 | ||
33 | #include "sparc64-tdep.h" | |
34 | #include "nbsd-tdep.h" | |
35 | ||
36 | /* OpenBSD uses the traditional NetBSD core file format, even for | |
37 | ports that use ELF. The core files don't use multiple register | |
38 | sets. Instead, the general-purpose and floating-point registers | |
39 | are lumped together in a single section. Unlike on NetBSD, OpenBSD | |
40 | uses a different layout for its general-purpose registers than the | |
41 | layout used for ptrace(2). */ | |
42 | ||
43 | /* From <machine/reg.h>. */ | |
44 | const struct sparc_gregset sparc64obsd_core_gregset = | |
45 | { | |
46 | 0 * 8, /* "tstate" */ | |
47 | 1 * 8, /* %pc */ | |
48 | 2 * 8, /* %npc */ | |
49 | 3 * 8, /* %y */ | |
50 | -1, /* %fprs */ | |
51 | -1, | |
52 | 7 * 8, /* %g1 */ | |
53 | 22 * 8, /* %l0 */ | |
54 | 4 /* sizeof (%y) */ | |
55 | }; | |
56 | ||
57 | static void | |
58 | sparc64obsd_supply_gregset (const struct regset *regset, | |
59 | struct regcache *regcache, | |
60 | int regnum, const void *gregs, size_t len) | |
61 | { | |
62 | const char *regs = gregs; | |
63 | ||
9ea75c57 | 64 | sparc64_supply_gregset (&sparc64obsd_core_gregset, regcache, regnum, regs); |
1e067c66 MK |
65 | sparc64_supply_fpregset (regcache, regnum, regs + 288); |
66 | } | |
67 | \f | |
68 | ||
69 | /* Signal trampolines. */ | |
70 | ||
71 | /* The OpenBSD kernel maps the signal trampoline at some random | |
72 | location in user space, which means that the traditional BSD way of | |
73 | detecting it won't work. | |
74 | ||
75 | The signal trampoline will be mapped at an address that is page | |
76 | aligned. We recognize the signal trampoline by the looking for the | |
dc856692 MK |
77 | sigreturn system call. The offset where we can find the code that |
78 | makes this system call varies from release to release. For OpenBSD | |
79 | 3.6 and later releases we can find the code at offset 0xec. For | |
80 | OpenBSD 3.5 and earlier releases, we find it at offset 0xe8. */ | |
1e067c66 MK |
81 | |
82 | static const int sparc64obsd_page_size = 8192; | |
dc856692 | 83 | static const int sparc64obsd_sigreturn_offset[] = { 0xec, 0xe8, -1 }; |
1e067c66 MK |
84 | |
85 | static int | |
86 | sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
87 | { | |
88 | CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); | |
89 | unsigned long insn; | |
dc856692 | 90 | const int *offset; |
1e067c66 MK |
91 | |
92 | if (name) | |
93 | return 0; | |
94 | ||
dc856692 | 95 | for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) |
24f033e8 | 96 | { |
dc856692 MK |
97 | /* Check for "restore %g0, SYS_sigreturn, %g1". */ |
98 | insn = sparc_fetch_instruction (start_pc + *offset); | |
99 | if (insn != 0x83e82067) | |
100 | continue; | |
1e067c66 | 101 | |
dc856692 MK |
102 | /* Check for "t ST_SYSCALL". */ |
103 | insn = sparc_fetch_instruction (start_pc + *offset + 8); | |
104 | if (insn != 0x91d02000) | |
105 | continue; | |
106 | ||
107 | return 1; | |
5a5effe1 | 108 | } |
1e067c66 | 109 | |
dc856692 | 110 | return 0; |
1e067c66 MK |
111 | } |
112 | ||
113 | static struct sparc_frame_cache * | |
114 | sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache) | |
115 | { | |
116 | struct sparc_frame_cache *cache; | |
117 | CORE_ADDR addr; | |
118 | ||
119 | if (*this_cache) | |
120 | return *this_cache; | |
121 | ||
122 | cache = sparc_frame_cache (next_frame, this_cache); | |
123 | gdb_assert (cache == *this_cache); | |
124 | ||
125 | /* If we couldn't find the frame's function, we're probably dealing | |
126 | with an on-stack signal trampoline. */ | |
127 | if (cache->pc == 0) | |
128 | { | |
129 | cache->pc = frame_pc_unwind (next_frame); | |
130 | cache->pc &= ~(sparc64obsd_page_size - 1); | |
131 | ||
132 | /* Since we couldn't find the frame's function, the cache was | |
133 | initialized under the assumption that we're frameless. */ | |
134 | cache->frameless_p = 0; | |
135 | addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); | |
136 | cache->base = addr; | |
137 | } | |
138 | ||
139 | /* We find the appropriate instance of `struct sigcontext' at a | |
140 | fixed offset in the signal frame. */ | |
141 | addr = cache->base + BIAS + 128 + 16; | |
142 | cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame); | |
143 | ||
144 | return cache; | |
145 | } | |
146 | ||
147 | static void | |
148 | sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, | |
149 | struct frame_id *this_id) | |
150 | { | |
151 | struct sparc_frame_cache *cache = | |
152 | sparc64obsd_frame_cache (next_frame, this_cache); | |
153 | ||
154 | (*this_id) = frame_id_build (cache->base, cache->pc); | |
155 | } | |
156 | ||
157 | static void | |
158 | sparc64obsd_frame_prev_register (struct frame_info *next_frame, | |
159 | void **this_cache, | |
160 | int regnum, int *optimizedp, | |
161 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
162 | int *realnump, void *valuep) | |
163 | { | |
164 | struct sparc_frame_cache *cache = | |
165 | sparc64obsd_frame_cache (next_frame, this_cache); | |
166 | ||
1f67027d AC |
167 | trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum, |
168 | optimizedp, lvalp, addrp, realnump, valuep); | |
1e067c66 MK |
169 | } |
170 | ||
171 | static const struct frame_unwind sparc64obsd_frame_unwind = | |
172 | { | |
173 | SIGTRAMP_FRAME, | |
174 | sparc64obsd_frame_this_id, | |
175 | sparc64obsd_frame_prev_register | |
176 | }; | |
177 | ||
178 | static const struct frame_unwind * | |
179 | sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) | |
180 | { | |
181 | CORE_ADDR pc = frame_pc_unwind (next_frame); | |
182 | char *name; | |
183 | ||
184 | find_pc_partial_function (pc, &name, NULL, NULL); | |
185 | if (sparc64obsd_pc_in_sigtramp (pc, name)) | |
186 | return &sparc64obsd_frame_unwind; | |
187 | ||
188 | return NULL; | |
189 | } | |
190 | \f | |
191 | ||
192 | static void | |
193 | sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
194 | { | |
195 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
196 | ||
9ea75c57 | 197 | tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL); |
1e067c66 MK |
198 | tdep->sizeof_gregset = 832; |
199 | ||
1e067c66 MK |
200 | frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer); |
201 | ||
202 | sparc64_init_abi (info, gdbarch); | |
203 | ||
204 | set_solib_svr4_fetch_link_map_offsets | |
205 | (gdbarch, nbsd_lp64_solib_svr4_fetch_link_map_offsets); | |
206 | } | |
207 | ||
208 | \f | |
209 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
210 | void _initialize_sparc64obsd_tdep (void); | |
211 | ||
212 | void | |
213 | _initialize_sparc64obsd_tdep (void) | |
214 | { | |
215 | gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, | |
216 | GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); | |
217 | } |