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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 | |
77 | sigreturn system call. */ | |
78 | ||
79 | static const int sparc64obsd_page_size = 8192; | |
80 | ||
81 | static int | |
82 | sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
83 | { | |
84 | CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); | |
85 | unsigned long insn; | |
24f033e8 | 86 | int offset = 0; |
1e067c66 MK |
87 | |
88 | if (name) | |
89 | return 0; | |
90 | ||
24f033e8 | 91 | retry: |
1e067c66 | 92 | /* Check for "restore %g0, SYS_sigreturn, %g1". */ |
24f033e8 | 93 | insn = sparc_fetch_instruction (start_pc + offset + 0xec); |
1e067c66 | 94 | if (insn != 0x83e82067) |
24f033e8 MK |
95 | { |
96 | if (offset == 0) | |
97 | { | |
98 | /* In OpenBSD 3.5 and earlier releases, the code | |
99 | implementing the sigreturn system call was at a different | |
100 | offset within the signal trampoline. Try again. */ | |
101 | offset = -4; | |
102 | goto retry; | |
103 | } | |
104 | ||
105 | return 0; | |
106 | } | |
1e067c66 MK |
107 | |
108 | /* Check for "t ST_SYSCALL". */ | |
24f033e8 | 109 | insn = sparc_fetch_instruction (start_pc + offset + 0xf4); |
1e067c66 MK |
110 | if (insn != 0x91d02000) |
111 | return 0; | |
112 | ||
113 | return 1; | |
114 | } | |
115 | ||
116 | static struct sparc_frame_cache * | |
117 | sparc64obsd_frame_cache (struct frame_info *next_frame, void **this_cache) | |
118 | { | |
119 | struct sparc_frame_cache *cache; | |
120 | CORE_ADDR addr; | |
121 | ||
122 | if (*this_cache) | |
123 | return *this_cache; | |
124 | ||
125 | cache = sparc_frame_cache (next_frame, this_cache); | |
126 | gdb_assert (cache == *this_cache); | |
127 | ||
128 | /* If we couldn't find the frame's function, we're probably dealing | |
129 | with an on-stack signal trampoline. */ | |
130 | if (cache->pc == 0) | |
131 | { | |
132 | cache->pc = frame_pc_unwind (next_frame); | |
133 | cache->pc &= ~(sparc64obsd_page_size - 1); | |
134 | ||
135 | /* Since we couldn't find the frame's function, the cache was | |
136 | initialized under the assumption that we're frameless. */ | |
137 | cache->frameless_p = 0; | |
138 | addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); | |
139 | cache->base = addr; | |
140 | } | |
141 | ||
142 | /* We find the appropriate instance of `struct sigcontext' at a | |
143 | fixed offset in the signal frame. */ | |
144 | addr = cache->base + BIAS + 128 + 16; | |
145 | cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, next_frame); | |
146 | ||
147 | return cache; | |
148 | } | |
149 | ||
150 | static void | |
151 | sparc64obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, | |
152 | struct frame_id *this_id) | |
153 | { | |
154 | struct sparc_frame_cache *cache = | |
155 | sparc64obsd_frame_cache (next_frame, this_cache); | |
156 | ||
157 | (*this_id) = frame_id_build (cache->base, cache->pc); | |
158 | } | |
159 | ||
160 | static void | |
161 | sparc64obsd_frame_prev_register (struct frame_info *next_frame, | |
162 | void **this_cache, | |
163 | int regnum, int *optimizedp, | |
164 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
165 | int *realnump, void *valuep) | |
166 | { | |
167 | struct sparc_frame_cache *cache = | |
168 | sparc64obsd_frame_cache (next_frame, this_cache); | |
169 | ||
170 | trad_frame_prev_register (next_frame, cache->saved_regs, regnum, | |
171 | optimizedp, lvalp, addrp, realnump, valuep); | |
172 | } | |
173 | ||
174 | static const struct frame_unwind sparc64obsd_frame_unwind = | |
175 | { | |
176 | SIGTRAMP_FRAME, | |
177 | sparc64obsd_frame_this_id, | |
178 | sparc64obsd_frame_prev_register | |
179 | }; | |
180 | ||
181 | static const struct frame_unwind * | |
182 | sparc64obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) | |
183 | { | |
184 | CORE_ADDR pc = frame_pc_unwind (next_frame); | |
185 | char *name; | |
186 | ||
187 | find_pc_partial_function (pc, &name, NULL, NULL); | |
188 | if (sparc64obsd_pc_in_sigtramp (pc, name)) | |
189 | return &sparc64obsd_frame_unwind; | |
190 | ||
191 | return NULL; | |
192 | } | |
193 | \f | |
194 | ||
195 | static void | |
196 | sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
197 | { | |
198 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
199 | ||
9ea75c57 | 200 | tdep->gregset = regset_alloc (gdbarch, sparc64obsd_supply_gregset, NULL); |
1e067c66 MK |
201 | tdep->sizeof_gregset = 832; |
202 | ||
1e067c66 MK |
203 | frame_unwind_append_sniffer (gdbarch, sparc64obsd_sigtramp_frame_sniffer); |
204 | ||
205 | sparc64_init_abi (info, gdbarch); | |
206 | ||
207 | set_solib_svr4_fetch_link_map_offsets | |
208 | (gdbarch, nbsd_lp64_solib_svr4_fetch_link_map_offsets); | |
209 | } | |
210 | ||
211 | \f | |
212 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
213 | void _initialize_sparc64obsd_tdep (void); | |
214 | ||
215 | void | |
216 | _initialize_sparc64obsd_tdep (void) | |
217 | { | |
218 | gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, | |
219 | GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); | |
220 | } |