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1 | /* Target-dependent code for OpenBSD/sparc. |
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 "floatformat.h" | |
24 | #include "frame.h" | |
25 | #include "frame-unwind.h" | |
26 | #include "osabi.h" | |
27 | #include "solib-svr4.h" | |
28 | #include "symtab.h" | |
29 | #include "trad-frame.h" | |
30 | ||
31 | #include "gdb_assert.h" | |
32 | ||
33 | #include "sparc-tdep.h" | |
34 | #include "nbsd-tdep.h" | |
35 | ||
36 | /* Signal trampolines. */ | |
37 | ||
38 | /* The OpenBSD kernel maps the signal trampoline at some random | |
39 | location in user space, which means that the traditional BSD way of | |
40 | detecting it won't work. | |
41 | ||
42 | The signal trampoline will be mapped at an address that is page | |
43 | aligned. We recognize the signal trampoline by the looking for the | |
44 | sigreturn system call. */ | |
45 | ||
46 | static const int sparc32obsd_page_size = 4096; | |
47 | ||
48 | static int | |
49 | sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, char *name) | |
50 | { | |
51 | CORE_ADDR start_pc = (pc & ~(sparc32obsd_page_size - 1)); | |
52 | unsigned long insn; | |
53 | ||
54 | if (name) | |
55 | return 0; | |
56 | ||
57 | /* Check for "restore %g0, SYS_sigreturn, %g1". */ | |
58 | insn = sparc_fetch_instruction (start_pc + 0xec); | |
59 | if (insn != 0x83e82067) | |
60 | return 0; | |
61 | ||
62 | /* Check for "t ST_SYSCALL". */ | |
63 | insn = sparc_fetch_instruction (start_pc + 0xf4); | |
64 | if (insn != 0x91d02000) | |
65 | return 0; | |
66 | ||
67 | return 1; | |
68 | } | |
69 | ||
70 | static struct sparc_frame_cache * | |
71 | sparc32obsd_frame_cache (struct frame_info *next_frame, void **this_cache) | |
72 | { | |
73 | struct sparc_frame_cache *cache; | |
74 | CORE_ADDR addr; | |
75 | ||
76 | if (*this_cache) | |
77 | return *this_cache; | |
78 | ||
79 | cache = sparc_frame_cache (next_frame, this_cache); | |
80 | gdb_assert (cache == *this_cache); | |
81 | ||
82 | /* If we couldn't find the frame's function, we're probably dealing | |
83 | with an on-stack signal trampoline. */ | |
84 | if (cache->pc == 0) | |
85 | { | |
86 | cache->pc = frame_pc_unwind (next_frame); | |
87 | cache->pc &= ~(sparc32obsd_page_size - 1); | |
88 | ||
89 | /* Since we couldn't find the frame's function, the cache was | |
90 | initialized under the assumption that we're frameless. */ | |
91 | cache->frameless_p = 0; | |
92 | addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM); | |
93 | cache->base = addr; | |
94 | } | |
95 | ||
96 | cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame); | |
97 | ||
98 | return cache; | |
99 | } | |
100 | ||
101 | static void | |
102 | sparc32obsd_frame_this_id (struct frame_info *next_frame, void **this_cache, | |
103 | struct frame_id *this_id) | |
104 | { | |
105 | struct sparc_frame_cache *cache = | |
106 | sparc32obsd_frame_cache (next_frame, this_cache); | |
107 | ||
108 | (*this_id) = frame_id_build (cache->base, cache->pc); | |
109 | } | |
110 | ||
111 | static void | |
112 | sparc32obsd_frame_prev_register (struct frame_info *next_frame, | |
113 | void **this_cache, | |
114 | int regnum, int *optimizedp, | |
115 | enum lval_type *lvalp, CORE_ADDR *addrp, | |
116 | int *realnump, void *valuep) | |
117 | { | |
118 | struct sparc_frame_cache *cache = | |
119 | sparc32obsd_frame_cache (next_frame, this_cache); | |
120 | ||
121 | trad_frame_prev_register (next_frame, cache->saved_regs, regnum, | |
122 | optimizedp, lvalp, addrp, realnump, valuep); | |
123 | } | |
124 | ||
125 | static const struct frame_unwind sparc32obsd_frame_unwind = | |
126 | { | |
127 | SIGTRAMP_FRAME, | |
128 | sparc32obsd_frame_this_id, | |
129 | sparc32obsd_frame_prev_register | |
130 | }; | |
131 | ||
132 | static const struct frame_unwind * | |
133 | sparc32obsd_sigtramp_frame_sniffer (struct frame_info *next_frame) | |
134 | { | |
135 | CORE_ADDR pc = frame_pc_unwind (next_frame); | |
136 | char *name; | |
137 | ||
138 | find_pc_partial_function (pc, &name, NULL, NULL); | |
139 | if (sparc32obsd_pc_in_sigtramp (pc, name)) | |
140 | return &sparc32obsd_frame_unwind; | |
141 | ||
142 | return NULL; | |
143 | } | |
144 | \f | |
145 | ||
146 | static void | |
147 | sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) | |
148 | { | |
149 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); | |
150 | ||
151 | /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */ | |
152 | set_gdbarch_long_double_bit (gdbarch, 64); | |
153 | set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big); | |
154 | ||
566626fa MK |
155 | frame_unwind_append_sniffer (gdbarch, sparc32obsd_sigtramp_frame_sniffer); |
156 | ||
157 | set_solib_svr4_fetch_link_map_offsets | |
158 | (gdbarch, nbsd_ilp32_solib_svr4_fetch_link_map_offsets); | |
159 | } | |
160 | ||
161 | \f | |
162 | /* Provide a prototype to silence -Wmissing-prototypes. */ | |
163 | void _initialize_sparc32obsd_tdep (void); | |
164 | ||
165 | void | |
166 | _initialize_sparc32obsd_tdep (void) | |
167 | { | |
168 | gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD_ELF, | |
169 | sparc32obsd_init_abi); | |
170 | } |