1 /* Signal trampoline unwinder, for GDB the GNU Debugger.
3 Copyright (C) 2004, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
6 This file is part of GDB.
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 3 of the License, or
11 (at your option) any later version.
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.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "tramp-frame.h"
23 #include "frame-unwind.h"
28 #include "trad-frame.h"
29 #include "frame-base.h"
30 #include "gdb_assert.h"
34 const struct tramp_frame *tramp_frame;
37 struct tramp_frame_cache
40 const struct tramp_frame *tramp_frame;
41 struct trad_frame_cache *trad_cache;
44 static struct trad_frame_cache *
45 tramp_frame_cache (struct frame_info *this_frame,
48 struct tramp_frame_cache *tramp_cache = (*this_cache);
50 if (tramp_cache->trad_cache == NULL)
52 tramp_cache->trad_cache = trad_frame_cache_zalloc (this_frame);
53 tramp_cache->tramp_frame->init (tramp_cache->tramp_frame,
55 tramp_cache->trad_cache,
58 return tramp_cache->trad_cache;
62 tramp_frame_this_id (struct frame_info *this_frame,
64 struct frame_id *this_id)
66 struct trad_frame_cache *trad_cache
67 = tramp_frame_cache (this_frame, this_cache);
69 trad_frame_get_id (trad_cache, this_id);
73 tramp_frame_prev_register (struct frame_info *this_frame,
77 struct trad_frame_cache *trad_cache
78 = tramp_frame_cache (this_frame, this_cache);
80 return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
84 tramp_frame_start (const struct tramp_frame *tramp,
85 struct frame_info *this_frame, CORE_ADDR pc)
87 struct gdbarch *gdbarch = get_frame_arch (this_frame);
88 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
91 /* Search through the trampoline for one that matches the
92 instruction sequence around PC. */
93 for (ti = 0; tramp->insn[ti].bytes != TRAMP_SENTINEL_INSN; ti++)
95 CORE_ADDR func = pc - tramp->insn_size * ti;
100 gdb_byte buf[sizeof (tramp->insn[0])];
103 if (tramp->insn[i].bytes == TRAMP_SENTINEL_INSN)
105 if (!safe_frame_unwind_memory (this_frame,
106 func + i * tramp->insn_size,
107 buf, tramp->insn_size))
109 insn = extract_unsigned_integer (buf, tramp->insn_size, byte_order);
110 if (tramp->insn[i].bytes != (insn & tramp->insn[i].mask))
114 /* Trampoline doesn't match. */
119 tramp_frame_sniffer (const struct frame_unwind *self,
120 struct frame_info *this_frame,
123 const struct tramp_frame *tramp = self->unwind_data->tramp_frame;
124 CORE_ADDR pc = get_frame_pc (this_frame);
126 struct tramp_frame_cache *tramp_cache;
128 /* tausq/2004-12-12: We used to assume if pc has a name or is in a valid
129 section, then this is not a trampoline. However, this assumption is
130 false on HPUX which has a signal trampoline that has a name; it can
131 also be false when using an alternative signal stack. */
132 func = tramp_frame_start (tramp, this_frame, pc);
135 tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache);
136 tramp_cache->func = func;
137 tramp_cache->tramp_frame = tramp;
138 (*this_cache) = tramp_cache;
143 tramp_frame_prepend_unwinder (struct gdbarch *gdbarch,
144 const struct tramp_frame *tramp_frame)
146 struct frame_data *data;
147 struct frame_unwind *unwinder;
150 /* Check that the instruction sequence contains a sentinel. */
151 for (i = 0; i < ARRAY_SIZE (tramp_frame->insn); i++)
153 if (tramp_frame->insn[i].bytes == TRAMP_SENTINEL_INSN)
156 gdb_assert (i < ARRAY_SIZE (tramp_frame->insn));
157 gdb_assert (tramp_frame->insn_size <= sizeof (tramp_frame->insn[0].bytes));
159 data = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_data);
160 unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind);
162 data->tramp_frame = tramp_frame;
163 unwinder->type = tramp_frame->frame_type;
164 unwinder->unwind_data = data;
165 unwinder->sniffer = tramp_frame_sniffer;
166 unwinder->stop_reason = default_frame_unwind_stop_reason;
167 unwinder->this_id = tramp_frame_this_id;
168 unwinder->prev_register = tramp_frame_prev_register;
169 frame_unwind_prepend_unwinder (gdbarch, unwinder);