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tramp-frame.c
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1/* Signal trampoline unwinder, for GDB the GNU Debugger.
2
3 Copyright (C) 2004-2023 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 3 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, see <http://www.gnu.org/licenses/>. */
19
20#include "defs.h"
21#include "tramp-frame.h"
22#include "frame-unwind.h"
23#include "gdbcore.h"
24#include "symtab.h"
25#include "objfiles.h"
26#include "target.h"
27#include "trad-frame.h"
28#include "frame-base.h"
29
31{
32 const struct tramp_frame *tramp_frame;
33};
34
36{
37 CORE_ADDR func;
38 const struct tramp_frame *tramp_frame;
40};
41
42static struct trad_frame_cache *
44 void **this_cache)
45{
46 struct tramp_frame_cache *tramp_cache
47 = (struct tramp_frame_cache *) *this_cache;
48
49 if (tramp_cache->trad_cache == NULL)
50 {
51 tramp_cache->trad_cache = trad_frame_cache_zalloc (this_frame);
52 tramp_cache->tramp_frame->init (tramp_cache->tramp_frame,
53 this_frame,
54 tramp_cache->trad_cache,
55 tramp_cache->func);
56 }
57 return tramp_cache->trad_cache;
58}
59
60static void
62 void **this_cache,
63 struct frame_id *this_id)
64{
65 struct trad_frame_cache *trad_cache
66 = tramp_frame_cache (this_frame, this_cache);
67
68 trad_frame_get_id (trad_cache, this_id);
69}
70
71static struct value *
73 void **this_cache,
74 int prev_regnum)
75{
76 struct trad_frame_cache *trad_cache
77 = tramp_frame_cache (this_frame, this_cache);
78
79 return trad_frame_get_register (trad_cache, this_frame, prev_regnum);
80}
81
82static CORE_ADDR
83tramp_frame_start (const struct tramp_frame *tramp,
84 frame_info_ptr this_frame, CORE_ADDR pc)
85{
86 struct gdbarch *gdbarch = get_frame_arch (this_frame);
87 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
88 int ti;
89
90 /* Check if we can use this trampoline. */
91 if (tramp->validate && !tramp->validate (tramp, this_frame, &pc))
92 return 0;
93
94 /* Search through the trampoline for one that matches the
95 instruction sequence around PC. */
96 for (ti = 0; tramp->insn[ti].bytes != TRAMP_SENTINEL_INSN; ti++)
97 {
98 CORE_ADDR func = pc - tramp->insn_size * ti;
99 int i;
100
101 for (i = 0; 1; i++)
102 {
103 gdb_byte buf[sizeof (tramp->insn[0])];
104 ULONGEST insn;
105 size_t insn_size = tramp->insn_size;
106
107 if (tramp->insn[i].bytes == TRAMP_SENTINEL_INSN)
108 return func;
109 if (!safe_frame_unwind_memory (this_frame,
110 func + i * insn_size,
111 {buf, insn_size}))
112 break;
113 insn = extract_unsigned_integer (buf, insn_size, byte_order);
114 if (tramp->insn[i].bytes != (insn & tramp->insn[i].mask))
115 break;
116 }
117 }
118 /* Trampoline doesn't match. */
119 return 0;
120}
121
122static int
124 frame_info_ptr this_frame,
125 void **this_cache)
126{
127 const struct tramp_frame *tramp = self->unwind_data->tramp_frame;
128 CORE_ADDR pc = get_frame_pc (this_frame);
129 CORE_ADDR func;
130 struct tramp_frame_cache *tramp_cache;
131
132 /* tausq/2004-12-12: We used to assume if pc has a name or is in a valid
133 section, then this is not a trampoline. However, this assumption is
134 false on HPUX which has a signal trampoline that has a name; it can
135 also be false when using an alternative signal stack. */
136 func = tramp_frame_start (tramp, this_frame, pc);
137 if (func == 0)
138 return 0;
139 tramp_cache = FRAME_OBSTACK_ZALLOC (struct tramp_frame_cache);
140 tramp_cache->func = func;
141 tramp_cache->tramp_frame = tramp;
142 (*this_cache) = tramp_cache;
143 return 1;
144}
145
146void
148 const struct tramp_frame *tramp_frame)
149{
150 struct frame_data *data;
151 struct frame_unwind *unwinder;
152 int i;
153
154 /* Check that the instruction sequence contains a sentinel. */
155 for (i = 0; i < ARRAY_SIZE (tramp_frame->insn); i++)
156 {
158 break;
159 }
160 gdb_assert (i < ARRAY_SIZE (tramp_frame->insn));
161 gdb_assert (tramp_frame->insn_size <= sizeof (tramp_frame->insn[0].bytes));
162
164 unwinder = GDBARCH_OBSTACK_ZALLOC (gdbarch, struct frame_unwind);
165
166 data->tramp_frame = tramp_frame;
167 unwinder->type = tramp_frame->frame_type;
168 unwinder->unwind_data = data;
169 unwinder->sniffer = tramp_frame_sniffer;
171 unwinder->this_id = tramp_frame_this_id;
173 unwinder->prev_arch = tramp_frame->prev_arch;
175}
static ULONGEST extract_unsigned_integer(gdb::array_view< const gdb_byte > buf, enum bfd_endian byte_order)
Definition defs.h:480
void frame_unwind_prepend_unwinder(struct gdbarch *gdbarch, const struct frame_unwind *unwinder)
enum unwind_stop_reason default_frame_unwind_stop_reason(frame_info_ptr this_frame, void **this_cache)
CORE_ADDR get_frame_pc(frame_info_ptr frame)
Definition frame.c:2712
struct gdbarch * get_frame_arch(frame_info_ptr this_frame)
Definition frame.c:3027
bool safe_frame_unwind_memory(frame_info_ptr this_frame, CORE_ADDR addr, gdb::array_view< gdb_byte > buffer)
Definition frame.c:3017
#define FRAME_OBSTACK_ZALLOC(TYPE)
Definition frame.h:825
enum bfd_endian gdbarch_byte_order(struct gdbarch *gdbarch)
Definition gdbarch.c:1396
#define GDBARCH_OBSTACK_ZALLOC(GDBARCH, TYPE)
Definition gdbarch.h:327
void(* func)(remote_target *remote, char *)
const struct tramp_frame * tramp_frame
Definition tramp-frame.c:32
frame_sniffer_ftype * sniffer
enum frame_type type
frame_this_id_ftype * this_id
frame_prev_arch_ftype * prev_arch
frame_unwind_stop_reason_ftype * stop_reason
const struct frame_data * unwind_data
frame_prev_register_ftype * prev_register
struct frame_id this_id
Definition trad-frame.c:35
frame_info_ptr this_frame
Definition trad-frame.c:32
struct trad_frame_cache * trad_cache
Definition tramp-frame.c:39
const struct tramp_frame * tramp_frame
Definition tramp-frame.c:38
struct tramp_frame::@191 insn[48]
int(* validate)(const struct tramp_frame *self, frame_info_ptr this_frame, CORE_ADDR *pc)
Definition tramp-frame.h:76
frame_prev_arch_ftype * prev_arch
Definition tramp-frame.h:82
enum frame_type frame_type
Definition tramp-frame.h:50
void(* init)(const struct tramp_frame *self, frame_info_ptr this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func)
Definition tramp-frame.h:68
ULONGEST bytes
Definition tramp-frame.h:63
ULONGEST mask
Definition tramp-frame.h:64
Definition value.h:130
struct trad_frame_cache * trad_frame_cache_zalloc(frame_info_ptr this_frame)
Definition trad-frame.c:39
void trad_frame_get_id(struct trad_frame_cache *this_trad_cache, struct frame_id *this_id)
Definition trad-frame.c:227
struct value * trad_frame_get_register(struct trad_frame_cache *this_trad_cache, frame_info_ptr this_frame, int regnum)
Definition trad-frame.c:211
static int tramp_frame_sniffer(const struct frame_unwind *self, frame_info_ptr this_frame, void **this_cache)
static struct value * tramp_frame_prev_register(frame_info_ptr this_frame, void **this_cache, int prev_regnum)
Definition tramp-frame.c:72
static void tramp_frame_this_id(frame_info_ptr this_frame, void **this_cache, struct frame_id *this_id)
Definition tramp-frame.c:61
static CORE_ADDR tramp_frame_start(const struct tramp_frame *tramp, frame_info_ptr this_frame, CORE_ADDR pc)
Definition tramp-frame.c:83
static struct trad_frame_cache * tramp_frame_cache(frame_info_ptr this_frame, void **this_cache)
Definition tramp-frame.c:43
void tramp_frame_prepend_unwinder(struct gdbarch *gdbarch, const struct tramp_frame *tramp_frame)
#define TRAMP_SENTINEL_INSN
Definition tramp-frame.h:44