1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
|
/* Target-dependent code for GNU/Linux running on x86-64, for GDB.
Copyright 2001 Free Software Foundation, Inc.
Contributed by Jiri Smid, SuSE Labs.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "gdb_string.h"
#include "regcache.h"
#include "x86-64-tdep.h"
#include "dwarf2cfi.h"
#include "osabi.h"
#define LINUX_SIGTRAMP_INSN0 (0x48) /* mov $NNNNNNNN,%rax */
#define LINUX_SIGTRAMP_OFFSET0 (0)
#define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */
#define LINUX_SIGTRAMP_OFFSET1 (7)
static const unsigned char linux_sigtramp_code[] = {
/* mov $__NR_rt_sigreturn,%rax */
LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
/* syscall */
LINUX_SIGTRAMP_INSN1, 0x05
};
#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
/* If PC is in a sigtramp routine, return the address of the start of
the routine. Otherwise, return 0. */
static CORE_ADDR
x86_64_linux_sigtramp_start (CORE_ADDR pc)
{
unsigned char buf[LINUX_SIGTRAMP_LEN];
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
if (buf[0] != LINUX_SIGTRAMP_INSN0)
{
if (buf[0] != LINUX_SIGTRAMP_INSN1)
return 0;
pc -= LINUX_SIGTRAMP_OFFSET1;
if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
return 0;
}
if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
return 0;
return pc;
}
#define LINUX_SIGINFO_SIZE 0
/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
#define LINUX_SIGCONTEXT_PC_OFFSET 128
#define LINUX_SIGCONTEXT_FP_OFFSET 120
/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
address of the associated sigcontext structure. */
static CORE_ADDR
x86_64_linux_sigcontext_addr (struct frame_info *frame)
{
CORE_ADDR pc;
ULONGEST rsp;
pc = x86_64_linux_sigtramp_start (get_frame_pc (frame));
if (pc)
{
if (get_next_frame (frame))
/* If this isn't the top frame, the next frame must be for the
signal handler itself. The sigcontext structure is part of
the user context. */
return get_frame_base (get_next_frame (frame)) + LINUX_SIGINFO_SIZE +
LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
/* This is the top frame. */
rsp = read_register (SP_REGNUM);
return rsp + LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
}
error ("Couldn't recognize signal trampoline.");
return 0;
}
/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
saved program counter. */
static CORE_ADDR
x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
{
CORE_ADDR addr;
addr = x86_64_linux_sigcontext_addr (frame);
return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
}
/* Immediately after a function call, return the saved pc. */
CORE_ADDR
x86_64_linux_saved_pc_after_call (struct frame_info *frame)
{
if ((get_frame_type (frame) == SIGTRAMP_FRAME))
return x86_64_linux_sigtramp_saved_pc (frame);
return read_memory_integer (read_register (SP_REGNUM), 8);
}
/* Saved Pc. Get it from sigcontext if within sigtramp. */
CORE_ADDR
x86_64_linux_frame_saved_pc (struct frame_info *frame)
{
if ((get_frame_type (frame) == SIGTRAMP_FRAME))
return x86_64_linux_sigtramp_saved_pc (frame);
return cfi_get_ra (frame);
}
/* Return whether PC is in a GNU/Linux sigtramp routine. */
int
x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name)
{
if (name)
return strcmp ("__restore_rt", name) == 0;
return (x86_64_linux_sigtramp_start (pc) != 0);
}
CORE_ADDR
x86_64_linux_frame_chain (struct frame_info *fi)
{
ULONGEST addr;
CORE_ADDR fp, pc;
if (!(get_frame_type (fi) == SIGTRAMP_FRAME))
{
fp = cfi_frame_chain (fi);
if (fp)
return fp;
else
addr = get_frame_base (fi);
}
else
addr = get_frame_base (get_next_frame (fi));
addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8) + 8;
return fp;
}
CORE_ADDR
x86_64_init_frame_pc (int fromleaf, struct frame_info *fi)
{
CORE_ADDR addr;
if (get_next_frame (fi)
&& (get_frame_type (get_next_frame (fi)) == SIGTRAMP_FRAME))
{
addr = get_frame_base (get_next_frame (get_next_frame (fi)))
+ LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
}
else
return cfi_init_frame_pc (fromleaf, fi);
}
static void
x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
x86_64_init_abi (info, gdbarch);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern void _initialize_x86_64_linux_tdep (void);
void
_initialize_x86_64_linux_tdep (void)
{
gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
x86_64_linux_init_abi);
}
|
