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
|
/* GNU/Linux/AArch64 specific low level interface, for the in-process
agent library for GDB.
Copyright (C) 2015-2023 Free Software Foundation, Inc.
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 3 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, see <http://www.gnu.org/licenses/>. */
#include "server.h"
#include <sys/mman.h>
#include "tracepoint.h"
#include <elf.h>
#ifdef HAVE_GETAUXVAL
#include <sys/auxv.h>
#endif
#include "linux-aarch64-tdesc.h"
/* Each register saved by the jump pad is in a 16 byte cell. */
#define FT_CR_SIZE 16
#define FT_CR_FPCR 0
#define FT_CR_FPSR 1
#define FT_CR_CPSR 2
#define FT_CR_PC 3
#define FT_CR_SP 4
#define FT_CR_X0 5
#define FT_CR_GPR(n) (FT_CR_X0 + (n))
#define FT_CR_FPR(n) (FT_CR_GPR (31) + (n))
/* Mapping between registers collected by the jump pad and GDB's register
array layout used by regcache.
See linux-aarch64-low.c (aarch64_install_fast_tracepoint_jump_pad) for
more details. */
static const int aarch64_ft_collect_regmap[] = {
FT_CR_GPR (0),
FT_CR_GPR (1),
FT_CR_GPR (2),
FT_CR_GPR (3),
FT_CR_GPR (4),
FT_CR_GPR (5),
FT_CR_GPR (6),
FT_CR_GPR (7),
FT_CR_GPR (8),
FT_CR_GPR (9),
FT_CR_GPR (10),
FT_CR_GPR (11),
FT_CR_GPR (12),
FT_CR_GPR (13),
FT_CR_GPR (14),
FT_CR_GPR (15),
FT_CR_GPR (16),
FT_CR_GPR (17),
FT_CR_GPR (18),
FT_CR_GPR (19),
FT_CR_GPR (20),
FT_CR_GPR (21),
FT_CR_GPR (22),
FT_CR_GPR (23),
FT_CR_GPR (24),
FT_CR_GPR (25),
FT_CR_GPR (26),
FT_CR_GPR (27),
FT_CR_GPR (28),
/* FP */
FT_CR_GPR (29),
/* LR */
FT_CR_GPR (30),
FT_CR_SP,
FT_CR_PC,
FT_CR_CPSR,
FT_CR_FPR (0),
FT_CR_FPR (1),
FT_CR_FPR (2),
FT_CR_FPR (3),
FT_CR_FPR (4),
FT_CR_FPR (5),
FT_CR_FPR (6),
FT_CR_FPR (7),
FT_CR_FPR (8),
FT_CR_FPR (9),
FT_CR_FPR (10),
FT_CR_FPR (11),
FT_CR_FPR (12),
FT_CR_FPR (13),
FT_CR_FPR (14),
FT_CR_FPR (15),
FT_CR_FPR (16),
FT_CR_FPR (17),
FT_CR_FPR (18),
FT_CR_FPR (19),
FT_CR_FPR (20),
FT_CR_FPR (21),
FT_CR_FPR (22),
FT_CR_FPR (23),
FT_CR_FPR (24),
FT_CR_FPR (25),
FT_CR_FPR (26),
FT_CR_FPR (27),
FT_CR_FPR (28),
FT_CR_FPR (29),
FT_CR_FPR (30),
FT_CR_FPR (31),
FT_CR_FPSR,
FT_CR_FPCR
};
#define AARCH64_NUM_FT_COLLECT_GREGS \
(sizeof (aarch64_ft_collect_regmap) / sizeof(aarch64_ft_collect_regmap[0]))
/* Fill in REGCACHE with registers saved by the jump pad in BUF. */
void
supply_fast_tracepoint_registers (struct regcache *regcache,
const unsigned char *buf)
{
int i;
for (i = 0; i < AARCH64_NUM_FT_COLLECT_GREGS; i++)
supply_register (regcache, i,
((char *) buf)
+ (aarch64_ft_collect_regmap[i] * FT_CR_SIZE));
}
ULONGEST
get_raw_reg (const unsigned char *raw_regs, int regnum)
{
if (regnum >= AARCH64_NUM_FT_COLLECT_GREGS)
return 0;
return *(ULONGEST *) (raw_regs
+ aarch64_ft_collect_regmap[regnum] * FT_CR_SIZE);
}
/* Return target_desc to use for IPA, given the tdesc index passed by
gdbserver. Index is ignored, since we have only one tdesc
at the moment. SVE, pauth, MTE and TLS not yet supported. */
const struct target_desc *
get_ipa_tdesc (int idx)
{
return aarch64_linux_read_description ({});
}
/* Allocate buffer for the jump pads. The branch instruction has a reach
of +/- 128MiB, and the executable is loaded at 0x400000 (4MiB).
To maximize the area of executable that can use tracepoints, try
allocating at 0x400000 - size initially, decreasing until we hit
a free area. */
void *
alloc_jump_pad_buffer (size_t size)
{
uintptr_t addr;
uintptr_t exec_base = getauxval (AT_PHDR);
int pagesize;
void *res;
if (exec_base == 0)
exec_base = 0x400000;
pagesize = sysconf (_SC_PAGE_SIZE);
if (pagesize == -1)
perror_with_name ("sysconf");
addr = exec_base - size;
/* size should already be page-aligned, but this can't hurt. */
addr &= ~(pagesize - 1);
/* Search for a free area. If we hit 0, we're out of luck. */
for (; addr; addr -= pagesize)
{
/* No MAP_FIXED - we don't want to zap someone's mapping. */
res = mmap ((void *) addr, size,
PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
/* If we got what we wanted, return. */
if ((uintptr_t) res == addr)
return res;
/* If we got a mapping, but at a wrong address, undo it. */
if (res != MAP_FAILED)
munmap (res, size);
}
return NULL;
}
void
initialize_low_tracepoint (void)
{
/* SVE, pauth, MTE and TLS not yet supported. */
aarch64_linux_read_description ({});
}
|
