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
|
/*
* Copyright 2008, The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "DEBUG"
#include "utility.h"
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <backtrace/Backtrace.h>
#include <log/log.h>
const int SLEEP_TIME_USEC = 50000; // 0.05 seconds
const int MAX_TOTAL_SLEEP_USEC = 10000000; // 10 seconds
static int write_to_am(int fd, const char* buf, int len) {
int to_write = len;
while (to_write > 0) {
int written = TEMP_FAILURE_RETRY(write(fd, buf + len - to_write, to_write));
if (written < 0) {
// hard failure
ALOGE("AM write failure (%d / %s)\n", errno, strerror(errno));
return -1;
}
to_write -= written;
}
return len;
}
// Whitelist output desired in the logcat output.
bool is_allowed_in_logcat(enum logtype ltype) {
if ((ltype == ERROR)
|| (ltype == HEADER)
|| (ltype == REGISTERS)
|| (ltype == BACKTRACE)) {
return true;
}
return false;
}
void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
bool write_to_tombstone = (log->tfd != -1);
bool write_to_logcat = is_allowed_in_logcat(ltype)
&& log->crashed_tid != -1
&& log->current_tid != -1
&& (log->crashed_tid == log->current_tid);
bool write_to_activitymanager = (log->amfd != -1);
char buf[512];
va_list ap;
va_start(ap, fmt);
vsnprintf(buf, sizeof(buf), fmt, ap);
va_end(ap);
size_t len = strlen(buf);
if (len <= 0) {
return;
}
if (write_to_tombstone) {
TEMP_FAILURE_RETRY(write(log->tfd, buf, len));
}
if (write_to_logcat) {
__android_log_buf_write(LOG_ID_CRASH, ANDROID_LOG_INFO, LOG_TAG, buf);
if (write_to_activitymanager) {
int written = write_to_am(log->amfd, buf, len);
if (written <= 0) {
// timeout or other failure on write; stop informing the activity manager
log->amfd = -1;
}
}
}
}
int wait_for_sigstop(pid_t tid, int* total_sleep_time_usec, bool* detach_failed) {
bool allow_dead_tid = false;
for (;;) {
int status;
pid_t n = TEMP_FAILURE_RETRY(waitpid(tid, &status, __WALL | WNOHANG));
if (n == -1) {
ALOGE("waitpid failed: tid %d, %s", tid, strerror(errno));
break;
} else if (n == tid) {
if (WIFSTOPPED(status)) {
return WSTOPSIG(status);
} else {
ALOGE("unexpected waitpid response: n=%d, status=%08x\n", n, status);
// This is the only circumstance under which we can allow a detach
// to fail with ESRCH, which indicates the tid has exited.
allow_dead_tid = true;
break;
}
}
if (*total_sleep_time_usec > MAX_TOTAL_SLEEP_USEC) {
ALOGE("timed out waiting for stop signal: tid=%d", tid);
break;
}
usleep(SLEEP_TIME_USEC);
*total_sleep_time_usec += SLEEP_TIME_USEC;
}
if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
if (allow_dead_tid && errno == ESRCH) {
ALOGE("tid exited before attach completed: tid %d", tid);
} else {
*detach_failed = true;
ALOGE("detach failed: tid %d, %s", tid, strerror(errno));
}
}
return -1;
}
#if defined (__mips__)
#define DUMP_MEMORY_AS_ASCII 1
#else
#define DUMP_MEMORY_AS_ASCII 0
#endif
void dump_memory(log_t* log, pid_t tid, uintptr_t addr) {
char code_buffer[64];
char ascii_buffer[32];
uintptr_t p, end;
p = addr & ~(sizeof(long) - 1);
/* Dump 32 bytes before addr */
p -= 32;
if (p > addr) {
/* catch underflow */
p = 0;
}
/* Dump 256 bytes */
end = p + 256;
/* catch overflow; 'end - p' has to be multiples of 16 */
while (end < p) {
end -= 16;
}
/* Dump the code around PC as:
* addr contents ascii
* 0000000000008d34 ef000000e8bd0090 e1b00000512fff1e ............../Q
* 0000000000008d44 ea00b1f9e92d0090 e3a070fcef000000 ......-..p......
* On 32-bit machines, there are still 16 bytes per line but addresses and
* words are of course presented differently.
*/
while (p < end) {
char* asc_out = ascii_buffer;
int len = snprintf(code_buffer, sizeof(code_buffer), "%" PRIPTR " ", p);
for (size_t i = 0; i < 16/sizeof(long); i++) {
long data = ptrace(PTRACE_PEEKTEXT, tid, (void*)p, NULL);
if (data == -1 && errno != 0) {
// ptrace failed, probably because we're dumping memory in an
// unmapped or inaccessible page.
#ifdef __LP64__
len += sprintf(code_buffer + len, "---------------- ");
#else
len += sprintf(code_buffer + len, "-------- ");
#endif
} else {
len += sprintf(code_buffer + len, "%" PRIPTR " ",
static_cast<uintptr_t>(data));
}
#if DUMP_MEMORY_AS_ASCII
for (size_t j = 0; j < sizeof(long); j++) {
/*
* Our isprint() allows high-ASCII characters that display
* differently (often badly) in different viewers, so we
* just use a simpler test.
*/
char val = (data >> (j*8)) & 0xff;
if (val >= 0x20 && val < 0x7f) {
*asc_out++ = val;
} else {
*asc_out++ = '.';
}
}
#endif
p += sizeof(long);
}
*asc_out = '\0';
_LOG(log, logtype::MEMORY, " %s %s\n", code_buffer, ascii_buffer);
}
}
|
