1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <stdbool.h>
18 #include <fcntl.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <sys/types.h>
23 #include <sys/socket.h>
24 #include <unistd.h>
25
26 #include <cutils/debugger.h>
27 #include <cutils/sockets.h>
28
29 #define LOG_TAG "DEBUG"
30 #include <log/log.h>
31
32 #if defined(__LP64__)
33 #include <elf.h>
34
is32bit(pid_t tid)35 static bool is32bit(pid_t tid) {
36 char* exeline;
37 if (asprintf(&exeline, "/proc/%d/exe", tid) == -1) {
38 return false;
39 }
40 int fd = open(exeline, O_RDONLY | O_CLOEXEC);
41 free(exeline);
42 if (fd == -1) {
43 return false;
44 }
45
46 char ehdr[EI_NIDENT];
47 ssize_t bytes = read(fd, &ehdr, sizeof(ehdr));
48 close(fd);
49 if (bytes != (ssize_t) sizeof(ehdr) || memcmp(ELFMAG, ehdr, SELFMAG) != 0) {
50 return false;
51 }
52 if (ehdr[EI_CLASS] == ELFCLASS32) {
53 return true;
54 }
55 return false;
56 }
57 #endif
58
send_request(int sock_fd,void * msg_ptr,size_t msg_len)59 static int send_request(int sock_fd, void* msg_ptr, size_t msg_len) {
60 int result = 0;
61 if (TEMP_FAILURE_RETRY(write(sock_fd, msg_ptr, msg_len)) != (ssize_t) msg_len) {
62 result = -1;
63 } else {
64 char ack;
65 if (TEMP_FAILURE_RETRY(read(sock_fd, &ack, 1)) != 1) {
66 result = -1;
67 }
68 }
69 return result;
70 }
71
make_dump_request(debugger_action_t action,pid_t tid,int timeout_secs)72 static int make_dump_request(debugger_action_t action, pid_t tid, int timeout_secs) {
73 const char* socket_name;
74 debugger_msg_t msg;
75 size_t msg_len;
76 void* msg_ptr;
77
78 #if defined(__LP64__)
79 debugger32_msg_t msg32;
80 if (is32bit(tid)) {
81 msg_len = sizeof(debugger32_msg_t);
82 memset(&msg32, 0, msg_len);
83 msg32.tid = tid;
84 msg32.action = action;
85 msg_ptr = &msg32;
86
87 socket_name = DEBUGGER32_SOCKET_NAME;
88 } else
89 #endif
90 {
91 msg_len = sizeof(debugger_msg_t);
92 memset(&msg, 0, msg_len);
93 msg.tid = tid;
94 msg.action = action;
95 msg_ptr = &msg;
96
97 socket_name = DEBUGGER_SOCKET_NAME;
98 }
99
100 int sock_fd = socket_local_client(socket_name, ANDROID_SOCKET_NAMESPACE_ABSTRACT,
101 SOCK_STREAM | SOCK_CLOEXEC);
102 if (sock_fd < 0) {
103 return -1;
104 }
105
106 if (timeout_secs > 0) {
107 struct timeval tm;
108 tm.tv_sec = timeout_secs;
109 tm.tv_usec = 0;
110 if (setsockopt(sock_fd, SOL_SOCKET, SO_RCVTIMEO, &tm, sizeof(tm)) == -1) {
111 ALOGE("WARNING: Cannot set receive timeout value on socket: %s", strerror(errno));
112 }
113
114 if (setsockopt(sock_fd, SOL_SOCKET, SO_SNDTIMEO, &tm, sizeof(tm)) == -1) {
115 ALOGE("WARNING: Cannot set send timeout value on socket: %s", strerror(errno));
116 }
117 }
118
119 if (send_request(sock_fd, msg_ptr, msg_len) < 0) {
120 TEMP_FAILURE_RETRY(close(sock_fd));
121 return -1;
122 }
123
124 return sock_fd;
125 }
126
dump_backtrace_to_file(pid_t tid,int fd)127 int dump_backtrace_to_file(pid_t tid, int fd) {
128 return dump_backtrace_to_file_timeout(tid, fd, 0);
129 }
130
dump_backtrace_to_file_timeout(pid_t tid,int fd,int timeout_secs)131 int dump_backtrace_to_file_timeout(pid_t tid, int fd, int timeout_secs) {
132 int sock_fd = make_dump_request(DEBUGGER_ACTION_DUMP_BACKTRACE, tid, timeout_secs);
133 if (sock_fd < 0) {
134 return -1;
135 }
136
137 /* Write the data read from the socket to the fd. */
138 int result = 0;
139 char buffer[1024];
140 ssize_t n;
141 while ((n = TEMP_FAILURE_RETRY(read(sock_fd, buffer, sizeof(buffer)))) > 0) {
142 if (TEMP_FAILURE_RETRY(write(fd, buffer, n)) != n) {
143 result = -1;
144 break;
145 }
146 }
147 TEMP_FAILURE_RETRY(close(sock_fd));
148 return result;
149 }
150
dump_tombstone(pid_t tid,char * pathbuf,size_t pathlen)151 int dump_tombstone(pid_t tid, char* pathbuf, size_t pathlen) {
152 return dump_tombstone_timeout(tid, pathbuf, pathlen, 0);
153 }
154
dump_tombstone_timeout(pid_t tid,char * pathbuf,size_t pathlen,int timeout_secs)155 int dump_tombstone_timeout(pid_t tid, char* pathbuf, size_t pathlen, int timeout_secs) {
156 int sock_fd = make_dump_request(DEBUGGER_ACTION_DUMP_TOMBSTONE, tid, timeout_secs);
157 if (sock_fd < 0) {
158 return -1;
159 }
160
161 /* Read the tombstone file name. */
162 char buffer[100]; /* This is larger than the largest tombstone path. */
163 int result = 0;
164 ssize_t n = TEMP_FAILURE_RETRY(read(sock_fd, buffer, sizeof(buffer) - 1));
165 if (n <= 0) {
166 result = -1;
167 } else {
168 if (pathbuf && pathlen) {
169 if (n >= (ssize_t) pathlen) {
170 n = pathlen - 1;
171 }
172 buffer[n] = '\0';
173 memcpy(pathbuf, buffer, n + 1);
174 }
175 }
176 TEMP_FAILURE_RETRY(close(sock_fd));
177 return result;
178 }
179