1 /*
2 * Copyright (C) 2008 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <unistd.h>
32 #include <ctype.h>
33 #include <signal.h>
34 #include <sys/mman.h>
35 #include <errno.h>
36
37 #include "linker.h"
38
39 #include <sys/socket.h>
40 #include <sys/un.h>
41
42 void notify_gdb_of_libraries();
43
44 #define RETRY_ON_EINTR(ret,cond) \
45 do { \
46 ret = (cond); \
47 } while (ret < 0 && errno == EINTR)
48
49
socket_abstract_client(const char * name,int type)50 static int socket_abstract_client(const char *name, int type)
51 {
52 struct sockaddr_un addr;
53 size_t namelen;
54 socklen_t alen;
55 int s, err;
56
57 namelen = strlen(name);
58
59 // Test with length +1 for the *initial* '\0'.
60 if ((namelen + 1) > sizeof(addr.sun_path)) {
61 errno = EINVAL;
62 return -1;
63 }
64
65 /* This is used for abstract socket namespace, we need
66 * an initial '\0' at the start of the Unix socket path.
67 *
68 * Note: The path in this case is *not* supposed to be
69 * '\0'-terminated. ("man 7 unix" for the gory details.)
70 */
71 memset (&addr, 0, sizeof addr);
72 addr.sun_family = AF_LOCAL;
73 addr.sun_path[0] = 0;
74 memcpy(addr.sun_path + 1, name, namelen);
75
76 alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
77
78 s = socket(AF_LOCAL, type, 0);
79 if(s < 0) return -1;
80
81 RETRY_ON_EINTR(err,connect(s, (struct sockaddr *) &addr, alen));
82 if (err < 0) {
83 close(s);
84 s = -1;
85 }
86
87 return s;
88 }
89
debugger_signal_handler(int n)90 void debugger_signal_handler(int n)
91 {
92 unsigned tid;
93 int s;
94
95 /* avoid picking up GC interrupts */
96 signal(SIGUSR1, SIG_IGN);
97
98 tid = gettid();
99 s = socket_abstract_client("android:debuggerd", SOCK_STREAM);
100
101 if(s >= 0) {
102 /* debugger knows our pid from the credentials on the
103 * local socket but we need to tell it our tid. It
104 * is paranoid and will verify that we are giving a tid
105 * that's actually in our process
106 */
107 int ret;
108
109 RETRY_ON_EINTR(ret, write(s, &tid, sizeof(unsigned)));
110 if (ret == sizeof(unsigned)) {
111 /* if the write failed, there is no point to read on
112 * the file descriptor. */
113 RETRY_ON_EINTR(ret, read(s, &tid, 1));
114 notify_gdb_of_libraries();
115 }
116 close(s);
117 }
118
119 /* remove our net so we fault for real when we return */
120 signal(n, SIG_IGN);
121 }
122
debugger_init()123 void debugger_init()
124 {
125 signal(SIGILL, debugger_signal_handler);
126 signal(SIGABRT, debugger_signal_handler);
127 signal(SIGBUS, debugger_signal_handler);
128 signal(SIGFPE, debugger_signal_handler);
129 signal(SIGSEGV, debugger_signal_handler);
130 signal(SIGSTKFLT, debugger_signal_handler);
131 signal(SIGPIPE, debugger_signal_handler);
132 }
133