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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 | ||
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 | ||
90 | #include "linker_format.h" | |
91 | #include <../libc/private/logd.h> | |
92 | ||
93 | /* | |
94 | * Writes a summary of the signal to the log file. | |
95 | * | |
96 | * We could be here as a result of native heap corruption, or while a | |
97 | * mutex is being held, so we don't want to use any libc functions that | |
98 | * could allocate memory or hold a lock. | |
99 | */ | |
100 | static void logSignalSummary(int signum, const siginfo_t* info) | |
101 | { | |
102 | char buffer[128]; | |
103 | ||
104 | char* signame; | |
105 | switch (signum) { | |
106 | case SIGILL: signame = "SIGILL"; break; | |
107 | case SIGABRT: signame = "SIGABRT"; break; | |
108 | case SIGBUS: signame = "SIGBUS"; break; | |
109 | case SIGFPE: signame = "SIGFPE"; break; | |
110 | case SIGSEGV: signame = "SIGSEGV"; break; | |
111 | case SIGSTKFLT: signame = "SIGSTKFLT"; break; | |
112 | case SIGPIPE: signame = "SIGPIPE"; break; | |
113 | default: signame = "???"; break; | |
114 | } | |
115 | ||
116 | format_buffer(buffer, sizeof(buffer), | |
117 | "Fatal signal %d (%s) at 0x%08x (code=%d)", | |
118 | signum, signame, info->si_addr, info->si_code); | |
119 | ||
120 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", buffer); | |
121 | } | |
122 | ||
123 | /* | |
124 | * Catches fatal signals so we can ask debuggerd to ptrace us before | |
125 | * we crash. | |
126 | */ | |
127 | void debugger_signal_handler(int n, siginfo_t* info, void* unused) | |
128 | { | |
129 | unsigned tid; | |
130 | int s; | |
131 | ||
132 | logSignalSummary(n, info); | |
133 | ||
134 | tid = gettid(); | |
135 | s = socket_abstract_client("android:debuggerd", SOCK_STREAM); | |
136 | ||
137 | if(s >= 0) { | |
138 | /* debugger knows our pid from the credentials on the | |
139 | * local socket but we need to tell it our tid. It | |
140 | * is paranoid and will verify that we are giving a tid | |
141 | * that's actually in our process | |
142 | */ | |
143 | int ret; | |
144 | ||
145 | RETRY_ON_EINTR(ret, write(s, &tid, sizeof(unsigned))); | |
146 | if (ret == sizeof(unsigned)) { | |
147 | /* if the write failed, there is no point to read on | |
148 | * the file descriptor. */ | |
149 | RETRY_ON_EINTR(ret, read(s, &tid, 1)); | |
150 | notify_gdb_of_libraries(); | |
151 | } | |
152 | close(s); | |
153 | } | |
154 | ||
155 | /* remove our net so we fault for real when we return */ | |
156 | signal(n, SIG_DFL); | |
157 | } | |
158 | ||
159 | void debugger_init() | |
160 | { | |
161 | struct sigaction act; | |
162 | memset(&act, 0, sizeof(act)); | |
163 | act.sa_sigaction = debugger_signal_handler; | |
164 | act.sa_flags = SA_RESTART | SA_SIGINFO; | |
165 | sigemptyset(&act.sa_mask); | |
166 | ||
167 | sigaction(SIGILL, &act, NULL); | |
168 | sigaction(SIGABRT, &act, NULL); | |
169 | sigaction(SIGBUS, &act, NULL); | |
170 | sigaction(SIGFPE, &act, NULL); | |
171 | sigaction(SIGSEGV, &act, NULL); | |
172 | sigaction(SIGSTKFLT, &act, NULL); | |
173 | sigaction(SIGPIPE, &act, NULL); | |
174 | } |