The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 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 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 29 | #include "linker.h" |
| 30 | #include "linker_format.h" |
| 31 | |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 32 | #include <stdio.h> |
| 33 | #include <stdlib.h> |
| 34 | #include <unistd.h> |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 35 | #include <stdbool.h> |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 36 | #include <signal.h> |
Marco Nelissen | 3df3e67 | 2012-03-07 09:04:18 -0800 | [diff] [blame] | 37 | #include <sys/prctl.h> |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 38 | #include <errno.h> |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 39 | #include <sys/socket.h> |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 40 | #include <sys/un.h> |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 41 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 42 | #include <private/logd.h> |
Andy McFadden | ca9a071 | 2012-03-08 11:14:37 -0800 | [diff] [blame] | 43 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 44 | extern "C" int tgkill(int tgid, int tid, int sig); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 45 | |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 46 | #define DEBUGGER_SOCKET_NAME "android:debuggerd" |
| 47 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 48 | enum debugger_action_t { |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 49 | // dump a crash |
| 50 | DEBUGGER_ACTION_CRASH, |
| 51 | // dump a tombstone file |
| 52 | DEBUGGER_ACTION_DUMP_TOMBSTONE, |
| 53 | // dump a backtrace only back to the socket |
| 54 | DEBUGGER_ACTION_DUMP_BACKTRACE, |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 55 | }; |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 56 | |
| 57 | /* message sent over the socket */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 58 | struct debugger_msg_t { |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 59 | debugger_action_t action; |
| 60 | pid_t tid; |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 61 | }; |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 62 | |
Marco Nelissen | 3df3e67 | 2012-03-07 09:04:18 -0800 | [diff] [blame] | 63 | // see man(2) prctl, specifically the section about PR_GET_NAME |
| 64 | #define MAX_TASK_NAME_LEN (16) |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 65 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 66 | static int socket_abstract_client(const char* name, int type) { |
| 67 | sockaddr_un addr; |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 68 | |
| 69 | // Test with length +1 for the *initial* '\0'. |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 70 | size_t namelen = strlen(name); |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 71 | if ((namelen + 1) > sizeof(addr.sun_path)) { |
| 72 | errno = EINVAL; |
| 73 | return -1; |
| 74 | } |
| 75 | |
| 76 | /* This is used for abstract socket namespace, we need |
| 77 | * an initial '\0' at the start of the Unix socket path. |
| 78 | * |
| 79 | * Note: The path in this case is *not* supposed to be |
| 80 | * '\0'-terminated. ("man 7 unix" for the gory details.) |
| 81 | */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 82 | memset(&addr, 0, sizeof(addr)); |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 83 | addr.sun_family = AF_LOCAL; |
| 84 | addr.sun_path[0] = 0; |
| 85 | memcpy(addr.sun_path + 1, name, namelen); |
| 86 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 87 | socklen_t alen = namelen + offsetof(sockaddr_un, sun_path) + 1; |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 88 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 89 | int s = socket(AF_LOCAL, type, 0); |
| 90 | if (s == -1) { |
| 91 | return -1; |
| 92 | } |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 93 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 94 | int err = TEMP_FAILURE_RETRY(connect(s, (sockaddr*) &addr, alen)); |
| 95 | if (err == -1) { |
David 'Digit' Turner | 8bff9a3 | 2010-06-10 18:29:33 -0700 | [diff] [blame] | 96 | close(s); |
| 97 | s = -1; |
| 98 | } |
| 99 | |
| 100 | return s; |
| 101 | } |
| 102 | |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 103 | /* |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 104 | * Writes a summary of the signal to the log file. We do this so that, if |
| 105 | * for some reason we're not able to contact debuggerd, there is still some |
| 106 | * indication of the failure in the log. |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 107 | * |
| 108 | * We could be here as a result of native heap corruption, or while a |
| 109 | * mutex is being held, so we don't want to use any libc functions that |
| 110 | * could allocate memory or hold a lock. |
| 111 | */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 112 | static void logSignalSummary(int signum, const siginfo_t* info) { |
| 113 | const char* signame; |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 114 | switch (signum) { |
| 115 | case SIGILL: signame = "SIGILL"; break; |
| 116 | case SIGABRT: signame = "SIGABRT"; break; |
| 117 | case SIGBUS: signame = "SIGBUS"; break; |
| 118 | case SIGFPE: signame = "SIGFPE"; break; |
| 119 | case SIGSEGV: signame = "SIGSEGV"; break; |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 120 | #if defined(SIGSTKFLT) |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 121 | case SIGSTKFLT: signame = "SIGSTKFLT"; break; |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 122 | #endif |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 123 | case SIGPIPE: signame = "SIGPIPE"; break; |
| 124 | default: signame = "???"; break; |
| 125 | } |
| 126 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 127 | char threadname[MAX_TASK_NAME_LEN + 1]; // one more for termination |
Marco Nelissen | 3df3e67 | 2012-03-07 09:04:18 -0800 | [diff] [blame] | 128 | if (prctl(PR_GET_NAME, (unsigned long)threadname, 0, 0, 0) != 0) { |
| 129 | strcpy(threadname, "<name unknown>"); |
| 130 | } else { |
| 131 | // short names are null terminated by prctl, but the manpage |
| 132 | // implies that 16 byte names are not. |
| 133 | threadname[MAX_TASK_NAME_LEN] = 0; |
| 134 | } |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 135 | |
| 136 | char buffer[128]; |
| 137 | // "info" will be NULL if the siginfo_t information was not available. |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 138 | if (info != NULL) { |
| 139 | format_buffer(buffer, sizeof(buffer), |
| 140 | "Fatal signal %d (%s) at 0x%08x (code=%d), thread %d (%s)", |
| 141 | signum, signame, info->si_addr, info->si_code, gettid(), threadname); |
| 142 | } else { |
| 143 | format_buffer(buffer, sizeof(buffer), |
| 144 | "Fatal signal %d (%s), thread %d (%s)", |
| 145 | signum, signame, gettid(), threadname); |
| 146 | } |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 147 | |
| 148 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", buffer); |
| 149 | } |
| 150 | |
| 151 | /* |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 152 | * Returns true if the handler for signal "signum" has SA_SIGINFO set. |
| 153 | */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 154 | static bool haveSiginfo(int signum) { |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 155 | struct sigaction oldact, newact; |
| 156 | |
| 157 | memset(&newact, 0, sizeof(newact)); |
| 158 | newact.sa_handler = SIG_DFL; |
| 159 | newact.sa_flags = SA_RESTART; |
| 160 | sigemptyset(&newact.sa_mask); |
| 161 | |
| 162 | if (sigaction(signum, &newact, &oldact) < 0) { |
| 163 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", |
| 164 | "Failed testing for SA_SIGINFO"); |
| 165 | return 0; |
| 166 | } |
| 167 | bool ret = (oldact.sa_flags & SA_SIGINFO) != 0; |
| 168 | |
| 169 | if (sigaction(signum, &oldact, NULL) < 0) { |
| 170 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", |
| 171 | "Restore failed in test for SA_SIGINFO"); |
| 172 | } |
| 173 | return ret; |
| 174 | } |
| 175 | |
| 176 | /* |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 177 | * Catches fatal signals so we can ask debuggerd to ptrace us before |
| 178 | * we crash. |
| 179 | */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 180 | void debugger_signal_handler(int n, siginfo_t* info, void*) { |
Andy McFadden | 1fc5176 | 2012-01-26 13:21:19 -0800 | [diff] [blame] | 181 | char msgbuf[128]; |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 182 | |
Andy McFadden | 1db6f2d | 2012-10-02 13:53:13 -0700 | [diff] [blame] | 183 | /* |
| 184 | * It's possible somebody cleared the SA_SIGINFO flag, which would mean |
| 185 | * our "info" arg holds an undefined value. |
| 186 | */ |
| 187 | if (!haveSiginfo(n)) { |
| 188 | info = NULL; |
| 189 | } |
| 190 | |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 191 | logSignalSummary(n, info); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 192 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 193 | pid_t tid = gettid(); |
| 194 | int s = socket_abstract_client(DEBUGGER_SOCKET_NAME, SOCK_STREAM); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 195 | |
Andy McFadden | 1fc5176 | 2012-01-26 13:21:19 -0800 | [diff] [blame] | 196 | if (s >= 0) { |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 197 | /* debugger knows our pid from the credentials on the |
| 198 | * local socket but we need to tell it our tid. It |
| 199 | * is paranoid and will verify that we are giving a tid |
| 200 | * that's actually in our process |
| 201 | */ |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 202 | int ret; |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 203 | debugger_msg_t msg; |
| 204 | msg.action = DEBUGGER_ACTION_CRASH; |
| 205 | msg.tid = tid; |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 206 | ret = TEMP_FAILURE_RETRY(write(s, &msg, sizeof(msg))); |
Jeff Brown | b7630f0 | 2012-06-06 18:37:48 -0700 | [diff] [blame] | 207 | if (ret == sizeof(msg)) { |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 208 | /* if the write failed, there is no point to read on |
| 209 | * the file descriptor. */ |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 210 | ret = TEMP_FAILURE_RETRY(read(s, &tid, 1)); |
| 211 | int saved_errno = errno; |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 212 | notify_gdb_of_libraries(); |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 213 | errno = saved_errno; |
David 'Digit' Turner | 7934a79 | 2009-10-16 12:13:34 -0700 | [diff] [blame] | 214 | } |
Andy McFadden | 1fc5176 | 2012-01-26 13:21:19 -0800 | [diff] [blame] | 215 | |
| 216 | if (ret < 0) { |
| 217 | /* read or write failed -- broken connection? */ |
| 218 | format_buffer(msgbuf, sizeof(msgbuf), |
| 219 | "Failed while talking to debuggerd: %s", strerror(errno)); |
| 220 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf); |
| 221 | } |
| 222 | |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 223 | close(s); |
Andy McFadden | 1fc5176 | 2012-01-26 13:21:19 -0800 | [diff] [blame] | 224 | } else { |
| 225 | /* socket failed; maybe process ran out of fds */ |
| 226 | format_buffer(msgbuf, sizeof(msgbuf), |
| 227 | "Unable to open connection to debuggerd: %s", strerror(errno)); |
| 228 | __libc_android_log_write(ANDROID_LOG_FATAL, "libc", msgbuf); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 229 | } |
| 230 | |
| 231 | /* remove our net so we fault for real when we return */ |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 232 | signal(n, SIG_DFL); |
Andy McFadden | ca9a071 | 2012-03-08 11:14:37 -0800 | [diff] [blame] | 233 | |
| 234 | /* |
| 235 | * These signals are not re-thrown when we resume. This means that |
| 236 | * crashing due to (say) SIGPIPE doesn't work the way you'd expect it |
| 237 | * to. We work around this by throwing them manually. We don't want |
| 238 | * to do this for *all* signals because it'll screw up the address for |
| 239 | * faults like SIGSEGV. |
| 240 | */ |
| 241 | switch (n) { |
| 242 | case SIGABRT: |
| 243 | case SIGFPE: |
| 244 | case SIGPIPE: |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 245 | #ifdef SIGSTKFLT |
Andy McFadden | ca9a071 | 2012-03-08 11:14:37 -0800 | [diff] [blame] | 246 | case SIGSTKFLT: |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 247 | #endif |
Andy McFadden | ca9a071 | 2012-03-08 11:14:37 -0800 | [diff] [blame] | 248 | (void) tgkill(getpid(), gettid(), n); |
| 249 | break; |
| 250 | default: // SIGILL, SIGBUS, SIGSEGV |
| 251 | break; |
| 252 | } |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 253 | } |
| 254 | |
Elliott Hughes | 18a206c | 2012-10-29 17:37:13 -0700 | [diff] [blame] | 255 | void debugger_init() { |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 256 | struct sigaction act; |
| 257 | memset(&act, 0, sizeof(act)); |
| 258 | act.sa_sigaction = debugger_signal_handler; |
| 259 | act.sa_flags = SA_RESTART | SA_SIGINFO; |
| 260 | sigemptyset(&act.sa_mask); |
| 261 | |
| 262 | sigaction(SIGILL, &act, NULL); |
| 263 | sigaction(SIGABRT, &act, NULL); |
| 264 | sigaction(SIGBUS, &act, NULL); |
| 265 | sigaction(SIGFPE, &act, NULL); |
| 266 | sigaction(SIGSEGV, &act, NULL); |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 267 | #if defined(SIGSTKFLT) |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 268 | sigaction(SIGSTKFLT, &act, NULL); |
Raghu Gandham | d7daacb | 2012-07-31 12:07:22 -0700 | [diff] [blame] | 269 | #endif |
Andy McFadden | ec92af8 | 2011-07-29 12:46:34 -0700 | [diff] [blame] | 270 | sigaction(SIGPIPE, &act, NULL); |
The Android Open Source Project | 1dc9e47 | 2009-03-03 19:28:35 -0800 | [diff] [blame] | 271 | } |