272 lines
9 KiB
C++
272 lines
9 KiB
C++
/*
|
|
* Copyright (C) 2008 The Android Open Source Project
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include "linker.h"
|
|
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <sys/mman.h>
|
|
#include <sys/prctl.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/un.h>
|
|
#include <unistd.h>
|
|
|
|
extern "C" int tgkill(int tgid, int tid, int sig);
|
|
|
|
#if __LP64__
|
|
#define DEBUGGER_SOCKET_NAME "android:debuggerd64"
|
|
#else
|
|
#define DEBUGGER_SOCKET_NAME "android:debuggerd"
|
|
#endif
|
|
|
|
enum debugger_action_t {
|
|
// dump a crash
|
|
DEBUGGER_ACTION_CRASH,
|
|
// dump a tombstone file
|
|
DEBUGGER_ACTION_DUMP_TOMBSTONE,
|
|
// dump a backtrace only back to the socket
|
|
DEBUGGER_ACTION_DUMP_BACKTRACE,
|
|
};
|
|
|
|
/* message sent over the socket */
|
|
struct debugger_msg_t {
|
|
// version 1 included:
|
|
debugger_action_t action;
|
|
pid_t tid;
|
|
|
|
// version 2 added:
|
|
uintptr_t abort_msg_address;
|
|
};
|
|
|
|
// see man(2) prctl, specifically the section about PR_GET_NAME
|
|
#define MAX_TASK_NAME_LEN (16)
|
|
|
|
static int socket_abstract_client(const char* name, int type) {
|
|
sockaddr_un addr;
|
|
|
|
// Test with length +1 for the *initial* '\0'.
|
|
size_t namelen = strlen(name);
|
|
if ((namelen + 1) > sizeof(addr.sun_path)) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/* This is used for abstract socket namespace, we need
|
|
* an initial '\0' at the start of the Unix socket path.
|
|
*
|
|
* Note: The path in this case is *not* supposed to be
|
|
* '\0'-terminated. ("man 7 unix" for the gory details.)
|
|
*/
|
|
memset(&addr, 0, sizeof(addr));
|
|
addr.sun_family = AF_LOCAL;
|
|
addr.sun_path[0] = 0;
|
|
memcpy(addr.sun_path + 1, name, namelen);
|
|
|
|
socklen_t alen = namelen + offsetof(sockaddr_un, sun_path) + 1;
|
|
|
|
int s = socket(AF_LOCAL, type, 0);
|
|
if (s == -1) {
|
|
return -1;
|
|
}
|
|
|
|
int err = TEMP_FAILURE_RETRY(connect(s, reinterpret_cast<sockaddr*>(&addr), alen));
|
|
if (err == -1) {
|
|
close(s);
|
|
s = -1;
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
/*
|
|
* Writes a summary of the signal to the log file. We do this so that, if
|
|
* for some reason we're not able to contact debuggerd, there is still some
|
|
* indication of the failure in the log.
|
|
*
|
|
* We could be here as a result of native heap corruption, or while a
|
|
* mutex is being held, so we don't want to use any libc functions that
|
|
* could allocate memory or hold a lock.
|
|
*/
|
|
static void log_signal_summary(int signum, const siginfo_t* info) {
|
|
const char* signal_name;
|
|
switch (signum) {
|
|
case SIGILL: signal_name = "SIGILL"; break;
|
|
case SIGABRT: signal_name = "SIGABRT"; break;
|
|
case SIGBUS: signal_name = "SIGBUS"; break;
|
|
case SIGFPE: signal_name = "SIGFPE"; break;
|
|
case SIGSEGV: signal_name = "SIGSEGV"; break;
|
|
#if defined(SIGSTKFLT)
|
|
case SIGSTKFLT: signal_name = "SIGSTKFLT"; break;
|
|
#endif
|
|
case SIGPIPE: signal_name = "SIGPIPE"; break;
|
|
default: signal_name = "???"; break;
|
|
}
|
|
|
|
char thread_name[MAX_TASK_NAME_LEN + 1]; // one more for termination
|
|
if (prctl(PR_GET_NAME, (unsigned long)thread_name, 0, 0, 0) != 0) {
|
|
strcpy(thread_name, "<name unknown>");
|
|
} else {
|
|
// short names are null terminated by prctl, but the man page
|
|
// implies that 16 byte names are not.
|
|
thread_name[MAX_TASK_NAME_LEN] = 0;
|
|
}
|
|
|
|
// "info" will be NULL if the siginfo_t information was not available.
|
|
if (info != NULL) {
|
|
__libc_format_log(ANDROID_LOG_FATAL, "libc",
|
|
"Fatal signal %d (%s) at %p (code=%d), thread %d (%s)",
|
|
signum, signal_name, info->si_addr, info->si_code,
|
|
gettid(), thread_name);
|
|
} else {
|
|
__libc_format_log(ANDROID_LOG_FATAL, "libc",
|
|
"Fatal signal %d (%s), thread %d (%s)",
|
|
signum, signal_name, gettid(), thread_name);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if the handler for signal "signum" has SA_SIGINFO set.
|
|
*/
|
|
static bool have_siginfo(int signum) {
|
|
struct sigaction old_action, new_action;
|
|
|
|
memset(&new_action, 0, sizeof(new_action));
|
|
new_action.sa_handler = SIG_DFL;
|
|
new_action.sa_flags = SA_RESTART;
|
|
sigemptyset(&new_action.sa_mask);
|
|
|
|
if (sigaction(signum, &new_action, &old_action) < 0) {
|
|
__libc_format_log(ANDROID_LOG_WARN, "libc", "Failed testing for SA_SIGINFO: %s",
|
|
strerror(errno));
|
|
return false;
|
|
}
|
|
bool result = (old_action.sa_flags & SA_SIGINFO) != 0;
|
|
|
|
if (sigaction(signum, &old_action, NULL) == -1) {
|
|
__libc_format_log(ANDROID_LOG_WARN, "libc", "Restore failed in test for SA_SIGINFO: %s",
|
|
strerror(errno));
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* Catches fatal signals so we can ask debuggerd to ptrace us before
|
|
* we crash.
|
|
*/
|
|
void debuggerd_signal_handler(int n, siginfo_t* info, void*) {
|
|
/*
|
|
* It's possible somebody cleared the SA_SIGINFO flag, which would mean
|
|
* our "info" arg holds an undefined value.
|
|
*/
|
|
if (!have_siginfo(n)) {
|
|
info = NULL;
|
|
}
|
|
|
|
log_signal_summary(n, info);
|
|
|
|
pid_t tid = gettid();
|
|
int s = socket_abstract_client(DEBUGGER_SOCKET_NAME, SOCK_STREAM);
|
|
|
|
if (s >= 0) {
|
|
// debuggerd knows our pid from the credentials on the
|
|
// local socket but we need to tell it the tid of the crashing thread.
|
|
// debuggerd will be paranoid and verify that we sent a tid
|
|
// that's actually in our process.
|
|
debugger_msg_t msg;
|
|
msg.action = DEBUGGER_ACTION_CRASH;
|
|
msg.tid = tid;
|
|
msg.abort_msg_address = reinterpret_cast<uintptr_t>(gAbortMessage);
|
|
int ret = TEMP_FAILURE_RETRY(write(s, &msg, sizeof(msg)));
|
|
if (ret == sizeof(msg)) {
|
|
// if the write failed, there is no point trying to read a response.
|
|
ret = TEMP_FAILURE_RETRY(read(s, &tid, 1));
|
|
int saved_errno = errno;
|
|
notify_gdb_of_libraries();
|
|
errno = saved_errno;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
/* read or write failed -- broken connection? */
|
|
__libc_format_log(ANDROID_LOG_FATAL, "libc", "Failed while talking to debuggerd: %s",
|
|
strerror(errno));
|
|
}
|
|
|
|
close(s);
|
|
} else {
|
|
/* socket failed; maybe process ran out of fds */
|
|
__libc_format_log(ANDROID_LOG_FATAL, "libc", "Unable to open connection to debuggerd: %s",
|
|
strerror(errno));
|
|
}
|
|
|
|
/* remove our net so we fault for real when we return */
|
|
signal(n, SIG_DFL);
|
|
|
|
/*
|
|
* These signals are not re-thrown when we resume. This means that
|
|
* crashing due to (say) SIGPIPE doesn't work the way you'd expect it
|
|
* to. We work around this by throwing them manually. We don't want
|
|
* to do this for *all* signals because it'll screw up the address for
|
|
* faults like SIGSEGV.
|
|
*/
|
|
switch (n) {
|
|
case SIGABRT:
|
|
case SIGFPE:
|
|
case SIGPIPE:
|
|
#if defined(SIGSTKFLT)
|
|
case SIGSTKFLT:
|
|
#endif
|
|
(void) tgkill(getpid(), gettid(), n);
|
|
break;
|
|
default: // SIGILL, SIGBUS, SIGSEGV
|
|
break;
|
|
}
|
|
}
|
|
|
|
void debuggerd_init() {
|
|
struct sigaction action;
|
|
memset(&action, 0, sizeof(action));
|
|
sigemptyset(&action.sa_mask);
|
|
action.sa_sigaction = debuggerd_signal_handler;
|
|
action.sa_flags = SA_RESTART | SA_SIGINFO;
|
|
|
|
// Use the alternate signal stack if available so we can catch stack overflows.
|
|
action.sa_flags |= SA_ONSTACK;
|
|
|
|
sigaction(SIGABRT, &action, NULL);
|
|
sigaction(SIGBUS, &action, NULL);
|
|
sigaction(SIGFPE, &action, NULL);
|
|
sigaction(SIGILL, &action, NULL);
|
|
sigaction(SIGPIPE, &action, NULL);
|
|
sigaction(SIGSEGV, &action, NULL);
|
|
#if defined(SIGSTKFLT)
|
|
sigaction(SIGSTKFLT, &action, NULL);
|
|
#endif
|
|
sigaction(SIGTRAP, &action, NULL);
|
|
}
|