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/*
* 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 <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <signal.h>
#include <sys/mman.h>
#include <errno.h>
#include "linker.h"
#include <sys/socket.h>
#include <sys/un.h>
void notify_gdb_of_libraries();
#define RETRY_ON_EINTR(ret,cond) \
do { \
ret = (cond); \
} while (ret < 0 && errno == EINTR)
static int socket_abstract_client(const char *name, int type)
{
struct sockaddr_un addr;
size_t namelen;
socklen_t alen;
int s, err;
namelen = strlen(name);
// Test with length +1 for the *initial* '\0'.
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);
alen = namelen + offsetof(struct sockaddr_un, sun_path) + 1;
s = socket(AF_LOCAL, type, 0);
if(s < 0) return -1;
RETRY_ON_EINTR(err,connect(s, (struct sockaddr *) &addr, alen));
if (err < 0) {
close(s);
s = -1;
}
return s;
}
#include "linker_format.h"
#include <../libc/private/logd.h>
/*
* Writes a summary of the signal to the log file.
*
* 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 logSignalSummary(int signum, const siginfo_t* info)
{
char buffer[128];
char* signame;
switch (signum) {
case SIGILL: signame = "SIGILL"; break;
case SIGABRT: signame = "SIGABRT"; break;
case SIGBUS: signame = "SIGBUS"; break;
case SIGFPE: signame = "SIGFPE"; break;
case SIGSEGV: signame = "SIGSEGV"; break;
case SIGSTKFLT: signame = "SIGSTKFLT"; break;
case SIGPIPE: signame = "SIGPIPE"; break;
default: signame = "???"; break;
}
format_buffer(buffer, sizeof(buffer),
"Fatal signal %d (%s) at 0x%08x (code=%d)",
signum, signame, info->si_addr, info->si_code);
__libc_android_log_write(ANDROID_LOG_FATAL, "libc", buffer);
}
/*
* Catches fatal signals so we can ask debuggerd to ptrace us before
* we crash.
*/
void debugger_signal_handler(int n, siginfo_t* info, void* unused)
{
unsigned tid;
int s;
logSignalSummary(n, info);
tid = gettid();
s = socket_abstract_client("android:debuggerd", SOCK_STREAM);
if(s >= 0) {
/* debugger knows our pid from the credentials on the
* local socket but we need to tell it our tid. It
* is paranoid and will verify that we are giving a tid
* that's actually in our process
*/
int ret;
RETRY_ON_EINTR(ret, write(s, &tid, sizeof(unsigned)));
if (ret == sizeof(unsigned)) {
/* if the write failed, there is no point to read on
* the file descriptor. */
RETRY_ON_EINTR(ret, read(s, &tid, 1));
notify_gdb_of_libraries();
}
close(s);
}
/* remove our net so we fault for real when we return */
signal(n, SIG_DFL);
}
void debugger_init()
{
struct sigaction act;
memset(&act, 0, sizeof(act));
act.sa_sigaction = debugger_signal_handler;
act.sa_flags = SA_RESTART | SA_SIGINFO;
sigemptyset(&act.sa_mask);
sigaction(SIGILL, &act, NULL);
sigaction(SIGABRT, &act, NULL);
sigaction(SIGBUS, &act, NULL);
sigaction(SIGFPE, &act, NULL);
sigaction(SIGSEGV, &act, NULL);
sigaction(SIGSTKFLT, &act, NULL);
sigaction(SIGPIPE, &act, NULL);
}
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