| /* |
| * 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 <signal.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <ctype.h> |
| #include "logd.h" |
| |
| void *__stack_chk_guard = 0; |
| |
| /* Initialize the canary with a random value from /dev/urandom. |
| * If that fails, use the "terminator canary". */ |
| static void __attribute__ ((constructor)) |
| __guard_setup(void) |
| { |
| int fd; |
| |
| fd = open("/dev/urandom", O_RDONLY); |
| if (fd != -1) { |
| ssize_t len = read(fd, &__stack_chk_guard, |
| sizeof(__stack_chk_guard)); |
| close(fd); |
| if (len == sizeof(__stack_chk_guard)) |
| return; |
| } |
| |
| /* If that failed, switch to 'terminator canary' */ |
| ((unsigned char *)&__stack_chk_guard)[0] = 0; |
| ((unsigned char *)&__stack_chk_guard)[1] = 0; |
| ((unsigned char *)&__stack_chk_guard)[2] = '\n'; |
| ((unsigned char *)&__stack_chk_guard)[3] = 255; |
| } |
| |
| /* This is the crash handler. |
| * Does a best effort at logging and calls _exit to terminate |
| * the process immediately (without atexit handlers, etc.) */ |
| void __stack_chk_fail(void) |
| { |
| struct sigaction sa; |
| sigset_t sigmask; |
| static const char message[] = "stack corruption detected: aborted"; |
| char path[PATH_MAX]; |
| int count; |
| |
| /* Immediately block all (but SIGABRT) signal handlers from running code */ |
| sigfillset(&sigmask); |
| sigdelset(&sigmask, SIGABRT); |
| sigprocmask(SIG_BLOCK, &sigmask, NULL); |
| |
| /* Use /proc/self/exe link to obtain the program name for logging |
| * purposes. If it's not available, we set it to "<unknown>" */ |
| if ((count = readlink("/proc/self/exe", path, sizeof(path) - 1)) == -1) { |
| strlcpy(path, "<unknown>", sizeof(path)); |
| } else { |
| path[count] = '\0'; |
| } |
| |
| /* Do a best effort at logging. This ends up calling writev(2) */ |
| __libc_android_log_print(ANDROID_LOG_FATAL, path, message); |
| |
| /* Make sure there is no default action for SIGABRT */ |
| bzero(&sa, sizeof(struct sigaction)); |
| sigemptyset(&sa.sa_mask); |
| sa.sa_flags = 0; |
| sa.sa_handler = SIG_DFL; |
| sigaction(SIGABRT, &sa, NULL); |
| |
| /* Terminate the process and exit immediately */ |
| kill(getpid(), SIGABRT); |
| |
| _exit(127); |
| } |