1 /* 2 * Copyright (C) 2015 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 <assert.h> 30 #include <errno.h> 31 #include <stddef.h> 32 #include <stdlib.h> 33 #include <string.h> 34 #include <sys/auxv.h> 35 #include <sys/cdefs.h> 36 37 #include "private/bionic_arc4random.h" 38 #include "private/bionic_globals.h" 39 #include "private/libc_logging.h" 40 #include "private/KernelArgumentBlock.h" 41 42 void __libc_init_setjmp_cookie(libc_globals* globals, KernelArgumentBlock& args) { 43 long value; 44 __libc_safe_arc4random_buf(&value, sizeof(value), args); 45 46 // Mask off the last bit to store the signal flag. 47 globals->setjmp_cookie = value & ~1; 48 } 49 50 extern "C" __LIBC_HIDDEN__ long __bionic_setjmp_cookie_get(long sigflag) { 51 if (sigflag & ~1) { 52 __libc_fatal("unexpected sigflag value: %ld", sigflag); 53 } 54 55 return __libc_globals->setjmp_cookie | sigflag; 56 } 57 58 // Aborts if cookie doesn't match, returns the signal flag otherwise. 59 extern "C" __LIBC_HIDDEN__ long __bionic_setjmp_cookie_check(long cookie) { 60 if (__libc_globals->setjmp_cookie != (cookie & ~1)) { 61 __libc_fatal("setjmp cookie mismatch"); 62 } 63 64 return cookie & 1; 65 } 66 67 extern "C" __LIBC_HIDDEN__ long __bionic_setjmp_checksum_mismatch() { 68 __libc_fatal("setjmp checksum mismatch"); 69 } 70
