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      1 /*
      2  * Copyright (C) 2012 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 <stdio.h>
     30 #include <stdlib.h>
     31 #include <stdarg.h>
     32 #include <private/logd.h>
     33 
     34 /*
     35  * Runtime implementation of __builtin____vsnprintf_chk.
     36  *
     37  * See
     38  *   http://gcc.gnu.org/onlinedocs/gcc/Object-Size-Checking.html
     39  *   http://gcc.gnu.org/ml/gcc-patches/2004-09/msg02055.html
     40  * for details.
     41  *
     42  * This vsnprintf check is called if _FORTIFY_SOURCE is defined and
     43  * greater than 0.
     44  */
     45 int __vsnprintf_chk(
     46         char *dest,
     47         size_t supplied_size,
     48         int flags,
     49         size_t dest_len_from_compiler,
     50         const char *format,
     51         va_list va)
     52 {
     53     if (supplied_size > dest_len_from_compiler) {
     54         __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
     55             "*** vsnprintf buffer overflow detected ***\n");
     56         abort();
     57     }
     58 
     59     return vsnprintf(dest, supplied_size, format, va);
     60 }
     61