sys/libkern/stack_protector.c

   1 /*
   2  * Copyright (c) 2002 Hiroaki Etoh.
   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  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  17  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT,
  18  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  20  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  22  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  23  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  24  * POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include <sys/param.h>
  28 #include <sys/endian.h>
  29 #ifndef _KERNEL
  30 extern void panic(const char *, ...);
  31 #endif
  32
  33 void __stack_smash_handler(char[], int);
  34
  35 #if BYTE_ORDER == LITTLE_ENDIAN
  36 int __guard = 0x00000aff;
  37 #else
  38 int __guard = 0xff0a0000;
  39 #endif
  40
  41 void
  42 __stack_smash_handler(char func[], int damaged)
  43 {
  44 #ifdef __i386__ /* used in stand/boot */
  45         void *caller;
  46         __asm __volatile("movl 4(%%ebp), %0" : "=r" (caller));
  47         panic("stack overflow in function %p (%s)", caller, func);
  48 #else
  49         panic("stack overflow in function %s", func);
  50 #endif
  51 }