GenericBacktrace.c

/* Originally taken from glibc, b/c _Unwind_Backtrace is way too slow
   to be useful. Some minor modifications were made. --wlav */

#include "Hephaestus/Hephaestus.h"
#include "Hephaestus/GenericBacktrace.h"

#define BOUNDED_1(PTR) (PTR)

extern void *__libc_stack_end;


/* Definition of stack frame structure.  Generic version.
   Copyright (C) 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

struct layout
{
  void *__unbounded next;
  void *__unbounded return_address;
};


/* Return backtrace of current program state.  Generic version.
   Copyright (C) 1998, 2000, 2002, 2004, 2005 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

/* This implementation assumes a stack layout that matches the defaults
   used by gcc's `__builtin_frame_address' and `__builtin_return_address'
   (FP is the frame pointer register):

	  +-----------------+     +-----------------+
    FP -> | previous FP --------> | previous FP ------>...
	  |                 |     |                 |
	  | return address  |     | return address  |
	  +-----------------+     +-----------------+

  */

/* Get some notion of the current stack.  Need not be exactly the top
   of the stack, just something somewhere in the current frame.  */
#ifndef CURRENT_STACK_FRAME
# define CURRENT_STACK_FRAME  ({ char __csf; &__csf; })
#endif

/* By default we assume that the stack grows downward.  */
#ifndef INNER_THAN
# define INNER_THAN <
#endif

/* By default assume the `next' pointer in struct layout points to the
   next struct layout.  */
#ifndef ADVANCE_STACK_FRAME
# define ADVANCE_STACK_FRAME(next) BOUNDED_1 ( (struct layout*)(next) )
#endif


/* _________________________________________________________________________ */
int hhh_GenericBacktrace( void **array, int size )
{
   struct layout *current;
   void *__unbounded top_frame;
   void *__unbounded top_stack;
   int cnt = 0;

#if defined ( __i386 )
   __asm__( "movl %%ebp, %0" : "=g"(top_frame));
#elif defined ( __x86_64__ )
   __asm__( "movq %%rbp, %0" : "=g"(top_frame));
#else
   top_frame = __builtin_frame_address( 0 );
#endif

   top_stack = CURRENT_STACK_FRAME;

/* We skip the call to this function, it makes no sense to record it.  */
   current = BOUNDED_1( (struct layout*)top_frame );
   while ( cnt < size )
   {
      if ( (void*)current INNER_THAN top_stack
	  || !( (void*)current INNER_THAN __libc_stack_end ) )
      /* This means the address is out of range.  Note that for the
         toplevel we see a frame pointer with value NULL which clearly is
         out of range.  */
	 break;

      array[cnt++] = current->return_address;

      current = ADVANCE_STACK_FRAME( current->next );
   }

   return cnt;
}