Re: Patch to fix memory leak in bfd

[Nick Clifton <nickc@cygnus.com>]

Hi Ian,

: Thanks.  I wouldn't call that a memory leak--a memory leak is a case
: where memory is allocated but never freed.  What you fixed is a case
: of memory corruption.

True.

: Incidentally, that code appears to have another, less serious, bug,
: which is that if realloc or calloc fail, it should call bfd_set_error
: (bfd_error_no_memory).  Since it doesn't, a memory allocation failure
: will not be reported back to the user correctly.  Most code does this
: by calling bfd_malloc or bfd_realloc, in libbfd.c, rather than malloc
: or realloc.

Good point.  I have checked in the patch below to correct this.

Cheers
	Nick

1999-09-06  Nick Clifton  <nickc@cygnus.com>

	* elflink.h (elf_gc_record_vtentry): Use bfd_zmalloc and
	bfd_realloc instead of calloc and realloc.

Index: elflink.h
===================================================================
RCS file: /cvs/binutils/binutils/bfd/elflink.h,v
retrieving revision 1.31
diff -p -w -r1.31 elflink.h
*** elflink.h	1999/09/04 16:26:08	1.31
--- elflink.h	1999/09/06 08:56:54
*************** elf_gc_record_vtentry (abfd, sec, h, add
*** 6423,6448 ****
  
        if (ptr)
  	{
! 	  size_t oldbytes;
  
! 	  ptr = realloc (ptr-1, bytes);
! 	  if (ptr == NULL)
! 	    return false;
  
  	  oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof(boolean);
  	  memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
  	}
        else
! 	{
! 	  ptr = calloc (1, bytes);
  	  if (ptr == NULL)
  	    return false;
- 	}
  
        /* And arrange for that done flag to be at index -1.  */
        h->vtable_entries_used = ptr+1;
        h->vtable_entries_size = size;
      }
    h->vtable_entries_used[addend / FILE_ALIGN] = true;
  
    return true;
--- 6423,6449 ----
  
        if (ptr)
  	{
! 	  ptr = bfd_realloc (ptr - 1, bytes);
  	  
! 	  if (ptr != NULL)
! 	    {
! 	      size_t oldbytes;
  
  	      oldbytes = (h->vtable_entries_size/FILE_ALIGN + 1) * sizeof (boolean);
  	      memset (((char *)ptr) + oldbytes, 0, bytes - oldbytes);
  	    }
+ 	}
        else
! 	ptr = bfd_zmalloc (bytes);
! 
        if (ptr == NULL)
  	return false;
        
        /* And arrange for that done flag to be at index -1.  */
        h->vtable_entries_used = ptr + 1;
        h->vtable_entries_size = size;
      }
+   
    h->vtable_entries_used[addend / FILE_ALIGN] = true;
  
    return true;