Re: [objcopy]: zero to three bytes of padding in .gnu_debuglink section

[Alan Modra <amodra at gmail dot com>]

On Wed, Apr 06, 2011 at 05:54:59PM +0200, T Majchrowski wrote:
> 2011/4/6 Alan Modra <amodra@gmail.com>
> >
> > On Mon, Apr 04, 2011 at 10:31:41AM -0700, Majcher wrote:
> > > I found that .gnu_debuglink. section contains zero to three bytes of padding
> > > just after filename. I recognized that this padding may be different
> > > depending on which host is used to add gnu_debuglink via objcopy
> > > --add-gnu-debuglink. Is there any way to provide always a fixed value of
> > > that padding?
> >
> > No.
> >
> I checked sources, it seems so that it would quite easy to achieve
> just by changing
> 
> FROM: contents = malloc (debuglink_size );
> TO:      contents = calloc (debuglink_size,sizeof(char) );
> 
> in bfd/opncls.c

I misunderstood your question, thinking you were asking for a fixed
length of padding.  We already zero the padding.

  crc_offset = debuglink_size - 4;
  memcpy (contents, filename, filelen);
  memset (contents + filelen, 0, crc_offset - filelen);

  bfd_put_32 (abfd, crc32, contents + crc_offset);


-- 
Alan Modra
Australia Development Lab, IBM