Does a prelinked file size remain static

[Jakub Jelinek]

On Thu, Jun 28, 2007 at 04:09:25PM +0100, John Horne wrote:
> I have been trying to find out if a prelinked files size always remains
> the same. Some simple testing of unprelinking and then prelinking a file
> seems to indicate that the eventual size of the file does remain the
> same. I know that the files MD5 hash value, its inode number, and some
> other file attributes change, but I was wondering about the file size.
> Whilst the file does change size when going from unprelinked to
> prelinked (or vice-versa), once it is prelinked it then seems to remain
> the same regardless of how often the file is re-prelinked.

That's certainly not guaranteed.  For prelinked shared libraries after
reprelinking the size might change if due to some dependent library
upgrade there are fewer or more dependencies.
Say libfoo.so.1 depends on libbar.so.1, which after an upgrade
is linked also to libbaz.so.1, but wasn't linked against it in earlier
version.  When libfoo.so.1 is re-prelinked, it will grow file size.

For binaries, the number of dependendent libraries (and length of their
SONAMEs) isn't the only factor, also when new prelink conflicts are
needed or no longer needed affects the size.  See prelink.pdf for more
details.

	Jakub