Very Computer

I've been trying to write a simple test program which adds a new section
to an ELF format executable using libelf.  I've been able to get the test
program to work under Solaris, but under Irix and Linux I'm having
problems.

Under Irix, the modified executables always core dump.

Under Linux (using Michael Riepe's libelf), the modified executable core
dumps if the added section is too large (over a mega-byte).

Has anyone been able to write portable libelf code that works on all these
platforms or any two?  Is sample source available?

The only source code I found that uses libelf is the scheme interpreter
"Elk", but it only uses it to read symbols from ELF files.

Thanks - Chuck

rick

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

        Richard M. Goldstein

        64-bit Linkers, Libs & Executables
        SunSoft, Inc.

        "Without time we pick up all the streams,
        and find the leaves that drift out inbetween..."
                                -Kirkwood

The libelf examples in the elf_begin man page
do leave a lot to the imagination.

Perhaps if you posted the output of
        elfdump -h -o -L
before and after your transformation someone could
figure out (or make a useful guess) what was wrong
in the IRIX case.

Hard to guess given the limited info above.

|> I've been trying to write a simple test program which adds a new section
|> to an ELF format executable using libelf.  I've been able to get the test
|> program to work under Solaris, but under Irix and Linux I'm having
|> problems.

Changing the layout of a ELF binary can be very tricky, see for example
unexelf.c in the Emacs distribution.
--
Andreas Schwab                                      "And now for something

But, unexelf.c is complicated because it directly modifies an elf file -
it does not use libelf.  Using libelf would eliminate alot of the druggery
of recalculating file offsets, etc.

If anyone has written a version of unexelf.c which uses libelf, I'd love
to see it.

- Chuck