Re: Solution to --> Re: dlopen() bug on Linux/Alpha

[rth at cygnus dot com (Richard Henderson)]

In article <199801110859.JAA12769.cygnus.egcs.bugs@kotter.atko.at>,
Stefan Traby <stefan@sime.com> wrote:
>Please check another special condition: Make a simple program
>which does dlopen and dlsym (no, don't call main :-) on itself. 
>Simplified I mean dlopen(argv[0],...) but argv[0] may not contain
>the full path... 
>Does it work ?

If the main program is a regular executable (ET_EXEC), then no
it won't because dlopen will reject all but shared objects (ET_DYN).

If the main program is a shared object (yes this is possible), 
then the open will succeed.  It would of course be a bit pointless
but it would work.

>On a non glibc GNU-Linux/i386 system, linking with "-shared" makes the 
>program dump core _before_ main is called. SIGSEGV "#0 0x4 in ?? ()" 

This is only because the libc5 startup code is not sufficiently agile.
As I said, it is quite possible to directly execute shared objects.


r~