Re: RTLD_LAZY deferred symbol binding

[Szabolcs Nagy <nsz@port70.net>]

* Scherbatiy Alexander <alexander.scherbatiy@bell-sw.com> [2019-12-11 14:53:43 +0300]:
> Thank you. It works.
> 
> I looked at the ld help on linux Alpine and it shows
> > ld --help
> > -z lazy                     Mark object lazy runtime binding (default)
> 
> Should the lazy option be used by default or the documentation needs to be updated?

that's standard binutils documentation and it's correct:
i think alpine patches gcc to pass -z now, not ld (and
i think gentoo hardened does the same).

i guess alpine could maintain a toolchain documentation
where it describes the changes compared to upstream
defaults, but you can check their patches
https://git.alpinelinux.org/aports/tree/main/gcc

> 
> Thanks,
> Alexander.
> 
> 
> 11.12.2019, 13:35, "Szabolcs Nagy" <nsz@port70.net>:
> > * Scherbatiy Alexander <alexander.scherbatiy@bell-sw.com> [2019-12-11 13:09:36 +0300]:
> >>  # build sources
> >>  gcc -c -fPIC src/resolved_impl.c -Iinclude -o bin/shared/resolved_impl.o
> >>  gcc -c -fPIC src/shared_lib.c -Iinclude -o bin/shared/shared_lib.o
> >>  gcc -shared bin/shared/shared_lib.o bin/shared/resolved_impl.o -Iinclude -o bin/shared/libshared_lib.so
> >
> > ^^^^^^^^^^^^^^^
> >
> > you need to pass -Wl,-z,lazy (and verify it with readelf -d )
> > because alpine (and various other distros) defaults to -z now
> > (and then libc obviously cant do lazy binding no matter what
> > you specified in dlopen).