Re: [uclibc-ng-devel] __LDSO_STANDALONE_SUPPORT__ applies to dlopen

Hello Luca, I am not sure whether dlopen'ing an executable (and not a shared lib) is a supported feature of uClibc-ng... Man page of dlopen says it is for opening "shared lib". There has been a discussion on glibc bug tracker to widen the scope of dlopen and allow it to open executables ... but it seems Ulrich Drepper refused it, and then the discussion was revived and it still does not seem to hold a strong consensus. See https://sourceware.org/bugzilla/show_bug.cgi?id=11754 I didn't try, but I am guessing here that if it works, it is by accident. opening and mapping an ET_EXEC is needed indeed in the case of "standalone" (dynamic loader run as an executable and loading another executable given as argument). And the function used to do this, is also the one used by dlopen() to map the shared libs. I guess you are refering to https://elixir.bootlin.com/uclibc-ng/latest/source/ldso/ldso/dl-elf.c#L596 _dl_load_elf_shared_library is indeed used to load the ET_EXEC in the "ld.so used as an executable" from there: https://elixir.bootlin.com/uclibc-ng/latest/source/ldso/ldso/ldso.c#L601 And it is also called from https://elixir.bootlin.com/uclibc-ng/latest/source/ldso/ldso/dl-elf.c#L200 Which is itself called from dlopen: https://elixir.bootlin.com/uclibc-ng/latest/source/ldso/libdl/libdl.c#L372 So it seems the same function is used in 2 different contexts and that leads to the support of ET_EXEC which is valid in one context ... but I'm not sure it is valid in the other one (directly loading an ET_EXEC with dlopen). I hope this is clear. Maybe someone else can give a hint whether my guess is correct or not? Rich ? Waldemar ? Cheers, Yann Le 31/05/2019 à 14:15, Luca Lindhorst a écrit :