[Sjonny]

I've been wondering.. is it possible to write something to override the statically linked functions? In this case, most (if not all) functions have an SDL_ prefix. Would it be possible to LD_PRELOAD a library that loads a shared version of SDL and goes over all the function pointers to move them point them to a new location? Is there a tool for this?

[cesarb]

> I've been wondering.. is it possible to write something to override the statically linked functions?

SDL does have a built-in way to do that trick. A quick web search tells me it's called SDL_DYNAMIC_API.

[Sjonny]

cool, I never knew! Somehow the game I thought it would add a feature is still lacking it. For some reason rumble on my xbox joystick with Enter the Gungeon never worked. I thought it was because of an old SDL version, because experimentation showed that. But by using the SDL_DYNAMIC_API env and loading my system SDL the game still not added rumble to my joystick. Ohwell.

[seba_dos1]

SDL_DYNAMIC_API is a relatively recent addition (IIRC 2014), so static SDL2 builds from before that won't work this way.

[ds-]

It looks like SDL's public symbols are all global in lime.ndll so LD_PRELOADing SDL should do what you want. Of course it is possible that lime.ndll was built with -fno-semantic-interposition or equivalent in which case the functions might be called directly without going through the dynamic linker or even (partially) inlined.

[touisteur]

Well if you know where to fork, you could use Intel Pin and divert the CFG, favorite tool for binary 'patching'.

Edit: though here if it's a problem of file enumeration and access, I'd probably just LD_PRELOAD something to bypass libc file access functions and return the same result than the first time, with no delay.

[bregma]

Static linking means the features of the Linux dynamic loader, like using the environment variable LD_PRELOAD to pre-load a dynamic library, are not going to have any effect.