[Question] LinuxThreads, setuid - Is there user mode hook?

[Alon Bar-Lev <alon.barlev@gmail.com>]

Hello,

I am writing a provider that uses pthreads. The main program 
does not aware that the provider is using threads and it is 
not multithreaded.

After initialization the program setuid to nobody, the 
problem is that my threads remains in root id.

I read about discussions regarding LinuxThreads and figured 
out that I need to sync the uid,gid by my-self... :(

Is there a way in user mode to know when the process is 
setuid (some kind of callback)?

The best solution is to set this callback in every thread, 
so that it will setuid also when the main setuided.

Of course I can spawn a threads that pools the id of the 
main process... But there must be a better way to do that.

Best Regards,
Alon Bar-Lev.