I solved the issue with O3. Problem was that I worked with the stock cm9 build script, and that doesn't work well. So I started using an adapted version of stratosks/trailblazerz and this works. Want to test it myself before sharing...I am trying Linaro + O3 again
I applied your commit for the prebuild modemctl. But...I get the following error during building:
/home/kasper/android/system/prebuilt/linux-x86/toolchain/gcc-linaro-arm-linux-gnueabihf-2012.06-20120625_linux/bin/arm-linux-gnueabihf-ld: cannot find drivers/misc/samsung_modemctl/built-in.o: No such file or directory
If I go to kernel/drivers/misc/samsung_modemctl/ folder I see the built-in.o & builtin.o.gcc4.4.3 files there...