You can use EmbeddedProfiler, it's free for both Linux and Windwos.
The profiler is intrusive (by functionality) but it doens't require any code modifications. Just add a specific compiler flag (-finstrument-functios for gcc/MinGW or /GH for MSVC) and link the profiler's library. It can provide you a full call tree or just a funciton list. It has it's own analyzer GUI.