I build jsc for armv7 use softfp, when i run the following code, i get segmentfault var start = 1; function cb() { var arr = []; seg( function(n) { console.log(n); arr.push(n); }, start); } function seg(f, n) { f(n); if(n > 1000) return; seg(f, n+1); } cb(); I guess stack overflow so i increase stack size, but i still get segmentfault. Each death functions are executed 66 times. stack in SpeculativeJIT::runSlowPathGenerators When I close JIT,use LLINT ,I success. So I guess this is Bug for JIT