Hi, I built a systemtap1.4 on ubuntu 10.4 32 bits. And also cross-compile staprun to a develop board with kernel 2.6.35 x86. On the host pc side, stap -r /target-board/kernel xxx.stp -p 4 -m traceauto.ko then copy the traceauto.ko to the board, staprun -u -v -m traceauto.ko -c ./hello xxx.stp probe process("/ddtv/tracedrv/test/dhg/hello/hello").function("*").call { printf("USER, %s %s %s\n", thread_indent(1), pp(), $$parms) } probe process("/ddtv/tracedrv/test/dhg/hello/hello").function("*").return { printf("USER %s %s %s\n", thread_indent(-1), probefunc(), $$return) } probe end { printf ("end of tracing\n") } It only able to print "end of tracing", nothing in the hello is printed. Attached is the binary of traceauto.ko. BTW, it can trace kernel level code. Just not lucky on user-level code. Any help is great appreciated. Thanks, Zhiwei