Using SystemTap translator/driver (version 0.5.15/Red Hat elfutils 0.125 built 2007-08-01) If a probepoint falls on an empty line in a C function, stap throw's a semantic error. For eg with this stap script, # kernel/fork.c:1385 happens to be a line w/o any C statements in do_fork() in the kernel I am using. probe kernel.function("*@kernel/fork.c:1385") { printf("do_fork: %d\n", $clone_flags); } The error shown is: semantic error: no match for probe point while resolving probe point kernel.function("*@kernel/fork.c:1385") I would think that stap needs to find the next valid line which has a C statement and should insert the probepoint there.
This problem hits people easily if they need to use .statement() probes.
Another bug was the loss of $target vars in many .statement probes. That too is fixed in a committed fix.