How does stap execute probe aliases?

[Nan Xiao]

Hi all,

I try to execute the following script from this page
(https://sourceware.org/systemtap/SystemTap_Beginners_Guide/targetavailable.html#available):

# cat two_probes.stp
#!/usr/bin/stap
probe vm.pagefault = kernel.function("__handle_mm_fault@mm/memory.c") ?,
                     kernel.function("handle_mm_fault@mm/memory.c") ?
{
        name = "pagefault"
        write_access = (@defined($flags)
                        ? $flags & FAULT_FLAG_WRITE : $write_access)
        address =  $address
}

# ./two_probes.stp
semantic error: no probes found
Pass 2: analysis failed.  [man error::pass2]

Why can't the stap find the probes? Thanks in advance!

Best Regards
Nan Xiao