When running the following tap script on s390: probe kernel.function("*") {} I receive the following error. [...] semantic error: missing entrypc dwarf line record for function 'jprobe_return' semantic error: no match for probe point while: resolving probe point kernel.function("jprobe_return") jprobe_return() is tagged __kprobes so it should automatically blacklisted; However, the error is thrown before the blacklist is consulted. This results is that the tap script not building. Here is the void __kprobes jprobe_return(void) { asm volatile (".word 0x0002"); } I discussed this on the systemtap ml. >The problem here is that while some of these routines are blacklisted >> in the kernel (kprobe_register will fail), they are not blacklisted in >> the translator. We need to teach the translator to look for the >> kernel-side blacklist info too (the .kprobes section naming methinks), >> and treat it similarly to the .init/.exit special cases already >> present in tapsets.cxx. >> >> This way, function("*") will quietly exclude the blacklisted >> functions. >> >> - FChE Indeed this would be nice -- see bug #2639. http://sources.redhat.com/bugzilla/show_bug.cgi?id=2639 In the mean time, we can add additional functions to the static blacklist in the translator. See dwarf_query::build_blacklist(). It's unfortunate that we have to try to maintain this, but I suppose it's better than nothing. And, as you mention, kprobe_register will block these too, so this is really just a matter of *when* the error is caught. Josh
This issue needs to be retested since BZ2639 has been fixed. All '__kprobes' functions should be automatically blacklisted.
translator blacklist automatically includes kernel __kprobes functions now.