[Bug translator/10454] Raw number statement probes won't work without dwarf info

["jistone at redhat dot com" <sourceware-bugzilla at sourceware dot org>]

------- Additional Comments From jistone at redhat dot com  2009-07-28 19:30 -------
(In reply to comment #0)
> We hit this part of tapsets.cxx (query_cu):
> 
>           // Verify that a raw address matches the beginning of a
>           // statement. This is a somewhat lame check that the address
>           // is at the start of an assembly instruction.  Mark probes are in the
>           // middle of a macro and thus not strictly at a statement beginning.
>           // Guru mode may override this check.
> 
> It might be an idea to allow "misplaced statement expressions" for user space
> probes always since it isn't very "dangerous". Also note that "assembly
> instruction" isn't really what is being tested. It is really whether there is
> dwarf line info that says the statement given starts on a line.

Well, being the beginning of a statement is a sufficient condition for being the
beginning of an assembly instruction, right?  Sure, that's not a necessary
condition, but that's probably why this is a "somewhat lame check".

As for danger -- a misplaced probe in a user app won't bring down the system,
but it will likely break or even crash the application, which still violates our
philosophy of harmless probing.

-- 


http://sourceware.org/bugzilla/show_bug.cgi?id=10454

------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.