RE: [Linux-ia64] [PATCH] MCA recovery for TLB faults for 2.4

David Mosberger
2003-06-02T18:19:05Z

>>>>> On Mon, 2 Jun 2003 10:00:28 -0700, "Luck, Tony" <tony.luck@intel.com> said:

Tony> At the moment the trust level is extremely high. Linux
Tony> doesn't even provide a checksum for the ia64_os_mca_dispatch
Tony> entry code when it registers it with the SAL.

That's true.

Tony> A checksum in the list of saved translations would only be
Tony> part of reducing the level of trust ... we'd also need to
Tony> validate that the entire code path has the correct code (not
Tony> just the entry point). There are several other data items on
Tony> which the code also relies which a truly paranoid MCA handler
Tony> would also need to validate.

I probably just don't understand what the plan is here. Are you
planning to fix everything in one fell swoop? If not, I think
incrementally improving the situation makes sense (i.e., if you work
on piece X, make X as solid as possible; over time do this for more
and more pieces of the MCA subsystem). There is no doubt that making
the entire MCA subsystem as robust as possible involves a huge amount
of rather tricky work. Same goes for the INIT path, of course (there
are obvious ways to deadlock it right now; probably something that
could benefit from a reasonably generic lock-busting infrastructure).

--david