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    SubjectRe: [PATCH 04/10] x86: mce: fix error handling
    On Thu, Jul 29, 2010 at 12:10 +0200, walter harms wrote:
    > Andi Kleen schrieb:
    > >
    > >> IMO memmory allocation fails are dangerous in kernel mode. As it is
    > >> probably not exploitable because of boot time, it can destroy some
    > >> sensitive data like dirty disk caches those are going to be written on
    > >> disk.
    > >
    > > It's true for runtime, but not for normal boot time.
    > >
    > > Anyways if it happens on boot time the only thing you can do is panic,
    > > but someone else
    > > will likely panic anyways for you. Just ignoring it like your patch
    > > effectively does
    > > (because nothing will ever look at the ENOMEMs for an initcall) is wrong
    > > though
    > > In this case it's actually better to oops like the original code does.
    > >
    > > BTW even with your patch likely later code will crash anyways because it
    > > doesn't
    > > expect init code to fail.
    > >
    > NTL it is nice to have a error message. for users it is worse if you crash suddenly
    > with out warning than having a crash with "OOM" before because it gives you a clue
    > what is going on.
    > short:
    > please think of users that are not kernel developers give them a hint what went wrong.
    > to make thinks more easy on boot we could replace kalloc() with kmalloc_or_die().
    The thing is that this driver does not call kmalloc() explicitly, it
    uses function those call functions those call kmalloc() :)

    If we call BUG_ON() in init code, it would not make big overhead and
    would make fault exactly when bug was detected, independent from caller
    checks. Andi, are you fine with it?

    > When anyone runs out of mem on boottime you can panic() instantly.
    > just my to cents,
    > wh

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