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    SubjectRe: [PATCH][v6][RFC] livepatch/ppc: Enable livepatching on powerpc
    On Wed, Mar 09, 2016 at 05:59:40PM +1100, Balbir Singh wrote:
    >
    > Changelog v6:
    > 1. Experimental changes -- need loads of testing
    > Based on the assumption that very far TOC and LR values
    > indicate the call happened through a stub and the
    > stub return works differently from a local call which
    > uses klp_return_helper.

    Well, this is true, but the inverse is not.
    Less than 2GiB between LR and TOC is a necessary but not a sufficient
    condition for a local call.

    I see the problem with your code that it hardly detects calls from one module
    to another nearby. It will fail iff you mistake a global call to a module loaded
    earlier to be local while patching AND you access global data / 64-bit constants
    after that call before the TOC is sanitised again.

    Torsten

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