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    SubjectRe: Linux 2.6.17-rc2 - notifier chain problem?
    Chandra Seetharaman <sekharan@us.ibm.com> wrote:
    >
    > Thanks for the steps. With that i was able to reproduce the problem and
    > i found the bug.
    >
    > While i go ahead and generate the patch, i wanted to hear if my
    > conclusion is correct.
    >
    > The problem is due to the fact that most notifier registrations
    > incorrectly use __devinitdata to define the callback structure, as in:
    >
    > static struct notifier_block __devinitdata hrtimers_nb = {
    > .notifier_call = hrtimer_cpu_notify,
    > };
    >
    > devinitdata'd data is not _expected to be available_ after the
    > initialization(unless CONFIG_HOTPLUG is defined).
    >
    > I do not know how it was working until now :), anybody has a theory that
    > can explain it (or my conclusion is wrong) ?

    That sounds right. There are several __devinitdata notifier_blocks in the
    tree - please be sure to check them all.

    btw, it'd be pretty trivial to add runtime checking for this sort of thing:

    int addr_in_init_section(void *addr)
    {
    return addr >= __init_begin && addr < __init_end;
    }

    (x86-specific)
    (need to add __init_end to vmlinux.lds.S)

    then we could use that to check various things in various places...
    -
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