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    SubjectRe: Linux 2.4.1-ac15
    On Mon, 19 Feb 2001, Alan Cox wrote:
    > mod->next = module_list;

    put_mod_name() here.

    > module_list = mod; /* link it in */
    >
    > Note no write barrier.

    put_mod_name calls free_page which always implies a memory barrier. This
    isn't beautiful but it won't blow up either.

    Actually that isn't relevant since the actual table is copied _after_
    ex_table_{start,end}. We'll scan uninitialized memory and if some word
    happens to match the fault EIP we jump to the bogus fixup.

    > Delete is even worse
    >
    > We unlink the module
    > We free the memory
    >
    > At the same time another cpu may be walking the exception table that we free.

    True.

    Rusty had a patch that locked the module list properly IIRC.


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