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    SubjectRe: Bug#609371: linux-image-2.6.37-trunk-sparc64: module scsi_mod: Unknown relocation: 36
    * Steven Rostedt (rostedt@goodmis.org) wrote:
    > On Wed, 2011-01-19 at 13:40 -0800, David Miller wrote:
    >
    > > My concern is that if there is ever a u64 or similarly "long long"
    > > typed member in these tracing structures, it will not be aligned
    > > sufficiently to avoid unaligned access traps on 32-bit systems.
    >
    > The structure that gets placed in this section is the ftrace_event_call.
    > It consists only of pointers, a struct list_head, a couple of "int", and
    > a struct trace_event, which consists of: a struct hlist_node, a struct
    > list_head, an int, and a pointer.
    >
    > None of these are more than "long" and I don't foresee them needing a
    > long long type. I think assuming that a long is the largest item should
    > due.
    >
    > We can add a comment next to these structures specifying this
    > dependency, and hopefully it would be updated if we ever do include a
    > long long in them.

    I still wonder how a 32-bit system can generate an unaligned access trap for an
    access to a 64-bit variable aligned on 32-bit, given that there is, by
    definition, no 64-bit memory accesses available on the architecture ?

    Mathieu


    --
    Mathieu Desnoyers
    Operating System Efficiency R&D Consultant
    EfficiOS Inc.
    http://www.efficios.com


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