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    SubjectRe: [PATCH] x86/debug: Remove perpetually broken, unmaintainable dwarf annotations
    >>> On 28.05.15 at 13:20, <mingo@kernel.org> wrote:
    > * Jan Beulich <JBeulich@suse.com> wrote:
    >> Not sure why assembly code should look like C code. It's a matter of taste
    >> perhaps, and I can see your point, but I'm also not really eager to do
    > changes
    >> just to match other people's taste. And just like above - certainly not
    >> something for this patch I would think.
    >
    > Yeah, no, so this isn't going to work that way.
    >
    > On one hand you want dwarf annotations mostly for the out of tree
    > dwarf-unwinding
    > stack backtraces patch on SUSE kernels, while for the upstream kernel it's
    > mostly
    > just unreadable gunk in some of the most security sensitive code paths of
    > the
    > kernel, which only gets in the way of readability.
    >
    > But on the other hand you are unwilling to (or don't have the time to) do a
    > proper
    > job of making this palatable for upstream.
    >
    > That's unacceptable from the upstream kernel's POV, so instead of limping
    > forward
    > I'll do the attached patch: it gets rid of the unmaintainable dwarf mess
    > from low
    > level x86 assembly code. This isn't a new concern, a couple of years ago we
    > almost
    > did this.

    I can understand your motivation, yet I still view it as rather sad that
    you move this way. Indeed I don't have the time to do major rework
    in this area, but I don't think you can blame me for not having tried to
    at least investigate and eliminate breakage when I found such (which,
    as you say, happens every now and then). Yet I do recall people
    indicating that the unwind data can be useful for other than the
    out-of-tree live stack unwinder. I.e. those will be broken along with
    that code which we're _forced_ to maintain out-of-tree.

    > and meanwhile you can keep a revert of this patch ported to SUSE kernels in
    > whatever fashion you prefer.

    Funny suggestion - I don't think that's reasonable for us to do. Or if
    we were to, we could as well invest in doing the re-work you're asking
    for; I don't think anyone will have the time to do either.

    Jan



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