Re: [patch 13/26] Xen-paravirt_ops: Consistently wrap paravirt opscallsites to make them patchable

From: Linus Torvalds
Date: Mon Mar 19 2007 - 23:20:31 EST




On Mon, 19 Mar 2007, Andi Kleen wrote:
>
> Initially we had some bugs that accounted for near all failures, but they
> were all fixed in the latest version.

No. The real bugs were that the people involved wouldn't even accept that
unwinding information was inevitably buggy and/or incomplete.

That much more fundamental bug never got fixed, as far as I know.

I'm not going to merge anything that depends on unwind tables as things
stand. The pain just isn't worth it.

> > Please don't subject us to another couple months of hair-pulling only
> > to have Linus yank the thing out again, there are certainly more
> > useful things to spend time on :-)

Good call. Dwarf2 unwinding simply isn't worth doing. But I won't yank it
out, I simply won't merge it. It was more than just totally buggy code, it
was an inability of the people to understand that even bugfree code
isn't enough - you have to be able to also handle buggy data.

Linus
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