Re: [tip: x86/urgent] x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes

Borislav Petkov
2020-12-10T11:42:14Z

On Wed, Dec 09, 2020 at 03:01:47PM -0300, Arnaldo Carvalho de Melo wrote:
> Trying to swap this back into my brain...

I know *exactly* what you mean. :)

>
> Humm, if I'm building this on, say, aarch64 then asm/ will not be
> pointing to x86, right? Intel PT needs the x86 instruction decoder,
> right?

Yeah.

> I should've have wrote in the cset comment log if this was related to
> cross build failures I encountered, can't remember now :-\

I think that is it. There's inat.h in tools/arch/x86/include/asm/ too so
it needs to be exactly that one that gets included on other arches.

> And also it would be interesting to avoid updating both the kernel and
> the tools/ copy, otherwise one would have to test the tools build, which
> may break with such updates.
>
> The whole point of the copy is to avoid that, otherwise we could just
> use the kernel files directly.

Well, there's this diff -u thing which makes sure both copies are in sync.

Why did we ever copy the insn decoder to tools/?

There must've been some reason because otherwise we could probably use
the one in arch/x86/lib/, in tools/.

Yeah, this whole copying of headers back'n'forth is turning out to be
kinda hairy...

--
Regards/Gruss,
Boris.

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