Re: [PATCH v6 7/8] dynamic_debug: add asm-generic implementation for DYNAMIC_DEBUG_RELATIVE_POINTERS

From: Nick Desaulniers
Date: Mon Jun 17 2019 - 18:41:07 EST


On Mon, Jun 17, 2019 at 3:20 PM Rasmus Villemoes
<linux@xxxxxxxxxxxxxxxxxx> wrote:
>
> A 64 bit architecture can allow reducing the size of the kernel image by
> selecting HAVE_DYNAMIC_DEBUG_RELATIVE_POINTERS, but it must provide
> a proper DEFINE_DYNAMIC_DEBUG_METADATA macro for emitting the struct
> _ddebug in assembly. However, since that does not involve any
> instructions, this generic implementation should be usable by most if
> not all.
>
> It relies on
>
> (1) standard assembly directives that should work on
> all architectures
> (2) the "i" constraint for an constant, and
> (3) %cN emitting the constant operand N without punctuation
>
> and of course the layout of _ddebug being what one expects.
>
> Now, clang before 9.0 doesn't satisfy (3) for non-x86 targets.

Thanks so much for resending with this case fixed, and sorry I did not
implement (3) sooner! I appreciate your patience.
Acked-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>

I'm happy to help test this series, do you have a tree I could pull
these from quickly? Anything I should test at runtime besides a boot
test?
--
Thanks,
~Nick Desaulniers