Re: [PATCH v11 00/15] kasan: x86: arm64: KASAN tag-based mode for x86

[Peter Zijlstra]

On Tue, Mar 10, 2026 at 07:30:36PM +0000, Maciej Wieczor-Retman wrote:
> On 2026-03-10 at 20:00:22 +0100, Peter Zijlstra wrote:
> >On Tue, Mar 10, 2026 at 05:51:19PM +0000, Maciej Wieczor-Retman wrote:
> >
> >> ======= Compilation
> >> Clang was used to compile the series (make LLVM=1) since gcc doesn't
> >> seem to have support for KASAN tag-based compiler instrumentation on
> >> x86. Patchset does seem to compile with gcc without an issue but doesn't
> >> boot afterwards.
> >
> >Can you put all that under a specific CONFIG and make that depend on
> >CC_IS_CLANG?
> 
> I made HAVE_ARCH_KASAN_SW_TAGS depend on CC_IS_CLANG, and that controls all the
> software tags stuff, like ARCH_DISABLE_KASAN_INLINE through KASAN_SW_TAGS.
> And ARCH_NEEDS_DEFER_KASAN is for if KASAN is compiled but LAM is not available,
> so that it gets disabled in runtime.
> 
> But sure, I suppose I can add a separate CONFIG with CC_IS_CLANG to these three
> so the clang connection is more transparent.

Right, because building but not booting is BAD :-) While compiler
specific features are a dime a dozen.