Subject: Re: [PATCH v2] kselftest/arm64: Fix build failure with GCC-15

From: Catalin Marinas <[email-masked]>
Date: Fri, 24 Apr 2026 17:44:16 +0100

On Fri, Apr 24, 2026 at 05:07:42PM +0100, Mark Brown wrote:
> On Fri, Apr 24, 2026 at 04:51:24PM +0100, Catalin Marinas wrote:
> > On Wed, Apr 22, 2026 at 06:42:54PM +0100, Leo Yan wrote:
> 
> > > Building on Debian sid with GCC 15 fails:
> 
> > I think a better fix is to always define struct user_gcs and only
> > conditionally define NT_ARM_GCS (IOW, move the #endif higher).
> 
> I've not actually double checked that everything is wired up properly
> but I believe these days this should actually pick up asm/ptrace.h from
> the headers_install target so a current kernel copy.  We ought to be
> able to remove the local definition of struct user_gcs I think, there's
> still some weirdness with the NT_ definitions I can't remember but the
> struct should be fine.

OK, so it does look like it picks the kernel uapi/asm/ptrace.h. It
builds fine on Debian stable (no GCS anywhere) with including
asm/ptrace.h and removing struct user_gcs.

But I think we should include asm/ptrace.h in libc-gcs.h and not the
gcs-util.h header (for NT_ARM_GCS it's fine to keep in gcs-util.h).

-- 
Catalin