Re: [PATCH 12/46] x86/paravirt, lto: Mark native_steal_clock() as __visible_on_lto

Peter Zijlstra
2022-11-14T17:43:44Z

On Mon, Nov 14, 2022 at 12:43:10PM +0100, Jiri Slaby (SUSE) wrote:
> From: Andi Kleen <ak@linux.intel.com>
>
> Symbols referenced from assembler (either directly or e.f. from
> DEFINE_STATIC_KEY()) need to be global and visible in gcc LTO because
> they could end up in a different object file than the assembler. This
> can lead to linker errors without this patch.

> @@ -120,7 +120,7 @@ unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr,
> struct static_key paravirt_steal_enabled;
> struct static_key paravirt_steal_rq_enabled;
>
> -static u64 native_steal_clock(int cpu)
> +__visible_on_lto u64 native_steal_clock(int cpu)

More hate; same reason, DEFINE_STATIC_CALL() takes the function address
and stuffs it in a variable, WTF is GCC-LTO eliminating it?