Re: [PATCH] x86/speculation/l1tf: Add assembly guard for xtensa/ia64

From: Guenter Roeck
Date: Wed Aug 15 2018 - 18:37:04 EST

On Wed, Aug 15, 2018 at 02:56:46PM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> The stable backport of the
> x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings
> patch for 4.4 and 4.9 put new C code for !__HAVE_ARCH_PFN_MODIFY_ALLOWED
> code outside the assembler ifdef. This breaks the xtensa and ia64
> build as reported by 0day which somehow include this file
> into assembler.
> Just add an #ifdef __ASSEMBLY__ around the new code to fix this.
> This patch is only needed for 4.9 and 4.4 stable, the newer stables
> don't have this problem.
> Fixes: 7c5b42f82c13 ("x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings")
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>

This should be fixed in the final stable releases.
The problem was caused by a couple of missing backports.