On Fri, May 19, 2023 at 08:36:34PM +0200, Janusz Krzysztofik wrote:
> diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
> index 15ae4d6ba4768..56466afd04307 100644
> --- a/arch/x86/include/asm/pgtable.h
> +++ b/arch/x86/include/asm/pgtable.h
> @@ -654,8 +654,10 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
> #define pgprot_modify pgprot_modify
> static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
> {
> - pgprotval_t preservebits = pgprot_val(oldprot) & _PAGE_CHG_MASK;
> - pgprotval_t addbits = pgprot_val(newprot) & ~_PAGE_CHG_MASK;
> + unsigned long mask = _PAGE_CHG_MASK | _PAGE_CACHE_MASK;
> +
> + pgprotval_t preservebits = pgprot_val(oldprot) & mask;
> + pgprotval_t addbits = pgprot_val(newprot) & ~mask;
> return __pgprot(preservebits | addbits);
> }
>
> --
This certainly needs Jürgen and he's on CC already, moving him to To:.
Also, why isn't this a Xen-specific fix but you're keeping _PAGE_PAT for
baremetal too, i.e., modifying the generic function?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
