Re: [RFC][PATCH 05/10] x86/mm: do not auto-massage page protections

[Nadav Amit]

Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> wrote:

> 
> From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> 
> 
> +static inline pgprotval_t check_pgprot(pgprot_t pgprot)
> +{
> +	pgprotval_t massaged_val = massage_pgprot(pgprot);
> +
> +	WARN_ONCE(pgprot_val(pgprot) != massaged_val,
> +		  "attempted to set unsupported pgprot: %016lx "
> +		  "bits: %016lx supported: %016lx\n",
> +		  pgprot_val(pgprot),
> +		  pgprot_val(pgprot) ^ massaged_val,
> +		  __supported_pte_mask);

Perhaps use VM_WARN_ONCE instead to avoid any overhead on production
systems?