On Thu, 9 Feb 2017 08:30:59 +0530 "Aneesh Kumar K.V"
<aneesh.ku...@linux.vnet.ibm.com> wrote:
> With this our protnone becomes a present pte with READ/WRITE/EXEC bit cleared.
> By default we also set _PAGE_PRIVILEGED on such pte. This is now used to help
> us identify a protnone pte that as saved write bit. For such pte, we will
> clear
> the _PAGE_PRIVILEGED bit. The pte still remain non-accessible from both user
> and kernel.
I don't see how these patches differ from the ones which are presently
in -mm.
It helps to have a [0/n] email for a patch series and to put a version
number in there as well.
> +#define pte_mk_savedwrite pte_mk_savedwrite
> +static inline pte_t pte_mk_savedwrite(pte_t pte)
> +{
> + /*
> + * Used by Autonuma subsystem to preserve the write bit
> + * while marking the pte PROT_NONE. Only allow this
> + * on PROT_NONE pte
> + */
> + VM_BUG_ON((pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_RWX |
> _PAGE_PRIVILEGED)) !=
> + cpu_to_be64(_PAGE_PRESENT | _PAGE_PRIVILEGED));
> + return __pte(pte_val(pte) & ~_PAGE_PRIVILEGED);
> +}
> +
> +#define pte_savedwrite pte_savedwrite
> +static inline bool pte_savedwrite(pte_t pte)
> +{
> + /*
> + * Saved write ptes are prot none ptes that doesn't have
> + * privileged bit sit. We mark prot none as one which has
> + * present and pviliged bit set and RWX cleared. To mark
> + * protnone which used to have _PAGE_WRITE set we clear
> + * the privileged bit.
> + */
> + return !(pte_raw(pte) & cpu_to_be64(_PAGE_RWX | _PAGE_PRIVILEGED));
> +}
> +
> static inline pte_t pte_mkdevmap(pte_t pte)
> {
> return __pte(pte_val(pte) | _PAGE_SPECIAL|_PAGE_DEVMAP);
arch/powerpc/include/asm/book3s/64/pgtable.h doesn't have
pte_mkdevmap(). What tree are you patching here?
