On Fri, 8 Sep 2017 15:45:00 -0700
Ram Pai <linux...@us.ibm.com> wrote:
> arch-independent code expects the arch to map
> a pkey into the vma's protection bit setting.
> The patch provides that ability.
>
> Signed-off-by: Ram Pai <linux...@us.ibm.com>
> ---
> arch/powerpc/include/asm/mman.h | 8 +++++++-
> arch/powerpc/include/asm/pkeys.h | 18 ++++++++++++++++++
> 2 files changed, 25 insertions(+), 1 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 30922f6..067eec2 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -13,6 +13,7 @@
>
> #include <asm/cputable.h>
> #include <linux/mm.h>
> +#include <linux/pkeys.h>
> #include <asm/cpu_has_feature.h>
>
> /*
> @@ -22,7 +23,12 @@
> static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
> unsigned long pkey)
> {
> - return (prot & PROT_SAO) ? VM_SAO : 0;
> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
> + return (((prot & PROT_SAO) ? VM_SAO : 0) |
> + pkey_to_vmflag_bits(pkey));
> +#else
> + return ((prot & PROT_SAO) ? VM_SAO : 0);
> +#endif
> }
> #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>
> diff --git a/arch/powerpc/include/asm/pkeys.h
> b/arch/powerpc/include/asm/pkeys.h
> index 0cf115f..f13e913 100644
> --- a/arch/powerpc/include/asm/pkeys.h
> +++ b/arch/powerpc/include/asm/pkeys.h
> @@ -23,6 +23,24 @@
> #define VM_PKEY_BIT4 VM_HIGH_ARCH_4
> #endif
>
> +/* override any generic PKEY Permission defines */
> +#define PKEY_DISABLE_EXECUTE 0x4
> +#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\
> + PKEY_DISABLE_WRITE |\
> + PKEY_DISABLE_EXECUTE)
> +
> +static inline u64 pkey_to_vmflag_bits(u16 pkey)
> +{
> + if (!pkey_inited)
> + return 0x0UL;
> +
> + return (((pkey & 0x1UL) ? VM_PKEY_BIT0 : 0x0UL) |
> + ((pkey & 0x2UL) ? VM_PKEY_BIT1 : 0x0UL) |
> + ((pkey & 0x4UL) ? VM_PKEY_BIT2 : 0x0UL) |
> + ((pkey & 0x8UL) ? VM_PKEY_BIT3 : 0x0UL) |
> + ((pkey & 0x10UL) ? VM_PKEY_BIT4 : 0x0UL));
> +}
Assuming that there is a linear order between VM_PKEY_BIT4 to
VM_PKEY_BIT0, the conditional checks can be removed
(pkey & 0x1fUL) << VM_PKEY_BIT0?
Balbir Singh
