Le 12/04/2022 à 06:38, Anshuman Khandual a écrit :
> This defines and exports a platform specific custom vm_get_page_prot() via
> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes
> arch_vm_get_page_prot() as __vm_get_page_prot() and moves it near
> vm_get_page_prot().
>
> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/include/asm/mman.h | 12 ------------
> arch/powerpc/mm/book3s64/pgtable.c | 20 ++++++++++++++++++++
> 3 files changed, 21 insertions(+), 12 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 174edabb74fa..69e44358a235 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -140,6 +140,7 @@ config PPC
> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
> select ARCH_HAS_UACCESS_FLUSHCACHE
> select ARCH_HAS_UBSAN_SANITIZE_ALL
> + select ARCH_HAS_VM_GET_PAGE_PROT if PPC_BOOK3S_64
> select ARCH_HAVE_NMI_SAFE_CMPXCHG
> select ARCH_KEEP_MEMBLOCK
> select ARCH_MIGHT_HAVE_PC_PARPORT
> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
> index 7cb6d18f5cd6..1b024e64c8ec 100644
> --- a/arch/powerpc/include/asm/mman.h
> +++ b/arch/powerpc/include/asm/mman.h
> @@ -24,18 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
> }
> #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
>
> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
> -{
> -#ifdef CONFIG_PPC_MEM_KEYS
> - return (vm_flags & VM_SAO) ?
> - __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> - __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> -#else
> - return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> -#endif
> -}
> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
> -
> static inline bool arch_validate_prot(unsigned long prot, unsigned long addr)
> {
> if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
> index 052e6590f84f..d0319524e27f 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -7,6 +7,7 @@
> #include <linux/mm_types.h>
> #include <linux/memblock.h>
> #include <linux/memremap.h>
> +#include <linux/pkeys.h>
> #include <linux/debugfs.h>
> #include <misc/cxl-base.h>
>
> @@ -549,3 +550,22 @@ unsigned long memremap_compat_align(void)
> }
> EXPORT_SYMBOL_GPL(memremap_compat_align);
> #endif
> +
> +static pgprot_t __vm_get_page_prot(unsigned long vm_flags)
> +{
> +#ifdef CONFIG_PPC_MEM_KEYS
> + return (vm_flags & VM_SAO) ?
> + __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) :
> + __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags));
> +#else
> + return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
> +#endif
> +}
> +
> +pgprot_t vm_get_page_prot(unsigned long vm_flags)
> +{
> + return __pgprot(pgprot_val(protection_map[vm_flags &
> + (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
> + pgprot_val(__vm_get_page_prot(vm_flags)));
> +}
> +EXPORT_SYMBOL(vm_get_page_prot);
This looks functionnaly OK, but I think we could go in the same
direction as ARM and try to integrate __vm_get_page_prot() inside
vm_get_page_prot() to get something simpler and cleaner:
Something like below (untested):
pgprot_t vm_get_page_prot(unsigned long vm_flags)
{
unsigned long prot = pgprot_val(protection_map[vm_flags &
(VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]);
if (vm_flags & VM_SAO)
prot |= _PAGE_SAO
#ifdef CONFIG_PPC_MEM_KEYS
prot |= vmflag_to_pte_pkey_bits(vm_flags);
#endif
return __pgprot(prot);
}
