• Nicholas Piggin's avatar
    powerpc/64s: Remove PROT_SAO support · 5c9fa16e
    Nicholas Piggin authored
    ISA v3.1 does not support the SAO storage control attribute required to
    implement PROT_SAO. PROT_SAO was used by specialised system software
    (Lx86) that has been discontinued for about 7 years, and is not thought
    to be used elsewhere, so removal should not cause problems.
    
    We rather remove it than keep support for older processors, because
    live migrating guest partitions to newer processors may not be possible
    if SAO is in use (or worse allowed with silent races).
    
    - PROT_SAO stays in the uapi header so code using it would still build.
    - arch_validate_prot() is removed, the generic version rejects PROT_SAO
      so applications would get a failure at mmap() time.
    Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
    [mpe: Drop KVM change for the time being]
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    Link: https://lore.kernel.org/r/20200703011958.1166620-3-npiggin@gmail.com
    5c9fa16e
mman.h 771 Bytes