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powerpc: map vma key-protection bits to pte key bits.

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Map  the  key  protection  bits of the vma to the pkey bits in
the PTE.

The PTE  bits used  for pkey  are  3,4,5,6  and 57. The  first
four bits are the same four bits that were freed up  initially
in this patch series. remember? :-) Without those four bits
this patch wouldn't be possible.

BUT, on 4k kernel, bit 3, and 4 could not be freed up. remember?
Hence we have to be satisfied with 5, 6 and 7.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Ram Pai
2018-01-18 17:50:35 -08:00
committed by Michael Ellerman
parent 87bbabbed8
commit eb95d016ce
3 changed files with 42 additions and 1 deletions
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12
arch/powerpc/include/asm/pkeys.h
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@@ -41,6 +41,18 @@ static inline u64 pkey_to_vmflag_bits(u16 pkey)
return (((u64)pkey << VM_PKEY_SHIFT) & ARCH_VM_PKEY_FLAGS);
}
static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags)
{
if (static_branch_likely(&pkey_disabled))
return 0x0UL;
return (((vm_flags & VM_PKEY_BIT0) ? H_PTE_PKEY_BIT4 : 0x0UL) |
((vm_flags & VM_PKEY_BIT1) ? H_PTE_PKEY_BIT3 : 0x0UL) |
((vm_flags & VM_PKEY_BIT2) ? H_PTE_PKEY_BIT2 : 0x0UL) |
((vm_flags & VM_PKEY_BIT3) ? H_PTE_PKEY_BIT1 : 0x0UL) |
((vm_flags & VM_PKEY_BIT4) ? H_PTE_PKEY_BIT0 : 0x0UL));
}
static inline int vma_pkey(struct vm_area_struct *vma)
{
if (static_branch_likely(&pkey_disabled))