Messages in this thread Patch in this message | | | Subject | [PATCH 30/31] x86, pkeys: create an x86 arch_calc_vm_prot_bits() for VMA flags | From | Dave Hansen <> | Date | Wed, 06 Jan 2016 16:01:46 -0800 |
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From: Dave Hansen <dave.hansen@linux.intel.com>
calc_vm_prot_bits() takes PROT_{READ,WRITE,EXECUTE} bits and turns them in to the vma->vm_flags/VM_* bits. We need to do a similar thing for protection keys.
We take a protection key (4 bits) and encode it in to the 4 VM_PKEY_* bits.
Note: this code is not new. It was simply a part of the mprotect_pkey() patch in the past. I broke it out for use in the execute-only support.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> ---
b/arch/x86/include/uapi/asm/mman.h | 6 ++++++ 1 file changed, 6 insertions(+)
diff -puN arch/x86/include/uapi/asm/mman.h~pkeys-78-arch_calc_vm_prot_bits arch/x86/include/uapi/asm/mman.h --- a/arch/x86/include/uapi/asm/mman.h~pkeys-78-arch_calc_vm_prot_bits 2016-01-06 15:50:16.387641877 -0800 +++ b/arch/x86/include/uapi/asm/mman.h 2016-01-06 15:50:16.390642013 -0800 @@ -20,6 +20,12 @@ ((vm_flags) & VM_PKEY_BIT1 ? _PAGE_PKEY_BIT1 : 0) | \ ((vm_flags) & VM_PKEY_BIT2 ? _PAGE_PKEY_BIT2 : 0) | \ ((vm_flags) & VM_PKEY_BIT3 ? _PAGE_PKEY_BIT3 : 0)) + +#define arch_calc_vm_prot_bits(prot, key) ( \ + ((key) & 0x1 ? VM_PKEY_BIT0 : 0) | \ + ((key) & 0x2 ? VM_PKEY_BIT1 : 0) | \ + ((key) & 0x4 ? VM_PKEY_BIT2 : 0) | \ + ((key) & 0x8 ? VM_PKEY_BIT3 : 0)) #endif #include <asm-generic/mman.h> _
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