diff options
| author | Dave Hansen <dave.hansen@linux.intel.com> | 2016-02-12 13:02:10 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-18 09:31:51 +0100 |
| commit | 8f62c883222c9e3c06d60b5e55e307a3d1f18257 (patch) | |
| tree | 7b9a6263f7232ebc49bfeae15668b198d1a0b032 /arch/x86/include/uapi | |
| parent | 63c17fb8e5a46a16e10e82005748837fd11a2024 (diff) | |
x86/mm/pkeys: Add arch-specific VMA protection bits
Lots of things seem to do:
vma->vm_page_prot = vm_get_page_prot(flags);
and the ptes get created right from things we pull out
of ->vm_page_prot. So it is very convenient if we can
store the protection key in flags and vm_page_prot, just
like the existing permission bits (_PAGE_RW/PRESENT). It
greatly reduces the amount of plumbing and arch-specific
hacking we have to do in generic code.
This also takes the new PROT_PKEY{0,1,2,3} flags and
turns *those* in to VM_ flags for vma->vm_flags.
The protection key values are stored in 4 places:
1. "prot" argument to system calls
2. vma->vm_flags, filled from the mmap "prot"
3. vma->vm_page prot, filled from vma->vm_flags
4. the PTE itself.
The pseudocode for these for steps are as follows:
mmap(PROT_PKEY*)
vma->vm_flags = ... | arch_calc_vm_prot_bits(mmap_prot);
vma->vm_page_prot = ... | arch_vm_get_page_prot(vma->vm_flags);
pte = pfn | vma->vm_page_prot
Note that this provides a new definitions for x86:
arch_vm_get_page_prot()
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210210.FE483A42@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/uapi')
| -rw-r--r-- | arch/x86/include/uapi/asm/mman.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/mman.h b/arch/x86/include/uapi/asm/mman.h index 513b05f15bb4..e8562e0a2993 100644 --- a/arch/x86/include/uapi/asm/mman.h +++ b/arch/x86/include/uapi/asm/mman.h @@ -6,6 +6,22 @@ #define MAP_HUGE_2MB (21 << MAP_HUGE_SHIFT) #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +/* + * Take the 4 protection key bits out of the vma->vm_flags + * value and turn them in to the bits that we can put in + * to a pte. + * + * Only override these if Protection Keys are available + * (which is only on 64-bit). + */ +#define arch_vm_get_page_prot(vm_flags) __pgprot( \ + ((vm_flags) & VM_PKEY_BIT0 ? _PAGE_PKEY_BIT0 : 0) | \ + ((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)) +#endif + #include <asm-generic/mman.h> #endif /* _ASM_X86_MMAN_H */ |