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Date:	Thu, 17 Mar 2016 09:44:17 +0100
From:	Ingo Molnar <mingo@...nel.org>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	linux-kernel@...r.kernel.org, Dave Hansen <dave@...1.net>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Rik van Riel <riel@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Andy Lutomirski <luto@...nel.org>
Subject: [GIT PULL] Protection Keys (pkeys) support

Linus,

Please pull the latest mm-pkeys-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git mm-pkeys-for-linus

   # HEAD: 0d47638f80a02b15869f1fe1fc09e5bf996750fd x86/mm/pkeys: Fix mismerge of protection keys CPUID bits

This tree adds support for a new memory protection hardware feature that is 
available in upcoming Intel CPUs: 'protection keys' (pkeys).

There's a background article at LWN.net:

  https://lwn.net/Articles/643797/

The gist is that protection keys allow the encoding of user-controllable 
permission masks in the pte. So instead of having a fixed protection mask in the 
pte (which needs a system call to change and works on a per page basis), the user 
can map a (handful of) protection mask variants and can change the masks runtime 
relatively cheaply, without having to change every single page in the affected 
virtual memory range.

This allows the dynamic switching of the protection bits of large amounts of 
virtual memory, via user-space instructions. It also allows more precise control 
of MMU permission bits: for example the executable bit is separate from the read 
bit (see more about that below).

This tree adds the MM infrastructure and low level x86 glue needed for that, plus 
it adds a high level API to make use of protection keys - if a user-space 
application calls:

        mmap(..., PROT_EXEC);
  or
        mprotect(ptr, sz, PROT_EXEC);

(note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice this 
special case, and will set a special protection key on this memory range.  It also 
sets the appropriate bits in the Protection Keys User Rights (PKRU) register so 
that the memory becomes unreadable and unwritable.

So using protection keys the kernel is able to implement 'true' PROT_EXEC on x86 
CPUs: without protection keys PROT_EXEC implies PROT_READ as well. Unreadable 
executable mappings have security advantages: they cannot be read via information 
leaks to figure out ASLR details, nor can they be scanned for ROP gadgets - and 
they cannot be used by exploits for data purposes either.

We know about no user-space code that relies on pure PROT_EXEC mappings today, but 
binary loaders could start making use of this new feature to map binaries and 
libraries in a more secure fashion.

There is other pending pkeys work that offers more high level system call APIs to 
manage protection keys - but those are not part of this pull request.

Right now there's a Kconfig that controls this feature 
(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled (like most x86 
CPU feature enablement code that has no runtime overhead), but it's not 
user-configurable at the moment. If there's any serious problem with this then we 
can make it configurable and/or flip the default.

 Thanks,

	Ingo

---{ shortlog and diffstat generated manually }--------------->

Dave Hansen (38):
      mm/gup: Introduce get_user_pages_remote()
      mm/gup: Overload get_user_pages() functions
      mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm
      x86/fpu: Add placeholder for 'Processor Trace' XSAVE state
      x86/mm/pkeys: Add Kconfig option
      x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions
      x86/cpu, x86/mm/pkeys: Define new CR4 bit
      x86/fpu, x86/mm/pkeys: Add PKRU xsave fields and data structures
      x86/mm/pkeys: Add PTE bits for storing protection key
      x86/mm/pkeys: Add new 'PF_PK' page fault error code bit
      mm/core, x86/mm/pkeys: Store protection bits in high VMA flags
      x86/mm/pkeys: Add arch-specific VMA protection bits
      x86/mm/pkeys: Pass VMA down in to fault signal generation code
      signals, ia64, mips: Update arch-specific siginfos with pkeys field
      signals, pkeys: Notify userspace about protection key faults
      x86/mm/pkeys: Fill in pkey field in siginfo
      x86/mm/pkeys: Add functions to fetch PKRU
      mm/gup: Factor out VMA fault permission checking
      x86/mm/gup: Simplify get_user_pages() PTE bit handling
      mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys
      um, pkeys: Add UML arch_*_access_permitted() methods
      mm/core: Do not enforce PKEY permissions on remote mm access
      x86/mm/pkeys: Optimize fault handling in access_error()
      mm/core, x86/mm/pkeys: Differentiate instruction fetches
      x86/mm/pkeys: Dump PKRU with other kernel registers
      x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps
      x86/mm/pkeys: Add Kconfig prompt to existing config option
      x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
      mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits()
      mm/core, x86/mm/pkeys: Add arch_validate_pkey()
      x86/mm: Factor out LDT init from context init
      x86/fpu: Allow setting of XSAVE state
      x86/mm/pkeys: Allow kernel to modify user pkey rights register
      x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags
      mm/core, x86/mm/pkeys: Add execute-only protection keys support
      x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA
      mm/pkeys: Fix siginfo ABI breakage caused by new u64 field
      x86/mm/pkeys: Fix mismerge of protection keys CPUID bits

Ingo Molnar (1):
      Merge branches 'x86/fpu', 'x86/mm' and 'x86/asm' into x86/pkeys

 Documentation/kernel-parameters.txt         |   3 +++
 arch/cris/arch-v32/drivers/cryptocop.c      |   8 ++----
 arch/ia64/include/uapi/asm/siginfo.h        |  13 +++++++---
 arch/ia64/kernel/err_inject.c               |   3 +--
 arch/mips/include/uapi/asm/siginfo.h        |  13 +++++++---
 arch/mips/mm/gup.c                          |   3 +--
 arch/powerpc/include/asm/mman.h             |   5 ++--
 arch/powerpc/include/asm/mmu_context.h      |  12 +++++++++
 arch/s390/include/asm/mmu_context.h         |  12 +++++++++
 arch/s390/mm/gup.c                          |   4 +--
 arch/sh/mm/gup.c                            |   2 +-
 arch/sparc/mm/gup.c                         |   2 +-
 arch/um/include/asm/mmu_context.h           |  14 ++++++++++
 arch/unicore32/include/asm/mmu_context.h    |  12 +++++++++
 arch/x86/Kconfig                            |  16 ++++++++++++
 arch/x86/include/asm/cpufeature.h           |  55 +++++++++++++++++++++++++--------------
 arch/x86/include/asm/cpufeatures.h          |   6 ++++-
 arch/x86/include/asm/disabled-features.h    |  15 +++++++++++
 arch/x86/include/asm/fpu/internal.h         |   2 ++
 arch/x86/include/asm/fpu/types.h            |  12 +++++++++
 arch/x86/include/asm/fpu/xstate.h           |   3 ++-
 arch/x86/include/asm/mmu_context.h          |  85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
 arch/x86/include/asm/pgtable.h              |  38 +++++++++++++++++++++++++++
 arch/x86/include/asm/pgtable_types.h        |  39 ++++++++++++++++++++++++----
 arch/x86/include/asm/pkeys.h                |  34 ++++++++++++++++++++++++
 arch/x86/include/asm/required-features.h    |   7 +++++
 arch/x86/include/asm/special_insns.h        |  22 ++++++++++++++++
 arch/x86/include/uapi/asm/mman.h            |  22 ++++++++++++++++
 arch/x86/include/uapi/asm/processor-flags.h |   2 ++
 arch/x86/kernel/cpu/common.c                |  44 +++++++++++++++++++++++++++++++
 arch/x86/kernel/fpu/core.c                  |  63 ++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kernel/fpu/xstate.c                | 185 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 arch/x86/kernel/ldt.c                       |   4 +--
 arch/x86/kernel/process_64.c                |   2 ++
 arch/x86/kernel/setup.c                     |   9 +++++++
 arch/x86/mm/Makefile                        |   2 ++
 arch/x86/mm/fault.c                         | 150 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------------
 arch/x86/mm/gup.c                           |  45 ++++++++++++++++++++------------
 arch/x86/mm/mpx.c                           |   4 +--
 arch/x86/mm/pkeys.c                         | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/char/agp/frontend.c                 |   2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c     |   3 +--
 drivers/gpu/drm/etnaviv/etnaviv_gem.c       |   6 ++---
 drivers/gpu/drm/i915/i915_gem_userptr.c     |  10 +++----
 drivers/gpu/drm/radeon/radeon_ttm.c         |   3 +--
 drivers/gpu/drm/via/via_dmablit.c           |   3 +--
 drivers/infiniband/core/umem.c              |   2 +-
 drivers/infiniband/core/umem_odp.c          |   8 +++---
 drivers/infiniband/hw/mthca/mthca_memfree.c |   3 +--
 drivers/infiniband/hw/qib/qib_user_pages.c  |   3 +--
 drivers/infiniband/hw/usnic/usnic_uiom.c    |   2 +-
 drivers/iommu/amd_iommu_v2.c                |   1 +
 drivers/media/pci/ivtv/ivtv-udma.c          |   4 +--
 drivers/media/pci/ivtv/ivtv-yuv.c           |  10 +++----
 drivers/media/v4l2-core/videobuf-dma-sg.c   |   3 +--
 drivers/misc/mic/scif/scif_rma.c            |   2 --
 drivers/misc/sgi-gru/grufault.c             |   3 +--
 drivers/scsi/st.c                           |   2 --
 drivers/staging/android/ashmem.c            |   4 +--
 drivers/video/fbdev/pvr2fb.c                |   4 +--
 drivers/virt/fsl_hypervisor.c               |   5 ++--
 fs/exec.c                                   |   8 ++++--
 fs/proc/task_mmu.c                          |  14 ++++++++++
 include/asm-generic/mm_hooks.h              |  12 +++++++++
 include/linux/mm.h                          |  99 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 include/linux/mman.h                        |   6 ++---
 include/linux/pkeys.h                       |  33 ++++++++++++++++++++++++
 include/uapi/asm-generic/siginfo.h          |  17 ++++++++----
 kernel/events/uprobes.c                     |  10 +++++--
 kernel/signal.c                             |   4 +++
 mm/Kconfig                                  |   5 ++++
 mm/frame_vector.c                           |   2 +-
 mm/gup.c                                    | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------
 mm/ksm.c                                    |  12 ++++++---
 mm/memory.c                                 |   8 +++++-
 mm/mempolicy.c                              |   6 ++---
 mm/mmap.c                                   |  10 ++++++-
 mm/mprotect.c                               |   8 +++---
 mm/nommu.c                                  |  66 +++++++++++++++++++++++++++++++++--------------
 mm/process_vm_access.c                      |  11 +++++---
 mm/util.c                                   |   4 +--
 net/ceph/pagevec.c                          |   2 +-
 security/tomoyo/domain.c                    |   9 ++++++-
 virt/kvm/async_pf.c                         |   8 +++++-
 virt/kvm/kvm_main.c                         |  10 +++----
 85 files changed, 1406 insertions(+), 241 deletions(-)
 create mode 100644 arch/x86/include/asm/pkeys.h
 create mode 100644 arch/x86/mm/pkeys.c
 create mode 100644 include/linux/pkeys.h

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