From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932919AbcCQIoe (ORCPT ); Thu, 17 Mar 2016 04:44:34 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:35290 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932199AbcCQIo1 (ORCPT ); Thu, 17 Mar 2016 04:44:27 -0400 Date: Thu, 17 Mar 2016 09:44:17 +0100 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Dave Hansen , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Andrew Morton , Rik van Riel , Borislav Petkov , Andy Lutomirski Subject: [GIT PULL] Protection Keys (pkeys) support Message-ID: <20160317084417.GA29417@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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