linux.git/arch/x86/kernel/cpu/common.c, branch v4.13

x86/cpu: remove hypervisor specific set_cpu_features

2017-05-02T09:14:30+00:00

There is no user of x86_hyper->set_cpu_features() any more. Remove it.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: x86@kernel.org
Signed-off-by: Juergen Gross 
Reviewed-by: Boris Ostrovsky 
Signed-off-by: Juergen Gross

x86/xen/gdt: Use X86_FEATURE_XENPV instead of globals for the GDT fixup

2017-03-23T07:25:08+00:00

Xen imposes special requirements on the GDT.  Rather than using a
global variable for the pgprot, just use an explicit special case
for Xen -- this makes it clearer what's going on.  It also debloats
64-bit kernels very slightly.

Signed-off-by: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Garnier 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/e9ea96abbfd6a8c87753849171bb5987ecfeb523.1490218061.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/gdt: Fix setup_fixmap_gdt() to use the correct PA

2017-03-23T07:25:07+00:00

__pa() cannot be used on percpu pointers because they may be
virtually mapped.  Use per_cpu_ptr_to_phys() instead.

This fixes a boot crash on a some 32-bit configurations.  I assume
this is related to which allocation strategy is chosen by the percpu
core.

Signed-off-by: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Garnier 
Cc: Thomas Gleixner 
Fixes: 69218e47994d x86: ("Remap GDT tables in the fixmap section")
Link: http://lkml.kernel.org/r/22e0069c29fba31998f193201e359eebfdac4960.1490218061.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86: Make the GDT remapping read-only on 64-bit

2017-03-16T08:06:35+00:00

This patch makes the GDT remapped pages read-only, to prevent accidental
(or intentional) corruption of this key data structure.

This change is done only on 64-bit, because 32-bit needs it to be writable
for TSS switches.

The native_load_tr_desc function was adapted to correctly handle a
read-only GDT. The LTR instruction always writes to the GDT TSS entry.
This generates a page fault if the GDT is read-only. This change checks
if the current GDT is a remap and swap GDTs as needed. This function was
tested by booting multiple machines and checking hibernation works
properly.

KVM SVM and VMX were adapted to use the writeable GDT. On VMX, the
per-cpu variable was removed for functions to fetch the original GDT.
Instead of reloading the previous GDT, VMX will reload the fixmap GDT as
expected. For testing, VMs were started and restored on multiple
configurations.

Signed-off-by: Thomas Garnier 
Cc: Alexander Potapenko 
Cc: Andrew Morton 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Chris Wilson 
Cc: Christian Borntraeger 
Cc: Dmitry Vyukov 
Cc: Frederic Weisbecker 
Cc: Jiri Kosina 
Cc: Joerg Roedel 
Cc: Jonathan Corbet 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Len Brown 
Cc: Linus Torvalds 
Cc: Lorenzo Stoakes 
Cc: Luis R . Rodriguez 
Cc: Matt Fleming 
Cc: Michal Hocko 
Cc: Paolo Bonzini 
Cc: Paul Gortmaker 
Cc: Pavel Machek 
Cc: Peter Zijlstra 
Cc: Radim Krčmář 
Cc: Rafael J . Wysocki 
Cc: Rusty Russell 
Cc: Stanislaw Gruszka 
Cc: Thomas Gleixner 
Cc: Tim Chen 
Cc: Vitaly Kuznetsov 
Cc: kasan-dev@googlegroups.com
Cc: kernel-hardening@lists.openwall.com
Cc: kvm@vger.kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-pm@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Cc: zijun_hu 
Link: http://lkml.kernel.org/r/20170314170508.100882-3-thgarnie@google.com
Signed-off-by: Ingo Molnar

x86: Remap GDT tables in the fixmap section

2017-03-16T08:06:35+00:00

Each processor holds a GDT in its per-cpu structure. The sgdt
instruction gives the base address of the current GDT. This address can
be used to bypass KASLR memory randomization. With another bug, an
attacker could target other per-cpu structures or deduce the base of
the main memory section (PAGE_OFFSET).

This patch relocates the GDT table for each processor inside the
fixmap section. The space is reserved based on number of supported
processors.

For consistency, the remapping is done by default on 32 and 64-bit.

Each processor switches to its remapped GDT at the end of
initialization. For hibernation, the main processor returns with the
original GDT and switches back to the remapping at completion.

This patch was tested on both architectures. Hibernation and KVM were
both tested specially for their usage of the GDT.

Thanks to Boris Ostrovsky  for testing and
recommending changes for Xen support.

Signed-off-by: Thomas Garnier 
Cc: Alexander Potapenko 
Cc: Andrew Morton 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Ard Biesheuvel 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Chris Wilson 
Cc: Christian Borntraeger 
Cc: Dmitry Vyukov 
Cc: Frederic Weisbecker 
Cc: Jiri Kosina 
Cc: Joerg Roedel 
Cc: Jonathan Corbet 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Kees Cook 
Cc: Len Brown 
Cc: Linus Torvalds 
Cc: Lorenzo Stoakes 
Cc: Luis R . Rodriguez 
Cc: Matt Fleming 
Cc: Michal Hocko 
Cc: Paolo Bonzini 
Cc: Paul Gortmaker 
Cc: Pavel Machek 
Cc: Peter Zijlstra 
Cc: Radim Krčmář 
Cc: Rafael J . Wysocki 
Cc: Rusty Russell 
Cc: Stanislaw Gruszka 
Cc: Thomas Gleixner 
Cc: Tim Chen 
Cc: Vitaly Kuznetsov 
Cc: kasan-dev@googlegroups.com
Cc: kernel-hardening@lists.openwall.com
Cc: kvm@vger.kernel.org
Cc: lguest@lists.ozlabs.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-pm@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Cc: zijun_hu 
Link: http://lkml.kernel.org/r/20170314170508.100882-2-thgarnie@google.com
Signed-off-by: Ingo Molnar

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-03-07T22:42:34+00:00

Pull scheduler fixes from Ingo Molnar:
 "A fix for KVM's scheduler clock which (erroneously) was always marked
  unstable, a fix for RT/DL load balancing, plus latency fixes"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface
  sched/core: Fix pick_next_task() for RT,DL
  sched/fair: Make select_idle_cpu() more aggressive

sched/headers: Move task->mm handling methods to

2017-03-03T00:43:28+00:00

Move the following task->mm helper APIs into a new header file,
, to further reduce the size and complexity
of .

Here are how the APIs are used in various kernel files:

  # mm_alloc():
  arch/arm/mach-rpc/ecard.c
  fs/exec.c
  include/linux/sched/mm.h
  kernel/fork.c

  # __mmdrop():
  arch/arc/include/asm/mmu_context.h
  include/linux/sched/mm.h
  kernel/fork.c

  # mmdrop():
  arch/arm/mach-rpc/ecard.c
  arch/m68k/sun3/mmu_emu.c
  arch/x86/mm/tlb.c
  drivers/gpu/drm/amd/amdkfd/kfd_process.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/hw/hfi1/file_ops.c
  drivers/vfio/vfio_iommu_spapr_tce.c
  fs/exec.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/mmu_notifier.h
  include/linux/sched/mm.h
  kernel/fork.c
  kernel/futex.c
  kernel/sched/core.c
  mm/khugepaged.c
  mm/ksm.c
  mm/mmu_context.c
  mm/mmu_notifier.c
  mm/oom_kill.c
  virt/kvm/kvm_main.c

  # mmdrop_async_fn():
  include/linux/sched/mm.h

  # mmdrop_async():
  include/linux/sched/mm.h
  kernel/fork.c

  # mmget_not_zero():
  fs/userfaultfd.c
  include/linux/sched/mm.h
  mm/oom_kill.c

  # mmput():
  arch/arc/include/asm/mmu_context.h
  arch/arc/kernel/troubleshoot.c
  arch/frv/mm/mmu-context.c
  arch/powerpc/platforms/cell/spufs/context.c
  arch/sparc/include/asm/mmu_context_32.h
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/gpu/drm/i915/i915_gem_userptr.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/core/uverbs_main.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/exec.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  fs/proc/task_nommu.c
  fs/userfaultfd.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/events/uprobes.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/oom_kill.c
  mm/process_vm_access.c
  mm/rmap.c
  mm/swapfile.c
  mm/util.c
  virt/kvm/async_pf.c

  # mmput_async():
  include/linux/sched/mm.h
  kernel/fork.c
  mm/oom_kill.c

  # get_task_mm():
  arch/arc/kernel/troubleshoot.c
  arch/powerpc/platforms/cell/spufs/context.c
  drivers/android/binder.c
  drivers/gpu/drm/etnaviv/etnaviv_gem.c
  drivers/infiniband/core/umem.c
  drivers/infiniband/core/umem_odp.c
  drivers/infiniband/hw/mlx4/main.c
  drivers/infiniband/hw/mlx5/main.c
  drivers/infiniband/hw/usnic/usnic_uiom.c
  drivers/iommu/amd_iommu_v2.c
  drivers/iommu/intel-svm.c
  drivers/lguest/lguest_user.c
  drivers/misc/cxl/fault.c
  drivers/misc/mic/scif/scif_rma.c
  drivers/oprofile/buffer_sync.c
  drivers/vfio/vfio_iommu_type1.c
  drivers/vhost/vhost.c
  drivers/xen/gntdev.c
  fs/proc/array.c
  fs/proc/base.c
  fs/proc/task_mmu.c
  include/linux/sched/mm.h
  kernel/cpuset.c
  kernel/events/core.c
  kernel/exit.c
  kernel/fork.c
  kernel/ptrace.c
  kernel/sys.c
  kernel/trace/trace_output.c
  kernel/tsacct.c
  mm/memcontrol.c
  mm/memory.c
  mm/mempolicy.c
  mm/migrate.c
  mm/mmu_notifier.c
  mm/nommu.c
  mm/util.c

  # mm_access():
  fs/proc/base.c
  include/linux/sched/mm.h
  kernel/fork.c
  mm/process_vm_access.c

  # mm_release():
  arch/arc/include/asm/mmu_context.h
  fs/exec.c
  include/linux/sched/mm.h
  include/uapi/linux/sched.h
  kernel/exit.c
  kernel/fork.c

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/clock, x86/tsc: Rework the x86 'unstable' sched_clock() interface

2017-03-02T07:50:49+00:00

Wanpeng Li reported that since the following commit:

  acb04058de49 ("sched/clock: Fix hotplug crash")

... KVM always runs with unstable sched-clock even though KVM's
kvm_clock _is_ stable.

The problem is that we've tied clear_sched_clock_stable() to the TSC
state, and overlooked that sched_clock() is a paravirt function.

Solve this by doing two things:

 - tie the sched_clock() stable state more clearly to the TSC stable
   state for the normal (!paravirt) case.

 - only call clear_sched_clock_stable() when we mark TSC unstable
   when we use native_sched_clock().

The first means we can actually run with stable sched_clock in more
situations then before, which is good. And since commit:

  12907fbb1a69 ("sched/clock, clocksource: Add optional cs::mark_unstable() method")

... this should be reliable. Since any detection of TSC fail now results
in marking the TSC unstable.

Reported-by: Wanpeng Li 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Paolo Bonzini 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Fixes: acb04058de49 ("sched/clock: Fix hotplug crash")
Signed-off-by: Ingo Molnar

sched/headers: Prepare to move 'init_task' and 'init_thread_union' from to

2017-03-02T07:42:38+00:00

Update all usage sites first.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:27+00:00

We are going to split  out of , which
will have to be picked up from other headers and .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar