linux.git/arch/x86/include, branch v4.17

Merge branch 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-05-21T18:23:26+00:00

Merge speculative store buffer bypass fixes from Thomas Gleixner:

 - rework of the SPEC_CTRL MSR management to accomodate the new fancy
   SSBD (Speculative Store Bypass Disable) bit handling.

 - the CPU bug and sysfs infrastructure for the exciting new Speculative
   Store Bypass 'feature'.

 - support for disabling SSB via LS_CFG MSR on AMD CPUs including
   Hyperthread synchronization on ZEN.

 - PRCTL support for dynamic runtime control of SSB

 - SECCOMP integration to automatically disable SSB for sandboxed
   processes with a filter flag for opt-out.

 - KVM integration to allow guests fiddling with SSBD including the new
   software MSR VIRT_SPEC_CTRL to handle the LS_CFG based oddities on
   AMD.

 - BPF protection against SSB

.. this is just the core and x86 side, other architecture support will
come separately.

* 'speck-v20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
  bpf: Prevent memory disambiguation attack
  x86/bugs: Rename SSBD_NO to SSB_NO
  KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
  x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
  x86/bugs: Rework spec_ctrl base and mask logic
  x86/bugs: Remove x86_spec_ctrl_set()
  x86/bugs: Expose x86_spec_ctrl_base directly
  x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
  x86/speculation: Rework speculative_store_bypass_update()
  x86/speculation: Add virtualized speculative store bypass disable support
  x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
  x86/speculation: Handle HT correctly on AMD
  x86/cpufeatures: Add FEATURE_ZEN
  x86/cpufeatures: Disentangle SSBD enumeration
  x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
  x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
  KVM: SVM: Move spec control call after restore of GS
  x86/cpu: Make alternative_msr_write work for 32-bit code
  x86/bugs: Fix the parameters alignment and missing void
  x86/bugs: Make cpu_show_common() static
  ...

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-05-20T18:28:32+00:00

Pull x86 fixes from Thomas Gleixner:
 "An unfortunately larger set of fixes, but a large portion is
  selftests:

   - Fix the missing clusterid initializaiton for x2apic cluster
     management which caused boot failures due to IPIs being sent to the
     wrong cluster

   - Drop TX_COMPAT when a 64bit executable is exec()'ed from a compat
     task

   - Wrap access to __supported_pte_mask in __startup_64() where clang
     compile fails due to a non PC relative access being generated.

   - Two fixes for 5 level paging fallout in the decompressor:

      - Handle GOT correctly for paging_prepare() and
        cleanup_trampoline()

      - Fix the page table handling in cleanup_trampoline() to avoid
        page table corruption.

   - Stop special casing protection key 0 as this is inconsistent with
     the manpage and also inconsistent with the allocation map handling.

   - Override the protection key wen moving away from PROT_EXEC to
     prevent inaccessible memory.

   - Fix and update the protection key selftests to address breakage and
     to cover the above issue

   - Add a MOV SS self test"

[ Part of the x86 fixes were in the earlier core pull due to dependencies ]

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
  x86/apic/x2apic: Initialize cluster ID properly
  x86/boot/compressed/64: Fix moving page table out of trampoline memory
  x86/boot/compressed/64: Set up GOT for paging_prepare() and cleanup_trampoline()
  x86/pkeys: Do not special case protection key 0
  x86/pkeys/selftests: Add a test for pkey 0
  x86/pkeys/selftests: Save off 'prot' for allocations
  x86/pkeys/selftests: Fix pointer math
  x86/pkeys: Override pkey when moving away from PROT_EXEC
  x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
  x86/pkeys/selftests: Add PROT_EXEC test
  x86/pkeys/selftests: Factor out "instruction page"
  x86/pkeys/selftests: Allow faults on unknown keys
  x86/pkeys/selftests: Avoid printf-in-signal deadlocks
  x86/pkeys/selftests: Remove dead debugging code, fix dprint_in_signal
  x86/pkeys/selftests: Stop using assert()
  x86/pkeys/selftests: Give better unexpected fault error messages
  x86/selftests: Add mov_to_ss test
  x86/mpx/selftests: Adjust the self-test to fresh distros that export the MPX ABI
  x86/pkeys/selftests: Adjust the self-test to fresh distros that export the pkeys ABI
  ...

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

2018-05-20T17:01:38+00:00

Pull core fixes from Thomas Gleixner:

 - Unbreak the BPF compilation which got broken by the unconditional
   requirement of asm-goto, which is not supported by clang.

 - Prevent probing on exception masking instructions in uprobes and
   kprobes to avoid the issues of the delayed exceptions instead of
   having an ugly workaround.

 - Prevent a double free_page() in the error path of do_kexec_load()

 - A set of objtool updates addressing various issues mostly related to
   switch tables and the noreturn detection for recursive sibling calls

 - Header sync for tools.

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Detect RIP-relative switch table references, part 2
  objtool: Detect RIP-relative switch table references
  objtool: Support GCC 8 switch tables
  objtool: Support GCC 8's cold subfunctions
  objtool: Fix "noreturn" detection for recursive sibling calls
  objtool, kprobes/x86: Sync the latest  header with tools/objtool/arch/x86/include/asm/insn.h
  x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation
  uprobes/x86: Prohibit probing on MOV SS instruction
  kprobes/x86: Prohibit probing on exception masking instructions
  x86/kexec: Avoid double free_page() upon do_kexec_load() failure

x86/bugs: Rename SSBD_NO to SSB_NO

2018-05-18T09:17:30+00:00

The "336996 Speculative Execution Side Channel Mitigations" from
May defines this as SSB_NO, hence lets sync-up.

Signed-off-by: Konrad Rzeszutek Wilk 
Signed-off-by: Thomas Gleixner

kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME

2018-05-17T17:12:13+00:00

KVM_HINTS_DEDICATED seems to be somewhat confusing:

Guest doesn't really care whether it's the only task running on a host
CPU as long as it's not preempted.

And there are more reasons for Guest to be preempted than host CPU
sharing, for example, with memory overcommit it can get preempted on a
memory access, post copy migration can cause preemption, etc.

Let's call it KVM_HINTS_REALTIME which seems to better
match what guests expect.

Also, the flag most be set on all vCPUs - current guests assume this.
Note so in the documentation.

Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Paolo Bonzini

KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD

2018-05-17T15:09:21+00:00

Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM.  This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.

[ tglx: Folded the migration fixup from Paolo Bonzini ]

Signed-off-by: Tom Lendacky 
Signed-off-by: Thomas Gleixner

x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG

2018-05-17T15:09:21+00:00

Add the necessary logic for supporting the emulated VIRT_SPEC_CTRL MSR to
x86_virt_spec_ctrl().  If either X86_FEATURE_LS_CFG_SSBD or
X86_FEATURE_VIRT_SPEC_CTRL is set then use the new guest_virt_spec_ctrl
argument to check whether the state must be modified on the host. The
update reuses speculative_store_bypass_update() so the ZEN-specific sibling
coordination can be reused.

Signed-off-by: Thomas Gleixner

x86/bugs: Remove x86_spec_ctrl_set()

2018-05-17T15:09:20+00:00

x86_spec_ctrl_set() is only used in bugs.c and the extra mask checks there
provide no real value as both call sites can just write x86_spec_ctrl_base
to MSR_SPEC_CTRL. x86_spec_ctrl_base is valid and does not need any extra
masking or checking.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Borislav Petkov 
Reviewed-by: Konrad Rzeszutek Wilk

x86/bugs: Expose x86_spec_ctrl_base directly

2018-05-17T15:09:19+00:00

x86_spec_ctrl_base is the system wide default value for the SPEC_CTRL MSR.
x86_spec_ctrl_get_default() returns x86_spec_ctrl_base and was intended to
prevent modification to that variable. Though the variable is read only
after init and globaly visible already.

Remove the function and export the variable instead.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Borislav Petkov 
Reviewed-by: Konrad Rzeszutek Wilk

x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}

2018-05-17T15:09:19+00:00

Function bodies are very similar and are going to grow more almost
identical code. Add a bool arg to determine whether SPEC_CTRL is being set
for the guest or restored to the host.

No functional changes.

Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Konrad Rzeszutek Wilk