[SRU][Xenial][PULL] Update to upstream's implementation of Spectre v1 mitigation (LP: #1774181)

[Juerg Haefliger]

BugLink: https://bugs.launchpad.net/bugs/1774181

Xenial/Trusty/Precise are currently lacking full support of upstream's Spectre v1 mitigation. Add the missing patches and merge them with Ubuntu's current implementation.

The non-SAUCE patches are the stable 4.4 patches from 4.4.118 to 4.4.131. The rest will come in through follow-on updates to the current stable version 4.4.135.

The SAUCE patches is the add-on/difference between the original embargoed patchset and what finally landed in upstream.


== SRU Justification ==
Ubuntu's Spectre v1 mitigation is based on the original embargoed patchset which introduced a barrier macro to prevent speculation beyond array boundaries for user controlled indices. What eventually landed in upstream is slightly different and uses a barrier macro in combination with a masking solution (plus syscall table and user pointer sanitation). During the updates to newer stable upstream versions, all those patches were skipped. After reviewing them, we want to bring them back and merge them with the current implementation which brings us back in sync with upstream stable.

== Fix ==
Add all the missing Spectre v1 patches from upstream stable 4.4.118 to 4.4.131. Where appropriate, replace Ubuntu's additional barriers with the masking macro.

== Regression Potential ==
Low. The patches have been in upstream for quite a while now and we keep the speculation barriers that are currently in Ubuntu but not in upstream.

== Test Case ==
TBD.

Signed-off-by: Juerg Haefliger <juergh at canonical.com>
---
The following changes since commit 8a4cab02850143918a93afbd9dd284cdef0b84d3:

  UBUNTU: Ubuntu-4.4.0-128.154 (2018-05-25 16:01:29 +0200)

are available in the Git repository at:

  git://git.launchpad.net/~juergh/+git/xenial-linux lp1774181

for you to fetch changes up to 64d8307cf6ffc09278aeda29bed31a0e72a680c1:

  UBUNTU: SAUCE: bpf: Use barrier_nospec() instead of osb() (2018-06-05 17:27:01 +0200)

----------------------------------------------------------------
Dan Williams (12):
      array_index_nospec: Sanitize speculative array de-references
      x86: Implement array_index_mask_nospec
      x86: Introduce barrier_nospec
      x86/get_user: Use pointer masking to limit speculation
      x86/syscall: Sanitize syscall table de-references under speculation
      vfs, fdtable: Prevent bounds-check bypass via speculative execution
      nl80211: Sanitize array index in parse_txq_params
      x86/spectre: Report get_user mitigation for spectre_v1
      x86/kvm: Update spectre-v1 mitigation
      mpls, nospec: Sanitize array index in mpls_label_ok()
      nospec: Include <asm/barrier.h> dependency
      nospec: Kill array_index_nospec_mask_check()

Jiri Slaby (1):
      x86/syscall: Sanitize syscall table de-references under speculation fix

Juerg Haefliger (3):
      UBUNTU: SAUCE: Replace osb() calls with array_index_nospec()
      UBUNTU: SAUCE: Rename osb() to barrier_nospec()
      UBUNTU: SAUCE: bpf: Use barrier_nospec() instead of osb()

Mark Rutland (1):
      Documentation: Document array_index_nospec

Rasmus Villemoes (1):
      nospec: Allow index argument to have const-qualified type

Takashi Iwai (2):
      ALSA: seq: oss: Hardening for potential Spectre v1
      ALSA: hda: Hardening for potential Spectre v1

Will Deacon (1):
      nospec: Move array_index_nospec() parameter checking into separate macro

 Documentation/speculation.txt                      | 90 ++++++++++++++++++++++
 arch/arm/include/asm/barrier.h                     |  2 -
 arch/arm64/include/asm/barrier.h                   |  2 -
 arch/powerpc/include/asm/barrier.h                 |  3 +-
 arch/s390/include/asm/barrier.h                    | 13 ++--
 arch/x86/entry/common.c                            |  2 +
 arch/x86/entry/entry_64.S                          | 16 ++--
 arch/x86/include/asm/barrier.h                     | 30 +++++++-
 arch/x86/include/asm/msr.h                         |  2 +-
 arch/x86/kernel/cpu/bugs.c                         | 11 +--
 arch/x86/kvm/vmx.c                                 | 20 +++--
 arch/x86/lib/getuser.S                             | 10 +++
 drivers/net/wireless/ath/carl9170/main.c           |  3 +-
 drivers/scsi/qla2xxx/qla_mr.c                      |  5 +-
 .../thermal/int340x_thermal/int340x_thermal_zone.c |  3 +-
 fs/udf/misc.c                                      | 13 ++--
 include/linux/fdtable.h                            |  3 +-
 include/linux/nospec.h                             | 53 +++++++++++++
 kernel/bpf/core.c                                  |  6 +-
 kernel/user_namespace.c                            |  3 +-
 net/ipv4/raw.c                                     |  7 +-
 net/ipv6/raw.c                                     |  7 +-
 net/mpls/af_mpls.c                                 | 28 ++++---
 net/wireless/nl80211.c                             |  9 ++-
 sound/core/seq/oss/seq_oss_event.c                 | 15 ++--
 sound/core/seq/oss/seq_oss_midi.c                  |  2 +
 sound/core/seq/oss/seq_oss_synth.c                 | 75 ++++++++++--------
 sound/core/seq/oss/seq_oss_synth.h                 |  3 +-
 sound/pci/hda/hda_hwdep.c                          | 12 ++-
 29 files changed, 331 insertions(+), 117 deletions(-)
 create mode 100644 Documentation/speculation.txt