[SRU][Cosmic][PULL v2] Update speculation side-channel mitigations

[Tyler Hicks]

This is a cleaned up (followup patches applied and ACKs gathered) and
ready-to-pull revision of this thread:

  https://lists.ubuntu.com/archives/kernel-team/2019-March/099461.html

The following changes since commit fc64292e63e0272f049bcaf2184d3b9a4c8c0dbd:

  UBUNTU: Ubuntu-4.18.0-17.18 (2019-03-13 12:52:13 +0100)

are available in the git repository at:

  https://git.launchpad.net/~tyhicks/ubuntu/+source/linux/+git/cosmic speculation-v2

for you to fetch changes up to e95e21128468b63bca8e5a404504caeed780a15f:

  x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE (2019-03-27 19:42:16 +0000)

----------------------------------------------------------------
Jim Mattson (1):
      kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb

Jiri Kosina (2):
      x86/speculation: Apply IBPB more strictly to avoid cross-process data leak
      x86/speculation: Propagate information about RSB filling mitigation to sysfs

Peter Zijlstra (Intel) (1):
      sched/smt: Make sched_smt_present track topology

Thomas Gleixner (21):
      x86/speculation: Rename SSBD update functions
      x86/Kconfig: Select SCHED_SMT if SMP enabled
      sched/smt: Expose sched_smt_present static key
      x86/speculation: Rework SMT state change
      x86/l1tf: Show actual SMT state
      x86/speculation: Reorder the spec_v2 code
      x86/speculation: Mark string arrays const correctly
      x86/speculataion: Mark command line parser data __initdata
      x86/speculation: Unify conditional spectre v2 print functions
      x86/speculation: Add command line control for indirect branch speculation
      x86/process: Consolidate and simplify switch_to_xtra() code
      x86/speculation: Avoid __switch_to_xtra() calls
      x86/speculation: Prepare for conditional IBPB in switch_mm()
      ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS
      x86/speculation: Split out TIF update
      x86/speculation: Prevent stale SPEC_CTRL msr content
      x86/speculation: Prepare arch_smt_update() for PRCTL mode
      x86/speculation: Add prctl() control for indirect branch speculation
      x86/speculation: Enable prctl mode for spectre_v2_user
      x86/speculation: Add seccomp Spectre v2 user space protection mode
      x86/speculation: Provide IBPB always command line options

Thomas Lendacky (1):
      x86/speculation: Add support for STIBP always-on preferred mode

Tim Chen (7):
      x86/speculation: Update the TIF_SSBD comment
      x86/speculation: Clean up spectre_v2_parse_cmdline()
      x86/speculation: Remove unnecessary ret variable in cpu_show_common()
      x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()
      x86/speculation: Disable STIBP when enhanced IBRS is in use
      x86/speculation: Reorganize speculation control MSRs update
      x86/speculation: Prepare for per task indirect branch speculation control

WANG Chao (1):
      x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE

Waiman Long (1):
      x86/speculation: Change misspelled STIPB to STIBP

Zhenzhong Duan (3):
      x86/speculation: Add RETPOLINE_AMD support to the inline asm CALL_NOSPEC variant
      x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
      x86/retpoline: Remove minimal retpoline support

 Documentation/admin-guide/kernel-parameters.txt |  56 ++-
 Documentation/userspace-api/spec_ctrl.rst       |   9 +
 arch/x86/Kconfig                                |  12 +-
 arch/x86/Makefile                               |   5 +-
 arch/x86/include/asm/cpufeatures.h              |   1 +
 arch/x86/include/asm/msr-index.h                |   5 +-
 arch/x86/include/asm/nospec-branch.h            |  44 +-
 arch/x86/include/asm/spec-ctrl.h                |  20 +-
 arch/x86/include/asm/switch_to.h                |   3 -
 arch/x86/include/asm/thread_info.h              |  20 +-
 arch/x86/include/asm/tlbflush.h                 |   8 +-
 arch/x86/kernel/cpu/bugs.c                      | 544 ++++++++++++++++++------
 arch/x86/kernel/process.c                       | 101 ++++-
 arch/x86/kernel/process.h                       |  39 ++
 arch/x86/kernel/process_32.c                    |  10 +-
 arch/x86/kernel/process_64.c                    |  10 +-
 arch/x86/kvm/svm.c                              |  20 +-
 arch/x86/mm/tlb.c                               | 115 +++--
 include/linux/compiler-gcc.h                    |   2 +-
 include/linux/module.h                          |   2 +-
 include/linux/ptrace.h                          |   4 +-
 include/linux/sched.h                           |   9 +
 include/linux/sched/smt.h                       |  20 +
 include/uapi/linux/prctl.h                      |   1 +
 kernel/cpu.c                                    |  15 +-
 kernel/sched/core.c                             |  19 +-
 kernel/sched/sched.h                            |   4 +-
 scripts/Makefile.build                          |   2 -
 scripts/mod/modpost.c                           |   2 +-
 tools/include/uapi/linux/prctl.h                |   1 +
 30 files changed, 838 insertions(+), 265 deletions(-)
 create mode 100644 arch/x86/kernel/process.h
 create mode 100644 include/linux/sched/smt.h