[RESEND PATCH v6 00/12] x86: Enable FSGSBASE instructions

[Chang S. Bae]

Updates from v5 [5]:
* Drop the new tain flag (TAINT_INSECURE)
* Cleanup copy_thread_tls(), some changelog, and unnecessary comments on
  assembly macros
* Rearrange some helper updates appropriately (from patch 4 to 6)

Updates from v4 [4]:
* Remove the FSGSBASE assembly macros

Updates from v3 [3]:
* Raise minimum binutils requirement to use the new instructions directly
* Optimize FIND_PERCPU_BASE macro
* Rename some helper functions, __{rd,wr}gsbase_inactive()
* Use NOKPROBE_SYMBOL instead of __kprobes
* Rebase on top of the helper function fix [7]

Update from v2 [2]:
* Separate out the preparatory patches [6] (merged as of now)
* Bisect the paranoid_entry update patch
* Edit minor nits

Updates from v1 [1]:
* Update the GSBASE update mechanism on the paranoid entry/exit.
* Exclude ptracer backward compatibility patches.
* Include FSGSBASE documentation and enumerating capability
  for user space
* Add the TAINT_INSECURE flag.

[1] Version 1: https://lore.kernel.org/patchwork/cover/934843
[2] Version 2: https://lore.kernel.org/patchwork/cover/912063
[3] Version 3: https://lore.kernel.org/patchwork/cover/1002725
[4] Version 4: https://lore.kernel.org/patchwork/cover/1032799
[5] Version 5: https://lore.kernel.org/patchwork/cover/1038035
[6] https://lore.kernel.org/patchwork/cover/988180
[7] https://lore.kernel.org/patchwork/patch/1017513

Andi Kleen (3):
  x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions
  x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2
  x86/fsgsbase/64: Add documentation for FSGSBASE

Andy Lutomirski (4):
  x86/fsgsbase/64: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE
  x86/fsgsbase/64: Preserve FS/GS state in __switch_to() if FSGSBASE is
    on
  selftests/x86/fsgsbase: Test WRGSBASE
  x86/fsgsbase/64: Enable FSGSBASE by default and add a chicken bit

Chang S. Bae (5):
  kbuild: Raise the minimum required binutils version to 2.21
  x86/fsgsbase/64: Enable FSGSBASE instructions in the helper functions
  x86/fsgsbase/64: When copying a thread, use the FSGSBASE instructions
    if available
  x86/fsgsbase/64: Introduce the FIND_PERCPU_BASE macro
  x86/fsgsbase/64: Use the per-CPU base as GSBASE at the paranoid_entry

 .../admin-guide/kernel-parameters.txt         |   2 +
 Documentation/process/changes.rst             |   6 +-
 Documentation/x86/fsgs.txt                    | 104 +++++++++++++++++
 arch/x86/entry/entry_64.S                     |  71 +++++++++---
 arch/x86/include/asm/fsgsbase.h               |  95 ++++++++++++++--
 arch/x86/include/asm/inst.h                   |  15 +++
 arch/x86/include/uapi/asm/hwcap2.h            |   3 +
 arch/x86/kernel/cpu/common.c                  |  22 ++++
 arch/x86/kernel/process_64.c                  | 105 ++++++++++++++++--
 tools/testing/selftests/x86/fsgsbase.c        | 102 ++++++++++++++++-
 10 files changed, 484 insertions(+), 41 deletions(-)
 create mode 100644 Documentation/x86/fsgs.txt

-- 
2.19.1