ACK: [bionic:linux-azure-4.15][PULL REQUEST] LP#1877425 - linux-azure: Enable FSGSBASE instructions to support SGX

[Ian May]

Acked-by: Ian May <ian.may at canonical.com>


On 5/15/20 2:11 PM, Marcelo Henrique Cerri wrote:
> BugLink: http://bugs.launchpad.net/bugs/1877425
>
> The following changes since commit cd6b58b95a2a23466b65e676e05bce3df6b32e33:
>
>   UBUNTU: Ubuntu-azure-4.15-4.15.0-1083.93 (2020-04-30 10:53:28 -0700)
>
> are available in the Git repository at:
>
>   git://git.launchpad.net/~mhcerri/ubuntu/+source/linux/+git/azure azure-4.15-fsgsbase
>
> for you to fetch changes up to 9c2fdd5054467fd7f4ab94b1fa938550d3e52e90:
>
>   UBUNTU: SAUCE: x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2 (2020-05-07 12:21:13 -0300)
>
> ----------------------------------------------------------------
> Andi Kleen (2):
>       UBUNTU: SAUCE: x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions
>       UBUNTU: SAUCE: x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2
>
> Andy Lutomirski (8):
>       x86/entry/64: Further improve paranoid_entry comments
>       selftests/x86/fsgsbase: Test RD/WRGSBASE
>       selftests/x86/fsgsbase: Fix some test case bugs
>       Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test
>       UBUNTU: SAUCE: x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE
>       UBUNTU: SAUCE: x86/entry/64: Clean up paranoid exit
>       UBUNTU: SAUCE: x86/fsgsbase/64: Use FSGSBASE in switch_to() if available
>       UBUNTU: SAUCE: x86/fsgsbase/64: Enable FSGSBASE on 64bit by default and add a chicken bit
>
> Chang S. Bae (17):
>       x86/fsgsbase/64: Introduce FS/GS base helper functions
>       x86/fsgsbase/64: Make ptrace use the new FS/GS base helpers
>       x86/fsgsbase/64: Factor out FS/GS segment loading from __switch_to()
>       x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBER
>       x86/vdso: Introduce helper functions for CPU and node number
>       x86/vdso: Initialize the CPU/node NR segment descriptor earlier
>       x86/fsgsbase/64: Fix the base write helper functions
>       selftests/x86/fsgsbase: Test ptracer-induced GSBASE write
>       selftests/x86/fsgsbase: Test ptracer-induced GSBASE write with FSGSBASE
>       UBUNTU: SAUCE: x86/ptrace: Prevent ptrace from clearing the FS/GS selector
>       UBUNTU: SAUCE: selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write
>       UBUNTU: SAUCE: x86/entry/64: Switch CR3 before SWAPGS in paranoid entry
>       UBUNTU: SAUCE: x86/entry/64: Introduce the FIND_PERCPU_BASE macro
>       UBUNTU: SAUCE: x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit
>       UBUNTU: SAUCE: x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions
>       UBUNTU: SAUCE: x86/fsgsbase/64: Use FSGSBASE instructions on thread copy and ptrace
>       UBUNTU: SAUCE: selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE
>
> Dave Hansen (1):
>       x86/entry: Add some paranoid entry/exit CR3 handling comments
>
> Ingo Molnar (2):
>       x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
>       x86/fsgsbase/64: Clean up various details
>
> Tony Luck (1):
>       UBUNTU: SAUCE: x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation
>
>  Documentation/admin-guide/kernel-parameters.txt |   2 +
>  arch/x86/entry/calling.h                        |  40 ++++
>  arch/x86/entry/entry_64.S                       | 143 +++++++++---
>  arch/x86/entry/vdso/vgetcpu.c                   |   8 +-
>  arch/x86/entry/vdso/vma.c                       |  38 +---
>  arch/x86/include/asm/fsgsbase.h                 |  83 +++++++
>  arch/x86/include/asm/inst.h                     |  15 ++
>  arch/x86/include/asm/segment.h                  |  46 +++-
>  arch/x86/include/asm/vgtod.h                    |  26 ---
>  arch/x86/include/uapi/asm/hwcap2.h              |   3 +
>  arch/x86/kernel/cpu/bugs.c                      |   6 +-
>  arch/x86/kernel/cpu/common.c                    |  46 ++++
>  arch/x86/kernel/process_64.c                    | 281 ++++++++++++++++++++----
>  arch/x86/kernel/ptrace.c                        |  75 +------
>  tools/testing/selftests/x86/fsgsbase.c          | 225 +++++++++++++++++--
>  15 files changed, 798 insertions(+), 239 deletions(-)
>  create mode 100644 arch/x86/include/asm/fsgsbase.h
>
>