[PATCH 0/3] x86/umip: Fix UMIP insn decoder false positives

[Sean Christopherson <seanjc@google.com>]

Fix two false positives scenarios where the UMIP #GP logic will incorrectly
trigger emulation, e.g. due to a partially decoded instruction, or on
instructions like VMLAUNCH that usurp the register form of '0f 01'.

Tested with the hack-a-test patch at the end, but I haven't done any testing
using a real userspace (neither positive nor negative testing).

Sean Christopherson (3):
  x86/umip: Check that the instruction opcode is at least two bytes
  x86/umip: Fix decoding of register forms of 0F 01 (SGDT and SIDT
    aliases)
  *** DO NOT MERGE *** x86/umip: Lazy person's KUnit test for UMIP
    emulation

 arch/x86/kernel/umip.c | 71 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 69 insertions(+), 2 deletions(-)


base-commit: ce0b5eedcb753697d43f61dd2e27d68eb5d3150f
-- 
2.50.1.703.g449372360f-goog