[PATCH 0/5] vsyscall xonly mode

[Andy Lutomirski]

Hi all-

This adds a new "xonly" mode for vsyscalls and makes it the default.
xonly is a bit more secure -- Kees knows about an exploit that relied on
read access to the vsyscall page.  It's also nicer from a paging
perspective, as it doesn't require user access to any of the kernel
address space as far as the CPU is concerned.  This would, for example,
allow a much simpler implementation of per-process vsyscall disabling.

Andy Lutomirski (5):
  x86/vsyscall: Remove the vsyscall=native documentation
  x86/vsyscall: Add a new vsyscall=xonly mode
  x86/vsyscall: Document odd #PF's error code for vsyscalls
  selftests/x86/vsyscall: Verify that vsyscall=none blocks execution
  x86/vsyscall: Change the default vsyscall mode to xonly

 .../admin-guide/kernel-parameters.txt         | 11 ++-
 arch/x86/Kconfig                              | 32 ++++---
 arch/x86/entry/vsyscall/vsyscall_64.c         | 19 ++++-
 arch/x86/mm/fault.c                           |  7 ++
 tools/testing/selftests/x86/test_vsyscall.c   | 83 +++++++++++++------
 5 files changed, 107 insertions(+), 45 deletions(-)

-- 
2.21.0