[PATCH 0/3] arm64: Assorted GCS fixes

[Catalin Marinas]

The first patch fixes a kernel panic when LPA2 is enabled together with
GCS because of the PTE_SHARED bits in _PAGE_GCS{,RO} overlapping with
OA[9:8].

The second patch allows PROT_NONE mappings even with GCS, useful for
NUMA balancing.

The third patch is an optimisation that was added to the normal stacks
as well (when mapped with MAP_STACK) as it doesn't make sense to use a
THP for a small GCS mapping. This patch also updates the do_mmap() call
in alloc_gcs() to use PROT_WRITE instead of VM_WRITE for consistency.

Thanks.

Catalin Marinas (3):
  arm64: gcs: Do not set PTE_SHARED on GCS mappings if FEAT_LPA2 is
    enabled
  arm64: gcs: Allow PAGE_NONE mappings for NUMA balancing
  arm64: gcs: Do not map the guarded control stack as THP

 arch/arm64/include/asm/pgtable-prot.h |  4 ++--
 arch/arm64/mm/gcs.c                   |  8 ++++++--
 arch/arm64/mm/mmap.c                  | 10 +++++++++-
 3 files changed, 17 insertions(+), 5 deletions(-)