[PATCH v2 0/5] fixes for data/bss linear alias unmap series

From: Ard Biesheuvel

Date: Thu Jun 04 2026 - 11:31:09 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

Fixes for the data/bss linear alias unmap series:

- Fix KASAN related issue reported by Mark, by moving all KASAN page
tables out of BSS [on arm64], not just the ones defined under
arch/arm64

- Fix two issues spotted by Sashiko

- Fix the CKI reported WARN() splat on BBML2_NOABORT systems that try to
split block mappings too early.

Changes since v1:

- Split .bss..pgtbl changes off into separate patch
- Take Catalin's suggestion on how to address MTE issue with the
read-only zero page
- Improved commit logs

Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>

Ard Biesheuvel (5):
arm64: Rename page table BSS section to .bss..pgtbl
kasan: Move generic KASAN page tables out of BSS too
arm64: Avoid double evaluation of __ptep_get()
KVM: arm64: Omit tag sync on stage-2 mappings of the zero page
arm64: mm: Defer remap of linear alias of data/bss

arch/arm64/include/asm/linkage.h | 2 ++
arch/arm64/include/asm/mmu.h | 2 --
arch/arm64/include/asm/pgtable.h | 4 ----
arch/arm64/kernel/vmlinux.lds.S | 8 ++++----
arch/arm64/kvm/mmu.c | 5 +++++
arch/arm64/mm/fixmap.c | 6 +++---
arch/arm64/mm/kasan_init.c | 2 +-
arch/arm64/mm/mmu.c | 20 +++++++++++++-------
include/linux/linkage.h | 4 ++++
mm/kasan/init.c | 10 +++++-----
10 files changed, 37 insertions(+), 26 deletions(-)


base-commit: 63e0b6a5b6934d6a919d1c65ea185303200a1874
--
2.54.0.1032.g2f8565e1d1-goog