linux-kernel - [PATCH v12 0/7] support FEAT

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20260121190622.2218669-1-yeoreum.yun@arm.com>
Date: Wed, 21 Jan 2026 19:06:15 +0000
From: Yeoreum Yun <yeoreum.yun@....com>
To: linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	kvmarm@...ts.linux.dev,
	kvm@...r.kernel.org,
	linux-kselftest@...r.kernel.org
Cc: catalin.marinas@....com,
	will@...nel.org,
	maz@...nel.org,
	broonie@...nel.org,
	oliver.upton@...ux.dev,
	miko.lenczewski@....com,
	kevin.brodsky@....com,
	ardb@...nel.org,
	suzuki.poulose@....com,
	lpieralisi@...nel.org,
	scott@...amperecomputing.com,
	joey.gouly@....com,
	yuzenghui@...wei.com,
	pbonzini@...hat.com,
	shuah@...nel.org,
	mark.rutland@....com,
	arnd@...db.de,
	Yeoreum Yun <yeoreum.yun@....com>
Subject: [PATCH v12 0/7] support FEAT_LSUI

Since Armv9.6, FEAT_LSUI supplies the load/store instructions for
previleged level to access to access user memory without clearing
PSTATE.PAN bit.

This patchset support FEAT_LSUI and applies in futex atomic operation
and user_swpX emulation where can replace from ldxr/st{l}xr
pair implmentation with clearing PSTATE.PAN bit to correspondant
load/store unprevileged atomic operation without clearing PSTATE.PAN bit.

This patch based on v6.19-rc6

Patch History
==============
from v11 to v12:
  - rebase to v6.19-rc6
  - add CONFIG_ARM64_LSUI
  - enable LSUI when !CPU_BIG_ENDIAN and PAN presents.
  - drop the swp emulation with LSUI insns instead, disable it
    when LSUI presents.
  - some of small fixes (useless prefix and suffix and etc).
  - https://lore.kernel.org/all/20251214112248.901769-1-yeoreum.yun@arm.com/

from v10 to v11:
  - rebase to v6.19-rc1
  - use cast instruction to emulate deprecated swpb instruction
  - https://lore.kernel.org/all/20251103163224.818353-1-yeoreum.yun@arm.com/

from v9 to v10:
  - apply FEAT_LSUI to user_swpX emulation.
  - add test coverage for LSUI bit in ID_AA64ISAR3_EL1
  - rebase to v6.18-rc4
  - https://lore.kernel.org/all/20250922102244.2068414-1-yeoreum.yun@arm.com/

from v8 to v9:
  - refotoring __lsui_cmpxchg64()
  - rebase to v6.17-rc7
  - https://lore.kernel.org/all/20250917110838.917281-1-yeoreum.yun@arm.com/

from v7 to v8:
  - implements futex_atomic_eor() and futex_atomic_cmpxchg() with casalt
    with C helper.
  - Drop the small optimisation on ll/sc futex_atomic_set operation.
  - modify some commit message.
  - https://lore.kernel.org/all/20250816151929.197589-1-yeoreum.yun@arm.com/

from v6 to v7:
  - wrap FEAT_LSUI with CONFIG_AS_HAS_LSUI in cpufeature
  - remove unnecessary addition of indentation.
  - remove unnecessary mte_tco_enable()/disable() on LSUI operation.
  - https://lore.kernel.org/all/20250811163635.1562145-1-yeoreum.yun@arm.com/

from v5 to v6:
  - rebase to v6.17-rc1
  - https://lore.kernel.org/all/20250722121956.1509403-1-yeoreum.yun@arm.com/

from v4 to v5:
  - remove futex_ll_sc.h futext_lsui and lsui.h and move them to futex.h
  - reorganize the patches.
  - https://lore.kernel.org/all/20250721083618.2743569-1-yeoreum.yun@arm.com/

from v3 to v4:
  - rebase to v6.16-rc7
  - modify some patch's title.
  - https://lore.kernel.org/all/20250617183635.1266015-1-yeoreum.yun@arm.com/

from v2 to v3:
  - expose FEAT_LSUI to guest
  - add help section for LSUI Kconfig
  - https://lore.kernel.org/all/20250611151154.46362-1-yeoreum.yun@arm.com/

from v1 to v2:
  - remove empty v9.6 menu entry
  - locate HAS_LSUI in cpucaps in order
  - https://lore.kernel.org/all/20250611104916.10636-1-yeoreum.yun@arm.com/


Yeoreum Yun (7):
  arm64: Kconfig: add support for LSUI
  arm64: cpufeature: add FEAT_LSUI
  KVM: arm64: expose FEAT_LSUI to guest
  KVM: arm64: kselftest: set_id_regs: add test for FEAT_LSUI
  arm64: futex: refactor futex atomic operation
  arm64: futex: support futex with FEAT_LSUI
  arm64: armv8_deprecated: disable swp emulation when FEAT_LSUI present

 arch/arm64/Kconfig                            |  20 ++
 arch/arm64/include/asm/futex.h                | 322 +++++++++++++++---
 arch/arm64/kernel/armv8_deprecated.c          |  16 +
 arch/arm64/kernel/cpufeature.c                |  27 ++
 arch/arm64/kvm/sys_regs.c                     |   3 +-
 arch/arm64/tools/cpucaps                      |   1 +
 .../testing/selftests/kvm/arm64/set_id_regs.c |   1 +
 7 files changed, 339 insertions(+), 51 deletions(-)

--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}