From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev
Cc: Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oupton@kernel.org>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH 0/3] arm64: Unconditionally compile LSE/PAN/EPAN support
Date: Wed, 7 Jan 2026 18:06:58 +0000 [thread overview]
Message-ID: <20260107180701.2858276-1-maz@kernel.org> (raw)
FEAT_LSE and FEAT_PAN have been around for a *very* long time (ARMv8.1
was published 11 years ago), and it is about time we enable these by
default. The additional text is very small, the advantages pretty
large in terms of performance (LSE) and security (PAN), and it is very
hard to find a semi-modern machine that doesn't have these (even the
RPi5 is ARMv8.2...).
On top of that, FEAT_PAN3 (aka EPAN) is a very nice to have, and
naturally complement PAN for exec-only mappings.
Drop the configuration symbols for these three extensions, and let the
automatic detection of features to its job.
Only very lightly tested, but what could possibly go wrong? ;-)
Marc Zyngier (3):
arm64: Unconditionally enable LSE support
arm64: Unconditionally enable PAN support
arm64: Unconditionally enable EPAN support
arch/arm64/Kconfig | 46 -----------------------------
arch/arm64/configs/hardening.config | 3 --
arch/arm64/include/asm/cpucaps.h | 4 ---
arch/arm64/include/asm/insn.h | 23 ---------------
arch/arm64/include/asm/lse.h | 9 ------
arch/arm64/include/asm/uaccess.h | 6 ++--
arch/arm64/kernel/cpufeature.c | 8 -----
arch/arm64/kvm/at.c | 7 -----
arch/arm64/kvm/hyp/entry.S | 2 +-
arch/arm64/lib/insn.c | 2 --
arch/arm64/net/bpf_jit_comp.c | 7 -----
11 files changed, 3 insertions(+), 114 deletions(-)
--
2.47.3
next reply other threads:[~2026-01-07 18:07 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-07 18:06 Marc Zyngier [this message]
2026-01-07 18:06 ` [PATCH 1/3] arm64: Unconditionally enable LSE support Marc Zyngier
2026-01-07 18:07 ` [PATCH 2/3] arm64: Unconditionally enable PAN support Marc Zyngier
2026-01-22 11:21 ` Marc Zyngier
2026-01-22 17:02 ` Will Deacon
2026-01-07 18:07 ` [PATCH 3/3] arm64: Unconditionally enable EPAN support Marc Zyngier
2026-01-22 10:15 ` Will Deacon
2026-01-22 11:06 ` Marc Zyngier
2026-01-22 16:59 ` [PATCH 0/3] arm64: Unconditionally compile LSE/PAN/EPAN support Will Deacon
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