[PATCH 0/3] arm64: Unconditionally compile LSE/PAN/EPAN support

Marc Zyngier
2026-01-07T18:07:07Z

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(-)

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2.47.3