From: Sean Christopherson <seanjc@google.com>
To: Jonathan Corbet <corbet@lwn.net>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Peter Zijlstra <peterz@infradead.org>
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Stephen Rothwell <sfr@canb.auug.org.au>,
Michael Ellerman <mpe@ellerman.id.au>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Sean Christopherson <seanjc@google.com>
Subject: [PATCH 0/2] cpu: Fix default mitigation behavior
Date: Tue, 16 Apr 2024 17:15:05 -0700 [thread overview]
Message-ID: <20240417001507.2264512-1-seanjc@google.com> (raw)
This is effectively v2 of a previous series[*] that was intended to be
x86-only, but accidentally disabled CPU mitigations by default for every
other architectures. Unfortunately, the buggy code has already made it's
way to Linus' tree.
Patch 1 fixes that goof by adding a generic Kconfig to control the
default behavior.
Patch 2 disallows retroactively enabling mitigations via command line if
the kernel was built with CPU_MITIGATIONS=n, i.e. with
SPECULATION_MITIGATIONS=n on x86, as it's infeasible for the kernel to
provide sane, predictable behavior for this scenario.
[*] https://lore.kernel.org/all/20240409175108.1512861-1-seanjc@google.com
Sean Christopherson (2):
cpu: Re-enable CPU mitigations by default for !X86 architectures
cpu: Ignore "mitigations" kernel parameter if CPU_MITIGATIONS=n
Documentation/admin-guide/kernel-parameters.txt | 3 +++
arch/x86/Kconfig | 11 ++++++++---
drivers/base/Kconfig | 3 +++
kernel/cpu.c | 6 ++++--
4 files changed, 18 insertions(+), 5 deletions(-)
base-commit: 96fca68c4fbf77a8185eb10f7557e23352732ea2
--
2.44.0.683.g7961c838ac-goog
next reply other threads:[~2024-04-17 0:15 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-17 0:15 Sean Christopherson [this message]
2024-04-17 0:15 ` [PATCH 1/2] cpu: Re-enable CPU mitigations by default for !X86 architectures Sean Christopherson
2024-04-18 0:54 ` Michael Ellerman
2024-04-19 14:27 ` Geert Uytterhoeven
2024-04-19 14:37 ` Will Deacon
2024-04-19 16:05 ` Josh Poimboeuf
2024-04-19 16:46 ` Sean Christopherson
2024-04-19 17:34 ` Josh Poimboeuf
2024-04-19 23:57 ` Sean Christopherson
2024-04-19 23:27 ` Michael Ellerman
2024-04-17 0:15 ` [PATCH 2/2] cpu: Ignore "mitigations" kernel parameter if CPU_MITIGATIONS=n Sean Christopherson
2024-04-19 15:00 ` Borislav Petkov
2024-04-19 16:01 ` Sean Christopherson
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