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From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	stable@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
	David Brazdil <dbrazdil@google.com>,
	Will Deacon <will@kernel.org>
Subject: [PATCH 02/19] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs
Date: Fri, 18 Sep 2020 17:47:12 +0100	[thread overview]
Message-ID: <20200918164729.31994-3-will@kernel.org> (raw)
In-Reply-To: <20200918164729.31994-1-will@kernel.org>

From: Marc Zyngier <maz@kernel.org>

Commit 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack
thereof") changed the way we deal with ARCH_WORKAROUND_1, by moving most
of the enabling code to the .matches() callback.

This has the unfortunate effect that the workaround gets only enabled on
the first affected CPU, and no other.

In order to address this, forcefully call the .matches() callback from a
.cpu_enable() callback, which brings us back to the original behaviour.

Fixes: 73f381660959 ("arm64: Advertise mitigation of Spectre-v2, or lack thereof")
Cc: <stable@vger.kernel.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/cpu_errata.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 88966496806a..3fe64bf5a58d 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -599,6 +599,12 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
 	return (need_wa > 0);
 }
 
+static void
+cpu_enable_branch_predictor_hardening(const struct arm64_cpu_capabilities *cap)
+{
+	cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
 static const __maybe_unused struct midr_range tx2_family_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
 	MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),
@@ -890,9 +896,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	},
 #endif
 	{
+		.desc = "Branch predictor hardening",
 		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = check_branch_predictor,
+		.cpu_enable = cpu_enable_branch_predictor_hardening,
 	},
 #ifdef CONFIG_RANDOMIZE_BASE
 	{
-- 
2.28.0.681.g6f77f65b4e-goog


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  parent reply	other threads:[~2020-09-18 16:50 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-18 16:47 [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon
2020-09-18 16:47 ` [PATCH 01/19] arm64: Make use of ARCH_WORKAROUND_1 even when KVM is not enabled Will Deacon
2020-09-18 16:47 ` Will Deacon [this message]
2020-09-21 12:54   ` [PATCH 02/19] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs Sasha Levin
2020-09-18 16:47 ` [PATCH 03/19] arm64: Run ARCH_WORKAROUND_2 " Will Deacon
2020-09-18 17:13   ` Suzuki K Poulose
2020-09-18 16:47 ` [PATCH 04/19] arm64: Remove Spectre-related CONFIG_* options Will Deacon
2020-09-18 16:47 ` [PATCH 05/19] KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE Will Deacon
2020-09-18 16:47 ` [PATCH 06/19] KVM: arm64: Simplify install_bp_hardening_cb() Will Deacon
2020-09-18 16:47 ` [PATCH 07/19] arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2 Will Deacon
2020-09-18 16:47 ` [PATCH 08/19] arm64: Introduce separate file for spectre mitigations and reporting Will Deacon
2020-09-18 16:47 ` [PATCH 09/19] arm64: Rewrite Spectre-v2 mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 10/19] KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2 Will Deacon
2020-09-18 16:47 ` [PATCH 11/19] arm64: Group start_thread() functions together Will Deacon
2020-09-18 16:47 ` [PATCH 12/19] arm64: Treat SSBS as a non-strict system feature Will Deacon
2020-09-18 16:47 ` [PATCH 13/19] arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4 Will Deacon
2020-09-18 16:47 ` [PATCH 14/19] arm64: Move SSBD prctl() handler alongside other spectre mitigation code Will Deacon
2020-09-18 16:47 ` [PATCH 15/19] arm64: Rewrite Spectre-v4 " Will Deacon
2020-09-18 16:47 ` [PATCH 16/19] KVM: arm64: Simplify handling of ARCH_WORKAROUND_2 Will Deacon
2020-09-18 16:47 ` [PATCH 17/19] KVM: arm64: Get rid of kvm_arm_have_ssbd() Will Deacon
2020-09-18 16:47 ` [PATCH 18/19] KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state() Will Deacon
2020-09-18 16:47 ` [PATCH 19/19] arm64: Get rid of arm64_ssbd_state Will Deacon
2020-09-18 16:59 ` [PATCH 00/19] Fix and rewrite arm64 spectre mitigations Will Deacon

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