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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 03/19] arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs
Date: Fri, 18 Sep 2020 17:47:13 +0100	[thread overview]
Message-ID: <20200918164729.31994-4-will@kernel.org> (raw)
In-Reply-To: <20200918164729.31994-1-will@kernel.org>

From: Marc Zyngier <maz@kernel.org>

Commit 606f8e7b27bf ("arm64: capabilities: Use linear array for
detection and verification") changed the way we deal with per-CPU errata
by only calling the .matches() callback until one CPU is found to be
affected. At this point, .matches() stop being called, and .cpu_enable()
will be called on all CPUs.

This breaks the ARCH_WORKAROUND_2 handling, as only a single CPU will be
mitigated.

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

Fixes: 606f8e7b27bf ("arm64: capabilities: Use linear array for detection and verification")
Cc: <stable@vger.kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/kernel/cpu_errata.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3fe64bf5a58d..abfef5f3b5fd 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -457,6 +457,12 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 	return required;
 }
 
+static void cpu_enable_ssbd_mitigation(const struct arm64_cpu_capabilities *cap)
+{
+	if (ssbd_state != ARM64_SSBD_FORCE_DISABLE)
+		cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
 /* known invulnerable cores */
 static const struct midr_range arm64_ssb_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),
@@ -914,6 +920,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.capability = ARM64_SSBD,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = has_ssbd_mitigation,
+		.cpu_enable = cpu_enable_ssbd_mitigation,
 		.midr_range_list = arm64_ssb_cpus,
 	},
 #ifdef CONFIG_ARM64_ERRATUM_1418040
-- 
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 ` [PATCH 02/19] arm64: Run ARCH_WORKAROUND_1 enabling code on all CPUs Will Deacon
2020-09-21 12:54   ` Sasha Levin
2020-09-18 16:47 ` Will Deacon [this message]
2020-09-18 17:13   ` [PATCH 03/19] arm64: Run ARCH_WORKAROUND_2 " 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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