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From: David Brazdil <dbrazdil@google.com>
To: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: android-kvm@google.com, linux-kernel@vger.kernel.org,
	kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE
Date: Tue, 21 Jul 2020 10:44:44 +0100	[thread overview]
Message-ID: <20200721094445.82184-2-dbrazdil@google.com> (raw)
In-Reply-To: <20200721094445.82184-1-dbrazdil@google.com>

If there are spare bits in non-VHE hyp VA, KVM unconditionally replaces them
with a random tag chosen at init. Disable this if the kernel is built without
RANDOMIZE_BASE to align with kernel behavior.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kvm/va_layout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index a4f48c1ac28c..e0404bcab019 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -48,7 +48,7 @@ __init void kvm_compute_layout(void)
 	va_mask = GENMASK_ULL(tag_lsb - 1, 0);
 	tag_val = hyp_va_msb;
 
-	if (tag_lsb != (vabits_actual - 1)) {
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) {
 		/* We have some free bits to insert a random tag. */
 		tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);
 	}
-- 
2.27.0

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kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: David Brazdil <dbrazdil@google.com>
To: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: android-kvm@google.com, linux-kernel@vger.kernel.org,
	David Brazdil <dbrazdil@google.com>,
	kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE
Date: Tue, 21 Jul 2020 10:44:44 +0100	[thread overview]
Message-ID: <20200721094445.82184-2-dbrazdil@google.com> (raw)
In-Reply-To: <20200721094445.82184-1-dbrazdil@google.com>

If there are spare bits in non-VHE hyp VA, KVM unconditionally replaces them
with a random tag chosen at init. Disable this if the kernel is built without
RANDOMIZE_BASE to align with kernel behavior.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kvm/va_layout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index a4f48c1ac28c..e0404bcab019 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -48,7 +48,7 @@ __init void kvm_compute_layout(void)
 	va_mask = GENMASK_ULL(tag_lsb - 1, 0);
 	tag_val = hyp_va_msb;
 
-	if (tag_lsb != (vabits_actual - 1)) {
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) {
 		/* We have some free bits to insert a random tag. */
 		tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);
 	}
-- 
2.27.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: David Brazdil <dbrazdil@google.com>
To: Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
	Catalin Marinas <catalin.marinas@arm.com>,
	James Morse <james.morse@arm.com>,
	Julien Thierry <julien.thierry.kdev@gmail.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, android-kvm@google.com,
	kernel-team@android.com, David Brazdil <dbrazdil@google.com>
Subject: [PATCH 1/2] KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE
Date: Tue, 21 Jul 2020 10:44:44 +0100	[thread overview]
Message-ID: <20200721094445.82184-2-dbrazdil@google.com> (raw)
In-Reply-To: <20200721094445.82184-1-dbrazdil@google.com>

If there are spare bits in non-VHE hyp VA, KVM unconditionally replaces them
with a random tag chosen at init. Disable this if the kernel is built without
RANDOMIZE_BASE to align with kernel behavior.

Signed-off-by: David Brazdil <dbrazdil@google.com>
---
 arch/arm64/kvm/va_layout.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index a4f48c1ac28c..e0404bcab019 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -48,7 +48,7 @@ __init void kvm_compute_layout(void)
 	va_mask = GENMASK_ULL(tag_lsb - 1, 0);
 	tag_val = hyp_va_msb;
 
-	if (tag_lsb != (vabits_actual - 1)) {
+	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && tag_lsb != (vabits_actual - 1)) {
 		/* We have some free bits to insert a random tag. */
 		tag_val |= get_random_long() & GENMASK_ULL(vabits_actual - 2, tag_lsb);
 	}
-- 
2.27.0


  reply	other threads:[~2020-07-21  9:45 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-21  9:44 [PATCH 0/2] Unify non-VHE ASLR features behind CONFIG_RANDOMIZE_BASE David Brazdil
2020-07-21  9:44 ` David Brazdil
2020-07-21  9:44 ` David Brazdil
2020-07-21  9:44 ` David Brazdil [this message]
2020-07-21  9:44   ` [PATCH 1/2] KVM: arm64: Make nVHE ASLR conditional on RANDOMIZE_BASE David Brazdil
2020-07-21  9:44   ` David Brazdil
2020-07-21  9:44 ` [PATCH 2/2] KVM: arm64: Substitute RANDOMIZE_BASE for HARDEN_EL2_VECTORS David Brazdil
2020-07-21  9:44   ` David Brazdil
2020-07-21  9:44   ` David Brazdil
2020-07-28 11:04 ` [PATCH 0/2] Unify non-VHE ASLR features behind CONFIG_RANDOMIZE_BASE Marc Zyngier
2020-07-28 11:04   ` Marc Zyngier
2020-07-28 11:04   ` Marc Zyngier

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