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From: Christoffer Dall <cdall@linaro.org>
To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <marc.zyngier@arm.com>,
	Eric Auger <eric.auger@redhat.com>,
	Christoffer Dall <cdall@linaro.org>
Subject: [PATCH] KVM: arm/arm64: Hold slots_lock when unregisering kvm io bus devices
Date: Wed, 17 May 2017 21:18:06 +0200	[thread overview]
Message-ID: <20170517191806.3978-1-cdall@linaro.org> (raw)

We were not holding the kvm->slots_lock as required when calling
kvm_io_bus_unregister_dev() as required.

This only affects the error path, but still, let's do our due
dilligence.

Reported by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 9b0f681..201d5e2 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -614,15 +614,16 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
 	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, sgi_base,
 				      SZ_64K, &sgi_dev->dev);
-	mutex_unlock(&kvm->slots_lock);
 	if (ret) {
 		kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
 					  &rd_dev->dev);
-		return ret;
+		goto out;
 	}
 
 	vgic->vgic_redist_free_offset += 2 * SZ_64K;
-	return 0;
+out:
+	mutex_unlock(&kvm->slots_lock);
+	return ret;
 }
 
 static void vgic_unregister_redist_iodev(struct kvm_vcpu *vcpu)
@@ -647,10 +648,12 @@ static int vgic_register_all_redist_iodevs(struct kvm *kvm)
 
 	if (ret) {
 		/* The current c failed, so we start with the previous one. */
+		mutex_lock(&kvm->slots_lock);
 		for (c--; c >= 0; c--) {
 			vcpu = kvm_get_vcpu(kvm, c);
 			vgic_unregister_redist_iodev(vcpu);
 		}
+		mutex_unlock(&kvm->slots_lock);
 	}
 
 	return ret;
-- 
2.9.0

WARNING: multiple messages have this Message-ID (diff)
From: cdall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] KVM: arm/arm64: Hold slots_lock when unregisering kvm io bus devices
Date: Wed, 17 May 2017 21:18:06 +0200	[thread overview]
Message-ID: <20170517191806.3978-1-cdall@linaro.org> (raw)

We were not holding the kvm->slots_lock as required when calling
kvm_io_bus_unregister_dev() as required.

This only affects the error path, but still, let's do our due
dilligence.

Reported by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
 virt/kvm/arm/vgic/vgic-mmio-v3.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 9b0f681..201d5e2 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -614,15 +614,16 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
 	mutex_lock(&kvm->slots_lock);
 	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, sgi_base,
 				      SZ_64K, &sgi_dev->dev);
-	mutex_unlock(&kvm->slots_lock);
 	if (ret) {
 		kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
 					  &rd_dev->dev);
-		return ret;
+		goto out;
 	}
 
 	vgic->vgic_redist_free_offset += 2 * SZ_64K;
-	return 0;
+out:
+	mutex_unlock(&kvm->slots_lock);
+	return ret;
 }
 
 static void vgic_unregister_redist_iodev(struct kvm_vcpu *vcpu)
@@ -647,10 +648,12 @@ static int vgic_register_all_redist_iodevs(struct kvm *kvm)
 
 	if (ret) {
 		/* The current c failed, so we start with the previous one. */
+		mutex_lock(&kvm->slots_lock);
 		for (c--; c >= 0; c--) {
 			vcpu = kvm_get_vcpu(kvm, c);
 			vgic_unregister_redist_iodev(vcpu);
 		}
+		mutex_unlock(&kvm->slots_lock);
 	}
 
 	return ret;
-- 
2.9.0

             reply	other threads:[~2017-05-17 19:18 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-17 19:18 Christoffer Dall [this message]
2017-05-17 19:18 ` [PATCH] KVM: arm/arm64: Hold slots_lock when unregisering kvm io bus devices Christoffer Dall
2017-05-17 19:46 ` Auger Eric
2017-05-17 19:46   ` Auger Eric

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