From: Andrea Arcangeli <aarcange@redhat.com>
Date: Sat, 17 Dec 2016 18:13:32 +0000 (+0100)
Subject: kvm: take srcu lock around kvm_steal_time_set_preempted()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=cc0d907c0907561f108b2f4d4da24e85f18d0ca5;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

kvm: take srcu lock around kvm_steal_time_set_preempted()

kvm_memslots() will be called by kvm_write_guest_offset_cached() so
take the srcu lock.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8ce1139a08b5..445c51b6cf6d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2844,6 +2844,7 @@ static void kvm_steal_time_set_preempted(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 {
+	int idx;
 	/*
 	 * Disable page faults because we're in atomic context here.
 	 * kvm_write_guest_offset_cached() would call might_fault()
@@ -2853,7 +2854,13 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 	 * paging.
 	 */
 	pagefault_disable();
+	/*
+	 * kvm_memslots() will be called by
+	 * kvm_write_guest_offset_cached() so take the srcu lock.
+	 */
+	idx = srcu_read_lock(&vcpu->kvm->srcu);
 	kvm_steal_time_set_preempted(vcpu);
+	srcu_read_unlock(&vcpu->kvm->srcu, idx);
 	pagefault_enable();
 	kvm_x86_ops->vcpu_put(vcpu);
 	kvm_put_guest_fpu(vcpu);