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authorXiao Guangrong2011-01-12 08:39:18 +0100
committerMarcelo Tosatti2011-03-17 17:08:26 +0100
commit63f42e023ea270fde65fa27f0ca766e13faa5608 (patch)
tree8cad1e7f55d9c8b6db2c7dc83153b90a79b4927f /arch/x86/kvm/x86.c
parentKVM: VMX: Avoid atomic operation in vmx_vcpu_run (diff)
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KVM: fix rcu usage warning in kvm_arch_vcpu_ioctl_set_sregs()
Fix: [ 1001.499596] =================================================== [ 1001.499599] [ INFO: suspicious rcu_dereference_check() usage. ] [ 1001.499601] --------------------------------------------------- [ 1001.499604] include/linux/kvm_host.h:301 invoked rcu_dereference_check() without protection! ...... [ 1001.499636] Pid: 6035, comm: qemu-system-x86 Not tainted 2.6.37-rc6+ #62 [ 1001.499638] Call Trace: [ 1001.499644] [] lockdep_rcu_dereference+0x9d/0xa5 [ 1001.499653] [] gfn_to_memslot+0x8d/0xc8 [kvm] [ 1001.499661] [] gfn_to_hva+0x16/0x3f [kvm] [ 1001.499669] [] kvm_read_guest_page+0x1e/0x5e [kvm] [ 1001.499681] [] kvm_read_guest_page_mmu+0x53/0x5e [kvm] [ 1001.499699] [] load_pdptrs+0x3f/0x9c [kvm] [ 1001.499705] [] ? vmx_set_cr0+0x507/0x517 [kvm_intel] [ 1001.499717] [] kvm_arch_vcpu_ioctl_set_sregs+0x1f3/0x3c0 [kvm] [ 1001.499727] [] kvm_vcpu_ioctl+0x6a5/0xbc5 [kvm] Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
-rw-r--r--arch/x86/kvm/x86.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bcc0efce85bf..4be89e1c0147 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5574,7 +5574,7 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
struct kvm_sregs *sregs)
{
int mmu_reset_needed = 0;
- int pending_vec, max_bits;
+ int pending_vec, max_bits, idx;
struct desc_ptr dt;
dt.size = sregs->idt.limit;
@@ -5603,10 +5603,13 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
kvm_x86_ops->set_cr4(vcpu, sregs->cr4);
if (sregs->cr4 & X86_CR4_OSXSAVE)
update_cpuid(vcpu);
+
+ idx = srcu_read_lock(&vcpu->kvm->srcu);
if (!is_long_mode(vcpu) && is_pae(vcpu)) {
load_pdptrs(vcpu, vcpu->arch.walk_mmu, kvm_read_cr3(vcpu));
mmu_reset_needed = 1;
}
+ srcu_read_unlock(&vcpu->kvm->srcu, idx);
if (mmu_reset_needed)
kvm_mmu_reset_context(vcpu);