From 9fc77441e5e1bf80b794cc546d2243ee9f4afb75 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Sun, 16 Sep 2012 11:50:30 +0300 Subject: KVM: make processes waiting on vcpu mutex killable vcpu mutex can be held for unlimited time so taking it with mutex_lock on an ioctl is wrong: one process could be passed a vcpu fd and call this ioctl on the vcpu used by another process, it will then be unkillable until the owner exits. Call mutex_lock_killable instead and return status. Note: mutex_lock_interruptible would be even nicer, but I am not sure all users are prepared to handle EINTR from these ioctls. They might misinterpret it as an error. Cleanup paths expect a vcpu that can't be used by any userspace so this will always succeed - catch bugs by calling BUG_ON. Catch callers that don't check return state by adding __must_check. Signed-off-by: Michael S. Tsirkin Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/x86.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'arch/x86/kvm') diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c4d451ed157..19047eafa38 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6016,7 +6016,9 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) int r; vcpu->arch.mtrr_state.have_fixed = 1; - vcpu_load(vcpu); + r = vcpu_load(vcpu); + if (r) + return r; r = kvm_arch_vcpu_reset(vcpu); if (r == 0) r = kvm_mmu_setup(vcpu); @@ -6027,9 +6029,11 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { + int r; vcpu->arch.apf.msr_val = 0; - vcpu_load(vcpu); + r = vcpu_load(vcpu); + BUG_ON(r); kvm_mmu_unload(vcpu); vcpu_put(vcpu); @@ -6275,7 +6279,9 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) static void kvm_unload_vcpu_mmu(struct kvm_vcpu *vcpu) { - vcpu_load(vcpu); + int r; + r = vcpu_load(vcpu); + BUG_ON(r); kvm_mmu_unload(vcpu); vcpu_put(vcpu); } -- cgit v1.2.3