From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sean Christopherson Date: Wed, 18 Dec 2019 21:55:29 +0000 Subject: [PATCH v2 44/45] KVM: Move putting of vcpu->pid to kvm_vcpu_destroy() Message-Id: <20191218215530.2280-45-sean.j.christopherson@intel.com> List-Id: References: <20191218215530.2280-1-sean.j.christopherson@intel.com> In-Reply-To: <20191218215530.2280-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marc Zyngier , James Hogan , Paul Mackerras , Christian Borntraeger , Janosch Frank , Paolo Bonzini Cc: James Morse , Julien Thierry , Suzuki K Poulose , David Hildenbrand , Cornelia Huck , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kurz Move the putting of vcpu->pid to kvm_vcpu_destroy(). vcpu->pid is guaranteed to be NULL when kvm_vcpu_uninit() is called in the error path of kvm_vm_ioctl_create_vcpu(), e.g. it is explicitly nullified by kvm_vcpu_init() and is only changed by KVM_RUN. No functional change intended. Acked-by: Christoffer Dall Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 21533a472ead..6912d81ca32d 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -352,12 +352,6 @@ static int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id) static void kvm_vcpu_uninit(struct kvm_vcpu *vcpu) { - /* - * no need for rcu_read_lock as VCPU_RUN is the only place that - * will change the vcpu->pid pointer and on uninit all file - * descriptors are already gone. - */ - put_pid(rcu_dereference_protected(vcpu->pid, 1)); free_page((unsigned long)vcpu->run); } @@ -365,6 +359,13 @@ void kvm_vcpu_destroy(struct kvm_vcpu *vcpu) { kvm_arch_vcpu_destroy(vcpu); + /* + * No need for rcu_read_lock as VCPU_RUN is the only place that changes + * the vcpu->pid pointer, and at destruction time all file descriptors + * are already gone. + */ + put_pid(rcu_dereference_protected(vcpu->pid, 1)); + kvm_vcpu_uninit(vcpu); kmem_cache_free(kvm_vcpu_cache, vcpu); } -- 2.24.1