From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: [PATCH] KVM: arm/arm64: Stop leaking vcpu pid references Date: Wed, 8 Jun 2016 17:24:45 +0100 Message-ID: <1465403085-2358-1-git-send-email-james.morse@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 7DF8749D6F for ; Wed, 8 Jun 2016 12:22:40 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Nsdw2SI4NFuD for ; Wed, 8 Jun 2016 12:22:39 -0400 (EDT) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 5453349D6A for ; Wed, 8 Jun 2016 12:22:39 -0400 (EDT) List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier , kvmarm@lists.cs.columbia.edu List-Id: kvmarm@lists.cs.columbia.edu kvm provides kvm_vcpu_uninit(), which amongst other things, releases the last reference to the struct pid of the task that was last running the vcpu. On arm64 built with CONFIG_DEBUG_KMEMLEAK, starting a guest with kvmtool, then killing it with SIGKILL results (after some considerable time) in: > cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff80007d5ea080 (size 128): > comm "lkvm", pid 2025, jiffies 4294942645 (age 1107.776s) > hex dump (first 32 bytes): > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [] create_object+0xfc/0x278 > [] kmemleak_alloc+0x34/0x70 > [] kmem_cache_alloc+0x16c/0x1d8 > [] alloc_pid+0x34/0x4d0 > [] copy_process.isra.6+0x79c/0x1338 > [] _do_fork+0x74/0x320 > [] SyS_clone+0x18/0x20 > [] el0_svc_naked+0x24/0x28 > [] 0xffffffffffffffff On x86 kvm_vcpu_uninit() is called on the path from kvm_arch_destroy_vm(), on arm no equivalent call is made. Add the call to kvm_arch_vcpu_free(). Signed-off-by: James Morse Fixes: 749cf76c5a36 ("KVM: ARM: Initial skeleton to compile KVM support") Cc: # 3.10+ Acked-by: Marc Zyngier --- arch/arm/kvm/arm.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 893941ec98dc..f1bde7c4e736 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -263,6 +263,7 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu) kvm_timer_vcpu_terminate(vcpu); kvm_vgic_vcpu_destroy(vcpu); kvm_pmu_vcpu_destroy(vcpu); + kvm_vcpu_uninit(vcpu); kmem_cache_free(kvm_vcpu_cache, vcpu); } -- 2.8.0.rc3