From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [BUG] kvm: dereference srcu-protected pointer without srcu_read_lock() held Date: Wed, 21 Apr 2010 11:17:22 +0300 Message-ID: <4BCEB492.1020902@redhat.com> References: <4BCC2543.7050104@cn.fujitsu.com> <4BCC295D.1040807@cn.fujitsu.com> <4BCC2B9D.8050008@redhat.com> <20100420014504.GB17981@amt.cnet> <4BCD49C9.8090604@cn.fujitsu.com> <20100420222108.GM2628@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Lai Jiangshan , Marcelo Tosatti , LKML , kvm@vger.kernel.org To: paulmck@linux.vnet.ibm.com Return-path: Received: from mx1.redhat.com ([209.132.183.28]:44846 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752326Ab0DUIR2 (ORCPT ); Wed, 21 Apr 2010 04:17:28 -0400 In-Reply-To: <20100420222108.GM2628@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 04/21/2010 01:21 AM, Paul E. McKenney wrote: > >> Subject: [PATCH] kvm: add missing srcu_read_lock() >> >> I got this dmesg due to srcu_read_lock() is missing in >> kvm_mmu_notifier_release(). >> >> =================================================== >> [ INFO: suspicious rcu_dereference_check() usage. ] >> --------------------------------------------------- >> arch/x86/kvm/x86.h:72 invoked rcu_dereference_check() without protection! >> >> other info that might help us debug this: >> >> >> rcu_scheduler_active = 1, debug_locks = 0 >> 2 locks held by qemu-system-x86/3100: >> #0: (rcu_read_lock){.+.+..}, at: [] __mmu_notifier_release+0x38/0xdf >> #1: (&(&kvm->mmu_lock)->rlock){+.+...}, at: [] kvm_mmu_zap_all+0x21/0x5e [kvm] >> >> stack backtrace: >> Pid: 3100, comm: qemu-system-x86 Not tainted 2.6.34-rc3-22949-gbc8a97a-dirty #2 >> Call Trace: >> [] lockdep_rcu_dereference+0xaa/0xb3 >> [] unalias_gfn+0x56/0xab [kvm] >> [] gfn_to_memslot+0x16/0x25 [kvm] >> [] gfn_to_rmap+0x17/0x6e [kvm] >> [] rmap_remove+0xa0/0x19d [kvm] >> [] kvm_mmu_zap_page+0x109/0x34d [kvm] >> [] kvm_mmu_zap_all+0x35/0x5e [kvm] >> [] kvm_arch_flush_shadow+0x16/0x22 [kvm] >> [] kvm_mmu_notifier_release+0x15/0x17 [kvm] >> [] __mmu_notifier_release+0x88/0xdf >> [] ? __mmu_notifier_release+0x38/0xdf >> [] ? exit_mm+0xe0/0x115 >> [] exit_mmap+0x2c/0x17e >> [] mmput+0x2d/0xd4 >> [] exit_mm+0x108/0x115 >> [...] >> > Queued, thank you, Lai! > Paul, I'd like to merge this via the kvm tree. -- error compiling committee.c: too many arguments to function