linux-kernel - Re: [PATCH 2/2] KVM MMU: fix race in invlpg code

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4BE1686D.9000902@cn.fujitsu.com>
Date:	Wed, 05 May 2010 20:45:33 +0800
From:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	KVM list <kvm@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] KVM MMU: fix race in invlpg code



Avi Kivity wrote:

>>       spin_lock(&vcpu->kvm->mmu_lock);
>> +    index = kvm_page_table_hashfn(gfn);
>> +    bucket =&vcpu->kvm->arch.mmu_page_hash[index];
>> +    hlist_for_each_entry_safe(s, node, tmp, bucket, hash_link)
>> +        if (s == sp) {
>> +            if (s->gfn == gfn&&  s->role.word == role.word)
>> +                live = true;
>> +            break;
>> +        }
>> +
>> +    if (!live)
>> +        goto unlock_exit;
>> +
>>    
> 
> Did you try the root_count method?  I think it's cleaner.

Avi, Thanks for your idea.

I have considered this method, but i'm not sure when it's the good time
to real free this page, and i think we also need a way to synchronize the
real free path and this path. Do you have any comment for it :-(

Xiao
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/