linux-kernel - Re: [PATCH] KVM: Deal with nested sleeps in kvm_vcpu

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 for Android: free password hash cracker in your pocket

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

Message-ID: <4405c412-f9df-ed43-8050-4d4a90d5dcc5@redhat.com>
Date:   Fri, 2 Dec 2022 19:27:38 +0100
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Space Meyer <spm@...gle.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        kpsingh@...nel.org
Subject: Re: [PATCH] KVM: Deal with nested sleeps in kvm_vcpu_block()

On 12/2/22 16:52, Space Meyer wrote:
>> Also, this does not work I think, because there is
>> add_wait_queue()/remove_wait_queue() pair.  Adding it is not easy
>> because KVM is using a struct rcuwait here instead of a wait_queue_t.
> Ah, sorry. I really was a bit quick on this one. I agree nothing would ever call
> woken_wake_function, hence my patch doesn't make sense. Looking at the rcuwait
> code I don't see something similar to wait_woken.
> 
> Do you see some other way we could avoid the pattern susceptible to the nested
> sleeping problem?

No, I think we should just treat them as bugs and fix them.

Paolo