linux-kernel - Re: [PATCH v2] kvm: Replace vcpu->swait with rcuwait

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: <22800f1b-3bdb-15b4-7592-93a7b244b45a@redhat.com>
Date:   Mon, 20 Apr 2020 19:25:28 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Marc Zyngier <maz@...nel.org>, Davidlohr Bueso <dave@...olabs.net>
Cc:     tglx@...utronix.de, kvm@...r.kernel.org,
        Davidlohr Bueso <dbueso@...e.de>, peterz@...radead.org,
        torvalds@...ux-foundation.org, bigeasy@...utronix.de,
        linux-kernel@...r.kernel.org, rostedt@...dmis.org,
        linux-mips@...r.kernel.org, Paul Mackerras <paulus@...abs.org>,
        joel@...lfernandes.org, will@...nel.org,
        kvmarm@...ts.cs.columbia.edu
Subject: Re: [PATCH v2] kvm: Replace vcpu->swait with rcuwait

On 20/04/20 19:12, Marc Zyngier wrote:
>>
>>
>> -    trace_kvm_vcpu_wakeup(block_ns, waited, vcpu_valid_wakeup(vcpu));
>> +    trace_kvm_vcpu_wakeup(block_ns, !block_check,
>> vcpu_valid_wakeup(vcpu));
> 
> This looks like a change in the semantics of the tracepoint. Before
> this change, 'waited' would have been true if the vcpu waited at all.
> Here, you'd have false if it has been interrupted by a signal, even
> if the vcpu has waited for a period of time.
True, good catch.  Perhaps add macros prepare_to_rcuwait and
finish_rcuwait?

Paolo