linux-kernel - Re: [PATCH v10 05/16] s390/vfio-ap: implement in-use callback for vfio

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: <b6810e67-1e50-d62c-8c9e-57429e8a239f@linux.ibm.com>
Date:   Tue, 29 Sep 2020 10:00:01 -0400
From:   Tony Krowiak <akrowiak@...ux.ibm.com>
To:     Halil Pasic <pasic@...ux.ibm.com>
Cc:     linux-s390@...r.kernel.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org, freude@...ux.ibm.com, borntraeger@...ibm.com,
        cohuck@...hat.com, mjrosato@...ux.ibm.com,
        alex.williamson@...hat.com, kwankhede@...dia.com,
        fiuczy@...ux.ibm.com, frankja@...ux.ibm.com, david@...hat.com,
        imbrenda@...ux.ibm.com, hca@...ux.ibm.com, gor@...ux.ibm.com
Subject: Re: [PATCH v10 05/16] s390/vfio-ap: implement in-use callback for
 vfio_ap driver



On 9/25/20 5:29 AM, Halil Pasic wrote:
> On Fri, 21 Aug 2020 15:56:05 -0400
> Tony Krowiak <akrowiak@...ux.ibm.com> wrote:
>
>> +
>> +bool vfio_ap_mdev_resource_in_use(unsigned long *apm, unsigned long *aqm)
>> +{
>> +	bool in_use;
>> +
>> +	mutex_lock(&matrix_dev->lock);
>> +	in_use = !!vfio_ap_mdev_verify_no_sharing(NULL, apm, aqm);
>> +	mutex_unlock(&matrix_dev->lock);
> See also my comment for patch 4. AFAIU as soon as you release the lock
> the in_use may become outdated in any moment.

See my response to your comment for patch 4.

>
>> +
>> +	return in_use;
>> +}