linux-kernel - Re: [PATCH v3] xen/evtchn: Introduce new IOCTL to bind static evtchn

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: <9a917f42-1a22-0c75-459e-db30c17dbe78@epam.com>
Date:   Tue, 18 Jul 2023 14:50:09 +0000
From:   Oleksandr Tyshchenko <Oleksandr_Tyshchenko@...m.com>
To:     Rahul Singh <rahul.singh@....com>,
        "xen-devel@...ts.xenproject.org" <xen-devel@...ts.xenproject.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:     Juergen Gross <jgross@...e.com>,
        Stefano Stabellini <sstabellini@...nel.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        David Woodhouse <dwmw@...zon.co.uk>,
        Jane Malalane <jane.malalane@...rix.com>
Subject: Re: [PATCH v3] xen/evtchn: Introduce new IOCTL to bind static evtchn



On 18.07.23 14:31, Rahul Singh wrote:


Hello Rahul


> Xen 4.17 supports the creation of static evtchns. To allow user space
> application to bind static evtchns introduce new ioctl
> "IOCTL_EVTCHN_BIND_STATIC". Existing IOCTL doing more than binding
> that’s why we need to introduce the new IOCTL to only bind the static
> event channels.
> 
> Static evtchns to be available for use during the lifetime of the
> guest. When the application exits, __unbind_from_irq() ends up being
> called from release() file operations because of that static evtchns
> are getting closed. To avoid closing the static event channel, add the
> new bool variable "is_static" in "struct irq_info" to mark the event
> channel static when creating the event channel to avoid closing the
> static evtchn.
> 
> Also, take this opportunity to remove the open-coded version of the
> evtchn close in drivers/xen/evtchn.c file and use xen_evtchn_close().
> 
> Signed-off-by: Rahul Singh <rahul.singh@....com>
> ---
> v3:
>   * Remove the open-coded version of the evtchn close in drivers/xen/evtchn.c

Thanks!

Looks like there is one unmentioned change in change-log since v2:
* Make sure that evtchn hasn't been added yet before binding it in 
evtchn_ioctl():case IOCTL_EVTCHN_BIND_STATIC

Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>

> v2:
>   * Use bool in place u8 to define is_static variable.
>   * Avoid closing the static evtchns in error path.
> ---

[snip]