linux-kernel - RE: [PATCH 3/3] drivers: Add visorbus to the drivers/virt directory

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] [day] [month] [year] [list]

Date:   Sun, 11 Sep 2016 14:46:19 +0000
From:   "Sell, Timothy C" <Timothy.Sell@...sys.com>
To:     'Greg KH' <gregkh@...uxfoundation.org>
CC:     "Kershner, David A" <David.Kershner@...sys.com>,
        "dzickus@...hat.com" <dzickus@...hat.com>,
        "prarit@...hat.com" <prarit@...hat.com>,
        "driverdev-devel@...uxdriverproject.org" 
        <driverdev-devel@...uxdriverproject.org>,
        *S-Par-Maintainer <SParMaintainer@...sys.com>,
        "janani.rvchndrn@...il.com" <janani.rvchndrn@...il.com>,
        "corbet@....net" <corbet@....net>,
        "jes.sorensen@...hat.com" <jes.sorensen@...hat.com>,
        "Binder, David Anthony" <David.Binder@...sys.com>,
        "hofrat@...dl.org" <hofrat@...dl.org>,
        "dan.j.williams@...el.com" <dan.j.williams@...el.com>,
        "nhorman@...hat.com" <nhorman@...hat.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "hpa@...or.com" <hpa@...or.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "sudipm.mukherjee@...il.com" <sudipm.mukherjee@...il.com>,
        "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>
Subject: RE: [PATCH 3/3] drivers: Add visorbus to the drivers/virt directory

On Sun, 11 Sep 2016 02:17:10 -0700, Greg KH wrote:
> On Tue, Aug 30, 2016 at 04:29:07PM +0000, Sell, Timothy C wrote:
>> E.g., so even though no obvious error-recovery occurs above in-response to
>> kzalloc() failures, the fact that -CONTROLVM_RESP_ERROR_KMALLOC_FAILED is
>> provided to bus_epilog() is in-fact sufficient to report the error.
>> 
>> Is this making sense?

> Yes, it does a bit more, but, you should make this more explicit.

Agreed.  I believe your recommendation below is the right way to accomplish
this.

>> Can you suggest how we might modify our code to make this error-handling /
>> recovery strategy clearer?

> Have a real error be returned by the function, and then have the caller
> handle the error by propagating it back to the firmware through the
> message.  That might save you a lot of boiler-plate error handling logic
> as well, right?

> That will make it obvious that if an error happens, it is caught, and
> how it is handled correctly.

> Does that help?

Yes it does.  We'll work out a scheme where all of these functions in fact
return their status code to a common dispatch function, whose job it will
be to send this status code back to the firmware.  This might even let us
consolidate/eliminate a few of the other functions we have that deal with
various ways of formatting firmware responses, by encompassing their logic
into this common dispatch function.

That strategy should make it clearer and more explicit as to what is
going on here.

Thanks!

Tim Sell