From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
"Julien Grall" <julien@xen.org>
Subject: Re: [PATCH] x86/traps: 'Fix' safety of read_registers() in #DF path
Date: Fri, 16 Oct 2020 13:07:39 +0100 [thread overview]
Message-ID: <5807e645-7242-125a-03cf-c7c23f28dfa3@citrix.com> (raw)
In-Reply-To: <7f3272d5-8ec7-26ec-33ec-2281539920e2@suse.com>
On 16/10/2020 12:55, Jan Beulich wrote:
> On 16.10.2020 13:24, Andrew Cooper wrote:
>> On a tangent, what are your views WRT backport beyond 4.14?
>>
>> Back then, it was #DB which was adjacent to the guard frame (which was
>> not present), but it doesn't use show_registers() by default, so I think
>> the problem is mostly hidden.
> I wasn't fully decided yet, but as long as it applies reasonably
> cleanly I think I'm leaning towards also putting it on 4.13.
> 4.12 closes anyway once 4.12.4 is out, and I don't think I want
> to pick up not-really-urgent changes for putting there beyond
> the few ones that I already have (and that I mean to put in
> alongside the XSA fixes on Tuesday); I could be talked into it,
> though.
The question I was asking was really "should I try and make an
equivalent fix for 4.13 and older".
While the base premise of the fix would be the same, the logic in
load_system_tables() is different, and the commit message is completely
wrong.
I only encountered this problem with added instrumentation in the #DB
handler, which is why I'm questioning the utility of going to this effort.
~Andrew
next prev parent reply other threads:[~2020-10-16 12:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 13:49 [PATCH] x86/traps: 'Fix' safety of read_registers() in #DF path Andrew Cooper
2020-10-13 15:51 ` Jan Beulich
2020-10-14 18:00 ` Andrew Cooper
2020-10-15 7:27 ` Jan Beulich
2020-10-16 10:58 ` Andrew Cooper
2020-10-16 11:03 ` Jan Beulich
2020-10-16 11:24 ` Andrew Cooper
2020-10-16 11:55 ` Jan Beulich
2020-10-16 12:07 ` Andrew Cooper [this message]
2020-10-16 12:14 ` Jan Beulich
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