From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.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 14:14:03 +0200 [thread overview]
Message-ID: <8f8da1a9-47dd-57d6-a91f-de90de36ea22@suse.com> (raw)
In-Reply-To: <5807e645-7242-125a-03cf-c7c23f28dfa3@citrix.com>
On 16.10.2020 14:07, Andrew Cooper wrote:
> 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".
Oh, I see.
> 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.
Yeah, then probably not worth it.
Jan
prev parent reply other threads:[~2020-10-16 12:14 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
2020-10-16 12:14 ` Jan Beulich [this message]
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