From: Peter Zijlstra <peterz@infradead.org>
To: Lai Jiangshan <jiangshanlai+lkml@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Andy Lutomirski <luto@amacapital.net>,
LKML <linux-kernel@vger.kernel.org>, X86 ML <x86@kernel.org>,
Lai Jiangshan <laijs@linux.alibaba.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
andrew.cooper3@citrix.com, daniel.thompson@linaro.org
Subject: Re: [PATCH 0/6] x86/entry: disallow #DB more
Date: Fri, 29 May 2020 10:00:36 +0200 [thread overview]
Message-ID: <20200529080036.GH706495@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAJhGHyAZVVyQx_3gEtcxF_NaOov4=oR9kN4qO4FAR==hTNa+4Q@mail.gmail.com>
On Fri, May 29, 2020 at 07:05:54AM +0800, Lai Jiangshan wrote:
> On Fri, May 29, 2020 at 6:48 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > On Fri, May 29, 2020 at 06:42:46AM +0800, Lai Jiangshan wrote:
> > > On Fri, May 29, 2020 at 4:25 AM Peter Zijlstra <peterz@infradead.org> wrote:
> > > >
> > > > These patches disallow #DB during NMI/#MC and allow removing a lot of fugly code.
> > > >
> > >
> > > Hello
> > >
> > > Will #DB be allowed in #DF?
> >
> > No, that whole thing is noinstr.
>
> But it calls many functions, including die(), panic().
> We don't want #DB to interfere how it die() and panic().
> Since it is in fragile #DF, the #DB may mess it up and
> make #DF fails to report and die.
The only recoverable #DF is the ESPFIX shit. If we do not take that,
we're on the way to panic(), I really can't be arsed if you crash the
box before that, we're going to die anyway.
prev parent reply other threads:[~2020-05-29 8:00 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 20:19 Peter Zijlstra
2020-05-28 20:19 ` [PATCH 1/6] x86/entry: Introduce local_db_{save,restore}() Peter Zijlstra
2020-05-28 20:52 ` Andrew Cooper
2020-05-28 21:15 ` Peter Zijlstra
2020-05-28 21:33 ` Peter Zijlstra
2020-05-29 17:28 ` Andy Lutomirski
2020-05-29 19:02 ` Peter Zijlstra
2020-05-28 21:36 ` Andrew Cooper
2020-05-28 20:19 ` [PATCH 2/6] x86/entry, nmi: Disable #DB Peter Zijlstra
2020-05-28 20:19 ` [PATCH 3/6] x86/entry, mce: Disallow #DB during #MC Peter Zijlstra
2020-05-28 20:19 ` [PATCH 4/6] x86/entry: Optimize local_db_save() for virt Peter Zijlstra
2020-05-29 17:24 ` Sean Christopherson
2020-05-28 20:19 ` [PATCH 5/6] x86/entry: Remove debug IDT frobbing Peter Zijlstra
2020-05-28 20:19 ` [RFC][PATCH 6/6] x86/entry: Remove DBn stacks Peter Zijlstra
2020-05-28 22:35 ` Lai Jiangshan
2020-05-28 22:37 ` Peter Zijlstra
2020-05-28 22:42 ` [PATCH 0/6] x86/entry: disallow #DB more Lai Jiangshan
2020-05-28 22:48 ` Peter Zijlstra
2020-05-28 23:05 ` Lai Jiangshan
2020-05-29 8:00 ` Peter Zijlstra [this message]
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