From: Will Deacon <will@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
contact@xogium.me, linux-kernel@vger.kernel.org,
stable@vger.kernel.org, Russell King <linux@armlinux.org.uk>,
Ingo Molnar <mingo@redhat.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] panic: Ensure preemption is disabled during panic()
Date: Thu, 3 Oct 2019 21:53:04 +0100 [thread overview]
Message-ID: <20191003205303.ge324uspaaocfxq4@willie-the-truck> (raw)
In-Reply-To: <20191002144558.87531ea9f68b535453fedd3e@linux-foundation.org>
Hi Andrew,
Thanks for having a look.
On Wed, Oct 02, 2019 at 02:45:58PM -0700, Andrew Morton wrote:
> On Wed, 2 Oct 2019 13:35:38 +0100 Will Deacon <will@kernel.org> wrote:
> > Disable preemption in 'panic()' before re-enabling interrupts.
> >
> > ...
> >
> > --- a/kernel/panic.c
> > +++ b/kernel/panic.c
> > @@ -180,6 +180,7 @@ void panic(const char *fmt, ...)
> > * after setting panic_cpu) from invoking panic() again.
> > */
> > local_irq_disable();
> > + preempt_disable_notrace();
> >
> > /*
> > * It's possible to come here directly from a panic-assertion and
>
> We still do a lot of stuff (kexec, kgdb, etc) after this
> preempt_disable() and I worry that something in there will now trigger
> a might_sleep() warning as a result?
Given that interrupts are already disabled at this point, I don't think
we'll get any additional warnings here by disabling preemption as well.
Will
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prev parent reply other threads:[~2019-10-03 20:53 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-02 12:35 [PATCH] panic: Ensure preemption is disabled during panic() Will Deacon
2019-10-02 20:58 ` Kees Cook
2019-10-03 20:56 ` Will Deacon
2019-10-04 9:11 ` Petr Mladek
2019-10-04 9:29 ` Russell King - ARM Linux admin
2019-10-04 10:49 ` Will Deacon
2019-10-04 11:15 ` Petr Mladek
2019-10-04 13:51 ` Feng Tang
2019-10-07 8:02 ` Jiri Kosina
2019-10-02 21:45 ` Andrew Morton
2019-10-03 20:53 ` Will Deacon [this message]
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