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From: Borislav Petkov <bp@alien8.de>
To: Matt Fleming <matt@codeblueprint.co.uk>
Cc: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Kweh Hock Leong <hock.leong.kweh@intel.com>,
	"Bryan O'Donoghue" <pure.logic@nexus-software.ie>,
	joeyli <jlee@suse.com>
Subject: Re: [PATCH] efi/capsule: Make efi_capsule_pending() lockless
Date: Wed, 4 May 2016 11:30:31 +0200	[thread overview]
Message-ID: <20160504093031.GA4074@pd.tnic> (raw)
In-Reply-To: <20160503141201.GW2839@codeblueprint.co.uk>

On Tue, May 03, 2016 at 03:12:01PM +0100, Matt Fleming wrote:
> We can find ourselves in the reboot code even if the admin has not
> executed the reboot command. The trace above shows we entered because
> the kernel panic()'d and it was booted with panic=-1.

I knew you were gonna say something like that...

> Right. You could find yourself in this situation if you're in the
> middle of a capsule update and the box panics and reboots. Like you
> said, there's really not much you can do there to ensure the update
> completes. Your best option is to just not block and hang the machine.

Hmmm, so panic() does bust_spinlocks() and efi_capsule_pending() could
look at oops_in_progress which is set by bust_spinlocks() and that would
probably solve the panic case but maybe the normal reboot case would
still hang...

> Note that in the panic() -> emergency_restart() case the reboot
> notifiers are not called at all.

And then there's that.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.

  reply	other threads:[~2016-05-04  9:30 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-30 22:13 [PATCH] efi/capsule: Make efi_capsule_pending() lockless Matt Fleming
2016-05-03  9:02 ` Borislav Petkov
2016-05-03 14:12   ` Matt Fleming
2016-05-04  9:30     ` Borislav Petkov [this message]
2016-05-04 11:46       ` Matt Fleming
2016-05-04 12:20         ` Borislav Petkov
2016-05-04 13:36           ` Matt Fleming
2016-05-04 14:35           ` Matt Fleming
2016-05-05 14:27             ` Kweh, Hock Leong
2016-05-05 14:36               ` Matt Fleming
2016-05-05 14:55                 ` One Thousand Gnomes
2016-05-06  1:32               ` Bryan O'Donoghue

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