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Date: Tue, 21 Nov 2023 12:40:08 -0600
From: Bjorn Helgaas <helgaas@kernel.org>
To: Daniel Stodden <dns@arista.com>
Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com>,
	Logan Gunthorpe <logang@deltatee.com>, linux-pci@vger.kernel.org
Subject: Re: [PATCH v3] switchtec: Fix stdev_release crash after suprise
 device loss.
Message-ID: <20231121184008.GA249064@bhelgaas>
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In-Reply-To: <BDEC1856-B689-433B-9227-4CCA5969C2F2@arista.com>

On Tue, Nov 21, 2023 at 10:23:51AM -0800, Daniel Stodden wrote:
> > On Nov 20, 2023, at 1:25 PM, Bjorn Helgaas <helgaas@kernel.org> wrote:
> > On Mon, Nov 13, 2023 at 01:21:50PM -0800, Daniel Stodden wrote:
> >> A pci device hot removal may occur while stdev->cdev is held open. The
> >> call to stdev_release is then delivered during close or exit, at a
> >> point way past switchtec_pci_remove. Otherwise the last ref would
> >> vanish with the trailing put_device, just before return.
> >> 
> >> At that later point in time, the device layer has alreay removed
> >> stdev->mrpc_mmio map. Also, the stdev->pdev reference was not a
> > 
> > I guess this should say the "stdev->mmio_mrpc" (not "mrpc_mmio")?
> 
> Eww. My fault. Could you still correct that?

Yep, I speculatively made that change already, so thanks for
confirming it :)

https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git/commit/?h=switchtec&id=f9724598e29d

Bjorn