> From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
> Sent: Wednesday, May 15, 2019 1:35 AM
> To: Dexuan Cui <decui@microsoft.com>; lorenzo.pieralisi@arm.com; Michael
> Kelley <mikelley@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>
> Cc: stable@vger.kernel.org
> Subject: FAILED: patch "[PATCH] PCI: hv: Add hv_pci_remove_slots() when we
> unload the driver" failed to apply to 4.14-stable tree
> 
> 
> The patch below does not apply to the 4.14-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
> 
> thanks,
> 
> greg k-h
> 
> ------------------ original commit in Linus's tree ------------------
> 
> From 15becc2b56c6eda3d9bf5ae993bafd5661c1fad1 Mon Sep 17 00:00:00
> 2001
> From: Dexuan Cui <decui@microsoft.com>
> Date: Mon, 4 Mar 2019 21:34:48 +0000
> Subject: [PATCH] PCI: hv: Add hv_pci_remove_slots() when we unload the
> driver
> 
> When we unload the pci-hyperv host controller driver, the host does not
> send us a PCI_EJECT message.
> 
> In this case we also need to make sure the sysfs PCI slot directory is
> removed, otherwise a command on a slot file eg:
> 
> "cat /sys/bus/pci/slots/2/address"
> 
> will trigger a
> 
> "BUG: unable to handle kernel paging request"
> 
> and, if we unload/reload the driver several times we would end up with
> stale slot entries in PCI slot directories in /sys/bus/pci/slots/
> 
> root@localhost:~# ls -rtl  /sys/bus/pci/slots/
> total 0
> drwxr-xr-x 2 root root 0 Feb  7 10:49 2
> drwxr-xr-x 2 root root 0 Feb  7 10:49 2-1
> drwxr-xr-x 2 root root 0 Feb  7 10:51 2-2
> 
> Add the missing code to remove the PCI slot and fix the current
> behaviour.
> 
> Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot
> information")
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> [lorenzo.pieralisi@arm.com: reformatted the log]
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> Cc: stable@vger.kernel.org
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c
> b/drivers/pci/controller/pci-hyperv.c
> index 30f16b882746..b489412e3502 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1486,6 +1486,21 @@ static void hv_pci_assign_slots(struct
> hv_pcibus_device *hbus)
>  	}
>  }
> 
> +/*
> + * Remove entries in sysfs pci slot directory.
> + */
> +static void hv_pci_remove_slots(struct hv_pcibus_device *hbus)
> +{
> +	struct hv_pci_dev *hpdev;
> +
> +	list_for_each_entry(hpdev, &hbus->children, list_entry) {
> +		if (!hpdev->pci_slot)
> +			continue;
> +		pci_destroy_slot(hpdev->pci_slot);
> +		hpdev->pci_slot = NULL;
> +	}
> +}
> +
>  /**
>   * create_root_hv_pci_bus() - Expose a new root PCI bus
>   * @hbus:	Root PCI bus, as understood by this driver
> @@ -2680,6 +2695,7 @@ static int hv_pci_remove(struct hv_device *hdev)
>  		pci_lock_rescan_remove();
>  		pci_stop_root_bus(hbus->pci_bus);
>  		pci_remove_root_bus(hbus->pci_bus);
> +		hv_pci_remove_slots(hbus);
>  		pci_unlock_rescan_remove();
>  		hbus->state = hv_pcibus_removed;
>  	}

Hi,
I backported the patch for linux-4.14.y.

Please use the attached patch, which is [PATCH 2/3]

Thanks,
-- Dexuan