RE: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

Ok, I will resend.

> -Original Message-
> From: Greg KH [mailto:g...@kroah.com]
> Sent: Saturday, February 25, 2017 12:02 AM
> To: Long Li <lon...@microsoft.com>
> Cc: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang
> <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>;
> de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; linux-
> p...@vger.kernel.org
> Subject: Re: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> On Fri, Feb 24, 2017 at 09:49:17PM +, Long Li wrote:
> > A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Properly wrap your changelog comments at 72 columns like your editor is
> telling you to do...

RE: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

Ok, I will resend.

> -Original Message-
> From: Greg KH [mailto:g...@kroah.com]
> Sent: Saturday, February 25, 2017 12:02 AM
> To: Long Li 
> Cc: KY Srinivasan ; Haiyang Zhang
> ; Bjorn Helgaas ;
> de...@linuxdriverproject.org; linux-kernel@vger.kernel.org; linux-
> p...@vger.kernel.org
> Subject: Re: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> On Fri, Feb 24, 2017 at 09:49:17PM +, Long Li wrote:
> > A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Properly wrap your changelog comments at 72 columns like your editor is
> telling you to do...

Re: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Greg KH]

On Fri, Feb 24, 2017 at 09:49:17PM +, Long Li wrote:
> A PCI_EJECT message can arrive at the same time we are calling 
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS 
> message or in create_root_hv_pci_bus(), in this case we could potentailly 
> modify the bus from multiple places. Properly lock the bus access.

Properly wrap your changelog comments at 72 columns like your editor is
telling you to do...

Re: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Greg KH]

On Fri, Feb 24, 2017 at 09:49:17PM +, Long Li wrote:
> A PCI_EJECT message can arrive at the same time we are calling 
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS 
> message or in create_root_hv_pci_bus(), in this case we could potentailly 
> modify the bus from multiple places. Properly lock the bus access.

Properly wrap your changelog comments at 72 columns like your editor is
telling you to do...

[Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

A PCI_EJECT message can arrive at the same time we are calling 
pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS message 
or in create_root_hv_pci_bus(), in this case we could potentailly modify the 
bus from multiple places. Properly lock the bus access.

Thanks Dexuan Cui  for pointing out the race condition in 
create_root_hv_pci_bus().

Signed-off-by: Long Li 
Reported-by: Xiaofeng Wang 
Acked-by: K. Y. Srinivasan 
---
 drivers/pci/host/pci-hyperv.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 4a37598..33c75c9 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct 
hv_pcibus_device *hbus)
hbus->pci_bus->msi = >msi_chip;
hbus->pci_bus->msi->dev = >hdev->device;
 
+   pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_bus_assign_resources(hbus->pci_bus);
pci_bus_add_devices(hbus->pci_bus);
+   pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
 }
@@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct work_struct 
*work)
pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
   wslot);
if (pdev) {
+   pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
+   pci_unlock_rescan_remove();
}
 
memset(, 0, sizeof(ctxt));
-- 
1.8.5.6

[Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

A PCI_EJECT message can arrive at the same time we are calling 
pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS message 
or in create_root_hv_pci_bus(), in this case we could potentailly modify the 
bus from multiple places. Properly lock the bus access.

Thanks Dexuan Cui  for pointing out the race condition in 
create_root_hv_pci_bus().

Signed-off-by: Long Li 
Reported-by: Xiaofeng Wang 
Acked-by: K. Y. Srinivasan 
---
 drivers/pci/host/pci-hyperv.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 4a37598..33c75c9 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct 
hv_pcibus_device *hbus)
hbus->pci_bus->msi = >msi_chip;
hbus->pci_bus->msi->dev = >hdev->device;
 
+   pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_bus_assign_resources(hbus->pci_bus);
pci_bus_add_devices(hbus->pci_bus);
+   pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
 }
@@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct work_struct 
*work)
pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
   wslot);
if (pdev) {
+   pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
+   pci_unlock_rescan_remove();
}
 
memset(, 0, sizeof(ctxt));
-- 
1.8.5.6

RE: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[KY Srinivasan]

> -Original Message-
> From: Long Li [mailto:lon...@exchange.microsoft.com]
> Sent: Monday, January 23, 2017 9:46 PM
> To: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang
> <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org; Long Li <lon...@microsoft.com>
> Subject: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> [This sender failed our fraud detection checks and may not be who they
> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing]
> 
> From: Long Li <lon...@microsoft.com>
> 
> A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Thanks Dexuan Cui <de...@microsoft.com> for pointing out the race
> condition in create_root_hv_pci_bus().
> 
> Signed-off-by: Long Li <lon...@microsoft.com>
> Reported-by: Xiaofeng Wang <xiaof...@redhat.com>

Acked-by: K. Y. Srinivasan <k...@microsoft.com>

> ---
>  drivers/pci/host/pci-hyperv.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index 4a37598..33c75c9 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> hv_pcibus_device *hbus)
> hbus->pci_bus->msi = >msi_chip;
> hbus->pci_bus->msi->dev = >hdev->device;
> 
> +   pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_bus_assign_resources(hbus->pci_bus);
> pci_bus_add_devices(hbus->pci_bus);
> +   pci_unlock_rescan_remove();
> hbus->state = hv_pcibus_installed;
> return 0;
>  }
> @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> work_struct *work)
> pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> 0,
>wslot);
> if (pdev) {
> +   pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> pci_dev_put(pdev);
> +   pci_unlock_rescan_remove();
> }
> 
> memset(, 0, sizeof(ctxt));
> --
> 1.8.5.6

RE: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[KY Srinivasan]

> -Original Message-
> From: Long Li [mailto:lon...@exchange.microsoft.com]
> Sent: Monday, January 23, 2017 9:46 PM
> To: KY Srinivasan ; Haiyang Zhang
> ; Bjorn Helgaas 
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org; Long Li 
> Subject: [Resend PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> [This sender failed our fraud detection checks and may not be who they
> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing]
> 
> From: Long Li 
> 
> A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Thanks Dexuan Cui  for pointing out the race
> condition in create_root_hv_pci_bus().
> 
> Signed-off-by: Long Li 
> Reported-by: Xiaofeng Wang 

Acked-by: K. Y. Srinivasan 

> ---
>  drivers/pci/host/pci-hyperv.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index 4a37598..33c75c9 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> hv_pcibus_device *hbus)
> hbus->pci_bus->msi = >msi_chip;
> hbus->pci_bus->msi->dev = >hdev->device;
> 
> +   pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_bus_assign_resources(hbus->pci_bus);
> pci_bus_add_devices(hbus->pci_bus);
> +   pci_unlock_rescan_remove();
> hbus->state = hv_pcibus_installed;
> return 0;
>  }
> @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> work_struct *work)
> pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> 0,
>wslot);
> if (pdev) {
> +   pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> pci_dev_put(pdev);
> +   pci_unlock_rescan_remove();
> }
> 
> memset(, 0, sizeof(ctxt));
> --
> 1.8.5.6

RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

Hi Bjorn,

The patch is still pending (along with 1/2 v3). Please let me know if you want 
me to resend the two patches.

Thanks

Long

> -Original Message-
> From: KY Srinivasan
> Sent: Tuesday, October 4, 2016 1:49 PM
> To: Long Li <lon...@microsoft.com>; Haiyang Zhang
> <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org
> Subject: RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> 
> 
> > -Original Message-
> > From: Long Li
> > Sent: Monday, October 3, 2016 11:43 PM
> > To: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang
> > <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>
> > Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> > ker...@vger.kernel.org; Long Li <lon...@microsoft.com>
> > Subject: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> >
> > This sender failed our fraud detection checks and may not be who they
> > appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing
> >
> > From: Long Li <lon...@microsoft.com>
> >
> > A PCI_EJECT message can arrive at the same time we are calling
> > pci_scan_child_bus in the workqueue for the previous
> PCI_BUS_RELATIONS
> > message or in create_root_hv_pci_bus(), in this case we could
> > potentailly modify the bus from multiple places. Properly lock the bus
> access.
> >
> > Thanks Dexuan Cui <de...@microsoft.com> for pointing out the race
> > condition in create_root_hv_pci_bus().
> >
> > Signed-off-by: Long Li <lon...@microsoft.com>
> > Tested-by: Cathy Avery <cav...@redhat.com>
> > Reported-by: Xiaofeng Wang <xiaof...@redhat.com>
> 
> Acked-by: KY Srinivasan <k...@microsoft.com>
> 
> > ---
> >  drivers/pci/host/pci-hyperv.c | 4 
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index 4a37598..33c75c9 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> > hv_pcibus_device *hbus)
> > hbus->pci_bus->msi = >msi_chip;
> > hbus->pci_bus->msi->dev = >hdev->device;
> >
> > +   pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_bus_assign_resources(hbus->pci_bus);
> > pci_bus_add_devices(hbus->pci_bus);
> > +   pci_unlock_rescan_remove();
> > hbus->state = hv_pcibus_installed;
> > return 0;
> >  }
> > @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> > work_struct *work)
> > pdev =
> > pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> > 0,
> >wslot);
> > if (pdev) {
> > +   pci_lock_rescan_remove();
> > pci_stop_and_remove_bus_device(pdev);
> > pci_dev_put(pdev);
> > +   pci_unlock_rescan_remove();
> > }
> >
> > memset(, 0, sizeof(ctxt));
> > --
> > 1.8.5.6

RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

Hi Bjorn,

The patch is still pending (along with 1/2 v3). Please let me know if you want 
me to resend the two patches.

Thanks

Long

> -Original Message-
> From: KY Srinivasan
> Sent: Tuesday, October 4, 2016 1:49 PM
> To: Long Li ; Haiyang Zhang
> ; Bjorn Helgaas 
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org
> Subject: RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> 
> 
> > -Original Message-
> > From: Long Li
> > Sent: Monday, October 3, 2016 11:43 PM
> > To: KY Srinivasan ; Haiyang Zhang
> > ; Bjorn Helgaas 
> > Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> > ker...@vger.kernel.org; Long Li 
> > Subject: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> >
> > This sender failed our fraud detection checks and may not be who they
> > appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing
> >
> > From: Long Li 
> >
> > A PCI_EJECT message can arrive at the same time we are calling
> > pci_scan_child_bus in the workqueue for the previous
> PCI_BUS_RELATIONS
> > message or in create_root_hv_pci_bus(), in this case we could
> > potentailly modify the bus from multiple places. Properly lock the bus
> access.
> >
> > Thanks Dexuan Cui  for pointing out the race
> > condition in create_root_hv_pci_bus().
> >
> > Signed-off-by: Long Li 
> > Tested-by: Cathy Avery 
> > Reported-by: Xiaofeng Wang 
> 
> Acked-by: KY Srinivasan 
> 
> > ---
> >  drivers/pci/host/pci-hyperv.c | 4 
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/pci/host/pci-hyperv.c
> > b/drivers/pci/host/pci-hyperv.c index 4a37598..33c75c9 100644
> > --- a/drivers/pci/host/pci-hyperv.c
> > +++ b/drivers/pci/host/pci-hyperv.c
> > @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> > hv_pcibus_device *hbus)
> > hbus->pci_bus->msi = >msi_chip;
> > hbus->pci_bus->msi->dev = >hdev->device;
> >
> > +   pci_lock_rescan_remove();
> > pci_scan_child_bus(hbus->pci_bus);
> > pci_bus_assign_resources(hbus->pci_bus);
> > pci_bus_add_devices(hbus->pci_bus);
> > +   pci_unlock_rescan_remove();
> > hbus->state = hv_pcibus_installed;
> > return 0;
> >  }
> > @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> > work_struct *work)
> > pdev =
> > pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> > 0,
> >wslot);
> > if (pdev) {
> > +   pci_lock_rescan_remove();
> > pci_stop_and_remove_bus_device(pdev);
> > pci_dev_put(pdev);
> > +   pci_unlock_rescan_remove();
> > }
> >
> > memset(, 0, sizeof(ctxt));
> > --
> > 1.8.5.6

RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[KY Srinivasan]

> -Original Message-
> From: Long Li
> Sent: Monday, October 3, 2016 11:43 PM
> To: KY Srinivasan <k...@microsoft.com>; Haiyang Zhang
> <haiya...@microsoft.com>; Bjorn Helgaas <bhelg...@google.com>
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org; Long Li <lon...@microsoft.com>
> Subject: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> This sender failed our fraud detection checks and may not be who they
> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing
> 
> From: Long Li <lon...@microsoft.com>
> 
> A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Thanks Dexuan Cui <de...@microsoft.com> for pointing out the race
> condition in create_root_hv_pci_bus().
> 
> Signed-off-by: Long Li <lon...@microsoft.com>
> Tested-by: Cathy Avery <cav...@redhat.com>
> Reported-by: Xiaofeng Wang <xiaof...@redhat.com>

Acked-by: KY Srinivasan <k...@microsoft.com>

> ---
>  drivers/pci/host/pci-hyperv.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index 4a37598..33c75c9 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> hv_pcibus_device *hbus)
> hbus->pci_bus->msi = >msi_chip;
> hbus->pci_bus->msi->dev = >hdev->device;
> 
> +   pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_bus_assign_resources(hbus->pci_bus);
> pci_bus_add_devices(hbus->pci_bus);
> +   pci_unlock_rescan_remove();
> hbus->state = hv_pcibus_installed;
> return 0;
>  }
> @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> work_struct *work)
> pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> 0,
>wslot);
> if (pdev) {
> +   pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> pci_dev_put(pdev);
> +   pci_unlock_rescan_remove();
> }
> 
> memset(, 0, sizeof(ctxt));
> --
> 1.8.5.6

RE: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[KY Srinivasan]

> -Original Message-
> From: Long Li
> Sent: Monday, October 3, 2016 11:43 PM
> To: KY Srinivasan ; Haiyang Zhang
> ; Bjorn Helgaas 
> Cc: de...@linuxdriverproject.org; linux-...@vger.kernel.org; linux-
> ker...@vger.kernel.org; Long Li 
> Subject: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject
> 
> This sender failed our fraud detection checks and may not be who they
> appear to be. Learn about spoofing at http://aka.ms/LearnAboutSpoofing
> 
> From: Long Li 
> 
> A PCI_EJECT message can arrive at the same time we are calling
> pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS
> message or in create_root_hv_pci_bus(), in this case we could potentailly
> modify the bus from multiple places. Properly lock the bus access.
> 
> Thanks Dexuan Cui  for pointing out the race
> condition in create_root_hv_pci_bus().
> 
> Signed-off-by: Long Li 
> Tested-by: Cathy Avery 
> Reported-by: Xiaofeng Wang 

Acked-by: KY Srinivasan 

> ---
>  drivers/pci/host/pci-hyperv.c | 4 
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
> index 4a37598..33c75c9 100644
> --- a/drivers/pci/host/pci-hyperv.c
> +++ b/drivers/pci/host/pci-hyperv.c
> @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct
> hv_pcibus_device *hbus)
> hbus->pci_bus->msi = >msi_chip;
> hbus->pci_bus->msi->dev = >hdev->device;
> 
> +   pci_lock_rescan_remove();
> pci_scan_child_bus(hbus->pci_bus);
> pci_bus_assign_resources(hbus->pci_bus);
> pci_bus_add_devices(hbus->pci_bus);
> +   pci_unlock_rescan_remove();
> hbus->state = hv_pcibus_installed;
> return 0;
>  }
> @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct
> work_struct *work)
> pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain,
> 0,
>wslot);
> if (pdev) {
> +   pci_lock_rescan_remove();
> pci_stop_and_remove_bus_device(pdev);
> pci_dev_put(pdev);
> +   pci_unlock_rescan_remove();
> }
> 
> memset(, 0, sizeof(ctxt));
> --
> 1.8.5.6

[PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

From: Long Li 

A PCI_EJECT message can arrive at the same time we are calling 
pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS message 
or in create_root_hv_pci_bus(), in this case we could potentailly modify the 
bus from multiple places. Properly lock the bus access.

Thanks Dexuan Cui  for pointing out the race condition in 
create_root_hv_pci_bus().

Signed-off-by: Long Li 
Tested-by: Cathy Avery 
Reported-by: Xiaofeng Wang 
---
 drivers/pci/host/pci-hyperv.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 4a37598..33c75c9 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct 
hv_pcibus_device *hbus)
hbus->pci_bus->msi = >msi_chip;
hbus->pci_bus->msi->dev = >hdev->device;
 
+   pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_bus_assign_resources(hbus->pci_bus);
pci_bus_add_devices(hbus->pci_bus);
+   pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
 }
@@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct work_struct 
*work)
pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
   wslot);
if (pdev) {
+   pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
+   pci_unlock_rescan_remove();
}
 
memset(, 0, sizeof(ctxt));
-- 
1.8.5.6

[PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject

[Long Li]

From: Long Li 

A PCI_EJECT message can arrive at the same time we are calling 
pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS message 
or in create_root_hv_pci_bus(), in this case we could potentailly modify the 
bus from multiple places. Properly lock the bus access.

Thanks Dexuan Cui  for pointing out the race condition in 
create_root_hv_pci_bus().

Signed-off-by: Long Li 
Tested-by: Cathy Avery 
Reported-by: Xiaofeng Wang 
---
 drivers/pci/host/pci-hyperv.c | 4 
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 4a37598..33c75c9 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct 
hv_pcibus_device *hbus)
hbus->pci_bus->msi = >msi_chip;
hbus->pci_bus->msi->dev = >hdev->device;
 
+   pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_bus_assign_resources(hbus->pci_bus);
pci_bus_add_devices(hbus->pci_bus);
+   pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
 }
@@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct work_struct 
*work)
pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0,
   wslot);
if (pdev) {
+   pci_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
+   pci_unlock_rescan_remove();
}
 
memset(, 0, sizeof(ctxt));
-- 
1.8.5.6