Re: [Patch v2] PCI: hv: Fix sleep while in non-sleep context when removing child devices from the bus

[Wei Liu]

On Mon, Aug 30, 2021 at 04:13:27PM -0700, longli@xxxxxxxxxxxxxxxxx wrote:
> From: Long Li <longli@xxxxxxxxxxxxx>
> 
> In hv_pci_bus_exit, the code is holding a spinlock while calling
> pci_destroy_slot(), which takes a mutex.
> 
> This is not safe for spinlock. Fix this by moving the children to be
> deleted to a list on the stack, and removing them after spinlock is
> released.
> 
> Fixes: 94d22763207a ("PCI: hv: Fix a race condition when removing the device")
> 
> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>
> Cc: Wei Liu <wei.liu@xxxxxxxxxx>
> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Cc: Rob Herring <robh@xxxxxxxxxx>
> Cc: "Krzysztof Wilczyński" <kw@xxxxxxxxx>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: Michael Kelley <mikelley@xxxxxxxxxxxxx>
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Link: https://lore.kernel.org/linux-hyperv/20210823152130.GA21501@kili/
> Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>

Reviewed-by: Wei Liu <wei.liu@xxxxxxxxxx>