> Subject: [bug report] PCI: hv: Fix a race condition when removing the device
>
> Hello Long Li,
>
> The patch 94d22763207a: "PCI: hv: Fix a race condition when removing the
> device" from May 12, 2021, leads to the following Smatch static checker
> warning:
>
> drivers/pci/controller/pci-hyperv.c:3294 hv_pci_bus_exit()
> warn: sleeping in atomic context
>
> drivers/pci/controller/pci-hyperv.c
> 3287
> 3288 if (!keep_devs) {
> 3289 /* Delete any children which might still exist. */
> 3290 spin_lock_irqsave(&hbus->device_list_lock, flags);
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> This takes a spinlock.
>
> 3291 list_for_each_entry_safe(hpdev, tmp, &hbus->children,
> list_entry) {
> 3292 list_del(&hpdev->list_entry);
> 3293 if (hpdev->pci_slot)
> --> 3294 pci_destroy_slot(hpdev->pci_slot);
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The
> pci_destroy_slot() function takes a mutex and you can't take a mutex when
> you're holding a spinlock because it can sleep.
>
> 3295 /* For the two refs got in new_pcichild_device() */
> 3296 put_pcichild(hpdev);
> 3297 put_pcichild(hpdev);
> 3298 }
> 3299 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
> 3300 }
> 3301
> 3302 ret = hv_send_resources_released(hdev);
> 3303 if (ret) {
> 3304 dev_err(&hdev->device,
>
> regards,
> dan carpenter
Thank you, Dan. I have submitted a patch to fix this.
Long
