Re: [PATCH v15 2/5] PCI: Fix AB-BA deadlock between device_lock and pci_rescan_remove_lock in remove_store

[sashiko-bot@kernel.org]

> From: Ionut Nechita <ionut.nechita@windriver.com>
> 
> remove_store() calls pci_stop_and_remove_bus_device_locked() which
> takes pci_rescan_remove_lock first, then device_lock during driver
> release.  Meanwhile, unbind_store() takes device_lock first (via
> device_driver_detach), and the driver's .remove() callback may call
> pci_disable_sriov() -> sriov_del_vfs() -> pci_lock_rescan_remove().
> 
> This creates an AB-BA deadlock:
> 
>   CPU0 (remove_store)               CPU1 (unbind_store)
>   --------------------              --------------------
>   pci_lock_rescan_remove()
>                                     device_lock()
>                                     driver .remove()
> [ ... ]
> Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
> Reviewed-by: Benjamin Block <bblock@linux.ibm.com>
> Tested-by: Benjamin Block <bblock@linux.ibm.com>
> Signed-off-by: Ionut Nechita <ionut.nechita@windriver.com>
> Signed-off-by: Benjamin Block <bblock@linux.ibm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/cover.1790267348.git.bblock@linux.ibm.com?part=2