Re: [PATCH v15 1/5] PCI/IOV: Make pci_lock_rescan_remove() reentrant and protect sriov_add_vfs/sriov_del_vfs

[sashiko-bot@kernel.org]

> From: Ionut Nechita <ionut.nechita@windriver.com>
> 
> After reverting commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove
> locking when enabling/disabling SR-IOV") and moving the lock to
> sriov_numvfs_store(), the path through driver .remove() (e.g. rmmod,
> or manual unbind) that calls pci_disable_sriov() directly remains
> unprotected against concurrent hotplug events. This affects any SR-IOV
> capable driver that calls pci_disable_sriov() from its .remove()
> callback (i40e, ice, mlx5, bnxt, etc.).
> 
> On s390, platform-generated hot-unplug events for VFs can race with
> sriov_del_vfs() when a PF driver is being unloaded. The platform event
> handler takes pci_rescan_remove_lock, but sriov_del_vfs() does not,
> leading to double removal and list corruption.
> 
> [ ... ]
> Suggested-by: Lukas Wunner <lukas@wunner.de>
> Suggested-by: Benjamin Block <bblock@linux.ibm.com>
> Signed-off-by: Ionut Nechita <ionut.nechita@windriver.com>
> [bblock@linux.ibm.com: rebase on v7.3, READ_/WRITE_ONCE changes, comments]
> 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=1