Messages in this thread | | | From | Dexuan Cui <> | Subject | RE: [PATCH] PCI: hv: Add hv_pci_remove_slots() when we unload the driver | Date | Wed, 13 Feb 2019 00:17:35 +0000 |
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> From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Sent: Tuesday, February 12, 2019 4:13 AM > ... > This patch fixes three bugs: > > 1) set hpdev->pci_slot to NULL > 2) move code destroying the slot inside a locked region in > hv_eject_device_work() > 3) Add missing slots removal code in hv_pci_remove() > > We need three patches, not one. > > (1) and (2), I am not entirely sure we want them in stable kernels, > since they are potential bugs, waiting for your input. > > Lorenzo
(1) is actually unnecessary, as I suppose hpdev should be freed at a later place in the same function hv_eject_device_work -> put_pcichild() -> kfree(hpdev). But today I think I found a refcount bug in the hot-remove case and the "kfree(hpdev)" is never called in the hot-remove case. I'll further dig into this and make some extra patches.
About (2), it's a race condition that can happen when the device is being hot-removed and we're unloading the pci-hyperv driver at the same time. This is not a normal usage, so I agree it doesn't really need to go into the stables.
(3) should go into the stables.
I'll make 3 separate patches, and extra patches for the refcount issue, and possible other minor issues.
Thanks, -- Dexuan
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