[PATCH 4.1 034/159] powerpc/pseries: Fix corrupted pdn list

From: Greg Kroah-Hartman
Date: Sat Sep 26 2015 - 17:16:17 EST

4.1-stable review patch. If anyone has any objections, please let me know.


From: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>

commit 590c7567a2895f939525ead57b0334c6d47986f0 upstream.

Commit cca87d30 ("powerpc/pci: Refactor pci_dn") introduced pdn
list for SRIOV VFs. It means the pdn is be put into the child list
of its parent pdn when the pdn is created. When doing PCI hot
unplugging on pSeries, the PCI device node as well as its pdn are
released through procfs entry "powerpc/ofdt". Some one else grabs
the memory chunk of the pdn and update it accordingly. At the same
time, the pdn is still tracked in the child list of parent pdn. It
leads to corrupted child list in the parent pdn.

This fixes above issue by removing the pdn from the child list of
its parent pdn when the device node is detached from the system.
Note the pdn is free'd when the device node is released if the
device node is dynamic one. Otherwise, the device node as well
as the pdn won't be released.

Fixes: cca87d30 ("powerpc/pci: Refactor pci_dn")
Reported-by: Santwana Samantray <santwana.samantray@xxxxxxxxxx>
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/powerpc/platforms/pseries/setup.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -268,6 +268,11 @@ static int pci_dn_reconfig_notifier(stru
eeh_dev_init(PCI_DN(np), pci->phb);
+ pci = PCI_DN(np);
+ if (pci)
+ list_del(&pci->list);
+ break;

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