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powerpc/eeh: avoid possible crash when edev->pdev changes

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If a PCI device is removed during eeh_pe_report_edev(), edev->pdev
will change and can cause a crash, hold the PCI rescan/remove lock
while taking a copy of edev->pdev->bus.

Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240617140240.580453-1-ganeshgr@linux.ibm.com
This commit is contained in:
Ganesh Goudar 2024-06-17 19:32:40 +05:30 committed by Michael Ellerman
parent 1a14150e16
commit a1216e62d0
1 changed files with 5 additions and 2 deletions
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7
arch/powerpc/kernel/eeh_pe.c
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@ -849,6 +849,7 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
{ {
struct eeh_dev *edev; struct eeh_dev *edev;
struct pci_dev *pdev; struct pci_dev *pdev;
struct pci_bus *bus = NULL;
if (pe->type & EEH_PE_PHB) if (pe->type & EEH_PE_PHB)
return pe->phb->bus; return pe->phb->bus;
@ -859,9 +860,11 @@ struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
/* Retrieve the parent PCI bus of first (top) PCI device */ /* Retrieve the parent PCI bus of first (top) PCI device */
edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry); edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry);
pci_lock_rescan_remove();
pdev = eeh_dev_to_pci_dev(edev); pdev = eeh_dev_to_pci_dev(edev);
if (pdev) if (pdev)
return pdev->bus; bus = pdev->bus;
pci_unlock_rescan_remove();
return NULL; return bus;
} }