Hi Krishna, On 5/9/24 7:05 AM, Krishna Kumar wrote: > Description of the problem: The hotplug driver for powerpc > (pci/hotplug/pnv_php.c) gives kernel crash when we try to > hot-unplug/disable the PCIe switch/bridge from the PHB. > > > Root Cause of Crash: The crash is due to the reason that, though the msi > data structure has been released during disable/hot-unplug path and it > has been assigned with NULL, still during unregistartion the code was > again trying to explicitly disable the msi which causes the Null pointer > dereference and kernel crash. > > > Proposed Fix : The fix is to correct the check during unregistration path > so that the code should not try to invoke pci_disable_msi/msix() if its > data structure is already freed. > > > Signed-off-by: Krishna Kumar <krishnak@xxxxxxxxxxxxx> I've tested this on a POWER9 box and can confirm that it fixes the panics when hotplugging PCIe bridges. Tested-by: Shawn Anastasio <sanastasio@xxxxxxxxxxxxxxxxxxxxx> Thanks, Shawn
