Re: [PATCH] PCI/AER: Add a null check before eeh_ops->notify_resume callback.

Vaibhav Jain [off-list ref] writes:

This patch puts a NULL check before branching to the address pointed
to by eeh_ops->notify_resume in eeh_report_resume(). The callback
is used to notify the arch EEH code that a pci device is back
online.

For PPC64 presently, only an implementation for pseries platform is
available and not for powernv. Hence without this patch EEH recovery
on all non-virtualized hosts is causing a kernel panic when
CONFIG_PCI_IOV is set. The panic is usually is of the form:

EEH: Notify device driver to resume
Unable to handle kernel paging request for instruction fetch
Faulting instruction address: 0x00000000
Oops: Kernel access of bad area, sig: 11 [#1]
<snip>
LR eeh_report_resume+0x218/0x220
Call Trace:
 eeh_report_resume+0x1f0/0x220 (unreliable)
 eeh_pe_dev_traverse+0x98/0x170
 eeh_handle_normal_event+0x3f4/0x650
 eeh_handle_event+0x188/0x380
 eeh_event_handler+0x208/0x210
 kthread+0x168/0x1b0
 ret_from_kernel_thread+0x5c/0xb4

Cc: Bryant G. Ly <redacted>
Fixes: 856e1eb9bdd4("PCI/AER: Add uevents in AER and EEH error/resume")
Signed-off-by: Vaibhav Jain <redacted>

10 out of 10 for the change log!

But yeah this is already fixed in my fixes branch, thanks anyway.

cheers