On (Tue) 22 Jul 2014 [17:26:41], Laszlo Ersek wrote:
> "vmstate_xhci_event" was introduced in commit 37352df3 ("xhci: add live
> migration support"), and first released in v1.6.0. The field list in this
> VMSD is not terminated with the VMSTATE_END_OF_LIST() macro.
>
> During normal use (ie. migration), the issue is practically invisible,
> because the "vmstate_xhci_event" object (with the unterminated field list)
> is only ever referenced -- via "vmstate_xhci_intr" -- if xhci_er_full()
> returns true, for the "ev_buffer" test. Since that field_exists() check
> (apparently) almost always returns false, we almost never traverse
> "vmstate_xhci_event" during migration, which hides the bug.
>
> However, Amit's vmstate checker forces recursion into this VMSD as well,
> and the lack of VMSTATE_END_OF_LIST() breaks the field list terminator
> check (field->name != NULL) in dump_vmstate_vmsd(). The result is
> undefined behavior, which in my case translates to infinite recursion
> (because the loop happens to overflow into "vmstate_xhci_intr", which then
> links back to "vmstate_xhci_event").
>
> Add the missing terminator.
>
> Signed-off-by: Laszlo Ersek <ler...@redhat.com>
Thanks for spotting this!
Reviewed-by: Amit Shah <amit.s...@redhat.com>
Amit
