On Wed, 2016-01-27 at 14:24 +0200, Corneliu ZUZU wrote: > When __p2m_get_mem_access gets called, the p2m lock is already taken > by either get_page_from_gva or p2m_get_mem_access. > > Possible code paths: > 1) -> get_page_from_gva > -> p2m_mem_access_check_and_get_page > -> __p2m_get_mem_access > 2) -> p2m_get_mem_access > -> __p2m_get_mem_access > > In both cases if __p2m_get_mem_access subsequently gets to > call p2m_lookup (happens if !radix_tree_lookup(...)), a hypervisor > hang will occur, since p2m_lookup also spin-locks on the p2m lock. > > This bug-fix simply replaces the p2m_lookup call from > __p2m_get_mem_access > with a call to __p2m_lookup. > > Following Ian's suggestion, we also add an ASSERT to ensure that > the p2m lock is taken upon __p2m_get_mem_access entry. > > Signed-off-by: Corneliu ZUZU <cz...@bitdefender.com>
Acked + applied, thanks. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
