On Mon, 2016-01-11 at 21:19 +0530, Aneesh Kumar K.V wrote: > Core kernel expect swp_entry_t to be consisting of > only swap type and swap offset. We should not leak pte bits to > swp_entry_t. This breaks swapoff which use the swap type and offset > to build a swp_entry_t and later compare that to the swp_entry_t > obtained from linux page table pte. Leaking pte bits to swp_entry_t > breaks that comparison and results in us looping in try_to_unuse. > > The stack trace can be anywhere below try_to_unuse() in mm/swapfile.c, > since swapoff is circling around and around that function, reading from > each used swap block into a page, then trying to find where that page > belongs, looking at every non-file pte of every mm that ever swapped. > > Reported-by: Hugh Dickins <hu...@google.com> > Suggested-by: Hugh Dickins <hu...@google.com> > Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com>
Thanks. I slightly edited the wording in the change log and added: Fixes: 6a119eae942c ("powerpc/mm: Add a _PAGE_PTE bit") cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev