On Tue, 06 Sep 2016 09:49:36 -0700 Dan Williams <[email protected]> wrote:
> Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings > currently results in the following VM_BUG_ONs: > > kernel BUG at mm/huge_memory.c:1105! > task: ffff88045f16b140 task.stack: ffff88045be14000 > RIP: 0010:[<ffffffff81268f9b>] [<ffffffff81268f9b>] > follow_trans_huge_pmd+0x2cb/0x340 > [..] > Call Trace: > [<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0 > [<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0 > [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 > [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 > [<ffffffff81307656>] show_smap+0xa6/0x2b0 > > kernel BUG at fs/proc/task_mmu.c:585! > RIP: 0010:[<ffffffff81306469>] [<ffffffff81306469>] > smaps_pte_range+0x499/0x4b0 > Call Trace: > [<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0 > [<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0 > [<ffffffff8123c8a2>] walk_page_vma+0x62/0x80 > [<ffffffff81307696>] show_smap+0xa6/0x2b0 > > These locations are sanity checking page flags that must be set for an > anonymous transparent huge page, but are not set for the zone_device > pages associated with dax mappings. Acked-by: Andrew Morton <[email protected]>
