The thread "avoid alloc memory on offline node" https://lkml.org/lkml/2018/6/7/251 Asked at one point why the kzalloc_node was crashing rather than returning memory from a valid node. The thread ended up fixing the immediate causes of the crash but left open the case of bad proximity values being in DSDT tables without corrisponding SRAT/SLIT entries as is happening on another machine. Its also easy to fix that, but we should also harden the allocator sufficiently that it doesn't crash when passed an invalid node id. There are a couple possible ways to do this, and i've attached two separate patches which individually fix that problem. The first detects the offline node before calling the new_slab code path when it becomes apparent that the allocation isn't going to succeed. The second actually hardens node_zonelist() and prepare_alloc_pages() in the face of NODE_DATA(nid) returning a NULL zonelist. This latter case happens if the node has never been initialized or is possibly out of range. There are other places (NODE_DATA & online_node) which should be checking if the node id's are > MAX_NUMNODES. Jeremy Linton (2): slub: Avoid trying to allocate memory on offline nodes mm: harden alloc_pages code paths against bogus nodes include/linux/gfp.h | 2 ++ mm/page_alloc.c | 2 ++ mm/slub.c | 2 ++ 3 files changed, 6 insertions(+) -- 2.14.3
