Re: WARNING in kvmalloc_node

[Michal Hocko]

On Tue 13-02-18 18:55:33, Matthew Wilcox wrote:
> On Tue, Feb 13, 2018 at 03:59:01PM -0800, syzbot wrote:
[...]
> >  kvmalloc include/linux/mm.h:541 [inline]
> >  kvmalloc_array include/linux/mm.h:557 [inline]
> >  __ptr_ring_init_queue_alloc include/linux/ptr_ring.h:474 [inline]
> >  ptr_ring_init include/linux/ptr_ring.h:492 [inline]
> >  __cpu_map_entry_alloc kernel/bpf/cpumap.c:359 [inline]
> >  cpu_map_update_elem+0x3c3/0x8e0 kernel/bpf/cpumap.c:490
> >  map_update_elem kernel/bpf/syscall.c:698 [inline]
> 
> Blame the BPF people, not the MM people ;-)

Yes. kvmalloc (the vmalloc part) doesn't support GFP_ATOMIC semantic.
-- 
Michal Hocko
SUSE Labs