[ +Jason, +Jesper ] On 02/14/2018 09:43 AM, Michal Hocko wrote: > 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 ;-)
Heh, not really. ;-) > Yes. kvmalloc (the vmalloc part) doesn't support GFP_ATOMIC semantic. Agree, that doesn't work. Bug was added in commit 0bf7800f1799 ("ptr_ring: try vmalloc() when kmalloc() fails"). Jason, please take a look at fixing this, thanks!