| Message ID | a11e92b8ba4f5270437caa629307c300bca37976.1508251210.git.daniel@iogearbox.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
| Series | Fix for BPF devmap percpu allocation splat | expand |
On Tue, Oct 17, 2017 at 04:55:54PM +0200, Daniel Borkmann wrote: > PCPU_MIN_UNIT_SIZE is an implementation detail of the percpu > allocator. Given we support __GFP_NOWARN now, lets just let > the allocation request fail naturally instead. The two call > sites from BPF mistakenly assumed __GFP_NOWARN would work, so > no changes needed to their actual __alloc_percpu_gfp() calls > which use the flag already. > > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org>
On 10/17/2017 07:55 AM, Daniel Borkmann wrote: > PCPU_MIN_UNIT_SIZE is an implementation detail of the percpu > allocator. Given we support __GFP_NOWARN now, lets just let > the allocation request fail naturally instead. The two call > sites from BPF mistakenly assumed __GFP_NOWARN would work, so > no changes needed to their actual __alloc_percpu_gfp() calls > which use the flag already. > > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> > --- Nice cleanup. Thanks! Acked-by: John Fastabend <john.fastabend@gmail.com>
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 98c0f00..e263673 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -98,7 +98,7 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr) array_size += (u64) attr->max_entries * elem_size * num_possible_cpus(); if (array_size >= U32_MAX - PAGE_SIZE || - elem_size > PCPU_MIN_UNIT_SIZE || bpf_array_alloc_percpu(array)) { + bpf_array_alloc_percpu(array)) { bpf_map_area_free(array); return ERR_PTR(-ENOMEM); } diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 431126f..6533f08 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -317,10 +317,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr) */ goto free_htab; - if (percpu && round_up(htab->map.value_size, 8) > PCPU_MIN_UNIT_SIZE) - /* make sure the size for pcpu_alloc() is reasonable */ - goto free_htab; - htab->elem_size = sizeof(struct htab_elem) + round_up(htab->map.key_size, 8); if (percpu)
PCPU_MIN_UNIT_SIZE is an implementation detail of the percpu allocator. Given we support __GFP_NOWARN now, lets just let the allocation request fail naturally instead. The two call sites from BPF mistakenly assumed __GFP_NOWARN would work, so no changes needed to their actual __alloc_percpu_gfp() calls which use the flag already. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> --- kernel/bpf/arraymap.c | 2 +- kernel/bpf/hashtab.c | 4 ---- 2 files changed, 1 insertion(+), 5 deletions(-)