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xdp: Fix cleanup on map free for devmap_hash map type 

Tetsuo pointed out that it was not only the device unregister hook that was
broken for devmap_hash types, it was also cleanup on map free. So better
fix this as well.

While we're at it, there's no reason to allocate the netdev_map array for
DEVMAP_HASH, so skip that and adjust the cost accordingly.

Fixes: 6f9d451ab1 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191121133612.430414-1-toke@redhat.com
This commit is contained in:
Toke Høiland-Jørgensen 2019-11-21 14:36:12 +01:00 committed by Alexei Starovoitov
parent 1f60750401
commit 071cdecec5
1 changed files with 46 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
kernel/bpf/devmap.c
View File

@ -74,7 +74,7 @@ struct bpf_dtab_netdev {
struct bpf_dtab {
struct bpf_map map;
struct bpf_dtab_netdev **netdev_map;
struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
struct list_head __percpu *flush_list;
struct list_head list;
@ -101,6 +101,12 @@ static struct hlist_head *dev_map_create_hash(unsigned int entries)
return hash;
}
static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
int idx)
{
return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
}
static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
{
int err, cpu;
@ -120,8 +126,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
bpf_map_init_from_attr(&dtab->map, attr);
/* make sure page count doesn't overflow */
cost = (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
cost += sizeof(struct list_head) * num_possible_cpus();
cost = (u64) sizeof(struct list_head) * num_possible_cpus();
if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
dtab->n_buckets = roundup_pow_of_two(dtab->map.max_entries);
@ -129,6 +134,8 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
if (!dtab->n_buckets) /* Overflow check */
return -EINVAL;
cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
} else {
cost += (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
}
/* if map size is larger than memlock limit, reject it */
@ -143,24 +150,22 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
for_each_possible_cpu(cpu)
INIT_LIST_HEAD(per_cpu_ptr(dtab->flush_list, cpu));
dtab->netdev_map = bpf_map_area_alloc(dtab->map.max_entries *
sizeof(struct bpf_dtab_netdev *),
dtab->map.numa_node);
if (!dtab->netdev_map)
goto free_percpu;
if (attr->map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
dtab->dev_index_head = dev_map_create_hash(dtab->n_buckets);
if (!dtab->dev_index_head)
goto free_map_area;
goto free_percpu;
spin_lock_init(&dtab->index_lock);
} else {
dtab->netdev_map = bpf_map_area_alloc(dtab->map.max_entries *
sizeof(struct bpf_dtab_netdev *),
dtab->map.numa_node);
if (!dtab->netdev_map)
goto free_percpu;
}
return 0;
free_map_area:
bpf_map_area_free(dtab->netdev_map);
free_percpu:
free_percpu(dtab->flush_list);
free_charge:
@ -228,21 +233,40 @@ static void dev_map_free(struct bpf_map *map)
cond_resched();
}
for (i = 0; i < dtab->map.max_entries; i++) {
struct bpf_dtab_netdev *dev;
if (dtab->map.map_type == BPF_MAP_TYPE_DEVMAP_HASH) {
for (i = 0; i < dtab->n_buckets; i++) {
struct bpf_dtab_netdev *dev;
struct hlist_head *head;
struct hlist_node *next;
dev = dtab->netdev_map[i];
if (!dev)
continue;
head = dev_map_index_hash(dtab, i);
free_percpu(dev->bulkq);
dev_put(dev->dev);
kfree(dev);
hlist_for_each_entry_safe(dev, next, head, index_hlist) {
hlist_del_rcu(&dev->index_hlist);
free_percpu(dev->bulkq);
dev_put(dev->dev);
kfree(dev);
}
}
kfree(dtab->dev_index_head);
} else {
for (i = 0; i < dtab->map.max_entries; i++) {
struct bpf_dtab_netdev *dev;
dev = dtab->netdev_map[i];
if (!dev)
continue;
free_percpu(dev->bulkq);
dev_put(dev->dev);
kfree(dev);
}
bpf_map_area_free(dtab->netdev_map);
}
free_percpu(dtab->flush_list);
bpf_map_area_free(dtab->netdev_map);
kfree(dtab->dev_index_head);
kfree(dtab);
}
@ -263,12 +287,6 @@ static int dev_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
return 0;
}
static inline struct hlist_head *dev_map_index_hash(struct bpf_dtab *dtab,
int idx)
{
return &dtab->dev_index_head[idx & (dtab->n_buckets - 1)];
}
struct bpf_dtab_netdev *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);