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Message-ID: <156258334726.1664.3203645971059402915.stgit@alrua-x1>
Date: Mon, 08 Jul 2019 12:55:47 +0200
From: Toke Høiland-Jørgensen <toke@...hat.com>
To: Daniel Borkmann <daniel@...earbox.net>
Cc: Alexei Starovoitov <ast@...nel.org>, netdev@...r.kernel.org,
David Miller <davem@...emloft.net>,
Jesper Dangaard Brouer <brouer@...hat.com>,
Jakub Kicinski <jakub.kicinski@...ronome.com>,
Björn Töpel <bjorn.topel@...il.com>,
Yonghong Song <yhs@...com>
Subject: [PATCH bpf-next v3 2/6] xdp: Refactor devmap allocation code for
reuse
From: Toke Høiland-Jørgensen <toke@...hat.com>
The subsequent patch to add a new devmap sub-type can re-use much of the
initialisation and allocation code, so refactor it into separate functions.
Signed-off-by: Toke Høiland-Jørgensen <toke@...hat.com>
Acked-by: Yonghong Song <yhs@...com>
---
kernel/bpf/devmap.c | 137 +++++++++++++++++++++++++++++++--------------------
1 file changed, 84 insertions(+), 53 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index d83cf8ccc872..a2fe16362129 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -60,7 +60,7 @@ struct xdp_bulk_queue {
struct bpf_dtab_netdev {
struct net_device *dev; /* must be first member, due to tracepoint */
struct bpf_dtab *dtab;
- unsigned int bit;
+ unsigned int idx; /* keep track of map index for tracepoint */
struct xdp_bulk_queue __percpu *bulkq;
struct rcu_head rcu;
};
@@ -75,28 +75,22 @@ struct bpf_dtab {
static DEFINE_SPINLOCK(dev_map_lock);
static LIST_HEAD(dev_map_list);
-static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
+static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr,
+ bool check_memlock)
{
- struct bpf_dtab *dtab;
int err, cpu;
u64 cost;
- if (!capable(CAP_NET_ADMIN))
- return ERR_PTR(-EPERM);
-
/* check sanity of attributes */
if (attr->max_entries == 0 || attr->key_size != 4 ||
attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK)
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
/* Lookup returns a pointer straight to dev->ifindex, so make sure the
* verifier prevents writes from the BPF side
*/
attr->map_flags |= BPF_F_RDONLY_PROG;
- dtab = kzalloc(sizeof(*dtab), GFP_USER);
- if (!dtab)
- return ERR_PTR(-ENOMEM);
bpf_map_init_from_attr(&dtab->map, attr);
@@ -107,9 +101,7 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
/* if map size is larger than memlock limit, reject it */
err = bpf_map_charge_init(&dtab->map.memory, cost);
if (err)
- goto free_dtab;
-
- err = -ENOMEM;
+ return -EINVAL;
dtab->flush_list = alloc_percpu(struct list_head);
if (!dtab->flush_list)
@@ -124,19 +116,38 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
if (!dtab->netdev_map)
goto free_percpu;
- spin_lock(&dev_map_lock);
- list_add_tail_rcu(&dtab->list, &dev_map_list);
- spin_unlock(&dev_map_lock);
-
- return &dtab->map;
+ return 0;
free_percpu:
free_percpu(dtab->flush_list);
free_charge:
bpf_map_charge_finish(&dtab->map.memory);
-free_dtab:
- kfree(dtab);
- return ERR_PTR(err);
+ return -ENOMEM;
+}
+
+static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
+{
+ struct bpf_dtab *dtab;
+ int err;
+
+ if (!capable(CAP_NET_ADMIN))
+ return ERR_PTR(-EPERM);
+
+ dtab = kzalloc(sizeof(*dtab), GFP_USER);
+ if (!dtab)
+ return ERR_PTR(-ENOMEM);
+
+ err = dev_map_init_map(dtab, attr, true);
+ if (err) {
+ kfree(dtab);
+ return ERR_PTR(err);
+ }
+
+ spin_lock(&dev_map_lock);
+ list_add_tail_rcu(&dtab->list, &dev_map_list);
+ spin_unlock(&dev_map_lock);
+
+ return &dtab->map;
}
static void dev_map_free(struct bpf_map *map)
@@ -235,7 +246,7 @@ static int bq_xmit_all(struct xdp_bulk_queue *bq, u32 flags,
out:
bq->count = 0;
- trace_xdp_devmap_xmit(&obj->dtab->map, obj->bit,
+ trace_xdp_devmap_xmit(&obj->dtab->map, obj->idx,
sent, drops, bq->dev_rx, dev, err);
bq->dev_rx = NULL;
__list_del_clearprev(&bq->flush_node);
@@ -412,17 +423,52 @@ static int dev_map_delete_elem(struct bpf_map *map, void *key)
return 0;
}
-static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
- u64 map_flags)
+static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
+ struct bpf_dtab *dtab,
+ u32 ifindex,
+ unsigned int idx)
{
- struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
- struct net *net = current->nsproxy->net_ns;
gfp_t gfp = GFP_ATOMIC | __GFP_NOWARN;
+ struct bpf_dtab_netdev *dev;
+ struct xdp_bulk_queue *bq;
+ int cpu;
+
+ dev = kmalloc_node(sizeof(*dev), gfp, dtab->map.numa_node);
+ if (!dev)
+ return ERR_PTR(-ENOMEM);
+
+ dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq),
+ sizeof(void *), gfp);
+ if (!dev->bulkq) {
+ kfree(dev);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ for_each_possible_cpu(cpu) {
+ bq = per_cpu_ptr(dev->bulkq, cpu);
+ bq->obj = dev;
+ }
+
+ dev->dev = dev_get_by_index(net, ifindex);
+ if (!dev->dev) {
+ free_percpu(dev->bulkq);
+ kfree(dev);
+ return ERR_PTR(-EINVAL);
+ }
+
+ dev->idx = idx;
+ dev->dtab = dtab;
+
+ return dev;
+}
+
+static int __dev_map_update_elem(struct net *net, struct bpf_map *map,
+ void *key, void *value, u64 map_flags)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
struct bpf_dtab_netdev *dev, *old_dev;
u32 ifindex = *(u32 *)value;
- struct xdp_bulk_queue *bq;
u32 i = *(u32 *)key;
- int cpu;
if (unlikely(map_flags > BPF_EXIST))
return -EINVAL;
@@ -434,31 +480,9 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
if (!ifindex) {
dev = NULL;
} else {
- dev = kmalloc_node(sizeof(*dev), gfp, map->numa_node);
- if (!dev)
- return -ENOMEM;
-
- dev->bulkq = __alloc_percpu_gfp(sizeof(*dev->bulkq),
- sizeof(void *), gfp);
- if (!dev->bulkq) {
- kfree(dev);
- return -ENOMEM;
- }
-
- for_each_possible_cpu(cpu) {
- bq = per_cpu_ptr(dev->bulkq, cpu);
- bq->obj = dev;
- }
-
- dev->dev = dev_get_by_index(net, ifindex);
- if (!dev->dev) {
- free_percpu(dev->bulkq);
- kfree(dev);
- return -EINVAL;
- }
-
- dev->bit = i;
- dev->dtab = dtab;
+ dev = __dev_map_alloc_node(net, dtab, ifindex, i);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
}
/* Use call_rcu() here to ensure rcu critical sections have completed
@@ -472,6 +496,13 @@ static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
return 0;
}
+static int dev_map_update_elem(struct bpf_map *map, void *key, void *value,
+ u64 map_flags)
+{
+ return __dev_map_update_elem(current->nsproxy->net_ns,
+ map, key, value, map_flags);
+}
+
const struct bpf_map_ops dev_map_ops = {
.map_alloc = dev_map_alloc,
.map_free = dev_map_free,
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