Some minor code cleanups, while going over it I also noticed that
we're accounting the bitmap only for one CPU currently, so fix that
up as well.
Signed-off-by: Daniel Borkmann <dan...@iogearbox.net>
Acked-by: Alexei Starovoitov <a...@kernel.org>
---
kernel/bpf/devmap.c | 100 +++++++++++++++++++++-------------------------------
1 file changed, 41 insertions(+), 59 deletions(-)
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index fa08181..bfecabf 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -48,30 +48,30 @@
* calls will fail at this point.
*/
#include <linux/bpf.h>
-#include <linux/jhash.h>
#include <linux/filter.h>
-#include <linux/rculist_nulls.h>
-#include "percpu_freelist.h"
-#include "bpf_lru_list.h"
-#include "map_in_map.h"
struct bpf_dtab_netdev {
struct net_device *dev;
- int key;
- struct rcu_head rcu;
struct bpf_dtab *dtab;
+ unsigned int bit;
+ struct rcu_head rcu;
};
struct bpf_dtab {
struct bpf_map map;
struct bpf_dtab_netdev **netdev_map;
- unsigned long int __percpu *flush_needed;
+ unsigned long __percpu *flush_needed;
struct list_head list;
};
static DEFINE_SPINLOCK(dev_map_lock);
static LIST_HEAD(dev_map_list);
+static u64 dev_map_bitmap_size(const union bpf_attr *attr)
+{
+ return BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long);
+}
+
static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
{
struct bpf_dtab *dtab;
@@ -95,11 +95,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
dtab->map.map_flags = attr->map_flags;
dtab->map.numa_node = bpf_map_attr_numa_node(attr);
- err = -ENOMEM;
-
/* make sure page count doesn't overflow */
cost = (u64) dtab->map.max_entries * sizeof(struct bpf_dtab_netdev *);
- cost += BITS_TO_LONGS(attr->max_entries) * sizeof(unsigned long);
+ cost += dev_map_bitmap_size(attr) * num_possible_cpus();
if (cost >= U32_MAX - PAGE_SIZE)
goto free_dtab;
@@ -110,12 +108,9 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
if (err)
goto free_dtab;
- err = -ENOMEM;
/* A per cpu bitfield with a bit per possible net device */
- dtab->flush_needed = __alloc_percpu(
- BITS_TO_LONGS(attr->max_entries) *
- sizeof(unsigned long),
- __alignof__(unsigned long));
+ dtab->flush_needed = __alloc_percpu(dev_map_bitmap_size(attr),
+ __alignof__(unsigned long));
if (!dtab->flush_needed)
goto free_dtab;
@@ -128,12 +123,12 @@ static struct bpf_map *dev_map_alloc(union bpf_attr *attr)
spin_lock(&dev_map_lock);
list_add_tail_rcu(&dtab->list, &dev_map_list);
spin_unlock(&dev_map_lock);
- return &dtab->map;
+ return &dtab->map;
free_dtab:
free_percpu(dtab->flush_needed);
kfree(dtab);
- return ERR_PTR(err);
+ return ERR_PTR(-ENOMEM);
}
static void dev_map_free(struct bpf_map *map)
@@ -178,9 +173,6 @@ static void dev_map_free(struct bpf_map *map)
kfree(dev);
}
- /* At this point bpf program is detached and all pending operations
- * _must_ be complete
- */
free_percpu(dtab->flush_needed);
bpf_map_area_free(dtab->netdev_map);
kfree(dtab);
@@ -190,7 +182,7 @@ static int dev_map_get_next_key(struct bpf_map *map, void
*key, void *next_key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
u32 index = key ? *(u32 *)key : U32_MAX;
- u32 *next = (u32 *)next_key;
+ u32 *next = next_key;
if (index >= dtab->map.max_entries) {
*next = 0;
@@ -199,29 +191,16 @@ static int dev_map_get_next_key(struct bpf_map *map, void
*key, void *next_key)
if (index == dtab->map.max_entries - 1)
return -ENOENT;
-
*next = index + 1;
return 0;
}
-void __dev_map_insert_ctx(struct bpf_map *map, u32 key)
+void __dev_map_insert_ctx(struct bpf_map *map, u32 bit)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed);
- __set_bit(key, bitmap);
-}
-
-struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
-{
- struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
- struct bpf_dtab_netdev *dev;
-
- if (key >= map->max_entries)
- return NULL;
-
- dev = READ_ONCE(dtab->netdev_map[key]);
- return dev ? dev->dev : NULL;
+ __set_bit(bit, bitmap);
}
/* __dev_map_flush is called from xdp_do_flush_map() which _must_ be signaled
@@ -248,7 +227,6 @@ void __dev_map_flush(struct bpf_map *map)
continue;
netdev = dev->dev;
-
__clear_bit(bit, bitmap);
if (unlikely(!netdev || !netdev->netdev_ops->ndo_xdp_flush))
continue;
@@ -261,43 +239,49 @@ void __dev_map_flush(struct bpf_map *map)
* update happens in parallel here a dev_put wont happen until after reading
the
* ifindex.
*/
-static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
+struct net_device *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
struct bpf_dtab_netdev *dev;
- u32 i = *(u32 *)key;
- if (i >= map->max_entries)
+ if (key >= map->max_entries)
return NULL;
- dev = READ_ONCE(dtab->netdev_map[i]);
- return dev ? &dev->dev->ifindex : NULL;
+ dev = READ_ONCE(dtab->netdev_map[key]);
+ return dev ? dev->dev : NULL;
}
-static void dev_map_flush_old(struct bpf_dtab_netdev *old_dev)
+static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
+{
+ struct net_device *dev = __dev_map_lookup_elem(map, *(u32 *)key);
+
+ return dev ? &dev->ifindex : NULL;
+}
+
+static void dev_map_flush_old(struct bpf_dtab_netdev *dev)
{
- if (old_dev->dev->netdev_ops->ndo_xdp_flush) {
- struct net_device *fl = old_dev->dev;
+ if (dev->dev->netdev_ops->ndo_xdp_flush) {
+ struct net_device *fl = dev->dev;
unsigned long *bitmap;
int cpu;
for_each_online_cpu(cpu) {
- bitmap = per_cpu_ptr(old_dev->dtab->flush_needed, cpu);
- __clear_bit(old_dev->key, bitmap);
+ bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu);
+ __clear_bit(dev->bit, bitmap);
- fl->netdev_ops->ndo_xdp_flush(old_dev->dev);
+ fl->netdev_ops->ndo_xdp_flush(dev->dev);
}
}
}
static void __dev_map_entry_free(struct rcu_head *rcu)
{
- struct bpf_dtab_netdev *old_dev;
+ struct bpf_dtab_netdev *dev;
- old_dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
- dev_map_flush_old(old_dev);
- dev_put(old_dev->dev);
- kfree(old_dev);
+ dev = container_of(rcu, struct bpf_dtab_netdev, rcu);
+ dev_map_flush_old(dev);
+ dev_put(dev->dev);
+ kfree(dev);
}
static int dev_map_delete_elem(struct bpf_map *map, void *key)
@@ -309,8 +293,8 @@ static int dev_map_delete_elem(struct bpf_map *map, void
*key)
if (k >= map->max_entries)
return -EINVAL;
- /* Use synchronize_rcu() here to ensure any rcu critical sections
- * have completed, but this does not guarantee a flush has happened
+ /* Use call_rcu() here to ensure any rcu critical sections have
+ * completed, but this does not guarantee a flush has happened
* yet. Because driver side rcu_read_lock/unlock only protects the
* running XDP program. However, for pending flush operations the
* dev and ctx are stored in another per cpu map. And additionally,
@@ -334,10 +318,8 @@ static int dev_map_update_elem(struct bpf_map *map, void
*key, void *value,
if (unlikely(map_flags > BPF_EXIST))
return -EINVAL;
-
if (unlikely(i >= dtab->map.max_entries))
return -E2BIG;
-
if (unlikely(map_flags == BPF_NOEXIST))
return -EEXIST;
@@ -355,7 +337,7 @@ static int dev_map_update_elem(struct bpf_map *map, void
*key, void *value,
return -EINVAL;
}
- dev->key = i;
+ dev->bit = i;
dev->dtab = dtab;
}
--
1.9.3
