mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-05 18:39:59 +00:00
bpf: minor cleanups for dev_map
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 <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
e4a8e817d3
commit
af4d045cee
1 changed files with 41 additions and 59 deletions
|
@ -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)
|
||||
{
|
||||
if (old_dev->dev->netdev_ops->ndo_xdp_flush) {
|
||||
struct net_device *fl = old_dev->dev;
|
||||
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 (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;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue