Commit 572a5767 authored by David S. Miller's avatar David S. Miller

Merge branch 'bpf-minor-cleanups'

Daniel Borkmann says:

====================
Two minor BPF cleanups

Two minor cleanups on devmap and redirect I still had
in my queue.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents cd36c3a2 af4d045c
......@@ -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;
......@@ -110,11 +108,8 @@ 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),
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;
}
......
......@@ -1835,29 +1835,6 @@ static const struct bpf_func_proto bpf_redirect_proto = {
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags)
{
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
if (unlikely(flags))
return XDP_ABORTED;
ri->ifindex = ifindex;
ri->flags = flags;
ri->map = map;
return XDP_REDIRECT;
}
static const struct bpf_func_proto bpf_redirect_map_proto = {
.func = bpf_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_sk_redirect_map, struct bpf_map *, map, u32, key, u64, flags)
{
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
......@@ -2506,13 +2483,11 @@ static int __bpf_tx_xdp(struct net_device *dev,
err = dev->netdev_ops->ndo_xdp_xmit(dev, xdp);
if (err)
return err;
if (map)
__dev_map_insert_ctx(map, index);
else
dev->netdev_ops->ndo_xdp_flush(dev);
return err;
return 0;
}
void xdp_do_flush_map(void)
......@@ -2520,15 +2495,13 @@ void xdp_do_flush_map(void)
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
struct bpf_map *map = ri->map_to_flush;
ri->map = NULL;
ri->map_to_flush = NULL;
if (map)
__dev_map_flush(map);
}
EXPORT_SYMBOL_GPL(xdp_do_flush_map);
int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
......@@ -2545,14 +2518,12 @@ int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp,
err = -EINVAL;
goto out;
}
if (ri->map_to_flush && (ri->map_to_flush != map))
if (ri->map_to_flush && ri->map_to_flush != map)
xdp_do_flush_map();
err = __bpf_tx_xdp(fwd, map, xdp, index);
if (likely(!err))
ri->map_to_flush = map;
out:
trace_xdp_redirect(dev, fwd, xdp_prog, XDP_REDIRECT, err);
return err;
......@@ -2594,20 +2565,17 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb)
ri->ifindex = 0;
if (unlikely(!dev)) {
bpf_warn_invalid_xdp_redirect(index);
goto err;
return -EINVAL;
}
if (unlikely(!(dev->flags & IFF_UP)))
goto err;
return -ENETDOWN;
len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
if (skb->len > len)
goto err;
return -E2BIG;
skb->dev = dev;
return 0;
err:
return -EINVAL;
}
EXPORT_SYMBOL_GPL(xdp_do_generic_redirect);
......@@ -2620,6 +2588,7 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags)
ri->ifindex = ifindex;
ri->flags = flags;
return XDP_REDIRECT;
}
......@@ -2631,6 +2600,29 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = {
.arg2_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags)
{
struct redirect_info *ri = this_cpu_ptr(&redirect_info);
if (unlikely(flags))
return XDP_ABORTED;
ri->ifindex = ifindex;
ri->flags = flags;
ri->map = map;
return XDP_REDIRECT;
}
static const struct bpf_func_proto bpf_xdp_redirect_map_proto = {
.func = bpf_xdp_redirect_map,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_ANYTHING,
.arg3_type = ARG_ANYTHING,
};
bool bpf_helper_changes_pkt_data(void *func)
{
if (func == bpf_skb_vlan_push ||
......@@ -3233,7 +3225,7 @@ xdp_func_proto(enum bpf_func_id func_id)
case BPF_FUNC_redirect:
return &bpf_xdp_redirect_proto;
case BPF_FUNC_redirect_map:
return &bpf_redirect_map_proto;
return &bpf_xdp_redirect_map_proto;
default:
return bpf_base_func_proto(func_id);
}
......
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