diff options
Diffstat (limited to 'net/core/filter.c')
| -rw-r--r-- | net/core/filter.c | 68 |
1 files changed, 30 insertions, 38 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index fd423ce3da34..c25eb36f1320 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3246,31 +3246,33 @@ static void *__xdp_map_lookup_elem(struct bpf_map *map, u32 index) } } -static inline bool xdp_map_invalid(const struct bpf_prog *xdp_prog, - unsigned long aux) +void bpf_clear_redirect_map(struct bpf_map *map) { - return (unsigned long)xdp_prog->aux != aux; + struct bpf_redirect_info *ri; + int cpu; + + for_each_possible_cpu(cpu) { + ri = per_cpu_ptr(&bpf_redirect_info, cpu); + /* Avoid polluting remote cacheline due to writes if + * not needed. Once we pass this test, we need the + * cmpxchg() to make sure it hasn't been changed in + * the meantime by remote CPU. + */ + if (unlikely(READ_ONCE(ri->map) == map)) + cmpxchg(&ri->map, map, NULL); + } } static int xdp_do_redirect_map(struct net_device *dev, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + struct bpf_prog *xdp_prog, struct bpf_map *map) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); - unsigned long map_owner = ri->map_owner; - struct bpf_map *map = ri->map; u32 index = ri->ifindex; void *fwd = NULL; int err; ri->ifindex = 0; - ri->map = NULL; - ri->map_owner = 0; - - if (unlikely(xdp_map_invalid(xdp_prog, map_owner))) { - err = -EFAULT; - map = NULL; - goto err; - } + WRITE_ONCE(ri->map, NULL); fwd = __xdp_map_lookup_elem(map, index); if (!fwd) { @@ -3296,12 +3298,13 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + struct bpf_map *map = READ_ONCE(ri->map); struct net_device *fwd; u32 index = ri->ifindex; int err; - if (ri->map) - return xdp_do_redirect_map(dev, xdp, xdp_prog); + if (map) + return xdp_do_redirect_map(dev, xdp, xdp_prog, map); fwd = dev_get_by_index_rcu(dev_net(dev), index); ri->ifindex = 0; @@ -3325,24 +3328,17 @@ EXPORT_SYMBOL_GPL(xdp_do_redirect); static int xdp_do_generic_redirect_map(struct net_device *dev, struct sk_buff *skb, struct xdp_buff *xdp, - struct bpf_prog *xdp_prog) + struct bpf_prog *xdp_prog, + struct bpf_map *map) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); - unsigned long map_owner = ri->map_owner; - struct bpf_map *map = ri->map; u32 index = ri->ifindex; void *fwd = NULL; int err = 0; ri->ifindex = 0; - ri->map = NULL; - ri->map_owner = 0; + WRITE_ONCE(ri->map, NULL); - if (unlikely(xdp_map_invalid(xdp_prog, map_owner))) { - err = -EFAULT; - map = NULL; - goto err; - } fwd = __xdp_map_lookup_elem(map, index); if (unlikely(!fwd)) { err = -EINVAL; @@ -3379,13 +3375,14 @@ int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); + struct bpf_map *map = READ_ONCE(ri->map); u32 index = ri->ifindex; struct net_device *fwd; int err = 0; - if (ri->map) - return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog); - + if (map) + return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog, + map); ri->ifindex = 0; fwd = dev_get_by_index_rcu(dev_net(dev), index); if (unlikely(!fwd)) { @@ -3416,8 +3413,7 @@ BPF_CALL_2(bpf_xdp_redirect, u32, ifindex, u64, flags) ri->ifindex = ifindex; ri->flags = flags; - ri->map = NULL; - ri->map_owner = 0; + WRITE_ONCE(ri->map, NULL); return XDP_REDIRECT; } @@ -3430,8 +3426,8 @@ static const struct bpf_func_proto bpf_xdp_redirect_proto = { .arg2_type = ARG_ANYTHING, }; -BPF_CALL_4(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags, - unsigned long, map_owner) +BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, + u64, flags) { struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); @@ -3440,15 +3436,11 @@ BPF_CALL_4(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex, u64, flags ri->ifindex = ifindex; ri->flags = flags; - ri->map = map; - ri->map_owner = map_owner; + WRITE_ONCE(ri->map, map); return XDP_REDIRECT; } -/* Note, arg4 is hidden from users and populated by the verifier - * with the right pointer. - */ static const struct bpf_func_proto bpf_xdp_redirect_map_proto = { .func = bpf_xdp_redirect_map, .gpl_only = false, |