New flag BPF_F_XDP_DEV_BOUND_ONLY plus all the infra to have a way to associate a netdev with a BPF program at load time. Some existing 'offloaded' routines are renamed to 'dev_bound' for consistency with the rest. Also moved a bunch of code around to avoid forward declarations. netdevsim checks are dropped in favor of generic check in dev_xdp_attach. Cc: John Fastabend <john.fastabend@xxxxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxx> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Cc: Willem de Bruijn <willemb@xxxxxxxxxx> Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Cc: Anatoly Burakov <anatoly.burakov@xxxxxxxxx> Cc: Alexander Lobakin <alexandr.lobakin@xxxxxxxxx> Cc: Magnus Karlsson <magnus.karlsson@xxxxxxxxx> Cc: Maryam Tahhan <mtahhan@xxxxxxxxxx> Cc: xdp-hints@xxxxxxxxxxxxxxx Cc: netdev@xxxxxxxxxxxxxxx Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx> --- drivers/net/netdevsim/bpf.c | 4 - include/linux/bpf.h | 24 ++- include/uapi/linux/bpf.h | 5 + kernel/bpf/core.c | 4 +- kernel/bpf/offload.c | 293 ++++++++++++++++++++------------- kernel/bpf/syscall.c | 9 +- net/core/dev.c | 5 + tools/include/uapi/linux/bpf.h | 5 + 8 files changed, 218 insertions(+), 131 deletions(-) diff --git a/drivers/net/netdevsim/bpf.c b/drivers/net/netdevsim/bpf.c index 50854265864d..f60eb97e3a62 100644 --- a/drivers/net/netdevsim/bpf.c +++ b/drivers/net/netdevsim/bpf.c @@ -315,10 +315,6 @@ nsim_setup_prog_hw_checks(struct netdevsim *ns, struct netdev_bpf *bpf) NSIM_EA(bpf->extack, "xdpoffload of non-bound program"); return -EINVAL; } - if (!bpf_offload_dev_match(bpf->prog, ns->netdev)) { - NSIM_EA(bpf->extack, "program bound to different dev"); - return -EINVAL; - } state = bpf->prog->aux->offload->dev_priv; if (WARN_ON(strcmp(state->state, "xlated"))) { diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f8d3a93703f3..ca22e8b8bd82 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1261,7 +1261,8 @@ struct bpf_prog_aux { enum bpf_prog_type saved_dst_prog_type; enum bpf_attach_type saved_dst_attach_type; bool verifier_zext; /* Zero extensions has been inserted by verifier. */ - bool offload_requested; + bool dev_bound; /* Program is bound to the netdev. */ + bool offload_requested; /* Program is bound and offloaded to the netdev. */ bool attach_btf_trace; /* true if attaching to BTF-enabled raw tp */ bool func_proto_unreliable; bool sleepable; @@ -2451,7 +2452,7 @@ void __bpf_free_used_maps(struct bpf_prog_aux *aux, bool bpf_prog_get_ok(struct bpf_prog *, enum bpf_prog_type *, bool); int bpf_prog_offload_compile(struct bpf_prog *prog); -void bpf_prog_offload_destroy(struct bpf_prog *prog); +void bpf_prog_dev_bound_destroy(struct bpf_prog *prog); int bpf_prog_offload_info_fill(struct bpf_prog_info *info, struct bpf_prog *prog); @@ -2479,7 +2480,13 @@ bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev); void unpriv_ebpf_notify(int new_state); #if defined(CONFIG_NET) && defined(CONFIG_BPF_SYSCALL) -int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr); +int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr); +void bpf_dev_bound_netdev_unregister(struct net_device *dev); + +static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) +{ + return aux->dev_bound; +} static inline bool bpf_prog_is_offloaded(const struct bpf_prog_aux *aux) { @@ -2507,12 +2514,21 @@ void sock_map_unhash(struct sock *sk); void sock_map_destroy(struct sock *sk); void sock_map_close(struct sock *sk, long timeout); #else -static inline int bpf_prog_offload_init(struct bpf_prog *prog, +static inline int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) { return -EOPNOTSUPP; } +static inline void bpf_dev_bound_netdev_unregister(struct net_device *dev) +{ +} + +static inline bool bpf_prog_is_dev_bound(const struct bpf_prog_aux *aux) +{ + return false; +} + static inline bool bpf_prog_is_offloaded(struct bpf_prog_aux *aux) { return false; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 464ca3f01fe7..fa28603a48e7 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1156,6 +1156,11 @@ enum bpf_link_type { */ #define BPF_F_XDP_HAS_FRAGS (1U << 5) +/* If BPF_F_XDP_DEV_BOUND_ONLY is used in BPF_PROG_LOAD command, the loaded + * program becomes device-bound but can access XDP metadata. + */ +#define BPF_F_XDP_DEV_BOUND_ONLY (1U << 6) + /* link_create.kprobe_multi.flags used in LINK_CREATE command for * BPF_TRACE_KPROBE_MULTI attach type to create return probe. */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 641ab412ad7e..d434a994ee04 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2554,8 +2554,8 @@ static void bpf_prog_free_deferred(struct work_struct *work) #endif bpf_free_used_maps(aux); bpf_free_used_btfs(aux); - if (bpf_prog_is_offloaded(aux)) - bpf_prog_offload_destroy(aux->prog); + if (bpf_prog_is_dev_bound(aux)) + bpf_prog_dev_bound_destroy(aux->prog); #ifdef CONFIG_PERF_EVENTS if (aux->prog->has_callchain_buf) put_callchain_buffers(); diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c index f5769a8ecbee..f714c941f8ea 100644 --- a/kernel/bpf/offload.c +++ b/kernel/bpf/offload.c @@ -41,7 +41,7 @@ struct bpf_offload_dev { struct bpf_offload_netdev { struct rhash_head l; struct net_device *netdev; - struct bpf_offload_dev *offdev; + struct bpf_offload_dev *offdev; /* NULL when bound-only */ struct list_head progs; struct list_head maps; struct list_head offdev_netdevs; @@ -56,7 +56,6 @@ static const struct rhashtable_params offdevs_params = { }; static struct rhashtable offdevs; -static bool offdevs_inited; static int bpf_dev_offload_check(struct net_device *netdev) { @@ -72,12 +71,124 @@ bpf_offload_find_netdev(struct net_device *netdev) { lockdep_assert_held(&bpf_devs_lock); - if (!offdevs_inited) - return NULL; return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); } -int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) +static int __bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, + struct net_device *netdev) +{ + struct bpf_offload_netdev *ondev; + int err; + + ondev = kzalloc(sizeof(*ondev), GFP_KERNEL); + if (!ondev) + return -ENOMEM; + + ondev->netdev = netdev; + ondev->offdev = offdev; + INIT_LIST_HEAD(&ondev->progs); + INIT_LIST_HEAD(&ondev->maps); + + err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); + if (err) { + netdev_warn(netdev, "failed to register for BPF offload\n"); + goto err_unlock_free; + } + + if (offdev) + list_add(&ondev->offdev_netdevs, &offdev->netdevs); + return 0; + +err_unlock_free: + up_write(&bpf_devs_lock); + kfree(ondev); + return err; +} + +static void __bpf_prog_dev_bound_destroy(struct bpf_prog *prog) +{ + struct bpf_prog_offload *offload = prog->aux->offload; + + if (offload->dev_state) + offload->offdev->ops->destroy(prog); + + /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */ + bpf_prog_free_id(prog, true); + + list_del_init(&offload->offloads); + kfree(offload); + prog->aux->offload = NULL; +} + +static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, + enum bpf_netdev_command cmd) +{ + struct netdev_bpf data = {}; + struct net_device *netdev; + + ASSERT_RTNL(); + + data.command = cmd; + data.offmap = offmap; + /* Caller must make sure netdev is valid */ + netdev = offmap->netdev; + + return netdev->netdev_ops->ndo_bpf(netdev, &data); +} + +static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) +{ + WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); + /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ + bpf_map_free_id(&offmap->map, true); + list_del_init(&offmap->offloads); + offmap->netdev = NULL; +} + +static void __bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, + struct net_device *netdev) +{ + struct bpf_offload_netdev *ondev, *altdev = NULL; + struct bpf_offloaded_map *offmap, *mtmp; + struct bpf_prog_offload *offload, *ptmp; + + ASSERT_RTNL(); + + ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); + if (WARN_ON(!ondev)) + return; + + WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); + + /* Try to move the objects to another netdev of the device */ + if (offdev) { + list_del(&ondev->offdev_netdevs); + altdev = list_first_entry_or_null(&offdev->netdevs, + struct bpf_offload_netdev, + offdev_netdevs); + } + + if (altdev) { + list_for_each_entry(offload, &ondev->progs, offloads) + offload->netdev = altdev->netdev; + list_splice_init(&ondev->progs, &altdev->progs); + + list_for_each_entry(offmap, &ondev->maps, offloads) + offmap->netdev = altdev->netdev; + list_splice_init(&ondev->maps, &altdev->maps); + } else { + list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) + __bpf_prog_dev_bound_destroy(offload->prog); + list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) + __bpf_map_offload_destroy(offmap); + } + + WARN_ON(!list_empty(&ondev->progs)); + WARN_ON(!list_empty(&ondev->maps)); + kfree(ondev); +} + +int bpf_prog_dev_bound_init(struct bpf_prog *prog, union bpf_attr *attr) { struct bpf_offload_netdev *ondev; struct bpf_prog_offload *offload; @@ -87,7 +198,7 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) attr->prog_type != BPF_PROG_TYPE_XDP) return -EINVAL; - if (attr->prog_flags) + if (attr->prog_flags & ~BPF_F_XDP_DEV_BOUND_ONLY) return -EINVAL; offload = kzalloc(sizeof(*offload), GFP_USER); @@ -102,11 +213,25 @@ int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) if (err) goto err_maybe_put; + prog->aux->offload_requested = !(attr->prog_flags & BPF_F_XDP_DEV_BOUND_ONLY); + down_write(&bpf_devs_lock); ondev = bpf_offload_find_netdev(offload->netdev); if (!ondev) { - err = -EINVAL; - goto err_unlock; + if (!bpf_prog_is_offloaded(prog->aux)) { + /* When only binding to the device, explicitly + * create an entry in the hashtable. See related + * bpf_dev_bound_try_remove_netdev. + */ + err = __bpf_offload_dev_netdev_register(NULL, offload->netdev); + if (err) + goto err_unlock; + ondev = bpf_offload_find_netdev(offload->netdev); + } + if (!ondev) { + err = -EINVAL; + goto err_unlock; + } } offload->offdev = ondev->offdev; prog->aux->offload = offload; @@ -209,27 +334,28 @@ bpf_prog_offload_remove_insns(struct bpf_verifier_env *env, u32 off, u32 cnt) up_read(&bpf_devs_lock); } -static void __bpf_prog_offload_destroy(struct bpf_prog *prog) +static void bpf_dev_bound_try_remove_netdev(struct net_device *dev) { - struct bpf_prog_offload *offload = prog->aux->offload; - - if (offload->dev_state) - offload->offdev->ops->destroy(prog); + struct bpf_offload_netdev *ondev; - /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */ - bpf_prog_free_id(prog, true); + if (!dev) + return; - list_del_init(&offload->offloads); - kfree(offload); - prog->aux->offload = NULL; + ondev = bpf_offload_find_netdev(dev); + if (ondev && !ondev->offdev && list_empty(&ondev->progs)) + __bpf_offload_dev_netdev_unregister(NULL, dev); } -void bpf_prog_offload_destroy(struct bpf_prog *prog) +void bpf_prog_dev_bound_destroy(struct bpf_prog *prog) { + rtnl_lock(); down_write(&bpf_devs_lock); - if (prog->aux->offload) - __bpf_prog_offload_destroy(prog); + if (prog->aux->offload) { + bpf_dev_bound_try_remove_netdev(prog->aux->offload->netdev); + __bpf_prog_dev_bound_destroy(prog); + } up_write(&bpf_devs_lock); + rtnl_unlock(); } static int bpf_prog_offload_translate(struct bpf_prog *prog) @@ -343,22 +469,6 @@ int bpf_prog_offload_info_fill(struct bpf_prog_info *info, const struct bpf_prog_ops bpf_offload_prog_ops = { }; -static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, - enum bpf_netdev_command cmd) -{ - struct netdev_bpf data = {}; - struct net_device *netdev; - - ASSERT_RTNL(); - - data.command = cmd; - data.offmap = offmap; - /* Caller must make sure netdev is valid */ - netdev = offmap->netdev; - - return netdev->netdev_ops->ndo_bpf(netdev, &data); -} - struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) { struct net *net = current->nsproxy->net_ns; @@ -408,15 +518,6 @@ struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) return ERR_PTR(err); } -static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) -{ - WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); - /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ - bpf_map_free_id(&offmap->map, true); - list_del_init(&offmap->offloads); - offmap->netdev = NULL; -} - void bpf_map_offload_map_free(struct bpf_map *map) { struct bpf_offloaded_map *offmap = map_to_offmap(map); @@ -549,7 +650,7 @@ static bool __bpf_offload_dev_match(struct bpf_prog *prog, struct bpf_offload_netdev *ondev1, *ondev2; struct bpf_prog_offload *offload; - if (!bpf_prog_is_offloaded(prog->aux)) + if (!bpf_prog_is_dev_bound(prog->aux)) return false; offload = prog->aux->offload; @@ -595,32 +696,11 @@ bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, struct net_device *netdev) { - struct bpf_offload_netdev *ondev; int err; - ondev = kzalloc(sizeof(*ondev), GFP_KERNEL); - if (!ondev) - return -ENOMEM; - - ondev->netdev = netdev; - ondev->offdev = offdev; - INIT_LIST_HEAD(&ondev->progs); - INIT_LIST_HEAD(&ondev->maps); - down_write(&bpf_devs_lock); - err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); - if (err) { - netdev_warn(netdev, "failed to register for BPF offload\n"); - goto err_unlock_free; - } - - list_add(&ondev->offdev_netdevs, &offdev->netdevs); - up_write(&bpf_devs_lock); - return 0; - -err_unlock_free: + err = __bpf_offload_dev_netdev_register(offdev, netdev); up_write(&bpf_devs_lock); - kfree(ondev); return err; } EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); @@ -628,43 +708,8 @@ EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, struct net_device *netdev) { - struct bpf_offload_netdev *ondev, *altdev; - struct bpf_offloaded_map *offmap, *mtmp; - struct bpf_prog_offload *offload, *ptmp; - - ASSERT_RTNL(); - down_write(&bpf_devs_lock); - ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); - if (WARN_ON(!ondev)) - goto unlock; - - WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); - list_del(&ondev->offdev_netdevs); - - /* Try to move the objects to another netdev of the device */ - altdev = list_first_entry_or_null(&offdev->netdevs, - struct bpf_offload_netdev, - offdev_netdevs); - if (altdev) { - list_for_each_entry(offload, &ondev->progs, offloads) - offload->netdev = altdev->netdev; - list_splice_init(&ondev->progs, &altdev->progs); - - list_for_each_entry(offmap, &ondev->maps, offloads) - offmap->netdev = altdev->netdev; - list_splice_init(&ondev->maps, &altdev->maps); - } else { - list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) - __bpf_prog_offload_destroy(offload->prog); - list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) - __bpf_map_offload_destroy(offmap); - } - - WARN_ON(!list_empty(&ondev->progs)); - WARN_ON(!list_empty(&ondev->maps)); - kfree(ondev); -unlock: + __bpf_offload_dev_netdev_unregister(offdev, netdev); up_write(&bpf_devs_lock); } EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); @@ -673,18 +718,6 @@ struct bpf_offload_dev * bpf_offload_dev_create(const struct bpf_prog_offload_ops *ops, void *priv) { struct bpf_offload_dev *offdev; - int err; - - down_write(&bpf_devs_lock); - if (!offdevs_inited) { - err = rhashtable_init(&offdevs, &offdevs_params); - if (err) { - up_write(&bpf_devs_lock); - return ERR_PTR(err); - } - offdevs_inited = true; - } - up_write(&bpf_devs_lock); offdev = kzalloc(sizeof(*offdev), GFP_KERNEL); if (!offdev) @@ -710,3 +743,29 @@ void *bpf_offload_dev_priv(struct bpf_offload_dev *offdev) return offdev->priv; } EXPORT_SYMBOL_GPL(bpf_offload_dev_priv); + +void bpf_dev_bound_netdev_unregister(struct net_device *dev) +{ + struct bpf_offload_netdev *ondev; + + ASSERT_RTNL(); + + down_write(&bpf_devs_lock); + ondev = bpf_offload_find_netdev(dev); + if (ondev && !ondev->offdev) + __bpf_offload_dev_netdev_unregister(NULL, ondev->netdev); + up_write(&bpf_devs_lock); +} + +static int __init bpf_offload_init(void) +{ + int err; + + down_write(&bpf_devs_lock); + err = rhashtable_init(&offdevs, &offdevs_params); + up_write(&bpf_devs_lock); + + return err; +} + +late_initcall(bpf_offload_init); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 13bc96035116..11c558be4992 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2491,7 +2491,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) BPF_F_TEST_STATE_FREQ | BPF_F_SLEEPABLE | BPF_F_TEST_RND_HI32 | - BPF_F_XDP_HAS_FRAGS)) + BPF_F_XDP_HAS_FRAGS | + BPF_F_XDP_DEV_BOUND_ONLY)) return -EINVAL; if (!IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && @@ -2575,7 +2576,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) prog->aux->attach_btf = attach_btf; prog->aux->attach_btf_id = attr->attach_btf_id; prog->aux->dst_prog = dst_prog; - prog->aux->offload_requested = !!attr->prog_ifindex; + prog->aux->dev_bound = !!attr->prog_ifindex; prog->aux->sleepable = attr->prog_flags & BPF_F_SLEEPABLE; prog->aux->xdp_has_frags = attr->prog_flags & BPF_F_XDP_HAS_FRAGS; @@ -2598,8 +2599,8 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr) atomic64_set(&prog->aux->refcnt, 1); prog->gpl_compatible = is_gpl ? 1 : 0; - if (bpf_prog_is_offloaded(prog->aux)) { - err = bpf_prog_offload_init(prog, attr); + if (bpf_prog_is_dev_bound(prog->aux)) { + err = bpf_prog_dev_bound_init(prog, attr); if (err) goto free_prog_sec; } diff --git a/net/core/dev.c b/net/core/dev.c index 5d51999cba30..194f8116aad4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -9228,6 +9228,10 @@ static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack NL_SET_ERR_MSG(extack, "Using offloaded program without HW_MODE flag is not supported"); return -EINVAL; } + if (bpf_prog_is_dev_bound(new_prog->aux) && !bpf_offload_dev_match(new_prog, dev)) { + NL_SET_ERR_MSG(extack, "Program bound to different device"); + return -EINVAL; + } if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) { NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device"); return -EINVAL; @@ -10813,6 +10817,7 @@ void unregister_netdevice_many_notify(struct list_head *head, /* Shutdown queueing discipline. */ dev_shutdown(dev); + bpf_dev_bound_netdev_unregister(dev); dev_xdp_uninstall(dev); netdev_offload_xstats_disable_all(dev); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 464ca3f01fe7..fa28603a48e7 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -1156,6 +1156,11 @@ enum bpf_link_type { */ #define BPF_F_XDP_HAS_FRAGS (1U << 5) +/* If BPF_F_XDP_DEV_BOUND_ONLY is used in BPF_PROG_LOAD command, the loaded + * program becomes device-bound but can access XDP metadata. + */ +#define BPF_F_XDP_DEV_BOUND_ONLY (1U << 6) + /* link_create.kprobe_multi.flags used in LINK_CREATE command for * BPF_TRACE_KPROBE_MULTI attach type to create return probe. */ -- 2.39.0.rc1.256.g54fd8350bd-goog