v4.19.13 snapshot.
diff --git a/kernel/bpf/offload.c b/kernel/bpf/offload.c
new file mode 100644
index 0000000..177a524
--- /dev/null
+++ b/kernel/bpf/offload.c
@@ -0,0 +1,669 @@
+/*
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
+ *
+ * This software is licensed under the GNU General License Version 2,
+ * June 1991 as shown in the file COPYING in the top-level directory of this
+ * source tree.
+ *
+ * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
+ * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
+ * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+ */
+
+#include <linux/bpf.h>
+#include <linux/bpf_verifier.h>
+#include <linux/bug.h>
+#include <linux/kdev_t.h>
+#include <linux/list.h>
+#include <linux/lockdep.h>
+#include <linux/netdevice.h>
+#include <linux/printk.h>
+#include <linux/proc_ns.h>
+#include <linux/rhashtable.h>
+#include <linux/rtnetlink.h>
+#include <linux/rwsem.h>
+
+/* Protects offdevs, members of bpf_offload_netdev and offload members
+ * of all progs.
+ * RTNL lock cannot be taken when holding this lock.
+ */
+static DECLARE_RWSEM(bpf_devs_lock);
+
+struct bpf_offload_dev {
+ struct list_head netdevs;
+};
+
+struct bpf_offload_netdev {
+ struct rhash_head l;
+ struct net_device *netdev;
+ struct bpf_offload_dev *offdev;
+ struct list_head progs;
+ struct list_head maps;
+ struct list_head offdev_netdevs;
+};
+
+static const struct rhashtable_params offdevs_params = {
+ .nelem_hint = 4,
+ .key_len = sizeof(struct net_device *),
+ .key_offset = offsetof(struct bpf_offload_netdev, netdev),
+ .head_offset = offsetof(struct bpf_offload_netdev, l),
+ .automatic_shrinking = true,
+};
+
+static struct rhashtable offdevs;
+static bool offdevs_inited;
+
+static int bpf_dev_offload_check(struct net_device *netdev)
+{
+ if (!netdev)
+ return -EINVAL;
+ if (!netdev->netdev_ops->ndo_bpf)
+ return -EOPNOTSUPP;
+ return 0;
+}
+
+static struct bpf_offload_netdev *
+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)
+{
+ struct bpf_offload_netdev *ondev;
+ struct bpf_prog_offload *offload;
+ int err;
+
+ if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS &&
+ attr->prog_type != BPF_PROG_TYPE_XDP)
+ return -EINVAL;
+
+ if (attr->prog_flags)
+ return -EINVAL;
+
+ offload = kzalloc(sizeof(*offload), GFP_USER);
+ if (!offload)
+ return -ENOMEM;
+
+ offload->prog = prog;
+
+ offload->netdev = dev_get_by_index(current->nsproxy->net_ns,
+ attr->prog_ifindex);
+ err = bpf_dev_offload_check(offload->netdev);
+ if (err)
+ goto err_maybe_put;
+
+ down_write(&bpf_devs_lock);
+ ondev = bpf_offload_find_netdev(offload->netdev);
+ if (!ondev) {
+ err = -EINVAL;
+ goto err_unlock;
+ }
+ prog->aux->offload = offload;
+ list_add_tail(&offload->offloads, &ondev->progs);
+ dev_put(offload->netdev);
+ up_write(&bpf_devs_lock);
+
+ return 0;
+err_unlock:
+ up_write(&bpf_devs_lock);
+err_maybe_put:
+ if (offload->netdev)
+ dev_put(offload->netdev);
+ kfree(offload);
+ return err;
+}
+
+static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd,
+ struct netdev_bpf *data)
+{
+ struct bpf_prog_offload *offload = prog->aux->offload;
+ struct net_device *netdev;
+
+ ASSERT_RTNL();
+
+ if (!offload)
+ return -ENODEV;
+ netdev = offload->netdev;
+
+ data->command = cmd;
+
+ return netdev->netdev_ops->ndo_bpf(netdev, data);
+}
+
+int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env)
+{
+ struct netdev_bpf data = {};
+ int err;
+
+ data.verifier.prog = env->prog;
+
+ rtnl_lock();
+ err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data);
+ if (err)
+ goto exit_unlock;
+
+ env->prog->aux->offload->dev_ops = data.verifier.ops;
+ env->prog->aux->offload->dev_state = true;
+exit_unlock:
+ rtnl_unlock();
+ return err;
+}
+
+int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env,
+ int insn_idx, int prev_insn_idx)
+{
+ struct bpf_prog_offload *offload;
+ int ret = -ENODEV;
+
+ down_read(&bpf_devs_lock);
+ offload = env->prog->aux->offload;
+ if (offload)
+ ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+static void __bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+ struct bpf_prog_offload *offload = prog->aux->offload;
+ struct netdev_bpf data = {};
+
+ data.offload.prog = prog;
+
+ if (offload->dev_state)
+ WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data));
+
+ /* 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;
+}
+
+void bpf_prog_offload_destroy(struct bpf_prog *prog)
+{
+ rtnl_lock();
+ down_write(&bpf_devs_lock);
+ if (prog->aux->offload)
+ __bpf_prog_offload_destroy(prog);
+ up_write(&bpf_devs_lock);
+ rtnl_unlock();
+}
+
+static int bpf_prog_offload_translate(struct bpf_prog *prog)
+{
+ struct netdev_bpf data = {};
+ int ret;
+
+ data.offload.prog = prog;
+
+ rtnl_lock();
+ ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data);
+ rtnl_unlock();
+
+ return ret;
+}
+
+static unsigned int bpf_prog_warn_on_exec(const void *ctx,
+ const struct bpf_insn *insn)
+{
+ WARN(1, "attempt to execute device eBPF program on the host!");
+ return 0;
+}
+
+int bpf_prog_offload_compile(struct bpf_prog *prog)
+{
+ prog->bpf_func = bpf_prog_warn_on_exec;
+
+ return bpf_prog_offload_translate(prog);
+}
+
+struct ns_get_path_bpf_prog_args {
+ struct bpf_prog *prog;
+ struct bpf_prog_info *info;
+};
+
+static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data)
+{
+ struct ns_get_path_bpf_prog_args *args = private_data;
+ struct bpf_prog_aux *aux = args->prog->aux;
+ struct ns_common *ns;
+ struct net *net;
+
+ rtnl_lock();
+ down_read(&bpf_devs_lock);
+
+ if (aux->offload) {
+ args->info->ifindex = aux->offload->netdev->ifindex;
+ net = dev_net(aux->offload->netdev);
+ get_net(net);
+ ns = &net->ns;
+ } else {
+ args->info->ifindex = 0;
+ ns = NULL;
+ }
+
+ up_read(&bpf_devs_lock);
+ rtnl_unlock();
+
+ return ns;
+}
+
+int bpf_prog_offload_info_fill(struct bpf_prog_info *info,
+ struct bpf_prog *prog)
+{
+ struct ns_get_path_bpf_prog_args args = {
+ .prog = prog,
+ .info = info,
+ };
+ struct bpf_prog_aux *aux = prog->aux;
+ struct inode *ns_inode;
+ struct path ns_path;
+ char __user *uinsns;
+ void *res;
+ u32 ulen;
+
+ res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args);
+ if (IS_ERR(res)) {
+ if (!info->ifindex)
+ return -ENODEV;
+ return PTR_ERR(res);
+ }
+
+ down_read(&bpf_devs_lock);
+
+ if (!aux->offload) {
+ up_read(&bpf_devs_lock);
+ return -ENODEV;
+ }
+
+ ulen = info->jited_prog_len;
+ info->jited_prog_len = aux->offload->jited_len;
+ if (info->jited_prog_len & ulen) {
+ uinsns = u64_to_user_ptr(info->jited_prog_insns);
+ ulen = min_t(u32, info->jited_prog_len, ulen);
+ if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) {
+ up_read(&bpf_devs_lock);
+ return -EFAULT;
+ }
+ }
+
+ up_read(&bpf_devs_lock);
+
+ ns_inode = ns_path.dentry->d_inode;
+ info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+ info->netns_ino = ns_inode->i_ino;
+ path_put(&ns_path);
+
+ return 0;
+}
+
+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;
+ struct bpf_offload_netdev *ondev;
+ struct bpf_offloaded_map *offmap;
+ int err;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return ERR_PTR(-EPERM);
+ if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+ attr->map_type != BPF_MAP_TYPE_HASH)
+ return ERR_PTR(-EINVAL);
+
+ offmap = kzalloc(sizeof(*offmap), GFP_USER);
+ if (!offmap)
+ return ERR_PTR(-ENOMEM);
+
+ bpf_map_init_from_attr(&offmap->map, attr);
+
+ rtnl_lock();
+ down_write(&bpf_devs_lock);
+ offmap->netdev = __dev_get_by_index(net, attr->map_ifindex);
+ err = bpf_dev_offload_check(offmap->netdev);
+ if (err)
+ goto err_unlock;
+
+ ondev = bpf_offload_find_netdev(offmap->netdev);
+ if (!ondev) {
+ err = -EINVAL;
+ goto err_unlock;
+ }
+
+ err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC);
+ if (err)
+ goto err_unlock;
+
+ list_add_tail(&offmap->offloads, &ondev->maps);
+ up_write(&bpf_devs_lock);
+ rtnl_unlock();
+
+ return &offmap->map;
+
+err_unlock:
+ up_write(&bpf_devs_lock);
+ rtnl_unlock();
+ kfree(offmap);
+ 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);
+
+ rtnl_lock();
+ down_write(&bpf_devs_lock);
+ if (offmap->netdev)
+ __bpf_map_offload_destroy(offmap);
+ up_write(&bpf_devs_lock);
+ rtnl_unlock();
+
+ kfree(offmap);
+}
+
+int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value)
+{
+ struct bpf_offloaded_map *offmap = map_to_offmap(map);
+ int ret = -ENODEV;
+
+ down_read(&bpf_devs_lock);
+ if (offmap->netdev)
+ ret = offmap->dev_ops->map_lookup_elem(offmap, key, value);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+int bpf_map_offload_update_elem(struct bpf_map *map,
+ void *key, void *value, u64 flags)
+{
+ struct bpf_offloaded_map *offmap = map_to_offmap(map);
+ int ret = -ENODEV;
+
+ if (unlikely(flags > BPF_EXIST))
+ return -EINVAL;
+
+ down_read(&bpf_devs_lock);
+ if (offmap->netdev)
+ ret = offmap->dev_ops->map_update_elem(offmap, key, value,
+ flags);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+int bpf_map_offload_delete_elem(struct bpf_map *map, void *key)
+{
+ struct bpf_offloaded_map *offmap = map_to_offmap(map);
+ int ret = -ENODEV;
+
+ down_read(&bpf_devs_lock);
+ if (offmap->netdev)
+ ret = offmap->dev_ops->map_delete_elem(offmap, key);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key)
+{
+ struct bpf_offloaded_map *offmap = map_to_offmap(map);
+ int ret = -ENODEV;
+
+ down_read(&bpf_devs_lock);
+ if (offmap->netdev)
+ ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+struct ns_get_path_bpf_map_args {
+ struct bpf_offloaded_map *offmap;
+ struct bpf_map_info *info;
+};
+
+static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data)
+{
+ struct ns_get_path_bpf_map_args *args = private_data;
+ struct ns_common *ns;
+ struct net *net;
+
+ rtnl_lock();
+ down_read(&bpf_devs_lock);
+
+ if (args->offmap->netdev) {
+ args->info->ifindex = args->offmap->netdev->ifindex;
+ net = dev_net(args->offmap->netdev);
+ get_net(net);
+ ns = &net->ns;
+ } else {
+ args->info->ifindex = 0;
+ ns = NULL;
+ }
+
+ up_read(&bpf_devs_lock);
+ rtnl_unlock();
+
+ return ns;
+}
+
+int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map)
+{
+ struct ns_get_path_bpf_map_args args = {
+ .offmap = map_to_offmap(map),
+ .info = info,
+ };
+ struct inode *ns_inode;
+ struct path ns_path;
+ void *res;
+
+ res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args);
+ if (IS_ERR(res)) {
+ if (!info->ifindex)
+ return -ENODEV;
+ return PTR_ERR(res);
+ }
+
+ ns_inode = ns_path.dentry->d_inode;
+ info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev);
+ info->netns_ino = ns_inode->i_ino;
+ path_put(&ns_path);
+
+ return 0;
+}
+
+static bool __bpf_offload_dev_match(struct bpf_prog *prog,
+ struct net_device *netdev)
+{
+ struct bpf_offload_netdev *ondev1, *ondev2;
+ struct bpf_prog_offload *offload;
+
+ if (!bpf_prog_is_dev_bound(prog->aux))
+ return false;
+
+ offload = prog->aux->offload;
+ if (!offload)
+ return false;
+ if (offload->netdev == netdev)
+ return true;
+
+ ondev1 = bpf_offload_find_netdev(offload->netdev);
+ ondev2 = bpf_offload_find_netdev(netdev);
+
+ return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev;
+}
+
+bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev)
+{
+ bool ret;
+
+ down_read(&bpf_devs_lock);
+ ret = __bpf_offload_dev_match(prog, netdev);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_match);
+
+bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map)
+{
+ struct bpf_offloaded_map *offmap;
+ bool ret;
+
+ if (!bpf_map_is_dev_bound(map))
+ return bpf_map_offload_neutral(map);
+ offmap = map_to_offmap(map);
+
+ down_read(&bpf_devs_lock);
+ ret = __bpf_offload_dev_match(prog, offmap->netdev);
+ up_read(&bpf_devs_lock);
+
+ return ret;
+}
+
+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:
+ up_write(&bpf_devs_lock);
+ kfree(ondev);
+ return err;
+}
+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:
+ up_write(&bpf_devs_lock);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister);
+
+struct bpf_offload_dev *bpf_offload_dev_create(void)
+{
+ struct bpf_offload_dev *offdev;
+ int err;
+
+ down_write(&bpf_devs_lock);
+ if (!offdevs_inited) {
+ err = rhashtable_init(&offdevs, &offdevs_params);
+ if (err)
+ return ERR_PTR(err);
+ offdevs_inited = true;
+ }
+ up_write(&bpf_devs_lock);
+
+ offdev = kzalloc(sizeof(*offdev), GFP_KERNEL);
+ if (!offdev)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&offdev->netdevs);
+
+ return offdev;
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_create);
+
+void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev)
+{
+ WARN_ON(!list_empty(&offdev->netdevs));
+ kfree(offdev);
+}
+EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy);