diff options
| -rw-r--r-- | include/linux/bpf.h | 16 | ||||
| -rw-r--r-- | include/uapi/linux/bpf.h | 7 | ||||
| -rw-r--r-- | kernel/bpf/bpf_iter.c | 85 | ||||
| -rw-r--r-- | kernel/bpf/map_iter.c | 30 | ||||
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 7 |
5 files changed, 128 insertions, 17 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f9c4bb08f616..4175cf1f4665 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -107,6 +107,9 @@ struct bpf_map_ops { /* BTF name and id of struct allocated by map_alloc */ const char * const map_btf_name; int *map_btf_id; + + /* bpf_iter info used to open a seq_file */ + const struct bpf_iter_seq_info *iter_seq_info; }; struct bpf_map_memory { @@ -1207,12 +1210,18 @@ int bpf_obj_get_user(const char __user *pathname, int flags); int __init bpf_iter_ ## target(args) { return 0; } struct bpf_iter_aux_info { + struct bpf_map *map; }; +typedef int (*bpf_iter_check_target_t)(struct bpf_prog *prog, + struct bpf_iter_aux_info *aux); + #define BPF_ITER_CTX_ARG_MAX 2 struct bpf_iter_reg { const char *target; + bpf_iter_check_target_t check_target; u32 ctx_arg_info_size; + enum bpf_iter_link_info req_linfo; struct bpf_ctx_arg_aux ctx_arg_info[BPF_ITER_CTX_ARG_MAX]; const struct bpf_iter_seq_info *seq_info; }; @@ -1223,6 +1232,13 @@ struct bpf_iter_meta { u64 seq_num; }; +struct bpf_iter__bpf_map_elem { + __bpf_md_ptr(struct bpf_iter_meta *, meta); + __bpf_md_ptr(struct bpf_map *, map); + __bpf_md_ptr(void *, key); + __bpf_md_ptr(void *, value); +}; + int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info); void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info); bool bpf_iter_prog_supported(struct bpf_prog *prog); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 54d0c886e3ba..828c2f6438f2 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -246,6 +246,13 @@ enum bpf_link_type { MAX_BPF_LINK_TYPE, }; +enum bpf_iter_link_info { + BPF_ITER_LINK_UNSPEC = 0, + BPF_ITER_LINK_MAP_FD = 1, + + MAX_BPF_ITER_LINK_INFO, +}; + /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command * * NONE(default): No further bpf programs allowed in the subtree. diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 8fa94cb1b5a0..363b9cafc2d8 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -14,11 +14,13 @@ struct bpf_iter_target_info { struct bpf_iter_link { struct bpf_link link; + struct bpf_iter_aux_info aux; struct bpf_iter_target_info *tinfo; }; struct bpf_iter_priv_data { struct bpf_iter_target_info *tinfo; + const struct bpf_iter_seq_info *seq_info; struct bpf_prog *prog; u64 session_id; u64 seq_num; @@ -35,7 +37,8 @@ static DEFINE_MUTEX(link_mutex); /* incremented on every opened seq_file */ static atomic64_t session_id; -static int prepare_seq_file(struct file *file, struct bpf_iter_link *link); +static int prepare_seq_file(struct file *file, struct bpf_iter_link *link, + const struct bpf_iter_seq_info *seq_info); static void bpf_iter_inc_seq_num(struct seq_file *seq) { @@ -199,11 +202,25 @@ done: return copied; } +static const struct bpf_iter_seq_info * +__get_seq_info(struct bpf_iter_link *link) +{ + const struct bpf_iter_seq_info *seq_info; + + if (link->aux.map) { + seq_info = link->aux.map->ops->iter_seq_info; + if (seq_info) + return seq_info; + } + + return link->tinfo->reg_info->seq_info; +} + static int iter_open(struct inode *inode, struct file *file) { struct bpf_iter_link *link = inode->i_private; - return prepare_seq_file(file, link); + return prepare_seq_file(file, link, __get_seq_info(link)); } static int iter_release(struct inode *inode, struct file *file) @@ -218,8 +235,8 @@ static int iter_release(struct inode *inode, struct file *file) iter_priv = container_of(seq->private, struct bpf_iter_priv_data, target_private); - if (iter_priv->tinfo->reg_info->seq_info->fini_seq_private) - iter_priv->tinfo->reg_info->seq_info->fini_seq_private(seq->private); + if (iter_priv->seq_info->fini_seq_private) + iter_priv->seq_info->fini_seq_private(seq->private); bpf_prog_put(iter_priv->prog); seq->private = iter_priv; @@ -318,6 +335,11 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog) static void bpf_iter_link_release(struct bpf_link *link) { + struct bpf_iter_link *iter_link = + container_of(link, struct bpf_iter_link, link); + + if (iter_link->aux.map) + bpf_map_put_with_uref(iter_link->aux.map); } static void bpf_iter_link_dealloc(struct bpf_link *link) @@ -370,14 +392,13 @@ int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) { struct bpf_link_primer link_primer; struct bpf_iter_target_info *tinfo; + struct bpf_iter_aux_info aux = {}; struct bpf_iter_link *link; + u32 prog_btf_id, target_fd; bool existed = false; - u32 prog_btf_id; + struct bpf_map *map; int err; - if (attr->link_create.target_fd || attr->link_create.flags) - return -EINVAL; - prog_btf_id = prog->aux->attach_btf_id; mutex_lock(&targets_mutex); list_for_each_entry(tinfo, &targets, list) { @@ -390,6 +411,13 @@ int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) if (!existed) return -ENOENT; + /* Make sure user supplied flags are target expected. */ + target_fd = attr->link_create.target_fd; + if (attr->link_create.flags != tinfo->reg_info->req_linfo) + return -EINVAL; + if (!attr->link_create.flags && target_fd) + return -EINVAL; + link = kzalloc(sizeof(*link), GFP_USER | __GFP_NOWARN); if (!link) return -ENOMEM; @@ -403,21 +431,45 @@ int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog) return err; } + if (tinfo->reg_info->req_linfo == BPF_ITER_LINK_MAP_FD) { + map = bpf_map_get_with_uref(target_fd); + if (IS_ERR(map)) { + err = PTR_ERR(map); + goto cleanup_link; + } + + aux.map = map; + err = tinfo->reg_info->check_target(prog, &aux); + if (err) { + bpf_map_put_with_uref(map); + goto cleanup_link; + } + + link->aux.map = map; + } + return bpf_link_settle(&link_primer); + +cleanup_link: + bpf_link_cleanup(&link_primer); + return err; } static void init_seq_meta(struct bpf_iter_priv_data *priv_data, struct bpf_iter_target_info *tinfo, + const struct bpf_iter_seq_info *seq_info, struct bpf_prog *prog) { priv_data->tinfo = tinfo; + priv_data->seq_info = seq_info; priv_data->prog = prog; priv_data->session_id = atomic64_inc_return(&session_id); priv_data->seq_num = 0; priv_data->done_stop = false; } -static int prepare_seq_file(struct file *file, struct bpf_iter_link *link) +static int prepare_seq_file(struct file *file, struct bpf_iter_link *link, + const struct bpf_iter_seq_info *seq_info) { struct bpf_iter_priv_data *priv_data; struct bpf_iter_target_info *tinfo; @@ -433,21 +485,21 @@ static int prepare_seq_file(struct file *file, struct bpf_iter_link *link) tinfo = link->tinfo; total_priv_dsize = offsetof(struct bpf_iter_priv_data, target_private) + - tinfo->reg_info->seq_info->seq_priv_size; - priv_data = __seq_open_private(file, tinfo->reg_info->seq_info->seq_ops, + seq_info->seq_priv_size; + priv_data = __seq_open_private(file, seq_info->seq_ops, total_priv_dsize); if (!priv_data) { err = -ENOMEM; goto release_prog; } - if (tinfo->reg_info->seq_info->init_seq_private) { - err = tinfo->reg_info->seq_info->init_seq_private(priv_data->target_private, NULL); + if (seq_info->init_seq_private) { + err = seq_info->init_seq_private(priv_data->target_private, &link->aux); if (err) goto release_seq_file; } - init_seq_meta(priv_data, tinfo, prog); + init_seq_meta(priv_data, tinfo, seq_info, prog); seq = file->private_data; seq->private = priv_data->target_private; @@ -463,6 +515,7 @@ release_prog: int bpf_iter_new_fd(struct bpf_link *link) { + struct bpf_iter_link *iter_link; struct file *file; unsigned int flags; int err, fd; @@ -481,8 +534,8 @@ int bpf_iter_new_fd(struct bpf_link *link) goto free_fd; } - err = prepare_seq_file(file, - container_of(link, struct bpf_iter_link, link)); + iter_link = container_of(link, struct bpf_iter_link, link); + err = prepare_seq_file(file, iter_link, __get_seq_info(iter_link)); if (err) goto free_file; diff --git a/kernel/bpf/map_iter.c b/kernel/bpf/map_iter.c index 1a69241fb1e2..8a1f9b3355d0 100644 --- a/kernel/bpf/map_iter.c +++ b/kernel/bpf/map_iter.c @@ -98,10 +98,38 @@ static struct bpf_iter_reg bpf_map_reg_info = { .seq_info = &bpf_map_seq_info, }; +static int bpf_iter_check_map(struct bpf_prog *prog, + struct bpf_iter_aux_info *aux) +{ + return -EINVAL; +} + +DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta, + struct bpf_map *map, void *key, void *value) + +static const struct bpf_iter_reg bpf_map_elem_reg_info = { + .target = "bpf_map_elem", + .check_target = bpf_iter_check_map, + .req_linfo = BPF_ITER_LINK_MAP_FD, + .ctx_arg_info_size = 2, + .ctx_arg_info = { + { offsetof(struct bpf_iter__bpf_map_elem, key), + PTR_TO_RDONLY_BUF_OR_NULL }, + { offsetof(struct bpf_iter__bpf_map_elem, value), + PTR_TO_RDWR_BUF_OR_NULL }, + }, +}; + static int __init bpf_map_iter_init(void) { + int ret; + bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id; - return bpf_iter_reg_target(&bpf_map_reg_info); + ret = bpf_iter_reg_target(&bpf_map_reg_info); + if (ret) + return ret; + + return bpf_iter_reg_target(&bpf_map_elem_reg_info); } late_initcall(bpf_map_iter_init); diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 54d0c886e3ba..828c2f6438f2 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -246,6 +246,13 @@ enum bpf_link_type { MAX_BPF_LINK_TYPE, }; +enum bpf_iter_link_info { + BPF_ITER_LINK_UNSPEC = 0, + BPF_ITER_LINK_MAP_FD = 1, + + MAX_BPF_ITER_LINK_INFO, +}; + /* cgroup-bpf attach flags used in BPF_PROG_ATTACH command * * NONE(default): No further bpf programs allowed in the subtree. |