diff options
Diffstat (limited to 'kernel/bpf/inode.c')
| -rw-r--r-- | kernel/bpf/inode.c | 172 |
1 files changed, 154 insertions, 18 deletions
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index bf6da59ae0d0..ed13645bd80c 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -150,8 +150,154 @@ static int bpf_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) return 0; } +struct map_iter { + void *key; + bool done; +}; + +static struct map_iter *map_iter(struct seq_file *m) +{ + return m->private; +} + +static struct bpf_map *seq_file_to_map(struct seq_file *m) +{ + return file_inode(m->file)->i_private; +} + +static void map_iter_free(struct map_iter *iter) +{ + if (iter) { + kfree(iter->key); + kfree(iter); + } +} + +static struct map_iter *map_iter_alloc(struct bpf_map *map) +{ + struct map_iter *iter; + + iter = kzalloc(sizeof(*iter), GFP_KERNEL | __GFP_NOWARN); + if (!iter) + goto error; + + iter->key = kzalloc(map->key_size, GFP_KERNEL | __GFP_NOWARN); + if (!iter->key) + goto error; + + return iter; + +error: + map_iter_free(iter); + return NULL; +} + +static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct bpf_map *map = seq_file_to_map(m); + void *key = map_iter(m)->key; + + if (map_iter(m)->done) + return NULL; + + if (unlikely(v == SEQ_START_TOKEN)) + goto done; + + if (map->ops->map_get_next_key(map, key, key)) { + map_iter(m)->done = true; + return NULL; + } + +done: + ++(*pos); + return key; +} + +static void *map_seq_start(struct seq_file *m, loff_t *pos) +{ + if (map_iter(m)->done) + return NULL; + + return *pos ? map_iter(m)->key : SEQ_START_TOKEN; +} + +static void map_seq_stop(struct seq_file *m, void *v) +{ +} + +static int map_seq_show(struct seq_file *m, void *v) +{ + struct bpf_map *map = seq_file_to_map(m); + void *key = map_iter(m)->key; + + if (unlikely(v == SEQ_START_TOKEN)) { + seq_puts(m, "# WARNING!! The output is for debug purpose only\n"); + seq_puts(m, "# WARNING!! The output format will change\n"); + } else { + map->ops->map_seq_show_elem(map, key, m); + } + + return 0; +} + +static const struct seq_operations bpffs_map_seq_ops = { + .start = map_seq_start, + .next = map_seq_next, + .show = map_seq_show, + .stop = map_seq_stop, +}; + +static int bpffs_map_open(struct inode *inode, struct file *file) +{ + struct bpf_map *map = inode->i_private; + struct map_iter *iter; + struct seq_file *m; + int err; + + iter = map_iter_alloc(map); + if (!iter) + return -ENOMEM; + + err = seq_open(file, &bpffs_map_seq_ops); + if (err) { + map_iter_free(iter); + return err; + } + + m = file->private_data; + m->private = iter; + + return 0; +} + +static int bpffs_map_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + + map_iter_free(map_iter(m)); + + return seq_release(inode, file); +} + +/* bpffs_map_fops should only implement the basic + * read operation for a BPF map. The purpose is to + * provide a simple user intuitive way to do + * "cat bpffs/pathto/a-pinned-map". + * + * Other operations (e.g. write, lookup...) should be realized by + * the userspace tools (e.g. bpftool) through the + * BPF_OBJ_GET_INFO_BY_FD and the map's lookup/update + * interface. + */ +static const struct file_operations bpffs_map_fops = { + .open = bpffs_map_open, + .read = seq_read, + .release = bpffs_map_release, +}; + static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw, - const struct inode_operations *iops) + const struct inode_operations *iops, + const struct file_operations *fops) { struct inode *dir = dentry->d_parent->d_inode; struct inode *inode = bpf_get_inode(dir->i_sb, dir, mode); @@ -159,6 +305,7 @@ static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw, return PTR_ERR(inode); inode->i_op = iops; + inode->i_fop = fops; inode->i_private = raw; bpf_dentry_finalize(dentry, inode, dir); @@ -167,12 +314,15 @@ static int bpf_mkobj_ops(struct dentry *dentry, umode_t mode, void *raw, static int bpf_mkprog(struct dentry *dentry, umode_t mode, void *arg) { - return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops); + return bpf_mkobj_ops(dentry, mode, arg, &bpf_prog_iops, NULL); } static int bpf_mkmap(struct dentry *dentry, umode_t mode, void *arg) { - return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops); + struct bpf_map *map = arg; + + return bpf_mkobj_ops(dentry, mode, arg, &bpf_map_iops, + map->btf ? &bpffs_map_fops : NULL); } static struct dentry * @@ -279,13 +429,6 @@ int bpf_obj_pin_user(u32 ufd, const char __user *pathname) ret = bpf_obj_do_pin(pname, raw, type); if (ret != 0) bpf_any_put(raw, type); - if ((trace_bpf_obj_pin_prog_enabled() || - trace_bpf_obj_pin_map_enabled()) && !ret) { - if (type == BPF_TYPE_PROG) - trace_bpf_obj_pin_prog(raw, ufd, pname); - if (type == BPF_TYPE_MAP) - trace_bpf_obj_pin_map(raw, ufd, pname); - } out: putname(pname); return ret; @@ -352,15 +495,8 @@ int bpf_obj_get_user(const char __user *pathname, int flags) else goto out; - if (ret < 0) { + if (ret < 0) bpf_any_put(raw, type); - } else if (trace_bpf_obj_get_prog_enabled() || - trace_bpf_obj_get_map_enabled()) { - if (type == BPF_TYPE_PROG) - trace_bpf_obj_get_prog(raw, ret, pname); - if (type == BPF_TYPE_MAP) - trace_bpf_obj_get_map(raw, ret, pname); - } out: putname(pname); return ret; |