Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2020-08-08

The following pull-request contains BPF updates for your *net* tree.

We've added 11 non-merge commits during the last 2 day(s) which contain
a total of 24 files changed, 216 insertions(+), 135 deletions(-).

The main changes are:

1) Fix UAPI for BPF map iterator before it gets frozen to allow for more
   extensions/customization in future, from Yonghong Song.

2) Fix selftests build to undo verbose build output, from Andrii Nakryiko.

3) Fix inlining compilation error on bpf_do_trace_printk() due to variable
   argument lists, from Stanislav Fomichev.

4) Fix an uninitialized pointer warning at btf__parse_raw() in libbpf,
   from Daniel T. Lee.

5) Fix several compilation warnings in selftests with regards to ignoring
   return value, from Jianlin Lv.

6) Fix interruptions by switching off timeout for BPF tests, from Jiri Benc.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 29 insertions, 29 deletions

diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c
index 363b9cafc2d8..b6715964b685 100644
--- a/kernel/bpf/bpf_iter.c
+++ b/kernel/bpf/bpf_iter.c
@@ -338,8 +338,8 @@ 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);
+	if (iter_link->tinfo->reg_info->detach_target)
+		iter_link->tinfo->reg_info->detach_target(&iter_link->aux);
 }
 
 static void bpf_iter_link_dealloc(struct bpf_link *link)
@@ -390,15 +390,35 @@ bool bpf_link_is_iter(struct bpf_link *link)
 
 int bpf_iter_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 {
+	union bpf_iter_link_info __user *ulinfo;
 	struct bpf_link_primer link_primer;
 	struct bpf_iter_target_info *tinfo;
-	struct bpf_iter_aux_info aux = {};
+	union bpf_iter_link_info linfo;
 	struct bpf_iter_link *link;
-	u32 prog_btf_id, target_fd;
+	u32 prog_btf_id, linfo_len;
 	bool existed = false;
-	struct bpf_map *map;
 	int err;
 
+	if (attr->link_create.target_fd || attr->link_create.flags)
+		return -EINVAL;
+
+	memset(&linfo, 0, sizeof(union bpf_iter_link_info));
+
+	ulinfo = u64_to_user_ptr(attr->link_create.iter_info);
+	linfo_len = attr->link_create.iter_info_len;
+	if (!ulinfo ^ !linfo_len)
+		return -EINVAL;
+
+	if (ulinfo) {
+		err = bpf_check_uarg_tail_zero(ulinfo, sizeof(linfo),
+					       linfo_len);
+		if (err)
+			return err;
+		linfo_len = min_t(u32, linfo_len, sizeof(linfo));
+		if (copy_from_user(&linfo, ulinfo, linfo_len))
+			return -EFAULT;
+	}
+
 	prog_btf_id = prog->aux->attach_btf_id;
 	mutex_lock(&targets_mutex);
 	list_for_each_entry(tinfo, &targets, list) {
@@ -411,13 +431,6 @@ 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;
@@ -431,28 +444,15 @@ 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 (tinfo->reg_info->attach_target) {
+		err = tinfo->reg_info->attach_target(prog, &linfo, &link->aux);
 		if (err) {
-			bpf_map_put_with_uref(map);
-			goto cleanup_link;
+			bpf_link_cleanup(&link_primer);
+			return err;
 		}
-
-		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,