Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-06-06

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 50 files changed, 1887 insertions(+), 527 deletions(-).

The main changes are:

1) Add a user space notification mechanism via epoll when a struct_ops
   object is getting detached/unregistered, from Kui-Feng Lee.

2) Big batch of BPF selftest refactoring for sockmap and BPF congctl
   tests, from Geliang Tang.

3) Add BTF field (type and string fields, right now) iterator support
   to libbpf instead of using existing callback-based approaches,
   from Andrii Nakryiko.

4) Extend BPF selftests for the latter with a new btf_field_iter
   selftest, from Alan Maguire.

5) Add new kfuncs for a generic, open-coded bits iterator,
   from Yafang Shao.

6) Fix BPF selftests' kallsyms_find() helper under kernels configured
   with CONFIG_LTO_CLANG_THIN, from Yonghong Song.

7) Remove a bunch of unused structs in BPF selftests,
   from David Alan Gilbert.

8) Convert test_sockmap section names into names understood by libbpf
   so it can deduce program type and attach type, from Jakub Sitnicki.

9) Extend libbpf with the ability to configure log verbosity
   via LIBBPF_LOG_LEVEL environment variable, from Mykyta Yatsenko.

10) Fix BPF selftests with regards to bpf_cookie and find_vma flakiness
    in nested VMs, from Song Liu.

11) Extend riscv32/64 JITs to introduce shift/add helpers to generate Zba
    optimization, from Xiao Wang.

12) Enable BPF programs to declare arrays and struct fields with kptr,
    bpf_rb_root, and bpf_list_head, from Kui-Feng Lee.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  selftests/bpf: Drop useless arguments of do_test in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp in bpf_tcp_ca
  selftests/bpf: Use start_test in test_dctcp_fallback in bpf_tcp_ca
  selftests/bpf: Add start_test helper in bpf_tcp_ca
  selftests/bpf: Use connect_to_fd_opts in do_test in bpf_tcp_ca
  libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
  selftests/bpf: Add btf_field_iter selftests
  selftests/bpf: Fix send_signal test with nested CONFIG_PARAVIRT
  libbpf: Remove callback-based type/string BTF field visitor helpers
  bpftool: Use BTF field iterator in btfgen
  libbpf: Make use of BTF field iterator in BTF handling code
  libbpf: Make use of BTF field iterator in BPF linker code
  libbpf: Add BTF field iterator
  selftests/bpf: Ignore .llvm.<hash> suffix in kallsyms_find()
  selftests/bpf: Fix bpf_cookie and find_vma in nested VM
  selftests/bpf: Test global bpf_list_head arrays.
  selftests/bpf: Test global bpf_rb_root arrays and fields in nested struct types.
  selftests/bpf: Test kptr arrays and kptrs in nested struct fields.
  bpf: limit the number of levels of a nested struct type.
  bpf: look into the types of the fields of a struct type recursively.
  ...
====================

Link: https://lore.kernel.org/r/20240606223146.23020-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 28 insertions, 6 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index f45ed6adc092..869265852d51 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -3151,6 +3151,13 @@ static void bpf_link_show_fdinfo(struct seq_file *m, struct file *filp)
 }
 #endif
 
+static __poll_t bpf_link_poll(struct file *file, struct poll_table_struct *pts)
+{
+	struct bpf_link *link = file->private_data;
+
+	return link->ops->poll(file, pts);
+}
+
 static const struct file_operations bpf_link_fops = {
 #ifdef CONFIG_PROC_FS
 	.show_fdinfo	= bpf_link_show_fdinfo,
@@ -3160,6 +3167,16 @@ static const struct file_operations bpf_link_fops = {
 	.write		= bpf_dummy_write,
 };
 
+static const struct file_operations bpf_link_fops_poll = {
+#ifdef CONFIG_PROC_FS
+	.show_fdinfo	= bpf_link_show_fdinfo,
+#endif
+	.release	= bpf_link_release,
+	.read		= bpf_dummy_read,
+	.write		= bpf_dummy_write,
+	.poll		= bpf_link_poll,
+};
+
 static int bpf_link_alloc_id(struct bpf_link *link)
 {
 	int id;
@@ -3202,7 +3219,9 @@ int bpf_link_prime(struct bpf_link *link, struct bpf_link_primer *primer)
 		return id;
 	}
 
-	file = anon_inode_getfile("bpf_link", &bpf_link_fops, link, O_CLOEXEC);
+	file = anon_inode_getfile("bpf_link",
+				  link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
+				  link, O_CLOEXEC);
 	if (IS_ERR(file)) {
 		bpf_link_free_id(id);
 		put_unused_fd(fd);
@@ -3230,7 +3249,9 @@ int bpf_link_settle(struct bpf_link_primer *primer)
 
 int bpf_link_new_fd(struct bpf_link *link)
 {
-	return anon_inode_getfd("bpf-link", &bpf_link_fops, link, O_CLOEXEC);
+	return anon_inode_getfd("bpf-link",
+				link->ops->poll ? &bpf_link_fops_poll : &bpf_link_fops,
+				link, O_CLOEXEC);
 }
 
 struct bpf_link *bpf_link_get_from_fd(u32 ufd)
@@ -3240,7 +3261,7 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd)
 
 	if (!f.file)
 		return ERR_PTR(-EBADF);
-	if (f.file->f_op != &bpf_link_fops) {
+	if (f.file->f_op != &bpf_link_fops && f.file->f_op != &bpf_link_fops_poll) {
 		fdput(f);
 		return ERR_PTR(-EINVAL);
 	}
@@ -4972,7 +4993,7 @@ static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
 					     uattr);
 	else if (f.file->f_op == &btf_fops)
 		err = bpf_btf_get_info_by_fd(f.file, f.file->private_data, attr, uattr);
-	else if (f.file->f_op == &bpf_link_fops)
+	else if (f.file->f_op == &bpf_link_fops || f.file->f_op == &bpf_link_fops_poll)
 		err = bpf_link_get_info_by_fd(f.file, f.file->private_data,
 					      attr, uattr);
 	else
@@ -5107,7 +5128,7 @@ static int bpf_task_fd_query(const union bpf_attr *attr,
 	if (!file)
 		return -EBADF;
 
-	if (file->f_op == &bpf_link_fops) {
+	if (file->f_op == &bpf_link_fops || file->f_op == &bpf_link_fops_poll) {
 		struct bpf_link *link = file->private_data;
 
 		if (link->ops == &bpf_raw_tp_link_lops) {
@@ -5417,10 +5438,11 @@ static int link_detach(union bpf_attr *attr)
 	return ret;
 }
 
-static struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
+struct bpf_link *bpf_link_inc_not_zero(struct bpf_link *link)
 {
 	return atomic64_fetch_add_unless(&link->refcnt, 1, 0) ? link : ERR_PTR(-ENOENT);
 }
+EXPORT_SYMBOL(bpf_link_inc_not_zero);
 
 struct bpf_link *bpf_link_by_id(u32 id)
 {