[RFC PATCH bpf-next v3 02/12] bpf: initial support for attaching struct ops to cgroups
From: Hui Zhu <hidden>
Date: 2026-01-23 08:56:31
Also in:
bpf, cgroups, linux-kselftest, linux-mm, lkml
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
From: Roman Gushchin <roman.gushchin@linux.dev> When a struct ops is being attached and a bpf link is created, allow to pass a cgroup fd using bpf attr, so that struct ops can be attached to a cgroup instead of globally. Attached struct ops doesn't hold a reference to the cgroup, only preserves cgroup id. Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> --- include/linux/bpf.h | 1 + kernel/bpf/bpf_struct_ops.c | 13 +++++++++++++ 2 files changed, 14 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 031682f1ad39..7c15bac782fc 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -1885,6 +1885,7 @@ struct bpf_struct_ops_link { struct bpf_link link; struct bpf_map __rcu *map; wait_queue_head_t wait_hup; + u64 cgroup_id; }; struct bpf_link_primer {
diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c
index de01cf3025b3..f575c5cd0dc8 100644
--- a/kernel/bpf/bpf_struct_ops.c
+++ b/kernel/bpf/bpf_struct_ops.c@@ -13,6 +13,7 @@ #include <linux/btf_ids.h> #include <linux/rcupdate_wait.h> #include <linux/poll.h> +#include <linux/cgroup.h> struct bpf_struct_ops_value { struct bpf_struct_ops_common_value common;
@@ -1377,6 +1378,18 @@ int bpf_struct_ops_link_create(union bpf_attr *attr) } bpf_link_init(&link->link, BPF_LINK_TYPE_STRUCT_OPS, &bpf_struct_ops_map_lops, NULL, attr->link_create.attach_type); +#ifdef CONFIG_CGROUPS + if (attr->link_create.cgroup.relative_fd) { + struct cgroup *cgrp; + + cgrp = cgroup_get_from_fd(attr->link_create.cgroup.relative_fd); + if (IS_ERR(cgrp)) + return PTR_ERR(cgrp); + + link->cgroup_id = cgroup_id(cgrp); + cgroup_put(cgrp); + } +#endif /* CONFIG_CGROUPS */ err = bpf_link_prime(&link->link, &link_primer); if (err)
--
2.43.0