From: Martin KaFai Lau <martin.lau@linux.dev>
To: bpf@vger.kernel.org
Cc: 'Alexei Starovoitov ' <ast@kernel.org>,
'Andrii Nakryiko ' <andrii@kernel.org>,
'Daniel Borkmann ' <daniel@iogearbox.net>,
'Shakeel Butt ' <shakeel.butt@linux.dev>,
'Roman Gushchin ' <roman.gushchin@linux.dev>,
'Amery Hung ' <ameryhung@gmail.com>,
netdev@vger.kernel.org
Subject: [RFC PATCH bpf-next 04/12] bpf: Remove unnecessary prog_list_prog() check
Date: Tue, 19 May 2026 14:58:11 -0700 [thread overview]
Message-ID: <20260519215841.2984970-5-martin.lau@linux.dev> (raw)
In-Reply-To: <20260519215841.2984970-1-martin.lau@linux.dev>
From: Martin KaFai Lau <martin.lau@kernel.org>
Both replace_effective_prog() and purge_effective_progs() test
the "!prog_list_prog(pl)" to skip a 'detaching' pl.
When detaching a pl, pl->prog and pl->link are set to NULL in case
the update_effective_progs() failed.
However, replace_effective_prog() is not detaching a pl,
so the case "!prog_list_prog()" will not happen.
In purge_effective_prog(), the pl->prog and pl->link are restored
before calling purge_effective_progs(), so the case "!prog_list_prog()"
will not happen either.
This patch removes them as a prep work for the upcoming work
in attaching struct_ops to cgroup. When attaching a struct_ops
to cgroup, there is a link->map case and the prog_list_prog()
will not consider the link->map. The replace_effective_prog()
and purge_effective_progs() will then incorrectly skip a pl
with struct_ops map attached to it.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
kernel/bpf/cgroup.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 876f6a81a9b6..71591f6dc458 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -946,8 +946,6 @@ static void replace_effective_prog(struct cgroup *cgrp,
head = &cg->bpf.progs[atype];
hlist_for_each_entry(pl, head, node) {
- if (!prog_list_prog(pl))
- continue;
if (pl->link == link)
goto found;
pos++;
@@ -1099,8 +1097,6 @@ static void purge_effective_progs(struct cgroup *cgrp, struct bpf_prog *prog,
head = &cg->bpf.progs[atype];
hlist_for_each_entry(pl, head, node) {
- if (!prog_list_prog(pl))
- continue;
if (pl->prog == prog && pl->link == link)
goto found;
pos++;
--
2.53.0-Meta
next prev parent reply other threads:[~2026-05-19 21:59 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 21:58 [RFC PATCH bpf-next 00/12] bpf: A common way to attach struct_ops to a cgroup Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 01/12] bpf: Remove __rcu tagging in st_link->map Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 02/12] bpf: Make struct_ops tasks_rcu grace period optional Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 03/12] bpf: Add bpf_struct_ops accessor helpers Martin KaFai Lau
2026-05-19 21:58 ` Martin KaFai Lau [this message]
2026-05-19 21:58 ` [RFC PATCH bpf-next 05/12] bpf: Replace prog_list_prog() check with direct pl->prog and pl->link check Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 06/12] bpf: Add prog_list_init_item(), prog_list_replace_item(), and prog_list_id() Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 07/12] bpf: Move LSM trampoline unlink into bpf_cgroup_link_auto_detach() Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 08/12] bpf: Add a few bpf_cgroup_array_* helper functions Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 09/12] bpf: Add infrastructure to support attaching struct_ops to cgroups Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 10/12] bpf: tcp: Support selected sock_ops callbacks as struct_ops Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 11/12] libbpf: Support attaching struct_ops to a cgroup Martin KaFai Lau
2026-05-19 21:58 ` [RFC PATCH bpf-next 12/12] selftests/bpf: Test " Martin KaFai Lau
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