From: Amery Hung <ameryhung@gmail.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, alexei.starovoitov@gmail.com,
andrii@kernel.org, daniel@iogearbox.net, eddyz87@gmail.com,
memxor@gmail.com, martin.lau@kernel.org, shakeel.butt@linux.dev,
roman.gushchin@linux.dev, kuniyu@google.com,
kerneljasonxing@gmail.com, ameryhung@gmail.com,
kernel-team@meta.com
Subject: [PATCH bpf-next v2 05/15] bpf: Replace prog_list_prog() check with direct pl->prog and pl->link check
Date: Tue, 23 Jun 2026 10:49:53 -0700 [thread overview]
Message-ID: <20260623175006.3136053-6-ameryhung@gmail.com> (raw)
In-Reply-To: <20260623175006.3136053-1-ameryhung@gmail.com>
From: Martin KaFai Lau <martin.lau@kernel.org>
prog_list_length() and compute_effective_progs() use !prog_list_prog(pl)
to skip a 'detaching' pl.
When pl->link is not NULL, prog_list_prog(pl) returns
the pl->link->link.prog. This does not work for the upcoming struct_ops
patch where pl->link is not NULL but pl->link->link.prog is NULL,
because a struct_ops map is attached to the cgroup instead of a BPF prog.
To prepare for the upcoming struct_ops patch, this patch
replaces the prog_list_prog() test with the
"!pl->prog && !pl->link". In __cgroup_bpf_detach(),
both pl->prog and pl->link are set to NULL, so testing
"!pl->prog && !pl->link" is the same test to tell
if a pl is being detached. This change should be a no-op.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Amery Hung <ameryhung@gmail.com>
---
kernel/bpf/cgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index b64f6757096c..b100c04cb9c8 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -408,7 +408,7 @@ static u32 prog_list_length(struct hlist_head *head, int *preorder_cnt)
u32 cnt = 0;
hlist_for_each_entry(pl, head, node) {
- if (!prog_list_prog(pl))
+ if (!pl->prog && !pl->link)
continue;
if (preorder_cnt && (pl->flags & BPF_F_PREORDER))
(*preorder_cnt)++;
@@ -482,7 +482,7 @@ static int compute_effective_progs(struct cgroup *cgrp,
init_bstart = bstart;
hlist_for_each_entry(pl, &p->bpf.progs[atype], node) {
- if (!prog_list_prog(pl))
+ if (!pl->prog && !pl->link)
continue;
if (pl->flags & BPF_F_PREORDER) {
--
2.53.0-Meta
next prev parent reply other threads:[~2026-06-23 17:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-23 17:49 [PATCH bpf-next v2 00/15] bpf: A common way to attach struct_ops to a cgroup Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 01/15] bpf: Remove __rcu tagging in st_link->map Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 02/15] bpf: Make struct_ops tasks_rcu grace period optional Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 03/15] bpf: Add bpf_struct_ops accessor helpers Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 04/15] bpf: Remove unnecessary prog_list_prog() check Amery Hung
2026-06-23 17:49 ` Amery Hung [this message]
2026-06-23 17:49 ` [PATCH bpf-next v2 06/15] bpf: Add prog_list_init_item(), prog_list_replace_item(), and prog_list_id() Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 07/15] bpf: Move LSM trampoline unlink into bpf_cgroup_link_auto_detach() Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 08/15] bpf: Add a few bpf_cgroup_array_* helper functions Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 09/15] bpf: Add infrastructure to support attaching struct_ops to cgroups Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 10/15] bpf: Allow all struct_ops to use bpf_dynptr_from_skb() Amery Hung
2026-06-23 17:49 ` [PATCH bpf-next v2 11/15] bpf: tcp: Support selected sock_ops callbacks as struct_ops Amery Hung
2026-06-23 17:50 ` [PATCH bpf-next v2 12/15] bpf: tcp: Support parse/len/write header option hooks in bpf_tcp_ops Amery Hung
2026-06-23 17:50 ` [PATCH bpf-next v2 13/15] libbpf: Support attaching struct_ops to a cgroup Amery Hung
2026-06-23 17:50 ` [PATCH bpf-next v2 14/15] selftests/bpf: Test " Amery Hung
2026-06-23 17:50 ` [PATCH bpf-next v2 15/15] selftests/bpf: Add test for bpf_tcp_ops header option hooks Amery Hung
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