From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 820A8384CCE; Thu, 21 May 2026 03:24:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779333873; cv=none; b=t3ajEQzVKy/EnjPy05PyqzOxYOoLagc9rAZFqf+aOarFmX+Sk7sS8n/py/Mx2reasprbMCFtIYOoIj4bhd2CXRdUdVF07N8keFrbkZye2n4yORTHJDbg1jdN9RiVlybTpj9dXPRcVjpbKQCMBw0ZrL0n+5A2XA+kgkMMHl5O340= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779333873; c=relaxed/simple; bh=n1u7wfvS9KQ/rHla2vNiEZSupvdE/D2/76zixfz2PDg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KQPF/0MU4RQGXUguEe4KAEJtSLK7lH0fOse+afD5Y36JIGnXR8K942nMyyaYpvNu2MkwLTuIJyfaxaiDjgMQ38Q3QD0a7ZagQQO2A4qzz+PajfH6jXC/KcSun4/SRjepSyGbDUw+Z7Jkev2dan38kO6b7CUKgLj0+1D2UWljmzQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=TkZSwgeR; arc=none smtp.client-ip=95.215.58.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="TkZSwgeR" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779333870; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qkrmEkazbdspFx3y70iFA03SYZiuUXZn+VIyQDVFkvg=; b=TkZSwgeRPvCb7Mm5yNXOe8N+hh3znna4Me3OqrFOyvc3l9gHFhx+9UsVOe7BU1xuHdTIuT iktUIyVK2wL8WL3KzLc5dEehmnS+S/sxY/nF8pKDnXiCO632iNco2of0YaYmsfqYtoteG1 7uEb0TVDhomWN9LvEOO52xtm9aRvoX4= From: Kaitao Cheng To: ast@kernel.org, corbet@lwn.net, martin.lau@linux.dev, daniel@iogearbox.net, andrii@kernel.org, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, shuah@kernel.org, chengkaitao@kylinos.cn, skhan@linuxfoundation.org, memxor@gmail.com Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, vmalik@redhat.com, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next v11 4/8] bpf: Introduce the bpf_list_del kfunc. Date: Thu, 21 May 2026 11:23:02 +0800 Message-ID: <20260521032306.97118-5-kaitao.cheng@linux.dev> In-Reply-To: <20260521032306.97118-1-kaitao.cheng@linux.dev> References: <20260521032306.97118-1-kaitao.cheng@linux.dev> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Kaitao Cheng Allow users to remove any node from a linked list. We have added an additional parameter bpf_list_head *head to bpf_list_del, as the verifier requires the head parameter to check whether the lock is being held. Signed-off-by: Kaitao Cheng Reviewed-by: Eduard Zingerman --- kernel/bpf/helpers.c | 10 ++++++++++ kernel/bpf/verifier.c | 6 +++++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 59855b434f0b..804c201c28f3 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -2601,6 +2601,15 @@ __bpf_kfunc struct bpf_list_node *bpf_list_pop_back(struct bpf_list_head *head) return __bpf_list_del(head, h->prev); } +__bpf_kfunc struct bpf_list_node *bpf_list_del(struct bpf_list_head *head, + struct bpf_list_node *node__nonown_allowed) +{ + struct bpf_list_node_kern *kn = (void *)node__nonown_allowed; + + /* verifier guarantees node is a list node rather than list head */ + return __bpf_list_del(head, &kn->list_head); +} + __bpf_kfunc struct bpf_list_node *bpf_list_front(struct bpf_list_head *head) { struct list_head *h = (struct list_head *)head; @@ -4733,6 +4742,7 @@ BTF_ID_FLAGS(func, bpf_list_push_back, KF_IMPLICIT_ARGS) BTF_ID_FLAGS(func, bpf_list_push_back_impl) BTF_ID_FLAGS(func, bpf_list_pop_front, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_list_pop_back, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_list_del, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_list_front, KF_RET_NULL) BTF_ID_FLAGS(func, bpf_list_back, KF_RET_NULL) BTF_ID_FLAGS(func, bpf_task_acquire, KF_ACQUIRE | KF_RCU | KF_RET_NULL) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index f3cf8d85bea0..35eebb5e7769 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10961,6 +10961,7 @@ enum special_kfunc_type { KF_bpf_list_push_back, KF_bpf_list_pop_front, KF_bpf_list_pop_back, + KF_bpf_list_del, KF_bpf_list_front, KF_bpf_list_back, KF_bpf_cast_to_kern_ctx, @@ -11029,6 +11030,7 @@ BTF_ID(func, bpf_list_push_back_impl) BTF_ID(func, bpf_list_push_back) BTF_ID(func, bpf_list_pop_front) BTF_ID(func, bpf_list_pop_back) +BTF_ID(func, bpf_list_del) BTF_ID(func, bpf_list_front) BTF_ID(func, bpf_list_back) BTF_ID(func, bpf_cast_to_kern_ctx) @@ -11549,6 +11551,7 @@ static bool is_bpf_list_api_kfunc(u32 btf_id) return is_bpf_list_push_kfunc(btf_id) || btf_id == special_kfunc_list[KF_bpf_list_pop_front] || btf_id == special_kfunc_list[KF_bpf_list_pop_back] || + btf_id == special_kfunc_list[KF_bpf_list_del] || btf_id == special_kfunc_list[KF_bpf_list_front] || btf_id == special_kfunc_list[KF_bpf_list_back]; } @@ -11671,7 +11674,8 @@ static bool check_kfunc_is_graph_node_api(struct bpf_verifier_env *env, switch (node_field_type) { case BPF_LIST_NODE: - ret = is_bpf_list_push_kfunc(kfunc_btf_id); + ret = is_bpf_list_push_kfunc(kfunc_btf_id) || + kfunc_btf_id == special_kfunc_list[KF_bpf_list_del]; break; case BPF_RB_NODE: ret = (is_bpf_rbtree_add_kfunc(kfunc_btf_id) || -- 2.50.1 (Apple Git-155)