From patchwork Wed Jan 8 01:07:19 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13929739 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 D77B71DFFD; Wed, 8 Jan 2025 00:55:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736297729; cv=none; b=lYuRJ8CIKmVX6onPSXfvrJBj3AdDPvskX/x5TC2OUl2GPdu5j/cJ9SmcsidUMCd7V0CDi0iQBiQXH3VsociLVlxBAhsyDhqzX03aEkIwJGZUDi2H2rpBgmLNdMizAu+ni7IbIAwH2RuFmIM4PH9usiCvtT07odUTADLJkbNp4VM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736297729; c=relaxed/simple; bh=OaeQP4EayPGKx0jec3R854zhhMGyvzlvCYKHU1bdgqI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=LLPrULhvPKzYg+eVm3i6fECSY6AaMELhnaWaijlGdnZsWTmKtzSjSWCWP54MT+0mrU2qvCmoE4FbO9xK1AhtYZ4/ojPLJsjHOfK3RrFxG+zYy4w0Yt4d2nDAA8q+7Of37rkguhBO2EX5RD/Zi0Q5SzI0dcduce4C5MNd9qDPfeQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4YSTwR54z0z4f3lfV; Wed, 8 Jan 2025 08:55:03 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 14E841A0D64; Wed, 8 Jan 2025 08:55:25 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgBHq1_1zH1nBtZdAQ--.51859S11; Wed, 08 Jan 2025 08:55:24 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, netdev@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , houtao1@huawei.com, xukuohai@huawei.com Subject: [PATCH bpf-next v2 07/16] bpf: Disable migration when destroying sock storage Date: Wed, 8 Jan 2025 09:07:19 +0800 Message-Id: <20250108010728.207536-8-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20250108010728.207536-1-houtao@huaweicloud.com> References: <20250108010728.207536-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgBHq1_1zH1nBtZdAQ--.51859S11 X-Coremail-Antispam: 1UD129KBjvJXoW7Kr13CFW5ZF17Xr1xCry8Krg_yoW8AF1UpF Z7tr9xKr4DX3yrursxJan3AryfAw4aga47K395Cw1Sqrs3XF98Kw1fCFnY9a43Aryvqryx Xwn0qF98Cr4xZa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPvb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2 AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6r W5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_JFI_Gr1lIxAIcVC0I7IYx2IY6xkF 7I0E14v26r4UJVWxJr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14 v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuY vjxUF9NVUUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao When destroying sock storage, it invokes bpf_local_storage_destroy() to remove all storage elements saved in the sock storage. The destroy procedure will call bpf_selem_free() to free the element, and bpf_selem_free() calls bpf_obj_free_fields() to free the special fields in map value (e.g., kptr). Since kptrs may be allocated from bpf memory allocator, migrate_{disable|enable} pairs are necessary for the freeing of these kptrs. To simplify reasoning about when migrate_disable() is needed for the freeing of these dynamically-allocated kptrs, let the caller to guarantee migration is disabled before invoking bpf_obj_free_fields(). Therefore, the patch adds migrate_{disable|enable} pair in bpf_sock_storage_free(). The migrate_{disable|enable} pairs in the underlying implementation of bpf_obj_free_fields() will be removed by The following patch. Signed-off-by: Hou Tao --- net/core/bpf_sk_storage.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index 2f4ed83a75ae6..aa536ecd5d390 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -50,15 +50,16 @@ void bpf_sk_storage_free(struct sock *sk) { struct bpf_local_storage *sk_storage; + migrate_disable(); rcu_read_lock(); sk_storage = rcu_dereference(sk->sk_bpf_storage); - if (!sk_storage) { - rcu_read_unlock(); - return; - } + if (!sk_storage) + goto out; bpf_local_storage_destroy(sk_storage); +out: rcu_read_unlock(); + migrate_enable(); } static void bpf_sk_storage_map_free(struct bpf_map *map)