From patchwork Thu Jan 28 02:19:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kuniyuki Iwashima X-Patchwork-Id: 373148 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8586EC433E6 for ; Thu, 28 Jan 2021 02:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4EFD664DC4 for ; Thu, 28 Jan 2021 02:20:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231181AbhA1CU1 (ORCPT ); Wed, 27 Jan 2021 21:20:27 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:32492 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231137AbhA1CUS (ORCPT ); Wed, 27 Jan 2021 21:20:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.co.jp; i=@amazon.co.jp; q=dns/txt; s=amazon201209; t=1611800418; x=1643336418; h=from:to:cc:subject:date:message-id:mime-version; bh=nxnE6peKQuQI6EPAUsAkzTReC/Ivi8beCiT3uzrFH3A=; b=eFPJUo+s9hUWTbuFbZE28PkOcI+j4F4ySM5xfsweEi6Y/+syrdUDC7+X vYsggnyVcJY7CVMaoJCFOzBzTg9QFsLhHAbGKqT3SKVvQtFypBBjj6T70 JD+sLF2Y7lFF6ojp2sNRrETluoAXWTkX1HteJT0Rr+iDNS/7Whptgv+aw E=; X-IronPort-AV: E=Sophos;i="5.79,381,1602547200"; d="scan'208";a="78132507" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-5bdc5131.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 28 Jan 2021 02:19:36 +0000 Received: from EX13MTAUWB001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan3.pdx.amazon.com [10.236.137.198]) by email-inbound-relay-2b-5bdc5131.us-west-2.amazon.com (Postfix) with ESMTPS id 32BBFA1C40; Thu, 28 Jan 2021 02:19:35 +0000 (UTC) Received: from EX13D04ANC001.ant.amazon.com (10.43.157.89) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 28 Jan 2021 02:19:34 +0000 Received: from 38f9d3582de7.ant.amazon.com (10.43.161.253) by EX13D04ANC001.ant.amazon.com (10.43.157.89) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Thu, 28 Jan 2021 02:19:30 +0000 From: Kuniyuki Iwashima To: "David S . Miller" , Jakub Kicinski , Eric Dumazet CC: Amit Shah , Kuniyuki Iwashima , Kuniyuki Iwashima , , , Tariq Toukan , "Boris Pismenny" Subject: [PATCH v3 net-next] net: Remove redundant calls of sk_tx_queue_clear(). Date: Thu, 28 Jan 2021 11:19:04 +0900 Message-ID: <20210128021905.57471-1-kuniyu@amazon.co.jp> X-Mailer: git-send-email 2.17.2 (Apple Git-113) MIME-Version: 1.0 X-Originating-IP: [10.43.161.253] X-ClientProxiedBy: EX13D43UWA001.ant.amazon.com (10.43.160.44) To EX13D04ANC001.ant.amazon.com (10.43.157.89) Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The commit 41b14fb8724d ("net: Do not clear the sock TX queue in sk_set_socket()") removes sk_tx_queue_clear() from sk_set_socket() and adds it instead in sk_alloc() and sk_clone_lock() to fix an issue introduced in the commit e022f0b4a03f ("net: Introduce sk_tx_queue_mapping"). On the other hand, the original commit had already put sk_tx_queue_clear() in sk_prot_alloc(): the callee of sk_alloc() and sk_clone_lock(). Thus sk_tx_queue_clear() is called twice in each path. If we remove sk_tx_queue_clear() in sk_alloc() and sk_clone_lock(), it currently works well because (i) sk_tx_queue_mapping is defined between sk_dontcopy_begin and sk_dontcopy_end, and (ii) sock_copy() called after sk_prot_alloc() in sk_clone_lock() does not overwrite sk_tx_queue_mapping. However, if we move sk_tx_queue_mapping out of the no copy area, it introduces a bug unintentionally. Therefore, this patch adds a runtime check to take care of the order of sock_copy() and sk_tx_queue_clear() and removes sk_tx_queue_clear() from sk_prot_alloc() so that it does the only allocation and its callers initialize fields. v3: * Remove Fixes: tag * Add BUILD_BUG_ON * Remove sk_tx_queue_clear() from sk_prot_alloc() instead of sk_alloc() and sk_clone_lock() v2: https://lore.kernel.org/netdev/20210127132215.10842-1-kuniyu@amazon.co.jp/ * Remove Reviewed-by: tag v1: https://lore.kernel.org/netdev/20210127125018.7059-1-kuniyu@amazon.co.jp/ CC: Tariq Toukan CC: Boris Pismenny Signed-off-by: Kuniyuki Iwashima --- net/core/sock.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/core/sock.c b/net/core/sock.c index bbcd4b97eddd..cfbd62a5e079 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1657,6 +1657,16 @@ static void sock_copy(struct sock *nsk, const struct sock *osk) #ifdef CONFIG_SECURITY_NETWORK void *sptr = nsk->sk_security; #endif + + /* If we move sk_tx_queue_mapping out of the private section, + * we must check if sk_tx_queue_clear() is called after + * sock_copy() in sk_clone_lock(). + */ + BUILD_BUG_ON(offsetof(struct sock, sk_tx_queue_mapping) < + offsetof(struct sock, sk_dontcopy_begin) || + offsetof(struct sock, sk_tx_queue_mapping) >= + offsetof(struct sock, sk_dontcopy_end)); + memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin)); memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end, @@ -1690,7 +1700,6 @@ static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority, if (!try_module_get(prot->owner)) goto out_free_sec; - sk_tx_queue_clear(sk); } return sk;