From patchwork Sat Nov 21 03:06:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yunsheng Lin X-Patchwork-Id: 330258 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=-16.8 required=3.0 tests=BAYES_00, 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 7FD73C56202 for ; Sat, 21 Nov 2020 03:10:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47CB12240B for ; Sat, 21 Nov 2020 03:10:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727078AbgKUDKC (ORCPT ); Fri, 20 Nov 2020 22:10:02 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:8382 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725791AbgKUDKC (ORCPT ); Fri, 20 Nov 2020 22:10:02 -0500 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4CdJLF3Kclz706C; Sat, 21 Nov 2020 11:09:41 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.487.0; Sat, 21 Nov 2020 11:09:49 +0800 From: Yunsheng Lin To: , , , , , , , , , , , , , , , , CC: , , Subject: [PATCH net-next v2 1/2] lockdep: Introduce in_softirq lockdep assert Date: Sat, 21 Nov 2020 11:06:15 +0800 Message-ID: <1605927976-232804-2-git-send-email-linyunsheng@huawei.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1605927976-232804-1-git-send-email-linyunsheng@huawei.com> References: <1605927976-232804-1-git-send-email-linyunsheng@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.58] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The current semantic for napi_consume_skb() is that caller need to provide non-zero budget when calling from NAPI context, and breaking this semantic will cause hard to debug problem, because _kfree_skb_defer() need to run in atomic context in order to push the skb to the particular cpu' napi_alloc_cache atomically. So add the lockdep_assert_in_softirq() to assert when the running context is not in_softirq, in_softirq means softirq is serving or BH is disabled. Because the softirq context can be interrupted by hard IRQ or NMI context, so lockdep_assert_in_softirq() need to assert about hard IRQ or NMI context too. Suggested-by: Jakub Kicinski Signed-off-by: Yunsheng Lin --- include/linux/lockdep.h | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index f559487..f5e3d81 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -594,6 +594,12 @@ do { \ this_cpu_read(hardirqs_enabled))); \ } while (0) +#define lockdep_assert_in_softirq() \ +do { \ + WARN_ON_ONCE(__lockdep_enabled && \ + (!in_softirq() || in_irq() || in_nmi())); \ +} while (0) + #else # define might_lock(lock) do { } while (0) # define might_lock_read(lock) do { } while (0) @@ -605,6 +611,7 @@ do { \ # define lockdep_assert_preemption_enabled() do { } while (0) # define lockdep_assert_preemption_disabled() do { } while (0) +# define lockdep_assert_in_softirq() do { } while (0) #endif #ifdef CONFIG_PROVE_RAW_LOCK_NESTING