From patchwork Sat Feb 27 00:06:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shuah Khan X-Patchwork-Id: 388029 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=-18.8 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, 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 858E4C433E6 for ; Sat, 27 Feb 2021 00:08:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 586B864F0E for ; Sat, 27 Feb 2021 00:08:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230010AbhB0AHr (ORCPT ); Fri, 26 Feb 2021 19:07:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229967AbhB0AHp (ORCPT ); Fri, 26 Feb 2021 19:07:45 -0500 Received: from mail-io1-xd36.google.com (mail-io1-xd36.google.com [IPv6:2607:f8b0:4864:20::d36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C535EC061786 for ; Fri, 26 Feb 2021 16:07:04 -0800 (PST) Received: by mail-io1-xd36.google.com with SMTP id p16so11509541ioj.4 for ; Fri, 26 Feb 2021 16:07:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/Zkk2haeiidsDP/ZwhF5BhqM9bPgv7fbdC7NxG6iRRw=; b=ZqyQCczX3RZW7Jszm8n6gTRjBH3oMoNrIOAtNYn3E0o4VlY0Ny9fXxmpeFdgAlUMRu o1cdHDYUKTpe1O+SoymyQ2X1REjAiQ0hlXiaEgQH8DCDxOvJfyRMSqKje5KJ71QhXVpe LlhlaZLTkZYMGTRJqaQBMUtC+NDbKFm0N4Qvs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/Zkk2haeiidsDP/ZwhF5BhqM9bPgv7fbdC7NxG6iRRw=; b=bjktEqEYKfy4tHWVltD9vN0kDnZFW2C1R7ugPoaFsSJjvuDsbyFmYVELaCbguyJhcv ORLAx2560zb92ZO6MTHsnoXXW5e60X83vgCTfDvNtqwo9oAsGrFi6RPxdnU7Ps6bdfx9 42lhTbkLoOTdmkJAwnEAdUaCk9S1trIDYioX1dUSJN1JiFg8KscGe68qVaK8EA7TDla7 VfmLR6qhcjtnJVIXO4oqbESsqztVauzsPfMoqzAX8f7x4WItJxLNJY2RDFWXycINZoU0 T5YHU/arG0qhsSvIKPHl2UjQgprA1I5LMt8LXsvBVVMBVACYkSmh4NfuQoAy9dGdqTES c7wQ== X-Gm-Message-State: AOAM533uROzs/43UT+dAe8feqrwlfEodZZwmwcW8csmYYMpMYBgHhc0+ VX7etBqndd/fXFc0ScP1Dr6Yyw== X-Google-Smtp-Source: ABdhPJyKxa0J4mJ1Q3Us1nF3cWKJxJOJv3J6flPS+IR1ljgqemUo/UlwUf5R3XFcSZdCq19XPZPoZA== X-Received: by 2002:a02:cc2a:: with SMTP id o10mr5563036jap.62.1614384424250; Fri, 26 Feb 2021 16:07:04 -0800 (PST) Received: from shuah-t480s.internal (c-24-9-64-241.hsd1.co.comcast.net. [24.9.64.241]) by smtp.gmail.com with ESMTPSA id w16sm5228805ilh.35.2021.02.26.16.07.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 26 Feb 2021 16:07:03 -0800 (PST) From: Shuah Khan To: peterz@infradead.org, mingo@redhat.com, will@kernel.org, kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org Cc: Shuah Khan , ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/3] lockdep: add lockdep_assert_not_held() Date: Fri, 26 Feb 2021 17:06:58 -0700 Message-Id: X-Mailer: git-send-email 2.27.0 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Some kernel functions must be called without holding a specific lock. Add lockdep_assert_not_held() to be used in these functions to detect incorrect calls while holding a lock. lockdep_assert_not_held() provides the opposite functionality of lockdep_assert_held() which is used to assert calls that require holding a specific lock. Incorporates suggestions from Peter Zijlstra to avoid misfires when lockdep_off() is employed. The need for lockdep_assert_not_held() came up in a discussion on ath10k patch. ath10k_drain_tx() and i915_vma_pin_ww() are examples of functions that can use lockdep_assert_not_held(). Link: https://lore.kernel.org/lkml/37a29c383bff2fb1605241ee6c7c9be3784fb3c6.1613171185.git.skhan@linuxfoundation.org/ Link: https://lore.kernel.org/linux-wireless/871rdmu9z9.fsf@codeaurora.org/ Signed-off-by: Shuah Khan --- include/linux/lockdep.h | 11 ++++++++--- kernel/locking/lockdep.c | 6 +++++- 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 7b7ebf2e28ec..dbd9ea846b36 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -301,8 +301,12 @@ extern void lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie); #define lockdep_depth(tsk) (debug_locks ? (tsk)->lockdep_depth : 0) -#define lockdep_assert_held(l) do { \ - WARN_ON(debug_locks && !lockdep_is_held(l)); \ +#define lockdep_assert_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 0); \ + } while (0) + +#define lockdep_assert_not_held(l) do { \ + WARN_ON(debug_locks && lockdep_is_held(l) == 1); \ } while (0) #define lockdep_assert_held_write(l) do { \ @@ -393,7 +397,8 @@ extern int lockdep_is_held(const void *); #define lockdep_is_held_type(l, r) (1) #define lockdep_assert_held(l) do { (void)(l); } while (0) -#define lockdep_assert_held_write(l) do { (void)(l); } while (0) +#define lockdep_assert_not_held(l) do { (void)(l); } while (0) +#define lockdep_assert_held_write(l) do { (void)(l); } while (0) #define lockdep_assert_held_read(l) do { (void)(l); } while (0) #define lockdep_assert_held_once(l) do { (void)(l); } while (0) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index c6d0c1dc6253..818d0ceed3eb 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -5539,8 +5539,12 @@ noinstr int lock_is_held_type(const struct lockdep_map *lock, int read) unsigned long flags; int ret = 0; + /* + * avoid false negative lockdep_assert_held() and + * lockdep_assert_not_held() + */ if (unlikely(!lockdep_enabled())) - return 1; /* avoid false negative lockdep_assert_held() */ + return -1; raw_local_irq_save(flags); check_flags(flags);