From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 5E596C67839 for ; Thu, 13 Dec 2018 04:34:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A37820873 for ; Thu, 13 Dec 2018 04:34:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="MLFD1iEL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A37820873 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=arista.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729559AbeLMEey (ORCPT ); Wed, 12 Dec 2018 23:34:54 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:35588 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728782AbeLMEew (ORCPT ); Wed, 12 Dec 2018 23:34:52 -0500 Received: by mail-ed1-f65.google.com with SMTP id x30so919128edx.2 for ; Wed, 12 Dec 2018 20:34:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=cm38oINcLG5XGUCUAQ9j58l/pe6tRlIMeIheYi170Yw=; b=MLFD1iELn/iNfIACUM6xLVDTUdj6GnH7S5Tvu2uWV2+whASKPLZ5PLjsuIWGzWSYWc 42MfMycdEWFzFunVUAtqVrsEL9TLTpxHX3LqLXMIivT7FOtTCkwRJ9Dnv8lkoqpcWYnB n2Aut0bqKQ8hhd6MoIIcfO0O9X2AzT6Fg3ZOqUuRhtR7jWl8Ape0ckwGTEJqJRDInXGz KDZn5I8RFK47jA6DA1D+l6Gf+ftuLYglScx85W17rnY/SotkPyqXR4D7LTBc+AMoLliw yimzo6LF21CgVE36N7LlVLuHdpA21ldXEhB5R83WtVt6KBnocKW50Sc3nXvy3kw+hmLV G+LQ== 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:mime-version :content-transfer-encoding; bh=cm38oINcLG5XGUCUAQ9j58l/pe6tRlIMeIheYi170Yw=; b=UAybJyCEiin7/hVVNnKAWi86fsYvX91LP5W9SjHJF+IsTKiNWvbK++T9RwsnShdirf HWOwQ8V/BN9QYpz8ML+giZiBErH3krl1jmhtaf155ZHBlW3/2F5+r7jy6k1fTh0oC9Lp LEK3KvD8qADfFUkSe/shu4w2EHqybM25OYQ7DYNUltNXQ8nUmjaAZ0L01xgXPb8dtEhB o0/gpKHQzF3usTcr554L90qxv8K6wyhrEZEAj0eO/ewb1hmsxYmIh2jnVvStKGgyLc6q 1/UfHKgdoc6Ymlxy6U4OlZnUYvLOPWmze/6D5as2pis2vUIG4hGTUulxTRAbRY3AAtWS G0eA== X-Gm-Message-State: AA+aEWbFVkYvMkrFc8ToJ9P7Vyz4OZIVeoLsRwHTNnebJaK6OfS4/cbj qiJsEL/+bFeHLNYg9Aay0sYV83zSouA= X-Google-Smtp-Source: AFSGD/UOLuuEUrj8ppQLJCkNyT1pT+cyr3m/Nt06hnRKE4u4m/i/cZVg4y1X1VxTdD6IgctPbddW7g== X-Received: by 2002:a17:906:81cc:: with SMTP id e12-v6mr17560370ejx.138.1544675689276; Wed, 12 Dec 2018 20:34:49 -0800 (PST) Received: from Mindolluin.ire.aristanetworks.com ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id j8sm298416ede.55.2018.12.12.20.34.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Dec 2018 20:34:48 -0800 (PST) From: Dmitry Safonov To: linux-kernel@vger.kernel.org Cc: 0x7f454c46@gmail.com, Dmitry Safonov , kernel test robot , Andrew Morton , Ingo Molnar , Peter Zijlstra , Sergey Senozhatsky , Thomas Gleixner , Waiman Long Subject: [PATCH 1/2] debugobjects: Warn wrong annotation outside bucket lock Date: Thu, 13 Dec 2018 04:34:46 +0000 Message-Id: <20181213043447.23006-1-dima@arista.com> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org debugobjects checks during initialization where the real object resides. Kernel must use debug_object_init() or debug_object_init_on_stack() accordingly. I'm not sure if it's worth to check debug_object initialization place, but it seems to be well-documented. If initialization function finds that the debug object actually resides in a different place than was annotated, warning is being printed. Unfortunately, it becomes error-prone to use WARN() or printing under debugobjects bucket lock: printk() may defer work to workqueue, and realization of workqueues uses debugobjects. Further, console drivers use page allocator, potentially vmalloc() or slub/slab. Which reasonably makes lockdep to go nuts as there are debug_check_no_obj_freed() checks in allocators. Move printings out of debugobjets bucket lock to address the potential lockups. Link: lkml.kernel.org/r/20181211091154.GL23332@shao2-debian Reported-by: kernel test robot Cc: Andrew Morton Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Sergey Senozhatsky Cc: Thomas Gleixner Cc: Waiman Long Signed-off-by: Dmitry Safonov --- lib/debugobjects.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 55437fd5128b..98968219405b 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -368,13 +368,14 @@ static void debug_object_is_on_stack(void *addr, int onstack) WARN_ON(1); } -static void -__debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) +static bool +__debug_object_init(void *addr, struct debug_obj_descr *descr) { enum debug_obj_state state; struct debug_bucket *db; struct debug_obj *obj; unsigned long flags; + bool allocated = false; fill_pool(); @@ -389,9 +390,9 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) debug_objects_enabled = 0; raw_spin_unlock_irqrestore(&db->lock, flags); debug_objects_oom(); - return; + return false; } - debug_object_is_on_stack(addr, onstack); + allocated = true; } switch (obj->state) { @@ -406,7 +407,7 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) state = obj->state; raw_spin_unlock_irqrestore(&db->lock, flags); debug_object_fixup(descr->fixup_init, addr, state); - return; + return allocated; case ODEBUG_STATE_DESTROYED: debug_print_object(obj, "init"); @@ -416,6 +417,7 @@ __debug_object_init(void *addr, struct debug_obj_descr *descr, int onstack) } raw_spin_unlock_irqrestore(&db->lock, flags); + return allocated; } /** @@ -428,7 +430,8 @@ void debug_object_init(void *addr, struct debug_obj_descr *descr) if (!debug_objects_enabled) return; - __debug_object_init(addr, descr, 0); + if (__debug_object_init(addr, descr)) + debug_object_is_on_stack(addr, 0); } EXPORT_SYMBOL_GPL(debug_object_init); @@ -443,7 +446,8 @@ void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) if (!debug_objects_enabled) return; - __debug_object_init(addr, descr, 1); + if (__debug_object_init(addr, descr)) + debug_object_is_on_stack(addr, 1); } EXPORT_SYMBOL_GPL(debug_object_init_on_stack); -- 2.20.0