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=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 4C2F8C433DB for ; Wed, 6 Jan 2021 01:18:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E2B822D01 for ; Wed, 6 Jan 2021 01:18:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726657AbhAFBSd (ORCPT ); Tue, 5 Jan 2021 20:18:33 -0500 Received: from mail.kernel.org ([198.145.29.99]:60152 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726244AbhAFBSc (ORCPT ); Tue, 5 Jan 2021 20:18:32 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D197F22D6F; Wed, 6 Jan 2021 01:17:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609895871; bh=gLFu+KgQ4ck58W8mpBbjs74dHggSLHFYOf67lC5Cr3I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uif8275PxW3KW/QFDS83CgQMCU8FRKEU74nYX24qobr0YhgYZ7Yat4jReuiCK9xBh i2YhNYMtxbwPSP2nctigH6YbL9EHvPP42z7n4AhQv1bDlpgkCM4iaD6Rpft217gQeM 2gvHLjq0fM20fgLr+R5SvOuMyQO/NTD8LhDDoKtxXhLS7hcAM9f8OqYKU0O0iOKm23 0cgFCUzXLXc33Bd59PYlhfBTutUNy5MGTRj+Tw3ykxsa/fSdwlhsKm0LVNmmVxH9zR zn5XseL8WDdomGn1DZ2EBqGN74Y/x2nXYZZDlu0+ykt3uYsXOk0fbCMuOMDvcJcq2A EF1wttLK4d63g== From: paulmck@kernel.org To: linux-kernel@vger.kernel.org, rcu@vger.kernel.org, linux-mm@kvack.org Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, ming.lei@redhat.com, axboe@kernel.dk, kernel-team@fb.com, "Paul E. McKenney" Subject: [PATCH mm,percpu_ref,rcu 2/6] mm: Make mem_dump_obj() handle NULL and zero-sized pointers Date: Tue, 5 Jan 2021 17:17:46 -0800 Message-Id: <20210106011750.13709-2-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210106011603.GA13180@paulmck-ThinkPad-P72> References: <20210106011603.GA13180@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" This commit makes mem_dump_obj() call out NULL and zero-sized pointers specially instead of classifying them as non-paged memory. Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Andrew Morton Cc: Reported-by: Andrii Nakryiko Acked-by: Vlastimil Babka Signed-off-by: Paul E. McKenney --- mm/util.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/mm/util.c b/mm/util.c index da46f9d..92f23d2 100644 --- a/mm/util.c +++ b/mm/util.c @@ -997,7 +997,12 @@ int __weak memcmp_pages(struct page *page1, struct page *page2) void mem_dump_obj(void *object) { if (!virt_addr_valid(object)) { - pr_cont(" non-paged (local) memory.\n"); + if (object == NULL) + pr_cont(" NULL pointer.\n"); + else if (object == ZERO_SIZE_PTR) + pr_cont(" zero-size pointer.\n"); + else + pr_cont(" non-paged (local) memory.\n"); return; } if (kmem_valid_obj(object)) { -- 2.9.5