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=-17.0 required=3.0 tests=BAYES_00,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 ED82BC4361B for ; Wed, 9 Dec 2020 01:13:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0C3C23A5A for ; Wed, 9 Dec 2020 01:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726421AbgLIBNq (ORCPT ); Tue, 8 Dec 2020 20:13:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:37570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726138AbgLIBNq (ORCPT ); Tue, 8 Dec 2020 20:13:46 -0500 From: paulmck@kernel.org Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, iamjoonsoo.kim@lge.com, andrii@kernel.org, "Paul E. McKenney" , Christoph Lameter , Pekka Enberg , David Rientjes , linux-mm@kvack.org Subject: [PATCH v2 sl-b 2/5] mm: Make mem_dump_obj() handle NULL and zero-sized pointers Date: Tue, 8 Dec 2020 17:13:00 -0800 Message-Id: <20201209011303.32737-2-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20201209011124.GA31164@paulmck-ThinkPad-P72> References: <20201209011124.GA31164@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: rcu@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 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 d0e60d2..8c2449f 100644 --- a/mm/util.c +++ b/mm/util.c @@ -985,7 +985,12 @@ 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