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=-6.9 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_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 050C7C49ED7 for ; Tue, 17 Sep 2019 03:08:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B87B320678 for ; Tue, 17 Sep 2019 03:07:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="REG49xGh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392051AbfIQDH6 (ORCPT ); Mon, 16 Sep 2019 23:07:58 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:33306 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727097AbfIQDH6 (ORCPT ); Mon, 16 Sep 2019 23:07:58 -0400 Received: by mail-pg1-f193.google.com with SMTP id n190so1194820pgn.0 for ; Mon, 16 Sep 2019 20:07:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=mC6reeLllG3tF2NGATVusvm3oTh/ZeLAirz0mAmwKGU=; b=REG49xGhZhHYiGFM2hICQTZzW4lia4QX30FXYwvGuS401EBzo1mcKjiy2TWor2jIKA qptnpbz5TtzQs1mW9OBjbysxGPUsSW/wUhrb+cMjWACtBZIeO+aLtsCDN3i0Q1AlgXh8 mlMBpSnASWmIP7pVhe2unH9IwaAB02rrhQLlE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=mC6reeLllG3tF2NGATVusvm3oTh/ZeLAirz0mAmwKGU=; b=WwT/5Fcw76+B44w+z4tBWjinQuwVDfre8d2an4Wneg1GRYNUYFpg60GDSsazY4ZEqq v155ogk02XiyabefeYUyB3r8E4/w0lQkCdXgg0l6AI5MT49BUTdOKiC8vwbIcgaeSow0 fY4VTxXSaSN/uLtMpXn6ztNwUfrXbOpU9cYKhZ5tqBQPA5Yn8TygxgiDa/dPrlewK8bK JAiqMnzJS45NjyJtoeRxXiDDQ9Ix8HWIVhZPN5uL4Fc4X00LpNq9jgiD+F0Q4xdRy4Tc NPhGZeO75i/aIee4jvPTSP+4BI8FeUgCHiDcdHpqAMwNIIKP78ucBVRj+8uJiJUpkqsQ C5PQ== X-Gm-Message-State: APjAAAWhFif5mTb7lnjF5Fw/h/4vjT8tyh/CqxwZJ2wBfo1EKDttfRKq ikZTbP7wOUxQcNzFKEqO/Xe7jQ== X-Google-Smtp-Source: APXvYqwSSU6JluvKcdZk0NzjKCQ0GNYxqiYDtSxDE+xrHz+cECKkm4QKWmRnQHdFbogeGO5EhjkO6Q== X-Received: by 2002:a62:ed17:: with SMTP id u23mr1771458pfh.147.1568689677775; Mon, 16 Sep 2019 20:07:57 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id g5sm558647pfh.133.2019.09.16.20.07.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Sep 2019 20:07:56 -0700 (PDT) Date: Mon, 16 Sep 2019 20:07:55 -0700 From: Kees Cook To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH] lockdep: Make print_lock() address visible Message-ID: <201909162006.3138C81AE0@keescook> References: <20190917013946.9EC51C60479@www.outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190917013946.9EC51C60479@www.outflux.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 16, 2019 at 06:39:46PM -0700, keescook@chromium.org wrote: > commit 519248f36d6f3c80e176f6fa844c10d94f1f5990 > Author: Paul E. McKenney > Date: Thu May 30 05:39:25 2019 -0700 > > lockdep: Make print_lock() address visible > > Security is a wonderful thing, but so is the ability to debug based on > lockdep warnings. This commit therefore makes lockdep lock addresses > visible in the clear. > > Signed-off-by: Paul E. McKenney > > diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c > index 4861cf8e274b..4aca3f4379d2 100644 > --- a/kernel/locking/lockdep.c > +++ b/kernel/locking/lockdep.c > @@ -620,7 +620,7 @@ static void print_lock(struct held_lock *hlock) > return; > } > > - printk(KERN_CONT "%p", hlock->instance); > + printk(KERN_CONT "%px", hlock->instance); > print_lock_name(lock); > printk(KERN_CONT ", at: %pS\n", (void *)hlock->acquire_ip); > } Just to clarify: this is only visible under CONFIG_LOCKDEP, yes? That's not a state anyone would run a production system under, I'd hope. -- Kees Cook