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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,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 0BE0FC4742C for ; Thu, 5 Nov 2020 23:47:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B55E3217A0 for ; Thu, 5 Nov 2020 23:47:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604620063; bh=rNcDc0nqZb3mhX8p82fY0o843TlkCTSfcdWRyKKOYtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=bTXBfFm6cDDVUpbA0cVx3C7FygkXTIpp0+7GhKdCnuhiPByABWlljGDKgipISjEiH QIMwC0fx8zcGgoch+TfawZLNXI3J4QdtvJCHLkQZYC1gFfSc8t26VNbie2iVO50SJP NdKTXYxHd+Ta4uMdvLuU5YVKx19IG8Ym8TCNOEII= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732920AbgKEXrm (ORCPT ); Thu, 5 Nov 2020 18:47:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:46062 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732743AbgKEXr2 (ORCPT ); Thu, 5 Nov 2020 18:47:28 -0500 Received: from paulmck-ThinkPad-P72.home (50-39-104-11.bvtn.or.frontiernet.net [50.39.104.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F394520885; Thu, 5 Nov 2020 23:47:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604620048; bh=rNcDc0nqZb3mhX8p82fY0o843TlkCTSfcdWRyKKOYtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oqOaUJ27rSn/JntrufbKXmvGU7jM2SaKMTy4Wl63Atm1CS6oWlmtyRsAEPP609Y88 y8wZKEx0cBEf/LWR1LrLBL2LIrJoPFIiwNx6G76rVmTKN1RZHsKhrrhBN9KSh12yX+ UoeHEb+CQI9cyaCgE9GN/j5fMFHfptFj7clCLMY0= From: paulmck@kernel.org 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, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 17/28] torture: Force weak-hashed pointers on console log Date: Thu, 5 Nov 2020 15:47:08 -0800 Message-Id: <20201105234719.23307-17-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20201105234658.GA23142@paulmck-ThinkPad-P72> References: <20201105234658.GA23142@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Paul E. McKenney" Although the rcutorture scripting now deals correctly with full-up security-induced pointer obfuscation, it is still counter-productive for kernel hackers who are analyzing console output. This commit therefore sets the debug_boot_weak_hash kernel boot parameter, which enables printing of weak-hashed pointers for torture-test runs. Please note that this change applies only to runs initiated by the kvm.sh scripting. If you are instead using modprobe and rmmod, it is your responsibility to build and boot the underlying kernel to your taste. Please note further that this change does not result in a security hole in normal use. The rcutorture testing runs with a negligible userspace, no networking, and no user interaction. Besides which, there is no data of value that can be extracted from an rcutorture guest OS that could not also be extracted from the host that this guest is running on. Suggested-by: Anna-Maria Gleixner Signed-off-by: Paul E. McKenney --- tools/testing/selftests/rcutorture/bin/functions.sh | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/rcutorture/bin/functions.sh b/tools/testing/selftests/rcutorture/bin/functions.sh index 51f3464..8266349 100644 --- a/tools/testing/selftests/rcutorture/bin/functions.sh +++ b/tools/testing/selftests/rcutorture/bin/functions.sh @@ -169,6 +169,7 @@ identify_qemu () { # Output arguments for the qemu "-append" string based on CPU type # and the TORTURE_QEMU_INTERACTIVE environment variable. identify_qemu_append () { + echo debug_boot_weak_hash local console=ttyS0 case "$1" in qemu-system-x86_64|qemu-system-i386) -- 2.9.5