From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f70.google.com (mail-pg0-f70.google.com [74.125.83.70]) by kanga.kvack.org (Postfix) with ESMTP id 60F196B000E for ; Mon, 18 Jun 2018 04:28:02 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id b7-v6so4962394pgv.5 for ; Mon, 18 Jun 2018 01:28:02 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id r59-v6si14062788plb.314.2018.06.18.01.28.01 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 Jun 2018 01:28:01 -0700 (PDT) From: Greg Kroah-Hartman Subject: [PATCH 4.16 244/279] x86/pkeys/selftests: Fix pkey exhaustion test off-by-one Date: Mon, 18 Jun 2018 10:13:49 +0200 Message-Id: <20180618080618.870305371@linuxfoundation.org> In-Reply-To: <20180618080608.851973560@linuxfoundation.org> References: <20180618080608.851973560@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dave Hansen , Andrew Morton , Dave Hansen , Linus Torvalds , Michael Ellermen , Peter Zijlstra , Ram Pai , Shuah Khan , Thomas Gleixner , linux-mm@kvack.org, Ingo Molnar , Sasha Levin 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dave Hansen [ Upstream commit f50b4878329ab61d8e05796f655adeb6f5fb57c6 ] In our "exhaust all pkeys" test, we make sure that there is the expected number available. Turns out that the test did not cover the execute-only key, but discussed it anyway. It did *not* discuss the test-allocated key. Now that we have a test for the mprotect(PROT_EXEC) case, this off-by-one issue showed itself. Correct the off-by- one and add the explanation for the case we missed. Signed-off-by: Dave Hansen Cc: Andrew Morton Cc: Dave Hansen Cc: Linus Torvalds Cc: Michael Ellermen Cc: Peter Zijlstra Cc: Ram Pai Cc: Shuah Khan Cc: Thomas Gleixner Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20180509171350.E1656B95@viggo.jf.intel.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/x86/protection_keys.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/tools/testing/selftests/x86/protection_keys.c +++ b/tools/testing/selftests/x86/protection_keys.c @@ -1163,12 +1163,15 @@ void test_pkey_alloc_exhaust(int *ptr, u pkey_assert(i < NR_PKEYS*2); /* - * There are 16 pkeys supported in hardware. One is taken - * up for the default (0) and another can be taken up by - * an execute-only mapping. Ensure that we can allocate - * at least 14 (16-2). + * There are 16 pkeys supported in hardware. Three are + * allocated by the time we get here: + * 1. The default key (0) + * 2. One possibly consumed by an execute-only mapping. + * 3. One allocated by the test code and passed in via + * 'pkey' to this function. + * Ensure that we can allocate at least another 13 (16-3). */ - pkey_assert(i >= NR_PKEYS-2); + pkey_assert(i >= NR_PKEYS-3); for (i = 0; i < nr_allocated_pkeys; i++) { err = sys_pkey_free(allocated_pkeys[i]);