From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751334AbdBWW3b (ORCPT ); Thu, 23 Feb 2017 17:29:31 -0500 Received: from mga02.intel.com ([134.134.136.20]:42972 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751242AbdBWW3a (ORCPT ); Thu, 23 Feb 2017 17:29:30 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,198,1484035200"; d="scan'208";a="52028700" Subject: [PATCH 2/2] selftests, x86, pkeys: test with random, unallocated protection keys To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Dave Hansen , shuah@kernel.org, linux-kselftest@vger.kernel.org From: Dave Hansen Date: Thu, 23 Feb 2017 14:26:04 -0800 References: <20170223222603.A022ED65@viggo.jf.intel.com> In-Reply-To: <20170223222603.A022ED65@viggo.jf.intel.com> Message-Id: <20170223222604.D3AE8473@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Shuah, I assume you'll take this patch in through the selftests tree. -- From: Dave Hansen The kernel pkeys code had a minor bug where it did some large shifts to an integer which is undefined behavior in C. It didn't cause any real harm, but it is screwy behavior that the kernel should have rejected. Add a test case for this. Signed-off-by: Dave Hansen ec: Kirill A. Shutemov Cc: Shuah Khan Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: x86@kernel.org --- b/tools/testing/selftests/x86/protection_keys.c | 25 ++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff -puN tools/testing/selftests/x86/protection_keys.c~pkeys-better-selftests-of-random-pkey tools/testing/selftests/x86/protection_keys.c --- a/tools/testing/selftests/x86/protection_keys.c~pkeys-better-selftests-of-random-pkey 2017-02-23 14:21:05.168391529 -0800 +++ b/tools/testing/selftests/x86/protection_keys.c 2017-02-23 14:23:03.244671815 -0800 @@ -1123,6 +1123,30 @@ void test_pkey_syscalls_on_non_allocated } /* Assumes that all pkeys other than 'pkey' are unallocated */ +void test_pkey_syscalls_on_non_allocated_random_pkey(int *ptr, u16 pkey) +{ + int err; + int nr_tests = 0; + + while (nr_tests < 1000) { + int test_pkey = rand(); + + /* do not test with the pkey we know is good */ + if (pkey == test_pkey) + continue; + + dprintf1("trying free/mprotect bad pkey: %2d\n", test_pkey); + err = sys_pkey_free(test_pkey); + pkey_assert(err); + + err = sys_mprotect_pkey(ptr, PAGE_SIZE, PROT_READ, test_pkey); + pkey_assert(err); + + nr_tests++; + } +} + +/* Assumes that all pkeys other than 'pkey' are unallocated */ void test_pkey_syscalls_bad_args(int *ptr, u16 pkey) { int err; @@ -1320,6 +1344,7 @@ void (*pkey_tests[])(int *ptr, u16 pkey) test_executing_on_unreadable_memory, test_ptrace_of_child, test_pkey_syscalls_on_non_allocated_pkey, + test_pkey_syscalls_on_non_allocated_random_pkey, test_pkey_syscalls_bad_args, test_pkey_alloc_exhaust, }; _