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 0FC726B000E for ; Fri, 27 Apr 2018 13:50:01 -0400 (EDT) Received: by mail-pg0-f70.google.com with SMTP id b18-v6so2117967pgv.14 for ; Fri, 27 Apr 2018 10:50:01 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTPS id h185si1642671pfe.332.2018.04.27.10.49.59 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 Apr 2018 10:50:00 -0700 (PDT) Subject: [PATCH 8/9] x86, pkeys, selftests: add allow faults on unknown keys From: Dave Hansen Date: Fri, 27 Apr 2018 10:45:40 -0700 References: <20180427174527.0031016C@viggo.jf.intel.com> In-Reply-To: <20180427174527.0031016C@viggo.jf.intel.com> Message-Id: <20180427174540.91C386B5@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, Dave Hansen , linuxram@us.ibm.com, tglx@linutronix.de, dave.hansen@intel.com, mpe@ellerman.id.au, mingo@kernel.org, akpm@linux-foundation.org, shuah@kernel.org From: Dave Hansen The exec-only pkey is allocated inside the kernel and userspace is not told what it is. So, allow PK faults to occur that have an unknown key. Signed-off-by: Dave Hansen Cc: Ram Pai Cc: Thomas Gleixner Cc: Dave Hansen Cc: Michael Ellermen Cc: Ingo Molnar Cc: Andrew Morton Cc: Shuah Khan --- b/tools/testing/selftests/x86/protection_keys.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff -puN tools/testing/selftests/x86/protection_keys.c~pkeys-selftests-unknown-exec-only-key tools/testing/selftests/x86/protection_keys.c --- a/tools/testing/selftests/x86/protection_keys.c~pkeys-selftests-unknown-exec-only-key 2018-03-26 10:22:37.549170187 -0700 +++ b/tools/testing/selftests/x86/protection_keys.c 2018-03-26 10:22:37.553170187 -0700 @@ -922,13 +922,21 @@ void *malloc_pkey(long size, int prot, u } int last_pkru_faults; +#define UNKNOWN_PKEY -2 void expected_pk_fault(int pkey) { dprintf2("%s(): last_pkru_faults: %d pkru_faults: %d\n", __func__, last_pkru_faults, pkru_faults); dprintf2("%s(%d): last_si_pkey: %d\n", __func__, pkey, last_si_pkey); pkey_assert(last_pkru_faults + 1 == pkru_faults); - pkey_assert(last_si_pkey == pkey); + + /* + * For exec-only memory, we do not know the pkey in + * advance, so skip this check. + */ + if (pkey != UNKNOWN_PKEY) + pkey_assert(last_si_pkey == pkey); + /* * The signal handler shold have cleared out PKRU to let the * test program continue. We now have to restore it. _