Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751688AbdGPD6x (ORCPT ); Sat, 15 Jul 2017 23:58:53 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:35079 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751517AbdGPD6s (ORCPT ); Sat, 15 Jul 2017 23:58:48 -0400 From: Ram Pai To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, dave.hansen@intel.com, hbabu@us.ibm.com, linuxram@us.ibm.com, arnd@arndb.de, akpm@linux-foundation.org, corbet@lwn.net, mingo@redhat.com, mhocko@kernel.org Subject: [RFC v6 19/62] powerpc: ability to create execute-disabled pkeys Date: Sat, 15 Jul 2017 20:56:21 -0700 Message-Id: <1500177424-13695-20-git-send-email-linuxram@us.ibm.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1500177424-13695-1-git-send-email-linuxram@us.ibm.com> References: <1500177424-13695-1-git-send-email-linuxram@us.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1808 Lines: 62 powerpc has hardware support to disable execute on a pkey. This patch enables the ability to create execute-disabled keys. Signed-off-by: Ram Pai --- arch/powerpc/include/asm/pkeys.h | 12 ++++++++++++ arch/powerpc/mm/pkeys.c | 10 ++++++++++ 2 files changed, 22 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 1943e6b..0e744f1 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -2,6 +2,18 @@ #define _ASM_PPC64_PKEYS_H extern bool pkey_inited; +/* override any generic PKEY Permission defines */ +#undef PKEY_DISABLE_ACCESS +#define PKEY_DISABLE_ACCESS 0x1 +#undef PKEY_DISABLE_WRITE +#define PKEY_DISABLE_WRITE 0x2 +#undef PKEY_DISABLE_EXECUTE +#define PKEY_DISABLE_EXECUTE 0x4 +#undef PKEY_ACCESS_MASK +#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\ + PKEY_DISABLE_WRITE |\ + PKEY_DISABLE_EXECUTE) + #define arch_max_pkey() 32 #define AMR_RD_BIT 0x1UL #define AMR_WR_BIT 0x2UL diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 98d0391..b9ad98d 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -73,6 +73,7 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { u64 new_amr_bits = 0x0ul; + u64 new_iamr_bits = 0x0ul; if (!is_pkey_enabled(pkey)) return -1; @@ -85,5 +86,14 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, init_amr(pkey, new_amr_bits); + /* + * By default execute is disabled. + * To enable execute, PKEY_ENABLE_EXECUTE + * needs to be specified. + */ + if ((init_val & PKEY_DISABLE_EXECUTE)) + new_iamr_bits |= IAMR_EX_BIT; + + init_iamr(pkey, new_iamr_bits); return 0; } -- 1.7.1