Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751534AbdGPD6s (ORCPT ); Sat, 15 Jul 2017 23:58:48 -0400 Received: from mail-qk0-f196.google.com ([209.85.220.196]:36096 "EHLO mail-qk0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437AbdGPD6o (ORCPT ); Sat, 15 Jul 2017 23:58:44 -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 17/62] powerpc: implementation for arch_set_user_pkey_access() Date: Sat, 15 Jul 2017 20:56:19 -0700 Message-Id: <1500177424-13695-18-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: 2509 Lines: 88 This patch provides the detailed implementation for a user to allocate a key and enable it in the hardware. It provides the plumbing, but it cannot be used till the system call is implemented. The next patch will do so. Signed-off-by: Ram Pai --- arch/powerpc/include/asm/pkeys.h | 10 +++++++++- arch/powerpc/mm/pkeys.c | 27 +++++++++++++++++++++++++++ 2 files changed, 36 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h index 7f5c21d..1943e6b 100644 --- a/arch/powerpc/include/asm/pkeys.h +++ b/arch/powerpc/include/asm/pkeys.h @@ -3,6 +3,10 @@ extern bool pkey_inited; #define arch_max_pkey() 32 +#define AMR_RD_BIT 0x1UL +#define AMR_WR_BIT 0x2UL +#define IAMR_EX_BIT 0x1UL +#define AMR_BITS_PER_PKEY 2 #define ARCH_VM_PKEY_FLAGS (VM_PKEY_BIT0 | VM_PKEY_BIT1 | VM_PKEY_BIT2 | \ VM_PKEY_BIT3 | VM_PKEY_BIT4) #define AMR_BITS_PER_PKEY 2 @@ -113,10 +117,14 @@ static inline int arch_override_mprotect_pkey(struct vm_area_struct *vma, return 0; } +extern int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val); static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey, unsigned long init_val) { - return 0; + if (!pkey_inited) + return -1; + return __arch_set_user_pkey_access(tsk, pkey, init_val); } static inline void pkey_mm_init(struct mm_struct *mm) diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index 04ee361..98d0391 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -17,6 +17,10 @@ bool pkey_inited; #define pkeyshift(pkey) ((arch_max_pkey()-pkey-1) * AMR_BITS_PER_PKEY) +static bool is_pkey_enabled(int pkey) +{ + return !!(read_uamor() & (0x3ul << pkeyshift(pkey))); +} static inline void init_amr(int pkey, u8 init_bits) { @@ -60,3 +64,26 @@ void __arch_deactivate_pkey(int pkey) { pkey_status_change(pkey, false); } + +/* + * set the access right in AMR IAMR and UAMOR register + * for @pkey to that specified in @init_val. + */ +int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey, + unsigned long init_val) +{ + u64 new_amr_bits = 0x0ul; + + if (!is_pkey_enabled(pkey)) + return -1; + + /* Set the bits we need in AMR: */ + if (init_val & PKEY_DISABLE_ACCESS) + new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT; + else if (init_val & PKEY_DISABLE_WRITE) + new_amr_bits |= AMR_WR_BIT; + + init_amr(pkey, new_amr_bits); + + return 0; +} -- 1.7.1