From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x243.google.com (mail-qt0-x243.google.com [IPv6:2607:f8b0:400d:c0d::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3zN3jM48L8zF0w7 for ; Fri, 19 Jan 2018 12:52:07 +1100 (AEDT) Received: by mail-qt0-x243.google.com with SMTP id f4so439298qtj.6 for ; Thu, 18 Jan 2018 17:52:07 -0800 (PST) Sender: Ram Pai From: Ram Pai To: mpe@ellerman.id.au, mingo@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, arnd@arndb.de Cc: linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, dave.hansen@intel.com, benh@kernel.crashing.org, paulus@samba.org, khandual@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, hbabu@us.ibm.com, mhocko@kernel.org, bauerman@linux.vnet.ibm.com, ebiederm@xmission.com, linuxram@us.ibm.com Subject: [PATCH v10 09/27] powerpc: ability to create execute-disabled pkeys Date: Thu, 18 Jan 2018 17:50:30 -0800 Message-Id: <1516326648-22775-10-git-send-email-linuxram@us.ibm.com> In-Reply-To: <1516326648-22775-1-git-send-email-linuxram@us.ibm.com> References: <1516326648-22775-1-git-send-email-linuxram@us.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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/uapi/asm/mman.h | 6 ++++++ arch/powerpc/mm/pkeys.c | 16 ++++++++++++++++ 2 files changed, 22 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/include/uapi/asm/mman.h b/arch/powerpc/include/uapi/asm/mman.h index e63bc37..65065ce 100644 --- a/arch/powerpc/include/uapi/asm/mman.h +++ b/arch/powerpc/include/uapi/asm/mman.h @@ -30,4 +30,10 @@ #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ +/* Override any generic PKEY permission defines */ +#define PKEY_DISABLE_EXECUTE 0x4 +#undef PKEY_ACCESS_MASK +#define PKEY_ACCESS_MASK (PKEY_DISABLE_ACCESS |\ + PKEY_DISABLE_WRITE |\ + PKEY_DISABLE_EXECUTE) #endif /* _UAPI_ASM_POWERPC_MMAN_H */ diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c index eca04cd..39e9814 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -29,6 +29,14 @@ int pkey_initialize(void) int os_reserved, i; /* + * We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral + * generic defines for PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE. + * Ensure that the bits a distinct. + */ + BUILD_BUG_ON(PKEY_DISABLE_EXECUTE & + (PKEY_DISABLE_ACCESS | PKEY_DISABLE_WRITE)); + + /* * Disable the pkey system till everything is in place. A subsequent * patch will enable it. */ @@ -181,10 +189,18 @@ 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 -EINVAL; + if (init_val & PKEY_DISABLE_EXECUTE) { + if (!pkey_execute_disable_supported) + return -EINVAL; + new_iamr_bits |= IAMR_EX_BIT; + } + init_iamr(pkey, new_iamr_bits); + /* Set the bits we need in AMR: */ if (init_val & PKEY_DISABLE_ACCESS) new_amr_bits |= AMR_RD_BIT | AMR_WR_BIT; -- 1.7.1