From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x242.google.com (mail-qk0-x242.google.com [IPv6:2607:f8b0:400d:c09::242]) (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 3xpsrf4H8JzDrcp for ; Sat, 9 Sep 2017 08:46:58 +1000 (AEST) Received: by mail-qk0-x242.google.com with SMTP id g128so2327254qke.0 for ; Fri, 08 Sep 2017 15:46:58 -0700 (PDT) Sender: Ram Pai From: Ram Pai To: mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Cc: 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 09/25] powerpc: ability to create execute-disabled pkeys Date: Fri, 8 Sep 2017 15:44:57 -0700 Message-Id: <1504910713-7094-18-git-send-email-linuxram@us.ibm.com> In-Reply-To: <1504910713-7094-1-git-send-email-linuxram@us.ibm.com> References: <1504910713-7094-1-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 ab45cc2..f272b09 100644 --- a/arch/powerpc/include/uapi/asm/mman.h +++ b/arch/powerpc/include/uapi/asm/mman.h @@ -45,4 +45,10 @@ #define MAP_HUGE_1GB (30 << MAP_HUGE_SHIFT) /* 1GB HugeTLB Page */ #define MAP_HUGE_16GB (34 << MAP_HUGE_SHIFT) /* 16GB HugeTLB Page */ +/* 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 cc5be6a..2282864 100644 --- a/arch/powerpc/mm/pkeys.c +++ b/arch/powerpc/mm/pkeys.c @@ -24,6 +24,14 @@ void __init 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 patch further down the * line will enable it. @@ -120,10 +128,18 @@ 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_support) + 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