From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755762AbcDKPyd (ORCPT ); Mon, 11 Apr 2016 11:54:33 -0400 Received: from mga02.intel.com ([134.134.136.20]:52849 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755450AbcDKPy2 (ORCPT ); Mon, 11 Apr 2016 11:54:28 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,462,1455004800"; d="scan'208";a="782560168" Subject: [PATCH 0/8] System Calls for Memory Protection Keys To: linux-kernel@vger.kernel.org Cc: Dave Hansen , linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org From: Dave Hansen Date: Mon, 11 Apr 2016 08:54:22 -0700 Message-Id: <20160411155422.A2B8FD0C@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Memory Protection Keys for User pages (pkeys) is a CPU feature which will first appear on Skylake Servers, but will also be supported on future non-server parts. It provides a mechanism for enforcing page-based protections, but without requiring modification of the page tables when an application changes wishes to change permissions. Patches to implement execute-only mapping support using pkeys was merged in to 4.6. But, to do anything else useful with pkeys, an application needs to be able to set the pkey field in the PTE (obviously has to be done in-kernel) and make changes to the "rights" register (using unprivileged instructions). An application also needs to have an an allocator for the keys themselves. If two different parts of an application both want to protect their data with pkeys, they first need to know which key to use for their individual purposes. This set introduces 5 system calls, in 3 logical groups: 1. PTE pkey setting (sys_pkey_mprotect(), patches #1-3) 2. Key allocation (sys_pkey_alloc() / sys_pkey_free(), patch #4) 3. Rights register manipulation (sys_pkey_set/get(), patch #5) These patches build on top of "core" pkeys support already in 4.6. This set is specifically built on f87e0434a, which is tip/x86/urgent since it contained a documentation fix. I have manpages written for some of these syscalls, and have submitted them for review to the manpages list. This set is also available here: git://git.kernel.org/pub/scm/linux/kernel/git/daveh/x86-pkeys.git pkeys-v031 I've written a set of unit tests for these interfaces, which is available as the last patch in the series and integrated in to kselftests. === diffstat === Dave Hansen (8): x86, pkeys: add fault handling for PF_PK page fault bit mm: implement new pkey_mprotect() system call x86, pkeys: make mprotect_key() mask off additional vm_flags x86: wire up mprotect_key() system call x86, pkeys: allocation/free syscalls x86, pkeys: add pkey set/get syscalls pkeys: add details of system call use to Documentation/ x86, pkeys: add self-tests Documentation/x86/protection-keys.txt | 63 + arch/alpha/include/uapi/asm/mman.h | 5 + arch/mips/include/uapi/asm/mman.h | 5 + arch/parisc/include/uapi/asm/mman.h | 5 + arch/x86/entry/syscalls/syscall_32.tbl | 5 + arch/x86/entry/syscalls/syscall_64.tbl | 5 + arch/x86/include/asm/mmu.h | 8 + arch/x86/include/asm/mmu_context.h | 25 +- arch/x86/include/asm/pkeys.h | 83 +- arch/x86/kernel/fpu/xstate.c | 73 +- arch/x86/mm/fault.c | 9 + arch/x86/mm/pkeys.c | 38 +- arch/xtensa/include/uapi/asm/mman.h | 5 + include/linux/pkeys.h | 39 +- include/uapi/asm-generic/mman-common.h | 5 + mm/mprotect.c | 134 +- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/pkey-helpers.h | 186 +++ tools/testing/selftests/x86/protection_keys.c | 1199 +++++++++++++++++ 19 files changed, 1863 insertions(+), 31 deletions(-) Cc: linux-api@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: linux-mm@kvack.org Cc: x86@kernel.org Cc: torvalds@linux-foundation.org Cc: akpm@linux-foundation.org