From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f46.google.com (mail-pa0-f46.google.com [209.85.220.46]) by kanga.kvack.org (Postfix) with ESMTP id 57F27828DF for ; Fri, 29 Jan 2016 13:17:43 -0500 (EST) Received: by mail-pa0-f46.google.com with SMTP id ho8so45056215pac.2 for ; Fri, 29 Jan 2016 10:17:43 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id l9si2100720pfi.44.2016.01.29.10.17.20 for ; Fri, 29 Jan 2016 10:17:21 -0800 (PST) Subject: [PATCH 26/31] x86, pkeys: add arch_validate_pkey() From: Dave Hansen Date: Fri, 29 Jan 2016 10:17:20 -0800 References: <20160129181642.98E7D468@viggo.jf.intel.com> In-Reply-To: <20160129181642.98E7D468@viggo.jf.intel.com> Message-Id: <20160129181720.887AFBC2@viggo.jf.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, x86@kernel.org, torvalds@linux-foundation.org, Dave Hansen , dave.hansen@linux.intel.com From: Dave Hansen The syscall-level code is passed a protection key and need to return an appropriate error code if the protection key is bogus. We will be using this in subsequent patches. Note that this also begins a series of arch-specific calls that we need to expose in otherwise arch-independent code. We create a linux/pkeys.h header where we will put *all* the stubs for these functions. Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner --- b/arch/x86/Kconfig | 1 + b/arch/x86/include/asm/pkeys.h | 6 ++++++ b/include/linux/pkeys.h | 25 +++++++++++++++++++++++++ b/mm/Kconfig | 2 ++ 4 files changed, 34 insertions(+) diff -puN /dev/null arch/x86/include/asm/pkeys.h --- /dev/null 2015-12-10 15:28:13.322405854 -0800 +++ b/arch/x86/include/asm/pkeys.h 2016-01-28 15:52:28.284767218 -0800 @@ -0,0 +1,6 @@ +#ifndef _ASM_X86_PKEYS_H +#define _ASM_X86_PKEYS_H + +#define arch_max_pkey() (boot_cpu_has(X86_FEATURE_OSPKE) ? 16 : 1) + +#endif /*_ASM_X86_PKEYS_H */ diff -puN arch/x86/Kconfig~pkeys-71-arch_validate_pkey arch/x86/Kconfig --- a/arch/x86/Kconfig~pkeys-71-arch_validate_pkey 2016-01-28 15:52:28.279766989 -0800 +++ b/arch/x86/Kconfig 2016-01-28 15:52:28.285767264 -0800 @@ -156,6 +156,7 @@ config X86 select X86_DEV_DMA_OPS if X86_64 select X86_FEATURE_NAMES if PROC_FS select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS + select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS config INSTRUCTION_DECODER def_bool y diff -puN /dev/null include/linux/pkeys.h --- /dev/null 2015-12-10 15:28:13.322405854 -0800 +++ b/include/linux/pkeys.h 2016-01-28 15:52:28.285767264 -0800 @@ -0,0 +1,25 @@ +#ifndef _LINUX_PKEYS_H +#define _LINUX_PKEYS_H + +#include +#include + +#ifdef CONFIG_ARCH_HAS_PKEYS +#include +#else /* ! CONFIG_ARCH_HAS_PKEYS */ +#define arch_max_pkey() (1) +#endif /* ! CONFIG_ARCH_HAS_PKEYS */ + +/* + * This is called from mprotect_pkey(). + * + * Returns true if the protection keys is valid. + */ +static inline bool validate_pkey(int pkey) +{ + if (pkey < 0) + return false; + return (pkey < arch_max_pkey()); +} + +#endif /* _LINUX_PKEYS_H */ diff -puN mm/Kconfig~pkeys-71-arch_validate_pkey mm/Kconfig --- a/mm/Kconfig~pkeys-71-arch_validate_pkey 2016-01-28 15:52:28.281767081 -0800 +++ b/mm/Kconfig 2016-01-28 15:52:28.286767310 -0800 @@ -671,3 +671,5 @@ config FRAME_VECTOR config ARCH_USES_HIGH_VMA_FLAGS bool +config ARCH_HAS_PKEYS + bool _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org