From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f199.google.com (mail-pg1-f199.google.com [209.85.215.199]) by kanga.kvack.org (Postfix) with ESMTP id B8BE26B1CB6 for ; Mon, 19 Nov 2018 16:55:01 -0500 (EST) Received: by mail-pg1-f199.google.com with SMTP id t26so4674344pgu.18 for ; Mon, 19 Nov 2018 13:55:01 -0800 (PST) Received: from mga11.intel.com (mga11.intel.com. [192.55.52.93]) by mx.google.com with ESMTPS id s8si4586261plq.345.2018.11.19.13.55.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 19 Nov 2018 13:55:00 -0800 (PST) From: Yu-cheng Yu Subject: [RFC PATCH v6 06/11] x86/cet/ibt: Add arch_prctl functions for IBT Date: Mon, 19 Nov 2018 13:49:29 -0800 Message-Id: <20181119214934.6174-7-yu-cheng.yu@intel.com> In-Reply-To: <20181119214934.6174-1-yu-cheng.yu@intel.com> References: <20181119214934.6174-1-yu-cheng.yu@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Andy Lutomirski , Balbir Singh , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue Cc: Yu-cheng Yu Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE to include Indirect Branch Tracking features. Introduce: arch_prctl(ARCH_X86_CET_SET_LEGACY_BITMAP, unsigned long *addr) Enable the Indirect Branch Tracking legacy code bitmap. The parameter 'addr' is a pointer to a user buffer that has: *addr = IBT bitmap base address *(addr + 1) = IBT bitmap size Signed-off-by: H.J. Lu Signed-off-by: Yu-cheng Yu --- arch/x86/include/uapi/asm/prctl.h | 2 ++ arch/x86/kernel/cet_prctl.c | 21 +++++++++++++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index d962f0ec9ccf..5eb9aeb5c662 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -18,5 +18,7 @@ #define ARCH_X86_CET_DISABLE 0x3002 #define ARCH_X86_CET_LOCK 0x3003 #define ARCH_X86_CET_ALLOC_SHSTK 0x3004 +#define ARCH_X86_CET_GET_LEGACY_BITMAP 0x3005 /* deprecated */ +#define ARCH_X86_CET_SET_LEGACY_BITMAP 0x3006 #endif /* _ASM_X86_PRCTL_H */ diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c index 320dbb620d61..a752d73cb1f4 100644 --- a/arch/x86/kernel/cet_prctl.c +++ b/arch/x86/kernel/cet_prctl.c @@ -21,6 +21,8 @@ static int handle_get_status(unsigned long arg2) if (current->thread.cet.shstk_enabled) features |= GNU_PROPERTY_X86_FEATURE_1_SHSTK; + if (current->thread.cet.ibt_enabled) + features |= GNU_PROPERTY_X86_FEATURE_1_IBT; shstk_base = current->thread.cet.shstk_base; shstk_size = current->thread.cet.shstk_size; @@ -56,6 +58,17 @@ static int handle_alloc_shstk(unsigned long arg2) return 0; } +static int handle_bitmap(unsigned long arg2) +{ + unsigned long addr, size; + + if (get_user(addr, (unsigned long __user *)arg2) || + get_user(size, (unsigned long __user *)arg2 + 1)) + return -EFAULT; + + return cet_setup_ibt_bitmap(addr, size); +} + int prctl_cet(int option, unsigned long arg2) { if (!cpu_x86_cet_enabled()) @@ -70,6 +83,8 @@ int prctl_cet(int option, unsigned long arg2) return -EPERM; if (arg2 & GNU_PROPERTY_X86_FEATURE_1_SHSTK) cet_disable_free_shstk(current); + if (arg2 & GNU_PROPERTY_X86_FEATURE_1_IBT) + cet_disable_ibt(); return 0; @@ -80,6 +95,12 @@ int prctl_cet(int option, unsigned long arg2) case ARCH_X86_CET_ALLOC_SHSTK: return handle_alloc_shstk(arg2); + /* + * Allocate legacy bitmap and return address & size to user. + */ + case ARCH_X86_CET_SET_LEGACY_BITMAP: + return handle_bitmap(arg2); + default: return -EINVAL; } -- 2.17.1