From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yu-cheng Yu Subject: [PATCH v5 06/11] x86/cet/ibt: Add arch_prctl functions for IBT Date: Thu, 11 Oct 2018 08:16:49 -0700 Message-ID: <20181011151654.27221-7-yu-cheng.yu@intel.com> References: <20181011151654.27221-1-yu-cheng.yu@intel.com> Return-path: In-Reply-To: <20181011151654.27221-1-yu-cheng.yu@intel.com> Sender: linux-kernel-owner@vger.kernel.org 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 , Pa Cc: Yu-cheng Yu List-Id: linux-arch.vger.kernel.org Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE to include Indirect Branch Tracking features. Introduce: arch_prctl(ARCH_X86_CET_GET_LEGACY_BITMAP, unsigned long *addr) Enable the Indirect Branch Tracking legacy code bitmap. Allocate the bitmap if the task does not have one. The parameter 'addr' is a pointer to a user buffer. On returning to the caller, the kernel fills the following: *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 | 1 + arch/x86/kernel/cet_prctl.c | 35 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index d962f0ec9ccf..fd4eae92c733 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -18,5 +18,6 @@ #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 #endif /* _ASM_X86_PRCTL_H */ diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c index 320dbb620d61..dc7e9785f5e7 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 +58,31 @@ static int handle_alloc_shstk(unsigned long arg2) return 0; } +static int handle_bitmap(unsigned long arg2) +{ + unsigned long addr, size; + + if (current->thread.cet.ibt_enabled) { + int err; + + err = cet_setup_ibt_bitmap(); + if (err) + return err; + + addr = current->thread.cet.ibt_bitmap_addr; + size = current->thread.cet.ibt_bitmap_size; + } else { + addr = 0; + size = 0; + } + + if (put_user(addr, (unsigned long __user *)arg2) || + put_user(size, (unsigned long __user *)arg2 + 1)) + return -EFAULT; + + return 0; +} + int prctl_cet(int option, unsigned long arg2) { if (!cpu_x86_cet_enabled()) @@ -70,6 +97,8 @@ 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 +109,12 @@ 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_GET_LEGACY_BITMAP: + return handle_bitmap(arg2); + default: return -EINVAL; } -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga17.intel.com ([192.55.52.151]:21581 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727400AbeJKWtp (ORCPT ); Thu, 11 Oct 2018 18:49:45 -0400 From: Yu-cheng Yu Subject: [PATCH v5 06/11] x86/cet/ibt: Add arch_prctl functions for IBT Date: Thu, 11 Oct 2018 08:16:49 -0700 Message-ID: <20181011151654.27221-7-yu-cheng.yu@intel.com> In-Reply-To: <20181011151654.27221-1-yu-cheng.yu@intel.com> References: <20181011151654.27221-1-yu-cheng.yu@intel.com> Sender: linux-arch-owner@vger.kernel.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 Message-ID: <20181011151649.73X5m44iiQrOEuE0SByWNvBt9abixHAdNC2ptL4u_NI@z> Update ARCH_X86_CET_STATUS and ARCH_X86_CET_DISABLE to include Indirect Branch Tracking features. Introduce: arch_prctl(ARCH_X86_CET_GET_LEGACY_BITMAP, unsigned long *addr) Enable the Indirect Branch Tracking legacy code bitmap. Allocate the bitmap if the task does not have one. The parameter 'addr' is a pointer to a user buffer. On returning to the caller, the kernel fills the following: *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 | 1 + arch/x86/kernel/cet_prctl.c | 35 +++++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/arch/x86/include/uapi/asm/prctl.h b/arch/x86/include/uapi/asm/prctl.h index d962f0ec9ccf..fd4eae92c733 100644 --- a/arch/x86/include/uapi/asm/prctl.h +++ b/arch/x86/include/uapi/asm/prctl.h @@ -18,5 +18,6 @@ #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 #endif /* _ASM_X86_PRCTL_H */ diff --git a/arch/x86/kernel/cet_prctl.c b/arch/x86/kernel/cet_prctl.c index 320dbb620d61..dc7e9785f5e7 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 +58,31 @@ static int handle_alloc_shstk(unsigned long arg2) return 0; } +static int handle_bitmap(unsigned long arg2) +{ + unsigned long addr, size; + + if (current->thread.cet.ibt_enabled) { + int err; + + err = cet_setup_ibt_bitmap(); + if (err) + return err; + + addr = current->thread.cet.ibt_bitmap_addr; + size = current->thread.cet.ibt_bitmap_size; + } else { + addr = 0; + size = 0; + } + + if (put_user(addr, (unsigned long __user *)arg2) || + put_user(size, (unsigned long __user *)arg2 + 1)) + return -EFAULT; + + return 0; +} + int prctl_cet(int option, unsigned long arg2) { if (!cpu_x86_cet_enabled()) @@ -70,6 +97,8 @@ 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 +109,12 @@ 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_GET_LEGACY_BITMAP: + return handle_bitmap(arg2); + default: return -EINVAL; } -- 2.17.1