Linux-arch Archive on lore.kernel.org
 help / color / Atom feed
From: Yu-cheng Yu <yu-cheng.yu@intel.com>
To: x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	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 <arnd@arndb.de>,
	Andy Lutomirski <luto@kernel.org>,
	Balbir Singh <bsingharora@gmail.com>,
	Borislav Petkov <bp@alien8.de>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Eugene Syromiatnikov <esyr@redhat.com>,
	Florian Weimer <fweimer@redhat.com>,
	"H.J. Lu" <hjl.tools@gmail.com>, Jann Horn <jannh@google.com>,
	Jonathan Corbet <corbet@lwn.net>,
	Kees Cook <keescook@chromium.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Nadav Amit <nadav.amit@gmail.com>,
	Oleg Nesterov <oleg@redhat.com>, Pavel Machek <pavel@ucw.cz>,
	Peter Zijlstra <peterz@infradead.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
	Vedvyas Shanbhogue <vedvyas.shanbhogue@intel.com>,
	Dave Martin <Dave.Martin@arm.com>,
	Weijiang Yang <weijiang.yang@intel.com>,
	Pengfei Xu <pengfei.xu@intel.com>
Cc: Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: [PATCH v14 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack
Date: Mon, 12 Oct 2020 08:38:29 -0700
Message-ID: <20201012153850.26996-6-yu-cheng.yu@intel.com> (raw)
In-Reply-To: <20201012153850.26996-1-yu-cheng.yu@intel.com>

Shadow Stack provides protection against function return address
corruption.  It is active when the processor supports it, the kernel has
CONFIG_X86_SHADOW_STACK_USER, and the application is built for the feature.
This is only implemented for the 64-bit kernel.  When it is enabled, legacy
non-shadow stack applications continue to work, but without protection.

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
---
 arch/x86/Kconfig                      | 33 +++++++++++++++++++++++++++
 scripts/as-x86_64-has-shadow-stack.sh |  4 ++++
 2 files changed, 37 insertions(+)
 create mode 100755 scripts/as-x86_64-has-shadow-stack.sh

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7101ac64bb20..415fcc869afc 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1927,6 +1927,39 @@ config X86_INTEL_TSX_MODE_AUTO
 	  side channel attacks- equals the tsx=auto command line parameter.
 endchoice
 
+config AS_HAS_SHADOW_STACK
+	def_bool $(success,$(srctree)/scripts/as-x86_64-has-shadow-stack.sh $(CC))
+	help
+	  Test the assembler for shadow stack instructions.
+
+config X86_CET
+	def_bool n
+
+config ARCH_HAS_SHADOW_STACK
+	def_bool n
+
+config X86_SHADOW_STACK_USER
+	prompt "Intel Shadow Stacks for user-mode"
+	def_bool n
+	depends on CPU_SUP_INTEL && X86_64
+	depends on AS_HAS_SHADOW_STACK
+	select ARCH_USES_HIGH_VMA_FLAGS
+	select X86_CET
+	select ARCH_HAS_SHADOW_STACK
+	help
+	  Shadow Stacks provides protection against program stack
+	  corruption.  It's a hardware feature.  This only matters
+	  if you have the right hardware.  It's a security hardening
+	  feature and apps must be enabled to use it.  You get no
+	  protection "for free" on old userspace.  The hardware can
+	  support user and kernel, but this option is for user space
+	  only.
+	  Support for this feature is only known to be present on
+	  processors released in 2020 or later.  CET features are also
+	  known to increase kernel text size by 3.7 KB.
+
+	  If unsure, say N.
+
 config EFI
 	bool "EFI runtime service support"
 	depends on ACPI
diff --git a/scripts/as-x86_64-has-shadow-stack.sh b/scripts/as-x86_64-has-shadow-stack.sh
new file mode 100755
index 000000000000..fac1d363a1b8
--- /dev/null
+++ b/scripts/as-x86_64-has-shadow-stack.sh
@@ -0,0 +1,4 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+echo "wrussq %rax, (%rbx)" | $* -x assembler -c -
-- 
2.21.0


  parent reply index

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-12 15:38 [PATCH v14 00/26] Control-flow Enforcement: " Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 01/26] Documentation/x86: Add CET description Yu-cheng Yu
2020-11-06 17:34   ` Borislav Petkov
2020-11-06 18:16     ` Yu, Yu-cheng
2020-11-06 18:28       ` Borislav Petkov
2020-11-06 18:32         ` Yu, Yu-cheng
2020-10-12 15:38 ` [PATCH v14 02/26] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2020-11-06 18:49   ` Borislav Petkov
2020-11-06 19:48     ` Yu, Yu-cheng
2020-11-06 20:11       ` Borislav Petkov
2020-11-06 20:14         ` Yu, Yu-cheng
2020-10-12 15:38 ` [PATCH v14 03/26] x86/fpu/xstate: Introduce CET MSR XSAVES supervisor states Yu-cheng Yu
2020-10-12 19:58   ` Cyrill Gorcunov
2020-10-12 20:48     ` Yu, Yu-cheng
2020-10-12 15:38 ` [PATCH v14 04/26] x86/cet: Add control-protection fault handler Yu-cheng Yu
2020-10-12 15:38 ` Yu-cheng Yu [this message]
2020-10-12 15:38 ` [PATCH v14 06/26] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 07/26] x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 08/26] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 09/26] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 10/26] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 11/26] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY_HW to _PAGE_COW Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 12/26] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 13/26] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 15/26] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 16/26] mm: Add guard pages around a shadow stack Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 17/26] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 18/26] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 19/26] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 20/26] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 21/26] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 22/26] binfmt_elf: Define GNU_PROPERTY_X86_FEATURE_1_AND properties Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 23/26] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 24/26] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 25/26] x86/cet/shstk: Add arch_prctl functions for " Yu-cheng Yu
2020-10-12 15:38 ` [PATCH v14 26/26] mm: Introduce PROT_SHSTK " Yu-cheng Yu
  -- strict thread matches above, loose matches on Subject: below --
2020-10-09 18:32 [PATCH v14 00/26] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2020-10-09 18:32 ` [PATCH v14 05/26] x86/cet/shstk: Add Kconfig option for user-mode " Yu-cheng Yu

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201012153850.26996-6-yu-cheng.yu@intel.com \
    --to=yu-cheng.yu@intel.com \
    --cc=Dave.Martin@arm.com \
    --cc=arnd@arndb.de \
    --cc=bp@alien8.de \
    --cc=bsingharora@gmail.com \
    --cc=corbet@lwn.net \
    --cc=dave.hansen@linux.intel.com \
    --cc=esyr@redhat.com \
    --cc=fweimer@redhat.com \
    --cc=gorcunov@gmail.com \
    --cc=hjl.tools@gmail.com \
    --cc=hpa@zytor.com \
    --cc=jannh@google.com \
    --cc=keescook@chromium.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=mike.kravetz@oracle.com \
    --cc=mingo@redhat.com \
    --cc=nadav.amit@gmail.com \
    --cc=oleg@redhat.com \
    --cc=pavel@ucw.cz \
    --cc=pengfei.xu@intel.com \
    --cc=peterz@infradead.org \
    --cc=ravi.v.shankar@intel.com \
    --cc=rdunlap@infradead.org \
    --cc=tglx@linutronix.de \
    --cc=vedvyas.shanbhogue@intel.com \
    --cc=weijiang.yang@intel.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-arch Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arch/0 linux-arch/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arch linux-arch/ https://lore.kernel.org/linux-arch \
		linux-arch@vger.kernel.org
	public-inbox-index linux-arch

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-arch


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git