From: Borislav Petkov <bp@alien8.de>
To: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: 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@amacapital.net>,
Balbir Singh <bsingharora@gmail.com>,
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>
Subject: Re: [PATCH v5 04/27] x86/fpu/xstate: Add XSAVES system states for shadow stack
Date: Thu, 8 Nov 2018 19:40:38 +0100 [thread overview]
Message-ID: <20181108184038.GJ7543@zn.tnic> (raw)
In-Reply-To: <20181011151523.27101-5-yu-cheng.yu@intel.com>
On Thu, Oct 11, 2018 at 08:15:00AM -0700, Yu-cheng Yu wrote:
> Intel Control-flow Enforcement Technology (CET) introduces the
> following MSRs into the XSAVES system states.
>
> IA32_U_CET (user-mode CET settings),
> IA32_PL3_SSP (user-mode shadow stack),
> IA32_PL0_SSP (kernel-mode shadow stack),
> IA32_PL1_SSP (ring-1 shadow stack),
> IA32_PL2_SSP (ring-2 shadow stack).
And?
That commit message got chopped off here, it seems.
> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
> ---
> arch/x86/include/asm/fpu/types.h | 22 +++++++++++++++++++++
> arch/x86/include/asm/fpu/xstate.h | 4 +++-
> arch/x86/include/uapi/asm/processor-flags.h | 2 ++
> arch/x86/kernel/fpu/xstate.c | 10 ++++++++++
> 4 files changed, 37 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
> index 202c53918ecf..e55d51d172f1 100644
> --- a/arch/x86/include/asm/fpu/types.h
> +++ b/arch/x86/include/asm/fpu/types.h
> @@ -114,6 +114,9 @@ enum xfeature {
> XFEATURE_Hi16_ZMM,
> XFEATURE_PT_UNIMPLEMENTED_SO_FAR,
> XFEATURE_PKRU,
> + XFEATURE_RESERVED,
> + XFEATURE_SHSTK_USER,
> + XFEATURE_SHSTK_KERNEL,
>
> XFEATURE_MAX,
> };
> @@ -128,6 +131,8 @@ enum xfeature {
> #define XFEATURE_MASK_Hi16_ZMM (1 << XFEATURE_Hi16_ZMM)
> #define XFEATURE_MASK_PT (1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR)
> #define XFEATURE_MASK_PKRU (1 << XFEATURE_PKRU)
> +#define XFEATURE_MASK_SHSTK_USER (1 << XFEATURE_SHSTK_USER)
> +#define XFEATURE_MASK_SHSTK_KERNEL (1 << XFEATURE_SHSTK_KERNEL)
>
> #define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
> #define XFEATURE_MASK_AVX512 (XFEATURE_MASK_OPMASK \
> @@ -229,6 +234,23 @@ struct pkru_state {
> u32 pad;
> } __packed;
>
> +/*
> + * State component 11 is Control flow Enforcement user states
Why the Camel-cased naming?
"Control" then "flow" then capitalized again "Enforcement".
Fix all occurrences pls, especially the user-visible strings.
> + */
> +struct cet_user_state {
> + u64 u_cet; /* user control flow settings */
> + u64 user_ssp; /* user shadow stack pointer */
Prefix both with "usr_" instead.
> +} __packed;
> +
> +/*
> + * State component 12 is Control flow Enforcement kernel states
> + */
> +struct cet_kernel_state {
> + u64 kernel_ssp; /* kernel shadow stack */
> + u64 pl1_ssp; /* ring-1 shadow stack */
> + u64 pl2_ssp; /* ring-2 shadow stack */
Just write "privilege level" everywhere - not "ring".
Btw, do you see how the type and the name of all those other fields in
that file are tabulated? Except yours...
> +} __packed;
> +
> struct xstate_header {
> u64 xfeatures;
> u64 xcomp_bv;
> diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
> index d8e2ec99f635..18b60748a34d 100644
> --- a/arch/x86/include/asm/fpu/xstate.h
> +++ b/arch/x86/include/asm/fpu/xstate.h
> @@ -28,7 +28,9 @@
> XFEATURE_MASK_Hi16_ZMM | \
> XFEATURE_MASK_PKRU | \
> XFEATURE_MASK_BNDREGS | \
> - XFEATURE_MASK_BNDCSR)
> + XFEATURE_MASK_BNDCSR | \
> + XFEATURE_MASK_SHSTK_USER | \
> + XFEATURE_MASK_SHSTK_KERNEL)
>
> #ifdef CONFIG_X86_64
> #define REX_PREFIX "0x48, "
> diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
> index bcba3c643e63..25311ec4b731 100644
> --- a/arch/x86/include/uapi/asm/processor-flags.h
> +++ b/arch/x86/include/uapi/asm/processor-flags.h
> @@ -130,6 +130,8 @@
> #define X86_CR4_SMAP _BITUL(X86_CR4_SMAP_BIT)
> #define X86_CR4_PKE_BIT 22 /* enable Protection Keys support */
> #define X86_CR4_PKE _BITUL(X86_CR4_PKE_BIT)
> +#define X86_CR4_CET_BIT 23 /* enable Control flow Enforcement */
> +#define X86_CR4_CET _BITUL(X86_CR4_CET_BIT)
>
> /*
> * x86-64 Task Priority Register, CR8
> diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
> index 605ec6decf3e..ad36ea28bfd1 100644
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -35,6 +35,9 @@ static const char *xfeature_names[] =
> "Processor Trace (unused)" ,
> "Protection Keys User registers",
> "unknown xstate feature" ,
> + "Control flow User registers" ,
> + "Control flow Kernel registers" ,
> + "unknown xstate feature" ,
So there are two "unknown xstate feature" array elems now...
> static short xsave_cpuid_features[] __initdata = {
> @@ -48,6 +51,9 @@ static short xsave_cpuid_features[] __initdata = {
> X86_FEATURE_AVX512F,
> X86_FEATURE_INTEL_PT,
> X86_FEATURE_PKU,
> + 0, /* Unused */
What's that for?
> + X86_FEATURE_SHSTK, /* XFEATURE_SHSTK_USER */
> + X86_FEATURE_SHSTK, /* XFEATURE_SHSTK_KERNEL */
> };
--
Regards/Gruss,
Boris.
Good mailing practices for 400: avoid top-posting and trim the reply.
next prev parent reply other threads:[~2018-11-08 18:40 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 15:14 [PATCH v5 00/27] Control Flow Enforcement: Shadow Stack Yu-cheng Yu
2018-10-11 15:14 ` [PATCH v5 01/27] x86/cpufeatures: Add CPUIDs for Control Flow Enforcement Technology (CET) Yu-cheng Yu
2018-10-11 16:43 ` Borislav Petkov
2018-10-11 16:45 ` Yu-cheng Yu
2018-10-11 15:14 ` [PATCH v5 02/27] x86/fpu/xstate: Change names to separate XSAVES system and user states Yu-cheng Yu
2018-10-15 17:03 ` Borislav Petkov
2018-10-11 15:14 ` [PATCH v5 03/27] x86/fpu/xstate: Introduce XSAVES system states Yu-cheng Yu
2018-10-17 10:41 ` Borislav Petkov
2018-10-17 22:39 ` Randy Dunlap
2018-10-17 22:58 ` Borislav Petkov
2018-10-17 23:17 ` Randy Dunlap
2018-10-18 9:26 ` Borislav Petkov
2018-10-18 9:31 ` Pavel Machek
2018-10-18 12:10 ` Borislav Petkov
2018-10-18 18:33 ` Randy Dunlap
2018-10-18 9:24 ` Pavel Machek
2018-10-11 15:15 ` [PATCH v5 04/27] x86/fpu/xstate: Add XSAVES system states for shadow stack Yu-cheng Yu
2018-11-08 18:40 ` Borislav Petkov [this message]
2018-11-08 20:40 ` Yu-cheng Yu
2018-11-08 23:52 ` Borislav Petkov
2018-11-11 11:31 ` Pavel Machek
2018-11-11 11:31 ` Pavel Machek
2018-11-11 14:59 ` Andy Lutomirski
2018-11-11 19:02 ` Pavel Machek
2018-11-08 20:46 ` Andy Lutomirski
2018-11-08 21:01 ` Yu-cheng Yu
2018-11-08 21:22 ` Andy Lutomirski
2018-11-08 21:31 ` Cyrill Gorcunov
2018-11-08 22:01 ` Andy Lutomirski
2018-11-08 22:18 ` Cyrill Gorcunov
2018-11-08 21:48 ` Dave Hansen
2018-11-08 22:00 ` Matthew Wilcox
2018-11-08 23:35 ` Dave Hansen
2018-11-09 0:32 ` Matthew Wilcox
2018-11-09 0:45 ` Andy Lutomirski
2018-11-09 17:13 ` Dave Hansen
2018-11-09 17:17 ` Matthew Wilcox
2018-11-09 17:20 ` Dave Hansen
2018-11-09 17:28 ` Dave Hansen
2018-11-11 11:31 ` Pavel Machek
2018-10-11 15:15 ` [PATCH v5 05/27] Documentation/x86: Add CET description Yu-cheng Yu
2018-11-13 18:43 ` Borislav Petkov
2018-11-13 21:02 ` Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 06/27] x86/cet: Control protection exception handler Yu-cheng Yu
2018-11-14 18:44 ` Borislav Petkov
2018-11-14 20:19 ` Yu-cheng Yu
2018-11-14 20:28 ` Borislav Petkov
2018-10-11 15:15 ` [PATCH v5 07/27] mm/mmap: Create a guard area between VMAs Yu-cheng Yu
2018-10-11 20:39 ` Jann Horn
2018-10-11 20:49 ` Yu-cheng Yu
2018-10-11 20:55 ` Andy Lutomirski
2018-10-12 21:49 ` Yu-cheng Yu
2018-10-12 13:17 ` Matthew Wilcox
2018-10-11 20:49 ` Dave Hansen
2018-10-12 10:24 ` Florian Weimer
2018-10-11 15:15 ` [PATCH v5 08/27] x86/cet/shstk: Add Kconfig option for user-mode shadow stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 09/27] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 10/27] mm/mmap: Prevent Shadow Stack VMA merges Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 11/27] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 12/27] x86/mm: Introduce _PAGE_DIRTY_SW Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 13/27] drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 14/27] x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for _PAGE_DIRTY_SW Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 15/27] x86/mm: Shadow stack page fault error checking Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 16/27] mm: Handle shadow stack page fault Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 17/27] mm: Handle THP/HugeTLB " Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 18/27] mm: Update can_follow_write_pte/pmd for shadow stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 19/27] mm: Introduce do_mmap_locked() Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 20/27] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 21/27] x86/cet/shstk: Introduce WRUSS instruction Yu-cheng Yu
2018-11-06 18:43 ` Dave Hansen
2018-11-06 18:55 ` Andy Lutomirski
2018-11-06 20:21 ` Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 22/27] x86/cet/shstk: Signal handling for shadow stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 23/27] x86/cet/shstk: ELF header parsing of Shadow Stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 24/27] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 25/27] mm/mmap: Add Shadow stack pages to memory accounting Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 26/27] x86/cet/shstk: Add arch_prctl functions for Shadow Stack Yu-cheng Yu
2018-10-11 15:15 ` [PATCH v5 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Yu-cheng Yu
2018-10-11 19:21 ` [PATCH v5 00/27] Control Flow Enforcement: Shadow Stack Dave Hansen
2018-10-11 19:29 ` Yu-cheng Yu
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