From: Yu-cheng Yu <yu-cheng.yu@intel.com> To: Borislav Petkov <bp@alien8.de> 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>, 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 Subject: Re: [RFC PATCH v4 03/27] x86/fpu/xstate: Enable XSAVES system states Date: Thu, 04 Oct 2018 08:47:35 -0700 [thread overview] Message-ID: <beb7872250b61e42c0069a4aab710b31f804d72c.camel@intel.com> (raw) In-Reply-To: <20181002171554.GE29601@zn.tnic> On Tue, 2018-10-02 at 19:15 +0200, Borislav Petkov wrote: > On Fri, Sep 21, 2018 at 08:03:27AM -0700, Yu-cheng Yu wrote: > > > > diff --git a/arch/x86/include/asm/fpu/xstate.h > > b/arch/x86/include/asm/fpu/xstate.h > > index 9b382e5157ed..a32dc5f8c963 100644 > > --- a/arch/x86/include/asm/fpu/xstate.h > > +++ b/arch/x86/include/asm/fpu/xstate.h > > @@ -19,10 +19,10 @@ > > #define XSAVE_YMM_SIZE 256 > > #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) > > > > -/* System features */ > > -#define XFEATURE_MASK_SYSTEM (XFEATURE_MASK_PT) > > Previous patch renames it, this patch deletes it. Why do we need all > that unnecessary churn? > > Also, this patch is trying to do a couple of things at once and > reviewing it is not trivial. Please split the changes logically. Yes, if we leave XFEATURE_MASK_SUPERVISOR unchanged in the previous patch, this patch becomes much simpler. Perhaps we don't even need to split this one. > > diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c > > index 19f8df54c72a..dd2c561c4544 100644 > > --- a/arch/x86/kernel/fpu/xstate.c > > +++ b/arch/x86/kernel/fpu/xstate.c > > @@ -51,13 +51,16 @@ static short xsave_cpuid_features[] __initdata = { > > }; > > > > /* > > - * Mask of xstate features supported by the CPU and the kernel: > > + * Mask of xstate features supported by the CPU and the kernel. > > + * This is the result from CPUID query, SUPPORTED_XFEATURES_MASK, > > + * and boot_cpu_has(). > > */ > > This needs to explain what both masks are - user and system. "CPU" and > "kernel" is not "user" and "all". > > > u64 xfeatures_mask_user __read_mostly; > > +u64 xfeatures_mask_all __read_mostly; The first one is all supported "user" states; the latter is "system" and "user" states combined. I will put in comments. Yu-cheng
WARNING: multiple messages have this Message-ID (diff)
From: Yu-cheng Yu <yu-cheng.yu@intel.com> To: Borislav Petkov <bp@alien8.de> 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>, 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: [RFC PATCH v4 03/27] x86/fpu/xstate: Enable XSAVES system states Date: Thu, 04 Oct 2018 08:47:35 -0700 [thread overview] Message-ID: <beb7872250b61e42c0069a4aab710b31f804d72c.camel@intel.com> (raw) Message-ID: <20181004154735.ONaS0t7bisiz7S-u-IHd2NRN2V047cyRfKHTw4McNTc@z> (raw) In-Reply-To: <20181002171554.GE29601@zn.tnic> On Tue, 2018-10-02 at 19:15 +0200, Borislav Petkov wrote: > On Fri, Sep 21, 2018 at 08:03:27AM -0700, Yu-cheng Yu wrote: > > > > diff --git a/arch/x86/include/asm/fpu/xstate.h > > b/arch/x86/include/asm/fpu/xstate.h > > index 9b382e5157ed..a32dc5f8c963 100644 > > --- a/arch/x86/include/asm/fpu/xstate.h > > +++ b/arch/x86/include/asm/fpu/xstate.h > > @@ -19,10 +19,10 @@ > > #define XSAVE_YMM_SIZE 256 > > #define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET) > > > > -/* System features */ > > -#define XFEATURE_MASK_SYSTEM (XFEATURE_MASK_PT) > > Previous patch renames it, this patch deletes it. Why do we need all > that unnecessary churn? > > Also, this patch is trying to do a couple of things at once and > reviewing it is not trivial. Please split the changes logically. Yes, if we leave XFEATURE_MASK_SUPERVISOR unchanged in the previous patch, this patch becomes much simpler. Perhaps we don't even need to split this one. > > diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c > > index 19f8df54c72a..dd2c561c4544 100644 > > --- a/arch/x86/kernel/fpu/xstate.c > > +++ b/arch/x86/kernel/fpu/xstate.c > > @@ -51,13 +51,16 @@ static short xsave_cpuid_features[] __initdata = { > > }; > > > > /* > > - * Mask of xstate features supported by the CPU and the kernel: > > + * Mask of xstate features supported by the CPU and the kernel. > > + * This is the result from CPUID query, SUPPORTED_XFEATURES_MASK, > > + * and boot_cpu_has(). > > */ > > This needs to explain what both masks are - user and system. "CPU" and > "kernel" is not "user" and "all". > > > u64 xfeatures_mask_user __read_mostly; > > +u64 xfeatures_mask_all __read_mostly; The first one is all supported "user" states; the latter is "system" and "user" states combined. I will put in comments. Yu-cheng
next prev parent reply other threads:[~2018-10-04 15:47 UTC|newest] Thread overview: 142+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-09-21 15:03 [RFC PATCH v4 00/27] Control Flow Enforcement: Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 01/27] x86/cpufeatures: Add CPUIDs for Control-flow Enforcement Technology (CET) Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 16:27 ` Peter Zijlstra 2018-09-25 16:27 ` Peter Zijlstra 2018-09-25 16:29 ` Yu-cheng Yu 2018-09-25 16:29 ` Yu-cheng Yu 2018-09-28 16:51 ` Borislav Petkov 2018-09-28 16:51 ` Borislav Petkov 2018-09-28 16:56 ` Yu-cheng Yu 2018-09-28 16:56 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 02/27] x86/fpu/xstate: Change some names to separate XSAVES system and user states Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 16:37 ` Peter Zijlstra 2018-09-25 16:37 ` Peter Zijlstra 2018-10-02 15:29 ` Borislav Petkov 2018-10-02 15:29 ` Borislav Petkov 2018-10-02 16:21 ` Yu-cheng Yu 2018-10-02 16:21 ` Yu-cheng Yu 2018-10-02 16:30 ` Dave Hansen 2018-10-02 16:30 ` Dave Hansen 2018-10-02 16:37 ` Borislav Petkov 2018-10-02 16:37 ` Borislav Petkov 2018-10-02 16:39 ` Dave Hansen 2018-10-02 16:39 ` Dave Hansen 2018-10-02 16:43 ` Yu-cheng Yu 2018-10-02 16:43 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 03/27] x86/fpu/xstate: Enable XSAVES system states Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-25 17:03 ` Peter Zijlstra 2018-09-25 17:03 ` Peter Zijlstra 2018-09-25 17:23 ` Yu-cheng Yu 2018-09-25 17:23 ` Yu-cheng Yu 2018-10-02 17:15 ` Borislav Petkov 2018-10-02 17:15 ` Borislav Petkov 2018-10-04 15:47 ` Yu-cheng Yu [this message] 2018-10-04 15:47 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 04/27] x86/fpu/xstate: Add XSAVES system states for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 05/27] Documentation/x86: Add CET description Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 06/27] x86/cet: Control protection exception handler Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 10:39 ` Eugene Syromiatnikov 2018-10-03 10:39 ` Eugene Syromiatnikov 2018-10-03 16:11 ` Yu-cheng Yu 2018-10-03 16:11 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 07/27] x86/cet/shstk: Add Kconfig option for user-mode shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 08/27] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 09/27] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 13:38 ` Matthew Wilcox 2018-10-03 13:38 ` Matthew Wilcox 2018-10-03 14:05 ` Dave Hansen 2018-10-03 14:05 ` Dave Hansen 2018-10-03 16:07 ` Yu-cheng Yu 2018-10-03 16:07 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 10/27] drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 13:19 ` Eugene Syromiatnikov 2018-10-03 13:19 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 11/27] x86/mm: Introduce _PAGE_DIRTY_SW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 12/27] x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for _PAGE_DIRTY_SW Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 13/27] x86/mm: Shadow stack page fault error checking Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 14/27] mm: Handle shadow stack page fault Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 15/27] mm: Handle THP/HugeTLB " Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 16/27] mm: Update can_follow_write_pte/pmd for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 17/27] mm: Introduce do_mmap_locked() Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 18/27] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 15:08 ` Eugene Syromiatnikov 2018-10-03 15:08 ` Eugene Syromiatnikov 2018-10-03 15:12 ` Yu-cheng Yu 2018-10-03 15:12 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 19/27] x86/cet/shstk: Introduce WRUSS instruction Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 4:15 ` Eugene Syromiatnikov 2018-10-03 4:15 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 20/27] x86/cet/shstk: Signal handling for shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 14:36 ` Eugene Syromiatnikov 2018-10-03 14:36 ` Eugene Syromiatnikov 2018-10-03 16:46 ` Jann Horn 2018-10-03 16:46 ` Jann Horn 2018-09-21 15:03 ` [RFC PATCH v4 21/27] x86/cet/shstk: ELF header parsing of Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 23:27 ` Eugene Syromiatnikov 2018-10-03 23:27 ` Eugene Syromiatnikov 2018-10-09 21:15 ` Yu-cheng Yu 2018-10-09 21:15 ` Yu-cheng Yu 2018-10-15 23:40 ` Kees Cook 2018-10-15 23:40 ` Kees Cook 2018-10-16 17:23 ` Yu-cheng Yu 2018-10-16 17:23 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 22/27] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 23/27] mm/map: Add Shadow stack pages to memory accounting Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 16:55 ` Randy Dunlap 2018-09-21 16:55 ` Randy Dunlap 2018-09-21 17:21 ` Yu-cheng Yu 2018-09-21 17:21 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 24/27] mm/mmap: Create a guard area between VMAs Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 4:56 ` Eugene Syromiatnikov 2018-10-03 4:56 ` Eugene Syromiatnikov 2018-10-03 5:36 ` Andy Lutomirski 2018-10-03 5:36 ` Andy Lutomirski 2018-10-03 16:00 ` Yu-cheng Yu 2018-10-03 16:00 ` Yu-cheng Yu 2018-10-03 16:18 ` Andy Lutomirski 2018-10-03 16:18 ` Andy Lutomirski 2018-10-03 16:32 ` Eugene Syromiatnikov 2018-10-03 16:32 ` Eugene Syromiatnikov 2018-10-03 16:40 ` Yu-cheng Yu 2018-10-03 16:40 ` Yu-cheng Yu 2018-10-03 16:52 ` Jann Horn 2018-10-03 16:52 ` Jann Horn 2018-10-03 21:21 ` Eugene Syromiatnikov 2018-10-03 21:21 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 25/27] mm/mmap: Prevent Shadow Stack VMA merges Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 15:03 ` [RFC PATCH v4 26/27] x86/cet/shstk: Add arch_prctl functions for Shadow Stack Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-10-03 17:57 ` Eugene Syromiatnikov 2018-10-03 17:57 ` Eugene Syromiatnikov 2018-09-21 15:03 ` [RFC PATCH v4 27/27] x86/cet/shstk: Add Shadow Stack instructions to opcode map Yu-cheng Yu 2018-09-21 15:03 ` Yu-cheng Yu 2018-09-21 22:53 ` [RFC PATCH v4 00/27] Control Flow Enforcement: Shadow Stack Dave Hansen 2018-09-21 22:53 ` Dave Hansen 2018-09-24 15:25 ` Yu-cheng Yu 2018-09-24 15:25 ` Yu-cheng Yu
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