From: Borislav Petkov <bp@alien8.de>
To: "Yu, Yu-cheng" <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@kernel.org>,
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>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>
Subject: Re: [PATCH v15 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack
Date: Mon, 30 Nov 2020 19:15:00 +0100 [thread overview]
Message-ID: <20201130181500.GH6019@zn.tnic> (raw)
In-Reply-To: <98e1b159-bf32-5c67-455b-f798023770ef@intel.com>
On Sat, Nov 28, 2020 at 08:23:59AM -0800, Yu, Yu-cheng wrote:
> We have X86_BRANCH_TRACKING_USER too. My thought was, X86_CET means any of
> kernel/user shadow stack/ibt.
It is not about what it means - it is what you're going to use/need. You have
ifdeffery both with X86_CET and X86_SHADOW_STACK_USER.
This one
+#ifdef CONFIG_X86_SHADOW_STACK_USER
+#define DISABLE_SHSTK 0
+#else
+#define DISABLE_SHSTK (1 << (X86_FEATURE_SHSTK & 31))
+#endif
for example, is clearly wrong and wants to be #ifdef CONFIG_X86_CET, for
example. Unless I'm missing something totally obvious.
In any case, you need to analyze what Kconfig defines the code will
need and to what they belong and add only the minimal subset needed.
Our Kconfig symbols space is already nuts so adding more needs to be
absolutely justified.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-11-30 18:15 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 16:21 [PATCH v15 00/26] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 01/26] Documentation/x86: Add CET description Yu-cheng Yu
2020-11-30 18:26 ` Nick Desaulniers
2020-11-30 18:34 ` Yu, Yu-cheng
2020-11-30 19:38 ` Fāng-ruì Sòng
2020-11-30 19:47 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 02/26] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 03/26] x86/fpu/xstate: Introduce CET MSR XSAVES supervisor states Yu-cheng Yu
2020-11-26 11:02 ` Borislav Petkov
2020-11-30 17:45 ` [NEEDS-REVIEW] " Dave Hansen
2020-11-30 18:06 ` Yu, Yu-cheng
2020-11-30 18:12 ` Dave Hansen
2020-11-30 18:17 ` Yu, Yu-cheng
2020-11-30 23:16 ` Yu, Yu-cheng
2020-12-01 22:26 ` Dave Hansen
2020-12-01 22:35 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 04/26] x86/cet: Add control-protection fault handler Yu-cheng Yu
2020-11-26 18:49 ` Borislav Petkov
2020-11-10 16:21 ` [PATCH v15 05/26] x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack Yu-cheng Yu
2020-11-27 17:10 ` Borislav Petkov
2020-11-28 16:23 ` Yu, Yu-cheng
2020-11-30 18:15 ` Borislav Petkov [this message]
2020-11-30 22:48 ` Yu, Yu-cheng
2020-12-01 16:02 ` Borislav Petkov
2020-11-30 19:56 ` Nick Desaulniers
2020-11-30 20:30 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 06/26] x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW Yu-cheng Yu
2020-12-03 9:19 ` Borislav Petkov
2020-12-03 15:12 ` Dave Hansen
2020-12-03 15:56 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 07/26] x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages Yu-cheng Yu
2020-12-07 16:36 ` Borislav Petkov
2020-12-07 17:11 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 08/26] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2020-12-08 17:50 ` Borislav Petkov
2020-12-08 18:25 ` Yu, Yu-cheng
2020-12-08 18:47 ` Borislav Petkov
2020-12-08 19:24 ` Yu, Yu-cheng
2020-12-10 17:41 ` Borislav Petkov
2020-12-10 18:10 ` Yu, Yu-cheng
2020-11-10 16:21 ` [PATCH v15 09/26] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 10/26] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 11/26] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY_HW to _PAGE_COW Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 12/26] mm: Introduce VM_SHSTK for shadow stack memory Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 13/26] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2020-11-10 16:21 ` [PATCH v15 14/26] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 15/26] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 16/26] mm: Add guard pages around a shadow stack Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 17/26] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 18/26] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 19/26] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 20/26] x86/cet/shstk: User-mode shadow stack support Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 21/26] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 22/26] binfmt_elf: Define GNU_PROPERTY_X86_FEATURE_1_AND properties Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 23/26] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 24/26] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 25/26] x86/cet/shstk: Add arch_prctl functions for " Yu-cheng Yu
2020-11-10 16:22 ` [PATCH v15 26/26] mm: Introduce PROT_SHSTK " Yu-cheng Yu
2020-11-27 9:29 ` [PATCH v15 00/26] Control-flow Enforcement: Shadow Stack Balbir Singh
2020-11-28 16:31 ` Yu, Yu-cheng
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