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>,
Dave Martin <Dave.Martin@arm.com>,
Weijiang Yang <weijiang.yang@intel.com>,
Pengfei Xu <pengfei.xu@intel.com>,
Haitao Huang <haitao.huang@intel.com>,
Rick P Edgecombe <rick.p.edgecombe@intel.com>
Subject: Re: [PATCH v29 23/32] x86/cet/shstk: Add user-mode shadow stack support
Date: Fri, 27 Aug 2021 20:46:35 +0200 [thread overview]
Message-ID: <YSkzC1lw+btvE71X@zn.tnic> (raw)
In-Reply-To: <c876d0aa-865d-e48d-0b56-f9d66762f869@intel.com>
On Fri, Aug 27, 2021 at 11:37:34AM -0700, Yu, Yu-cheng wrote:
> Right now, the kernel does lazy restore, and it waits until right before a
> task goes back to ring-3 to restore xstates. If a task needs to write to
> any xstate registers before that (e.g. for signals), it restores the whole
> xstates first and clears TIF_NEED_FPU_LOAD, which will prevent xstates being
> restored again later.
shstk_setup() allocates a shadow stack for the task and puts its pointer
in MSR_IA32_PL3_SSP.
What does that have to do with a task having to write any xstate
registers?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-08-27 18:46 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 18:11 [PATCH v29 00/32] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 01/32] Documentation/x86: Add CET description Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 02/32] x86/cet/shstk: Add Kconfig option for Shadow Stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 03/32] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 04/32] x86/cpufeatures: Introduce CPU setup and option parsing for CET Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 05/32] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 06/32] x86/cet: Add control-protection fault handler Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 07/32] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 08/32] x86/mm: Move pmd_write(), pud_write() up in the file Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 09/32] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2021-08-21 19:20 ` Edgecombe, Rick P
2021-08-22 2:59 ` Edgecombe, Rick P
2021-08-20 18:11 ` [PATCH v29 10/32] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 11/32] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 12/32] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Yu-cheng Yu
2021-08-26 10:42 ` Borislav Petkov
2021-08-20 18:11 ` [PATCH v29 13/32] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 14/32] mm: Introduce VM_SHADOW_STACK for shadow stack memory Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 15/32] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2021-08-26 10:55 ` Borislav Petkov
2021-08-20 18:11 ` [PATCH v29 16/32] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 17/32] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 18/32] mm: Add guard pages around a shadow stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 19/32] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 20/32] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 21/32] mm/mprotect: Exclude shadow stack from preserve_write Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 22/32] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 23/32] x86/cet/shstk: Add user-mode shadow stack support Yu-cheng Yu
2021-08-26 16:25 ` Borislav Petkov
2021-08-27 18:10 ` Yu, Yu-cheng
2021-08-27 18:21 ` Borislav Petkov
2021-08-27 18:37 ` Yu, Yu-cheng
2021-08-27 18:46 ` Borislav Petkov [this message]
2021-08-27 20:25 ` Dave Hansen
2021-09-01 13:00 ` Borislav Petkov
2021-09-01 15:24 ` Dave Hansen
2021-08-20 18:11 ` [PATCH v29 24/32] x86/process: Change copy_thread() argument 'arg' to 'stack_size' Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 25/32] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2021-08-26 16:50 ` Borislav Petkov
2021-08-26 17:22 ` H.J. Lu
2021-08-26 17:28 ` Borislav Petkov
2021-08-26 17:33 ` Yu, Yu-cheng
2021-08-26 17:25 ` Yu, Yu-cheng
2021-08-20 18:11 ` [PATCH v29 26/32] x86/cet/shstk: Introduce shadow stack token setup/verify routines Yu-cheng Yu
2021-08-26 17:21 ` Borislav Petkov
2021-08-20 18:11 ` [PATCH v29 27/32] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 28/32] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 29/32] x86/cet/shstk: Add arch_prctl functions for shadow stack Yu-cheng Yu
2021-08-20 18:11 ` [PATCH v29 30/32] mm: Move arch_calc_vm_prot_bits() to arch/x86/include/asm/mman.h Yu-cheng Yu
2021-08-20 18:12 ` [PATCH v29 31/32] mm: Update arch_validate_flags() to test vma anonymous Yu-cheng Yu
2021-08-20 18:12 ` [PATCH v29 32/32] mm: Introduce PROT_SHADOW_STACK for shadow stack Yu-cheng Yu
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