From: "Yu, Yu-cheng" <yu-cheng.yu@intel.com>
To: Andy Lutomirski <luto@kernel.org>
Cc: X86 ML <x86@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
linux-arch <linux-arch@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
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>,
Haitao Huang <haitao.huang@intel.com>
Subject: Re: [PATCH v27 24/31] x86/cet/shstk: Handle thread shadow stack
Date: Tue, 25 May 2021 08:04:43 -0700 [thread overview]
Message-ID: <bae19cd9-e1ff-3ce4-f2e5-a12f34beb090@intel.com> (raw)
In-Reply-To: <CALCETrVQ70VvZPf_tH5KOspYx6KwDg07dodzobBSABxMyc1xJw@mail.gmail.com>
On 5/22/2021 4:39 PM, Andy Lutomirski wrote:
> On Fri, May 21, 2021 at 3:14 PM Yu-cheng Yu <yu-cheng.yu@intel.com> wrote:
>> diff --git a/arch/x86/kernel/shstk.c b/arch/x86/kernel/shstk.c
>> index 5ea2b494e9f9..8e5f772181b9 100644
>> --- a/arch/x86/kernel/shstk.c
>> +++ b/arch/x86/kernel/shstk.c
>> @@ -71,6 +71,53 @@ int shstk_setup(void)
>> return 0;
>> }
>>
>> +int shstk_alloc_thread_stack(struct task_struct *tsk, unsigned long clone_flags,
>> + unsigned long stack_size)
>> +{
>
> ...
>
>> + state = get_xsave_addr(&tsk->thread.fpu.state.xsave, XFEATURE_CET_USER);
>> + if (!state)
>> + return -EINVAL;
>> +
>
> The get_xsave_addr() API is horrible, and we already have one
> egregiously buggy instance in the kernel. Let's not add another
> dubious use case.
>
> If state == NULL, this means that CET_USER is in its init state.
> CET_USER in the init state should behave identically regardless of
> whether XINUSE[CET_USER] is set. Can you please adjust this code
> accordingly?
>
I will work on that.
Thanks,
Yu-cheng
next prev parent reply other threads:[~2021-05-25 15:06 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-21 22:11 [PATCH v27 00/31] Control-flow Enforcement: Shadow Stack Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 01/31] Documentation/x86: Add CET description Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 02/31] x86/cet/shstk: Add Kconfig option for Shadow Stack Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 03/31] x86/cpufeatures: Add CET CPU feature flags for Control-flow Enforcement Technology (CET) Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 04/31] x86/cpufeatures: Introduce CPU setup and option parsing for CET Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 05/31] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 06/31] x86/cet: Add control-protection fault handler Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 07/31] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 08/31] x86/mm: Move pmd_write(), pud_write() up in the file Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 09/31] x86/mm: Introduce _PAGE_COW Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 10/31] drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 11/31] x86/mm: Update pte_modify for _PAGE_COW Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 12/31] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 13/31] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Yu-cheng Yu
2021-05-21 22:25 ` Axel Rasmussen
2021-05-22 1:58 ` Yu, Yu-cheng
2021-05-21 22:11 ` [PATCH v27 14/31] mm: Introduce VM_SHADOW_STACK for shadow stack memory Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 15/31] x86/mm: Shadow Stack page fault error checking Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 16/31] x86/mm: Update maybe_mkwrite() for shadow stack Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 17/31] mm: Fixup places that call pte_mkwrite() directly Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 18/31] mm: Add guard pages around a shadow stack Yu-cheng Yu
2021-05-21 22:11 ` [PATCH v27 19/31] mm/mmap: Add shadow stack pages to memory accounting Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 20/31] mm: Update can_follow_write_pte() for shadow stack Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 21/31] mm/mprotect: Exclude shadow stack from preserve_write Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 22/31] mm: Re-introduce vm_flags to do_mmap() Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 23/31] x86/cet/shstk: Add user-mode shadow stack support Yu-cheng Yu
2021-07-19 18:23 ` Edgecombe, Rick P
2021-07-20 17:13 ` Yu, Yu-cheng
2021-05-21 22:12 ` [PATCH v27 24/31] x86/cet/shstk: Handle thread shadow stack Yu-cheng Yu
2021-05-22 23:39 ` Andy Lutomirski
2021-05-25 15:04 ` Yu, Yu-cheng [this message]
2021-07-21 18:14 ` John Allen
2021-07-21 18:28 ` Florian Weimer
2021-07-21 18:34 ` Yu, Yu-cheng
2021-07-28 21:34 ` John Allen
2021-07-21 18:37 ` Dave Hansen
2021-07-21 20:14 ` H.J. Lu
2021-05-21 22:12 ` [PATCH v27 25/31] x86/cet/shstk: Introduce shadow stack token setup/verify routines Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 26/31] x86/cet/shstk: Handle signals for shadow stack Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 27/31] ELF: Introduce arch_setup_elf_property() Yu-cheng Yu
2021-05-25 10:54 ` Catalin Marinas
2021-05-21 22:12 ` [PATCH v27 28/31] x86/cet/shstk: Add arch_prctl functions for shadow stack Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 29/31] mm: Move arch_calc_vm_prot_bits() to arch/x86/include/asm/mman.h Yu-cheng Yu
2021-05-21 22:12 ` [PATCH v27 30/31] mm: Update arch_validate_flags() to test vma anonymous Yu-cheng Yu
2021-05-25 11:00 ` Catalin Marinas
2021-05-25 15:03 ` Yu, Yu-cheng
2021-05-21 22:12 ` [PATCH v27 31/31] mm: Introduce PROT_SHADOW_STACK for shadow stack Yu-cheng Yu
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