From: "szabolcs.nagy@arm.com" <szabolcs.nagy@arm.com>
To: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
"fweimer@redhat.com" <fweimer@redhat.com>
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Subject: Re: [PATCH v7 01/41] Documentation/x86: Add CET shadow stack description
Date: Tue, 7 Mar 2023 13:03:41 +0000 [thread overview]
Message-ID: <ZAc2LQEfvRLCknQQ@arm.com> (raw)
In-Reply-To: <a205aed2171a0a463e3bb7179e8dd63bd4012e7e.camel@intel.com>
The 03/06/2023 18:08, Edgecombe, Rick P wrote:
> On Mon, 2023-03-06 at 17:31 +0100, Florian Weimer wrote:
> > I assume there is no desire at all on the kernel side that
> > sigaltstack
> > transparently allocates the shadow stack?
>
> It could have some nice benefit for some apps, so I did look into it.
>
> > Because there is no
> > deallocation function today for sigaltstack?
>
> Yea, this is why we can't do it transparently. There was some
> discussion up the thread on this.
changing/disabling the alt stack is not valid while a handler is
executing on it. if we don't allow jumping out and back to an
alt stack (swapcontext) then there can be only one alt stack
live per thread and change/disable can do the shadow stack free.
if jump back is allowed (linux even makes it race-free with
SS_AUTODISARM) then the life-time of alt stack is extended
beyond change/disable (jump back to an unregistered alt stack).
to support jump back to an alt stack the requirements are
1) user has to manage an alt shadow stack together with the alt
stack (requies user code change, not just libc).
2) kernel has to push a restore token on the thread shadow stack
on signal entry (at least in case of alt shadow stack, and
deal with corner cases around shadow stack overflow).
next prev parent reply other threads:[~2023-03-07 13:05 UTC|newest]
Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-27 22:29 [PATCH v7 00/41] Shadow stacks for userspace Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 01/41] Documentation/x86: Add CET shadow stack description Rick Edgecombe
2023-03-01 14:21 ` Szabolcs Nagy
2023-03-01 14:38 ` Szabolcs Nagy
2023-03-01 18:07 ` Edgecombe, Rick P
2023-03-01 18:32 ` Edgecombe, Rick P
2023-03-02 16:34 ` szabolcs.nagy
2023-03-03 22:35 ` Edgecombe, Rick P
2023-03-06 16:20 ` szabolcs.nagy
2023-03-06 16:31 ` Florian Weimer
2023-03-06 18:08 ` Edgecombe, Rick P
2023-03-07 13:03 ` szabolcs.nagy [this message]
2023-03-07 14:00 ` Florian Weimer
2023-03-07 16:14 ` Szabolcs Nagy
2023-03-06 18:05 ` Edgecombe, Rick P
2023-03-06 20:31 ` Liang, Kan
2023-03-02 16:14 ` szabolcs.nagy
2023-03-02 21:17 ` Edgecombe, Rick P
2023-03-03 16:30 ` szabolcs.nagy
2023-03-03 16:57 ` H.J. Lu
2023-03-03 17:39 ` szabolcs.nagy
2023-03-03 17:50 ` H.J. Lu
2023-03-03 17:41 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 02/41] x86/shstk: Add Kconfig option for shadow stack Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 03/41] x86/cpufeatures: Add CPU feature flags for shadow stacks Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 04/41] x86/cpufeatures: Enable CET CR4 bit for shadow stack Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 05/41] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 06/41] x86/fpu: Add helper for modifying xstate Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 07/41] x86: Move control protection handler to separate file Rick Edgecombe
2023-03-01 15:38 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 08/41] x86/shstk: Add user control-protection fault handler Rick Edgecombe
2023-03-01 18:06 ` Borislav Petkov
2023-03-01 18:14 ` Edgecombe, Rick P
2023-03-01 18:37 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 09/41] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 10/41] x86/mm: Move pmd_write(), pud_write() up in the file Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 11/41] mm: Introduce pte_mkwrite_kernel() Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 12/41] s390/mm: Introduce pmd_mkwrite_kernel() Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 13/41] mm: Make pte_mkwrite() take a VMA Rick Edgecombe
2023-03-01 7:03 ` Christophe Leroy
2023-03-01 8:16 ` David Hildenbrand
2023-03-02 12:19 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 14/41] x86/mm: Introduce _PAGE_SAVED_DIRTY Rick Edgecombe
2023-03-02 12:48 ` Borislav Petkov
2023-03-02 17:01 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 15/41] x86/mm: Update ptep/pmdp_set_wrprotect() for _PAGE_SAVED_DIRTY Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 16/41] x86/mm: Start actually marking _PAGE_SAVED_DIRTY Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 17/41] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 18/41] mm: Introduce VM_SHADOW_STACK for shadow stack memory Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 19/41] x86/mm: Check shadow stack page fault errors Rick Edgecombe
2023-03-03 14:00 ` Borislav Petkov
2023-03-03 14:39 ` Dave Hansen
2023-02-27 22:29 ` [PATCH v7 20/41] x86/mm: Teach pte_mkwrite() about stack memory Rick Edgecombe
2023-03-03 15:37 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 21/41] mm: Add guard pages around a shadow stack Rick Edgecombe
2023-03-06 8:08 ` Borislav Petkov
2023-03-07 1:29 ` Edgecombe, Rick P
2023-03-07 10:32 ` Borislav Petkov
2023-03-07 10:44 ` David Hildenbrand
2023-03-08 22:48 ` Edgecombe, Rick P
2023-03-17 17:09 ` Deepak Gupta
2023-02-27 22:29 ` [PATCH v7 22/41] mm/mmap: Add shadow stack pages to memory accounting Rick Edgecombe
2023-03-06 13:01 ` Borislav Petkov
2023-03-06 18:11 ` Edgecombe, Rick P
2023-03-06 18:16 ` Borislav Petkov
2023-03-07 10:42 ` David Hildenbrand
2023-03-17 17:12 ` Deepak Gupta
2023-03-17 17:16 ` Dave Hansen
2023-03-17 17:28 ` Deepak Gupta
2023-03-17 17:42 ` Edgecombe, Rick P
2023-03-17 19:26 ` Deepak Gupta
2023-02-27 22:29 ` [PATCH v7 23/41] mm: Re-introduce vm_flags to do_mmap() Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 24/41] mm: Don't allow write GUPs to shadow stack memory Rick Edgecombe
2023-03-06 13:10 ` Borislav Petkov
2023-03-06 18:15 ` Andy Lutomirski
2023-03-06 18:33 ` Edgecombe, Rick P
2023-03-06 18:57 ` Andy Lutomirski
2023-03-07 1:47 ` Edgecombe, Rick P
2023-03-17 17:05 ` Deepak Gupta
2023-02-27 22:29 ` [PATCH v7 25/41] x86/mm: Introduce MAP_ABOVE4G Rick Edgecombe
2023-03-06 18:09 ` Borislav Petkov
2023-03-07 1:10 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 26/41] mm: Warn on shadow stack memory in wrong vma Rick Edgecombe
2023-03-08 8:53 ` Borislav Petkov
2023-03-08 23:36 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 27/41] x86/mm: Warn if create Write=0,Dirty=1 with raw prot Rick Edgecombe
2023-02-27 22:54 ` Kees Cook
2023-03-08 9:23 ` Borislav Petkov
2023-03-08 23:35 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 28/41] x86: Introduce userspace API for shadow stack Rick Edgecombe
2023-03-08 10:27 ` Borislav Petkov
2023-03-08 23:32 ` Edgecombe, Rick P
2023-03-09 12:57 ` Borislav Petkov
2023-03-09 16:56 ` Edgecombe, Rick P
2023-03-09 23:51 ` Borislav Petkov
2023-03-10 1:13 ` Edgecombe, Rick P
2023-03-10 2:03 ` H.J. Lu
2023-03-10 20:00 ` H.J. Lu
2023-03-10 20:27 ` Edgecombe, Rick P
2023-03-10 20:43 ` H.J. Lu
2023-03-10 21:01 ` Edgecombe, Rick P
2023-03-10 11:40 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 29/41] x86/shstk: Add user-mode shadow stack support Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 30/41] x86/shstk: Handle thread shadow stack Rick Edgecombe
2023-03-02 17:34 ` Szabolcs Nagy
2023-03-02 21:48 ` Edgecombe, Rick P
2023-03-08 15:26 ` Borislav Petkov
2023-03-08 20:03 ` Edgecombe, Rick P
2023-03-09 14:12 ` Borislav Petkov
2023-03-09 16:59 ` Edgecombe, Rick P
2023-03-09 17:04 ` Borislav Petkov
2023-03-09 20:29 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 31/41] x86/shstk: Introduce routines modifying shstk Rick Edgecombe
2023-03-09 16:48 ` Borislav Petkov
2023-03-09 17:03 ` Edgecombe, Rick P
2023-03-09 17:22 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 32/41] x86/shstk: Handle signals for shadow stack Rick Edgecombe
2023-03-09 17:02 ` Borislav Petkov
2023-03-09 17:16 ` Edgecombe, Rick P
2023-03-09 23:35 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 33/41] x86/shstk: Introduce map_shadow_stack syscall Rick Edgecombe
2023-03-02 17:22 ` Szabolcs Nagy
2023-03-02 21:21 ` Edgecombe, Rick P
2023-03-09 18:55 ` Deepak Gupta
2023-03-09 19:39 ` Edgecombe, Rick P
2023-03-09 21:08 ` Deepak Gupta
2023-03-10 0:14 ` Edgecombe, Rick P
2023-03-10 21:00 ` Deepak Gupta
2023-03-10 21:43 ` Edgecombe, Rick P
2023-03-16 20:07 ` Deepak Gupta
2023-03-14 7:19 ` Mike Rapoport
2023-03-16 19:30 ` Deepak Gupta
2023-03-20 11:35 ` Szabolcs Nagy
2023-03-10 16:11 ` Borislav Petkov
2023-03-10 17:12 ` Edgecombe, Rick P
2023-03-10 20:05 ` Borislav Petkov
2023-03-10 20:19 ` Edgecombe, Rick P
2023-03-10 20:26 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 34/41] x86/shstk: Support WRSS for userspace Rick Edgecombe
2023-03-10 16:44 ` Borislav Petkov
2023-03-10 17:16 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 35/41] x86: Expose thread features in /proc/$PID/status Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 36/41] x86/shstk: Wire in shadow stack interface Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 37/41] selftests/x86: Add shadow stack test Rick Edgecombe
2023-02-27 22:29 ` [PATCH v7 38/41] x86/fpu: Add helper for initing features Rick Edgecombe
2023-03-11 12:54 ` Borislav Petkov
2023-03-13 2:45 ` Edgecombe, Rick P
2023-03-13 11:03 ` Borislav Petkov
2023-03-13 16:10 ` Edgecombe, Rick P
2023-03-13 17:10 ` Borislav Petkov
2023-03-13 23:31 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 39/41] x86: Add PTRACE interface for shadow stack Rick Edgecombe
2023-03-11 15:06 ` Borislav Petkov
2023-03-13 2:53 ` Edgecombe, Rick P
2023-02-27 22:29 ` [PATCH v7 40/41] x86/shstk: Add ARCH_SHSTK_UNLOCK Rick Edgecombe
2023-03-11 15:11 ` Borislav Petkov
2023-03-13 3:04 ` Edgecombe, Rick P
2023-03-13 11:05 ` Borislav Petkov
2023-02-27 22:29 ` [PATCH v7 41/41] x86/shstk: Add ARCH_SHSTK_STATUS Rick Edgecombe
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