From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "peterz@infradead.org" <peterz@infradead.org>
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Subject: Re: [PATCH v3 27/37] x86/shstk: Introduce routines modifying shstk
Date: Wed, 16 Nov 2022 22:38:19 +0000 [thread overview]
Message-ID: <cb4c70dd57f43fd46a47e0bf7d3c759b0b313f83.camel@intel.com> (raw)
In-Reply-To: <Y3S5AKhLaU+YuUpQ@hirez.programming.kicks-ass.net>
On Wed, 2022-11-16 at 11:18 +0100, Peter Zijlstra wrote:
> > >
> > > Should you write a 64bit value even if the task receiving a
> > > signal is
> > > 32bit ?
> >
> > 32 bit support was also dropped.
>
> How? Task could start life as 64bit, frob LDT to set up 32bit code
> segment and jump into it and start doing 32bit syscalls, then what?
>
> AFAICT those 32bit syscalls will end up doing SA_IA32_ABI sigframes.
Hmm, good point. This series used to support normal 32 bit apps via
ia32 emulation which would have handled this. But I removed it (blocked
in the enabling logic) because it didn't seem like it would get enough
use to justify the extra code. That doesn't block this scenario here
though.
Pardon the possibly naive question, but is this 32/64 bit mixing
something any normal, shstk-desiring, applications would actually do? O
r more that they could do?
Thanks,
Rick
next prev parent reply other threads:[~2022-11-16 22:38 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-04 22:35 [PATCH v3 00/37] Shadow stacks for userspace Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 01/37] Documentation/x86: Add CET description Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 02/37] x86/cet/shstk: Add Kconfig option for Shadow Stack Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 03/37] x86/cpufeatures: Add CPU feature flags for shadow stacks Rick Edgecombe
2022-11-07 17:41 ` Borislav Petkov
2022-11-04 22:35 ` [PATCH v3 04/37] x86/cpufeatures: Enable CET CR4 bit for shadow stack Rick Edgecombe
2022-11-07 18:00 ` Borislav Petkov
2022-11-07 18:19 ` Edgecombe, Rick P
2022-11-07 18:37 ` Borislav Petkov
2022-11-07 19:19 ` Edgecombe, Rick P
2022-11-07 19:30 ` Borislav Petkov
2022-11-07 19:33 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 05/37] x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 06/37] x86/fpu: Add helper for modifying xstate Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 07/37] x86/cet: Add user control-protection fault handler Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 08/37] x86/mm: Remove _PAGE_DIRTY from kernel RO pages Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 09/37] x86/mm: Move pmd_write(), pud_write() up in the file Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 10/37] x86/mm: Introduce _PAGE_COW Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 11/37] x86/mm: Update pte_modify for _PAGE_COW Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 12/37] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 13/37] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Rick Edgecombe
2022-11-15 11:20 ` Peter Zijlstra
2022-11-15 17:18 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 14/37] mm: Introduce VM_SHADOW_STACK for shadow stack memory Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 15/37] x86/mm: Check Shadow Stack page fault errors Rick Edgecombe
2022-11-15 11:47 ` Peter Zijlstra
2022-11-15 20:03 ` Edgecombe, Rick P
2022-11-15 21:07 ` Peter Zijlstra
2022-11-15 23:13 ` Edgecombe, Rick P
2022-11-16 10:09 ` Peter Zijlstra
2022-11-04 22:35 ` [PATCH v3 16/37] x86/mm: Update maybe_mkwrite() for shadow stack Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 17/37] mm: Fixup places that call pte_mkwrite() directly Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 18/37] mm: Add guard pages around a shadow stack Rick Edgecombe
2022-11-15 12:04 ` Peter Zijlstra
2022-11-15 20:40 ` Edgecombe, Rick P
2022-11-15 20:56 ` Peter Zijlstra
2022-11-15 21:49 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 19/37] mm/mmap: Add shadow stack pages to memory accounting Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 20/37] mm/mprotect: Exclude shadow stack from preserve_write Rick Edgecombe
2022-11-15 12:05 ` Peter Zijlstra
2022-11-15 20:41 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 21/37] mm: Re-introduce vm_flags to do_mmap() Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 22/37] mm: Don't allow write GUPs to shadow stack memory Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 23/37] mm: Warn on shadow stack memory in wrong vma Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 24/37] x86: Introduce userspace API for CET enabling Rick Edgecombe
2022-11-15 12:26 ` Peter Zijlstra
2022-11-15 13:03 ` Peter Zijlstra
2022-11-15 20:55 ` Edgecombe, Rick P
2022-11-15 14:25 ` Peter Zijlstra
2022-11-15 20:55 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 25/37] x86/shstk: Add user-mode shadow stack support Rick Edgecombe
2022-11-15 12:32 ` Peter Zijlstra
2022-11-15 21:46 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 26/37] x86/shstk: Handle thread shadow stack Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 27/37] x86/shstk: Introduce routines modifying shstk Rick Edgecombe
2022-11-15 14:18 ` Peter Zijlstra
2022-11-15 23:42 ` Edgecombe, Rick P
2022-11-16 10:18 ` Peter Zijlstra
2022-11-16 22:38 ` Edgecombe, Rick P [this message]
2022-11-17 14:17 ` Peter Zijlstra
2022-11-18 17:05 ` Edgecombe, Rick P
2022-11-15 14:22 ` Peter Zijlstra
2022-11-15 20:56 ` Edgecombe, Rick P
2022-11-04 22:35 ` [PATCH v3 28/37] x86/shstk: Handle signals for shadow stack Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 29/37] x86/shstk: Introduce map_shadow_stack syscall Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 30/37] x86/shstk: Support wrss for userspace Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 31/37] x86: Expose thread features in /proc/$PID/status Rick Edgecombe
2022-11-04 22:35 ` [PATCH v3 32/37] x86/cet/shstk: Wire in CET interface Rick Edgecombe
2022-11-04 22:36 ` [PATCH v3 33/37] selftests/x86: Add shadow stack test Rick Edgecombe
2022-11-04 22:36 ` [PATCH v3 34/37] x86/fpu: Add helper for initing features Rick Edgecombe
2022-11-04 22:36 ` [PATCH v3 35/37] x86/cet: Add PTRACE interface for CET Rick Edgecombe
2022-11-15 14:43 ` Peter Zijlstra
2022-11-15 22:23 ` Edgecombe, Rick P
2022-11-17 12:25 ` Schimpe, Christina
2022-11-17 14:14 ` Peter Zijlstra
2022-11-18 17:20 ` Edgecombe, Rick P
2022-11-18 17:25 ` Schimpe, Christina
2022-11-17 19:57 ` Edgecombe, Rick P
2022-11-18 16:21 ` Schimpe, Christina
2022-11-18 17:18 ` Edgecombe, Rick P
2022-11-21 7:40 ` Mike Rapoport
2022-11-21 15:52 ` Edgecombe, Rick P
2022-11-22 9:36 ` Mike Rapoport
2022-11-04 22:36 ` [PATCH v3 36/37] x86/cet/shstk: Add ARCH_CET_UNLOCK Rick Edgecombe
2022-11-15 14:47 ` Peter Zijlstra
2022-11-15 20:01 ` Edgecombe, Rick P
2022-11-15 20:57 ` Peter Zijlstra
2022-11-15 21:00 ` Dave Hansen
2022-11-15 21:21 ` Peter Zijlstra
2022-11-04 22:36 ` [RFC 37/37] fs/binfmt_elf: Block old shstk elf bit Rick Edgecombe
2022-11-04 22:56 ` H.J. Lu
2022-11-06 9:33 ` Florian Weimer
2022-11-07 16:49 ` Edgecombe, Rick P
2022-11-07 16:55 ` Florian Weimer
2022-11-07 17:37 ` Edgecombe, Rick P
2022-11-07 19:10 ` H.J. Lu
2022-11-07 21:10 ` Edgecombe, Rick P
2022-11-07 21:21 ` H.J. Lu
2022-11-07 21:34 ` Edgecombe, Rick P
2022-11-07 21:47 ` H.J. Lu
2022-11-07 22:46 ` Edgecombe, Rick P
2022-11-07 23:45 ` H.J. Lu
2022-11-08 9:14 ` Florian Weimer
2022-11-07 16:49 ` Edgecombe, Rick P
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