Re: [PATCH v21 06/26] x86/cet: Add control-protection fault handler
From: Andy Lutomirski
Date: Wed Feb 24 2021 - 14:31:55 EST
On Wed, Feb 24, 2021 at 11:20 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
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On Wed, Feb 24, 2021 at 09:56:13AM -0800, Yu, Yu-cheng wrote:
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> No. Maybe I am doing too much. The GP fault sets si_addr to zero, for
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> example. So maybe do the same here?
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No, you're looking at this from the wrong angle. This is going to be
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user-visible and the moment it gets upstream, it is cast in stone.
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So the whole use case of what luserspace needs to do or is going to do
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or wants to do on a SEGV_CPERR, needs to be described, agreed upon by
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people etc before it goes out. And thus clarified whether the address
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gets copied out or not.
I vote 0. The address is in ucontext->gregs[REG_RIP] [0] regardless.
Why do we need to stick a copy somewhere else?
[0] or however it's spelled. i can never remember.
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Thx.
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--
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Regards/Gruss,
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Boris.
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