Messages in this thread | | | Date | Mon, 13 Mar 2023 18:10:31 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v7 38/41] x86/fpu: Add helper for initing features |
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On Mon, Mar 13, 2023 at 04:10:14PM +0000, Edgecombe, Rick P wrote: > This seems more clear. I'm sorry for the noise here though, because > this has made me realize that the initing logic should never be hit. We > used to support the full CET_U state in ptrace, but then dropped it to > just the SSP and only allowed it when shadow stack is active.
Right, you do check that at function entry.
> This means that CET_U will always have at least the CET_SHSTK_EN bit > set and so not be in the init state. So this can probably just warn > and bail if it sees an init state.
I don't mind the additional checks as this is a security thing so sanity checks are good, especially if they're cheap.
And you don't need to reinit the buffer - just scream loudly when get_xsave_addr() returns NULL.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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