linux-kernel - Re: [PATCH v7 38/41] x86/fpu: Add helper for initing features

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Message-ID: <46894d1c79815739faeffa657dadbabaee437068.camel@intel.com>
Date:   Mon, 13 Mar 2023 23:31:59 +0000
From:   "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>
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Subject: Re: [PATCH v7 38/41] x86/fpu: Add helper for initing features

On Mon, 2023-03-13 at 18:10 +0100, Borislav Petkov wrote:
> > 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.

Ok, will do this instead in "x86: Add PTRACE interface for shadow
stack".