Re: [PATCH v5 32/32] x86/mm: Add support to make use of Secure Memory Encryption

From	Borislav Petkov <bp@alien8.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 32/32] x86/mm: Add support to make use of Secure Memory Encryption
Date	2017-05-31 11:20 +0200
Message-ID	<tN7Xk-2RF-23@gated-at.bofh.it> (permalink)
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On Tue, May 30, 2017 at 10:48:27AM -0500, Tom Lendacky wrote:
> I'll look at doing that instead of removing the support for the whole
> file.

Right, so I don't think the stack protector is even ready that early -
we do set it up later:

        /* Set up %gs.
         *
         * The base of %gs always points to the bottom of the irqstack
         * union.  If the stack protector canary is enabled, it is
         * located at %gs:40.  Note that, on SMP, the boot cpu uses
         * init data section till per cpu areas are set up.
         */
        movl    $MSR_GS_BASE,%ecx
        movl    initial_gs(%rip),%eax
        movl    initial_gs+4(%rip),%edx
        wrmsr

so I think marking the function "no-stack-protector" is the only option
right now. We can always look at fixing that later.

-- 
Regards/Gruss,
    Boris.

Good mailing practices for 400: avoid top-posting and trim the reply.

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Re: [PATCH v5 32/32] x86/mm: Add support to make use of Secure  Memory Encryption Borislav Petkov <bp@alien8.de> - 2017-05-31 11:20 +0200

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