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    SubjectRe: [PATCH 02/35] x86/cet/shstk: Add Kconfig option for Shadow Stack
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    On Mon, Feb 07 2022 at 14:39, Dave Hansen wrote:

    > On 1/30/22 13:18, Rick Edgecombe wrote:
    >> +config X86_SHADOW_STACK
    >> + prompt "Intel Shadow Stack"
    >> + def_bool n
    >> + depends on AS_WRUSS
    >> + depends on ARCH_HAS_SHADOW_STACK
    >> + select ARCH_USES_HIGH_VMA_FLAGS
    >> + help
    >> + Shadow Stack protection is a hardware feature that detects function
    >> + return address corruption. This helps mitigate ROP attacks.
    >> + Applications must be enabled to use it, and old userspace does not
    >> + get protection "for free".
    >> + Support for this feature is present on Tiger Lake family of
    >> + processors released in 2020 or later. Enabling this feature
    >> + increases kernel text size by 3.7 KB.
    >
    > I guess the "2020" comment is still OK. But, given that it's on AMD and
    > a could of other Intel models, maybe we should just leave this at:
    >
    > CPUs supporting shadow stacks were first released in 2020.

    Yes.

    > If we say anything. We mostly want folks to just go read the
    > documentation if they needs more details.

    Also the kernel text size increase blurb is pretty useless as that's a
    number which is wrong from day one.

    Thanks,

    tglx

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