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    SubjectRe: [PATCH] x86/mm+efi: Avoid creating W+X mappings
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    On 9/23/22 14:19, Kees Cook wrote:
    >> But currently, PAE is not even enabled in the i386_defconfig, and
    >> defaults to off. This means people that are unaware of this won't
    >> enable it, and will be running without NX support.
    > And they all make me cry. ;)

    It's been like that for a long time, presumably because the defconfig
    should *boot* in as many cases as possible. It wouldn't be hard to
    change. It also wouldn't be hard to default to HIGHMEM4G (non-PAE) on
    targeted builds for CPUs that don't support it. Patch attached to do
    that, if anyone else has an opinion.

    We should probably just leave i386 alone, but it breaks my heart to see
    Kees in tears.diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
    index f9920f1341c8..fad978c7b7c5 100644
    --- a/arch/x86/Kconfig
    +++ b/arch/x86/Kconfig
    @@ -1363,9 +1363,14 @@ config X86_CPUID
    with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
    /dev/cpu/31/cpuid.

    +config CPU_HAS_PAE
    + def_bool y
    + depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
    +
    choice
    prompt "High Memory Support"
    default HIGHMEM4G
    + default HIGHMEM64G if CPU_HAS_PAE
    depends on X86_32

    config NOHIGHMEM
    @@ -1412,7 +1417,7 @@ config HIGHMEM4G

    config HIGHMEM64G
    bool "64GB"
    - depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6
    + depends on CPU_HAS_PAE
    select X86_PAE
    help
    Select this if you have a 32-bit processor and more than 4
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