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    SubjectRe: [PATCH v3 07/10] x86/fpu/xstate: Update copy_kernel_to_xregs_err() for XSAVES supervisor states
    On Sat, Mar 28, 2020 at 09:43:04AM -0700, Yu-cheng Yu wrote:
    > The function copy_kernel_to_xregs_err() uses XRSTOR, which can work with
    > standard or compacted format without supervisor xstates. However, when
    > supervisor xstates are present, XRSTORS must be used. Fix it by using
    > XRSTORS when XSAVES is enabled.
    >
    > I also considered if there were additional cases where XRSTOR might be
    > mistakenly called instead of XRSTORS. There are only three XRSTOR sites
    > in kernel:
    >
    > 1. copy_kernel_to_xregs_booting(), already switches between XRSTOR and
    > XRSTORS based on X86_FEATURE_XSAVES.
    > 2. copy_user_to_xregs(), which *needs* XRSTOR because it is copying from
    > userspace and must never copy supervisor state with XRSTORS.
    > 3. copy_kernel_to_xregs_err() mistakenly used XRSTOR only. Fixed in
    > this patch.

    Avoid having "This patch" or "This commit" in the commit message. It is
    tautologically useless.

    Also, do

    $ git grep 'This patch' Documentation/process

    for more details.

    --
    Regards/Gruss,
    Boris.

    https://people.kernel.org/tglx/notes-about-netiquette

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