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    SubjectRe: [tip:x86/urgent] x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs
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    Dear Andy,


    On 09/17/17 20:19, tip-bot for Andy Lutomirski wrote:
    > Commit-ID: 4ba55e65f471d011d3ba2ac2022180ea0877d68e
    > Gitweb: http://git.kernel.org/tip/4ba55e65f471d011d3ba2ac2022180ea0877d68e
    > Author: Andy Lutomirski <luto@kernel.org>
    > AuthorDate: Sun, 17 Sep 2017 09:03:51 -0700
    > Committer: Ingo Molnar <mingo@kernel.org>
    > CommitDate: Sun, 17 Sep 2017 18:59:09 +0200
    >
    > x86/mm/32: Load a sane CR3 before cpu_init() on secondary CPUs
    >
    > For unknown historical reasons (i.e. Borislav doesn't recall),
    > 32-bit kernels invoke cpu_init() on secondary CPUs with
    > initial_page_table loaded into CR3. Then they set
    > current->active_mm to &init_mm and call enter_lazy_tlb() before
    > fixing CR3.

    If this should be changed, I’d be happy to help.

    > This means that the x86 TLB code gets invoked while CR3
    > is inconsistent, and, with the improved PCID sanity checks I added,
    > we warn.
    >
    > Fix it by loading swapper_pg_dir (i.e. init_mm.pgd) earlier.
    >
    > Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
    > Reported-by: Pavel Machek <pavel@ucw.cz>
    > Signed-off-by: Andy Lutomirski <luto@kernel.org>
    > Cc: Borislav Petkov <bp@alien8.de>
    > Cc: Borislav Petkov <bpetkov@suse.de>
    > Cc: Linus Torvalds <torvalds@linux-foundation.org>
    > Cc: Peter Zijlstra <peterz@infradead.org>
    > Cc: Thomas Gleixner <tglx@linutronix.de>
    > Fixes: 72c0098d92ce ("x86/mm: Reinitialize TLB state on hotplug and resume")
    > Link: http://lkml.kernel.org/r/30cdfea504682ba3b9012e77717800a91c22097f.1505663533.git.luto@kernel.org

    This should use the HTTPS protocol.

    > Signed-off-by: Ingo Molnar <mingo@kernel.org>
    > ---
    > arch/x86/kernel/smpboot.c | 13 +++++++------
    > 1 file changed, 7 insertions(+), 6 deletions(-)

    […]

    Thank you for the fix.

    Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> (Lenovo X60t)


    Kind regards,

    Paul

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