Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 8 May 2017 12:32:46 +0300 | Subject | Re: [tip:x86/mm] x86/boot/32: Defer resyncing initial_page_table until per-cpu is set up |
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On Mon, May 8, 2017 at 9:31 AM, Jan Kiszka <jan.kiszka@siemens.com> wrote: > On 2017-03-23 10:14, tip-bot for Andy Lutomirski wrote: >> The x86 smpboot trampoline expects initial_page_table to have the >> GDT mapped. If the GDT ends up in a virtually mapped per-cpu page, >> then it won't be in the page tables at all until perc-pu areas are >> set up. The result will be a triple fault the first time that the >> CPU attempts to access the GDT after LGDT loads the perc-pu GDT. >> >> This appears to be an old bug, but somehow the GDT fixmap rework >> is triggering it. This seems to have something to do with the >> memory layout.
> This breaks the boot on our Intel Quark platform (IOT2000, similar to > Galileo Gen2). Reverting it over master makes it work again. Any idea > what goes wrong? Let me know how I can help debugging this.
JFYI: As of today linux-next when _kexec:ed_ works fine to me
Perhaps I can test this later with direct boot from SD card.
-- With Best Regards, Andy Shevchenko
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