Messages in this thread | | | Date | Fri, 21 Nov 2014 10:24:35 -0800 | Subject | Re: frequent lockups in 3.18rc4 | From | Linus Torvalds <> |
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On Fri, Nov 21, 2014 at 9:34 AM, Steven Rostedt <rostedt@goodmis.org> wrote: > > I see. You have issues with the use of current->active_mm instead of > just doing a read_cr3() (and I'm sure other things).
Yes. And I have this memory of it actually mattering, where we'd get get the page fault, but see that the (wrong) page table is already populated, and say "ti wasn't a vmalloc fault", and then go down the oops path.
Of course, the context switch itself has changed completely over the years, but I think it would still be true with NMI. "active_mm" may point to a different page table than the one the CPU is actually using, and then the whole thing is bogus.
Linus
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