Re: [PATCH] x86: Remove WARN_ON(in_nmi()) from vmalloc_fault

[Ingo Molnar]

* Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> Since the NMI iretq nesting has been fixed, there's no reason that
> an NMI handler can not take a page fault for vmalloc'd code. No locks
> are taken in that code path, and the software now handles nested NMIs
> when the fault re-enables NMIs on iretq.
> 
> Not only that, if the vmalloc_fault() WARN_ON_ONCE() is hit, and that
> warn on triggers a vmalloc fault for some reason, then we can go into
> an infinite loop (the WARN_ON_ONCE() does the WARN() before updating
> the variable to make it happen "once").
> 
> Reported-by: "Liu, Chuansheng" <chuansheng.liu@xxxxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

Would be nice to see the warning quoted that triggered this.

Thanks,

	Ingo
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