Re: [PATCHv2 1/2] tracing - fix recursive user stack trace

Andi Kleen
2010-11-11T10:34:18Z

On Thu, Nov 11, 2010 at 10:09:08AM +0100, Jiri Olsa wrote:
> The user stack trace can fault when examining the trace. Which
> would call the do_page_fault handler, which would trace again,
> which would do the user stack trace, which would fault and call
> do_page_fault again ...
>
> Thus this is causing a recursive bug. We need to have a recursion
> detector here.

I suspect this problem is in more trace points: any NMI or MCE
trace point or any other trace point that can be triggered
from a page. so it seems to be a general bug fix independent
of the other patch.

-Andi