Messages in this thread | | | Date | Mon, 22 May 2017 11:26:51 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] perf/x86/intel: Drop kernel samples even though :u is specified |
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On Mon, May 22, 2017 at 09:45:30AM +0100, Mark Rutland wrote: > On Mon, May 22, 2017 at 10:12:22AM +0800, Jin, Yao wrote:
> > But the code is being ugly and hard to maintain. And frankly I don't > > know kernel address space for all arch. > > > > Any idea? Could we just do at x86 side this time? > > Can we not check user_mode(regs) for all architectures? > > !user_mode(regs) implies a kernel sample.
Yes, that should work at that point. We specifically already rely on user_mode() in the generic code.
On x86 we specifically set regs->cs to match regs->ip (in cases where this isn't necessarily so) before calling into the generic code to make this work.
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