Messages in this thread | | | Date | Mon, 5 Apr 2010 21:40:58 +0200 | From | Frederic Weisbecker <> | Subject | Re: Random scheduler/unaligned accesses crashes with perf lock events on sparc 64 |
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On Mon, Apr 05, 2010 at 12:22:33PM -0700, David Miller wrote: > From: Frederic Weisbecker <fweisbec@gmail.com> > Date: Mon, 5 Apr 2010 08:57:04 +0200 > > > It seems to happen after an unaligned access fixup. > > You shouldn't be getting the unaligned fixup in the first place, > especially in the locations where you see them. I suspect that > once you see first fixup, all of the registers in the cpu have > been corrupted in one way or another. > > I suspect something fundamental gets corrupted, for example the > current register window (%cwp) is corrupted and that screws up all of > the registers so every single function starts accessing garbage. > > My suspicions lie in three places, the ftrace mcount() > stubs, stack_trace_flush(), or the new perf_arch_save_caller_regs() > since those are the three places offhand that could make > us potentially make us return to function in the wrong > register window.
It happens without CONFIG_FUNCTION_TRACER as well (but it happens when the function tracer runs). And I hadn't your perf_arch_save_caller_regs() when I triggered this.
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