On Wed, Apr 30, 2014 at 11:13:57AM +0200, Thomas Gleixner wrote: > On Tue, 29 Apr 2014, Dave Jones wrote: > > This is trickier to reproduce than it first seemed, as logging slows > > things down so much. But after a few hours, it logged that the > > call that triggered this was.. > > > > futex(uaddr=0x7f55ff8c4000, op=0x6, val=0x200000006223800b, > > utime=0x7f55ff8c4000, uaddr2=0x7f55ff8c4000, val3=-123) > > > > Those addresses come from an mmap we made on startup.. > > > > [init] mapping[3]: (zeropage PROT_READ | PROT_WRITE) 0x7f55ff8c4000 (1MB) > > > > op = FUTEX_LOCK_PI > > > > val seems to be garbage. > > > > I'll do another run, just to see if it's always the same set of values, > > but it's going to probably take an overnight run. > > Do you have the full fuzzing log, so I can see what happened > before/around that?
This is tough, because it takes a long time to reproduce when the logging is enabled, and that ends up generating a lot of output. I've tried to cut it down some using just 4 threads, but that's still over 30M of logs. http://www.codemonkey.org.uk/junk/futex.tar.xz In this run, child0 was the pid that faulted. You can see the last line in trinity-child0.log has a similar fingerprint to the trace above. One thing that does look suspicious, is that all 4 threads were doing op=0x6 right before the kernel went south. Hope this helps. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
