On 14.03.2013, at 16:51, Christoffer Dall wrote: > On Thu, Mar 14, 2013 at 5:13 AM, Alexander Graf <agraf@xxxxxxx> wrote: >> >> On 14.03.2013, at 12:12, Alexander Graf wrote: >> >>> Howdy, >>> >>> After I managed to get 3.9 successfully up and working on my Arndale system, I started to stress test KVM. I simply took a kernel tree and compiled it until it failed: >>> >>> #!/bin/bash -e >>> >>> while true; do >>> make clean >>> make -j4 >>> done >>> >>> This eventually happened after a few successful runs: >>> >>> crypto/serpent_generic.c: In function ‘__serpent_decrypt’: >>> crypto/serpent_generic.c:560:1: internal compiler error: Segmentation fault >>> Please submit a full bug report, >>> with preprocessed source if appropriate. >>> See <http://bugs.opensuse.org/> for instructions. >>> make[1]: *** [crypto/serpent_generic.o] Error 1 >>> make: *** [crypto] Error 2 >>> make: *** Waiting for unfinished jobs.... >>> >>> >>> Does anyone have an idea how to debug this? Will mentioned TLB breakage that he had a branch for, so I'm going to try his branch next as guest kernel. > > Hi Alex, > > I've never seen anything like this on 3.6-based Arndale kernel, but > that's not to say that I dont' believe you. Do you get the same error > every time? I've had it on 3.7 as well. It only occurs when you leave a big compile job run in an endless loop for a few hours. But so far, I've been able to reproduce it on every Arndale board I got my hands on. > If so, how would a TLB error result in a segmentation fault, unless it > is triggered by a vary precise sequence of events that overwrites > kernel VMAs unintentionally or something like that? As per Will's suggestion I disabled ASLR inside of the guest now and so far haven't seen any segmentation faults. I don't think this is really KVM related. For the glorious details, I'll happily leave that to Will, as I have no idea why he even thought that my issues could be related to his tree. But given that disabling ASLR does help and that he did mention exactly that as an indication of the problems he was thinking of, I'm fairly confident that he knows what's going on :). > Just to make sure, did you compile both your guest and your host as > ARM (not thumb-2)? Yes :). Alex _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
