On Tue, Jan 09, 2018 at 05:05:51PM +0100, Peter Zijlstra wrote: > On Tue, Jan 09, 2018 at 10:56:52AM -0500, Vince Weaver wrote: > > On Tue, 9 Jan 2018, Peter Zijlstra wrote: > > > > > So CONFIG_PAGE_TABLE_ISOLATION=y and booting with "pti=off" makes it > > > 'work', right? > > > > yes. Previously I was changing CONFIG_PAGE_TABLE_ISOLATION and > > recompiling, but just now I booted with it set to yes and pti=off and the > > fuzzer has been running fine for a half hour (usually it crashes in under > > 5 minutes). > > > > I did see these in the logs which I don't think I've seen before. > > > > WARNING: stack recursion on stack type 2 > > WARNING: can't dereference iret registers at 000000000783fea8 for ip > > paranoid_entry+0x2e/0x90 > > WARNING: can't dereference registers at 00000000f0698d17 for ip > > paranoid_entry+0x4c/0x90 > > WARNING: stack going in the wrong direction? ip=native_sched_clock+0x9/0x90 > > I've seen that last one, but not the ones before. Josh, this isn't > healty, right? :-)
Looks like some funky things may be happening on the stack there, though we have seen some issues related to ORC getting confused by paravirt patching. I'm a bit swamped at the moment but I'll look deeper as time permits... -- Josh
