On Sat, 22 Nov 2014 19:57:07 -0800 Peter Grehan <gre...@freebsd.org> wrote:
> Hi Shawn, > > > Interesting. I'll have to do more digging. Because removing map_at_zero > > support is the same as keeping it at the default of 0. It's not possible > > that our ASLR implementation is affecting bhyve, since our ASLR > > implementation is in sys_mmap and the elf image activator. At this > > stage, bhyve's vmm.ko is directly accessing vm_map_*, which we haven't > > touched. > > One thing you may be able to try is ktrace the bhyveload process and > see which syscall is failing. Oliver fixed the problem. bhyve's vmm.ko uses VM_MIN_ADDRESS, which defaults to NULL in FreeBSD. We modified that to be at 64k to prevent NULL dereferences. Combine that with the removal of map_at_zero, NULL deref is not possible anymore. But since we bumped VM_MIN_ADDRESS up, bhyve's vmm.ko no longer attempts to map at NULL (which it absolutely needs to). The change Oliver made simply uses 0 instead of VM_MIN_ADDRESS. If this is a change FreeBSD wants upstream, we'd love it merged upstream. Commit for reference: https://github.com/HardenedBSD/hardenedBSD/commit/23bd719ce1e3a8cc42fc8317b1c7c6d9e74dcba0 Thanks, Shawn _______________________________________________ freebsd-virtualization@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization To unsubscribe, send any mail to "freebsd-virtualization-unsubscr...@freebsd.org"
