>>> On 07.04.17 at 16:00, <andrew.coop...@citrix.com> wrote: > ...rather than leaving fragments of old instructions in place. This reduces > the chances of something going further-wrong (as the debug trap will be > caught > and terminate the guest) in a cascade-failure where we end up executing the > instruction fragments. > > Before: > (XEN) d2v0 exception 6 (ec=0000) in emulation stub (line 6239) > (XEN) d2v0 stub: c4 e1 44 77 c3 80 d0 82 ff ff ff d1 90 ec 90 > > After: > (XEN) d3v0 exception 6 (ec=0000) in emulation stub (line 6239) > (XEN) d3v0 stub: c4 e1 44 77 c3 cc cc cc cc cc cc cc cc cc cc > > To make this work, the int3 handler needs to be extended to attempt recovery > rather than simply returning back to Xen context. While altering do_int3(), > leave an obvious sign if an embedded breakpoint has been hit and not dealt > with by debugging facilities. > > (XEN) Hit embedded breakpoint at ffff82d0803d01f6 > [extable.c#stub_selftest+0xda/0xee] > > Extend the selftests to include int3, and add an extra printk indicating the > start of the recovery selftests, to avoid leaving otherwise-spurious faults > visible in the log. > > (XEN) build-id: 55d7e6f420b4f0ce277f776be620f43d7cb8646c > (XEN) Running stub recovery selftests... > (XEN) traps.c:3466: GPF (0000): ffff82d0bffff041 [ffff82d0bffff041] -> > ffff82d08035937a > (XEN) traps.c:813: Trap 12: ffff82d0bffff040 [ffff82d0bffff040] -> > ffff82d08035937a > (XEN) traps.c:1215: Trap 3: ffff82d0bffff041 [ffff82d0bffff041] -> > ffff82d08035937a > (XEN) ACPI sleep modes: S3 > > Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
Reviewed-by: Jan Beulich <jbeul...@suse.com> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org https://lists.xen.org/xen-devel
