On Sat, 23 Jun 2018, Fenghua Yu wrote: > On Sun, Jun 24, 2018 at 02:55:08AM +0200, Thomas Gleixner wrote: > > On Sat, 23 Jun 2018, Fenghua Yu wrote: > > > On Sat, Jun 23, 2018 at 11:17:03AM +0200, Thomas Gleixner wrote: > > > > On Fri, 22 Jun 2018, Fenghua Yu wrote: > > It's not treated as failure. The firmware simply does not have an handler > > for #AC installed and dies. I hope you yelled at the firmware people > > already. > > I think firmware does handle the split lock in its #AC handler because > firmware shows the following log and system hangs: > > !!!! IA32 Exception Type - 11(#AC - Alignment Check) CPU Apic ID - 00000014! > ! > ExceptionData - 00000000 > EIP - 6A9DB6C3, CS - 00000010, EFLAGS - 00010006 > ...
They even have a handler which makes the thing die, but never bothered to enable #AC in the first place. So the handler is there to catch the case that an operating system dares to enable #AC. Thank god, I don't have to review that source code. Thanks, tglx