On Thu, Jul 04, 2019 at 12:00:57AM +0200, Peter Zijlstra wrote: > On Wed, Jul 03, 2019 at 01:27:09PM -0700, Andy Lutomirski wrote: > > On Wed, Jul 3, 2019 at 3:28 AM root <pet...@infradead.org> wrote: > > > > @@ -1338,18 +1347,9 @@ ENTRY(error_entry) > > > movq %rax, %rsp /* switch stack */ > > > ENCODE_FRAME_POINTER > > > pushq %r12 > > > - > > > - /* > > > - * We need to tell lockdep that IRQs are off. We can't do this > > > until > > > - * we fix gsbase, and we should do it before enter_from_user_mode > > > - * (which can take locks). > > > - */ > > > - TRACE_IRQS_OFF > > > > This hunk looks wrong. Am I missing some other place that handles the > > case where we enter from kernel mode and IRQs were on? > > > > - CALL_enter_from_user_mode > > > ret > > > > > > .Lerror_entry_done: > > > - TRACE_IRQS_OFF > > > ret > > > > > > /* > > Did you perchance mean to complain about the .Lerror_entry_done one? > > Because I'm not seeing how the one before CALL_enter_from_user_mode can > ever be from-kernel. > > But yes, that .Lerror_entry_done one looks fishy.
That works because idtentry will now do an unconditional TRACE_IRQS_OFF, note how the patch removes the .if \paranoid around that.
