Hi, We run CRIU tests for tip/auto-latest regularly, and a few days ago our test job started to detect this warning in a kernel log:
[ 44.235786] WARNING: can't dereference iret registers at ffff8801c5f17fe0 for ip ffffffff95f0d94b What does it mean? How critical is it? Our test job fails if it detects any warning in a kernel log. Maybe we need to investigate reasons of this warning and try to eliminate it? Here are logs: https://travis-ci.org/avagin/linux/jobs/289676634 Thanks, Andrei On Fri, Oct 13, 2017 at 03:02:01PM -0500, Josh Poimboeuf wrote: > The ORC unwinder has been stable in testing so far. Give it much wider > testing by making it the default in kconfig for x86_64. It's not yet > supported for 32-bit, so leave frame pointers as the default there. > > Suggested-by: Ingo Molnar <mi...@kernel.org> > Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> > --- > arch/x86/Kconfig.debug | 33 +++++++++++++++++---------------- > 1 file changed, 17 insertions(+), 16 deletions(-) > > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug > index f274dbb87c26..a4ff214fb760 100644 > --- a/arch/x86/Kconfig.debug > +++ b/arch/x86/Kconfig.debug > @@ -358,27 +358,13 @@ config PUNIT_ATOM_DEBUG > > choice > prompt "Choose kernel unwinder" > - default UNWINDER_FRAME_POINTER > + default UNWINDER_ORC if X86_64 > + default UNWINDER_FRAME_POINTER if X86_32 > ---help--- > This determines which method will be used for unwinding kernel stack > traces for panics, oopses, bugs, warnings, perf, /proc/<pid>/stack, > livepatch, lockdep, and more. > > -config UNWINDER_FRAME_POINTER > - bool "Frame pointer unwinder" > - select FRAME_POINTER > - ---help--- > - This option enables the frame pointer unwinder for unwinding kernel > - stack traces. > - > - The unwinder itself is fast and it uses less RAM than the ORC > - unwinder, but the kernel text size will grow by ~3% and the kernel's > - overall performance will degrade by roughly 5-10%. > - > - This option is recommended if you want to use the livepatch > - consistency model, as this is currently the only way to get a > - reliable stack trace (CONFIG_HAVE_RELIABLE_STACKTRACE). > - > config UNWINDER_ORC > bool "ORC unwinder" > depends on X86_64 > @@ -395,6 +381,21 @@ config UNWINDER_ORC > Enabling this option will increase the kernel's runtime memory usage > by roughly 2-4MB, depending on your kernel config. > > +config UNWINDER_FRAME_POINTER > + bool "Frame pointer unwinder" > + select FRAME_POINTER > + ---help--- > + This option enables the frame pointer unwinder for unwinding kernel > + stack traces. > + > + The unwinder itself is fast and it uses less RAM than the ORC > + unwinder, but the kernel text size will grow by ~3% and the kernel's > + overall performance will degrade by roughly 5-10%. > + > + This option is recommended if you want to use the livepatch > + consistency model, as this is currently the only way to get a > + reliable stack trace (CONFIG_HAVE_RELIABLE_STACKTRACE). > + > config UNWINDER_GUESS > bool "Guess unwinder" > depends on EXPERT
