Messages in this thread | | | Date | Wed, 11 Apr 2018 08:35:53 +0800 | From | Fengguang Wu <> | Subject | Re: [lkp-robot] [bisect done] e71e836f46 [ 17.567570] WARNING: CPU: 0 PID: 1 at arch/x86/include/asm/pgtable.h:540 __change_page_attr_set_clr |
| |
Hi Dave,
On Tue, Apr 10, 2018 at 01:59:21PM -0700, Dave Hansen wrote: >On 04/09/2018 06:12 PM, kernel test robot wrote: >> +-----------------------------------------------------------------------+------------+------------+------------+------------+ >> | | 64c8075940 | e71e836f46 | 0564258fb2 | 87e1e2f51c | >> +-----------------------------------------------------------------------+------------+------------+------------+------------+ >> | boot_successes | 35 | 0 | 19 | 11 | >> | boot_failures | 0 | 26 | | | >> | WARNING:at_arch/x86/include/asm/pgtable.h:#__change_page_attr_set_clr | 0 | 26 | | | >> | RIP:__change_page_attr_set_clr | 0 | 26 | | | >> +-----------------------------------------------------------------------+------------+------------+------------+------------+ > >LKP folks, does this mean that the system didn't boot in all the places >that we saw this warning? Or does this just say that it *had* the >warning 26 times?
The 'e71e836f46' column means there are 0 boots (sorry boot_successes might be a bit confusing) with clean dmesg and 26 boots with warning/error dmesg. It indicates that WARNING is 100% reproducible.
boot_successes + boot_failures = total test boots
>I looked into this a bit. This LKP report points the finger at this >commit which trips over a new debugging WARN_ON() I added: > >[patch 06/11] x86/mm: Remove extra filtering in pageattr code > >It's because set_memory_nx() encounters the (unsupported) _PAGE_GLOBAL >bit while clearing _PAGE_NX. I never saw this in testing because this >patch: > >[PATCH 10/11] x86/pti: never implicitly clear _PAGE_GLOBAL for kernel image > >explicitly clears out _PAGE_GLOBAL long before the set_memory_nx() call. >So I *think* this is a transient issue resulting in bad ordering of the >_PAGE_GLOBAL patch set. I believe it is harmless.
Right. The '0564258fb2' and '87e1e2f51c' columns mean the 'tip/x86/pti' and 'tip/master' branch HEADs boot clean. So it's a transient warning inside the branch.
Thanks, Fengguang
| |