Re: [Xen-devel] 92a0f81d89 ("x86/cpu_entry_area: Move it out of the fixmap"): BUG: kernel hang in boot stage

2017-12-23 Thread Thomas Gleixner 
On Sun, 24 Dec 2017, kernel test robot wrote:

> Greetings,
> 
> 0day kernel testing robot got the below dmesg and the first bad commit is
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.x86/pti
> 
> commit 92a0f81d89571e3e8759366e050ee05cc545ef99
> Author: Thomas Gleixner 
> AuthorDate: Wed Dec 20 18:51:31 2017 +0100
> Commit: Ingo Molnar 
> CommitDate: Fri Dec 22 20:13:05 2017 +0100
> 
> x86/cpu_entry_area: Move it out of the fixmap

Yes, I'm an idiot.

 for (; start < end; start += PMD_SIZE)

which works fine when start + PMD_SIZE does not wrap around to 0 

Fix is on the way to git.

Thanks,

tglx

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[Xen-devel] 92a0f81d89 ("x86/cpu_entry_area: Move it out of the fixmap"): BUG: kernel hang in boot stage

2017-12-23 Thread kernel test robot 
Greetings,

0day kernel testing robot got the below dmesg and the first bad commit is

https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git WIP.x86/pti

commit 92a0f81d89571e3e8759366e050ee05cc545ef99
Author: Thomas Gleixner 
AuthorDate: Wed Dec 20 18:51:31 2017 +0100
Commit: Ingo Molnar 
CommitDate: Fri Dec 22 20:13:05 2017 +0100

x86/cpu_entry_area: Move it out of the fixmap

Put the cpu_entry_area into a separate P4D entry. The fixmap gets too big
and 0-day already hit a case where the fixmap PTEs were cleared by
cleanup_highmap().

Aside of that the fixmap API is a pain as it's all backwards.

Signed-off-by: Thomas Gleixner 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: linux-ker...@vger.kernel.org
Signed-off-by: Ingo Molnar 

ed1bbc40a0  x86/cpu_entry_area: Move it to a separate unit
92a0f81d89  x86/cpu_entry_area: Move it out of the fixmap
679d0580c1  x86/ldt: Make the LDT mapping RO
3056af3db3  Merge branch 'WIP.x86/pti.base'
+---+++++
|   | ed1bbc40a0 | 92a0f81d89 | 679d0580c1 | 
3056af3db3 |
+---+++++
| boot_successes| 77 | 0  | 0  | 0  
|
| boot_failures | 0  | 26 | 43 | 19 
|
| BUG:kernel_hang_in_boot_stage | 0  | 26 | 43 | 19 
|
+---+++++

[0.00] Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
[0.00] BRK [0x07cb7000, 0x07cb7fff] PGTABLE
[0.00] BRK [0x07cb8000, 0x07cb8fff] PGTABLE
[0.00] BRK [0x07cb9000, 0x07cb9fff] PGTABLE
[0.00] BRK [0x07cba000, 0x07cbafff] PGTABLE
BUG: kernel hang in boot stage


  # HH:MM RESULT GOOD 
BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD
git bisect start 858ee49740dd2f7e85f1b45c2af708b6c08f0771 v4.14 --
git bisect good 7fbbd5cbebf118a9e09f5453f686656a167c3d1c  # 23:18  G 11 
00   0  x86/entry/64: Remove the SYSENTER stack canary
git bisect good 4fe2d8b11a370af286287a2661de9d4e6c9a145a  # 23:27  G 11 
00   0  x86/entry: Rename SYSENTER_stack to CPU_ENTRY_AREA_entry_stack
git bisect good dd95f1a4b5ca904c78e6a097091eb21436478abb  # 23:39  G 11 
00   0  x86/mm: Put MMU to hardware ASID translation in one place
git bisect  bad 613e396bc0d4c7604fba23256644e78454c68cf6  # 23:47  B  0 
2   16   0  init: Invoke init_espfix_bsp() from mm_init()
git bisect good ed1bbc40a0d10e0c5c74fe7bdc6298295cf40255  # 23:58  G 11 
00   0  x86/cpu_entry_area: Move it to a separate unit
git bisect  bad 92a0f81d89571e3e8759366e050ee05cc545ef99  # 00:07  B  0
11   36  11  x86/cpu_entry_area: Move it out of the fixmap
# first bad commit: [92a0f81d89571e3e8759366e050ee05cc545ef99] 
x86/cpu_entry_area: Move it out of the fixmap
git bisect good ed1bbc40a0d10e0c5c74fe7bdc6298295cf40255  # 00:19  G 31 
00   0  x86/cpu_entry_area: Move it to a separate unit
# extra tests on HEAD of tip/master
git bisect  bad 3056af3db33464f58e51ddcc9fd5552413e3a6f2  # 00:55  B  0 
5   27   8  Merge branch 'WIP.x86/pti.base'
# extra tests on tree/branch tip/WIP.x86/pti
git bisect  bad 679d0580c1655be350392a66a45cedc9f4c5e139  # 01:14  B  0 
2   42  26  x86/ldt: Make the LDT mapping RO
# extra tests on tree/branch tip/master
git bisect  bad 3056af3db33464f58e51ddcc9fd5552413e3a6f2  # 01:14  B  0
19   33   0  Merge branch 'WIP.x86/pti.base'

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/lkp  Intel Corporation


dmesg-quantal-lkp-hsw01-11:20171224000613:i386-randconfig-a1-201751:4.14.0-00142-g92a0f81:2.gz
Description: application/gzip
#!/bin/bash

kernel=$1

kvm=(
qemu-system-x86_64
-enable-kvm
-cpu kvm64
-kernel $kernel
-m 512
-smp 2
-device e1000,netdev=net0
-netdev user,id=net0
-boot order=nc
-no-reboot
-watchdog i6300esb
-watchdog-action debug
-rtc base=localtime
-serial stdio
-display none
-monitor null
)

append=(
root=/dev/ram0
hung_task_panic=1
debug
apic=debug
sysrq_always_enabled
rcupdate.rcu_cpu_stall_timeout=100
net.ifnames=0