915f3e3f76 ("mac80211_hwsim: Replace bogus hrtimer clockid"): BUG: kernel reboot-without-warning in test stage

Greetings,

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

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

commit 915f3e3f76c05b2da93c4cc278eebc2d9219d9f4
Author:     Thomas Gleixner [off-list ref]
AuthorDate: Sat Feb 25 11:27:37 2017 +0100
Commit:     Linus Torvalds [off-list ref]
CommitDate: Sat Feb 25 09:48:16 2017 -0800

    mac80211_hwsim: Replace bogus hrtimer clockid
    
    mac80211_hwsim initializes a hrtimer with clockid CLOCK_MONOTONIC_RAW.
    That's not supported.
    
    Use CLOCK_MONOTNIC instead.
    
    Signed-off-by: Thomas Gleixner [off-list ref]
    Signed-off-by: Linus Torvalds [off-list ref]

9e31489029  Merge tag 'openrisc-for-linus' of git://github.com/openrisc/linux
915f3e3f76  mac80211_hwsim: Replace bogus hrtimer clockid
b1b6f83ac9  Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
9829d9f31f  Add linux-next specific files for 20170904
+-------------------------------------------------+------------+------------+------------+---------------+
|                                                 | 9e31489029 | 915f3e3f76 | b1b6f83ac9 | next-20170904 |
+-------------------------------------------------+------------+------------+------------+---------------+
| boot_successes                                  | 0          | 608        | 222        | 225           |
| boot_failures                                   | 7          | 12         | 6          | 6             |
| WARNING:at_kernel/time/hrtimer.c:#hrtimer_init  | 7          |            |            |               |
| BUG:kernel_reboot-without-warning_in_test_stage | 0          | 12         | 6          | 6             |
+-------------------------------------------------+------------+------------+------------+---------------+

[   25.291724] can: request_module (can-proto-0) failed.
[   25.306088] can: request_module (can-proto-3) failed.
[   25.365624] irda_setsockopt: not allowed to set MAXSDUSIZE for this socket type!


                                                          # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD
git bisect start v4.11 v4.10 --
git bisect  bad ce70df089143c49385b4f32f39d41fb50fbf6a7c  # 04:18  B      0    10   34   0  mm, gup: fix typo in gup_p4d_range()
git bisect  bad 94eae8034002401d71ae950106659e16add36e77  # 04:18  B      0    14   42   0  Merge tag 'platform-drivers-x86-v4.11-1' of git://git.infradead.org/linux-platform-drivers-x86
git bisect good 7bb033829ef3ecfc491c0ed0197966e8f197fbdc  # 04:34  G    218     0  218 1088  Merge tag 'rodata-v4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
git bisect good a3919caaa27a5fde1cbda46e394bb17953e104a1  # 04:48  G    221     0  221 1091  Merge tag 'rproc-v4.11' of git://github.com/andersson/remoteproc
git bisect good d5500a074741b78b7f778b4ab3415d5ecdcda0a7  # 05:04  G    224     0  224 1094  Merge tag 'usercopy-v4.11-rc1.fix' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
git bisect  bad 915f3e3f76c05b2da93c4cc278eebc2d9219d9f4  # 05:04  B      0    12   40   0  mac80211_hwsim: Replace bogus hrtimer clockid
git bisect good 1802979ab1ee8ec5a72987ad518f5a91bf41cd89  # 05:17  G    220     0  220 2720  Merge branch 'for-linus' of git://git.kernel.dk/linux-block
git bisect good f8e6859ea9d06ae1565b21278c4e10fbce5f1eab  # 05:35  G    222     0  222 1092  Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
git bisect good 9e314890292c0dd357eadef6a043704fa0b4c157  # 05:55  G    222     0  222 2733  Merge tag 'openrisc-for-linus' of git://github.com/openrisc/linux
# first bad commit: [915f3e3f76c05b2da93c4cc278eebc2d9219d9f4] mac80211_hwsim: Replace bogus hrtimer clockid
git bisect good 9e314890292c0dd357eadef6a043704fa0b4c157  # 06:27  G    658     0  658 3395  Merge tag 'openrisc-for-linus' of git://github.com/openrisc/linux
# extra tests on HEAD of leon-rdma/rdma-next
git bisect  bad b8d87db63989c2914a7ea986270aae1ce13371cd  # 06:33  B     43     2    0   0  IB/ipoib: Fix sysfs Pkey create<->remove possible deadlock
# extra tests on tree/branch linus/master
git bisect  bad b1b6f83ac938d176742c85757960dec2cf10e468  # 06:38  B      9     1    0   0  Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
# extra tests with first bad commit reverted
git bisect good c4093689658e2a9893463f739582aea1cbb151f7  # 07:06  G    219     0  219 411  Revert "mac80211_hwsim: Replace bogus hrtimer clockid"
# extra tests on tree/branch linux-next/master
git bisect  bad 9829d9f31f6c0e4984545e03032f14ccca6eeb68  # 07:18  B     75     3    0   0  Add linux-next specific files for 20170904

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

On Tue, 5 Sep 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/torvalds/linux.git master

commit 915f3e3f76c05b2da93c4cc278eebc2d9219d9f4
Author:     Thomas Gleixner [off-list ref]
AuthorDate: Sat Feb 25 11:27:37 2017 +0100
Commit:     Linus Torvalds [off-list ref]
CommitDate: Sat Feb 25 09:48:16 2017 -0800

    mac80211_hwsim: Replace bogus hrtimer clockid
    
    mac80211_hwsim initializes a hrtimer with clockid CLOCK_MONOTONIC_RAW.
    That's not supported.
    
    Use CLOCK_MONOTNIC instead.

Sorry, no. That bisect is completely bogus. The commit in question merily
replaces the unsupported clockid with a valid one.

Thanks,

	tglx

On 2017-09-05 09:12:40 [+0200], Thomas Gleixner wrote:

Sorry, no. That bisect is completely bogus. The commit in question merily
replaces the unsupported clockid with a valid one.

The bisect is correct. It just has problems to express itself properly. So
the table says:

| WARNING:at_kernel/time/hrtimer.c:#hrtimer_init  | 7   |     |    |   |                                                                                
| BUG:kernel_reboot-without-warning_in_test_stage | 0   | 12  | 6  | 6 |                                                                                

which means _before_ your commit it counted a warning in hrtimer_init()
(an unsupported clock id was used). With your commit, the warning was
gone and I *think* the userland then printed
"BUG:kernel_reboot-without-warning_in_test_stage" because it had no
warning.
It seems that the bot learned to live with that warning which was around
for more than three years. Now that you removed it, it seems to be a
mistake to do so because nobody complained about it so far.

Thanks,

	tglx

Sebastian

On Tue, 5 Sep 2017, Sebastian Andrzej Siewior wrote:

On 2017-09-05 09:12:40 [+0200], Thomas Gleixner wrote:

quoted

Sorry, no. That bisect is completely bogus. The commit in question merily
replaces the unsupported clockid with a valid one.

The bisect is correct. It just has problems to express itself properly. So
the table says:

| WARNING:at_kernel/time/hrtimer.c:#hrtimer_init  | 7   |     |    |   |                                                                                
| BUG:kernel_reboot-without-warning_in_test_stage | 0   | 12  | 6  | 6 |                                                                                

which means _before_ your commit it counted a warning in hrtimer_init()
(an unsupported clock id was used). With your commit, the warning was
gone and I *think* the userland then printed
"BUG:kernel_reboot-without-warning_in_test_stage" because it had no
warning.
It seems that the bot learned to live with that warning which was around
for more than three years. Now that you removed it, it seems to be a
mistake to do so because nobody complained about it so far.

Thanks for the translation. I'll never learn to decode these reports.

       tglx