Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is git://anongit.freedesktop.org/drm/drm-intel topic/core-for-CI commit 7928ca5cc786fdc0269342f1b9e22c2af939b989 Author: Daniel Vetter <daniel.vetter(a)ffwll.ch&gt; AuthorDate: Tue Mar 20 17:02:58 2018 +0100 Commit: Chris Wilson <chris(a)chris-wilson.co.uk&gt; CommitDate: Mon Aug 13 08:45:13 2018 +0100 RFC: debugobjects: capture stack traces at _init() time Sometimes it's really easy to know which object has gone boom and where the offending code is, and sometimes it's really hard. One case we're trying to hunt down is when module unload catches a live debug object, with a module with lots of them. Capture a full stack trace from debug_object_init() and dump it when there's a problem. FIXME: Should we have a separate Kconfig knob for the backtraces, they're quite expensive? Atm I'm just selecting it for the general debug object stuff. v2: Drop the locks for gathering&storing the backtrace. This is required because depot_save_stack can call free_pages (to drop it's preallocation), which can call debug_check_no_obj_freed, which will recurse into the db->lock spinlocks. Cc: Philippe Ombredanne <pombredanne(a)nexb.com&gt; Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org&gt; Cc: Thomas Gleixner <tglx(a)linutronix.de&gt; Cc: Kate Stewart <kstewart(a)linuxfoundation.org&gt; Cc: Daniel Vetter <daniel.vetter(a)ffwll.ch&gt; Cc: Waiman Long <longman(a)redhat.com&gt; Acked-by-for-CI-testing: Chris Wilson <chris(a)chris-wilson.co.uk&gt; Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com&gt; Link: https://patchwork.freedesktop.org/patch/msgid/20180320160258.11381-1-dani... 7d5f8ade6d kernel/panic: Repeat the line and caller information at the end of the OOPS 7928ca5cc7 RFC: debugobjects: capture stack traces at _init() time 97263ba0a2 usb/icl: Work around ACPI boottime crash +-----------------------------------------------------------------------------+------------+------------+------------+ | | 7d5f8ade6d | 7928ca5cc7 | 97263ba0a2 | +-----------------------------------------------------------------------------+------------+------------+------------+ | boot_successes | 38 | 0 | 0 | | boot_failures | 1 | 17 | 11 | | BUG:kernel_reboot-without-warning_in_test_stage | 1 | | | | BUG:kernel_hang_in_early-boot_stage,last_printk:early_console_in_setup_code | 0 | 17 | 11 | +-----------------------------------------------------------------------------+------------+------------+------------+ early console in setup code BUG: kernel hang in early-boot stage, last printk: early console in setup code Linux version 4.18.0-00007-g7928ca5 #1 Command line: root=/dev/ram0 hung_task_panic=1 debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 net.ifnames=0 printk.devkmsg=on panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 drbd.minor_count=8 systemd.log_level=err ignore_loglevel console=tty0 earlyprintk=ttyS0,115200 console=ttyS0,115200 vga=normal rw link=/cephfs/kbuild/run-queue/quantal-ivb41/x86_64-randconfig-s1-08300637/linux-devel:devel-catchup-201808300657:7928ca5cc786fdc0269342f1b9e22c2af939b989:bisect-linux-0/.vmlinuz-7928ca5cc786fdc0269342f1b9e22c2af939b989-20180830124809-1:quantal-ivb41-37 branch=linux-devel/devel-catchup-201808300657 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-s1-08300637/gcc-6/7928ca5cc786fdc0269342f1b9e22c2af939b989/vmlinuz-4.18.0-00007-g7928ca5 drbd.minor_count=8 rcuperf.shutdown=0 Elapsed time: 370 # HH:MM RESULT GOOD BAD GOOD_BUT_DIRTY DIRTY_NOT_BAD git bisect start 4d30a6ec667c3be5e517c6db7386b7cbeae0d241 5b394b2ddf0347bef56e50c69a58773c94343ff3 -- git bisect bad 6a62e337f13403ec965bc73faa931e91b977ea5a # 08:08 B 0 11 26 0 Merge 'linux-review/Andrey-Konovalov/khwasan-kernel-hardware-assisted-address-sanitizer/20180830-045630' into devel-catchup-201808300657 git bisect bad b415cf311a6e49d23247404e903da92cd46e8784 # 08:24 B 0 4 20 1 Merge 'linux-review/Dong-Aisheng/clk-new-APIs-to-handle-all-available-clocks/20180830-053055' into devel-catchup-201808300657 git bisect good d2b261c3aae27dd7968c9b130a8c6a64b9a17252 # 08:44 G 11 0 0 0 Merge 'andersson-remoteproc/for-next' into devel-catchup-201808300657 git bisect good 926c9f4523c971273cbe47e5e294a303848dd5c3 # 09:07 G 11 0 0 0 Merge 'linux-review/Takuya-Yamamoto/x86-mm-Fix-typo-in-arch-x86-mm-extable-c/20180830-054810' into devel-catchup-201808300657 git bisect good fdece75721e7dbefaa1bcd698d3c59e4e8dd87ea # 09:21 G 11 0 0 0 Merge 'jkirsher-next-queue/40GbE' into devel-catchup-201808300657 git bisect bad 8deb227aaae37122397122729af6c8b0a82c5e36 # 09:49 B 0 7 22 0 Merge 'drm-tip/drm-tip' into devel-catchup-201808300657 git bisect good 5df52391ddbed869c7d67b00fbb013bd64334115 # 10:12 G 11 0 0 0 drm/i915/dsc: Fix PPS register definition macros for 2nd VDSC engine git bisect good d2c53b337ef53bb874d4be076b6d51ae1498ab2a # 10:43 G 11 0 0 0 drm/bridge: ti-sn65dsi86: Fix 0-day build error git bisect good 88b946fd55d4f30e0284ca1b357dae8bb2a461a9 # 11:16 G 11 0 0 0 Merge remote-tracking branch 'drm-misc/drm-misc-next' into drm-tip git bisect good 87246f7fd572f9c3db752708730d68cc9eb08d72 # 11:35 G 11 0 0 0 ALSA: intel_hdmi: Use the new non-cached allocation git bisect bad b211ab33a398c50a45fe4076b5687343d5df4c07 # 12:01 B 0 1 16 0 net/sch_generic: Shut up noise git bisect good 5a1da908eb54d9a36d8d9a2f731658e8a50d7831 # 12:21 G 10 0 0 0 lockdep: Up MAX_LOCKDEP_CHAINS git bisect good 7d5f8ade6d1cc269fe9feedb747875da774456bf # 12:38 G 11 0 1 1 kernel/panic: Repeat the line and caller information at the end of the OOPS git bisect bad 7928ca5cc786fdc0269342f1b9e22c2af939b989 # 12:55 B 0 4 19 0 RFC: debugobjects: capture stack traces at _init() time # first bad commit: [7928ca5cc786fdc0269342f1b9e22c2af939b989] RFC: debugobjects: capture stack traces at _init() time git bisect good 7d5f8ade6d1cc269fe9feedb747875da774456bf # 13:03 G 32 0 0 1 kernel/panic: Repeat the line and caller information at the end of the OOPS # extra tests with debug options git bisect bad 7928ca5cc786fdc0269342f1b9e22c2af939b989 # 13:28 B 0 11 26 0 RFC: debugobjects: capture stack traces at _init() time # extra tests on HEAD of linux-devel/devel-catchup-201808300657 git bisect bad 4d30a6ec667c3be5e517c6db7386b7cbeae0d241 # 13:28 B 0 13 31 0 0day head guard for 'devel-catchup-201808300657' # extra tests on tree/branch drm-drm-intel/topic/core-for-CI git bisect bad 97263ba0a2a07e9c0fb2cc133ef8f7ebc4c5aea1 # 13:57 B 0 1 16 0 usb/icl: Work around ACPI boottime crash # extra tests with first bad commit reverted git bisect good e2033a9bc1e10aa0b5a4592fb1d724289c68ed22 # 14:16 G 11 0 1 1 Revert "RFC: debugobjects: capture stack traces at _init() time" --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation