Greetings, 0day kernel testing robot got the below dmesg and the first bad commit is https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git x86/boot commit feefa5789e48c24af580d79c6746240bcc78b95d Author: Andy Lutomirski <luto(a)kernel.org&gt; AuthorDate: Wed Nov 30 10:38:06 2016 -0800 Commit: Andy Lutomirski <luto(a)kernel.org&gt; CommitDate: Thu Dec 1 16:34:27 2016 -0800 x86/microcode/intel: Replace sync_core() with cpuid_eax(1) The Intel microcode driver is using sync_core() to mean "do CPUID with EAX=1". I want to rework sync_core(), but first the Intel microcode driver needs to stop depending on its current behavior. Reported-by: Henrique de Moraes Holschuh <hmh(a)hmh.eng.br&gt; Acked-by: Borislav Petkov <bp(a)alien8.de&gt; Signed-off-by: Andy Lutomirski <luto(a)kernel.org&gt; +--------------------------------------------------------------------------------------+------------+------------+------------+ | | 82acde18a1 | feefa5789e | 455b60a09e | +--------------------------------------------------------------------------------------+------------+------------+------------+ | boot_successes | 64 | 0 | 0 | | boot_failures | 1 | 26 | 33 | | invoked_oom-killer:gfp_mask=0x | 1 | | | | Mem-Info | 1 | | | | BUG:kernel_reboot-without-warning_in_early-boot_stage,last_printk:Booting_the_kernel | 0 | 26 | 33 | +--------------------------------------------------------------------------------------+------------+------------+------------+ Booting the kernel. Elapsed time: 10 BUG: kernel reboot-without-warning in early-boot stage, last printk: Booting the kernel. Linux version 4.9.0-rc7-00026-gfeefa57 #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 systemd.log_level=err ignore_loglevel earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0 vga=normal rw link=/kbuild-tests/run-queue/kvm/i386-randconfig-b0-12020650/linux-devel:devel-catchup-201612020908:feefa5789e48c24af580d79c6746240bcc78b95d:bisect-linux-9/.vmlinuz-feefa5789e48c24af580d79c6746240bcc78b95d-20161202130234-1-ivb41 branch=linux-devel/devel-catchup-201612020908 BOOT_IMAGE=/pkg/linux/i386-randconfig-b0-12020650/gcc-5/feefa5789e48c24af580d79c6746240bcc78b95d/vmlinuz-4.9.0-rc7-00026-gfeefa57 drbd.minor_count=8 git bisect start 455b60a09e0ac592eb1cbf7fbeb5078d55b03658 e5517c2a5a49ed5e99047008629f1cd60246ea0e -- git bisect bad 68c246be35a057aeb0191362c8ce3e9233131695 # 10:10 0- 22 Merge 'spi/for-next' into devel-catchup-201612020908 git bisect good f99e9d25682f3ba1fc85758617ade5bf35622cac # 10:24 22+ 0 Merge 'jpoimboe/objtool-dwarf' into devel-catchup-201612020908 git bisect bad 429958f27e9b5c481f887bae325d6cdc93ac16ad # 10:57 0- 24 Merge 'linux-review/Maninder-Singh/mach-omap2-fixing-wrong-strcat-for-Non-NULL-terminated-string/20161202-083203' into devel-catchup-201612020908 git bisect good 3ce2b9c4860c51fde7bad42a9dc8b292ed86b80a # 11:16 22+ 0 Merge 'horosco/4.9-head-wqe-stats' into devel-catchup-201612020908 git bisect good 840b89d0acd4cc578b60f01a42edb41928652d78 # 11:37 22+ 0 Merge 'linux-review/Laurent-Pinchart/ARM-omap3-beagleboard-xm-dt-Add-ethernet-to-the-device-tree/20161202-083710' into devel-catchup-201612020908 git bisect bad 18d0c1a27cc2b79132b07329199edc80baff14c6 # 12:30 0- 7 Merge 'luto/x86/boot' into devel-catchup-201612020908 git bisect bad feefa5789e48c24af580d79c6746240bcc78b95d # 13:03 0- 22 x86/microcode/intel: Replace sync_core() with cpuid_eax(1) git bisect good 82acde18a108b8e353180dd6febcc2876df33f24 # 13:37 22+ 0 Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" # first bad commit: [feefa5789e48c24af580d79c6746240bcc78b95d] x86/microcode/intel: Replace sync_core() with cpuid_eax(1) git bisect good 82acde18a108b8e353180dd6febcc2876df33f24 # 13:40 63+ 1 Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" # extra tests on HEAD of linux-devel/devel-catchup-201612020908 git bisect bad 455b60a09e0ac592eb1cbf7fbeb5078d55b03658 # 13:40 0- 33 0day head guard for 'devel-catchup-201612020908' # extra tests on tree/branch luto/x86/boot git bisect bad 729cba59b32fb70bf59979db325a2ea17b014d8d # 14:07 0- 16 x86/asm: Change sync_core() to use MOV to CR2 to serialize # extra tests with first bad commit reverted git bisect bad a04d8d7edeb0e4288ac091640840373f2d16618d # 14:27 0- 25 Revert "x86/microcode/intel: Replace sync_core() with cpuid_eax(1)" # extra tests on tree/branch linus/master git bisect good 2caceb3294a78c389b462e7e236a4e744a53a474 # 14:46 61+ 0 Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs # extra tests on tree/branch linux-next/master git bisect good 0e22494734b51937ca451b7c0a0d27a8ab54f518 # 15:04 66+ 68 Add linux-next specific files for 20161201 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/lkp Intel Corporation