FYI, we noticed the following commit: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/rt commit 0451490e4fb9b8375c6dba1466a1fc837127fc36 ("sched/rtmutex: Refactor rt_mutex_setprio()") on test machine: vm-lkp-wsx03-openwrt-i386: 1 threads qemu-system-i386 -enable-kvm with 192M memory caused below changes: +------------------------------------------+------------+------------+ | | 834d149f85 | 0451490e4f | +------------------------------------------+------------+------------+ | boot_successes | 7 | 0 | | boot_failures | 1 | 6 | | BUG:kernel_test_crashed | 1 | | | backtrace:acpi_get_cpuid | 1 | 6 | | backtrace:early_init_pdc | 1 | 6 | | backtrace:acpi_early_processor_set_pdc | 1 | 6 | | backtrace:acpi_init | 1 | 6 | | backtrace:kernel_init_freeable | 1 | 6 | | BUG:unable_to_handle_kernel | 0 | 6 | | Oops | 0 | 6 | | EIP_is_at_rt_mutex_adjust_prio | 0 | 6 | | Kernel_panic-not_syncing:Fatal_exception | 0 | 6 | | backtrace:rt_mutex_lock | 0 | 6 | | backtrace:rht_deferred_worker | 0 | 1 | +------------------------------------------+------------+------------+ [ 0.541051] UBSAN: Undefined behaviour in drivers/acpi/acpica/dsutils.c:641:16 [ 0.542040] index -1 is out of range for type 'acpi_operand_object *[9]' [ 0.542780] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc2-00316-g0451490 #1 [ 0.543593] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 [ 0.544556] 00000000 00200086 8ac6dc28 814015e0 00000001 8ac6dc4c ffffffff 8ac6dc38 [ 0.545522] 81453fce 8ac6dc38 81c38fcc 8ac6dc88 814544fb 8196e248 8ac6dc50 81c38fe4 [ 0.546493] 00200282 8100312d 81262f13 810ef937 8149d52f 00000002 d8415601 d8415605 [ 0.547455] Call Trace: [ 0.547737] [<814015e0>] dump_stack+0x78/0xb8 [ 0.548226] [<81453fce>] ubsan_epilogue+0xe/0x40 [ 0.548746] [<814544fb>] __ubsan_handle_out_of_bounds+0x6b/0x90 [ 0.549401] [<8100312d>] ? update_vsyscall+0x24d/0x290 [ 0.549978] [<81262f13>] ? cache_alloc_debugcheck_after+0x73/0x2d0 [ 0.550733] [<810ef937>] ? debug_check_no_locks_freed+0x167/0x1d0 [ 0.551402] [<8149d52f>] ? acpi_os_release_object+0x8/0xc [ 0.552005] [<810ef937>] ? debug_check_no_locks_freed+0x167/0x1d0 [ 0.552675] [<8149d52f>] ? acpi_os_release_object+0x8/0xc [ 0.553273] [<814b002c>] acpi_ds_create_operand+0x20b/0x298 [ 0.553897] [<814b01ad>] acpi_ds_create_operands+0xf4/0x139 [ 0.554514] [<8149d52f>] ? acpi_os_release_object+0x8/0xc [ 0.555113] [<814d15c8>] ? acpi_ut_delete_generic_state+0x13/0x15 [ 0.555793] [<814c7d16>] ? acpi_ps_pop_scope+0xb4/0x109 [ 0.556365] [<814b077b>] acpi_ds_exec_end_op+0xe3/0x4b6 [ 0.557024] [<814c6adf>] acpi_ps_parse_loop+0x618/0x68a [ 0.557609] [<814ce34d>] ? acpi_ut_remove_reference+0x25/0x28 [ 0.558247] [<814ae2b3>] ? acpi_ds_call_control_method+0x12a/0x198 [ 0.558937] [<814c7935>] acpi_ps_parse_aml+0x92/0x285 [ 0.559503] [<814c835e>] acpi_ps_execute_method+0x1aa/0x1da [ 0.560123] [<814c154b>] acpi_ns_evaluate+0x1ee/0x269 [ 0.560687] [<814c4cfb>] acpi_evaluate_object+0x105/0x1fb [ 0.561283] [<814a4cf8>] acpi_get_phys_id+0x32/0x195 [ 0.561844] [<814a4f88>] acpi_get_cpuid+0xb/0x15 [ 0.562358] [<81dd6b73>] early_init_pdc+0x81/0x95 [ 0.562892] [<814c4932>] acpi_ns_walk_namespace+0xd9/0x1b5 [ 0.563505] [<814c4b12>] acpi_walk_namespace+0x76/0xa0 [ 0.564075] [<81dd6af2>] ? set_no_mwait+0x34/0x34 [ 0.564607] [<81dd623e>] ? acpi_sleep_init+0x121/0x121 [ 0.565180] [<81dd6baf>] acpi_early_processor_set_pdc+0x28/0x40 [ 0.565842] [<81dd6af2>] ? set_no_mwait+0x34/0x34 [ 0.566364] [<81dd6384>] acpi_init+0x146/0x273 [ 0.566876] [<81dd623e>] ? acpi_sleep_init+0x121/0x121 [ 0.567453] [<810005c5>] do_one_initcall+0x135/0x1f0 [ 0.568007] [<81416380>] ? strchr+0x20/0x20 [ 0.568482] [<81d96543>] ? repair_env_string+0x16/0x83 [ 0.569053] [<81dd623e>] ? acpi_sleep_init+0x121/0x121 [ 0.569629] [<810ad261>] ? parse_args+0x321/0x500 [ 0.570156] [<81d97079>] kernel_init_freeable+0x1aa/0x261 [ 0.570766] [<8177dedc>] kernel_init+0xc/0x120 [ 0.571264] [<810c0eed>] ? schedule_tail+0xd/0xd0 [ 0.571802] [<817892a2>] ret_from_kernel_thread+0xe/0x24 [ 0.572388] [<8177ded0>] ? rest_init+0xb0/0xb0 [ 0.572895] ================================================================================ [ 0.574675] ACPI: Interpreter enabled [ 0.575127] ACPI: (supports S0 S5) FYI, raw QEMU command line is: qemu-system-i386 -enable-kvm -kernel /pkg/linux/i386-randconfig-c0-06140409/gcc-6/0451490e4fb9b8375c6dba1466a1fc837127fc36/vmlinuz-4.7.0-rc2-00316-g0451490 -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-lkp-wsx03-openwrt-i386-10/rand_boot-1-openwrt-i386.cgz-i386-randconfig-c0-06140409-0451490e4fb9b8375c6dba1466a1fc837127fc36-20160614-56570-u4zhh1-0.yaml~ ARCH=i386 kconfig=i386-randconfig-c0-06140409 branch=linux-devel/devel-hourly-2016061400 commit=0451490e4fb9b8375c6dba1466a1fc837127fc36 BOOT_IMAGE=/pkg/linux/i386-randconfig-c0-06140409/gcc-6/0451490e4fb9b8375c6dba1466a1fc837127fc36/vmlinuz-4.7.0-rc2-00316-g0451490 max_uptime=600 RESULT_ROOT=/result/boot/1/vm-lkp-wsx03-openwrt-i386/openwrt-i386.cgz/i386-randconfig-c0-06140409/gcc-6/0451490e4fb9b8375c6dba1466a1fc837127fc36/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-lkp-wsx03-openwrt-i386-10::dhcp drbd.minor_count=8' -initrd /fs/sdc1/initrd-vm-lkp-wsx03-openwrt-i386-10 -m 192 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdc1/disk0-vm-lkp-wsx03-openwrt-i386-10,media=disk,if=virtio -drive file=/fs/sdc1/disk1-vm-lkp-wsx03-openwrt-i386-10,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-lkp-wsx03-openwrt-i386-10 -serial file:/dev/shm/kboot/serial-vm-lkp-wsx03-openwrt-i386-10 -daemonize -display none -monitor null Thanks, Kernel Test Robot