Greeting, FYI, we noticed the following commit (built with gcc-9): commit: 52507cfaffe900c4d23931e9863bd54b4b980d65 ("futex: Replace PF_EXITPIDONE with a state") https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable-rc.git linux-5.4.y in testcase: boot on test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 8G caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace): +------------------------------------------------------------------+------------+------------+ | | 8012f98f92 | 52507cfaff | +------------------------------------------------------------------+------------+------------+ | boot_successes | 0 | 0 | | boot_failures | 14 | 16 | | UBSAN:Undefined_behaviour_in_arch/x86/kernel.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/tbprint.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/tbutils.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/tbdata.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/tbxface.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/workqueue.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/nsaccess.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/utstring.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_lib/string.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_arch/x86/kernel/alternative.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_arch/x86/realmode/init.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_crypto/algapi.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/exit.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/sched/cputime.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/locking/lockdep.c | 14 | 16 | | EIP:arch_local_irq_restore | 6 | 10 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/tbxfload.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/dsmthdat.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/psargs.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/dsinit.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/evgpeinit.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/nsinit.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/evregion.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/utpredef.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/sysfs.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/rsxface.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/rsutils.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/rsaddr.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/rscalc.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/acpi/acpica/rsmisc.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_lib/zlib_inflate/inffast.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_fs/readdir.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_crypto/api.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_drivers/base/devres.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/linux/compiler.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/uapi/linux/swab.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/linux/unaligned/access_ok.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/af_inet.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/net/ip.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/ipconfig.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/ip_input.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/udp.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/signal.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/ip6_offload.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/ip6_input.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/net/ipv6.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/route.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/icmp.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/net/ip6_checksum.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/ndisc.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/addrconf_core.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/addrconf.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv6/ip6_fib.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/linux/skbuff.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/tcp_offload.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/tcp_ipv4.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/linux/tcp.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_include/net/dsfield.h | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/tcp_input.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_kernel/module.c | 14 | 16 | | UBSAN:Undefined_behaviour_in_net/ipv4/tcp_minisocks.c | 2 | | | EIP:arch_local_irq_enable | 5 | 9 | | EIP:delay_tsc | 4 | 7 | | UBSAN:Undefined_behaviour_in_net/ipv4/ip_output.c | 1 | | | EIP:restore_nameidata | 1 | | | EIP:lock_is_held_type | 1 | 1 | | EIP:do_exit | 1 | | | EIP:native_safe_halt | 2 | 4 | | UBSAN:Undefined_behaviour_in_net/ipv6/raw.c | 3 | 6 | | UBSAN:Undefined_behaviour_in_include/net/ndisc.h | 3 | 6 | | UBSAN:Undefined_behaviour_in_include/net/neighbour.h | 3 | 6 | | UBSAN:Undefined_behaviour_in_net/ipv6/datagram.c | 3 | 6 | | EIP:rcutorture_one_extend | 1 | | | EIP:cache_alloc_debugcheck_after | 1 | | | UBSAN:Undefined_behaviour_in_kernel/events/core.c | 0 | 16 | | EIP:tcp_seq_start | 0 | 1 | | EIP:check_poison_obj | 0 | 1 | | EIP:assert_no_holes | 0 | 1 | | EIP:torture_random | 0 | 1 | | EIP:__legitimize_mnt | 0 | 1 | | EIP:wait_for_random_bytes | 0 | 1 | +------------------------------------------------------------------+------------+------------+ If you fix the issue, kindly add following tag Reported-by: kernel test robot [ 2.955817] ================================================================================ [ 2.956899] UBSAN: Undefined behaviour in kernel/events/core.c:11620:2 [ 2.957921] member access within misaligned address (ptrval) for type 'struct perf_event' [ 2.958918] which requires 8 byte alignment [ 2.959435] CPU: 0 PID: 13 Comm: cryptomgr_test Not tainted 5.4.0-00037-g52507cfaffe900 #1 [ 2.960440] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 2.961471] Call Trace: [ 2.961790] dump_stack+0x16/0x18 [ 2.962218] ubsan_epilogue+0xb/0x32 [ 2.962677] ubsan_type_mismatch_common+0xb0/0x104 [ 2.963285] __ubsan_handle_type_mismatch_v1+0x2c/0x32 [ 2.963939] perf_event_exit_task+0x6c/0x5eb [ 2.964502] ? rcu_read_lock_sched_held+0x20/0x40 [ 2.965095] ? fpu__drop+0x1b6/0x1c1 [ 2.965462] do_exit+0x9df/0x189d [ 2.965462] ? kfree+0x15c/0x169 [ 2.965462] __module_put_and_exit+0xa/0xa [ 2.965462] cryptomgr_test+0x40/0x40 [ 2.965462] kthread+0x1a8/0x1ad [ 2.965462] ? crypto_alg_put+0x56/0x56 [ 2.965462] ? kthread_create_worker_on_cpu+0x17/0x17 [ 2.965462] ret_from_fork+0x19/0x24 [ 2.965462] ================================================================================ [ 2.965484] ================================================================================ [ 2.966503] UBSAN: Undefined behaviour in kernel/events/core.c:11620:2 [ 2.967528] member access within misaligned address (ptrval) for type 'struct perf_event' [ 2.968554] which requires 8 byte alignment [ 2.969082] CPU: 0 PID: 13 Comm: cryptomgr_test Not tainted 5.4.0-00037-g52507cfaffe900 #1 [ 2.970093] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 [ 2.971131] Call Trace: [ 2.971458] dump_stack+0x16/0x18 [ 2.971907] ubsan_epilogue+0xb/0x32 [ 2.972374] ubsan_type_mismatch_common+0xb0/0x104 [ 2.972971] __ubsan_handle_type_mismatch_v1+0x2c/0x32 [ 2.973611] perf_event_exit_task+0x85/0x5eb [ 2.974150] ? rcu_read_lock_sched_held+0x20/0x40 [ 2.974740] ? fpu__drop+0x1b6/0x1c1 [ 2.975200] do_exit+0x9df/0x189d [ 2.975462] ? kfree+0x15c/0x169 [ 2.975462] __module_put_and_exit+0xa/0xa [ 2.975462] cryptomgr_test+0x40/0x40 [ 2.975462] kthread+0x1a8/0x1ad [ 2.975462] ? crypto_alg_put+0x56/0x56 [ 2.975462] ? kthread_create_worker_on_cpu+0x17/0x17 [ 2.975462] ret_from_fork+0x19/0x24 [ 2.975462] ================================================================================ To reproduce: # build kernel cd linux cp config-5.4.0-00037-g52507cfaffe900 .config make HOSTCC=gcc-9 CC=gcc-9 ARCH=i386 olddefconfig prepare modules_prepare bzImage git clone https://github.com/intel/lkp-tests.git cd lkp-tests bin/lkp qemu -k job-script # job-script is attached in this email Thanks, Rong Chen