FYI, we noticed the below changes on https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master commit c6d308534aef6c99904bf5862066360ae067abc4 ("UBSAN: run-time undefined behavior sanity checker") [ 0.000000] WARNING: lockdep init error: lock 'report_lock' was acquired before lockdep_init(). [ 0.000000] Call stack leading to lockdep invocation was: [ 0.000000] [] save_stack_trace+0x26/0x16d [ 0.000000] [] __lock_acquire+0x237/0x15a4 [ 0.000000] [] lock_acquire+0x11a/0x1a9 [ 0.000000] [] _raw_spin_lock_irqsave+0x39/0x49 [ 0.000000] [] ubsan_prologue+0x1e/0x51 [ 0.000000] [] __ubsan_handle_type_mismatch+0xbd/0x14a [ 0.000000] [] reserve_ebda_region+0x8b/0x1bb [ 0.000000] [] i386_start_kernel+0xf6/0x102 [ 0.000000] [] 0xffffffff [ 0.000000] ------------------------ [ 0.000000] | Locking API testsuite: [ 0.000000] ---------------------------------------------------------------------------- [ 0.000000] | spin |wlock |rlock |mutex | wsem | rsem | [ 0.000000] -------------------------------------------------------------------------- [ 0.000000] A-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-B-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-B-C-C-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-C-A-B-C deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-B-C-C-D-D-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-C-D-B-D-D-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] A-B-C-D-B-C-D-A deadlock:failed|failed| ok |failed|failed|failed| [ 0.000000] double unlock: ok | ok | ok | ok | ok | ok | [ 0.000000] initialize held: ok | ok | ok | ok | ok | ok | [ 0.000000] bad unlock order: ok | ok | ok | ok | ok | ok | [ 0.000000] -------------------------------------------------------------------------- [ 0.000000] recursive read-lock: | ok | |failed| [ 0.000000] recursive read-lock #2: | ok | |failed| [ 0.000000] mixed read-write-lock: |failed| |failed| [ 0.000000] mixed write-read-lock: |failed| |failed| [ 0.000000] -------------------------------------------------------------------------- [ 0.000000] hard-irqs-on + irq-safe-A/12:failed|failed| ok | [ 0.000000] soft-irqs-on + irq-safe-A/12:failed|failed| ok | [ 0.000000] hard-irqs-on + irq-safe-A/21:failed|failed| ok | [ 0.000000] soft-irqs-on + irq-safe-A/21:failed|failed| ok | [ 0.000000] sirq-safe-A => hirqs-on/12:failed|failed| ok | [ 0.000000] sirq-safe-A => hirqs-on/21:failed|failed| ok | [ 0.000000] hard-safe-A + irqs-on/12:failed|failed| ok | [ 0.000000] soft-safe-A + irqs-on/12:failed|failed| ok | [ 0.000000] hard-safe-A + irqs-on/21:failed|failed| ok | [ 0.000000] soft-safe-A + irqs-on/21:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/123:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/123:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/132:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/132:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/213:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/213:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/231:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/231:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/312:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/312:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #1/321:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #1/321:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/123:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/123:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/132:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/132:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/213:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/213:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/231:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/231:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/312:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/312:failed|failed| ok | [ 0.000000] hard-safe-A + unsafe-B #2/321:failed|failed| ok | [ 0.000000] soft-safe-A + unsafe-B #2/321:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/123:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/123:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/132:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/132:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/213:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/213:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/231:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/231:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/312:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/312:failed|failed| ok | [ 0.000000] hard-irq lock-inversion/321:failed|failed| ok | [ 0.000000] soft-irq lock-inversion/321:failed|failed| ok | [ 0.000000] hard-irq read-recursion/123: ok | [ 0.000000] soft-irq read-recursion/123: ok | [ 0.000000] hard-irq read-recursion/132: ok | [ 0.000000] soft-irq read-recursion/132: ok | [ 0.000000] hard-irq read-recursion/213: ok | [ 0.000000] soft-irq read-recursion/213: ok | [ 0.000000] hard-irq read-recursion/231: ok | [ 0.000000] soft-irq read-recursion/231: ok | [ 0.000000] hard-irq read-recursion/312: ok | [ 0.000000] soft-irq read-recursion/312: ok | [ 0.000000] hard-irq read-recursion/321: ok | [ 0.000000] soft-irq read-recursion/321: ok | [ 0.000000] -------------------------------------------------------------------------- [ 0.000000] | Wound/wait tests | [ 0.000000] --------------------- [ 0.000000] ww api failures: ok | ok | ok | [ 0.000000] ww contexts mixing:failed| ok | [ 0.000000] finishing ww context: ok | ok | ok | ok | [ 0.000000] locking mismatches: ok | ok | ok | [ 0.000000] EDEADLK handling: ok | ok | ok | ok | ok | ok | ok | ok | ok | ok | [ 0.000000] spinlock nest unlocked: ok | [ 0.000000] ----------------------------------------------------- [ 0.000000] |block | try |context| [ 0.000000] ----------------------------------------------------- [ 0.000000] context:failed| ok | ok | [ 0.000000] try:failed| ok |failed| [ 0.000000] block:failed| ok |failed| [ 0.000000] spinlock:failed| ok |failed| [ 0.000000] -------------------------------------------------------- [ 0.000000] 141 out of 253 testcases failed, as expected. | [ 0.000000] ---------------------------------------------------- [ 0.000000] allocated 4718592 bytes of page_ext Thanks, Ying Huang