System crash in utrace_report_clone after running a stap script periodically

Issue

• Server crash after running the following stap script periodically

global blp_execbuf[2048]

probe kprocess.exec {
    blp_execbuf[filename]++
}

probe timer.ms(5000), end, error {
    foreach ([filename] in blp_execbuf)
        printf("%u %s\n", blp_execbuf[filename], filename)
    delete blp_execbuf
    printf("\n")
}

• Call trace

 #0 [ffff8114cf91fbe0] crash_kexec at ffffffff800af85a
 #1 [ffff8114cf91fca0] __die at ffffffff80065117
 #2 [ffff8114cf91fce0] do_page_fault at ffffffff8006748d
 #3 [ffff8114cf91fdd0] error_exit at ffffffff8005dde9
    [exception RIP: utrace_report_clone+84]
    RIP: ffffffff800c3d62  RSP: ffff8114cf91fe88  RFLAGS: 00010202
    RAX: ffffffff88b8ab00  RBX: ffff811e2ce648c0  RCX: ffff81086a503080
    RDX: 00000000003d0f00  RSI: ffff811fca0397e0  RDI: ffff811e2ce648c0
    RBP: 0000000000000000   R8: 0000000000009877   R9: 0000000000000035
    R10: ffff810b60be3600  R11: 0000000052bbd60c  R12: ffff811fca0397e0
    R13: 0000000000000000  R14: ffff811aafe69780  R15: ffff81086a503080
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #4 [ffff8114cf91fed0] do_fork at ffffffff8003137d
 #5 [ffff8114cf91ff50] ptregscall_common at ffffffff8005d427
    RIP: 000000340b8d4091  RSP: 0000000040b9db58  RFLAGS: 00000202
    RAX: ffffffffffffffda  RBX: 000000004278c940  RCX: ffffffffffffffff
    RDX: 000000004278c9d0  RSI: 000000004278a280  RDI: 00000000003d0f00
    RBP: 0000000000000000   R8: 000000004278c940   R9: 000000004278c940
    R10: 000000004278c9d0  R11: 0000000000000202  R12: 0000000000000000
    R13: 0000000000000007  R14: 0000000040ba1000  R15: 0000000000001000
    ORIG_RAX: 0000000000000038  CS: 0033  SS: 002b