Hard lockup in free_one_page()->_raw_spin_lock() because sosreport command is reading from /proc/pagetypeinfo

Issue

• System crashed due to hard lockup.
• The crash occurred while collecting sosreport on RHEL 7.
• System crash backtrace shows exception RIP: pagetypeinfo_showfree_print+0x73

crash> bt
PID: 58188  TASK: ffff938a4d4f1fa0  CPU: 2   COMMAND: "sosreport"
 #0 [ffff9483bf488e48] crash_nmi_callback at ffffffffb8c551d7
 #1 [ffff9483bf488e58] nmi_handle at ffffffffb931d8cc
 #2 [ffff9483bf488eb0] do_nmi at ffffffffb931dba8
 #3 [ffff9483bf488ef0] end_repeat_nmi at ffffffffb931cd69
    [exception RIP: pagetypeinfo_showfree_print+0x73]
    RIP: ffffffffb8db7173  RSP: ffff938b9fcbfda0  RFLAGS: 00000006
    RAX: fffff0c9946d7020  RBX: ffff96073ffd5528  RCX: 0000000000000000
    RDX: 00000000001c7764  RSI: ffffffffb9676ab1  RDI: 0000000000000000
    RBP: ffff938b9fcbfdd0   R8: 000000000000000a   R9: 00000000fffffffe
    R10: 0000000000000000  R11: ffff938b9fcbfc36  R12: ffff942b97758240
    R13: ffffffffb942f730  R14: ffff96073ffd5000  R15: ffff96073ffd5180
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
--- <NMI exception stack> ---
 #4 [ffff938b9fcbfda0] pagetypeinfo_showfree_print at ffffffffb8db7173
 #5 [ffff938b9fcbfdd8] walk_zones_in_node at ffffffffb8db74df
 #6 [ffff938b9fcbfe20] pagetypeinfo_show at ffffffffb8db7a29
 #7 [ffff938b9fcbfe48] seq_read at ffffffffb8e45c3c
 #8 [ffff938b9fcbfeb8] proc_reg_read at ffffffffb8e95070
 #9 [ffff938b9fcbfed8] vfs_read at ffffffffb8e1f2af
#10 [ffff938b9fcbff08] sys_read at ffffffffb8e2017f
#11 [ffff938b9fcbff50] system_call_fastpath at ffffffffb932579b
    RIP: 00007f720ddaec00  RSP: 00007fff8b2bb110  RFLAGS: 00010246
    RAX: 0000000000000000  RBX: 000000000271dbc0  RCX: 00007f7205b567e8
    RDX: 0000000000004000  RSI: 000000000272df74  RDI: 000000000000000b
    RBP: 00007f720e0823a0   R8: ffffffffffffffff   R9: 0000000000000000
    R10: 0000000000000022  R11: 0000000000000246  R12: 0000000000004000
    R13: 0000000000000d70  R14: 00007f720e081858  R15: 000000000272df74
    ORIG_RAX: 0000000000000000  CS: 0033  SS: 002b