==================================================================
BUG: KCSAN: data-race in osq_lock / osq_lock

write to 0xffff88812bf2b054 of 4 bytes by task 17686 on cpu 1:
 osq_lock+0x89/0x2f0 kernel/locking/osq_lock.c:99
 rwsem_optimistic_spin+0x5f/0x320 kernel/locking/rwsem.c:800
 rwsem_down_write_slowpath+0x109/0x950 kernel/locking/rwsem.c:1150
 __down_write kernel/locking/rwsem.c:1392 [inline]
 down_write+0x88/0x90 kernel/locking/rwsem.c:1535
 i_mmap_lock_write include/linux/fs.h:526 [inline]
 unlink_file_vma+0x5b/0x90 mm/mmap.c:168
 free_pgtables+0x14f/0x200 mm/memory.c:396
 exit_mmap+0x151/0x300 mm/mmap.c:3162
 __mmput kernel/fork.c:1079 [inline]
 mmput+0xea/0x280 kernel/fork.c:1100
 exec_mmap fs/exec.c:1048 [inline]
 flush_old_exec+0x655/0xfd0 fs/exec.c:1281
 load_elf_binary+0x69a/0x2ec0 fs/binfmt_elf.c:847
 search_binary_handler fs/exec.c:1659 [inline]
 search_binary_handler+0x127/0x420 fs/exec.c:1636
 exec_binprm fs/exec.c:1702 [inline]
 __do_execve_file.isra.0+0xb76/0x11d0 fs/exec.c:1822
 do_execveat_common fs/exec.c:1868 [inline]
 do_execve fs/exec.c:1885 [inline]
 __do_sys_execve fs/exec.c:1961 [inline]
 __se_sys_execve fs/exec.c:1956 [inline]
 __x64_sys_execve+0x62/0x80 fs/exec.c:1956
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290

read to 0xffff88812bf2b054 of 4 bytes by task 17681 on cpu 0:
 osq_lock+0x170/0x2f0 kernel/locking/osq_lock.c:143
 rwsem_optimistic_spin+0x5f/0x320 kernel/locking/rwsem.c:800
 rwsem_down_write_slowpath+0x109/0x950 kernel/locking/rwsem.c:1150
 __down_write kernel/locking/rwsem.c:1392 [inline]
 down_write+0x88/0x90 kernel/locking/rwsem.c:1535
 i_mmap_lock_write include/linux/fs.h:526 [inline]
 unlink_file_vma+0x5b/0x90 mm/mmap.c:168
 free_pgtables+0xbe/0x200 mm/memory.c:382
 unmap_region+0x21c/0x270 mm/mmap.c:2626
 __do_munmap+0x661/0xb60 mm/mmap.c:2845
 do_munmap mm/mmap.c:2856 [inline]
 mmap_region+0x165/0xd50 mm/mmap.c:1749
 do_mmap+0x6d4/0xba0 mm/mmap.c:1577
 do_mmap_pgoff include/linux/mm.h:2353 [inline]
 vm_mmap_pgoff+0x12d/0x190 mm/util.c:496
 ksys_mmap_pgoff+0x2d8/0x420 mm/mmap.c:1629
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:91 [inline]
 __x64_sys_mmap+0x91/0xc0 arch/x86/kernel/sys_x86_64.c:91

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17681 Comm: blkid Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================