open(/proc/self/mem, O_RDWR)            = 3   OK
open(/proc/self/mem, O_RDWR|O_EXCL)     = -1  Device busy
open(/proc/child/mem, O_RDWR|O_EXCL)    = 3   OK
BUG-REPRODUCED: EBUSY on O_EXCL after non-EXCL write open+close
rc=0
open(/proc/self/mem, O_RDWR)            = 3   OK
open(/proc/self/mem, O_RDWR|O_EXCL)     = -1  Device busy
open(/proc/child/mem, O_RDWR|O_EXCL)    = 3   OK
BUG-REPRODUCED: EBUSY on O_EXCL after non-EXCL write open+close
rc=0