Hi Song, > root@virt-test:~# ~/a.out > 11 > semaphore 0 > semaphore 0 > semaphore 2 <<< when the uprobe is enabled Yes, this happens when multiple vmas points to the same file portion. Can you check /proc/`pgrep a.out`/maps. Logic is simple. If we are going to patch an instruction, increment the reference counter. If we are going to unpatch an instruction, decrement the reference counter. In this case, we patched instruction twice and thus incremented reference counter twice as well. Ravi
