Mastering Linux Kernel Development

Detaching shared memory

Likewise, to detach the shared memory from the process address space, shmdt() is invoked. As IPC shared memory regions are persistent in the kernel, they continue to exist even after the processes detach:

int shmdt(const void *shmaddr);

The segment at the address specified by shmaddr is detached from the address space of the calling process.

Each of these interface operations invoke relevant system calls implemented in the <ipc/shm.c> source file.