Implement the syscall `shmctl`

kernel/src/syscall/shmctl.rs

@@ -35,4 +35,67 @@ bitflags! {
 }
 
 pub fn sys_shmctl(id: i32, cmd: i32, buf: u64, _ctx: &Context) -> Result<SyscallReturn> {
+    debug!("[sys_shmctl] id = {}, cmd = {}, buf = {:#x}", id, cmd, buf);
+
+    if id < 0 {
+        return_errno!(Errno::EINVAL);
+    }
+
+    let manager = SHM_OBJ_MANAGER.get().ok_or(Errno::EINVAL)?;
+    let shm_obj = {
+        let guard = manager.read();
+        match guard.get_shm_obj(id as u64) {
+            Some(shm_obj) => shm_obj,
+            None => return_errno!(Errno::EINVAL),
+        }
+    };
+
+    let cmd = ShmCtlCmd::from_bits(cmd).ok_or(Errno::EINVAL)?;
+
+    match cmd {
+        ShmCtlCmd::IPC_RMID => {
+            let mut guard = manager.write();
+
+            // Remove key mapping immediately to block further lookups by key
+            if let Some(key) = shm_obj.key() {
+                guard.remove_key_mapping(key);
+            }
+
+            // Mark the segment to be destroyed
+            shm_obj.set_deleted();
+
+            // Try to delete the shared memory object when no process is attached
+            guard.try_delete_shm_obj(id as u64)?;
+
+            Ok(SyscallReturn::Return(0))
+        }
+        ShmCtlCmd::IPC_SET => {
+            let shm_ds: ShmidDs = current_userspace!().read_val(buf as usize)?;
+
+            // FIXME: Check if the current process has the permission to set
+            // the attributes
+
+            // Update the attributes of the shared memory object
+            shm_obj.set_attributes(
+                InodeMode::from_bits_truncate(shm_ds.shm_perm.mode),
+                shm_ds.shm_perm.uid,
+                shm_ds.shm_perm.gid,
+            )?;
+
+            Ok(SyscallReturn::Return(0))
+        }
+        ShmCtlCmd::IPC_STAT => {
+            // Get the attributes of the shared memory object
+            let shm_ds = shm_obj.get_attributes()?;
+
+            // Write the attributes to the user space
+            current_userspace!().write_val(buf as usize, &shm_ds)?;
+
+            Ok(SyscallReturn::Return(0))
+        }
+        _ => {
+            warn!("Unsupported shmctl command: {:?}", cmd);
+            return_errno!(Errno::EINVAL);
+        }
+    }
 }