Dealloc TCB on detach/join rather than exit.

redox-rt/src/thread.rs

@@ -58,11 +58,6 @@ pub unsafe fn exit_this_thread(stack_base: *mut (), stack_size: usize) -> ! {
     // TODO: modify interface so it writes directly to the thread fd?
     let status_fd = tcb.thread_fd().dup_into_upper(b"status").unwrap();
 
-    let tcb_ptr = unsafe { crate::Tcb::current_ptr() };
-    if let Some(tcb_ptr) = tcb_ptr {
-        let _ = unsafe { syscall::funmap(tcb_ptr as usize, syscall::PAGE_SIZE) };
-    }
-
     let mut buf = [0; size_of::<usize>() * 3];
     plain::slice_from_mut_bytes(&mut buf)
         .unwrap()

src/ld_so/tcb.rs

@@ -107,6 +107,7 @@ impl Tcb {
                     stack_base: core::ptr::null_mut(),
                     stack_size: 0,
                     os_tid: UnsafeCell::new(OsTid::default()),
+                    tcb_selfref: UnsafeCell::new(tcb_ptr),
                 },
 
                 dtv_ptr: ptr::null_mut(),

src/pthread/mod.rs

@@ -32,6 +32,8 @@ pub unsafe fn init() {
         stack_base: ptr::null_mut(),
         stack_size: 0,
 
+        tcb_selfref: UnsafeCell::new(core::ptr::null_mut()),
+
         os_tid: UnsafeCell::new(Sys::current_os_tid()),
     };
 
@@ -43,9 +45,11 @@ pub unsafe fn init() {
         thread.stack_size = STACK_SIZE;
     }
 
-    unsafe { Tcb::current() }
-        .expect_notls("no TCB present for main thread")
-        .pthread = thread;
+    let current_tcb = unsafe { Tcb::current() }.expect_notls("no TCB present for main thread");
+    current_tcb.pthread = thread;
+    unsafe {
+        current_tcb.pthread.tcb_selfref.get().write(current_tcb);
+    }
 }
 
 //static NEXT_INDEX: AtomicU32 = AtomicU32::new(FIRST_THREAD_IDX + 1);
@@ -73,6 +77,8 @@ pub struct Pthread {
     pub(crate) stack_base: *mut c_void,
     pub(crate) stack_size: usize,
 
+    pub(crate) tcb_selfref: UnsafeCell<*mut Tcb>,
+
     pub os_tid: UnsafeCell<OsTid>,
 }
 
@@ -317,6 +323,13 @@ unsafe fn dealloc_thread(thread: &Pthread) {
     unsafe {
         OS_TID_TO_PTHREAD.lock().remove(&thread.os_tid.get().read());
     }
+    #[cfg(target_os = "redox")]
+    unsafe {
+        let tcb = thread.tcb_selfref.get().read();
+        if !tcb.is_null() {
+            let _ = syscall::funmap(tcb as usize, syscall::PAGE_SIZE);
+        }
+    }
 }
 pub const SIGRT_RLCT_CANCEL: usize = 33;
 pub const SIGRT_RLCT_TIMER: usize = 34;