chore: remove heap_bottom since it's unused (#105)

Author: AsakuraMizu

api/src/syscall/task/clone.rs

@@ -183,7 +183,6 @@ pub fn sys_clone(
         );
         proc_data.set_umask(old_proc_data.umask());
         // Inherit heap pointers from parent to ensure child's heap state is consistent after fork
-        proc_data.set_heap_bottom(old_proc_data.get_heap_bottom());
         proc_data.set_heap_top(old_proc_data.get_heap_top());
 
         {

api/src/syscall/task/execve.rs

@@ -60,7 +60,6 @@ pub fn sys_execve(
     *proc_data.exe_path.write() = loc.absolute_path()?.to_string();
     *proc_data.cmdline.write() = Arc::new(args);
 
-    proc_data.set_heap_bottom(USER_HEAP_BASE);
     proc_data.set_heap_top(USER_HEAP_BASE);
 
     *proc_data.signal.actions.lock() = Default::default();

core/src/task.rs

@@ -201,8 +201,6 @@ pub struct ProcessData {
     pub aspace: Arc<Mutex<AddrSpace>>,
     /// The resource scope
     pub scope: RwLock<Scope>,
-    /// The user heap bottom
-    heap_bottom: AtomicUsize,
     /// The user heap top
     heap_top: AtomicUsize,
 
@@ -242,7 +240,6 @@ impl ProcessData {
             cmdline: RwLock::new(cmdline),
             aspace,
             scope: RwLock::new(Scope::new()),
-            heap_bottom: AtomicUsize::new(crate::config::USER_HEAP_BASE),
             heap_top: AtomicUsize::new(crate::config::USER_HEAP_BASE),
 
             rlim: RwLock::default(),
@@ -262,16 +259,6 @@ impl ProcessData {
         })
     }
 
-    /// Get the bottom address of the user heap.
-    pub fn get_heap_bottom(&self) -> usize {
-        self.heap_bottom.load(Ordering::Acquire)
-    }
-
-    /// Set the bottom address of the user heap.
-    pub fn set_heap_bottom(&self, bottom: usize) {
-        self.heap_bottom.store(bottom, Ordering::Release)
-    }
-
     /// Get the top address of the user heap.
     pub fn get_heap_top(&self) -> usize {
         self.heap_top.load(Ordering::Acquire)