重构系统调用模块 (#267)

* 完成系统调用模块重构

* 更新github workflow

kernel/src/mm/syscall.rs

@@ -0,0 +1,43 @@
+use crate::{
+    include::bindings::bindings::mm_stat_t,
+    syscall::{Syscall, SystemError},
+};
+
+extern "C" {
+    fn sys_do_brk(new_addr: usize) -> usize;
+    fn sys_do_sbrk(incr: isize) -> usize;
+    fn sys_do_mstat(dst: *mut mm_stat_t, from_user: bool) -> usize;
+}
+impl Syscall {
+    pub fn brk(new_addr: usize) -> Result<usize, SystemError> {
+        let ret = unsafe { sys_do_brk(new_addr) };
+        if (ret as isize) < 0 {
+            return Err(
+                SystemError::from_posix_errno(-(ret as isize) as i32).expect("brk: Invalid errno")
+            );
+        }
+        return Ok(ret);
+    }
+
+    pub fn sbrk(incr: isize) -> Result<usize, SystemError> {
+        let ret = unsafe { sys_do_sbrk(incr) };
+        if (ret as isize) < 0 {
+            return Err(
+                SystemError::from_posix_errno(-(ret as isize) as i32).expect("sbrk: Invalid errno")
+            );
+        }
+        return Ok(ret);
+    }
+
+    /// 获取内存统计信息
+    ///
+    /// TODO: 该函数不是符合POSIX标准的，在将来需要删除！
+    pub fn mstat(dst: *mut mm_stat_t, from_user: bool) -> Result<usize, SystemError> {
+        let ret = unsafe { sys_do_mstat(dst, from_user) };
+        if (ret as isize) < 0 {
+            return Err(SystemError::from_posix_errno(-(ret as isize) as i32)
+                .expect("mstat: Invalid errno"));
+        }
+        return Ok(ret);
+    }
+}