syscall-exec

usr/rust/src/bin/exec.rs

@@ -11,7 +11,8 @@ use user::syscall::{sys_exec, sys_fork};
 
 #[no_mangle]
 pub fn main() -> usize {
-    sys_exec("/rust/hello_world".as_ptr() as *const u8);
+    println!("this is exec_test ^o^");
+    sys_exec("/rust/hello_world".as_ptr());
     println!("should not arrive here. exec error.");
     0
 }

usr/rust/src/bin/user_shell.rs

@@ -13,6 +13,13 @@ use alloc::string::String;
 use user::io::getc;
 use user::syscall::{sys_exec, sys_exit, sys_fork};
 
+unsafe fn to_cstr(s: &mut String) -> *const u8 {
+    let ptr = s.as_mut_ptr();
+    let len = s.len();
+    *ptr.add(len) = 0;
+    ptr
+}
+
 #[no_mangle]
 pub fn main() {
     println!("Rust user shell");
@@ -26,7 +33,7 @@ pub fn main() {
                 if !line.is_empty() {
                     println!("searching for program {}", line);
                     if sys_fork() == 0 {
-                        sys_exec(line.as_ptr());
+                        sys_exec(unsafe { to_cstr(&mut line) });
                         sys_exit(0);
                     }
                     line.clear();