Change get/set name to CStrings

Author: DOhlsson

src/sys/prctl.rs

@@ -138,24 +138,21 @@ pub fn get_pdeathsig() -> Result<Option<Signal>> {
 }
 
 /// Set the name of the calling thread. Strings longer than 15 bytes will be truncated.
-pub fn set_name(name: &str) -> Result<()> {
-    let name = CString::new(name.as_bytes()).unwrap();
-
+pub fn set_name(name: &CStr) -> Result<()> {
     let res = unsafe { libc::prctl(libc::PR_SET_NAME, name.as_ptr(), 0, 0, 0) };
 
     Errno::result(res).map(drop)
 }
 
 /// Return the name of the calling thread
-pub fn get_name() -> Result<String> {
+pub fn get_name() -> Result<CString> {
     // Size of buffer determined by linux/sched.h TASK_COMM_LEN
     let buf = [0u8; 16];
 
     let res = unsafe { libc::prctl(libc::PR_GET_NAME, &buf, 0, 0, 0) };
 
     let len = buf.iter().position(|&c| c == 0).unwrap_or(buf.len());
-    let cstr = CStr::from_bytes_with_nul(&buf[..=len]).map_err(|_| Errno::EINVAL)?;
-    let name = cstr.to_str().map_err(|_| Errno::EINVAL)?;
+    let name = CStr::from_bytes_with_nul(&buf[..=len]).map_err(|_| Errno::EINVAL)?;
 
     Errno::result(res).map(|_| name.to_owned())
 }

test/sys/test_prctl.rs

@@ -1,6 +1,8 @@
 #[cfg(target_os = "linux")]
 #[cfg(feature = "process")]
 mod test_prctl {
+    use std::ffi::CStr;
+
     use nix::sys::prctl;
 
     #[cfg_attr(qemu, ignore)]
@@ -68,17 +70,17 @@ mod test_prctl {
     fn test_get_set_name() {
         let original = prctl::get_name().unwrap();
 
-        let long_name = String::from("0123456789abcdefghijklmn");
-        prctl::set_name(&long_name).unwrap();
+        let long_name = CStr::from_bytes_with_nul(b"0123456789abcdefghijklmn\0").unwrap();
+        prctl::set_name(long_name).unwrap();
         let res = prctl::get_name().unwrap();
 
         // name truncated by kernel to TASK_COMM_LEN
-        assert_eq!(&long_name[..15], res);
+        assert_eq!(&long_name.to_str().unwrap()[..15], res.to_str().unwrap());
 
-        let short_name = String::from("01234567");
-        prctl::set_name(&short_name).unwrap();
+        let short_name = CStr::from_bytes_with_nul(b"01234567\0").unwrap();
+        prctl::set_name(short_name).unwrap();
         let res = prctl::get_name().unwrap();
-        assert_eq!(short_name, res);
+        assert_eq!(short_name.to_str().unwrap(), res.to_str().unwrap());
 
         prctl::set_name(&original).unwrap();
     }