diff --git a/kernel/src/syscall/mod.rs b/kernel/src/syscall/mod.rs
index f704adc..e2ee608 100644
--- a/kernel/src/syscall/mod.rs
+++ b/kernel/src/syscall/mod.rs
@@ -58,7 +58,7 @@ pub fn syscall(id: usize, args: [usize; 6], tf: &mut TrapFrame) -> isize {
         024 => sys_yield(),
         033 => sys_dup2(args[0], args[1]),
 //        034 => sys_pause(),
-        035 => sys_sleep(args[0]), // TODO: nanosleep
+        035 => sys_nanosleep(args[0] as *const TimeSpec),
         039 => sys_getpid(),
         041 => sys_socket(args[0], args[1], args[2]),
         042 => sys_connect(args[0], args[1] as *const SockaddrIn, args[2]),
diff --git a/kernel/src/syscall/proc.rs b/kernel/src/syscall/proc.rs
index 447a81f..1838b28 100644
--- a/kernel/src/syscall/proc.rs
+++ b/kernel/src/syscall/proc.rs
@@ -199,14 +199,11 @@ pub fn sys_exit(exit_code: isize) -> ! {
     unreachable!();
 }
 
-pub fn sys_sleep(time: usize) -> SysResult {
-    info!("sleep: time: {}", time);
-    if time >= 1 << 31 {
-        thread::park();
-    } else {
-        use core::time::Duration;
-        thread::sleep(Duration::from_millis(time as u64 * 10));
-    }
+pub fn sys_nanosleep(req: *const TimeSpec) -> SysResult {
+    process().memory_set.check_ptr(req)?;
+    let time = unsafe { req.read() };
+    info!("nanosleep: time: {:#?}", time);
+    thread::sleep(time.to_duration());
     Ok(0)
 }
 
diff --git a/kernel/src/syscall/time.rs b/kernel/src/syscall/time.rs
index 6eef594..95789ca 100644
--- a/kernel/src/syscall/time.rs
+++ b/kernel/src/syscall/time.rs
@@ -4,6 +4,7 @@ use super::*;
 use crate::arch::consts::USEC_PER_TICK;
 use crate::arch::driver::rtc_cmos;
 use lazy_static::lazy_static;
+use core::time::Duration;
 
 lazy_static! {
     pub static ref EPOCH_BASE: u64 = unsafe { rtc_cmos::read_epoch() };
@@ -11,7 +12,7 @@ lazy_static! {
 }
 
 #[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Debug, Copy, Clone)]
 pub struct TimeVal {
     sec: u64,
     usec: u64,
@@ -28,19 +29,15 @@ impl TimeVal {
 }
 
 #[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Debug, Copy, Clone)]
 pub struct TimeSpec {
     sec: u64,
     nsec: u64,
 }
 
 impl TimeSpec {
-    pub fn to_msec(&self) -> u64 {
-        self.sec * 1000 + self.nsec / 1000_000
-    }
-
-    pub fn to_usec(&self) -> u64 {
-        self.sec * 1000_000 + self.nsec / 1000
+    pub fn to_duration(&self) -> Duration {
+        Duration::new(self.sec, self.nsec as u32)
     }
 }