Add support for clock_nanosleep

Also replace nanosleep implementation with clock_nanosleep

src/Enclave.edl

@@ -141,7 +141,8 @@ enclave {
         void occlum_ocall_rdtsc([out] uint32_t* low, [out] uint32_t* high);
         void occlum_ocall_get_timerslack([out] int *timer_slack);
 
-        int occlum_ocall_nanosleep(
+        int occlum_ocall_clock_nanosleep(
+            clockid_t clockid, int flags,
             [in] const struct timespec* req,
             [out] struct timespec* rem
         ) propagate_errno;

src/libos/src/syscall/mod.rs

@@ -318,7 +318,7 @@ macro_rules! process_syscall_table_with_callback {
             (ClockSettime = 227) => handle_unsupported(),
             (ClockGettime = 228) => do_clock_gettime(clockid: clockid_t, ts_u: *mut timespec_t),
             (ClockGetres = 229) => do_clock_getres(clockid: clockid_t, res_u: *mut timespec_t),
-            (ClockNanosleep = 230) => handle_unsupported(),
+            (ClockNanosleep = 230) => do_clock_nanosleep(clockid: clockid_t, flags: i32, request: *const timespec_t, remain: *mut timespec_t),
             (ExitGroup = 231) => do_exit_group(exit_status: i32, user_context: *mut CpuContext),
             (EpollWait = 232) => do_epoll_wait(epfd: c_int, events: *mut libc::epoll_event, maxevents: c_int, timeout: c_int),
             (EpollCtl = 233) => do_epoll_ctl(epfd: c_int, op: c_int, fd: c_int, event: *const libc::epoll_event),
@@ -885,6 +885,27 @@ fn do_clock_getres(clockid: clockid_t, res_u: *mut timespec_t) -> Result<isize>
     Ok(0)
 }
 
+fn do_clock_nanosleep(
+    clockid: clockid_t,
+    flags: i32,
+    req_u: *const timespec_t,
+    rem_u: *mut timespec_t,
+) -> Result<isize> {
+    let req = {
+        check_ptr(req_u)?;
+        timespec_t::from_raw_ptr(req_u)?
+    };
+    let rem = if !rem_u.is_null() {
+        check_mut_ptr(rem_u)?;
+        Some(unsafe { &mut *rem_u })
+    } else {
+        None
+    };
+    let clockid = time::ClockID::from_raw(clockid)?;
+    time::do_clock_nanosleep(clockid, flags, &req, rem)?;
+    Ok(0)
+}
+
 // TODO: handle remainder
 fn do_nanosleep(req_u: *const timespec_t, rem_u: *mut timespec_t) -> Result<isize> {
     let req = {

src/libos/src/time/mod.rs

@@ -188,29 +188,63 @@ pub fn do_clock_getres(clockid: ClockID) -> Result<timespec_t> {
     Ok(res)
 }
 
-pub fn do_nanosleep(req: &timespec_t, rem: Option<&mut timespec_t>) -> Result<()> {
+const TIMER_ABSTIME: i32 = 0x01;
+
+pub fn do_clock_nanosleep(
+    clockid: ClockID,
+    flags: i32,
+    req: &timespec_t,
+    rem: Option<&mut timespec_t>,
+) -> Result<()> {
     extern "C" {
-        fn occlum_ocall_nanosleep(
+        fn occlum_ocall_clock_nanosleep(
             ret: *mut i32,
+            clockid: clockid_t,
+            flags: i32,
             req: *const timespec_t,
             rem: *mut timespec_t,
         ) -> sgx_status_t;
     }
-    unsafe {
+
     let mut ret = 0;
     let mut u_rem: timespec_t = timespec_t { sec: 0, nsec: 0 };
-        let sgx_status = occlum_ocall_nanosleep(&mut ret, req, &mut u_rem);
+    match clockid {
+        ClockID::CLOCK_REALTIME
+        | ClockID::CLOCK_MONOTONIC
+        | ClockID::CLOCK_BOOTTIME
+        | ClockID::CLOCK_PROCESS_CPUTIME_ID => {}
+        ClockID::CLOCK_THREAD_CPUTIME_ID => {
+            return_errno!(EINVAL, "CLOCK_THREAD_CPUTIME_ID is not a permitted value");
+        }
+        _ => {
+            return_errno!(EOPNOTSUPP, "does not support sleeping against this clockid");
+        }
+    }
+    let sgx_status = unsafe {
+        occlum_ocall_clock_nanosleep(&mut ret, clockid as clockid_t, flags, req, &mut u_rem)
+    };
     assert!(sgx_status == sgx_status_t::SGX_SUCCESS);
-        assert!(ret == 0 || libc::errno() == Errno::EINTR as i32);
+    assert!(ret == 0 || ret == Errno::EINTR as i32);
     if ret != 0 {
         assert!(u_rem.as_duration() <= req.as_duration() + (*TIMERSLACK).to_duration());
+        // rem is only valid if TIMER_ABSTIME flag is not set
+        if flags != TIMER_ABSTIME {
             if let Some(rem) = rem {
                 *rem = u_rem;
             }
+        }
         return_errno!(EINTR, "sleep interrupted");
     }
-    }
-    Ok(())
+    return Ok(());
+}
+
+pub fn do_nanosleep(req: &timespec_t, rem: Option<&mut timespec_t>) -> Result<()> {
+    // POSIX.1 specifies that nanosleep() should measure time against
+    // the CLOCK_REALTIME clock.  However, Linux measures the time using
+    // the CLOCK_MONOTONIC clock.
+    // Here we follow the POSIX.1
+    let clock_id = ClockID::CLOCK_REALTIME;
+    return do_clock_nanosleep(clock_id, 0, req, rem);
 }
 
 pub fn do_thread_getcpuclock() -> Result<timespec_t> {

src/pal/src/ocalls/time.c

@@ -16,8 +16,9 @@ void occlum_ocall_clock_getres(int clockid, struct timespec *res) {
     clock_getres(clockid, res);
 }
 
-int occlum_ocall_nanosleep(const struct timespec *req, struct timespec *rem) {
-    return nanosleep(req, rem);
+int occlum_ocall_clock_nanosleep(clockid_t clockid, int flags, const struct timespec *req,
+                                 struct timespec *rem) {
+    return clock_nanosleep(clockid, flags, req, rem);
 }
 
 int occlum_ocall_thread_getcpuclock(struct timespec *tp) {