Add time syscall and default localtime support

src/libos/src/syscall/mod.rs

@@ -285,7 +285,7 @@ macro_rules! process_syscall_table_with_callback {
             (Lremovexattr = 198) => handle_unsupported(),
             (Fremovexattr = 199) => handle_unsupported(),
             (Tkill = 200) => do_tkill(tid: pid_t, sig: c_int),
-            (Time = 201) => handle_unsupported(),
+            (Time = 201) => do_time(tloc_u: *mut time_t),
             (Futex = 202) => do_futex(futex_addr: *const i32, futex_op: u32, futex_val: i32, timeout: u64, futex_new_addr: *const i32, bitset: u32),
             (SchedSetaffinity = 203) => do_sched_setaffinity(pid: pid_t, cpusize: size_t, buf: *const c_uchar),
             (SchedGetaffinity = 204) => do_sched_getaffinity(pid: pid_t, cpusize: size_t, buf: *mut c_uchar),
@@ -833,6 +833,17 @@ fn do_clock_gettime(clockid: clockid_t, ts_u: *mut timespec_t) -> Result<isize>
     Ok(0)
 }
 
+fn do_time(tloc_u: *mut time_t) -> Result<isize> {
+    let ts = time::do_clock_gettime(time::ClockID::CLOCK_REALTIME)?;
+    if !tloc_u.is_null() {
+        check_mut_ptr(tloc_u)?;
+        unsafe {
+            *tloc_u = ts.sec();
+        }
+    }
+    Ok(ts.sec() as isize)
+}
+
 fn do_clock_getres(clockid: clockid_t, res_u: *mut timespec_t) -> Result<isize> {
     if res_u.is_null() {
         return Ok(0);

test/time/main.c

@@ -50,6 +50,24 @@ int test_clock_getres() {
     return 0;
 }
 
+// ============================================================================
+// Test cases for localtime
+// ============================================================================
+
+int test_get_localtime() {
+    time_t t = time(NULL);
+    if (t == (time_t) -1) {
+        THROW_ERROR("failed to get time");
+    }
+    struct tm *local_time = localtime(&t);
+    if (local_time == NULL) {
+        THROW_ERROR("failed to convert a time value to a local time");
+    }
+    printf("Offset to GMT is %lds.\n", local_time->tm_gmtoff);
+    printf("The time zone is '%s'.\n", local_time->tm_zone);
+    return 0;
+}
+
 // ============================================================================
 // Test suite
 // ============================================================================
@@ -58,6 +76,7 @@ static test_case_t test_cases[] = {
     TEST_CASE(test_gettimeofday),
     TEST_CASE(test_clock_gettime),
     TEST_CASE(test_clock_getres),
+    TEST_CASE(test_get_localtime),
 };
 
 int main() {

tools/occlum

@@ -157,15 +157,19 @@ cmd_init() {
     mkdir -p image/tmp
     mkdir -p image/dev
     mkdir -p image/proc
+    mkdir -p image/etc
     local occlum_glibc_lib=/opt/occlum/glibc/lib
+    local occlum_glibc_etc=/opt/occlum/glibc/etc
     local cpu_lib=/sys/devices/system/cpu
     if [ -d "$occlum_glibc_lib" ]; then
         mkdir -p "image/$occlum_glibc_lib"
         mkdir -p "image/$cpu_lib"
+        mkdir -p "image/$occlum_glibc_etc"
     fi
     # add default /etc/hosts
-    mkdir -p image/etc
     echo "127.0.0.1   localhost" > image/etc/hosts
+    # add default timezone file
+    cp /etc/localtime image/etc/
 
     # add musl
     local occlum_musl_lib=/usr/local/occlum/x86_64-linux-musl/lib
@@ -195,6 +199,8 @@ cmd_init() {
                 "/usr/lib64/libstdc++.so.6" \
                 "/usr/lib64/libgcc_s.so.1"
         fi
+        cp -t "image/$occlum_glibc_etc" \
+            /etc/localtime
         cp -t "image/$cpu_lib" \
             "$cpu_lib/online"
     fi
@@ -207,6 +213,9 @@ cmd_init() {
     mkdir -p initfs/etc
     # add default /etc/hosts
     echo "127.0.0.1   localhost" > initfs/etc/hosts
+    # add default timezone file
+    cp /etc/localtime initfs/etc/
+
     # add musl
     local occlum_musl_lib=/usr/local/occlum/x86_64-linux-musl/lib
     cp -t initfs/lib \