Add getgroups syscall

src/libos/src/process/syscalls.rs

@@ -410,3 +410,22 @@ pub fn do_geteuid() -> Result<isize> {
 pub fn do_getegid() -> Result<isize> {
     Ok(0)
 }
+
+// Occlum is a single user enviroment, so only group 0 is supported
+pub fn do_getgroups(size: isize, buf_ptr: *mut u32) -> Result<isize> {
+    if size < 0 {
+        return_errno!(EINVAL, "buffer size is incorrect");
+    } else if size == 0 {
+        //Occlum only has 1 group
+        Ok(1)
+    } else {
+        let size = size as usize;
+        check_array(buf_ptr, size)?;
+
+        let group_list = unsafe { std::slice::from_raw_parts_mut(buf_ptr, size) };
+        group_list[0] = 0;
+
+        //Occlum only has 1 group
+        Ok(1)
+    }
+}

src/libos/src/syscall/mod.rs

@@ -41,9 +41,9 @@ use crate::net::{
 };
 use crate::process::{
     do_arch_prctl, do_clone, do_exit, do_exit_group, do_futex, do_getegid, do_geteuid, do_getgid,
-    do_getpgid, do_getpid, do_getppid, do_gettid, do_getuid, do_prctl, do_set_tid_address,
+    do_getgroups, do_getpgid, do_getpid, do_getppid, do_gettid, do_getuid, do_prctl,
-    do_spawn_for_glibc, do_spawn_for_musl, do_wait4, pid_t, posix_spawnattr_t, FdOp,
+    do_set_tid_address, do_spawn_for_glibc, do_spawn_for_musl, do_wait4, pid_t, posix_spawnattr_t,
-    SpawnFileActions, ThreadStatus,
+    FdOp, SpawnFileActions, ThreadStatus,
 };
 use crate::sched::{do_getcpu, do_sched_getaffinity, do_sched_setaffinity, do_sched_yield};
 use crate::signal::{
@@ -200,7 +200,7 @@ macro_rules! process_syscall_table_with_callback {
             (Setsid = 112) => handle_unsupported(),
             (Setreuid = 113) => handle_unsupported(),
             (Setregid = 114) => handle_unsupported(),
-            (Getgroups = 115) => handle_unsupported(),
+            (Getgroups = 115) => do_getgroups(size: isize, buf_ptr: *mut u32),
             (Setgroups = 116) => handle_unsupported(),
             (Setresuid = 117) => handle_unsupported(),
             (Getresuid = 118) => handle_unsupported(),

test/Makefile

@@ -16,7 +16,7 @@ FAIL_LOG = $(BUILD_DIR)/test/.fail
 TEST_DEPS := client data_sink naughty_child
 # Tests: need to be compiled and run by test-% target
 TESTS ?= env empty hello_world malloc mmap file fs_perms getpid spawn sched pipe time \
-	truncate readdir mkdir open stat link symlink chmod chown tls pthread uname rlimit \
+	truncate readdir mkdir open stat link symlink chmod chown tls pthread system_info rlimit \
 	server server_epoll unix_socket cout hostfs cpuid rdtsc device sleep exit_group \
 	ioctl fcntl eventfd emulate_syscall access signal sysinfo prctl rename procfs wait \
 	spawn_attribute statfs

test/system_info/main.c

@@ -0,0 +1,48 @@
+#include <sys/utsname.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include "test.h"
+
+static int test_uname() {
+    struct utsname name;
+    uname(&name);
+    printf("sysname = %s\n", (const char *)&name.sysname);
+    printf("nodename = %s\n", (const char *)&name.nodename);
+    printf("release = %s\n", (const char *)&name.release);
+    printf("version = %s\n", (const char *)&name.version);
+    printf("machine = %s\n", (const char *)&name.machine);
+    printf("domainname = %s\n", (const char *)&name.__domainname);
+
+    return 0;
+}
+
+static int test_getgroups() {
+    int group_num = getgroups(0, NULL);
+    if (group_num != 1) {
+        THROW_ERROR("getgroups failed to get size");
+    }
+
+    gid_t group_list[1] = {1};
+
+    group_num = getgroups(group_num, group_list);
+
+    printf("group_num %d group %d\n", group_num, group_list[0]);
+    if (group_num != 1 || group_list[0] != 0) {
+        THROW_ERROR("getgroups failed to get group_list");
+    }
+    return 0;
+}
+
+// ============================================================================
+// Test suite main
+// ============================================================================
+
+static test_case_t test_cases[] = {
+    TEST_CASE(test_uname),
+    TEST_CASE(test_getgroups),
+};
+
+int main(int argc, const char *argv[]) {
+    return test_suite_run(test_cases, ARRAY_SIZE(test_cases));
+}

test/uname/main.c

@@ -1,14 +0,0 @@
-#include <sys/utsname.h>
-#include <stdio.h>
-
-int main(void) {
-    struct utsname name;
-    uname(&name);
-    printf("sysname = %s\n", (const char *)&name.sysname);
-    printf("nodename = %s\n", (const char *)&name.nodename);
-    printf("release = %s\n", (const char *)&name.release);
-    printf("version = %s\n", (const char *)&name.version);
-    printf("machine = %s\n", (const char *)&name.machine);
-    printf("domainname = %s\n", (const char *)&name.__domainname);
-    return 0;
-}