Report host uid/gid credentials under NODERAWFS

src/lib/libsigs.js

@@ -255,9 +255,13 @@ sigs = {
   __syscall_ftruncate64__sig: 'iij',
   __syscall_getcwd__sig: 'ipp',
   __syscall_getdents64__sig: 'iipp',
+  __syscall_getegid32__sig: 'i',
+  __syscall_geteuid32__sig: 'i',
+  __syscall_getgid32__sig: 'i',
   __syscall_getpeername__sig: 'iippiii',
   __syscall_getsockname__sig: 'iippiii',
   __syscall_getsockopt__sig: 'iiiippi',
+  __syscall_getuid32__sig: 'i',
   __syscall_ioctl__sig: 'iiip',
   __syscall_linkat__sig: 'iipipi',
   __syscall_listen__sig: 'iiiiiii',

src/lib/libsyscall.js

@@ -1084,6 +1084,23 @@ var SyscallsLibrary = {
     }
     return 0;
   },
+  __syscall_getuid32__nothrow: true,
+  __syscall_geteuid32__nothrow: true,
+  __syscall_getgid32__nothrow: true,
+  __syscall_getegid32__nothrow: true,
+#if NODERAWFS
+  // NODERAWFS reports the real host process credentials (0 on Windows, which
+  // has no uid/gid concept).
+  __syscall_getuid32: () => process.getuid?.() ?? 0,
+  __syscall_geteuid32: () => process.geteuid?.() ?? 0,
+  __syscall_getgid32: () => process.getgid?.() ?? 0,
+  __syscall_getegid32: () => process.getegid?.() ?? 0,
+#else
+  __syscall_getuid32: () => 0,
+  __syscall_geteuid32: () => 0,
+  __syscall_getgid32: () => 0,
+  __syscall_getegid32: () => 0,
+#endif
   __syscall_dup3: (fd, newfd, flags) => {
     if (fd === newfd) return -{{{ cDefs.EINVAL }}};
     if (flags & ~{{{ cDefs.O_CLOEXEC }}}) return -{{{ cDefs.EINVAL }}};

system/lib/libc/emscripten_syscall_stubs.c

@@ -129,22 +129,6 @@ weak int __syscall_setdomainname(const char *name, size_t len) {
   return -EPERM;
 }
 
-weak uid_t __syscall_getuid32(void) {
-  return 0;
-}
-
-weak gid_t __syscall_getgid32(void) {
-  return 0;
-}
-
-weak uid_t __syscall_geteuid32(void) {
-  return 0;
-}
-
-weak gid_t __syscall_getegid32(void) {
-  return 0;
-}
-
 weak int __syscall_getresuid32(uid_t *ruid, uid_t *euid, uid_t *suid) {
   *ruid = 0;
   *euid = 0;

system/lib/wasmfs/syscalls.cpp

@@ -1864,6 +1864,13 @@ int __syscall_linkat(int olddirfd,
   return -EMLINK;
 }
 
+// NODERAWFS credential reporting is implemented in the legacy JS syscall layer
+// only.
+uid_t __syscall_getuid32(void) { return 0; }
+uid_t __syscall_geteuid32(void) { return 0; }
+gid_t __syscall_getgid32(void) { return 0; }
+gid_t __syscall_getegid32(void) { return 0; }
+
 // epoll is implemented in the legacy (non-WASMFS) JS syscall layer only.
 int __syscall_epoll_create1(int flags) { return -ENOSYS; }
 

test/codesize/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
-  "a.out.js": 269157,
-  "a.out.nodebug.wasm": 588047,
-  "total": 857204,
+  "a.out.js": 269335,
+  "a.out.nodebug.wasm": 588128,
+  "total": 857463,
   "sent": [
     "IMG_Init",
     "IMG_Load",
@@ -240,9 +240,13 @@
     "__syscall_ftruncate64",
     "__syscall_getcwd",
     "__syscall_getdents64",
+    "__syscall_getegid32",
+    "__syscall_geteuid32",
+    "__syscall_getgid32",
     "__syscall_getpeername",
     "__syscall_getsockname",
     "__syscall_getsockopt",
+    "__syscall_getuid32",
     "__syscall_ioctl",
     "__syscall_linkat",
     "__syscall_listen",
@@ -1767,9 +1771,13 @@
     "env.__syscall_ftruncate64",
     "env.__syscall_getcwd",
     "env.__syscall_getdents64",
+    "env.__syscall_getegid32",
+    "env.__syscall_geteuid32",
+    "env.__syscall_getgid32",
     "env.__syscall_getpeername",
     "env.__syscall_getsockname",
     "env.__syscall_getsockopt",
+    "env.__syscall_getuid32",
     "env.__syscall_ioctl",
     "env.__syscall_linkat",
     "env.__syscall_listen",
@@ -2209,9 +2217,6 @@
     "__subvti3",
     "__synccall",
     "__syscall_acct",
-    "__syscall_getegid32",
-    "__syscall_geteuid32",
-    "__syscall_getgid32",
     "__syscall_getgroups32",
     "__syscall_getpgid",
     "__syscall_getpid",
@@ -2221,7 +2226,6 @@
     "__syscall_getresuid32",
     "__syscall_getrusage",
     "__syscall_getsid",
-    "__syscall_getuid32",
     "__syscall_madvise",
     "__syscall_mincore",
     "__syscall_mlock",
@@ -4636,8 +4640,11 @@
     "$getdelim",
     "$getdents",
     "$getdomainname",
+    "$getegid",
     "$getentropy",
     "$getenv",
+    "$geteuid",
+    "$getgid",
     "$getgroups",
     "$gethostbyaddr",
     "$gethostbyaddr_r",
@@ -4678,6 +4685,7 @@
     "$gettext",
     "$gettid",
     "$gettimeofday",
+    "$getuid",
     "$getw",
     "$getwchar",
     "$glob",

test/fs/test_getuid_noderawfs.c

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2026 The Emscripten Authors.  All rights reserved.
+ * Emscripten is available under two separate licenses, the MIT license and the
+ * University of Illinois/NCSA Open Source License.  Both these licenses can be
+ * found in the LICENSE file.
+ */
+
+#include <assert.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <emscripten.h>
+
+int main() {
+  // NODERAWFS reports the real host process credentials. Other backends report
+  // 0 and are covered by test/unistd/misc.c.
+  assert(getuid() == EM_ASM_INT({ return process.getuid(); }));
+  assert(geteuid() == EM_ASM_INT({ return process.geteuid(); }));
+  assert(getgid() == EM_ASM_INT({ return process.getgid(); }));
+  assert(getegid() == EM_ASM_INT({ return process.getegid(); }));
+
+  printf("done\n");
+  return 0;
+}

test/test_core.py

@@ -5987,6 +5987,13 @@ def test_fs_utimensat_nofollow(self):
   def test_fs_fadvise_fallocate(self):
     self.do_runf('fs/test_fadvise_fallocate.c', 'done\n')
 
+  @no_windows('no uid/gid concept on windows')
+  def test_fs_getuid_noderawfs(self):
+    # The default backends report 0 and are covered by unistd/misc.c. This test
+    # verifies NODERAWFS reports the real host process credentials.
+    self.setup_noderawfs_test()
+    self.do_runf('fs/test_getuid_noderawfs.c', 'done\n')
+
   @no_windows('https://github.com/emscripten-core/emscripten/issues/8882')
   @crossplatform
   @also_with_nodefs_both