6 files changed, 63 insertions, 0 deletions
diff --git a/lib/libc/include/unistd.h b/lib/libc/include/unistd.h
index db56ecd..301e926 100644
--- a/lib/libc/include/unistd.h
+++ b/lib/libc/include/unistd.h
@@ -47,6 +47,8 @@ __BEGIN_DECLS
 int sysconf(int name);
 int setuid(uid_t new);
 
+uid_t getuid(void);
+
 ssize_t read(int fd, void *buf, size_t count);
 ssize_t write(int fd, const void *buf, size_t count);
 
diff --git a/lib/libc/src/unistd/getuid.c b/lib/libc/src/unistd/getuid.c
new file mode 100644
index 0000000..644faa5
--- /dev/null
+++ b/lib/libc/src/unistd/getuid.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2023-2025 Ian Marco Moffett and the Osmora Team.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Hyra nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+uid_t
+getuid(void)
+{
+    return syscall(SYS_getuid);
+}
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 05288f4..51c2579 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -57,6 +57,7 @@
 #define SYS_getpid  16
 #define SYS_getppid 17
 #define SYS_setuid  18
+#define SYS_getuid  19
 
 #if defined(_KERNEL)
 /* Syscall return value and arg type */
diff --git a/sys/include/sys/ucred.h b/sys/include/sys/ucred.h
index b44a7fe..f8cbbe0 100644
--- a/sys/include/sys/ucred.h
+++ b/sys/include/sys/ucred.h
@@ -48,8 +48,10 @@ struct ucred {
 };
 
 int setuid(uid_t new);
+uid_t getuid(void);
 
 #if defined(_KERNEL)
 scret_t sys_setuid(struct syscall_args *scargs);
+scret_t sys_getuid(struct syscall_args *scargs);
 #endif
 #endif  /* !_SYS_UCRED_H_ */
diff --git a/sys/kern/kern_cred.c b/sys/kern/kern_cred.c
index e1202fc..017b22a 100644
--- a/sys/kern/kern_cred.c
+++ b/sys/kern/kern_cred.c
@@ -56,6 +56,19 @@ setuid(uid_t new)
     return 0;
 }
 
+uid_t
+getuid(void)
+{
+    struct proc *td;
+
+    td = this_td();
+    if (td == NULL) {
+        return -1;
+    }
+
+    return td->cred.ruid;
+}
+
 /*
  * setuid() syscall
  *
@@ -66,3 +79,9 @@ sys_setuid(struct syscall_args *scargs)
 {
     return setuid(scargs->arg0);
 }
+
+scret_t
+sys_getuid(struct syscall_args *scargs)
+{
+    return getuid();
+}
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index 276c7c7..a28d2dd 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -58,6 +58,7 @@ scret_t(*g_sctab[])(struct syscall_args *) = {
     sys_getpid, /* SYS_getpid */
     sys_getppid, /* SYS_getppid */
     sys_setuid,  /* SYS_setuid */
+    sys_getuid,  /* SYS_getuid */
 };
 
 const size_t MAX_SYSCALLS = NELEM(g_sctab);