kernel+libc: Add mkdir()

apps/app.c

@@ -1,6 +1,7 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <sys/stat.h>
 #include <time.h>
 #include <unistd.h>
 
@@ -14,7 +15,10 @@ int main()
     atexit(bye);
     printf("Welcome to %s from userspace (pid %d)!\n", "Luna", getpid());
 
-    int fd = open("/etc/motd", O_RDONLY);
+    mkdir("/home", 0);
+    mkdir("/home/user", 0);
+
+    int fd = open("/home/user/notes.txt", O_RDWR | O_CREAT);
     if (fd < 0)
     {
         perror("open");
@@ -25,7 +29,7 @@ int main()
     ssize_t nread = read(fd, buffer, sizeof(buffer));
     buffer[nread] = 0;
 
-    printf("/etc/motd says: %s", buffer);
+    printf("/home/user/notes.txt says: %s", buffer);
 
     close(fd);
 

kernel/CMakeLists.txt

@@ -29,6 +29,7 @@ set(SOURCES
     src/sys/open.cpp
     src/sys/file.cpp
     src/sys/id.cpp
+    src/sys/mkdir.cpp
     src/fs/VFS.cpp
     src/fs/tmpfs/FileSystem.cpp
     src/InitRD.cpp

kernel/src/sys/mkdir.cpp

@@ -0,0 +1,18 @@
+#include "Log.h"
+#include "fs/VFS.h"
+#include "memory/MemoryManager.h"
+#include "sys/Syscall.h"
+
+Result<u64> sys_mkdir(Registers*, SyscallArgs args)
+{
+    u64 path_address = args[0];
+    if (!MemoryManager::validate_userspace_string(path_address)) return err(EFAULT);
+
+    const char* path = (const char*)path_address;
+
+    kinfoln("mkdir: attempting to create %s", path);
+
+    TRY(VFS::create_directory(path));
+
+    return 0;
+}

libc/CMakeLists.txt

@@ -12,6 +12,7 @@ set(SOURCES
     src/atexit.cpp
     src/ctype.cpp
     src/time.cpp
+    src/sys/stat.cpp
     src/sys/mman.cpp
 )
 

libc/include/sys/mman.h

@@ -1,7 +1,7 @@
 /* sys/mman.h: Memory allocation and deallocation. */
 
-#ifndef _LUNA_MMAN_H
+#ifndef _SYS_MMAN_H
-#define _LUNA_MMAN_H
+#define _SYS_MMAN_H
 
 #include <bits/mmap-flags.h>
 #include <sys/types.h>

libc/include/sys/stat.h

@@ -0,0 +1,20 @@
+/* sys/stat.h: stat() routine and friends. */
+
+#ifndef _SYS_STAT_H
+#define _SYS_STAT_H
+
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+    /* Create a directory. */
+    int mkdir(const char* path, mode_t mode);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

libc/src/sys/stat.cpp

@@ -0,0 +1,13 @@
+#include <bits/errno-return.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <unistd.h>
+
+extern "C"
+{
+    int mkdir(const char* path, mode_t)
+    {
+        long rc = syscall(SYS_mkdir, path);
+        __errno_return(rc, int);
+    }
+}

libluna/include/luna/Syscall.h

@@ -2,7 +2,7 @@
 
 #define enumerate_syscalls(_e)                                                                                         \
     _e(exit) _e(console_write) _e(clock_gettime) _e(allocate_memory) _e(deallocate_memory) _e(usleep) _e(open)         \
-        _e(close) _e(read) _e(getpid) _e(write) _e(lseek)
+        _e(close) _e(read) _e(getpid) _e(write) _e(lseek) _e(mkdir)
 
 enum Syscalls
 {