Add an lstat() syscall and use it to make "ls" nicer.

Kernel/Syscall.cpp

@@ -68,6 +68,8 @@ DWORD handle(DWORD function, DWORD arg1, DWORD arg2, DWORD arg3)
         return current->sys$spawn((const char*)arg1);
     case Syscall::GetDirEntries:
         return current->sys$get_dir_entries((int)arg1, (void*)arg2, (size_t)arg3);
+    case Syscall::PosixLstat:
+        return current->sys$lstat((const char*)arg1, (void*)arg2);
     case Syscall::PosixOpen:
         //kprintf("syscall: open('%s', %u)\n", arg1, arg2);
         return current->sys$open((const char*)arg1, (size_t)arg2);

Kernel/Syscall.h

@@ -27,6 +27,7 @@ enum Function {
     PosixMmap = 0x1995,
     PosixMunmap = 0x1996,
     GetDirEntries = 0x1997,
+    PosixLstat = 0x1998,
 };
 
 void initialize();

Kernel/Task.cpp

@@ -700,13 +700,22 @@ int Task::sys$close(int fd)
     return 0;
 }
 
+int Task::sys$lstat(const char* path, void* statbuf)
+{
+    auto handle = VirtualFileSystem::the().open(move(path));
+    if (!handle)
+        return -1;
+    handle->stat((Unix::stat*)statbuf);
+    return 0;
+}
+
 int Task::sys$open(const char* path, size_t pathLength)
 {
     Task::checkSanity("sys$open");
 #ifdef DEBUG_IO
     kprintf("Task::sys$open(): PID=%u, path=%s {%u}\n", m_pid, path, pathLength);
 #endif
-    auto* handle = current->openFile(String(path, pathLength));
+    auto* handle = openFile(String(path, pathLength));
     if (handle)
         return handle->fd();
     return -1;

Kernel/Task.h

@@ -92,6 +92,7 @@ public:
     int sys$open(const char* path, size_t pathLength);
     int sys$close(int fd);
     int sys$read(int fd, void* outbuf, size_t nread);
+    int sys$lstat(const char*, void* statbuf);
     int sys$seek(int fd, int offset);
     int sys$kill(pid_t pid, int sig);
     int sys$geterror() { return m_error; }

Kernel/VGA.cpp

@@ -10,6 +10,7 @@ PRIVATE BYTE current_attr = 0x07;
 
 void vga_scroll_up()
 {
+    InterruptDisabler disabler;
     memcpy(vga_mem, vga_mem + 160, 160 * 24);
     memset(vga_mem + (160 * 24), 0, 160);
 }