Kernel/LibC: Implement fchmod

The whole system can crash when debug output and tty output are done at
the same time. This patch is just a hack to prevent the crash :D

kernel/include/kernel/Process.h

@@ -119,8 +119,9 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_pread(int fd, void* buffer, size_t count, off_t offset);
 
-		BAN::ErrorOr<long> sys_chmod(const char*, mode_t);
-		BAN::ErrorOr<long> sys_chown(const char*, uid_t, gid_t);
+		BAN::ErrorOr<long> sys_chmod(const char* path, mode_t mode);
+		BAN::ErrorOr<long> sys_fchmod(int fildes, mode_t mode);
+		BAN::ErrorOr<long> sys_chown(const char* path, uid_t uid, gid_t gid);
 
 		BAN::ErrorOr<long> sys_socket(int domain, int type, int protocol);
 		BAN::ErrorOr<long> sys_getsockname(int socket, sockaddr* address, socklen_t* address_len);

kernel/kernel/Debug.cpp

@@ -8,6 +8,7 @@
 
 #include <ctype.h>
 
+bool g_disable_debug = false;
 extern Kernel::TerminalDriver* g_terminal_driver;
 
 namespace Debug
@@ -70,6 +71,9 @@ namespace Debug
 	{
 		using namespace Kernel;
 
+		if (g_disable_debug)
+			return;
+
 		if (Kernel::Serial::has_devices())
 			return Kernel::Serial::putchar_any(ch);
 		if (Kernel::TTY::is_initialized())

kernel/kernel/Process.cpp

@@ -1103,6 +1103,18 @@ namespace Kernel
 		return 0;
 	}
 
+	BAN::ErrorOr<long> Process::sys_fchmod(int fildes, mode_t mode)
+	{
+		if (mode & S_IFMASK)
+			return BAN::Error::from_errno(EINVAL);
+
+		LockGuard _(m_process_lock);
+		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
+		TRY(inode->chmod(mode));
+
+		return 0;
+	}
+
 	BAN::ErrorOr<long> Process::sys_chown(const char* path, uid_t uid, gid_t gid)
 	{
 		LockGuard _(m_process_lock);

kernel/kernel/kernel.cpp

@@ -65,6 +65,7 @@ static bool should_disable_serial(BAN::StringView full_command_line)
 	return false;
 }
 
+extern bool g_disable_debug;
 static ParsedCommandLine cmdline;
 
 static void parse_command_line()
@@ -81,6 +82,8 @@ static void parse_command_line()
 			cmdline.disable_smp = true;
 		else if (argument == "nousb")
 			cmdline.disable_usb = true;
+		else if (argument == "nodebug")
+			g_disable_debug = true;
 		else if (argument.starts_with("ps2="))
 		{
 			if (argument.size() != 5 || !isdigit(argument[4]))

userspace/libraries/LibC/include/sys/syscall.h

@@ -55,6 +55,7 @@ __BEGIN_DECLS
 	O(SYS_TTY_CTRL,			tty_ctrl)		\
 	O(SYS_POWEROFF,			poweroff)		\
 	O(SYS_CHMOD,			chmod)			\
+	O(SYS_FCHMOD,			fchmod)			\
 	O(SYS_CREATE,			create)			\
 	O(SYS_CREATE_DIR,		create_dir)		\
 	O(SYS_UNLINK,			unlink) 		\

userspace/libraries/LibC/sys/stat.cpp

@@ -13,9 +13,9 @@ int chmod(const char* path, mode_t mode)
 	return syscall(SYS_CHMOD, path, mode);
 }
 
-int fchmod(int, mode_t)
+int fchmod(int fildes, mode_t mode)
 {
-	ASSERT_NOT_REACHED();
+	return syscall(SYS_FCHMOD, fildes, mode);
 }
 
 int fstat(int fildes, struct stat* buf)

userspace/programs/Shell/main.cpp

@@ -197,6 +197,18 @@ BAN::Vector<BAN::Vector<BAN::String>> parse_command(BAN::StringView command_view
 	{
 		char c = command_view[i];
 
+		if (i + 1 < command_view.size() && c == '\\')
+		{
+			char next = command_view[i + 1];
+			if (next == '\'' || next == '"')
+			{
+				if (i + 1 < command_view.size())
+					MUST(current_arg.push_back(next));
+				i++;
+				continue;
+			}
+		}
+
 		switch (state)
 		{
 			case State::Normal: