Kernel/LibC: Replace terminal syscalls with ioctls

isatty, tc{get,set}attr, tc{get,set}pgrp are now implemented as ioctls
instead of separate syscalls

kernel/include/kernel/Process.h

@@ -56,6 +56,7 @@ namespace Kernel
 		pid_t pid() const { return m_pid; }
 
 		bool is_session_leader() const { return pid() == sid(); }
+		bool is_pgrpg_in_this_session(pid_t) const;
 
 		const char* name() const { return m_cmdline.empty() ? "<unknown>" : m_cmdline.front().data(); }
 
@@ -63,9 +64,6 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_exit(int status);
 
-		BAN::ErrorOr<long> sys_tcgetattr(int fildes, termios*);
-		BAN::ErrorOr<long> sys_tcsetattr(int fildes, int optional_actions, const termios*);
-
 		BAN::ErrorOr<long> sys_fork(uintptr_t rsp, uintptr_t rip);
 		BAN::ErrorOr<long> sys_exec(const char* path, const char* const* argv, const char* const* envp);
 
@@ -186,7 +184,6 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_smo_map(SharedMemoryObjectManager::Key);
 
 		BAN::ErrorOr<long> sys_ttyname(int fildes, char* name, size_t namesize);
-		BAN::ErrorOr<long> sys_isatty(int fildes);
 		BAN::ErrorOr<long> sys_posix_openpt(int flags);
 		BAN::ErrorOr<long> sys_ptsname(int fildes, char* buffer, size_t buffer_len);
 
@@ -218,9 +215,6 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_pthread_self();
 		BAN::ErrorOr<long> sys_pthread_kill(pthread_t thread, int signal);
 
-		BAN::ErrorOr<long> sys_tcgetpgrp(int fd);
-		BAN::ErrorOr<long> sys_tcsetpgrp(int fd, pid_t pgid);
-
 		BAN::ErrorOr<long> sys_clock_gettime(clockid_t, timespec*);
 
 		BAN::ErrorOr<long> sys_load_keymap(const char* path);

kernel/include/kernel/Terminal/TTY.h

@@ -33,9 +33,6 @@ namespace Kernel
 	public:
 		virtual BAN::ErrorOr<void> set_font(LibFont::Font&&) { return BAN::Error::from_errno(EINVAL); }
 
-		void set_foreground_pgrp(pid_t pgrp) { m_foreground_pgrp = pgrp; }
-		pid_t foreground_pgrp() const { return m_foreground_pgrp; }
-
 		BAN::ErrorOr<void> tty_ctrl(int command, int flags);
 
 		// for kprint
@@ -52,9 +49,6 @@ namespace Kernel
 		void on_key_event(LibInput::KeyEvent);
 		void handle_input_byte(uint8_t);
 
-		void get_termios(termios*);
-		BAN::ErrorOr<void> set_termios(const termios*);
-
 		virtual bool is_tty() const override { return true; }
 
 		virtual dev_t rdev() const final override { return m_rdev; }
@@ -87,10 +81,12 @@ namespace Kernel
 		bool putchar(uint8_t ch);
 		void do_backspace();
 
+		termios get_termios();
+
 	private:
 		const dev_t m_rdev;
 
-		pid_t m_foreground_pgrp { 0 };
+		BAN::Atomic<pid_t> m_foreground_pgrp { 0 };
 
 		struct tty_ctrl_t
 		{