Kernel: Don't assume paths of TTYs and pseudo terminals anymore

The obsolete ttyname and ptsname syscalls are removed.
LibC doesn't rely on these anymore, and it helps simplifying the Kernel
in many places, so it's an overall an improvement.

In addition to that, /proc/PID/tty node is removed too as it is not
needed anymore by userspace to get the attached TTY of a process, as
/dev/tty (which is already a character device) represents that as well.

8 files changed, 13 insertions, 51 deletions

diff --git a/Kernel/TTY/MasterPTY.cpp b/Kernel/TTY/MasterPTY.cpp
index ce3f27f05e..b0217bde42 100644
--- a/Kernel/TTY/MasterPTY.cpp
+++ b/Kernel/TTY/MasterPTY.cpp
@@ -18,23 +18,19 @@ namespace Kernel {
 
 ErrorOr<NonnullRefPtr<MasterPTY>> MasterPTY::try_create(unsigned int index)
 {
-    auto pts_name = TRY(KString::formatted("/dev/pts/{}", index));
-    auto tty_name = TRY(pts_name->try_clone());
-
     auto buffer = TRY(DoubleBuffer::try_create());
-    auto master_pty = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) MasterPTY(index, move(buffer), move(pts_name))));
-    auto slave_pty = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) SlavePTY(*master_pty, index, move(tty_name))));
+    auto master_pty = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) MasterPTY(index, move(buffer))));
+    auto slave_pty = TRY(adopt_nonnull_ref_or_enomem(new (nothrow) SlavePTY(*master_pty, index)));
     master_pty->m_slave = slave_pty;
     master_pty->after_inserting();
     slave_pty->after_inserting();
     return master_pty;
 }
 
-MasterPTY::MasterPTY(unsigned index, NonnullOwnPtr<DoubleBuffer> buffer, NonnullOwnPtr<KString> pts_name)
+MasterPTY::MasterPTY(unsigned index, NonnullOwnPtr<DoubleBuffer> buffer)
     : CharacterDevice(200, index)
     , m_index(index)
     , m_buffer(move(buffer))
-    , m_pts_name(move(pts_name))
 {
     auto& process = Process::current();
     set_uid(process.uid());
@@ -52,11 +48,6 @@ MasterPTY::~MasterPTY()
     PTYMultiplexer::the().notify_master_destroyed({}, m_index);
 }
 
-KString const& MasterPTY::pts_name() const
-{
-    return *m_pts_name;
-}
-
 ErrorOr<size_t> MasterPTY::read(OpenFileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
 {
     if (!m_slave && m_buffer->is_empty())
@@ -140,7 +131,7 @@ ErrorOr<void> MasterPTY::ioctl(OpenFileDescription& description, unsigned reques
 
 ErrorOr<NonnullOwnPtr<KString>> MasterPTY::pseudo_path(const OpenFileDescription&) const
 {
-    return KString::formatted("ptm:{}", m_pts_name);
+    return KString::formatted("ptm:{}", m_index);
 }
 
 }
diff --git a/Kernel/TTY/MasterPTY.h b/Kernel/TTY/MasterPTY.h
index 5b5714c6f0..e6e4eea17c 100644
--- a/Kernel/TTY/MasterPTY.h
+++ b/Kernel/TTY/MasterPTY.h
@@ -20,7 +20,6 @@ public:
     virtual ~MasterPTY() override;
 
     unsigned index() const { return m_index; }
-    KString const& pts_name() const;
     ErrorOr<size_t> on_slave_write(const UserOrKernelBuffer&, size_t);
     bool can_write_from_slave() const;
     void notify_slave_closed(Badge<SlavePTY>);
@@ -29,7 +28,7 @@ public:
     virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(const OpenFileDescription&) const override;
 
 private:
-    explicit MasterPTY(unsigned index, NonnullOwnPtr<DoubleBuffer> buffer, NonnullOwnPtr<KString> pts_name);
+    explicit MasterPTY(unsigned index, NonnullOwnPtr<DoubleBuffer> buffer);
     // ^CharacterDevice
     virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override;
     virtual ErrorOr<size_t> write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t) override;
@@ -44,7 +43,6 @@ private:
     unsigned m_index;
     bool m_closed { false };
     NonnullOwnPtr<DoubleBuffer> m_buffer;
-    NonnullOwnPtr<KString> m_pts_name;
 };
 
 }
diff --git a/Kernel/TTY/SlavePTY.cpp b/Kernel/TTY/SlavePTY.cpp
index 3c431a4158..defcf346ae 100644
--- a/Kernel/TTY/SlavePTY.cpp
+++ b/Kernel/TTY/SlavePTY.cpp
@@ -36,11 +36,10 @@ bool SlavePTY::unref() const
     return did_hit_zero;
 }
 
-SlavePTY::SlavePTY(MasterPTY& master, unsigned index, NonnullOwnPtr<KString> tty_name)
+SlavePTY::SlavePTY(MasterPTY& master, unsigned index)
     : TTY(201, index)
     , m_master(master)
     , m_index(index)
-    , m_tty_name(move(tty_name))
 {
     auto& process = Process::current();
     set_uid(process.uid());
@@ -55,11 +54,6 @@ SlavePTY::~SlavePTY()
     dbgln_if(SLAVEPTY_DEBUG, "~SlavePTY({})", m_index);
 }
 
-KString const& SlavePTY::tty_name() const
-{
-    return *m_tty_name;
-}
-
 void SlavePTY::echo(u8 ch)
 {
     if (should_echo_input()) {
diff --git a/Kernel/TTY/SlavePTY.h b/Kernel/TTY/SlavePTY.h
index 73e283c38f..15c576471e 100644
--- a/Kernel/TTY/SlavePTY.h
+++ b/Kernel/TTY/SlavePTY.h
@@ -27,7 +27,6 @@ public:
 
 private:
     // ^TTY
-    virtual KString const& tty_name() const override;
     virtual ErrorOr<size_t> on_tty_write(const UserOrKernelBuffer&, size_t) override;
     virtual void echo(u8) override;
 
@@ -39,12 +38,11 @@ private:
     virtual ErrorOr<void> close() override;
 
     friend class MasterPTY;
-    SlavePTY(MasterPTY&, unsigned index, NonnullOwnPtr<KString> pts_name);
+    SlavePTY(MasterPTY&, unsigned index);
 
     RefPtr<MasterPTY> m_master;
     time_t m_time_of_last_write { 0 };
     unsigned m_index { 0 };
-    NonnullOwnPtr<KString> m_tty_name;
 
     mutable IntrusiveListNode<SlavePTY> m_list_node;
 
diff --git a/Kernel/TTY/TTY.cpp b/Kernel/TTY/TTY.cpp
index 5a98100c87..aff9b326d1 100644
--- a/Kernel/TTY/TTY.cpp
+++ b/Kernel/TTY/TTY.cpp
@@ -183,22 +183,18 @@ void TTY::emit(u8 ch, bool do_evaluate_block_conditions)
 
     if (should_generate_signals()) {
         if (ch == m_termios.c_cc[VINFO]) {
-            dbgln("{}: VINFO pressed!", tty_name());
             generate_signal(SIGINFO);
             return;
         }
         if (ch == m_termios.c_cc[VINTR]) {
-            dbgln("{}: VINTR pressed!", tty_name());
             generate_signal(SIGINT);
             return;
         }
         if (ch == m_termios.c_cc[VQUIT]) {
-            dbgln("{}: VQUIT pressed!", tty_name());
             generate_signal(SIGQUIT);
             return;
         }
         if (ch == m_termios.c_cc[VSUSP]) {
-            dbgln("{}: VSUSP pressed!", tty_name());
             generate_signal(SIGTSTP);
             if (auto original_process_parent = m_original_process_parent.strong_ref()) {
                 [[maybe_unused]] auto rc = original_process_parent->send_signal(SIGCHLD, nullptr);
@@ -361,10 +357,10 @@ void TTY::generate_signal(int signal)
         return;
     if (should_flush_on_signal())
         flush_input();
-    dbgln_if(TTY_DEBUG, "{}: Send signal {} to everyone in pgrp {}", tty_name(), signal, pgid().value());
+    dbgln_if(TTY_DEBUG, "Send signal {} to everyone in pgrp {}", signal, pgid().value());
     InterruptDisabler disabler; // FIXME: Iterate over a set of process handles instead?
     Process::for_each_in_pgrp(pgid(), [&](auto& process) {
-        dbgln_if(TTY_DEBUG, "{}: Send signal {} to {}", tty_name(), signal, process);
+        dbgln_if(TTY_DEBUG, "Send signal {} to {}", signal, process);
         // FIXME: Should this error be propagated somehow?
         [[maybe_unused]] auto rc = process.send_signal(signal, nullptr);
     });
@@ -382,8 +378,7 @@ ErrorOr<void> TTY::set_termios(const termios& t)
     ErrorOr<void> rc;
     m_termios = t;
 
-    dbgln_if(TTY_DEBUG, "{} set_termios: ECHO={}, ISIG={}, ICANON={}, ECHOE={}, ECHOK={}, ECHONL={}, ISTRIP={}, ICRNL={}, INLCR={}, IGNCR={}, OPOST={}, ONLCR={}",
-        tty_name(),
+    dbgln_if(TTY_DEBUG, "set_termios: ECHO={}, ISIG={}, ICANON={}, ECHOE={}, ECHOK={}, ECHONL={}, ISTRIP={}, ICRNL={}, INLCR={}, IGNCR={}, OPOST={}, ONLCR={}",
         should_echo_input(),
         should_generate_signals(),
         in_canonical_mode(),
@@ -571,11 +566,6 @@ ErrorOr<void> TTY::ioctl(OpenFileDescription&, unsigned request, Userspace<void*
     return EINVAL;
 }
 
-ErrorOr<NonnullOwnPtr<KString>> TTY::pseudo_path(const OpenFileDescription&) const
-{
-    return tty_name().try_clone();
-}
-
 void TTY::set_size(unsigned short columns, unsigned short rows)
 {
     m_rows = rows;
diff --git a/Kernel/TTY/TTY.h b/Kernel/TTY/TTY.h
index 1c49b9e1bb..7f5c7e6ad3 100644
--- a/Kernel/TTY/TTY.h
+++ b/Kernel/TTY/TTY.h
@@ -26,9 +26,6 @@ public:
     virtual bool can_read(const OpenFileDescription&, u64) const override;
     virtual bool can_write(const OpenFileDescription&, u64) const override;
     virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) override final;
-    virtual ErrorOr<NonnullOwnPtr<KString>> pseudo_path(const OpenFileDescription&) const override;
-
-    virtual KString const& tty_name() const = 0;
 
     unsigned short rows() const { return m_rows; }
     unsigned short columns() const { return m_columns; }
diff --git a/Kernel/TTY/VirtualConsole.cpp b/Kernel/TTY/VirtualConsole.cpp
index 151783bbd3..ec7ad35c90 100644
--- a/Kernel/TTY/VirtualConsole.cpp
+++ b/Kernel/TTY/VirtualConsole.cpp
@@ -104,9 +104,7 @@ void VirtualConsole::set_graphical(bool graphical)
 
 UNMAP_AFTER_INIT NonnullRefPtr<VirtualConsole> VirtualConsole::create(size_t index)
 {
-    auto pts_name = MUST(KString::formatted("/dev/tty/{}", index));
-
-    auto virtual_console_or_error = DeviceManagement::try_create_device<VirtualConsole>(index, move(pts_name));
+    auto virtual_console_or_error = DeviceManagement::try_create_device<VirtualConsole>(index);
     // FIXME: Find a way to propagate errors
     VERIFY(!virtual_console_or_error.is_error());
     return virtual_console_or_error.release_value();
@@ -176,10 +174,9 @@ void VirtualConsole::refresh_after_resolution_change()
     flush_dirty_lines();
 }
 
-UNMAP_AFTER_INIT VirtualConsole::VirtualConsole(const unsigned index, NonnullOwnPtr<KString> tty_name)
+UNMAP_AFTER_INIT VirtualConsole::VirtualConsole(const unsigned index)
     : TTY(4, index)
     , m_index(index)
-    , m_tty_name(move(tty_name))
     , m_console_impl(*this)
 {
     initialize();
diff --git a/Kernel/TTY/VirtualConsole.h b/Kernel/TTY/VirtualConsole.h
index 4cb4bf4c90..3401b5657e 100644
--- a/Kernel/TTY/VirtualConsole.h
+++ b/Kernel/TTY/VirtualConsole.h
@@ -84,13 +84,12 @@ public:
     void emit_char(char);
 
 private:
-    explicit VirtualConsole(const unsigned index, NonnullOwnPtr<KString> tty_name);
+    explicit VirtualConsole(const unsigned index);
     // ^KeyboardClient
     virtual void on_key_pressed(KeyEvent) override;
 
     // ^TTY
     virtual ErrorOr<size_t> on_tty_write(const UserOrKernelBuffer&, size_t) override;
-    virtual KString const& tty_name() const override { return *m_tty_name; }
     virtual void echo(u8) override;
 
     // ^TerminalClient
@@ -112,8 +111,6 @@ private:
     bool m_active { false };
     bool m_graphical { false };
 
-    NonnullOwnPtr<KString> m_tty_name;
-
 private:
     void initialize();