Kernel: Keep TTY names in character buffers instead of Strings

Just going over some little unnecessary little kmalloc allocations.

7 files changed, 27 insertions, 31 deletions

diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp
index 84f02cef54..7dbe1cbab0 100644
--- a/Kernel/Process.cpp
+++ b/Kernel/Process.cpp
@@ -966,7 +966,8 @@ int Process::sys$ttyname_r(int fd, char* buffer, ssize_t size)
     auto tty_name = description->tty()->tty_name();
     if (size < tty_name.length() + 1)
         return -ERANGE;
-    strcpy(buffer, tty_name.characters());
+    memcpy(buffer, tty_name.characters_without_null_termination(), tty_name.length());
+    buffer[tty_name.length()] = '\0';
     return 0;
 }
 
diff --git a/Kernel/TTY/SlavePTY.cpp b/Kernel/TTY/SlavePTY.cpp
index 129eb00e07..63a9932241 100644
--- a/Kernel/TTY/SlavePTY.cpp
+++ b/Kernel/TTY/SlavePTY.cpp
@@ -10,7 +10,7 @@ SlavePTY::SlavePTY(MasterPTY& master, unsigned index)
     , m_master(master)
     , m_index(index)
 {
-    m_tty_name = String::format("/dev/pts/%u", m_index);
+    ksprintf(m_tty_name, "/dev/pts/%u", m_index);
     set_uid(current->process().uid());
     set_gid(current->process().gid());
     DevPtsFS::register_slave_pty(*this);
@@ -25,7 +25,7 @@ SlavePTY::~SlavePTY()
     DevPtsFS::unregister_slave_pty(*this);
 }
 
-String SlavePTY::tty_name() const
+StringView SlavePTY::tty_name() const
 {
     return m_tty_name;
 }
diff --git a/Kernel/TTY/SlavePTY.h b/Kernel/TTY/SlavePTY.h
index 9bf1c5f9cc..03bd892f19 100644
--- a/Kernel/TTY/SlavePTY.h
+++ b/Kernel/TTY/SlavePTY.h
@@ -14,7 +14,7 @@ public:
 
 private:
     // ^TTY
-    virtual String tty_name() const override;
+    virtual StringView tty_name() const override;
     virtual ssize_t on_tty_write(const u8*, ssize_t) override;
 
     // ^CharacterDevice
@@ -29,5 +29,5 @@ private:
 
     RefPtr<MasterPTY> m_master;
     unsigned m_index;
-    String m_tty_name;
+    char m_tty_name[32];
 };
diff --git a/Kernel/TTY/TTY.cpp b/Kernel/TTY/TTY.cpp
index f3931a43ed..1e71a7547e 100644
--- a/Kernel/TTY/TTY.cpp
+++ b/Kernel/TTY/TTY.cpp
@@ -62,17 +62,17 @@ void TTY::emit(u8 ch)
 {
     if (should_generate_signals()) {
         if (ch == m_termios.c_cc[VINTR]) {
-            dbgprintf("%s: VINTR pressed!\n", tty_name().characters());
+            dbg() << tty_name() << ": VINTR pressed!";
             generate_signal(SIGINT);
             return;
         }
         if (ch == m_termios.c_cc[VQUIT]) {
-            dbgprintf("%s: VQUIT pressed!\n", tty_name().characters());
+            dbg() << tty_name() << ": VQUIT pressed!";
             generate_signal(SIGQUIT);
             return;
         }
         if (ch == m_termios.c_cc[VSUSP]) {
-            dbgprintf("%s: VSUSP pressed!\n", tty_name().characters());
+            dbg() << tty_name() << ": VSUSP pressed!";
             generate_signal(SIGTSTP);
             return;
         }
@@ -84,10 +84,10 @@ void TTY::generate_signal(int signal)
 {
     if (!pgid())
         return;
-    dbgprintf("%s: Send signal %d to everyone in pgrp %d\n", tty_name().characters(), signal, pgid());
+    dbg() << tty_name() << ": Send signal " << signal << " to everyone in pgrp " << pgid();
     InterruptDisabler disabler; // FIXME: Iterate over a set of process handles instead?
     Process::for_each_in_pgrp(pgid(), [&](auto& process) {
-        dbgprintf("%s: Send signal %d to %d\n", tty_name().characters(), signal, process.pid());
+        dbg() << tty_name() << ": Send signal " << signal << " to " << process;
         process.send_signal(signal, nullptr);
         return IterationDecision::Continue;
     });
@@ -96,22 +96,17 @@ void TTY::generate_signal(int signal)
 void TTY::set_termios(const termios& t)
 {
     m_termios = t;
-    dbgprintf("%s set_termios: ECHO=%u, ISIG=%u, ICANON=%u\n",
-        tty_name().characters(),
-        should_echo_input(),
-        should_generate_signals(),
-        in_canonical_mode());
-    dbgprintf("%s set_termios: ECHOE=%u, ECHOK=%u, ECHONL=%u\n",
-        tty_name().characters(),
-        (m_termios.c_lflag & ECHOE) != 0,
-        (m_termios.c_lflag & ECHOK) != 0,
-        (m_termios.c_lflag & ECHONL) != 0);
-    dbgprintf("%s set_termios: ISTRIP=%u, ICRNL=%u, INLCR=%u, IGNCR=%u\n",
-        tty_name().characters(),
-        (m_termios.c_iflag & ISTRIP) != 0,
-        (m_termios.c_iflag & ICRNL) != 0,
-        (m_termios.c_iflag & INLCR) != 0,
-        (m_termios.c_iflag & IGNCR) != 0);
+    dbg() << tty_name() << " set_termios: "
+          << "ECHO=" << should_echo_input()
+          << ", ISIG=" << should_generate_signals()
+          << ", ICANON=" << in_canonical_mode()
+          << ", ECHOE=" << ((m_termios.c_lflag & ECHOE) != 0)
+          << ", ECHOK=" << ((m_termios.c_lflag & ECHOK) != 0)
+          << ", ECHONL=" << ((m_termios.c_lflag & ECHONL) != 0)
+          << ", ISTRIP=" << ((m_termios.c_iflag & ISTRIP) != 0)
+          << ", ICRNL=" << ((m_termios.c_iflag & ICRNL) != 0)
+          << ", INLCR=" << ((m_termios.c_iflag & INLCR) != 0)
+          << ", IGNCR=" << ((m_termios.c_iflag & IGNCR) != 0);
 }
 
 int TTY::ioctl(FileDescription&, unsigned request, unsigned arg)
diff --git a/Kernel/TTY/TTY.h b/Kernel/TTY/TTY.h
index 55768b0f72..6a9d47fa2f 100644
--- a/Kernel/TTY/TTY.h
+++ b/Kernel/TTY/TTY.h
@@ -18,7 +18,7 @@ public:
     virtual int ioctl(FileDescription&, unsigned request, unsigned arg) override final;
     virtual String absolute_path(const FileDescription&) const override { return tty_name(); }
 
-    virtual String tty_name() const = 0;
+    virtual StringView 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 653fd4d3df..f8586077d4 100644
--- a/Kernel/TTY/VirtualConsole.cpp
+++ b/Kernel/TTY/VirtualConsole.cpp
@@ -41,7 +41,7 @@ VirtualConsole::VirtualConsole(unsigned index, InitialContents initial_contents)
     : TTY(4, index)
     , m_index(index)
 {
-    m_tty_name = String::format("/dev/tty%u", m_index);
+    ksprintf(m_tty_name, "/dev/tty%u", m_index);
     set_size(80, 25);
     m_horizontal_tabs = static_cast<u8*>(kmalloc(columns()));
     for (unsigned i = 0; i < columns(); ++i)
@@ -541,7 +541,7 @@ ssize_t VirtualConsole::on_tty_write(const u8* data, ssize_t size)
     return size;
 }
 
-String VirtualConsole::tty_name() const
+StringView VirtualConsole::tty_name() const
 {
     return m_tty_name;
 }
diff --git a/Kernel/TTY/VirtualConsole.h b/Kernel/TTY/VirtualConsole.h
index e9211b2142..b663d61b81 100644
--- a/Kernel/TTY/VirtualConsole.h
+++ b/Kernel/TTY/VirtualConsole.h
@@ -32,7 +32,7 @@ private:
 
     // ^TTY
     virtual ssize_t on_tty_write(const u8*, ssize_t) override;
-    virtual String tty_name() const override;
+    virtual StringView tty_name() const override;
 
     // ^CharacterDevice
     virtual const char* class_name() const override { return "VirtualConsole"; }
@@ -87,5 +87,5 @@ private:
     Vector<u8> m_parameters;
     Vector<u8> m_intermediates;
     u8* m_horizontal_tabs { nullptr };
-    String m_tty_name;
+    char m_tty_name[32];
 };