tty: simple optimization for a very hot path

We can do the valaddr once on Fuzix as we don't have threads or sleep races
to worry about

diff --git a/Kernel/tty.c b/Kernel/tty.c
index ec8e27d..6a90fdb 100644 (file)
--- a/Kernel/tty.c
+++ b/Kernel/tty.c
@@ -106,6 +106,9 @@ int tty_write(uint8_t minor, uint8_t rawflag, uint8_t flag)
 
        used(rawflag);
 
+       if (!valaddr(udata.u_base, udata.u_count))
+               return -1;
+
        t = &ttydata[minor];
 
        while (udata.u_done != udata.u_count) {
@@ -136,7 +139,7 @@ int tty_write(uint8_t minor, uint8_t rawflag, uint8_t flag)
                        if (udata.u_sysio)
                                c = *udata.u_base;
                        else
-                               c = ugetc(udata.u_base);
+                               c = _ugetc(udata.u_base);
 
                        if (t->termios.c_oflag & OPOST) {
                                if (c == '\n' && (t->termios.c_oflag & ONLCR))