n_tty: Fix handling of control characters and continuations

Fix process_output_block to detect continuation characters correctly
and to handle control characters even when O_OLCUC is enabled.  Make
similar change to do_output_char().

Signed-off-by: Joe Peterson <joe@skyrush.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 15 insertions, 9 deletions

diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index a223823544bf..30b0426b3788 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -351,10 +351,12 @@ static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
                         tty->column--;
                 break;
         default:
-                if (O_OLCUC(tty))
-                        c = toupper(c);
-                if (!iscntrl(c) && !is_continuation(c, tty))
-                        tty->column++;
+                if (!iscntrl(c)) {
+                        if (O_OLCUC(tty))
+                                c = toupper(c);
+                        if (!is_continuation(c, tty))
+                                tty->column++;
+                }
                 break;
         }
 
@@ -425,7 +427,9 @@ static ssize_t process_output_block(struct tty_struct *tty,
                 nr = space;
 
         for (i = 0, cp = buf; i < nr; i++, cp++) {
-                switch (*cp) {
+                unsigned char c = *cp;
+
+                switch (c) {
                 case '\n':
                         if (O_ONLRET(tty))
                                 tty->column = 0;
@@ -447,10 +451,12 @@ static ssize_t process_output_block(struct tty_struct *tty,
                                 tty->column--;
                         break;
                 default:
-                        if (O_OLCUC(tty))
-                                goto break_out;
-                        if (!iscntrl(*cp))
-                                tty->column++;
+                        if (!iscntrl(c)) {
+                                if (O_OLCUC(tty))
+                                        goto break_out;
+                                if (!is_continuation(c, tty))
+                                        tty->column++;
+                        }
                         break;
                 }
         }