n_tty: Uninline tty_copy_to_user()

Merge the multiple tty_copy_to_user() calls into a single copy
sequence within tty_copy_to_user().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 15 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index c37c15d2f782..b2b01d5439b7 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -162,12 +162,23 @@ static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
         return put_user(x, ptr);
 }
 
-static inline int tty_copy_to_user(struct tty_struct *tty,
-                                        void __user *to,
-                                        const void *from,
-                                        unsigned long n)
+static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
+                            size_t tail, size_t n)
 {
         struct n_tty_data *ldata = tty->disc_data;
+        size_t size = N_TTY_BUF_SIZE - tail;
+        const void *from = read_buf_addr(ldata, tail);
+        int uncopied;
+
+        if (n > size) {
+                tty_audit_add_data(tty, from, size, ldata->icanon);
+                uncopied = copy_to_user(to, from, size);
+                if (uncopied)
+                        return uncopied;
+                to += size;
+                n -= size;
+                from = ldata->read_buf;
+        }
 
         tty_audit_add_data(tty, from, n, ldata->icanon);
         return copy_to_user(to, from, n);
@@ -2074,7 +2085,6 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
         } else if (eol != size)
                 found = 1;
 
-        size = N_TTY_BUF_SIZE - tail;
         n = eol - tail;
         if (n > N_TTY_BUF_SIZE)
                 n += N_TTY_BUF_SIZE;
@@ -2086,17 +2096,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
                 eof_push = !n && ldata->read_tail != ldata->line_start;
         }
 
-        n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu size:%zu more:%zu\n",
-                    __func__, eol, found, n, c, size, more);
-
-        if (n > size) {
-                ret = tty_copy_to_user(tty, *b, read_buf_addr(ldata, tail), size);
-                if (ret)
-                        return -EFAULT;
-                ret = tty_copy_to_user(tty, *b + size, ldata->read_buf, n - size);
-        } else
-                ret = tty_copy_to_user(tty, *b, read_buf_addr(ldata, tail), n);
+        n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu tail:%zu more:%zu\n",
+                    __func__, eol, found, n, c, tail, more);
 
+        ret = tty_copy_to_user(tty, *b, tail, n);
         if (ret)
                 return -EFAULT;
         *b += n;