Merge branch 'for-linus' of git://git.kernel.dk/linux-block

[cascardo/linux.git] / drivers / tty / n_tty.c

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index ed77614..e49c2bc 100644 (file)
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2054,13 +2054,13 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
        size_t eol;
        size_t tail;
        int ret, found = 0;
-       bool eof_push = 0;
 
        /* N.B. avoid overrun if nr == 0 */
-       n = min(*nr, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
-       if (!n)
+       if (!*nr)
                return 0;
 
+       n = min(*nr + 1, smp_load_acquire(&ldata->canon_head) - ldata->read_tail);
+
        tail = ldata->read_tail & (N_TTY_BUF_SIZE - 1);
        size = min_t(size_t, tail + n, N_TTY_BUF_SIZE);
 
@@ -2081,12 +2081,11 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
        n = eol - tail;
        if (n > N_TTY_BUF_SIZE)
                n += N_TTY_BUF_SIZE;
-       n += found;
-       c = n;
+       c = n + found;
 
-       if (found && !ldata->push && read_buf(ldata, eol) == __DISABLED_CHAR) {
-               n--;
-               eof_push = !n && ldata->read_tail != ldata->line_start;
+       if (!found || read_buf(ldata, eol) != __DISABLED_CHAR) {
+               c = min(*nr, c);
+               n = c;
        }
 
        n_tty_trace("%s: eol:%zu found:%d n:%zu c:%zu size:%zu more:%zu\n",
@@ -2116,7 +2115,7 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
                        ldata->push = 0;
                tty_audit_push(tty);
        }
-       return eof_push ? -EAGAIN : 0;
+       return 0;
 }
 
 extern ssize_t redirected_tty_write(struct file *, const char __user *,
@@ -2273,10 +2272,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
 
                if (ldata->icanon && !L_EXTPROC(tty)) {
                        retval = canon_copy_from_read_buf(tty, &b, &nr);
-                       if (retval == -EAGAIN) {
-                               retval = 0;
-                               continue;
-                       } else if (retval)
+                       if (retval)
                                break;
                } else {
                        int uncopied;