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path: root/drivers/tty/n_tty.c
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Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r--drivers/tty/n_tty.c22
1 files changed, 9 insertions, 13 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index ed776149261e..e49c2bce551d 100644
--- 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;