xtensa: ISS: don't hang if stdin EOF is reached

commit 362014c8d9d51d504c167c44ac280169457732be upstream.

Simulator stdin may be connected to a file, when its end is reached
kernel hangs in infinite loop inside rs_poll, because simc_poll always
signals that descriptor 0 is readable and simc_read always returns 0.
Check simc_read return value and exit loop if it's not positive. Also
don't rewind polling timer if it's zero.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
Max Filippov 2016-02-09 01:02:38 +03:00 committed by Willy Tarreau
parent 929522bfe4
commit fd5924d8b3
1 changed files with 6 additions and 4 deletions

View File

@ -100,21 +100,23 @@ static void rs_poll(unsigned long priv)
{
struct tty_port *port = (struct tty_port *)priv;
int i = 0;
int rd = 1;
unsigned char c;
spin_lock(&timer_lock);
while (simc_poll(0)) {
simc_read(0, &c, 1);
rd = simc_read(0, &c, 1);
if (rd <= 0)
break;
tty_insert_flip_char(port, c, TTY_NORMAL);
i++;
}
if (i)
tty_flip_buffer_push(port);
mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
if (rd)
mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
spin_unlock(&timer_lock);
}