Commit 362014c8 authored Feb 09, 2016 by Max Filippov Committed by Chris Zankel Mar 11, 2016

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



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>

parent bb2f3486

arch/xtensa/platforms/iss/console.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -100,20 +100,22 @@ 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);


		if (rd)
		mod_timer(&serial_timer, jiffies + SERIAL_TIMER_VALUE);
		spin_unlock(&timer_lock);
		}