Commit 30fafd92 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

n_hdlc: simplify freeing of buffer list 



n_hdlc_release contains four loops to free each buffer list. Create a
helper (n_hdlc_free_buf_list) and call it for every list instead. It
makes n_hdlc_release more readable.

We are switching from "for (;;)" to "do {} while (buf)" which avoids the
"if (buf)" completely -- kfree is a nop for NULL pointers.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20200219084118.26491-7-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c549725f

drivers/tty/n_hdlc.c

+14 −31
Original line number Diff line number Diff line
@@ -215,6 +215,16 @@ static struct tty_ldisc_ops n_hdlc_ldisc = { 
	.flush_buffer   = flush_rx_queue,

};



static void n_hdlc_free_buf_list(struct n_hdlc_buf_list *list)

{

	struct n_hdlc_buf *buf;



	do {

		buf = n_hdlc_buf_get(list);

		kfree(buf);

	} while (buf);

}



/**

 * n_hdlc_release - release an n_hdlc per device line discipline info structure

 * @n_hdlc - per device line discipline info structure
@@ -222,7 +232,6 @@ static struct tty_ldisc_ops n_hdlc_ldisc = { 
static void n_hdlc_release(struct n_hdlc *n_hdlc)

{

	struct tty_struct *tty = n_hdlc2tty (n_hdlc);

	struct n_hdlc_buf *buf;



	/* Ensure that the n_hdlcd process is not hanging on select()/poll() */

	wake_up_interruptible (&tty->read_wait);
@@ -231,37 +240,11 @@ static void n_hdlc_release(struct n_hdlc *n_hdlc) 
	if (tty->disc_data == n_hdlc)

		tty->disc_data = NULL;	/* Break the tty->n_hdlc link */



	/* Release transmit and receive buffers */

	for(;;) {

		buf = n_hdlc_buf_get(&n_hdlc->rx_free_buf_list);

		if (buf) {

			kfree(buf);

		} else

			break;

	}

	for(;;) {

		buf = n_hdlc_buf_get(&n_hdlc->tx_free_buf_list);

		if (buf) {

			kfree(buf);

		} else

			break;

	}

	for(;;) {

		buf = n_hdlc_buf_get(&n_hdlc->rx_buf_list);

		if (buf) {

			kfree(buf);

		} else

			break;

	}

	for(;;) {

		buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);

		if (buf) {

			kfree(buf);

		} else

			break;

	}

	n_hdlc_free_buf_list(&n_hdlc->rx_free_buf_list);

	n_hdlc_free_buf_list(&n_hdlc->tx_free_buf_list);

	n_hdlc_free_buf_list(&n_hdlc->rx_buf_list);

	n_hdlc_free_buf_list(&n_hdlc->tx_buf_list);

	kfree(n_hdlc);

	

}	/* end of n_hdlc_release() */



/**

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