[arch-commits] Commit in linux/trunk (1 file)
Jan Steffens
heftig at archlinux.org
Wed Mar 15 20:33:58 UTC 2017
Date: Wednesday, March 15, 2017 @ 20:33:57
Author: heftig
Revision: 290893
Remove unused patch
Deleted:
linux/trunk/0001-tty-n_hdlc-get-rid-of-racy-n_hdlc_tbuf.patch
---------------------------------------------------+
0001-tty-n_hdlc-get-rid-of-racy-n_hdlc_tbuf.patch | 311 --------------------
1 file changed, 311 deletions(-)
Deleted: 0001-tty-n_hdlc-get-rid-of-racy-n_hdlc_tbuf.patch
===================================================================
--- 0001-tty-n_hdlc-get-rid-of-racy-n_hdlc_tbuf.patch 2017-03-15 20:05:05 UTC (rev 290892)
+++ 0001-tty-n_hdlc-get-rid-of-racy-n_hdlc_tbuf.patch 2017-03-15 20:33:57 UTC (rev 290893)
@@ -1,311 +0,0 @@
->From 1dea7a8061ad9212f4464464a80d0dcd477eceab Mon Sep 17 00:00:00 2001
-From: Alexander Popov <alex.popov () linux com>
-Date: Tue, 28 Feb 2017 19:28:54 +0300
-Subject: [PATCH 1/1] tty: n_hdlc: get rid of racy n_hdlc.tbuf
-
-Currently N_HDLC line discipline uses a self-made singly linked list for
-data buffers and has n_hdlc.tbuf pointer for buffer retransmitting after
-an error.
-
-The commit be10eb7589337e5defbe214dae038a53dd21add8
-("tty: n_hdlc add buffer flushing") introduced racy access to n_hdlc.tbuf.
-After tx error concurrent flush_tx_queue() and n_hdlc_send_frames() can put
-one data buffer to tx_free_buf_list twice. That causes double free in
-n_hdlc_release().
-
-Let's use standard kernel linked list and get rid of n_hdlc.tbuf:
-in case of tx error put current data buffer after the head of tx_buf_list.
-
-Signed-off-by: Alexander Popov <alex.popov () linux com>
----
- drivers/tty/n_hdlc.c | 132 +++++++++++++++++++++++++++------------------------
- 1 file changed, 69 insertions(+), 63 deletions(-)
-
-diff --git a/drivers/tty/n_hdlc.c b/drivers/tty/n_hdlc.c
-index eb27883..728c824 100644
---- a/drivers/tty/n_hdlc.c
-+++ b/drivers/tty/n_hdlc.c
-@@ -114,7 +114,7 @@
- #define DEFAULT_TX_BUF_COUNT 3
-
- struct n_hdlc_buf {
-- struct n_hdlc_buf *link;
-+ struct list_head list_item;
- int count;
- char buf[1];
- };
-@@ -122,8 +122,7 @@ struct n_hdlc_buf {
- #define N_HDLC_BUF_SIZE (sizeof(struct n_hdlc_buf) + maxframe)
-
- struct n_hdlc_buf_list {
-- struct n_hdlc_buf *head;
-- struct n_hdlc_buf *tail;
-+ struct list_head list;
- int count;
- spinlock_t spinlock;
- };
-@@ -136,7 +135,6 @@ struct n_hdlc_buf_list {
- * @backup_tty - TTY to use if tty gets closed
- * @tbusy - reentrancy flag for tx wakeup code
- * @woke_up - FIXME: describe this field
-- * @tbuf - currently transmitting tx buffer
- * @tx_buf_list - list of pending transmit frame buffers
- * @rx_buf_list - list of received frame buffers
- * @tx_free_buf_list - list unused transmit frame buffers
-@@ -149,7 +147,6 @@ struct n_hdlc {
- struct tty_struct *backup_tty;
- int tbusy;
- int woke_up;
-- struct n_hdlc_buf *tbuf;
- struct n_hdlc_buf_list tx_buf_list;
- struct n_hdlc_buf_list rx_buf_list;
- struct n_hdlc_buf_list tx_free_buf_list;
-@@ -159,6 +156,8 @@ struct n_hdlc {
- /*
- * HDLC buffer list manipulation functions
- */
-+static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list,
-+ struct n_hdlc_buf *buf);
- static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
- struct n_hdlc_buf *buf);
- static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *list);
-@@ -208,16 +207,9 @@ static void flush_tx_queue(struct tty_struct *tty)
- {
- struct n_hdlc *n_hdlc = tty2n_hdlc(tty);
- struct n_hdlc_buf *buf;
-- unsigned long flags;
-
- while ((buf = n_hdlc_buf_get(&n_hdlc->tx_buf_list)))
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, buf);
-- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock, flags);
-- if (n_hdlc->tbuf) {
-- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, n_hdlc->tbuf);
-- n_hdlc->tbuf = NULL;
-- }
-- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
- }
-
- static struct tty_ldisc_ops n_hdlc_ldisc = {
-@@ -283,7 +275,6 @@ static void n_hdlc_release(struct n_hdlc *n_hdlc)
- } else
- break;
- }
-- kfree(n_hdlc->tbuf);
- kfree(n_hdlc);
-
- } /* end of n_hdlc_release() */
-@@ -402,13 +393,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
- n_hdlc->woke_up = 0;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock, flags);
-
-- /* get current transmit buffer or get new transmit */
-- /* buffer from list of pending transmit buffers */
--
-- tbuf = n_hdlc->tbuf;
-- if (!tbuf)
-- tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
--
-+ tbuf = n_hdlc_buf_get(&n_hdlc->tx_buf_list);
- while (tbuf) {
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)sending frame %p, count=%d\n",
-@@ -420,7 +405,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
-
- /* rollback was possible and has been done */
- if (actual == -ERESTARTSYS) {
-- n_hdlc->tbuf = tbuf;
-+ n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf);
- break;
- }
- /* if transmit error, throw frame away by */
-@@ -435,10 +420,7 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
-
- /* free current transmit buffer */
- n_hdlc_buf_put(&n_hdlc->tx_free_buf_list, tbuf);
--
-- /* this tx buffer is done */
-- n_hdlc->tbuf = NULL;
--
-+
- /* wait up sleeping writers */
- wake_up_interruptible(&tty->write_wait);
-
-@@ -448,10 +430,12 @@ static void n_hdlc_send_frames(struct n_hdlc *n_hdlc, struct tty_struct *tty)
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)frame %p pending\n",
- __FILE__,__LINE__,tbuf);
--
-- /* buffer not accepted by driver */
-- /* set this buffer as pending buffer */
-- n_hdlc->tbuf = tbuf;
-+
-+ /*
-+ * the buffer was not accepted by driver,
-+ * return it back into tx queue
-+ */
-+ n_hdlc_buf_return(&n_hdlc->tx_buf_list, tbuf);
- break;
- }
- }
-@@ -749,7 +733,8 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
- int error = 0;
- int count;
- unsigned long flags;
--
-+ struct n_hdlc_buf *buf = NULL;
-+
- if (debuglevel >= DEBUG_LEVEL_INFO)
- printk("%s(%d)n_hdlc_tty_ioctl() called %d\n",
- __FILE__,__LINE__,cmd);
-@@ -763,8 +748,10 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
- /* report count of read data available */
- /* in next available frame (if any) */
- spin_lock_irqsave(&n_hdlc->rx_buf_list.spinlock,flags);
-- if (n_hdlc->rx_buf_list.head)
-- count = n_hdlc->rx_buf_list.head->count;
-+ buf = list_first_entry_or_null(&n_hdlc->rx_buf_list.list,
-+ struct n_hdlc_buf, list_item);
-+ if (buf)
-+ count = buf->count;
- else
- count = 0;
- spin_unlock_irqrestore(&n_hdlc->rx_buf_list.spinlock,flags);
-@@ -776,8 +763,10 @@ static int n_hdlc_tty_ioctl(struct tty_struct *tty, struct file *file,
- count = tty_chars_in_buffer(tty);
- /* add size of next output frame in queue */
- spin_lock_irqsave(&n_hdlc->tx_buf_list.spinlock,flags);
-- if (n_hdlc->tx_buf_list.head)
-- count += n_hdlc->tx_buf_list.head->count;
-+ buf = list_first_entry_or_null(&n_hdlc->tx_buf_list.list,
-+ struct n_hdlc_buf, list_item);
-+ if (buf)
-+ count += buf->count;
- spin_unlock_irqrestore(&n_hdlc->tx_buf_list.spinlock,flags);
- error = put_user(count, (int __user *)arg);
- break;
-@@ -825,14 +814,14 @@ static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
- poll_wait(filp, &tty->write_wait, wait);
-
- /* set bits for operations that won't block */
-- if (n_hdlc->rx_buf_list.head)
-+ if (!list_empty(&n_hdlc->rx_buf_list.list))
- mask |= POLLIN | POLLRDNORM; /* readable */
- if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
- mask |= POLLHUP;
- if (tty_hung_up_p(filp))
- mask |= POLLHUP;
- if (!tty_is_writelocked(tty) &&
-- n_hdlc->tx_free_buf_list.head)
-+ !list_empty(&n_hdlc->tx_free_buf_list.list))
- mask |= POLLOUT | POLLWRNORM; /* writable */
- }
- return mask;
-@@ -856,7 +845,12 @@ static struct n_hdlc *n_hdlc_alloc(void)
- spin_lock_init(&n_hdlc->tx_free_buf_list.spinlock);
- spin_lock_init(&n_hdlc->rx_buf_list.spinlock);
- spin_lock_init(&n_hdlc->tx_buf_list.spinlock);
--
-+
-+ INIT_LIST_HEAD(&n_hdlc->rx_free_buf_list.list);
-+ INIT_LIST_HEAD(&n_hdlc->tx_free_buf_list.list);
-+ INIT_LIST_HEAD(&n_hdlc->rx_buf_list.list);
-+ INIT_LIST_HEAD(&n_hdlc->tx_buf_list.list);
-+
- /* allocate free rx buffer list */
- for(i=0;i<DEFAULT_RX_BUF_COUNT;i++) {
- buf = kmalloc(N_HDLC_BUF_SIZE, GFP_KERNEL);
-@@ -884,53 +878,65 @@ static struct n_hdlc *n_hdlc_alloc(void)
- } /* end of n_hdlc_alloc() */
-
- /**
-+ * n_hdlc_buf_return - put the HDLC buffer after the head of the specified list
-+ * @buf_list - pointer to the buffer list
-+ * @buf - pointer to the buffer
-+ */
-+static void n_hdlc_buf_return(struct n_hdlc_buf_list *buf_list,
-+ struct n_hdlc_buf *buf)
-+{
-+ unsigned long flags;
-+
-+ spin_lock_irqsave(&buf_list->spinlock, flags);
-+
-+ list_add(&buf->list_item, &buf_list->list);
-+ buf_list->count++;
-+
-+ spin_unlock_irqrestore(&buf_list->spinlock, flags);
-+}
-+
-+/**
- * n_hdlc_buf_put - add specified HDLC buffer to tail of specified list
-- * @list - pointer to buffer list
-+ * @buf_list - pointer to buffer list
- * @buf - pointer to buffer
- */
--static void n_hdlc_buf_put(struct n_hdlc_buf_list *list,
-+static void n_hdlc_buf_put(struct n_hdlc_buf_list *buf_list,
- struct n_hdlc_buf *buf)
- {
- unsigned long flags;
-- spin_lock_irqsave(&list->spinlock,flags);
--
-- buf->link=NULL;
-- if (list->tail)
-- list->tail->link = buf;
-- else
-- list->head = buf;
-- list->tail = buf;
-- (list->count)++;
--
-- spin_unlock_irqrestore(&list->spinlock,flags);
--
-+
-+ spin_lock_irqsave(&buf_list->spinlock, flags);
-+
-+ list_add_tail(&buf->list_item, &buf_list->list);
-+ buf_list->count++;
-+
-+ spin_unlock_irqrestore(&buf_list->spinlock, flags);
- } /* end of n_hdlc_buf_put() */
-
- /**
- * n_hdlc_buf_get - remove and return an HDLC buffer from list
-- * @list - pointer to HDLC buffer list
-+ * @buf_list - pointer to HDLC buffer list
- *
- * Remove and return an HDLC buffer from the head of the specified HDLC buffer
- * list.
- * Returns a pointer to HDLC buffer if available, otherwise %NULL.
- */
--static struct n_hdlc_buf* n_hdlc_buf_get(struct n_hdlc_buf_list *list)
-+static struct n_hdlc_buf *n_hdlc_buf_get(struct n_hdlc_buf_list *buf_list)
- {
- unsigned long flags;
- struct n_hdlc_buf *buf;
-- spin_lock_irqsave(&list->spinlock,flags);
--
-- buf = list->head;
-+
-+ spin_lock_irqsave(&buf_list->spinlock, flags);
-+
-+ buf = list_first_entry_or_null(&buf_list->list,
-+ struct n_hdlc_buf, list_item);
- if (buf) {
-- list->head = buf->link;
-- (list->count)--;
-+ list_del(&buf->list_item);
-+ buf_list->count--;
- }
-- if (!list->head)
-- list->tail = NULL;
--
-- spin_unlock_irqrestore(&list->spinlock,flags);
-+
-+ spin_unlock_irqrestore(&buf_list->spinlock, flags);
- return buf;
--
- } /* end of n_hdlc_buf_get() */
-
- static char hdlc_banner[] __initdata =
---
-2.7.4
-
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