forked from Minki/linux
TTY/Serial fixes for 4.11-rc2
Here are 2 bugfixes for tty stuff for 4.11-rc2. One of them resolves the pretty bad bug in the n_hdlc code that Alexander Popov found and fixed and has been reported everywhere. The other just fixes a samsung serial driver issue when DMA fails on some systems. Both have been in linux-next with no reported issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCWMOjpg8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ykWqQCdGhbRifnxpafp5N7+aHpDHhptCnoAoK6S6gDY hn2PYO9gz8oUxXmjwdqo =hsvZ -----END PGP SIGNATURE----- Merge tag 'tty-4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes frpm Greg KH: "Here are two bugfixes for tty stuff for 4.11-rc2. One of them resolves the pretty bad bug in the n_hdlc code that Alexander Popov found and fixed and has been reported everywhere. The other just fixes a samsung serial driver issue when DMA fails on some systems. Both have been in linux-next with no reported issues" * tag 'tty-4.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: samsung: Continue to work if DMA request fails tty: n_hdlc: get rid of racy n_hdlc.tbuf
This commit is contained in:
Linus Torvalds
commit
434fd6353b
@ -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);
|
||||
@ -883,54 +877,66 @@ 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 =
|
||||
|
||||
@ -1031,8 +1031,10 @@ static int s3c64xx_serial_startup(struct uart_port *port)
|
||||
if (ourport->dma) {
|
||||
ret = s3c24xx_serial_request_dma(ourport);
|
||||
if (ret < 0) {
|
||||
dev_warn(port->dev, "DMA request failed\n");
|
||||
return ret;
|
||||
dev_warn(port->dev,
|
||||
"DMA request failed, DMA will not be used\n");
|
||||
devm_kfree(port->dev, ourport->dma);
|
||||
ourport->dma = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user