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-rw-r--r--drivers/tty/tty_buffer.c16
-rw-r--r--include/linux/tty.h1
2 files changed, 15 insertions, 2 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 8ebd9f88a6f6..f1d30f6945af 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -255,11 +255,16 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size,
if (change || left < size) {
/* This is the slow path - looking for new buffers to use */
if ((n = tty_buffer_alloc(port, size)) != NULL) {
+ unsigned long iflags;
+
n->flags = flags;
buf->tail = n;
+
+ spin_lock_irqsave(&buf->flush_lock, iflags);
b->commit = b->used;
- smp_mb();
b->next = n;
+ spin_unlock_irqrestore(&buf->flush_lock, iflags);
+
} else if (change)
size = 0;
else
@@ -443,6 +448,7 @@ static void flush_to_ldisc(struct work_struct *work)
mutex_lock(&buf->lock);
while (1) {
+ unsigned long flags;
struct tty_buffer *head = buf->head;
int count;
@@ -450,14 +456,19 @@ static void flush_to_ldisc(struct work_struct *work)
if (atomic_read(&buf->priority))
break;
+ spin_lock_irqsave(&buf->flush_lock, flags);
count = head->commit - head->read;
if (!count) {
- if (head->next == NULL)
+ if (head->next == NULL) {
+ spin_unlock_irqrestore(&buf->flush_lock, flags);
break;
+ }
buf->head = head->next;
+ spin_unlock_irqrestore(&buf->flush_lock, flags);
tty_buffer_free(port, head);
continue;
}
+ spin_unlock_irqrestore(&buf->flush_lock, flags);
count = receive_buf(tty, head, count);
if (!count)
@@ -512,6 +523,7 @@ void tty_buffer_init(struct tty_port *port)
struct tty_bufhead *buf = &port->buf;
mutex_init(&buf->lock);
+ spin_lock_init(&buf->flush_lock);
tty_buffer_reset(&buf->sentinel, 0);
buf->head = &buf->sentinel;
buf->tail = &buf->sentinel;
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 1c3316a47d7e..036cccd80d9f 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -61,6 +61,7 @@ struct tty_bufhead {
struct tty_buffer *head; /* Queue head */
struct work_struct work;
struct mutex lock;
+ spinlock_t flush_lock;
atomic_t priority;
struct tty_buffer sentinel;
struct llist_head free; /* Free queue head */