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Input: serio_raw - perform proper locking when adding clients to list

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Make sure we hold serio lock when adding clients to client list so that
we do not race with serio_raw_release() removing clients from the same
list.

Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov
2011-10-10 18:30:26 -07:00
parent 7c5bbb2eb7
commit 843e784afe
1 changed files with 5 additions and 3 deletions
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8
drivers/input/serio/serio_raw.c
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@@ -106,7 +106,10 @@ static int serio_raw_open(struct inode *inode, struct file *file)
file->private_data = client; file->private_data = client;
kref_get(&serio_raw->kref); kref_get(&serio_raw->kref);
serio_pause_rx(serio_raw->serio);
list_add_tail(&client->node, &serio_raw->client_list); list_add_tail(&client->node, &serio_raw->client_list);
serio_continue_rx(serio_raw->serio);
out: out:
mutex_unlock(&serio_raw_mutex); mutex_unlock(&serio_raw_mutex);
@@ -138,10 +141,9 @@ static int serio_raw_release(struct inode *inode, struct file *file)
static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c) static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
{ {
unsigned long flags;
int empty; int empty;
spin_lock_irqsave(&serio_raw->serio->lock, flags); serio_pause_rx(serio_raw->serio);
empty = serio_raw->head == serio_raw->tail; empty = serio_raw->head == serio_raw->tail;
if (!empty) { if (!empty) {
@@ -149,7 +151,7 @@ static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN; serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN;
} }
spin_unlock_irqrestore(&serio_raw->serio->lock, flags); serio_continue_rx(serio_raw->serio);
return !empty; return !empty;
} }