Currently, when EVIOCG[type] ioctl call is issued and bits_to_user fails,
then SYN_DROPPED event is inserted in the event queue always.
However, it is not compulsory that some events are flushed out on every
EVIOCG[type] ioctl call like in case of empty event queue and in case when
EVIOCG[type] ioctl is issued for say A type of events but event queue does
not have any A type of events but some other type of events.
Therefore, insert SYN_DROPPED event only when some events have been flushed
out from event queue plus bits_to_user fails.
Signed-off-by: Aniroop Mathur <a.mathur@xxxxxxxxxxx>
---
drivers/input/evdev.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index e9ae3d5..f8b295e 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -108,9 +108,11 @@ static bool __evdev_is_filtered(struct evdev_client *client,
}
/* flush queued events of type @type, caller must hold client->buffer_lock */
-static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
+static unsigned int __evdev_flush_queue(struct evdev_client *client,
+ unsigned int type)
{
unsigned int i, head, num;
+ unsigned int drop_count = 0;
unsigned int mask = client->bufsize - 1;
bool is_report;
struct input_event *ev;
@@ -129,9 +131,11 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
if (ev->type == type) {
/* drop matched entry */
+ drop_count++;
continue;
} else if (is_report && !num) {
/* drop empty SYN_REPORT groups */
+ drop_count++;
continue;
} else if (head != i) {
/* move entry to fill the gap */
@@ -151,6 +155,7 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
}
client->head = head;
+ return drop_count;
}
static void __evdev_queue_syn_dropped(struct evdev_client *client)
@@ -920,6 +925,7 @@ static int evdev_handle_get_val(struct evdev_client *client,
int ret;
unsigned long *mem;
size_t len;
+ unsigned int drop_count = 0;
len = BITS_TO_LONGS(maxbit) * sizeof(unsigned long);
mem = kmalloc(len, GFP_KERNEL);
@@ -933,12 +939,12 @@ static int evdev_handle_get_val(struct evdev_client *client,
spin_unlock(&dev->event_lock);
- __evdev_flush_queue(client, type);
+ drop_count = __evdev_flush_queue(client, type);
spin_unlock_irq(&client->buffer_lock);
ret = bits_to_user(mem, maxbit, maxlen, p, compat);
- if (ret < 0)
+ if (ret < 0 && drop_count > 0)
evdev_queue_syn_dropped(client);
kfree(mem);
--
2.6.2
--
To unsubscribe from this list: send the line "unsubscribe linux-input" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
