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authorDima Zavin <dima@android.com>2011-12-30 15:16:44 -0800
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2011-12-30 15:26:34 -0800
commit566cf5b6e34504aaccb76167ecccd7e7e69e6456 (patch)
tree41b3c2b291b96218d92c8a8d321b7400b0a01006 /drivers/input
parent36a281e25276f2d138bbbca4170d11453323cce1 (diff)
Input: evdev - only allow reading events if a full packet is present
Without this, it was possible for the reader to get ahead of packet_head. If the input device generated a partial packet *right* after the reader got ahead, then we can get into a situation where the device is marked readable, but read always returns 0 until the next packet is finished (i.e a SYN is generated by the input driver). This situation can also happen if we overflow the buffer while a reader is trying to read an event out. Signed-off-by: Dima Zavin <dima@android.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input')
-rw-r--r--drivers/input/evdev.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 4cf25347b01..03344b3c7c1 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -369,7 +369,7 @@ static int evdev_fetch_next_event(struct evdev_client *client,
spin_lock_irq(&client->buffer_lock);
- have_event = client->head != client->tail;
+ have_event = client->packet_head != client->tail;
if (have_event) {
*event = client->buffer[client->tail++];
client->tail &= client->bufsize - 1;