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| author | Dima Zavin <dima@android.com> | 2011-12-30 15:16:44 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2011-12-30 15:26:34 -0800 |
| commit | 566cf5b6e34504aaccb76167ecccd7e7e69e6456 (patch) | |
| tree | 41b3c2b291b96218d92c8a8d321b7400b0a01006 /drivers/input | |
| parent | 36a281e25276f2d138bbbca4170d11453323cce1 (diff) | |
| download | blackbird-op-linux-566cf5b6e34504aaccb76167ecccd7e7e69e6456.tar.gz blackbird-op-linux-566cf5b6e34504aaccb76167ecccd7e7e69e6456.zip | |
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.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 4cf25347b015..03344b3c7c15 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; |
