[PATCH 3/3] input: evdev: do not block waiting for an event if fd is nonblock
flat view
STALE5413d
From: Dima Zavin <hidden>
Date: 2011-12-16 18:07:28
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
If there is a full packet in the buffer, and we overflow that buffer right after checking for that condition, it would have been possible for us to block indefinitely (rather, until the next full packet) even if the file was marked as O_NONBLOCK. Cc: Jeff Brown <redacted> Signed-off-by: Dima Zavin <redacted> --- drivers/input/evdev.c | 14 ++++++-------- 1 files changed, 6 insertions(+), 8 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 2e563af..2fb77e1 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c@@ -391,14 +391,12 @@ static ssize_t evdev_read(struct file *file, char __user *buffer, if (count < input_event_size()) return -EINVAL; - if (client->packet_head == client->tail && evdev->exist && - (file->f_flags & O_NONBLOCK)) - return -EAGAIN; - - retval = wait_event_interruptible(evdev->wait, - client->packet_head != client->tail || !evdev->exist); - if (retval) - return retval; + if (!(file->f_flags & O_NONBLOCK)) { + retval = wait_event_interruptible(evdev->wait, + client->packet_head != client->tail || !evdev->exist); + if (retval) + return retval; + } if (!evdev->exist) return -ENODEV;
--
1.7.3.1