[PATCH 3/6] Input: uinput - return number of bytes copied on partial reads
STALE5298d
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2012-03-31 06:06:31
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
If uinput_read() fails after copying several events to userspace we need to return number of bytes successfully copied, not -EFAULT. Signed-off-by: Dmitry Torokhov <redacted> --- drivers/input/misc/uinput.c | 13 +++++++------ 1 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 5339c1d..a33a7b3 100644
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c@@ -455,7 +455,8 @@ static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos) { struct uinput_device *udev = file->private_data; - int retval = 0; + size_t read = 0; + int retval; if (count < input_event_size()) return -EINVAL;
@@ -478,23 +479,23 @@ static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, } while (udev->head != udev->tail && - retval + input_event_size() <= count) { - if (input_event_to_user(buffer + retval, + read + input_event_size() <= count) { + if (input_event_to_user(buffer + read, &udev->buff[udev->tail])) { retval = -EFAULT; goto out; } udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE; - retval += input_event_size(); + read += input_event_size(); } - if (retval == 0 && (file->f_flags & O_NONBLOCK)) + if (read == 0 && (file->f_flags & O_NONBLOCK)) retval = -EAGAIN; out: mutex_unlock(&udev->mutex); - return retval; + return read ?: retval; } static unsigned int uinput_poll(struct file *file, poll_table *wait)
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1.7.7.6