put_user() may fail, if so return -EFAULT and do not update driver
pointers.
Signed-off-by: Kulikov Vasiliy <segooon@xxxxxxxxx>
---
drivers/staging/panel/panel.c | 17 +++++++++++------
1 files changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/panel/panel.c b/drivers/staging/panel/panel.c
index f58da32..57f4946 100644
--- a/drivers/staging/panel/panel.c
+++ b/drivers/staging/panel/panel.c
@@ -1589,25 +1589,30 @@ void lcd_init(void)
static ssize_t keypad_read(struct file *file,
char *buf, size_t count, loff_t *ppos)
{
-
+ int buflen = keypad_buflen;
unsigned i = *ppos;
char *tmp = buf;
+ int start = keypad_start;
- if (keypad_buflen == 0) {
+ if (buflen == 0) {
if (file->f_flags & O_NONBLOCK)
return -EAGAIN;
interruptible_sleep_on(&keypad_read_wait);
if (signal_pending(current))
return -EINTR;
+ buflen = keypad_buflen;
}
- for (; count-- > 0 && (keypad_buflen > 0);
- ++i, ++tmp, --keypad_buflen) {
- put_user(keypad_buffer[keypad_start], tmp);
- keypad_start = (keypad_start + 1) % KEYPAD_BUFFER;
+ for (; count-- > 0 && (buflen > 0);
+ ++i, ++tmp, --buflen) {
+ if (put_user(keypad_buffer[start], tmp))
+ return -EFAULT;
+ start = (start + 1) % KEYPAD_BUFFER;
}
*ppos = i;
+ keypad_buflen = buflen;
+ keypad_start = start;
return tmp - buf;
}
--
1.7.0.4
--
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