On Thu, Apr 22, 2021 at 2:12 AM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > The intent here was to return negative error codes but it actually > returns positive values. The problem is that type promotion with > ternary operations is quite complicated. > > "ret" is an int. "copied" is a u32. And the snoop_file_read() function > returns long. What happens is that "ret" is cast to u32 and becomes > positive then it's cast to long and it's still positive. > > Fix this by removing the ternary so that "ret" is type promoted directly > to long. > > Fixes: 3772e5da4454 ("drivers/misc: Aspeed LPC snoop output using misc chardev") > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Reviewed-by: Patrick Venture <venture@xxxxxxxxxx> > --- > drivers/soc/aspeed/aspeed-lpc-snoop.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c > index 210455efb321..eceeaf8dfbeb 100644 > --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c > +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c > @@ -94,8 +94,10 @@ static ssize_t snoop_file_read(struct file *file, char __user *buffer, > return -EINTR; > } > ret = kfifo_to_user(&chan->fifo, buffer, count, &copied); > + if (ret) > + return ret; > > - return ret ? ret : copied; > + return copied; > } > > static __poll_t snoop_file_poll(struct file *file, > -- > 2.30.2 >