n_tty: Fix calculation of size in canon_copy_from_read_buf

There was a hardcoded value of 4096 which should have been N_TTY_BUF_SIZE.
This caused reads from tty to fail with EFAULT when they shouldn't have
done if N_TTY_BUF_SIZE was declared to be something other than 4096.

Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mark Tomlinson 2015-05-18 12:01:48 +12:00 committed by Greg Kroah-Hartman
parent 392bceedb1
commit da555db6b0

View file

@ -2070,8 +2070,8 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
size = N_TTY_BUF_SIZE - tail;
n = eol - tail;
if (n > 4096)
n += 4096;
if (n > N_TTY_BUF_SIZE)
n += N_TTY_BUF_SIZE;
n += found;
c = n;