Messages in this thread | | | Date | Wed, 15 May 2013 17:03:17 +0200 | From | Jiri Slaby <> | Subject | Re: [PATCH] tty: Add missing lock in n_tty_write() |
| |
On 05/15/2013 12:56 PM, Joerg Roedel wrote: > The call of the tty->ops->write callback is protected by > output_lock in all other places I looked at. So it seems the > lock in this code-branch is missing, so take the output_lock > there too. > > Cc: stable@vger.kernel.org > Signed-off-by: Joerg Roedel <joro@8bytes.org> > --- > drivers/tty/n_tty.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c > index d655416..ffb94a4 100644 > --- a/drivers/tty/n_tty.c > +++ b/drivers/tty/n_tty.c > @@ -2058,10 +2058,14 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, > if (tty->ops->flush_chars) > tty->ops->flush_chars(tty); > } else { > + struct n_tty_data *l = tty->disc_data; > + > + mutex_lock(&l->output_lock); > while (nr > 0) { > c = tty->ops->write(tty, b, nr); > if (c < 0) { > retval = c; > + mutex_unlock(&l->output_lock); > goto break_out; > } > if (!c) > @@ -2069,6 +2073,7 @@ static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, > b += c; > nr -= c; > } > + mutex_unlock(&l->output_lock); > } > if (!nr) > break; >
Are you fixing any bug here? output_lock does not protect tty->ops->write on the other places, not tty->ops->write.
thanks, -- js suse labs
| |