Messages in this thread | | | Date | Tue, 16 Aug 2022 10:21:30 +0300 (EEST) | From | Ilpo Järvinen <> | Subject | Re: [PATCH] tty: Fix lookahead_buf crash with serdev |
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On Tue, 16 Aug 2022, Vincent Whitchurch wrote:
> Do not follow a NULL pointer if the tty_port_client_operations does not > implement the ->lookahead_buf() callback, which is the case with > serdev's ttyport. > > Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely") > Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> > --- > drivers/tty/tty_buffer.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c > index 9fdecc795b6b..a1c97d4a45fb 100644 > --- a/drivers/tty/tty_buffer.c > +++ b/drivers/tty/tty_buffer.c > @@ -493,7 +493,8 @@ static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head) > if (~head->flags & TTYB_NORMAL) > f = flag_buf_ptr(head, head->lookahead); > > - port->client_ops->lookahead_buf(port, p, f, count); > + if (port->client_ops->lookahead_buf) > + port->client_ops->lookahead_buf(port, p, f, count);
While this works, I'd put the preceeding calculations of p and f into the same block as they just prep parameters for the call.
> head->lookahead += count; > } > } >
-- i.
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