From b342dd512f7af0e0e14e29c3e1f863150cfc46ff Mon Sep 17 00:00:00 2001 From: Chen Gang Date: Thu, 27 Dec 2012 15:51:31 +0800 Subject: [PATCH] drivers/tty/serial: extern function which for release resource, need check pointer, before free it for extern function uart_remove_one_port: need check pointer whether be NULL, before the main work. just like what the other extern function uart_add_one_port has done. uart_add_one_port and uart_remove_one_port are pair information: for the callers (such as drivers/tty/serial/jsm: jsm_tty.c, jsm_driver.c) they realy assume that: they still can call uart_remove_one_port, after uart_add_one_port failed we (as an extern function), have to understand it (just like kfree). Signed-off-by: Chen Gang Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index b5c4e64f2990..ca98a3f65fe1 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2643,6 +2643,7 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state = drv->state + uport->line; struct tty_port *port = &state->port; + int ret = 0; BUG_ON(in_interrupt()); @@ -2657,6 +2658,11 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) * succeeding while we shut down the port. */ mutex_lock(&port->mutex); + if (!state->uart_port) { + mutex_unlock(&port->mutex); + ret = -EINVAL; + goto out; + } uport->flags |= UPF_DEAD; mutex_unlock(&port->mutex); @@ -2680,9 +2686,10 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) uport->type = PORT_UNKNOWN; state->uart_port = NULL; +out: mutex_unlock(&port_mutex); - return 0; + return ret; } /* -- 2.39.2