[PATCH 2/4] serial: kgdb_nmi: Use container_of() to locate private data

From: Daniel Thompson
Date: Wed May 14 2014 - 10:56:53 EST


This corrects a crash in kgdb_nmi_tty_shutdown() which occurs when
the function is called with port->tty set to NULL.

All conversions between struct tty_port and struct kgdb_nmi_tty_priv
have been switched to direct calls to container_of() to improve code
clarity and consistancy.

Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
---
drivers/tty/serial/kgdb_nmi.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
index 5f673b7..d51b2a1 100644
--- a/drivers/tty/serial/kgdb_nmi.c
+++ b/drivers/tty/serial/kgdb_nmi.c
@@ -84,11 +84,6 @@ struct kgdb_nmi_tty_priv {
STRUCT_KFIFO(char, KGDB_NMI_FIFO_SIZE) fifo;
};

-static struct kgdb_nmi_tty_priv *kgdb_nmi_port_to_priv(struct tty_port *port)
-{
- return container_of(port, struct kgdb_nmi_tty_priv, port);
-}
-
/*
* Our debugging console is polled in a tasklet, so we'll check for input
* every tick. In HZ-less mode, we should program the next tick. We have
@@ -118,7 +113,7 @@ static void kgdb_tty_recv(int ch)
* do that, and actually, we can't: we're in NMI context, no locks are
* possible.
*/
- priv = kgdb_nmi_port_to_priv(kgdb_nmi_port);
+ priv = container_of(kgdb_nmi_port, struct kgdb_nmi_tty_priv, port);
kfifo_in(&priv->fifo, &c, 1);
kgdb_tty_poke();
}
@@ -216,7 +211,8 @@ static void kgdb_nmi_tty_receiver(unsigned long data)

static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)
{
- struct kgdb_nmi_tty_priv *priv = tty->driver_data;
+ struct kgdb_nmi_tty_priv *priv =
+ container_of(port, struct kgdb_nmi_tty_priv, port);

kgdb_nmi_port = port;
tasklet_schedule(&priv->tlet);
@@ -225,7 +221,8 @@ static int kgdb_nmi_tty_activate(struct tty_port *port, struct tty_struct *tty)

static void kgdb_nmi_tty_shutdown(struct tty_port *port)
{
- struct kgdb_nmi_tty_priv *priv = port->tty->driver_data;
+ struct kgdb_nmi_tty_priv *priv =
+ container_of(port, struct kgdb_nmi_tty_priv, port);

tasklet_kill(&priv->tlet);
kgdb_nmi_port = NULL;
--
1.9.0

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