[PATCH 08/16] drivers, net, hamradio: convert sixpack.refcnt from atomic_t to refcount_t
From: elena.reshetova@intel.com (Elena Reshetova)
Date: 2017-03-28 08:58:32
Also in:
linux-hams, linux-rdma, linux-wireless, lkml, netdev
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <redacted> Signed-off-by: Kees Cook <redacted> Signed-off-by: David Windsor <redacted> --- drivers/net/hamradio/6pack.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 922bf44..ea6c975 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c@@ -35,7 +35,7 @@ #include <linux/tcp.h> #include <linux/semaphore.h> #include <linux/compat.h> -#include <linux/atomic.h> +#include <linux/refcount.h> #define SIXPACK_VERSION "Revision: 0.3.0"
@@ -120,7 +120,7 @@ struct sixpack { struct timer_list tx_t; struct timer_list resync_t; - atomic_t refcnt; + refcount_t refcnt; struct semaphore dead_sem; spinlock_t lock; };
@@ -381,7 +381,7 @@ static struct sixpack *sp_get(struct tty_struct *tty) read_lock(&disc_data_lock); sp = tty->disc_data; if (sp) - atomic_inc(&sp->refcnt); + refcount_inc(&sp->refcnt); read_unlock(&disc_data_lock); return sp;
@@ -389,7 +389,7 @@ static struct sixpack *sp_get(struct tty_struct *tty) static void sp_put(struct sixpack *sp) { - if (atomic_dec_and_test(&sp->refcnt)) + if (refcount_dec_and_test(&sp->refcnt)) up(&sp->dead_sem); }
@@ -580,7 +580,7 @@ static int sixpack_open(struct tty_struct *tty) sp->dev = dev; spin_lock_init(&sp->lock); - atomic_set(&sp->refcnt, 1); + refcount_set(&sp->refcnt, 1); sema_init(&sp->dead_sem, 0); /* !!! length of the buffers. MTU is IP MTU, not PACLEN! */
@@ -676,7 +676,7 @@ static void sixpack_close(struct tty_struct *tty) * We have now ensured that nobody can start using ap from now on, but * we have to wait for all existing users to finish. */ - if (!atomic_dec_and_test(&sp->refcnt)) + if (!refcount_dec_and_test(&sp->refcnt)) down(&sp->dead_sem); /* We must stop the queue to avoid potentially scribbling
--
2.7.4