Thread (63 messages) 63 messages, 12 authors, 2017-03-21
STALE3343d

[PATCH 20/29] drivers, s390: convert qeth_reply.refcnt from atomic_t to refcount_t

From: Elena Reshetova <elena.reshetova@intel.com>
Date: 2017-03-06 14:38:46
Also in: linux-bcache, linux-media, linux-pci, linux-raid, linux-s390, linux-scsi, linux-serial, lkml, xen-devel
Subsystem: networking drivers, s390 architecture, s390 network drivers, the rest · Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Heiko Carstens, Vasily Gorbik, Alexander Gordeev, Alexandra Winter, Aswin Karuvally, 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/s390/net/qeth_core.h      | 3 ++-
 drivers/s390/net/qeth_core_main.c | 8 +++-----
 2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index e7addea..e2c81d21 100644
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -20,6 +20,7 @@
 #include <linux/ethtool.h>
 #include <linux/hashtable.h>
 #include <linux/ip.h>
+#include <linux/refcount.h>
 
 #include <net/ipv6.h>
 #include <net/if_inet6.h>
@@ -641,7 +642,7 @@ struct qeth_reply {
 	int rc;
 	void *param;
 	struct qeth_card *card;
-	atomic_t refcnt;
+	refcount_t refcnt;
 };
 
 
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 315d8a2..a2bf13f 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -555,7 +555,7 @@ static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card)
 
 	reply = kzalloc(sizeof(struct qeth_reply), GFP_ATOMIC);
 	if (reply) {
-		atomic_set(&reply->refcnt, 1);
+		refcount_set(&reply->refcnt, 1);
 		atomic_set(&reply->received, 0);
 		reply->card = card;
 	}
@@ -564,14 +564,12 @@ static struct qeth_reply *qeth_alloc_reply(struct qeth_card *card)
 
 static void qeth_get_reply(struct qeth_reply *reply)
 {
-	WARN_ON(atomic_read(&reply->refcnt) <= 0);
-	atomic_inc(&reply->refcnt);
+	refcount_inc(&reply->refcnt);
 }
 
 static void qeth_put_reply(struct qeth_reply *reply)
 {
-	WARN_ON(atomic_read(&reply->refcnt) <= 0);
-	if (atomic_dec_and_test(&reply->refcnt))
+	if (refcount_dec_and_test(&reply->refcnt))
 		kfree(reply);
 }
 
-- 
2.7.4


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help