From: Ilya Dryomov <idryomov@gmail.com>
Date: Tue, 26 Jul 2016 13:22:35 +0000 (+0200)
Subject: libceph: add an ONSTACK initializer for oids
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=281dbe5db81c6137def9757e07a7aea14b1ed86e;p=linux-beck.git

libceph: add an ONSTACK initializer for oids

An on-stack oid in ceph_ioctl_get_dataloc() is not initialized,
resulting in a WARN and a NULL pointer dereference later on.  We will
have more of these on-stack in the future, so fix it with a convenience
macro.

Fixes: d30291b985d1 ("libceph: variable-sized ceph_object_id")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
---

diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index be6b1657b1af..0946f2d4a81f 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -183,7 +183,7 @@ static long ceph_ioctl_get_dataloc(struct file *file, void __user *arg)
 	struct ceph_osd_client *osdc =
 		&ceph_sb_to_client(inode->i_sb)->client->osdc;
 	struct ceph_object_locator oloc;
-	struct ceph_object_id oid;
+	CEPH_DEFINE_OID_ONSTACK(oid);
 	u64 len = 1, olen;
 	u64 tmp;
 	struct ceph_pg pgid;
diff --git a/include/linux/ceph/osdmap.h b/include/linux/ceph/osdmap.h
index 9ccf4dbe55f8..21d7f048959f 100644
--- a/include/linux/ceph/osdmap.h
+++ b/include/linux/ceph/osdmap.h
@@ -115,6 +115,11 @@ static inline void ceph_oid_init(struct ceph_object_id *oid)
 	oid->name_len = 0;
 }
 
+#define CEPH_OID_INIT_ONSTACK(oid)					\
+    ({ ceph_oid_init(&oid); oid; })
+#define CEPH_DEFINE_OID_ONSTACK(oid)					\
+	struct ceph_object_id oid = CEPH_OID_INIT_ONSTACK(oid)
+
 static inline bool ceph_oid_empty(const struct ceph_object_id *oid)
 {
 	return oid->name == oid->inline_name && !oid->name_len;