[PATCH v6 03/18] of: overlay: add missing of_node_get() in __of_attach_node_sysfs

From: frowand.list@gmail.com
To: Rob Herring <robh+dt@kernel.org>,
	Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>, Alan Tull <atull@kernel.org>,
	Moritz Fischer <mdf@kernel.org>
Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	devicetree@vger.kernel.org, linux-fpga@vger.kernel.org
Subject: [PATCH v6 03/18] of: overlay: add missing of_node_get() in __of_attach_node_sysfs
Date: Mon,  5 Nov 2018 07:25:00 -0800	[thread overview]
Message-ID: <1541431515-25197-4-git-send-email-frowand.list@gmail.com> (raw)
In-Reply-To: <1541431515-25197-1-git-send-email-frowand.list@gmail.com>

From: Frank Rowand <frank.rowand@sony.com>

There is a matching of_node_put() in __of_detach_node_sysfs()

Remove misleading comment from function header comment for
of_detach_node().

This patch may result in memory leaks from code that directly calls
the dynamic node add and delete functions directly instead of
using changesets.

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
---

This patch should result in powerpc systems that dynamically
allocate a node, then later deallocate the node to have a
memory leak when the node is deallocated.

The next patch in the series will fix the leak.

 drivers/of/dynamic.c | 3 ---
 drivers/of/kobj.c    | 4 +++-
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 12c3f9a15e94..146681540487 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -272,9 +272,6 @@ void __of_detach_node(struct device_node *np)
 
 /**
  * of_detach_node() - "Unplug" a node from the device tree.
- *
- * The caller must hold a reference to the node.  The memory associated with
- * the node is not freed until its refcount goes to zero.
  */
 int of_detach_node(struct device_node *np)
 {
diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c
index 7a0a18980b98..c72eef988041 100644
--- a/drivers/of/kobj.c
+++ b/drivers/of/kobj.c
@@ -133,6 +133,9 @@ int __of_attach_node_sysfs(struct device_node *np)
 	}
 	if (!name)
 		return -ENOMEM;
+
+	of_node_get(np);
+
 	rc = kobject_add(&np->kobj, parent, "%s", name);
 	kfree(name);
 	if (rc)
@@ -159,6 +162,5 @@ void __of_detach_node_sysfs(struct device_node *np)
 		kobject_del(&np->kobj);
 	}
 
-	/* finally remove the kobj_init ref */
 	of_node_put(np);
 }
-- 
Frank Rowand <frank.rowand@sony.com>

