On 11/7/18 4:14 AM, Michael Ellerman wrote:

frowand.list@gmail.com writes:

quoted

From: Frank Rowand <redacted>

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 <redacted>

This seems sensible to me. I guess we could argue about whether the
sysfs code needs its own reference, but it certainly doesn't hurt that
it does, as long as it's handled symmetrically - which it is now.

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

quoted

---

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.

I think this should go in the changelog, it's useful information that we
don't want to lose track of once this is applied.

Will do.

-Frank

Either that or we actually squash the two patches together when applying
to avoid the bisection break.

cheers

quoted

 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>