On Fri, Aug 15, 2014 at 11:52 AM, Grant Likely [off-list ref] wrote:

On Fri, Aug 15, 2014 at 11:45 AM, Grant Likely [off-list ref] wrote:

quoted

On Tue, 12 Aug 2014 18:46:36 -0700, Stephen Boyd [off-list ref] wrote:

quoted

On 08/12/14 17:57, Stepan Moskovchenko wrote:

quoted

diff --git a/drivers/of/device.c b/drivers/of/device.c
index f685e55..3e116f6 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c

@@ -54,7 +54,7 @@ int of_device_add(struct platform_device *ofdev)

    /* name and id have to be set so that the platform bus doesn't get
     * confused on matching */
-   ofdev->name = dev_name(&ofdev->dev);
+   ofdev->name = kstrdup(dev_name(&ofdev->dev), GFP_KERNEL);
    ofdev->id = -1;

    /* device_add will assume that this device is on the same node as

@@ -76,6 +76,7 @@ EXPORT_SYMBOL(of_device_register);
 void of_device_unregister(struct platform_device *ofdev)
 {
    device_unregister(&ofdev->dev);
+   kfree(ofdev->name);

This probably ought to be swapped because we don't know if ofdev isn't
pointing to freed memory after device_unregister().

Actually, the only safe place to free the memory is inside the
platform_device release function. platform_device_release() in
drivers/base/platform.c. Unfortunately there isn't a good way from that
function to figure out if the name has been allocated the 'OF' way.

It is not safe to free it here because there could still be references
to the platform_device after device_unregister exits.

We could fix the problem by making platform_device_alloc() also do a
kstrdup() when assigning the name. Then the release function can
unconditionally free the name field. Care to try that out?

I don't know how well received that will be though. The vast majority
of non-OF callers of platform_device_alloc() pass in a static string
that will never disappear.

Another possible solutions: Override the release function for platform
devices allocated by of_device_alloc() to free the name field.

g.
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