Patchwork [2/2] drivers/net/phy/mdio-bitbang.c: Call mdiobus_unregister before mdiobus_free

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Submitter Peter Senna Tschudin
Date Oct. 28, 2012, 4:12 p.m.
Message ID <1351440721-9121-2-git-send-email-peter.senna@gmail.com>
Download mbox | patch
Permalink /patch/194716/
State Accepted
Delegated to: David Miller
Headers show

Comments

Peter Senna Tschudin - Oct. 28, 2012, 4:12 p.m.
Based on commit b27393aecf66199f5ddad37c302d3e0cfadbe6c0

Calling mdiobus_free without calling mdiobus_unregister causes
BUG_ON(). This patch fixes the issue.

The semantic patch that found this issue(http://coccinelle.lip6.fr/):
// <smpl>
@@
expression E;
@@
  ... when != mdiobus_unregister(E);

+ mdiobus_unregister(E);
  mdiobus_free(E);
// </smpl>

Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
---
This problem is somewhat mystifying. If the patch is correct, there were
probably many OOPSese caused by not calling mdiobus_unregister...
Reporting anyway...

 drivers/net/phy/mdio-bitbang.c | 1 +
 1 file changed, 1 insertion(+)
David Miller - Nov. 3, 2012, 1:36 a.m.
From: Peter Senna Tschudin <peter.senna@gmail.com>
Date: Sun, 28 Oct 2012 17:12:01 +0100

> Based on commit b27393aecf66199f5ddad37c302d3e0cfadbe6c0
> 
> Calling mdiobus_free without calling mdiobus_unregister causes
> BUG_ON(). This patch fixes the issue.
> 
> The semantic patch that found this issue(http://coccinelle.lip6.fr/):
> // <smpl>
> @@
> expression E;
> @@
>   ... when != mdiobus_unregister(E);
> 
> + mdiobus_unregister(E);
>   mdiobus_free(E);
> // </smpl>
> 
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>

Applied.
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Patch

diff --git a/drivers/net/phy/mdio-bitbang.c b/drivers/net/phy/mdio-bitbang.c
index daec9b0..6428fcb 100644
--- a/drivers/net/phy/mdio-bitbang.c
+++ b/drivers/net/phy/mdio-bitbang.c
@@ -234,6 +234,7 @@  void free_mdio_bitbang(struct mii_bus *bus)
 	struct mdiobb_ctrl *ctrl = bus->priv;
 
 	module_put(ctrl->ops->owner);
+	mdiobus_unregister(bus);
 	mdiobus_free(bus);
 }
 EXPORT_SYMBOL(free_mdio_bitbang);