[PATCH] device_shutdown can loop if the driver frees itself

[Greg KH]

[PATCH] device_shutdown can loop if the driver frees itself

This patch changes device_shutdown() to use the newly introduced safe
reverse list traversal.  We experienced loops on system reboot if we had
removed and re-inserted our device from the device list.

We noticed this problem on PPC405. Our PCI IDE device comes and goes a lot.

Our hypothesis was that there was a loop caused by the driver->shutdown
freeing memory.  It is possible that we do something wrong as well, but
being unable to reboot is kind of nasty.

Signed-off-by: Michael Richardson <mcr@xxxxxxxxxxxxxxxxxxxxx>
Cc: Patrick Mochel <mochel@xxxxxxxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
commit 9c08a938ce5a3e1c9d5f764dc6ae844cb1af76ff
tree 9bd0a984b2e5466454e2633783786a516fe14484
parent 2d7b5a70e01ff8b1b054d8313362e454e3057c5a
author Michael Richardson <mcr@xxxxxxxxxxxxxxxxxxxxxx> Mon, 09 Jan 2006 01:04:51 -0800
committer Greg Kroah-Hartman <gregkh@xxxxxxx> Fri, 13 Jan 2006 11:26:12 -0800

 drivers/base/power/shutdown.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/shutdown.c b/drivers/base/power/shutdown.c
index a47bb74..c2475f3 100644
--- a/drivers/base/power/shutdown.c
+++ b/drivers/base/power/shutdown.c
@@ -35,10 +35,10 @@ extern int sysdev_shutdown(void);
  */
 void device_shutdown(void)
 {
-	struct device * dev;
+	struct device * dev, *devn;
 
 	down_write(&devices_subsys.rwsem);
-	list_for_each_entry_reverse(dev, &devices_subsys.kset.list,
+	list_for_each_entry_safe_reverse(dev, devn, &devices_subsys.kset.list,
 				kobj.entry) {
 		if (dev->bus && dev->bus->shutdown) {
 			dev_dbg(dev, "shutdown\n");

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