From: Alan Stern <[EMAIL PROTECTED]>

This patch (as1013) was suggested by David Woodhouse; it fixes a race
in the driver core.  If a device is unregistered at the same time as
its driver is unloaded, the driver's code pages may be unmapped while
the remove method is still running.  The calls to get_driver() and
put_driver() were intended to prevent this, but they don't work if the
driver's module count has already dropped to 0.

Instead, the patch keeps the device on the driver's list until after
the remove method has returned.  This forces the necessary
synchronization to occur.

Signed-off-by: Alan Stern <[EMAIL PROTECTED]>
Signed-off-by: David Woodhouse <[EMAIL PROTECTED]>
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
 drivers/base/dd.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 5492264..b0726eb 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -289,11 +289,10 @@ static void __device_release_driver(struct device * dev)
 {
        struct device_driver * drv;
 
-       drv = get_driver(dev->driver);
+       drv = dev->driver;
        if (drv) {
                driver_sysfs_remove(dev);
                sysfs_remove_link(&dev->kobj, "driver");
-               klist_remove(&dev->knode_driver);
 
                if (dev->bus)
                        blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
@@ -306,7 +305,7 @@ static void __device_release_driver(struct device * dev)
                        drv->remove(dev);
                devres_release_all(dev);
                dev->driver = NULL;
-               put_driver(drv);
+               klist_remove(&dev->knode_driver);
        }
 }
 
-- 
1.5.3.8

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to