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Subject[PATCH] pcmcia: Fix broken abuse of dev->driver_data
From: Alan Cox <alan@redhat.com>

PCMCIA abuses dev->private_data in the probe methods. Unfortunately it
continues to abuse it after calling drv->probe() which leads to crashes and
other nasties (such as bogus probes of multifunction devices) giving errors like

pcmcia: registering new device pcmcia0.1
kernel: 0.1: GetNextTuple: No more items

Extract the passed data before calling the driver probe function that way
we don't blow up when the driver reuses dev->private_data as its right.

As its close to the final release just move the hack so it works out,
hopefully someone will be sufficiently embarrassed to produce a nice rework
for 2.6.28.

Signed-off-by: Alan Cox <alan@redhat.com>
---

drivers/pcmcia/ds.c | 23 ++++++++++++++---------
1 files changed, 14 insertions(+), 9 deletions(-)


diff --git a/drivers/pcmcia/ds.c b/drivers/pcmcia/ds.c
index 4174d96..853d342 100644
--- a/drivers/pcmcia/ds.c
+++ b/drivers/pcmcia/ds.c
@@ -426,6 +426,18 @@ static int pcmcia_device_probe(struct device * dev)
p_dev = to_pcmcia_dev(dev);
p_drv = to_pcmcia_drv(dev->driver);
s = p_dev->socket;
+
+ /* The PCMCIA code passes the match data in via dev->driver_data
+ * which is an ugly hack. Once the driver probe is called it may
+ * and often will overwrite the match data so we must save it first
+ *
+ * handle pseudo multifunction devices:
+ * there are at most two pseudo multifunction devices.
+ * if we're matching against the first, schedule a
+ * call which will then check whether there are two
+ * pseudo devices, and if not, add the second one.
+ */
+ did = p_dev->dev.driver_data;

ds_dbg(1, "trying to bind %s to %s\n", p_dev->dev.bus_id,
p_drv->drv.name);
@@ -455,21 +467,14 @@ static int pcmcia_device_probe(struct device * dev)
goto put_module;
}

- /* handle pseudo multifunction devices:
- * there are at most two pseudo multifunction devices.
- * if we're matching against the first, schedule a
- * call which will then check whether there are two
- * pseudo devices, and if not, add the second one.
- */
- did = p_dev->dev.driver_data;
if (did && (did->match_flags & PCMCIA_DEV_ID_MATCH_DEVICE_NO) &&
(p_dev->socket->device_count == 1) && (p_dev->device_no ==
0)) pcmcia_add_device_later(p_dev->socket, 0);

- put_module:
+put_module:
if (ret)
module_put(p_drv->owner);
- put_dev:
+put_dev:
if (ret)
put_device(dev);
return (ret);
--
<meme>discombobulated echidna</meme>

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