[PATCH linux-next] agp: correct missing cleanup on error in agp_add_bridge

From: Kevin Winchester
Date: Sat Jul 25 2009 - 21:30:37 EST



While investigating a kmemleak detected leak, I encountered the
agp_add_bridge function. It appears to be responsible for freeing
the agp_bridge_data in the case of a failure, but it is only doing
so for some errors.

Fix it to always free the bridge data if a failure condition is
encountered.

Signed-off-by: Kevin Winchester <kjwinchester@xxxxxxxxx>
---

Note that this seems like a reasonable change to me, but this patch
did not get rid of the kmemleak report, so I don't even have that as
evidence of its correctness. Please review.

diff --git a/drivers/char/agp/backend.c b/drivers/char/agp/backend.c
index cfa5a64..aebd82c 100644
--- a/drivers/char/agp/backend.c
+++ b/drivers/char/agp/backend.c
@@ -263,18 +263,22 @@ int agp_add_bridge(struct agp_bridge_data *bridge)
{
int error;

- if (agp_off)
- return -ENODEV;
+ if (agp_off) {
+ error = -ENODEV;
+ goto err_put_bridge;
+ }

if (!bridge->dev) {
printk (KERN_DEBUG PFX "Erk, registering with no pci_dev!\n");
- return -EINVAL;
+ error = -EINVAL;
+ goto err_put_bridge;
}

/* Grab reference on the chipset driver. */
if (!try_module_get(bridge->driver->owner)) {
dev_info(&bridge->dev->dev, "can't lock chipset driver\n");
- return -EINVAL;
+ error = -EINVAL;
+ goto err_put_bridge;
}

error = agp_backend_initialize(bridge);
@@ -304,6 +308,7 @@ frontend_err:
agp_backend_cleanup(bridge);
err_out:
module_put(bridge->driver->owner);
+err_put_bridge:
agp_put_bridge(bridge);
return error;
}

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