question about drivers/pinctrl/pinctrl-at91.c

From: Julia Lawall
Date: Sat Dec 08 2012 - 10:55:56 EST


The function at91_dt_node_to_map in drivers/pinctrl/pinctrl-at91.c contains the following code:

new_map = devm_kzalloc(pctldev->dev, sizeof(*new_map) * map_num, GFP_KERNEL);
if (!new_map)
return -ENOMEM;

*map = new_map;
*num_maps = map_num;

/* create mux map */
parent = of_get_parent(np);
if (!parent) {
kfree(new_map);
return -EINVAL;
}

This is clearly not correct, because the combination of devm_kzalloc and kfree risks creating a double free. But I am not sure how best to fix it. Is the data structure intended to normally exist until the driver's remove function is called? If so, perhaps the devm_kzalloc is OK. If I just remove the kfree, then the structure will persist until the remove function is called, even though there was an error, which is perhaps not good. So I could change the kfree to devm_kfree?

thanks,
julia
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