question about drivers/power/88pm860x_charger.c

From: Julia Lawall
Date: Sat Dec 08 2012 - 11:37:36 EST


The function pm860x_charger_probe in the file drivers/power/88pm860x_charger.c contains the following code:

count = pdev->num_resources;
for (i = 0, j = 0; i < count; i++) {
info->irq[j] = platform_get_irq(pdev, i);
if (info->irq[j] < 0)
continue;
j++;
}
info->irq_nums = j;

and then later the following code:

for (i = 0; i < ARRAY_SIZE(info->irq); i++) {
ret = request_threaded_irq(info->irq[i], NULL,
pm860x_irq_descs[i].handler,
IRQF_ONESHOT, pm860x_irq_descs[i].name, info);
...
}

and finally, in the function pm860x_charger_remove, the code:

free_irq(info->irq[0], info);
for (i = 0; i < info->irq_nums; i++)
free_irq(info->irq[i], info);

It looks like the irq_nums field is being used to record how many platform_get_irq calls were successful, but this information is not used in the second block of code, where request_threaded_irq is called. So it would seem that all of the requested irqs should be freed, and not just the first irq_nums of them.

The remove code also looks like a double free of info->irq[0].

Could I just get rid of the irq_nums field completely? It doesn't seem to be used elsewhere. Also, I was planning to use devm_request_threaded_irq, so then there won't be a need for the explicit frees at all.

This file also contains a kfree of devm_kzalloc'd data, which is why I looked at it in the first place.

thanks,
julia
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