On 04/09/2017 08:52, Leo Yan wrote:
> After applied Stefan Wahren patch ("ARM: cpuidle: Avoid memleak if init
> fail") there have no memleak issue, but the code is not consistent to
> handle initialization failure between driver registration and device
> registration. And when device registration fails, it misses to
> unregister the driver.
>
> So this patch is to refine failure handling in init flow, it adds two
> 'goto' tags: when register device fails, it goto 'init_dev_fail' tag and
> free 'dev' structure and unregister driver; when register driver fails,
> it goto 'init_drv_fail' tag and free 'drv' structure.
>
> Cc: Daniel Lezcano <[email protected]>
> Cc: Stefan Wahren <[email protected]>
> Signed-off-by: Leo Yan <[email protected]>
> ---
> drivers/cpuidle/cpuidle-arm.c | 25 ++++++++++++++++---------
> 1 file changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle-arm.c b/drivers/cpuidle/cpuidle-arm.c
> index 52a7505..f419f6a 100644
> --- a/drivers/cpuidle/cpuidle-arm.c
> +++ b/drivers/cpuidle/cpuidle-arm.c
> @@ -86,10 +86,13 @@ static int __init arm_idle_init(void)
>
> for_each_possible_cpu(cpu) {
>
> + drv = NULL;
^^^^^
This initialization is not needed.
> + dev = NULL;
> +
> drv = kmemdup(&arm_idle_driver, sizeof(*drv), GFP_KERNEL);
> if (!drv) {
> ret = -ENOMEM;
> - goto out_fail;
> + goto init_drv_fail;
Here we can jump directly to out_fail, no ?
> }
>
> drv->cpumask = (struct cpumask *)cpumask_of(cpu);
> @@ -104,13 +107,13 @@ static int __init arm_idle_init(void)
> ret = dt_init_idle_driver(drv, arm_idle_state_match, 1);
> if (ret <= 0) {
> ret = ret ? : -ENODEV;
> - goto init_fail;
> + goto init_drv_fail;
goto out_kfree_drv;
> }
>
> ret = cpuidle_register_driver(drv);
> if (ret) {
> pr_err("Failed to register cpuidle driver\n");
> - goto init_fail;
> + goto init_drv_fail;
goto out_unregister_drv;
etc ...
> return 0;
> -init_fail:
> +
> +init_dev_fail:
> + kfree(dev);
> + cpuidle_unregister_driver(drv);
> +
> +init_drv_fail:
> kfree(drv);
> -out_fail:
> +
So, the code should end up with:
out_kfree_dev:
kfree(dev);
out_unregister_drv:
cpuidle_unregister_drv(drv);
out_kfree_drv:
kfree(drv);
> while (--cpu >= 0) {
> dev = per_cpu(cpuidle_devices, cpu);
> cpuidle_unregister_device(dev);
>
Perhaps it could nicer to create a function with the rollback embedded:
for_each_possible_cpu(cpu) {
ret = arm_idle_init_cpu(cpu)
if (ret)
goto out_fail;
}
return 0;
out_fail:
while (--cpu >= 0) {
cpuidle_unregister_device(per_cpu(cpuidle_devices,cpu));
cpuidle_unregister_driver(cpuidle_get_cpu_driver(dev));
kfree(dev);
kfree(drv);
}
return ret;
And arm_idle_init_cpu(int cpu) does what is currently in the loop content.
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