lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Thu, 3 Apr 2014 11:58:04 +0100
From:	Charles Keepax <>
To:	Mark Brown <>
Subject: Re: [PATCH] regulator: core: Get and put regulator of_node

On Wed, Apr 02, 2014 at 05:53:54PM +0100, Mark Brown wrote:
> To make this correct we need to at least ensure that the node passed
> into the regulator API is valid and referenced at that time so there
> should only be an issue for the core if the reference is dropped after
> that.  In the above case the device model is holding a reference since
> this is the of_node for the device itself so taking the reference won't
> hurt but is redundant.  In cases where we have more than one regulator
> and are using of_regulator_match() then things are more tricky.
> Something needs to drop the references it returns (which isn't happening
> at all at the minute).

>From what I can see of_regulator_match isn't taking any
references at the minute? for_each_child_of_node will get a
reference but it will also put that when we process the next
child. We copy the pointer to the child into match->of_node
but don't manually increment the reference at all. So
of_regulator_match has no effect on the reference count of the

>  Doing it while doing the match and register
> seems simple and neat from an error handling point of view so having the
> core take an additional reference during the registration would join up
> with that.

The main issue I have is that devm_regualtor_register is a bit
awkward. With regulator_register you will always be calling
regulator_unregister so you can put the of_node there but with
devm there isn't really a good place to put the of_node.

Would perhaps a sensible thing here be to add an of_node_get to
of_regulator_match, since we seem to be expecting that to
increase the ref count. And then just add an of_node_put to
regulator_unregister. And for anything directly using
regulator_register/devm_regulator_register they should add a
manual of_node_get?

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists