linux-kernel - Re: [PATCH RESEND 1/2] regulator: arizona-ldo1: Improve handling of regulator unbinding

lists.openwall.net		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 linux-cve-announce 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]

Message-ID: <20200122131149.GE3833@sirena.org.uk>
Date:   Wed, 22 Jan 2020 13:11:49 +0000
From:   Mark Brown <broonie@...nel.org>
To:     Charles Keepax <ckeepax@...nsource.cirrus.com>
Cc:     lee.jones@...aro.org, lgirdwood@...il.com,
        linux-kernel@...r.kernel.org, patches@...nsource.cirrus.com
Subject: Re: [PATCH RESEND 1/2] regulator: arizona-ldo1: Improve handling of
 regulator unbinding

On Wed, Jan 22, 2020 at 11:08:41AM +0000, Charles Keepax wrote:

> The current unbinding process for Madera has some issues. The trouble
> is runtime PM is disabled as the first step of the process, but

Why not just leave runtime PM active until all the subdevices are gone?
This is a really bad hack and it's going to be fragile.

> +static int madera_ldo1_remove(struct platform_device *pdev)
> +{
> +	struct madera *madera = dev_get_drvdata(pdev->dev.parent);
> +
> +	if (madera->internal_dcvdd) {
> +		regulator_disable(madera->dcvdd);
> +		regulator_put(madera->dcvdd);
> +	}

This is going to break bisection since it will result in double
disables, it'd be fine to do the MFD change first since that'd just
leak a reference to enable on a regulator which is about to be discarded
entirely anyway but this reordering (and whatever other changes you've
done since v1) means you add a double free.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)