linux-kernel - Re: [PATCH 5.10 100/122] gpio: mpc8xxx: Fix a potential double iounmap call in mpc8xxx

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Date:   Wed, 22 Sep 2021 11:05:19 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Pavel Machek <pavel@...x.de>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Christophe JAILLET <christophe.jaillet@...adoo.fr>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>,
        Sasha Levin <sashal@...nel.org>
Subject: Re: [PATCH 5.10 100/122] gpio: mpc8xxx: Fix a potential double
 iounmap call in mpc8xxx_probe()

On Tue, Sep 21, 2021 at 11:25:26PM +0200, Pavel Machek wrote:
> Hi!
> 
> > [ Upstream commit 7d6588931ccd4c09e70a08175cf2e0cf7fc3b869 ]
> > 
> > Commit 76c47d1449fc ("gpio: mpc8xxx: Add ACPI support") has switched to a
> > managed version when dealing with 'mpc8xxx_gc->regs'. So the corresponding
> > 'iounmap()' call in the error handling path and in the remove should be
> > removed to avoid a double unmap.
> 
> This is wrong, AFAICT. 5.10 does not have 76c47d1449fc ("gpio:
> mpc8xxx: Add ACPI support") so iounmap is still neccessary and this
> adds a memory leak.

Ah, but then I have to drop 889a1b3f35db ("gpio: mpc8xxx: Use
'devm_gpiochip_add_data()' to simplify the code and avoid a leak") from
the 5.10 queue as it depends on this one.

Can you provide a working backport of that commit so that I can queue up
the fix?

thanks,

greg k-h