linux-kernel - Re: [PATCH] powerpc/pseries: Fix of_node_put() underflow during pseries remove

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Date:   Mon, 24 Jul 2017 20:42:34 +1000
From:   Michael Ellerman <mpe@...erman.id.au>
To:     Laurent Vivier <lvivier@...hat.com>, linux-kernel@...r.kernel.org
Cc:     David Gibson <david@...son.dropbear.id.au>,
        linuxppc-dev@...ts.ozlabs.org,
        Tyrel Datwyler <tyreld@...ux.vnet.ibm.com>,
        Thomas Huth <thuth@...hat.com>
Subject: Re: [PATCH] powerpc/pseries: Fix of_node_put() underflow during pseries remove

Laurent Vivier <lvivier@...hat.com> writes:

> As for commit 68baf692c435 ("powerpc/pseries: Fix of_node_put()
> underflow during DLPAR remove"), the call to of_node_put()
> must be removed from pSeries_reconfig_remove_node().
>
> dlpar_detach_node() and pSeries_reconfig_remove_node() call
> of_detach_node(), and thus the node should not be released
> in this case too.
>
> Signed-off-by: Laurent Vivier <lvivier@...hat.com>
> ---
>  arch/powerpc/platforms/pseries/reconfig.c | 1 -
>  1 file changed, 1 deletion(-)

Thanks. I'll spare you the swearing about why we have the same bug in
two places.

As for the other fix, I'll add:

Fixes: 0829f6d1f69e ("of: device_node kobject lifecycle fixes")
Cc: stable@...r.kernel.org # v3.15+

cheers

> diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
> index e5bf1e8..011ef21 100644
> --- a/arch/powerpc/platforms/pseries/reconfig.c
> +++ b/arch/powerpc/platforms/pseries/reconfig.c
> @@ -82,7 +82,6 @@ static int pSeries_reconfig_remove_node(struct device_node *np)
>  
>  	of_detach_node(np);
>  	of_node_put(parent);
> -	of_node_put(np); /* Must decrement the refcount */
>  	return 0;
>  }
>  
> -- 
> 2.9.4