Re: [PATCH] Revert "ata: ahci_platform: convert kcalloc to devm_kcalloc"

[Marcel Ziswiler <marcel.ziswiler@toradex.com>]

On Tue, 2018-07-17 at 13:57 +0300, Mikko Perttunen wrote:
> Thanks!

Yes, that fixes Apalis TK1 crashing as of late as well.

> Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>

Tested-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>

> On 17.07.2018 13:49, Corentin Labbe wrote:
> > Since ahci_platform_put_resources() use target_pwrs after "devm_"
> > freed
> > it, we cannot use devm_kcalloc for allocating target_pwrs.
> > 
> > This reverts commit bd0038b1b4f499d814d8f33a55b1df5ea6cf3b85.
> > 
> > Reported-by: Mikko Perttunen <mperttunen@nvidia.com>
> > Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
> > ---
> >   drivers/ata/libahci_platform.c | 8 +++++++-
> >   1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/ata/libahci_platform.c
> > b/drivers/ata/libahci_platform.c
> > index fe8939e161ea..2ceebaf2ed56 100644
> > --- a/drivers/ata/libahci_platform.c
> > +++ b/drivers/ata/libahci_platform.c
> > @@ -271,6 +271,8 @@ static void ahci_platform_put_resources(struct
> > device *dev, void *res)
> >   	for (c = 0; c < hpriv->nports; c++)
> >   		if (hpriv->target_pwrs && hpriv->target_pwrs[c])
> >   			regulator_put(hpriv->target_pwrs[c]);
> > +
> > +	kfree(hpriv->target_pwrs);
> >   }
> >   
> >   static int ahci_platform_get_phy(struct ahci_host_priv *hpriv,
> > u32 port,
> > @@ -406,7 +408,11 @@ struct ahci_host_priv
> > *ahci_platform_get_resources(struct platform_device *pdev)
> >   		rc = -ENOMEM;
> >   		goto err_out;
> >   	}
> > -	hpriv->target_pwrs = devm_kcalloc(dev, hpriv->nports,
> > sizeof(*hpriv->target_pwrs), GFP_KERNEL);
> > +	/*
> > +	 * We cannot use devm_ here, since
> > ahci_platform_put_resources() uses
> > +	 * target_pwrs after devm_ have freed memory
> > +	 */
> > +	hpriv->target_pwrs = kcalloc(hpriv->nports, sizeof(*hpriv-
> > >target_pwrs), GFP_KERNEL);
> >   	if (!hpriv->target_pwrs) {
> >   		rc = -ENOMEM;
> >   		goto err_out;