1. Patchew
  2. linux
  3. [PATCH 0/7] soc: aspeed: lpc-snoop: Miscellaneous fixes
  4. View patch

[PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid

Andrew Jeffery posted 7 patches 8 months, 1 week ago
There is a newer version of this series
[PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid
Posted by Andrew Jeffery 8 months, 1 week ago 
of_device_get_match_data() can return NULL, though shouldn't in current
circumstances. Regardless, initialise model_data closer to use so it's
clear we need to test for validity prior to dereferencing.

Fixes: 2dee584bc9e3 ("drivers/misc: (aspeed-lpc-snoop): Add ast2400 to compat")
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
---
 drivers/soc/aspeed/aspeed-lpc-snoop.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
index e9d9a8e60a6f062c0b53c9c02e5d73768453998d..28f034b8a3b7226efe20cbe30a7da0c2b49fbd96 100644
--- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
+++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
@@ -186,10 +186,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
 				   struct device *dev,
 				   int channel, u16 lpc_port)
 {
-	int rc = 0;
+	const struct aspeed_lpc_snoop_model_data *model_data;
 	u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
-	const struct aspeed_lpc_snoop_model_data *model_data =
-		of_device_get_match_data(dev);
+	int rc = 0;
+
 
 	if (lpc_snoop->chan[channel].enabled)
 		return -EBUSY;
@@ -236,9 +236,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
 	regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
 	regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
 			   lpc_port << snpwadr_shift);
-	if (model_data->has_hicrb_ensnp)
-		regmap_update_bits(lpc_snoop->regmap, HICRB,
-				hicrb_en, hicrb_en);
+
+	model_data = of_device_get_match_data(dev);
+	if (model_data && model_data->has_hicrb_ensnp)
+		regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en);
 
 	lpc_snoop->chan[channel].enabled = true;
 

-- 
2.39.5
Re: [PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid
Posted by Jean Delvare 8 months ago 
On Fri, 11 Apr 2025 10:38:33 +0930, Andrew Jeffery wrote:
> of_device_get_match_data() can return NULL, though shouldn't in current
> circumstances. Regardless, initialise model_data closer to use so it's
> clear we need to test for validity prior to dereferencing.
> 
> Fixes: 2dee584bc9e3 ("drivers/misc: (aspeed-lpc-snoop): Add ast2400 to compat")
> Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
> ---
>  drivers/soc/aspeed/aspeed-lpc-snoop.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> index e9d9a8e60a6f062c0b53c9c02e5d73768453998d..28f034b8a3b7226efe20cbe30a7da0c2b49fbd96 100644
> --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> @@ -186,10 +186,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
>  				   struct device *dev,
>  				   int channel, u16 lpc_port)
>  {
> -	int rc = 0;
> +	const struct aspeed_lpc_snoop_model_data *model_data;
>  	u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
> -	const struct aspeed_lpc_snoop_model_data *model_data =
> -		of_device_get_match_data(dev);
> +	int rc = 0;
> +

Duplicate blank line.

>  
>  	if (lpc_snoop->chan[channel].enabled)
>  		return -EBUSY;
> @@ -236,9 +236,10 @@ static int aspeed_lpc_enable_snoop(struct aspeed_lpc_snoop *lpc_snoop,
>  	regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en, hicr5_en);
>  	regmap_update_bits(lpc_snoop->regmap, SNPWADR, snpwadr_mask,
>  			   lpc_port << snpwadr_shift);
> -	if (model_data->has_hicrb_ensnp)
> -		regmap_update_bits(lpc_snoop->regmap, HICRB,
> -				hicrb_en, hicrb_en);
> +
> +	model_data = of_device_get_match_data(dev);
> +	if (model_data && model_data->has_hicrb_ensnp)
> +		regmap_update_bits(lpc_snoop->regmap, HICRB, hicrb_en, hicrb_en);
>  
>  	lpc_snoop->chan[channel].enabled = true;
>  
> 

Acked-by: Jean Delvare <jdelvare@suse.de>

-- 
Jean Delvare
SUSE L3 Support
Re: [PATCH 3/7] soc: aspeed: lpc-snoop: Ensure model_data is valid
Posted by Andrew Jeffery 8 months ago 
On Wed, 2025-04-16 at 14:19 +0200, Jean Delvare wrote:
> On Fri, 11 Apr 2025 10:38:33 +0930, Andrew Jeffery wrote:
> > of_device_get_match_data() can return NULL, though shouldn't in
> > current
> > circumstances. Regardless, initialise model_data closer to use so
> > it's
> > clear we need to test for validity prior to dereferencing.
> > 
> > Fixes: 2dee584bc9e3 ("drivers/misc: (aspeed-lpc-snoop): Add ast2400
> > to compat")
> > Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
> > ---
> >  drivers/soc/aspeed/aspeed-lpc-snoop.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> > 
> > diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > index
> > e9d9a8e60a6f062c0b53c9c02e5d73768453998d..28f034b8a3b7226efe20cbe30
> > a7da0c2b49fbd96 100644
> > --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> > @@ -186,10 +186,10 @@ static int aspeed_lpc_enable_snoop(struct
> > aspeed_lpc_snoop *lpc_snoop,
> >                                    struct device *dev,
> >                                    int channel, u16 lpc_port)
> >  {
> > -       int rc = 0;
> > +       const struct aspeed_lpc_snoop_model_data *model_data;
> >         u32 hicr5_en, snpwadr_mask, snpwadr_shift, hicrb_en;
> > -       const struct aspeed_lpc_snoop_model_data *model_data =
> > -               of_device_get_match_data(dev);
> > +       int rc = 0;
> > +
> 
> Duplicate blank line.

I'll clean that up.

> 
> >  
> >         if (lpc_snoop->chan[channel].enabled)
> >                 return -EBUSY;
> > @@ -236,9 +236,10 @@ static int aspeed_lpc_enable_snoop(struct
> > aspeed_lpc_snoop *lpc_snoop,
> >         regmap_update_bits(lpc_snoop->regmap, HICR5, hicr5_en,
> > hicr5_en);
> >         regmap_update_bits(lpc_snoop->regmap, SNPWADR,
> > snpwadr_mask,
> >                            lpc_port << snpwadr_shift);
> > -       if (model_data->has_hicrb_ensnp)
> > -               regmap_update_bits(lpc_snoop->regmap, HICRB,
> > -                               hicrb_en, hicrb_en);
> > +
> > +       model_data = of_device_get_match_data(dev);
> > +       if (model_data && model_data->has_hicrb_ensnp)
> > +               regmap_update_bits(lpc_snoop->regmap, HICRB,
> > hicrb_en, hicrb_en);
> >  
> >         lpc_snoop->chan[channel].enabled = true;
> >  
> > 
> 
> Acked-by: Jean Delvare <jdelvare@suse.de>
> 

Thanks,

Andrew

Patchew 2.1-devel-b67e4c2

© 2016 - 2025 Red Hat, Inc.