[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[Viresh Kumar]

In of_dma_controller_register() routine we are calling of_get_property() as an
parameter to be32_to_cpup(). In case the property doesn't exist we will get a
crash.

This patch changes this code to check if we got a valid property first and then
runs be32_to_cpup() on it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---

My mails are broken, i have pushed this patch here:

http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/dma-of-fix

 drivers/dma/of-dma.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index 69d04d2..09c7ad1 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -93,6 +93,7 @@ int of_dma_controller_register(struct device_node *np,
 {
 	struct of_dma	*ofdma;
 	int		nbcells;
+	const __be32	*prop;
 
 	if (!np || !of_dma_xlate) {
 		pr_err("%s: not enough information provided\n", __func__);
@@ -103,8 +104,11 @@ int of_dma_controller_register(struct device_node *np,
 	if (!ofdma)
 		return -ENOMEM;
 
-	nbcells = be32_to_cpup(of_get_property(np, "#dma-cells", NULL));
-	if (!nbcells) {
+	prop = of_get_property(np, "#dma-cells", NULL);
+	if (prop)
+		nbcells = be32_to_cpup(prop);
+
+	if (!prop || !nbcells) {
 		pr_err("%s: #dma-cells property is missing or invalid\n",
 		       __func__);
 		kfree(ofdma);
-- 
1.7.12.rc2.18.g61b472e

[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[Vinod Koul]

On Fri, Mar 15, 2013 at 02:18:20PM +0530, Viresh Kumar wrote:
> In of_dma_controller_register() routine we are calling of_get_property() as an
> parameter to be32_to_cpup(). In case the property doesn't exist we will get a
> crash.
> 
> This patch changes this code to check if we got a valid property first and then
> runs be32_to_cpup() on it.
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> 
> My mails are broken, i have pushed this patch here:
I noticed you used git send-email. Usually it will send patch properly
independent of whatever MUA you use. So I have the patch and its applied now :)

--
~Vinod 
> 
> http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/dma-of-fix
> 
>  drivers/dma/of-dma.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
> index 69d04d2..09c7ad1 100644
> --- a/drivers/dma/of-dma.c
> +++ b/drivers/dma/of-dma.c
> @@ -93,6 +93,7 @@ int of_dma_controller_register(struct device_node *np,
>  {
>  	struct of_dma	*ofdma;
>  	int		nbcells;
> +	const __be32	*prop;
>  
>  	if (!np || !of_dma_xlate) {
>  		pr_err("%s: not enough information provided\n", __func__);
> @@ -103,8 +104,11 @@ int of_dma_controller_register(struct device_node *np,
>  	if (!ofdma)
>  		return -ENOMEM;
>  
> -	nbcells = be32_to_cpup(of_get_property(np, "#dma-cells", NULL));
> -	if (!nbcells) {
> +	prop = of_get_property(np, "#dma-cells", NULL);
> +	if (prop)
> +		nbcells = be32_to_cpup(prop);
> +
> +	if (!prop || !nbcells) {
>  		pr_err("%s: #dma-cells property is missing or invalid\n",
>  		       __func__);
>  		kfree(ofdma);
> -- 
> 1.7.12.rc2.18.g61b472e
> 
> 

[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[Viresh Kumar]

On 21 March 2013 15:16, Vinod Koul <vinod.koul@intel.com> wrote:
> On Fri, Mar 15, 2013 at 02:18:20PM +0530, Viresh Kumar wrote:
>> In of_dma_controller_register() routine we are calling of_get_property() as an
>> parameter to be32_to_cpup(). In case the property doesn't exist we will get a
>> crash.
>>
>> This patch changes this code to check if we got a valid property first and then
>> runs be32_to_cpup() on it.
>>
>> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>> ---
>>
>> My mails are broken, i have pushed this patch here:
> I noticed you used git send-email. Usually it will send patch properly
> independent of whatever MUA you use.

Probably not!! Its the famous (Infamous) Microsoft exchange server working in
background and it breaks mails without treating mails coming from git send-email
specially :)

> So I have the patch and its applied now :)

I have seen this kind of discrimination on breaking patches based on the size of
patch. If its very small (like this one), you may get a unbroken patch
but if the size
is a bit large then nobody can save you :)

--
viresh

[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[Vinod Koul]

On Thu, Mar 21, 2013 at 03:48:50PM +0530, Viresh Kumar wrote:
> On 21 March 2013 15:16, Vinod Koul <vinod.koul@intel.com> wrote:
> > On Fri, Mar 15, 2013 at 02:18:20PM +0530, Viresh Kumar wrote:
> >> In of_dma_controller_register() routine we are calling of_get_property() as an
> >> parameter to be32_to_cpup(). In case the property doesn't exist we will get a
> >> crash.
> >>
> >> This patch changes this code to check if we got a valid property first and then
> >> runs be32_to_cpup() on it.
> >>
> >> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> >> ---
> >>
> >> My mails are broken, i have pushed this patch here:
> > I noticed you used git send-email. Usually it will send patch properly
> > independent of whatever MUA you use.
> 
> Probably not!! Its the famous (Infamous) Microsoft exchange server working in
> background and it breaks mails without treating mails coming from git send-email
> specially :)
I have seen usually receiving patches is a problem, not sending. at least at my
work place till now my sent patches have not been broken but what I receive has
thus forcing me to use non exchange accounts for receiving email but somehow situation
is better for receiving too :)
--
~Vinod
> 
> > So I have the patch and its applied now :)
> 
> I have seen this kind of discrimination on breaking patches based on the size of
> patch. If its very small (like this one), you may get a unbroken patch
> but if the size
> is a bit large then nobody can save you :)

> 
> --
> viresh

[PATCH] DMA: OF: Check properties value before running be32_to_cpup() on it

[Amit Kucheria]

On Thu, Mar 21, 2013 at 4:08 PM, Vinod Koul <vinod.koul@intel.com> wrote:
> On Thu, Mar 21, 2013 at 03:48:50PM +0530, Viresh Kumar wrote:
>> On 21 March 2013 15:16, Vinod Koul <vinod.koul@intel.com> wrote:
>> > On Fri, Mar 15, 2013 at 02:18:20PM +0530, Viresh Kumar wrote:
>> >> In of_dma_controller_register() routine we are calling of_get_property() as an
>> >> parameter to be32_to_cpup(). In case the property doesn't exist we will get a
>> >> crash.
>> >>
>> >> This patch changes this code to check if we got a valid property first and then
>> >> runs be32_to_cpup() on it.
>> >>
>> >> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
>> >> ---
>> >>
>> >> My mails are broken, i have pushed this patch here:
>> > I noticed you used git send-email. Usually it will send patch properly
>> > independent of whatever MUA you use.
>>
>> Probably not!! Its the famous (Infamous) Microsoft exchange server working in
>> background and it breaks mails without treating mails coming from git send-email
>> specially :)
> I have seen usually receiving patches is a problem, not sending. at least at my
> work place till now my sent patches have not been broken but what I receive has
> thus forcing me to use non exchange accounts for receiving email but somehow situation
> is better for receiving too :)
> --
> ~Vinod
>>
>> > So I have the patch and its applied now :)
>>
>> I have seen this kind of discrimination on breaking patches based on the size of
>> patch. If its very small (like this one), you may get a unbroken patch
>> but if the size
>> is a bit large then nobody can save you :)

I've seen the Exchange bug in both forms[1]  - munging incoming
patches as well as outgoing ones. It almost feels like the Exchange
team's benevolent ploy to get companies to migrate away from Exchange
so they can end-of-life those servers and stop developing Exchange
further for the general betterment of humankind.[2]

[1] Since as far back as 8 years ago!
[2] That or they get bonuses based on how much they disrupt open
source communities. ;-)